The challenges, opportunities and future of comparative physiology in the Global South: perspectives of early-career researchers.

Researchers in the Global South (GS, developing countries) make valuable contributions to the field of comparative physiology, but face economic and scientific disparities and several unique challenges compared with colleagues in the Global North (developed countries). This Perspective highlights some of the challenges, knowledge gaps and disparities in opportunity faced by GS researchers, especially those at early-career stages. We propose collaborative solutions to help address these issues, and advocate for promoting investment and cultural and societal change for a more inclusive research community.

Bat thermoregulation in the heat: seasonal variation in evaporative cooling capacities in four species of European bats.

Phenotypic flexibility is an important source of physiological variation in endotherms and plays an integral role in species' response to rapid environmental changes. Studies of phenotypic flexibility have focused on winter acclimatization and cold endurance, and there are fewer data on summer acclimatization and adjustments in heat dissipation capacity, especially in Temperate-Zone species. We used indirect calorimetry and thermometry to test if thermoregulation at high air temperatures (T) varies between spring and summer in four species of European vespertilionid bats: Nyctalus noctula, Pipistrellus nathusii, P.

Solving the conundrum of intra-specific variation in metabolic rate: A multidisciplinary conceptual and methodological toolkit: New technical developments are opening the door to an understanding of why metabolic rate varies among individual animals of a species: New technical developments are opening the door to an understanding of why metabolic rate varies among individual animals of a species.

Researchers from diverse disciplines, including organismal and cellular physiology, sports science, human nutrition, evolution and ecology, have sought to understand the causes and consequences of the surprising variation in metabolic rate found among and within individual animals of the same species. Research in this area has been hampered by differences in approach, terminology and methodology, and the context in which measurements are made. Recent advances provide important opportunities to identify and address the key questions in the field.

Is torpor a water conservation strategy? Heterothermic responses to acute water and food deprivation are repeatable among individuals of Phodopus sungorus.

Energy conservation is a clear function of torpor. Although many studies imply that torpor is also a water-saving strategy, the experimental evidence linking water availability with torpor is inconclusive. We tested the relative roles of water and energy shortages in driving torpor, using the Siberian hamster Phodopus sungorus as a model species.

Effects of very low-carbohydrate vs. high-carbohydrate weight loss diets on psychological health in adults with obesity and type 2 diabetes: a 2-year randomized controlled trial.

Aims: Very low-carbohydrate (LC) diets are popular for type 2 diabetes (T2DM) management; however, long-term effects on psychological health remain largely unknown. This study reports the effects of a LC diet on mood and cognitive function after 2 years and explores the potential predictors of changes in psychological health.

Methods: 115 adults (57% males; age: 58.

The Effects of Vitamin D-Enriched Mushrooms and Vitamin D3 on Cognitive Performance and Mood in Healthy Elderly Adults: A Randomised, Double-Blinded, Placebo-Controlled Trial.

Despite abundant cross-sectional evidence that low vitamin D status is associated with risk of cognitive decline in ageing, interventional evidence for benefits of vitamin D supplementation is lacking. This study was a 6 month randomised, double-blinded placebo-controlled clinical trial of the effects of vitamin D3 (D3), enhanced vitamin D2 in a mushroom matrix (D2M), standard mushroom (SM) and placebo (PL) on cognition and mood in = 436 healthy older male (49%) and female volunteers aged ≥ 60 years. Primary end points were change in serum vitamin D metabolites (25-OH-D, 25-OH-D2 and 25-OH-D3), cognitive performance, and mood over 24 weeks.

Investigating the Linear Thermal Expansion of Additively Manufactured Multi-Material Joining between Invar and Steel.

This work investigated the linear thermal expansion properties of a multi-material specimen fabricated with Invar M93 and A36 steel. A sequence of tests was performed to investigate the viability of additively manufactured Invar M93 for lowering the coefficient of thermal expansion (CTE) in multi-material part tooling. Invar beads were additively manufactured on a steel base plate using a fiber laser system, and samples were taken from the steel, Invar, and the interface between the two materials.

Mitigating Scatter in Mechanical Properties in AISI 410 Fabricated via Arc-Based Additive Manufacturing Process.

Wire-based metal additive manufacturing utilizes the ability of additive manufacturing to fabricate complex geometries with high deposition rates (above 7 kg/h), thus finding applications in the fabrication of large-scale components, such as stamping dies. Traditionally, the workhorse materials for stamping dies have been martensitic steels. However, the complex thermal gyrations induced during additive manufacturing can cause the evolution of an inhomogeneous microstructure, which leads to a significant scatter in the mechanical properties, especially the toughness.

Nutritional adequacy of very low- and high-carbohydrate, low saturated fat diets in adults with type 2 diabetes: A secondary analysis of a 2-year randomised controlled trial.

Background: Growing evidence supports use of very low-carbohydrate (LC) diets for glycaemic control in type 2 diabetes. However, limited data on the micronutrient adequacy of LC diets exist.

Objective: This study compared the long-term effects of a very low-carbohydrate, high unsaturated/low saturated fat (LC) diet to a high-carbohydrate, low-fat (HC) diet on micronutrient biomarkers in adults with obesity and type 2 diabetes.

Correction to: Comparison of the effects of weight loss from a high-protein versus standard-protein energy-restricted diet on strength and aerobic capacity in overweight and obese men.

The original version of this article unfortunately contained a mistake.

Magnitude and Dynamics of the T-Cell Response to SARS-CoV-2 Infection at Both Individual and Population Levels.

T cells are involved in the early identification and clearance of viral infections and also support the development of antibodies by B cells. This central role for T cells makes them a desirable target for assessing the immune response to SARS-CoV-2 infection. Here, we combined two high-throughput immune profiling methods to create a quantitative picture of the T-cell response to SARS-CoV-2.

Seasonal variation in body composition in an Afrotropical passerine bird: increases in pectoral muscle mass are, unexpectedly, associated with lower thermogenic capacity.

Phenotypic flexibility in avian metabolic rates and body composition have been well-studied in high-latitude species, which typically increase basal metabolic rate (BMR) and summit metabolism (M) when acclimatized to winter conditions. Patterns of seasonal metabolic acclimatization are more variable in lower-latitude birds that experience milder winters, with fewer studies investigating adjustments in avian organ and muscle masses in the context of metabolic flexibility in these regions. We quantified seasonal variation (summer vs winter) in the masses of organs and muscles frequently associated with changes in BMR (gizzard, intestines and liver) and M (heart and pectoral muscles), in white-browed sparrow-weavers (Plocepasser mahali).

Phenotypic flexibility of metabolic rate and evaporative water loss does not vary across a climatic gradient in an Afrotropical passerine bird.

Small birds inhabiting northern temperate and boreal latitudes typically increase metabolic rates during cold winters or acclimation to low air temperatures (). Recent studies suggest considerable variation in patterns of seasonal metabolic acclimatization in birds from subtropical and tropical regions with milder winters, but there remains a dearth of acclimation studies investigating metabolic flexibility among lower-latitude birds. We used short-term thermal acclimation experiments to investigate phenotypic flexibility in basal metabolic rate (BMR), thermoneutral evaporative water loss (EWL) and summit metabolism () in three populations of white-browed sparrow-weavers () along a climatic and aridity gradient.

Seasonal Metabolic Acclimatization Varies in Direction and Magnitude among Years in Two Arid-Zone Passerines.

Adaptive plasticity in avian thermal physiology is increasingly apparent, with a well-studied example being metabolic upregulation during cold winters in small birds inhabiting temperate and boreal latitudes. Recent studies have revealed greater variation in the direction and magnitude of seasonal metabolic adjustments among subtropical/tropical birds experiencing milder winters compared with higher-latitude counterparts, suggesting that patterns could vary among years within populations. We quantified seasonal metabolic variation (summer vs.

Nanopore Sequencing of an Expanded Genetic Alphabet Reveals High-Fidelity Replication of a Predominantly Hydrophobic Unnatural Base Pair.

Unnatural base pairs (UBPs) have been developed and used for a variety of applications as well as for the engineering of semisynthetic organisms (SSOs) that store and retrieve increased information. However, these applications are limited by the availability of methods to rapidly and accurately determine the sequence of unnatural DNA. Here we report the development and application of the MspA nanopore to sequence DNA containing the d-d UBP.

Speech-to-text assistive technology for the written expression of students with traumatic brain injuries: A single case experimental study.

Traumatic brain injury in childhood (TBI) is a chronic health condition. As decreased memory, language, and rapid psychomotor impairments are known to accompany pediatric TBI (Babikian et al., 2011), students who have experienced a moderate-to-severe TBI are at particular risk for academic deficits, including writing difficulties.

Altering meal timing to improve cognitive performance during simulated nightshifts.

Altering meal timing could improve cognition, alertness, and thus safety during the nightshift. This study investigated the differential impact of consuming a meal, snack, or not eating during the nightshift on cognitive performance (ANZCTR12615001107516). 39 healthy participants (59% male, age mean±SD: 24.

A Mobile Phone App Designed to Support Weight Loss Maintenance and Well-Being (MotiMate): Randomized Controlled Trial.

Background: Few people successfully maintain lost weight over the longer term. Mobile phones have the potential to deliver weight loss management programs that can encourage self-monitoring while also providing some behavioral therapy to assist users in developing personal skills that may be necessary for improved longer term weight loss maintenance.

Objective: The aim of this study was to evaluate a program supporting weight maintenance, which uses a behaviorally based mobile phone app to manage weight, food, exercise, mood, and stress.

Reaction norms for heat tolerance and evaporative cooling capacity do not vary across a climatic gradient in a passerine bird.

There is increasing evidence for considerable phenotypic flexibility in endotherm thermal physiology, a phenomenon with far-reaching implications for the evolution of traits related to heat tolerance. Numerous studies have documented intraspecific variation in avian thermoregulatory traits, but few have revealed the shapes of thermoregulatory reaction norms or how these might vary among populations. We investigated phenotypic flexibility in the ability of a model Afrotropical passerine bird (the white-browed sparrow-weaver, Plocepasser mahali) to handle high air temperatures (T).

Subjective Hunger, Gastric Upset, and Sleepiness in Response to Altered Meal Timing during Simulated Shiftwork.

Shiftworkers report eating during the night when the body is primed to sleep. This study investigated the impact of altering food timing on subjective responses. Healthy participants ( = 44, 26 male, age Mean ± SD = 25.

Increasing the accuracy of nanopore DNA sequencing using a time-varying cross membrane voltage.

Nanopore DNA sequencing is limited by low base-calling accuracy. Improved base-calling accuracy has so far relied on specialized base-calling algorithms, different nanopores and motor enzymes, or biochemical methods to re-read DNA molecules. Two primary error modes hamper sequencing accuracy: enzyme mis-steps and sequences with indistinguishable signals.

Predictors of Lifestyle Intervention Attrition or Weight Loss Success in Women with Polycystic Ovary Syndrome Who Are Overweight or Obese.

Polycystic ovary syndrome (PCOS) is a common condition in reproductive-aged women. Weight management is a first-line treatment for PCOS according to international evidence-based guidelines. However, the factors associated with attrition or success in weight loss interventions are not known for women with PCOS.

Interactions between humidity and evaporative heat dissipation in a passerine bird.

Environmental humidity is thought to be a major determinant of evaporative cooling capacity at high air temperatures (T), but the technical challenges of experimentally manipulating humidity in respirometry chambers have resulted in far less being known about the effects of humidity compared to those of T. We tested the prediction that at T approaching and exceeding normothermic body temperature (T), high humidity would result in higher T, lower evaporative water loss (EWL) and/or higher resting metabolic rate (RMR) in a passerine bird, the white-browed sparrow-weaver (Plocepasser mahali). We used open-system flow-through respirometry to measure EWL, RMR and T in sparrow-weavers experiencing T = 36-44 °C and chamber humidities of 6, 13, 19 or 25 g m.

Determining the effects of DNA sequence on Hel308 helicase translocation along single-stranded DNA using nanopore tweezers.

Motor enzymes that process nucleic-acid substrates play vital roles in all aspects of genome replication, expression, and repair. The DNA and RNA nucleobases are known to affect the kinetics of these systems in biologically meaningful ways. Recently, it was shown that DNA bases control the translocation speed of helicases on single-stranded DNA, however the cause of these effects remains unclear.