Homophileurus neptunus Dechambre, a new junior synonym of H. waldenfelsi Endrödi (Coleoptera: Scarabaeidae: Dynastinae: Phileurini)

Homophileurus neptunus Dechambre was found to be conspecific with H. waldenfelsi Endrödi after examination of types, descriptions, and illustrations. Accordingly, H. neptunus is placed in junior synonymy with H. waldenfelsi, new synonymy. Homophileurus waldenfelsi is an uncommon species and occurs in Ecuador, Colombia, Brazil, and Peru. Brazil and Peru are new country records

The effect of multiple paternity on genetic diversity during and after colonisation

In metapopulations, genetic variation of local populations is influenced by the genetic content of the founders, and of migrants following establishment. We analyse the effect of multiple paternity on genetic diversity using a model in which the highly promiscuous marine snail Littorina saxatilis expands from a mainland to colonise initially empty islands of an archipelago. Migrant females carry a large number of eggs fertilised by 1 - 10 mates. We quantify the genetic diversity of the population in terms of its heterozygosity: initially during the transient colonisation process, and at long times when the population has reached an equilibrium state with migration. During colonisation, multiple paternity increases the heterozygosity by 10 - 300 % in comparison with the case of single paternity. The equilibrium state, by contrast, is less strongly affected: multiple paternity gives rise to 10 - 50 % higher heterozygosity compared with single paternity. Further we find that far from the mainland, new mutations spreading from the mainland cause bursts of high genetic diversity separated by long periods of low diversity. This effect is boosted by multiple paternity. We conclude that multiple paternity facilitates colonisation and maintenance of small populations, whether or not this is the main cause for the evolution of extreme promiscuity in Littorina saxatilis.Comment: 7 pages, 5 figures, electronic supplementary materia

Aerobic capacity reference data in 3816 healthy men and women 20-90 years

Purpose: To provide a large reference material on aerobic fitness and exercise physiology data in a healthy population of Norwegian men and women aged 20–90 years. Methods: Maximal and sub maximal levels of VO2, heart rate, oxygen pulse, and rating of perceived exertion (Borg scale: 6–20) were measured in 1929 men and 1881 women during treadmill running. Results: The highest VO2max and maximal heart rate among men and women were observed in the youngest age group (20–29 years) and was 54.4±8.4 mL·kg−1·min−1 and 43.0±7.7 mL·kg−1·min−1 (sex differences, p<0.001) and 196±10 beats·min−1 and 194±9 beats·min−1 (sex differences, p<0.05), respectively, with a subsequent reduction of approximately 3.5 mL·kg−1·min−1 and 6 beats·min−1 per decade. The highest oxygen pulses were observed in the 3 youngest age groups (20–29 years, 30–39 years, 40–49 years) among men and women; 22.3 mL·beat−1±3.6 and 14.7 mL·beat−1±2.7 (sex differences, p<0.001), respectively, with no significant difference between these age groups. After the age of 50 we observed an 8% reduction per decade among both sexes. Borg scores appear to give a good estimate of the relative exercise intensity, although observing a slightly different relationship than reported in previous reference material from small populations. Conclusion: This is the largest European reference material of objectively measured parameters of aerobic fitness and exercise-physiology in healthy men and women aged 20–90 years, forming the basis for an easily accessible, valid and understandable tool for improved training prescription in healthy men and women.© 2013 Loe et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Utilizing small nutrient compounds as enhancers of exercise-induced mitochondrial biogenesis.

Endurance exercise, when performed regularly as part of a training program, leads to increases in whole-body and skeletal muscle-specific oxidative capacity. At the cellular level, this adaptive response is manifested by an increased number of oxidative fibers (Type I and IIA myosin heavy chain), an increase in capillarity and an increase in mitochondrial biogenesis. The increase in mitochondrial biogenesis (increased volume and functional capacity) is fundamentally important as it leads to greater rates of oxidative phosphorylation and an improved capacity to utilize fatty acids during sub-maximal exercise. Given the importance of mitochondrial biogenesis for skeletal muscle performance, considerable attention has been given to understanding the molecular cues stimulated by endurance exercise that culminate in this adaptive response. In turn, this research has led to the identification of pharmaceutical compounds and small nutritional bioactive ingredients that appear able to amplify exercise-responsive signaling pathways in skeletal muscle. The aim of this review is to discuss these purported exercise mimetics and bioactive ingredients in the context of mitochondrial biogenesis in skeletal muscle. We will examine proposed modes of action, discuss evidence of application in skeletal muscle in vivo and finally comment on the feasibility of such approaches to support endurance-training applications in humans

Interstitial Glucose and Physical Exercise in Type 1 Diabetes: Integrative Physiology, Technology, and the Gap In-Between

Continuous and flash glucose monitoring systems measure interstitial fluid glucose concentrations within a body compartment that is dramatically altered by posture and is responsive to the physiological and metabolic changes that enable exercise performance in individuals with type 1 diabetes. Body fluid redistribution within the interstitial compartment, alterations in interstitial fluid volume, changes in rate and direction of fluid flow between the vasculature, interstitium and lymphatics, as well as alterations in the rate of glucose production and uptake by exercising tissues, make for caution when interpreting device read-outs in a rapidly changing internal environment during acute exercise. We present an understanding of the physiological and metabolic changes taking place with acute exercise and detail the blood and interstitial glucose responses with different forms of exercise, namely sustained endurance, high-intensity, and strength exercises in individuals with type 1 diabetes. Further, we detail novel technical information on currently available patient devices. As more health services and insurance companies advocate their use, understanding continuous and flash glucose monitoring for its strengths and limitations may offer more confidence for patients aiming to manage glycemia around exercise

Temperature-dependent release of ATP from human erythrocytes: Mechanism for the control of local tissue perfusion

Copyright @ 2012 The AuthorsThis article has been made available through the Brunel Open Access Publishing Fund.Human limb muscle and skin blood flow increases significantly with elevations in temperature, possibly through physiological processes that involve temperature-sensitive regulatory mechanisms. Here we tested the hypothesis that the release of the vasodilator ATP from human erythrocytes is sensitive to physiological increases in temperature both in vitro and in vivo, and examined potential channel/transporters involved. To investigate the source of ATP release, whole blood, red blood cells (RBCs), plasma and serum were heated in vitro to 33, 36, 39 and 42°C. In vitro heating augmented plasma or ‘bathing solution’ ATP in whole blood and RBC samples, but not in either isolated plasma or serum samples. Heat-induced ATP release was blocked by niflumic acid and glibenclamide, but was not affected by inhibitors of nucleoside transport or anion exchange. Heating blood to 42°C enhanced (P < 0.05) membrane protein abundance of cystic fibrosis transmembrane conductance regulator (CFTR) in RBCs. In a parallel in vivo study in humans exposed to whole-body heating at rest and during exercise, increases in muscle temperature from 35 to 40°C correlated strongly with elevations in arterial plasma ATP (r2 = 0.91; P = 0.0001), but not with femoral venous plasma ATP (r2 = 0.61; P = 0.14). In vitro, however, the increase in ATP release from RBCs was similar in arterial and venous samples heated to 39°C. Our findings demonstrate that erythrocyte ATP release is sensitive to physiological increases in temperature, possibly via activation of CFTR-like channels, and suggest that temperature-dependent release of ATP from erythrocytes might be an important mechanism regulating human limb muscle and skin perfusion in conditions that alter blood and tissue temperature.This article is made available through the Brunel Open Access Publishing Fund

Mechanisms of exercise-induced improvements in the contractile apparatus of the mammalian myocardium

One of the main outcomes of aerobic endurance exercise training is the improved maximal oxygen uptake, and this is pivotal to the improved work capacity that follows the exercise training. Improved maximal oxygen uptake in turn is at least partly achieved because exercise training increases the ability of the myocardium to produce a greater cardiac output. In healthy subjects, this has been demonstrated repeatedly over many decades. It has recently emerged that this scenario may also be true under conditions of an initial myocardial dysfunction. For instance, myocardial improvements may still be observed after exercise training in post-myocardial infarction heart failure. In both health and disease, it is the changes that occur in the individual cardiomyocytes with respect to their ability to contract that by and large drive the exercise training-induced adaptation to the heart. Here, we review the evidence and the mechanisms by which exercise training induces beneficial changes in the mammalian myocardium, as obtained by means of experimental and clinical studies, and argue that these changes ultimately alter the function of the whole heart and contribute to the changes in whole-body function

Increased muscle blood supply and transendothelial nutrient and insulin transport induced by food intake and exercise: effect of obesity and ageing.

This review concludes that a sedentary lifestyle, obesity and ageing impair the vasodilator response of the muscle microvasculature to insulin, exercise and VEGF-A and reduce microvascular density. Both impairments contribute to the development of insulin resistance, obesity and chronic age-related diseases. A physically active lifestyle keeps both the vasodilator response and microvascular density high. Intravital microscopy has shown that microvascular units (MVUs) are the smallest functional elements to adjust blood flow in response to physiological signals and metabolic demands on muscle fibres. The luminal diameter of a common terminal arteriole (TA) controls blood flow through up to 20 capillaries belonging to a single MVU. Increases in plasma insulin and exercise/muscle contraction lead to recruitment of additional MVUs. Insulin also increases arteriolar vasomotion. Both mechanisms increase the endothelial surface area and therefore transendothelial transport of glucose, fatty acids (FAs) and insulin by specific transporters, present in high concentrations in the capillary endothelium. Future studies should quantify transporter concentration differences between healthy and at risk populations as they may limit nutrient supply and oxidation in muscle and impair glucose and lipid homeostasis. An important recent discovery is that VEGF-B produced by skeletal muscle controls the expression of FA transporter proteins in the capillary endothelium and thus links endothelial FA uptake to the oxidative capacity of skeletal muscle, potentially preventing lipotoxic FA accumulation, the dominant cause of insulin resistance in muscle fibres

GPS-intervals for registration of habitat choice, movement patterns, growth, and mortality in beef cattle : a preparation for practical tests in Kenya

Tillväxt och dödlighet hos nötboskap kopplat till födobrist, sjukdom och rovdjur är av hög vikt att följa. Framför allt när det gäller extensiva produktionssystem. I denna litteraturstudie undersöks vilka mätintervaller som är lämpligast att nyttja vid GPS-övervakning. GPS-övervakning ger möjlighet att studera hur stor inverkan som köttboskapens miljö har på deras habitatval samt rörelsemönster. Litteraturstudien undersöker även hur habitatet och miljön påverkar djurens tillväxt samt dödlighet. Här diskuteras olika betsstrategier, rådande system på Ol Pejeta, utmaningar och potentiella lösningar med hjälp av läst material. Litteraturstudien föreslår lämpligt mätintervall utifrån vad målet med själva mätningen är. Resultaten visar att olika intervaller passar för olika ändamål, vilket i korthet besvarar litteraturstudiens frågeställningar. Rör det sig om mätning för tillväxt, dödlighet och aktiv betesplanering lämpar sig korta intervaller. Görs mätningar för att utröna habitatval och rörelsemönster, exempelvis i markbevarande syfte, lämpar sig de längre intervallerna bäst. Detta i en förhoppning om hållbara förhållningsätt i betesplaneringen för både människa och boskap, i samexistens med rovdjur och annat vilt.Growth and mortality in cattle linked to food shortages, disease and predators is of great importance to track. Especially when it comes to extensive production systems. This literature study investigates what intervals seem most suitable to use for GPS monitoring. GPS-surveillance gives the opportunity to monitor how big of an impact the beef cattle’s environment has on their choice of habitat and movement patterns. The literature study also examines how the habitat and environment affect the animals' growth and mortality. Different grazing strategies, existing systems at Ol Pejeta, challenges and potential solutions are discussed here with the help of read material. The literature study suggests a suitable measurement interval based on the goal of the measurement itself. The results show that different intervals are suited for different purposes, which in short answers the questions of the literature study. If the GPS-measuring concerns growth, mortality, and active grazing management the short intervals are suitable. If measurements are for estimating habitat choice and movement patterns of the animals, or for example for soil conservation purposes, the longer intervals are best suited. This is in the hope of sustainable approaches in grazing planning, suited for both humans and livestock, in coexistence with predators and other game

Physics-Based Modeling of Phase-Change Memory Devices and Materials

Artificial intelligence (AI) has become a key enabler in many applications but requires fast and energy-efficient computation. IBM is exploring an “Analog AI acceleration approach using phase change memories (PCM). As such, there is a need to accurately model the physics inside each PCM cell, including the interplay between thermal and electrical dynamics, and the impact of PCM polycrystal grains and grain boundaries in materials such as Ge2Sb2Te5. The thesis uses an existing thermo electrodynamic Technology Computer-Aided Design (TCAD), which was created at IBM, to simulate the intermediate resistance states critical to the “Analog AI application. The thesis discusses the simulations thermal behavior, simulates against industrial tools, and uses the three-dimensional conservation of energy to confirm the requirement of a TCAD tool. As an accurate thermal simulator, the thesis continues to discuss and implement Poole Frenkel to simulate against experimental PCM device data. Thereafter, it discusses the complication of chalcogenide material and the impact of the polycrystalline electrical impact of grain boundaries. The availability of an accurate TCAD simulation is expected to have significant impact on the understanding and design of future Analog AI systems