3,202 research outputs found

    Green light for gene targeting in plants

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    Annual and Season Weight Changes in a Thirteen-Lined Ground Squirrel Population, Itasca State Park, Minnesota

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    The ecology of the thirteen-lined ground squirrel (Citellus tridecemlineotus) has been under investigation since 1954 on the grounds of the University of Minnesota Forestry and Biological Station located in Itasca State Park, Minnesota. Over the 11-year period, data have been collected on individuals of this small, relatively isolated, population. Studies of population dynamics, movements, activity patterns, and weights have been stressed, chiefly during the three summer months of June, July, and August. In 1964, the senior author carried out field work for the entire season from April 30 to September 14

    Amphicarpic Legumes for Tropical Pasture Persistence

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    Amphicarpy, by which a plant produces underground seeds in addition to aerial fruits, is found in many plant families and in species of at least 15 legume genera. First studies on the tropical Centrosema rotundifolium and subtropical Macroptilium panduratum revealed for both species, besides their stoloniferous growth habit, two important mechanisms for survival under unfavorable conditions: (1) Underground meristems and reserve organs, and (2) regeneration from a soil seed reserve based on underground, aerial-flowering independent, seed production. Underground seed production was for both species particularly high on very sandy soils, but amphicarpy enables the plants to exhibit a plasticity response to unfavourable soil conditions by changing resource allocation from underground to above-ground reproduction. The latter, which seems to be influenced by cross-pollination and thus aids gene-recombination, favours spreading of plant populations whereas underground reproduction ensures population survival on-site. Preliminary information on the agronomic potential of both species is given and several research needs are highlighted

    Forschungspolitik als Ordnungspolitik: Das Modell Fraunhofer-Gesellschaft und seine Genese im Forschungssystem der Bundesrepublik Deutschland

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    Das Papier untersucht die Genese und Institutionalisierung der Fraunhofer-Gesellschaft als Organisation für die Vertragsforschung im außeruniversitären Forschungssystem der Bundesrepublik. In der Folge interorganisatorischer Domänenkonf likte wurde die Gesellschaft in der Mitte der fünfziger Jahre zunächst aus der Forschungsfinanzierung des Bundes ausgeschlossen. Im Interesse ihrer Überlebenssicherung nutzte sie die Gelegenheit, mit Unterstützung vor allem durch das Land Baden-Württemberg in der industriellen Vertragsforschung tätig zu werden, drohte mit diesem Konzept aber an Schwellenproblemen zu scheitern. Militärische Forschungsmittel ermöglichten es der Gesellschaft, diese Schwellenprobleme zu überwinden und ein moderates, aber stabiles Wachstum der zivilen Vertragsforschung herbeizuführen. An diese Entwicklung knüpfte die Reform der Gesellschaft durch die Bundesregierung und ihr Ausbau zur Trägerorganisation in der angewandten Forschung am Anfang der siebziger Jahre lediglich an. Das "Modell Fraunhofer-Gesellschaft" beruht auf institutionellen Strukturen, die sich in einem Prozeß von situativ ineinandergreifenden Verkettungen und einer daraus resultierenden pfad-abhängigen Wachstumsdynamik der Vertragsforschung herausgebildet haben.This paper examines the genesis and institutionalization of the Fraunhofer-Gesellschaft (FhG) as an organization for contract-research in the West-German research system outside the universities. As a result of interorganizational conf licts of domain in the midf ifties, the FhG was for the time being excluded from state-funding. The society survived by taking the chance of conducting contract-research subsidized mainly by Baden-Württemberg. The concept of contractresearch, however, was on the brink of failure due to threshold-problems. Military research funds made it possible for the FhG to cross these threshold-problems and to induce a moderate but stable growth of civilian contract-research. The reformation of the society by the federal government and its extension to the mainly responsible institution in the field of applied research during the early seventies only picked up this development. The "Modell Fraunhofer-Gesellschaft" is based on institutional structures which emerged in a process of situative "lock-ins" leading to a pathdependend increase of contract-research.Vorbemerkung Verzeichnis der Abkürzungen 1 Vom "Lumpensammler" zum Forschungskonzern. Das Rätsel der zwei Fraunhofer-Gesellschaften 2 Der kurze Aufstieg und rasche Niedergang der Fraunhofer-Gesellschaft als "komplementäre" Forschungsorganisation am Beginn der fünfziger Jahre 2.1 Gründungsabsicht und Zielverschiebung. Von der bayerischen Landeseinrichtung zur dritten "Säule" des bundesdeutschen Forschungssystems 2.2 Das Königsteiner Abkommen und der Domänenkonflikt mit der Deutschen Forschungsgemeinschaft und der Max-Planck-Gesellschaft 2.3 Bruch mit dem Stifterverband und dem Bundesministerium für Wirtschaft. Der vorläufige Ausschluß der FhG aus der Forschungsförderung des Bundes 3 Vertragsforschung als Nischenstrategie. Das forschungspolitische Konzept der südwestlichen Länder und der Beitrag der militärischen Forschung zum "Modell Fraunhofer-Gesellschaft" 3.1 Forschungspolitik im Dienst der Industriepolitik. Das Interesse Baden-Württembergs an der Vertragsforschung und die neue Identität der FhG 3.2 Der Teufelskreis von fehlenden Mitteln für die Eigenforschung und ausbleibenden Erträgen aus der Vertragsforschung 3.3 Militärische Forschung als Eigenforschung. Auswege aus dem Dilemma 3. 3 .1 Der Abbau des Juliusturms und die Isolation der militärischen Forschung 3.3.2 Die Funktion militärischer Projektmittel für das organisatorische Wachstum der FhG 3. 4 Dezentrale Akquisition und zentrale Mittelverteilung. Organisatorische Strukturmerkmale der FhG als Folge chronisch knapper Mittel für die Eigenforschung 4 Vom Kompetenzstreit zwischen Bund und Ländern zur ordnungspolitischen Aufteilung des Forschungssystems 4.1 Das Autonomiebestreben der großen Forschungsorganisationen und die Rolle der angewandten Forschung in der DFG 4.2 Das neue Interesse an einer "dritten Säule" des bundesdeutschen Forschungssystems nach dem Verwaltungsabkommen von 1964 4. 3 Von der Förderung der industriellen Forschung als "Ausnahmefall" zur Technologiepolitik des Bundes 5 Retrospektive Sinngebung und Ordnungspolitik. Die Funktion der Strukturreform am Beginn der siebziger Jahr

    Effects of commercial fishing regulations on stranding rates of bottlenose dolphin (Tursiops truncatus).

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    Fisheries management actions taken to protect one species can have unintended, and sometimes positive, consequences on other species. For example, regulatory measures to reduce fishing effort in the winter gillnet fishery for spiny dogfish (Squalus acanthias) off North Carolina (NC) also led to decreases in the number of bycaught bottlenose dolphins (Tursiops truncatus). This study found that a marked decrease in fishing effort for spiny dogfish in NC also corresponded with a marked decrease in winter stranding rates of bottlenose dolphins with entanglement lesions (P= 0.002). Furthermore, from 1997 through 2002, there was a significant positive correlation (r2 = 0.79; P= 0.0003) between seasonal bycatch estimates of bottlenose dolphins in gill nets and rates of stranded dolphins with entanglement lesions. With this information, stranding thresholds were developed that would enable the detection of those increases in bycatch in near real-time. This approach is valuable because updated bycatch estimates from observer data usually have a time-lag of two or more years. Threshold values could be used to detect increases in stranding rates, triggering managers immediately to direct observer effort to areas of potentially high bycatch or to institute mitigation measures. Thus, observer coverage and stranding investigations can be used in concert for more effective fishery management

    Elevated UV-B radiation reduces genome stability in plants

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    Long-term depletion of the stratospheric ozone layer contributes to an increase in terrestrial solar ultraviolet-B radiation1,2,3^{1,2,3}. This has deleterious effects on living organisms, such as DNA damage4,5^{4,5}. When exposed to elevated ultraviolet-B radiation (UV-B; 280–315 nm), plants display a wide variety of physiological and morphological responses characterized as acclimation and adaptation6^{6}. Here we show, using special sun simulators, that elevated solar UV-B doses increase the frequency of somatic homologous DNA rearrangements in Arabidopsis and tobacco plants. Increases in recombination are accompanied by a strong induction of photolyase and Rad51 gene expression. These genes are putatively involved in major DNA repair pathways, photoreactivation and recombination repair7,8^{7,8}. In mutant Arabidopsis plants that are deficient in photoreactivating ultraviolet-induced cyclobutane pyrimidine dimers, recombination under elevated UV-B regimes greatly exceeds wild-type levels. Our results show that homologous recombination repair pathways might be involved in eliminating UV-B-induced DNA lesions in plants. Thus, increases in terrestrial solar UV-B radiation as forecasted for the early 21st century may affect genome stability in plants
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