Tracing Water Sources of Terrestrial Animal Populations with Stable Isotopes: Laboratory Tests with Crickets and Spiders

Fluxes of carbon, nitrogen, and water between ecosystem components and organisms have great impacts across levels of biological organization. Although much progress has been made in tracing carbon and nitrogen, difficulty remains in tracing water sources from the ecosystem to animals and among animals (the “water web”). Naturally occurring, non-radioactive isotopes of hydrogen and oxygen in water provide a potential method for tracing water sources. However, using this approach for terrestrial animals is complicated by a change in water isotopes within the body due to differences in activity of heavy and light isotopes during cuticular and transpiratory water losses. Here we present a technique to use stable water isotopes to estimate the mean mix of water sources in a population by sampling a group of sympatric animals over time. Strong correlations between H and O isotopes in the body water of animals collected over time provide linear patterns of enrichment that can be used to predict a mean mix of water sources useful in standard mixing models to determine relative source contribution. Multiple temperature and humidity treatment levels do not greatly alter these relationships, thus having little effect on our ability to estimate this population-level mix of water sources. We show evidence for the validity of using multiple samples of animal body water, collected across time, to estimate the isotopic mix of water sources in a population and more accurately trace water sources. The ability to use isotopes to document patterns of animal water use should be a great asset to biologists globally, especially those studying drylands, droughts, streamside areas, irrigated landscapes, and the effects of climate change

The impact of viral mutations on recognition by SARS-CoV-2 specific T cells.

We identify amino acid variants within dominant SARS-CoV-2 T cell epitopes by interrogating global sequence data. Several variants within nucleocapsid and ORF3a epitopes have arisen independently in multiple lineages and result in loss of recognition by epitope-specific T cells assessed by IFN-γ and cytotoxic killing assays. Complete loss of T cell responsiveness was seen due to Q213K in the A∗01:01-restricted CD8+ ORF3a epitope FTSDYYQLY207-215; due to P13L, P13S, and P13T in the B∗27:05-restricted CD8+ nucleocapsid epitope QRNAPRITF9-17; and due to T362I and P365S in the A∗03:01/A∗11:01-restricted CD8+ nucleocapsid epitope KTFPPTEPK361-369. CD8+ T cell lines unable to recognize variant epitopes have diverse T cell receptor repertoires. These data demonstrate the potential for T cell evasion and highlight the need for ongoing surveillance for variants capable of escaping T cell as well as humoral immunity.This work is supported by the UK Medical Research Council (MRC); Chinese Academy of Medical Sciences(CAMS) Innovation Fund for Medical Sciences (CIFMS), China; National Institute for Health Research (NIHR)Oxford Biomedical Research Centre, and UK Researchand Innovation (UKRI)/NIHR through the UK Coro-navirus Immunology Consortium (UK-CIC). Sequencing of SARS-CoV-2 samples and collation of data wasundertaken by the COG-UK CONSORTIUM. COG-UK is supported by funding from the Medical ResearchCouncil (MRC) part of UK Research & Innovation (UKRI),the National Institute of Health Research (NIHR),and Genome Research Limited, operating as the Wellcome Sanger Institute. T.I.d.S. is supported by a Well-come Trust Intermediate Clinical Fellowship (110058/Z/15/Z). L.T. is supported by the Wellcome Trust(grant number 205228/Z/16/Z) and by theUniversity of Liverpool Centre for Excellence in Infectious DiseaseResearch (CEIDR). S.D. is funded by an NIHR GlobalResearch Professorship (NIHR300791). L.T. and S.C.M.are also supported by the U.S. Food and Drug Administration Medical Countermeasures Initiative contract75F40120C00085 and the National Institute for Health Research Health Protection Research Unit (HPRU) inEmerging and Zoonotic Infections (NIHR200907) at University of Liverpool inpartnership with Public HealthEngland (PHE), in collaboration with Liverpool School of Tropical Medicine and the University of Oxford.L.T. is based at the University of Liverpool. M.D.P. is funded by the NIHR Sheffield Biomedical ResearchCentre (BRC – IS-BRC-1215-20017). ISARIC4C is supported by the MRC (grant no MC_PC_19059). J.C.K.is a Wellcome Investigator (WT204969/Z/16/Z) and supported by NIHR Oxford Biomedical Research Centreand CIFMS. The views expressed are those of the authors and not necessarily those of the NIHR or MRC

Is it safe and efficacious for women with lymphedema secondary to breast cancer to lift heavy weights during exercise: a randomised controlled trial

Purpose: Resistance exercise has great potential to aid in the management of breast cancer-related lymphedema (BCRL); however, little is known regarding optimal exercise prescription. The pervasive view is that resistance exercise with heavy loads may be contraindicated, disregarding the dose-response relationship that exists between the load utilised in resistance exercise and the magnitude of structural and functional improvements. No previous research has examined various resistance exercise prescriptions for the management of BCRL. This study compared the effects of high load and low load resistance exercise on the extent of swelling, severity of symptoms, physical function and quality of life in women with BCRL. Methods: Sixty-two women with a clinical diagnosis of BCRL (\u3e5 % inter-limb discrepancy) were randomly assigned to a high-load resistance exercise (n = 22), low-load resistance exercise (n = 21) or usual care (n = 19) group. Participants in the experimental groups completed a 3-month moderate- to high-intensity resistance exercise program in which the load of the exercises was manipulated from 10-6 repetition maximum (75-85 % of one repetition maximum [1RM]) for the high-load group or from 20-15 repetition maximum (55-65 % 1RM) for the low-load group. Outcome measures included the extent of swelling in the affected arm, symptom severity, physical function and quality of life. Results: There were no differences between groups in the extent of affected arm swelling or severity of symptoms. The change in muscle strength, muscle endurance and quality of life-physical functioning was significantly greater in both high-load and low-load groups compared with the control group (p \u3c 0.040). Change in quality of life-physical function was significantly associated with the change in symptom severity and muscle strength. No lymphedema exacerbations or other adverse events occurred during this trial. Conclusion: Women with BCRL can safely lift heavy weights during upper body resistance exercise without fear of lymphedema exacerbation or increased symptom severity. Implications for Cancer Survivors: Women with breast cancer-related lymphedema can be informed that appropriately prescribed and supervised upper body resistance exercise is safe and can aid in the management of lymphedema through improvements in physical function and quality of life

Acute whole-body vibration elicits post-activation potentiation

Whole-body vibration (WBV) leads to a rapid increase in intra-muscular temperature and enhances muscle power. The power-enhancing effects by WBV can, at least in part, be explained by intra-muscular temperature. However, this does not exclude possible neural effects of WBV occurring at the spinal level. The aim of this study was to examine if muscle twitch and patellar reflex properties were simultaneously potentiated from an acute bout of WBV in a static squat position. Six male and six female athletes performed three interventions for 5 min, static squat with WBV (WBV+, 26 Hz), static squat without WBV (WBV−) and stationary cycling (CYCL, 70 W). Transcutaneous muscle stimulation consisting of a single 200 μs pulse and three patellar tendon taps were administered prior to and then 90 s, 5, 10 min post-intervention. Ninety-seconds after WBV+ muscle twitch peak force (PF) and rate of force development (RFD) were significantly higher (P < 0.01) compared to WBV− and CYCL. However the patellar tendon reflex was not potentiated. An acute continuous bout of WBV caused a post-activation potentiation (PAP) of muscle twitch potentiation (TP) compared to WBV− and CYCL indicating that a greater myogenic response was evident compared to a neural-mediated effect of a reflex potentiation (RP)