4,981 research outputs found
Male Flat Jockeys Do Not Display Deteriorations in Bone Density or Resting Metabolic Rate in Accordance With Race Riding Experience: Implications for RED-S.
Despite consistent reports of poor bone health in male jockeys, it is not yet known if this is a consequence of low energy availability or lack of an osteogenic stimulus. Given the rationale that low energy availability is a contributing factor in low bone health, we tested the hypothesis that both hip and lumbar bone mineral density (BMD) should progressively worsen in accordance with the years of riding. In a cross-sectional design, male apprentice (n=17) and senior (n=14) jockeys (matched for body mass and fat free mass) were assessed for hip and lumbar spine BMD as well as both measured and predicted resting metabolic rate (RMR). Despite differences (P0.05) in hip (-0.9 Ā± 1.1 v -0.8 Ā± 0.7) and lumbar Z-scores (-1.3 Ā± 1.4 v -1.5 Ā± 1) or measured RMR (1459 Ā± 160 v 1500 Ā± 165 kcal.d-1) between apprentices and senior jockeys, respectively. Additionally, years of race riding did not demonstrate any significant correlations (P>0.05) with either hip or lumbar spine BMD. Measured RMR was also not different (P>0.05) from predicted RMR in either apprentice (1520 Ā± 44 kcal.d-1) or senior jockeys (1505 Ā± 70 kcal.d-1). When considered with previously published data examining under-reporting of energy intake and direct assessments of energy expenditure, we suggest that low BMD in jockeys is not due to low energy availability per se, but rather, the lack of an osteogenic stimulus associated with riding
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Pendant drops shed from a liquid lens formed by liquid draining down the inner wall of a wide vertical tube
When a viscous liquid empties from an initially full, wide vertical tube, the drainage behaviour changes from a filament to a regime in which individual drops are shed by a lens formed at the end of the tube: liquid drains down the wall and the lens grows until it becomes unstable. This drop shedding regime was investigated for four Newtonian liquids (rapeseed oil, glycerol, honey and golden syrup) in three tube sizes and two tube materials (Bond number based on tube i.d. > 1 in all cases). The drop mass increased modestly with flow rate and the equivalent sphere diameter, d, was strongly related to the capillary length Lc ā” (Ī³/Ļg)1/2 rather than the tube diameter. The results were fitted to a correlation of the form d/Lc = f(Bond, Reynolds, Morton, sin(contact angle)) derived from dimensional analysis. The data were compared with existing models for drop formation from filled narrow capillaries and a new, simple model based on a quasi-static model of the lens. Agreement with these models was poor, particularly for larger tubes, indicating the need for more detailed analysis. Insights into the dynamics, generated by video analysis of the lens shape, are presented
Wireless monitoring of liver hemodynamics in vivo
Liver transplants have their highest technical failure rate in the first two weeks following surgery. Currently, there are limited devices for continuous, real-time monitoring of the graft. In this work, a three wavelengths system is presented that combines near-infrared spectroscopy and photoplethysmography with a processing method that can uniquely measure and separate the venous and arterial oxygen contributions. This strategy allows for the quantification of tissue oxygen consumption used to study hepatic metabolic activity and to relate it to tissue stress. The sensor is battery operated and communicates wirelessly with a data acquisition computer which provides the possibility of implantation provided sufficient miniaturization. In two in vivo porcine studies, the sensor tracked perfusion changes in hepatic tissue during vascular occlusions with a root mean square error (RMSE) of 0.135 mL/min/g of tissue. We show the possibility of using the pulsatile wave to measure the arterial oxygen saturation similar to pulse oximetry. The signal is also used to extract the venous oxygen saturation from the direct current (DC) levels. Arterial and venous oxygen saturation changes were measured with an RMSE of 2.19% and 1.39% respectively when no vascular occlusions were induced. This error increased to 2.82% and 3.83% when vascular occlusions were induced during hypoxia. These errors are similar to the resolution of a commercial oximetry catheter used as a reference. This work is the first realization of a wireless optical sensor for continuous monitoring of hepatic hemodynamics. Ā© 2014 Akl et al
A thematic analysis of smokersā and non-smokersā accounts of E-cigarettes
This study explored smokersā and non-smokersā accounts of E-cigarettes. A total of 51 UK-based participants, 20 men and 31 women, responded to open-ended questions online. Inductive thematic analysis identified that the factors that influence E-cigarette behaviour and opinion in adult smokers and non-smokers are related to social context, informative sources, practical aspects and health implications. Participants presented varying accounts of E-cigarettes, suggesting that individual narratives regarding E-cigarettes are multi-faceted. This is important information for health professionals and policy makers tasked with advising on E-cigarette use
Why don't serum vitamin D concentrations associate with BMD by DXA? A case of being 'bound' to the wrong assay? Implications for vitamin D screening.
BACKGROUND: The association between bone mineral density (BMD) and serum25-hydroxyvitamin D (25(OH)D) concentration is weak, particularly in certain races (eg, BlackAfrican vs Caucasian) and in athletic populations. We aimed to examine if bioavailable vitamin D rather than serum 25(OH)D was related to markers of bone health within a racially diverse athletic population. METHODS: In 604 male athletes (Arab (n=327), Asian (n=48), Black(n=108), Caucasian (n=53)and Hispanic (n=68)), we measured total 25(OH)D, vitamin D-binding protein and BMD by DXA. Bioavailable vitamin D was calculated using the free hormone hypothesis. RESULTS: From 604 athletes, 21.5% (n=130) demonstrated severe 25(OH)D deficiency, 37.1% (n=224) deficiency, 26% (n=157) insufficiency and 15.4% (n=93) sufficiency. Serum 25(OH)D concentrations were not associated with BMD at any site. After adjusting for age and race, bioavailable vitamin D was associated with BMD (spine, neck and hip). Mean serum vitamin D binding protein concentrations were not associated with 25(OH)D concentrations (p=0.392). CONCLUSION: Regardless of age or race, bioavailable vitamin D and not serum 25(OH)D was associated with BMD in a racially diverse athletic population. If vitamin D screening is warranted, clinicians should use appropriate assays to calculate vitamin D binding protein and bioavailable vitamin D levels concentrations than serum 25(OH)D. In turn, prophylactic vitamin D supplementation to 'correct' insufficient athletes should not be based on serum 25(OH)D measures
GB Apprentice Jockeys Do Not Have the Body Composition to Make Current Minimum Race Weights: Is It Time to Change the Weights or Change the Jockeys?
Flat jockeys in Great Britain (GB) are classified as apprentices if they are aged less than 26 years and/or have ridden less than 95 winners. To gain experience, apprentices are allocated a weight allowance of up to 7 lb (3.2 kg). Given that there is no off-season in GB flat horseracing, jockeys are required to maintain their racing weight all year round. In light of recent work determining that current apprentices are considerably heavier than previous generations and that smaller increases have been made in the minimum weight, the aim of this study was to assess if the minimum weight in GB was achievable. To make the minimum weight (50.8 kg) with the maximal weight allowance requires a body mass of ā¼46.6 kg while maintaining a fat mass >2.5 kg (the lowest fat mass previously reported in weight-restricted males). Thirty-two male apprentice jockeys were assessed for body composition using dual-energy X-ray absorptiometry. The mean (SD) total mass and fat mass were 56 (2.9) kg and 7.2 (1.8) kg, respectively. Given that the lowest theoretical body mass for this group was 51.2 (2.3) kg, only one of 32 jockeys was deemed feasible to achieve the minimum weight with their current weight allowance and maintaining fat mass >2.5 kg. Furthermore, urine osmolality of 780 (260) mOsmol/L was seen, with 22 (out of 32) jockeys classed as dehydrated (>700 mOsmols/L), indicating that body mass would be higher when euhydrated. Additionally, we observed that within new apprentice jockeys licensed during this study (N = 41), only one jockey was able to achieve the minimum weight. To facilitate the goal of achieving race weight with minimal disruptions to well-being, the authorsā data suggest that the minimum weight for GB apprentices should be raised
Implementing One Health approaches to Emerging Infectious Disease: Reflections on the socio-political, ethical and legal dimensions
Background: āOne Healthā represents a call for health researchers and practitioners at the human, animal and
environmental interfaces to work together to mitigate the risks of emerging and re-emerging infectious diseases
(EIDs). A One Health approach emphasizing inter-disciplinary co-operation is increasingly seen as necessary for
effective EID control and prevention. There are, however, socio-political, ethical and legal challenges, which must be
met by such a One Health approach.
Discussion: Based on the philosophical review and critical analysis of scholarship around the theory and practice of
One Health it is clear that EID events are not simply about pathogens jumping species barriers; they are comprised
of complex and contingent sets of relations that involve socioeconomic and socio-political drivers and
consequences with the latter extending beyond the impact of the disease. Therefore, the effectiveness of policies
based on One Health depends on their implementation and alignment with or modification of public values.
Summary: Despite its strong motivating rationale, implementing a One Health approach in an integrated and
considered manner can be challenging, especially in the face of a perceived crisis. The effective control and
prevention of EIDs therefore requires: (i) social science research to improve understanding of how EID threats and
responses play out; (ii) the development of an analytic framework that catalogues case experiences with EIDs,
reflects their dynamic nature and promotes inter-sectoral collaboration and knowledge synthesis; (iii) genuine
public engagement processes that promote transparency, education and capture peopleās preferences; (iv) a set of
practical principles and values that integrate ethics into decision-making procedures, against which policies and
public health responses can be assessed; (v) integration of the analytic framework and the statement of principles
and values outlined above; and (vi) a focus on genuine reform rather than rhetoric.
Keywords: One health, Emerging infectious disease, Zoonoses, Bioethics, Health policy, Health lawThe work was funded by NHMRC grant #1083079 and seed funding from
the Marie Bashir Institute for Infectious Disease and Biosecurity and the
School of Public Health at the University of Sydney
Implementing One Health approaches to Emerging Infectious Disease: Reflections on the socio-political, ethical and legal dimensions
Background: āOne Healthā represents a call for health researchers and practitioners at the human, animal and environmental interfaces to work together to mitigate the risks of emerging and re-emerging infectious diseases (EIDs). A One Health approach emphasizing inter-disciplinary co-operation is increasingly seen as necessary for effective EID control and prevention. There are, however, socio-political, ethical and legal challenges, which must be met by such a One Health approach. Discussion: Based on the philosophical review and critical analysis of scholarship around the theory and practice of One Health it is clear that EID events are not simply about pathogens jumping species barriers; they are comprised of complex and contingent sets of relations that involve socioeconomic and socio-political drivers and consequences with the latter extending beyond the impact of the disease. Therefore, the effectiveness of policies based on One Health depends on their implementation and alignment with or modification of public values. Summary: Despite its strong motivating rationale, implementing a One Health approach in an integrated and considered manner can be challenging, especially in the face of a perceived crisis. The effective control and prevention of EIDs therefore requires: (i) social science research to improve understanding of how EID threats and responses play out; (ii) the development of an analytic framework that catalogues case experiences with EIDs, reflects their dynamic nature and promotes inter-sectoral collaboration and knowledge synthesis; (iii) genuine public engagement processes that promote transparency, education and capture peopleās preferences; (iv) a set of practical principles and values that integrate ethics into decision-making procedures, against which policies and public health responses can be assessed; (v) integration of the analytic framework and the statement of principles and values outlined above; and (vi) a focus on genuine reform rather than rhetoric. Keywords: One health, Emerging infectious disease, Zoonoses, Bioethics, Health policy, Health lawThe work was funded by NHMRC grant #1083079 and seed funding from the Marie Bashir Institute for Infectious Disease and Biosecurity and the School of Public Health at the University of Sydney
Blood Cholinesterases from Washington State Orchard Workers
Court-ordered monitoring of blood cholinesterases (ChEs) from orchard workers in Washington State is underway. In 2008, the mean red blood cell acetylcholinesterase (AChE, EC 3.1.1.7) activity was 9.65Ā Ā±Ā 1.11Ā Ī¼moles/min/ml (nĀ =Ā 1,793) and the mean serum (BChE, 3.1.1.6) activity was 5.19Ā Ā±Ā 0.90Ā Ī¼moles/min/ml (nĀ =Ā 1,811). Determinations were made using the Ellman assay and automated equipment of Pathology Associates Medical Laboratories (PAML), Spokane, Washington
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