Djungarian Hamsters Exhibit Temperature-Dependent Dietary Fat Choice In Long Days

Previous studies have shown that whole-animal thermal responses of ectotherms and heterotherms (e.g., hibernators), both of which experience a wide range of body temperatures, are related to the saturation level of somatic lipids, which in turn can be influenced by the ratio of saturated and unsaturated fatty acids in the diet. This study demonstrates that Djungarian hamsters held in long days display ambient temperature dependent choice of dietary fats, increasing their preference for saturated fats when ambient temperature increases ( to 27 degreesC) and later reversing this preference when ambient temperature is returned to its original value ( 8 degreesC). Changes in percent contribution of the unsaturated and saturated diets in response to temperature were accomplished almost solely by changes in the amount of unsaturated diet consumed. Temperature-dependent fatty acid choice occurs at a stage in the annual cycle when Djungarian hamsters do not enter spontaneous daily torpor and therefore experience only small changes in core body temperature. These results suggest that temperature-dependent fatty acid choice may occur in a wide range of animals, including nonheterothermic endotherms

Dietary Lipid Saturation Influences Environmental Temperature Preference But Not Resting Metabolic Rate In The Djungarian Hamster (Phodopus Sungorus)

Heterothermic rodents increase self-selection of diets rich in polyunsaturated fatty acids (PUFAs) when exposed to cold, short days, or short-day melatonin profiles, and Djungarian hamsters (Phodopus sungorus) do so in long days in response to cold exposure alone. To determine whether Djungarian hamsters are also capable of selecting a thermal environment in response to dietary lipid composition, continuously normothermic hamsters were fed either a PUF-rich diet or a diet rich in saturated fatty acids (SFAs) for 6-10 wk and given a choice of thermal environments. As predicted, SF-fed hamsters were more likely than PUFA-fed hamsters to occupy the single heated corner of their cage (P = 0.0005) and were most likely to show this diet-related difference in behavior when T a fell within the thermal neutral zone. Respirometry revealed no effect of diet on whole-animal or mass-specific resting metabolic rate or on lower critical temperature. The results are more consistent with the homeoviscous adaptation hypothesis, which predicts that organisms should make physiological and/or behavioral adjustments that preserve membrane fluidity within a relatively small range, than with the membrane pacemaker hypothesis, which predicts that high PUFA content in membrane phospholipids should increase basal metabolic rate

Political feasibility of 1.5°C societal transformations: the role of social justice

Constraining global climate change to 1.5°C is commonly understood to require urgent and deep societal transformations. Yet such transformations are not always viewed as politically feasible; finding ways to enhance the political feasibility of ambitious decarbonization trajectories is needed. This paper reviews the role of social justice as an organizing principle for politically feasible 1.5°C transformations. A social justice lens usefully focuses attention on 1) protecting vulnerable people from climate change impacts, 2) protecting people from disruptions of transformation, and 3) enhancing the process of envisioning and implementing an equitable post-carbon society. However, justice-focused arguments could also have unintended consequences, such as being deployed against climate action. Hence proactively engaging with social justice is critical in navigating 1.5°C societal transformations

Roboter Charlie zu Besuch in der Schule

Um Kinder beim Erlernen überfachlicher Kompetenzen zu unterstützen, haben Forschende der Berner Fachhochschule einen humanoiden Roboter in zwei Primarschulklassen eingesetzt. Dabei konnten sie wichtige Erkenntnisse zur Mensch-Maschine-Interaktion sammeln. Diese helfen, digitale Ansätze im Gesundheitswesen umzusetzen

Fitness Correlates Of Song Repertoire Size In Free-Living Song Sparrows (Melospiza Melodia)

Models of sexual selection propose that exaggerated secondary sexual ornaments indicate a male\u27s own fitness and the fitness of his offspring. These hypotheses have rarely been thoroughly tested in free-living individuals because overall fitness, as opposed to fitness components, is difficult to measure. We used 20 years of data from song sparrows ( Melospiza melodia) inhabiting Mandarte Island, British Columbia, Canada, to test whether a male\u27s song repertoire size, a secondary sexual trait, predicted overall measures of male or offspring fitness. Males with larger song repertoires contributed more independent and recruited offspring, and independent and recruited grandoffspring, to Mandarte\u27s population. This was because these males lived longer and reared a greater proportion of hatched chicks to independence from parental care, not because females mated to males with larger repertoires laid or hatched more eggs. Furthermore, independent offspring of males with larger repertoires were more likely to recruit and then to leave more grandoffspring than were offspring of males with small repertoires. Although we cannot distinguish whether observed fitness variation reflected genetic or environmental effects on males or their offspring, these data suggest that female song sparrows would gain immediate and intergenerational fitness benefits by pairing with males with large song repertoires

Scaling tests of the improved Kogut-Susskind quark action

Improved lattice actions for Kogut-Susskind quarks have been shown to improve rotational symmetry and flavor symmetry. In this work we find improved scaling behavior of the rho and nucleon masses expressed in units of a length scale obtained from the static quark potential, and better behavior of the Dirac operator in instanton backgrounds.Comment: 4 pages, 4 figures, Revte

Stroboscopic Visual Training for Coaching Practitioners: A Comprehensive Literature Review

Background: The importance of vision and its impact upon an athlete’s performance has long been recognized by elite athletic communities. In recent decades, stroboscopic training methods have been developed to help train athletes from a visual, perceptual, and cognitive perspective using strobe glasses. Objective: Herein a comprehensive literature review was conducted to investigate the effectiveness of strobe glasses in training collegiate and professional athletes. Methods: This comprehensive literature review investigates the origins, attention influences, tasks, practitioner takeaways, and cost feasibility of stroboscopic visual training.Results: The findings from this review show promise of benefits from utilizing strobe glasses during training scenarios, particularly for improving fast or impulsive tasks. Strobe glasses can be accommodated into varying sporting environments and training regimens while being affordable to athletic, coaching, and training departments or centers. Studies investigating the direct influence of stroboscopic training on subsequent performance demonstrate viable methods for strengthening fundamental visual abilities. Notably, these fundamental abilities have been shown to correlate with improved game performance. Though early results are promising, there are still significant areas for further research and more comprehensive designs of stroboscopic training studies. Conclusion: This review highlights potential benefits and existing research gaps concerning the use of stroboscopic eyewear as an intervention method in sports. The delineation of optimal applications for strobe glasses is undetermined; however, information presented in this review can be meaningfully applied by coaching practitioners who are considering adopting the technology

Mercury in fish and adverse reproductive outcomes: results from South Carolina

Mercury is a metal with widespread distribution in aquatic ecosystems and significant neurodevelopmental toxicity in humans. Fish biomonitoring for total mercury has been conducted in South Carolina (SC) since 1976, and consumption advisories have been posted for many SC waterways. However, there is limited information on the potential reproductive impacts of mercury due to recreational or subsistence fish consumption. To address this issue, geocoded residential locations for live births from the Vital Statistics Registry (1995–2005, N = 362,625) were linked with spatially interpolated total mercury concentrations in fish to estimate potential mercury exposure from consumption of locally caught fish. Generalized estimating equations were used to test the hypothesis that risk of low birth weight (LBW, <2,500 grams) or preterm birth (PTB, <37 weeks clinical gestation) was greater among women living in areas with elevated total mercury in fish, after adjustment for confounding. Separate analyses estimated term LBW and PTB risks using residential proximity to rivers with fish consumption advisories to characterize exposure. Term LBW was more likely among women residing in areas in the upper quartile of predicted total mercury in fish (odds ratio [OR] = 1.04; 95% confidence interval [CI]: 1.00-1.09) or within 8 kilometers of a river with a ‘do not eat’ fish advisory (1.05; 1.00-1.11) compared to the lowest quartile, or rivers without fish consumption restrictions, respectively. When stratified by race, risks for term LBW or PTB were 10-18% more likely among African-American (AA) mothers living in areas with the highest total fish mercury concentrations. To our knowledge, this is the first study to examine the relationship between fish total mercury concentrations and adverse reproductive outcomes in a large population-based sample that included AA women. The ecologic nature of exposure assessment in this study precludes causal inference. However, the results suggest a need for more detailed investigations to characterize patterns of local fish consumption and potential dose–response relationships between mercury exposure and adverse reproductive outcomes, particularly among AA mothers.https://doi.org/10.1186/1476-072X-13-3

Cost of Antibiotic Resistance and the Geometry of Adaptation

The distribution of effects of beneficial mutations is key to our understanding of biological adaptation. Yet, empirical estimates of this distribution are scarce, and its functional form is largely unknown. Theoretical models of adaptation predict that the functional form of this distribution should depend on the distance to the optimum. Here, we estimate the rate and distribution of adaptive mutations that compensate for the effect of a single deleterious mutation, which causes antibiotic resistance. Using a system with multiple molecular markers, we estimate the distribution of fitness effects of mutations at two distances from the adaptive peak in 60 populations of Escherichia coli. We find that beneficial mutations, which can contribute to compensatory evolution, occur at very high rates, of the order of 10−5 per genome per generation and can be detected within a few tens of generations. They cause an average fitness increase of 2.5% and 3.6%, depending on the cost of resistance, which is expected under Fisher's geometrical model of adaptation. Moreover, we provide the first description of the distribution of beneficial mutations, segregating during the process of compensatory evolution, to antibiotic resistances bearing different costs. Hence, these results have important implications to understanding the spread and maintenance of antibiotic resistance in bacteria