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  • Electron microscopy  (1,196)
  • evolution  (693)
  • 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
  • Bacteria
  • Springer  (2,053)
  • Lagos (Nigeria)  (6)
  • Istituto Nazionale di Geofisica e Vulcanologia  (5)
  • American Chemical Society
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  • 1
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    Springer Nature | Springer
    Publication Date: 2024-04-05
    Description: This open access book offers a comprehensive overview of the role and potential of microorganisms in the degradation and preservation of cultural materials (e.g. stone, metals, graphic documents, textiles, paintings, glass, etc.). Microorganisms are a major cause of deterioration in cultural artefacts, both in the case of outdoor monuments and archaeological finds. This book covers the microorganisms involved in biodeterioration and control methods used to reduce their impact on cultural artefacts. Additionally, the reader will learn more about how microorganisms can be used for the preservation and protection of cultural artefacts through bio-based and eco-friendly materials. New avenues for developing methods and materials for the conservation of cultural artefacts are discussed, together with concrete advances in terms of sustainability, effectiveness and toxicity, making the book essential reading for anyone interested in microbiology and the preservation of cultural heritage.
    Keywords: Microbiology ; Cultural Heritage ; Microbial Ecology ; Microbial Genetics and Genomics ; Enzymology ; Applied Microbiology ; Microbial Genetics ; Industrial Microbiology ; Open Access ; Restoration ; Conservation ; Biodeterioration ; Bioweathering ; Bioremediation ; Biocleaning ; Biotechnology ; Green Chemistry ; Fungi ; Bacteria ; Artwork ; Antimicrobial protection ; Biocides ; Microbiology (non-medical) ; Cultural studies ; Social & cultural history ; Ecological science, the Biosphere ; Genetics (non-medical) ; Biochemistry ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSG Microbiology (non-medical) ; thema EDItEUR::J Society and Social Sciences::JB Society and culture: general::JBC Cultural and media studies::JBCC Cultural studies ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSA Life sciences: general issues::PSAF Ecological science, the Biosphere ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSB Biochemistry
    Language: English
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  • 2
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    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24208 | 19325 | 2018-05-19 06:39:34 | 24208 | Fisheries Society of Nigeria
    Publication Date: 2021-07-15
    Description: The microbial load of four different fish species from five different market locations in Ibadan metropolis were determined using standard microbiological procedures. The bacteria count of fish sampled from Ojo market was the highest while the bacteria count of the fish sample from Bodija market was the lowest. There was no significant difference (p〈0.05) in the microbial load of the fish sampled from various market locations in Ibadan metropolis. Similarly, there was no significant difference (p〉0.05) in the microbial load on various fish species sold in Ibadan metropolis. The isolated bacteria from the study were: E. coli, Salmonella spp, Klebsiella spp, Staphylococcus aureus, Aerosomonas spp, Pseudomonas spp, Vibrio spp, Serratia spp, Chromobacterium spp, Enterobacteria spp and Shigella spp. The fungi count of fish sampled from Omi markets was the highest while the fungi count of the fish sampled from Ojo market was the lowest. The following fungi were however isolated from the study: Aspergillus flavus, Penicillium spp, Fusarium oxysporum, Trrichoderma spp and Ceotrichium albidium. The study shows that reheating may be necessary to destroy or inactivate micro-organisms in smoked fish before consumption.
    Description: Includes: 2 tables and 2 figures.;Also includes: 17 refernces.
    Keywords: Fisheries ; Nigeria ; Ibadan ; Bacteria ; Fungi ; Market ; Fish species ; freshwater environment ; Microbial contamination ; Microorganisms ; Bacteria ; Freshwater fish ; Cured products ; Sample contamination ; Fungi ; Public health ; Quality assurance ; Disinfection
    Repository Name: AquaDocs
    Type: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 223-227
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  • 3
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    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24166 | 19325 | 2018-05-13 18:40:22 | 24166 | Fisheries Society of Nigeria
    Publication Date: 2021-07-15
    Description: Probiotics are a promising feed additive to stimulate animal growth and secure a low disease response in aquaculture industry where there are high stocking densities in shrimp and fish production. Fermented locust beans (Parkia biglobosa) are known to be rich in protein and used as food condiment. Probiotic bacteria were isolated from this locally available food material. Culture and characterizations of isolates were carried out. Sugar fermentation patterns were determined by using an API 50 CHL system and incubation were performed anaerobically at 37~'C. MRS broth culture grown at 37~'C overnight was added to 9ml of MRS Agar and the bacteria were incubated at 37~'C for 24 and 48 hrs. Discrete and single colony of lactobacillus was isolated using colony morphology and biochemical tests. The most significant viable taxa isolated was Lactobacillus fermentum at a pH range of (3.0-8.0), while the least viable taxa isolated was Leuconostoc mesenteroides ssp. Microscopically they were Grampositive, rod shaped, non- motile, catalase negative and absence of Endospore.
    Description: Includes: 2 tables and 2 plates.;Also includes: 15 references.
    Keywords: Aquaculture ; Nigeria ; Lagos ; Locust bean ; Probiotics ; Lactobacillus ; Probiotics ; freshwater environment ; Feed ; Additives ; Aquaculture ; Microorganisms ; Bacteria ; Disease resistance ; Fermented products ; Fish culture ; Shrimp culture
    Repository Name: AquaDocs
    Type: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 60-63
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  • 4
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    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24224 | 19325 | 2018-05-19 07:11:26 | 24224 | Fisheries Society of Nigeria
    Publication Date: 2021-07-15
    Description: Jabi Lake is a natural water body in Abuja Federal Capital Territory (FCT). It was expanded for commercial fishing following relocation of Nigeria's headquarters to Abuja in 1993. Quantitative analysis of microbiological status of water and fish from the Lake was carried out. Samples were collected from the dam site, open water, middle lake and inlet. Result reveal that total coliform count which are indicators of pollution are high (2.0 x 103 cfu/ml, 1.1 x 103 cfu/ml, 1.0 x 103 cfu/ml and 1.1 x 103 cfu/ml for dam site, open water, middle lake, and inlet respectively). Total viable count too is high (9.2 x 103 cfu/ml, 4.9 x 103 cfu/ml, 4.6 x 103 cfu/ml and 4.9 x 103 cfu/ml for dam site, open water, middle lake and inlet respectively). There are no coliform bacteria in the muscle of the fish. High bacterial load is an indication of biological pollution and these calls for restraint on the side of those who are using the lake as site for refuse dump.
    Description: Includes: 10 references.
    Keywords: Fisheries ; Pollution ; Nigeria ; Jabi Lake ; Jabi lake ; Water ; Fish ; Bacteria ; freshwater environment ; Microbiology ; Fish ; Pollution ; Water pollution ; Lake fisheries ; Fishery surveys ; Bacteria ; Baseline studies ; Water sampling ; Microbial contamination ; Muscles ; Freshwater fish ; Pollution surveys ; Water analysis ; Freshwater pollution
    Repository Name: AquaDocs
    Type: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 284-286
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  • 5
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    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24185 | 19325 | 2018-05-16 14:41:02 | 24185 | Fisheries Society of Nigeria
    Publication Date: 2021-07-15
    Description: Bacteria has been implicated in food poisoning, and smoked fish is not an exception.Generally, fish is highly susceptible to spoilage; therefore this study evaluated the bacteria load in smoked fish from three major locations in Shiroro area of Niger State namely; Gwada, Kuta and Zumba.The smoked fish samples collected from these locations were smeared at both the gills and head regions of the fishes. The bacteria samples identified were Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermis, Pseudomonas aeruginosa, and Samonella typhi, which were common to all the three locations sampled, while only Streptococcus feacaliswas only was found to be present in both Kuta and Zumba location.The frequency of occurrence of these 68 bacteria samples isolated ranges from 8 - 20%, with Bacillius subtilis having the highest occurrence and Pseudomonas aeruginosa have the least occurrence. Out of the total 68 samples, 14 skin samples (20.6%) and 5 gills samples (7.4%) exceeded the acceptable limits of total mesophilic aerobic counts which were 10〈sup〉6〈/sup〉 - 10〈sup〉7〈/sup〉 cfu/g. In the case of total coliform counts, 12 skin samples (17.6%) and 7 gills samples (10.3%) exceeded the acceptable limit which is 4.0 x 102, while in the case of Staphylococcus aureus, 4 skin samples (5.9%) and 2 gills samples (2.9%) exceeded the acceptable limit which is 103 cfu/g. Similarly 3 skin samples (4.4%) and 1 gill sample (1.5%) exceeded the acceptable limit of Salmonella typhi which is 104 cfu/g.
    Description: Includes: 4 tables.;Also includes: 21 references.
    Keywords: Fisheries ; Health ; Escherichia coli ; Bacillus subtilis ; Staphylococcus aureus ; Staphylococcus epidermis ; Pseeudomonas aeruginosa ; Nigeria ; Shiroro L. ; Bacteria ; Smoked (Clarias spp) fish ; Location and recommended values ; brackishwater environment ; freshwater environment ; marine environment ; Bacteria ; Food poisoning ; Cured products ; Fish ; Fish spoilage ; Acceptability ; Lake fisheries ; Gills ; Brain ; Evaluation
    Repository Name: AquaDocs
    Type: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 140-144
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  • 6
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    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24222 | 19325 | 2018-05-19 07:06:04 | 24222 | Fisheries Society of Nigeria
    Publication Date: 2021-07-15
    Description: A total of 2,800 tilapia (Oreochromis niloticus) were stocked in seven duplicates 5 by 4 m2 earthen ponds in NIFFR Integrated Farm, New-Bussa, Niger-State. Raw and sterilized poultry manure of 0.13 to 0.52 kg/m3 concentrations were used to fertilize the ponds with the unfertilized ponds serving as control. The following bacteria were isolated from the cow dung manure; Escherichia coli, E. co1iOl57:H7, Aeromonas hydrophila,Salmonella typhi, Shigella dysenteriae and Staphylococcus aureus. The fish samples from the 0.13 and 0.26 kg/m3 sterilized manure fertilized ponds had zero count in the muscles while samples from other ponds had pathogens in their fish muscles. The study revealed that fish samples from sterilized manures were better in terms of microbial safety for fish productions hence sterilized manure are recommended for use in fish production to ensure the microbial safety of the fish, handlers and that of the consumers.
    Description: includes: 13 references.
    Keywords: Aquaculture ; Oreochromis niloticus ; Escherichia coli ; Aeromonas hydrophila ; Samonela typhi ; Shigella dysenteriae ; Staphylococcus aureus ; Nigeria ; Niger State ; Catfish ; Pathogens ; Microbial quality ; Raw and sterilized manue ; freshwater environment ; Bacteria ; Freshwater fish ; Fish culture ; Fish ponds ; Manure ; Microorganisms ; Freshwater aquaculture ; Aquaculture products ; Food fish ; Quality assurance ; Muscles ; Microbial contamination
    Repository Name: AquaDocs
    Type: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 278-280
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  • 7
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    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24596 | 19325 | 2018-05-20 16:13:09 | 24596 | Fisheries Society of Nigeria
    Publication Date: 2021-07-15
    Description: Sixty apparently healthy Heterobranchus bidorsalis and Clarias anguillaris from NIFFR were cultured and 30 each from Monai and wara villages as wild environments were obtained for the studies. The total bacterial load varied from 2.2 x l05 to 1.08 x l08 and 2.27 x 105 to 6.3 x l08 CFU/g of the skin of C. anguillaris and H.bidorsalis in the culture respectively, while the load varied from 1.77 x 105 to 1.17 x l08 and 2.27 x 105 to 9.0 x l07 CFU/g in the wild respectively. Eleven bacterial general species were identified which include: Bacillus species B.firmus, Pseudomonas species, P. aeruginosa, Escherichia coli, Klebsiella aerogenes, K. ozaenae, Staphylococcus aureus, Streptococcus species, S.faecalis, and Aeromonas species. The aims of this investigation is to compare the type and the load of bacteria isolates on the skin of catfish in both culture and wild environment.
    Description: Includes: 7 references.
    Keywords: Aquaculture ; Fisheries ; Clarias anguillaris ; Heterobranchus bidorsalis ; Nigeria ; Kainji L. ; Comparative study ; Bacteria ; Skin ; Clarias ; Heterobranchus ; Kainji Lake ; freshwater environment ; automation
    Repository Name: AquaDocs
    Type: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 119-122
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  • 8
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gosselin, K. M., Nelson, R. K., Spivak, A. C., Sylva, S. P., Van Mooy, B. A. S., Aeppli, C., Sharpless, C. M., O’Neil, G. W., Arrington, E. C., Reddy, C. M., & Valentine, D. L. Production of two highly abundant 2-methyl-branched fatty acids by blooms of the globally significant marine cyanobacteria Trichodesmium erythraeum. ACS Omega, 6(35), (2021): 22803–22810, https://doi.org/10.1021/acsomega.1c03196.
    Description: The bloom-forming cyanobacteria Trichodesmium contribute up to 30% to the total fixed nitrogen in the global oceans and thereby drive substantial productivity. On an expedition in the Gulf of Mexico, we observed and sampled surface slicks, some of which included dense blooms of Trichodesmium erythraeum. These bloom samples contained abundant and atypical free fatty acids, identified here as 2-methyldecanoic acid and 2-methyldodecanoic acid. The high abundance and unusual branching pattern of these compounds suggest that they may play a specific role in this globally important organism.
    Description: This work was funded with grants from the National Science Foundation grants OCE-1333148, OCE-1333162, and OCE-1756254 and the Woods Hole Oceanographic Institution (IR&D). GCxGC analysis made possible by WHOI’s Investment in Science Fund.
    Keywords: Lipids ; Alkyls ; Bacteria ; Genetics ; Chromatography
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 9
    Publication Date: 2017-04-04
    Description: Balanced information and education are fundamental prerequisites for risk prevention and preparedness. Among others, children embody our best chance to implant appropriate behaviors that will be recalled during hazardous situations and to involve adults according to a knowledge chain reaction. In this work, scientists challenge their communication skills to built a set of hands-on and learn-by-play based laboratory activities, for primary and secondary schools, addressing three major issues: (1) the location of earthquakes and volcanoes on Earth; (2) earthquakes and eruptions mechanisms; (3) earthquakes unpredictability. Students are asked to place volcanoes and earthquakes epicenters (issue 1) on a wooden plate puzzle according to Plate dynamics. To addresses eruption mechanisms (issue 2) and related hazard, we use backing soda forced blowing out from a volcano vent and suggest that a pyroclastic flow is fast, it can spread over a large area and raise high up to the stratosphere. Earthquake mechanisms (issue 2) are discussed describing the energy buildup, release, and transfer, using a wooden sticks bendand- break analogy. The display of acoustic waves caused by the breakage in different situations allows understanding of both the rupture energy and the wave attenuation. Earthquakes occurrence (issue 3) is addressed using steadily pulled blocks sliding on a frictional surface, where pins simulate asperities. These activities were tested, involving thousands of students. Discussions with students and teachers and the analysis of the answers to specific questionnaires gave us confidence that we proposed proper tools to raise risk awareness
    Description: Published
    Description: 89-93
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: restricted
    Keywords: Seismic and volcanic hazards, Outreach, Education ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 10
    Publication Date: 2020-02-24
    Description: In 2011 a research project on volcanic risk assessment at La Réunion Island (Project Aléa, Institute de Physique du Globe de Paris, France) was conducted in order to determine more efficient strategies to manage future volcanic crises. The project included the evaluation of volcanic scenarios through field and historical data analysis, as well as a survey on volcanic risk perception in resident population. A clear scientific information and an effective communication with public play a crucial role in risk mitigation strategies. In particular, the evaluation of the public perception during both volcanic crises and dormant periods is an important element in developing actions focused on specific social and cultural contexts. A questionnaire was developed based on the ones used in similar researches conducted on Italian active volcanoes. Items were designed to measure variables connected with personal perception of hazard and risk, trust in mitigation actions and in information received about these aspects. In addition, specific items related to the peculiarities of La Réunion Island environment were included. A total of 2,000 questionnaires were distributed taking into account factors such as the proximity to the volcano and the involvement of communities in recent volcanic emergencies. Main results coming out from this survey, if on the one hand show an adequate residents’ perception of natural hazards, on the other hand highlight their poor knowledge of the island’ active volcano, a similar lacking knowledge of emergency plan for volcanic crises, but also a high confidence in scientists to provide accurate and reliable information on volcanic risk and hazards in contrast with Local Authorities. Remarkable findings of this study assess some key elements that should be considered by the institutions in charge for defining policies aimed to volcanic risk mitigation and management of future volcanic crises.
    Description: Unpublished
    Description: 1V. Storia e struttura dei sistemi vulcanici
    Description: reserved
    Keywords: risk perception, volcanic hazards ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 11
    Publication Date: 2017-04-04
    Description: This book is one out of 8 IAEG XII Congress volumes, and deals with education and the professional ethics, which scientists, regulators, and practitioners of engineering geology inevitably have to face through the purposes, methods, limitations, and findings of their works. This volume presents contributions on the professional responsibilities of engineering geologists; the interaction of engineering geologists with other professionals; recognition of the engineering geological profession and its particular contribution to society, culture, and economy; and implications for the education of engineering geologists at tertiary level and in further education schemes. Issues treated in this volume are: the position of engineering geology within the geo-engineering profession; professional ethics and communication; resource use and re-use; managing risk in a litigious world; engineering and geological responsibility; and engineering geology at tertiary level. The Engineering Geology for Society and Territory volumes of the IAEG XII Congress held in Torino from September 15-19, 2014, analyze the dynamic role of engineering geology in our changing world and build on the four main themes of the congress: Environment, processes, issues, and approaches.
    Description: Published
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: 5A. Energia e georisorse
    Description: 6A. Monitoraggio ambientale, sicurezza e territorio
    Description: open
    Keywords: Geoethics ; Geoeducation ; Professional Ethics ; Engineering Geology ; Communication ; Society ; Risks management ; Georesources ; Geological responsibility ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book
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  • 12
    Publication Date: 2017-04-04
    Description: The defence against natural hazards involves many actors with different roles: geoscientists, decision makers, local authorities, mass media, citizens. A proper management of georisks requires that each role is well-defined and governed by shared operational protocols, especially during the emergency phase, so that overlapping and misunderstanding don’t jeopardize population safety and economic activities. To achieve good results in this direction, it is necessary to undertake a careful evaluation of the limits and expectations of each component of society and the respect of legitimate aspirations and prerogatives. An effective defence system against natural hazards should be planned rationally and based on scientific data, in order to avoid alarmism among citizens, misleading sensationalism by media, careless decisions by politicians, as well as approximation in managing different phases of the risk cycle. Taking into consideration geoethical aspects related to natural hazards can be helpful to make geoscientists aware of their responsibilities towards society and to clarify the role they can play in the interaction with other actors, aiming at more efficacious actions for georisk mitigation.
    Description: Published
    Description: 59-62
    Description: 4T. Fisica dei terremoti e scenari cosismici
    Description: 4V. Vulcani e ambiente
    Description: 4A. Clima e Oceani
    Description: 6A. Monitoraggio ambientale, sicurezza e territorio
    Description: restricted
    Keywords: Geoethics ; Natural hazards ; Risks ; Society ; Responsibility ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.08. Risk::05.08.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 13
    Publication Date: 2020-02-24
    Description: The communication process between the geoscientists and native communities in risk areas can significantly affect disaster prevention and land use planning. In Peru, the problem of disaster prevention is a fundamental policy due to unfamiliarity and deficiency of the associate information on the population. It is possible that talk of disaster prevention it will be an unlikely ideal in a country where most towns have settled on unplanned projects by the constant change and the lack of interest from the authorities in such topics. However, it is anachronistic that the rural communities and towns continue to live without a plan to enable them to improve their quality of life. The correct use of geoscience information in the mass media can help in this work. The characteristics of the enterprise in Peru require more training by professionals in the geosciences and support communication specialists. In this paper, we analyze the problem of communication for disaster prevention in Peru, with the aim of contributing to the articulation of a disaster prevention strategy.
    Description: Published
    Description: 81-83
    Description: 3T. Pericolosità sismica e contributo alla definizione del rischio
    Description: 4V. Vulcani e ambiente
    Description: 6A. Monitoraggio ambientale, sicurezza e territorio
    Description: reserved
    Keywords: Communication process ; Disaster prevention ; Risk management ; Peru ; Geoethics ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.08. Risk::05.08.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 14
    Publication Date: 2020-10-26
    Description: One of the main objectives of the ITACA (ITalian ACcelerometric Archive) strong motion database, promoted by the Italian Department of Civil Protection, was to improve the characterization of the recording sites from a geological and geophysical point of view and to provide their seismic classification according to the seismic norms pertinent to Italy, namely the Eurocode 8 and the National Technical Norms for Constructions. A standard format to summarize the available information for the recording stations was first produced, in terms of a technical report dynamically linked to the database, i.e., some of the relevant information is automatically updated when the corresponding fields of the database are modified. Then, an important activity of collection, qualification and synthesis of available data was carried out, especially for stations that recorded the strongest earthquakes in Italy in the last 40 years, and for which a relevant number of studies have been published. In spite of this activity, among the more than 700 strong motion stations present in the ITACA database, only a limited number of them could be characterized by quantitative information on subsurface soil properties. For this reason, a dual seismic site classification criterion was implemented, either based on the standard Vs,30 scheme, or, in the absence of such information, based on an expert opinion supported by shallow geology maps, mostly at 1:100,000 scale, and when available on the H/V ratios calculated on recordings. Owing to the relevance in the Italian geographic and morphological context, a special care was also given to the topographic classification of stations, based on suitable criteria developed within a GIS environment.
    Description: Published
    Description: 1779-1796
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: open
    Keywords: ITACA database ; Strong motion station ; General characterization ; Site classification ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 05. General::05.02. Data dissemination::05.02.02. Seismological data ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 15
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    Springer
    Publication Date: 2017-04-04
    Description: Previous research works proved the existence of a synchronization between speech and holds in adults and in 9 year old children with a rich linguistic vocabulary and advanced language skills. When and how does this synchrony develop during child language acquisition? Could it be observed also in children younger than 9? The present work aims to answer the above questions reporting on the analysis of narrations produced by three different age groups of Italian children (9, 5 and 3 year olds). Measurements are provided on the amount of synchronization between speech pauses and holds in the three different groups, as a function of the duration of the narrations. The results show that, as far as the reported data concerns, in children, as in adults, holds and speech pauses are to a certain extent synchronized and play similar functions, suggesting that they may be considered as a multi-determined phenomenon exploited by the speaker under the guidance of a unified planning process to satisfy a communicative intention. In addition, considering the role that speech pauses play in communication, we speculate on the possibility that holds may serve to similar purposes supporting the hypothesis that gestures as speech are an expressive resource that can take on different functions depending on the communicative demand. While speech pauses are likely to play the role of signalling mental activation processes aimed at replacing the “old spoken content” of the communicative plan with a new one, holds may signal mental activation processes aimed at replacing the “old visible bodily action” with new ones reflecting the representational and/or propositional contribution of gestures to the new communicative plan.
    Description: Published
    Description: 252-272
    Description: 5.9. Formazione e informazione
    Description: restricted
    Keywords: Speech pauses, holds, synchrony, child narrations ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 16
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    Istituto Nazionale di Geofisica e Vulcanologia
    Publication Date: 2017-04-04
    Description: This is the first volume of an international scientific journal that is dedicated to issues of geoethics and geological culture. Its goal is to inform the Italian and international scientific communities about what emerged at the GeoItalia 2011 conference, attended by not only Italian geoscientists. At this conference, the geoscientists questioned their role in society and the responsibilities that they have to assume as scholars of the planet Earth and experts of the territory. They highlighted the need for rediscovery of the cultural values of geology as a science that can contribute to the construction of correct social knowledge, and the need to be aware that geoethics cannot exist without a real awareness among geoscientists of the cultural value of the Earth sciences.
    Description: Published
    Description: 331
    Description: 5.9. Formazione e informazione
    Description: JCR Journal
    Description: open
    Keywords: Geoethics ; Geoetica ; Geological Culture ; Earth Sciences ; Philosophy ; Education ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 17
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    Istituto Nazionale di Geofisica e Vulcanologia
    Publication Date: 2017-04-04
    Description: Prof. Giulio Giorello is amongst the most prominent philosophers of science in Italy and in the world. He is currently Professor of the Philosophy of Science at the University of Milan, Director of the Series ‘Science and Ideas’ (Raffaele Cortina Books Editor), and Literary Journalist of the cultural pages of the Corriere della Sera, one of the most important of the Italian newspapers. In this keynote presentation, in interview form, he talks about the value that the Earth sciences have had through history, framing this group of disciplines in ethical and epistemological terms, and highlighting some important elements that have to be considered in geological activities.
    Description: Published
    Description: 343-346
    Description: 5.9. Formazione e informazione
    Description: JCR Journal
    Description: open
    Keywords: Geoethics ; Geological Culture ; Geoetica ; Giulio Giorello ; Earth Sciences ; Interview ; Philosophy ; Epistemology ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 18
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    Istituto Nazionale di Geofisica e Vulcanologia
    Publication Date: 2017-04-04
    Description: The international debate in the field of geoethics focuses on some of the most important environmental emergencies, while highlighting the great responsibilities of geoscientists, whatever field they work in, and the important social, cultural and economic repercussions that their choices can have on society. The GeoItalia 2009 and 2011 conferences that were held in Rimini and Turin, respectively, and were organized by the Italian Federation of Earth Science, were two important moments for the promotion of geoethics in Italy. They were devoted to the highlighting of how, and with what tools and contents, can the geosciences contribute to the cultural renewal of society. They also covered the active roles of geoscientists in the dissemination of scientific information, contributing in this way to the correct construction of social knowledge. Geology is culture, and as such it can help to dispel misconceptions and cultural stereotypes that concern natural phenomena, disasters, resources, and land management. Geological culture consists of methods, goals, values, history, ways of thinking about nature, and specific sensitivity for approaching problems and their solutions. So geology has to fix referenced values, as indispensable prerequisites for geoethics. Together, geological culture and geoethics can strengthen the bond that joins people to their territory, and can help to find solutions and answers to some important challenges in the coming years regarding natural risks, resources, and climate change. Starting from these considerations, we stress the importance of establishing an ethical criterion for Earth scientists, to focus attention on the issue of the responsibility of geoscientists, and the need to more clearly define their scientific identity and the value of their specificities.
    Description: Published
    Description: 335-341
    Description: 5.9. Formazione e informazione
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    Description: open
    Keywords: Geoethics ; Education ; History of science ; Public issues ; General (Philosophy of Earth sciences) ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
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  • 19
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    Istituto Nazionale di Geofisica e Vulcanologia
    Publication Date: 2017-04-04
    Description: Franco Ferrarotti, Professor emeritus at ‘La Sapienza’ University of Rome; since winning the first Chair in this discipline in Italy in 1961, he has been considered the Father of Italian Sociology. An independent Member of Italian Parliament in the third government (1958-1963), a member of the New York Academy of Sciences, and a ‘visiting Professor’ at many universities in Europe, North America, Russia, Japan and Latin America. Franco Ferrarotti has taught and still teaches in Europe and America, and he has received many awards throughout his career. In this interview, he talks about the social aspects and consequences of Earth sciences studies.
    Description: Published
    Description: 347-348
    Description: 5.9. Formazione e informazione
    Description: JCR Journal
    Description: open
    Keywords: Geoethics ; Geological Culture ; Geoetica ; Social aspects ; Geologists activity ; Scientific information ; Society ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
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  • 20
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    Istituto Nazionale di Geofisica e Vulcanologia
    Publication Date: 2017-04-04
    Description: We argue here that the introduction of an ethical code of conduct that follows the example of the Hippocratic Oath of physicians will help geologists to acquire binding awareness of their professional and social responsibilities. The ethical behavior and obligations of modern geologists involve, but are not limited to, the following issues: correct land/ environment use and management; respect of truth and science; and protection of the Earth systems, on both the local and global scales, and therefore, of our well-being. We believe that for geoligists, the explicit acceptance of an ethical code will help to promote: (i) an awareness of their social role, expertise and sense of belonging to a professional community; (ii) an understanding of the expectations of citizens and society; and (iii) cultural growth, with better use of research and implementation of scientific and professional skills. All this should enhance the public recognition of the social mission of geologists, which is essential for the well-being of society. Therefore, we suggest that like in the majority of medical schools, ethical training should be a part of the university curriculum for students in geology.
    Description: Published
    Description: 365-369
    Description: 5.9. Formazione e informazione
    Description: JCR Journal
    Description: open
    Keywords: Geoethics ; Geological Culture ; Geoetica ; Hippocratic Oath ; Geologists ; Social responsibility ; 05. General::05.03. Educational, History of Science, Public Issues::05.03.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
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  • 21
    Publication Date: 2022-05-26
    Description: © The Authors 2009. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Functional & Integrative Genomics 10 (2010): 97-110, doi:10.1007/s10142-009-0142-y.
    Description: Bacteria of the genus Shewanella can thrive in different environments and demonstrate significant variability in their metabolic and ecophysiological capabilities including cold and salt tolerance. Genomic characteristics underlying this variability across species are largely unknown. In this study, we address the problem by a comparison of the physiological, metabolic, and genomic characteristics of 19 sequenced Shewanella species. We have employed two novel approaches based on association of a phenotypic trait with the number of the trait-specific protein families (Pfam domains) and on the conservation of synteny (order in the genome) of the trait-related genes. Our first approach is top-down and involves experimental evaluation and quantification of the species’ cold tolerance followed by identification of the correlated Pfam domains and genes with a conserved synteny. The second, a bottom-up approach, predicts novel phenotypes of the species by calculating profiles of each Pfam domain among their genomes and following pair-wise correlation of the profiles and their network clustering. Using the first approach, we find a link between cold and salt tolerance of the species and the presence in the genome of a Na+/H+ antiporter gene cluster. Other cold-tolerance-related genes include peptidases, chemotaxis sensory transducer proteins, a cysteine exporter, and helicases. Using the bottom-up approach, we found several novel phenotypes in the newly sequenced Shewanella species, including degradation of aromatic compounds by an aerobic hybrid pathway in Shewanella woodyi, degradation of ethanolamine by Shewanella benthica, and propanediol degradation by Shewanella putrefaciens CN32 and Shewanella sp. W3-18-1.
    Description: This research was supported by the U.S. Department of Energy (DOE) Office of Biological and Environmental Research under the Genomics: GTL Program via the Shewanella Federation consortium.
    Keywords: Phenotypic trait ; Bacteria ; Molecular mechanisms of cold tolerance ; Shewanella ; Protein families
    Repository Name: Woods Hole Open Access Server
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  • 22
    Publication Date: 2017-04-04
    Description: Red Pompeian paintings, very famous for their deep intensity, are currently suffering from darkening. The origins of this darkening degradation are not clearly identified yet and remain a major issue for curators. In the specific case of cinnabar (HgS)-based red pigment, a photoinduced conversion into black metacinnabar is usually suspected. This work is focused on the blackening of red cinnabar paintings coated on a sparry calcite mortar. Different samples exhibiting different levels of degradation were selected upon visual observations and analyzed by synchrotron-based microanalytical techniques. Atomic and molecular compositions of the different debased regions revealed two possible degradation mechanisms. On one hand, micro X-ray fluorescence elemental maps show peculiar distributions of chlorine and sulfur. On the other hand, X-ray absorption spectroscopy performed at both Cl and S K-edges confirms the presence of characteristic degradation products: (i) Hg- Cl compounds (e.g., corderoite, calomel, and terlinguaite), which may result from the reaction with exogenous NaCl, in gray areas; (ii) gypsum, produced by the calcite sulfation, in black coatings. Metacinnabar is never detected. Finally, a cross section was analyzed to map the in-depth alteration gradient. Reduced and oxidized sulfur distributions reveal that the sulfated black coating consists of a 5-ím-thick layer covering intact cinnabar.
    Description: Published
    Description: 7484-7492
    Description: reserved
    Keywords: Microspectroscopy Analysis ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
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  • 23
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    Journal of ornithology 141 (2000), S. 263-274 
    ISSN: 1439-0361
    Keywords: Systematics ; evolution ; anagenesis ; genealogy ; reference system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Verglichen mit anderen Tiergruppen, scheint die artliche Bestandsaufnahme der rezenten Vögel nahezu abgeschlossen zu sein. Doch ist das System der Vögel weiterhin umstritten und mit vielen Neuerungen konfrontiert. Die Gründe dafür liegen hauptsächlich in neuen, vor allem molekularbiologischen Methoden und in den unerwartet reichen Fossilfunden der jüngsten Zeit. Als Beispiele werden Altgaumenvögel, Kranichvögel, Ibisse, Flamingos, Mausvögel, Hopfe und Sperlingsvögel kurz behandelt. Die hier erzielten Fortschritte lassen die Befürchtung Stresemanns, die Großsystematik der Vögel sei mit den vorhandenen Methoden phylogenetisch nicht interpretierbar, zunächst als unbergründet erscheinen. Doch erwachsen einer solchen Interpretation andere Hindernisse, deren Bedeutung bisher zu wenig beachtet wurde, nämlich Parallelentwicklungen, die viel verbreiteter sind als gemeinhin angenommen. Ihre Häufigkeit lässt sich sogar mit evolutionsbiologischen Argumenten begründen. Es ist deshalb nicht zu erwarten, dass die Diskussionen um das „richtige“ System bald verstummen. Um dennoch die Eindeutigkeit der Information in nicht-systematischen Veröffentlichungen zu wahren, wird empfohlen ein etabliertes Referenzsystem auf Zeit zu wählen.
    Notes: Summary Unlike in most animal classes the inventory of extant species of the class Aves seems to be almost complete. Nevertheless avian systematics is challenged by many novelties and seems far from being settled. This is caused mainly by the application of novel methods of molecular analysis to phylogenetic problems and by the unexpectedly rich fossil record collected within the last 10–20 years. Examples from the Palaeognathae, Gruiformes, Threskiornithidae, Phoenicopteridae, Coliiformes, Upupiformes and Passeriformes are briefly treated. The progress in the field seems to disprove Stresemann's pessimistic view that the phylogeny of higher categories (orders) cannot be reconstructed by the available methods. However, phylogenetic interpretations are impeded by obstacles not considered by Stresemann and highly underestimated in most cases, namely by multiple independent developments leading to identical features. Frequent parallel developments are to be expected for theoretical evolutionary reasons. The diagnosis of such homoplasies can be extremely difficult or even impossible. Therefore we cannot expect the discussion about the “best” system of birds to end in the near future. Considering this dynamic situation in systematics, it is recommended to maintain unambiguousness of information in not strictly systematic publications by refering to a well established system as a temporally limited reference.
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  • 24
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    Acta biotheoretica 48 (2000), S. 137-147 
    ISSN: 1572-8358
    Keywords: Sex ; sexual selection ; mate selection ; evolution ; ploidy ; assortative mating ; recombination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using computer simulations I studied the simultaneous effect of variable environments, mutation rates, ploidy, number of loci subject to evolution and random and assortative mating on various reproductive systems. The simulations showed that mutants for sex and recombination are evolutionarily stable, displacing alleles for monosexuality in diploid populations mating assortatively under variable selection pressure. Assortative mating reduced excessive allelic variance induced by recombination and sex, especially among diploids. Results suggest a novel adaptive value for sex and recombination. They show that the adaptive value of diploidy and that of the segregation of sexes is different to that of sex and recombination. The results suggest that the emergence of sex had to be preceded by the emergence of diploid monosexual organisms and provide an explanation for the emergence and maintenance of sex among diploids and for the scarcity of sex among haploid organisms.
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  • 25
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    Entomologia experimentalis et applicata 97 (2000), S. 237-249 
    ISSN: 1570-7458
    Keywords: herbivores ; predators ; parasitoids ; mutualism ; induced defence ; behaviour ; ecology ; evolution ; sensory physiology ; plant fitness ; pathogens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Herbivorous and carnivorous arthropods use plant volatiles when foraging for food. In response to herbivory, plants emit a blend that may be quantitatively and qualitatively different from the blend emitted when intact. This induced volatile blend alters the interactions of the plant with its environment. We review recent developments regarding the induction mechanism as well as the ecological consequences in a multitrophic and evolutionary context. It has been well established that carnivores (predators and parasitoids) are attracted by the volatiles induced by their herbivorous victims. This concerns an active plant response. In the case of attraction of predators, this is likely to result in a fitness benefit to the plant, because through consumption a predator removes the herbivores from the plant. However, the benefit to the plant is less clear when parasitoids are attracted, because parasitisation does usually not result in an instantaneous or in a complete termination of consumption by the herbivore. Recently, empirical evidence has been obtained that shows that the plant's response can increase plant fitness, in terms of seed production, due to a reduced consumption rate of parasitized herbivores. However, apart from a benefit from attracting carnivores, the induced volatiles can have a serious cost because there is an increasing number of studies that show that herbivores can be attracted. However, this does not necessarily result in settlement of the herbivores on the emitting plant. The presence of cues from herbivores and/or carnivores that indicate that the plant is a competitor- and/or enemy-dense space, may lead to an avoidance response. Thus, the benefit of emission of induced volatiles is likely to depend on the prevailing faunal composition. Whether plants can adjust their response and influence the emission of the induced volatiles, taking the prevalent environmental conditions into account, is an interesting question that needs to be addressed. The induced volatiles may also affect interactions of the emitting plant with its neighbours, e.g., through altered competitive ability or by the neighbour exploiting the emitted information. Major questions to be addressed in this research field comprise mechanistic aspects, such as the identification of the minimally effective blend of volatiles that explains the attraction of carnivores to herbivore-infested plants, and evolutionary aspects such as the fitness consequences of induced volatiles. The elucidation of mechanistic aspects is important for addressing ecological and evolutionary questions. For instance, an important tool to address ecological and evolutionary aspects would be to have plant pairs that differ in only a single trait. Such plants are likely to become available in the near future as a result of mechanistic studies on signal-transduction pathways and an increased interest in molecular genetics.
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  • 26
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    Entomologia experimentalis et applicata 95 (2000), S. 141-149 
    ISSN: 1570-7458
    Keywords: ecology ; reproductive success ; fecundity ; intraspecific competition ; evolution ; pest outbreaks ; pest control ; chemical control ; economic threshold ; oilseed rape ; turnip rape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Populations of the rapeseed pollen beetle Meligethes aeneus F. (Col., Nitidulidae) from areas with 0–16 years of history of intensive rapeseed growing were compared for key ecological characters. During the first 16 years of rapeseed cultivation the reproductive success of M. aeneus increased 200–300% over that of the beetles living on the natural host plants, cruciferous weeds. The increase was linear over time and statistically highly significant, and it did not appear to be related to food quality or to the size of the beetles. During the same period the tolerance to intraspecific competition decreased, possibly due to the relative absence of such competition on the new crop. Furthermore, the optimum population density for M. aeneus to maximize the size of its next generation on summer turnip rape was determined to be 0.5–1.0 beetles/plant, which is slightly below the economic threshold for chemical control (1 beetle/plant). Therefore the practical protection of the rapeseed yield also ensures the highest possible pest population size for the next year. These mechanisms may in part explain the particular noxiousness of the species as a pest all over Europe. In general these data show that after the introduction of a new crop plant into a region, significant changes during the recruitment process in a pestiferous insect may take place, contributing to the future pest status of the insect. It is suggested that such genetic and ecological changes in insects may be a more common mechanism than previously thought in initiating and sustaining pest outbreaks, and that conventional pest management methods may enhance that effect.
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  • 27
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    Journal of insect behavior 13 (2000), S. 71-86 
    ISSN: 1572-8889
    Keywords: copulatory courtship ; behavioral interactions ; songs ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract D. birchii and D. serrata, two endemic Australian Drosophila species, have a copulatory courtship. The males of these species begin to court the female after mounting her and often go on with the courtship after the copulation is over. In the present paper we have described behavioral interactions between the male and the female and analyzed acoustic signals produced by the flies during courtship. Species differences were more pronounced in female than in male behavior. Variation within the species was obvious in the relative proportions of time the flies spent in different behaviors. Even though courtship took place nearly solely during copulation, some remains of precopulatory courtship were observed in both species. It is suggested that copulatory courtship exhibited by D. birchii and D. serrata flies is a derived rather than a primitive character.
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  • 28
    ISSN: 1572-9028
    Keywords: rutile supported V2O5–WO3 catalyst ; evolution ; NO reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This paper concerns the relation between surface structure of crystalline vanadia-like active species on vanadia–tungsta catalyst and their activity in the selective reduction of NO by ammonia to nitrogen. The investigations were performed for Ti–Sn-rutile-supported isopropoxy-derived catalyst. The SCR activity and surface species structure were determined for the freshly prepared catalyst, for the catalyst previously used in NO reduction by ammonia (320 ppm NO, 335 ppm NH3 and 2.35 vol% O2) at 573 K as well as for the catalyst previously annealed at 573 K in helium stream containing 2.35 vol% O2. The crystalline islands, exposing main V2O5 surface, with some tungsten atoms substituted for V-ones, were found, with XPS and FT Raman spectroscopy, to be present at the surface of the freshly prepared catalyst. A profound evolution of the active species during the catalyst use at 573 K was observed. Dissociative water adsorption on V5+OW6+ sites is discussed as mainly responsible for the catalyst activity at 473 K and that on both V5+OW6+ and V4+OW6+ sites as determining the activity at 523 K.
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  • 29
    ISSN: 1433-4909
    Keywords: Key words Extreme thermophile ; Thermosipho ; Thermotogales ; Deep-sea hydrothermal vent ; Bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A novel barophilic, extremely thermophilic bacterium was isolated from a deep-sea hydrothermal vent chimney at the Iheya Basin, in the Okinawa area, Japan. The cells were found to be rod shaped and surrounded by a sheath-like outer structure; the organism did not possess flagella and was not motile. Growth was observed between 45° and 80°C (optimum, 72°C, 45 min doubling time), pH 5.3 and 9.3 (optimum, pH 7.2–7.6), 6.6 and 79 g/l sea salts (optimum, 40 g/l), and 0.1 and 60 MPa (optimum, 20 MPa). Strain IHB1 was found to be a strictly anaerobic chemoorganotroph capable of utilizing yeast extract and proteinaceous substrates such as peptone and tryptone. Elemental sulfur or thiosulfate acted as electron acceptors improving growth. The isolate was able to utilize casein as a sole carbon and energy source in the presence of thiosulfate. The G + C content of the genomic DNA was 31.4 mol%. Phylogenetic analysis based on 16S rDNA sequences and DNA–DNA hybridization analysis indicated that the isolate is closely related to Thermosipho africanus; however, it represents a species distinct from the previously described members of the genus Thermosipho. On the basis of the physiological and molecular properties, we propose that the new isolate represents a new species, which we name Thermosipho japonicus sp. nov. (type strain: IHB1; JCM10495).
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  • 30
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    Foundations of science 5 (2000), S. 429-456 
    ISSN: 1572-8471
    Keywords: awareness ; reflexive awareness and consciousness ; evolution ; experience and pattern matching ; symbolic language
    Source: Springer Online Journal Archives 1860-2000
    Topics: Natural Sciences in General
    Notes: Abstract An evolutionary point of view is proposed to make more appropriate distinctions between experience, awareness and consciousness. Experience can be defined as a characteristic linked closely to specific pattern matching, a characteristic already apparent at the molecular level at least. Awareness can be regarded as the special experience of one or more central, final modules in the animal neuronal brain. Awareness is what experience is to animals. Finally, consciousness could be defined as reflexive awareness. The ability for reflexive awareness is distinctly different from animal and human awareness and depends upon the availability of a separate frame of reference, as provided by symbolic language. As such, words have made reflexive awareness – a specific and infrequent form of awareness – possible. Conciousness might be defined as the experience evoked by considering, i.e. thinking about experiences themselves. If there is a hard problem of explaining consciousness, than this actually must be considered as the hard problem already met when trying to explain basic experience, since its nature remains elusive.
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  • 31
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    Journal for general philosophy of science 31 (2000), S. 57-73 
    ISSN: 1572-8587
    Keywords: complex systems ; evolution ; nonlinearity ; pre-determination ; self-organization ; soft management ; structure-attractors ; synergetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract The philosophical consequences of synergetics, the interdisciplinary theory of evolution and self-organization of complex systems, are being drawn in the paper. The idea of discreteness of evolutionary paths is in the focus of attention. Although the future is open, and there are many alternative evolutionary paths for complex systems, not any arbitrary (either conceivable or desirable) evolutionary path is feasible in a given system. There are discrete spectra of possible evolutionary paths which are determined exclusively by inner properties of the corresponding systems. Synergetics allows us to reveal general laws of self-organization and, therefore, certain limits of arbitrariness of nature in choosing possible paths of evolution as well as in constructing of a complex evolutionary whole. A comparative analysis between the modern synergetic notions and a few ideas of the Western philosophy (F. Nietzsche, N. Hartmann, M. Heidegger) and of the Eastern teachings (Taoism, Buddhism) is made.
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  • 32
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    International journal of value-based management 13 (2000), S. 297-308 
    ISSN: 1572-8528
    Keywords: morality ; moral systems ; behavior ; evolution ; adaptation ; natural selection ; altruism ; reciprocal altruism ; fitness ; reciprocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract The ethical and moral behavior of Homo sapiens is no longer the exclusive domain of religion and philosophy because we recognize that such behavior affects the reproductive success of individuals within the species. We are a social species and therefore our survival is influenced by our capacity for cooperation and our willingness to take risks for kin. Emotions, some of which are found in other species, help to mediate our altruistic behavior. The reproductive benefits of helping kin, especially offspring, are readily seen. Helping non-kin can be beneficial if individuals can differentiate between ‘reciprocators’ and ‘non-reciprocators’ and direct altruistic behavior toward reciprocators. Also, if third parties are favorably impressed by observing altruistic behavior, the rewards need not come from the recipient of the altruistic behavior.
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  • 33
    ISSN: 1432-0789
    Keywords: Keywords Aggregate stability ; Bacteria ; Burnt soil ; Compost ; Fungi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The restoration of soil microbial activities is a basic step in the reclamation of burnt soils. For this reason, the ability of municipal solid waste compost to accelerate the re-establishment of bacterial and fungal populations, as well as to re-establish physical properties in a burnt soil, was evaluated in a field experiment. Four treatments were performed by adding different doses of compost (0, 0.5, 1 and 2 kg compost m–2 soil) to a burnt Calcic Rodoxeralf soil, and the changes in microbial populations, salt content, aggregate stability and bulk density were evaluated for 1 year. Initially, the addition of compost had a negative effect on soil microbial populations, but 3 months after compost addition, the number of viable fungal propagules increased in all the amended soils. This positive effect lasted until the end of the experiment. From 30 days onwards, all the amended soils showed a greater total number of bacterial cell forming units than the unamended burnt soil. Organic amendment increased the percentage of 2- to 4-mm aggregates, although the effect on the stability of the 0.2- to 2-mm aggregates and on bulk density was less noticeable.
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  • 34
    ISSN: 1572-9737
    Keywords: conservation genetics ; Equus ; evolution ; mitochondrial DNA control region ; mitochondrial 12S rRNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The evolution, taxonomy and conservation of the genus Equuswere investigated by examining the mitochondrial DNA sequences of thecontrol region and 12S rRNA gene. The phylogenetic analysis of thesesequences provides further evidence that the deepest node in thephylogeny of the extant species is a divergence between twolineages; one leading to the ancestor of modern horses (E.ferus, domestic and przewalskii) and the other to thezebra and ass ancestor, with the later speciation events of the zebrasand asses occurring either as one or more rapid radiations, or withextensive secondary contact after speciation. Examination of the geneticdiversity within species suggested that two of the E. hemionussubspecies (E. h. onager and E. h. kulan) onlyrecently diverged, and perhaps, are insufficiently different to beclassified as separate subspecies. The genetic divergence betweendomestic and wild forms of E. ferus (horse) and E.africanus (African ass) was no greater than expected within anequid species. In E. burchelli (plains zebra) there was anindication of mtDNA divergence between populations increasing withdistance. The implications of these results for equid conservation arediscussed and recommendations are made for conservation action.
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  • 35
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    Journal of the history of biology 33 (2000), S. 457-491 
    ISSN: 1573-0387
    Keywords: J. B. S. Haldane ; biology ; politics ; genetics ; evolution ; population genetics ; physiology ; Darwinism ; experimental biology ; eugenics ; Britain ; Russia ; India ; Soviet ; Communism ; socialism ; philosophy ; vision ; literature ; popularization ; religion ; human experimentation ; bioethics ; Venus ; Mars ; science fiction ; technocracy ; futurology ; H. G. Wells ; Julian Huxley ; Olaf Stapledon ; C. S. Lewis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract This paper seeks to reinterpret the life and work of J. B. S. Haldane by focusing on an illuminating but largely ignored essay he published in1927, “The Last Judgment” – the sequel to his better known work, Daedalus (1924). This astonishing essay expresses a vision of the human future over the next 40,000,000 years, one that revises and updates Wellsian futurism with the long range implications of the “new biology” for human destiny. That vision served as a kind of lifelong credo, one that infused and informed his diverse scientific work, political activities, and popular writing, and that gave unity and coherence to his remarkable career.
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    Journal of the history of biology 33 (2000), S. 221-246 
    ISSN: 1573-0387
    Keywords: August Weismann ; ciliates ; Clifford Dobell ; cytology ; death ; Emile Maupas ; evolution ; Herbert Spencer Jennings ; Otto Bütschli ; Paramecium ; rejuvenescence ; sex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract In the period 1875–1920, a debate about the generality and applicability of evolutionary theory to all organisms was motivated by work on unicellular ciliates like Paramecium because of their peculiar nuclear dualism and life cycles. The French cytologist Emile Maupas and the German zoologist August Weismann argued in the 1880s about the evolutionary origins and functions of sex (which in the ciliates is not linked to reproduction), and death (which appeared to be the inevitable fate of lineages denied sexual conjugation), an argument rooted in the question of whether the ciliates and their processes where homologous to other cellular organisms. In the beginning of the twentieth century, this question of homology came to be less important as the ciliates were used by the British protozoologist Clifford Dobell and the American zoologist Herbert Spencer Jennings to study evolutionary processes in general rather than problems of development and cytology. For them, homology mattered less than analogy. This story illustrates two partially distinct problems in evolutionary biology: first, the question of whether all living things have common features and origins; and second, whether their history and current nature can be described by identical mechanisms. Where Maupas (contra Weismann) made the ciliates qualitatively the same as all other organisms in order to create a cohesive evolutionary theory for biology, Jennings and Dobell made them qualitatively different in order to achieve the same end.
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  • 37
    ISSN: 1432-2021
    Keywords: Key words Cristobalite ; Tridymite ; Phase transformation ; Electron microscopy
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    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract Using minimum exposure techniques, it is feasible to perform high resolution electron microscopy on the α-cristobalite phase of (Si0.9 Ge0.1)O2, which is extremely radiation sensitive. Such images reveal atomic scale information of twins and tridymite-like stacking faults on (1 1 1)β planes, as well as of domain boundaries resulting from the β→α transition. Polytype structures are formed in certain cases. Morphological features suggest that the phase transformation cristobalite → tridymite proceeds by means of a zonal dislocation mediated synchro-shear process on (1 1 1)β planes; the geometry of this process is analyzed.
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  • 38
    ISSN: 1432-1017
    Keywords: Key words X-ray crystallography ; Electron microscopy ; Biological databases
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    Topics: Biology , Physics
    Notes: Abstract Advances in structural biology are opening greater opportunities for understanding biological structures from the cellular to the atomic level. Particularly promising are the links that can be established between the information provided by electron microscopy and the atomic structures derived from X-ray crystallography and nuclear magnetic resonance spectroscopy. Combining such different kinds of structural data can result in novel biological information on the interaction of biomolecules in large supramolecular assemblies. As a consequence, the need to develop new databases in the field of structural biology that allow for an integrated access to data from all the experimental techniques is becoming critical. Pilot studies performed in recent years have already established a solid background as far as the basic information that an integrated macromolecular structure database should contain, as well as the basic principles for integration. These efforts started in the context of the BioImage project, and resulted in a first complete database prototype that provided a versatile platform for the linking of atomic models or X-ray diffraction data with electron microscopy information. Analysis of the requirements needed to combine data at different levels of resolution have resulted in sets of specifications that make possible the integration of all these different types in the context of a web environment. The case of a structural study linking electron microscopy and X-ray data, which is already contained within the BioImage data base and in the Protein Data Bank, is used here to illustrate the current approach, while a general discussion highlights the urgent need for integrated databases.
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  • 39
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    The environmentalist 20 (2000), S. 257-271 
    ISSN: 1573-2991
    Keywords: evolution ; tides ; sea level ; time series
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The increasing use of computers since the 1960s, has implied the digitization of observations in meteorology, oceanography and other observational sciences. Enough data has been accumulated to suggest that some patterns of evolution in the world may be discernable. The present article deals with what appears as changing tides around Canada.
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  • 40
    ISSN: 1573-4927
    Keywords: ancient endogenous provirus ; evolution ; retrotransposition
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A new family of murine endogenous proviruses (VL6.0) is described here. The intact provirus is near 6 kb in length and shows a genomic organization of 5" LTR, gag, pol, env, and 3" LTR. The primer binding site (PBS) is that of a tRNAgly. The lack of functional open reading frames and occurrence of significant gaps in most, if not all, members of this group show it to be ancient. Our estimate of copy number per haploid genome is 30+. Members of this group have been isolated from Mus musculus domesticus, M. m. casteneus, M. m. hortulanus, M. caroli, and M. spretus. The occurrence of these sequences throughout such diverse members of the genus Mus may indicate that the date of the original infection predated the divergence of the extant Mus lineages at around 2.5 million years ago. Analysis of gap (deletion/insertion) patterns indicates that these sequences may have proliferated within the Mus genome by a mechanism of reverse transcriptase-mediated transposition. As yet, there are no closely related murine retroviruses described. The closest mammalian retrovirus based on sequence similarity is from the miniature swine (Sus scrofa).
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  • 41
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    Physics and chemistry of minerals 27 (2000), S. 480-494 
    ISSN: 1432-2021
    Keywords: Key words Olivine ; Grain boundary ; Partial melt ; Electron microscopy
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    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract The microstructure of olivine-olivine grain boundaries has been studied in experimentally deformed (1200–1227 °C, 300 MPa) partially molten olivine and olivine-orthopyroxene rocks. In-situ melting produced ∼1 vol% melt in all samples studied. Grain boundary analyses were carried out using a number of transmission electron microscopy techniques. The grain boundary chemistry in undeformed olivine-orthopyroxene starting material showed evidence for the presence of an intergranular phase along some, but not all, of the olivine-olivine boundaries. In the deformed samples, ultrathin Si-rich, Al- and Ca-bearing amorphous films have been observed along all investigated olivine-olivine grain boundaries. The chemistry of the grain boundaries, which is considered to be indicative for the presence of a thin film, was measured with energy-dispersive X-ray spectroscopy (EDX) and energy-filtering imaging. The amorphous nature of the films was confirmed with diffuse dark field imaging, Fresnel fringe imaging, and high-resolution electron microscopy. The films range in thickness from 0.6 to 3.0 nm, and EDX analyses show that the presence of Al and Ca is restricted to this ultrathin film along the grain boundaries. Because thin melt films have been observed in all the samples, they are thought to be stable features of the melt microstructure in deformed partially molten rocks. The transition from the occasional presence of films in the undeformed starting material to the general occurrence of the films in deformed materials suggests that deformation promotes the formation and distribution of the films. Alternatively, hot-pressing may be too short for films to develop along all grain boundaries. A difference in creep strength between the studied samples could not be attributed to grain boundary melt films, as these have been found in all deformed samples. However, a weakening effect of grain boundary melt films on olivine rheology could not be ruled out due to the lack of confirmed melt-film free experiments.
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  • 42
    ISSN: 1618-2545
    Keywords: biogeography ; calmodulin ; DNA sequence ; elongation factor EF-1α ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phylogenetic relationships within theGibberella fujikuroi species complex were extended to newly discovered strains using nucleotide characters obtained by sequencing polymerase chain reaction (PCR) amplified DNA from 4 loci used in a previous study [nuclear large subunit 28S rDNA, nuclear ribosomal internal transcribed spacer (ITS) region, mitochondriaal small subunit (mtSSU) ribosomal DNA, and β-tubulin] together with two newly sampled protein-encoding nuclear genes, translation elongation factor EF-1α and calmodulin. Sequences from the ribosomal ITS region were analyzed separately and found to contain of two highly divergent, nonorthologous ITS2 types. Phylogenetic analysis of the individual and combined datasets identified 10 new phylogenetically distinct species distributed among the following three areas: 2 within Asia and 4 within both Africa and South America. Hypotheses of the monophyly ofFusarium subglutinans and its two formae speciales, f. sp.pini and f. sp.ananas, were strongly rejected by a likelihood analysis. Maximum parsimony results further indicate that the protein-encoding nuclear genes provide considerably more phylogenetic signal that the ribosomal genes sequenced. Relative apparent synapomorphy analysis was used to detect long-branch attraction taxa and to obtain a statistical measure of phylogenetic signal in the individual and combined datasets.
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  • 43
    ISSN: 1618-2545
    Keywords: Ascomycota ; evolution ; pyrenomycetes ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To investigate the systematic position of the unitunicate pyremomycetePapulosa amerospora, we performed phylogenetic analyses of SSU rDNA sequences from 37 ascomycetes. Among these sequences were some new ones from taxa that might be related toPapulosa: Hyponectriaceae (Hyponectria buxi, Monographella nivalis), Phyllachorales (Phyllachora graminis), and Xylariales (Barrmaelia melanotes, Poronia punctata). Our results showed 100% bootstrap support for a clade of all unitunicate pyrenomycetes, the class Sordariomycetes. We also found strong support for recognizing the subclasses Hypocreomycetidae and Xylariomycetidae. The remaining taxa, belonging to subclass Sordariomycetidae, appeared as a polyphyletic group in one analysis, but was monophyletic when shorter SSU sequences were used.Barrmaelia melanotes, Poronia punctata, Hyponectria buxi, andMonographella nivalis are members of Xylariomycetidae, but we could not determine whetherMonographella should be included in Hyponectriaceae. The new family Papulosaceae is erected forPapulosa on molecular and morphological bases, but the exact systematic position ofPapulosa within subclass Sordariomycetidae is still uncertain, since the genus did not cluster consistently with any of the included taxa. Phyllachorales are not closely related to Diaporthales, as previously suggested.
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  • 44
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    Glycoconjugate journal 17 (2000), S. 465-483 
    ISSN: 1573-4986
    Keywords: N-acetylglucosaminyltransferases ; glycosylation ; glycoproteins ; Golgi complex ; evolution ; development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This review covers discoveries made over the past 30–35 years that were important to our understanding of the synthetic pathway required for initiation of the antennae or branches on complex N-glycans and O-glycans. The review deals primarily with the author's contributions but the relevant work of other laboratories is also discussed. The focus of the review is almost entirely on the glycosyltransferases involved in the process. The following topics are discussed. (1) The localization of the synthesis of complex N-glycan antennae to the Golgi apparatus. (2) The “evolutionary boundary” at the stage in N-glycan processing where there is a change from oligomannose to complex N-glycans; this switch correlates with the appearance of multicellular organisms. (3) The discovery of the three enzymes which play a key role in this switch, N-acetylglucosaminyltransferases I and II and mannosidase II. (4) The “yellow brick road” which leads from oligomannose to highly branched complex N-glycans with emphasis on the enzymes involved in the process and the factors which control the routes of synthesis. (5) A short discussion of the characteristics of the enzymes involved and of the genes that encode them. (6) The role of complex N-glycans in mammalian and Caenorhabditis elegans development. (7) The crystal structure of N-acetylglucosaminyltransferase I. (8) The discovery of the enzymes which synthesize O-glycan cores 1, 2, 3 and 4 and their elongation.
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  • 45
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    Journal of bioeconomics 2 (2000), S. 9-23 
    ISSN: 1573-6989
    Keywords: evolution ; altruism ; morality ; utilitarianism ; Marxism ; Rawls ; fairness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Economics
    Notes: Abstract Several evolutionary mechanisms have been identified in the literature that would generate altruism in humans. The most powerful (except for kin selection) and most controversial is group selection, as recently analyzed by Sober & D.S. Wilson. I do not take a stand on the issue of the existence of group selection. Instead, I examine the level of human altruism that could exist if group selection were an engine of human evolution. For the Sober & Wilson mechanism to work, groups practicing altruism must grow faster than other groups. I call altruistic behavior that would lead to faster growth ‘efficient altruism’. This often consists of cooperation in a prisoner's dilemma. ltruistic acts such as helping a temporarily hungry or injured person would qualify as efficient altruism. Efficient altruism would also require monitoring recipients to avoid shirking. Utilitarianism would be an ethical system consistent with efficient altruism, but Marxism or the Rawlsian system would not. Discussions of efficient altruism also help understand intuitions about fairness. We perceive those behaviors as ‘fair’ that are consistent with efficient altruism. It is important to understand that, even if humans are selected to be altruistic, the forms of altruism that might exist must be carefully considered and ircumscribed.
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  • 46
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    Biology and philosophy 15 (2000), S. 443-463 
    ISSN: 1572-8404
    Keywords: David Hull ; evolution ; selection
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    Topics: Biology , Philosophy
    Notes: Abstract One of the principal difficulties in assessing Science as aProcess (Hull 1988) is determining the relationship between the various elements of Hull's theory. In particular, it is hard to understand precisely how conceptual selection is related to Hull's account of the social dynamics of science. This essay aims to clarify the relation between these aspects of his theory by examining his discussion of the``demic structure'' of science. I conclude that the social account cando significant explanatory work independently of the selectionistaccount. Further, I maintain that Hull's treatment of the demicstructure of science points us toward an important set of issues insocial epistemology. If my reading of Science as a Process iscorrect, then most of Hull's critics (e.g., those who focus solelyon his account of conceptual selection) have ignored promisingaspects of his theory.
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    Biology and philosophy 15 (2000), S. 493-508 
    ISSN: 1572-8404
    Keywords: complexity ; entropy balance ; environment independence ; evolution ; information fundamental identity ; uncertainty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Some real objects show a very particular tendency: that of becomingindependent with regard to the uncertainty of their surroundings. This isachieved by the exchange of three quantities: matter, energy andinformation. A conceptual framework, based on both Non-equilibriumThermodynamic and the Mathematical Theory of Communication is proposedin order to review the concept of change in living individuals. Three mainsituations are discussed in this context: passive independence inconnection with resistant living forms (such as seeds, spores, hibernation,...), active independence in connection with the life span of aliving individual (whether an ant or an ant farm), and the newindependence in connection with the general debate of biological evolution.
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    Biology and philosophy 15 (2000), S. 641-668 
    ISSN: 1572-8404
    Keywords: complexity ; evolution ; function ; modularity ; parts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract The functional complexity, or the number of functions, of organisms hasfigured prominently in certain theoretical and empirical work inevolutionary biology. Large-scale trends in functional complexity andcorrelations between functional complexity and other variables, such assize, have been proposed. However, the notion of number of functions hasalso been operationally intractable, in that no method has been developedfor counting functions in an organism in a systematic and reliable way.Thus, studies have had to rely on the largely unsupported assumption thatnumber of functions can be measured indirectly, by using number ofmorphological, physiological, and behavioral “parts” as a proxy. Here, amodel is developed that supports this assumption. Specifically, the modelpredicts that few parts will have many functions overlapping in them, andtherefore the variance in number of functions per part will be low. If so,then number of parts is expected to be well correlated with number offunctions, and we can use part counts as proxies for function counts incomparative studies of organisms, even when part counts are low. Alsodiscussed briefly is a strategy for identifying certain kinds of parts inorganisms in a systematic way.
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  • 49
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    Biology and philosophy 15 (2000), S. 713-732 
    ISSN: 1572-8404
    Keywords: Darwin ; error theory ; ethics ; evolution ; evolutionary ethics ; Mackie ; naturalistic fallacy ; Ruse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Suppose that the human tendency to think of certain actions andomissions as morally required – a notion that surely lies at the heart of moral discourse – is a trait that has been naturallyselected for. Many have thought that from this premise we canjustify or vindicate moral concepts. I argue that this is mistaken, and defend Michael Ruse's view that the moreplausible implication is an error theory – the idea thatmorality is an illusion foisted upon us by evolution. Thenaturalistic fallacy is a red herring in this debate,since there is really nothing that counts as a ‘fallacy’ at all. If morality is an illusion, it appears to followthat we should, upon discovering this, abolish moraldiscourse on pain of irrationality. I argue that thisconclusion is too hasty, and that we may be able usefullyto employ a moral discourse, warts and all, withoutbelieving in it.
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  • 50
    ISSN: 1618-2545
    Keywords: Ascomycota ; evolution ; molecular clock ; plant pathogen ; powdery mildew
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phylogenetic relationships of Erysiphales within Ascomycota were inferred from the newly determined sequences of the 18S rDNA and partial sequences of the 28S rDNA including the D1 and D2 regions of 10 Erysiphales taxa. Phylogenetic analyses revealed that the Erysiphales form a distinct clade among ascomycetous fungi suggesting that the Erysiphales diverged from a single ancestral taxon. The Myxotrichaceae of the Onygenales was distantly related to the other onygenalean families and was the sister group to the Erysiphales calde, with which it combined to form a clade. The Erysiphales/Myxotrichaceae clade was also closely related to some discomycetous fungi (Leotiales, Cyttariales and Thelebolaceae) including taxa that form cleistothecial ascomata. The present molecular analyses as well as previously reported morphological observations suggest the possible existence of a novel evolutionary pathway from cleistothecial discomycetous fungi to Erysiphales and Myxotrichaceae. However, since most of these fungi, except for the Erysiphales, are saprophytic on dung and/or plant materials, the questions of how and why an obligate biotroph like the Erysiphales radiated from the saprophytic fungi remain to be addressed. We also estimated the radiation time of the Erysiphales using the 18S rDNA sequences and the two molecular clockes that have been previously reported. The calculation showed that the Erysiphales split from the Myxotrichaceae 190–127 myr ago. Since the radiation time of the Erysiphales does not exceed 230 myr ago, even when allowance is made for the uncertainty of the molecular clocks, it is possible to consider that the Erysiphales evolved after the radiation of angiosperms. The results of our calculation also showed that the first radiation within the Erysiphales (138–92 myr ago) coincided with the date of a major diversification of angiosperms (130–90 myr ago). These results may support our early assumption that the radiation of the Erysiphales coincided with the evolution of angiosperm plants.
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  • 51
    ISSN: 1619-0904
    Keywords: Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC) ; In vivo biocompatibility ; Artificial endocrine pancreas ; Electron microscopy ; Glucose sensor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Biocompatibility is important to assure a mild body reaction to an implanted device and its long-term stability and functionality. In diabetes research, subcutaneously implanted glucose monitoring systems need biocompatible surfaces for long-term application. The biocompatibility of poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC), a material similar to the phospholipid layer of a cell membrane, was compared in vivo with the biocompatibility of polyurethane (PU), polyvinyl alcohol (PVA), and cuprophane (CUP). Needle-type glucose sensors and hollow-fiber probes used for microdialysis were coated with these four different biomaterials and implanted subcutaneously in 18 rats and 7 healthy volunteers. At set intervals, the implants and, in the case of the rats, also the surrounding tissue were removed and characterized by light and electron microscopy. MPC-coated sensors and hollow-fiber probes showed smooth and thin deposits in flat layers, whereas the surface deposits on PU- and PVA-coated sensors and those on CUP hollow-fiber probes appeared as rough, irregular, and dense attachments of aggregated cells and protein. This study confirmed results from earlier in vitro tests by showing the biocompatibility and reliability of MPC. Even though the amount of protein and cells attached to the MPC surface was not as low as expected from in vitro experiments, the biocompatibility and long-term stability of the implanted devices were superior to those of PU, PVA, and CUP.
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  • 52
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    Neural processing letters 11 (2000), S. 29-38 
    ISSN: 1573-773X
    Keywords: evolution ; online ; game ; neural ; network ; genetic ; real-time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In standard neuro-evolution, a population of networks is evolved in a task, and the network that best solves the task is found. This network is then fixed and used to solve future instances of the problem. Networks evolved in this way do not handle real-time interaction very well. It is hard to evolve a solution ahead of time that can cope effectively with all the possible environments that might arise in the future and with all the possible ways someone may interact with it. This paper proposes evolving feedforward neural networks online to create agents that improve their performance through real-time interaction. This approach is demonstrated in a game world where neural-network-controlled individuals play against humans. Through evolution, these individuals learn to react to varying opponents while appropriately taking into account conflicting goals. After initial evaluation offline, the population is allowed to evolve online, and its performance improves considerably. The population not only adapts to novel situations brought about by changing strategies in the opponent and the game layout, but it also improves its performance in situations that it has already seen in offline training. This paper will describe an implementation of online evolution and shows that it is a practical method that exceeds the performance of offline evolution alone.
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  • 53
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    Journal of mammalian evolution 7 (2000), S. 1-22 
    ISSN: 1573-7055
    Keywords: Dasyurus ; marsupials ; control region ; mtDNA ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract There has been a great deal of interest in determining phylogenetic relationships within the family Dasyuridae due to the widespread distribution, ecological diversity, and relative plesiomorphy of this taxon within the Australasian marsupial radiation. In the past, it has been extremely problematic to determine the phylogenetic relationships among species within Dasyurus, with numerous studies using both morphological and molecular characters providing different topologies. Here, the mitochondrial DNA (mtDNA) control region is used as a novel set of characters in an attempt to identify relationships among the six closely related extant species. Sequences were obtained from multiple individuals representing all extant species of quolls including, when possible, individuals from different geographical regions. Sequences were analyzed using both parsimony criteria and neighbor-joining methods. Results presented here concur with those of Krajewski et al. (1997) in (1) placing D. geoffroii in a highly supported clade with D. spartacus, (2) resolving a monophyletic group of D. albopunctatus + D. geoffroii + D. spartacus, and (3) placing D. hallucatus as the sister taxon to all other species of quolls. Results also show two highly supported and geographically distinct clades of D. maculatus (Tasmanian and mainland) that do not correspond to the currently used subspecific nomenclature. Preliminary results also indicate that there are different clades among geographic groups of D. hallucatus that warrant further investigation. The mtDNA control region is a highly variable locus and may be used in forensic tests for species identification in this genus.
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  • 54
    ISSN: 1573-6857
    Keywords: evolution ; Oryza ; retrotransposon ; rice ; wild species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Oryza officinalis complex is a genetically diverse, tertiary genepool of rice. We analyzed part of the primary structure of the integrase coding domain (ICD) of a gypsy-like retrotransposon from species of the O. officinalis species complex. PCR was performed with degenerate primers that hybridized to conserved sequences in the integrase genes of gypsy-type retrotransposons, using total DNA from different species of the O. officinalis complex as templates. Cloning and sequencing of the PCR products showed that the amplified fragments are highly homologous to each other (75–90%) and belong to one family of retrotransposons that is related to the previously studied RIRE-2 element from rice. Two main subfamilies of 292 and 351 bp were distinguished. Analysis of primary sequence data supports previous reports that sequence divergence during vertical transmission has been the major influence on the evolution of gypsy-type retrotransposons in Oryza species. Based on sequence data phylogenetic relationships among species of the O. officinalis complex were estimated. The data suggests that O. eichingeri is more closely related to the ancestral species of the complex.
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    International journal of primatology 21 (2000), S. 421-444 
    ISSN: 1573-8604
    Keywords: phylogenetics ; biogeography ; speciation ; Ateles ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We used the results of phylogenetic analyses of relationships among spider monkeys (Ateles) based on mitochondrial and nuclear DNA to investigate questions of their evolutionary origins and speciation mechanisms. We employed the concept of a local molecular clock to date nodes of interest (corresponding to hypothesized species and subspecies) in the various phylograms for comparison to hypothesized biogeographical events that might have affected speciation. We considered various mechanisms—Pleistocene refuge formation, riverine barriers, geological fluctuations, and ecological changes associated with these mechanisms—for their contribution to speciation in Ateles. Most speciation among the various species of Ateles occurred during the middle to late Pliocene, suggesting that Pleistocene refuge formation was not a key speciation mechanism. However, it is likely that the genetic structure of populations of Ateles was modified to some extent by refuge formation. Additionally, riverine barriers do not seem to interrupt gene flow significantly among Ateles. No river formed a barrier among species of Ateles, with the exception of the lower Amazon and possibly some of the black-water rivers draining the Guianan highlands. Large-scale geographic changes associated with the continued rise of the eastern and western cordilleras of the northern Andes and associated changes in habitat were the most important causes of speciation in Ateles. The various factors that modify genetic structure in Ateles are important to consider in order to protect endangered primate genera in the Neotropics.
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  • 56
    ISSN: 1573-8604
    Keywords: vocalization ; sexual advertisement ; predator advertisement ; taxonomy ; evolution ; mouse lemur ; primate ; Madagascar
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Advertisement calls are often important noninvasive tools for discriminating cryptic species and for assessing specific diversity and speciation patterns in nature. We investigated the contribution of these calls to uncover specific diversity in nocturnal Malagasy lemurs. We compared sexual advertisement and predator advertisement calls of two mouse lemur species, western gray and eastern rufous mouse lemurs (Microcebus murinus and M. rufus, respectively) living in two contrasting habitats (dry deciduous vs. rain forest), and analyzed them statistically. Both species emitted several highly variable whistle calls in the context of predator-avoidance. Intrapopulation variation was high and overlapped interspecific variation. Sexual advertisement calls, given in the mating context, displayed a totally distinct, species-specific acoustic structure. Whereas gray mouse lemurs produced rapidly multifrequency modulated, long trill calls, rufous mouse lemurs gave slowly frequency-modulated short chirp calls. Our results suggest specific status for gray and rufous mouse lemurs and indicate the importance of predation and social needs in shaping vocal communication.
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    Evolutionary ecology 14 (2000), S. 665-692 
    ISSN: 1573-8477
    Keywords: disease ; evolution ; frequency-dependent selection ; genetic diversity ; life history ; lifespan ; polymorphism ; reproduction rate ; resistance ; specificity ; virulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pathogens and parasites can be strong agents of selection, and often exhibit some degree of genetic specificity for individual host strains. Here we show that this host–pathogen specificity can affect the evolution of host life history traits. All else equal, evolution should select for genes that increase individuals' reproduction rates or lifespans (and thus total reproduction per individual). Using a simple host–pathogen model, we show that when the genetic specificity of pathogen infection is low, host strains with higher reproduction rates or longer lifespans drive slower-reproducing or shorter-lived host strains to extinction, as one would expect. However, when pathogens exhibit specificity for host strains with different life history traits, the evolutionary advantages of these traits can be greatly diminished by pathogen-mediated selection. Given sufficient host–pathogen specificity, pathogen-mediated selection can maintain polymorphism in host traits that are correlated with pathogen resistance traits, despite large intrinsic fitness differences among host strains. These results have two important implications. First, selection on host life history traits will be weaker than expected, whenever host fitness is significantly affected by genotype-specific pathogen attack. Second, where polymorphism in host traits is maintained by pathogen-mediated selection, preserving the genetic diversity of host species may require preserving their pathogens as well.
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  • 58
    ISSN: 1615-6110
    Keywords: Cladistics ; evolution ; Illiciales ; Illicium ; ITS ; star anise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA were determined for 15 species ofIllicium (Illiciaceae) to examine phylogenetic relationships. The ITS trees show a major dichotomy between the two North American species (I. floridanum andI. parviflorum) and the remaining east Asian species. This suggests that the existing division between two sections (sect.Illicium and sect.Cymbostemon) ofIllicium based on tepal characters in unnatural. The ITS phylogeny shows congruence with palynology: of the species examined, the three species (I. angustisepalum, I. anisatum andI. fargesii) from sect.Illicium that possess trizonocolpate pollen consistently form a clade, although nesting within a clade consisting of the species of sect.Cymbostemon, which generally have trisyncolpate pollen. The low ITS sequence divergence and the close relationship among east Asian species suggest a recent diversification of this group of species or an unusual slowdown of sequence mutations.
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  • 59
    ISSN: 1615-6110
    Keywords: In situ hybridization ; evolution ; NOR ; rDNA ; Muscari
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the subgenusLeopoldia of the genusMuscari, M. comosum is an exceptional species because it presents the most asymmetrical karyotype of the group and because its only active NOR is located in the fifth chromosome pair, while in the other species it is located in the first or second chromosome pairs (all the species have 2n = 18 chromosomes). SinceM. comosum has a derived karyotype different from those of the other species of the group, the resulting question is whether, in the first and second chromosome pair of this species, ribosomal cistrons persist. Observations after fluorescence in situ hybridization (FISH) using rDNA probes indicate that there are indeed ribosomal loci in the first and second chromosome pairs of this species, although these loci are inactive with respect to nucleolus organization. The location of rDNA regions in another three species of the same genus (M. atlanticum, M. dionysicum andM. matritensis) provides a basis for examining the significance of these findings in relation to the evolution of the ribosomal loci in this genus. Our observations indicate that in the genusMuscari, the largest sites for rRNA genes are not necessarily active, and, therefore, the activation of these regions is not related to the number of copies but to a specific regulation mechanism.
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  • 60
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    Journal of economics 71 (2000), S. 1-30 
    ISSN: 1617-7134
    Keywords: evolution ; local interaction ; cooperation ; prisoner's dilemma ; Markov processes ; C78
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract We study local interaction within a population located on a connected graph. Subjects engage in several bilateral interactions during each round in a generalized Prisoners' Dilemma (PD). In each round of play one randomly selected player gets the possibility to update the action he plays in this PD. All individuals use the update rule “Win Cooperate, Lose Defect,” a multi-player variant of Tit-for-Tat. Theoretical results on the set of stable states of the associated dynamics are provided for the cases with and without rare mutations. Simulations provide insight into the probability distribution over these stable states. In both cases a rather high probability is assigned to stable states with a moderate level of cooperation implying that dominated strategies are used. Furthermore, the probability of reaching the stable state with Nash equilibrium play is small.
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  • 61
    ISSN: 1615-6102
    Keywords: Electron microscopy ; Photoreceptor ; Visual membrane ; Photic radiation damage ; Retina ; Crustacea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Visual membranes of the crayfish eye either belong to the small, distally placed rhabdomere of retinula cell R8 or are part of the much more voluminous proximal rhabdom, made up of rhabdomeres belonging to cells R1–R7. Under various conditions of environmental stress (e.g., prolonged darkness, elevated temperature, bright light with and without a concomitant rise in temperature, flickering lights) the visual membranes of R8 prove far more resistant to structural damage than those of R1–R7. Membrane damage is known to occur when dormant lipoxygenases become activated, for example through heat. Since R8 is the only type of visual cell in the crayfish retina that does not contain grains of screening pigment, the view that screening-pigment granules could “aggravate” or even “trigger” membrane damage in times of stress is strengthened. Functionally, R8's strong resistance to physical damage when exposed to flickering lights points to a role of the distal rhabdom in the movement detection system of the crayfish eye.
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  • 62
    ISSN: 1573-5028
    Keywords: evolution ; C4 plant ; maize ; ribulose-bisphosphate carboxylase
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    Topics: Biology
    Notes: Abstract The small subunit of ribulose-bisphosphate carboxylase (Rubisco), encoded by rbcS, is essential for photosynthesis in both C3 and C4 plants, even though the cell specificity of rbcS expression is different between C3 and C4 plants. The C3 rbcS is specifically expressed in mesophyll cells, while the C4 rbcS is expressed in bundle sheath cells, and not mesophyll cells. Two chimeric genes were constructed consisting of the structural gene encoding β-glucuronidase (GUS) controlled by the two promoters from maize (C4) and rice (C3) rbcS genes. These constructs were introduced into a C4 plant, maize. Both chimeric genes were specifically expressed in photosynthetic organs, such as leaf blade, but not in non-photosynthetic organs. The expressions of the genes were also regulated by light. However, the rice promoter drove the GUS activity mainly in mesophyll cells and relatively low in bundle sheath cells, while the maize rbcS promoter induced the activity specifically in bundle sheath cells. These results suggest that the rice promoter contains some cis-acting elements responding in an organ-pecific and light-inducible regulation manner in maize but does not contain element(s) for bundle sheath cell-specific expression, while the maize promoter does contain such element(s). Based on this result, we discuss the similarities and differences between the rice (C3) and maize (C4) rbcS promoter in terms of the evolution of the C4 photosynthetic gene.
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  • 63
    ISSN: 1573-5036
    Keywords: evolution ; glutamine synthetase ; sequences ; subunit composition ; Trientalis europaea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ion-exchange chromatography of extracts from Trientalis europaea L. leaf tissue have been shown to contain two distinct isoforms of glutamine synthetase (GS). However, analysis by Western blotting has shown that the first peak to elute contains a mixture of large and small GS subunits, whilst the second peak is comprised entirely of a smaller subunit. This is contrary to the widespread assumptions concerning plant GS biochemistry. Isolation of intact chloroplasts and subsequent extraction of GS, followed by ion-exchange chromatography, has shown that the first peak to elute contains a large subunit, and the second chloroplastic peak is composed entirely of the small subunit. This smaller subunit may be present due to it being encoded by a separate chloroplastic GS gene, or it may be present as a product of post-translational modification. DNA sequencing has been used to try and determine which of these may be occurring. The three partial DNA sequences (505 nucleotides) we have obtained from T. europaea have been compared with 64 other sequences available on the NCBI database, which have mainly been obtained from crop species. Neighbour joining and parsimony analysis (1000 bootstrap) has shown support (∼30%) for the separation of plant GS from all other phyla. Within the plant phylum, there is total support for the separation of chloroplastic and cytosolic GS (100%), whilst the cytosolic sequences divide further into monocot and dicot species (77% support by NJ). Further subgroups of plants from the same families is also suggested. This is consistent with previous work containing fewer, but longer (∼1000 nucleotides) GS sequences. The addition of GS sequences obtained from wild plant species, such as T. europaea, to the large amount of information already available on the database, will permit a better understanding of the evolution of this important enzyme.
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  • 64
    ISSN: 1573-5079
    Keywords: anatomy ; C3 and C4 photosynthesis ; Chenopodiaceae ; cotyledon ; deserts ; evolution ; leaf ; Salsola
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Most species of the genus Salsola (Chenopodiaceae) that have been examined exhibit C4 photosynthesis in leaves. Four Salsola species from Central Asia were investigated in this study to determine the structural and functional relationships in photosynthesis of cotyledons compared to leaves, using anatomical (Kranz versus non-Kranz anatomy, chloroplast ultrastructure) and biochemical (activities of photosynthetic enzymes of the C3 and C4 pathways, 14C labeling of primary photosynthesis products and 13C/12C carbon isotope fractionation) criteria. The species included S. paulsenii from section Salsola, S. richteri from section Coccosalsola, S. laricina from section Caroxylon, and S. gemmascens from section Malpigipila. The results show that all four species have a C4 type of photosynthesis in leaves with a Salsoloid type Kranz anatomy, whereas both C3 and C4 types of photosynthesis were found in cotyledons. S. paulsenii and S. richteri have NADP- (NADP-ME) C4 type biochemistry with Salsoloid Kranz anatomy in both leaves and cotyledons. In S. laricina, both cotyledons and leaves have NAD-malic enzyme (NAD-ME) C4 type photosynthesis; however, while the leaves have Salsoloid type Kranz anatomy, cotyledons have Atriplicoid type Kranz anatomy. In S. gemmascens, cotyledons exhibit C3 type photosynthesis, while leaves perform NAD-ME type photosynthesis. Since the four species studied belong to different Salsola sections, this suggests that differences in photosynthetic types of leaves and cotyledons may be used as a basis or studies of the origin and evolution of C4 photosynthesis in the family Chenopodiaceae.
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  • 65
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    Genetic resources and crop evolution 47 (2000), S. 385-393 
    ISSN: 1573-5109
    Keywords: Citrullus lanatus ; cluster analysis ; evolution ; morphology ; watermelon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Morphological data recorded from field trials using Citrullus lanatus germplasm collected in Namibia were used to analyse and compare the various morphotypes of this species. The experiment comprised wild types and local landraces as well as commercial cultivars. Cluster analysis supported the indigenous classification system used in Namibia, in which Citrullus types are distinguished based on gross morphology, ecology and usage and grouped into seed, cooking and fresh-eating (watermelon) types. Commercial watermelon cultivars formed a distinct cluster. Wide variation was found within the local types whereas the genetic basis of the commercial type appears to be narrow. The commercial cultivars were most closely related to local watermelon types and more distantly related to the wild types, whereas the cooking melons form an intermediate group.
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  • 66
    ISSN: 1573-5117
    Keywords: reflecting organ ; upper lip ; Myodocopa ; chemical cues ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Multifunctions of the upper lip in a bioluminescent myodocopid Vargula hilgendorfii were studied by video observation and histological method. The localization of luciferin and luciferase gland cells within the upper lip was partly successful. Two long protrusions of the upper lip, both of V. hilgendorfii and a non-luminescent species of the same family, immediately anterior to the mouth, were found to show very flexible movement especially while eating, as if smearing on the food surface a secretion from the protrusions (glands), which may support the hypothesized secretion of digestive enzymes from the upper lip. This hypothesis is further supported by the new finding of a pair of ducts which connect the basal part of the upper lip with the posterior digestive duct (stomach). Comparative studies of V. hilgendorfii with several sympatric non-luminescent species of the same family have also revealed that it has a characteristic reflecting organ immediately posterior to the anus. It is a conical small protrusion, as if dangling from the ventral edge of the abdomen at the apex of the cone. It is observable only in live specimens, when the furca, which is located outwardly to the organ, is sufficiently transparent. When illuminated, the reflecting organ reflects the distinct light. The diameter of the mirror (chemical composition provisionally analyzed) is about 6–8% of the carapace length. The organ develops from the very first stage of its ontogeny without reference to sex, which suggests that the function may be related to intraspecific signaling or predatory deterrence.
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  • 67
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    Hydrobiologia 419 (2000), S. 31-63 
    ISSN: 1573-5117
    Keywords: morphology ; ontogeny ; Ostracoda ; evolution ; fifth limb ; crustacean phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The chaetotaxy (shape, structure and distribution of setae) of appendages and valve allometry during the post embryonic ontogeny of the cyprididine ostracod Eucypris virens are described. It is shown that the basic ontogenetic development of E. virens is very similar to that of other species of the family Cyprididae. During ontogeny, the chaetotaxy shows continual development on all podomeres of the limbs with the exception of the last podomere on the antennulae. The long setae on the exopodite and protopodite of the antennae have a natatory function until the actual natatory setae develop in later instars. Aesthetascs (presumed chemoreceptors) ya and y3 are the first to develop and may have an important function in the first instars. Cyprididae require a pediform limb in the posterior of the body presumably to help them to attach to substrates and this is reflected by the pediform nature of one limb at all times throughout all instars. This study has also shown that the fifth limb is most probably of thoracic origin and hence ostracods have only one pair of maxillae.
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    Hydrobiologia 419 (2000), S. 7-11 
    ISSN: 1573-5117
    Keywords: morphology ; palaeontology ; ecology ; genetics ; Ostracoda ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Morphology, palaeontology, genetics and ecology are the main scientific domains contributing theories, concepts and new data to evolutionary biology. Ostracods are potentially very good model organisms for evolutionary studies because they combine an excellent fossil record with a wide extant distribution and, therefore, allow studies on both patterns and processes leading to extant diversity. This preface provides an overview of the 15 contributions to the present volume and concludes that this set of papers supports the claim that ostracod studies are situated in all main evolutionary domains.
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  • 69
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    Hydrobiologia 417 (2000), S. 91-99 
    ISSN: 1573-5117
    Keywords: evolution ; phylogeny ; larval characters ; morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The plesiomorphic mode of crustacean development is widely accepted to be via a larva called the nauplius. Extant taxa like the Cephalocarida, Branchiopoda, Ostracoda, Mystacocarida, Copepoda, Cirripedia, Ascothoracida, Facetotecta, Euphausiacea and Penaeidea hatch from an egg as a free-living nauplius. Other crustaceans show an embryonic phase of development suggestive of a naupliar organization. Several features of the nauplius larva have been proposed as diagnostic characters for the Crustacea: a median (nauplius) eye; at least three pairs of head appendages (antennules, antennae, mandibles); a posteriorly directed fold (the labrum) extending over the mouth and a cephalic (nauplius) shield. The relationship between trilobite protaspis with at least four appendages and the crustacean nauplius remains unclear, but reports of a copepod orthonauplius with four appendages are rejected. Swimming is suggested to represent the underived mode of locomotion for the crustacean nauplius, and that naupliar swimming directly results in naupliar feeding which also is underived.
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  • 70
    ISSN: 1573-5117
    Keywords: population genetics ; evolution ; allozymes ; DNA ; marine genetics ; Acanthaster planci
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The basic assumptions that widespread marine species should show little spatial variation in genetic structure, given their high potential for dispersal on ocean currents, is being questioned. This has taken some time because there are few studies of widespread marine species over oceanic scales, few data sets that have the high density of sampling required for the detection of fine population structure, and there is little incentive to look further if initial analyses suggest the expected result. The interpretation of the population genetic structure of crown-of-thorns starfish (Acanthaster planci) has been found to vary considerably depending on the sample set included in the analyses and on the method of analysis used. Scatter plots of genetic distance or θ, and spatial autocorrelation approaches gave markedly different results ranging from no structure to isolation by distance. Only visual examination of maps of patterns of variation in allele variation first detected that crown-of-thorns starfish occupy large regions with little between population differentiation, but between which there are markedly higher levels of differentiation. These findings highlight the care required in interpreting population structure, particularly where there are few sample points. Many marine species may have population structures where sharp genetic disjunctions, not associated with any obvious environmental boundaries, separate regions of relative genetic homogeneity. Such population structures are very different from those traditionally assumed and are not yet understood. Further advances in understanding the genetic structure of marine species will demand an iterative approach where a greater number of samples are collected over particular regions identified by earlier interpretations.
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    Hydrobiologia 420 (2000), S. 15-27 
    ISSN: 1573-5117
    Keywords: phylogeny ; evolution ; allozymes ; rDNA ; DNA sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The first application of molecular systematics to sponges was in the 1980s, using allozyme divergence to dis-criminate between conspecific and congeneric sponge populations. Since this time, a fairly large database has been accumulated and, although the first findings seemed to indicate that sponge species were genetically more divergent than those of other marine invertebrates, a recent review of the available dataset indicates that levels of interspecific gene identities in most sponges fall within the normal range found between species of other invertebrates. Nevertheless, some sponge genera have species that are extremely divergent from each other, suggesting a possible polyphyly of these genera. In the 1990s, molecular studies comparing sequences of ribosomal RNA have been used to reappraise the phylogenetic relationships among sponge genera, families, orders and classes. Both the 18S small subunit and the 28S large subunit rRNA genes have been sequenced (41 complete or partial and 75 partial sequences, respectively). Sequences of 18S rRNA show good support for Porifera being true Metazoa, but they are not informative for resolving relationships among genera, families or orders. 28S rRNA domains D1 and D2 appear to be more informative for the terminal nodes and provide resolution for internal topologies in sufficiently closely related species, but the deep nodes between orders or classes cannot be resolved using this molecule. Recently, a more conserved gene, Hsp70, has been used to try to resolve the relationships in the deep nodes. Metazoan monophyly is very well supported. Nevertheless, the divergence between the three classes of Porifera, as well as the divergence between Porifera, Cnidaria and Ctenophora, is not resolved. Research is in progress using other genes such as those of the homeodomain, the tyrosine kinase domain, and those coding for the aggregation factor. For the moment the dataset for these genes is too restricted to resolve the phylogenetic relationships of these phyla. However, whichever the genes, the phylogenies obtained suggest that Porifera could be paraphyletic and that the phylogenetic relationships of most of the families and orders of the Demospongiae have to be reassessed. The Calcarea and Hexactinellida are still to be studied at the molecular level.
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  • 72
    ISSN: 1573-5133
    Keywords: Cyprinidae ; piscivores ; prey fish ; small barbs ; species flock ; evolution ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The endemic cyprinid species flock in Lake Tana consists of 15 species of large hexaploid barbs, eight of which are piscivorous. Previously, it was assumed that all piscivores preyed on the same small barb species, Barbus trispilopleura. In this paper we present a description of morphology and ecology of a new abundant small barb species, Barbus tanapelagius sp. nova (holotype RMNH 33731) from Lake Tana, Ethiopia, which appears to be the major prey species for the large pelagic piscivorous barbs. B. tanapelagius differs clearly in morphology from the other 3 small, diploid Barbus species known from Lake Tana, B. trispilopleura Boulenger, 1902, B. humilis Boulenger, 1902 and B. pleurogramma Boulenger, 1902. Conspicuous differences are its elongated body, large eye diameter, prominent and hooked lower jaw contour and colouration. Preliminary data suggest that B. tanapelagius also differs ecologically from the other small Barbus spp. by its pelagic, strictly zooplanktivorous feeding and its occurrence mainly in the deeper, offshore waters. The other small Barbus species are most probably largely benthic feeders and dominant in the shallow inshore waters. Previous views about the evolution of the present 8 endemic piscivorous large barb species therefore require reconsideration, as the present paper shows a more complex scenario including several prey species.
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    Hydrobiologia 420 (2000), S. 55-62 
    ISSN: 1573-5117
    Keywords: chromosomes ; evolution ; nucleolar organizer region
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The number of cytogenetic studies of marine fish has increased in recent years. Fish groups, such as Perciformes, which comprises many of the extant marine teleosts of economic importance, show little divergence in chromosome number and most species display a diploid number of 48 acrocentric chromosomes. In the Serranidae, Sparidae, Sciaenidae (Perciformes) and Mugilidae (Mugiliformes) small chromosome variations are restricted to subtle heterochromatin or nucleolar organizer region (NOR) modifications. There appears to exist a strict relationship between both absence of geographic barriers throughout the marine environment and high mobility of these animals (eggs, larvae, or adults), with a rarity of chromosome rearrangement at the macrostructural level. Moreover, a cellular homeostasis might also be important to karyotype maintenance among these fishes, limiting changes in the chromosome complement to cryptic chromosome rearrangements. Other groups, such as Blenniidae, Gobiidae and Scorpaenidae, for instance, show more extensive chromosome diversity, which is probably related to limited mobility. Numerical and structural chromosome polymorphisms and several sexual chromosome systems are recurrent among these fishes. A wide karyotypic diversification also characterizes the Tetraodontiformes, an interesting fish group with peculiar morphological, physiological and ecological characteristics.
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    Environmental biology of fishes 57 (2000), S. 443-449 
    ISSN: 1573-5133
    Keywords: parental care ; feeding behaviour ; evolution ; trade-off ; individual differences ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The function of the fin digging behaviour in increasing food availability for the offspring was analysed in the convict cichlid, Cichlasoma (Archocentrus) nigrofasciatum. Consistent individual differences in the frequency of fin digging were found in the parental fish. Examination of the gastrointestinal tract of young revealed that higher frequency of parental fin digging was associated with higher consumption of large and more profitable prey (Diptera larvae), which inhabited deep horizons of the bottom substrate and possibly were difficult to access without parental assistance. Thus, parental fin digging was initially associated with a significant increase of the offspring growth rate. However, at later brood intervals, when parental care ceased, the young of the high-digging parents were characterised by a poorer consumption of small larvae that were most accessible for them without parental aid and represented an increasingly more important component of their ration than large larvae. Offspring of the low-digging parents, on the other hand, presumably as a result of their individual experience, showed a considerably better consumption of small larvae, increasing their growth rate. As a consequence, prior parental fin digging did not affect the offspring body size after independence. Thus, there exist pronounced individual differences and alternative parental styles in the convict cichlid.
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    Plant molecular biology 42 (2000), S. 151-166 
    ISSN: 1573-5028
    Keywords: evolution ; homeodomain protein ; knox gene ; meristem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Knotted-like homeobox (knox) genes constitute a gene family in plants. Class I knox genes are expressed in shoot apical meristems, and (with notable exceptions) not in lateral organ primordia. Class II genes have more diverse expression patterns. Loss and gain of function mutations indicate that knox genes are important regulators of meristem function. Gene duplication has contributed to the evolution of families of homeodomain proteins in metazoans. We believe that similar mechanisms have contributed to the diversity of knox gene function in plants. Knox genes may have contributed to the evolution of compound leaves in tomato and could be involved in the evolution of morphological traits in other species. Alterations in cis-regulatory regions in some knox genes correlate with novel patterns of gene expression and distinctive morphologies. Preliminary data from the analysis of class I knox gene expression illustrates the evolution of complex patterns of knox expression is likely to have occurred through loss and gain of domains of gene expression.
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  • 76
    ISSN: 1573-5028
    Keywords: angiosperm ; development ; evolution ; fern ; gymnosperm ; MADS-box gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evolutionary developmental genetics (evodevotics) is a novel scientific endeavor which assumes that changes in developmental control genes are a major aspect of evolutionary changes in morphology. Understanding the phylogeny of developmental control genes may thus help us to understand the evolution of plant and animal form. The principles of evodevotics are exemplified by outlining the role of MADS-box genes in the evolution of plant reproductive structures. In extant eudicotyledonous flowering plants, MADS-box genes act as homeotic selector genes determining floral organ identity and as floral meristem identity genes. By reviewing current knowledge about MADS-box genes in ferns, gymnosperms and different types of angiosperms, we demonstrate that the phylogeny of MADS-box genes was strongly correlated with the origin and evolution of plant reproductive structures such as ovules and flowers. It seems likely, therefore, that changes in MADS-box gene structure, expression and function have been a major cause for innovations in reproductive development during land plant evolution, such as seed, flower and fruit formation.
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    Plant molecular biology 42 (2000), S. 181-194 
    ISSN: 1573-5028
    Keywords: actinorhiza ; endomycorrhizae ; evolution ; Frankia ; haemoglobins ; nod factors ; nodulation ; phylogeny ; rhizobia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this review we will first describe the different steps leading to nodule formation, and these will be compared with processes of non-symbiotic plant development and growth. In general, aspects of both actinorhizal as well as rhizobial symbiosis are described, but in several cases, the emphasis will be on the Rhizobium-legume symbiosis because more knowledge of this system is available. Subsequently, the phylogeny of nodulating plants is described and a comparison is made between several aspects of legume and actinorhizal nodulation. At the end of this paper the relationship between nodule symbiosis and endomycorrhizal symbiosis is described, and it is discussed to what extent the development of root nodules involves unique properties, or whether processes and genes have been recruited from common plant development and the endomycorrhizal symbiosis.
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    Journal of bioenergetics and biomembranes 32 (2000), S. 227-236 
    ISSN: 1573-6881
    Keywords: NDP kinase ; subunit interaction ; quaternary structure ; evolution ; mixed oligomers ; Dictyostelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Nucleoside (NDP) diphosphate kinases are oligomeric enzymes. Most are hexameric, but somebacterial enzymes are tetrameric. Hexamers and tetramers are constructed by assemblingidentical dimers. The hexameric structure is important for protein stability, as demonstratedby studies with natural mutants (the Killer-of-prune mutant ofDrosophila NDP kinase andthe S120G mutant of the human NDP kinase A in neuroblastomas) and with mutants obtainedby site-directed mutagenesis. It is also essential for enzymic activity. The function of the tetrameric structure is unclear.
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  • 79
    ISSN: 1573-6849
    Keywords: evolution ; genome ; Gossypium ; polyploidization ; repetitive element ; retrotransposon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Retrotransposons constitute a ubiquitous and dynamic component of plant genomes. Intragenomic and intergenomic comparisons of related genomes offer potential insights into retrotransposon behavior and genomic effects. Here, we have used fluorescent in-situ hybridization to determine the chromosomal distributions of a Ty1-copia-like retrotransposon in the cotton AD-genome tetraploid Gossypium hirsutum and closely related putative A- and D-genome diploid ancestors. Retrotransposon clone A108 hybridized to all G. hirsutum chromosomes, approximately equal in intensity in the A- and D-subgenomes. Similar results were obtained by hybridization of A108 to the A-genome diploid G. arboreum, whereas no signal was detected on chromosomes of the D-genome diploid G. raimondii. The significance and potential causes of these observations are discussed.
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    Genetica 109 (2000), S. 105-111 
    ISSN: 1573-6857
    Keywords: Drosophila ; evolution ; heterochromatin ; Y chromosome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Y chromosome evolution is characterized by the expansion of genetic inertness along the Y chromosome and changes in the chromosome structure, especially the tendency of becoming heterochromatic. It is generally assumed that the sex chromosome pair has developed from a pair of homologues. In an evolutionary process the proto-Y-chromosome, with a very short differential segment, develops in its final stage into a completely heterochromatic and to a great extends genetically eroded Y chromosome. The constraints evolving the Y chromosome have been the objects of speculation since the discovery of sex chromosomes. Several models have been suggested. We use the exceptional situation of the in Drosophila mirandato analyze the molecular process in progress involved in Y chromosome evolution. We suggest that the first steps in the switch from a euchromatic proto-Y-chromosome into a completely heterochromatic Y chromosome are driven by the accumulation of transposable elements, especially retrotransposons inserted along the evolving nonrecombining part of the Y chromosome. In this evolutionary process trapping and accumulation of retrotransposons on the proto-Y-chromosome should lead to conformational changes that are responsible for successive silencing of euchromatic genes, both intact or already mutated ones and eventually transform functionally euchromatic domains into genetically inert heterochromatin. Accumulation of further mutations, deletions, and duplications followed by the evolution and expansion of tandem repetitive sequence motifs of high copy number (satellite sequences) together with a few vital genes for male fertility will then represent the final state of the degenerated Y chromosome.
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  • 81
    ISSN: 1573-6849
    Keywords: cat ; chromosome painting ; comparative mapping ; dog ; evolution ; human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Domestic cats and dogs are important companion animals and model animals in biomedical research. The cat has a highly conserved karyotype, closely resembling the ancestral karyotype of mammals, while the dog has one of the most extensively rearranged mammalian karyotypes investigated so far. We have constructed the first detailed comparative chromosome map of the domestic dog and cat by reciprocal chromosome painting. Dog paints specific for the 38 autosomes and the X chromosomes delineated 68 conserved chromosomal segments in the cat, while reverse painting of cat probes onto red fox and dog chromosomes revealed 65 conserved segments. Most conserved segments on cat chromosomes also show a high degree of conservation in G-banding patterns compared with their canine counterparts. At least 47 chromosomal fissions (breaks), 25 fusions and one inversion are needed to convert the cat karyotype to that of the dog, confirming that extensive chromosome rearrangements differentiate the karyotypes of the cat and dog. Comparative analysis of the distribution patterns of conserved segments defined by dog paints on cat and human chromosomes has refined the human/cat comparative genome map and, most importantly, has revealed 15 cryptic inversions in seven large chromosomal regions of conserved synteny between humans and cats.
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  • 82
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    Journal of chemical ecology 26 (2000), S. 1773-1794 
    ISSN: 1573-1561
    Keywords: Grasshoppers ; polyphagy ; graminivory ; evolution ; secondary compound ; peritrophic envelope ; midgut ceca ; learning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Modern grasshoppers probably evolved from polyphagous ancestors endowed with the ability to tolerate many plant secondary compounds. This tolerance involves various behavioral and anatomical adaptations. Polyphagous grasshoppers have a relatively low level of sensitivity to the taste of many secondary compounds, and, if they do respond to the taste, have the capacity to habituate. This gives time for the induction of detoxifying enzymes so that unpalatable but potentially nutritious plants may be eaten safely. Associative learning involving secondary compounds may be important in food aversion learning, enabling the insects to avoid foods that have inappropriate nutrients, for example. Learning is also involved when grasshoppers develop associations between the taste of chemicals in the surface waxes of plants and internal leaf chemistry, enabling them to make faster decisions about the acceptability of a plant. Anatomically, the midgut ceca of polyphagous grasshoppers have well-developed posterior arms, and it is possible that these are especially important in detoxification, while some species, in addition, have a specialized pocket region in which macromolecules accumulate to be eliminated from the body when the lining of peritrophic envelope is drawn out. Polyphagous species also have thick peritrophic envelopes to which various phenolics become adsorbed. Finally, the midgut environment contains surfactants that reduce tannin–protein complexing except at very high tannin concentrations. Some polyphagous species can utilize secondary compounds as defensive substances or, in one case, in cuticular sclerotization. Grass feeding has evolved on numerous occasions from these polyphagous ancestors, and it has been associated with a loss of many of the characters providing protection from secondary compounds.
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    Origins of life and evolution of the biospheres 30 (2000), S. 459-466 
    ISSN: 1573-0875
    Keywords: biogenesis ; biological ; coevolution ; evolution ; models ; origin of life
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract What was the first living molecule – RNA or protein?This question embodies the major disagreement instudies on the origin of life. The fact that incontemporary cells RNA polymerase is a protein andpeptidyl transferase consists of RNA suggests theexistence of a mutual catalytic dependence betweenthese two kinds of biopolymers. I suggest that thisdependence is a `frozen accident', a remnant from thefirst living system. This system is proposed to be acombination of an RNA molecule capable of catalyzingamino acid polymerization and the resulting proteinfunctioning as an RNA-dependent RNA polymerase. Thespecificity of the protein synthesis is thought to beachieved by the composition of the surrounding mediumand the specificity of the RNA synthesis – by Watson– Crick base pairing. Despite its apparent simplicity,the system possesses a great potential to evolve intoa primitive ribosome and further to life, as it isseen today. This model provides a possible explanationfor the origin of the interaction between nucleicacids and protein. Based on the suggested system, Ipropose a new definition of life as a system ofnucleic acid and protein polymerases with a constantsupply of monomers, energy and protection.
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    Antonie van Leeuwenhoek 77 (2000), S. 235-239 
    ISSN: 1572-9699
    Keywords: Aspergillus section Fumigati ; β-tubulin gene ; evolution ; phylogenetic analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Isolates representing newly described Neosartorya species, and isolates with abnormal morphologies from Aspergillus section Fumigati were examined by phylogenetic analysis of sequences of part of their β-tubulin gene. Phylogenetic analyses supported the earlier suggestions that heterothallism is a derived character, and that sexuality was lost several times during the evolution of Aspergillus section Fumigati. The heterothallic N. fennelliae and N. udagawae strains were found to be closely related to the homothallic Neosartorya sp. NRRL 4179 and N. aureola, respectively. Aspergillus sp. FRR 1266, which was earlier described as a variant of A. fumigatus, was found to be closely related to A. viridinutans. Another abnormal asexual isolate was found to be closely related to A. fumigatus and N. fischeri. Phylogenetic relationships among newly described Neosartorya species and other taxa were successfully established based on phylogenetic analysis of β-tubulin sequences.
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    Antonie van Leeuwenhoek 77 (2000), S. 117-133 
    ISSN: 1572-9699
    Keywords: Archaea ; Bacteria ; hydrothermal vents ; in situ hybridization ; molecular ecology ; probes ; 16S rRNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The study of the structure and diversity of hydrothermal vent microbial communities has long been restricted to the morphological description of microorganisms and the use of enrichment culture-based techniques. Until recently the identification of the culturable fraction required the isolation of pure cultures followed by testing for multiple physiological and biochemical traits. However, peculiar inhabitants of the hydrothermal ecosystem such as the invertebrate endosymbionts and the dense microbial mat filaments have eluded laboratory cultivation. Substantial progress has been achieved in recent years in techniques for the identification of microorganisms in natural environments. Application of molecular approaches has revealed the existence of unique and previously unrecognized microorganisms. These have provided fresh insight into the ecology, diversity and evolution of mesophilic and thermophilic microbial communities from the deep-sea hydrothermal ecosystem. This review reports the main discoveries made through the introduction of these powerful techniques in the study of deep-sea hydrothermal vent microbiology.
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  • 86
    ISSN: 1573-5079
    Keywords: chlorophyll a ; Chl a-binding protein ; evolution ; light-harvesting complex ; LHC I ; Porphyridium cruentum ; reconstitution ; red alga ; zeaxanthin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Porphyridium cruentum light harvesting complex (LHC) binds Chl a, zeaxanthin and β-carotene and comprises at least 6 polypeptides of a multigene family. We describe the first in vitro reconstitution of a red algal light-harvesting protein (LHCaR1) with Chl a/carotenoid extracts from P. cruentum. The reconstituted pigment complex (rLHCaR1) is spectrally similar to the native LHC I, with an absorption maximum at 670 nm, a 77 K fluorescence emission peak at 677 nm (ex. 440 nm), and similar circular dichroism spectra. Molar ratios of 4.0 zeaxanthin, 0.3 β-carotene and 8.2 Chl a per polypeptide for rLHCaR1 are similar to those of the native LHC I complex (3.1 zeaxanthin, 0.5 β-carotene, 8.5 Chl a). The binding of 8 Chl a molecules per apoprotein is consistent with 8 putative Chl-binding sites in the predicted transmembrane helices of LHCaR1. Two of the putative Chl a binding sites (helix 2) in LHCaR1 were assigned to Chl b in Chl a/b-binding (CAB) LHC II [Kühlbrandt et al. (1994) Nature 367: 614–21]. This suggests either that discrimination for binding of Chl a or Chl b is not very specific at these sites or that specificity of binding sites evolved separately in CAB proteins. LHCaR1 can be reconstituted with varying ratios of carotenoids, consistent with our previous observation that the carotenoid to Chl ratio is substantially higher in P. cruentum grown under high irradiance. Also notable is that zeaxanthin does not act as an accessory light-harvesting pigment, even though it is highly likely that it occupies the position assigned to lutein in the CAB LHCs.
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  • 87
    ISSN: 1573-5109
    Keywords: evolution ; genetic resources ; RAPDs ; seed protein electrophoresis ; taxonomy ; Vicia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The genetic diversity of 58 wild and weedy populations representing taxa within the V. sativa aggregate from the former USSR, 4 cultivars of V. sativa, 2 accessions of V. cordata and 3 accessions of V. macrocarpa from Mediterranean countries were analysed using randomly amplified DNA fragments (RAPDs) and seed protein electrophoresis (SDS-PAGE). Interspecific variation between taxa in the V. sativa aggregate could readily be detected using both techniques. RAPDs and seed protein patterns were found to be an effective means of identifying accessions that cannot be identified clearly by morphological criteria alone. RAPD and seed protein analysis revealed a clear relationship between observed genetic variation of populations and their geographical distribution. Populations from each region had their own gene pools. Geographical variation was detected in V. segetalis. The degree of genetic divergence between local populations was usually related to proximity. In several locations where wild and weedy populations of different V. sativa agg. taxa grow sympatrically, intermediate forms could be detected at the DNA and protein levels. Both RAPD and seed protein analysis support the view that the V. sativa aggregate consists of 8 taxa warranting recognition at the species level. Several species in this aggregate are evolving intra-specific groups which can readily be detected at the molecular level.
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  • 88
    ISSN: 1573-5117
    Keywords: cladocerans ; life history ; demography ; size structure ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Daphnia models for individual growth and population dynamics have been developed in the manner of models developed by Gurney, McCauley, Andersen and others. All or most of the earlier models were parameterized for Daphnia pulex; we have used the D. pulex model as a baseline model for other species of Daphnia such as magna, galeata and also Bosmina longirostris. Because of the lack of ample data for D. magna, D. galeata and B. longirostris, some of the physiological data had to be relied on the other species whose data were available and in some case calibrated. We were able to produce reasonable results for individual growth as well as population dynamics under the controlled laboratory conditions. Most of the results were compared with the available laboratory data for population as well as growth. All the simulations have been done under high and low food concentrations. The animals are assumed to be feeding on green algae (Chlamydomonas reinhardtti) under the laboratory conditions of 18–20°C. The continuous growth until the end of the life was observed in smaller B. longirostris, whereas rapid growth in the beginning and slower after the start of the reproduction was observed in Daphnia species. The smaller species matured earlier than larger species. B. longirostris population sustained better than Daphnia species in medium food concentrations.
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    Genetica 108 (2000), S. 57-72 
    ISSN: 1573-6857
    Keywords: Alu ; evolution ; human specific ; polymorphism ; retroposition ; SINES ; 7SL RNA ; YAP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Aluinsertional elements, the most abundant class of SINEs in humans are dimeric sequences approximately 300 bp in length derived from the 7SL RNA gene. These sequences contain a bipartite RNA pol III promoter, a central poly A tract, a 3′ poly A tail, numerous CpG islands and are bracketed by short direct repeats. An estimated 500,000 to 1 × 106units are dispersed throughout the human haploid genome primarily in AT rich neighborhoods located within larger GC dense chromosomal regions via a mechanism known as retroposition. Retroposition activity of Aluelements is determined by both internal and flanking regulatory elements as well as distant genes affecting transcription or transcript stability. Aluelements impact the organization and expression of the human genome at many levels including the processes of recombination, transcription and translation. Twelve subfamilies of Aluare defined by distinct patterns of diagnostic base substitutions. Subfamilies may be classified as young, intermediate or old reflecting the time since the start of retroposition by their members. Some insertions of the youngest subfamilies are not yet fixed in the human species and represent polymorphic loci. Alus are excellent molecular markers for a variety of reasons. They aid in tracing the complex pattern of duplication and rearrangements that occurred during the evolution of primate genome. Unlike other mutations, Alusequences are rarely lost completely once retroposed, have a defined ancestral state and are free from homoplasy since independent and identical insertions are highly unlikely. Because of these characteristics, Alus are literally molecular fossils. Polymorphic Aluloci are especially useful in studies of human genetic diversity and in pedigree and forensicanalysis.
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    Journal of comparative physiology 170 (2000), S. 531-535 
    ISSN: 1432-136X
    Keywords: Key words Large intestine ; Furrow of proximal colon ; Digesta ; Bacteria ; Soft and hard feces ; Nutrias ; Myocastor coypus ; AbbreviationsN nitrogen ; TAA total amino acids ; DAP diaminopimelic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The bacterial level of soft feces is higher than that of hard feces in nutrias. This suggests the heterogeneity of bacterial density in the large intestine. To show the heterogeneity of bacteria in the contents of the large intestine in nutrias, we divided the contents of the large intestine into 12 regions, then measured the nitrogen (N), total amino acids (TAA) and diaminopimelic acid (DAP), a bacterial marker, of these regions. Levels of N, TAA and DAP varied along the cross section of the proximal colon. The greater curvature of the main lumen and furrow had higher N, TAA and DAP concentrations than the lesser curvature. We also examined the involvement of the furrow in producing two types of feces differing in bacterial nitrogen content by surgically preventing the flow of the furrow contents. We compared the concentrations of N, TAA and DAP between soft and hard feces among operated, sham-operated and intact animals. Surgical closure of the furrow abolished the difference in levels of N, TAA and DAP between soft and hard feces, suggesting that the furrow of the proximal colon is responsible for making the bacterial density higher in soft feces than in hard feces.
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    Journal of logic, language and information 9 (2000), S. 419-424 
    ISSN: 1572-9583
    Keywords: Artificial Intelligence ; computability ; constructibility ; culture ; evolution ; society ; symbol grounding ; Turing ; Turing Machine ; Turing Test
    Source: Springer Online Journal Archives 1860-2000
    Topics: Linguistics and Literary Studies , Computer Science
    Notes: Abstract The Turing Test (TT), as originally specified, centres on theability to perform a social role. The TT can be seen as a test of anability to enter into normal human social dynamics. In this light itseems unlikely that such an entity can be wholly designed in an“off-line” mode; rather a considerable period of training insitu would be required. The argument that since we can pass the TT,and our cognitive processes might be implemented as a Turing Machine(TM), that consequently a TM that could pass the TT could be built, isattacked on the grounds that not all TMs are constructible in a plannedway. This observation points towards the importance of developmentalprocesses that use random elements (e.g., evolution), but in these casesit becomes problematic to call the result artificial. This hasimplications for the means by which intelligent agents could bedeveloped.
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    Journal of optimization theory and applications 107 (2000), S. 559-571 
    ISSN: 1573-2878
    Keywords: nonlocal conditions ; mild solutions ; evolution ; controllability ; fixed points
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper, we establish sufficient conditions for the controllability ofsecond-order differential inclusions in Banach spaces with nonlocalconditions. We rely on a fixed-point theorem for condensing maps due toMartelli.
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    World journal of microbiology and biotechnology 16 (2000), S. 495-497 
    ISSN: 1573-0972
    Keywords: Bacteria ; biodegradation ; 2,4-D ; soil microcosm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Bacterial isolates (NJ 10 and NJ 15) capable of degrading the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) were isolated from agricultural soil by enrichment culture technique. The isolates exhibited substantial growth in mineral salt medium supplemented with 0.1–0.5% of 2,4-D as a sole source of carbon and energy. Based on their morphological, cultural and biochemical characteristics, the isolates NJ 10 and NJ 15 have been identified as Pseudomonas species and Pseudomonas aeruginosa, respectively. Biodegradation studies in a soil microcosm enriched with pure cultures of the isolates demonstrated a time-dependent disappearance of 2,4-D from the 100 mg/kg herbicide-amended soil. The HPLC data analysis revealed 96.6 and 99.8% degradation in the soil inoculated with the pure cultures of isolates NJ 10 and NJ 15, respectively with in 20 days of incubation at 30 °C. Both the isolates showed significant solubilization of inorganic phosphate [Ca3(PO4)2] on the specific Pikovskaya's medium.
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    World journal of microbiology and biotechnology 16 (2000), S. 115-134 
    ISSN: 1573-0972
    Keywords: Bacteria ; biocontrol ; biological control ; compost ; disease ; fungi ; microbiology ; pathogen ; suppression ; turf ; turfgrass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The relationships among the chemical, physical and biological aspects of compost and their role in suppression of turfgrass pathogens are reviewed. The composting process, mediated by microbial activity, is affected by physical and chemical characteristics which include temperature, aeration, moisture content, C:N ratio and pH. In the absence of parameter restrictions, the microbial community follows a predictable successional pattern resulting in the re-colonization of compost with metabolically active mesophilic populations that can be suppressive towards plant pathogens. Although mechanisms of suppression are not fully understood, those postulated include physiochemical and biological characteristics. The physiochemical characteristics of composts can alter suppressive properties through direct effects on pathogens and antagonistic microorganisms, or indirect effects on host systems through the supply of nutrients, improvement of soil structure, porosity and water retention capabilities, along with other factors. Biological characteristics centre on microbial community involvement in suppressive mechanisms, which can include one or a combination of competition for nutrients, antibiosis, lytic and other extracellular enzyme production, parasitism, predation and host-mediated induction of resistance. As a result of the potential benefits of compost, there is considerable interest in determining the capacity for composts to suppress turfgrass pathogens. Although the exact mechanisms of suppression are largely unknown, there appear to be several factors that play an integrated role. The use of composts that successfully suppress turfgrass diseases will permit a reduction in the use of chemical controls, and slow the development of fungicide resistance.
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  • 95
    ISSN: 1573-3297
    Keywords: Artificial selection ; correlated responses ; nest-building behavior ; Mus domesticus ; realized heritability ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Previous divergent selection for nest-building behavior at 22 ± 1°C resulted in a 40-fold difference between the high and the low lines in amount of cotton used to build a nest. Correlated responses to selection indicated positive genetic correlations with body weight, nest-building at 4 ± 1°C, and litter size and negative genetic correlations with food consumption. At generation 46, the replicate high-selected (High 1 × High 2), randomly bred control (Control 1 × Control 2), and low-selected (Low 1 × Low 2) lines were crossed and the F1 showed significant heterosis for nest-building behavior. Regression of the F3 on the F2 generation gave heritability estimates of 0.16 ± 0.10 for the high and 0.07 ± 0.10 for the low cross, revealing a potential to break the selection limit (at least in the high direction), which had been reached at about 20 generations of selection. Indeed, renewed selection resulted in responses in both the high and the low directions of nesting, yielding realized heritabilities of 0.29 ± 0.02 and 0.30 ± 0.004, respectively. Replicated renewed selection, using the F3 generation as the base population, in the high direction of nesting resulted in correlated increases in nest-building at 4 ± 1°C, litter size, and food consumption. Body weight did not change. The positive correlation with food consumption is opposite in sign compared to the original selection experiment. This indicates that the evolutionary potential of a population to adapt to a changing environment not only depends on its current genetic variability in one adaptive trait, but may be constrained by genetic correlations changing over the course of selection.
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    Evolutionary ecology 14 (2000), S. 25-38 
    ISSN: 1573-8477
    Keywords: animal coloration ; body temperature ; ectotherm ; evolution ; Orthoptera ; poly-morphism ; Tetrix subulata ; thermoregulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ectothermic animals rely on external heat sources and behavioral thermoregulation to control body temperature, and are characterized by possessing physiological and behavioural traits which are temperature dependent. It has therefore been suggested that constraints on the range of body temperatures available to individuals imposed by phenotypic properties, such as coloration, may translate into differential fitness and selection against thermally inferior phenotypes. In this paper, I report an association between thermal preferences and thermal capacity (the ability to warm up when insolated) across different genetically coded color morphs of the pygmy grasshopper Tetrix subulata. Data on behavioral thermoregulation of individuals in a laboratory thermal gradient revealed a preference for higher body temperatures in females than in males, and significant variation among colour morphs in preferred body temperatures in females, but not in males. The variation in females was in perfect accordance with estimates of morph-specific differences in thermal capacity. Thus, dark morphs not only attain higher temperatures when exposed to augmented illumination, but also prefer higher body temperatures, compared to paler morphs. This intra-population divergence probably reflects an underlying variation among colour morphs in temperature optima, and is consistent with the notion that coloration, behaviour and physiology evolve in concert.
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    Journal of bioeconomics 2 (2000), S. 153-168 
    ISSN: 1573-6989
    Keywords: altruism ; culture ; evolution ; group selection ; natural selection ; new institutional economics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Economics
    Notes: Abstract When transactions and information are costly and exchange is non-simultaneous, ‘institutions matter’. They matter because exchange under these circumstances subjects the participants to potentially harmful behaviors by other participants, among which are: opportunistic behavior, agency, the free-rider problem, cheating, moral hazard, and adverse selection. Institutions constrain these behaviors, allowing the participants to take advantage of the gains from trade and specialization, and thereby facilitating cooperation. Individuals adhere to institutional rules because they gain by doing so. Because the individual gains are inseparable from the structure of the institutions, the institutions themselves necessarily become the focus of the analysis—as we see in the new institutional economics (NIE). The new group selection position in biology involves a similar shift in focus from the level of the individual to the group when studying the evolution of altruism. But some of the proponents of group selection go further, arguing that altruism in biology evolves because it is in the interest of the group, but not the individual. In fact, group level analysis is necessary in biology, as in the NIE, because it allows for the discovery of ‘institutions’ that constrain cheating, opportunistic behavior, etc., thereby making participation in the group in the long-run self-interest of the individual.
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    Entomologia experimentalis et applicata 91 (1999), S. 359-368 
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ssp. arcuata ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; host plant range ; near-isogenic ; Y-linkage ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Y-linked gene (R-gene) in the flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) confer the ability of larvae to survive on types of the plant Barbarea vulgaris R.Br. (Brassicaceae) which are immune to attack by susceptible conspecifics. Two near-isogenic flea beetle lines were developed. The YE-line contained the Y-linked R-gene, and male larvae from this line survived on B. vulgaris. The ST-line did not contain the gene and did not survive on the plant. The YE-line had been developed through 8–9 generations of backcrosses (YE-males with ST-females) and the two lines were considered to be isogenic except for genes located on the Y-chromosome. A single copy of the Y-linked gene is sufficient to transfer a susceptible genotype (ST) into a resistant genotype (YE) which is able to utilize a plant that is immune to attack by specimens without R-genes. The Y-linked gene had no effects on survival on other plant species tested. The gene did not have any effect on developmental times and weights of adult beetles reared on other plants than B. vulgaris. Developmental times of larvae with the Y-linked gene were longer on B. vulgaris than on normal host plants, R. sativus and S. arvensis, but the adults obtained the same size on these plant species. No trade-offs of the Y-linked gene were discovered. The results suggest that the occurrence of the Y-linked gene is a derived trait which has enabled the flea beetle to expand its host plant range. The evolution of a host shift to B. vulgaris seems not to be favoured by the presence of this single gene.
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    Entomologia experimentalis et applicata 91 (1999), S. 29-35 
    ISSN: 1570-7458
    Keywords: chemoreception ; deterrents ; Pieris ; Brassicaceae ; cardenolides ; host-plant selection ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pieris butterflies (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants. They exploit glucosinolates, secondary plant metabolites chemotaxonomically characteristic for this plant family, as token stimuli. In addition to particular glucosinolates, some genera of the Cruciferae contain cardenolides, steroidal allelochemicals that act as potent feeding and oviposition deterrents to several Pieris species. We investigated the sensory mechanisms by which these compounds are perceived in larvae. Pieris caterpillars and many other lepidopterous species are endowed with so-called generalist deterrent receptors, that respond to a broad spectrum of secondary plant substances. In Pieris caterpillars we found a second type of deterrent chemoreceptor in maxillary styloconic taste sensilla. This neuron is very sensitive to cardenolides (threshold 0.1–0.3 μM). The generalist deterrent receptor also responds to these substances but its threshold lies at 50–100× higher concentrations. In behavioural preference experiments Pieris brassicae L. caterpillars preferred cardenolide-treated cabbage leaf discs when confronted with a choice between them and a deterrent substance that does not occur in the Brassicaceae. The cardenolides acted as potent deterrents when offered against untreated cabbage leaf discs. This demonstrates that the balance of activity elicited in the two types of deterrent chemoreceptors determines the behavioural decision.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Acta biotheoretica 47 (1999), S. 29-40 
    ISSN: 1572-8358
    Keywords: Sexual selection ; mate selection ; gamete selection ; evolution ; ploidy ; asssortative mating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Results of an agent-based computer simulation of the evolution of diploid sexual organisms showed that several mate selection strategies confer much higher average fitness to the simulated populations, and higher evolutionary stability to the alleles coding for these strategies, than random mating. Strategies which select for 'good genes' were very successful, and so were strategies based on assortative mating. The results support the hypothesis that mating is not likely to be random in nature and that the most successful mate selection strategies are those based on assortative mating or on advantageous genes.
    Type of Medium: Electronic Resource
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