THE INFLUENCE OF SPEED ON PATELLOFEMORAL JOINT KINETICS IN RECREATIONAL RUNNERS

This study aimed to determine the influence of running speed on patellofemoral joint (PFJ) kinetics. Twenty recreational runners ran on an instrumented treadmill at four running speeds with simultaneous 3D motion capture. A musculoskeletal model derived peak and cumulative (per 1km of continuous running) PFJ force and stress for each speed. Peak PFJ force and stress significantly increased with faster speeds. In contrast, cumulative PFJ measures decreased with faster speeds. Running at faster speeds increases the magnitude of peak PFJ kinetics but conversely results in less accumulated force over a set distance. Clinicians and coaches should be aware of the relatively high PFJ cumulative force and stress associated with slow running (~2.5 m/s) and consider moderate-speed interval running as part of overuse knee injury prevention and management plans

Metabolomic profiles are gender, disease and time specific in the interleukin-10 gene-deficient mouse model of inflammatory bowel disease.

Metabolomic profiling can be used to study disease-induced changes in inflammatory bowel diseases (IBD). The aim of this study was to investigate the difference in the metabolomic profile of males and females as they developed IBD. Using the IL-10 gene-deficient mouse model of IBD and wild-type mice, urine at age 4, 6, 8, 12, 16, and 20 weeks was collected and analyzed by nuclear magnetic resonance (NMR) spectroscopy. Multivariate data analysis was employed to assess differences in metabolomic profiles that occurred as a consequence of IBD development and severity (at week 20). These changes were contrasted to those that occurred as a consequence of gender. Our results demonstrate that both IL-10 gene-deficient and wild-type mice exhibit gender-related changes in urinary metabolomic profile over time. Some male-female separating metabolites are common to both IL-10 gene-deficient and control wild-type mice and, therefore, appear to be related predominantly to gender maturation. In addition, we were able to identify gender-separating metabolites that are unique for IL-10 gene-deficient and wild-type mice and, therefore, may be indicative of a gender-specific involvement in the development and severity of the intestinal inflammation. The comparison of the gender-separating metabolomic profile from IL-10 gene-deficient mice and wild-type mice during the development of IBD allowed us to identify changes in profile patterns that appear to be imperative in the development of intestinal inflammation, but yet central to gender-related differences in IBD development. The knowledge of metabolomic profile differences by gender and by disease severity has potential clinical implications in the design of both biomarkers of disease as well as the development of optimal therapies

Recovery from bleaching is mediated by threshold densities of background thermo-tolerant symbiont types in a reef-building coral

Sensitive molecular analyses show that most corals host a complement of Symbiodinium genotypes that includes thermotolerant types in low abundance. While tolerant symbiont types are hypothesized to facilitate tolerance to temperature and recovery from bleaching, empirical data on their distribution and relative abundance in corals under ambient and stress conditions are still rare. We quantified visual bleaching and mortality of coral hosts, along with relative abundance of C- and D-type Symbiodinium cells in 82 Acropora millepora colonies from three locations on the Great Barrier Reef transplanted to a central inshore site over a 13 month period. Our analyses reveal dynamic change in symbiont associations within colonies and among populations over time. Coral bleaching and declines in C-but not D-type symbionts were observed in transplanted corals. Survival and recovery of 25% of corals from one population was associated with either initial D-dominance or an increase in D-type symbionts that could be predicted by a minimum pre-stress D:C ratio of 0.003. One-third of corals from this population became D dominated at the bleached stage despite no initial detection of this symbiont type, but failed to recover and died in mid to late summer. These results provide a predictive threshold minimum density of background D-type symbionts in A. millepora, above which survival following extreme thermal stress is increased

Recovery from bleaching is mediated by threshold densities of background thermo-tolerant symbiont types in a reef-building coral

Sensitive molecular analyses show that most corals host a complement of Symbiodinium genotypes that includes thermotolerant types in low abundance. While tolerant symbiont types are hypothesized to facilitate tolerance to temperature and recovery from bleaching, empirical data on their distribution and relative abundance in corals under ambient and stress conditions are still rare. We quantified visual bleaching and mortality of coral hosts, along with relative abundance of C- and D-type Symbiodinium cells in 82 Acropora millepora colonies from three locations on the Great Barrier Reef transplanted to a central inshore site over a 13 month period. Our analyses reveal dynamic change in symbiont associations within colonies and among populations over time. Coral bleaching and declines in C-but not D-type symbionts were observed in transplanted corals. Survival and recovery of 25% of corals from one population was associated with either initial D-dominance or an increase in D-type symbionts that could be predicted by a minimum pre-stress D:C ratio of 0.003. One-third of corals from this population became D dominated at the bleached stage despite no initial detection of this symbiont type, but failed to recover and died in mid to late summer. These results provide a predictive threshold minimum density of background D-type symbionts in A. millepora, above which survival following extreme thermal stress is increased

Does regular exercise reduce the pain and stiffness of osteoarthritis?

Exercise helps reduce the pain, but it's unclear whether it helps with stiffness. Exercise moderately reduces pain in elderly patients with osteoarthritis (strength of recommendation [SOR]: A, 3 systematic reviews, including high-quality studies) and has a small effect on reducing self-reported disability (SOR: B, 2 systematic reviews, including reviews of smaller studies). No studies have evaluated the effect of exercise on stiffness

Sequential fishways reconnect a coastal river

River regulation infrastructure has been implicated in worldwide aquatic biodiversity loss. Instream barriers such as weirs prevent fish migration and the impact can be particularly severe for diadromous species. Fishways are frequently installed on in-stream barriers to reconnect migratory pathways and rehabilitate diadromous populations. We monitored a coastal fish community’s response to fish passage restoration at ten predominantly low-level weirs in the lowland reaches of the Nepean River in south-eastern Australia. Pre-fishways, there was a gradient of reduced species diversity in an upstream direction including the absence of many diadromous species, despite the regular inundation frequency of most weirs. Post-fishways, species diversity was still greater in the downstream monitoring sites; however, there was evidence of a positive change in fish community structure from upstream sites. Most notably, three diadromous species rapidly expanded their distribution upstream and one amphidromous species expanded its downstream distribution. This study demonstrates appropriately designed successive fishways can successfully reconnect river systems for an entire fish community, encompassing species with a broad range of swimming abilities and diverse life histories

Diabetes and corneal endothelial cell characteristics: a study based on Eye Bank data

The aim of the article is to determine whether corneal endothelial cell density and other characteristics, such as cell area, pleomorphism and polymegathism, are affected by diabetes. Corneal endothelial cell density and other characteristics of donor eyes collected during 2007 and 2008 in a local Eye Bank were measured by the HAI Eyebank Specular Microscope System. Adult donors aged 21 or older who consented to research were divided into healthy versus compromised eye-status groups based on eye disease or past eye surgeries. Differences in corneal measures between diabetic and non-diabetic subjects were analyzed separately in each group via Mixed Models ANCOVA, with Diabetes as the fixed effect, Donor as the random effect, and Age as the continuous covariate. A total of 253 subjects met study criteria, of which 81 (32%) had diabetes. In the 180 subjects with healthy eye status, the medians (ranges) of age were 62 (29-78) years among 52 diabetics (29%), versus 57 (21-79) years among non-diabetics (P=0.013). In the 73 subjects with compromised eye status, the medians (ranges) of age were 70 (32-78) years among 29 diabetics (40%), versus 70 (29-79) years among nondiabetics (P=0.77). Between diabetics and non-diabetics, eye disease and past eye surgeries were well-balanced in the compromised eye-status group, while race and sex were wellbalanced in both eye-status groups. Results from separate analyses on the two groups indicated that diabetes did not affect corneal cell density or other corneal-cell characteristics analyzed. Even though diabetics constituted a large percentage of the Eye Bank donor population, this disease did not have a statistically significant impact on corneal endothelial cell density, cell area, pleomorphism or polymegathism