Dose Response of a Novel Exogenous Ketone Supplement on Physiological, Perceptual and Performance Parameters

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Five decades of radioglaciology

Radar sounding is a powerful geophysical approach for characterizing the subsurface conditions of terrestrial and planetary ice masses at local to global scales. As a result, a wide array of orbital, airborne, ground-based, and in situ instruments, platforms and data analysis approaches for radioglaciology have been developed, applied or proposed. Terrestrially, airborne radar sounding has been used in glaciology to observe ice thickness, basal topography and englacial layers for five decades. More recently, radar sounding data have also been exploited to estimate the extent and configuration of subglacial water, the geometry of subglacial bedforms and the subglacial and englacial thermal states of ice sheets. Planetary radar sounders have observed, or are planned to observe, the subsurfaces and near-surfaces of Mars, Earth's Moon, comets and the icy moons of Jupiter. In this review paper, and the thematic issue of the Annals of Glaciology on ‘Five decades of radioglaciology’ to which it belongs, we present recent advances in the fields of radar systems, missions, signal processing, data analysis, modeling and scientific interpretation. Our review presents progress in these fields since the last radio-glaciological Annals of Glaciology issue of 2014, the context of their history and future prospects

Low and High Carbohydrate Diets on Performance, Metabolism and Cardiometabolic Health in Middle-Aged Athletes

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Variable relationship between accumulation and temperature in West Antarctica for the past 31,000 years

The Antarctic contribution to sea level is a balance between ice loss along the margin and accumulation in the interior. Accumulation records for the past few decades are noisy and show inconsistent relationships with temperature. We investigate the relationship between accumulation and temperature for the past 31 ka using high-resolution records from the West Antarctic Ice Sheet (WAIS) Divide ice core in West Antarctica. Although the glacial-interglacial increases result in high correlation and moderate sensitivity for the full record, the relationship shows considerable variability through time with high correlation and high sensitivity for the 0–8 ka period but no correlation for the 8–15 ka period. This contrasts with a general circulation model simulation which shows homogeneous sensitivities between temperature and accumulation across the entire time period. These results suggest that variations in atmospheric circulation are an important driver of Antarctic accumulation but they are not adequately captured in model simulations. Model-based projections of future Antarctic accumulation, and its impact on sea level, should be treated with caution

Concentration-Dependent Effects of a Dietary Ketone Ester on Components of Energy Balance in Mice

Exogenous ketones may provide therapeutic benefit in treatment of obesity. Administration of the ketone ester (KE) R,S-1,3-butanediol acetoacetate diester (BD-AcAc) decreases body weight in mice, but effects on energy balance have not been extensively characterized. The purpose of this investigation was to explore concentration-dependent effects of BD-AcAc on energy intake and expenditure in mice. Forty-two male C57BL/6J mice were randomly assigned to one of seven isocaloric diets ( = 6 per group): (1) Control (CON, 0% KE by kcals); (2) KE5 (5% KE); (3) KE10 (10% KE); (4) KE15 (15% KE); (5) KE20 (20% KE); (6) KE25 (25% KE); and (7) KE30 (30% KE) for 3 weeks. Energy intake and body weight were measured daily. Fat mass (FM), lean body mass (LBM), and energy expenditure (EE) were measured at completion of the study. Differences among groups were compared to CON using ANOVA and ANCOVA. Mean energy intake was similar between CON and each concentration of KE, except KE30 which was 12% lower than CON ( \u3c 0.01). KE25 and KE30 had lower body weight and FM compared to CON, while only KE30 had lower LBM ( \u3c 0.03). Adjusted resting and total EE were lower in KE30 compared to CON ( \u3c 0.03), but similar for all other groups. A diet comprised of 30% energy from BD-AcAc results in lower energy intake, coincident with lower body weight and whole animal adiposity; while KE20 and KE25 have significantly lower body weight and adiposity effects independent of changes in energy intake or expenditure

A comprehensive SARS-CoV-2 and COVID-19 review, Part 2: host extracellular to systemic effects of SARS-CoV-2 infection

COVID-19, the disease caused by SARS-CoV-2, has caused significant morbidity and mortality worldwide. The betacoronavirus continues to evolve with global health implications as we race to learn more to curb its transmission, evolution, and sequelae. The focus of this review, the second of a three-part series, is on the biological effects of the SARS-CoV-2 virus on post-acute disease in the context of tissue and organ adaptations and damage. We highlight the current knowledge and describe how virological, animal, and clinical studies have shed light on the mechanisms driving the varied clinical diagnoses and observations of COVID-19 patients. Moreover, we describe how investigations into SARS-CoV-2 effects have informed the understanding of viral pathogenesis and provide innovative pathways for future research on the mechanisms of viral diseases

Prevention and treatment of muscle wasting with ketone supplementation

Methods and compositions for treating or preventing muscle wasting resulting from an underlying disease or disorder, such as cancer cachexia. A therapeutically effective amount of a ketogenic supplementâsuch as R,S 1,3 butanediol diacetoacetate, R,S 1,3-butanediol acetoacetate diester, derivatives thereof, or combinations thereofâis administered to a patient or subject in need. The ketogenic supplement may further include a medium chain triglyceride in combination with the ketone ester

Prevention and treatment of muscle wasting with ketone supplementation

Methods and compositions for treating or preventing muscle wasting resulting from an underlying disease or disorder, such as cancer cachexia. A therapeutically effective amount of a ketogenic supplementâsuch as R,S 1,3 butanediol diacetoacetate, R,S 1,3-butanediol acetoacetate diester, derivatives thereof, or combinations thereofâis administered to a patient or subject in need. The ketogenic supplement may further include a medium chain triglyceride in combination with the ketone ester

Exploring the Viability of Exogenous Ketones as Weight Loss Supplements

Objectives: 70.7% of Americans over 20 years of age are overweight or obese. Currently, the main strategy for weight loss is caloric restriction. Ketone bodies have been shown to facilitate voluntary caloric restriction through altering the appetite stimulating hormone ghrelin. However, these non-toxic ketone bodies have not been evaluated as weight loss supplements. C57BL6J mice were used to determine the weight loss efficacy of exogenous ketones by adding synthetic (R/S 1,3-Butanediol Acetoacetate Diester and 1,3-Butanediol) and natural (Beta-hydroxybutyrate and Beta-hydroxybutyrate + Medium Chain Triglycerides) ketogenic agents to standard rodent chow ab-libitum. Methods: Six groups (R/S 1,3-butanediol acetoacetate diester, 1,3-butanediol, beta-hydroxybutyrate, beta-hydroxybutyrate + medium chain triglycerides, caloric restriction, standard diet ad-libitum) were housed 2–5 animals per cage and monitored to ensure appropriate acclimation prior to intervention. Mice were treated for two weeks with ketogenic agents, adjusting % of agent daily to ensure 20% weight loss was achieved. Results: All ketogenic agents induced weight loss and voluntary caloric restriction. Weight loss for beta-hydroxybutyrate and beta-hydroxybutyrate + medium chain triglycerides was explained by caloric restriction alone. However, R/S 1,3-butanediol acetoacetate diester induced weight loss at lower dosages which could not be explained by caloric restriction alone. Conclusions: Taken together, all ketogenic agents may assist in weight loss. However, R/S 1,3-butanediol acetoacetate diester appears to be a more potent non-toxic ketogenic supplement that facilitates weight loss via both voluntary caloric restriction and caloric restriction-independent mechanisms. Future studies should explore caloric-restriction independent weight loss mechanisms of R/S 1,3-butanediol acetoacetate diester