524 research outputs found

    Pilot Study of a Web-Delivered Multicomponent Intervention for Rural Teens with Poorly Controlled Type 1 Diabetes

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    Objective. The purpose of this study was to examine the feasibility and effectiveness of a web-delivered multicomponent behavioral and family-based intervention targeting self-regulation and self-monitoring of blood glucose levels (SMBG) and glycemic control (HbA1c) in teens with type 1 diabetes (T1DM) living in rural US. Methods. 15 teens with poorly controlled T1DM participated in a 25-week web-delivered intervention with two phases, active treatment (weekly treatment sessions and working memory training program) and maintenance treatment (fading of treatment sessions). Results. Almost all (13 of 15) participants completed at least 14 of 15 treatment sessions and at least 20 of 25 working memory training sessions. SMBG was increased significantly at end of active and maintenance treatment, and HbA1c was decreased at end of active treatment (’s ≤ 0.05). Executive functioning improved at end of maintenance treatment: performance on working memory and inhibitory control tasks significantly improved (’s ≤ 0.02) and parents reported fewer problems with executive functioning (). Improvement in inhibitory control was correlated with increases in SMBG and decreases in HbA1c. Conclusions. An innovative web-delivered and multicomponent intervention was feasible for teens with poorly controlled T1DM and their families living in rural US and associated with significant improvements in SMBG and HbA1c

    ROSAT Evidence for Intrinsic Oxygen Absorption in Cooling Flow Galaxies and Groups

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    Using spatially resolved, deprojected ROSAT PSPC spectra of 10 of the brightest cooling flow galaxies and groups with low Galactic column densities we have detected intrinsic absorption over energies ~0.4-0.8 keV in half of the sample. Since no intrinsic absorption is indicated for energies below ~0.4 keV, the most reasonable model for the absorber is collisionally ionized gas at temperatures T=10^{5-6} K with most of the absorption arising from ionized states of oxygen but with a significant contribution from carbon and nitrogen. The soft X-ray emission of this warm gas can explain the sub-Galactic column densities of cold gas inferred within the central regions of most of the systems. Attributing the absorption to ionized gas reconciles the large columns of cold H and He inferred from EINSTEIN and ASCA with the lack of such columns inferred from ROSAT. Within the central ~10-20 kpc, where the constraints are most secure, the estimated mass of the ionized absorber is consistent with most (perhaps all) of the matter deposited by a cooling flow over the lifetime of the flow. Since the warm absorber produces no significant H or He absorption the large absorber masses are consistent with the negligible atomic and molecular H inferred from HI and CO observations of cooling flows. It is also found that if T > ~2x10^5 K then the optical and UV emission implied by the warm gas does not violate published constraints. Finally, we discuss how the prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified with new CHANDRA and XMM observations. (Abridged)Comment: 17 pages (5 figures), Accepted for publication in ApJ, expanded discussion of multiphase spectral models, theoretical implications of warm gas in cooling flows, and the statistical significance of the oxygen absorptio

    Two-Dimensional Infrared Spectroscopy of Antiparallel β-Sheet Secondary Structure

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    We investigate the sensitivity of femtosecond Fourier transform two-dimensional infrared spectroscopy to protein secondary structure with a study of antiparallel β-sheets. The results show that 2D IR spectroscopy is more sensitive to structural differences between proteins than traditional infrared spectroscopy, providing an observable that allows comparison to quantitative models of protein vibrational spectroscopy. 2D IR correlation spectra of the amide I region of poly-L-lysine, concanavalin A, ribonuclease A, and lysozyme show cross-peaks between the IR-active transitions that are characteristic of amide I couplings for polypeptides in antiparallel hydrogen-bonding registry. For poly-L-lysine, the 2D IR spectrum contains the eight-peak structure expected for two dominant vibrations of an extended, ordered antiparallel β-sheet. In the proteins with antiparallel β-sheets, interference effects between the diagonal and cross-peaks arising from the sheets, combined with diagonally elongated resonances from additional amide transitions, lead to a characteristic “Z”-shaped pattern for the amide I region in the 2D IR spectrum. We discuss in detail how the number of strands in the sheet, the local configurational disorder in the sheet, the delocalization of the vibrational excitation, and the angle between transition dipole moments affect the position, splitting, amplitude, and line shape of the cross-peaks and diagonal peaks.

    Radio Sources in Low-Luminosity Active Galactic Nuclei. I. VLA Detections of Compact, Flat-Spectrum Cores

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    We report a 0.2" resolution, 15 GHz survey of a sample of 48 low-luminosity active galactic nuclei with the Very Large Array. Compact radio emission has been detected in 57% (17 of 30) of LINERs and low-luminosity Seyferts, at least 15 of which have a flat to inverted radio spectrum (alpha > -0.3). The compact radio cores are found in both type 1 (i.e. with broad Halpha) and type 2 (without broad Halpha) nuclei. The 2 cm radio power is significantly correlated with the emission-line ([OI] lambda6300) luminosity. While the present observations are consistent with the radio emission originating in star-forming regions, higher resolution radio observations of 10 of the detected sources, reported in a companion paper (Falcke et al. 2000), show that the cores are very compact (= 10^8K) and probably synchrotron self-absorbed, ruling out a starburst origin. Thus, our results suggest that at least 50% of low-luminosity Seyferts and LINERs in the sample are accretion powered, with the radio emission presumably coming from jets or advection-dominated accretion flows. We have detected only 1 of 18 `transition' (i.e. LINER + HII) nuclei observed, indicating their radio cores are significantly weaker than those of `pure' LINERs.Comment: To appear in the Astrophysical Journal, October 20, 200

    AGN-Induced Cavities in NGC 1399 and NGC 4649

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    We present an analysis of archival Chandra and VLA observations of the E0 galaxy NGC 1399 and the E2 galaxy NGC 4649 in which we investigate cavities in the surrounding X-ray emitting medium caused by the central AGN. We calculate the jet power required for the AGN to evacuate these cavities and find values of ~8x10^{41} erg/s and ~14x10^{41} erg/s for the lobes of NGC 1399 and ~7x10^{41} erg/s and ~6x10^{41} erg/s for those of NGC 4649. We also calculate the k/f values for each cavity, where k is the ratio of the total particle energy to that of electrons radiating in the range of 10 MHz to 10 GHz, and f is the volume filling factor of the plasma in the cavity. We find that the values of k/f for the lobes of NGC 1399 are ~93 and ~190, and those of the lobes of NGC 4649 are ~15000 and ~12000. We conclude that the assumed spectrum describes the electron distribution in the lobes of NGC 1399 reasonably well, and that there are few entrained particles. For NGC 4649, either there are many entrained particles or the model spectrum does not accurately describe the population of electrons.Comment: 8 pages, 2 figures, accepted for publication in MNRA

    A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2

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    The cryogenic dark matter experiment CRESST-II aims at the direct detection of WIMPs via elastic scattering off nuclei in scintillating CaWO4_4 crystals. We present a new, highly improved, detector design installed in the current run of CRESST-II Phase 2 with an efficient active rejection of surface-alpha backgrounds. Using CaWO4_4 sticks instead of metal clamps to hold the target crystal, a detector housing with fully-scintillating inner surface could be realized. The presented detector (TUM40) provides an excellent threshold of 0.60{\sim}\,0.60\,keV and a resolution of σ0.090\sigma\,{\approx}\,0.090 keV (at 2.60\,keV). With significantly reduced background levels, TUM40 sets stringent limits on the spin-independent WIMP-nucleon scattering cross section and probes a new region of parameter space for WIMP masses below 3\,GeV/c2^2. In this paper, we discuss the novel detector design and the surface-alpha event rejection in detail.Comment: 9 pages, 6 figure

    The Two-dimensional XMM-Newton Group Survey: z<0.012 groups

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    We present the results of the 2-dimensional XMM-Newton Group Survey (2dXGS), an archival study of nearby galaxy groups. In this paper we consider eleven nearby systems (z<0.012) in Mulchaey et al. (2003), which span a broad range in X-ray luminosity from 10^40 to 10^43 ergs/s. We measure the iron abundance and temperature distribution in these systems and derive pressure and entropy maps. We find statistically significant evidence for structure in the entropy and pressure of the gas component of seven groups on the 10-20% level. The XMM-Newton data for the three groups with best statistics also suggest patchy metalicity distributions within the central 20--50 kpc of the brightest group galaxy, probed with 2-10 kpc resolution. This provides insights into the processes associated with thermalization of the stellar mass loss. Analysis of the global properties of the groups reveals a subclass of X-ray faint groups, which are characterized by both higher entropy and lower pressure. We suggest that the merger history of the central elliptical is responsible for both the source and the observed thermodynamical properties of the hot gas of the X-ray faint groups.Comment: 18 pages, ApJ, 646, 143, 200

    The Effects of Cocaine on Different Redox Forms of Cysteine and Homocysteine, and on Labile, Reduced Sulfur in the Rat Plasma Following Active versus Passive Drug Injections

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    Received: 28 November 2012 / Revised: 19 April 2013 / Accepted: 6 May 2013 / Published online: 16 May 2013 The Author(s) 2013. This article is published with open access at Springerlink.comThe aim of the present studies was to evaluate cocaine-induced changes in the concentrations of different redox forms of cysteine (Cys) and homocysteine (Hcy), and products of anaerobic Cys metabolism, i.e., labile, reduced sulfur (LS) in the rat plasma. The above-mentioned parameters were determined after i.p. acute and subchronic cocaine treatment as well as following i.v. cocaine self-administration using the yoked procedure. Additionally, Cys, Hcy, and LS levels were measured during the 10-day extinction training in rats that underwent i.v. cocaine administration. Acute i.p. cocaine treatment increased the total and protein-bound Hcy contents, decreased LS, and did not change the concentrations of Cys fractions in the rat plasma. In turn, subchronic i.p. cocaine administration significantly increased free Hcy and lowered the total and protein-bound Cys concentrations while LS level was unchanged. Cocaine self-administration enhanced the total and protein-bound Hcy levels, decreased LS content, and did not affect the Cys fractions. On the other hand, yoked cocaine infusions did not alter the concentration of Hcy fractions while decreased the total and protein-bound Cys and LS content. This extinction training resulted in the lack of changes in the examined parameters in rats with a history of cocaine self-administration while in the yoked cocaine group an increase in the plasma free Cys fraction and LS was seen. Our results demonstrate for the first time that cocaine does evoke significant changes in homeostasis of thiol amino acids Cys and Hcy, and in some products of anaerobic Cys metabolism, which are dependent on the way of cocaine administration

    Associations among the parent–adolescent relationship, aggression and delinquency in different ethnic groups: a replication across two Dutch samples

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    Background: The aim of the present study is to examine whether the patterns of association between the quality of the parent-adolescent relationship on the one hand, and aggression and delinquency on the other hand, are the same for boys and girls of Dutch and Moroccan origin living in the Netherlands. Since inconsistent results have been found previously, the present study tests the replicability of the model of associations in two different Dutch samples of adolescents. Method: Study 1 included 288 adolescents (M age = 14.9, range 12-17 years) all attending lower secondary education. Study 2 included 306 adolescents (M age = 13.2, range = 12-15 years) who were part of a larger community sample with oversampling of at risk adolescents. Results: Multigroup structural analyses showed that neither in Study 1 nor in Study 2 ethnic or gender differences were found in the patterns of associations between support, autonomy, disclosure, and negativity in the parent-adolescent relationship and aggression and delinquency. The patterns were largely similar for both studies. Mainly negative quality of the relationship in both studies was found to be strongly related to both aggression and delinquency. Discussion: Results show that family processes that affect adolescent development, show a large degree of universality across gender and ethnicity

    Radio Sources in Low-Luminosity Active Galactic Nuclei. III. "AGNs" in a Distance-Limited Sample of "LLAGNs"

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    (abbreviated): This paper presents the results of a high resolution radio imaging survey of all known (96) low-luminosity active galactic nuclei (LLAGNs) at D<19Mpc. We find that almost half of all LINERs and low-luminosity Seyferts have flat-spectrum radio cores when observed at 150mas resolution. Higher (2mas) resolution observations of a flux-limited subsample have provided a 100% (16 of 16) detection rate of pc-scale radio cores, with implied brightness temperatures > 10^8 K. The five LLAGNs with the highest core radio fluxes also have pc-scale `jets.' Compact radio cores are almost exclusively found in massive ellipticals and in type1 nuclei. The core radio power is correlated with the nuclear optical `broad' Halpha luminosity, the nuclear optical `narrow' emission line luminosity and width, and with the galaxy luminosity. In these correlations LLAGNs fall close to the low-luminosity extrapolations of more powerful AGNs. About half of all LLAGNs with multiple epoch data show significant inter-year radio variability. Investigation of a sample of ~150 nearby bright galaxies, most of them LLAGNs, shows that the nuclear (<150mas size) radio power is strongly correlated with both the black hole mass and the galaxy bulge luminosity; linear regression fits to all ~150 galaxies give: log P(2cm) = 1.31 log M_blackhole + 8.77 and log P(2cm) = 1.89 log L_B(bulge) - 0.17. Low accretion rates are implied in both advection- and jet-type models. In brief, all evidence points towards the presence of accreting massive black holes in a large fraction, perhaps all, of LLAGNs.Comment: to appear in A&
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