11,340 research outputs found
The gray matter structural connectome and its relationship to alcohol relapse: Reconnecting for recovery.
Gray matter (GM) atrophy associated with alcohol use disorders (AUD) affects predominantly the frontal lobes. Less is known how frontal lobe GM loss affects GM loss in other regions and how it influences drinking behavior or relapse after treatment. The profile similarity index (PSI) combined with graph analysis allows to assess how GM loss in one region affects GM loss in regions connected to it, ie, GM connectivity. The PSI was used to describe the pattern of GM connectivity in 21 light drinkers (LDs) and in 54 individuals with AUD (ALC) early in abstinence. Effects of abstinence and relapse were determined in a subgroup of 36 participants after 3 months. Compared with LD, GM losses within the extended brain reward system (eBRS) at 1-month abstinence were similar between abstainers (ABST) and relapsers (REL), but REL had also GM losses outside the eBRS. Lower GM connectivities in ventro-striatal/hypothalamic and dorsolateral prefrontal regions and thalami were present in both ABST and REL. Between-networks connectivity loss of the eBRS in ABST was confined to prefrontal regions. About 3 months later, the GM volume and connectivity losses had resolved in ABST, and insula connectivity was increased compared with LD. GM losses and GM connectivity losses in REL were unchanged. Overall, prolonged abstinence was associated with a normalization of within-eBRS connectivity and a reconnection of eBRS structures with other networks. The re-formation of structural connectivities within and across networks appears critical for cognitive-behavioral functioning related to the capacity to maintain abstinence after outpatient treatment
Dosage Effects of Histamine-2 Receptor Antagonist on the Primary Prophylaxis of Non-Steroidal Anti-Inflammatory Drug (NSAID)-Associated Peptic Ulcers: A Retrospective Cohort Study
postprin
Recommended from our members
Influence of southern hemispheric biomass burning on midtropospheric distributions of nonmethane hydrocarbons and selected halocarbons over the remote South Pacific
Aircraft measurements of nonmethane hydrocarbons (NMHCs) and halocarbons were made over the remote South Pacific Ocean during late August-early October 1996 for NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics A (PEM-Tropics A). This paper discusses the large-scale spatial distributions of selected trace gases encountered during PEM-Tropics A. The PEM-Tropics A observations are compared to measurements made over the southwestern pacific in early November 1995 as part of Aerosol Characterization Experiment (ACE 1). Continental pollution in the form of layers containing elevated levels of O3 was observed during a majority of PEM-Tropics flights, as well as during several ACE 1 flights. The chemical composition of these air masses indicates that they were not fresh and were derived from nonurban combustion sources. The substantial impact of biomass burning on the vertical structure of the South Pacific troposphere is discussed. Copyright 1999 by the American Geophysical Union
Responsiveness and construct validity of a symptom scale for acute otitis media
BACKGROUND:: Because resolution of symptoms is a primary goal of antimicrobial therapy in children with acute otitis media (AOM), measurement of symptoms in studies of antimicrobial effectiveness in such children is important. We have developed a scale for measuring symptoms of AOM in young children (AOM-SOS), and we present data on its construct validity and responsiveness. METHODS:: We followed children 3 months to 3 years of age with AOM, who were receiving antimicrobial treatment, using the AOM-SOS scale. The scale was administered at the enrollment visit, as a twice-a-day diary measure, and at the follow-up visit (days 5-7). To evaluate construct validity, we examined the correlation, at entry, between AOM-SOS scores and scores on other measures of pain and functional status. To evaluate the scale's responsiveness, we examined the change in scale scores from entry to follow-up. We also examined the levels of agreement between the scale scores and overall assessments of the children by parents. RESULTS:: We enrolled 70 children (mean age 12.5 months) of whom 57 returned for follow-up. The magnitude of the correlations between the AOM-SOS scale scores and other measures of pain and functional status ranged from 0.56 to 0.84. The responsiveness of the AOM-SOS, as measured by the standardized response mean was 1.20. CONCLUSIONS:: These data support the validity and responsiveness of the AOM-SOS; the scale seems to measure effectively both pain and overall functional status in young children with AOM. Changes in score over the first few days of illness were substantial and generally matched the assessments both of parents and of clinicians. The AOM-SOS promises to be useful as an outcome measure in clinical studies of AOM
Gate-controlled Guiding of Electrons in Graphene
Ballistic semiconductor structures have allowed the realization of
optics-like phenomena in electronics, including magnetic focusing and lensing.
An extension that appears unique to graphene is to use both n and p carrier
types to create electronic analogs of optical devices having both positive and
negative indices of refraction. Here, we use gate-controlled density with both
p and n carrier types to demonstrate the analog of the fiber-optic guiding in
graphene. Two basic effects are investigated: (1) bipolar p-n junction guiding,
based on the principle of angle-selective transmission though the graphene p-n
interface, and (2) unipolar fiber-optic guiding, using total internal
reflection controlled by carrier density. Modulation of guiding efficiency
through gating is demonstrated and compared to numerical simulations, which
indicates that interface roughness limits guiding performance, with
few-nanometer effective roughness extracted. The development of p-n and
fiber-optic guiding in graphene may lead to electrically reconfigurable wiring
in high-mobility devices.Comment: supplementary materal at
http://marcuslab.harvard.edu/papers/OG_SI.pd
Axion Protection from Flavor
The QCD axion fails to solve the strong CP problem unless all explicit PQ
violating, Planck-suppressed, dimension n<10 operators are forbidden or have
exponentially small coefficients. We show that all theories with a QCD axion
contain an irreducible source of explicit PQ violation which is proportional to
the determinant of the Yukawa interaction matrix of colored fermions.
Generically, this contribution is of low operator dimension and will
drastically destabilize the axion potential, so its suppression is a necessary
condition for solving the strong CP problem. We propose a mechanism whereby the
PQ symmetry is kept exact up to n=12 with the help of the very same flavor
symmetries which generate the hierarchical quark masses and mixings of the SM.
This "axion flavor protection" is straightforwardly realized in theories which
employ radiative fermion mass generation and grand unification. A universal
feature of this construction is that the heavy quark Yukawa couplings are
generated at the PQ breaking scale.Comment: 16 pages, 2 figure
Long Lived Fourth Generation and the Higgs
A chiral fourth generation is a simple and well motivated extension of the
standard model, and has important consequences for Higgs phenomenology. Here we
consider a scenario where the fourth generation neutrinos are long lived and
have both a Dirac and Majorana mass term. Such neutrinos can be as light as 40
GeV and can be the dominant decay mode of the Higgs boson for Higgs masses
below the W-boson threshold. We study the effect of the Majorana mass term on
the Higgs branching fractions and reevaluate the Tevatron constraints on the
Higgs mass. We discuss the prospects for the LHC to detect the semi-invisible
Higgs decays into fourth generation neutrino pairs. Under the assumption that
the lightest fourth generation neutrino is stable, it's thermal relic density
can be up to 20% of the observed dark matter density in the universe. This is
in agreement with current constraints on the spin dependent neutrino-neutron
cross section, but can be probed by the next generation of dark matter direct
detection experiments.Comment: v1: 19 pages, 5 figures; v2: References added; v3: version to appear
in JHE
Muscle Glycogen Utilisation during an Australian Rules Football Game.
PURPOSE: To better understand the carbohydrate (CHO) requirement of Australian Football (AF) match play by quantifying muscle glycogen utilisation during an in-season AF match. METHODS: After a 24 h CHO loading protocol of 8 g/kg and 2 g/kg in the pre-match meal, two elite male forward players had biopsies sampled from m. vastus lateralis before and after participation in a South Australian Football League game. Player A (87.2kg) consumed water only during match play whereas player B (87.6kg) consumed 88 g CHO via CHO gels. External load was quantified using global positioning system technology. RESULTS: Player A completed more minutes on the ground (115 vs. 98 min) and covered greater total distance (12.2 vs. 11.2 km) than Player B, though with similar high-speed running (837 vs. 1070 m) and sprinting (135 vs. 138 m), respectively. Muscle glycogen decreased by 66% in Player A (Pre-: 656, Post-: 223 mmol∙kg-1 dw) and 24% in Player B (Pre-: 544, Post-: 416 mmol∙kg-1 dw), respectively. CONCLUSION: Pre-match CHO loading elevated muscle glycogen concentrations (i.e. >500 mmol.kg-1 dw), the magnitude of which appears sufficient to meet the metabolic demands of elite AF match play. The glycogen cost of AF match play may be greater than soccer and rugby and CHO feeding may also spare muscle glycogen use. Further studies using larger sample sizes are now required to quantify the inter-individual variability of glycogen cost of match play (including muscle and fibre-type specific responses) as well examine potential metabolic and ergogenic effects of CHO feeding
Demography and disorders of German Shepherd Dogs under primary veterinarycare in the UK
The German Shepherd Dog (GSD) has been widely used for a variety of working roles. However, concerns for the health and welfare of the GSD have been widely aired and there is evidence that breed numbers are now in decline in the UK. Accurate demographic and disorder data could assist with breeding and clinical prioritisation. The VetCompassTM Programme collects clinical data on dogs under primary veterinary care in the UK. This study included all VetCompassTM dogs under veterinary care during 2013. Demographic, mortality and clinical diagnosis data on GSDs were extracted and reported
- …
