275 research outputs found
Geröllanalytische Gliederung der pleistozÀnen Kiessande nordwestlich von Hannover
Die spĂ€telster- bis drenthezeitlichen Kiessande des Steinhuder Meer-Raumes wurden statistisch auf ihren Geröllbestand (Fraktion 6,3â12,5 mm) untersucht. In zwei Tiefenbereichen wurde das VerhĂ€ltnis von nordischen zu palĂ€ozoisch-einheimischen Geröllen ausgewertet. Die nordischen sind vom Inlandeis und dessen SchmelzwĂ€ssern geschĂŒttet, die palĂ€ozoischeinheimischen von FlĂŒssen aus dem S angeliefert. Der einheimische Kies-Anteil lieĂ sich nach dem Flammenmergel- und Buntsandstein-Gehalt dem FluĂsystem der Weser bzw. der Leine zuordnen. Nach der Geröllanalyse hat der spĂ€telsterzeitliche Kiessand altpleistozĂ€ne Rinnen endgĂŒltig verfĂŒllt. Im oberen, drenthezeitlichen Abschnitt lĂ€Ăt sich die Vermischung und Verzahnung der nordischen Schmelzwassersande mit den von SĂŒden geschĂŒtteten Leine-Kiessanden quantitativ belegen (Abb. 7). Der nordische Kiessand enthĂ€lt Schollen und Beimengungen von Oberterrassenkies der Weser. Die Ergebnisse werden mit frĂŒheren geröllanalytischen Untersuchungen im Raum Hannover vergleichen, und daraus neue Hinweise zur FluĂgeschichte der (unteren) Leine gewonnen.researc
Biological processes and links to the physics
Analysis of the temporal and spatial variability of biological processes and identification of the main variables that drive the dynamic regime of marine ecosystems is complex. Correlation between physical variables and long-term changes in ecosystems has routinely been identified, but the specific mechanisms involved remain often unclear. Reasons for this could be various: the ecosystem can be very sensitive to the seasonal timing of the anomalous physical forcing; the ecosystem can be contemporaneously influenced by many physical variables and the ecosystem can generate intrinsic variability on climate time scales. Marine ecosystems are influenced by a variety of physical factors, e.g., light, temperature, transport, turbulence. Temperature has a fundamental forcing function in biology, with direct influences on rate processes of organisms and on the distribution of mobile species that have preferred temperature ranges. Light and transport also affect the physiology and distribution of marine organisms. Small-scale turbulence determines encounter between larval fish and their prey and additionally influences the probability of successful pursuit and ingestion.
The impact of physical forcing variations on biological processes is studied through long-term observations, process studies, laboratory experiments, retrospective analysis of existing data sets and modelling. This manuscript reviews the diversity of physical influences on biological processes, marine organisms and ecosystems and their variety of responses to physical forcing with special emphasis on the dynamics of zooplankton and fish stocks
Child Sexual Abuse by Catholic Priests, Deacons, and Male Members of Religious Orders in the Authority of the German Bishopsâ Conference 1946â2014
This study explores the extent of sexual abuse of minors by members of the Catholic Church in Germany. It is the first comprehensive study to examine this extent in a European country. The goals of this study are as follows: (a) to analyze whether the extent and characteristics of sexual abuse in a European country are comparable to those in the United States and Australia and (b) how discrepancies can be explained. The personnel files of 38,156 Catholic Priests, deacons, and male members of religious orders in the authority of the German Bishopsâ Conference were analyzed. The study period lasted from 1946 to 2014. All 27 German dioceses took part in this study. A total of 4.4% of all clerics (N = 1,670) from 1946 to 2014 were alleged to have committed sexual abuse, and 3,677 children or adolescents were identified as victims. These results are similar to those from comparable studies in the United States. Sexual abuse of minors within the authority of the Catholic Church seems to be a worldwide phenomenon
The pregnant man: race, difference and subjectivity in Alan Patonâs Kalahari writing
In South African imaginative writing and scholarly research, there is currently an extensive
and wide-ranging interest in the âBushmanâ, either as a tragic figure of colonial history, as
a contested site of misrepresentation, or even as an exemplary model of environmental
consciousness. Writing and research about âBushmenâ has not only become pervasive in
the academy, but also a site of controversy and theoretical contestation. It is in this context
that this paper investigates the meaning and significance of âBushmenâ for Alan Paton, one
of South Africaâs most well-known writers. Patonâs writing is not usually associated with
âBushmanâ studies, yet this article shows that the âBushmanâ became a highly charged and
ambivalent figure in his imagination. Patonâs problematic ideas are contextualised more
carefully by looking at the broader context of South African letters. The article initially
analyses Patonâs representation of âBushmenâ in his Lost City of the Kalahari travel narrative
(1956, published in 2005. Pietermaritzburg: KZN Press), and also discusses unpublished
archival photographs. A study of the figure of the âBushmanâ throughout the entire
corpus of his writing, ranging from early journalism to late autobiography, allows us to
trace the shift of his views, enabling us to reflect not only on Patonâs thinking about racial
otherness, but also gauge the extent to which his encounter with the Kalahari Bushmen
destabilised his sense of self, finally also preventing the publication of the travelogueDepartment of HE and Training approved lis
Modeling violations of the race model inequality in bimodal paradigms: co-activation from decision and non-decision components
The redundant-signals paradigm (RSP) is designed to investigate response behavior in perceptual tasks in which response-relevant targets are defined by either one or two features, or modalities. The common finding is that responses are speeded for redundantly compared to singly defined targets. This redundant-signals effect (RSE) can be accounted for by race models if the response times do not violate the race model inequality (RMI). When there are violations of the RMI, race models are effectively excluded as a viable account of the RSE. The common alternative is provided by co-activation accounts, which assume that redundant target signals are integrated at some processing stage. However, âco-activationâ has mostly been only indirectly inferred and the accounts have only rarely been explicitly modeled; if they were modeled, the RSE has typically been assumed to have a decisional locus. Yet, there are also indications in the literature that the RSE might originate, at least in part, at a non-decisional or motor stage. In the present study, using a distribution analysis of sequential-sampling models (ex-Wald and Ratcliff Diffusion model), the locus of the RSE was investigated for two bimodal (audio-visual) detection tasks that strongly violated the RMI, indicative of substantial co-activation. Three model variants assuming different loci of the RSE were fitted to the quantile reaction time proportions: a decision, a non-decision, and a combined variant both to vincentized group as well as individual data. The results suggest that for the two bimodal detection tasks, co-activation has a shared decisional and non-decisional locus. These findings point to the possibility that the mechanisms underlying the RSE depend on the specifics (task, stimulus, conditions, etc.) of the experimental paradigm
Whodunnit? Electrophysiological correlates of agency judgements.
Sense of agency refers to the feeling that "I" am responsible for those external events that are directly produced by one's own voluntary actions. Recent theories distinguish between a non-conceptual "feeling" of agency linked to changes in the processing of self-generated sensory events, and a higher-order judgement of agency, which attributes sensory events to the self. In the current study we explore the neural correlates of the judgement of agency by means of electrophysiology. We measured event-related potentials to tones that were either perceived or not perceived as triggered by participants' voluntary actions and related these potentials to later judgements of agency over the tones. Replicating earlier findings on predictive sensory attenuation, we found that the N1 component was attenuated for congruent tones that corresponded to the learned action-effect mapping as opposed to incongruent tones that did not correspond to the previously acquired associations between actions and tones. The P3a component, but not the N1, directly reflected the judgement of agency: deflections in this component were greater for tones judged as self-generated than for tones judged as externally produced. The fact that the outcome of the later agency judgement was predictable based on the P3a component demonstrates that agency judgements incorporate early information processing components and are not purely reconstructive, post-hoc evaluations generated at time of judgement
A mathematical model for breath gas analysis of volatile organic compounds with special emphasis on acetone
Recommended standardized procedures for determining exhaled lower respiratory
nitric oxide and nasal nitric oxide have been developed by task forces of the
European Respiratory Society and the American Thoracic Society. These
recommendations have paved the way for the measurement of nitric oxide to
become a diagnostic tool for specific clinical applications. It would be
desirable to develop similar guidelines for the sampling of other trace gases
in exhaled breath, especially volatile organic compounds (VOCs) which reflect
ongoing metabolism. The concentrations of water-soluble, blood-borne substances
in exhaled breath are influenced by: (i) breathing patterns affecting gas
exchange in the conducting airways; (ii) the concentrations in the
tracheo-bronchial lining fluid; (iii) the alveolar and systemic concentrations
of the compound. The classical Farhi equation takes only the alveolar
concentrations into account. Real-time measurements of acetone in end-tidal
breath under an ergometer challenge show characteristics which cannot be
explained within the Farhi setting. Here we develop a compartment model that
reliably captures these profiles and is capable of relating breath to the
systemic concentrations of acetone. By comparison with experimental data it is
inferred that the major part of variability in breath acetone concentrations
(e.g., in response to moderate exercise or altered breathing patterns) can be
attributed to airway gas exchange, with minimal changes of the underlying blood
and tissue concentrations. Moreover, it is deduced that measured end-tidal
breath concentrations of acetone determined during resting conditions and free
breathing will be rather poor indicators for endogenous levels. Particularly,
the current formulation includes the classical Farhi and the Scheid series
inhomogeneity model as special limiting cases.Comment: 38 page
Computational generation and screening of RNA motifs in large nucleotide sequence pools
Although identification of active motifs in large random sequence pools is central to RNA in vitro selection, no systematic computational equivalent of this process has yet been developed. We develop a computational approach that combines target pool generation, motif scanning and motif screening using secondary structure analysis for applications to 1012â1014-sequence pools; large pool sizes are made possible using program redesign and supercomputing resources. We use the new protocol to search for aptamer and ribozyme motifs in pools up to experimental pool size (1014 sequences). We show that motif scanning, structure matching and flanking sequence analysis, respectively, reduce the initial sequence pool by 6â8, 1â2 and 1 orders of magnitude, consistent with the rare occurrence of active motifs in random pools. The final yields match the theoretical yields from probability theory for simple motifs and overestimate experimental yields, which constitute lower bounds, for aptamers because screening analyses beyond secondary structure information are not considered systematically. We also show that designed pools using our nucleotide transition probability matrices can produce higher yields for RNA ligase motifs than random pools. Our methods for generating, analyzing and designing large pools can help improve RNA design via simulation of aspects of in vitro selection
Spin Structure of the Proton from Polarized Inclusive Deep-Inelastic Muon-Proton Scattering
We have measured the spin-dependent structure function in inclusive
deep-inelastic scattering of polarized muons off polarized protons, in the
kinematic range and . A
next-to-leading order QCD analysis is used to evolve the measured
to a fixed . The first moment of at is .
This result is below the prediction of the Ellis-Jaffe sum rule by more than
two standard deviations. The singlet axial charge is found to be . In the Adler-Bardeen factorization scheme, is
required to bring in agreement with the Quark-Parton Model. A
combined analysis of all available proton and deuteron data confirms the
Bjorken sum rule.Comment: 33 pages, 22 figures, uses ReVTex and smc.sty. submitted to Physical
Review
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