Jockey Falls, Injuries, and Fatalities Associated With Thoroughbred and Quarter Horse Racing in California, 2007-2011.

BackgroundDespite the popularity of the horse racing industry in the United States and the wide recognition that horse racing is one of the most hazardous occupations, little focused research into the prevention of falls by and injuries to jockeys has been conducted.PurposeTo describe the incidence rates and characteristics of falls and injuries to Thoroughbred and Quarter Horse racing jockeys in the state of California.Study designDescriptive epidemiology study.MethodsData on race-day falls and injuries were extracted from jockey accident reports submitted to the California Horse Racing Board from January 2007 to December 2011. Denominator data, number of jockey race rides, were obtained from commercial and industry databases. Jockey fall, injury, and fatality incidence rates and ratios in Thoroughbred and Quarter Horse flat races were estimated using Poisson regression. Characteristics of falls and injuries are described and compared.ResultsIn Thoroughbred races, 184 jockey injuries occurred from 360 reported jockey falls, 180,646 race rides, 23,500 races, and 3350 race meetings. In Quarter Horse races, 85 jockey injuries occurred from 145 jockey falls, 46,106 race rides, 6320 races, and 1053 race meetings. Jockey falls occurred at a rate of 1.99 falls per 1000 rides in Thoroughbred races, with 51% of falls resulting in jockey injury, and 3.14 falls per 1000 rides in Quarter Horse races, with 59% of falls resulting in jockey injury. The majority of falls occurred during a race, with catastrophic injury or sudden death of the horse reported as the most common cause in both Thoroughbred (29%) and Quarter Horse (44%) races. During the period studied, 1 jockey fatality resulted from a fall. Jockey fall rates were lower but injury rates were comparable to those reported internationally.ConclusionOn average, a licensed jockey in California can expect to have a fall every 502 rides in Thoroughbred races and every 318 rides in Quarter Horse races. While jockey fall rates were lower, injury rates were similar to those in other racing jurisdictions. The high proportion of jockey falls caused by horse fatalities should be further investigated

Relationship Between Historical Lameness, Medication Usage, Surgery, and Exercise With Catastrophic Musculoskeletal Injury in Racehorses

Background: The rate of catastrophic musculoskeletal injuries (CMI) in racehorses is high in the United States compared to other countries. Few modifiable risk factors related to lameness, medication, and surgery history have been identified.Objective: To detect management factors that increase risk of CMI by comparing medical histories between horses that sustained, and horses that did not sustain, a CMI.Study design: Case-control.Methods: Racehorse necropsy data (May 2012-June 2013) were obtained through the California Horse Racing Board Postmortem Program. Attending veterinarians of Thoroughbreds (TB) and Quarter Horses (QH) that experienced CMI, and of three matched control horses, were invited to complete an online veterinary medical history survey. We investigated associations between CMI and lameness, medication, surgery, and exercise history using multivariable logistic regression.Results: There were 146 TB (45 cases, 101 controls) and 17 QH (11 cases, 6 controls) surveys completed. TB cases were more likely to show signs of lameness within the 3 months prior to death compared to controls. A high proportion of both cases (64.3%) and controls (76.8%) were administered medications, but unraced TB case horses were more likely to have been administered systemic medications compared to those that previously raced. TB cases were more likely to have raced with greater intensity during their career, but had eased off in the month preceding CMI. For QHs, there was insufficient power to detect significant differences between cases and controls that showed signs of lameness, or that were administered medications. Surgery history was not associated with CMI.Main limitation: Insufficient power to detect small effect sizes.Conclusions: The study provides information that can be used to aid in identification of horses at high risk for catastrophic injury, and management factors that can be modified to reduce the risk for all horses

Sustaining dancer wellbeing through independent professional dance careers

Dancers dedicate their lives to their art. The lucky few dancers who reach professional careers, must navigate a casualised industry, balance financial pressures and maintain performance fitness. This research aimed to provide practical considerations for dancers to support their health and wellbeing through independent, professional dance careers. Dancers from Australian contemporary dance company Co3 participated in a training program involving psychological and physiotherapy assessments and fitness training in conjunction with a major performance season. Focus groups with company dancers and staff investigated the perceived efficacy of the training program within the company schedule and in supporting dancer wellbeing. Dancers were highly engaged with the training program. Dancers expressed various benefits and challenges in incorporating the training within the demands of their careers. Themes identified from the dancer responses included making time, program specificity, dance fitness, connecting as a company, dancer monitoring and scheduling. A need to maintain collegiality outside of contracted times through communities of practice was identified across many of the themes. It is posited that the human capital of dance is challenged through the casualisation of the dance sector and requires careful attention from aspiring dancers

Sex reversal explains some, but not all, climate-mediated sex ratio variation within a viviparous reptile

Evolutionary transitions in sex-determining systems have occurred frequently yet understanding how they occur remains a major challenge. In reptiles, transitions from genetic to temperature-dependent sex determination can occur if the gene products that determine sex evolve thermal sensitivity, resulting in sex-reversed individuals. However, evidence of sex reversal is limited to oviparous reptiles. Here we used thermal experiments to test whether sex reversal is responsible for differences in sex determination in a viviparous reptile, Carinascincus ocellatus, a species with XY sex chromosomes and population-specific sex ratio response to temperature. We show that sex reversal is occurring and that its frequency is related to temperature. Sex reversal was unidirectional (phenotypic males with XX genotype) and observed in both high- and low-elevation populations. We propose that XX-biased genotypic sex ratios could produce either male- or female-biased phenotypic sex ratios as observed in low-elevation C. ocellatus under variable rates of XX sex reversal. We discuss reasons why sex reversal may not influence sex ratios at high elevation. Our results suggest that the mechanism responsible for evolutionary transitions from genotypic to temperature-dependent sex determination is more complex than can be explained by a single process such as sex reversal

Evidence of discrete yellowfin tuna (Thunnus albacares) populations demands rethink of management for this globally important resource

Tropical tuna fisheries are central to food security and economic development of many regions of the world. Contemporary population assessment and management generally assume these fisheries exploit a single mixed spawning population, within ocean basins. To date population genetics has lacked the required power to conclusively test this assumption. Here we demonstrate heterogeneous population structure among yellowfin tuna sampled at three locations across the Pacific Ocean (western, central, and eastern) via analysis of double digest restriction-site associated DNA using Next Generation Sequencing technology. The differences among locations are such that individuals sampled from one of the three regions examined can be assigned with close to 100% accuracy demonstrating the power of this approach for providing practical markers for fishery independent verification of catch provenance in a way not achieved by previous techniques. Given these results, an extended pan-tropical survey of yellowfin tuna using this approach will not only help combat the largest threat to sustainable fisheries (i.e. illegal, unreported, and unregulated fishing) but will also provide a basis to transform current monitoring, assessment, and management approaches for this globally significant species

Episodic population fragmentation and gene flow reveal a trade-off between heterozygosity and allelic richness

In episodic environments like deserts, populations of some animal species exhibit irregular fluctuations such that populations are alternately large and connected or small and isolated. Such dynamics are typically driven by periodic resource pulses due, for example, to large but infrequent rainfall events. The repeated population bottlenecks resulting from fragmentation should lower genetic diversity over time, yet species undergoing these fluctuations appear to maintain high levels of genetic diversity. To resolve this apparent paradox, we simulated a metapopulation of constant size undergoing repeat episodes of fragmentation and change in gene flow to mimic outcomes experienced by mammals in an Australian desert. We show that episodic fragmentation and gene flow have contrasting effects on two measures of genetic diversity: heterozygosity and allelic richness. Specifically, fragmentation into many, small subpopulations, coupled with periods of infrequent gene flow, preserves allelic richness at the expense of heterozygosity. In contrast, fragmentation into a few, large subpopulations maintains heterozygosity at the expense of allelic richness. The strength of the trade-off between heterozygosity and allelic richness depends on the amount of gene flow and the frequency of gene flow events. Our results imply that the type of genetic diversity maintained among species living in strongly fluctuating environments will depend on the way populations fragment, with our results highlighting different mechanisms for maintaining allelic richness and heterozygosity in small, fragmented populations

NMR structure of μ-conotoxin GIIIC : leucine 18 induces local repacking of the N-terminus resulting in reduced NaV channel potency

mu-Conotoxins are potent and highly specific peptide blockers of voltage-gated sodium channels. In this study, the solution structure of mu-conotoxin GIIIC was determined using 2D NMR spectroscopy and simulated annealing calculations. Despite high sequence similarity, GIIIC adopts a three-dimensional structure that differs from the previously observed conformation of mu-conotoxins GIIIA and GIIIB due to the presence of a bulky, non-polar leucine residue at position 18. The side chain of L18 is oriented towards the core of the molecule and consequently the N-terminus is re-modeled and located closer to L18. The functional characterization of GIIIC defines it as a canonical mu-conotoxin that displays substantial selectivity towards skeletal muscle sodium channels (Na-V), albeit with similar to 2.5-fold lower potency than GIIIA. GIIIC exhibited a lower potency of inhibition of Na(V)1.4 channels, but the same Na-V selectivity profile when compared to GIIIA. These observations suggest that single amino acid differences that significantly affect the structure of the peptide do in fact alter its functional properties. Our work highlights the importance of structural factors, beyond the disulfide pattern and electrostatic interactions, in the understanding of the functional properties of bioactive peptides. The latter thus needs to be considered when designing analogues for further applications

Angiosperm symbioses with non-mycorrhizal fungal partners enhance N acquisition from ancient organic matter in a warming maritime Antarctic

In contrast to the situation in plants inhabiting most of the world’s ecosystems, mycorrhizal fungi are usually absent from roots of the only two native vascular plant species of maritime Antarctica, Deschampsia antarctica and Colobanthus quitensis. Instead, a range of ascomycete fungi, termed dark septate endophytes (DSEs), frequently colonise the roots of these plant species. We demonstrate that colonisation of Antarctic vascular plants by DSEs facilitates not only the acquisition of organic nitrogen as early protein breakdown products, but also as non-proteinaceous D-amino acids and their short peptides, accumulated in slowly-decomposing organic matter, such as moss peat. Our findings suggest that, in a warming maritime Antarctic, this symbiosis has a key role in accelerating the replacement of formerly dominant moss communities by vascular plants, and in increasing the rate at which ancient carbon stores laid down as moss peat over centuries or millennia are returned to the atmosphere as CO2.Additional co-authors: Richard D Bardgett, David W Hopkins and Davey L Jone