9,791 research outputs found

    A Multiwavelength Investigation of Unidentified EGRET Sources

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    Statistical studies indicate that the 271 point sources of high-energy gamma rays belong to two groups: a Galactic population and an isotropic extragalactic population. Many unidentified extragalactic sources are certainly blazars, and it is the intention of this work to uncover gamma-ray blazars missed by previous attempts. Until recently, searches for blazar counterparts to unidentified EGRET sources have focused on finding AGN that have 5-GHz radio flux densities S_5 near or above 1 Jy. However, the recent blazar identification of 3EG J2006-2321 (S_5 = 260 mJy) and other work suggest that careful studies of weaker flat-spectrum sources may be fruitful. In this spirit, error circles of 4 high-latitude unidentified EGRET sources have been searched for 5-GHz sources. The gamma-ray sources are 3EG J1133+0033, 3EG J1212+2304, 3EG J1222+2315, and 3EG J1227+4302. Within the error contours of each of the four sources are found 6 radio candidates; by observing the positions of the radio sources with the 0.81-m Tenagra II telescope it is determined that 14 of these 24 radio sources have optical counterparts with R < 22. Eight of these from two different EGRET sources have been observed in the B, V, and R bands in more than one epoch and the analysis of these data is ongoing. Any sources that are found to be variable will be the objects of multi-epoch polarimetry studies.Comment: 6 pages, 2 tables. To appear in Astrophysics & Space Scienc

    The host of the SN-less GRB 060505 in high resolution

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    The spiral host galaxy of GRB 060505 at z=0.089 was the site of a puzzling long duration burst without an accompanying supernova. Studies of the burst environment by Th\"one et al. (2008) suggested that this GRB came from the collapse of a massive star and that the GRB site was a region with properties different from the rest of the galaxy. We reobserved the galaxy in high spatial resolution using the VIMOS integral-field unit (IFU) at the VLT with a spaxel size of 0.67 arcsec. Furthermore, we use long slit high resolution data from HIRES/Keck at two different slit positions covering the GRB site, the center of the galaxy and an HII region next to the GRB region. We compare the properties of different HII regions in the galaxy with the GRB site and study the global and local kinematic properties of this galaxy. The resolved data show that the GRB site has the lowest metallicity in the galaxy with around 1/3 Z_solar, but its specific SFR (SSFR) of 7.4 M_solar/yr/L/L* and age (determined by the Halpha EW) are similar to other HII regions in the host. The galaxy shows a gradient in metallicity and SSFR from the bulge to the outskirts as it is common for spiral galaxies. This gives further support to the theory that GRBs prefer regions of higher star-formation and lower metallicity, which, in S-type galaxies, are more easily found in the spiral arms than in the centre. Kinematic measurements of the galaxy do not show evidence for large perturbations but a minor merger in the past cannot be excluded. This study confirms the collapsar origin of GRB060505 but reveals that the properties of the HII region surrounding the GRB were not unique to that galaxy. Spatially resolved observations are key to know the implications and interpretations of unresolved GRB hosts observations at higher redshifts.Comment: 15 pages, 16 figures, 6 tables; resubmitted to MNRAS after minor revision

    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

    Simulations of Weighted Tree Automata

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    Simulations of weighted tree automata (wta) are considered. It is shown how such simulations can be decomposed into simpler functional and dual functional simulations also called forward and backward simulations. In addition, it is shown in several cases (fields, commutative rings, Noetherian semirings, semiring of natural numbers) that all equivalent wta M and N can be joined by a finite chain of simulations. More precisely, in all mentioned cases there exists a single wta that simulates both M and N. Those results immediately yield decidability of equivalence provided that the semiring is finitely (and effectively) presented.Comment: 17 pages, 2 figure

    Exploring British adolescent rugby league players' experiences of professional academies and dropout.

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    The purposes of this study were threefold: to explore former rugby league players’ experiences of professional academy environments, to understand their reasons for dropping out of the sport, and to explore their recommendations for optimising future talent development environments. Semi-structured interviews were conducted with nine ex-professional academy rugby league players up to one year after dropping out of playing rugby. A combination of inductive and deductive thematic analysis was employed to analyse the data. The thematic analysis revealed three general dimensions: talent development pathways, reasons for dropout, and recommendations. The findings suggest that players’ talent development experiences, and the reasons for dropout could be explained by a complex interaction of micro (e.g. negative academy experiences), meso (e.g. education), exo (e.g. player pathway structures), and macro systems (e.g. transitions to other clubs). It is concluded from these findings that talent development pathways which lack a long-term focus, and emphasise early success are likely to result in increased risk of burnout, de-motivation, and subsequent dropout. From an applied perspective, talent development pathways must consider the many personal and environmental factors which interact to determine an individual’s talent development trajectory. Furthermore, by recognising the multiple factors that may influence development, the effectiveness of development pathways may be enhanced by neither excluding “potential” through inappropriate early identification, nor ignoring crucial talent development variables that contribute toward the fulfilment of potential

    The Spectral Lag of GRB060505: A Likely Member of the Long Duration Class

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    Two long gamma-ray bursts, GRB 060505 and GRB 060614, occurred in nearby galaxies at redshifts of 0.089 and 0.125 respectively. Due to their proximity and durations, deep follow-up campaigns to search for supernovae (SNe) were initiated. However none were found in either case, to limits more than two orders of magnitude fainter than the prototypical GRB-associated SN, 1998bw. It was suggested that the bursts, in spite of their durations (4 and 102 s), belonged to the population of short GRBs which has been shown to be unrelated to SNe. In the case of GRB 060614 this argument was based on a number of indicators, including the negligible spectral lag, which is consistent with that of short bursts. GRB 060505 has a shorter duration, but no spectral lag was measured. We present the spectral lag measurements of GRB 060505 using Suzakus Wide Area Monitor and the Swift Burst Alert Telescope. We find that the lag is 0.36+/- 0.05 s, inconsistent with the lags of short bursts and consistent with the properties of long bursts and SN-GRBs. These results support the association of GRB 060505 with other low-luminosity GRBs also found in star-forming galaxies and indicates that at least some massive stars may die without bright SNe.Comment: Accepted by ApJL, 5 pages, 3 Figure

    Flexible Lipid Bilayers in Implicit Solvent

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    A minimalist simulation model for lipid bilayers is presented. Each lipid is represented by a flexible chain of beads in implicit solvent. The hydrophobic effect is mimicked through an intermolecular pair potential localized at the ``water''/hydrocarbon tail interface. This potential guarantees realistic interfacial tensions for lipids in a bilayer geometry. Lipids self assemble into bilayer structures that display fluidity and elastic properties consistent with experimental model membrane systems. Varying molecular flexibility allows for tuning of elastic moduli and area/molecule over a range of values seen in experimental systems.Comment: 5 pages, 5 figure

    Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts

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    The identification and localization of a marker protein for the intermembrane space between the outer and inner chloroplast envelopes is described. This 64-kDa protein is very rapidly labeled by [Îł-32P]ATP at very low (30 nM) ATP concentrations and the phosphoryl group exhibits a high turnover rate. It was possible to establish the presence of the 64-kDa protein in this plastid compartment by using different chloroplast envelope separation and isolation techniques. In addition comparison of labeling kinetics by intact and hypotonically lysed pea chloroplasts support the localization of the 64-kDa protein in the intermembrane space. The 64-kDa protein was present and could be labeled in mixed envelope membranes isolated from hypotonically lysed plastids. Mixed envelope membranes incorporated high amounts of 32P from [Îł-32P]ATP into the 64-kDa protein, whereas separated outer and inner envelope membranes did not show significant phosphorylation of this protein. Water/Triton X-114 phase partitioning demonstrated that the 64-kDa protein is a hydrophilic polypeptide. These findings suggest that the 64-kDa protein is a soluble protein trapped in the space between the inner and outer envelope membranes. After sonication of mixed envelope membranes, the 64-kDa protein was no longer present in the membrane fraction, but could be found in the supernatant after a 110000 Ă— g centrifugation

    Planning, Delivering, and Evaluating an Extension In-Service Training Program for Developing Local Food Systems: Lessons Learned

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    The social movement focused on re-localizing food systems is oriented toward recreating relationships between producers, consumers, and other community stakeholders. Sustaining community efforts to build local food systems requires preparation of county Extension educators to understand how food supply chains function as systems, facilitate community partnerships, and create equitable access to locally produced food. This paper shares how North Carolina Cooperative Extension designed, delivered, and evaluated a local foods in-service training on these three topics, as well as shares lessons learned through the process. The implications of this study are helpful for Extension educators planning, delivering, and evaluating in-service training programs that support development of local food systems
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