132 research outputs found

    Metastable states as a key to the dynamics of supercooled liquids

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    Computer simulations of a model glass-forming system are presented, which are particularly sensitive to the correlation between the dynamics and the topography of the potential energy landscape. This analysis clearly reveals that in the supercooled regime the dynamics is strongly influenced by the presence of deep valleys in the energy landscape, corresponding to long-lived metastable amorphous states. We explicitly relate non-exponential relaxation effects and dynamic heterogeneities to these metastable states and thus to the specific topography of the energy landscape

    Ambiente kapazitive EKG-Messung - Elektroden, Systeme und Konzepte

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    Kapazitive Elektroden sind ein vielversprechender Ansatz für alltagstaugliche EKG-Systeme, da sie Biosignale auch ohne direkten Hautkontakt erfassen können. Im Rahmen der Arbeit werden textile kapazitive Elektroden entwickelt, die für ambiente Szenarien geeignet sind und an 2 Beispielsystemen demonstriert: einem textilintegrierten System zum mobilen EKG-Monitoring, und einem ambienten System zur EKG-Ableitung im Automobil. Daneben werden Konzepte zum Umgang mit Bewegungsartefakten vorgestell

    Identification of binding proteins for cholesterol absorption inhibitors as components of the intestinal cholesterol transporter

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    AbstractTo identify protein components of the intestinal cholesterol transporter, rabbit small intestinal brush border membrane vesicles were submitted to photoaffinity labeling using photoreactive derivatives of 2-azetidinone cholesterol absorption inhibitors. An integral membrane protein of Mr 145.3±7.5 kDa was specifically labeled in brush border membrane vesicles from rabbit jejunum and ileum. Its labeling was concentration-dependently inhibited by the presence of cholesterol absorption inhibitors whereas bile acids, D-glucose, fatty acids or cephalexin had no effect. The inhibitory potency of 2-azetidinones to inhibit photolabeling of the 145 kDa protein correlated with their in vivo activity to inhibit intestinal cholesterol absorption. These results suggest that an integral membrane protein of Mr 145 kDa is (a component of) the cholesterol absorption system in the brush border membrane of small intestinal enterocytes

    The potential energy landscape of a model glass former: thermodynamics, anharmonicities, and finite size effects

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    It is possible to formulate the thermodynamics of a glass forming system in terms of the properties of inherent structures, which correspond to the minima of the potential energy and build up the potential energy landscape in the high-dimensional configuration space. In this work we quantitatively apply this general approach to a simulated model glass-forming system. We systematically vary the system size between N=20 and N=160. This analysis enables us to determine for which temperature range the properties of the glass former are governed by the regions of the configuration space, close to the inherent structures. Furthermore, we obtain detailed information about the nature of anharmonic contributions. Moreover, we can explain the presence of finite size effects in terms of specific properties of the energy landscape. Finally, determination of the total number of inherent structures for very small systems enables us to estimate the Kauzmann temperature

    A time travel through nematology in Germany – From the beginnings to the use of artificial intelligence

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    Das Nachrichtenblatt für den Deutschen Pflanzenschutzdienst, unser heutiges Journal für Kulturpflanzen, feiert seinen 100. Geburtstag. Seinem Ziel, „den im praktischen Pflanzenschutzdienst Tätigen Belehrung und Informationen (zu) übermitteln“, wie Otto Appel zur Einführung schrieb, ist es bis heute treu geblieben. Dies gilt auch für den Bereich der Nematologie. Die Themen haben sich dabei über die Zeit weiterentwickelt. Standen früher Biologie und Wirtspflanzenspektrum einzelner Arten pflanzenparasitärer Nematoden im Fokus des Interesses, so sind es heute Wirt-Parasit Interaktionen, Resistenz und Toleranz von Kulturpflanzen oder der Einfluss von Klimawandel und Globalisierung auf die Verbreitung und das Schadpotenzial der Nematoden. Der vorliegende Beitrag blickt zurück auf die Themen vor 100 Jahren, stellt am Beispiel laufender Arbeiten am Julius Kühn-Institut aktuelle Forschungsthemen vor und gibt einen Ausblick auf die Themen der Zukunft.The Nachrichtenblatt für den Deutschen Pflanzenschutzdienst, today's Journal of Cultivated Plants, celebrates its 100th birthday. It has remained true to its goal of “providing instruc­tion and information to those involved in the practical plant protection service” to this day as stated in its first issue by Otto Appel. This also applies to the field of nematology. The topics have expanded over time and developed further on an international level. While the main focus was initially on the biology and host plant spectrum of the various nematode species, today it is on host-parasite interactions, resistance and tolerance of cultivated plants and the influence of climate change and globalization on the distribution and harmful effects of nematodes. The present article looks back at the topics 100 years ago, presents current research topics using the example of ongoing work at the Julius Kühn Institute and provides an outlook on the topics of the future

    Nonequilibrium spectral diffusion due to laser heating in stimulated photon echo spectroscopy of low temperature glasses

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    A quantitative theory is developed, which accounts for heating artifacts in three-pulse photon echo (3PE) experiments. The heat diffusion equation is solved and the average value of the temperature in the focal volume of the laser is determined as a function of the 3PE waiting time. This temperature is used in the framework of nonequilibrium spectral diffusion theory to calculate the effective homogeneous linewidth of an ensemble of probe molecules embedded in an amorphous host. The theory fits recently observed plateaus and bumps without introducing a gap in the distribution function of flip rates of the two-level systems or any other major modification of the standard tunneling model.Comment: 10 pages, Revtex, 6 eps-figures, accepted for publication in Phys. Rev.

    Basic CSF parameters and MRZ reaction help in differentiating MOG antibody-associated autoimmune disease versus multiple sclerosis

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    BackgroundMyelin oligodendrocyte glycoprotein antibody-associated autoimmune disease (MOGAD) is a rare monophasic or relapsing inflammatory demyelinating disease of the central nervous system (CNS) and can mimic multiple sclerosis (MS). The variable availability of live cell-based MOG-antibody assays and difficulties in interpreting low-positive antibody titers can complicate diagnosis. Literature on cerebrospinal fluid (CSF) profiles in MOGAD versus MS, one of the most common differential diagnoses, is scarce. We here analyzed the value of basic CSF parameters to i) distinguish different clinical MOGAD manifestations and ii) differentiate MOGAD from MS.MethodsThis is retrospective, single-center analysis of clinical and laboratory data of 30 adult MOGAD patients and 189 adult patients with relapsing-remitting multiple sclerosis. Basic CSF parameters included CSF white cell count (WCC) and differentiation, CSF/serum albumin ratio (QAlb), intrathecal production of immunoglobulins, CSF-restricted oligoclonal bands (OCB) and MRZ reaction, defined as intrathecal production of IgG reactive against at least 2 of the 3 viruses measles (M), rubella (R) and varicella zoster virus (Z).ResultsMOGAD patients with myelitis were more likely to have a pleocytosis, a QAlb elevation and a higher WCC than those with optic neuritis, and, after review and combined analysis of our and published cases, they also showed a higher frequency of intrathecal IgM synthesis. Compared to MS, MOGAD patients had significantly more frequently neutrophils in CSF and WCC>30/µl, QAlb>10×10-3, as well as higher mean QAlb values, but significantly less frequently CSF plasma cells and CSF-restricted OCB. A positive MRZ reaction was present in 35.4% of MS patients but absent in all MOGAD patients. Despite these associations, the only CSF parameters with relevant positive likelihood ratios (PLR) indicating MOGAD were QAlb>10×10-3 (PLR 12.60) and absence of CSF-restricted OCB (PLR 14.32), whereas the only relevant negative likelihood ratio (NLR) was absence of positive MRZ reaction (NLR 0.00).ConclusionBasic CSF parameters vary considerably in different clinical phenotypes of MOGAD, but QAlb>10×10-3 and absence of CSF-restricted OCB are highly useful to differentiate MOGAD from MS. A positive MRZ reaction is confirmed as the strongest CSF rule-out parameter in MOGAD and could be useful to complement the recently proposed diagnostic criteria

    Amicus Brief: Kumho Tire v. Carmichael

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    This brief addresses the issue of jury performance and jury responses to expert testimony. It reviews and summaries a substantial body of research evidence about jury behavior that has been produced over the past quarter century. The great weight of that evidence challenges the view that jurors abdicate their responsibilities as fact finders when faced with expert evidence or that they are pro-plaintiff, anti-defendant, and anti-business. The Petitioners and amici on behalf of petitioners make a number of overlapping, but empirically unsupported, assertions about jury behavior in response to expert testimony, namely that juries are frequently incapable of critically evaluation expert testimony, are easily confused, give inordinate weight to expert testimony, are awed by science, defer to the opinions of unreliable experts, and, implicitly, that in civil trials juries tilt in favor of plaintiffs and against corporations

    Exploring the evidence base for national and regional policy interventions to combat resistance

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    The effectiveness of existing policies to control antimicrobial resistance is not yet fully understood. A strengthened evidence base is needed to inform effective policy interventions across countries with different income levels and the human health and animal sectors. We examine three policy domains—responsible use, surveillance, and infection prevention and control—and consider which will be the most effective at national and regional levels. Many complexities exist in the implementation of such policies across sectors and in varying political and regulatory environments. Therefore, we make recommendations for policy action, calling for comprehensive policy assessments, using standardised frameworks, of cost-effectiveness and generalisability. Such assessments are especially important in low-income and middle-income countries, and in the animal and environmental sectors. We also advocate a One Health approach that will enable the development of sensitive policies, accommodating the needs of each sector involved, and addressing concerns of specific countries and regions
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