46 research outputs found
Liver Transplantation for Alcoholic Liver Disease: A Consideration of Reasons For and Against
Orthotopic liver transplantation is a clinical procedure that has been accepted widely as the treatment of choice for individuals with advanced chronic liver disease. As such, its application to the important clinical problem of alcoholic liver disease is inevitable. The arguments for and against liver transplantation for individuals with advanced alcoholic liver disease are presented. Copyright © 1989, Wiley Blackwell. All rights reserve
Smoking Comorbidity in Alcoholism: Neurobiological and Neurocognitive Consequences
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65249/1/j.1530-0277.2006.00034.x.pd
The Role of Friends’ Disruptive Behavior in the Development of Children’s Tobacco Experimentation: Results from a Preventive Intervention Study
Having friends who engage in disruptive behavior in childhood may be a risk factor for childhood tobacco experimentation. This study tested the role of friends’ disruptive behavior as a mediator of the effects of a classroom based intervention on children’s tobacco experimentation. 433 Children (52% males) were randomly assigned to the Good Behavior Game (GBG) intervention, a universal preventive intervention targeting disruptive behavior, and facilitating positive prosocial peer interactions. Friends’ disruptive behavior was assessed from age 7–10 years. Participants’ experimentation with tobacco was assessed annually from age 10–13. Reduced rates in tobacco experimentation and friends’ disruptive behavior were found among GBG children, as compared to controls. Support for friends’ disruptive behavior as a mediator in the link between intervention status and tobacco experimentation was found. These results remained after controlling for friends’ and parental smoking status, and child ADHD symptoms. The results support the role of friends’ disruptive behavior in preadolescents’ tobacco experimentation
Decision making as a predictor of first ecstasy use: a prospective study
Ecstasy (+/- 3,4-methylenedioxymethamphetamine) is a widely used recreational drug that may damage the serotonin system and may entail neuropsychological dysfunctions. Few studies investigated predictors for ecstasy use. Self-reported impulsivity does not predict the initiation of ecstasy use; the question is if neuropsychological indicators of impulsivity can predict first ecstasy use. This study tested the hypothesis that a neuropsychological indicator of impulsivity predicts initiation of ecstasy use. Decision-making strategy and decision-making reaction times were examined with the Iowa Gambling Task in 149 ecstasy-naive subjects. The performance of 59 subjects who initiated ecstasy use during a mean follow-up period of 18 months (range, 11-26) was compared with the performance of 90 subjects that remained ecstasy-naive. Significant differences in decision-making strategy between female future ecstasy users and female persistent ecstasy-naive subjects were found. In addition, the gap between decision-making reaction time after advantageous choices and reaction time after disadvantageous choices was smaller in future ecstasy users than in persistent ecstasy-naives. Decision-making strategy on a gambling task was predictive for future use of ecstasy in female subjects. Differences in decision-making time between future ecstasy users and persistent ecstasy-naives may point to lower punishment sensitivity or higher impulsivity in future ecstasy users. Because differences were small, the clinical relevance is questionabl
Black hole spin: theory and observation
In the standard paradigm, astrophysical black holes can be described solely
by their mass and angular momentum - commonly referred to as `spin' - resulting
from the process of their birth and subsequent growth via accretion. Whilst the
mass has a standard Newtonian interpretation, the spin does not, with the
effect of non-zero spin leaving an indelible imprint on the space-time closest
to the black hole. As a consequence of relativistic frame-dragging, particle
orbits are affected both in terms of stability and precession, which impacts on
the emission characteristics of accreting black holes both stellar mass in
black hole binaries (BHBs) and supermassive in active galactic nuclei (AGN).
Over the last 30 years, techniques have been developed that take into account
these changes to estimate the spin which can then be used to understand the
birth and growth of black holes and potentially the powering of powerful jets.
In this chapter we provide a broad overview of both the theoretical effects of
spin, the means by which it can be estimated and the results of ongoing
campaigns.Comment: 55 pages, 5 figures. Published in: "Astrophysics of Black Holes -
From fundamental aspects to latest developments", Ed. Cosimo Bambi, Springer:
Astrophysics and Space Science Library. Additional corrections mad
Absence of a thick atmosphere on the terrestrial exoplanet LHS 3844b
Most known terrestrial planets orbit small stars with radii less than 60 per cent of that of the Sun. Theoretical models predict that these planets are more vulnerable to atmospheric loss than their counterparts orbiting Sun-like stars. To determine whether a thick atmosphere has survived on a small planet, one approach is to search for signatures of atmospheric heat redistribution in its thermal phase curve. Previous phase curve observations of the super-Earth 55 Cancri e (1.9 Earth radii) showed that its peak brightness is offset from the substellar point (latitude and longitude of 0 degrees)—possibly indicative of atmospheric circulation. Here we report a phase curve measurement for the smaller, cooler exoplanet LHS 3844b, a 1.3-Earth-radii world in an 11-hour orbit around the small nearby star LHS 3844. The observed phase variation is symmetric and has a large amplitude, implying a dayside brightness temperature of 1,040 ± 40 kelvin and a nightside temperature consistent with zero kelvin (at one standard deviation). Thick atmospheres with surface pressures above 10 bar are ruled out by the data (at three standard deviations), and less-massive atmospheres are susceptible to erosion by stellar wind. The data are well fitted by a bare-rock model with a low Bond albedo (lower than 0.2 at two standard deviations). These results support theoretical predictions that hot terrestrial planets orbiting small stars may not retain substantial atmospheres