4,437 research outputs found

    Moral and Ethical Reflections on Human Organ Transplantation

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    Frontal Metabolite Concentration Deficits in Opiate Dependence Relate to Substance Use, Cognition, and Self-Regulation.

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    ObjectiveProton magnetic resonance spectroscopy (1H MRS) in opiate dependence showed abnormalities in neuronal viability and glutamate concentration in the anterior cingulate cortex (ACC). Metabolite levels in dorsolateral prefrontal cortex (DLPFC) or orbitofrontal cortex (OFC) and their neuropsychological correlates have not been investigated in opiate dependence.MethodsSingle-volume proton MRS at 4 Tesla and neuropsychological testing were conducted in 21 opiate-dependent individuals (OD) on buprenorphine maintenance therapy. Results were compared to 28 controls (CON) and 35 alcohol-dependent individuals (ALC), commonly investigated treatment-seekers providing context for OD evaluation. Metabolite concentrations were measured from ACC, DLPFC, OFC and parieto-occipital cortical (POC) regions.ResultsCompared to CON, OD had lower concentrations of N-acetylaspartate (NAA), glutamate (Glu), creatine +phosphocreatine (Cr) and myo-Inositol (mI) in the DLPFC and lower NAA, Cr, and mI in the ACC. OD, ALC, and CON were equivalent on metabolite levels in the POC and γ-aminobutyric acid (GABA) concentration did not differ between groups in any region. In OD, prefrontal metabolite deficits in ACC Glu as well as DLPFC NAA and choline containing metabolites (Cho) correlated with poorer working memory, executive and visuospatial functioning; metabolite deficits in DLPFC Glu and ACC GABA and Cr correlated with substance use measures. In the OFC of OD, Glu and choline-containing metabolites were elevated and lower Cr concentration related to higher nonplanning impulsivity. Compared to 3 week abstinent ALC, OD had significant DLPFC metabolite deficits.ConclusionThe anterior frontal metabolite profile of OD differed significantly from that of CON and ALC. The frontal lobe metabolite abnormalities in OD and their neuropsychological correlates may play a role in treatment outcome and could be explored as specific targets for improved OD treatment

    The Influence of Alcohol Consumption on Fighting, Shoplifting and Vandalism in Young Adults

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    Experimental studies support the conventional belief that people behave more aggressively whilst under the influence of alcohol. To examine how these experimental findings manifest in real life situations, this study uses a method for estimating evidence for causality with observational data—‘situational decomposition’ to examine the association between alcohol consumption and crime in young adults from the Avon Longitudinal Study of Parents and Children. Self-report questionnaires were completed at age 24 years to assess typical alcohol consumption and frequency, participation in fighting, shoplifting and vandalism in the previous year, and whether these crimes were committed under the influence of alcohol. Situational decomposition compares the strength of two associations, (1) the total association between alcohol consumption and crime (sober or intoxicated) versus (2) the association between alcohol consumption and crime committed while sober. There was an association between typical alcohol consumption and total crime for fighting [OR (95% CI): 1.47 (1.29, 1.67)], shoplifting [OR (95% CI): 1.25 (1.12, 1.40)], and vandalism [OR (95% CI): 1.33 (1.12, 1.57)]. The associations for both fighting and shoplifting had a small causal component (with the association for sober crime slightly smaller than the association for total crime). However, the association for vandalism had a larger causal component

    Water Quality Observations from Space: A Review of Critical Issues and Challenges

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    Water is the basis of all life on this planet. Yet, approximately one in seven people in the world do not have access to safe water. Water can become unsafe due to contamination by various organic and inorganic compounds due to various natural and anthropogenic processes. Identifying and monitoring water quality changes in space and time remains a challenge, especially when contamination events occur over large geographic areas. This study investigates recent advances in remote sensing that allow us to detect and monitor the unique spectral characteristics of water quality events over large areas. Based on an extensive literature review, we focus on three critical water quality problems as part of this study: algal blooms, acid mine drainage, and suspended solids. We review the advances made in applications of remote sensing in each of these issues, identify the knowledge gaps and limitations of current studies, analyze the existing approaches in the context of global environmental changes, and discuss potential ways to combine multi-sensor methods and different wavelengths to develop improved approaches. Synthesizing the findings of these studies in the context of the three specific tracks will help stakeholders to utilize, share, and embed satellite-derived earth observations for monitoring and tracking the ever-evolving water quality in the earth’s limited freshwater reserves

    Reconstructing phase-resolved hysteresis loops from first-order reversal curves

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    The first order reversal curve (FORC) method is a magnetometry based technique used to capture nanoscale magnetic phase separation and interactions with macroscopic measurements using minor hysteresis loop analysis. This makes the FORC technique a powerful tool in the analysis of complex systems which cannot be effectively probed using localized techniques. However, recovering quantitative details about the identified phases which can be compared to traditionally measured metrics remains an enigmatic challenge. We demonstrate a technique to reconstruct phase-resolved magnetic hysteresis loops by selectively integrating the measured FORC distribution. From these minor loops, the traditional metrics - including the coercivity and saturation field, and the remanent and saturation magnetization - can be determined. In order to perform this analysis, special consideration must be paid to the accurate quantitative management of the so-called reversible features. This technique is demonstrated on three representative materials systems, high anisotropy FeCuPt thin-films, Fe nanodots, and SmCo/Fe exchange spring magnet films, and shows excellent agreement with the direct measured major loop, as well as the phase separated loops

    Parallel variation of mass transport and heterogeneous and homogeneous electron transfer rates in hybrid redox polyether molten salts

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    Metal complexes can be prepared as highly viscous (semisolid), room temperature molten salts by combining them with oligomeric polyether substituents. The fluidity and transport properties of these hybrid redox polyether melts can be systematically manipulated by changing the oligomeric chain lengths and by adding unattached oligomers as plasticizers. This paper describes the voltammetrically measured transport properties of several Co(II) polypyridine (2,2‘-bipyridine, phenanthroline) melts. The properties evaluated are the physical self-diffusion coefficient (DPHYS) of the cationic complex in its melt, the diffusivity of its counterion (DCION), the heterogeneous electron-transfer rate constant (kHET) of the Co(III/II) oxidation at the electrode surface, and the rate constant (kEX) for homogeneous electron self-exchange between Co(II) and Co(I) in the mixed valent layer next to the electrode. These dynamics parameters change in parallel manners, over a large (\u3e103) range of values, when the melt fluidity is changed by plasticizers or temperature. While kHET and kEX both change systematically with DPHYS, they change on a more nearly proportional basis with DCION. The latter relationship is interpreted as a kind of solvent dynamics control in which both the homogeneous Co(II/I) and heterogeneous Co(III/II) reaction rates are controlled by the ionic atmosphere relaxation time constant, namely, the time constant of redistribution of counterions following an electron-transfer step that has produced a nonequilibrium charge distribution. DCION provides a measure of the ion atmosphere relaxation rate

    Development and testing of a prototype indicator-based tool for identification of potential problem areas for marine litter in Europe's seas

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    We demonstrate a prototype multi-metric indicator-based assessment tool (i.e. Marine Litter Assessment Tool - MALT) for mapping and identification of ‘problem areas’ and ‘non-problem areas’ regarding the occurrence of marine litter in Europe's seas. The study is based on a European-wide data set consisting of three marine litter indicators: (1) litter at the seafloor, (2) beach litter and (3) floating micro-litter. This publicly available data allowed litter status to be determined in 1,957,081 km2 (19.1 %) of the total area of Europe's seas (10,243,474 km2). Of the area assessed, 25.8 % (505,030 km2) was found to be ‘non-problem areas’ whilst ‘problem areas’ accounted for 74.2 % (1,452,051 km2). This indicates that marine litter is a large-scale problem in Europe's seas.publishedVersio

    Longitudinal analysis of the relationship between changes in smoking and changes in drinking in a community sample: The Winnipeg Health and Drinking Survey.

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    Smoking cigarettes and drinking alcohol are positively correlated in cross-sectional studies of the general population. However, it is unclear whether changes in quantity of drinking over time are related to changes in amount of smoking over time. This investigation examined, with structural equation modeling, the relationship of changes in drinking to changes in smoking over 2 years among 344 adults who reported cigarette smoking and alcohol use at baseline in 1989-1990 or at follow-up in 1991-1992 or both. Surprisingly, no significant relationships were found between changes in smoking and changes in drinking. This lack of effect suggests that changes in the quantity or intensity of drinking and of smoking are not related in any important way in nonclinical populations.Social Sciences and Humanities Research Counci
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