5,655 research outputs found

    Cognitive mediators of the effect of peer victimization on loneliness

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    The impact of stress on psychological adjustment may be mediated by cognitive interpretations (i.e., appraisals) of events for individuals. Defining characteristics of loneliness suggest that appraisals of blame, threat, and perceived control may be particularly important in this domain. AIMS: To evaluate the extent to which cognitive appraisals (perceived control, threat, and blame) can mediate the effect of peer victimization on loneliness. SAMPLE: One hundred and ten children (54 boys, 56 girls) aged 8-12 years attending mainstream schools in Scotland. METHOD: Self-report measures of peer victimization, appraisal, and loneliness. RESULTS: Perceived control partially mediated the effects of peer victimization on loneliness, but neither blame nor threat were mediators. All three measures of control were significantly associated with loneliness at the bivariate level, but only perceived control was significant when the appraisals were entered as predictors in a hierarchical multiple linear regression. CONCLUSIONS: The results highlight the importance of research designs assessing multiple categories of appraisal. Furthermore, they suggest that intervention efforts aiming to combat feelings of loneliness within a peer victimization context should address children's appraisals of perceived control

    Measurement of human capabilities

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    The paper is motivated by sustained interest in the capabilities approach to welfare economics combined with the purported paucity of economic statistics that measure capabilities at the individual level. Specifically, it takes a focal account of normatively desirable capabilities constitutive of a good life and operationalizes that account by means of a new survey instrument used to elicit information about capabilities at the individual level. The paper explores the extent to which these capabilities are co-variates of a life satisfaction measure of utility (happiness) and finds that many are. Aspects of robustness are explored using standard socio-demographic variables as well as a relatively novel control for personality; in addition, a range of different models are explored and sub-population differences are examined

    The Gravitational Action in Asymptotically AdS and Flat Spacetimes

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    The divergences of the gravitational action are analyzed for spacetimes that are asymptotically anti-de Sitter and asymptotically flat. The gravitational action is rendered finite using a local counterterm prescription, and the relation of this method to the traditional reference spacetime is discussed. For AdS, an iterative procedure is devised that determines the counterterms efficiently. For asymptotically flat space, we use a different method to derive counterterms which are sufficient to remove divergences in most cases.Comment: 25 pages; v2: one paragraph added, refs update

    The Men's Safer Sex (MenSS) trial: protocol for a pilot randomised controlled trial of an interactive digital intervention to increase condom use in men

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    Introduction: Sexually transmitted infections (STI) are a major public health problem. Condoms provide effective protection but there are many barriers to use. Face-to-face health promotion interventions are resource-intensive and show mixed results. Interactive digital interventions may provide a suitable alternative, allowing private access to personally tailored behaviour change support. We have developed an interactive digital intervention (the Men's Safer Sex (MenSS) website) which aims to increase condom use in men. We describe the protocol for a pilot trial to assess the feasibility of a full-scale randomised controlled trial of the MenSS website in addition to usual sexual health clinical care.Methods and analysis: Participants: Men aged 16 or over who report female sexual partners and recent unprotected sex or suspected acute STI. Participants (N=166) will be enrolled using a tablet computer in clinic waiting rooms. All trial procedures will be online, that is, eligibility checks; study consent; trial registration; automated random allocation; and data submission. At baseline and at 3, 6 and 12 months, an online questionnaire will assess condom use, self-reported STI diagnoses, and mediators of condom use (eg, knowledge, intention). Reminders will be by email and mobile phone. The primary outcome is condom use, measured at 3 months. STI rates will be recorded from sexual health clinic medical records at 12 months. The feasibility of a cost-effectiveness analysis will be assessed, to calculate incremental cost per STI prevented (Chlamydia or Gonorrhoea), from the NHS perspective.Ethics and dissemination: Ethical approval: City and East NHS Research Ethics Committee (reference number 13 LO 1801). Findings will be made available through publication in peer-reviewed journals, and to participants and members of the public via Twitter and from the University College London eHealth Unit website. Raw data will be made available on request

    High Gaussicity feedhorns for sub-/ millimeter wave applications

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    In feedhorn design, the power coupling to the fundamental free-space LG00 mode, or Gaussicity, is a good proxy for high performance, particularly the sidelobe and cross-polar levels and the near-field behavior. Gaussicity can be maximized by ensuring that the first few horn modes reach the aperture with the appropriate phase and amplitude relationship. We present two feedhorn designs for which the Gaussicity was maximized in order to achieve high performance. The first is a 94 GHz corrugated horn with a tanh-linear profile, manufactured by electroforming, which achieves a Gaussicity of 99.92% at band center and sidelobes at the -60 dB level. The second is a 340 GHz smooth-walled spline horn which achieves a Gaussicity of >99.2% over a 10% bandwidth, sidelobes below -30 dB and excellent near-field behavior. This design has been successfully fabricated in E-plane split block suitable for low volume manufacture, for example for imaging arrays.Postprin

    Fabrication of Nanometer and Micrometer Scale Protein Structures by Site-Specific Immobilization of Histidine-Tagged Proteins to Aminosiloxane Films with Photoremovable Protein-Resistant Protecting Groups

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    The site-specific immobilization of histidine-tagged proteins to patterns formed by far-field and near-field exposure of films of aminosilanes with protein-resistant photolabile protecting groups is demonstrated. After deprotection of the aminosilane, either through a mask or using a scanning near-field optical microscope, the amine terminal groups are derivatized first with glutaraldehyde and then with N-(5-amino-1-carboxypentyl)iminodiacetic acid to yield a nitrilo triacetic acid (NTA) terminated surface. After complexation with Ni2+, this surface binds histidine-tagged GFP and CpcA-PEB in a site-specific fashion. The chemistry is simple and reliable, and leads to extensive surface functionalization. Bright fluorescence is observed in fluorescence microscopy images of micrometer- and nanometer-scale patterns. X-ray photoelectron spectroscopy is used to study quantitatively the efficiency of photodeprotection and the reactivity of the modified surfaces. The efficiency of the protein binding process is investigated quantitatively by ellipsometry and by fluorescence microscopy. We find that regions of the surface not exposed to UV light bind negligible amounts of His-tagged proteins, indicating that the oligo(ethylene glycol) adduct on the nitrophenyl protecting group confers excellent protein resistance; in contrast, exposed regions bind His-GFP very effectively, yielding strong fluorescence that is almost completely removed on treatment of the surface with imidazole, confirming a degree of site-specific binding in excess of 90%. This simple strategy offers a versatile generic route to the spatially selective site-specific immobilization of proteins at surfaces

    Optimization and measurement of a smoothly profiled horn for a W-band gyro-TWA

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    In this paper, a smoothly profiled horn was designed and manufactured to replace a corrugated output horn for a W-band gyro-TWA with improved ultra-high vacuum compatibility. It was optimized for high vacuum integrity, low reflection, high fundamental Gaussian mode content, low side lobe levels and high directivity over the frequency bandwidth of 90 - 100 GHz. Over this operating frequency band the reflectivity was better than -37 dB and the coupling to a fundamental Gaussian mode was above 97%. The far field pattern showed a directivity of approximately 27 dB in the measurement with side lobes lower than -30 dB

    Towards increased concentration sensitivity for continuous wave EPR investigations of spin-labeled biological macromolecules at high fields

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    This work was performed at the National High Magnetic Field Laboratory (NHMFL), which is supported by the National Science Foundation (DMR-1157490) and the State of Florida. L.S. acknowledges support from the National Institutes of Health (AI091693) and the NHMFL User Collaboration Grants Program (Award No. 5080). G.E.F. acknowledges support from the National Science Foundation (MCB-1329467) and the National Institutes of Health (GM105409 and S10RR031603). S.H. acknowledges support from the National Science Foundation (DMR-1309463). J.M.E acknowledges support from the National Science Foundation (DGE-0802270).High-field, high-frequency electron paramagnetic resonance (EPR) spectroscopy at W- (∼95 GHz) and D-band (∼140 GHz) is important for investigating the conformational dynamics of flexible biological macromolecules because this frequency range has increased spectral sensitivity to nitroxide motion over the 100 ps to 2 ns regime. However, low concentration sensitivity remains a roadblock for studying aqueous samples at high magnetic fields. Here, we examine the sensitivity of a non-resonant thin-layer cylindrical sample holder, coupled to a quasi-optical induction-mode W-band EPR spectrometer (HiPER), for continuous wave (CW) EPR analyses of: (i) the aqueous nitroxide standard, TEMPO; (ii) the unstructured to α-helical transition of a model IDP protein; and (iii) the base-stacking transition in a kink-turn motif of a large 232 nt RNA. For sample volumes of ∼50 μL, concentration sensitivities of 2-20 μM were achieved, representing a ∼10-fold enhancement compared to a cylindrical TE011 resonator on a commercial Bruker W-band spectrometer. These results therefore highlight the sensitivity of the thin-layer sample holders employed in HiPER for spin-labeling studies of biological macromolecules at high fields, where applications can extend to other systems that are facilitated by the modest sample volumes and ease of sample loading and geometry.PostprintPeer reviewe

    Simple, Direct Routes to Polymer Brush Traps and Nanostructures for Studies of Diffusional Transport in Supported Lipid Bilayers

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    Patterned poly(oligo ethylene glycol) methyl ether methacrylate (POEGMEMA) brush structures may be formed by using a combination of atom-transfer radical polymerization (ATRP) and UV photopatterning. UV photolysis is used to selectively dechlorinate films of 4-(chloromethyl)phenyltrichlorosilane (CMPTS) adsorbed on silica surfaces, by exposure either through a mask or using a two-beam interferometer. Exposure through a mask yields patterns of carboxylic acid-terminated adsorbates. POEGMEMA may be grown from intact Cl initiators that were masked during exposure. Corrals, traps, and other structures formed in this way enable the patterning of proteins, vesicles, and, following vesicle rupture, supported lipid bilayers (SLBs). Bilayers adsorbed on the carboxylic acid-terminated surfaces formed by C–Cl bond photolysis in CMPTS exhibit high mobility. SLBs do not form on POEGMEMA. Using traps consisting of carboxylic acid-functionalized regions enclosed by POEGMEMA structures, electrophoresis may be observed in lipid bilayers containing a small amount of a fluorescent dye. Segregation of dye at one end of the traps was measured by fluorescence microscopy. The increase in the fluorescence intensity was found to be proportional to the trap length, while the time taken to reach the maximum value was inversely proportional to the trap length, indicating uniform, rapid diffusion in all of the traps. Nanostructured materials were formed using interferometric lithography. Channels were defined by exposure of CMPTS films to maxima in the interferogram, and POEGMEMA walls were formed by ATRP. As for the micrometer-scale patterns, bilayers did not form on the POEGMEMA structures, and high lipid mobilities were measured in the polymer-free regions of the channels
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