Nutrition in athletes: carbohydrates, fats, proteins, calories

This issue of eMedRef provides information to clinicians on the nutritional needs of athletes

Beta-Carotene and Exercise Performance: Effects on Race Performance, Oxidative Stress, and Maximal Oxygen Consumption.

There is evidence in the literature that suggests a possible worthwhile role of antioxidants during athletic endeavors and exercise performance. Several studies have evaluated the antioxidant ability of beta-carotene and demonstrated a beneficial influence. However, these studies have investigated beta-carotene\u27s effects within an antioxidant mixture which included other antioxidant vitamins. Consequently, this study attempted to isolate the antioxidant role of beta-carotene during exercise. Three parameters of beta-carotene influence were measured using eleven well-trained runners: serum malondialdehyde (MDA) concentration (a marker of free radical generation), 5000 meter race performance, and maximum oxygen consumption (VO2max). Subjects were tested using a double-blinded cross-over design. During the supplemental phase, each subject ingested 25000 IU beta-carotene daily. The results indicated that the beta-carotene had no statistically significant effect on MDA levels or VO2max. However, there was a statistically significant Improvement in 5000 meter race performance. In addition, 64% of the subjects noted a subjective benefit from the use of beta-carotene supplementation. Therefore, results of this study indicate that beta-carotene can provide a beneficial influence on race performance in well-trained runners. However, this investigation did not furnish an adequate explanation of the mechanism by which this occurs

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

The Role of Pre- and Postnatal Timing of Family Risk Factors on Child Behavior at 36 months

Children growing up in disharmonious families with anxious/depressed mothers are at risk for emotional and behavioral difficulties, however whether these associations reflect postnatal environment, prenatal exposure, or an overall liability is still unclear. This study used prospectively collected data from 24,259 participants of the Norwegian Mother and Child Cohort Study (MoBa). Mothers reported on anxiety/depression and family disharmony twice in pregnancy and twice post pregnancy, as well as on their child’s physical aggression and crying behavior at age 36 months. First, results from an autoregressive cross-lagged model showed a substantial stability in both maternal anxiety/depression and family disharmony from pregnancy to 18 months postnatal, but there was no indication that family disharmony led to maternal anxiety/depression, or the other way around. Second, structural equation models further suggests that the main risk derived from an overall liability, that is, a lasting effect of family risks that spanned the two time periods

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements