280 research outputs found
Parallel Recursive State Compression for Free
This paper focuses on reducing memory usage in enumerative model checking,
while maintaining the multi-core scalability obtained in earlier work. We
present a tree-based multi-core compression method, which works by leveraging
sharing among sub-vectors of state vectors.
An algorithmic analysis of both worst-case and optimal compression ratios
shows the potential to compress even large states to a small constant on
average (8 bytes). Our experiments demonstrate that this holds up in practice:
the median compression ratio of 279 measured experiments is within 17% of the
optimum for tree compression, and five times better than the median compression
ratio of SPIN's COLLAPSE compression.
Our algorithms are implemented in the LTSmin tool, and our experiments show
that for model checking, multi-core tree compression pays its own way: it comes
virtually without overhead compared to the fastest hash table-based methods.Comment: 19 page
Effect of a 28-d treatment with L-796568, a novel beta(3)-adrenergic receptor agonist, on energy expenditure and body composition in obese men
Research Department of Human Nutrition, The Royal Veterinary and Agricultural University, Copenhagen, Denmark. [email protected] BACKGROUND: Stimulation of energy expenditure (EE) with selective thermogenic beta-adrenergic agonists may be a promising approach for treating obesity. OBJECTIVE: We analyzed the effects of the highly selective human beta(3)-adrenergic agonist L-796568 on 24-h EE, substrate oxidation, and body composition in obese, weight-stable men. DESIGN: In this 2-center, double-blind, randomized, parallel-group study, we measured 24-h EE before and after 28 d of treatment with L-796568 (375 mg/d) or placebo during weight maintenance (ie, without dietary intervention) in nondiabetic, nonsmoking men aged 25-49 y with body mass index (in kg/m(2)) of 28-35 (n = 10 subjects per treatment group). RESULTS: The mean change in 24-h EE from before to after treatment did not differ significantly between groups (92 +/- 586 and 86 +/- 512 kJ/24 h for the L-796568 and placebo groups, respectively). The change in 24-h nonprotein respiratory quotient from before to after treatment did not differ significantly between groups (0.009 +/- 0.021 and 0.009 +/- 0.029, respectively). No changes in glucose tolerance were observed, but triacylglycerol concentrations decreased significantly with L-796568 treatment compared with placebo (-0.76 +/- 0.76 and 0.42 +/- 0.31 mmol/L, respectively; P < 0.002). Overall, treatment-related changes in body composition were not observed, but higher plasma L-796568 concentrations in the L-796568 group were associated with greater decreases in fat mass (r = -0.69, P < 0.03). CONCLUSIONS: Treatment with L-796568 for 28 d had no major lipolytic or thermogenic effect but it lowered triacylglycerol concentrations. This lack of chronic effect on energy balance is likely explained by insufficient recruitment of beta(3)-responsive tissues in humans, down-regulation of the beta(3)-adrenergic receptor-mediated effects with chronic dosing, or both. Publication Types: Clinical Trial Randomized Controlled Tria
Centrality dependence of charged-particle pseudorapidity distributions from d+Au collisions at sqrt(s_{NN})=200 GeV
Charged-particle pseudorapidity densities are presented for the d+Au reaction
at sqrt{s_{NN}}=200 GeV with -4.2 <= eta <= 4.2$. The results, from the BRAHMS
experiment at RHIC, are shown for minimum-bias events and 0-30%, 30-60%, and
60-80% centrality classes. Models incorporating both soft physics and hard,
perturbative QCD-based scattering physics agree well with the experimental
results. The data do not support predictions based on strong-coupling,
semi-classical QCD. In the deuteron-fragmentation region the central 200 GeV
data show behavior similar to full-overlap d+Au results at sqrt{s_{NN}}=19.4
GeV.Comment: 4 pages, 3figures; expanded discussion of uncertainties; added 60-80%
centrality range; added additional discussion on centrality selection bia
Scanning the phases of QCD with BRAHMS
BRAHMS has the ability to study relativistic heavy ion collisions from the
final freeze-out of hadrons all the way back to the initial wave-function of
the gold nuclei. This is accomplished by studying hadrons with a very wide
range of momenta and angles. In doing so we can scan various phases of QCD,
from a hadron gas, to a quark gluon plasma and perhaps to a color glass
condensate.Comment: 8 pages, 6 figures, proceedings of plenary talk at Quark Matter 2004
conferenc
High Pt Hadron Spectra at High Rapidity
We report the measurement of charged hadron production at different
pseudo-rapidity values in deuteron+gold as well as proton+proton collisions at
= 200GeV at RHIC. The nuclear modification factors and
are used to investigate new behaviors in the deuteron+gold system as
function of rapidity and the centrality of the collisions respectively.Comment: Nine pages 4 figures to be published in the QM2004 Proceedings, typos
corrected and one reference adde
Counterion Condensation and Fluctuation-Induced Attraction
We consider an overall neutral system consisting of two similarly charged
plates and their oppositely charged counterions and analyze the electrostatic
interaction between the two surfaces beyond the mean-field Poisson-Boltzmann
approximation. Our physical picture is based on the fluctuation-driven
counterion condensation model, in which a fraction of the counterions is
allowed to ``condense'' onto the charged plates. In addition, an expression for
the pressure is derived, which includes fluctuation contributions of the whole
system. We find that for sufficiently high surface charges, the distance at
which the attraction, arising from charge fluctuations, starts to dominate can
be large compared to the Gouy-Chapmann length. We also demonstrate that
depending on the valency, the system may exhibit a novel first-order binding
transition at short distances.Comment: 15 pages, 8 figures, to appear in PR
Charged particle densities from Au+Au collisions at sqrt{s_{NN}}=130 GeV
We present charged particle densities as a function of pseudorapidity and
collision centrality for the 197Au+197Au reaction at sqrt{s_{NN}}=130 GeV. An
integral charged particle multiplicity of 3860+/-300 is found for the 5% most
central events within the pseudorapidity range -4.7 <= eta <= 4.7. At
mid-rapidity an enhancement in the particle yields per participant nucleon pair
is observed for central events. Near to the beam rapidity, a scaling of the
particle yields consistent with the ``limiting fragmentation'' picture is
observed. Our results are compared to other recent experimental and theoretical
discussions of charged particle densities in ultra-relativistic heavy-ion
collisions.Comment: 14 pages, 4 figures; to be published in Phys. Lett.
The effect of protein and glycemic index on children's body composition: the DiOGenes randomized study
OBJECTIVE: To investigate the effect of protein and glycemic index (GI) on body composition among European children in the randomized, 6-month dietary intervention DiOGenes (diet, obesity, and genes) family-based study.
PATIENTS AND METHODS: In the study, 827 children (381 boys and 446 girls), aged 5 to 18 years, completed baseline examinations. Families with parents who lost >= 8% of their weight during an 8-week run-in low-calorie diet period were randomly assigned to 1 of 5 ad libitum diets: low protein (LP)/low glycemic index (LGI); LP/high GI (HGI); high protein (HP)/LGI; HP/HGI; and control diet. The target difference was 15 GI U between the LGI/HGI groups and 13 protein percentage points between the LP/HP groups. There were 658 children examined after 4 weeks. Advice on food-choice modification was provided at 6 visits during this period. No advice on weight loss was provided because the focus of the study was the ability of the diets to affect outcomes through appetite regulation. Anthropometric measurements and body composition were assessed at baseline, week 4, and week 26.
RESULTS: In the study, 465 children (58.1%) completed all assessments. The achieved differences between the GI and protein groups were 2.3 GI U and 4.9 protein percentage points, respectively. The LP/HGI group increased body fat percentage significantly more than the other groups (P = .040; partial eta(2) = 0.039), and the percentage of overweight/obese children in the HP/LGI group decreased significantly during the intervention (P = .031).
CONCLUSIONS: Neither GI nor protein had an isolated effect on body composition. However, the LP/HGI combination increased body fat, whereas the HP/LGI combination was protective against obesity in this sample of children
Diets with high or low protein content and glycemic index for weight-loss maintenance
BACKGROUND:
Studies of weight-control diets that are high in protein or low in glycemic index have reached varied conclusions, probably owing to the fact that the studies had insufficient power.
METHODS:
We enrolled overweight adults from eight European countries who had lost at least 8% of their initial body weight with a 3.3-MJ (800-kcal) low-calorie diet. Participants were randomly assigned, in a two-by-two factorial design, to one of five ad libitum diets to prevent weight regain over a 26-week period: a low-protein and low-glycemic-index diet, a low-protein and high-glycemic-index diet, a high-protein and low-glycemic-index diet, a high-protein and high-glycemic-index diet, or a control diet.
RESULTS:
A total of 1209 adults were screened (mean age, 41 years; body-mass index [the weight in kilograms divided by the square of the height in meters], 34), of whom 938 entered the low-calorie-diet phase of the study. A total of 773 participants who completed that phase were randomly assigned to one of the five maintenance diets; 548 completed the intervention (71%). Fewer participants in the high-protein and the low-glycemic-index groups than in the low-protein-high-glycemic-index group dropped out of the study (26.4% and 25.6%, respectively, vs. 37.4%; P=0.02 and P=0.01 for the respective comparisons). The mean initial weight loss with the low-calorie diet was 11.0 kg. In the analysis of participants who completed the study, only the low-protein-high-glycemic-index diet was associated with subsequent significant weight regain (1.67 kg; 95% confidence interval [CI], 0.48 to 2.87). In an intention-to-treat analysis, the weight regain was 0.93 kg less (95% CI, 0.31 to 1.55) in the groups assigned to a high-protein diet than in those assigned to a low-protein diet (P=0.003) and 0.95 kg less (95% CI, 0.33 to 1.57) in the groups assigned to a low-glycemic-index diet than in those assigned to a high-glycemic-index diet (P=0.003). The analysis involving participants who completed the intervention produced similar results. The groups did not differ significantly with respect to diet-related adverse events.
CONCLUSIONS:
In this large European study, a modest increase in protein content and a modest reduction in the glycemic index led to an improvement in study completion and maintenance of weight loss
Nuclear Modification Factor for Charged Pions and Protons at Forward Rapidity in Central Au+Au Collisions at 200 GeV
We present spectra of charged pions and protons in 0-10% central Au+Au
collisions at GeV at mid-rapidity () and forward
pseudorapidity () measured with the BRAHMS experiment at RHIC. The
spectra are compared to spectra from p+p collisions at the same energy scaled
by the number of binary collisions. The resulting nuclear modification factors
for central Au+Au collisions at both and exhibit suppression
for charged pions but not for (anti-)protons at intermediate . The
ratios have been measured up to GeV/ at the two
rapidities and the results indicate that a significant fraction of the charged
hadrons produced at intermediate range are (anti-)protons at both
mid-rapidity and
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