1,372 research outputs found

    Modeling Scientists as Agents. How Scientists Cope with the Challenges of the New Public Management of Science

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    The paper at hand applies agent-based modeling and simulations (ABMS) as a tool to reconstruct and to analyze how the science system works. A Luhmannian systems perspective is combined with a model of decision making of individual actors. Additionally, changes in the socio-political context of science, such as the introduction of „new public management\", are considered as factors affecting the functionality of the system as well as the decisions of individual scientists (e.g. where to publish their papers). Computer simulation helps to understand the complex interplay of developments at the macro (system) and the micro (actor) level.Systems Theory, Theory of Action and Decision Making, Academic Publication System, Science System, New Public Management, Agent-Based Modeling and Simulation

    <i>Muenstraia</i>, ein neues Rugosa-Genus (Anthozoa) aus dem Obersilur und Unterdevon

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    Muenstraia n. gen. ist eine der ältesten ahermatypischen Rugosa (Subordo Cyathaxoniina) und umfasst neben der Typusart Muenstraia franconica n. sp. (Ludlovium, Elbersreuther Orthoceratitenkalk, Frankenwald) drei weitere Arten: Muenstraia squarrosa (Sutherland, 1965) (unteres Ludlovium, Henryhouse-Formation, Oklahoma), Muenstraia sp. (oberes Lochkovium, Yukon-Gebiet), Muenstraia thuringica n. sp. (Pragium, Thüringisches Schiefergebirge und Tafilalt). Die Gattung kann von dem isolierten, nur aus Xinjiang bekannten Protozaphrentis Yü, 1957 des hohen Mittelordoviz abgeleitet werden; wichtige Deszendenten im Ludlovian sind Laccophyllum Simpson, 1900 und Sutherlandinia Weyer, 1972.Der Bauplan entspricht dem seit Schindewolf (1931) traditionellen Konzept der Gattung Petraia Münster, 1839, die aber nach Revision (Weyer 2000) ihrer wahren Typusart Petraia decussata Münster, 1839 aus dem oberen Famennium einer anderen Entwicklungsreihe angehört (Neaxoninae Hill, 1981, jetzt Petraiidae Koninck, 1872). Für die dadurch namenlos gewordene Familia "Petraiidae" (etwa sensu Hill 1981) werden die bisher als Synonym ruhenden Protozaphrentidae Ivanovskiy, 1959 verfügbar, denen noch Duncanella Nicholson, 1874 sowie die Sutherlandiniinae Weyer, 1972 und die Ditoecholasmatinae Sutherland, 1965 zugeordnet sind.Muenstraia, a new genus of Rugosa (Anthozoa) from the Late Silurian and Early DevonianThe new taxon, one of the most ancient members of the ahermatypic suborder Cyathaxoniina, includes the type species Muenstraia franconica n. sp. (Ludlovian, Elbersreuth Orthoceratites-Limestone Formation. Upper Franconia, Germany) and three further species: Muenstraia squarrosa (Sutherland, 1965) (lower Ludlovian, Henryhouse Formation, Oklahoma, USA), Muenstraia sp. (upper Lochkovian, Yukon Territories, Canada). Muenstraia thuringica n. sp. (middle/upper Pragian, Tentaculitid Limestone Formation, Thuringian Mountains, Germany, and middle Pragian, Tafilalt, Morocco). The genus descends from the isolated Upper Middle Ordovician Protozaphrentis Yü, 1957, only known from Xinjiang in China; it is the ancestor of two new phylogenetic lines starting in the Ludlovian with Laccophyllum Simpson, 1900, and Sutherlandinia Weyer, 1972.Morphology and diagnosis are identical with the (since Schindewolf 1931) traditional definition of the genus Petraia Münster, 1839, which represents according to a revision of its real and Upper Famennian type species Petraia decussata Münster, 1839 (Weyer 2000) another phylogenetic line (Neaxoninae Hill, 1981, now Petraiidae Koninck, 1872). Therefore, the valid name of the family "Petraiidae" (sensu Hill 1981) becomes Protozaphrentidae Ivanovskiy, 1959, which comprise also Duncanella Nicholson, 1874, and both the Sutherlandiniinae Weyer, 1972 and Ditoecholasmatinae Sutherland, 1965.doi:10.1002/mmng.2001004010

    Outbreak of Rift Valley fever affecting veterinarians and farmers in South Africa, 2008

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    Background. During 2008, Rift Valley fever (RVF) virus re-emerged in South Africa as focal outbreaks in several provinces. Aims. To investigate an outbreak affecting cattle farmers and farm workers, and the staff and students of a veterinary school, assess the prevalence of infection during the outbreak, document the clinical presentation of cases, and identify potential risk factors. Methods. We conducted a cross-sectional serological survey of exposed veterinarians and farmers, who were examined to determine the presence of current or recent illness. Blood specimens were collected for virus isolation, nucleic acid detection and serology. A subset was interviewed using a standardised questionnaire to obtain data on recent exposures and risk factors for infection. Results. Of 53 participants potentially exposed to infected domestic ruminants, 15% had evidence of recent infection and 4% evidence of past exposure to the RVF virus. The prevalence of acute infection was 21% in veterinarians compared with 9% in farmers and farm workers. After a mean incubation period of 4.3 days, the most frequent symptoms experienced included myalgia (100%), headache (88%) and malaise (75%). No asymptomatic cases were identified. Transmission by direct contact with infected animals was the major risk factor in these professional groups. Performing animal autopsies was significantly associated with acute infection (risk ratio 16.3, 95% confidence interval 2.3 - 114.2). Conclusions. Increased risks associated with veterinary practices highlight a need for the use of personal protective equipment, and identify veterinarians as a primary target group for future vaccination

    Large-sized Early Permian "caninioid" corals from the Karavanke Mountains, Slovenia

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    © 2016, The Paleontological Society.A new monospecific "caninioid" genus, Preisingerella n. gen., from the lower Permian of the Karavanke Mountains (Southern Alps, Slovenia) is erected. The type species is Preisingerella stegovnikensis n. sp. The new taxon can be differentiated from other Caninia-type genera by its specific ontogeny and features of its dissepimentarium. Corals with such morphology had a wide distribution during the Carboniferous and early Permian, occurring in mostly shallow-water carbonate rocks. The phylogenetic relationships within this group are mostly unclear due to similarities in the adult stages. The earlier stages reveal the main distinguishing features that are decisive for a generic assignment, but these have rarely been well preserved and properly considered. The new taxon is compared with related genera of the Cyathopsidae and species of Caninella Gorskiy, 1938 characterized by lateral dissepiments. Large numbers of specimens of the new species, representing a monospecific assemblage, have been collected from the Born Formation at Mt. Stegovnik. Sedimentological and microfacies characteristics, as well as macro-and microfossil assemblages, underline this correlation. The fusulinoidean assemblage of the Born Formation, with Sphaeroschwagerina carniolica (Kahler and Kahler, 1937), as the predominant species, corresponds to the time span between the Sphaeroschwagerina moelleri-Schwagerina fecunda and Pseudofusulina moelleri zones, indicating a late Asselian to early Sakmarian age in the Southern Urals

    Acceleration of Diffusional Jumps of Interstitial Fe with Increasing Ge Concentration in Si1 − x Ge x Alloys Observed by Mössbauer Spectroscopy

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    Radioactive 57Mn isotopes have been implanted into Si1 − x Ge x crystals (x ≤ 0.1) at elevated temperatures for Mössbauer studies of the diffusion of interstitial 57Fe daughter atoms. The atomic jump frequency is found to increase upon Ge alloying. This is attributed to a lowering of the activation energy, i.e. the saddle point energy at hexagonal interstitial sites with Ge neighbour atom

    Biogenic non-crystalline U (IV) revealed as major component in uranium ore deposits

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    Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U (VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U (IV) generated through biologically mediated U (VI) reduction is the predominant U (IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (-1/458-89%) of U is bound as U (IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U (VI) represent only minor components. The uranium deposit exhibited mostly 238 U-enriched isotope signatures, consistent with largely biotic reduction of U (VI) to U (IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U (IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.University of Wyomin
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