1,214 research outputs found
F10RS SGR No. 5 (Athletic Dept)
A RESOLUTION
To acknowledge and thank the Athletic Department at Louisiana State University for its contribution to the University
Role of dopamine D1-like receptors in methamphetamine locomotor responses of D2 receptor knockout mice
Behavioral sensitization to psychostimulants manifests as an increased locomotor response with repeated administration. Dopamine systems are accepted to play a fundamental role in sensitization, but the role of specific dopamine receptor subtypes has not been completely defined. This study used the combination of dopamine D2 receptor-deficient mice and a D1-like antagonist to examine dopamine D1 and D2 receptor involvement in acute and sensitized locomotor responses to methamphetamine. Absence of the dopamine D2 receptor resulted in attenuation of the acute stimulant effects of methamphetamine. Mutant and wild-type mice exhibited sensitization that lasted longer within the time period of the challenge test in the mutant animals. Pretreatment with the D1-like receptor antagonist SCH 23390 produced more potent reductions in the acute and sensitized locomotor responses to methamphetamine in D2 receptor-deficient mice than in wild-type mice; however, the expression of locomotor sensitization when challenged with methamphetamine alone was equivalently attenuated by previous treatment with SCH 23390. These data suggest that dopamine D2 receptors play a key role in the acute stimulant and sensitizing effects of methamphetamine and act in concert with D1-like receptors to influence the acquisition of methamphetamine-induced behavioral sensitization, traits that may influence continued methamphetamine use.Fil: Kelly, M. A.. Oregon Health And Science University; Estados UnidosFil: Low, M. J.. Oregon Health And Science University; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Phillips, T. J.. Oregon Health And Science University; Estados Unido
The relation of optical/UV and X-ray emission in low-luminosity active galactic nuclei
We study the relation of optical/UV and X-ray emission in the low luminosity
active galactic nuclei (LLAGNs), using a sample of 49 sources including 28
local Seyfert galaxies and 21 low-ionization nuclear emission-line regions
(LINERs) with the optical/UV spectral luminosity at the wavelength
\lambda=2500\AA, 23.0\leq \log L_{\nu(2500\AA)(erg/s/Hz)\leq 27.7, and the
X-ray spectral luminosity at 2 keV, 20.5\leq \log L_{\nu(2 keV)}\leq 25.3. The
strong correlations are found between the X-ray luminosity and the optical/UV
to X-ray index, \alpha_{ox}, with the optical/UV luminosity, with the slopes
very similar to the findings for the luminous AGNs in the previous works. The
correlation between \alpha_{ox} and L_{\nu(2 keV) is very weak as that found
for the luminous AGNs in the majority of previous similar works. We also study
the relation between $\alpha_{\rm ox} and the Eddington ratio L_{bol}/L_{Edd}
for our sample and find a significant anti-correlation for the sources with
L_{bol}/L_{Edd}\lesssim 10^{-3}, which is opposite to the correlation between
the two variables for the luminous AGNs. Using the advection dominated
accretion flow (ADAF) model, we roughly reproduce this anti-correlationship for
the two variables for the LLAGNs. This result strongly supports the ADAF as a
candidate accretion mode in LLAGNs.Comment: 21 pages, 1 table, 5 figures. Accepted for publication in Ap
START-online: acceptability and feasibility of an online intervention for carers of people living with dementia
BACKGROUND: With increasing numbers of people living with dementia relying on family to care for them at home, there is an urgent need for practical and evidence-based programs to support carers in maintaining their mental health and well-being. The objective of this study was to evaluate the acceptability and feasibility of a modified STrAtegies for RelaTives (START) program delivered online (START-online). METHOD: A mixed-methods non-blinded evaluation of START-online (using Zoom as videoconferencing platform) for acceptability and feasibility (completion rates and qualitative feedback through surveys and focus groups) and quantitative evaluation. This occurred at the National Ageing Research Institute, in metropolitan Victoria, Australia. RESULTS: Twenty-nine eligible carers were referred, 20 (70%) consented to the study. Of these, 16 (80%) completed all 8 sessions, 2 completed only 3 sessions, and 2 withdrew. Carers' qualitative feedback indicated that the therapist interaction was valued, content and online delivery of the program was acceptable. Feedback was mixed on the appropriate stage of caring. CONCLUSION: START-online was feasible and acceptable for carers, including those living outside of metropolitan areas who might otherwise be unable to access face-to-face programs. With the recent COVID-19 pandemic necessitating social distancing to avoid infection, interventions such as this one have increasing relevance in the provision of flexible services
Design and analysis of distributed utility maximization algorithm for multihop wireless network with inaccurate feedback
Distributed network utility maximization (NUM) is receiving increasing interests for cross-layer optimization problems in multihop wireless networks. Traditional distributed NUM algorithms rely heavily on feedback information between different network elements, such as traffic sources and routers. Because of the distinct features of multihop wireless networks such as time-varying channels and dynamic network topology, the feedback information is usually inaccurate, which represents as a major obstacle for distributed NUM application to wireless networks. The questions to be answered include if distributed NUM algorithm can converge with inaccurate feedback and how to design effective distributed NUM algorithm for wireless networks. In this paper, we first use the infinitesimal perturbation analysis technique to provide an unbiased gradient estimation on the aggregate rate of traffic sources at the routers based on locally available information. On the basis of that, we propose a stochastic approximation algorithm to solve the distributed NUM problem with inaccurate feedback. We then prove that the proposed algorithm can converge to the optimum solution of distributed NUM with perfect feedback under certain conditions. The proposed algorithm is applied to the joint rate and media access control problem for wireless networks. Numerical results demonstrate the convergence of the proposed algorithm
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The LSST DESC data challenge 1: Generation and analysis of synthetic images for next-generation surveys
Data Challenge 1 (DC1) is the first synthetic data set produced by the Rubin Observatory Legacy Survey of Space and Time (LSST) Dark Energy Science Collaboration (DESC). DC1 is designed to develop and validate data reduction and analysis and to study the impact of systematic effects that will affect the LSST data set. DC1 is comprised of r-band observations of 40 deg2 to 10 yr LSST depth. We present each stage of the simulation and analysis process: (a) generation, by synthesizing sources from cosmological N-body simulations in individual sensor-visit images with different observing conditions; (b) reduction using a development version of the LSST Science Pipelines; and (c) matching to the input cosmological catalogue for validation and testing. We verify that testable LSST requirements pass within the fidelity of DC1. We establish a selection procedure that produces a sufficiently clean extragalactic sample for clustering analyses and we discuss residual sample contamination, including contributions from inefficiency in star-galaxy separation and imperfect deblending. We compute the galaxy power spectrum on the simulated field and conclude that: (i) survey properties have an impact of 50 per cent of the statistical uncertainty for the scales and models used in DC1; (ii) a selection to eliminate artefacts in the catalogues is necessary to avoid biases in the measured clustering; and (iii) the presence of bright objects has a significant impact (2-6) in the estimated power spectra at small scales (> 1200), highlighting the impact of blending in studies at small angular scales in LSST
Deep Chandra X-ray Imaging of a Nearby Radio Galaxy 4C+29.30: X-ray/Radio Connection
We report results from our deep Chandra X-ray observations of a nearby radio
galaxy, 4C+29.30 (z=0.0647). The Chandra image resolves structures on
sub-arcsec to arcsec scales, revealing complex X-ray morphology and detecting
the main radio features: the nucleus, a jet, hotspots, and lobes. The nucleus
is absorbed (N(H)=3.95 (+0.27/-0.33)x10^23 atoms/cm^2) with an unabsorbed
luminosity of L(2-10 keV) ~ (5.08 +/-0.52) 10^43 erg/s characteristic of Type 2
AGN. Regions of soft (<2 keV) X-ray emission that trace the hot interstellar
medium (ISM) are correlated with radio structures along the main radio axis
indicating a strong relation between the two. The X-ray emission beyond the
radio source correlates with the morphology of optical line-emitting regions.
We measured the ISM temperature in several regions across the galaxy to be kT ~
0.5 with slightly higher temperatures (of a few keV) in the center and in the
vicinity of the radio hotspots. Assuming these regions were heated by weak
shocks driven by the expanding radio source, we estimated the corresponding
Mach number of 1.6 in the southern regions. The thermal pressure of the X-ray
emitting gas in the outermost regions suggest the hot ISM is slightly
under-pressured with respect to the cold optical-line emitting gas and
radio-emitting plasma, which both seem to be in a rough pressure equilibrium.
We conclude that 4C+29.30 displays a complex view of interactions between the
jet-driven radio outflow and host galaxy environment, signaling feedback
processes closely associated with the central active nucleus.Comment: ApJ in pres
A novel histological index for evaluation of environmental enteric dysfunction identifies geographic-specific features of enteropathy among children with suboptimal growth
Background: A major limitation to understanding the etiopathogenesis of environmental enteric dysfunction (EED) is the lack of a comprehensive, reproducible histologic framework for characterizing the small bowel lesions. We hypothesized that the development of such a system will identify unique histology features for EED, and that some features might correlate with clinical severity.Methods: Duodenal endoscopic biopsies from two cohorts where EED is prevalent (Pakistan, Zambia) and North American children with and without gluten sensitive enteropathy (GSE) were processed for routine hematoxylin & eosin (H&E) staining, and scanned to produce whole slide images (WSIs) which we shared among study pathologists via a secure web browser-based platform. A semi-quantitative scoring index composed of 11 parameters encompassing tissue injury and response patterns commonly observed in routine clinical practice was constructed by three gastrointestinal pathologists, with input from EED experts. The pathologists then read the WSIs using the EED histology index, and inter-observer reliability was assessed. The histology index was further used to identify within- and between-child variations as well as features common across and unique to each cohort, and those that correlated with host phenotype.Results: Eight of the 11 histologic scoring parameters showed useful degrees of variation. The overall concordance across all parameters was 96% weighted agreement, kappa 0.70, and Gwet\u27s AC 0.93. Zambian and Pakistani tissues shared some histologic features with GSE, but most features were distinct, particularly abundance of intraepithelial lymphocytes in the Pakistani cohort, and marked villous destruction and loss of secretory cell lineages in the Zambian cohort.Conclusions: We propose the first EED histology index for interpreting duodenal biopsies. This index should be useful in future clinical and translational studies of this widespread, poorly understood, and highly consequential disorder, which might be caused by multiple contributing processes, in different regions of the world
ATF6 is essential for human cone photoreceptor development
Endoplasmic reticulum (ER) stress and Unfolded Protein Response (UPR) signaling promote the pathology of many human diseases. Loss-of-function variants of the UPR regulator Activating Transcription Factor 6 (ATF6) cause severe congenital vision loss diseases such as achromatopsia by unclear pathomechanisms. To investigate this, we generated retinal organoids from achromatopsia patient induced pluripotent stem cells carrying ATF6 disease variants and from gene-edited ATF6 null hESCs. We found that achromatopsia patient and ATF6 null retinal organoids failed to form cone structures concomitant with loss of cone phototransduction gene expression, while rod photoreceptors developed normally. Adaptive optics retinal imaging of achromatopsia patients carrying ATF6 variants also showed absence of cone inner/outer segment structures but preserved rod structures, mirroring the defect in cone formation observed in our retinal organoids. These results establish that ATF6 is essential for human cone development. Interestingly, we find that a selective small molecule ATF6 signaling agonist restores the transcriptional activity of some ATF6 disease-causing variants and stimulates cone growth and gene expression in patient retinal organoids carrying these variants. These findings support that pharmacologic targeting of the ATF6 pathway can promote human cone development and should be further explored for blinding retinal diseases
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