Sex differences in the associations between L-arginine pathway metabolites, skeletal muscle mass and function, and their responses to resistance exercise, in old age

This work was supported by the Biotechnology and Biological Sciences Research Council (BB/J015911/1) and was registered at clinicaltrials.gov (ClinicalTrials. gov Identifier: NCT02843009). Supplementary email included with articlePeer reviewedPostprin

Size-selective mortality during freshwater and marine life stages of steelhead related to freshwater growth in the Skagit River, Washington

Wild steelhead trout, Oncorhynchus mykiss, in the Puget Sound are currently in decline, and very little is known about the early life history of these threatened fish. This study evaluated consequences of early growth and survival to smolt or adult stages in different precipitation zones of the Skagit River Basin, Washington. The objectives of this study were to determine whether significant size-selective mortality (SSM) in wild steelhead could be detected between freshwater stages and returning adults; and if so, how the magnitude of SSM varied among juveniles rearing in different precipitation zones (snow and mixed rain-snow). Wild steelhead were sampled as juveniles, smolts, and adults, and scales were measured to compare back-calculated size distributions and growth rates of rearing juveniles with individuals that survived from an earlier life stage to the smolt and adult stages. Back-calculated size-at-annulus comparisons indicated that steelhead in the snow zone were significantly larger at annulus-1 than those in the mixed zone. Steelhead sampled as adults were significantly larger than those sampled as juveniles at annuli-1, -2, and -3, and larger than those sampled as smolts at annuli-2 and -3, Steelhead sampled as smolts were larger than those sampled as juveniles at annuli-1 and -2, but smolts and juveniles were the same size at annulus-3. The disparity in size-at-age-2 and -3 between steelhead sampled at earlier and later life stages suggested that fast growth during the second or third freshwater growing seasons was vitally important for survival to adulthood, and that both freshwater and marine survival could be attributed, in part, to size attained at earlier life stages in freshwater. Efforts for recovery of threatened Puget Sound steelhead could benefit by considering SSM in freshwater environments, and identifying factors that limit growth during early life stages

Anuros da Reserva Natural Salto Morato, Guaraqueçaba, Paraná, Brasil

O objetivo do presente estudo é apresentar a lista de espécies de anfíbios da Reserva Natural Salto Morato (RNSM), uma reserva de Mata Atlântica no Estado do Paraná, sul do Brasil. O parque está localizado no litoral norte do Paraná, na divisa com o Estado de São Paulo. Nós amostramos ambientes lênticos e lóticos, bromélias e serrapilheira durante os meses de setembro de 2006 a março de 2007. Na RNSM foram registradas 42 espécies de anfíbios anuros, pertencentes a nove famílias, sendo uma espécie endêmica da área de estudo. Nós registramos 14 modos reprodutivos dos anuros na área de estudo. Na RNSM, 50% das espécies de anuros ocorreram em mais de 50% das amostragens, 26% das espécies foram registradas entre 25-50% das amostragens e 24% das espécies foram raras, ocorrendo em menos de 25% das amostragens. A RNSM até o presente momento é a área com a maior diversidade de anfíbios e de modos reprodutivos do Paraná. Esses fatores evidenciam a importância da RNSM para a conservação dos anfíbios.Here we present a survey of amphibian species of the Reserva Natural Salto Morato (RNSM), an Atlantic rainforest reserve in Paraná, southern Brazil. We sampled lentic and lotic water bodies, phytotelmata and leaf litter from September 2006 to March 2007. We found 42 species from nine families, one of which is endemic to the study area. Additionally, we recorded 14 reproductive modes. In the RNSM, 50% of anuran species occur in more than 50% of samples, 26% of species occurred between 25 and 50% of samples, and 24% were rare, occurring in less than 25% of samples. The reserve holds the highest diversity of amphibians and reproductive modes in Paraná. Our results emphasize the importance of RNSM for amphibian conservation.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Estadual Paulista - UNESP Instituto de Biociências, Letras e Ciências Exatas Departamento de Zoologia e BotânicaUniversidade Federal da Fronteira Sul - UFFSUniversidade Estadual Paulista - UNESP Instituto de Biociências, Letras e Ciências Exatas Departamento de Zoologia e Botânic

Oral Glucose-Lowering Agents vs Insulin for Gestational Diabetes:A Randomized Clinical Trial

Importance: Metformin and glyburide monotherapy are used as alternatives to insulin in managing gestational diabetes. Whether a sequential strategy of these oral agents results in noninferior perinatal outcomes compared with insulin alone is unknown. Objective: To test whether a treatment strategy of oral glucose-lowering agents is noninferior to insulin for prevention of large-for-gestational-age infants. Design, Setting, and Participants: Randomized, open-label noninferiority trial conducted at 25 Dutch centers from June 2016 to November 2022 with follow-up completed in May 2023. The study enrolled 820 individuals with gestational diabetes and singleton pregnancies between 16 and 34 weeks of gestation who had insufficient glycemic control after 2 weeks of dietary changes (defined as fasting glucose &gt;95 mg/dL [&gt;5.3 mmol/L], 1-hour postprandial glucose &gt;140 mg/dL [&gt;7.8 mmol/L], or 2-hour postprandial glucose &gt;120 mg/dL [&gt;6.7 mmol/L], measured by capillary glucose self-testing). Interventions: Participants were randomly assigned to receive metformin (initiated at a dose of 500 mg once daily and increased every 3 days to 1000 mg twice daily or highest level tolerated; n = 409) or insulin (prescribed according to local practice; n = 411). Glyburide was added to metformin, and then insulin substituted for glyburide, if needed, to achieve glucose targets. Main Outcomes and Measures: The primary outcome was the between-group difference in the percentage of infants born large for gestational age (birth weight &gt;90th percentile based on gestational age and sex). Secondary outcomes included maternal hypoglycemia, cesarean delivery, pregnancy-induced hypertension, preeclampsia, maternal weight gain, preterm delivery, birth injury, neonatal hypoglycemia, neonatal hyperbilirubinemia, and neonatal intensive care unit admission. Results: Among 820 participants, the mean age was 33.2 (SD, 4.7) years). In participants randomized to oral agents, 79% (n = 320) maintained glycemic control without insulin. With oral agents, 23.9% of infants (n = 97) were large for gestational age vs 19.9% (n = 79) with insulin (absolute risk difference, 4.0%; 95% CI, -1.7% to 9.8%; P =.09 for noninferiority), with the confidence interval of the risk difference exceeding the absolute noninferiority margin of 8%. Maternal hypoglycemia was reported in 20.9% with oral glucose-lowering agents and 10.9% with insulin (absolute risk difference, 10.0%; 95% CI, 3.7%-21.2%). All other secondary outcomes did not differ between groups. Conclusions and Relevance: Treatment of gestational diabetes with metformin and additional glyburide, if needed, did not meet criteria for noninferiority compared with insulin with respect to the proportion of infants born large for gestational age.</p

Consensus recommendations for the use of automated insulin delivery technologies in clinical practice

The significant and growing global prevalence of diabetes continues to challenge people with diabetes (PwD), healthcare providers, and payers. While maintaining near-normal glucose levels has been shown to prevent or delay the progression of the long-term complications of diabetes, a significant proportion of PwD are not attaining their glycemic goals. During the past 6 years, we have seen tremendous advances in automated insulin delivery (AID) technologies. Numerous randomized controlled trials and real-world studies have shown that the use of AID systems is safe and effective in helping PwD achieve their long-term glycemic goals while reducing hypoglycemia risk. Thus, AID systems have recently become an integral part of diabetes management. However, recommendations for using AID systems in clinical settings have been lacking. Such guided recommendations are critical for AID success and acceptance. All clinicians working with PwD need to become familiar with the available systems in order to eliminate disparities in diabetes quality of care. This report provides much-needed guidance for clinicians who are interested in utilizing AIDs and presents a comprehensive listing of the evidence payers should consider when determining eligibility criteria for AID insurance coverage

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

MUSCLE DISUSE AS A PIVOTAL PROBLEM IN SARCOPENIA-RELATED MUSCLE LOSS AND DYSFUNCTION

An age-associated loss of muscle mass and strength – sarcopenia – begins at around the fifth decade of life, with mass being lost at ~0.5-1.2% per year and strength at ~3% per year. Sarcopenia can contribute to a variety of negative health outcomes, including an increased risk for falls and fractures, the development of metabolic diseases like type 2 diabetes mellitus, and increase the chance of requiring assisted living. Linear sarcopenic declines in muscle mass and strength are, however, punctuated by transient periods of muscle disuse that can accelerate losses of muscle and strength, which could result in increased risk for the aforementioned conditions. Muscle disuse is recognizable with bed rest or immobilization (for example, due to surgery or acute illness requiring hospitalization); however, recent work has shown that even a relative reduction in ambulation (reduced daily steps) results in significant reductions in muscle mass, strength and possibly an increase in disease risk. Although reduced ambulation is a seemingly “benign” form of disuse, compared to bed rest and immobilization, reports have documented that 2-3 weeks of reduced daily steps may induce: negative changes in body composition, reductions in muscle strength and quality, anabolic resistance, and decrements in glycemic control in older adults. Importantly, periods of reduced ambulation likely occur fairly frequently and appear more difficult to fully recover from, in older adults. Here we explore the consequences of muscle disuse due to reduced ambulatory activity in older adults, with frequent comparisons to established models of disuse: bed rest and immobilization.</jats:p