55 research outputs found

    Net phytoplankton and zooplankton in the New York Bight, January 1976 to February 1978, with comments on the effects of wind, Gulf Stream eddies, and slope water intrusions

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    Results are given of monthly net phytoplankton and zooplankton sampling from a 10 m depth in shelf, slope, and Gulf Stream eddy water along a transect running southeastward from Ambrose Light, New York, in 1976, 1977, and early 1978. Plankton abundance and temperature at 10 m and sea surface salinity at each station are listed. The effects of atmospheric forcing and Gulf Stream eddies on plankton distribution and abundance arc discussed. The frequency of Gulf Stream eddy passage through the New York Bight corresponded with the frequency of tropical-subtropical net phytoplankton in the samples. Gulf Stream eddies injected tropical-subtropical zooplankton onto the shelf and removed shelfwater and its entrained zooplankton. Wind-induced offshore Ekman transport corresponded generally with the unusual timing of two net phytoplankton maxima. Midsummer net phytoplankton maxima were recorded following the passage of Hurricane Belle (August 1976) and a cold front (July 1977). Tropical-subtropical zooplankton which had been injected onto the outer shelf by Gulf Stream eddies were moved to the inner shelf by a wind-induced current moving up the Hudson Shelf Valley. (PDF file contains 47 pages.

    Variability of Temperature and Salinity in the Middle Atlantic Bight and Gulf of Maine

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    Monitoring of the waters of the Middle Atlantic Bight and Gulf of Maine has been conducted by the MARMAP Ships of Opportunity Program since the early 1970's. Presented in this atlas are portrayals of the temporal and spatial patterns of surface and bottom temperature and surface salinity for these areas during the period 1978-1990. These patterns are shown in the form of time-space diagrams for single-year and multiyear (base period) time frames. Each base period figure shows thirteen-year (1978-1990) mean conditions, sample variance in the form of standard deviations of the measured values, and data locations. Each single-year figure displays annual conditions, sampling locations, and departures of annual conditions from the thirteen-year means, expressed as algebraic anomalies and standardized anomalies. (PDF file contains 112 pages.

    Einfluss ökologischer Bewirtschaftung und verschiedener Kulturen auf die Regenwurmfauna

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    Problemstellung/Ziele:Vorkommen und Artenzusammensetzung der Regenwurmpopulation haben eine grosse Bedeutung im nachhaltigen Ackerbau. Als Architekten und Bauarbeiter des Bodens beeinflussen die Regenwürmer verschiedene Parameter der Bodenfruchtbarkeit und damit das Wachstums der Kulturpflanzen. Der Landwirt beeinflusst das Regenwurmvorkommen bei vorgegebenem Standort und Fruchtfolge vor allem durch Bewirtschaftungsmassnahmen wie Düngung, Pflanzenschutz und Bodenbearbeitung. Um Richtung und Ausmass dieser Einflüsse zu erkennen untersuchten wir von 1997 bis 2001 die Regenwurmpopulationen im ökologischen und den integrierten Anbausystemen des Vergleichsversuches Burgrain (D. Dubois, 1999). Fazit: Ökologische Bewirtschaftung förderte auf Burgrain spezifisch das Vorkommen von anözischen Lumbricus und endogäischen Arten; hingegen nicht das Vorkommen von anözischen Nicodrilus Arten. Letztere wurden hingegen sehr deutlich durch die kulturbedingten Bewirtschaftungsmassnahmen beeinflusst. Besonders das Pflügen im Oktober vor Winterweizen wirkte sich negativ auf die tiefgrabenden anözischen Nicodrilus Arten aus. Hier gilt es Verbesserungsmöglichkeiten zu prüfen

    Genetic diversity and population structure inferred from the partially duplicated genome of domesticated carp, Cyprinus carpio L.

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    Genetic relationships among eight populations of domesticated carp (Cyprinus carpio L.), a species with a partially duplicated genome, were studied using 12 microsatellites and 505 AFLP bands. The populations included three aquacultured carp strains and five ornamental carp (koi) variants. Grass carp (Ctenopharyngodon idella) was used as an outgroup. AFLP-based gene diversity varied from 5% (grass carp) to 32% (koi) and reflected the reasonably well understood histories and breeding practices of the populations. A large fraction of the molecular variance was due to differences between aquacultured and ornamental carps. Further analyses based on microsatellite data, including cluster analysis and neighbor-joining trees, supported the genetic distinctiveness of aquacultured and ornamental carps, despite the recent divergence of the two groups. In contrast to what was observed for AFLP-based diversity, the frequency of heterozygotes based on microsatellites was comparable among all populations. This discrepancy can potentially be explained by duplication of some loci in Cyprinus carpio L., and a model that shows how duplication can increase heterozygosity estimates for microsatellites but not for AFLP loci is discussed. Our analyses in carp can help in understanding the consequences of genotyping duplicated loci and in interpreting discrepancies between dominant and co-dominant markers in species with recent genome duplication

    Colza – La discipline reine des grandes cultures bio

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    La culture du colza est risquée mais intéressante: elle permet de réaliser une marge brute aussi élevée qu’avec du blé. Et la demande d’huile de colza pressée à froid est nettement supérieure à l’offre. Les temps sont donc favorables pour ceux qui – bien préparés – désirent s’attaquer à la «discipline reine» des grandes cultures biologiques. Depuis 2005, la surface des cultures biologiques de colza a passé en Suisse de 5 à 150 hectares. Une histoire à succès qui continue: les coopératives Biofarm et PROGANA cherchent de nouveaux producteurs pour couvrir la demande durablement forte d’huile de colza biologique pressée à froid

    Raps – die Königsdisziplin im Bioackerbau

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    Der Rapsanbau ist risikobehaftet, aber durchaus interessant: Es lässt sich ein ähnlich hoher Deckungsbeitrag erwirtschaften wie mit Weizen. Und die Nachfrage nach kalt gepresstem Biorapsöl übersteigt das Angebot deutlich. Gute Zeiten für Einsteigerinnen und Einsteiger die sich – gut vorbereitet – an die «Königsdisziplin» des Bioackerbaus wagen wollen. Die Anbaufläche von Bioraps in der Schweiz konnte seit dem Jahr 2000 von 5 auf 150 Hektaren gesteigert werden. Eine Erfolgsgeschichte mit Fortsetzung: Die Biofarm Genossenschaft sucht weitere Produzenten, um die anhaltend grosse Nachfrage nach kalt gepresstem Biorapsöl zu decken

    Biodiversity of 52 chicken populations assessed by microsatellite typing of DNA pools

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    In a project on the biodiversity of chickens funded by the European Commission (EC), eight laboratories collaborated to assess the genetic variation within and between 52 populations from a wide range of chicken types. Twenty-two di-nucleotide microsatellite markers were used to genotype DNA pools of 50 birds from each population. The polymorphism measures for the average, the least polymorphic population (inbred C line) and the most polymorphic population (Gallus gallus spadiceus) were, respectively, as follows: number of alleles per locus, per population: 3.5, 1.3 and 5.2; average gene diversity across markers: 0.47, 0.05 and 0.64; and proportion of polymorphic markers: 0.91, 0.25 and 1.0. These were in good agreement with the breeding history of the populations. For instance, unselected populations were found to be more polymorphic than selected breeds such as layers. Thus DNA pools are effective in the preliminary assessment of genetic variation of populations and markers. Mean genetic distance indicates the extent to which a given population shares its genetic diversity with that of the whole tested gene pool and is a useful criterion for conservation of diversity. The distribution of population-specific (private) alleles and the amount of genetic variation shared among populations supports the hypothesis that the red jungle fowl is the main progenitor of the domesticated chicken

    Genomic microsatellites identify shared Jewish ancestry intermediate between Middle Eastern and European populations

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    <p>Abstract</p> <p>Background</p> <p>Genetic studies have often produced conflicting results on the question of whether distant Jewish populations in different geographic locations share greater genetic similarity to each other or instead, to nearby non-Jewish populations. We perform a genome-wide population-genetic study of Jewish populations, analyzing 678 autosomal microsatellite loci in 78 individuals from four Jewish groups together with similar data on 321 individuals from 12 non-Jewish Middle Eastern and European populations.</p> <p>Results</p> <p>We find that the Jewish populations show a high level of genetic similarity to each other, clustering together in several types of analysis of population structure. Further, Bayesian clustering, neighbor-joining trees, and multidimensional scaling place the Jewish populations as intermediate between the non-Jewish Middle Eastern and European populations.</p> <p>Conclusion</p> <p>These results support the view that the Jewish populations largely share a common Middle Eastern ancestry and that over their history they have undergone varying degrees of admixture with non-Jewish populations of European descent.</p

    Departures of 1996 Temperatures and Salinities in the Middle Atlantic Bight and Gulf of Maine from Historical Means

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