1,353 research outputs found

    Structural and torsional properties of the Trachycarpus fortunei palm petiole

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    The Trachycarpus fortunei palm is a good example of a palm with a large leaf blade supported by a correspondingly large petiole. The way in which the material and functional properties of the petiole interact is analysed using engineering and botanical methods with a view to understanding how the petiole functions from a structural standpoint. Initially, the histological aspects of the petiole are analysed at a microscopic level from sections of the petiole taken at regular intervals along its axis, in order to determine the density and location of the vascular bundles. A modified torsion rig was used to measure the torsion and shear stress variation along petiole sample lengths. Knowledge of vascular bundle placement within the petiole sections and their torsional loading characteristics contribute to understanding the petiole function

    Psychometric evaluation of the German version of a social support scale of FAFHES (family functioning, family health and social support)

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    This is the peer reviewed version which has been published in final form at https://doi.org/10.1111/scs.12700. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.BACKGROUND: Family members often need to be supported in informal care of the elderly and desire to be involved into care planning and decision-making. Valid and reliable instruments are needed to measure how family members perceive the care and support they receive from nurses for older family members living at home. AIM: The purpose of this study was to translate the 20-item social support scale of the Family Functioning, Family Health and Social Support (FAFHES) questionnaire from English to German and test the validity and reliability of the scale among Swiss-German-speaking family caregivers of home-dwelling elderly people who receive home healthcare services. METHODS: A cross-sectional study was conducted to test the empirical and psychometric properties of the translated and culturally adapted version of the social support questionnaire. A factor analysis with the principal component analysis PCA was used to test construct validity. The internal consistency of items was measured with the Cronbach`s alpha coefficient. RESULTS: After a rigorous translation process the original 20-item questionnaire was adapted into a 19-item version and tested with family caregivers (n = 207) of home-dwelling elderly. Psychometric testing of the German version of the social support questionnaire revealed that the three factors - affirmation, affect and concrete aid - were congruent with the original questionnaire. The accounted variance was 79.5% and the internal consistency determined by the Cronbach's alpha was 0.973. CONCLUSION: The German version of the social support scale of the FAFHES questionnaire is a valid and reliable instrument to assess family perceived support on three dimensions - affirmation, affect and concrete aid - received from nursing professionals. The questionnaire should be tested further in other German-speaking population

    Enzyme replacement reverses abnormal cerebrovascular responses in Fabry disease

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    BACKGROUND: Fabry disease is a lysosomal X-linked enzyme deficiency of α-galactosidase A associated with an increased mortality and morbidity due to renal failure, cardiac disease and early onset stroke. METHODS: We examined the functional blood flow response of the brain after visual stimulation (reversing checkerboard pattern), and cerebral vasoreactivity following acetazolamide (15 mg/kg) with [(15)O]H(2)O and positron emission tomography (PET) in Fabry disease. Twenty-six hemizygous patients (age range 19–47 years) were enrolled in a randomized double-blind placebo-controlled 6-month trial of enzyme replacement therapy administered by intravenous infusion every two weeks. Regional cerebral blood flow (rCBF) was measured with PET at the beginning and end of the trial. RESULTS: Fabry patients had a significantly greater increase in rCBF following visual stimulation and acetazolamide challenge compared to controls. Visual reactivity was normal. The time for recovery of the cerebral vasculature following acetazolamide was prolonged in Fabry patients compared to controls. The abnormal rCBF response induced by visual stimulation and acetazolamide decreased significantly following enzyme replacement therapy, as did the prolonged recovery of the cerebral vasculature. CONCLUSIONS: Enzyme replacement therapy reverses the exaggerated cerebrovascular response in Fabry disease

    Considering the role of cognitive control in expert performance

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    © 2014, Springer Science+Business Media Dordrecht. Dreyfus and Dreyfus’ (1986) influential phenomenological analysis of skill acquisition proposes that expert performance is guided by non-cognitive responses which are fast, effortless and apparently intuitive in nature. Although this model has been criticised (e.g., by Breivik Journal of Philosophy of Sport, 34, 116–134 2007, Journal of the Philosophy of Sport, 40, 85–106 2013; Eriksen 2010; Montero Inquiry:An interdisciplinary Journal of Philosophy, 53, 105–122 2010; Montero and Evans 2011) for over-emphasising the role that intuition plays in facilitating skilled performance, it does recognise that on occasions (e.g., when performance goes awry for some reason) a form of ‘detached deliberative rationality’ may be used by experts to improve their performance. However, Dreyfus and Dreyfus (1986) see no role for calculative problem solving or deliberation (i.e., drawing on rules or mental representations) when performance is going well. In the current paper, we draw on empirical evidence, insights from athletes, and phenomenological description to argue that ‘continuous improvement’ (i.e., the phenomenon whereby certain skilled performers appear to be capable of increasing their proficiency even though they are already experts; Toner and Moran 2014) among experts is mediated by cognitive (or executive) control in three distinct sporting situations (i.e., in training, during pre-performance routines, and while engaged in on-line skill execution). We conclude by arguing that Sutton et al. Journal of the British Society for Phenomenology, 42, 78–103 (2011) ‘applying intelligence to the reflexes’ (AIR) approach may help to elucidate the process by which expert performers achieve continuous improvement through analytical/mindful behaviour during training and competition

    Tuberculosis in alpaca (Lama pacos) on a farm in Ireland. 1. A clinical report

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    This case report describes tuberculosis (TB) due to infection with Mycobacterium bovis (M. bovis) in alpaca (Lama pacos) on a farm in Ireland. Two severely debilitated alpaca were presented to the University Veterinary Hospital, University College Dublin in November 2004. Bloods were taken, and haematology and biochemistry results were indicative of chronic infection. Radiological examination showed evidence of diffuse granulomatous pneumonia suggestive of tuberculosis. On necropsy there were granulomatous lesions present throughout many body organs including lung, liver, kidney, intestine as well on peritoneum and mesentery. Culture of acid-fast bacilli from lesions led to a diagnosis of tuberculosis due to M. bovis. The use of intradermal skin testing proved inefficient and unreliable for ante mortem diagnosis of tuberculosis in alpaca. Infection due to M. bovis should be considered among the differential diagnoses of debilitating diseases in alpaca, particularly those farmed in areas known to be traditional black spots for tuberculosis in cattle

    MCL-CAw: A refinement of MCL for detecting yeast complexes from weighted PPI networks by incorporating core-attachment structure

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    Abstract Background The reconstruction of protein complexes from the physical interactome of organisms serves as a building block towards understanding the higher level organization of the cell. Over the past few years, several independent high-throughput experiments have helped to catalogue enormous amount of physical protein interaction data from organisms such as yeast. However, these individual datasets show lack of correlation with each other and also contain substantial number of false positives (noise). Over these years, several affinity scoring schemes have also been devised to improve the qualities of these datasets. Therefore, the challenge now is to detect meaningful as well as novel complexes from protein interaction (PPI) networks derived by combining datasets from multiple sources and by making use of these affinity scoring schemes. In the attempt towards tackling this challenge, the Markov Clustering algorithm (MCL) has proved to be a popular and reasonably successful method, mainly due to its scalability, robustness, and ability to work on scored (weighted) networks. However, MCL produces many noisy clusters, which either do not match known complexes or have additional proteins that reduce the accuracies of correctly predicted complexes. Results Inspired by recent experimental observations by Gavin and colleagues on the modularity structure in yeast complexes and the distinctive properties of "core" and "attachment" proteins, we develop a core-attachment based refinement method coupled to MCL for reconstruction of yeast complexes from scored (weighted) PPI networks. We combine physical interactions from two recent "pull-down" experiments to generate an unscored PPI network. We then score this network using available affinity scoring schemes to generate multiple scored PPI networks. The evaluation of our method (called MCL-CAw) on these networks shows that: (i) MCL-CAw derives larger number of yeast complexes and with better accuracies than MCL, particularly in the presence of natural noise; (ii) Affinity scoring can effectively reduce the impact of noise on MCL-CAw and thereby improve the quality (precision and recall) of its predicted complexes; (iii) MCL-CAw responds well to most available scoring schemes. We discuss several instances where MCL-CAw was successful in deriving meaningful complexes, and where it missed a few proteins or whole complexes due to affinity scoring of the networks. We compare MCL-CAw with several recent complex detection algorithms on unscored and scored networks, and assess the relative performance of the algorithms on these networks. Further, we study the impact of augmenting physical datasets with computationally inferred interactions for complex detection. Finally, we analyse the essentiality of proteins within predicted complexes to understand a possible correlation between protein essentiality and their ability to form complexes. Conclusions We demonstrate that core-attachment based refinement in MCL-CAw improves the predictions of MCL on yeast PPI networks. We show that affinity scoring improves the performance of MCL-CAw.http://deepblue.lib.umich.edu/bitstream/2027.42/78256/1/1471-2105-11-504.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78256/2/1471-2105-11-504-S1.PDFhttp://deepblue.lib.umich.edu/bitstream/2027.42/78256/3/1471-2105-11-504-S2.ZIPhttp://deepblue.lib.umich.edu/bitstream/2027.42/78256/4/1471-2105-11-504.pdfPeer Reviewe

    Selective probing of magnetic order on Tb and Ir sites in stuffed Tb<sub>2+x</sub>Ir<sub>2-x</sub>O<sub>7-y</sub> using resonant X-ray scattering

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    We study the magnetic structure of the ``stuffed" (Tb-rich) pyrochlore iridate Tb2+x_{2+x}Ir2x_{2-x}O7y_{7-y}, using resonant elastic x-ray scattering (REXS). In order to disentangle contributions from Tb and Ir magnetic sublattices, experiments were performed at the Ir L3L_3 and Tb M5M_5 edges, which provide selective sensitivity to Ir 5d5d and Tb 4f4f magnetic moments, respectively. At the Ir L3L_3 edge, we found the onset of long-range k=0{\bf k}={\bf 0} magnetic order below TNIrT_{N}^\text{Ir}\sim\,71\,K, consistent with the expected signal of all-in all-out (AIAO) magnetic order. Using a single-ion model to calculate REXS cross-sections, we estimate an ordered magnetic moment of μ5dIr0.34(3)μB\mu_{5d}^{\text{Ir}} \approx 0.34(3)\,\mu_B at 5\,K. At the Tb M5M_5 edge, long-range k=0{\bf k}={\bf 0} magnetic order appeared below 40\sim40\,K, also consistent with an AIAO magnetic structure on the Tb site. Additional insight into the magnetism of the Tb sublattice is gleaned from measurements at the M5M_5 edge in applied magnetic fields up to 6\,T, which is found to completely suppress the Tb AIAO magnetic order. In zero applied field, the observed gradual onset of the Tb sublattice magnetisation with temperature suggests that it is induced by the magnetic order on the Ir site. The persistence of AIAO magnetic order, despite the greatly reduced ordering temperature and moment size compared to stoichiometric Tb2_{2}Ir2_{2}O7_{7}, for which TNIr=130T_{N}^{\text{Ir}} =130\,K and μ5dIr=0.56μB\mu_{5d}^{\text{Ir}}=0.56\,\mu_B, indicates that stuffing could be a viable means of tuning the strength of electronic correlations, thereby potentially offering a new strategy to achieve topologically non-trivial band crossings in pyrochlore iridates

    Genetic Identification of a Network of Factors that Functionally Interact with the Nucleosome Remodeling ATPase ISWI

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    Nucleosome remodeling and covalent modifications of histones play fundamental roles in chromatin structure and function. However, much remains to be learned about how the action of ATP-dependent chromatin remodeling factors and histone-modifying enzymes is coordinated to modulate chromatin organization and transcription. The evolutionarily conserved ATP-dependent chromatin-remodeling factor ISWI plays essential roles in chromosome organization, DNA replication, and transcription regulation. To gain insight into regulation and mechanism of action of ISWI, we conducted an unbiased genetic screen to identify factors with which it interacts in vivo. We found that ISWI interacts with a network of factors that escaped detection in previous biochemical analyses, including the Sin3A gene. The Sin3A protein and the histone deacetylase Rpd3 are part of a conserved histone deacetylase complex involved in transcriptional repression. ISWI and the Sin3A/Rpd3 complex co-localize at specific chromosome domains. Loss of ISWI activity causes a reduction in the binding of the Sin3A/Rpd3 complex to chromatin. Biochemical analysis showed that the ISWI physically interacts with the histone deacetylase activity of the Sin3A/Rpd3 complex. Consistent with these findings, the acetylation of histone H4 is altered when ISWI activity is perturbed in vivo. These findings suggest that ISWI associates with the Sin3A/Rpd3 complex to support its function in vivo
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