1,326 research outputs found

    Reproduction and Dispersal of Biological Soil Crust Organisms

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    Biological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms—including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. The list of organismal groups that make up BSC communities in various and unique combinations include—free living, lichenized, and mycorrhizal fungi, chemoheterotrophic bacteria, cyanobacteria, diazotrophic bacteria and archaea, eukaryotic algae, and bryophytes. The various BSC organismal groups demonstrate several common characteristics including—desiccation and extreme temperature tolerance, production of various soil binding chemistries, a near exclusive dependency on asexual reproduction, a pattern of aerial dispersal over impressive distances, and a universal vulnerability to a wide range of human-related perturbations. With this publication, we provide literature-based insights as to how each organismal group contributes to the formation and maintenance of the structural and functional attributes of BSCs, how they reproduce, and how they are dispersed. We also emphasize the importance of effective application of molecular and microenvironment sampling and assessment tools in order to provide cogent and essential answers that will allow scientists and land managers to better understand and manage the biodiversity and functional relationships of soil crust communities

    A Magnetic Resonance Realization of Decoherence-Free Quantum Computation

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    We report the realization, using nuclear magnetic resonance techniques, of the first quantum computer that reliably executes an algorithm in the presence of strong decoherence. The computer is based on a quantum error avoidance code that protects against a class of multiple-qubit errors. The code stores two decoherence-free logical qubits in four noisy physical qubits. The computer successfully executes Grover's search algorithm in the presence of arbitrarily strong engineered decoherence. A control computer with no decoherence protection consistently fails under the same conditions.Comment: 5 pages with 3 figures, revtex4, accepted by Physical Review Letters; v2 minor revisions to conten

    Independent and Interactive Associations of Negative Affect, Restraint, and Impulsivity in Relation to Binge Eating Among Women

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    There is growing recognition that impulsivity may serve as an underlying risk factor for binge eating. In addition, the association of impulsivity with binge eating may be moderated by other affective and cognitive risk factors. This study examined independent and interactive associations of negative affect, dietary restraint, and facets of impulsivity with binge eating. A diverse sample of 566 undergraduate women completed online questionnaires of study variables. Results revealed a three-way interaction of negative affect, dietary restraint, and attentional impulsivity in relation to binge eating. Women who were high on each of these three variables reported the greatest levels of binge eating. In addition, a two-way interaction was found for negative affect and nonplanning impulsivity in relation to binge eating, such that nonplanning impulsivity strengthened the association between negative affect and binge eating. Attentional and nonplanning facets of impulsivity may function as an underlying trait-level risk factor interacts with affective and/or cognitive risk (e.g., negative affect, dietary restraint) factors to predict elevated binge eating

    Rethinking Orgnac 3 in Time and Space: Implications for Reconstructing Neandertal Origins

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    An important aim in paleoanthropological and archaeological research is to clarify the poorly resolved record of the Middle Pleistocene (MP). Filling in the gaps of the Eurasian MP furthers our understanding of the behavioral and biological evolution of archaic humans, Neanderthals, Denisovans and their ancestors. Orgnac 3, located in Mediterranean France, is particularly suited to address these issues. This paper introduces the site to new readers, summarizes the previous work performed on the site and its material, and offers different views based on new analysis of its faunal material. Based on the currently available evidence, the Orgnac 3 sequence is likely far older than previously thought and might date to OISs 12-8, not only 9-8 as traditionally proposed. The hominin teeth, which have not been described in detail or assigned to a taxon, would date to ~375 - 400,000 years ago, the focal period of the Neandertal/Denisovan/modern human population divergence debate. More accurate and precise analyses of Orgnac 3's paleontological, archaeological and geological material are needed to clarify our understanding of hominin evolution during the MP.L’un des objectifs importants de la recherche paléoanthropologique et archéologique est de clarifier les données qui restent encore mal cernées du Pléistocène moyen (PM). Combler les lacunes du PM eurasiatique nous permet de mieux comprendre l'évolution comportementale et biologique des humains archaïques, des Néandertaliens, des Denisoviens, et de leurs ancêtres. Orgnac 3, situé en France méditerranéenne, est particulièrement adapté pour aborder ces questions. Cet article présente le site à de nouveaux lecteurs, résume les travaux antérieurs réalisés sur le site et son matériel, et propose différents points de vue fondés sur une nouvelle analyse de son matériel faunique. Sur la base des éléments de démonstration actuellement disponibles, il faut envisager que la séquence d'Orgnac 3 soit probablement beaucoup plus ancienne que ce qui est généralement accepté. Cette vaste séquence pourrait ainsi dater des OIS 12-8, et non seulement des OIS 9-8 comme cela a été traditionnellement proposé. Les dents d'homininés, qui n'ont pas été décrites en détail ni assignées à un taxon, dateraient d'environ 375 à 400 000 ans, période centrale du débat sur la divergence entre les populations néandertalienne, dénisovienne et humaine moderne. Des analyses plus exactes et plus précises du matériel paléontologique, archéologique et géologique d'Orgnac 3 sont nécessaires pour clarifier notre compréhension de l'évolution des homininés pendant le PM

    Reconsidération d’Orgnac 3 dans le temps et l’espace : implications pour la reconstruction des origines néandertaliennes – version abrégée

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    L’un des objectifs importants de la recherche paléoanthropologique et archéologique est de clarifier les données qui restent encore mal cernées du Pléistocène moyen (PM). Combler les lacunes du PM eurasiatique nous permet de mieux comprendre l'évolution comportementale et biologique des humains archaïques, des Néandertaliens, des Denisoviens, et de leurs ancêtres. Orgnac 3, situé en France méditerranéenne, est particulièrement adapté pour aborder ces questions. Cet article présente le site à de nouveaux lecteurs, résume les travaux antérieurs réalisés sur le site et son matériel, et propose différents points de vue fondés sur une nouvelle analyse de son matériel faunique. Sur la base des éléments de démonstration actuellement disponibles, il faut envisager que la séquence d'Orgnac 3 soit probablement beaucoup plus ancienne que ce qui est généralement accepté. Cette vaste séquence pourrait ainsi dater des OIS 12-8, et non seulement des OIS 9-8 comme cela a été traditionnellement proposé. Les dents d'homininés, qui n'ont pas été décrites en détail ni assignées à un taxon, dateraient d'environ 375 à 400 000 ans, période centrale du débat sur la divergence entre les populations néandertalienne, dénisovienne et humaine moderne. Des analyses plus exactes et plus précises du matériel paléontologique, archéologique et géologique d'Orgnac 3 sont nécessaires pour clarifier notre compréhension de l'évolution des homininés pendant le PM.An important aim in paleoanthropological and archaeological research is to clarify the poorly resolved record of the Middle Pleistocene (MP). Filling in the gaps of the Eurasian MP furthers our understanding of the behavioral and biological evolution of archaic humans, Neanderthals, Denisovans and their ancestors. Orgnac 3, located in Mediterranean France, is particularly suited to address these issues. This paper introduces the site to new readers, summarizes the previous work performed on the site and its material, and offers different views based on new analysis of its faunal material. Based on the currently available evidence, the Orgnac 3 sequence is likely far older than previously thought and might date to OISs 12-8, not only 9-8 as traditionally proposed. The hominin teeth, which have not been described in detail or assigned to a taxon, would date to ~375 - 400,000 years ago, the focal period of the Neandertal/Denisovan/modern human population divergence debate. More accurate and precise analyses of Orgnac 3's paleontological, archaeological and geological material are needed to clarify our understanding of hominin evolution during the MP

    Exploring the reactivity of 2-trichloromethylbenzoxazoles for access to substituted benzoxazoles

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    The reactivity of 2-trichloromethylbenzoxazoles towards various nucleophiles, under metal free or iron-catalyzed conditions, for the synthesis of substituted benzoxazoles is described. These methods allow for selective substitution at either the 2- or 2’- position of the benzoxazoles using the same starting materials / reagents. This approach allows for the controlled synthesis of a variety of key derivatives from a single 2-trichloromethylbenzoxazole starting material

    Interactive Voice Response-An Innovative Approach to Post-Stroke Depression Self-Management Support

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    Automated interactive voice response (IVR) call systems can provide systematic monitoring and self-management support to depressed patients, but it is unknown if stroke patients are able and willing to engage in IVR interactions. We sought to assess the feasibility and acceptability of IVR as an adjunct to post-stroke depression follow-up care. The CarePartner program is a mobile health program designed to optimize depression self-management, facilitate social support from a caregiver, and strengthen connections between stroke survivors and primary care providers (PCPs). Ischemic stroke patients and an informal caregiver, if available, were recruited during the patient's acute stroke hospitalization or follow-up appointment. The CarePartner program was activated in patients with depressive symptoms during their stroke hospitalization or follow-up. The 3-month intervention consisted of weekly IVR calls monitoring both depressive symptoms and medication adherence along with tailored suggestions for depressive symptom self-management. After each completed IVR call, informal caregivers were automatically updated, and, if needed, the subject's PCP was notified. Of the 56 stroke patients who enrolled, depressive symptoms were identified in 13 (23 %) subjects. Subjects completed 74 % of the weekly IVR assessments. A total of six subjects did not complete the outcome assessment, including two non-study-related deaths. PCPs were notified five times, including two times for suicidal ideation and three times for medication non-adherence. Stroke patients with depressive symptoms were able to engage in an IVR call system. Future studies are needed to explore the efficacy of an IVR approach for post-stroke self-management and monitoring of stroke-related outcomes

    Multimodality labeling strategies for the investigation of nanocrystalline cellulose biodistribution in a mouse model of breast cancer

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    Methods We have developed a nuclear and fluorescence labeling strategy for nanocrystalline cellulose (CNC), an emerging biomaterial with versatile chemistry and facile preparation from renewable sources. We modified CNC through 1,1′-carbonyldiimidazole (CDI) activation with radiometal chelators desferrioxamine B and 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), allowing for the labeling with zirconium-89 (t½ = 78.41 h) and copper-64 (t½ = 12.70 h), respectively, for non-invasive positron emission tomography (PET) imaging. The far-red fluorescent dye Cy5 was added for ex vivo optical imaging, microscopy and flow cytometry. The multimodal CNC were evaluated in the syngeneic orthotopic 4T1 tumor model of human stage IV breast cancer. Results Modified CNC exhibited low cytotoxicity in RAW 264.7 macrophages over 96 h, and high radiolabel stability in vitro. After systemic administration, radiolabeled CNC were rapidly sequestered to the organs of the reticulo-endothelial system (RES), indicating immune recognition and no passive tumor targeting by the enhanced permeability and retention (EPR) effect. Modification with NOTA was a more favorable strategy in terms of radiolabeling yield, specific radioactivity, and both the radiolabel and dispersion stability in physiological conditions. Flow cytometry analysis of Cy5-positive immune cells from the spleen and tumor corroborated the uptake of CNC to phagocytic cells. Conclusions Future studies on the in vivo behavior of CNC should be concentrated on improving the nanomaterial stability and circulation half-life under physiological conditions and optimizing further the labeling yields for the multimodality imaging strategy presented. Advances in knowledge Our studies constitute one of the first accounts of a multimodality nuclear and fluorescent probe for the evaluation of CNC biodistribution in vivo and outline the pitfalls in radiometal labeling strategies for future evaluation of targeted CNC-based drug delivery systems. Implications for patient care Quantitative and sensitive molecular imaging methods provide information on the structure–activity relationships of the nanomaterial and guide the translation from in vitro models to clinically relevant animal models.Peer reviewe
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