13,978 research outputs found
Equilibrium Selection in Global Games with Strategic Complementarities
We study games with strategic complementarities, arbitrary numbers of players and actions, and slightly noisy payoff signals. We prove limit uniqueness: as the signal noise vanishes, the game has a unique strategy profile that survives iterative dominance. This generalizes a result of Carlsson and van Damme (1993) for two player, two action games. Te surviving profile, however, may depend on fine details of the structure of the noise. We provide sufficient conditions on payoffs for there to be noise-independent selection.Equilibrium Selection, Global Games, Strategic Complementarities, Supermodular Games
Children with 5′-end NF1 gene mutations are more likely to have glioma
Objective:To ascertain the relationship between the germline NF1 gene mutation and glioma development in patients with neurofibromatosis type 1 (NF1).Methods:The relationship between the type and location of the germline NF1 mutation and the presence of a glioma was analyzed in 37 participants with NF1 from one institution (Washington University School of Medicine [WUSM]) with a clinical diagnosis of NF1. Odds ratios (ORs) were calculated using both unadjusted and weighted analyses of this data set in combination with 4 previously published data sets.Results:While no statistical significance was observed between the location and type of the NF1 mutation and glioma in the WUSM cohort, power calculations revealed that a sample size of 307 participants would be required to determine the predictive value of the position or type of the NF1 gene mutation. Combining our data set with 4 previously published data sets (n = 310), children with glioma were found to be more likely to harbor 5′-end gene mutations (OR = 2; p = 0.006). Moreover, while not clinically predictive due to insufficient sensitivity and specificity, this association with glioma was stronger for participants with 5′-end truncating (OR = 2.32; p = 0.005) or 5′-end nonsense (OR = 3.93; p = 0.005) mutations relative to those without glioma.Conclusions:Individuals with NF1 and glioma are more likely to harbor nonsense mutations in the 5′ end of the NF1 gene, suggesting that the NF1 mutation may be one predictive factor for glioma in this at-risk population.</jats:sec
Randomized Polypill Crossover Trial in People Aged 50 and Over
PMCID: PMC3399742This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Recommended from our members
A kinetics and mechanistic study of the atmospherically relevant reaction between molecular chlorine and dimethyl sulfide (DMS)
A gas-phase kinetics study of the atmospherically important reaction between Cl2 and dimethyl sulfide (DMS)Cl2 + CH3SCH3 → products has been made using a flow-tube interfaced to a photoelectron spectrometer. The rate constant for this reaction has been measured at 1.6 and 3.0 torr at T = (294 ± 2) K as (3.4 ± 0.7) × 10–14 cm3 molecule–1 s–1. Reaction (1) has been found to proceed via an intermediate, (CH3)2SCl2, to give CH3SCH2Cl and HCl as the products. The mechanism of this reaction and the structure of the intermediate were investigated using electronic structure calculations. A comparison of the mechanisms of the reactions between Cl atoms and DMS, and Cl2 and DMS has been made and the relevance of the results to atmospheric chemistry is discussed
The Effects of Caffeine Ingestion on Sodium-Aided Hyperhydration
Sodium-aided hyperhydration has been shown to reduce rates of dehydration, improve performance, and alleviate markers of physical stress during endurance exercise in the heat. Caffeine use as an ergogenic and through casual consumption of foods is common among endurance athletes; but caffeine can have diuretic effects and its use prior to exercise may compromise hydration status and exercise performance by promoting fluid excretion. PURPOSE: To investigate the effects of caffeine consumption on sodium-aided hyperhydration. METHODS: Fifteen well-hydrated male subjects (21 ± 2 yr, 176 ± 6 cm, 80.2 ± 10.1 kg) who were free from known renal, digestive, and cardiovascular disease underwent five hyperhydration strategies. Each strategy began with a complete bladder void from which urine specific gravity was measured. The bladder void was followed immediately by ingestion of 20 mL H2O ∙ kg bm-1 combined with either no treatment (NT), placebo (P), 5 mg caffeine ∙ kg bm-1 (Caf), 110 mg NaCl ∙ kg bm-1 (Na), or 5 mg caffeine ∙ kg bm-1 plus 110 mg NaCl ∙ kg bm-1 (CafNa) administered in a randomized, double-blind, crossover manner. Subjects then rested quietly for two hours, performing a bladder void every 15 minutes. Total urine production during the two hour collection periods for each strategy were compared using repeated measures ANOVA with Sidak post hoc analyses. Levels of significance were set a priori at P \u3c 0.05. RESULTS: Urine specific gravity measured before each strategy (1.006 ±0.003) did not differ significantly between treatments or subjects and indicated that subjects were well and similarly hydrated at the beginning of each hyperhydration strategy. Total urine productions as a percentage of fluid consumed were 103% (NT), 102% (P), 116% (Caf), 68% (Na), and 85% (CafNa). No significant difference was detected between NT and P (P = 1.00); however, significant differences were detected between all of the other comparisons (P = 0.025 - \u3c 0.001). CONSLUSIONS: The results confirmed that hyperhydration can be attained when water consumption is accompanied by sodium ingestion but is not achieved when pure water is consumed without sodium. The current results also suggest that consumption of 5 mg caffeine ∙ kg bm-1 with 20 mL H2O ∙ kg bm-1 prevents hyperhydration and that co-consuming 5 mg caffeine ∙ kg bm-1 plus 110 mg NaCl ∙ kg bm-1 with 20 mL H2O ∙ kg bm-1 promotes hyperhydration. However, the hyperhydration attained from the CafNa strategy is significantly less than hyperhydration levels achieved from consuming the sodium and water doses without caffeine
Time-Course of Diuresis During Sodium-Aided Hyperhydration Protocols With and Without Caffeine
When used alone, both caffeine and sodium-aided hyperhydration (SAH) are ergogenic. When caffeine is used in conjunction with SAH, diuresis occurs, but hyperhydration is still achieved albeit at lower levels when compared to SAH alone. Caffeine has been shown to be ergogenic when taken as little as 5 min, or as much as 6 hr prior to the start of exercise. Thus, determining the temporal aspects of caffeine induced diuresis when used in conjunction with SAH may lead to superior pre-exercise nutritional strategies. PURPOSE: To investigate the time-course of caffeine-induced diuresis during a 90 min SAH protocol. METHODS Subjects were 15 males (21 ± 2 yr, 176 ± 6 cm, 80.2 ± 10.1 kg) free from known renal, digestive, and cardiovascular disease. Each underwent 2 hyperhydration strategies in a randomized, double-blind fashion. Both protocols began with a complete bladder void and measurement of urine specific gravity (USG) followed immediately by ingestion of a bolus of 20 mL H2O ∙ kg bm-1 combined with either 110 mg NaCl ∙ kg bm-1 (Na), or 5 mg caffeine ∙ kg bm-1 + 110 mg NaCl ∙ kg bm-1 (CafNa). Subjects then rested quietly for 90 min, performing a measured bladder void every 15 min. Urine excretions were expressed as a percentage of the total fluid consumed during each of the hyperhydration protocols. USG and total urine excreted (TUE) during the trials were compared using paired t-tests. Urine excretion (UE) for each of the 15 min collection periods for the two conditions were compared using a two-way repeated measures ANOVA with Sidak post hoc analyses. Levels of significance were set a priori at P \u3c 0.05. RESULTS: USGs were 1.007 ± 0.003 (Na) and 1.005 ± 0.004 (CafNa) (P=0.34). TUE were 62.7±13.2% (Na) and 78.7±12.5% (CafNa) (P=0.001). UE for the Na and CafNa for each collection period respectively were 13.1±7.5%, 21.9±12.9% (15 min, P \u3c 0.01), 11.7±3.3%, 13.8±3.8% (30 min, P=.30), 13.2±2.8%, 15.3±2.4% (45 min, P=0.32), 12.2±4.1%, 13.7±5.1% (60 min, P= 0.46), 8.4±6.3%, 8.9±4% (75 min, P= 0.80) and 4.7±3.6%, 4.4±2.8% (90 min P= 0.87).CONCLUSION: TUE was significantly higher in CafNa compared to Na; however, caffeine induced diuresis occurred only during the initial 15 min following consumption of the treatments
β-agonist Regulate Skeletal Actin Gene Expression Post-transcriptionally
Previously reported studies have provided evidence that ractopamine regulates the expression of skeletal α- actin, but the molecular mechanisms underlying these effects are poorly understood. This was the first study to look specifically at the effects of ractopamine on the transcriptional regulation of a contractile protein in myotube cultures. Our model was sufficient to evaluate the anabolic effects of ractopamine in porcine skeletal muscle. However, we were unable to identify a cis-acting DNA element within the cloned porcine skeletal α-actin promoter that conferred transcriptional responsiveness to ractopamine in porcine skeletal muscle. Thus, it appears that ractopamine promotes the accumulation of skeletal α- actin mRNA in porcine skeletal muscle via a posttranscriptional mechanism. Elucidation of the mechanism whereby ractopamine increase skeletal muscle growth will aid in the development of new strategies, both genetic and pharmacological, to improve lean tissue deposition in livestock species
Effects Of Caffeine Dose Timing On Total Urine Excretion During Sodium-Aided Hyperhydration Protocols
When used alone, both caffeine and sodium-aided hyperhydration (SAH) can be ergogenic. Although caffeine use in conjunction with SAH promotes diuresis, hyperhydration can be achieved, albeit at lower levels compared to SAH alone. Previous caffeine and SAH work has suggested most of the caffeine induced diuresis occurs within 15 min of consumption of a bolus of caffeine, sodium and water. This response suggests that caffeine-induces diuresis for only 15 min following its consumption, and/or that the diuretic effects of caffeine are dependent on hydration levels. PURPOSE: To determine the effects of caffeine, consumed at different time-points, on diuresis during SAH protocols. METHODS: Subjects were 17 healthy males (23 ± 5 yr, 177 ± 8 cm, 83.4 ± 15.3 kg). Each performed 4, 90 min hyperhydration trials in a randomized, double-blind fashion. Protocols began with a bladder void and measurement of urine specific gravity (USG) followed by ingestion of 15 mL H2O ∙ kg bm-1 with one of four treatments: Placebo (PL), 70.5 mg NaCl ∙ kg bm-1 (Na), or a combination of NaCl and caffeine consumed in two different strategies: 70.5 mg NaCl + 5 mg caffeine ∙ kg bm-1 taken at the start of the trial (NaCaf0), or 70.5 mg NaCl ∙ kg bm-1 taken at the start and 5 mg caffeine ∙ kg bm-1 taken at 75 min of the trial (NaCaf75). After consuming the water, subjects rested for 90 min performing a measured bladder void every 15 min. Total urine excreted (TUE) was expressed as a percentage of the total fluid consumed during the hyperhydration protocols. USG and TUE were compared using one-way repeated measures ANOVA with Sidak post hoc analyses. Levels of significance were set a priori at P \u3c 0.05. RESULTS: USGs were 1.007 ± 0.003 (PL), 1.008 ± 0.003 (Na), 1.007 ± 0.004 (NaCaf0), and 1.009 ± 0.004 (NaCaf75) (P \u3e 0.05). TUE for PL (87 ± 30%) was significantly higher than all other protocols (P \u3c 0.05). TUE for NaCaf0 (73 ± 16%) was significantly higher than Na (56 ± 18%, P = 0.02) and NaCaf75 (52 ± 13% P \u3c 0.01). NSD in TUE was observed between Na and NaCaf75. CONCLUSION: The results reaffirm that, when caffeine is consumed at the beginning of a SAH strategy, hyperhydration can be achieved, but at a lower level compared to SAH without caffeine. The results also suggest that waiting to consume caffeine until 75 min after water is consumed does not result in caffeine induced diuresis during a SAH protocol
Using the A/T/N framework to examine driving in preclinical Alzheimer’s disease
The A/T/N classification system is the foundation of the 2018 NIA-AA Research Framework and is intended to guide the Alzheimer disease (AD) research agenda for the next 5–10 years. Driving is a widespread functional activity that may be particularly useful in investigation of functional changes in pathological AD before onset of cognitive symptoms. We examined driving in preclinical AD using the A/T/N framework and found that the onset of driving difficulties is most associated with abnormality of both amyloid and tau pathology, rather than amyloid alone. These results have implications for participant selection into clinical trials and for the application time of interventions aimed at prolonging the time of safe driving among older adults with preclinical AD
- …