The physiological impact of high?intensity interval training in octogenarians with comorbidities

BackgroundDeclines in cardiorespiratory fitness (CRF) and fat-free mass (FFM) with age are linked to mortality, morbidity and poor quality of life. High-intensity interval training (HIIT) has been shown to improve CRF and FFM in many groups, but its efficacy in the very old, in whom comorbidities are present is undefined. We aimed to assess the efficacy of and physiological/metabolic responses to HIIT, in a cohort of octogenarians with comorbidities (e.g. hypertension and osteoarthritis).MethodsTwenty-eight volunteers (18 men, 10 women, 81.2 ± 0.6 years, 27.1 ± 0.6 kg·m−2) with American Society of Anaesthesiology (ASA) Grade 2–3 status each completed 4 weeks (12 sessions) HIIT after a control period of equal duration. Before and after each 4 week period, subjects underwent body composition assessments and cardiopulmonary exercise testing. Quadriceps muscle biopsies (m. vastus lateralis) were taken to quantify anabolic signalling, mitochondrial oxidative phosphorylation, and cumulative muscle protein synthesis (MPS) over 4-weeks.ResultsIn comorbid octogenarians, HIIT elicited improvements in CRF (anaerobic threshold: +1.2 ± 0.4 ml·kg−1·min−1, P = 0.001). HIIT also augmented total FFM (47.2 ± 1.4 to 47.6 ± 1.3 kg, P = 0.04), while decreasing total fat mass (24.8 ± 1.3 to 24 ± 1.2 kg, P = 0.0002) and body fat percentage (33.1 ± 1.5 to 32.1 ± 1.4%, P = 0.0008). Mechanistically, mitochondrial oxidative phosphorylation capacity increased after HIIT (i.e. citrate synthase activity: 52.4 ± 4 to 67.9 ± 5.1 nmol·min−1·mg−1, P = 0.005; membrane protein complexes (C): C-II, 1.4-fold increase, P = 0.002; C-III, 1.2-fold increase, P = 0.03), as did rates of MPS (1.3 ± 0.1 to 1.5 ± 0.1%·day−1, P = 0.03). The increase in MPS was supported by up-regulated phosphorylation of anabolic signalling proteins (e.g. AKT, p70S6K, and 4E-BP1; all P < 0.05). There were no changes in any of these parameters during the control period. No adverse events were reported throughout the study.ConclusionsThe HIIT enhances skeletal muscle mass and CRF in octogenarians with disease, with up-regulation of MPS and mitochondrial capacity likely underlying these improvements. HIIT can be safely delivered to octogenarians with disease and is an effective, time-efficient intervention to improve muscle mass and physical function in a short time frame

Nuclear isobar separation for Penning trap mass measurements at TRIUMF

Nuclear mass values are an important experimental input for research in nuclear theory, astrophysics, and fundamental symmetries. Penning trap experiments such as TRIUMF’s Ion Trap for Atomic and Nuclear Science (TITAN) have produced the most precise mass values available for many exotic nuclei. TITAN has measured masses for nuclei with half-lives as short as 8 ms with a relative precision down to 10 −8 . TITAN has recently installed a multiple reflection time of flight (MR-ToF) mass separator to isolate rare isotopes for mass measurements even when they are obscured by intense isobaric backgrounds. The MR-ToF can act as a mass filter, producing isobarically pure samples, and it can also operate as a mass spectrometer, destroying a sample to rapidly produce a mass spectrum of an entire ion beam. In the following I provide a pedagogical introduction to the operating principles of the system and report on the results of initial commissioning

Improving environmental odor measurements: comparison of lab-based standard method and portable odor measurement technology

Current standard odor measurement methods are lab-based and require substantial investment in hardware, sample collection, training, and maintenance. Odor samples must be collected in the field using bags and brought to the lab to test. This can be a time-consuming process, with the possibility of the sample loss. The actual odor measurements are based on dilution olfactometry, embodied in the AC’SCENT® International Olfactometer, following the ASTM E679-04 standard. In recent years a portable olfactometer, the Scentroid SM100i, has been developed for odor measurements. The portable olfactometer has many advantages over lab-based standard method, especially the lower cost-per-sample. However, very little is known about the performance and reliability of portable olfactometer where the dilutions are controlled with orifices in metallic plates. It is important to evaluate the Scentroid SM100i accuracy to determine the usefulness of using it as a comparable technology for odor measurements. The main objective of this research is to compare the performance of the lab-based ASTM E679-04 method with portable odor measurement technology. Specific objectives include: (1) determining the accuracy of the dilution ratios specified by the manufacturer of both the AC’SCENT International Olfactometer and the Scentroid SM100i; (2) comparing results between olfactometers using n-butanol, a commonly used standard gas in the olfactometry field, and (3) determining the accuracy of odor measurement using real odor samples collected from livestock farms in Iowa. The AC’SCENT olfactometer had an average percent error between the factory specifications and measured dilution ratios of 5.23% compared with 14.1% for Scentroid SM100i (using plate i-2 with dilution range most comparable to the AC’SCENT olfactometer). The use of other dilution plates resulted in average percent errors ranging from 9.68% to 25.31%. The Scentroid SM100i deviated from the manufacturer specifications for flowrates and dilution ratios, but these flowrates were generally consistent with each dilution setting. Overall, the Scentroid SM100i overestimated the odor concentrations with the mean difference of 22.9% (ranging from 0.95% to 93.34%). When the post-measurement adjustment using dilution correction was made, the mean percent average difference was 11.8%.This article is published as Maurer, Devin L., Alexandrea M. Bragdon, Brandon C. Short, Heekwon Ahn, and Jacek A. Koziel. "Improving environmental odor measurements: comparison of lab-based standard method and portable odor measurement technology." Archives of Environmental Protection 44, no. 2 (2018): 100-107. DOI: 10.24425/119699. Posted with permission.</p

Clade age and diversification rate variation explain disparity in species richness among water scavenger beetle (Hydrophilidae) lineages.

Explaining the disparity of species richness across the tree of life is one of the great challenges in evolutionary biology. Some lineages are exceptionally species rich, while others are relatively species poor. One explanation for heterogeneity among clade richness is that older clades are more species rich because they have had more time to accrue diversity than younger clades. Alternatively, disparity in species richness may be due to among-lineage diversification rate variation. Here we investigate diversification in water scavenger beetles (Hydrophilidae), which vary in species richness among major lineages by as much as 20 fold. Using a time-calibrated phylogeny and comparative methods, we test for a relationship between clade age and species richness and for shifts in diversification rate in hydrophilids. We detected a single diversification rate increase in Megasternini, a relatively young and species rich clade whose diversity might be explained by the stunning diversity of ecological niches occupied by this clade. We find that Amphiopini, an old clade, is significantly more species poor than expected, possibly due to its restricted geographic range. The remaining lineages show a correlation between species richness and clade age, suggesting that both clade age and variation in diversification rates explain the disparity in species richness in hydrophilids. We find little evidence that transitions between aquatic, semiaquatic, and terrestrial habitats are linked to shifts in diversification rates

Distribution of habitat types across the major clades of water scavenger beetles.

<p>Distribution of habitat types across the major clades of water scavenger beetles.</p

Time-calibrated phylogeny for major lineages of Hydrophilidae, along with estimated species richness values.

<p>The star indicates the location of the diversification rate increase determined by our MEDUSA analysis.</p