Consistent declines in aquatic biodiversity across diverse domains of life in rivers impacted by surface coal mining.

The rivers of Appalachia (United States) are among the most biologically diverse freshwater ecosystems in the temperate zone and are home to numerous endemic aquatic organisms. Throughout the Central Appalachian ecoregion, extensive surface coal mines generate alkaline mine drainage that raises the pH, salinity, and trace element concentrations in downstream waters. Previous regional assessments have found significant declines in stream macroinvertebrate and fish communities after draining these mined areas. Here, we expand these assessments with a more comprehensive evaluation across a broad range of organisms (bacteria, algae, macroinvertebrates, all eukaryotes, and fish) using high-throughput amplicon sequencing of environmental DNA (eDNA). We collected water samples from 93 streams in Central Appalachia (West Virginia, United States) spanning a gradient of mountaintop coal mining intensity and legacy to assess how this land use alters downstream water chemistry and affects aquatic biodiversity. For each group of organisms, we identified the sensitive and tolerant taxa along the gradient and calculated stream specific conductivity thresholds in which large synchronous declines in diversity were observed. Streams below mining operations had steep declines in diversity (-18 to -41%) and substantial shifts in community composition that were consistent across multiple taxonomic groups. Overall, large synchronous declines in bacterial, algal, and macroinvertebrate communities occurred even at low levels of mining impact at stream specific conductivity thresholds of 150-200 µS/cm that are substantially below the current U.S. Environmental Protection Agency aquatic life benchmark of 300 µS/cm for Central Appalachian streams. We show that extensive coal surface mining activities led to the extirpation of 40% of biodiversity from impacted rivers throughout the region and that current water quality criteria are likely not protective for many groups of aquatic organisms.

Contaminant Subsidies to Riparian Food Webs in Appalachian Streams Impacted by Mountaintop Removal Coal Mining.

Selenium is highly elevated in Appalachian streams and stream organisms that receive alkaline mine drainage from mountaintop removal coal mining compared to unimpacted streams in the region. Adult aquatic insects can be important vectors of waterborne contaminants to riparian food webs, yet pathways of Se transport and exposure of riparian organisms are poorly characterized. We investigated Se concentrations in stream and riparian organisms to determine whether mining extent increased Se uptake in stream biofilms and insects and if these insects were effective Se biovectors to riparian spiders. Biofilm Se concentration increased (p = 0.006) with mining extent, reaching a maximum value of 16.5 µg/g of dw. Insect and spider Se increased with biofilm Se (p = 0.004, p = 0.003), reaching 95 and 26 µg/g of dw, respectively, in mining-impacted streams. Adult insect biomass was not related to mining extent or Se concentrations in biofilm. Even though Se concentrations in aquatic insects were significantly and positively related to mining extent, aquatic insect Se flux was not associated with mining extent because the mass of emerging insects did not change appreciably over the mining gradient. Insect and spider Se concentrations were among the highest reported in the literature, regularly exceeding the bird Se dietary risk threshold of 5 µg/g of dw. Risks of Se exposure and toxicity related to mining are thus not constrained to aquatic systems but extend to terrestrial habitats and food webs.

Impact of Short-Term Creatine Supplementation on Muscular Performance among Breast Cancer Survivors.

Breast cancer (BC) is one of the most common cancers in the United States. Advances in detection and treatment have resulted in an increased survival rate, meaning an increasing population experiencing declines in muscle mass and strength. Creatine supplementation has consistently demonstrated improvements in strength and muscle performance in older adults, though these findings have not been extended to cancer populations. PURPOSE: The purpose of this study was to investigate the effects of short-term creatine supplementation on muscular performance in BC survivors. METHODS: Using a double-blind, placebo-controlled, randomized design, 19 female BC survivors (mean ± SD age = 57.63 ± 10.77 years) were assigned to creatine (SUPP) (n = 9) or dextrose placebo (PLA) (n = 10) groups. The participants completed two familiarization sessions, then two test sessions, each separated by 7 days, where the participants supplemented with 5 g of SUPP or PLA 4 times/day between sessions. The testing sessions included sit-to-stand power, isometric/isokinetic peak torque, and upper/lower body strength via 10 repetition maximum (10RM) tests. The interaction between supplement (SUPP vs. PLA) and time (Pre vs. Post) was examined using a group × time ANOVA and effect sizes. RESULTS: No significant effects were observed for sit-to-stand power (p = 0.471; ηp2 = 0.031), peak torque at 60°/second (p = 0.533; ηp2 = 0.023), peak torque at 120°/second (p = 0.944; ηp2 < 0.001), isometric peak torque (p = 0.905; ηp2 < 0.001), 10RM chest press (p = 0.407; ηp2 = 0.041), and 10RM leg extension (p = 0.932; ηp2 < 0.001). However, a large effect size for time occurred for the 10RM chest press (ηp2 = 0.531) and leg extension (ηp2 = 0.422). CONCLUSION: Seven days of creatine supplementation does not influence muscular performance among BC survivors.

Considerations for designing trials targeting muscle dysfunction in exercise oncology.

Individuals diagnosed with cancer commonly experience a significant decline in muscle mass and physical function collectively referred to as cancer related muscle dysfunction. This is concerning because impairments in functional capacity are associated with an increased risk for the development of disability and subsequent mortality. Notably, exercise offers a potential intervention to combat cancer related muscle dysfunction. Despite this, research is limited on the efficacy of exercise when implemented in such a population. Thus, the purpose of this mini review is to offer critical considerations for researchers seeking to design studies pertaining to cancer related muscle dysfunction. Namely, 1) defining the condition of interest, 2) determining the most appropriate outcome and methods of assessment, 3) establishing the best timepoint (along the cancer continuum) to intervene, and 4) understanding how exercise prescription can be configured to optimize outcomes.

Passive mechanical properties of the left ventricular myocardium and extracellular matrix in hearts with chronic volume overload from mitral regurgitation.

Cardiac volume overload from mitral regurgitation (MR) is a trigger for left ventricular dilatation, remodeling, and ultimate failure. While the functional and structural adaptations to this overload are known, the adaptation of myocardial mechanical properties remains unknown. Using a rodent model of MR, in this study, we discern changes in the passive material properties of the intact and decellularized myocardium. Eighty Sprague-Dawley rats (350-400 g) were assigned to two groups: (1) MR (n = 40) and (2) control (n = 40). MR was induced in the beating heart by perforating the mitral leaflet with a 23G needle, and rats were terminated at 2, 10, 20, or 40 weeks (n = 10/time-point). Echocardiography was performed at baseline and termination, and explanted hearts were used for equibiaxial mechanical testing of the intact myocardium and after decellularization. Two weeks after inducing severe MR, the myocardium was more extensible compared to control, however, stiffness and extensibility of the extracellular matrix did not differ from control at this timepoint. By 20 weeks, the myocardium was stiffer with a higher elastic modulus of 1920 ± 246 kPa, and a parallel rise in extracellular matrix stiffness. Despite some matrix stiffening, it only contributed to 31% and 36% of the elastic modulus of the intact tissue in the circumferential and longitudinal directions. At 40 weeks, similar trends of increasing stiffness were observed, but the contribution of extracellular matrix remained relatively low. Chronic MR induces ventricular myocardial stiffening, which seems to be driven by the myocyte compartment of the muscle, and not the extracellular matrix.

Ecosystem modification and network position impact insect-mediated contaminant fluxes from a mountaintop mining-impacted river network.

Aquatic-terrestrial contaminant transport via emerging aquatic insects has been studied across contaminant classes and aquatic ecosystems, but few studies have quantified the magnitude of these insect-mediated contaminant fluxes, limiting our understanding of their drivers. Using a recent conceptual model, we identified watershed mining extent, settling ponds, and network position as potential drivers of selenium (Se) fluxes from a mountaintop coal mining-impacted river network. Mining extent drove insect Se concentration (p = 0.008, R2 = 0.406), but ponding and network position were the principal drivers of Se flux through their impact on insect production. Se fluxes were 18 times higher from ponded, mined tributaries than from unponded ones and were comparable to fluxes from larger, productive mainstem sites. Thus, contaminant fluxes were highest in the river mainstem or below ponds, indicating that without considering controls on insect production, contaminant fluxes and their associated risks for predators like birds and bats can be misestimated.

Use of the distress thermometer to evaluate symptoms, outcome and satisfaction in a specialist psycho-oncology service.

OBJECTIVE: The National Institute for Health and Care Excellence recommends the use of structured tools to improve holistic care for patients with cancer. The Distress Thermometer and Problem Checklist (DT) is commonly used for screening in physical health settings. However, it has not been integrated into the clinical pathway within specialist psycho-oncology services. We used the DT to examine the broad clinical effectiveness of psycho-oncology intervention and to ascertain factors from the DT linked to an improved outcome. We also evaluated patients' satisfaction with their care. METHOD: We asked 111 adult outpatients referred to York Psycho-Oncology Service to complete the DT at their first appointment. Individuals offered a period of psycho-oncology care re-rated their emotional distress, problems and service satisfaction on the DT at discharge. RESULTS: Median distress scores decreased significantly (from 6 to 4, Wilcoxon's z = -4.83, P < .001) indicating a large clinical effect size (Cohen's d = 1.22). Frequency of emotional problems (anxiety, depression and anger) fell significantly by 15-24% despite no significant change in patients' physical health or practical problems. Number of emotional problems was the best predictor of distress at discharge (beta = 0.468, P = .002). Satisfaction was high and correlated with lower distress scores (r = -0.42, P = .005) and fewer emotional problems (r = -0.31, P = .04) at discharge but not with number of appointments attended. Qualitative thematic analysis showed patients particularly value supportive listening and advice on coping strategies from professionals independent of their physical care. CONCLUSION: The DT is an acceptable and useful tool for enhancing the delivery of structured psycho-oncology care. It may also provide evidence to support the effectiveness of specialist psycho-oncology interventions.

BMP signaling in wing development: A critical perspective on quantitative image analysis.

Bone Morphogenetic Proteins (BMPs) are critical for pattern formation in many animals. In numerous tissues, BMPs become distributed in spatially non-uniform profiles. The gradients of signaling activity can be detected by a number of biological assays involving fluorescence microscopy. Quantitative analyses of BMP gradients are powerful tools to investigate the regulation of BMP signaling pathways during development. These approaches rely heavily on images as spatial representations of BMP activity levels, using them to infer signaling distributions that inform on regulatory mechanisms. In this perspective, we discuss current imaging assays and normalization methods used to quantify BMP activity profiles with a focus on the Drosophila wing primordium. We find that normalization tends to lower the number of samples required to establish statistical significance between profiles in controls and experiments, but the increased resolvability comes with a cost. Each normalization strategy makes implicit assumptions about the biology that impacts our interpretation of the data. We examine the tradeoffs for normalizing versus not normalizing, and discuss their impacts on experimental design and the interpretation of resultant data.