Diastereoselective β-hydroxy vinylsulfone isomerizations.

Vinylic phenylsulfones containing a β-hydroxyl stereocenter undergo a diastereoselective isomerization to the corresponding allylic isomer upon treatment with 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU).

Global change and premature hatching of aquatic embryos.

Anthropogenically induced changes to the natural world are increasingly exposing organisms to stimuli and stress beyond that to which they are adapted. In aquatic systems, it is thought that certain life stages are more vulnerable than others, with embryos being flagged as highly susceptible to environmental stressors. Interestingly, evidence from across a wide range of taxa suggests that aquatic embryos can hatch prematurely, potentially as an adaptive response to external stressors, despite the potential for individual costs linked with underdeveloped behavioural and/or physiological functions.

Hyperoxia disproportionally benefits the aerobic performance of large fish at elevated temperature.

Increasing evidence shows that larger fish are more vulnerable to acute warming than smaller individuals of the same species. This size-dependency of thermal tolerance has been ascribed to differences in aerobic performance, largely owing to a decline in oxygen supply relative to demand. To shed light on these ideas, we examined metabolic allometry in 130 rainbow trout ranging from 12 to 358 g under control conditions (17°C) and in response to acute heating (to 25°C), with and without supplemental oxygen (100% versus 150% air saturation).

Estimating maximum oxygen uptake of fishes during swimming and following exhaustive chase - different results, biological bases and applications.

The maximum rate at which animals take up oxygen from their environment (ṀO2,max) is a crucial aspect of their physiology and ecology. In fishes, ṀO2,max is commonly quantified by measuring oxygen uptake either during incremental swimming tests or during recovery from an exhaustive chase. In this Commentary, we compile recent studies that apply both techniques to the same fish and show that the two methods typically yield different mean estimates of ṀO2,max for a group of individuals.

Paternal dietary macronutrient balance and energy intake drive metabolic and behavioral differences among offspring.

Paternal diet can influence the phenotype of the next generation, yet, the dietary components inducing specific responses in the offspring are not identified. Here, we use the Nutritional Geometry Framework to determine the effects of pre-conception paternal dietary macronutrient balance on offspring metabolic and behavioral traits in mice. Ten isocaloric diets varying in the relative proportion of protein, fats, and carbohydrates are fed to male mice prior to mating.

Specific dynamic action: the energy cost of digestion or growth?

The physiological processes underlying the post-prandial rise in metabolic rate, most commonly known as the 'specific dynamic action' (SDA), remain debated and controversial. This Commentary examines the SDA response from two opposing hypotheses: (i) the classic interpretation, where the SDA represents the energy cost of digestion, versus (ii) the alternative view that much of the SDA represents the energy cost of growth. The traditional viewpoint implies that individuals with a reduced SDA should grow faster given the same caloric intake, but experimental evidence for this effect remains scarce and inconclusive.

Hydroxyl-Directed Regio- and Diastereoselective Allylic Sulfone Reductions with [Sm(HO)]I.

Allylic 1,2- and 1,3-hydroxy phenyl sulfones undergo regioselective and diastereoselective desulfonylation with double bond migration upon treatment with [Sm(HO)]I. Selectivity in these reactions is thought to arise from the formation of a chelated organosamarium intermediate followed by intramolecular protonation by samarium-bound water, which is supported by observed diastereoselectivity and stereospecificity trends along with deuterium labeling experiments. The reaction was then featured in the synthesis of the phenolic fragment of the thailandamide natural products.

Supplemental oxygen does not improve growth but can enhance reproductive capacity of fish.

Fish tend to grow faster as the climate warms but attain a smaller adult body size following an earlier age at sexual maturation. Despite the apparent ubiquity of this phenomenon, termed the temperature-size rule (TSR), heated scientific debates have revealed a poor understanding of the underlying mechanisms. At the centre of these debates are prominent but marginally tested hypotheses which implicate some form of 'oxygen limitation' as the proximate cause.

Daily thermal variability does not modify long-term gene expression relative to stable thermal environments: A case study of a tropical fish.

Global warming is leading to an increase in the frequency and intensity of extreme weather events, magnifying the breadth of temperatures faced by ectotherms across days and seasons. Despite the importance and ecological relevance of diurnal thermal variability, the vast majority of knowledge on gene expression patterns and physiology stems from animals acclimated to constant temperatures or in the early stages of exposure to a new temperature regime. If heterothermal environments modulate responses differently from constant thermal environments, our existing capacity to forecast impacts of climate warming may be compromised.

Evidence for energy reallocation, not oxygen limitation, driving the deceleration in growth of adult fish.

The lifetime growth of almost all fishes follows a biphasic relationship - juvenile growth is rapid and adult growth subsequently decelerates. For a trend that is so ubiquitous, there is no general agreement as to the underlying mechanisms causing adult growth to decelerate. Ongoing theories argue that adult growth slows because either the gills fail to supply the body with surplus oxygen needed for continued somatic gain (i.

Extreme original data yield extreme decline effects.

Clements et al. respond to Munday's claim that his "reanalysis shows there is not an extreme decline effect in fish ocean acidification studies". They contend that extreme data reported in early studies authored by Dixson and Munday indeed result in an "extreme" decline effect in this field, and conclude that the decline effect is primarily driven by papers by particular authors.

Chronic experimental hyperoxia elevates aerobic scope: a valid method to test for physiological oxygen limitations in fish.

Experimental hyperoxia has been shown to enhance the maximum oxygen uptake capacity of fishes under acute conditions, potentially offering an avenue to test prominent physiological hypotheses attempting to explain impacts of climate warming on fish populations (e.g., gill-oxygen limitation driving declines in fish size).

Behavioural temperature regulation is a low priority in a coral reef fish (Plectropomus leopardus): insights from a novel behavioural thermoregulation system.

Current understanding of behavioural thermoregulation in aquatic ectotherms largely stems from systems such as 'shuttle boxes', which are generally limited in their capacity to test large-bodied species. Here, we introduce a controlled system that allows large aquatic ectotherms to roam freely in a tank at sub-optimal temperatures, using thermal refuges to increase body temperature to their thermal optimum as desired. Of the 10 coral grouper (Plectropomus leopardus; length ∼400 mm) implanted with thermal loggers, three fish maintained themselves at the ambient tank temperature of 17.

Investigating the gill-oxygen limitation hypothesis in fishes: intraspecific scaling relationships of metabolic rate and gill surface area.

Many ectotherms have shown a reduction in maximum body size in the past decades in parallel with climate warming. Indeed, some models forecast a maximum body size decline of 14%-24% by 2050 for numerous fish species. The gill-oxygen limitation (GOL) hypothesis is perhaps the most prominent concept regarding the physiological mechanisms underlying the observed trends, implicating oxygen uptake limitations in driving the decline in fish body size with warming.

Meta-analysis reveals an extreme "decline effect" in the impacts of ocean acidification on fish behavior.

Ocean acidification-decreasing oceanic pH resulting from the uptake of excess atmospheric CO2-has the potential to affect marine life in the future. Among the possible consequences, a series of studies on coral reef fish suggested that the direct effects of acidification on fish behavior may be extreme and have broad ecological ramifications. Recent studies documenting a lack of effect of experimental ocean acidification on fish behavior, however, call this prediction into question.

Targeted newborn metabolomics: prediction of gestational age from cord blood.

Objective: Our study sought to determine whether metabolites from a retrospective collection of banked cord blood specimens could accurately estimate gestational age and to validate these findings in cord blood samples from Busia, Uganda.

Study Design: Forty-seven metabolites were measured by tandem mass spectrometry or enzymatic assays from 942 banked cord blood samples. Multiple linear regression was performed, and the best model was used to predict gestational age, in weeks, for 150 newborns from Busia, Uganda.

Nutrition, anxiety and hormones. Why sex differences matter in the link between obesity and behavior.

Obesity and mood disorders are two of the most serious health issues of modern times. These health conditions are often linked, with obesity acting both as a cause and consequence of anxiety and depression. Although sex differences in the relationship between obesity and mood disorders are observed in clinical populations, the relative influence of biology versus societal conditioning is unclear.

Amoebic gill disease increases energy requirements and decreases hypoxia tolerance in Atlantic salmon (Salmo salar) smolts.

Globally, Atlantic salmon (Salmo salar Linnaeus) aquaculture is now routinely affected by amoebic gill disease (AGD; Neoparamoeba perurans). The disease proliferates throughout the summer and is implicated in decreasing tolerance of salmon to environmental perturbations, yet little empirical evidence exists to support these observations. Using salmon acclimated to 15 or 19 °C, our aim was to determine the effects of clinically light-moderate (industry-relevant) AGD on metabolism (ṀO and ṀO), aerobic scope (ṀO - ṀO), excess post-exercise oxygen consumption (EPOC), and hypoxia tolerance.

Effect of universal HIV testing and treatment on socioeconomic wellbeing in rural Kenya and Uganda: a cluster-randomised controlled trial.

Background: Universal testing and treatment for HIV has shown promise as an approach to reduce mortality and lower HIV incidence. Evidence on the economic effects of this approach on individuals and households in low-resource settings is scarce. We aimed to examine the effect of universal HIV testing and treatment on a range of economic outcomes.

Piperaquine-Induced QTc Prolongation Decreases With Repeated Monthly Dihydroartemisinin-Piperaquine Dosing in Pregnant Ugandan Women.

Background: Intermittent preventive treatment with monthly dihydroartemisinin-piperaquine (DHA-PQ) is highly effective at preventing both malaria during pregnancy and placental malaria. Piperaquine prolongs the corrected QT interval (QTc), and it is possible that repeated monthly dosing could lead to progressive QTc prolongation. Intensive characterization of the relationship between piperaquine concentration and QTc interval throughout pregnancy can inform effective, safe prevention guidelines.

Provider and Patient Perspectives of Rapid ART Initiation and Streamlined HIV Care: Qualitative Insights From Eastern African Communities.

The Sustainable East Africa Research in Community Health (SEARCH), a universal test and treat (UTT) trial, implemented 'Streamlined Care'-a multicomponent strategy including rapid linkage to care and antiretroviral therapy (ART) start, 3-monthly refills, viral load counseling, and accessible, patient-centered care provision. To understand patient and provider experiences of Streamlined Care to inform future care innovations, we conducted in-depth interviews with patients ( = 18) and providers ( = 28) at baseline (2014) and follow-up (2015) ( = 17 patients;  = 21 providers). Audio recordings were transcribed, translated, and deductively and inductively coded.