ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (118)
  • evolution  (60)
  • kinetics  (58)
  • Springer  (118)
  • American Chemical Society
  • 1995-1999  (118)
  • 1997  (118)
  • 1
    Electronic Resource
    Electronic Resource
    Genetics of the ability of Phyllotreta nemorum larvae to survive in an atypical host plant, Barbarea vulgaris ssp. arcuata (1997)
    Springer
    Entomologia experimentalis et applicata 82 (1997), S. 37-44 
    Details
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; genetics ; sex-linkage ; X- and Y-chromosome ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A polymorphism in host plant exploitation has been discovered in the flea beetle, Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) where one resistant population is able to use Barbarea vulgaris R.Br. ssp. arcuata (Opiz.) Simkovics (Brassicaceae) as a host plant while a susceptible population is not. Crosses (F1, F2, and backcrosses) between the two flea beetle populations were made, and survival of the progeny on B. v. ssp. arcuata was measured. The ability of P. nemorum larvae to survive in this plant species depended on the presence of major, dominant genes (R-genes). The two most abundant R-genes in the resistant flea beetle population were X- and Y-linked, respectively. The use of B. v. ssp. arcuata as a natural host plant by the resistant population of P. nemorum seems to be an extension of the host plant range of the species. The role of sex-linked genes in the evolution of host range is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002938912809
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Variation in defences of the plant Barbarea vulgaris and in counteradaptations by the flea beetle Phyllotreta nemorum (1997)
    Springer
    Entomologia experimentalis et applicata 82 (1997), S. 25-35 
    Details
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; resistance ; host plant ; variation ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several sorts of variation in the interaction between the insect, Phyllotreta nemorum L. (Coleoptera:Chrysomelidae:Alticinae), and the plant, Barbarea vulgaris R.Br. (Brassicaceae), have been discovered: 1) genetic differences in the levels of defences in the plant, 2) genetic differences in the ability of insects to cope with the plant defences, 3) seasonal variation in levels of defences in the plant, and 4) differences between leaf types in levels of defences. Two plant accessions were suitable for larval development throughout the season while the remaining nine accessions were more or less unsuitable for larvae from the ‘susceptible’ T-population at least at certain times of the year. All accessions were suitable for the ‘resistant’ E-population throughout the year. There was a seasonal variation in levels of defences in some accessions which were unsuitable for the T-population during the summer period when beetles were present, but not during autumn and spring when the beetle were hibernating. Upper (younger) cauline leaves of these accessions had higher levels of defences than lower (older) cauline leaves. The resistant E-population used B. vulgaris as a natural host plant while the susceptible T-population did not. The use of B. vulgaris as a natural host plant by the E-population of P. nemorum seems to be an extension of the host plant range of the species. Variation in plant defences may have facilitated the switch in host plant use by the resistant flea beetle population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002990929647
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Equilibria and kinetics characterisation of two different structured nutshell-derived activated carbons (1997)
    Springer
    Adsorption 3 (1997), S. 267-275 
    Details
    ISSN: 1572-8757
    Keywords: characterisation ; equilibria ; kinetics ; micropore size distribution ; n-butane ; nutshell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Adsorption equilibria and dynamics ofn-butane on two activated carbon samples prepared from the physical activation of nutshell are studied in this paper. The micropore size distribution (MPSD) is considered as the main source of solid heterogeneity. Lennard-Jones' potential theory and Dubinin's theory (TVFM) are used in the equilibria data to derive the MPSD, which is well fitted by a Gamma distribution function. The adsorption energy distribution derived from the MPSD is very asymmetric for both the samples studied, and this energy distribution used in the HMSD/HMSMD kinetics models for the study of adsorption dynamics ofn-butane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01653629
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    On the kinetics of degradation of cellulose (1997)
    Springer
    Cellulose 4 (1997), S. 1-5 
    Details
    ISSN: 1572-882X
    Keywords: paper ; degradation ; ageing ; kinetics ; modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018408515574
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Kinetic studies on oxidation of aromatic donor molecules by horseradish peroxidase and lactoperoxidase (1997)
    Springer
    BioMetals 10 (1997), S. 23-26 
    Details
    ISSN: 1572-8773
    Keywords: aromatic donor molecules ; horseradish peroxidase ; kinetics ; lactoperoxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Based on kinetic evidence, it has been shown for the first time that the mode of binding of aromatic donor molecules is similar in horseradish peroxidase and lactoperoxidase; also that the nature of the heme plays an important role in the reaction with hydrogen peroxide, and has no effect on the reaction of the intermediate compound II with aromatic substrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018310618995
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Colonization and evolution of lakes on the central Norwegian coast following deglaciation and land uplift 9500 to 7800 years B.P. (1997)
    Springer
    Journal of paleolimnology 18 (1997), S. 269-281 
    Details
    ISSN: 1573-0417
    Keywords: colonization ; evolution ; lakes ; Norway ; deglaciation ; land uplift ; invertebrates ; Chironomidae ; Porifera ; Bryozoa ; diatoms ; Charophyta ; tsunami
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Invertebrate colonization of lakes following the uplift of land from the sea was studied in four lakes, currently situated between 39 and 24 m a.s.l., on the central Norwegian coast. The lakes were isolated from the sea between 9500 and 7700 years B.P. Animal and algal remains picked from core samples showed that the first colonizers preserved as fossils were usually members of the Chironomidae, Daphnidae/Chydoridae, Acarina, Porifera (Ephydatia mülleri and Spongilla lacustris), Bryozoa (Cristatella mucedo and Plumatella spp.) and Charophyta (Chara sp.). Of the chironomids, the genus Chironomus was present in the oldest lacustrine layers of all four lakes, but other genera recorded at the marine/lacustrine boundary were Dicrotendipes, Procladius (?), Einfeldia, Microtendipes, and Glyptotendipes. Remains of the caddis fly family Limnephilidae were also present in the earliest lacustrine sediments in Kvennavatnet and Kvernavatnet. The oldest invertebrate fauna is typical for mesotrophic lakes. However, chironomids and mites have been present in this area from at least about 10 500 years B.P. A diverse chironomid community was established between 300 and 800 years after isolation from the sea at Kvernavatnet on the island of Hitra, while only between 80 and 120 years passed before a comparably diverse community developed at Kvennavatnet on the mainland coast. A similar development of the invertebrate fauna occurred in Kvennavatnet, Kvernavatnet and Storkuvatnet. However, Litjvatnet deviates greatly from the ‘normal’ pattern because a tsunami disturbed the bottom sediments and fauna. The tsunami, a gigantic sea wave, was caused by a submarine slide from the Norwegian continental slope. It reached Litjvatnet, today located 24 m a.s.l., but was not traced in Storkuvatnet at 30 m a.s.l. This event happened about 7200 years B.P.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007934825272
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Evolution of novel metabolic pathways for the degradation of chloroaromatic compounds (1997)
    Springer
    Antonie van Leeuwenhoek 71 (1997), S. 159-178 
    Details
    ISSN: 1572-9699
    Keywords: aromatic pathways ; chlorobenzenes ; evolution ; genes ; plasmids ; pseudomonas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chlorobenzenes are substrates not easily metabolized by existing bacteria in the environment. Specific strains, however, have been isolated from polluted environments or in laboratory selection procedures that use chlorobenzenes as their sole carbon and energy source. Genetic analysis indicated that these bacteria have acquired a novel combination of previously existing genes. One of these gene clusters contains the genes for an aromatic ring dioxy-genase and a dihydrodiol dehydrogenase. The other contains the genes for a chlorocatechol oxidative pathway. Comparison of such gene clusters with those from other aromatics degrading bacteria reveals that this process of recombining or assembly of existing genetic material must have occurred in many of them. Similarities of gene functions between pathways suggest that incorporation of existing genetic material has been the most important mechanism of expanding a metabolic pathway. Only in a few cases a horizontal expansion, that is acqui sition of gene functions to accomodate a wider range of substrates which are then all transformed in one central pathway, is observed on the genetic level. Evidence is presented indicating that the assembly process may trigger a faster divergence of nearby gene sequences. Further ‘fine-tuning’, for example by developing a proper regulation, is then the next step in the adaptation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000166400935
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Evolution of bacterial genomes (1997)
    Springer
    Antonie van Leeuwenhoek 71 (1997), S. 265-270 
    Details
    ISSN: 1572-9699
    Keywords: bacteria ; DNA ; evolution ; genome ; RNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This review examines evolution of bacterial genomes with an emphasis on RNA based life, the transition to functional DNA and small evolving genomes (possibly plasmids) that led to larger, functional bacterial genomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000123216769
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Bacterial evolution and metabolism (1997)
    Springer
    Antonie van Leeuwenhoek 71 (1997), S. 257-263 
    Details
    ISSN: 1572-9699
    Keywords: bacteria ; energy ; evolution ; genome ; metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This article examines the relationship between (or dependence of) bacterial evolution in prokaryotes and metabolism, and the changing physical-chemical conditions present during early evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000175217677
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Molecular evolution in bacteria: Surfaces, cathodes and anodes (1997)
    Springer
    Antonie van Leeuwenhoek 71 (1997), S. 363-368 
    Details
    ISSN: 1572-9699
    Keywords: assembly ; anode ; bacteria ; cathode ; DNA ; evolution ; genetics ; molecular ; surfaces
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Molecular evolution is examined in bacteria with an emphasis on mineral surfaces, membranes, cathodes and anodes. In early molecular evolution, cathode-anode system may have been naturally occurring on a nm to µm scale. Secondly, the cathode-anode system could have been separated by a primitive, permeable lipid or microsphere on a mineral surface, that was a precursor of a more advanced membrane with a charge differential on either side of the membrane. These aspects will be considered from a theoretical evolutionary perspective.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000271219036
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Molecular evolution and optimization (1997)
    Springer
    Antonie van Leeuwenhoek 72 (1997), S. 251-259 
    Details
    ISSN: 1572-9699
    Keywords: bacteria ; catalysis ; DNA ; enzyme ; evolution ; microorganisms ; optimization ; RNA ; time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microbial populations (and life) not only evolve, they optimize. The transition from a random, unorganized, lifeless Earth to the present situation, where the Earth is virtually covered with nucleic acids and diverse and complex species, required numerous molecular changes and the integration of metabolic pathways over billions of years. Primitive prokaryotic life was dependent on and constrained by the physical-chemical conditions on the Earth, while slowly reshaping conditions present. In this review, molecular evolution and molecular optimization are examined with an emphasis on the order in which evolutionary events occurred.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000456825081
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Bioavailability of a new effervescent tablet of ibuprofen in healthy volunteers (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 505-506 
    Details
    ISSN: 1432-1041
    Keywords: Key words Ibuprofen; effervescent tablets ; kinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002280050327
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Studies on the non-isothermal kinetics of the thermal decomposition of [Cu(NBOCTB)][Cu(NO3)4]· H2O (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 917-923 
    Details
    ISSN: 1572-8943
    Keywords: copper compound ; coupled technique ; kinetics ; macrocyclic complex ; non-isothermal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal decomposition process of the complex [Cu(NBOCTB)][Cu(NO3)4] H2O has been studied by TG and DTG technique, and possible intermediates of the thermal decomposition have also been conjectured from the TG and DTG curves. The results suggest that the decomposition of the complex involves five steps: The non-isothermal kinetics of steps 1, 2 and 3 have been studied by means of the Achar and Coats-Redfern method based on TG and DTG curves. Step 1 is a ‘Coring and Growth’ mechanism (n= 1), its kinetic equation may be expressed as: dα/dt=Ae−E/RT(1−α). Steps 2 and 3 are both ‘two order chemical reaction’ mechanisms, their kinetic equations can be expressed as: dα/dt=Ae−E/RT(1−α)2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01997197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    The thermal degradation kinetics of isomeric poly(dipropyl itaconates) (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 87-94 
    Details
    ISSN: 1572-8943
    Keywords: kinetics ; poly(di-propyl itaconates) ; polymer structure ; thermal degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Non-isothermal thermogravimetry was performed in a dynamic nitrogen atmosphere, on a series of poly(di-n-propyl itaconates) (PDnPI) and poly(di-iso-propyl itaconates) (PDiPI) which had been prepared in the presence of various amounts of the chain transfer agentn-dodecyl mercaptan (DDM). Differential thermogravimetry (DTG) showed that both polymers degraded in two stages. The DTG curve of PDnPI had a large first peak followed by a smaller shoulder, whereas the DTG curve of PDiPI was composed of two peaks of almost equal heights. The addition of DDM during the polymerisations in both cases resulted in a similar decrease in the relative area of the first peak.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01987424
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Thermooxidative degradation of an unsaturated polyester resin (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 183-191 
    Details
    ISSN: 1572-8943
    Keywords: kinetics ; thermooxidative degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The results of non-isothermal kinetic analysis of the thermooxidative degradation in air and oxygen of an unsaturated polyester resin are presented. It has been shown that the thermooxidative degradation in oxygen occurs at lower temperatures than the thermooxidative degradation in air. The kinetic parameters of the thermooxidative degradation depend on the heating rate and the oxygen pressure. Two straight lines of InAvs. E (A is the preexponential factor andE is the activation energy), characteristic for the compensation effect, have been obtained for the thermooxidative degradation in air and in oxygen respectively. The difference between the intercepts of these straight lines can be explained by dependence of the pre-exponential factor on the oxygen pressure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01987438
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Comparative studies on some analytical methods (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 857-862 
    Details
    ISSN: 1572-8943
    Keywords: analytical methods ; kinetics ; powder milk ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This work present comparative results on powder milk storage quality, obtained from analytical methods. Protein content was determined conventional (Kjeldahl) and colorimetric with biuret reagent at 540 nm and integral quality by thermogravimetric and biological methods. A method was developed for the protein separation of powder milk. Powder milk was submitted to degradation processes at 45, 60 and 80°C for 20 days. The results indicated that protein content values were inconsistent if determinations by Kjeldahl and colorimetric methods and biological tests were compared. There is evidence of thermal decomposition of powder milk as detected by biological and thermogravimetric methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01996770
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Application of thermogravimetry in the quality control of mebendazole (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 937-941 
    Details
    ISSN: 1572-8943
    Keywords: kinetics ; mebendazole ; quality control ; technology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A study was made of the thermal behavior of the starting materials, their mixtures and the resulting mebendazole tablets. The thermal curves were obtained with a Shimadzu thermobalance, model TGA-50, using an air flow of 50 mL min−1 and a heating rate of 10°C min−1 in the temperature interval 30–900°C. The reaction constant velocities for the mebendazole salt and tablets were determined isothermally, using the Arrhenius expression. The thermal stability of mebendazole tablets is lower than that of the mebendazole salt, due to the presence of starch and lactose in the composition. Analysis of the data reveals that thermogravimetry is a powerful tool in pharmaceutical technology and quality control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01996779
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Kinetic analysis of crude oils by a weighted mean activation energy approach (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 343-348 
    Details
    ISSN: 1572-8943
    Keywords: activation energy ; combustion ; crude oil ; differential scanning calorimetry ; kinetics ; thermogravimetric analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A weighted mean activation energy method was applied to describe the reactivity and combustibility of crude oils via simultaneous TG/DTG. Thermal experiments were conducted with a non-isothermal method at a heating rate of 10
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979278
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Kinetics of thermal dehydration and decomposition of Fe(III) chloride hydrate (FeCl3·xH 2O) (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 385-401 
    Details
    ISSN: 1572-8943
    Keywords: dehydration and decomposition ; kinetics ; Fe(III) chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Fe(III) chloride hydrate (FeCl3·xH2O) undergoes simultaneous dehydration and dehydrochlorination from its molten phase in the temperature range 100–200
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979283
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Fermentation alcoolique (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 413-425 
    Details
    ISSN: 1572-8943
    Keywords: alcoholic fermentation ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The control of alcoholic fermentation is necessary to obtain a quality wine. The overall dynamic and phenomenological modelling already applied to the simulation of this type of reaction enables us to suggest, in this study, a simple model (of which two variants), are relatively satisfactory. The first variant does not take into account the variation of the ambient temperature; the model translates exactly the first phase of the experimental curve or the moment when highest temperatures are measured. The relaxation phase is less well described because of influence of variation of the ambient temperature is relatively important. The second one considers the system depending on the ambient temperature, the model is correct for the relaxation phase too (the reaction temperature decreases, it nears the ambient temperature). The advantage of this model: It permits one to determine the reaction enthalpy and the kinetic parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979285
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Thermally stimulated creep study of bismaleimide/carbon fiber composite (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 623-634 
    Details
    ISSN: 1572-8943
    Keywords: bismalleimide/carbon fiber composite ; DMA ; kinetics ; TSC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The correlation between structure/microstructure and thermomechanical properties has been investigated by the Thermally Stimulated Creep (TSC) technique in a high performance thermostable thermoset matrix composite. The high resolving power of this technique allows us to analyse the α retardation mode. The kinetics of molecular movements liberated at the glass transition has been investigated by the technique of fractional loading: the analysis of each elementary process gives the real compliance and the retardation time as a function of temperature. The values of the activation parameters show the existence of a compensation phenomenon which characterizes the microstructure. It also gives access to the loss compliance of the composite material as a function of temperature and frequency. The predictive calculation of loss compliance has been validated by the results obtained by dynamic mechanical analysis (DMA).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979508
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Einfluß der Sensor-Zeitkonstanten auf die Auswertbarkeit von Ta-Daten (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 769-782 
    Details
    ISSN: 1572-8943
    Keywords: kinetics ; non-linear optimization ; reactor time constants ; software ; time constants of sensors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract All temperature sensors have a finitely time constant. The influence of the sensor time constant gts on the results of kinetic evaluation is demonstrated at four reaction types. The ignorance of the sensor indolence gives incorrect activation parameters. Therefore the determination of Τs is necessary. For the estimation of parameters the nonlinear evaluation program TA-kin was used. With its help it is possible to find the real parameters, also when Τs=32 s, if the real Τs-value was entered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01997182
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Kinetic studies on the thermal dissociation of β-cyclodextrin-cinnamyl alcohol inclusion complex (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1517-1525 
    Details
    ISSN: 1572-8943
    Keywords: β-cyclodextrin ; cinnamyl alcohol ; kinetics ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stability of β-cyclodextrin-cinnamyl alcohol inclusion complex (β-CD·C9H10·8H2O) was investigated using TG and DSC. The mass loss took place in three stages: the dehydration occurred between 50–120°C; the dissociation of β-CD·C9H10O occurred in the range of 210–260°C; and the decomposition of β-CD began at 280°C. The dissociation of β-CD·C9H10O was studied by means of thermogravimetry, and the results showed: the dissociation of β-CD·C9H10O was dominated by a two-dimensional diffusion process (D2). The activation energyE was 161.2 kJ mol−1, the pre-exponential factorA was 4.5×1013 min−1. Cyclodextrin is able to form inclusion complexes with a great variety of guest molecules, and the interesting of studies focussed on the energy binding cyclodextrin and the guest molecule. In this paper, β-cyclodextrin-cinnamyl alcohol inclusion complex was studied by fluorescence spectrophotometry and infrared absorption spectroscopy, and the results show: the stable energy of inclusion complexes of β-CD with weakly polar guest molecules consists mainly of Van der Waals interaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983712
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Neural networks for kinetic parameters determination, signal filtering and deconvolution in thermal analysis (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1553-1564 
    Details
    ISSN: 1572-8943
    Keywords: deconvolution ; differential scanning calorimetry ; feedforward neural networks ; kinetics ; signal filtering ; simulations ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Feedforward neural networks have been used for kinetic parameters determination and signal filtering in differential scanning calorimetry. The proper learning function was chosen and the network topology was optimized, using an empiric procedure. The learning process was achieved using simulated thermoanalytical curves. The resilient-propagation algorithm have led to the best minimization of the error computed over all the patterns. Relative errors on the thermodynamic and kinetic parameters were evaluated and compared to those obtained with the usual thermal analysis methods (single scan methods). The errors are much lower, especially in presence of noisy signals. Then, our program was adapted to simulate thermal effects with known thermodynamic and kinetic parameters, generated electrically, using a PC computer and an electronic interface on the serial port. These thermal effects have been generated by using an inconel thread.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983715
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Reaction pathway and kinetics of the thermal decomposition of synthetic brochantite (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1467-1475 
    Details
    ISSN: 1572-8943
    Keywords: CRTA ; DSC ; kinetics ; synthetic brochantite ; TG-DTA ; thermal decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reaction pathway of the thermal decomposition of synthetic brochantite, Cu4(OH)6SO4, to copper(II) oxide was investigated through the detailed kinetic characterization of the thermal dehydration and desulferation processes. The dehydration process was characterized by dividing into two overlapped kinetic processes with a possible formation of an intermediate compound, Cu4O(OH)4SO4. The dehydrated sample, Cu4O3SO4, was found first to be amorphous by means of XRD, followed by the crystallization to a mixture of CuO and CuO-CuSO4 at around 776 K. The specific surface area and the crystallization behaviour of the amorphous dehydrated compound depend largely on the dehydration conditions. The thermal desulferation process is influenced by the gross diffusion of the gaseous product SO3, which is governed by the advancement of the overall reaction interface from the top surface of the sample particle assemblage to the bottom.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983705
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Statistical analysis of thermoanalytical experimental data (1997)
    Springer
    Journal of thermal analysis and calorimetry 50 (1997), S. 455-462 
    Details
    ISSN: 1572-8943
    Keywords: kinetics ; statistical analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A statistical technique based on the Wilcockson criterion is suggested for estimation of the reproducibility of thermoanalytical experiments. Reduction of the whole physicochemical process to a quasi-one-stage process is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01980505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Thermal behaviour and non-isothermal decomposition kinetics of some Nd(III) coordination compounds (1997)
    Springer
    Journal of thermal analysis and calorimetry 50 (1997), S. 425-430 
    Details
    ISSN: 1572-8943
    Keywords: decomposition ; kinetics ; non-isothermal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The authors present the results concerning the thermal behaviour of three polynuclear coordination compounds of Nd(III) and Co(II) or Fe(III) with triptophan. For the dehydration steps the values of the non-isothermal kinetic parameters have been determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01980502
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Mechanism and kinetics of inorganic sulphates decomposition (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1227-1241 
    Details
    ISSN: 1572-8943
    Keywords: inorganic sulphates ; kinetics ; mechanism ; thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Thermal decomposition of different inorganic sulphates are presented. A number of techniques, but mainly TG and DTA, are used to prove the mechanism and kinetics of CaSO4, BaSO4, FeSO4·xH2O, Al2(SO4)3·xH2O under various gas atmospheres. It is shown how the partial pressure of gas components and heating rate may effect the mechanism and kinetic parameters. There are also examples on the effects of some additives and initial treatment on the thermal processes. On the base of the results obtained some recommendations are given concerning the precautions to be taken into account in the thermal decomposition studies and the sulphur recovering.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983679
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Influence of the particle size distribution on the CRTA curves for the solid-state reactions of interface shrinkage type (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1477-1484 
    Details
    ISSN: 1572-8943
    Keywords: CRTA ; kinetics ; particle size distribution ; rate jump method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetic curves at infinite temperature for the solid-state reactions of the interface shrinkage type were drawn theoretically by taking account the particle size distribution in the sample mixture. The CRTA curves for the reactions with the particle size distribution can be drawn by utilizing the universal kinetic curves at infinite temperature. The proper kinetic treatment for the CRTA curves with the particle size distribution is discussed in connection with the property of the kinetic equation with respect to the particle size distribution. The present kinetic consideration is taken as a simulation for the reactions with a certain distribution in α among the reactant particles, produced preferably by the mass and heat transfer phenomena during the thermoanalytical measurements. The merit of the rate jump method by a single cyclic CRTA curve is also discussed on the basis of the present results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983706
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Low/high temperature relationships in dinitramide salts by DEA/DSC and study of oxidation of aluminum powders by DSC/TG (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1161-1170 
    Details
    ISSN: 1572-8943
    Keywords: basicity ; dinitramides ; kinetics ; oxidation ; tanδ ; transition temperatures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The dinitramide salts of ammonia (ADN), hexamethylenetetramine (HDN), potassium (KDN), and sodium (NaDN) showed a linear relationship between the DSC rate of decomposition at the peak maximum and the DEA tanδ value at the low temperature transition peak. As the cation basicity increased in the series ADN〈HDN〈KDN〈NaDN, there was an increase in the low temperature transition peak, the energy barrier for relaxation, and the decomposition peak temperature, and a decrease in the tanδ value at the low temperature transition peak, specific heat capacity, and the rate and enthalpy of decomposition. The more basic salts were more thermally stable (i.e., higher decomposition temperature) and less energetic (i.e., lower enthalpy of decomposition). The more internal free volume (disorder) present in these salts, the higher the rates of relaxation and decomposition. Five aluminum powders of different surface areas were analyzed by DSC in platinum sample pans, and it was found that the enthalpy and rate of oxidation increased as the particle size of Al decreased while the enthalpy of the Al melt decreased. TG showed a two-step weight gain in the oxidation of Al with plateaus in the 650 and 1130°C regions and the percent weight gain increased as the particle size of Al decreased. Variable DSC and TG heating rate studies showed that the activation energies for the first step in the oxidation process increased as the particle size of Al increased.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983671
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    The thermal dehydration and decomposition of Ba[Cu(C2O4)2(H2O)]·5H2O (1997)
    Springer
    Journal of thermal analysis and calorimetry 50 (1997), S. 33-50 
    Details
    ISSN: 1572-8943
    Keywords: Ba[Cu(C2O4)2(H2O)]·5H2O ; decomposition ; dehydration ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal behaviour of Ba[Cu(C2O4)2(H2O)]·5H2O in N2 and in O2 has been examined using thermogravimetry (TG) and differential scanning calorimetry (DSC). The dehydration starts at relatively low temperatures (about 80°C), but continues until the onset of the decomposition (about 280°C). The decomposition takes place in two major stages (onsets 280 and 390°C). The mass of the intermediate after the first stage corresponded to the formation of barium oxalate and copper metal and, after the second stage, to the formation of barium carbonate and copper metal. The enthalpy for the dehydration was found to be 311±30 kJ mol−1 (or 52±5 kJ (mol of H2O)−1). The overall enthalpy change for the decomposition of Ba[Cu(C2O4)2] in N2 was estimated from the combined area of the peaks of the DSC curve as −347 kJ mol−1. The kinetics of the thermal dehydration and decomposition were studied using isothermal TG. The dehydration was strongly deceleratory and the α-time curves could be described by the three dimensional diffusion (D3) model. The values of the activation energy and the pre-exponential factor for the dehydration were 125±4 kJ mol−1 and (1.38±0.08)×1015 min−1, respectively. The decomposition was complex, consisting of at least two concurrent processes. The decomposition was analysed in terms of two overlapping deceleratory processes. One process was fast and could be described by the contracting-geometry model withn=5. The other process was slow and could also be described by the contracting-geometry model, but withn=2. The values ofE a andA were 206±23 kJ mol−1 and (2.2±0.5)×1019 min−1, respectively, for the fast process, and 259±37 kJ mol−1 and (6.3±1.8)×1023 min−1, respectively, for the slow process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979547
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Thermal behaviour of some derivatives of malic acid with calcium and strontium (1997)
    Springer
    Journal of thermal analysis and calorimetry 48 (1997), S. 359-366 
    Details
    ISSN: 1572-8943
    Keywords: decomposition ; kinetics ; non-isothermal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Results are presented on the thermal behaviour of two derivatives of malic acid. The decomposition intermediates obtained at about 400
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979280
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Physico-geometric kinetics of solid-state reactions by thermal analyses (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 45-56 
    Details
    ISSN: 1572-8943
    Keywords: accommodation function ; fractional reaction ; kinetics ; solid-state reaction ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The physico-geometric kinetics for the solid-state reactions by thermoanalytical (TA) measurements were reexamined by focusing some fundamental aspects: (1) the fundamental kinetic equation, (2) the kinetic model function, (3) the fractional reaction α, and (4) the apparent kinetic parameters. It was pointed out that some pitfalls in the practical kinetic study are originated by the disagreement between the kinetic information from the TA measurements and the theory of the physico-geometric kinetics. In order to increase the degree of coordination between the theory and practice, several attempts were made from both the theoretical and experimental points of views. The significance of the apparent kinetic parameters was discussed with a possible orientation for obtaining the reliable kinetic parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01987420
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Catalytic degradation of polyethylene evaluated by TG (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 255-260 
    Details
    ISSN: 1572-8943
    Keywords: catalytic degradation ; kinetics ; polyethylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract HZSM-5 zeolite was screened as catalyst for high density polyethylene degradation at 450
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01987446
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Thermochemical characterization of phenolic resins (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 261-268 
    Details
    ISSN: 1572-8943
    Keywords: kinetics ; phenol-formaldehyde resins ; pyrolysis-GC ; thermal degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Phenol-formaldehyde resins (I andII), synthesised at a monomer feed ratio of F/P = 1.0 and 1.5, were cured at 130
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01987447
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Steps in a minefield (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 17-32 
    Details
    ISSN: 1572-8943
    Keywords: Arrhenius equation ; compensation ; distinguishability ; kinetics ; mechanisms ; nonisothermal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This paper is a review of some of the controversial kinetic aspects of thermal analysis, starting from the ‘šesták questions’ posed in 1979 and looking at developments in some areas since that time. Aspects considered include: temperature programmes and variations, models and mechanisms, kinetic parameters, distinguishability and extent of fit of kinetic models, complementary evidence for kinetic models, the Arrhenius equation and the compensation effect. The value of the ideas of non-isothermal kinetics in chemical education is emphasized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01987418
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Temperature resolved X-ray diffraction as a tool of thermal analysis (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1025-1037 
    Details
    ISSN: 1572-8943
    Keywords: crystallographic evaluation ; evaluation with difference procedure ; kinetics ; Rietveld refinement ; X-ray diffraction ; temperature resolved
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Time and temperature resolved X-ray diffraction was used for thermal analysis. Series of diffraction patterns were measured, while the samples are heated/cooled stepwise or isothermally with freely selectable temperature programs. The method was applied for the investigation of the phase transitions of ammonium nitrate and HMX (1,3,5,7-tetranitro-1,3,5,7-tetraaza-cyclooctane), when the identification of phases was required. Its capability in the field of kinetics is demonstrated with the isothermal investigation of the solid state reaction of ammonium nitrate with copper oxide and the non-isothermal investigation of the high temperature corrosion of nickel, which was performed by means of a difference procedure. For obtaining structural details peak fitting and Rietveld refinement were applied for the investigation of ammonium nitrate and HMX.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01996790
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Thermal analysis of Beypazari lignite (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 617-625 
    Details
    ISSN: 1572-8943
    Keywords: combustion ; kinetics ; lignite ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Beypazari lignite was investigated by differential scanning calorimetry (DSC), thermogravimetry (TG), high pressure thermogravimetry (HPTG) and combustion cell experiments. All the experiments were conducted at non-isothermal heating conditions with a heating rate of 10°C min−1, in the temperature range of 20–700°C. DSC-TG data were analysed using an Arrhenius-type reaction model assuming a first-order reaction. For the HPTG data the Coats and Redfern equation was used for kinetic analysis. In the combustion cell experiments the Fassihi and Brigham approach was used in order to calculate kinetic data. Finally a comparison is made between the kinetic results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01996744
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Combustion characteristics of crude oil-limestone mixtures (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 609-615 
    Details
    ISSN: 1572-8943
    Keywords: combustion ; crude oil ; kinetics ; thermogravimetric analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract High pressure thermogravimetric analysis (HPTG) was used in order to study the oxidation of crude oil in a porous medium under pressurised conditions for simulation of in-situ combustion during oil recovery. Three distinct reaction regions were observed from the HPTG curves in an oxidising environment subjected to a constant heating rate. These were low temperature oxidation, fuel deposition and high temperature oxidation. The method of Coats and Redfern was used to obtain kinetic parameters and the results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01996743
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Kinetic studies on the thermal dissociation of the inclusion complex of β-cyclodextrin with cinnamic aldehyde (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1527-1533 
    Details
    ISSN: 1572-8943
    Keywords: β-cyclodextrin ; cinnamic aldehyde ; kinetics ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stability of the inclusion complex of β-CD with cinnamic aldehyde was investigated by means of TG and DSC. The mass loss takes place in three stages: dehydration occurs at 50–120°C; dissociation of β-CD·C9H8O proceeds in the range 200–260°C; and decomposition of β-CD begins at 280°C. The kinetics of the dissociation of β-CD·C9H8O was studied by means of thermogravimetry both at constant temperature and with linearly increasing temperature. The results demonstrate that the dissociation of β-CD·C9H8O is dominated by a one-dimensional diffusion process. The activation energyE is 160 kJ mol−1, and the pre-exponential factorA is 5.8×1014 min−1. Scanning electron microscope observations and the results of crystal structure analysis are in good agreement with those of thermogravimetry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983713
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Bias in isothermal time-to-event studies due to approach to test temperature (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 1485-1492 
    Details
    ISSN: 1572-8943
    Keywords: bias ; constant temperature stability ; isothermal crystallization ; kinetics ; oxidative induction time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Oxidative induction time (OIT), constant temperature stability (CTS) and isothermal crystallization are examples of isothermal time-to-event (TTE) measurements obtained using differential scanning calorimetry. In TTE experiments, a test specimen is heated/cooled at a constant rate from the setup temperature to an isothermal test temperature. Once the test temperature is achieved, a clock is started and the time to the thermal event (e.g., onset to oxidation, thermal decomposition or crystallization exotherm peak) is measured. Such TTE values may be used to rank stability of the material at the test temperature. Some portion of the reaction of interest, however, takes place during the pre-isothermal period as the test specimen approaches the test temperature. This amount of reaction is unmeasured and represents a bias in the resultant TTE value. An equation has been derived and numerically integrated to estimate this bias. This approach shows that the bias is dependent upon the activation energy of the test reaction, the heating/cooling rate used and the temperature range between the melting temperature and the test temperature. For commonly used heating rates, the bias for OIT and CTS tests is small. Further, the myth that isothermal crystallization kinetics determinations required high cooling rates is dispelled with the bias of less than 0.9 min resulting from heating rates as low as 10°C min−1. Knowledge of magnitude of this bias permits the selection of experimental conditions without the expense of high heating/cooling rate apparatus or extra cost cooling accessories.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01983707
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Modelling the kinetics of solute segregation to partial dislocations for isothermal microcalorimetric evaluations (1997)
    Springer
    Journal of thermal analysis and calorimetry 50 (1997), S. 533-545 
    Details
    ISSN: 1572-8943
    Keywords: Cu-19 at% Al ; dislocations ; kinetics ; segregation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A model is proposed to describe the kinetics of solute segregation to partial dislocations in solid solutions of cold-rolled alloys. The case when half edge and half screw dislocations are present is considered. The model gives account of the kinetic behaviour observed in a deformed Cu-19 at% Al alloy where two unknown processes could be assessed during calorimetric isothermal experiments. The faster process corresponds to segregation to screw dissociated dislocations while the slower one corresponds to segregation to edge dissociated dislocations. Experimental activation energies, larger for edge dislocations, are close to that for pipe diffusion along the partials corrected by pinner binding energy terms. It is also predicted that segregation occurs faster as the dislocation density is increased. A quantitative comparison of experimental results with model predictions is given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01979026
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Oxidation behavior of an Fe-38Ni-13Co-4.7Nb-1.5Ti-0.4Si superalloy at high temperature in Ar-H2O atmospheres (1997)
    Springer
    Oxidation of metals 47 (1997), S. 411-426 
    Details
    ISSN: 1573-4889
    Keywords: oxidation ; Incoloy 909 ; superalloy ; scale ; high temperature ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The oxidation of an Fe-38Ni-13Co-4.7Nb-1.5Ti-0.4Si superalloy (Incoloy 909 type alloy), was investigated at temperatures between 1000 K and 1400 K in Ar-(1, 10%)H20 atmosphere using metallographic, electron probe microanalysis, and X-ray diffraction techniques. The oxide scales consist of an external scale and an internal scale which has an intergranular scale (above 1200 K) and an intergranular scale. The oxide phases in each scale are identified asα-Fe2,O3 (below 1200 K) or FeO (above 1300 K) and CoO · Fe2O3 and FeO · Nb2O5, respectively. The morphologies, the oxide phases and the oxidation rates do not depend on the partial pressure of H2O in the range between one and ten percent in Ar gas. The rate constants for the intergranular-scale formation in this alloy are about one-tenth as large as those in Fe-36%Ni alloy reported previously. At all the temperatures the scales grow according to a parabolic rate law and the apparent activation energies for the processes are estimated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02134784
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    On the oxidation ofα-Fe andε-Fe2N1−z : I. Oxidation kinetics and microstructural evolution of the oxide and nitride layers (1997)
    Springer
    Oxidation of metals 48 (1997), S. 87-109 
    Details
    ISSN: 1573-4889
    Keywords: oxidation ; kinetics ; iron ; iron-nitride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The oxidation of α-Fe and ɛ-Fe2N1−z at 573 K and 673 K in O2 at 1 atm was investigated by thermogravimetrical analysis, X-ray diffraction, light-optical microscopy, scanning electron microscopy and electron probe X-ray microanalysis. Upon oxidation at 573 K and 673 K, on α-Fe initially α-Fe2O3 develops, whereas on ɛ-Fe2N1−z initially Fe3O4 develops. In an early stage of oxidation the oxidation rate of ɛ-Fe2N1−z appears to be much larger than of α-Fe. This can be attributed largely to an effective surface area available for oxygen uptake, which is much larger for ɛ-Fe2N1−z than for α-Fe due to the porous structure of ɛ-Fe2N1−z as prepared by gaseous nitriding of iron. The development of a magnetite layer in-between the hematite layer and the α-Fe substrate, at a later stage of oxidation, enhances layer-growth kinetics. After 100 min oxidation at 673 K the (parabolic) oxidation rates for α-Fe and ɛ-Fe2N1−z become about equal, indicating that on both substrates the oxide growth is controlled by the same rate limiting step which is attributed to short-circuit diffusion of iron cations. Oxidizing ɛ-Fe2N1−z increases the nitrogen concentration in the remaining ɛ-iron nitride, because the outward flux of iron cations, necessary for oxide growth, leads to an accumulation of nitrogen atoms left behind.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01675263
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Scale formation on γ-TiAl during oxidation at 800 and 900°C in air and in He + 20% O2 (1997)
    Springer
    Oxidation of metals 48 (1997), S. 171-184 
    Details
    ISSN: 1573-4889
    Keywords: TiAl, corrosion ; high-temperature ; kinetics ; nitrogen dependence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The oxide scale formation on γ-TiAl at 800 and 900°C was studied using high temperature X-ray diffraction as anin situ-method. The experiments were performed in air and in He with 20 vol.% O2. The formation of alumina in the form of α-Al2O3 and of TiO2 in the form of rutile was observed in both atmospheres and the formation of TiN was detected in air. Depending on the atmosphere the diffraction peaks of two different additional phases were detected, which do not exist in any data base nor in the Ti-Al-O phase diagram. One of them, the Z-phase, appears in He with 20 vol.% O2 and the other, the X-phase, in air. The Zphase was also found at room temperature after oxidation at 900°C in air. The growth of both phases, X and Z, starts immediately with the oxidation process and follows the parabolic rate law.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01675267
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    High-temperature oxidation of pure titanium in CO2 and Ar-10%CO2 atmospheres (1997)
    Springer
    Oxidation of metals 48 (1997), S. 289-302 
    Details
    ISSN: 1573-4889
    Keywords: oxidation ; titanium ; rutile ; scale ; high temperature ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The oxidation behavior of pure titanium has been investigated in the temperature range of 1000 K to 1300 K in CO2 or Ar-10%CO2. Optical microscopy, electron probe microanalyses, and X-ray measurements on the oxide scales formed during oxidation indicate that their structures are nearly independent of temperature and the corrosion atmosphere. The scales consisted of two layers, an external one and an internal one, having a rutile (TiO2) structure. The parabolic rate law was confirmed for growth of the external scale and the permeation depth of oxygen in titanium with apparent activation energies of 266 and 226 kJ/mol, respectively. The rate-determining diffusion species in the oxidation processes are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01670504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    The Glycophorin A Gene Family in Gorillas: Structure, Expression, and Comparison with the Human and Chimpanzee Homologues (1997)
    Springer
    Biochemical genetics 35 (1997), S. 59-76 
    Details
    ISSN: 1573-4927
    Keywords: glycophorins ; gorilla ; evolution ; gene family ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Homologues of MN blood group antigens, encoded by members of the glycophorin A (GPA) gene family, are expressed in man, anthropoid apes, and some species of Old World monkeys. Previous studies had shown that a three-gene framework, most closely related to that in man, is present in the chimpanzee. Here we report the genomic structure, transcript map, and protein expression of the GYPA locus in gorillas. Compared to the corresponding human and chimpanzee homologues, gorilla GPA, GPB, and GPB/E genes each showed a high degree of sequence identity, with the same exon-intron organization. However, the expression of exons III, IV, or V encoding the extracellular or membrane domains of homologous glycophorins varied among the three species. Gorilla GPA and GPB/E genes were unique in that the former occurred in two allelic forms with or without the expression of exon III, whereas the latter contained one (ψ exon III) instead of two silenced exons (ψ exons III and IV). Differences from human but not chimpanzee GPA also included the presence of a hybrid M/N epitope and the absence of the sequon for N-glycosylation. Owing to the retention of a functional exon III, gorilla GPB was more similar to chimpanzee GPB than human GPB. A transspecies allele was identified in the gorilla that gave rise to the Henshaw (He)-like antigen similar to that found in man. These results provide further insight into the model for evolution of the GPA gene family, indicating that the mechanisms underlying inter- and intraspecific polymorphism of glycophorins could predate the divergence of gorillas as the consequence of gene duplication and diversification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022212630370
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    FTIR Spectroscopy, SAXS and Electrical Conductivity Studies of the Hydrolysis and Condensation of Zirconium and Titanium Alkoxides (1997)
    Springer
    Journal of sol gel science and technology 8 (1997), S. 41-47 
    Details
    ISSN: 1573-4846
    Keywords: zirconium butoxide ; titanium butoxide ; kinetics ; hydrolysis ; condensation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A continuous flowing-rapid mixing technique was combined with FTIR, SAXS and electrical conductivity to study the early stages of polymer formation and growth during the acid-catalyzed hydrolysis and condensation of titanium and zirconium alkoxides. Reaction times as short as 80 milliseconds were investigated. FTIR spectroscopy was used to monitor the water and M–OR concentrations during the reaction. Hydrolysis of ∼25–50% of the alkoxy groups was facile. The FTIR and SAXS data showed that condensation was also very rapid. The activity and mobility of the ions in the solution were monitored by electrical conductivity measurements. The decrease in the normalized solution conductivity during the reaction correlated with the loss of [M–OR]. Furthermore, the radius of gyration of the growing polymers increased rapidly in regimes where the conductivity and [M–OR] decreased fastest. This finding suggests that the mobility of some of the charge carrying species decreases because of the growth in size of the polymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026422315834
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    An approximate treatment of the transient state in the corrosion of binary alloys forming the most-stable oxide. Part I: Solid-solution alloys (1997)
    Springer
    Oxidation of metals 47 (1997), S. 91-115 
    Details
    ISSN: 1573-4889
    Keywords: binary alloys ; oxidation ; transient state ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The initial transient stage in the oxidation of binary alloys forming scales exclusively composed of the most stable oxide is examined by means of a simplified approach which avoids the numerical integration of the diffusion equation for the transport of the metal components in the alloy. At variance with previous solutions to this problem obtained by means of numerical methods, this treatment takes into account also the effect of the gas-scale reaction at the outer surface of the oxide. The concentration of the most-reactive component at the alloy surface changes gradually with time from the initial bulk value towards the corresponding steady-state value without involving any minimum, while the overall rate of the reaction presents a gradual transition from an initial nearly linear towards final parabolic behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01682373
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Multiple Functions for Secondary Metabolites in Encrusting Marine Invertebrates (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1527-1547 
    Details
    ISSN: 1573-1561
    Keywords: Secondary metabolites ; chemical defense ; evolution ; ascidians ; sponges
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We used three chemical fractions (spanning a wide range of polarities) from the extracts of four marine invertebrates, the spongesCrambe crambe andHemimycale columella and the ascidiansCystodytes dellechiajei andPolysyncraton lacazei, to test inhibition of cell division, photosynthesis, and settlement. We used assay organisms from the same habitat, seeking to determine whether a species may display diverse, ecologically relevant bioac-tivities and, if so, whether the same types of compound may be responsible for such activities. Cell division was strongly inhibited by the spongeC. crambe. A dichloromethane fraction fromC. crambe prevented development of sea urchinParacentrotus lividus eggs at a concentration of 10 μg/ml, as did the butanolic fraction, but at higher concentrations (50 and 100 μg/ml). At 50 μg/ml, the aqueous fraction ofC. crambe allowed cell division but prevented eggs from developing beyond the gastrula stage. Similar results were recorded with the dichloromethane fraction ofP. lacazei and from the aqueous fraction ofH. columella. Photosynthesis was unaffected by any of the species at 50 μg/ml. Larval settlement was inhibited by one or another fraction from the four species surveyed at a concentration of 50 μg/ml, althoughC. crambe exhibited the greatest amount of activity. We therefore found that various fractions displayed the same type of bioactivity, while compounds from the same fraction were responsible for multiple activities, suggesting that secondary metabolites are multiple-purpose tools in nature, which is relevant to our understanding of species ecology and evolution. Moreover, results showed that the assessment of the role of chemical compounds is significantly influenced by the assay organism, fractionation procedure, concentration, and duration of experiments. All these factors should be carefully considered when testing ecological hypotheses of the roles of chemically-mediated bioactivities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:JOEC.0000006420.04002.2e
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    LONG-TERM TRANSFORMATIONS AND REDISTRIBUTION OF POTENTIALLY TOXIC HEAVY METALS IN ARID-ZONE SOILS INCUBATED: I. UNDER SATURATED CONDITIONS (1997)
    Springer
    Water, air & soil pollution 95 (1997), S. 399-423 
    Details
    ISSN: 1573-2932
    Keywords: fractionation ; redistribution ; saturation ; kinetics ; heavy metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Solid-phase transformations of Cd, Cu, Cr, Ni and Zn, added as soluble salts at several levels to two arid-zone soils, were studied over a period of one year. The soils were maintained under a saturated-paste regime and sampled periodically. A selective sequential dissolution procedure was employed to determine the changes in metal distribution among six operationally defined solid-phase fractions. A function, Uts was introduced to measure the fractional attainment of equilibrium of the soils following a perturbation. The direction and rate of redistribution of the added metals in the soils were affected by the nature of the metal, the soil properties and the metal loading level. Cd added to the soils was transferred from the exchangeable (EXC) into the carbonate (CARB) fraction. When soluble Cu, Cr, Ni and Zn were added at low loading levels, metals were transferred from the reducible oxides(RO) bound and easily reducible oxides (ERO) bound fractions and the EXC fraction, into the CARB fraction. However, at the higher loading level, metals were transferred from the EXC and CARB fractions into the organic matter bound (OM), ERO and RO fractions. The Uts function approached lower values as incubation continued but remained removed from 1. The overall flux of metals among fractions was the combined result of the readjustment of the metals in the native soil to changing conditions due to saturation, and the transfer of added soluble metals to the less labile fractions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026450118082
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    FTIR spectroscopy, SAXS and electrical conductivity studies of the hydrolysis and condensation of zirconium and titanium alkoxides (1997)
    Springer
    Journal of sol gel science and technology 8 (1997), S. 41-47 
    Details
    ISSN: 1573-4846
    Keywords: zirconium butoxide ; titanium butoxide ; kinetics ; hydrolysis ; condensation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A continuous flowing-rapid mixing technique was combined with FTIR, SAXS and electrical conductivity to study the early stages of polymer formation and growth during the acid-catalyzed hydrolysis and condensation of titanium and zirconium alkoxides. Reaction times as short as 80 milliseconds were investigated. FTIR spectroscopy was used to monitor the water and M−OR concentrations during the reaction. Hydrolysis of ∼25–50% of the alkoxy groups was facile. The FTIR and SAXS data showed that condensation was also very rapid. The activity and mobility of the ions in the solution were monitored by electrical conductivity measurements. The decrease in the normalized solution conductivity during the reaction correlated with the loss of [M−OR]. Furthermore, the radius of gyration of the growing polymers increased rapidly in regimes where the conductivity and [M−OR] decreased fastest. This finding suggests that the mobility of some of the charge carrying species decreases because of the growth in size of the polymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02436815
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Revision ofDoniophyton (Compositae, Barnadesioideae) (1997)
    Springer
    Plant systematics and evolution 206 (1997), S. 33-45 
    Details
    ISSN: 1615-6110
    Keywords: Compositae ; Barnadesioideae ; Doniophyton ; Chuquiraga ; Argentina ; Chile ; evolution ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This revision describes, illustrates and documents morphological variation inDoniophyton (Compositae, Barnadesioideae), restricted to Argentina and Chile. Two species are recognized,D. anomalum andD. weddellii (sp. nova), possessing distinct morphological and chromosomal features, elevational tolerances, and nearly allopatric distributions.Doniophyton weddellii occurs primarily in central to northern Andean Chile and Argentina from 1900–4000 m a. s. l.;D. anomalum is found principally in centralwestern Argentina and south into Patagonia at 0–1800 m a. s. l. Close relationship exists withChuquiraga of subfam.Barnadesioideae. It is hypothesized thatDoniophyton evolved out ofChuquiraga in the high central Andes between Chile and Argentina. It is suggested thatD. weddellii differentiated first, correlating with an aneuploid chromosomal decrease from n = 27 (inChuquiraga) to n = 25. Further evolution and chromosomal decrease to n = 24 resulted inD. anomalum, with accompanying migration into southern Andes and Patagonia. Nomenclatural changes result from examination of protologues and type specimens:Doniophyton anomalum replaces the commonly used nameD. patagonicum, and a new species,D. weddellii, is described for the taxon masquerading under the routinely used superfluous nameD. andicola.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00987939
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    “Just-so” stories about “inner cognitive Africa”: some doubts about Sorensen's evolutionary epistemology of thought experiments (1997)
    Springer
    Biology and philosophy 12 (1997), S. 207-224 
    Details
    ISSN: 1572-8404
    Keywords: evolution ; epistemology ; evolutionary epistemology ; naturalized epistemology ; thought experiments ; modality ; utility ; fitness ; adaptation ; reliability ; possible worlds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Roy Sorensen advances an evolutionary explanation of our capacity for thought experiments which doubles as a naturalized epistemological justification. I argue Sorensen”s explanation fails to satisfy key elements of environmental-selectionist explanations and so fails to carry epistemic force. I then argue that even if Sorensen succeeds in showing the adaptive utility of our capacity, he still fails to establish its reliability and hence epistemic utility. I conclude Sorensen”s account comes to little more than a “just-so story”.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017986908266
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Taking the ‘Error’ Out of Ruse‘s Error Theory (1997)
    Springer
    Biology and philosophy 12 (1997), S. 385-397 
    Details
    ISSN: 1572-8404
    Keywords: morality ; evolution ; error theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Michael Ruse‘s Darwinian metaethics has come under just criticism from Peter Woolcock (1993). But with modification it remains defensible. Ruse (1986) holds that people ordinarily have a false belief that there are objective moral obligations. He argues that the evolutionary story should be taken as an error theory, i.e., as a theory which explains the belief that there are obligations as arising from non-rational causes, rather than from inference or evidential reasons. Woolcock quite rightly objects that this position entails moral nihilism. However, I argue here that people generally have justified true beliefs about which acts promote their most coherent set of moral values, and hence, by definition, about which acts are right. What the evolutionary story explains is the existence of these values, but it is not an error theory for moral beliefs. Ordinary beliefs correspond to real moral properties, though these are not objective or absolute properties independent of anyone‘s subjective states. On its best footing, therefore, a Darwinian metaethics of the type Ruse offers is not an error theory and does not entail moral nihilism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006577007049
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Evolution of the Sacoglossa (Mollusca, Opisthobranchia) and the ecological associations with their food plants (1997)
    Springer
    Evolutionary ecology 11 (1997), S. 301-335 
    Details
    ISSN: 1573-8477
    Keywords: ecological associations ; evolution ; integrative biology ; Opisthobranchia ; resource tracking ; Sacoglossa ; Ulvophyceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evolution in the opisthobranch order Sacoglossa has been closely linked to their specialized suctorial herbivorous habits. All shelled Sacoglossa (about 20% of the species) feed on one algal genus, Caulerpa. The non-shelled Sacoglossa have 'radiated' to other diets, mainly siphonalean or septate green algae (Class Ulvophyceae). Comparing the phylogeny of sacoglossan genera with the phylogeny of the Ulvophyceae indicates that co-speciation may have taken place at the basal node of the Sacoglossa, and that host switching has taken place several times in the two non-shelled clades. It is suggested that the most important evolutionary process has been speciation by 'resource-tracking'; the resource tracked is most probably cell wall composition of the algal prey. The fossil record of extant sacoglossan genera dates back to the Eocene and, based on the fossil record of siphonalean green algae, the Sacoglossa most likely appeared in the Cretaceous. It is hypothesized that the ancestral sacoglossan was epifaunal, suctorial and herbivorous, and the 'ancestral' food plant was not Caulerpa, but filamentous, calcified, now extinct, Udoteaceae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018468420368
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    The evolution of dispersal in a two-patch system:Some consequences of differences between migrants and residents (1997)
    Springer
    Evolutionary ecology 11 (1997), S. 613-629 
    Details
    ISSN: 1573-8477
    Keywords: dispersal ; evolution ; evolutionarily stable strategy ; migrant ; resident ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We investigate how age-structure and differences in certain demographic traits between residents and immigrants of a single species act to determine the evolutionarily stable dispersal strategy in a two-patch environment that is heterogeneous in space but constant in time. These two factors have been neglected in previous models of the evolution of dispersal, which generally consider organisms with very simple life-cycles and assume that, whatever their origin, individuals in a given habitat have the same bio-demographic characteristics. However, there is increasing empirical evidence that dispersing individuals have different demographic properties from phylopatric ones. We develop a matrix model in which recruitment depends on local population densities. We assume that dispersal entails a proportional cost to immigrant fecundity, which can be compensated by differences in survival rates between immigrants and residents. The evolutionarily stable strategies (ESS) for dispersal are identified using a combination of analytical expressions and numerical simulations. Our results show that philopatry is selected (1) when dispersal rates do not vary in space, (2) when the metapopulation is a source-sink system and (3) when dispersal rates vary in space (asymmetric dispersal) and immigrants do not compensate for their reduced fecundity. We observe that non-zero asymmetric dispersal rates may be evolutionarily stable when (1) immigrants and residents are demographically alike and (2) immigrants compensate totally for their reduced fecundity through an increase in adult survival. Under these conditions, we find that the ESS occurs when the fitnesses at equilibrium in the two habitats, measured in our model by the realized reproductive rates, are each equal to unity. A comparison with previous studies suggests a unifying rule for the evolution of dispersal: the dispersal rates which permit the spatial homogenization of fitnesses are ESSs. This condition provides new insight into the evolutionary stability of source-sink systems. It also supports the hypothesis that immigrants have adapted demographic strategies, rather than the hypothesis that dispersal is costly and immigrants are at a disavantage compared with residents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10682-997-1516-z
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Tree-thinking and nemertean systematics, with a systematization of the Eureptantia (1997)
    Springer
    Hydrobiologia 365 (1997), S. 33-46 
    Details
    ISSN: 1573-5117
    Keywords: Phylogeny ; cladistics ; taxonomy ; systematics ; classification ; evolution ; history ; chronicle ; Nemertea ; Hoplonemertea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract I review how some influential nemertean systematistshave perceived and illustrated phylogenetic trees andargue that the nineteenth century nemerteantaxonomists still influence many contemporarynemertean taxonomists to a high degree. By showing hownineteenth century systematics differs from moremodern views on trees, I hope to convey the advantagesof a cladistic approach to tree-thinking and nemerteansystematics. Furthermore I propose a systematizationof the Eureptantia that illustrates the cladisticapproach to tree-thinking but, more importantly, isalso a better representation of eureptantic phylogenythan previous classifications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003174326275
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    No Evidence for a Y Chromosomal Effect on Alternative Behavioral Strategies in Mice (1997)
    Springer
    Behavior genetics 27 (1997), S. 477-482 
    Details
    ISSN: 1573-3297
    Keywords: Aggression ; nest-building behavior ; wild house mice ; behavioral strategies ; bidirectional selection ; Y chromosome ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract This study takes the first step toward testing a Y chromosomal effect on both aggression and thermoregulatory nest-building behavior in mouse lines either bidirecrionally selected for short (SAL) and long (LAL) attack latency or high (HIGH) and low (LOW) nest-building behavior. Using reciprocal crosses between SAL and LAL, and between HIGH and LOW, we found no indications for Y chromosomal effects on thermoregulatory nest-building behavior. As for aggression, we confirmed earlier studies on SAL and LAL, i.e., the origin of the Y chromosome influences attack latency, i.e., aggression. However, we did not find indications for a Y chromosomal effect on aggression in the HIGH and LOW lines. Since aggression and nest-building behavior have been shown to be characteristic parameters of two fundamentally different behavioral strategies, the present data underline the improbability of Y chromosomal genes underlying the genetic architecture of alternative behavioral strategies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1025678517986
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Comparative mapping of Xp22 genes in hominoids – evolutionary linear instability of their Y homologues (1997)
    Springer
    Chromosome research 5 (1997), S. 167-176 
    Details
    ISSN: 1573-6849
    Keywords: comparative mapping ; evolution ; hominoids ; X–Y homologous genes ; Y chromosome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several genes located within or proximal to the human PAR in Xp22 have homologues on the Y chromosome and escape, or partly escape, inactivation. To study the evolution of Xp22 genes and their Y homologues, we applied multicolour fluorescence in situ hybridization (FISH) to comparatively map DNA probes for the genes ANT3, XG, ARSD, ARSE (CDPX), PRK, STS, KAL and AMEL to prometaphase chromosomes of the human species and hominoid apes. We demonstrate that the genes residing proximal to the PAR have a highly conserved order on the higher primate X chromosomes but show considerable rearrangements on the Y chromosomes of hominoids. These rearrangements cannot be traced back to a simple model involving only a single or a few evolutionary events. The linear instability of the Y chromosomes gives some insight into the evolutionary isolation of large parts of the Y chromosomes and thus might reflect the isolated evolutionary history of the primate species over millions of years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018490713273
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Comparative analysis on the distribution of heterochromatin in Citrus, Poncirus and Fortunella chromosomes (1997)
    Springer
    Chromosome research 5 (1997), S. 86-92 
    Details
    ISSN: 1573-6849
    Keywords: chromosome banding ; citrus ; fluorochrome ; heterochromatin ; karyotype ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Double fluorochrome staining with chromomycin A3 (CMA) and 4′-6-diamidino-2-phenylindole (DAPI) was used to characterize and compare the distribution of constitutive heterochromatin along chromosomes of Citrus, Poncirus and Fortunella species. Only CMA-positive bands were distinguishable in metaphase chromosomes. Preferential distribution of heterochromatin in terminal regions, mainly of the long arm, and centromeric regions of a few long chromosomes was a common feature of these genera. Heteromorphism between possible homologous chromosomes was present in the majority of species. Citrus and Poncirus revealed some remarkably uniform chromosomes without any intensively fluorescing region, whereas Fortunella cultivars were differentiated by the presence of CMA bands in all chromosomes. Through measurements assisted by a computer, amounts of CMA-positive regions were shown to be highest in Fortunella. Similarities between Citrus and Poncirus suggest little heterochromatin diversification among karyotypes of these genera, whereas Fortunella, with higher amounts and more homogenous distribution of heterochromatin, is more divergent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018409922843
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Male-biased distribution of the human Y chromosomal genes SRY and ZFY in the lizard Calotes versicolor, which lacks sex chromosomes and temperature-dependent sex determination (1997)
    Springer
    Chromosome research 5 (1997), S. 413-419 
    Details
    ISSN: 1573-6849
    Keywords: evolution ; reptiles ; sex determination ; SRY ; ZFY
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the present investigation on the lizard Calotes versicolor, which lacks temperature-dependent sex determination, all the conventional cytological techniques used failed to resolve a distinguishable pair of sex chromosomes. However, probing of the genome with the human Y-linked genes SRY and ZFY showed sex-specific bias in their distribution. While the SRY probe hybridized to all the males, more than half of the females examined did not show any hybridization. ZFY hybridized to both the sexes, giving two bands; one was common to all the individuals of both sexes, but the other, of the lower molecular length, occurred in all the males but in less than 50% of females. This predominantly male-specific band is named AMF. The SRY-positive females were also positive for the AMF of ZFY. As positive as well as negative females were fertile and none of the males lacked SRY, it appears that SRY is essential for males only and that both the genes are syntenic in this species. This report raises interesting possibilities on the differentiation of the sex chromosomes in C. versicolor and evolution of SRY/ZFY on the Y chromosome of eutherian mammals through the ancestral group(s) that harbour sex-independent SRY- and ZFY-related genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018452526903
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Rice genetic resources: history, conservation, investigative characterization and use in Japan (1997)
    Springer
    Plant molecular biology 35 (1997), S. 69-77 
    Details
    ISSN: 1573-5028
    Keywords: rice ; wild rice ; Oryza spp. ; evolution ; conservation ; evaluation ; utilization ; germplasm ; genetic resources ; genebank
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rice has been grown in Japan for about 3000 years. Although both japonica and indica varieties have been grown in Japan, now japonica rices are grown. Japanese rice breeding has used an ecological breeding approach. While emphasis in rice breeding in the 1940's and 1950's focussed on yield in recent decades quality has been of major importance. Consumer preference and name recognition of high quality varieties, such as Koshihikari, has resulted in slow acceptance of new varieties. Rice germplasm was systematically collected throughout Japan between 1962 and 1963. Subsequent acquisition and collecting, in Japan and other countries, has resulted in 28,000 accessions being conserved in the National Genebank, based at the National institute of Agrobiological Resources (NIAR). Research on genetic diversity of rice using a range of techniques, for example esterase isozymes, has revealed clinal variation in rice radiating from the center of diversity of rice in and around southwest China. Newly found genes in traditional rice germplasm, such as genes for non-elongating mesocotyl, are now routinely identified on the rice genome. Pioneering studies on eco-genetic differentiation of species in the genus Oryza in Japan has revealed much about the complex genepool for which rice evolved. Pest and disease resistance sources, particularly to blast, bacterial blight and brown plant hopper, from many countries have been incorporated into Japanese varieties. Cold tolerance at the booting stage was found in the Indonesian variety Silewah. In the future in characterisation of rice germplasm and interaction between rice germplasm specialists and rice molecular scientists, both in Japan and internationally, will be corner stones to securing rice genetic diversity and rice improvement in the next century.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005784431759
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Analysis of multiple copies of geminiviral DNA in the genome of four closely related Nicotiana species suggest a unique integration event (1997)
    Springer
    Plant molecular biology 35 (1997), S. 313-321 
    Details
    ISSN: 1573-5028
    Keywords: integration ; geminivirus ; plant genomes ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previously, we discovered multiple direct repeats of geminivirus-related DNA (GRD) sequences clustered at a single chromosomal position in Nicotiana tabacum (tobacco). Here we show that, in addition to tobacco, multiple copies of these elements occur in the genomes of three related Nicotiana species, all in the section Tomentosae: N. tomentosiformis, N. tomentosa and N. kawakamii, but not in 9 other more distantly related Nicotiana species, nor in various other solanaceous and non-solanaecous plants. DNA sequence analysis of 18 GRD copies reveal 4 distinct, but highly related, sub-families: GRD5, GRD3 and GRD53 in tobacco; GRD5 in N. tomentosiformis and N. kawakamii; and GRD2 in N. tomentosa. In addition to novel sequences, all elements share significant but varying lengths of DNA sequence similarity with the geminiviral replication origin plus the adjacent rep gene. There is extended sequence similarity to REP protein at the deduced amino acid sequence level, including motifs associated with other rolling circle replication proteins. Our data suggest that all GRD elements descend from a unique geminiviral integration event, most likely in a common ancestor of these Tomentosae species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005885200550
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Mitochondrial Dehydrogenases in Different Taxa of Tetrahymena: Effect of Insulin (1997)
    Springer
    Bioscience reports 17 (1997), S. 529-535 
    Details
    ISSN: 1573-4935
    Keywords: Mitochondria ; mt-dehydrogenase ; evolution ; insulin ; hormonal effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mitochondrial dehydrogenase activity was measured in seven taxa of Tetrahymena (T. pyriformis G1, T. hegewishi, T. malaccensis, T. pigmentosa, T. shapiro, T. thermophila CU-399, T. thermophila MS-1). Enzyme activity was different in the taxa investigated. Insulin reduced enzyme activity in six of the seven taxa studied. The duration of activity reduction was relatively long (5–10 min.) in most of the cases, and in T. hegewishi this lasted up to the end of the measurements (30 min.). There was no interrelation between the basic dehydrogenase activity of the taxon and the effect of insulin. There was also no correlation between the degree of relationship (of the taxa) and the dehydrogenase profile after insulin treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1027308223168
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Imprinting Effects of Proline Containing Dipeptides (Proline-Glycine, Proline-Leucine, Proline-Valine and Their Retro Variants) in Tetrahymena. Evolutionary Conclusions (1997)
    Springer
    Bioscience reports 17 (1997), S. 537-542 
    Details
    ISSN: 1573-4935
    Keywords: Tetrahymena ; evolution ; hormones ; peptides ; signal molecule ; imprinting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Proline-glycine, proline-leucine and proline-valine dipeptides and their retro variants were used in the experiments to study the effects of pretreatment (imprinting) in Tetrahymena, by investigating fluorescein isothiocyanate (FITC)-conjugated peptide binding. The protozoan organism could differentiate between the proline-dipeptides containing different partner amino-acids and between the dipeptides having the amino acids in reversed positions. The effect of imprinting was positive or negative and this was dependent on the type of the partner amino acid and on its position. Pro-Gly and Pro-Leu induced positive imprinting (elevated FITC-dipeptide binding) and Pro-Val induced negative imprinting (decrease of FITC-peptide binding). There was positive imprinting induction in two cases for the retro FITC-peptide and in one case for the FITC-conjugate of the imprinter peptide itself. The highest positive imprinting (almost 60% increase) was induced by Pro-Gly for FITC-Gly-Pro. Considering earlier—chemotaxis—experiments, the results of the present—binding—studies run parallel with the physiological effects. The experiments call attention to the sharp differentiating ability of small peptides at a unicellular level, that could have some role in the selection of molecules for hormone formation, during evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1027360207238
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Modification of Clay Forms by Tufted Capuchins (Cebus apella) (1997)
    Springer
    International journal of primatology 18 (1997), S. 455-467 
    Details
    ISSN: 1573-8604
    Keywords: Cebus ; Homo ; evolution ; Paleolithic art ; tool-use
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We examined modification of clay forms by tufted capuchins (Cebus apella) by presenting groups of subjects with clay, paint, stones, leaves, and sticks. In Experiment 1, 7 of 10 subjects reshaped portable forms with their hands and with stones, and decorated them with leaves and paint. In Experiment 2, 9 subjects marked clay slabs manually and with stick and stone tools. The manipulative propensities of Cebus can help us to understand psychological processes that underlie artistic expression in Homo and Pan.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026394618857
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    To mark the host or the patch: Decisions of a parasitoid searching for concealed host larvae (1997)
    Springer
    Evolutionary ecology 11 (1997), S. 145-168 
    Details
    ISSN: 1573-8477
    Keywords: evolution ; Halticoptera laevigata ; host-marking pheromone ; parasitoids ; patch mark ; Tephritidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We found evidence for patch marking in the parasitic wasp Halticoptera laevigata (Hymenoptera: Pteromalidae) foraging for concealed hosts. Wasps attack larvae of the fruit fly Myoleja lucida (Diptera: Tephritidae) in fruits of honeysuckle. A special feature of this host-parasitoid system is the limited food supply of a patch (i.e. a fruit of honeysuckle), which allows the successful development of only a single host fly larva. Females of the parasitoid H. laevigata were found to mark the host patch with a pheromone and to abandon the patch following oviposition into a single host larva. Field data revealed that eggs of the parasitoid were spread out evenly among infested patches, with several larvae of the host fly left unparasitized in those patches that contained more than one host. Since many parasitic insects mark the parasitized host after oviposition, we assumed host marking to be the ancestral character state and studied the patch-marking behaviour of H. laevigata as a derived character state as an alternative foraging strategy. We used stochastic dynamic modelling to investigate under what conditions mutant (patch) markers would be able to invade a population of normal (larval) markers. The models suggested that, under a variety of conditions, wasps marking the patch obtained higher fitness than wasps only marking the larva. Consequently, the results from our model predict the evolution of the patch-marking behaviour found in the empirical investigation. Finally, we discuss alternative pathways to the evolution of patch marking and point out under what circumstances the evolution of a patch-marking behaviour can generally be expected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018495731755
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Recombinant Factor VIII SQ- Inactivation Kinetics in Aqueous Solution and the Influence of Disaccharides and Sugar Alcohols (1997)
    Springer
    Pharmaceutical research 14 (1997), S. 1679-1684 
    Details
    ISSN: 1573-904X
    Keywords: solution ; protein stability ; factor VIII ; formulation ; kinetics ; DSC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. To investigate the influence of various nonreducing disaccharides and sugar alcohols on the inactivation kinetics of recombinant factor VIII SQ (r-VIII SQ) in aqueous solution not containing albumin as a stabiliser. Methods. The stability of r-VIII SQ was followed using measurement of activity (VIII: C) and HPLC gel filtration at different temperatures. The thermal stability was investigated using differential scanning calorimetry (DSC). Results. The decline in VIII:C followed pseudo-first order kinetics. However, the Arrhenius plot was not linear for formulations without carbohydrate, demonstrating a distinct, reproducible curvature. The reaction rate at 5°C was faster than expected from the Arrhenius kinetics. The energy of activation (Ea) for formulations without added carbohydrates, derived from the linear part of the Arrhenius plot, varied between 77 and 86 kJ/mole in the temperature range 20−37°C. The addition of 600 mg/ml sucrose increased the Ea to 104 kJ/mole. DSC measurements showed thatTm′ was 64.2 ± 0.2°C for r-VIII SQ without stabiliser. This value increased linearly with increasing concentrations of carbohydrate. This stabilising effect is most probably explained by the theory of preferential hydration. Conclusions. The inactivation kinetics of r-VIII SQ in aqueous solution without addition of carbohydrates followed pseudo-first order kinetics but the Arrhenius plot was nonlinear. Sucrose and sorbitol both had highly stabilising effects on r-VIII SQ at concentrations above 300 mg/ml. The preparation containing 600 mg/ml sucrose was stable for at least 12 months at 5°C and 6 months at 25°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012163309468
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Evolution of flower shape inVeroniceae (Scrophulariaceae) (1997)
    Springer
    Plant systematics and evolution 205 (1997), S. 1-25 
    Details
    ISSN: 1615-6110
    Keywords: Veroniceae ; Scrophulariaceae ; Flower shape ; flower development ; quantitative developmental character ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Floral evolution in the tribeVeroniceae was examined using phylogenetic analysis combining 24 adult morphology and chromosome number characters with 22 qualitative and quantitative floral development characters. Taxa sampled included nine species ofVeroniceae and as an outgroup one species each ofDigitaleae andVerbasceae. Veronica, Besseya, andSynthyris formed one clade, subtended byPseudolysimachion and then by theHebe group;Veronicastrum orWulfenia represent the basal-most branch of the tribe. The ancestral flowers of theVeroniceae may have been small with moderately short corolla tubes and lobes; long corolla tubes arose four times in the tribe and large corolla lobes twice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00982795
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Floral divergence and convergence in the genusPelargonium (Geraniaceae) in southern Africa: Ecological and evolutionary considerations (1997)
    Springer
    Plant systematics and evolution 208 (1997), S. 71-97 
    Details
    ISSN: 1615-6110
    Keywords: Geraniaceae ; Pelargonium ; Bees ; beeflies ; birds ; butterflies ; long-proboscid flies ; convergence ; evolution ; floral ecology ; pollination ; pollination guilds ; pollination syndromes ; Southern Africa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Based on field observations and a survey of the available literature, the functional and evolutionary significance of floral characters ofPelargonium is investigated in relation to a recent infrageneric re-classification. Most of the 208Pelargonium taxa (recognized as species, subspecies or varieties) involved show bee and long-proboscid hovering fly pollination syndromes (about 60% and 25%, respectively), only 7% of the taxa are pollinated by butterflies, some 2 to 4% by hawkmoths and presumably 1% by birds. The heterogeneity ofPelargonium in terms of structural blossom types and pollination syndromes indicates an independent and repeated evolution of convergent flower morphs in the genus and even in sections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00986083
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Hybridization and evolution inCardamine (Brassicaceae) at Urnerboden, Central Switzerland: Biosystematic and molecular evidence (1997)
    Springer
    Plant systematics and evolution 204 (1997), S. 233-256 
    Details
    ISSN: 1615-6110
    Keywords: Brassicaceae ; Cardamine amara ; C. ×insueta ; C. rivularis ; C. schulzii ; Hybridization ; evolution ; amphiploidy ; introgression ; cpDNA ; isozymes ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hybridization between two diploid (2n = 2x = 16) species ofBrassicaceae, Cardamine rivularis andC. amara, at Urnerboden, Central Switzerland, resulted in the rather unusual triploid hybridC. insueta (2n = 3x = 24), and later on in the amphiploidC. schulzii (2n = 6x = 48). The hybrid and the neopolyploid species colonized successfully some man-made biotopes. Plants ofC. insueta are mostly functional females with non-dehiscent anthers, but true hermaphrodite individuals with partly sterile pollen grains also occur within the population. Analyses of cpDNA and nuclear DNA permitted to establish the parentage of the hybrid: the maternal parent which contributed unreduced egg cells proved to beC. rivularis whereas the normally reduced pollen originated fromC. amara. The pronounced genetic variability inC. insueta revealed by isozyme and RAPD analyses, at variance with the polarized segregation, heterogamy and strong vegetative reproduction of the hybrid, is possibly influenced by recurrent formation ofC. insueta which party results from backcrosses betweenC. insueta andC. rivularis but may also proceed by other pathways. The amphiploidCardamine schulzii has normally developed anthers but its pollen is sometimes highly sterile. The surprisingly uniform genetic make-up of the new amphiploid species might be related to its possible monotopic origin and/or young phylogenetic age but should be further assessed. Site management seems to be very important to a further development of hybridogenous populations and their parent species. In conclusion, the evolution at Urnerboden is discussed in the context of the traditional concept of multiple plant origins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00989208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Kinetics of vesicle formation (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 303-306 
    Details
    ISSN: 1435-1536
    Keywords: Key words Vesicle ; self-assembly ; hydrotrope ; stopped-flow ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The kinetics of vesicle formation from a hydrotrope (sodium xylenesulfonate) solution of a surfactant (Laureth 4) is studied by the use of a stopped-flow apparatus combined with a dynamic light scattering device to determine vesicle size in the system. The hydrotrope system studied presents a system with a high surfactant solubilization combined with vesicle formation simply by dilution with water. The kinetic results show a single exponential decay time. The kinetic analysis indicates that the vesicles are formed from a molecular solution which resulted from the shear in the stopped-flow device and grow by monomeric association.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050086
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Kinetics of interaction of 3-aminopropyltriethoxysilane with silica gel using elemental analysis and 29Si NMR spectra (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 672-680 
    Details
    ISSN: 1435-1536
    Keywords: Key words 3-aminopropyltriethoxy silane ; silica gel ; interaction ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  Three silica gel sample systems, modified with 3-amino-propyltriethoxy silane (APTS), were prepared by sequentially sampling the reaction mixture at various time intervals. The concentrations of 3-aminopropylsilyl groups (APS) bound on the silica surface were determined by elemental analysis. For the same sample systems, 29Si NMR intensities of an (–O)4Si species belonging only to the silica gel particles and corrected by a cross-polarization correction factor were also measured. Both the APS-concentrations and the correc-ted 29Si NMR intensities depended upon reaction time, reflecting the rate of the APTS–silica gel reaction. Kinetic analysis of these data was made by use of the Gauss–Newton method, and the overall reaction was found to consist of three reaction processes (an initial fast reaction, a slower second reaction and a much slower third reaction). In particular, the conversion of (–O)3SiOH to (–O)4Si is predominant in the second reaction process and the pore size of a silica gel particle affects the reaction mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050134
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Fruit component analysis of south Pacific coconut palm populations (1997)
    Springer
    Genetic resources and crop evolution 44 (1997), S. 327-335 
    Details
    ISSN: 1573-5109
    Keywords: Cocos nucifera ; diversity ; evolution ; germplasm ; genetic resources ; morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The south Pacific region contains a large genetic resource for the genetic improvement of coconut palms (Cocos nucifera L.). A study of the diversity in the species was made during 1992/3 using fruit component analysis on a representative sample from 29 distinct south Pacific populations in order to characterise the germplasm present in the region. A large diversity in fruit morphology was found that ranged from populations exhibiting wild-type characters in central Pacific to populations displaying domesticated characteristics in Rennell Island, the Sikaiana Islands, the Marquesas Islands, and in Papua New Guinea. Many populations exhibited fruit characteristics intermediate between the two, which were thought to have arisen due to introgressive hybridisation between the wild and domesticated populations. Continuous variation in fruit morphology was found in these populations, and cluster analysis arbitrarily divided the continuum into discrete groups which were consistent with geographic affinities. Groups were defined in Melanesia, Western Polynesia and Eastern Polynesia. The continuum displayed clinal variation from populations with small fruit and low husk content in the west to large fruit and more husk in the east of the region. The wild and domesticated populations were found in disjunct pockets throughout the area, and did not form part of the clines. Most populations consisted of a wide range of fruit morphology, from individuals expressing wild-type characters to those with domestic-type characters. The occurrence of both wild and domesticated populations within the clinal variation indicates that further exploration should be made to determine the presence of other potentially useful populations. While this activity is proceeding, collection and conservation can proceed using the classification already defined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008652618350
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Phylogeny of the Acipenseriformes: cytogenetic and molecular approaches (1997)
    Springer
    Environmental biology of fishes 48 (1997), S. 127-155 
    Details
    ISSN: 1573-5133
    Keywords: sturgeon ; paddlefish ; Huso ; Acipenser ; Scaphirhynchus ; Pseudoscaphirhynchus ; Polyodon ; Psephurus ; karyotype ; chromosome ; macrochromosome ; microchromosome ; genome ; DNA content ; 18S rRNA gene ; cytochrome ; 12S mtrRNA gene ; 16s mtrRNA gene ; rate of molecular evolution ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The review of the data on karyology and DNA content in Acipenseriformes shows that both extant families, the Polyodontidae and Acipenseridae, originated from a tetraploid ancestor which probably had a karyotype consisting of 120 macro- and microchromosomes and DNA content of about 3.2–3.8 pg per nucleus. The tetraploidization of the presumed 60-chromosome ancestor seems to have occurred at an early time of evolution of the group. The divergence of the Acipenseridae into Scaphirhyninae and Acipenserinae occurred without polyploidization. Within the genus Acipenser, polyploidization was one of the main genetic mechanisms of speciation by which 8n and 16n-ploid species were formed. Individual gene trees constructed for sequenced partial fragments of the 18S rRNA (230 base pairs, bp), 12S rRNA (185 bp), 16S rRNA (316 bp), and cytochrome b (270 bp) genes of two Eurasian (A. baerii and A. ruthenus) and two American (A. transmontanus and A. medirostris) species of Acipenser, Huso dauricus, Pseudoscaphirhynchus kaufmanni, Scaphirhynchus albus, and Polyodon spathula showed a low level of resolution; the analysis of a combined set of data for the four genes, however, gave better resolution. Our phylogeny based on molecular analysis had two major departures from existing morphological hypotheses: Huso dauricus is a sister-species to Acipenser instead of being basal to all acipenseriforms, and Scaphirhynchus and Pseudoscaphirhynchus do not form a monophyletic group. The phylogenetic tree constructed for the cytochrome b gene fragments (with inclusion of 7 additional species of Acipenser) supported the conclusion that octoploid species appeared at least three times within Acipenser.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007366100353
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Biopolitics: the newest synthesis? (1997)
    Springer
    Genetica 99 (1997), S. 173-184 
    Details
    ISSN: 1573-6857
    Keywords: evolution ; genetics ; neurophysiology ; philosophy ; politics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract On first impression, the disciplines of genetics and political science would appear to be unrelated. And yet, commencing more than 30 years ago, the interdisciplinary field known as Biopolitics has now taken hold. This essay traces the central thrust of the biopolitical research agenda. It describes, analyzes, and assesses how political scientists have sought to show connections between our species' genetic constitution and our species' political behavior. Important bridges between the two are the neurophysiology of the human brain and the role of evolutionary theory in charting man's adaptational political profile. The parameters of the emerging biopolitical literature raise profound policy questions, some of which are also characterized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018381714851
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Evolutionary links between telomeres and transposable elements (1997)
    Springer
    Genetica 100 (1997), S. 73-84 
    Details
    ISSN: 1573-6857
    Keywords: evolution ; heterochromatin ; retrotransposable elements ; telomerase ; telomeres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transposable elements are abundant in the genomes of higher organisms but are usually thought to affect cells only incidentally, by transposing in or near a gene and influencing its expression. Telomeres of Drosophila chromosomes are maintained by two non-LTR retrotransposons, HeT-A and TART. These are the first transposable elements with identified roles in chromosome structure. We suggest that these elements may be evolutionarily related to telomerase; in both cases an enzyme extends the end of a chromosome by adding DNA copied from an RNA template. The evolution of transposable elements from chromosomal replication mechanisms may have occurred multiple times, although in other organisms the new products have not replaced the endogenous telomerase, as they have in Drosophila. This is somewhat reminiscent of the oncogenes that have arisen from cellular genes. Perhaps the viruses that carry oncogenes have also arisen from cellular genetic systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018352706024
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    The evolution of Ty1-copia group retrotransposons in eukaryote genomes (1997)
    Springer
    Genetica 100 (1997), S. 185-195 
    Details
    ISSN: 1573-6857
    Keywords: biodiversity ; copia ; evolution ; genome organization ; retrotransposon ; Ty element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Ty1-copia group of LTR retrotransposons has been studied extensively in yeast and Drosophila, the organisms in which they were first discovered, and more recently in higher plant and vertebrate species. Their properties, such as copy number, sequence homogeneity, transcriptional and transpositional activity vary greatly between these different hosts. We will try to resolve these apparent discrepancies between these properties, explain any fundamental differences in the biology of the Ty1- copia group between hosts, and propose a general model for LTR retrotransposon evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018385713293
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Bare-Id, a representative of a family of BARE-like elements of the barley genome (1997)
    Springer
    Genetica 100 (1997), S. 231-240 
    Details
    ISSN: 1573-6857
    Keywords: barley ; evolution ; Hordeum ; retrotransposon ; Ty1-copia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In our search for transposable elements in barley, Hordeum vulgare, we have isolated and cloned two BamHI-fragments of 4.7 and 4.2 kb in length containing very abundant DNA sequences. The 4.7 kb fragment is homologous to the extended region, including more than half of the 5′-LTR and some part of the coding domain of BARE-1, a member of copia-like retrotransposon family of barley. The 4.2 kb fragment, bearing homology to BARE-1 and the WIS-2 family isolated from wheat, is unique among studied retroelements of cereals because it consists of two inverted parts, each containing homology to the LTR and UTL of BARE-1. Functional motifs for reverse transcription, two TATA-boxes and two primer-binding sites, were found within the LTRs. The element contained within this fragment was generated by significant rearrangement of a BARE-like retrotransposon, which included inversion of the extended 5′-terminal region and deletion of the internal domain. Therefore this element is named BARE-ID (BARE-inverted, deleted). A family of BARE-like elements is amplified in the H. vulgare genome compared with wild barley species. The terminal inverted repeat of BARE-ID was used as a probe for examination of evolutionary diversity within genus Hordeum. Our data are basically in agreement with the modern classification system. However, they do not support the combination of H. vulgare and H. bulbosum into one group with the same type of genome. New data concerning the possible origin of the polyploid species, H. secalinum, confirm that retrotransposons are a useful tool for phylogenetic studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018350100089
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Biopolitics: the newest synthesis? (1997)
    Springer
    Genetica 99 (1997), S. 173-184 
    Details
    ISSN: 1573-6857
    Keywords: evolution ; genetics ; neurophysiology ; philosophy ; politics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract On first impression, the disciplines of genetics and political science would appear to be unrelated. And yet, commencing more than 30 years ago, the interdisciplinary field known as Biopolitics has now taken hold. This essay traces the central thrust of the biopolitical research agenda. It describes, analyzes, and assesses how political scientists have sought to show connections between our species' genetic constitution and our species' political behavior. Important bridges between the two are the neurophysiology of the human brain and the role of evolutionary theory in charting man's adaptational political profile. The parameters of the emerging biopolitical literature raise profound policy questions, some of which are also characterized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02259521
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Mapping chromosomal homology between humans and the black-handed spider monkey by fluorescence in situ hybridization (1997)
    Springer
    Chromosome research 5 (1997), S. 527-536 
    Details
    ISSN: 1573-6849
    Keywords: Ateles geoffroyi ; chromosome painting ; cytogenetics ; evolution ; phylogeny ; Platyrrhini ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We hybridized human chromosome-specific DNA probes to metaphases of the New World monkey Ateles geoffroyito map the chromosomal homology between these two species. In the haploid Ateles geoffroyi karyotype the total number of signals was 51 for the 22 human autosomal probes used. Compared with Old World monkeys, the number of translocations found in the black-handed spider monkey karyotype was quite striking. The majority of these translocations are apparently Robertsonian and no reciprocal translocations were revealed. Nine autosomal human chromosome probes (11, 13, 14, 17, 18, 19, 20, 21, 22) provided only two signals each per metaphase, but six of these were translocated to subregions of different spider monkey chromosomes. The other 13 autosomal human chromosome paints (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 16) provided fragmented signals. Three human probes (5, 8, 10) provided signals located on two pairs of spider monkey chromosomes. Four human paints (2, 3, 4, 12) provided hybridization signals on three pairs of chromosomes. Probes 6, 7, 15 provided six signals each on two pairs of chromosomes; probe 16 gave eight signals on two pairs of spider monkey chromosomes and probe 1 gave 12 signals on four pairs of chromosomes. The synteny between segments to human 18/8 appears to be an apomorphic ancestral condition for all New World monkeys. A synteny between regions homologous to human 16/10, 5/7 and 2/16 HSA is probably an apomorphic ancestral condition for all Cebidae. The syntenic association 3/15 and 4/1 is an apomorphic condition for the Atelinae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018489602312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Zoo-fluorescence in situ hybridization analysis of human and Indian muntjac karyotypes (Muntiacus muntjak vaginalis) reveals satellite DNA clusters at the margins of conserved syntenic segments (1997)
    Springer
    Chromosome research 5 (1997), S. 254-261 
    Details
    ISSN: 1573-6849
    Keywords: chromosome ; evolution ; comparative mapping ; Indian muntjac ; satellite DNA ; zoo-fluorescence in situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Zoo-fluorescence in situ hybridization (FISH) with human whole chromosome-specific paint probes revealed extensive homoeologies between Indian muntjac (2n=6, 7 female, male) and human karyotypes (2n=46). Forty-two conserved syntenic segments, corresponding to all human chromosomes except the Y chromosome, produced a near-complete coverage of the muntjac complement and revealed margins of interspecific segmental homoeology. To test the hypothesis that interstitial satellite DNA loci, illuminated by a Chinese muntjac C5-satellite probe in Indian muntjac chromosome arms, mark ancestral fusion points (Lin CC, Sasi R, Fan YS, Chen Z-Q (1991) New evidence for tandem chromosome fusions in the karyotypic evolution of the Asian muntjacs. Chromosoma 101: 19–24), we combined Zoo-FISH with C5 satellite mapping. Twenty-six interstitial satellite DNA loci were detected in the haploid Indian muntjac genome and were found to co-localize with the margins of conserved human/Indian muntjac syntenic segments. These results were confirmed by two-colour FISH and are in accordance with the tandem fusion hypothesis for Indian muntjac chromosomes. Furthermore, conserved syntenic segment combinations detected in pig, cattle and Indian muntjac Zoo-FISH maps reveal ancestral artiodactyl chromosomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:CHRO.0000032298.22346.46
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    The Ty1-copia group of retrotransposons in plants: genomic organisation, evolution, and use as molecular markers (1997)
    Springer
    Genetica 100 (1997), S. 205-217 
    Details
    ISSN: 1573-6857
    Keywords: Ty1-copia ; retrotransposons ; retroelements ; plants ; genomic organisation ; evolution ; molecular marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genomic organisation and diversity of the Ty1-copia group retrotransposons has been investigated in several crop plants and their relatives from both dicotyledonous and monocotyledonous families, including potato ( Solanum tuberosum), faba beans ( Vicia faba), Vicia melanops, Vicia sativa, barley ( Hordeum vulgare), rye ( Secale cereale), and onion ( Allium cepa). Extreme heterogeneity in the sequence of the Ty1-copia retrotransposons from all these plants was revealed following sequence analysis of reverse transcriptase fragments. The estimated copy numbers of the Ty1-copia group retrotransposons for the genomes of S. tuberosum, L. esculentum, A. cepa, S. cereale, and V. faba is highly variable, ranging from a few hundred to approximately a million copies per genome. In situ hybridisation data from metaphase and prophase chromosomes of V. faba, S. cereale, and H. vulgare suggest that retrotransposon sequences are dispersed throughout the euchromatic regions of the genome but are almost undetectable in most heterochromatic regions. In contrast, similar data from metaphase chromosomes of A. cepa suggests that although retrotransposon sequences are dispersed throughout the euchromatic regions of the genome, they are predominantly concentrated in the terminal heterochromatin. These results are discussed in the context of the role played by the Ty1-copia group retrotransposons in the evolution of the plant genome. Lastly, the application of retrotransposon sequences as genetic markers for mapping genomes and for studying genetic biodiversity in plants is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018393931948
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Old age, multiple formations or genetic plasticity? Clonal diversity in the uniparental Caucasian rock lizard, Lacerta dahli (1997)
    Springer
    Genetica 101 (1997), S. 125-130 
    Details
    ISSN: 1573-6857
    Keywords: evolution ; Lacertadahli ; parthenogenesis ; uniparentality ; unisexuality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Allozyme variation at 35 gene loci is investigated in 161 specimens of the uniparental Caucasian lizard Lacerta dahli from several locations in Armenia and Georgia. All individuals are heterozygotic at 12 loci, and homozygotic at 21 loci. Variation at two loci results in five uniparental clones. One clone is widespread whereas four are geographically restricted and are represented by only one or two individuals. Because successful formation of uniparental clones is rare, and because the biparental species forming them are now allopatric, the most probable explanation for the origin of the observed clonal diversity is either mutation or recombination within the common clone. The rare clones have lower levels of enzyme activity at four loci, suggesting that these organisms may be genetically deficient. Although the evidence points to change in a pre-existing clone, the possibility of multiple origins cannot be ruled out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018392603062
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    On the origin of photosynthesis as inferred from sequence analysis (1997)
    Springer
    Photosynthesis research 51 (1997), S. 27-42 
    Details
    ISSN: 1573-5079
    Keywords: Photosystem I ; Photosystem II ; photosynthetic reaction center ; bacteriorhodopsin ; evolution ; UV-protection ; t Rhodopseudomonasviridis ; t Heliobacillus mobilis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sequence alignments between membrane-spanning segments of pheophytin-quinone-type photosynthetic reaction centers, FeS-type photosynthetic reaction centers, core chlorophyll-proteins of PS II, chlorophyll t a/t b-containing antenna proteins of plants and light-harvesting complexes of purple bacteria led us to postulate a large common ancestral pigment-carrying protein with more than 10 membrane spans. Its original function as a UV-protector of the primordial cell is discussed. It is conceivable that a purely dissipative photochemistry started still in the context of the UV-protection. We suggest that mutations causing the t loss of certain porphyrin-type pigments led to the acquisition of redox cofactors and paved the way for a gradual transition from dissipative to productive photochemistry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005726809084
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Thermal Stability and Decomposition Kinetics of the β-CD Cinnamic Aldehyde Inclusion Complex (1997)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 28 (1997), S. 95-103 
    Details
    ISSN: 1573-1111
    Keywords: Inclusion complex ; β-cyclodextrin ; thermal analysis ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stability of the β-CD cinnamic aldehyde inclusion complex wasinvestigated by TG and DSC. The weight loss takes place in three stages:dehydration occurs at 50–120 °C; the dissociationof β-CD⋅C9H8O occurs at 200–260 °C;and the decomposition of β-CD begins at 280 °C. Thekinetics of the dissociation of cinnamic aldehyde from the β-CD cavitywere studied by means of thermogravimetry both at constant temperatureand linear increasing temperature. The results show that the dissociationof β-CD⋅C9H8O is dominated by a one-dimensional diffusionprocess. The activation energy, E, is 160 kJ⋅mol-1. Thepre-exponential factor A is 5.8 × 1014 min-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007991708832
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Economics and Biological Evolution (1997)
    Springer
    Environmental and resource economics 9 (1997), S. 429-449 
    Details
    ISSN: 1573-1502
    Keywords: evolution ; economics ; pesticide resistance ; antibiotic resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Economics
    Notes: Abstract The employment of insecticides raises the relative fitness of resistant insects; the use of antibiotics applies selection pressure in favour of resistant strains of bacteria; lower limits on fish net mesh size raises the advantages of smaller adults. These are some of the many examples of the unintended impact of human activity upon biological evolution. Often this evolution has economic significance, as it does in the examples quoted. This paper examines some of the principles involved and provides a preliminary analysis of the extent to which the economically optimal inducement of evolution differs from that arising when changes in selection pressures are not anticipated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026411423178
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Inhibition of Nitrosomonas europaea by Monoterpenes from Coastal Redwood (Sequoia sempervirens) in Whole-Cell Studies (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 2583-2598 
    Details
    ISSN: 1573-1561
    Keywords: Nitrosomonas europaea ; nitrification ; inhibition ; kinetics ; monoterpenes ; Sequoia sempervirens ; conifers ; nitrogen cycling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Inhibition by allelochemicals, including monoterpenes, has been suggested as a factor in the extremely low nitrification rates observed in coastal redwood forests. Similarities between the molecular structure of known nitrification inhibitors and some conifer monoterpenes have been suggested as one reason for the inhibition of autotrophic nitrifiers by conifer monoterpenes. The effect of monolerpenes on nitrification rate and growth of Nitrosomonas europaea was examined in whole-cell pure culture experiments using the five most abundant monoterpenes in coastal redwood needles. These are (in order of decreasing concentration in the needles) limonene, α-pinenc, sabinene, myrcene, and γ-terpinene. Four of the five compounds significantly inhibited growth of N. europaea in batch culture experiments. Short-term kinetic studies of the two most inhibitory monoterpenes, limonene and α-pinene, were performed on whole cells to evaluate the mode of interaction between these chemicals and nitrification rates. Inhibition constants (K i) of limonene (38 μM) and α-pinene (95 μM) were determined. Lineweaver-Burk plots of nitrification in the presence of monoterpenes appear to fit a noncompetitive inhibition model; however, the mechanisms of inhibition may be more complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:JOEC.0000006668.48855.b7
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Cuticular Hydrocarbons as Chemotaxonomic Characters of Pine Engraver Beetles (Ips spp.) in the grandicollis Subgeneric Group (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1053-1099 
    Details
    ISSN: 1573-1561
    Keywords: Scolytidae ; Ips ; Orthotomicus ; Pinus ; evolution ; cuticular hydrocarbons ; chemotaxonomy ; methyl-branched hydrocarbons ; mass spectrometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Cuticular hydrocarbons were extracted, identified, and evaluated as chemotaxonomic characters from all species of adult Ips pine engraver beetles in the grandicollis subgeneric group. The grandicollis group consists of Ips grandicollis (Eichhoff), I. cribricollis (Eichhoff), I. lecontei Swaine, I. montanus (Eichhoff), I. paraconfusus Lanier, I. confusus (LeConte), and I. hoppingi Lanier. In order to provide outgroups for a phylogenetic analysis, cuticular hydrocarbons were also analyzed from Orthotomicus caelatus (Eichhoff), I. latidens (LeConte) (latidens subgeneric group), and I. pini (Say) (pini subgeneric group). Two hundred forty-eight hydrocarbon components were identified by gas chromatography–mass spectrometry. The members of the grandicollis group provided 206 of these compounds. The components represented eight classes: n-alkanes, alkenes, alkadienes, terminally branched methylalkanes, internally branched methylalkanes, dimethylalkanes, trimethylalkanes, and tetramethylalkanes. Different populations of O. caelatus, I. grandicollis, I. lecontei, I. montanus, I. paraconfusus, I. confusus, and I. hoppingi provided no evidence for interpopulational variation in cuticular hydrocarbons. Single populations only were analyzed for I. latidens, I. pini, and I. cribricollis. Sexual dimorphism in cuticular hydrocarbons occurred only in I. lecontei where females produced eight unique components with a pentatriacontane parent chain. Several phylogenetic analyses based on hydrocarbon phenotypes agreed in general with the established morphologically based system of relatedness and with published phylogenies reconstructed from protein and nucleic acid characters. Nearly all hydrocarbon analyses suggested a close relationship between I. grandicollis and I. cribricollis; between I. lecontei and I. montanus; and among the sibling species I. paraconfusus, I. confusus, and I. hoppingi. The presence or absence of specific n-alkanes (n-docosane, n-triacontane); certain dimethylalkanes (terminally branched with octacosane and triacontane parent chains and internally branched with heptacosane, hentriacontane, and docotriacontane parent chains); and 3,7,11-; 3,7,15-trimethylheptacosane permit facile discrimination of I. paraconfusus, I. confusus, and I. hoppingi. These three sibling species are difficult to resolve by external morphology. These data support the species status of I. hoppingi rather than it being considered a host race of the I. confusus complex. They also support the species status of I. cribricollis rather than it being considered part of I. grandicollis. In contrast to other published phylogenies reconstructed from molecular data, phylogenies reconstructed from cuticular hydrocarbons repeatedly place I. lecontei as an integral part of the grandicollis subgeneric group. Thus, cuticular hydrocarbon and pheromone alcohol composition of I. lecontei support its inclusion in the grandicollis subgeneric group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:JOEC.0000006388.92425.ec
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    The effect of various host species on the feeding performance of immature stages of the tick Hyalomma truncatum (Acari: Ixodidae) (1997)
    Springer
    Experimental and applied acarology 21 (1997), S. 551-559 
    Details
    ISSN: 1572-9702
    Keywords: Ticks ; Hyalomma truncatum ; feeding performance ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to determine the effect of various hosts on the feeding performance of the tick Hyalomma truncatum, we used three mammalian species as hosts. Larvae and nymphs of H. truncatum were fed, under controlled laboratory conditions, on gerbils, guinea-pigs and rabbits. The larvae fed for 4.3±1.4 days on gerbils, 5.6±1.3 days on guinea-pigs and 4.7±1.2 days on rabbits. The mean weights of the larvae which fed on the rabbits, guinea-pigs and gerbils were 0.58± 0.09, 0.46±0.04 and 0.45±0.04 mg. respectively. The feeding periods of the nymphs on gerbils, guinea-pigs and rabbits were 7.9±1.3, 8.6±1.3 and 9.6±2.2 days respectively. The mean weights of the nymphs which fed on the gerbils, guinea-pigs and rabbits were 22.5±2.8, 19.7±1.3 and 15.8±1.4 mg, respectively. Hyalomma truncatum demonstrated a life cycle of a three-host tick on gerbils and guinea-pigs and of a two-host tick on rabbits. The evolutionary advantage of a two-host cycle over a three-host cycle in metastriate ticks is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018444315709
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Bacterial evolution and silicon (1997)
    Springer
    Antonie van Leeuwenhoek 71 (1997), S. 271-276 
    Details
    ISSN: 1572-9699
    Keywords: bacteria ; evolution ; molecular ; silicon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This review examines the possible role of silicon in molecular evolution. It is possible silicon participated in early molecular evolution by providing a stable mineral surface or gel structure where the assembly and replication of primitive genetic information occurred. However, as molecular evolution proceeded, silicon was not required in the evolution of C-based organisms. Silicon can be accumulated by diatoms and other living organisms such as silicoflagellates, some xanthophytes, radiolarians and actinopods and plants such as grasses, ferns, horseradish, some trees and flowers, some sponges, insects and invertebrates and bacteria and fungi. Silicon also has a role in synthesis of DNA, DNA polymerase and thymidylate kinase activity in diatoms. It is not unreasonable to examine the role of silicon in early molecular evolution as it may have been part of a micro-environment in which assembly of genetic information occurred.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000183732698
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Chloroplast DNA diversity in brinjal eggplant (Solanum melongena L.) and related species (1997)
    Springer
    Euphytica 97 (1997), S. 295-301 
    Details
    ISSN: 1573-5060
    Keywords: chloroplast DNA ; brinjal eggplant ; Solanum incanum ; Solanum melongena ; Solanum aethiopicum ; systematics ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Chloroplast DNA (cpDNA) samples of brinjal eggplant (S. melongena) and representative related species including S. incanum sensu lato (or S. campylacanthum sensu stricto), S. lichtensteinii, S. marginatum, S. macrocarpon, S. anguivi and S. aethiopicum and also S. nigrum as an outgroup taxon, were digested by 14 restriction enzymes and analyzed by using electrophoresis and a cpDNA probe. All the species used here were clearly separated in the cpDNA analysis, except the pair S. anguivi and S. aethiopicum. From the dendrogram constructed by the unweighted pair-group method, it is suggested that S. incanum is the closest to S. melongena and the next closest species is S. macrocarpon followed by S. aethiopicum (and S. anguivi), S. lichtensteinii, S. marginatum and finally the outgroup taxon S. nigrum. The tree derived by the neighbour-joining method suggests phyletic relationships that agree with those indicated by crossability and seed coat anatomy, but conflict with conventional classifications based on morphology. In particular, members of sections Oliganthes and Melongena are not separated and no cpDNA variation was found within either of the morphologically diverse cultigens, S. aethiopicum and S. melongena. Paradoxically, the morphologically similar species S. incanum, S. lichtensteinii and S. marginatum have diverged greatly in their cpDNA. The significance of these results is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003000612441
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    The impact of molecular systematics on hypotheses for the evolution of root nodule symbioses and implications for expanding symbioses to new host plant genera (1997)
    Springer
    Plant and soil 194 (1997), S. 185-192 
    Details
    ISSN: 1573-5036
    Keywords: actinorhizal plants ; evolution ; nitrogen fixation ; phylogenetic hypotheses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Current taxonomic schemes place plants that can participate in root nodule symbioses among disparate groups of angiosperms. According to the classification scheme of Cronquist (1981) which is based primarily on the analysis of morphological characters, host plants of rhizobial symbionts are placed in subclasses Rosidae and Hamamelidae, and those of Frankia are distributed among subclasses Rosidae, Hamamelidae, Magnoliidae and Dilleniidae. This broad phylogenetic distribution of nodulated plants has engendered the notion that nitrogen fixing endosymbionts, particularly those of actinorhizal plants, can interact with a very broad range of unrelated host plant genotypes. New angiosperm phylogenies based on DNA sequence comparisons reveal a markedly different relationship among nodulated plants and indicate that they form a more coherent group than has previously been thought (Chase et al., 1993; Swensen et al., 1994; Soltis et al., 1995). Molecular data support a single origin of the predisposition for root nodule symbiosis (Soltis et al., 1995) and at the same time support the occurrence of multiple origins of symbiosis within this group (Doyle, 1994; Swensen, 1996; Swensen and Mullin, In Press).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004240004063
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Biological nitrogen fixation in non-leguminous field crops: Facilitating the evolution of an effective association between Azospirillum and wheat (1997)
    Springer
    Plant and soil 194 (1997), S. 65-79 
    Details
    ISSN: 1573-5036
    Keywords: Azospirillum brasilense ; evolution ; nifA-lacZ ; nifH-lacZ ; nitrogen fixation ; para-nodules ; symbiosis ; wheat ; 2 ; 4-D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Recent advances towards achieving significant nitrogen fixation by diazotrophs in symbioses with cereals are reviewed, referring to the literature on the evolution of effective symbioses involving rhizobia and Frankia as microsymbionts. Data indicating that strains of Acetobacter and Herbaspirillum colonizing specific cultivars of sugarcane as endophytes make a significant contribution to the nitrogen economy of this crop improves the prospects that similar associative systems may be developed for other gramineous species such as rice and wheat. By contrast, the transfer of nodulation genes similar to those in legumes or Parasponia to achieve nodulation in crops like rice and wheat is considered to be a more ambitious and distant goal. Progress in developing an effective associative system for cereals has been materially assisted by the development of genetic tools based on the application of lacZ and gusA fusions with the promoters of genes associated with nitrogen fixation. These reporter genes have provided clear evidence that ‘crack-entry’ at the points of emergence of lateral roots or of 2,4-D induced para-nodules is the most significant route of endophytic colonization. Furthermore, using the laboratory model of para-nodulated wheat, there is now evidence that the ability of azospirilla and other nitrogen fixing bacteria to colonize extensively as endophytes can be genetically controlled. The most successful strain of Azospirillum brasilense (Sp7-S) for endophytic colonization and nitrogen fixation in wheat seedlings is a mutant with reduced exopolysaccharide production. Most other strains of azospirilla do not colonize as endophytes and it is concluded that though these are poorly adapted to providing nitrogen for the host plant, they are well adapted for survival and persistence in soil. A research program combining the study of endophytic colonization by azospirilla with an examination of the factors controlling the effectiveness of association (oxygen tolerance and nitrogen transfer) is now being pursued. It is proposed that a process of facilitated evolution of para-nodulated wheat involving the stepwise genetic improvement of both the prospective microsymbionts and the cereal host will eventually lead to effective nitrogen-fixing associations. In the attempt to achieve this goal, continued study of the endophytes occurring naturally in sugar cane and other grasses (e.g. Azoarcus sp.) should be of assistance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004260222528
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Activation and deactivation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in three marine microalgae (1997)
    Springer
    Photosynthesis research 51 (1997), S. 93-106 
    Details
    ISSN: 1573-5079
    Keywords: activation ; deactivation ; induction ; irradiance ; kinetics ; photosynthesis ; phytoplankton ; Rubisco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was examined in three marine microalgae: the chlorophyte t Dunaliella tertiolecta and the chromophytes t Pavlova lutheri and t Thalassiosira pseudonana. The three species differed in the sensitivity of Rubisco activity in crude extracts to magnesium ion concentration, the presence of protease inhibitors, the duration of the incubation on activity, and the potential for full activation of Rubisco with 20 mM magnesium chloride and 20 mM bicarbonate t in vitro. t D. tertiolecta had responses that were similar to those described in vascular plants: regulation of initial activity on a gradient of irradiances; maximum initial activities that were 80– 90% of light-saturated photosynthesis; total activities that exceeded light-saturated photosynthesis by 30–100%; and deactivation of Rubisco in darkness. Both initial and total activity declined in darkness and increased on a return to growth irradiance. First-order time constants were about 9 min for deactivation and 3 min for reactivation of initial activity. The decline in total activity after a transition into darkness could not be reversed t in vitro but could be reversed by exposing t D. tertiolecta to light, a characteristic of regulation by CA1P. The responses of t T. pseudonana were qualitatively similar, except that recovery of initial activity was low and could only account for 30–40% of light-saturated photosynthesis. Rubisco from t T. pseudonana exposed to low irradiance could be activated t in vitro but at growth irradiance and higher, total activity was lower than initial activity. The time constants for deactivation and reactivation of initial activity after reciprocal switches between growth irradiance and darkness were 12–18 min and 3 min in t T. pseudonana. t P. lutheri showed no regulation of Rubisco activity in response to changes in irradiance or light-dark transitions. This may have been an artifact of the conditions chosen to measure activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005755621305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Mutation in a novel gene required for photomixotrophic growth leads to enhanced photoautotrophic growth of Synechocystis sp. PCC 6803 (1997)
    Springer
    Photosynthesis research 53 (1997), S. 243-252 
    Details
    ISSN: 1573-5079
    Keywords: cyanobacteria ; evolution ; glucose-sensitivity ; photoacclimation ; photosynthesis ; polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the glucose-tolerant strain of Synechocystis sp. PCC 6803, we found two types of cells with distinct growth properties. Under photoautotrophic conditions at any light intensity, one type gave larger colonies (designated WL) than the other (designated WS). Notably, the WL cells produced much larger colonies than the WS cells at higher light intensity. In contrast, growth of the WL cells was severely suppressed under mixotrophic conditions with glucose and light, while the WS cells grew normally. A gene which could complement the WL phenotype was obtained from a wild-type genomic library. The gene, designated pmgA, coded for a 23 kDa polypeptide of 204 amino acid residues with no apparent homology to known genes. In the WL genome, the base substitution of T for C at position 193 of pmgA caused replacement of Leu with Phe at position 65 of the product. The phenotype of pmgA disruption mutants was similar to that of the WL cells, indicating that the WS cells expressed a functional pmgA product. By direct sequencing of polymerase chain reaction-amplified pmgA from genomic DNA, it was revealed as an example of microevolution that WL had expelled WS from the photoautotrophic culture of wild-type in our laboratory for a year or so. Mixed culture in liquid also demonstrated that the WL cells increased gradually under photoautotrophic conditions, while they decreased rapidly under photomixotrophic conditions. These results suggest that pmgA product is essential for photomixotrophic growth, whereas it represses photoautotrophic growth. To our knowledge, the WL cells and pmgA-disrupted mutants are the first in cyanobacteria, which shows much improved photosynthetic growth than wild-type especially at high light intensity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005879905365
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    The role of marine biota in the evolution of terrestrial biota: Gases and genes (1997)
    Springer
    Biogeochemistry 39 (1997), S. 139-164 
    Details
    ISSN: 1573-515X
    Keywords: atmospheric composition ; elemental composition ; evolution ; marine biota ; soils ; terrestrial biota
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract There is greater biodiversity (in the senseof genetic distance among higher taxa) ofextant marine than of terrestrialO2-evolvers. In addition tocontributing the genes from one group ofalgae (Class Charophyceae, DivisionChlorophyta) to produce by evolution thedominant terrestrial plants (Embryophyta),the early marine O2-evolvers greatlymodified the atmosphere and hence the landsurface when the early terrestrialO2-evolvers grew. The earliestterrestrial phototrophs (from geochemicalevidence) occurred 1.2 Ga ago, over 0.7 Gabefore the Embryophyta evolved, but wellafter the earliest marine (cyanobacterial)O2 evolvers (3.45 Ga) and marineeukaryotic O2 evolvers (2.1 Ga). Evenby the time of evolution of the earliestterrestrial O2-evolvers the marineO2-evolvers had modified the atmosphereand land environment in at least thefollowing five ways. Once photosyntheticO2 paralleling organic C burial hadsatisfied marine (Fe2+, S2-reductants, atmospheric O2 built (1) upto a considerable fraction of the extantvalue (although some was consumed inoxidising terrestrial exposed Fe2+ and(2) provided stratospheric O3 and thusa UV-screen. (3) CO2 drawdown to∼20-30times the extant level is attributableto net production, and burial, of organic Cin the oceans (plus other geologicalprocesses). Furthermore, (4) theirproduction of volatile organic S compoundscould have helped to supply S to inland sitesbut also (5) delivered Cl and Br to thestratosphere thus lowering the O3 leveland the extent of UV screening.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005855528289
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Independent amplification of two classes of Tourists in some Oryza species (1997)
    Springer
    Genetica 101 (1997), S. 145-152 
    Details
    ISSN: 1573-6857
    Keywords: evolution ; Oryza ; Tourist ; transposable element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transposable elements similar to Tourist elements from maize were isolated from the rice genome. The elements were about 300 bp, exhibited short terminal inverted repeats (TIR), and appeared to show preferential insertion at TAA sites. Some rice Tourist elements seem to have recently transposed. Based on the sequences of cloned elements, two classes of rice Tourist elements have been identified. Members of these two classes apparently amplified independently at different times in the past.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018328423736
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Comparison of amitriptyline metabolism in hepatocytes from streptozocin-induced diabetic rats and from non-diabetic rats (1997)
    Springer
    Cell biology and toxicology 13 (1997), S. 131-137 
    Details
    ISSN: 1573-6822
    Keywords: diabetes ; rat ; cell culture ; antidepressant ; kinetics ; biotransformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Biotransformation of amitriptyline (AMI) was studied at different intervals in freshly isolated hepatocytes from healthy or streptozocin-induced diabetic rats in order to investigate the influence of the diabetic state. Levels of free and conjugated AMI, demethylated and hydroxylated metabolites, were assessed by HPLC analysis. In hepatocytes isolated from diabetic rats, AMI was less completely metabolized and the demethylation reaction became more important than in non-diabetic rat hepatocytes. Although the proportions of hydroxylated metabolites decreased in diabetic rats, it always remained predominant. Furthermore, glucuronidation of metabolites was greater, especially for (Z)-10-hydroxynortriptyline in diabetic animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:CBTO.0000010398.63757.4c
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...