1,782 research outputs found

    The nature and role of empathy in public librarianship

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    This article presents two recent studies, an AHRC-funded exploration of the role of empathy in community librarianship (Study 1) and an investigation of the role of empathy in service to minority ethnic users (Study 2). Qualitative elements of each methodology are presented, namely a series of focus groups with frontline staff, interviews with senior managers and a research workshop (Study 1), and a case study investigation of a public library in the heart of a Chinese community (Study 2). Synthesizing the data of both studies, an analysis is conducted of the relationship between the cultural identities of library staff and their ability to empathize with the public. It is concluded that empathy plays a role in facilitating effective communication between staff and users, but that a distinction should be made between intuitive and cognitive empathy, in considering the potential of staff training to develop appropriate levels of emotional response to members of all communities

    Negative Electron-electron Drag Between Narrow Quantum Hall Channels

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    Momentum transfer due to Coulomb interaction between two parallel, two-dimensional, narrow, and spatially separated layers, when a current I_{drive} is driven through one layer, is studied in the presence of a perpendicular magnetic field B. The current induced in the drag layer, I_{drag}, is evaluated self-consistently with I_{drive} as a parameter. I_{drag} can be positive or negative depending on the value of the filling factor \nu of the highest occupied bulk Landau level (LL). For a fully occupied LL, I_{drag} is negative, i.e., it flows opposite to I_{drive}, whereas it is positive for a half-filled LL. When the circuit is opened in the drag layer, a voltage \Delta V_{drag} develops in it; it is negative for a half-filled LL and positive for a fully occupied LL. This positive \Delta V_{drag}, expressing a negative Coulomb drag, results from energetically favored near-edge inter-LL transitions that occur when the highest occupied bulk LL and the LL just above it become degenerate.Comment: Text file in Latex/Revtex/preprint format, 7 separate PS figures, Physical Review B, in pres

    Frictional drag between non-equilibrium charged gases

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    The frictional drag force between separated but coupled two-dimensional electron gases of different temperatures is studied using the non-equilibrium Green function method based on the separation of center-of-mass and relative dynamics of electrons. As the mechanisms of producing the frictional force we include the direct Coulomb interaction, the interaction mediated via virtual and real TA and LA phonons, optic phonons, plasmons, and TA and LA phonon-electron collective modes. We found that, when the distance between the two electron gases is large, and at intermediate temperature where plasmons and collective modes play the most important role in the frictional drag, the possibility of having a temperature difference between two subsystems modifies greatly the transresistivity.Comment: 8figure

    Coulomb Drag Between Parallel Ballistic Quantum Wires

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    The Coulomb drag between parallel, {\it ballistic} quantum wires is studied theoretically in the presence of a perpendicular magnetic field B. The transresistance R_D shows peaks as a function of the Fermi level and splitting energy between the 1D subbands of the wires. The sharpest peaks appear when the Fermi level crosses the subband extrema so that the Fermi momenta are small. Two other kinds of peaks appear when either {\it intra}- or {\it inter}-subband transitions of electrons have maximum probability; the {\it intra}-subband transitions correspond to a small splitting energy. R_D depends on the field B in a nonmonotonic fashion: it decreases with B, as a result of the suppression of backscattering, and increases sharply when the Fermi level approaches the subband bottoms and the suppression is outbalanced by the increase of the Coulomb matrix elements and of the density of states.Comment: Text 14 pages in Latex/Revtex format, 4 Postscript figures. Phys. Rev. B,in pres

    GLP-1 released to the mesenteric lymph duct in mice: Effects of glucose and fat.

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    Using a newly developed in vivo model measuring glucagon-like peptide-1 (GLP-1) in gut lymphatics in mice, we quantified GLP-1 secretion in vivo after glucose versus fat ingestion with and without concomitant DPP-4 inhibition. The mesenteric lymphatic duct was cannulated in anesthetized C57BL6/J mice and lymph was collected in 30min intervals. Glucose or fat emulsion (Intralipid(R)) (0.03, 0.1 or 0.3kcal) with or without DPP-4-inhibition (NVP DPP728; 10μmol/kg) was administered by gastric gavage. Basal intact GLP-1 levels were 0.37±0.04pmol/l (n=61) in lymph compared to 0.07±0.03 in plasma (n=6; P=0.04) and basal DPP-4 activity was 4.7±0.3pmol/min/μl in lymph (n=23) compared to 22.3±0.9pmol/min/μl in plasma (n=8; P<0.001). Lymph flow increased from 1.2±0.1μl/min to 2.3±02μl/min at 30min after glucose and fat administration, with no difference between type of challenge or dose (n=81). Lymph GLP-1 levels increased calorie-dependently after both glucose and fat but with different time courses in that glucose induced a transient increase which had returned to baseline after 90min whereas the lipid induced a sustained increase which was still elevated above baseline after 210min. Lymph GLP-1 appearance during 210min was two to three-fold higher after glucose (7.4±2.3fmol at 0.3kcal) than after isocaloric fat (2.9±0.8fmol at 0.3kcal; P<0.001). The slope between caloric load and lymph GLP-1 appearance was, however, identical after glucose and fat. We conclude that lymph GLP-1 is higher than plasma GLP-1 whereas lymph DPP-4 activity is lower than plasma DPP-4 activity and that both glucose and fat clearly stimulate GLP-1 secretion calorie-dependently in vivo but with different time courses

    (μ-Formato-κ 2 O:O′)bis­[dicarbon­yl(η 5-cyclo­penta­dien­yl)iron(II)] tetra­fluoridoborate

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    In the structure of the title compound [Fe2(C5H5)2(CHO2)(CO)4]BF4, each FeII atom is coordinated in a pseudo-octa­hedral three-legged piano-stool fashion. The cyclo­penta­dienyl ligand occupies three fac coordination sites while the two carbonyl ligands and formate O atom occupy the remaining three sites

    The Quantum Hall Effect in Drag: Inter-layer Friction in Strong Magnetic Fields

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    We study the Coulomb drag between two spatially separated electron systems in a strong magnetic field, one of which exhibits the quantum Hall effect. At a fixed temperature, the drag mimics the behavior of σxx\sigma_{xx} in the quantum Hall system, in that it is sharply peaked near the transitions between neighboring plateaux. We assess the impact of critical fluctuations near the transitions, and find that the low temperature behavior of the drag measures an exponent η\eta that characterizes anomalous low frequency dissipation; the latter is believed to be present following the work of Chalker.Comment: 13 pages, Revtex 2.0, 1 figure upon request, P-93-11-09

    Chaperoning steroid hormone signaling via reversible acetylation

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    Glucocorticoid receptor (GR) and related steroid hormone receptors are ligand-dependent transcription factors whose regulation is critical for both homeostasis and diseases. The structural maturation of the GR has been shown to require the Hsp90 molecular chaperone complex. Evidence indicates that Hsp90-dependent maturation is critical for GR ligand binding capacity and activity. While the role for Hsp90 in GR function is well established, the regulation of this process is not well understood. Here we discuss a recent finding that identifies reversible protein acetylation controlled by the deacetylase HDAC6 as a novel mechanism that regulates Hsp90-dependent GR maturation. We will also speculate on the implications of this finding in steroid hormone signaling, oncogenic transformation and its potential therapeutic utility

    Frictional Coulomb drag in strong magnetic fields

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    A treatment of frictional Coulomb drag between two 2-dimensional electron layers in a strong perpendicular magnetic field, within the independent electron picture, is presented. Assuming fully resolved Landau levels, the linear response theory expression for the transresistivity ρ21\rho_{21} is evaluated using diagrammatic techniques. The transresistivity is given by an integral over energy and momentum transfer weighted by the product of the screened interlayer interaction and the phase-space for scattering events. We demonstrate, by a numerical analysis of the transresistivity, that for well-resolved Landau levels the interplay between these two factors leads to characteristic features in both the magnetic field- and the temperature dependence of ρ21\rho_{21}. Numerical results are compared with recent experiments.Comment: RevTeX, 34 pages, 8 figures included in tex

    Relationship between dietary intake and the development of type 2 diabetes in a Chinese population: The Hong Kong Dietary Survey

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    Objective To study the relationship between dietary intake and the development of type 2 diabetes among Chinese adults.Design A prospective cohort study. Dietary assessment was carried out using a validated FFQ. Principal component analysis was used to identify dietary patterns. Dietary glycaemic load and variety of snacks were also calculated.Setting A hospital-based centre at the Queen Mary Hospital in Hong Kong SAR, China.Subjects A total of 1010 Chinese adults aged 25-74 years who participated in a territory-wide dietary and cardiovascular risk factor prevalence survey in 1995-1996 were followed up for 9-14 years for the development of diabetes.Results A total of 690 (68·3 %) individuals completed follow-up during 2005-2008 and seventy-four cases of diabetes were identified over the follow-up period. Four dietary patterns were identified ('more snacks and drinks-, 'more vegetables, fruits and fish-, 'more meat and milk products- and 'more refined grains-). After adjustment for age, sex, BMI, waist-to-hip ratio, smoking, alcohol intake, participation in exercise/sports and family history of diabetes, the more vegetables, fruits and fish pattern was associated with a 14 % lower risk (OR per 1 sd increase in score = 0·76; 95 % CI 0·58, 0·99), whereas the more meat and milk products pattern was associated with a 39 % greater risk of diabetes (OR per 1 sd increase in score = 1·39; 95 % CI 1·04, 1·84). Dietary glycaemic load, rice intake, snack intake and variety of snacks were not independently associated with diabetes.Conclusions The more vegetables, fruits and fish pattern was associated with reduced risk and the more meat and milk products pattern was associated with an increased risk of diabetes. © 2011 The Authors.published_or_final_versio
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