2,490 research outputs found
Afterpulse Measurements of R7081 Photomultipliers for the Double Chooz Experiment
We present the results of afterpulse measurements performed as qualification
test for 473 inner detector photomultipliers of the Double Chooz experiment.
The measurements include the determination of a total afterpulse occurrence
probability as well as an average time distribution of these pulses.
Additionally, more detailed measurements with different light sources and
simultaneous charge and timing measurements were performed with a few
photomultipliers to allow a more detailed understanding of the effect. The
results of all measurements are presented and discussed
Vegetation characteristics of a brackish marsh on Gotland and foraging choices of migrating and brood rearing geese
Arctic breeding barnacle geese use brackish marshes along the coastline of the Baltic Sea intensively in spring, during short stopovers on their migration to breeding sites in northern Russia. We mapped the vegetation of one important spring staging and brood rearing site on the Swedish island of Gotland and investigated the habitat use of barnacle geese. The geese mainly use plant communities with a high cover of edible species and a low canopy height. These vegetation characteristics are best maintained through livestock grazing and the maintenance of current grazing practices will be responsible for future site use by small herbivores
Group Composition of Guinea Baboons (Papio papio) at a Water Place Suggests a Fluid Social Organization
Baboon social systems are among the most studied in primates. Solid knowledge of the hamadryas and savannah baboon systems has accumulated, leading to a dichotomic view of baboon social systems. Hamadryas baboons live in multilayered troops based on 1-male units whereas savannah baboons live in multimale multifemale groups based on a network of related females. Less attention has been paid to their West African congenerics, the Guinea baboons, Papio papio. To fill this gap, in 2007 we initiated a long-term study of a baboon troop ranging in the Niokolo Koba National Park in southeastern Senegal. Earlier studies suggested a tendency for a multilayered social system in Guinea baboons, similar to the hamadryas baboon organization. Therefore, as a first approach to analyzing variability in party size and composition, we observed members of the troop crossing an open area from a fixed point for 3Â mo during the dry and wet seasons. We counted individuals and recorded changes in composition of both arriving and departing parties. Party size and composition were highly variable on both a daily and a seasonal basis; 45.9% of the arriving parties changed in composition while crossing the open area, either splitting into smaller parties or fusing into larger ones, suggesting a fluid organization. Our data support the existence of neither a hamadryas baboon-like multilayered social organization nor a stable medium-sized multimale multifemale group as in savannah baboons. In light of our data we may need to revise the dichotomic view of baboon social systems and include space for greater variability of their social systems
Antiprädationsverhalten von Weißwangengänsen auf Kolguyev und Svalbard
Auch in den arktischen Brutgebieten sind Wildgänse und ihre Brut durch Fressfeinde wie den Eisfuchs (Alopex lagopus) oder die Eismöwe (Larus hyperboreus) gefährdet. In diesem Bericht wird am Beispiel von Weißwangengänsen (Branta leucopsis) das Verhalten der Vermeidung von Prädation auf Svalbard mit dem der auf Kolguyev brütenden Artgenossen untersucht. Die Unterschiede und Gemeinsamkeiten werden diskutiert.On the breeding grounds geese and their broods are threatened by predators like polar foxes (Alopex lagopus) or Glacous Gulls (Larus hyperboreus). In this review we compare antipredation behaviour of breeding and broad rearing Barnacle Geese (Branta leucopsis) on Svalbard and Kolguev. Similarities and differences are presented and discussed
Akzeptanz, Rollendifferenzierung und geschlechtsspezifisches Verhalten in Dyaden bei Botanischen BestimmungsĂĽbungen: Ein Vergleich zweier Medien
Die vorliegende Studie beschreibt geschlechts- und medienspezifische Effekte bei der Bestimmung von Pflanzen. Das Ziel bestand darin, explorativ zu untersuchen, welche Auswirkungen die Arbeit mit einer Online-Lernumgebung im Gegensatz zu bisherigen BestimmungsbĂĽchern auf die Prozesse in gemischt-geschlechtlichen Dyaden hat. Hierzu wurden vorrangig die Anzahlen medien- und pflanzenbezogener Aktionen der Probanden untersucht. Generell zeigt die Studie, dass keine schwerwiegenden geschlechtsspezifischen Effekte zu erwarten sind. Allerdings muss bei der Implementierung der Lernumgebung darauf geachtet werden, dass keine Rollendifferenzierung derart entsteht, dass innerhalb der Lerndyaden ein Proband den Computer bedient und der andere die Pflanze untersucht. Die Einstellung der Probanden gegenĂĽber der neuen Lernumgebung war positiv, so dass von Seiten der Studenten keine Akzeptanzprobleme bezĂĽglich der Implementierung in die Kurse zu erwarten sind
High-resolution nerve ultrasound abnormalities in POEMS syndrome: a comparative study
Background: High-resolution nerve ultrasound (HRUS) has been proven to be a valuable tool in the diagnosis of immune-mediated neuropathies, such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes) is an important differential diagnosis of CIDP. Until now, there have been no studies that could identify specific HRUS abnormalities in POEMS syndrome patients. Thus, the aim of this study was to assess possible changes and compare findings with CIDP patients. Methods: We retrospectively analyzed HRUS findings in three POEMS syndrome and ten CIDP patients by evaluating cross-sectional nerve area (CSA), echogenicity and additionally calculating ultrasound pattern scores (UPSA, UPSB, UPSC and UPSS) and homogeneity scores (HS). Results: CIDP patients showed greater CSA enlargement and higher UPSS (median 14 vs. 11), UPSA (median 11.5 vs. 8) and HS (median 5 vs. 3) compared with POEMS syndrome patients. However, every POEMS syndrome patient illustrated enlarged nerves exceeding reference values, which were not restricted to entrapment sites. In CIDP and POEMS syndrome, heterogeneous enlargement patterns could be identified, such as inhomogeneous, homogeneous and regional nerve enlargement. HRUS in CIDP patients visualized both increased and decreased echointensity, while POEMS syndrome patients pictured hypoechoic nerves with hyperechoic intraneural connective tissue. Discussion: This is the first study to demonstrate HRUS abnormalities in POEMS syndrome outside of common entrapment sites. Although nerve enlargement was more prominent in CIDP, POEMS syndrome patients revealed distinct echogenicity patterns, which might aid in its differentiation from CIDP. Future studies should consider HRUS and its possible role in determining diagnosis, prognosis and treatment response in POEMS syndrome
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