58 research outputs found
Random Magnetic Impurities and the Landau Problem
The 2-dimensional density of states of an electron is studied for a
Poissonian random distribution of point vortices carrying flux in unit
of the quantum of flux. It is shown that, for any given density of impurities,
there is a transition, when , from an "almost free"
density of state -with only a depletion of states at the bottom of the spectrum
characterized by a Lifschitz tail- to a Landau density of state with sharp
Landau level oscillations. Several evidences and arguments for this transition
-numerical and analytical- are presented.Comment: 22 pages, latex, 4 figures upon reques
Transcriptionally inducible Pleckstrin homology-like domain family A member 1 attenuates ErbB receptor activity by inhibiting receptor oligomerization
Naturalizing Institutions: Evolutionary Principles and Application on the Case of Money
Seasonal and annual variability of days with strong winds and wind damage in Krakow (Poland) during the period 2000–2007
The Pacific OPIC Project (Obesity Prevention In Communities) – Objectives and designs
Background: Evidence on how to reduce the increasing prevalence of youth obesity is urgently needed in many countries.
The Pacific OPIC Project (Obesity Prevention In Communities) is a series of linked studies in four countries (Fiji, Tonga,
New Zealand, Australia) which is designed to address this important problem.
Objectives: The studies aim to: 1) determine the overall impact of comprehensive, community-based intervention programs
on overweight/obesity prevalence in youth; 2) assess the feasibility of the specific intervention components and
their impacts on eating and physical activity patterns; 3) understand the socio-cultural factors that promote obesity and
how they can be influenced; 4) identify the effects of food-related policies in Fiji and Tonga and how they might be
changed; 5) estimate the overall burden of childhood obesity (including loss of quality of life); 6) estimate the costs (and
cost-effectiveness) of the intervention programs, and; 7) increase the capacity for obesity prevention research and action
in Pacific populations.
Design: The community studies use quasi-experimental designs with impact and outcome assessments being measured
in over 14,000 youth across the intervention and control communities in the four sites. The multi-strategy, multi-setting
interventions will run for 3 years before fi nal follow up data are collected in 2008. The interventions are being informed
by socio-cultural studies that will determine the family and societal influences on food intake, physical activity and body
size perception.
Progress and conclusions: Baseline studies have been completed and interventions are underway. Despite the many
challenges in implementing and evaluating community-based interventions, especially in the Pacifi c, the OPIC Project
will provide rich evidence about what works and what does not work for obesity prevention in youth from European and
Pacific backgrounds
Higher naloxone dosing in a quantitative systems pharmacology model that predicts naloxone-fentanyl competition at the opioid mu receptor level.
Rapid resuscitation of an opioid overdose with naloxone, an opioid antagonist, is critical. We developed an opioid receptor quantitative systems pharmacology (QSP) model for evaluation of naloxone dosing. In this model we examined three opioid exposure levels that have been reported in the literature (25 ng/ml, 50 ng/ml, and 75 ng/ml of fentanyl). The model predicted naloxone-fentanyl interaction at the mu opioid receptor over a range of three naloxone doses. For a 2 mg intramuscular (IM) dose of naloxone at lower fentanyl exposure levels (25 ng/ml and 50 ng/ml), the time to decreasing mu receptor occupancy by fentanyl to 50% was 3 and 10 minutes, respectively. However, at a higher fentanyl exposure level (75 ng/ml), a dose of 2 mg IM of the naloxone failed to reduce mu receptor occupancy by fentanyl to 50%. In contrast, naloxone doses of 5 mg and 10 mg IM reduced mu receptor occupancy by fentanyl to 50% in 5.5 and 4 minutes respectively. These results suggest that the current doses of naloxone (2 mg IM or 4 mg intranasal (IN)) may be inadequate for rapid reversal of toxicity due to fentanyl exposure and that increasing the dose of naloxone is likely to improve outcomes
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