26 research outputs found

    Self-similar solution of a nonsteady problem of nonisothermal vapour condensation on a droplet growing in diffusion regime

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    This paper presents a mathematically exact self-similar solution to the joint nonsteady problems of vapour diffusion towards a droplet growing in a vapour-gas medium and of removal of heat released by a droplet into a vapour-gas medium during vapour condensation. An equation for the temperature of the droplet is obtained; and it is only at that temperature that the self-similar solution exists. This equation requires the constancy of the droplet temperature and even defines it unambiguously throughout the whole period of the droplet growth. In the case of strong display of heat effects, when the droplet growth rate decreases significantly, the equation for the temperature of the droplet is solved analytically. It is shown that the obtained temperature fully coincides with the one that settles in the droplet simultaneously with the settlement of its diffusion regime of growth. At the obtained temperature of the droplet the interrelated nonsteady vapour concentration and temperature profiles of the vapour-gas medium around the droplet are expressed in terms of initial (prior to the nucleation of the droplet) parameters of the vapour-gas medium. The same parameters are used to formulate the law in accordance with which the droplet is growing in diffusion regime, and also to define the time that passes after the nucleation of the droplet till the settlement of diffusion regime of droplet growth, when the squared radius of the droplet becomes proportionate to time. For the sake of completeness the case of weak display of heat effects is been studied.Comment: 12 pages, 4 figure

    ProtSweep, 2Dsweep and DomainSweep: protein analysis suite at DKFZ

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    The wealth of transcript information that has been made publicly available in recent years has led to large pools of individual web sites offering access to bioinformatics software. However, finding out which services exist, what they can or cannot do, how to use them and how to feed results from one service to the next one in the right format can be very time and resource consuming, especially for non-experts

    Casting new light on the chronology of the loess/paleosol sequences in Lower Austria

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    Der vorliegende Artikel gibt einen Überblick ĂŒber neu datierte Abschnitte in bekannten Löss/PalĂ€oboden-Sequenzen Niederösterreichs. Die Ergebnisse der Datierungen im Profil Joching deuten darauf hin, dass es im letzten Hochglazial zur Lösssedimentation kam. Die meisten erfassten Alter sind jedoch Ă€lter als das letzte Hochglazial, was auf Erosionsprozesse hindeutet, die zur Abtragung der jĂŒngeren Lösse gefĂŒhrt hat. In dem Abschnitt zwischen ~28 ka and ~35 ka wurden ĂŒberwiegend Tundragleye gebildet. Eine intensivere interstadiale Bodenbildung ist nicht nachzuweisen. Dieses Ergebnis kann auch fĂŒr die stratigraphische Einstufung von ‚Stillfried B‘ (sensu Fink) von Bedeutung sein. Der folgende chronologische Abschnitt liegt zwischen ~35 ka and ~57 ka in Lösssedimenten mit eingeschalteten Tundragleyen. Auch dieser Abschnitt ist durch Umlagerungsprozesse charakterisiert. Im Zeitraum von ~57 ka bis ~106 ka befindet sich eine markante ZeitlĂŒcke, die vermutlich auf langandauernde und intensive Erosionsprozesse im Untersuchungsgebiet zurĂŒckzufĂŒhren ist. Die Ă€lteste Datierung in den Sedimenten des letzten Glazials mit 106 ± 12 ka befindet sich in Paudorf direkt ĂŒber dem ‚Stillfried A‘- Komplex (Paudorfer Bodenbildung). Direkt unter diesem Pedokomplex, bzw. vergleichbaren Pedokomplexen treten in Lössablagerungen Alter von 124 ± 2 5 ka (Göttweig-Aigen), 159 ± 20 ka (Paudorf 1), and 170 ± 16 ka (Joching) auf. DarĂŒber hinausgehende Alter konnten in Stratzing, Paudorf 2, Göttweig-Furth und Langenlois nachgewiesen werden

    Nonreceding hare lines: genetic continuity since the Late Pleistocene in European mountain hares (Lepus timidus)

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    Throughout time, climate changes have caused substantial rearrangements of habitats which have alternately promoted and disfavoured different types of taxa. At first glance, the mountain hare (Lepus timidus) shows the typical hallmarks of a cold-adapted species that has retreated to refugia since the onset of the current Holocene interglacial. In contrary to expectations, however, the species has a high contemporary genetic diversity with no clear differentiation between geographically isolated populations. In order to clarify the phylogeographic history of European mountain hares, we here analysed ancient DNA from the glacial populations that inhabited the previous midlatitude European tundra region. Our results reveal that the Ice Age hares had similar levels of genetic variation and lack of geographic structure as observed today, and the ancient samples were intermingled with modern individuals throughout the reconstructed evolutionary tree. This suggest a temporal genetic continuity in Europe, where the mountain hares were able to keep pace with the rapid changes at the last glacial/interglacial transition, and successfully track their shifting habitat to northern and alpine regions. Further, the temporal demographic analyses showed that the species’ population size in Europe appear to have been tightly linked with palaeoclimatic fluctuations, with increases and declines occurring during periods of global cooling and warming, respectively. Taken together, our results suggest that neither habitat shifts nor demographic fluctuations have had any substantial impact on the genetic diversity of European mountain hares. This remarkable resilience, which contrasts to a majority of previously investigated cold-adapted species, is likely due to its generalist nature which makes it less vulnerable to environmental changes

    A Spatial Distribution Study of Faunal Remains from Two Lower Magdalenian Occupation Levels in El MirĂłn Cave, Cantabria, Spain

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    Abstract: Human behaviour can be reconstructed by analysing specific activities and campsite organization using spatial analysis. The dense occupation layers of the Lower Cantabrian Magdalenian in the Northern Spain reveal varied aspects of Upper Palaeolithic lifeways, including evidence of specific localized activities. The outer vestibule of El Mirón cave has a particularly rich and intact Lower Magdalenian occupation horizon, Levels 15–17. The excavations in the outer vestibule “Cabin” area of the site revealed excellent bone preservation. Artefacts and faunal remains were individually recorded and sediments water-screened to yield a large sample of archaeological finds and spatial data. Zooarchaeological analysis provided the taxonomic, anatomic and taphonomic determination of the faunal individual finds. Smaller animal remains were categorized and counted; special attention was given to the identification of anthropogenic modifications such as burnt bones or bone flakes. These small refuse items are considered to be useful, in situ indicators of localized activities. The spatial distribution analysis of this dense and complex palimpsest of El Mirón Lower Cantabrian Magdalenian layers required GIS based methods including density analysis, heatmaps and cluster analysis. Based on the spatial distribution of Level 15 and 16 faunal remains, different activity areas were identified comprising hearth, working and dropping zones. These results imply the deliberately segregated use of space within the Lower Cantabrian Magdalenian site area, in which bone-processing activities played a central rol

    A Late Pleistocene to Holocene succession of leporid species in the southern Vienna Basin (Austria)

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    The new archaeological and palaeontological site of Smrcka Lorenz-Abris yielded three different leporid species in stratigraphical sequence, mirroring the effect of environmental changes and the influence of humans in this area. Lepus timidus is a species with a wide Late Pleistocene distribution, but disappeared in the Vienna Basin at the end of the Pleistocene. Lepus europaeus appeared in the Holocene and became dominant in lower altitudes in Austria. Interspecific competition as well as anthropogenic and natural environmental changes are the main factors that caused this replacement. At Smrcka Lorenz-Abris, L.europaeus became dominant around 7000 a BP. This site yielded the last evidence of a mountain hare in the Vienna Basin, with a preserved lower jaw that was dated to be from around14,000 a BP. The most recent immigrant is Oryctolagus cuniculus, which was introduced to Austria, and only found in the upper parts of the section

    Concerning specific language impairment: intelligibility in expressive language

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    Bereits im Alter von zwei Jahren unterscheiden sich expressiv sprachgestörte Kinder von sprachunauffĂ€lligen Kindern unter anderem durch EinschrĂ€nkungen des Konsonanteninventares. Methode und Patienten: In diesem Beitrag werden PCC-R-Werte von 19 expressiv sprachgestörten Kindern im Alter von vier bis sechs Jahren mit alters- und geschlechtsparallelisierten Kindern mit unauffĂ€lliger Sprachentwicklung verglichen. Ergebnisse: Untersuchungs- und Vergleichsgruppe unterscheiden sich signifikant voneinander, Alter und Geschlecht sowie nonverbale Intelligenz ĂŒben in beiden Gruppen keinen Einfluss aus. Eine Unterteilung der Konsonanten in frĂŒh, mittel- und spĂ€t erworbene zeigt, dass expressiv sprachgestörte Kinder bei spĂ€t erworbenen Konsonanten grĂ¶ĂŸere Defizite als bei frĂŒh- und mittel-erworbenen Konsonanten haben.Even in the age of two years toddlers with Expressive Language Impairment (SLI-E) differ regarding their phonetic inventories compared with an age-matched group developing normally. Method and Patients: PCC-R scores of 19 children with expressive language disorder, aged between four and six years, are compared with age and sex matched controls with normal language acquisition. Results: There are significant differences between PCC-R scores, children with expressive language disorder show lower scores than children with normal language acquisition. Age, sex and nonverbal intelligence do not influence performance measured with PCC-R. Analysis regarding early, middle and late consonants shows, that expressive language disordered children show bigger problems in aquiring late than early and middle consonants
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