753 research outputs found
Adolescent women induce lower blood alcohol levels than men in a laboratory alcohol self-administration experiment
Background
Adolescence is a critical period for the development of alcohol use disorders; drinking habits are rather unstable and genetic influences, such as male sex and a positive Family History of alcoholism (FH), are often masked by environmental factors such as peer pressure.
Methods
We investigated how sex and FH modulate alcohol use in a sample of 18-19-year-olds from the Dresden Longitudinal Study on Alcohol use in Young Adults (D-LAYA). Adolescents reported their real-life drinking in a TimeLine Follow-Back (TLFB) interview. They subsequently completed a training and an experimental session of free-access intravenous Alcohol Self-Administration (i.v. ASA) using the computer-assisted alcohol infusion system in order to control for environmental cues as well as for biological differences in alcohol pharmacokinetics. During i.v. ASA, we assessed subjective alcohol effects at eight time points.
Results
Women reported significantly less real-life drinking than men and achieved significantly lower mean arterial Blood Alcohol Concentrations (aBACs) in the laboratory. At the same time, women reported greater sedation relative to men and rated negative effects as high as did men. A positive FH was associated with lower real-life drinking in men but not in women. In the laboratory, FH was not linked to i.v. ASA. Greater real-life drinking was significantly positively associated with higher mean aBACs in the laboratory, and all i.v. ASA indices were highly correlated across the two sessions.
Conclusions
We conclude that adolescent women chose lower aBACs because they experienced adverse alcohol effects, namely sedation and negative effects, at lower aBACs than men. A positive FH was not apparent as risk factor for drinking in our young sample. The i.v. ASA method demonstrated good external validity as well as test-retest reliability, the latter indicating that a separate training session is not required when employing the i.v. ASA paradigm
Analysis of detector performance in a gigahertz clock rate quantum key distribution system
We present a detailed analysis of a gigahertz clock rate environmentally robust phase-encoded quantum key distribution (QKD) system utilizing several different single-photon detectors, including the first implementation of an experimental resonant cavity thin-junction silicon single-photon avalanche diode. The system operates at a wavelength of 850ânm using standard telecommunications optical fibre. A general-purpose theoretical model for the performance of QKD systems is presented with reference to these experimental results before predictions are made about realistic detector developments in this system. We discuss, with reference to the theoretical model, how detector operating parameters can be further optimized to maximize key exchange rates
Release from sheep-grazing appears to put some heart back into upland vegetation:A comparison of nutritional properties of plant species in long-term grazing experiments
Rewilding or wilding is a popularised means for enhancing the conservation value of marginal land. In the British uplands, it will involve a reduction, or complete removal, of livestock grazing (sheep), based on the belief that grazing has reduced plant species diversity, the âWet Desertâ hypothesis. The hope is that if livestock is removed, diversity will recover. If true, we hypothesise that the species extirpated/reduced by grazing and then recover on its removal would more nutritious compared to those that persisted. We test this hypothesis at Moor House National Nature Reserve (NorthâPennines), where seven sets of paired plots were established between 1953 and 1967 to compare ungrazed/sheepâgrazed vegetation. Within these plotâpairs, we compared leaf properties of seven focal species that occurred only, or were present in much greater abundance, in the absence of grazing to those of 10 common species that were common in both grazed and ungrazed vegetation. Each sample was analysed for macroânutrients, microânutrients, digestibility, palatability and decomposability. We ranked the species with respect to 22 variables based on effect size derived from Generalised Linear Modelling (GLM) and compared species using a Principal Components Analysis. We also assessed changes in abundance of the focal species through time using GLMs. Our results support the âWet Desertâ hypothesis, that is, that longâterm sheep grazing has selectively removed/reduced species like our focal ones and on recovery, they were more nutritious (macroânutrients, some microânutrients) palatable, digestible and decomposable than common species. Measured changes in abundance of the focal species suggest that their recovery will take 10â20âyears in blanket bog and 60âyears in highâaltitude grasslands. Collectively, these results suggest that sheep grazing has brought about biotic homogenization, and its removal in (re)wilding schemes will reverse this process eventually! The âwhite woolly maggotsâ have eaten at least part of the heart out of the highlands/uplands, and it will take some time for recovery
Becoming-Bertha: virtual difference and repetition in postcolonial 'writing back', a Deleuzian reading of Jean Rhysâs Wide Sargasso Sea
Critical responses to Wide Sargasso Sea have seized upon Rhysâs novel as an exemplary model of writing back. Looking beyond the actual repetitions which recall BrontĂ«âs text, I explore Rhysâs novel as an expression of virtual difference and becomings that exemplify Deleuzeâs three syntheses of time. Elaborating the processes of becoming that Deleuzeâs third synthesis depicts, Antoinetteâs fate emerges not as a violence against an original identity. Rather, what the reader witnesses is a series of becomings or masks, some of which are validated, some of which are not, and it is in the rejection of certain masks, forcing Antoinette to become-Bertha, that the greatest violence lies
No moderating effect of 5-HTTLPR on associations between antenatal anxiety and infant behavior.
OBJECTIVE: Maternal antenatal anxiety is associated with an increased risk of behavioral disturbances in offspring. Recent work has suggested that the effect of maternal antenatal anxiety on infant temperament at 6 months is moderated by the serotonin transporter polymorphism 5-HTTLPR, with carriers of the short allele more susceptible to the adverse behavioral outcomes of maternal antenatal anxiety. These findings, however, are yet to be replicated and extended beyond infancy. The aim of the current study was to assess this same potential moderator (5-HTTLPR) in a large population-based cohort study, and to determine whether or not the effects persist into childhood and early adolescence. METHOD: Data from the Avon Longitudinal Study of Children and Parents (ALSPAC) cohort (N = 3,946) were used to assess whether the 5-HTTLPR genotype moderated the association between self-reported maternal antenatal anxiety (Crown Crisp Index) in pregnancy, and child temperament at 6 months (Infant Temperament Questionnaire), and also later behavioral and emotional problems on the Strengths and Difficulties Questionnaire from age 4 to 13 years. RESULTS: We found no evidence to suggest that the 5-HTTLPR polymorphism moderated the effects of maternal antenatal anxiety on infant temperament at 6 months or infant behavioral and emotional problems from childhood through to adolescence. CONCLUSION: Our results, based on a large prospective community sample that assessed children from infancy to early adolescence, provide a thorough test of, but no evidence for, a genetic moderation of the effects of maternal antenatal anxiety by 5-HTTLPR
Treatment and Generalization of Functional Category Production in Agrammatic Aphasia
Previous work on treatment of production deficits in agrammatic aphasia has found generalization from trained to untrained sentences, but only if those sentences are linguistically related. This research extends this result to functional morphemes associated with different functional projections, IP and CP. Nine agrammatic patients were trained to produce sentences containing three types of functional morphemes (complementizers, past-tense inflection, and agreement). Behavioral measures showed a variable pattern of generalization between tense and agreement morphemes (within IP), but no generalization between complementizers and tense or agreement (between CP and IP). In addition, neuroimaging data showed reduced activation following treatment
Renormalization Group Approach to Field Theory at Finite Temperature
Scalar field theory at finite temperature is investigated via an improved
renormalization group prescription which provides an effective resummation over
all possible non-overlapping higher loop graphs. Explicit analyses for the
lambda phi^4 theory are performed in d=4 Euclidean space for both low and high
temperature limits. We generate a set of coupled equations for the mass
parameter and the coupling constant from the renormalization group flow
equation. Dimensional reduction and symmetry restoration are also explored with
our improved approach.Comment: 29 pages, can include figures in the body of the text using epsf.st
Factors associated with D-dimer levels in HIV-infected individuals.
BACKGROUND: Higher plasma D-dimer levels are strong predictors of mortality in HIV+ individuals. The factors associated with D-dimer levels during HIV infection, however, remain poorly understood. METHODS: In this cross-sectional study, participants in three randomized controlled trials with measured D-dimer levels were included (Nâ=â9,848). Factors associated with D-dimer were identified by linear regression. Covariates investigated were: age, gender, race, body mass index, nadir and baseline CD4+ count, plasma HIV RNA levels, markers of inflammation (C-reactive protein [CRP], interleukin-6 [IL-6]), antiretroviral therapy (ART) use, ART regimens, co-morbidities (hepatitis B/C, diabetes mellitus, prior cardiovascular disease), smoking, renal function (estimated glomerular filtration rate [eGFR] and cystatin C) and cholesterol. RESULTS: Women from all age groups had higher D-dimer levels than men, though a steeper increase of D-dimer with age occurred in men. Hepatitis B/C co-infection was the only co-morbidity associated with higher D-dimer levels. In this subgroup, the degree of hepatic fibrosis, as demonstrated by higher hyaluronic acid levels, but not viral load of hepatitis viruses, was positively correlated with D-dimer. Other factors independently associated with higher D-dimer levels were black race, higher plasma HIV RNA levels, being off ART at baseline, and increased levels of CRP, IL-6 and cystatin C. In contrast, higher baseline CD4+ counts and higher high-density lipoprotein cholesterol were negatively correlated with D-dimer levels. CONCLUSIONS: D-dimer levels increase with age in HIV+ men, but are already elevated in women at an early age due to reasons other than a higher burden of concomitant diseases. In hepatitis B/C co-infected individuals, hepatic fibrosis, but not hepatitis viral load, was associated with higher D-dimer levels
- âŠ