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  • 1
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    Genetic improvement of freshwater prawn, Macrobrachium rosenbergii (de Man) in India. Phase two: annual report for period January to December 2012 (2021)
    WorldFish | Bhubaneswar, India
    In:  http://aquaticcommons.org/id/eprint/12749 | 115 | 2013-12-03 13:46:30 | 12749 | WorldFish Center
    Details
    Publication Date: 2021-07-05
    Description: Macrobrachiurn rosenbergii is one of the widely cultured freshwater prawn species globally. India was the third largest producer of this species in 2007 and its aquaculture production rose to 43,000 metric tons (t) in 2005 froin less than 500 t in 1995. However, since then production has been declining and in 2008-09 it was 12,856 t, a reduction of more than 70% compared to 2005. There are several contributing factors to this decline, such as slow growth rate, poor survival, disease outbreaks, increase in cost of production, and availability of low risk alternative fish species. However, there is a consensus that poor seed quality leading to unsatisfactory growth and survival rates in ponds is one of the major reasons. Hence, the development of a systematic selective breeding program aimed at improving growth rate and ensuring high survival rate of this species was deemed a high priority. The Central Institute of Freshwater Aquaculture (CIFA), Bhubaneswar, India in collaboration with the WorldFish Center, Malaysia initiated a selective breeding program for this species in 2007.
    Description: CIFA - WorldFish Project on Genetic Improvement of Freshwater Prawn, Macrobrachium rosenbergii (de Man) in India (Phase Two)
    Keywords: Aquaculture ; Prawn culture ; Genetics ; Seed production ; Selective breeding ; Freshwater aquaculture ; India •Livestock and Fish
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 10
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  • 2
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    Strain comparisons in aquaculture species: a manual (2021)
    WorldFish | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/10991 | 115 | 2013-03-17 12:38:07 | 10991 | WorldFish Center
    Details
    Publication Date: 2021-06-25
    Description: When different strains or breeds of a particular species are available, the best choice is seldom immediately obvious for producers. Scientists are also interested in the relative performance of different strains because it provides a basis for recommendations to producers and it often stimulates the conduct of work aimed at unraveling the underlying biological mechanisms involved in the expression of such differences. Hence, strain or breed comparisons of some sort are frequently conducted. This manual is designed to provide general guidelines for the design of strain comparison trials in aquaculture species. Example analyzes are provided using SAS and SPSS. The manual is intended to serve a wide range of readers from developing countries with limited access to information. The users, however, are expected to have a basic knowledge of quantitative genetics and experience in statistical methods and data analysis as well as familiarity with computer software. The manual mainly focuses on the practical aspects of design and data analysis, and interpretation of results.
    Description: CGIAR Research Program Livestock & Fish
    Keywords: Aquaculture ; Aquaculture ; Genetics ; Selective breeding
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 31
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  • 3
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    Considerations about effective dissemination of improved fish strains (2021)
    WorldFish | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/10632 | 115 | 2013-07-12 04:44:53 | 10632 | WorldFish Center
    Details
    Publication Date: 2021-06-27
    Description: Aquaculture production systems in developing countries are largely based on the use of unimproved species and strains. As knowledge and experience are accumulated in relation to the management, feeding and animal health issues of such production systems, the availability of genetically more productive stock becomes imperative in order to more effectively use resources. For instance, there is little point in providing ideal water conditions and optimum feed quality to fish that do not have the potential to grow faster and to be harvested on time, providing a product of the desired quality. Refinements in the production system and improvement of the stock used must progress hand in hand. In this paper we deal separately with genetic and non-genetic issues pertaining to the multiplication and dissemination of improved strains. The separation is somewhat arbitrary, and as will be evident from our discussion, there is frequent interaction between the two.
    Description: CGIAR Research Program on Livestock and Fish
    Keywords: Aquaculture ; Aquaculture ; Genetics ; Selective breeding
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 15
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  • 4
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    The status of Arctic charr, Salvelinus alpinus (L.), in southern Scotland: a cause for concern (2021)
    In:  library@fba.org.uk | http://aquaticcommons.org/id/eprint/4537 | 1256 | 2011-09-29 16:17:32 | 4537 | Freshwater Biological Association
    Details
    Publication Date: 2021-07-04
    Description: The objective of this article is to review the populations of Arctic charr in the south of Scotland which have become locally extinct, and the reasons for their demise. In the British Isles, the Arctic charr in individual lakes have been isolated from each other for thousands of years and have developed a variety of phenotypic characteristics which are probably genetically based. About 200 populations of Arctic charr have been recorded from different parts of the British Isles: approximately 12 in England, 50 in Ireland, 175 in Scotland and four in Wales. The threats to charr from acidification, afforestation, engineering schemes, angling and fish farming are assessed, and the establishment of new populations is proposed as a method of replacing extinct stocks or providing an additional safeguard for valuable stocks in threatened waters.
    Keywords: Ecology ; Pollution ; Limnology ; Acidification ; Angling ; Animal populations ; Distribution records ; Ecosystem management ; Fish culture ; Freshwater fish ; Genetics ; Hydroelectric power plants ; Lakes Phenotypic variations ; Rare species ; Scotland ; Salvelinus alpinus
    Repository Name: AquaDocs
    Type: article , FALSE
    Format: application/pdf
    Format: application/pdf
    Format: 212-227
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  • 5
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    Risk analysis in aquaculture: A step-by-step introduction with worked examples (2021)
    WorldFish | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/16659 | 115 | 2015-04-13 11:44:30 | 16659 | WorldFish Center
    Details
    Publication Date: 2021-07-07
    Description: This publication is based on materials covered and outputs generated during the Workshop on Risk Assessment Methodologies and Tools for Aquaculture in Sub-Saharan Africa, which was jointly held by WorldFish and FAO in Siavonga, Zambia on 28 June - 2 July 2010. The workshop was delivered as a training exercise to 17 participants from seven sub-Saharan countries and was designed to highlight current methodologies and tools available for environmental risk analysis in aquaculture development. A key focus of the workshop was to encourage participants to consider hypothetical but realistic scenarios and to discuss issues relevant to evaluating the environmental risks of a given activity or scenario. This publication presents selected scenarios from the workshop and the outcomes of the deliberative process as developed by the participants. This publication is factual but not comprehensive, therefore any statements or estimations of risk do not represent the actual risks arising from the described scenario. It is intended to serve as an easily readable introduction to risk analysis, highlighting worked examples that will provide guidance on how a risk analysis may be approached in a similar situation.
    Description: Food and Agriculture Organization of the United Nations
    Description: CGIAR Research Program on Livestock and Fish
    Keywords: Agriculture ; Aquaculture ; Genetics ; GIFT ; Livestock and fish ; Training ; Tilapia
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 55
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  • 6
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    Perspectives from agriculture: advances in livestock breeding - implications for aquaculture genetics (2021)
    In:  http://aquaticcommons.org/id/eprint/9389 | 115 | 2012-10-19 08:53:08 | 9389 | WorldFish Center
    Details
    Publication Date: 2021-07-05
    Description: In this paper we present livestock breeding developments that could be taken into consideration in the genetic improvement of farmed aquaculture species, especially in freshwater fish. Firstly, the current breeding objective in aquatic species has focused almost exclusively on the improvement of body weight at harvest or on growth related traits. This is unlikely to be sufficient to meet the future needs of the aquaculture industry. To meet future demands breeding programs will most likely have to include additional traits, such as fitness related ones (survival, disease resistance), feed efficiency, or flesh quality, rather than only growth performance. In order to select for a multi-trait breeding objective, genetic variation in traits of interest and the genetic relationships among them need to be estimated. In addition, economic values for these traits will be required. Generally, there is a paucity of data on variable and fixed production costs in aquaculture, and this could be a major constraint in the further expansion of the breeding objectives. Secondly, genetic evaluation systems using the restricted maximum likelihood method (REML) and best linear unbiased prediction (BLUP) in a framework of mixed model methodology could be widely adopted to replace the more commonly used method of mass selection based on phenotypic performance. The BLUP method increases the accuracy of selection and also allows the management of inbreeding and estimation of genetic trends. BLUP is an improvement over the classic selection index approach, which was used in the success story of the genetically improved farmed tilapia (GIFT) in the Philippines, with genetic gains from 10 to 20 per cent per generation of selection. In parallel with BLUP, optimal genetic contribution theory can be applied to maximize genetic gain while constraining inbreeding in the long run in selection programs. Thirdly, by using advanced statistical methods, genetic selection can be carried out not only at the nucleus level but also in lower tiers of the pyramid breeding structure. Large scale across population genetic evaluation through genetic connectedness using cryopreserved sperm enables the comparison and ranking of genetic merit of all animals across populations, countries or years, and thus the genetically superior brood stock can be identified and widely used and exchanged to increase the rate of genetic progress in the population as a whole. It is concluded that sound genetic programs need to be established for aquaculture species. In addition to being very effective, fully pedigreed breeding programs would also enable the exploration of possibilities of integrating molecular markers (e.g., genetic tagging using DNA fingerprinting, marker (gene) assisted selection) and reproductive technologies such as in-vitro fertilization using cryopreserved spermatozoa.
    Keywords: Aquaculture ; Genetics ; Biotechnology ; Selective breeding ; Freshwater fish
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 39-45
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  • 7
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    Transgenic fish research (2021)
    In:  http://aquaticcommons.org/id/eprint/9520 | 115 | 2012-10-07 15:00:41 | 9520 | WorldFish Center
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    Publication Date: 2021-07-06
    Description: The article features two most commonly techniques for gene transfer in fish, microinjection and electroporation.
    Keywords: Aquaculture ; Fisheries ; Transgenic fish ; Gene transfer ; Genetics ; Methodology
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 26-28
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  • 8
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    Progress toward a global genealogy of common carp (Cyprinus carpio L.) strains using mitochondrial nucleotide sequences data (2021)
    In:  http://aquaticcommons.org/id/eprint/9538 | 115 | 2012-10-02 19:47:06 | 9538 | WorldFish Center
    Details
    Publication Date: 2021-07-07
    Description: As part of a study of genetic variation in the Vietnamese strains of the common carp (Cyprinus carpio L.) using direct DNA sequencing of mitochondrial control and ATPase6/8 gene regions, samples from a number of other countries were analyzed for comparison. Results show that the levels of sequence divergence in common carp is low on a global scale, with the Asian carp having the highest diversity while Koi and European carp are invariant. A genealogical analysis supports a close relationship among Vietnamese, Koi, Chinese Color and, to a lesser extent, European carp. Koi carp appear to have originated from a strain of Chinese red carp. There is considerable scope to extend this research through the analysis of additional samples of carp from around the world, especially from China, in order to generate a comprehensive global genealogy of common carp strains.
    Keywords: Aquaculture ; Fisheries ; Genetics ; DNA ; Cyprinus carpio
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 55-61
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  • 9
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    Aquaculture genetics research and issues in INGA member countries/institutions (2021)
    In:  http://aquaticcommons.org/id/eprint/9222 | 115 | 2012-11-29 08:56:11 | 9222 | WorldFish Center
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    Publication Date: 2021-07-03
    Description: The information presented here is extracted from the presentations and discussions at the Sixth Steering Committee Meeting of the International Network on Genetics in Aquaculture (INGA) held in Hanoi, Vietnam on 8-10 May 2001. The main topics discussed were: review of genetics research progress and planned activities in member countries and Associate Member institutions; genetics improvement technologies; strategies and action plans for distribution of improved fish breeds to small-scale farmers; ecological risk assessment for genetically improved fish breeds; methods for monitoring the uptake of improved strains and impact assessment; and network activities and collaborations.
    Keywords: Aquaculture ; Aquaculture ; Genetics ; International cooperation
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 61-65
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  • 10
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    From drawing board to dining table: the success story of the GIFT project (2021)
    In:  http://aquaticcommons.org/id/eprint/9223 | 115 | 2012-11-29 08:53:53 | 9223 | WorldFish Center
    Details
    Publication Date: 2021-07-03
    Description: As compared to crops and livestock, the genetic enhancement of fish is in its infancy. While significant progress has been achieved in the genetic improvement of temperate fish such as salmonids, no efforts were made until the late 1980s for the genetic improvement of tropical finfish, which account for about 90 percent of global aquaculture production. This paper traces the history of the Genetic Improvement of Farmed Tilapia (GIFT) project initiated in 1988 by the WorldFish Center and its partners for the development of methods for genetic enhancement of tropical finfish using Nile tilapia (Oreochromis niloticus) as a test species. It also describes the impacts of the project on the adoption of these methods for other species and the dissemination of improved breeds in several countries in Asia and the Pacific.
    Keywords: Aquaculture ; GIFT ; Tilapia culture ; WorldFish Center ; Genetics ; Oreochromis Niloticus
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 4-14
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  • 11
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    Genetic enhancement and conservation of aquatic biodiversity in Africa (2021)
    In:  http://aquaticcommons.org/id/eprint/9221 | 115 | 2012-11-29 08:46:37 | 9221 | WorldFish Center
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    Publication Date: 2021-07-03
    Description: There is a pressing need to enhance fish production in Africa through improved farm management and the use of improved fish breeds and/or alien species in aquaculture while at the same time conserve the aquatic genetic diversity. This paper presents the outcome of the Expert Consultation on Biosafety and Environmental Impact of Genetic Enhancement and Introduction of Improved Tilapia Strains/Alien Species in Africa held in Nairobi, Kenya on 20-23 February 2002. The main topics discussed were status of aquaculture in Africa and the role of genetic enhancement; potential benefits and risks involved in introduction of genetically improved strains and/or alien species with specific reference to tilapias; existing policies and legislation for the conservation of biodiversity, their strengths and weaknesses; capacity for undertaking genetic enhancement research and implementation of policies for the conservation of aquatic biodiversity.
    Keywords: Aquaculture ; Fisheries ; Biodiversity ; Genetics ; Aquaculture development ; Resource conservation ; Biotechnology ; Africa
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 48-49
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  • 12
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    The genetic characteristics of cephalic abnormality and its aquaculture implication in Clarias gariepinus (Burchell 1822) (2021)
    FISON | Lagos, Nigeria
    In:  http://aquaticcommons.org/id/eprint/23241 | 19325 | 2018-03-18 15:26:11 | 23241 | Fisheries Society of Nigeria
    Details
    Publication Date: 2021-07-13
    Description: Cephalic abnormality in nine mating groups involving Clarias gariepinus with cephalic abnormality, non Cephalic and Maiduguri origin were investigated to determine the level and the genetic basis of the occurrences and its aquaculture implication. The highest mean percentage survival in a Cephalic crossed with non cephalic group was 68.6% whereas the last mean percentage survival was 25.7% in the group of Maiduguri cross with Maiduguri parent. Cephalic abnormality was observed in the crosses with both female and male cephalic with a total frequency ranging from 0 % to 70.8. %. The least number of cephalic abnormality was 18.5% which involved a cross of non cephalic with cephalic, and the highest was 70.8%. This level of cephalic abnormality shows that the defect was hereditary. This result implies that, the genetic factor is a major contributor in the feature of cephalic abnormality in Clarias gariepinus.
    Description: Includes:-1 table.;3 appendixes.;11 refs.
    Keywords: Aquaculture ; Fisheries ; Clarias gariepinus ; Nigeria ; freshwater environment ; Diseases ; Deformation ; Fish culture ; Genetics ; Abnormalities ; Genetic abnormalities
    Repository Name: AquaDocs
    Type: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 199 - 208
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  • 13
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    Genetic improvement of tilapia: challenges and prospects in Nigeria (2021)
    FISON | Akure (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23373 | 19325 | 2018-04-10 16:09:38 | 23373 | Fisheries Society of Nigeria
    Details
    Publication Date: 2021-07-14
    Description: The contribution of tilapia aquaculture in Nigeria to world output is negligible due to stunting, poor market value among others. This paper evaluates the aquacultural credentials of tilapia, some genetic improvement technology in cultured tilapia, namely, ploidy, hormonal sex reversal. transgenic, hybridization, and the necessity of Genetic Improvement in accelerating tilapia production in Nigeria. Investigation reveals the presence of O. niloticus with the highest growth perfermancc index (~h1=3.11) for Lake Kanji which indicates high growth potential in suitable culture environment and could serve as a good starting point for genetic development. The presence of ”wesafu”, an ecotype cichlid, endemic to Epe lagoon, Lagos, which grows to 1500g in the wild, appears to be an excellent candidate for genetic improvement of a commercial strain for the growing aquaculture industry. Tilapia Genetic improvement in Nigeria is faced with a number of setbacks. This includes short- term, scattered and disjointed funding, inadequate genetic research facilities, ecological risk, inadequate skilled manpower and poor documentation of tilapia genetic resources among others. Considering the growing importance of tilapia culture, the need to document, conserve, evaluate and utilize tilapia genetic resources is highlighted to enhance the success of food security in Nigeria.
    Description: Includes:- 3 tables.;26 refs.
    Keywords: Aquaculture ; Oreochromis niloticus ; Nigeria ; Kainji L. ; freshwater environment ; Fish culture ; Genetics ; Selective breeding
    Repository Name: AquaDocs
    Type: conference_item , TRUE
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  • 14
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    Karyotype analysis of Garra rufa (Heckel, 1843) (Actinopterygii: Cyprinidae) in Fars Province (2021)
    In:  http://aquaticcommons.org/id/eprint/23657 | 18721 | 2018-07-15 07:24:27 | 23657 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-14
    Description: The number of chromosome and karyotype of Garra rufa (Heckel, 1843) was determined by the conventional preparation and Gimsa staining technique, using gill epithelia and kidney cells. In this investigation, 5 specimens of G. rufa were used which collected from Rodbal River, Firouzabad, Fars Province. Based on 30 chromosome spreads counts, the chromosome number was found to be 2n=50 with arm number NF=84. By using the ratio of long arm to short arm, the karyotype formula of 10 metacentric, 24 sub-metacentric and 16 sub-telocentric (10M +24SM +16St) was obtained.
    Keywords: Biology ; Genetics ; Chromosomes ; Freshwater ; Light microscopy ; Karyotypes ; Garra rufa ; Fars Province ; Iran
    Repository Name: AquaDocs
    Type: article , TRUE
    Format: application/pdf
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    Format: 11-18
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  • 15
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    Introducing molecular markers for Lernaea cyprinacea and Lernaea ctenopharyngodoni using RAPD technique (2021)
    In:  http://aquaticcommons.org/id/eprint/23658 | 18721 | 2018-07-15 07:37:24 | 23658 | Iranian Fisheries Science Research Institute
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    Publication Date: 2021-07-14
    Description: Molecular comparison of two parasites Lernaea cyprinacea and Lernaea ctenopharyngodoni was carried out using RAPD (Random Amplified Polymorphic DNA) technique. A total of 43 Lernaea specimens belonging to the two species were collected from the Guilan and Khouzestan Provinces. DNA was extracted using the Phenol-chloroform method. The quality and quantity of DNA was assessed using 1% Agarose gel electrophoresis and spectrophotometer. Polymerase Chain Reaction (PCR) was conducted on the target DNA under specific conditions and PCR products were subjected to electrophoresis on polyacrylamide gels (6%). Polyacrylamide gels were stained using silver nitrate and DNA bands were analyzed with BioCapt software. The genetic analysis was conducted using POP GEN 32 software. Forty two primers, 10 nucleotides each were used for PCR reaction. Totally, 397 RAPD loci were counted on polyacrylamide gel where 349 identical loci were polymorphic of which some bands may be used as genetic markers for the identification of both Lernaea species. Data analysis on PCR products showed higher genetic variation (1.15%) of L. ctenopharyngodon in the Guilan Province as compared to that of the Khouzestan (0.0%). However, genetic variation (27.46%) of L. cyprinacea in the Khouzestan Province was 7.26 times higher than that of the Guilan province (3.78%). The two species showed a genetic differentiation of approximately 88%. Based on the observed molecular differences, we state that L. ctenopharyngodoni is a genetically independent species from L. cyprinacea.
    Keywords: Biology ; Molecular structure ; Genetics ; DNA ; Freshwater ; Parasites ; Polymerase chain reaction ; Primers ; Nucleotides ; Lernaea ctenopharyngodoni ; Lernaea cyprinacea ; Gilan Province ; Khouzestan Province ; Iran
    Repository Name: AquaDocs
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  • 16
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    Molecular study of the populations of Artemia partenogenetica in Iran using PCR-RFLP Method (2021)
    In:  http://aquaticcommons.org/id/eprint/23679 | 18721 | 2018-07-18 06:36:39 | 23679 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-15
    Description: Considering the importance of genetic studies to manifest inter population differences in species, samples of Artemia partenogenetica were collected from seven inland lakes including Shoor and Inche-Borun lakes in Golestan Province, Hoze-Soltan and Namak lakes in Qom Province, Maharloo and Bakhteghan lakes in Fars Province and Mighan pool in Markazi Province. A total of 210 samples were subjected to DNA extraction by phenol-chloroform method. Primers were designed on a ribosomal fragment (16SrRNA) of the species' mtDNA sequence and the PCR was conducted on the samples. Digestion of the PCR product with approximately 1584bp lengths by 10 restriction endonuclease (AluI, EcoRI, Eco47I, HaeIII, HindIII, HinfI, MboI, MspI, RsaI, TaqI) showed 12 different haplotypes: 4 haplotypes in Shoor and Inche-Borun, 1 in Namak and Hoze-Soltan, 3 in Mighan pool, 1 in Bakhtegan and Maharloo and 3 in Maharloo. Haplotype diversity values within collected samples varied from zero in Hoze-Soltan, Namak and Bakhteghan samples to 0.7425 in Inche-Borun and Shoor while nucleotide diversity varied from zero in Hoze-Soltan, Namak and Bakhteghan, to 0.0077 in Mighan. The minimum nucleotide diversity among samples was zero between Hoze-Soltan vs. Namak and the maximum was 0.1700 between Inche-Borun and Shoor vs. Mighan. Nucleotide divergences among samples were least in Inche-Borun vs. Shoor (%-0.02) and most in Inche-Borun and Shoor vs. Mighan (%16.18), averaging to %3.40. The evolutionary distances between 12 haplotype showed that the maximum value belonged to Mighan haplotypes vs. Inche-Borun and Shoor haplotypes. Regarding the digestive patterns produced by each enzyme in the studied region, Eco47I is introduced as the population-specific marker of A. partenogenetica in Iran. Test of population differentiation based on haplotype frequencies were statistically significant (P≤0.001) with the exception of Hoze-Soltan vs. Namak and Inche-Borun vs. Shoor. We conclude that there are enough evidences in haplotypic level for dividing A. partenogenetica in Iran into five populations: Hoze-Soltan and Namak, Mighan, Maharloo, Bakhtegan, Incheh-Borun and Shoor.
    Keywords: Biology ; Population Genetics ; Genetics ; DNA ; Enzymes ; Marine ; RNA ; Nucleotide sequence ; Primers ; Nucleotides ; Artemia partenogenetica ; ISW ; Iran
    Repository Name: AquaDocs
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  • 17
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    The status of fish genetics and breeding towards sustainable aquaculture in Nigeria (2021)
    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24202 | 19325 | 2018-05-16 15:26:01 | 24202 | Fisheries Society of Nigeria
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    Publication Date: 2021-07-15
    Description: This paper, fish genetics and breeding in Nigeria addresses the application of genetics and breeding to fish farming with the view to enhanced aquaculture production in Nigeria. This production technique is not limited to the use of conventional breeding programs nor is it necessary to go through the basic developmental steps of selection and isolation that lead to the domestication and diversification of livestock and crops over thousands of years. With modern molecular genetic techniques and induced breeding, it is now possible to develop and create new fish species .
    Description: Includes: 12 references
    Keywords: Aquaculture ; Nigeria ; Delta State ; freshwater environment ; Genetics ; Sustainability ; Induced breeding ; Biotechnology ; Seed (aquaculture) ; Aquaculture techniques ; Fish culture
    Repository Name: AquaDocs
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    Format: 203-205
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  • 18
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    Biotechnology research at SEAFDEC/AQD (2021)
    In:  library@seafdec.org.ph | http://aquaticcommons.org/id/eprint/19972 | 2002 | 2016-02-26 15:20:49 | 19972 | Southeast Asian Fisheries Development Center, Aquaculture Department
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    Publication Date: 2021-07-06
    Keywords: Aquaculture ; Philippines ; Aquaculture development ; Algology ; Biotechnology ; Endocrinology ; Feed ; Genetics ; Laboratories ; Microbiology ; Research institutions ; Research programmes
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 13-14
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  • 19
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    How to operate tilapia hatcheries (2021)
    In:  library@seafdec.org.ph | http://aquaticcommons.org/id/eprint/20061 | 2002 | 2016-03-03 11:29:52 | 20061 | Southeast Asian Fisheries Development Center, Aquaculture Department
    Details
    Publication Date: 2021-07-07
    Keywords: Aquaculture ; Biology ; Oreochromis ; freshwater environment ; Biotechnology ; Breeding ; Breeding ponds ; Brood stocks ; Cage culture ; Culture tanks ; Fish culture ; Fry ; Genetics ; Hatcheries ; Hormones ; Hybridization ; Pond culture ; Seed (aquaculture) ; Seed production ; Sex characters ; Sex determination ; Sex reversal
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  • 20
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    Genetic analysis of six sterlet (Acipenser ruthenus) populations - recommendations for the plan of restitution in the Dniester River (2021)
    In:  http://aquaticcommons.org/id/eprint/22805 | 18721 | 2018-05-23 21:20:45 | 22805 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-10
    Description: The aim of the present study was the genetic analysis of the Dniester population of sterlet Acipenser ruthenus and comparison of it to five other sterlet populations, in order to develop a population recovery plan. The genetic analysis of six sterlet populations from Eurasian rivers (Dniester, Dnieper, Danube, Volga, Kama and Ob) was carried out using microsatellite DNA markers. The genetic variation and genetic distance between studied populations were evaluated. Significant genetic differentiation was detected between the analyzed populations through the pairwise genetic differentiation index (Fst) test. The DA measure of genetic distance between pairs of populations indicated that the shortest genetic distance (in relation to the Dniester population) was between the Dniester and the Dnieper populations (0.184). The results obtained represent a starting point of sterlet conservation program in Dniester River.
    Keywords: Aquaculture ; Biology ; Conservation ; Acipenser ruthenus ; Aquaculture ; Genetic analysis ; Microsatellite DNA ; Restitution ; Genetics ; Dniester river ; Dnieper river ; Danube river ; Volga river ; Kama river ; Poland ; populations
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  • 21
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    Application of AFLP molecular marker for genetic analysis of black pomfret Parastromateus niger from the Persian Gulf (2021)
    In:  http://aquaticcommons.org/id/eprint/22822 | 18721 | 2018-05-24 22:49:02 | 22822 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-10
    Description: Black pomfret Parastromateus niger is a commercially important fishery resource in the Persian Gulf but harvesting its stocks lacks genetic identification of populations. AFLP technique was applied to analyze genetic diversity and population structure of 32 fish from coastal waters of Bandar Abbas, Bushehr and Abadan with 7 EcoRI/MseI primer pair combinations. In total, 381 bands were produced of which, 46 were polymorphic (12.07%). Percentage of polymorphic bands was higher in Bushehr samples (91.30%) than in Abadan (84.78%) and Bandar Abbas (73.91%) samples. The highest level of heterozygosity based on Nei’s coefficient and Shannon’s index was observed in Bushehr fish (0.38±0.16 and 0.54±0.21). Observed and effective alleles ranged from 1.73±0.44 and 1.53±0.40 in Bandar Abbas samples to 1.91±0.28 and 1.70±0.34 in Bushehr samples. The average Fst was 0.19 indicating high genetic differentiation among the three locations. Gene flow with mean of 1.93 was the lowest level between Bandar Abbas and Abadan (1.24). Nei's genetic identity revealed the least genetic similarity between the samples of Bandar Abbas and Abadan (0.77). AMOVA analysis demonstrated 81% of the genetic variation within populations and 19% among populations. The UPGMA dendrogram clustered all 32 individuals into 3 groups. In some cases individuals from the same region were grouped together but in most cases, gene exchange was observed to be common among the groups. Analyses provided evidence for genetic differentiation among the three locations, indicating separate populations of black pomfret in the northern Persian Gulf.
    Keywords: Biology ; Fisheries ; Black pomfret ; Parastromateus niger ; AFLP molecular markers ; Population structure ; Genetics ; Bandar Abbas ; Bushehr ; Abadan ; Persian Gulf ; Iran
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  • 22
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    Assessing genetic diversity of populations of bartail flathead (Platycephalus indicus Linnaeus, 1758) in the northern part of the Persian Gulf using AFLP markers (2021)
    In:  http://aquaticcommons.org/id/eprint/22827 | 18721 | 2018-05-25 18:20:17 | 22827 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-10
    Description: Genetic diversity of six populations of bartail flathead (Platycephalus indicus Linnaeus, 1758) was investigated using amplified fragment length polymorphism (AFLP). A total of 118 reproducible bands amplified with ten AFLP primer combinations were obtained from 42 fishes that were collected from six different locations in the northern part of the Persian Gulf. The percentage of polymorphic bands was 57.06%. Nei’s genetic diversity was 0.1808±0.2074 - 0.2164±0.1903, and Shannon’s index was 0.2675±0.2949 - 0.3280±0.2727. The results of AMOVA analysis indicated that 66% and 34% of the genetic variation occurred within and among the populations and gene flow was 0.6454. The estimated level of population differentiation as measured by average Fst value across all loci was 0.327. Analyses revealed significant genetic differentiation with low gene flow among the six locations, indicating at least six separate populations of bartail flathead in the northern part of the Persian Gulf.
    Keywords: Biology ; Fisheries ; Management ; Genetic diversity ; Bartail flathead ; Platycephalus indicus ; AFLP ; Persian Gulf ; Genetics ; Iran
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  • 23
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    Molecular characterization of apolipoprotein A-I from the skin mucosa of Cyprinus carpio (2021)
    In:  http://aquaticcommons.org/id/eprint/23075 | 18721 | 2018-06-17 19:08:44 | 23075 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-12
    Description: Apolipoprotein A-I is the most abundant protein in Cyprinus carpio plasma that plays an important role in lipid transport and protection of the skin by means of its antimicrobial activity. A 527 bp cDNA fragment encoding C terminus part of apoA-I from the skin mucosa of common carp was isolated using RT-PCR. After GenBank database searching, a partial sequence containing a coding sequence (CDS) relating to this gene was found. Overlapping of the cDNA fragment with this CDS allowed us to obtain the full-length sequence including non-coding regions. This sequence has 1170 bp including a polyA tail of 18 bp plus 45 and 354 bp at the 3'- and 5'-untranslated regions, respectively. The complete sequence contained an open reading frame of 256 amino containing 5 amino acid propeptides with a predicted molecular mass of 29.967 kDa and theoretical pI of 6.13. The signal peptide of common carp apoA-I was predicted to have the most likely cleavage site between amino acid positions 17 and 18. Domain analysis of common carp apoA-I showed the conserved domain of Apolipoprotein A1/A4/E between amino acid resides 67 to 251. The similarity search indicated that common carp apoA-I matched apoA protein from the group of fish with 45-77% similarity, but showed relatively low levels of similarity to its mammalian counterparts (20-28%). It was shown that the secondary structure of C. carpio apoA-I consisted of a-helical predominantly amphipathic in nature and was characterized by the presence of thirteen conserved repeats.
    Keywords: Biology ; Fisheries ; Apolipoprotein A-I ; Common carp ; Cyprinus carpio ; Epidermal mucus ; Full-length sequence ; Genetics ; Iran
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  • 24
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    The induction of triploidy by cold shock in African giant catfish Clarias gariepinus, Burchell 1822 (2021)
    FISON | Minna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24085 | 19325 | 2018-05-12 14:21:06 | 24085 | Fisheries Society of Nigeria
    Details
    Publication Date: 2021-07-15
    Description: Application of genetic manipulation techniques on cultured fish have been employed in developed economies to increase food fish yield. In this study, a simple and safe biotechnology genetic manipulation technique was applied to produce triploid African giant catfish (Clarias gariepiirus Burchell 1822) larvae .Eggs numbering 100~c10 in quadruplicates from C. gariepinus were activated by milt from the same species and were subsequently transferred to a thermoregulated refrigerator maintained at 2degreesC for 20 min to suppress cell division, starting at 4 min after activation. Haploid larvae were produced by activating eggs with UV irradiated milt at 30000 uWcm-2 for 15 min. Fertility, hatchability and survival after one week for triploids were 82.5%, 69.8% and 61.3% against haploid and diploid controls, 100%, 15%, 0% and 100%,93%, 91 % (p 〈 0.05) respectively. Ploidy levels of the embryos cytogenetically were evaluated in day-old posthatched embryos incubated in 0.02% colchicine for 2-4 h. Head and yolk sac were discarded in 0.9% NaCl while remaining fragments were later treated with hypotonic solutions of distilled water for 5 min, and subsequently with diluted catfish serum 1: 4 for 25 min. Cells were fixed with 1:3 acetic acid ethanol mixture. Slide with the chromosome spreads were then stained with 20% Giemsa in phosphate buffered solution. Chromosome numbers obtained were 28~c2, 56~c2, and 75~c2 for haploid control, diploid control and triploid treatments respectively. Using a simple biotechnology technique as above, triploid C. gariepinus larvae were produced in the present study. The potential application on food fish security of triploid catfish in aquaculture especially in Nigeria is discussed.
    Description: Includes: 1 table and 1 plate.;Also includes: 20 refs.
    Keywords: Aquaculture ; Clarias gariepinus ; Nigeria ; Biotechnology ; Clarias gariepinus ; Chromosomes ; Aquaculture ; freshwater environment ; Genetics ; Cultured organisms ; Food fish ; Yield ; Biotechnology ; Fertility ; Hatching ; Sustainable development ; Aquaculture ; Aquaculture development ; Appropriate technology
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  • 25
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    Microsatellite DNA markers for analysis of genetic population structure of stellate sturgeon (Acipenser stellatus Pallas, 1771) in the North (Volga and Ural Rivers) and South Caspian Sea (Sefidrud and Gorganrud Rivers) (2021)
    In:  http://aquaticcommons.org/id/eprint/22902 | 18721 | 2018-06-06 00:55:28 | 22902 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-11
    Description: This study represents a large-scale population genetic analysis of the stellate sturgeon, Acipenser stellatus, in the Caspian Sea. In total, 192 samples of adult stellate sturgeon were collected from four commercial catch stations in the Northern (Volga and Ural Rivers) and Southern Caspian Sea (estuary of Sefidrud and Gorganrod Rivers-Iran). Fifteen sets of microsatellite primers developed from lake sturgeon (Acipenser fulvescens) and shovelnose sturgeon (Scaphirhynchus platorynchus) were tested on genomic DNA. Ten primer sets (LS-19, 34, 54, 68, Spl-105, 104, 163, 170, 173, 113) revealing polymorphic loci were used to analyze the genetic variation found in adults of the stellate sturgeon populations. Analyses revealed that the average number of alleles per locus was 13.05 (range 8 to 18 alleles per locus in regions, Ne=7.86). All sampled regions contained private alleles. The average observed and expected heterozygosities were 0.665 and 0.862, respectively. Deviations from Hardy-Weinberg equilibrium were seen in most cases. Average of Fis, Fit and Nm were 0.230, 0.261 and 7.498, respectively. Pairwise Population F_ST Values ranged from 0.019 to 0.035. F_ST, R_ST, and gene flow estimates in AMOVA indicated significant genetic differentiation among and regions, indicating that the populations were divergent. The genetic distance between populations indicates that the genetic difference among the studied populations is pronounced. These results together with highly significant R_ST of genotypic differences between these pairs of collections support the existence of different genetic populations along the Caspian Sea coast.
    Keywords: Biology ; Fisheries ; Genetic variability ; Genetic differentiation ; Acipenser stellatus ; Microsatellite markers ; Genetics ; Volga River ; Ural River ; Sefidrud River ; Gorganrud River ; Caspian Sea ; Iran
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    The ability of marine Bacillus spp. isolated from fish gastrointestinal tract and culture pond sediment to inhibit growth of aquatic pathogenic bacteria (2021)
    In:  http://aquaticcommons.org/id/eprint/22904 | 18721 | 2018-06-06 00:58:09 | 22904 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-11
    Description: In this research, antagonistic activity of two Bacillus species isolated from digestive tract of marine fish and culture pond of sea cucumber was studied. The inhibitory activity of Bacillus spp. isolates against some common pathogenic bacteria of fish was assessed using the agar diffusion method. The strain of B. subtilis G024 exhibited antimicrobial activity against Vibrio anguillarum, V. harveyi, V. vulnificus, Streptococcus sp. and Staphylococcus aureus; the isolate of B. amyloliquefaciens N004 inhibited growth in V. anguillarum, V. campbellii, V. vulnificus, V. parahamolyticus, Edwardsiella tarda, Streptococcus sp., B. cereus. Scanning electron microscopy (SEM) investigation of indicator bacteria showed that cell morphologies were strongly affected by the cell-free supernatant of the two Bacillus spp. isolates. It is determined that the culture filtrates contained inhibitors against growth of some pathogenic bacteria with different degrees of inhibition, although none of the culture filtrates could inhibit the growth of V. fluvialis, V. alginolyticus, V. splendidus. Based upon these characteristics, both of the antagonistic Bacillus spp. isolates could be the potential probiotics used in the aquaculture production.
    Keywords: Aquaculture ; Biology ; Fisheries ; Bacillus ; Antagonistic activity ; Scanning electron microscopy ; Probiotic ; Aquaculture ; Genetics ; China
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  • 27
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    Diversity of eukaryotic plankton of aquaculture ponds with Carassius auratus gibelio, using denaturing gradient gel electrophoresis (2021)
    In:  http://aquaticcommons.org/id/eprint/22971 | 18721 | 2018-06-08 21:26:05 | 22971 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-12
    Description: PCR-denaturing gradient gel electrophoresis (DGGE) and canonical correspondence analysis (CCA) were used to explore the relationship between eukaryotic plankton community succession and environmental factors in two aquaculture pond models with gibel carp Carassius auratus gibelio. The main culture species of pond 1 were gibel carp and grass carp, and the combined density was 46224 fingerling/ha (gibel carp/grass carp/silver carp/bighead carp, 17:4:6:1). The main culture species of pond 2 was gibel carp, and the combined density was 37551 fingerling/ha (gibel carp/silver carp/bighead carp, 52:1:1). Water samples were collected monthly. The results showed that the annual average concentrations of TP and PO_4-P in pond 1 were significantly higher than pond 2 (p〉0.05). The concentration of chlorophyll a (chl a) has no significantly difference between pond 1 and pond 2. DGGE profiles of 18S rRNA gene fragments from the two ponds revealed that the diversity of eukaryotic plankton assemblages was highly variable. 91 bands and 71 bands were detected in pond 1 and pond 2, respectively. The average Shannon–Wiener index of pond 1 was significantly higher than pond 2. Canonical correspondence analysis (CCA) revealed that temperature played a key role in the structure of the eukaryotic plankton community in both ponds, but the nutrient concentration did not affect it. Our results suggest that DGGE method is a cost-effective way to gain insight into seasonal dynamics of eukaryotic plankton communities in culture ponds, and the increase in the number of filter-feeding silver carp and bighead carp could increase the diversity of the eukaryotic plankton community.
    Description: The corresponding author is Dong (not Liu, as shown on title page of article).
    Keywords: Aquaculture ; Biology ; Ecology ; 18S rRNA genes ; PCR-denaturing gradient gel electrophoresis ; CCA ; Eukaryotic plankton community ; Environmental factors ; Genetics ; China
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  • 28
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    Intraspecific hybridization studies in three strains of Clarias gariepinus (2021)
    Fisheries Society of Nigeria | Lagos
    In:  http://aquaticcommons.org/id/eprint/23022 | 19325 | 2018-03-05 09:09:30 | 23022 | Fisheries Society of Nigeria
    Details
    Publication Date: 2021-07-12
    Description: Intraspecific hybridization studies were carried out in three strains of Clarias gariepinus obtained from three ecological zones in Nigeria: rainforest; (Onitsha strain), Guinea savanna, Kainji strain) and Montanne vegetation, (Jos strain) with the aim of improving the growth performance of the species. Nine genetic mating combinations were generated from the three strains and were successfully induced under controlled hatchery conditions. Indoor and outdoor growth parameters were monitored. The 19 days growth indoors showed significant difference (P〈O.05) in weight gain. Highest weight gain (2.76g) was obtained in Jos parental strain and cross involving female Jos and male Kainji, while the least was recorded in female Kainji and male Onitsha (0.062g). The 50 days outdoor growth performance also showed significant difference between the genetic mating combinations. Maximum weight gain (464.57g) was observed in female Kainji and male Onitsha, while female Jos and male Kainji gave 263.94g weight gain. There was no significant difference (P〉0.05) in length in both indoor and outdoor rearing. Based on this study, the cross-involving female Kainji and male Onitsha is recommended for fingerling production of Clarias gariepinus.
    Description: Includes:- 4 tables.;1 fig.;4 refs.
    Keywords: Aquaculture ; Fisheries ; Clarias gariepinus ; Nigeria ; freshwater environment ; Hybridization ; Breeding ; Genetics ; Hybrid culture
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  • 29
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    Growth improvement of F1 generation of Clarias gariepinus through selective breeding (2021)
    Fisheries Society of Nigeria | Kaduna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23309 | 19325 | 2018-03-30 15:18:56 | 23309 | Fisheries Society of Nigeria
    Details
    Publication Date: 2021-07-14
    Description: Selective breeding studies were carried out in four genetic mating combinations of Clarias gariepinus with the aim of improving its growth performance. F2 intraspecific and backcross were produced using the best male and female of the best genetic mating combination in the F generation in crosses of three wild strains of Clara gariepinus. The highest percentage hatchability (75%) was recorded in female Kainji parental and male Kainji F1. and the least (53.67%) in female and Male Kainji Fl. The cross involving female Kainji F1. and Male Kainji Parental had the best survival (49%) indoor and also best (38.67%) outdoor, while the least (37.67%) was recorded in female Kainji parental and Male Kainji F1 and also gave the least (32.67%) outdoor. The female Kainji F1, and male Kainji parental gave the best growth performance (1.61 g) at 19 days indoor rearing, while female and male Kainji parental gave the least (1.50g). At the end of seven months rearing outdoor, the female Kainji parental and male Kainji F1. gave the best growth performance of(222.49g) and the least (180.66) was recorded in female Kainji F1 and male Kainji parental.
    Description: Includes:- 3 tables.;2 figs.;14 refs.
    Keywords: Aquaculture ; Fisheries ; Clarias gariepinus ; Nigeria ; Fish genetics ; fish breeding ; freshwater environment ; Genetics ; Breeding ; Fish culture ; Growth rate ; Hybrid culture ; Hybrids
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    Comparison of diploid and triploid Heterobranchus bidorsalis using Polyacryl Amide Gel Electrophoresis (N-PAGE) (2021)
    FISON | Akure (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23409 | 19325 | 2018-04-12 09:02:51 | 23409 | Fisheries Society of Nigeria
    Details
    Publication Date: 2021-07-14
    Description: A comparative analysis on biochemistry and Polyacryl Amide Gel Electrophresis was carried out to determine the genetic diversity of diploid and triploid Heterobranchus bidorsalis. Sixteen samples of diploid and triploid farm-raised (mean weight; 512.6g and mean length; 41.6cm) were collected and the electrophoresis analysis was conducted using 5.5% Polyacryl Amide Gel and serum protein obtained from the blood of the live samples. 0.06% Coomassie blue was used for staining the gel while a mixture of ratio 1:2 of glacial acetic acid, meethanol and distilled water was used for de-staining the gel. The diploid and triploid possessed an equal total number of 23 electrophoretic protein bands. The molecular phylogenetics of both samples revealed low genetic variability. Results of this study will serve as a baseline analysis on the current genetic diversity of H. bidorsalis in Nigeria.
    Description: Includes:- 2 figs.;8 refs.
    Keywords: Fisheries ; Heterobranchus bidorsalis ; Nigeria ; Kontagora L. ; freshwater environment ; Genetics ; Diploids ; Experimental culture ; Nutritional requirements ; Fish
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    Survival, growth and feed utilization of the reciprocal hybrids of Clarias gariepinus (Burchell, 1822) and Heterobranchus bidorsalis (Geoffroy, 1809) in concrete tanks (2021)
    Fisheries Society of Nigeria | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23466 | 19325 | 2018-05-05 12:42:05 | 23466 | Fisheries Society of Nigeria
    Details
    Publication Date: 2021-07-14
    Description: An experiment was conducted to determine the survival rate, fertilization rate, growth performance and feed utilization of the reciprocal hybrids of Clarias gariepinus and Heterobranchus bidorsalis. Two genetic crosses were made: C. gariepinus (male) x H. bidorsalis (female)(Clariabranchus) and H. bidorsalis male x C. gariepinusmale (Heteroclarias. The experiment was divided into two phases; artificial propagation of the fish species using synthetic hormone and rearing the fry for 14 days; and rearing the 14 days old fry for 35 days. In the first phase of the experiment, survival of frys were estimated in each experimental unit (genetic cross) while in the second phase, growth and nutrient utilization were investigated. The result revealed that the highest %fertilization, hatching rate and %survival occurred in H. bidorsalisfemale x C. gariepinus male (Heteroclarias) and the differences were significant (p 〈 0.05). Percentage weight gain and specific growth rate were significantly (p 〈 0.05) higher in Clariabranchus than Heteroclarias. Based on the result of this study, reciprocal hybrids of Clarias gariepinus and Heterobranchus, bidorsalis is recommended for commercial aquacultural practices.
    Description: Includes:- 3 tables.;13 refs.
    Keywords: Aquaculture ; Clarias gariepinus ; Heterobranchus bidorsalis ; Heteroclarias ; Nigeria ; Lagos ; freshwater environment ; Survival ; Growth rate ; Feed efficiency ; Genetics ; Fish culture
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    Introducing genetic markers for identification and separation of 4 species of Persian Gulf and Oman Sea fishes using PCR- RFLP method (2021)
    In:  http://aquaticcommons.org/id/eprint/23674 | 18721 | 2018-07-17 03:28:56 | 23674 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-15
    Description: In order to introduce genetic markers of four species of fishes, 80 samples of each species, i.e. Parastromateus niger, Scomberomorus comersoniannus, Trachionotus mookalee and Caranx para were collected. DNA was extracted using phenol- chloroform method. The target gene (cytochrome b) was amplified by Thermal cycle (PCR) and the PCR product size estimated 1105 bp. In this research out of 27 DNAase enzymes which were used for PCR product enzyme digesting 8 enzymes (Bam HI, Alw 261, Rsa I, Mbo I, Alu I, Hinf I, Dpn I, Dde I) have cut side on target DNA and three enzymes of them Alu I, Hinf I and Mbo I showed polymorphism genetic differences while other enzymes displayed similar patterns. Variation of haplotypes from four species are as follows: BAA for P. niger, AAB for T. mookalee, ABA for C. para, and ACA for S. comersonianus. So it is possible to claim that each of the above Haplotypes may be used as genetic markers for each of the species.
    Keywords: Biology ; Genetics ; DNA ; Enzymes ; Biomarkers ; Identification ; Phenotypes ; Chloroform ; Haplotypes ; Gene polymorphism ; Genetic markers ; Caranx ; Marine ; Separation ; Polymerase chain reaction ; Phenotypic variations ; Cytochrome b ; DDE ; Trachionotus mookalee ; Parastromateus niger ; Caranx para ; Carangidae ; Scomberomorus comersoniannus ; Scomberomorus ; ISW ; Arabian Sea ; Oman Gulf ISW ; Persian Gulf ; Iran
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    Investigation of population genetic structure of common carp (Cyprinus carpio) in the south Caspian Sea using mtDNA method (PCR-RFLP) (2021)
    In:  http://aquaticcommons.org/id/eprint/23718 | 18721 | 2018-07-20 08:32:13 | 23718 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-15
    Description: The population genetic structure of common carp (Cyprinus carpio) was examined on 260 specimens from Tajan and Gorgan Rivers, Gorgan Gulf, Anzali Lagoon and other regions in east, middle and west of south Caspian Sea. DNA was extracted from fin tissue by phenol-chlorophorm method with a concentration of 50-100 nanograms. PCR was performed using ND-3/4 and ND-5/6 genes. The PCR products of samples were digested by 15 restriction endonuclease enzymes. The digested products accompanied with standard marker (50 pb). To measure fragment size, samples were run on a 6% vertical poyacrylamide gel. The fragments were visualized by silver staining of the polyacrylamide gel. Statistical analysis of data was performed by Reap software. We detected 14 and 12 different haplotypes in ND-3/4 and ND-5/6 genes of common carp. The mean values of haplotype diversity among populations were 0.59 and 0.48 and the average nucleotide diversity was 0.06 and 0.03 for ND3/4 and ND5/6 genes. Also, the mean values of nucleotide divergence among populations were 0.05% and 0.02%, respectively. The haplotype distribution was not significantly different between Mazandaran and Guilan coasts, Mazandaran and Golestan coasts, Golestan coast and Gorgan Gulf and Gorgan River (P〈0.05), but this divergence was significantly different between Guilan region and Anzali Lagoon, Guilan and Golestan coasts, Tajan and Gorgan Rivers (P〈0.05). We found a significant genetic divergence between some of the samples such that three genetic groups of common carp were identified in the southern part of the Caspian Sea.
    Keywords: Biology ; Population genetics ; Genetics ; DNA ; Freshwater fish ; Enzymes ; Lead ; Lagoons ; Mitochondrial DNA ; Coasts ; Nucleotide sequence ; Polymerase chain reaction ; Coastal lagoons ; Nucleotides ; Rivers ; Data processing ; Statistical analysis ; Computer programs ; Software ; Haplotypes ; Endonuclease ; Cyprinus carpio ; Brackish ; Gorgan R. Eurasia ; Caspian Sea ; Mazandaran Province ; Guilan Province ; Anzali Lagoon ; Caspian Sea ISW ; Iran
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    Development of breeding and fingerling production techniques for endangered long-whiskered catfish Sperata aor in captivity (2021)
    In:  http://aquaticcommons.org/id/eprint/22752 | 18721 | 2018-05-19 19:20:20 | 22752 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-09
    Description: An experiment was undertaken to develop a suitable seed production technique for Sperata aor in captivity. Naturally produced fry of aor was reared at different densities in nine nursery ponds 0.012 ha in size with an average depth of 0.8 m each. Three stocking densities tested, each of which was triplicated. Fry of aor stocked at 100,000/ha was designated as treatment-1 (T1), 150,000/ha as treatment-2 (T2) and 200,000/ha as treatment-3 (T3). All stocked fry were from the same age group with mean length and weight of 1.78 ± 0.28 cm and 0.24 ± 0.05 g, respectively. Fry in all the treatments were fed with SABINCO nursery feed (32.06% crude protein) for the first 14 days and starter-I (31.53% crude protein) for days 15 to 56. Physico-chemical parameters and plankton population of pond water were within the optimal level being better in T1 than those in T2 and T3. Growth in terms of final weight and length, weight and length gain, specific growth rate, daily growth rate, and survival of fingerlings were significantly higher in T1 followed by T2 and T3. Food conversion rate was significantly lower in T1 than in T2 and T3. Significantly higher number of fingerlings was produced in T3 than those in T2 and T1. Despite this, consistently higher net benefits were achieved from T1 than from T2 and T3. This is the first time report that stocking of 100,000 fry/ha appears to be the most suitable density for rearing of aor fingerlings in nursery ponds.
    Keywords: Biology ; Fisheries ; Sperata aor ; Fry ; Stocking density ; Fingerling ; Growth ; Production ; Genetics ; Malaysia
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    Diagnosis of endosulfan induced DNA damage in rohu (Labeo rohita, Hamilton) using comet assay (2021)
    In:  http://aquaticcommons.org/id/eprint/23014 | 18721 | 2018-06-13 22:19:30 | 23014 | Iranian Fisheries Science Research Institute
    Details
    Publication Date: 2021-07-12
    Description: Use of different pesticides in the agriculture sector, in order to boost crop yield within a short time period and low labor, has been tremendously increased since the last decade. Pesticide use has elevated crop yield but has produced a number of pronounced problems regarding environmental and health safety. The continuously deteriorating toxicological effects of these pesticides are not only hazardous to humans and land animals but also to economically important aquatic organisms such as fish. One of these extensively used pesticides is an organochlorine insecticide, endosulfan. Experiments conducted in the past have shown the deleterious effects of endosulfan on different aspects of various fish species but its genetic toxicity has not been well studied. The present study was conducted to diagnose the DNA damage induced by endosulfan in peripheral blood erythrocytes of an economically important teleost fish rohu, Labeo rohita (Hamilton, 1822) using comet assay. The fish were exposed to three different sub lethal concentrations (1, 1.5 and 2 µg L^-1) of endosulfan for 7, 14, 21 and 28 days. Rohu showed different extents of DNA damage at different concentrations and time, in terms of genetic damage index (GDI), percentage of damaged cells (% damaged cell) and cumulative tail length (µm) of the comets. Increase in DNA damage was observed to be concentration and time-dependent. The current study revealed the severe genotoxic effects of endosulfan in rohu, Labeo rohita. Therefore its discriminate use should be avoided as it can contribute to the decline of rohu in natural habitats. Also it should be considered as a hazardous threat for human consumption.
    Keywords: Biology ; Fisheries ; Health ; Pollution ; Endosulfan ; DNA damage ; Erythrocyte ; Comet assay ; Rohu ; Genetics ; Pakistan
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    Lessons from the breeding program on common carp in Hungary (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2597 | 115 | 2010-12-14 17:34:45 | 2597 | WorldFish Center
    Details
    Publication Date: 2021-06-25
    Description: Common carp is one of the most important cultured freshwater fish species in the world. Its production in freshwater areas is the second largest in Europe after rainbow trout. Common carp production in Europe was 146,845 t in 2004 (FAO Fishstat Plus 2006). Common carp production is concentrated mainly in Central and Eastern Europe. In Hungary, common carp has been traditionally cultured in earthen ponds since the late 19th century, following the sharp drop in catches from natural waters, due to the regulation of main river systems. Different production technologies and unintentional selection methods resulted in a wide variety of this species. Just before the intensification of rearing technology and the exchange of stocking materials among fish farms (early sixties), “landraces” of carp were collected from practically all Hungarian fish farms into a live gene bank at the Research Institute for Fisheries, Aquaculture and Irrigation (HAKI) at Szarvas (Bakos and Gorda 1995; Bakos and Gorda 2001). In order to provide highly productive hybrids for production purposes starting from 1964, different strains and crosses between Hungarian landraces were created and tested. During the last 40 years, approximately 150 two-, three-, and four-line hybrids were produced. While developing parental lines, methods of individual selection, inbreeding, backcrossing of lines, gynogenesis and sex reversal were used. This breeding program resulted in three outstanding hybrids: “Szarvas 215 mirror” and “Szarvas P31 scaly” for pond production, and “Szarvas P34 scaly” for angling waters. Besides satisfying the needs of industry, the live gene bank helped to conserve the biological diversity of Hungarian carp landraces. Fifteen Hungarian carp landraces are still maintained today in the gene bank. Through exchange programs fifteen foreign carp strains were added to the collection from Central and Eastern Europe, as well as Southeast Asia (Bakos and Gorda 2001). Besides developing the methodology to maintain live specimens in the gene bank, the National Carp Breeding Program has been initiated in cooperation with all the key stakeholders in Hungary, namely the National Association of Fish Producers (HOSZ), the National Institute for Agricultural Quality Control (OMMI), and the Research Institute for Fisheries, Aquaculture and Irrigation (HAKI). In addition, methodologies or technologies for broodstock management and carp performance testing have been developed. This National Carp Breeding Program is being implemented successfully since the mid-1990s.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Genetic drift ; Genetic diversity ; Fish culture ; Brood stocks ; Induced breeding ; Breeding success ; Research programmes
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    Genetic improvement and effective dissemination: keys to prosperous and sustainable aquaculture industries (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2589 | 115 | 2010-12-14 17:34:36 | 2589 | WorldFish Center
    Details
    Publication Date: 2021-06-25
    Description: There is an increasing demand for fish in the world due to a growing population, better economic situation in some sectors, and greater awareness of health issues in relation to food. Since capture fisheries have stagnated, fish farming has become a very fast growing food production system. In this presentation, the author gives an overview of the technologies that are available for genetic improvement of fish, and briefly discuss their merit in the context of a sustainable development. He also discusses the essential prerequisites for effective dissemination of improved stock to farmers. It is concluded that genetic improvement programs based on selective breeding can substantially contribute to sustainable fish production systems. Furthermore, if such genetic improvement programs are followed up with effective dissemination strategies, they can result in a positive impact on farmers' incomes.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Food fish ; Genetic drift
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    Maintaining the "public good" nature of improved fish strains: dissemination of knowledge and materials (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2600 | 115 | 2010-12-14 17:34:51 | 2600 | WorldFish Center
    Details
    Publication Date: 2021-06-26
    Description: Many sources of information that discuss currents problems of food security point to the importance of farmed fish as an ideal food source that can be grown by poor farmers, (Asian Development Bank 2004). Furthermore, the development of improved strains of fish suitable for low-input aquaculture such as Tilapia, has demonstrated the feasibility of an approach that combines “cutting edge science” with accessible technology, as a means for improving the nutrition and livelihoods of both the urban poor and poor farmers in developing countries (Mair et al. 2002). However, the use of improved strains of fish as a means of reducing hunger and improving livelihoods has proved to be difficult to sustain, especially as a public good, when external (development) funding sources devoted to this area are minimal1. In addition, the more complicated problem of delivery of an aquaculture system, not just improved fish strains and the technology, can present difficulties and may go explicitly unrecognized (from Sissel Rogne, as cited by Silje Rem 2002). Thus, the involvement of private partners has featured prominently in the strategy for transferring to the public technology related to improved Tilapia strains. Partnering with the private sector in delivery schemes to the poor should take into account both the public goods aspect and the requirement that the traits selected for breeding “improved” strains meet the actual needs of the resource poor farmer. Other dissemination approaches involving the public sector may require a large investment in capacity building. However, the use of public sector institutions as delivery agents encourages the maintaining of the “public good” nature of the products.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Genetic drift ; Fish culture ; Policies
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    Breeding programs on Atlantic salmon in Norway: lessons learned (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2596 | 115 | 2010-12-14 17:34:43 | 2596 | WorldFish Center
    Details
    Publication Date: 2021-06-25
    Description: An early establishment of selective breeding programs on Atlantic salmon has been crucial for the success of developing efficient and sustainable salmon farming in Norway. A national selective breeding program was initiated by AKVAFORSK at the beginning of the 1970s, by collecting fertilized eggs from more than 40 Norwegian river populations. Several private selective breeding programs were also initiated in the 1970s and 1980s. While these private programs were initiated using individual selection (i.e. massselection) to genetically improve growth, the national program was designed to gradually include all economically important traits in the breeding objective (i.e. growth, age at sexual maturation, disease resistance and quality traits) using a combined family and within-family selection strategy. Independent of which selection strategy and program design used, it is important to secure and maintain a broad genetic variation in the breeding populations to maximize selection response. It has been documented that genetically improved salmon from the national selective breeding program grow twice as fast as wild Atlantic salmon and require 25 per cent less feed, while salmon representing the private breeding programs all show an intermediate growth performance. As a result of efficient dissemination of genetically improved Atlantic salmon, the Norwegian salmon farming industry has reduced its feed costs by more than US$ 230 million per year! The national selective breeding program on Atlantic salmon was commercialized into a breeding company (AquaGen) in 1992. Five years later, several private companies and the AKVAFORSK Genetics Center (AFGC) established a second breeding company (SalmoBreed) using breeding candidates from one of the private breeding programs. These two breeding companies have similar products, but different strategies on how to organize the breeding program and to disseminate the genetically improved seed to the Norwegian salmon industry. Greater competition has increased the necessity to document the genetic gain obtained from the different programs and to market the economic benefits of farming the genetically improved breeds. Both breeding companies have organized their dissemination to get a sufficient share of the economic benefits in order to sustain and improve their breeding programs.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Genetic drift ; Genetic diversity ; Fish culture ; DNA ; Induced breeding ; Breeding success ; Research programmes
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    Policies on release of improved fish strains in China (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2599 | 115 | 2010-12-14 17:34:49 | 2599 | WorldFish Center
    Details
    Publication Date: 2021-06-26
    Description: Since 1991, the certification, release and maintenance of new species for aquaculture have become part of the national policy in China. During the past 15 years, this policy has been conducted and improved and has begun to show its significant role in Chinese fisheries. This paper describes the updated system of certification, release and maintenance of new species for aquaculture in China.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Genetic drift ; Genetic diversity ; Fish culture ; Induced breeding ; Breeding success ; Research programmes ; Policies
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  • 41
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    Potential applications of reproductive and molecular genetic technologies in the selective breeding of aquaculture species (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2595 | 115 | 2010-12-14 17:34:41 | 2595 | WorldFish Center
    Details
    Publication Date: 2021-06-25
    Description: The use of reproductive and genetic technologies can increase the efficiency of selective breeding programs for aquaculture species. Four technologies are considered, namely: marker-assisted selection, DNA fingerprinting, in-vitro fertilization, and cryopreservation. Marker-assisted selection can result in greater genetic gain, particularly for traits difficult or expensive to measure, than conventional selection methods, but its application is currently limited by lack of high density linkage maps and by the high cost of genotyping. DNA fingerprinting is most useful for genetic tagging and parentage verification. Both in-vitro fertilization and cryopreservation techniques can increase the accuracy of selection while controlling accumulation of inbreeding in long-term selection programs. Currently, the cost associated with the utilization of reproductive and genetic techniques is possibly the most important factor limiting their use in genetic improvement programs for aquatic species.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Genetic drift ; Genetic diversity ; Aquatic animals ; Fish culture ; DNA ; Induced breeding
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    Lessons from established breeding programs: terrestrial and aquatic animals (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2594 | 115 | 2011-09-29 18:45:03 | 2594 | WorldFish Center
    Details
    Publication Date: 2021-06-25
    Description: Some relevant components of selection program theory and implementation are reviewed. This includes pedigree recording, genetic evaluation, balancing genetic gains and genetic diversity and tactical integration of key issues. Lessons learned are briefly described – illustrating how existing method and tools can be useful when launching a program in a novel species, and yet highlighting the importance of proper understanding and custom application according to the biology and environments of that species.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Genetic drift ; Genetic diversity ; Aquatic animals
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    Lessons from the breeding program of rohu (2021)
    WorldFish Center | Penang, Malaysia
    In:  http://aquaticcommons.org/id/eprint/2598 | 115 | 2011-09-29 18:45:17 | 2598 | WorldFish Center
    Details
    Publication Date: 2021-06-25
    Description: For the first time in India, selective breeding work has been initiated at the Central Institute of Freshwater Aquaculture, Bhubaneswar, India in collaboration with the Institute of Aquaculture Research (AKVAFORSK), Norway. Rohu has been chosen as the model species because it enjoys the highest consumer preference among Indian major carps (IMC) although its performance was observed to be slower than other IMC. As this was the first ever selection work on any Indian major carp, many procedures and techniques for successful implementation of the programs were standardized (i.e. production of full-sib groups, establishment of model hatchery for selective breeding of carps, rearing of full-sib groups in partitioned nursery ponds, individual tagging with the Passive Integrated Transponder (PIT) tag, communal rearing, sampling, data analysis, field testing and dissemination of improved rohu). After four generations of selection, an average of 17 per cent higher growth per generation was observed in improved rohu.
    Keywords: Aquaculture ; Biotechnology ; Genetics ; Genetic drift ; Genetic diversity ; Fish culture ; Brood stocks ; Induced breeding ; Breeding success ; Research programmes ; India
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    Potential of genetics for aquaculture development in Africa (2021)
    In:  http://aquaticcommons.org/id/eprint/9113 | 115 | 2012-11-26 17:28:18 | 9113 | WorldFish Center
    Details
    Publication Date: 2021-07-02
    Description: Aquaculture in Africa is fairly insignificant by world standards and accounts for a mere 0.4 per cent of global aquaculture production. The application of genetics can play an important role in efforts to increase aquaculture production in Africa through methods such as selective breeding, hybridization, chromosome manipulation and use of YY “supermales”. Other issues that need to be addressed are limited genetic research facilities, funding, human capacity and suitable species for aquaculture.
    Keywords: Aquaculture ; Aquaculture development ; Tilapia ; Genetics ; Africa
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    Genetic diversity and selective breeding of red common carps in China (2021)
    In:  http://aquaticcommons.org/id/eprint/9312 | 115 | 2012-11-30 14:19:07 | 9312 | WorldFish Center
    Details
    Publication Date: 2021-07-04
    Description: China has a very rich genetic diversity in common carp (Cyprinus carpio) and the red common carp plays an important role in Chinese aquaculture and genetic studies. Selective breeding, particularly crossbreeding has been applied successfully to red common carps in China, and the products of these efforts have been in commercial use since the 1970s. However, knowledge of the quantitative and molecular genetics of these carps is limited. Studies were therefore undertaken to: (1) understand the genetic diversity and genetic relationship of red common carps in China; (2) understand the inheritance of color phenotype of Oujiang color carp; (3) select stable Oujiang color carp with fast growth rate and ornamental Oujiang color carp comparable with the Koi common carp from Japan; (4) study the culture performance and culture systems suitable for the Oujiang color carp in cages and paddies; (5) extend better quality fish and appropriate culture systems for small scale fish farmers in poor areas.
    Keywords: Aquaculture ; Genetics ; Biological diversity ; Fish culture ; Selective breeding ; China ; Cyprinus carpio
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    Marine fisheries, genetic effects and biodiversity (2021)
    In:  http://aquaticcommons.org/id/eprint/9429 | 115 | 2012-10-11 04:49:10 | 9429 | WorldFish Center
    Details
    Publication Date: 2021-07-06
    Description: Preservation of marine biodiversity deserves serious consideration as almost 65% of the earth's organisms (excluding insects) are marine. There is little knowledge at present on the status of marine biodiversity. However, the seas are an important source of protein for human consumption and genetic diversity is a key factor in ecosystem functioning, stability and resilience. Overfishing and destructive practices may have unalterable impact on marine biodiversity. This paper discusses measures that can be adopted to protect the most productive areas of the marine ecosystem.
    Keywords: Fisheries ; Marine fisheries ; Genetics ; Biological diversity ; Fishery management ; Resource conservation ; Ecosystem management
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    Approaches to national fish breeding programs: pointers from a tilapia pilot study (2021)
    In:  http://aquaticcommons.org/id/eprint/9178 | 115 | 2012-11-28 13:13:57 | 9178 | WorldFish Center
    Details
    Publication Date: 2021-07-03
    Description: Details are given of a framework for developing breeding programmes using experience from the Genetic Improvement of Farmed Tilapias project which focussed on Nile tilapias (Oreochromis niloticus ). The following aspects are outlined: Analysis of targeted production and marketing systems; Breeding goals; Systematic documentation and evaluation of available genetic resources and choice and genetic base; Number of strains; Breeding strategy; Selection criteria and evaluation; Production and dissemination of improved strains; and, social, economic and environmental impacts.
    Keywords: Aquaculture ; Breeding ; Genetics ; National planning ; Programmes ; Fish ; Oreochromis niloticus
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    Baseline biochemical and genetic profiles of four fishes from the River Nile (2021)
    In:  http://aquaticcommons.org/id/eprint/9362 | 115 | 2012-10-23 08:48:19 | 9362 | WorldFish Center
    Details
    Publication Date: 2021-07-05
    Description: Six enzyme systems coding for 10 loci and 6 proteins were examined in the blood of Polypterus senegalus, Clarias lazera, Tilapia nilotica and Protopterus annectens, using electrophoresis. Six loci were polymorphic in all the four species, three polymorphic in three species and one polymorphic in T. nilotica. Four protein loci were monomorphic in all the four species with variants in P. senegalus and T. nilotica. Haemoglobin can be used as a species-specific marker. Polymorphism was 53-56 per cent and average heterozygosity was 0.1-0.15.
    Keywords: Biology ; Fisheries ; Genetics ; Polypterus senegalus ; Clarias lazera ; Tilapia nilotica ; Protopterus annectens
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    Down to earth thoughts on conserving aquatic genetic diversity (2021)
    In:  http://aquaticcommons.org/id/eprint/9447 | 115 | 2012-10-12 05:19:00 | 9447 | WorldFish Center
    Details
    Publication Date: 2021-07-06
    Description: A discussion is presented on the topic of maintaining genetic diversity in aquatic ecosystems, considering the various threats caused by irreversible damage or loss to the environment. The current situation in aquaculture and future prospects regarding the conservation and protection of endangered species are outlined, describing the case of tilapias in Africa as one particular example of fish conservation.
    Keywords: Conservation ; Fisheries ; Resource conservation ; Aquatic organisms ; Genetics
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    Exotic species and genetically modified organisms in aquaculture and enhanced fisheries: ICLARM's position (2021)
    In:  http://aquaticcommons.org/id/eprint/9449 | 115 | 2012-10-12 05:21:23 | 9449 | WorldFish Center
    Details
    Publication Date: 2021-07-06
    Description: This article contains a discussion paper on the use of exotic species and genetically modified organisms in aquaculture and enhanced fisheries, together with a summary of ICLARM's (International Center for Living Aquatic Resources Management, Philippines) current position on this important topic.
    Keywords: Aquaculture ; Fisheries ; Biotechnology ; Genetics ; Aquaculture ; Genetically modified organisms
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    The Genetic Improvement of Farmed Tilapias (GIFT) project: the story so far (2021)
    In:  http://aquaticcommons.org/id/eprint/9451 | 115 | 2012-10-12 05:22:47 | 9451 | WorldFish Center
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    Publication Date: 2021-07-06
    Keywords: Aquaculture ; Genetics ; Selective breeding ; Research programmes ; ICLARM ; Tilapia
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    Genetic engineering of microorganisms: free release into the environment (2021)
    Freshwater Biological Association | Ambleside, UK
    In:  http://aquaticcommons.org/id/eprint/5250 | 3949 | 2020-08-23 05:42:00 | 5250 | Freshwater Biological Association
    Details
    Publication Date: 2021-07-09
    Description: Genetic engineering now makes possible the insertion of DNA from many organisms into other prokaryotic, eukaryotic and viral hosts. This technology has been used to construct a variety of such genetically engineered microorganisms (GEMs). The possibility of accidental or deliberate release of GEMs into the natural environment has recently raised much public concern. The prospect of deliberate release of these microorganisms has prompted an increased need to understand the processes of survival, expression, transfer and rearrangement of recombinant DNA molecules in microbial communities. The methodology which is being developed to investigate these processes will greatly enhance our ability to study microbial population ecology.
    Keywords: Biology ; Ecology ; Environment ; Aquatic environment ; Genetics ; Microorganisms ; England ; Annual report
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  • 53
    Electronic Resource
    Electronic Resource
    Genetic ecology: A new interdisciplinary science, fundamental for evolution, biodiversity and biosafety evaluations (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 429-437 
    Details
    ISSN: 1420-9071
    Keywords: Genetics ; ecology ; DNA-transfer ; conjugation ; transformation ; transduction ; transposons ; dormant cells ; epilithon ; microbial colonisation ; symbiosis ; virus resistance ; biosafety ; release of genes ; insults to humanity ; evolution ; biodiversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
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    URL: http://dx.doi.org/10.1007/BF01920741
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    Electronic Resource
    Electronic Resource
    Renal eicosanoids and blood pressure in genetically hypertensive rats of the lyon strain (1994)
    Springer
    Journal of biomedical science 1 (1994), S. 201-203 
    Details
    ISSN: 1423-0127
    Keywords: Hypertension ; Eicosanoid ; Rat ; Genetics ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The present paper reviews the evidence for a possible involvement of renal eicosanoids in the pathophysiology of high blood pressure in genetically hypertensive rats of the Lyon strain. Both in vivo and in vitro experiments suggest that an increased ability to synthesize the vasoconstrictor prostaglandin H2 and/or thromboxane A2 in renal vessels (1) acts as an autocrine amplifier of pressor agents and (2) may contribute to resetting the pressure natriuresis curve which is a prerequisite for the development and maintenance of hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253302
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  • 55
    Electronic Resource
    Electronic Resource
    Genetic analysis of a polyembryonic mutant in rye (1994)
    Springer
    Sexual plant reproduction 7 (1994), S. 290-296 
    Details
    ISSN: 1432-2145
    Keywords: Secale cereale ; Polyembryony ; Chromosome mosaics ; Rye ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have obtained one plant regenerated from rye tissue culture which showed a high percentage of polyembryonic seeds in its progeny. The mutation inducing the development of extra embryos is also influencing erroneous cell division, mitosis and meiosis. The genetic analysis indicated that the aptitude for polyembryonic seed formation is a heritable trait controlled by a dominant gene. However, for expression of the phenotype the female parent should have a specific cytoplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227712
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    Molecular marker-facilitated studies in an elite maize population: I. Linkage analysis and determination of QTL for morphological traits (1994)
    Springer
    Theoretical and applied genetics 88 (1994), S. 7-16 
    Details
    ISSN: 1432-2242
    Keywords: Maize ; Restriction fragment length polymorphisms (RFLPs) ; Qualitative and quantitative inheritance ; Plant breeding ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Restriction fragment length polymorphisms (RFLPs) and one morphological marker were used to investigate quantitative trait loci (QTL) for morphological and physiological traits evaluated on 150 F2∶3 maize (Zea mays L.) lines derived from the cross of elite U.S. Corn Belt inbreds Mo17 and H99. F2∶3 lines were grown in a replicated experiment and evaluated for plant and ear heights and flowering traits. QTL were identified for each trait, and genetic effects were determined. Estimated gene action for the flowering traits was predominantly overdominance. Both parents contributed toward increased values for anthesis and silk emergence. QTL for increased plant and ear heights were usually contributed by the taller parent, Mo17. Estimated gene action for these traits was mainly partial to overdominance. QTL for plant height were located in the vicinity of loci defined by alleles with qualitative effects on plant height.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222387
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    Chromosome assortment in Saccharum (1994)
    Springer
    Theoretical and applied genetics 89 (1994), S. 959-963 
    Details
    ISSN: 1432-2242
    Keywords: Sugarcane ; Polyploidy ; Genetics ; Evolution ; Breeding ; DNA markers ; Arbitrarily primed PCR ; RAPD markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent work has revealed random chromosome pairing and assortment in Saccharum spontaneum L., the most widely distributed, and morphologically and cytologically variable of the species of Saccharum. This conclusion was based on the analysis of a segregating population from across between S. spontaneum ‘SES 208’ and a spontaneously-doubled haploid of itself, derived from anther culture. To determine whether polysomic inheritance is common in Saccharum and whether it is observed in a typical biparental cross, we studied chromosome pairing and assortment in 44 progeny of a cross between euploid, meiotically regular, 2n=80 forms of Saccharum officinarum ‘LA Purple’ and Saccharum robustum ‘ Mol 5829’. Papuan 2n=80 forms of S. robustum have been suggested as the immediate progenitor species for cultivated sugarcane (S. officinarum). A total of 738 loci in LA Purple and 720 loci in Mol 5829 were amplified and typed in the progeny by arbitrarily primed PCR using 45 primers. Fifty and 33 single-dose polymorphisms were identified in the S. officinarum and S. robustum genomes, respectively (χ 2 at 98%). Linkage analysis of single-dose polymorphisms in both genomes revealed linkages in repulsion and coupling phases. In the S. officinarum genome, a map hypothesis gave 7 linkage groups with 17 linked and 33 unlinked markers. Four of 13 pairwise linkages were in repulsion phase and 9 were in coupling phase. In the S. robustum genome, a map hypothesis gave 5 linkage groups, defined by 12 markers, with 21 markers unlinked, and 2 of 9 pairwise linkages were in repulsion phase. Therefore, complete polysomic inheritance was not observed in either species, suggesting that chromosomal behavior is different from that observed by linkage analysis of over 500 markers in the S. spontaneum map. Implications of this finding for evolution and breeding are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224524
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    Genetic analysis of tolerance for phosphorous deficiency in rice (Oryza sativa L.) (1994)
    Springer
    Theoretical and applied genetics 89 (1994), S. 313-317 
    Details
    ISSN: 1432-2242
    Keywords: Genetics ; Rice ; Phosphorousefficiency ; Diallel analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The inheritance of phosphorous (P) — deficiency tolerance in rice was investigated by a sevenparent diallel. The parent materials involved were four P-efficient (IR20, IR54, IR28, and Mahsuri), one moderately P-efficient (TN1), and two P-inefficient (IR31406333-1 and IR34686-179-1-2-1), genotypes. Relative tilering ability (RTA) under P-deficient and P-supplemented soil conditions was the parameter used in determining the tolerance level of the different genotypes. Diallel graph analysis revealed that tolerant parents have an excess of recessive genes, while moderate and susceptible parents possess more dominant genes. Genetic-component analysis suggested that both additive and dominance gene effects are involved in the inheritance of P-deficiency tolerance in rice. The trait exhibited over doiminance as confirmed by the graphical analysis. Narrow-sense heritability of the trait was moderate (0.50) and environmental effects were low. Both the general combining ability (GCA) and the specific combining ability (SCA) were significant, but GCA was more prevalent than SCA. Tolerant parents exhibited a high GCA whereas susceptibles have a very poor GCA, suggesting that tolerant parents were mostly enriched in additive genes and susceptible parents in non-additive genes. Crosses involving two high general combiners showed low SCA effects whereas crosses between poor general combiners manifested highly-significant SCA values.
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    URL: http://dx.doi.org/10.1007/BF00225160
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    Resistance to potato leaf roll virus multiplication in potato is under major gene control (1994)
    Springer
    Theoretical and applied genetics 88 (1994), S. 754-758 
    Details
    ISSN: 1432-2242
    Keywords: Potato breeding ; Potato leaf roll virus ; Virus resistance ; Major gene resistance ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The concentration of potato leaf roll virus (PLRV), as measured by a quantitative enzyme-linked immunosorbent assay, in the foliage of potato plants (Solanum tuberosum) of cv ‘Maris Piper’ with secondary infection was 2900 ng/g leaf, whereas in clones G7445(1) and G7032(5) it was 180 ng/g leaf and 120 ng/g leaf, respectively. To examine the genetic control of resistance to PLRV multiplication, reciprocal crosses were made between the susceptible cultivar ‘Maris Piper’ and the two resistant clones, and the three parents were selfed. Seedling progenies of these families were grown to generate tubers of individual genotypes (clones). Clonally propagated plants were graft-inoculated, and their daughter tubers were collected and used to grow plants with secondary infection in which PLRV concentration was estimated. The expression of resistance to PLRV multiplication had a bimodal distribution in progenies from crosses between ‘Maris Piper’ and either resistant clone, and also in progeny from selfing the resistant parents, with genotypes segregating into high and low virus titre groups. Only the progeny obtained from selfing ‘Maris Piper’ did not segregate, all genotypes being susceptible to PLRV multiplication. The pattern of segregation obtained from these progenies fits more closely with the genetical hypothesis that resistance to PLRV multiplication is controlled by two unlinked dominant complementary genes, both of which are required for resistance, than with the simpler hypothesis that resistance is conferred by a single dominant gene, as published previously.
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    Molecular-marker-facilitated investigation of host-plant response to Exserohilum turcicum in maize (Zea mays L.): components of resistance (1994)
    Springer
    Theoretical and applied genetics 88 (1994), S. 305-313 
    Details
    ISSN: 1432-2242
    Keywords: Breeding ; Helminthosporium turcicum ; RFLP ; QTLs ; Disease-resistance ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract RFLPs were used to investigate components of host-plant response to Exserohilum turcicum in 150 unselected F2∶3 lines of a B52/Mo17 maize population. Following inoculation with spore suspensions of the pathogen (race 0), components of disease development were measured and then quantitative trait mapping was performed to identify the location and effects of quantitative trait loci (QTLs) determining host-plant response. Components of interest were the average number of lesions per leaf, the average percent leaf tissue diseased (severity) and the average size of lesions (cm2). Based on a LOD threshold of 2.31 (P〈0.05), the number of lesions appears to be associated with QTLs on chromosomes 1S, 3L, 5S. Severity was associated with analogous regions and, in addition, QTLs on chromosomes 7L and 8L. Most QTLs, for either of these two components, involve additive gene action and partial dominance or overdominance. In contrast, lesion size was associated with QTLs on chromosomes 7L and 5L; recessive gene action may be involved at 7L.
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    URL: http://dx.doi.org/10.1007/BF00223637
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    A linkage map of diploid Avena based on RFLP loci and a locus conferring resistance to nine isolates of Puccinia coronata var. ‘avenae’ (1994)
    Springer
    Theoretical and applied genetics 89 (1994), S. 831-837 
    Details
    ISSN: 1432-2242
    Keywords: Genetics ; Disease resistance ; Monocots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An F2 oat population was produced by crossing the diploid (n=7) species Avena strigosa (CI 3815) with A. wiestii (CI 1994), resistant and susceptible, respectively, to 40 isolates of Puccinia coronata, the causal agent of crown rust. Eighty-eight F2 individuals were used to construct an RFLP linkage map representing the A genome of cultivated hexaploid oat. Two hundred and eight RFLP loci have been placed into 10 linkage groups. This map covers 2416 cM, with an average of 12 cM between RFLP loci. Eighty-eight F3 lines, derived from F2 individuals used to construct the map, were screened for resistance to 9 isolates of P. coronata. One locus, Pca, was found to confer a dominant resistance phenotype to isolates 203, 258, 263, 264B, 290, 298, 325A, and 345. Pca also conferred resistance to isolate 276; however, an unlinked second gene may also be involved.
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    URL: http://dx.doi.org/10.1007/BF00224505
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    Behavioral and life-history components of division of labor in honey bees (Apis mellifera L.) (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 117-409 
    Details
    ISSN: 1432-0762
    Keywords: Social insects ; Apis mellifera ; Division of labor ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Variability exists among worker honey bees for components of division of labor. These components are of two types, those that affect foraging behavior and those that affect life-history characteristics of workers. Variable foraging behavior components are: the probability that foraging workers collect (1) pollen only; (2) nectar only; and (3) pollen and nectar on the same trip. Life history components are: (1) the age the workers initiate foraging behavior; (2) the length of the foraging life of a worker; and (3) worker length of life. We show how these components may interact to change the social organization of honey bee colonies and the lifetime foraging productivity of individual workers. Selection acting on foraging behavior components may result in changes in the proportion of workers collecting pollen and nectar. Selection acting on life-history components may affect the size of the foraging population and the distribution of workers between within nest and foraging activities. We suggest that these components define possible sociogenic “pathways” through which colony-level natural selection can change social organization. These pathways may be analogous to developmental pathways in the morphogenesis of individual organisms because small changes in behavioral or life history components of individual workers may lead to major changes in the organizational structure of colonies.
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    URL: http://dx.doi.org/10.1007/BF00167332
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    Reproductive competition in queenless honey bee colonies (Apis mellifera L.) (1994)
    Springer
    Behavioral ecology and sociobiology 35 (1994), S. 99-107 
    Details
    ISSN: 1432-0762
    Keywords: Key words Apis mellifera ; Genetics ; Drone production ; Allozymes ; Reproductive conflict
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previously we reported that there are subfamily differences in drone production in queenless honey bee colonies, but these biases are not always explained by subfamily differences in oviposition behavior. Here we determine whether these puzzling results are best explained by either inadequate sampling of the laying worker population or reproductive conflict among workers resulting in differential treatment of eggs and larvae. Using colonies composed of workers from electrophoretically distinct subfamilies, we collected samples of adult bees engaged in the following behavior: “true” egg laying, “false” egg laying, indeterminate egg laying, egg cannibalism, or nursing (contact with larvae). We also collected samples of drone brood at four different ages: 0 to 2.5-h-old eggs, 0 to 24-h-old eggs, 3 to 8-day-old larvae, and 9 to 14-day-old larvae and pupae. Allozyme analyses revealed significant subfamily differences in the likelihood of exhibiting egg laying, egg cannibalism, and nursing behavior, as well as significant subfamily differences in drone production. There were no subfamily differences among the different types of laying workers collected from each colony, suggesting that discrepancies between subfamily biases in egg-laying behavior and drone production are not due to inadequate sampling of the laying worker population. Subfamily biases in drone brood production within a colony changed significantly with brood age. Laying workers had significantly more developed ovaries than either egg cannibals or nurses, establishing a physiological correlate for the observed behavioral genetic differences. These results suggest there is reproductive conflict among subfamilies and individuals within queenless colonies of honey bees. The implications of these results for the evolution of reproductive conflict, in both queenright and queenless contexts, are discussed.
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    URL: http://dx.doi.org/10.1007/s002650050075
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    Genotypic differences in brood rearing in honey bee colonies: context-specific? (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 125-137 
    Details
    ISSN: 1432-0762
    Keywords: Social insects ; Apis mellifera ; Division of labor ; Genetics ; Nepotism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Three experiments were performed to determine whether brood care in honey bee colonies is influenced by colony genetic structure and by social context. In experiment 1, there were significant genotypic biases in the relative likelihood of rearing queens or workers, based on observations of individually labeled workers of known age belonging to two visually distinguishable subfamilies. In experiment 2, no genotypic biases in the relative likelihood of rearing drones or workers was detected, in the same colonies that were used in experiment 1. In experiment 3, there again were significant genotypic differences in the likelihood of rearing queens or workers, based on electrophoretic analyses of workers from a set of colonies with allozyme subfamily markers. There also was an overall significant trend for colonies to show greater subfamily differences in queen rearing when the queens were sisters (half- and super-sisters) rather than unrelated, but these differences were not consistent from trial to trial for some colonies. Results of experiments 1 and 3 demonstrate genotypic differences in queen rearing, which has been reported previously based on more limited behavioral observations. Results from all three experiments suggest that genotypic differences in brood care are influenced by social context and may be more pronounced when workers have a theoretical opportunity to practice nepotism. Finally, we failed to detect persistent interindividual differences in bees from either subfamily in the tendency to rear queen brood, using two different statistical tests. This indicates that the probability of queen rearing was influenced by genotypic differences but not by the effect of prior queen-rearing experience. These results suggest that subfamilies within a colony can specialize on a particular task, such as queen rearing, without individual workers performing that task for extended periods of time.
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    URL: http://dx.doi.org/10.1007/BF00164183
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    Reproductive competition in queenless honey bee colonies (Apis mellifera L.) (1994)
    Springer
    Behavioral ecology and sociobiology 35 (1994), S. 99-107 
    Details
    ISSN: 1432-0762
    Keywords: Apis mellifera ; Genetics ; Drone production ; Allozymes ; Reproductive conflict
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previously we reported that there are subfamily differences in drone production in queenless honey bee colonies, but these biases are not always explained by subfamily differences in oviposition behavior. Here we determine whether these puzzling results are best explained by either inadequate sampling of the laying worker population or reproductive conflict among workers resulting in differential treatment of eggs and larvae. Using colonies composed of workers from electrophoretically distinct subfamilies, we collected samples of adult bees engaged in the following behavior: “true” egg laying, “false” egg laying, indeterminate egg laying, egg cannibalism, or nursing (contact with larvae). We also collected samples of drone brood at four different ages: 0 to 2.5-h-old eggs, 0 to 24-h-old eggs, 3 to 8-day-old larvae, and 9 to 14-day-old larvae and pupae. Allozyme analyses revealed significant subfamily differences in the likelihood of exhibiting egg laying, egg cannibalism, and nursing behavior, as well as significant subfamily differences in drone production. There were no subfamily differences among the different types of laying workers collected from each colony, suggesting that discrepancies between subfamily biases in egg-laying behavior and drone production are not due to inadequate sampling of the laying worker population. Subfamily biases in drone brood production within a colony changed significantly with brood age. Laying workers had significantly more developed ovaries than either egg cannibals or nurses, establishing a physiological correlate for the observed behavioral genetic differences. These results suggest there is reproductive conflict among subfamilies and individuals within queenless colonies of honey bees. The implications of these results for the evolution of reproductive conflict, in both queenright and queenless contexts, are discussed.
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    URL: http://dx.doi.org/10.1007/BF00171499
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    Expression of a reporter gene is reduced by a ribozyme in transgenic plants (1994)
    Springer
    Molecular genetics and genomics 245 (1994), S. 465-470 
    Details
    ISSN: 1617-4623
    Keywords: Gene regulation ; Ribozyme ; npt-gene ; Transgenic tobacco ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A chimeric gene encoding a ribozyme under the control of the cauliflower mosaic virus (CaMV) 35S promoter was introduced into transgenic tobacco plants. In vivo activity of this ribozyme, which was designed to cleave npt mRNA, was previously demonstrated by transient expression assays in plant protoplasts. The ribozyme gene was transferred into transgenic tobacco plants expressing an rbcS-npt chimeric gene as an indicator. Five double transformants out of sixteen exhibited a reduction in the amount of active NPT enzyme. To measure the amount of ribozyme produced, in the absence of its target, the ribozyme and target genes were separated by genetic segregation. The steady-state concentrations of ribozyme and target RNA were shown to be similar in the resulting single transformants. Direct evidence for a correlation between reduced npt gene expression and ribozyme expression was provided by crossing a plant containing only the ribozyme gene with a transgenic plant expressing the npt gene under control of the 35S promoter, i.e. the same promoter used to direct ribozyme expression. The expression of npt was reduced in all progeny containing both transgenes. Both steady-state levels of npt mRNA and amounts of active NPT enzyme are decreased. In addition, our data indicate that, at least in stable transformants, a large excess of ribozyme over target is not a prerequisite for achieving a significant reduction in target gene expression.
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    Image formation of alkyl-pendent aromatic polyimide by photocoupling with aromatic ketones (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 214 (1994), S. 57-65 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Positive und negative Photostrukturen wurden in einem Polyimid (PI) aus 4,4′-Biphthalsäureanhydrid (BPA) und 4,4′-Diamino-3,3′-dimethyldiphenylmethan (DADMDPM), PI(BPA/DADMDPM) erzeugt, nachdem dieses mit Michlers Keton (MK) bzw. Benzophenon (BP) dotiert und einer ultravioletten Strahlung von 400 ± 50 nm ausgesetzt und naß entwickelt wurde. Das Prinzip der positiven Abbildung basiert auf dem Photokupplungseffekt von MK mit PI, der die Löslichkeit des Polyimids erhöht und so die Entwicklung eines Positivmusters ermöglicht. Die Erzeugung negativer Muster wird durch intermakromolekulare Wasserstoffbrücken zwischen der Carbonylgruppe des Imid-Rings und der Hydroxygruppe, die bei der photoinduzierten Kupplung von Benzophenon mit dem Polyimid gebildet wird, bewirkt. Die lithographische Auswertung zeigt, daß der mit MK dotierte, positive Polyimidfilm nicht in der Lage ist, brauchbare Muster zu erzeugen, da die UV-Wellenlängen von MK absorbiert werden, wodurch die Photokupplung in den tieferen Schichten des Films verhindert wird. Andererseits können in dem 0,6 μm dicken, mit Benzophenon dotierten Polyimidfilm sogar 2 μm schmale Linien aufgelöst werden.
    Notes: Positive and negative photostructures are formed after the polyimide (PI) of 4,4′-biphthalic anhydride (BPA) and 4,4′-diamino-3,3′-dimethyldiphenylmethane (DADMDPM), PI(BPA/DADMDPM) is doped with Michler′s ketone (MK) and benzophenone (BP), respectively, and is subjected to UV light (400 ± 50 nm) irradiation and solvent development. The principle of positive feature formation is based on the photocoupling of MK with PI, which increases PI solubility and thus enables a positive pattern to be developed. The phenomenon of negative photopatterning results from intermacromolecular H-bonding between the carbonyl group of the imide ring and the hydroxy group which is formed in the photoinduced coupling reaction between BP and PI. Lithographic evaluation shows that the MK-doped positive-acting PI film cannot form useful patterns because UV wavelengths are strongly absorbed by MK, which limits the depth of photocoupling in the film. On the other hand, 2-μm-wide lines can be resolved in the BP-doped negative-acting 0.6-μm-thick PI film.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052140106
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    Blends of polyamide 6 and poly(etheraroylhydrazide)s prepared concurrently with polyhydrazide polymerization (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 214 (1994), S. 101-113 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Polyhydrazid/Polyamid-Blends (PEHZ12/PA6) wurden durch Niedrigtemperatur-Polykondensation von 4,4′-Dichlorformyl-α,ω-diphenoxydodecan und Terephthaloyldihydrazid (TDH) zu Poly(etheraroylhydrazid) in Gegenwart von Polyamid 6 synthetisiert. Die DSC-Analysen lassen vermuten, daß die zwei Polymerkomponenten nicht wechselwirken. Bei der Extraktion des PA6-Anteils der Blends mit Ameisensäure zeigt die Charakterisierung des PEHZ12-Extraktionsrückstands aber, daß zumindest bei bestimmten Zusammensetzungen Wechselwirkungen zwischen den Komponenten auftreten. Modellreaktionen erlauben die Annahme, daß die PEHZ12-Polymerisation zwischen den Amino-Endgruppen des PA6 und den wachsenden PEHZ12-Polymerketten abläuft.
    Notes: Poly(etheraroylhydrazide) is synthesized in the presence of PA6 by means of low-temperature condensation polymerization of 4,4′-dichloroformyl-α,ω-diphenoxydodecane with terephthaloyl dihydrazide (TDH) in order to prepare polyhydrazide/poly-amide 6 (PEHZ12/PA6) blends. The thermal analysis of the blends by DSC seems to indicate that the two polymers are not interacting. Nevertheless, when the blends are subjected to an extraction process with formic acid in order to remove the PA6, the characterization of the residual PEHZ12 reveales that some interactions do occur between the constituent polymers, at least for selected compositions. Model experiments permit to hypothesize that the polymerization of PEHZ12 proceeds with a chemical interaction between amino end groups of PA6 and growing PEHZ12 chains.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052140110
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    Die kristallisation von polybutylenterephthalat (PBT) und polycarbonat (PC) im polymerblend PBT/PC (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 214 (1994), S. 179-196 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The crystallization behavior of PBT as well as PC is changed in the controlled-processed blend due to intermolecular interactions between the different macromolecules in molten state.If the kinetics of the crystallization process prevents a crystallization-induced separation, the partial miscibility of the amorphous phases, measured by the glass transition temperatures, will lead to a decrease of the crystallinity of PBT. The crystallinity, normalized to the concentration of PBT in the blend, is independent from the concentration of PC at low coolling rates.At high cooling rates, PBT is crystallizing stepwise in the blend PBT/PC 40/60 wt.-%. The crystallization temperature in the anisothermic crystallization process is increased at low contents of PC due to a changed nucleation mechanism. The half-time of crystallization is increasing in blends with an increasing PC-content in isothermic crystallization experiments.The normally amorphous PC crystallizes considerably fast in presence of PBT in PC-rich blends. The crystallization or change in the state of order of PC was measured in situ by X-ray diffraction. Calorimetric experiments confirm this result and allow a quantitative estimation of the PC-crystallinity, which amounts to some 20% in the blend PBT/PC 5/95 wt.-%.
    Notes: Das Kristallisationsverhalten sowohl von PBT als auch von PC ist im definiert verarbeiteten Blend infolge intermolekularer Wechselwirkungen zwischen den unterschiedlichen Molekülen in der Schmelze verändert.Die über die Glasübergangstemperaturen gemessene teilweise Mischbarkeit der amorphen Phasen führt bei PBT zu einer Erniedrigung des Kristallinitätsgrades, wenn die kinetischen Bedingungen des Kristallisationsprozesses keine kristallisationsbedingte Entmischung zulassen. Der auf den PBT-Anteil normierte Kristallinitätsgrad ist bei kleinen Abkühlgeschwindigkeiten vom PC-Anteil unabhängüg.In der Mischung PBT/PC 40/60 Gew.-% kommt es bei hohen Kühlraten zu einer fraktionierten Kristallisation. Die Kristallisationstemperatur bei anisothermer Kristallisation ist bei geringen PC-Gehalten durch Änderung des Keimbildungsmechanismus erhöht. Bei isothermer Kristallisation steigt mit zunehmendem PC-Anteil die Kristallisationshalbwertszeit des PBT an.Das normalerweise amorphe PC kann in Gegenwart von PBT in den PC-reichen Mischungen besonders schnell kristallisieren, wobei der Kristallisations- bzw. Ordnungsprozeß des PC in situ mittels der Röntgenbeugung gemessen wurde. Kalorimetrische Untersuchungen bestätigen dieses Ergebnis und erlauben eine quantitative Abschätzung des PC-Kristallinitätsgrades zu ca. 20% im Blend PBT/PC 5/95 Gew.-%.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052140116
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    Photoreactions in halogen-containing negative-tone novolac resists (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 214 (1994), S. 197-210 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Elementaranalytische sowie NMR-, IR- und UV-spektroskopische Untersuchungen zeigen, daß die Photolyse von Halogenphenolnovolaken zur Substitution der Halogenatome durch Wasserstoff, der Bildung chinoider Gruppen und intermolekularen Vernetzung führt. Die Geschwindigkeit der Halogeneliminierung hängt von der Art des Halogens ab. Sie steigt in der Reihenfolge F 〈 Cl 〈 Br 〈 I. Die Chloreliminierung aus der 4-Position ist gegenüber der aus der 2- und 3-Position begünstigt. Außerdem verläuft die Abspaltung para-ständiger Chloratome aus Dimeren schneller als aus Trioder Tetrameren. ESR-Messungen bei 77 K sowie die Laserblitzphotolyse bei 296 K deuten auf die intermediäre Bildung von Phenoxyl- und Arylradikalen. Lithographische Tests belegen die hohe UV-Empfindlichkeit von Resisten auf der Basis von Halogenphenolnovolaken. Im Vergleich zu nichthalogenhaltigen Novolakresisten wird eine 6 - 10fache (System: 4-Chlorphenolnovolak/4,4′-Bisazidobiphenyl (5%)) bzw. eine ca. 25fache (System: 4-Chlorphenol-/m-Cresolnovolak/Hexamethoxymethylmelamin (5%)) Steigerung der Empfindlichkeit erreicht. Zur Interpretation wird ein Mechanismus postuliert, demzufolge die durch Halogenabspaltung hervorgerufene Sekundärradikalbildung zu einer zusätzlichen Vernetzung beiträgt. In den melaminhaltigen Resisten katalysiert der gebildete Halogenwasserstoff (Hal· + RH → H-Hal + R·) außerdem die Reaktion der Melaminverbindung mit der Novolakmatrix.
    Notes: The photolysis of halogenophenol novolacs is determined by the substitution of halogens by hydrogen and the formation of quinoid groups and intermolecular crosslinks. This is concluded from elemental analysis, NMR, IR and optical absorption measurements. The rate of halogen release depends on the chemical nature of the halogen. It increases in the order F 〈 Cl 〈 Br 〈 I. Chlorine elimination from 4-position is favored over that from 2- and 3-position. Moreover, dimers release chlorine from 4-position much more readily than trimers and tetramers. ESR measurements at 77 K and flash photolysis studies at 296 K yielded evidence for the intermediate existence of phenoxyl and aryl radicals. Lithographic tests demonstrated the high UV-sensitivity of resist formulations based on halogen-containing novolacs. The increase in sensitivity relative to that of formulations based on nonhalogenated novolacs is 6 to 10fold system: 4-chlorophenol novolac/4,4′-bisazidobiphenyl (5%) and ca. 25fold system: 4-chlorophenol/m-cresol novolac/hexamethoxymethylmelamine (5%). A postulated reactions mechanism concerning the sensitivity increase takes into account that halogen elimination results in the formation of additional radicals that accelerate the rate of crosslinking. Moreover, hydrogen halide generated by hydrogen abstraction of halogen radicals (Hal· + RH → H-Hal + R·) provides for the acid required to catalyze the reaction of the melamine compound with the novolac matrix.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052140117
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    Crystallization behavior of polypropylene filled with calcium carbonate of various shape (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 215 (1994), S. 11-24 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Calciumcarbonate unterschiedlicher Teilchenform (sphäarisch, kubisch und nadelfäormig) wurden mit Polypropylen (PP) in einer Zwei-Walzen-Mäuhle gemischt und anschließend zu Platten gepreßt. Der Einflußder Teilchenform auf das Kristallisationsverhalten der PP/CaCO3-Composite, d.h. Kristallisationspeaktemperatur (Tmax), Kristallisationsverlauf usw., wurde mittels Differentialkalorimetrie untersucht. Der Wert von Tmax häangt von der Größe der Gesamtoberfläache der CaCO3-Teilchen ab; Tmax ist bei nadelfäormigen Teilchen gräoßer als bei kubischen oder sphäarischen und hauangt in allen Fäallen der nicht-isothermen Kristallisation von der Abkäuhlgeschwindigkeit und der vorher erreichten maximalen Temperatur ab.
    Notes: Calcium carbonate of various particle shape (spheric, cubic, needle-shaped type) and polypropylene (PP) were mixed on a two roll mill and the mixture was pressed into plates. The effect of particle shape on the crystallization behavior of PP/CaCO3 composites, such as crystallization peak temperature (TMAX), crystallized pattern, etc., was investigated with differential scanning calorimetry measurements. The value of TMAX is explained by the total surface area of added CaCO3 particles; TMAX of needle-shaped series is larger than that of cubic or spheric ones. TMAX of various shaped CaCO3-filled PP totally depends on the cooling rate and maximum temperature in the non-isothermal crystallization, respectively.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052150102
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    Cationic polyelectrolytes, XIIPart. XI cf.8.. PEG-precursor for water-soluble cationic polymers with tertiary n-atoms in the main chain (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 215 (1994), S. 107-119 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Durch Polyaddition von Polyethylenglykol (PEG) Oligoglycidylethern (Mn (PEG): 396,587, 1437 und 3554) mit asymmetrischen Diaminen, wie N,N-Dimethylund N,N-Diethyl-1,3-diaminopropan, wurden wasserläosliche kationische Polymere erhalten. Die Eigenschaften der kationischen Polymeren sind vom urspräunglichen PEG-Molekulargewicht und der Diaminreaktivitäat abhäangig. PEG mit Mn = 396 zeigt das beste Verhalten. In verdäunnten wäassrigen Läosungen und in wäassrigen 2M NaCl-Läosungen der Polymeren wurde das Polyelektrolytverhalten veranschaulicht. Die Gegenwart der PEG Kette bestimmt das Polyelektrolytverhalten in den 2M NaCl Läosungen.
    Notes: Water-soluble cationic polymers were obtained by polyaddition of poly(ethylene glycol) (PEG) diglycidylethers (M̄n of PEG were 396, 587, 1437 and 3554, resp.) with asymmetrical diamines such as N,N-dimethyl-1,3-diaminopropane and N,N-diethyl-1,3-diaminopropane. The cationic polymer properties depend on the PEG initial molecular weight and on the diamine reactivity too. PEG with M̄n = 396 had the best behaviour in these reactions. The polyelectrolyte feature of cationic polymers was emphasized both in dilute aqueous solutions and in 2M aqueous NaCl solutions. The polyelectrolyte behaviour in 2M aqueous NaCl solution is determined by the PEG chain presence.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052150109
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    Untersuchungen zur reaktion von o-kresol mit formaldehyd unter verwendung tertiärer amine (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 215 (1994), S. 139-145 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Reaktion von o-Kresol mit Formaldehyd wurde unter Verwendung verschiedener tertiäarer Amine als Katalysatoren untersucht. Der Einfluß der Reaktionsparameter Basizitäat, Temperatur, Reaktionszeit und Formaldehydkonzentration wird diskutiert. Für die bevorzugte Bildung von 2,4-Bis(hydroxymethyl)-6-methylphenol wurden optimierte Synthesebedingungen erarbeitet. Die Bildung von Zwei-bzw. Mehrkernprodukten konnte nicht ausgeschlossen werden.
    Notes: The reaction between o-cresol and formaldehyde was investigated using various tertiary amines as catalysts. The influence of the reaction parameters basicity, temperature, reaction time and concentration of formaldehyde was discussed. To yield preferentially 2,4-bis(hydroxymethyl)-6-methylphenol the conditions of synthesis were optimized. The formation of bi- and polynuclear products cannot be avoided.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052150112
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    Effect of addition of cellulose powder on the viscometric behavior of liquid crystalline solutions of ethyl cellulose in m-cresol (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 215 (1994), S. 189-200 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Scherviskositäat fläussigkristalliner Ethylcellulose, die mit Cellulosepulver unterschiedlicher Partikelgräoße gefäullt war, wurde bei konstantem Schergefäalle mit einem Kegel-Platte-Viskosimeter bestimmt. Der Einfluß des Cellulosepulvergehalts, des Läange/Breite-Verhäaltnisses der Pulverteilchen und der Temperatur auf das viskose Verhalten und die Phasenäubergäange wird diskutiert. Der Zusatz von Cellulosepulver erhäoht die Viskositäat und verringert die Aktivierungsenergie des Fließens(Ea), ohne jedoch die Phasenäubergäange zu beeinflussen. Die Viskositäat und die Aktivierungsenergie sind abhäangig vom Läange/Breite-Verhäaltnis der Pulverteilchen; mit zunehmender Gräoße dieses Verhäaltnisses wird die Viskositäatszunahme beschleunigt und die Aktivierungsenergie des Fließens erhäoht, wäahrend die Aktivierungsenergie mit steigendem Pulvergehalt abnimmt. Die Phasenumwandlungen sind unabhäangig von der Partikelform. Der Einfluß des Pulvergehalts auf Viskositäat und Aktivierungsenergie ist abhäangig von der Art der fläussigen Phase; in der anisotropen Phase ist der Einfluß geringer als in der isotropen Phase. Dies scheint von der Ausrichtung der Pulverteilchen und der stäabchenfäormigen Molekäule herzuräuhren.
    Notes: Steady-state shear viscosity for the liquid crystalline ethyl cellulose solution filled with cellulose powders was determined using a cone-plate-type viscometer and the effects of cellulose powder content, powder aspect ratio and temperature on the viscometric behavior and phase transformation were discussed. The addition of powder increased the viscosity and decreased the activation energy (Ea) for flow, but did not affect the phase transformation. The viscosity and Ea depended on the aspect ratio; with greater aspect ratio, the viscosity enhancement was accelerated and Ea as well as the decrease in Ea with powder content increased. The phase transformation did not depend on the aspect ratio, the dependences of viscosity and of Ea on powder content depended on the solution phase; the dependences for the anisotropic phase were smaller than those for the isotropic one. The findings appeared to originate from the alignments of powders and rod-like molecules.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052150116
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    Oxygen uptake methods as a tool to determine the mechanism of action of hindered amine light stabilizers1Paper presented at the “15th Annual International Conference on Advances in the Stabilization and Degradation of Polymers” in Luzern (Switzerland), June 2-4, 1993. (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 216 (1994), S. 37-44 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The UV-degradation of an unstabilized and two HALS stabilized polyethylene (PE) films is described. The degradations are characterized by measuring the oxygen uptake, the formation of CO and CO2, the FT-IR spectra, the mechanical properties, the stabilizer concentration and the oxygen content of the film.The oxygen uptake of the unstabilized PE film led to the expected changes in the IR spectra and embrittlement of the film, while the oxygen uptake by the HALS stabilized films caused only minor changes. The differences between the results for the unstabilized and the HALS stabilized polymers are explained assuming that the initiation of the photodegradation of PE is due to charge transfer complexes.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052160103
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    Current of status of exploitation of radical scavenging stabilizers in advanced polymer stabilizationPaper presented at the “15th Annual International Conference on Advances in the Stabilization and Degradation of Polymers” in Luzern (Switzerland), June 2-4, 1993. (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 216 (1994), S. 135-146 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Principal chemical pathways characteristic of active participation of radical scavenging polymer stabilizers (phenols, aromatic, hydroaromatic and hindered aliphatic amines) are outlined. Pathways resulting in a partial depletion or distortion of activity of stabilizers, in formation of polymer discolouring products, or in interactions in bifunctional stabilizers are involved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1994.052160109
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    Poly(butyleneterephtalate) photolysis and photooxidation : Identification of the ir-absorbing productsPaper presented at the “15th Annual International Conference on Advances in the Stabilization and Degradation of Polymers” in Luzern (Switzerland), June 2-4, 1993. (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 216 (1994), S. 155-167 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Irradiations (λ≥300 nm) of poly(butyleneterphtalate) films were carried out in both vacum and air. Photoproducts were investigated by FTIR spectroscopy, chemical derivatization reactions and physical treatments. The repartition of photoproducts in the polymer was shown to be heterogeneous. A scheme accounting for the main routes of PBT photolysis was found on the basis of photoproducts identification. Most of oxidation products were analogous to vacum photolysis species; the mechanism of photooxidation proposed implied both pure photolytical processes and a photo-induced oxidation route.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052160111
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    Photo- and radiation-induced degradation of synthetic polymers: Polymer structure and stabilityPaper presented at the “15th Annual International Conference on Advances in the Stabilization and Degradation of Polymers” in Luzern (Switzerland), June 2-4, 1993. (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 216 (1994), S. 225-241 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of polymer density, processing conditions (quenching of annealing), degree of crystallinity, size of crystallite and mobility of polymer chains on the photo-and radiation-induced degradation and the polymer stability have been studied by UV, FTIR spectroscopic, viscosity and mechanical property measurements. Four kinds of annealed or quenched polyethylene (PE) films varying densities were used to the studies. Polystyrene (PSt) films were used to investigate the effect of chain mobility on polymer degradation. The following results were obtained. 1.In linear low density (LLD) PE, greater amounts of crosslinking (irradiated in vacuum) and chain scission (irradiated in air) were noticed than in mediun density (MD) PE and high density (HD) PE samples.2.Polyene formation is favored in the case of the irradiation in vacuum for LLDPE.3.Polymer stability evaluated by mechanical property such as elongation at break (%) is superior in LLDPE to MDPE and HDPE for annealed and quenched samples.4.Segmental motion of polymer chain also affects the polymer stability
    Additional Material: 19 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052160115
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    Eigenschaften von binären mischungen aus polyethylenen hoher dichte mit ultrahoher und normaler molmasse (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 217 (1994), S. 43-49 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The study is on two component blends of high density polyethylenes, having normal and ultra-high molecular weight. The polyethylenes were homogenized by two routes: in powder state or by rolling in melt, then pressed at temperatures in the range from 140°C to 220°C. Comparative studies showed that the way of homogenizing of the components does practically not affect the main mechanical properties of the blends when pressed at temperatures ≥ 160°C. Of special interest are the characteristics of those systems where ultra-high molecular weight polyethylene is the matrix component.
    Notes: Untersucht wurden binäre Mischungen von Polyethylenen hoher Dichte rnit normaler und ultrahochmolekularer Molmasse, die auf zweierlei Weise - in Pulverform oder durch Walzen im Schmelzezustand - homogenisiert und bei Temperaturen zwischen 140 und 220°C gepreßt waren.Es wurde festgestellt, daß die Art der Homogenisierung der Komponenten praktisch keinen Einfluß auf die Eigenschaften bei Preßtemperaturen ≥ 160°C hat. Von besonderem Interesse sind die Eigenschaften der Systeme, in welchen das ultrahochmolekulare Polyethylen die Rolle der Matrixkomponente spielt.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052170105
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    Rôle des pigments dans une réaction de polymérisation sous lumière UV-visible (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 218 (1994), S. 81-109 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Das Verhalten eines neuartigen photoinitiierenden Systems, das die Polymerisation von pigmenthaltigen Schichten großer Dicke in einem Reaktionsschritt gestattet, wird dargestellt. Die verschiedenen Wechselwirkungen, die in einem pigmenthaltigen System auftreten, werden qualitativ beschrieben, und der Anteil der von einem Photoinitiator absorbierten Lichtintensität wird berechnet. Neben dem Absorptions- und Reflexionsverhalten von verschiedenen Pigmentklassen werden die optischen Eigenschaften verschiedener Strahlungsquellen untersucht, um die Strahlungsbereiche zu finden, die am besten mit den optischen Parametern der Pigmente korrespondieren. Weiterhin wird die Beschleunigung von Polymerisationen durch die photokatalytische Wirkung einiger Pigmente behandelt.
    Notes: Ce travail sur le rôe des pigments définit le comportement d'un nouveau systeme photosensible qui permet de polymériser des milieux épais et pigmentés selon un procédé en une seule étape. Les différentes interactions présentes en milieu pigmenté sont décrites de façon qualitative, et la part de l'intensité lumineuse absorbée par un photo-amorceur dans un systéme pigmenté est evaluée. Les propriétés optiques telles que l'absorption et la réflectance des différentes familles chimiques de pigments sont déterminées, et, en paralléle, les propriétés optiques des différentes sources d'irradiation sont étudiées de manière à répondre au mieux aux fenêtres de transmission des pigments. L'effet photocatalytique de certains pigments est mentionné, ceci afin d'amkliorer la réaction de polymérisation.
    Additional Material: 18 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052180107
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    Molar mass distribution of polybutadiene synthesized with nickel-based Ziegler-Natta catalysts, I (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 218 (1994), S. 153-162 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Herstellung von cis-1,4-Polybutadien erfolgte mittels Polymerisation von 1,3-Butadien mit einem Katalysatorsystem, das in einer zweistufigen Reaktion gebildet wird: (1) BF3 · O(C2H5)2 und Al(C2H5)3, (2) Ni(OOC8H15)2 und Al(C2H5)3, genannt in-situ-Katalysatorsystem.Die Molmassenverteilungen (MMD) der erhaltenen Polymeren sind mit der Größenausschlußchromatographie (SEC) untersucht worden. Sie lassen sich mit Summen aus Schulz-Flory-Funktionen (SFF) beschreiben. Veränderte Katalysatorformierungs- und Polymerisationsbedingungen beeinflussen die Parameter der SFF. Veränderte Peakflächen und Molmassenmittelwerte der Einzelpeaks zeigen, daß die Polymerisation über mehrere Arten aktiver Zentren verläuft.
    Notes: Cis-1,4-polybutadiene was produced by polymerization of 1,3-butadiene using a catalyst system formed by a two-step formation, Namely (1) BF3 . O(C2H5)2 and Al(C2H5)3, (2) Ni(OOC8H15)2 and Al(C2H5)3 named in-situ-catalyst.The molar mass distributions (MMD) of the polybutadienes are investigated by means of size exclusion chromatography (SEC). The MMD's were fitted by a sum of Schulz-Flory-Functions (SFF). Changed catalyst formation and polymerization conditions influenced the parameters of the SFF. Changed areas and changed molar mass averages indicate a polymerization with more than one peak maximum and kind of active species and lead to a better understanding of the polymerization.
    Additional Material: 9 Ill.
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    Synthesis and characterization of epoxy resins containing chromium acrylate (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 219 (1994), S. 1-10 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Durch Umsetzung von Chromacrylat mit Bisphenol A und einem Überschuß Epichlorhydrin wurden neuartige Epoxid-Harze hergestellt. Epoxy-Äquivalentgewicht, Gehalt an Hydroxygruppen und hydrolysierbarem Chlor sowie die Viskosität wurden bestimmt, und die Harze wurden mittels IR- und 1H-NMR-Spektroskopie charakterisiert. Die thermischen Eigenschaften der bei 30°C für 24 h mit Ciba Geigy HY 850 (aliphatisches Amin) gehärteten Harze wurden gemessen. Die Harze besitzen eine gute thermische und chemische Stabilität und eine gute elektrische Leitfähigkeit. Die Reaktion verläuft nach erster Ordnung; die Aktivierungsenergie beträgt 47 kJ mol-1 bzw. 34 kJ mol-1 mit bzw. ohne Chromacrylat. Aus spektroskopischen Untersuchungen wird geschlossen, daß das Chrom mit Bisphenol A einen Komplex bildet, der die Epoxidierung beschleunigt.
    Notes: Novel epoxy resins containing chromium acrylate have been synthesized by reacting chromium acrylate with bisphenol-A and excess epichlorohydrin. The quantities such as epoxy equivalent weight, hydroxy content, hydrolyzable chlorine content and viscosity have been determined. The resins have been characterized by IR and 1H NMR spectroscopy. The cured resins were evaluated for thermal properties. The curing of resins was carried out with Ciba Geigy HY 850 (aliphatic amine adduct) at 30°C for 24 h. The cured resins have excellent thermal and chemical resistance, in addition to an excellent electrical conductivity. The reaction follows first order kinetics with an activation energy of 47 kJ mol-1 and 34 kJ mol-1 in the presence and absence of chromium acrylate, respectively. The chromium forms a complex with bisphenol-A, as indicated by spectroscopic studies, which increases epoxidation.
    Additional Material: 6 Ill.
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    Interpenetrating polymer networks based on liquid natural rubber. 1. Synthesis and effect of nco/oh ratio on physical and mechanical properties (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 219 (1994), S. 67-76 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Interpenetrierende Polymernetzwerke (IPNs) aus Polystyrol und Polyurethan auf der Basis von hydroxyterminiertem Naturkautschuk mit unterschiedlichen NCO/OH-Verhältnissen wurden unter verschiedenen Reaktionsbedingungen hergestellt und zu widerstandsfähigen Filmen verarbeitet. Die IPNs wurden durch ihre physikalischen, mechanischen und morphologischen Eigenschaften wie Dichte, Shore-A-Härte, Vernetzungsdichte, Zugfestigkeit und Reißdehnung charakterisiert. Mit steigendem Polystyrolgehalt erhöhen sich auch Dichte, Shore-A-Härte und Zugfestigkeit, während die Reißdehnung abnimmt. Die Untersuchungen der Vernetzungsdichte lassen eine Phasenumkehr vermuten.
    Notes: Interpenetrating polymer networks (IPNs) of polyurethane based on hydroxyterminated natural rubber with varying NCO/OH ratios and polystyrene were synthesized under different experimental conditions. These IPNs were found to make tough films. The IPNs were characterized by their physical, mechanical and morphological properties like density, Shore-A hardness, crosslink density, tensile strength and elongation at break. The IPNs exhibited an increasing trend in density, Shore-A hardness and tensile strength with increasing polystyrene content, while elongation at break decreased with similar variation in polystyrene content. The crosslink density measurements indicated a possible phase inversion process.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1994.052190106
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    Plasma treatment of polyethylene ultrafiltration membranes (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 219 (1994), S. 117-124 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß einer Plasmabehandlung von Ultrafiltrationsmembranen aus Polyethylen auf die Fouling- und Reinigungseigenschaften bei der Filtration von Rinderserumalbumin werden diskutiert. Bei 2,45 GHz erzeugtes Luft-Plasma steigert die Hydrophilie der Membranoberfläche von 0 auf 60%. Der Durchfluß bleibt bei 90 bis 99%. Mit Plasma behandelte Membranen sind leichter zu reinigen als unbehandelte; dennoch sind sie anfälliger für die Ablagerung von Rinderserumalbumin.
    Notes: The effect of plasma treatment of polyethylene ultrafiltration membranes on fouling and cleaning phenomena during filtration of bovine serum albumin solutions is discussed. Air-plasma of 2.45 GHz raises the membrane surface hydrophilicity from 0 up to 60%. The flux is maintained at 90-99%. Plasma-treated membranes are easier to clean than untreated polyethylene membranes. Despite that, the plasma-modified membranes are susceptible to more intensive deposition of albumin.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052190110
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  • 85
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    Preparation and characteristics of immobilized glucose oxidase on membranes of photosensitive polymers (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 219 (1994), S. 101-115 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Immobilisierung von Glucose-Oxidase in einer Poly(vinylalkohol) (PVAL)-Membran in Gegenwart von UV-Photoinitiatoren wurde untersucht. Enzym-Membranen wurden aus PVAL-Diazoharz- und PVAL-Photoinitiator-Systemen durch Vernetzung mit UV-Licht hergestellt. Mit diesen immobilisierten Glucose-Oxidase-Membranen wurde eine wirkungsvolle Enzymelektrode entwickelt, deren Eigenschaften untersucht wurden. Der Einfluß der Photoinitiatorkonzentration in Poly(vinylalkohol) und der UV-Bestrahlungsdauer auf den Grad der Unlöslichkeit sowie die Aktivitätsausbeute der Membran wurden mit Glucose als Substrat untersucht. Temperatur- und pH-Abhängigkeit der relativen Aktivität, Stabilität bei mehrmaligem Gebrauch, Lagerstabilität und Kalibrierungsdiagramme der Enzym-Membranen wurden ermittelt. Eine beim Erstgebrauch auftretende Instabilitätserscheinung der Membranen wurde ebenfalls untersucht.
    Notes: A study of the immobilization of glucose oxidase on a poly(vinyl alcohol) (PVAL) membrane in the presence of UV sensitizers was carried out. Enzyme membranes were prepared from PVAL-diazoresin and PVAL-sensitizer systems, crosslinked by means of UV irradiation. An effective enzyme electrode was developed by using the immobilized glucose oxidase membrane, and its characteristics were investigated. The effects of the concentration of sensitizers in poly(vinyl alcohol) and UV irradiation time on the degree of insolubility as well as the activity yield of the membrane were examined for the immobilized glucose oxidase using glucose as a substrate. Temperature and pH dependences of the relative activity, stability in repeated use, storage stability and calibration plots of the enzyme membranes were evaluated. The unstability phenomenon, found in the initial use of the immobilized glucose oxidase membrane, which was prepared from PVAL-sensitizer system, was also investigated.
    Additional Material: 11 Ill.
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  • 86
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    Auswirkungen von Sterilisationsverfahren auf biologisch abbaubare Kunststoffe (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 219 (1994), S. 11-26 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Biopol, Biocellat and Mater-Bi, three biologically decomposable plastics have been tested for their use in medical industries. Biopol did not loose its stress and stiffness under sterilisation, and was also resistant against temperature and alcohol. Mater-Bi and Biocellat, the two other materials, did not satisfy the test applications. Water vapor sterilisation, temperature up to 60°C, at higher temperatures this material will embrittle.
    Notes: Für den Einsatz biologisch abbaubarer Kunststoffe in der pharmazeutischen Industrie und Medizintechnik wurden Produkte verschiedener Hersteller, wie Biopol, Biocellat und Mater-Bi untersucht. Dabei zeigte vor allem Biopol das notwendige Anforderungsprofil, d.h. die Anwendbarkeit aller Sterilisationsverfahren ohne Festigkeitsbzw. Steifigkeitsverluste sowie Temperatur- und Alkoholbeständigkeit. Dagegen wiesen die Werkstoffe Mater-Bi und Biocellat einige Schwachstellen auf. Bei Mater-Bi lagen diese bei der Wasserdampfsterilisation sowie bei der geringen thermischen und Medienbeständigkeit. Biocellat versprödet dagegen durch die erhöhte Temperatur bei der Dampfsterilisation, d.h. daß ein Einsatz über 60°C nicht möglich wäre.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052190102
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    Polymers and copolymers based on vinyl tetrazoles, 2Part 1 cf.10.. Alkylation of poly(5-vinyl tetrazole) (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 219 (1994), S. 89-99 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Alkylierung von Poly(5-vinyltetrazol) mit Dimethylsulfat und tert-Butylalkohol sowie Alkylhalogeniden RHal (R=CH3, C2H5, CH2—CH=CH2, n-C4H9 und t-C4H9) und die Kinetik dieser Reaktion wurden untersucht, um eine neue Herstellungsmethode für tetrazolhaltige Polymere mit wertvollen Eigenschaften zu entwickeln. Die vergleichenden Untersuchungen über die isomere Zusammensetzung und die spektroskopischen Daten von Poly(N-alkyl-5-vinyltetrazol)en, die durch die Alkylierung von Poly(5-vinyltetrazol) sowie durch die Copolymerisation der entsprechenden Monomeren hergestellt wurden, wurden mit IR-, 1H-NMR- und 13C-NMR-Spektroskopie durchgeführt. Der Alkylierungsumsatz beträgt bis zu 99,8%; dadurch können polymere Produkte erhalten werden, deren Zusammensetzung, Struktur und Eigenschaften denen der Homo- und Copolymeren sehr ähnlich sind.
    Notes: Alkylation of poly(5-vinyl tetrazole) with dimethyl sulfate and tert-butyl alcohol as well as with alkyl halides RHal (R=CH3, C2H5, CH2—CH=CH2, n-C4H9, t-C4H9) has been studied under various conditions in order to develop a new method of synthesis of tetrazole-containing polymers having a complex of valuable properties. The kinetic study of the process and comparison of isomeric compositions and spectroscopic characteristics (IR, 1H NMR and 13C NMR) of poly(N-alkyl-5-vinyl tetrazole)s synthesized by alkylation of poly(5-vinyl tetrazole) and of those prepared by (co)polymerization of the corresponding vinyl tetrazoles have been carried out. The alkylation is found to proceed to high conversion extents (up to 99.8%) and enables to obtain a wide variety of polymeric products having the composition, structure and properties very similar to those of homo- and copolymers.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052190108
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    Dyes for nonlinear optics prepared from 2-hydroxyethyl methacrylate. Nonlinear properties of the resulting copolymers (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 220 (1994), S. 75-87 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Farbstoffe mit nichtlinearen optischen Eigenschaften wurden in einer zweistufigen Synthese aus 2-Hydroxyethylmethacrylat (HEMA), 4-Carboxybenzaldehyd und verschiedenen Anilinderivaten hergestellt. Die Farbstoffe (aromatische Iminester von HEMA) wurden mit Styrol copolymerisiert, die erhaltenen Copolymere wurden mit DSC sowie IR-, 1H NMR- und UV-VIS-Spektroskopie charakterisiert, und ihre nichtlinearen Eigenschaften wurden untersucht. Es zeigte sich, daß die nichtlinearen Koeffizienten d31 und d33 vom Farbstoffgehalt der Copolymeren und der Art der elektronenspendenden Gruppen abhängig sind.
    Notes: Dyes for nonlinear optics have been synthesized in two steps from 2-hydroxyethyl methacrylate (HEMA), 4-carboxybenzaldehyde and various substituted anilines. The obtained dyes (aromatic imine esters of HEMA) have been copolymerized with styrene, the copolymers characterized by DSC as well as IR, 1H NMR and UV-VIS spectroscopy, and studied for their nonlinear properties. The d31 and d33 nonlinear coefficients proved to be dependent on the dye content of the copolymers and on the nature of electrondonating groups.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052200107
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    Viscosity behaviour of multivalent metal ion-containing carboxymethyl cellulose solutions (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 220 (1994), S. 123-132 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß von Ca2+-bzw. Al3+-Ionen auf das Viskositätsverhalten (Salzverträglichkeit) wäßriger Lösungen von Natriumcarboxymethylcellulose (CMC) sowohl mit unterschiedlichem Polymerisationsgrad (DP) als auch mit unterschiedlichem Substitutionsgrad (DS) und verschiedenartiger Substitutentenverteilung wurde untersucht. Aus Viskositätsmessungen mit einem Rotationsviskosimeter bei einer Scherrate von 500 s-1 geht hervor, daß die relative Abnahme der Viskosität im Ergebnis des Zusatzes der mehrwertigen Metallkationen unabhängig vom DP (im Bereich von 160 bis 900) der CMC ist. Homogen hergestellte CMC-Proben 2 mit einem größeren Gehalt an 2,3,6-Tri-O-carboxymethylglucose-Einheiten in der Polymerkette weisen im Vergleich zu heterogen hergestellten CMCs 1 bei gleichem Gesamt-DS eine höhere Salzverträglichkeit auf.
    Notes: The influence of Ca2+-and Al3+-ions, respectively, upon the viscosity behaviour (so-called salt tolerance) of aqueous solutions of sodium carboxymethyl cellulose (CMC) with different degree of polymerization (DP) and, on the other hand, with both different degree of substitution (DS) and distribution of substituents, was investigated. Viscosimetry by means of a rotational rheometer at a shear rate of 500 s-1 shows that the relative drop in viscosity as a result of addition of the multivalent metal cations is independent of DP (ranging from 160 to 900) of the CMC samples. Homogeneously synthesized CMCs (2) with a higher content of 2,3,6-tri-O-carboxymethyl glucose units in the polymer chain possess a significantly higher salt tolerance than those (1) prepared under heterogeneous reaction conditions at comparable total DS values.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052200111
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    Modification of melamine-formaldehyde moulding compounds with ethylene/vinyl acetate copolymers (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 222 (1994), S. 61-87 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Melamin-Formaldehyd-Harz-Formmassen (MF) wurden durch mechanisches Mischen mit Ethylen-Vinylacetat-Copolymeren (EVA) und teilverseiftem EVA modifiziert, wobei Etherbindungen zwischen dem hydrolysierten EVA und dem MF-Harz nachgewiesen werden konnten, die die mechanischen Eigenschaften von spritzgepreßten Formteilen im Vergleich zur Modifizierung mit EVA verbessern. Der Zusatz solcher Modifikatoren erhöht die Duktilität und verringert im Falle von EVA die Nachschwindung der überaus steifen MF-Matrix, solange der Modifikatoranteil gering bleibt. Dagegen werden die Steifigkeit und die Wärmeformbeständigkeit verschlechtert. Die durch solche unvernetzten Polymeren erreichbare Steigerung der Schlagzähigkeit bleibt allerdings unzureichend.
    Notes: Melamine-formaldehyde moulding compounds (MF) were modified by mechanical mixing with ethylene/vinyl acetate copolymers (EVA) and with partially hydrolysed EVA. Ether linkages between the hydrolysed material and the MF resin improve the mechanical properties of the transfer moulded parts containing the hydrolysed material compared to those made with EVA. The use of both modifying polymers improves the ductility and, in case of the partially hydrolysed material, the postshrinkage of the extremely rigid MF matrix, as long as the modification polymer content is kept low. On the contrary, Young's modulus and the heat deflection temperature are deteriorated. The improvement in impact strength by use of those uncrosslinked polymers is still insufficient.
    Additional Material: 17 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052220106
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    Synthesis and properties of biodegradable copolyesteramides: Nylon 6,6/∊-caprolactone copolymers, 1 (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 222 (1994), S. 111-123 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Eine Reihe von Copolyesteramiden mit Molekulargewichten zwischen 1000 und 7000 (GPC, NMR) wurden aus Adipinsäure/1,6-Hexandiamin/∊-Caprolacton bzw. Nylon 6,6-Salz/∊-Caprolacton hergestellt. Die thermischen Eigenschaften der synthetisierten Polymeren (Glasübergangs-, Schmelz-, und Zersetzungstemperaturen, Schmelzenthalpien) wurden durch DSC- und TGA-Messungen bestimmt und in Bezug auf das Comonomerverhältnis in der Ausgangsmischung diskutiert. Die Übereinstimmung der Copolymerzusammensetzung mit dem Ausgangscomonomerverhältnis wurde mit FT-IR- und NMR-Spektroskopie untersucht. Die Bioabbaubarkeit der Copolyesteramide wurde durch enzymatische Hydrolyse geprüft.
    Notes: A series of copolyesteramides based on adipic acid/1,6-hexane diamine/∊-caprolactone and Nylon 6,6 salt/∊-caprolactone were synthesized. Their molecular weights, determined by gel permeation chromatography and NMR spectroscopy, were found to lie within the range from 1000 up to 7000. Their thermal properties (glass transitions, melting points and heats of melting, and decomposition temperatures) were recorded with diferential scanning calorimetry and thermogravimetry, respectively, and correlated to the comonomer feed composition. The FT-IR and NMR spectra were also recorded in order to confirm the composition of the copolyesteramides and to compare them with that of the comonomer feed. The biodegradability of the synthesized copolymers was tested by enzymatic hydrolysis.
    Additional Material: 4 Ill.
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    Study of the condensation products of abietic acid with formaldehyde at high temperatures (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 222 (1994), S. 165-174 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Durch sulfonsäurekatalysierte Umsetzung von Abietinsäure und Paraformaldehyd bei hohen Temperaturen wurden neuartige Kondensationsprodukte erhalten. Als Nebenprodukte der Polykondensation werden eine Ketoverbindung sowie Wasser und Kohlendioxid gebildet. Die Carboxygruppen der Abietinsäure sind an der Kondensationsreaktion beteiligt. In Abwesenheit von Paraformaldehyd wurde das Abietinsäure/Sulfonsäurekatalysator-System untersucht, um zusätzliche Informationen über die Reaktion zu erhalten. Der Reaktionsverlauf hängt von der Temperatur und der chemischen Struktur des Katalysators ab. Ein möglicher Reaktionsmechanismus der Kondensation wird diskutiert.
    Notes: New condensation products have been synthesized by heating abietic acid and formaldehyde at high temperatures in the presence of sulfonic-type acid catalysts. The main polycondensation reaction is associated with a secondary one which leads to a ketonic compound, carbon dioxide and water. The carboxylic groups of abietic acid participate in this condensation reaction. The behaviour of the abietic acid-sulfonic acid catalyst system was studied in absence of formaldehyde to acquire additional information about the reaction. The process is defined by the reaction temperature and chemical nature of the catalyst. A possible mechanism of the condensation reaction is discussed on the basis of the obtained results.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052220112
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    Tailored polymers by cationic ring-opening polymerization (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 223 (1994), S. 1-11 
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    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: After a general classification of the cationic ring-opening polymerizations (CROP's) according to their polymerization mechanism, a number of examples of tailored polymers based on CROP are presented. The monomers used for the synthesis of these tailored structures are tetrahydrofuran (THF), N-tert-butyl aziridine (TBA), 2-methyl-1,3-oxazoline (MeOX) and 1,3-dioxolane (DXL).The polymer structures include different block and graft copolymers, macromonomers, star-shaped polymers, polymer networks and interpenetrating polymer networks (IPNs).
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052230101
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    Massgeschneiderte PolymereVortrag anläßlich der Tagung der Fachgruppe “Makromolekulare Chemie” der Gesellschaft Deutscher Chemiker über “Fortschritte in der Polymersynthese” in Bad Nauheim, 21.-22. März 1994. Synthesestrategien für Telechele, Makromonomere, Block- und Pfropfcopolymere (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 223 (1994), S. 29-46 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In diesem Beitrag wird ein überblick über neuere Entwicklungen auf dem Gebiet der Synthese von Telechelen, Makromonomeren, Block- und Pfropfcopolymeren gegeben. Synthesestrategien aus den Bereichen der Polykondensation, der radikalischen, anionischen und kationischen Polymerisation, der Kettenspaltung sowie der Criss-Cross-Cycloaddition werden diskutiert.
    Notes: New developments in the synthesis of telechelics, macromonomers, block- and graftcopolymers are presented. Synthetic strategies for them are demonstrated with examples from different fields such as polycondensation, radical, anionic, and cationic polymerization, chain cleavage and criss-cross-cycloaddition.
    Additional Material: 1 Tab.
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    Alkane als initiatoren zur radikalischen polymerizationHerrn Professor Dr. rer. nat. Dr.-Ing. E.h. Hansjörg Sinn mit den besten Wünschen zum 65. Geburtstag gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 223 (1994), S. 69-79 
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    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Alkanes with highly substituted carbon-carbon bonds can be cleaved in free radicals by homolytic dissociation under the influence of thermal energy. The energy of dissociation is mainly determined by the type and size of the respective substituents. For tetraarylbutane dinitriles the temperatures of decomposition are in the range of other technically used initiators. But nevertheless, these compounds are up to now rather seldom used to initiate free radical polymerizations. This is connected with the special mechanism of initiation: the formed highly substituted alkyl radicals are relatively stable and show only a rather low reactivity against the usually used monomers. Therefore, in the beginning of the polymerization the radical concentration is rather high which leads not only to addition to monomers but also to a pronounced primary radical termination. In some cases this termination process is reversible which results in an unusual polymerization kinetics. Depending on the type of monomer and the degree of reversibility of the primary radical termination, either a period of “dead-end” polymerization follows or the cleavage of the oligomers at the chain end results in a re-initiation process with a “normal” polymerization with increased rate. The reaction mechanism, kinetics and some possible applications of such initiating alkanes are reported.
    Additional Material: 3 Ill.
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    Cycloolefin-copolymere: Eine neue klasse transparenter thermoplasteHerrn Prof. Dr. H. Sinn zum 65. Geburtstag gewidmet. (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 223 (1994), S. 121-133 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Untersuchungen wesentlicher Aspekte der Polymerisation und der Eigenschaftsmodifikation auf Metallocen-Katalyse basierender Cycloolefin-Copolymere (COC) zeigen, daß mit dieser Monomer-Katalysator-Kombination eine neue Klasse transparenter Thermoplasten zugänglich gemacht wird. COC können mit Metallocenen in beliebiger zusammensetzung und mit kontrollierter Mikrostruktur hergestellt werden. Die somit erreichte und durch zusätzliche Modifikationen noch erweiterbare Breite des Eigenschaftsspektrums ermöglicht vielfältige Anwendungen dieser neuen Polymerklasse. Die wichtigsten Schlüsselfaktoren im rohstofflich-technologischen Bereich, die diese Struktur- und Eigenschaftsvielfalt ergeben, werden beispielhaft beschrieben.
    Notes: Investigation of the polymerization process and property modification of metallocene-based cycloolefin copolymers (COC) shows that this monomer-catalyst combination enables synthesis of a new class of transparent thermoplastic polymers. Metallocene catalysis offers much opportunity to vary the composition and microstructure of the copolymers. The breadth of the polymer spectrum which can be further widened by polymer modification enables many applications for this new class of thermoplastics. The key parameters that control structure and properties in the COC family are discussed in this paper.
    Additional Material: 6 Ill.
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    Funktionalisierte Kammpolymere: Synthesen, modifizierung und anwendungen (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 223 (1994), S. 165-175 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The present paper deals with the synthesis and modification of functionalized polymers characterized by a special molecular architecture. The reactivity of a functionalized polymer with comb-like structure can be controlled in a significant manner by the crystalline order of the side chains. In contrast, photocrosslinking of comblike polymers containing cinnamic components in the side chains influences the crystallization process. The air drying process of a modified polybutadiene system with comb-like structure was shown to depend sensitively on the side chain order. Enzymatic synthesis of new monomers and polymers is briefly reviewed. The complexing capability of cyclodextrines were used to synthesize polyrotaxanes. Finally, the synthesis of a chiral polymerizable dendrimer containing eight estergroups in the monomer unit is presented.
    Additional Material: 8 Ill.
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    Intramolekular vernetzte poly(organosiloxan)partikel (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 223 (1994), S. 203-216 
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    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Intramolecularly crosslinked poly(organosiloxane) particles are prepared by means of emulsion polycondensation or emulsion polymerization of alkoxysilanes or cyclic organic siloxanes. Starting from these intramolecularly crosslinked poly(organosiloxane) particles, graft copolymers are obtained by free-radical emulsion polymerization of unsaturated olefinic monomers (e.g. acrylates, styrene) in the presence of (functionalized) organosiloxanes. Intramolecularly crosslinked poly(siloxane) particles and their graft copolymers are characterized by means of light scattering (in dispersion), electron microscopy and thermal analyses (DSC, DMTA).
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/apmc.1994.052230115
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  • 99
    Electronic Resource
    Electronic Resource
    Study on poly(2,6-dimethyl-1,4-phenylene oxide)/SBS triblock copolymer blends (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 214 (1994), S. 153-167 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Zusammenhang zwischen der Mischbarkeit und den physikalischen Eigenschaften von Polymerblends aus Poly(2,6-dimethyl-1,4-phenylenoxid) (PPO), die in unterschiedlichen Zusammensetzungen in einem Doppelschneckenextruder mit Polystyrol, schlagzähem Polystyrol oder Styrol-Butadien-Copolymeren hergestellt wurden, wird diskutiert. Die Verträglichkeit der Komponenten wurde mittels DSC und DMA, die Morphologie der Blends mittels SEM untersucht. Mit abnehmendem Polystyrolanteil wurde eine schlechtere Mischbarkeit bei den Blends beobachtet, deren Kerbschlagempfindlichkeit sich erhöhte. Die Untersuchungsergebnisse werden mit dem Micellmodell interpretiert.
    Notes: The relationship between the miscibility and the physical properties of polymer blends of poly(2,6-dimethyl-1,4-phenylene oxide) and polystyrene (PS), high-impact polystyrene (IPS) and poly(styrene-block-butadiene-block-styrene) (SBS), which are blended in different compositions by a twin-screw extruder is discussed. The three types of SBS that were used are SBS1, SBS2 and SBS3 having different styrene/butadiene ratios. Dynamic mechanical analysis and differential scanning calorimetry were used to study the miscibility. The morphology was examined by SEM. The miscibility of the blends decreases with decreasing PS content. The notch sensitivity is improved by blending. Finally, the micelle model was used to explain the testing phenomena.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1994.052140114
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  • 100
    Electronic Resource
    Electronic Resource
    Water-soluble polyamides as potential drug carriers, VIIPresented in part at the Symposium on Water-soluble Polymers, 198th National Meeting Am. Chem. Soc., Miami Beach, Florida, 10-16 September 1989. For Part VI, cf1.. Synthesis of polymers containing intrachain- or extrachain-type amine ligands by interfacial polymerization (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 214 (1994), S. 137-152 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Aliphatische Polyamide mit Poly(ethylenoxid)-Kettensegmenten unterschiedlicher Länge wurden durch Grenzflächenpolymerisation aus Succinylchlorid und Jeffamine ED-900 (O,O'-Bis(2-aminopropyl)poly(ethylenglykol) 800) bzw. Jeffamine ED-2001 (O,O'-Bis(2-aminopropyl)poly(ethylenglykol) 1900) zur Verwendung als Trägersubstanzen für Medikamente synthetisiert. Copolyamide mit kurzkettigen Diamin- und Jeffamine-Segmenten sowie Polyamide aus Cystin und Diamineinheiten wurden auf die gleiche Weise hergestellt. Die Polymerisationen wurden im zweiphasigen System Dichlormethan/Wasser bei Temperaturen um 0°C durchgeführt. Die Polymerprodukte wurden durch stufenweise Dialyse in wäßriger Phase bis zu einem Molekulargewicht von 25000 fraktioniert, nach Gefriertrocknung als wasserlösliche Harze oder Feststoffe erhalten und durch Mikroanalyse sowie 1H NMR-Spektroskopie charakterisiert. Die inhärenten Viskositäten liegen im Bereich von 10-20 ml/g. Die Eignung eines repräsentativen Zielmoleküls zur Bindung von Medikamenten wurde durch eine kovalente Verankerung einer als Medikamentmodell fungierenden Ferrocen-Verbindung untersucht. Dabei wurde ein wasserlösliches Polymer-Ferrocen-Konjugat erhalten.
    Notes: Aliphatic polyamides comprising poly(ethylene oxide) chain segments of various lengths, designed for use as drug carriers, are synthesized by interfacial polymerization of succinyl chloride with the two Jeffamine types ED-900 and ED-2001, formally described by the supplier as O,O'-bis(2-aminopropyl)poly(ethylene glycol) 800 and O,O'-bis(2-aminopropyl)poly(ethylene glycol) 1900. Copolyamides comprising both short-chain diamine and Jeffamine segments are similarly prepared, as are polyamides made up of cystine and diamine segments. The polymerizations are performed in a two-phase methylene chloride-water system at temperatures near or below 0°C. The product polymers, crudely fractionated by staged aqueous-phase dialysis at an ultimate molecular-mass cut-off of 25000, are collected after freeze-drying as water-soluble resins or solids and are characterized microanalytically and by 1H NMR spectroscopy. Inherent viscosities are in the range of 10-20 ml g-1. The drug-binding potential of a representative target polymer is probed by the covalent anchoring of a ferrocene compound used as a drug model, giving a water-soluble polymer-ferrocene conjugate.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1994.052140113
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