620 research outputs found

    Calculation Of Electron Capture Cross Sections Of Collisions Of Be ÂČâș On H

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    Using the perturbed stationary state method, including electron translation factors, the authors have calculated electron capture cross sections for the helium-like ions Be2+ and B3+ incident on ground-state atomic hydrogen. The molecular structure calculation employs pseudo-potentials to represent the inactive K-shell electrons on the incident ions. The calculated cross sections vary rapidly in the 107 cm s-1 velocity range (E approximately 1 keV amu-1). The calculations show preferential transfer to the Be+(2s) and the B2+(2p) product states. The calculations for B3++H are in good agreement with experimental measurements of Cradall et al (1979). In addition, the calculations indicate the importance of including rotational coupling to 2 Pi states when determining state-to-state cross sections

    Charge Exchange Processes between Excited Helium and Fully Stripped Ions

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    We made a classical trajectory Monte Carlo (CTMC) calculation of state selective cross sections for processes between some light ions and excited helium. The results, useful for analysis of spectroscopic data of fusion devices, are in good agreement with theoretical predictions of scaling laws.Comment: LaTex, 8 pages, 4 figures (available on request to the authors), DFPD/94/TH/57, to be published in Phys. Rev.

    Caspase-2 is upregulated after sciatic nerve transection and its inhibition protects dorsal root ganglion neurons from Apoptosis after serum withdrawal

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    Sciatic nerve (SN) transection-induced apoptosis of dorsal root ganglion neurons (DRGN) is one factor determining the efficacy of peripheral axonal regeneration and the return of sensation. Here, we tested the hypothesis that caspase-2(CASP2) orchestrates apoptosis of axotomised DRGN both in vivo and in vitro by disrupting the local neurotrophic supply to DRGN. We observed significantly elevated levels of cleaved CASP2 (C-CASP2), compared to cleaved caspase-3 (C-CASP3), within TUNEL+DRGN and DRG glia (satellite and Schwann cells) after SN transection. A serum withdrawal cell culture model, which induced 40% apoptotic death in DRGN and 60% in glia, was used to model DRGN loss after neurotrophic factor withdrawal. Elevated C-CASP2 and TUNEL were observed in both DRGN and DRG glia, with C-CASP2 localisation shifting from the cytosol to the nucleus, a required step for induction of direct CASP2-mediated apoptosis. Furthermore, siRNAmediated downregulation of CASP2 protected 50% of DRGN from apoptosis after serum withdrawal, while downregulation of CASP3 had no effect on DRGN or DRG glia survival. We conclude that CASP2 orchestrates the death of SN-axotomised DRGN directly and also indirectly through loss of DRG glia and their local neurotrophic factor support. Accordingly, inhibiting CASP2 expression is a potential therapy for improving both the SN regeneration response and peripheral sensory recovery

    Complementary and Alternative Medicine Use as Health Self-Management: Rural Older Adults With Diabetes

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    This study describes complementary and alternative medicine (CAM) use among rural older adults with diabetes, delineates the relationship of health self-management predictors to CAM therapy use, and furthers conceptual development of CAM use within a health self-management framework

    APOBEC3B-mediated Corruption of the Tumor Cell Immunopeptidome Induces Heteroclitic Neoepitopes for Cancer Immunotherapy

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    APOBEC3B, an anti-viral cytidine deaminase which induces DNA mutations, has been implicated as a mediator of cancer evolution and therapeutic resistance. Mutational plasticity also drives generation of neoepitopes, which prime anti-tumor T cells. Here, we show that overexpression of APOBEC3B in tumors increases resistance to chemotherapy, but simultaneously heightens sensitivity to immune checkpoint blockade in a murine model of melanoma. However, in the vaccine setting, APOBEC3B-mediated mutations reproducibly generate heteroclitic neoepitopes in vaccine cells which activate de novo T cell responses. These cross react against parental, unmodified tumors and lead to a high rate of cures in both subcutaneous and intra-cranial tumor models. Heteroclitic Epitope Activated Therapy (HEAT) dispenses with the need to identify patient specific neoepitopes and tumor reactive T cells ex vivo. Thus, actively driving a high mutational load in tumor cell vaccines increases their immunogenicity to drive anti-tumor therapy in combination with immune checkpoint blockade

    Saving lives in road traffic—ethical aspects

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    Aim: This article aims at giving an overview of five ethical problem areas relating to traffic safety, thereby providing a general framework for analysing traffic safety from an ethical perspective and encouraging further discussion concerning problems, policies and technology in this area. Subjects and methods: The problems presented in the article are criminalisation, paternalism, privacy, justice and responsibility, and the reasons for choosing these are the following. First, they are all important areas in moral philosophy. Second, they are fairly general and it should be possible to categorise more specific problems under these headings. Ethical aspects of road traffic have not received the philosophical attention they deserve. Every year, more than 1 million people die globally in traffic accidents, and 20 to 50 million people are injured. Ninety per cent of the road traffic fatalities occur in low- and middle-income countries, where it is a growing problem. Politics, economics, culture and technology affect the number of fatalities and injuries, and the measures used to combat deaths in traffic as well as the role of road traffic should be ethically scrutinised. The topics are analysed and discussed from a moral-philosophical perspective, and the discussion includes both theory and applications. Results and conclusion: The author concludes with some thoughts on how the ethical discussion can be included in the public debate on how to save lives in road traffic. People in industrialised societies are so used to road traffic that it is almost seen as part of nature. Consequently, we do not acknowledge that we can introduce change and that we can affect the role we have given road traffic and cars. By acknowledging the ethical aspects of road traffic and illuminating the way the choices society makes are ethically charged, it becomes clear that there are alternative ways to design the road traffic system. The most important general conclusion is that discussion concerning these alternative ways of designing the system should be encouraged

    Miocene waterfowl and other birds from central Otago, New Zealand

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    Copyright © The Natural History Museum 2007Abundant fossil bird bones from the lower Bannockburn Formation, Manuherikia Group, an Early-Middle Miocene lacustrine deposit, 16–19 Ma, from Otago in New Zealand, reveal the “St Bathans Fauna” (new name), a first Tertiary avifauna of land and freshwater birds from New Zealand. At least 23 species of birds are represented by bones, and probable moa, Aves: Dinornithiformes, by eggshell. Anatids dominate the fauna with four genera and five species described as new: a sixth and largest anatid species is represented by just one bone. This is the most diverse Early-Middle Miocene duck fauna known worldwide. Among ducks, two species of dendrochenines are most numerous in the fauna, but a tadornine is common as well. A diving petrel (Pelecanoididae: Pelecanoides) is described, so extending the geological range of this genus worldwide from the Pliocene to the Middle Miocene, at least. The remaining 16 taxa are left undescribed but include: a large species of gull (Laridae); two small waders (Charadriiformes, genus indet.), the size of Charadrius bicinctus and Calidris ruficollis, respectively; a gruiform represented by one specimen similar to Aptornis; abundant rail (Rallidae) bones, including a common flightless rail and a rarer slightly larger taxon, about the size of Gallirallus philippensis; an ?eagle (Accipitridae); a pigeon (Columbidae); three parrots (Psittacidae); an owlet nightjar (Aegothelidae: Aegotheles sp.); a swiftlet (Apodidae: Collocalia sp.); and three passerine taxa, of which the largest is a member of the Cracticidae. The absence of some waterbirds, such as anserines (including swans), grebes (Podicipedidae) and shags (Phalacrocoracidae), among the abundant bones, indicates their probable absence from New Zealand in the Early-Middle Miocene.T. H. Worthy, A. J. D. Tennyson, C. Jones, J. A. McNamara and B. J. Dougla

    Wnt and Hedgehog Are Critical Mediators of Cigarette Smoke-Induced Lung Cancer

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    BACKGROUND: Lung cancer is the leading cause of cancer death in the world, and greater than 90% of lung cancers are cigarette smoke-related. Current treatment options are inadequate, because the molecular basis of cigarette-induced lung cancer is poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that human primary or immortalized bronchial epithelial cells exposed to cigarette smoke for eight days in culture rapidly proliferate, show anchorage-independent growth, and form tumors in nude mice. Using this model of the early stages of smoke-induced tumorigenesis, we examined the molecular changes leading to lung cancer. We observed that the embryonic signaling pathways mediated by Hedgehog and Wnt are activated by smoke. Pharmacological inhibition of these pathways blocked the transformed phenotype. CONCLUSIONS/SIGNIFICANCE: These experiments provide a model in which the early stages of smoke-induced tumorigenesis can be elicited, and should permit us to identify molecular changes driving this process. Results obtained so far indicate that smoke-induced lung tumors are driven by activation of two embryonic regulatory pathways, Hedgehog (Hh) and Wnt. Based on the current and emerging availability of drugs to inhibit Hh and Wnt signaling, it is possible that an understanding of the role of Hh and Wnt in lung cancer pathogenesis will lead to the development of new therapies
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