212 research outputs found

    Epstein-Barr virus infection in cardiothoracic transplant recipients

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    Surface Modification for the Improvement of Metal/Organic Semiconductor Interfaces

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    Organic electronics have become much of the forefront of scientific research due to their advantages over tradition electronics as well as their applications in consumer devices, medical devices, and harnessing renewable sources of energy. Despite their appeal, two major obstacles are responsible for poor performance and limited applications. These problems occur at the interface between the two main components of the devices, the organic semiconductor and the metal electrodes. The first, high electrical resistance, is a result of the misalignment between the metal’s free electrons and the organic semiconductor’s conduction band. We seek to capitalize on this misalignment using light-responsive molecular switches in the effort to create “smart” electronics. However, in order to use these molecular switches, we study how the switches interact with the metal surface, via surface infrared spectroscopy, so that a better understanding of how the system works can be obtained. This also allows for the elucidation of the criteria needed in order to select the appropriate molecules. The second problem, poor adhesion between the components, is due to the poor interaction between metal atoms and the organic molecules. This problem results in delamination of the layers and can also short the circuit. In order to circumvent this issue, we implement self-assembled monolayers on the organic semiconductor and further react them in order to tune the terminal functional group. As a result of these secondary reactions, stronger interactions between the metal and organic semiconductor can be achieved via confirmation with x-ray photoelectron spectroscopy

    The quantitative anatomy of the kangaroo

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    Nutritional and Social Environmental Effects on Parental Care

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    Parental care is likely to evolve when benefits of care are greater than costs. Provision of parental care may buffer vulnerable offspring against unpredictable or hazardous environments permitting parents to breed in situations too hostile for unassisted juvenile survival. The nature of environmental unpredictability faced by parents and their offspring (e.g., availability of nutritional resources, breeding resources and/or the strength of competition) provides the ecological context in which costs and benefits of parental traits are defined. Therefore investigations about how the environment might shape parental traits ought not only to be conducted in the laboratory but also in a natural setting where unanticipated parameters may have profound effects on theoretical predictions. I conducted a series of manipulative experiments and observational studies in the laboratory and in the field using burying beetles, Nicrophorus vespilloides, to examine the effects of environmental variation on parental competitive ability, reproductive productivity, longevity and the expression of parental sex-role differences and alternative reproductive tactics. In these beetles a relative size advantage confers success in contests for scarce and vital breeding resources so a central prediction was that reproductive success would be positively correlated with body size. In contrast I found that reproductive performance was favoured over contest success when nutritional resources were delayed temporarily during a developmental window. Larger beetles do win contests for breeding-resources but the benefits of being large depend on the quality of the social environment experienced (i.e., the relative size of an opponent). In a naturalistic setting, smaller males avoided direct contests because they attracted proportionately more females and as a result their breeding associations were more often monogamous. This has potential benefits for females because they avoid female-female contests and brood parasitism. Variation in the nutritional environment provided by parents (the carcass size on which offspring are reared) directly influences body size creating a dynamism between the nutritional and social environments experienced by these beetles depending on their size, which has ramifications for their individual success and maintenance of alternative strategies in the population as a whole.Natural Environment Research Counci

    Leading and Managing the 21st Century Research University: Creating, Implementing, and Sustaining Strategic Change

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    Universities are competing in an environment in which only the most adaptable to sustainable change will prosper. In order to evolve in this challenging time, universities must embrace strategies for transformational change. This paper reviews two case studies that illustrate the universal applicability of theories of Change Science for achieving sustainable change in stressful times of prosperity and austerity. Understanding the phases of the Change Process that include Creating Vision, Implementing Vision, and Sustaining Vision can promote sustainable change directly related to the culture and mission of the institution

    Experiences of diagnosis, stigma, culpability, and disclosure in male patients with hepatitis C virus: an interpretative phenomenological analysis

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    The current study aimed to explore the lived experience of patients with hepatitis C virus infection. Semi-structured interviews were conducted with seven male participants living with hepatitis C virus and were analysed using interpretative phenomenological analysis. Two master themes were identified: (1) diagnosis and the search for meaning and (2) impact of stigma on disclosure. Participants reported fears of contaminating others, feelings of stigma and concerns of disclosing the condition to others. Response to diagnosis, stigma and disclosure among the participants appeared to be interrelated and directly related to locus of blame for virus contraction. More specifically, hepatitis C virus transmission via medical routes led to an externalisation of culpability and an openness to disclosure. Transmission of hepatitis C virus as a direct result of intravenous drug use led to internalised blame and a fear of disclosure. The inter- and intra-personal consequences of hepatitis C virus explored in the current study have potential implications for tailoring future psychological therapy and psychoeducation to the specific needs of the hepatitis C virus population

    Environment and mate attractiveness in a wild insect

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    The role of female choice in sexual selection is well established, including the recognition that females choose their mates based on multiple cues. These cues may include intrinsic aspects of a male's phenotype as well as aspects of the environment associated with the male. The role of the spatial location of a potential mate has been well studied in territorial vertebrates. However, despite their role as laboratory models for studies of sexual selection, the potential for insects to choose their mates on the basis of location has scarcely been studied. We studied a natural population of individually tagged crickets (Gryllus campestris) in a meadow in Northern Spain. Adults typically move between burrows every few days, allowing us to examine how pairing success of males can be predicted by the burrow they occupy, independent of their own characteristics. We observed the entirety of ten independent breeding seasons to provide replication and to determine whether the relative importance of these factors is stable across years. We find that both male ID and the ID his burrow affect the likelihood that he is paired with a female, but the burrow has a consistently greater influence. Furthermore, the two factors interact: the relative attractiveness of an individual male depends on which burrow he occupies. Our finding demonstrates a close interaction between naturally and sexually selected traits. It also demonstrates that mate choice studies may benefit from considering not only obvious secondary sexual traits, but also more cryptic traits such as microhabitat choice. We show that female insects choosing to cohabit with a male place more importance on where he lives than on who he is, but the combination of the two is more important still. We know that female birds often choose a male based on the quality of his territory; our 10 years of observing crickets moving around a Spanish meadow to share burrows with members of the opposite sex, reveals insects can do the same.Peer reviewe

    Herschel SPIRE FTS Relative Spectral Response Calibration

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    Herschel/SPIRE Fourier transform spectrometer (FTS) observations contain emission from both the Herschel Telescope and the SPIRE Instrument itself, both of which are typically orders of magnitude greater than the emission from the astronomical source, and must be removed in order to recover the source spectrum. The effects of the Herschel Telescope and the SPIRE Instrument are removed during data reduction using relative spectral response calibration curves and emission models. We present the evolution of the methods used to derive the relative spectral response calibration curves for the SPIRE FTS. The relationship between the calibration curves and the ultimate sensitivity of calibrated SPIRE FTS data is discussed and the results from the derivation methods are compared. These comparisons show that the latest derivation methods result in calibration curves that impart a factor of between 2 and 100 less noise to the overall error budget, which results in calibrated spectra for individual observations whose noise is reduced by a factor of 2-3, with a gain in the overall spectral sensitivity of 23% and 21% for the two detector bands, respectively.Comment: 15 pages, 13 figures, accepted for publication in Experimental Astronom

    Methanogenesis from Mineral Carbonates, a Potential Indicator for Life on Mars

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    Priorities for the exploration of Mars involve the identification and observation of biosignatures that indicate the existence of life on the planet. The atmosphere and composition of the sediments on Mars suggest suitability for anaerobic chemolithotrophic metabolism. Carbonates are often considered as morphological biosignatures, such as stromatolites, but have not been considered as potential electron acceptors. Within the present study, hydrogenotrophic methanogen enrichments were generated from sediments that had received significant quantities of lime from industrial processes (lime kiln/steel production). These enrichments were then supplemented with calcium carbonate powder or marble chips as a sole source of carbon. These microcosms saw a release of inorganic carbon into the liquid phase, which was subsequently removed, resulting in the generation of methane, with 0.37 ± 0.09 mmoles of methane observed in the steel sediment enrichments supplemented with calcium carbonate powder. The steel sediment microcosms and lime sediments with carbonate powder enrichments were dominated by Methanobacterium sp., whilst the lime/marble enrichments were more diverse, containing varying proportions of Methanomassiliicoccus, Methanoculleus and Methanosarcina sp. In all microcosm experiments, acetic acid was detected in the liquid phase. Our results indicate that chemolithotrophic methanogenesis should be considered when determining biosignatures for life on Mars
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