Effect of Different Collegiate Sports on Cortical Bone in the Tibia

Objectives: The purpose of this study was to determine the effect of sports participation on cortical bone in the tibia. Methods: 53 female collegiate athletes (25 cross-country, 16 soccer, and 12 volleyball) and 20 inactive controls had the left distal 20% tibia scanned by pQCT. Cortical volumetric BMD (vBMD) was measured within the cortical shell at the anterior, posterior, medial, and lateral regions and standard deviations were calculated. Results: Total vBMD was greater in the control group (1161±5 mg/mm3) than each of the sports (p\u3c0.05). Soccer players (1147±5 mg/mm3) had greater vBMD than volleyball players (1136±7 mg/mm3) (p\u3c0.05), but similar to cross-country runners (1145±5 mg/mm3). Cortical thickness was greatest in soccer players (4.1±0.1 mm), while cross-country and control subjects (3.8±0.1 mm) had greater thickness than volleyball players (3.4±0.1 mm)(p\u3c0.05). Periosteal circumference was greater in volleyball players (71±1.4 mm) than soccer, cross-country, and control subjects (68±0.9, 69±0.8, and 66±1 mm, respectively; all, p\u3c0.05). vBMD variation within the cortical shell was greater among control subjects (70±6 mg/cm3) than each of the athlete groups, with soccer players having lower variation than cross country runners (within-in person SD 36±6 mg/cm3 and 54±5 mg/cm3 respectively; p\u3c0.05). Conclusion: These results indicate bone geometry and distribution within the cortical shell of the tibia varies depending upon sporting activities of young women

Follicle-stimulating Hormone is Independently Associated with Lean Mass but not BMD in Younger Postmenopausal Women

PURPOSE: Increased follicle-stimulating hormone (FSH) has been associated with lower bone mineral density (BMD) in animal models and longitudinal studies of women, but a direct effect has not been demonstrated.METHODS: We tested associations between FSH, non-bone body composition measures and BMD in 94 younger (aged 50 to 64 years) postmenopausal women without current use of hormone therapy, adjusting for sex hormone concentrations and clinical risk factors for osteoporosis. Lean mass, fat mass and areal BMD (aBMD) at the spine, femoral neck and total hip were measured using dual energy X-ray absorptiometry (DXA). Volumetric BMD (vBMD) was measured at the distal radius using peripheral quantitative computed tomography (pQCT).RESULTS: FSH was inversely correlated with lean and fat mass, bioavailable estradiol, spine and hip aBMD, and vBMD at the ultradistal radius. In the multivariable analysis, FSH was independently associated with lean mass (β=-0.099, p=0.005) after adjustment for age, race, years since menopause, bioavailable estradiol, bioavailable testosterone, LH, PTH, SHBG and urine N-telopeptide. FSH showed no statistically significant association with aBMD at any site or pQCT measures at the distal radius in adjusted models. Race was independently associated with aBMD, and race and urine N-telopeptide were independently associated with bone area and vBMD.CONCLUSIONS: After adjustment for hormonal measures and osteoporosis risk factors, higher concentrations of FSH were independently associated with lower lean mass, but not with BMD. Previously reported correlations between FSH and BMD might have been due to indirect associations via lean mass or weight

The combinatorics of the Baer-Specker group

Denote the integers by Z and the positive integers by N. The groups Z^k (k a natural number) are discrete, and the classification up to isomorphism of their (topological) subgroups is trivial. But already for the countably infinite power Z^N of Z, the situation is different. Here the product topology is nontrivial, and the subgroups of Z^N make a rich source of examples of non-isomorphic topological groups. Z^N is the Baer-Specker group. We study subgroups of the Baer-Specker group which possess group theoretic properties analogous to properties introduced by Menger (1924), Hurewicz (1925), Rothberger (1938), and Scheepers (1996). The studied properties were introduced independently by Ko\v{c}inac and Okunev. We obtain purely combinatorial characterizations of these properties, and combine them with other techniques to solve several questions of Babinkostova, Ko\v{c}inac, and Scheepers.Comment: To appear in IJ

Causality - Complexity - Consistency: Can Space-Time Be Based on Logic and Computation?

The difficulty of explaining non-local correlations in a fixed causal structure sheds new light on the old debate on whether space and time are to be seen as fundamental. Refraining from assuming space-time as given a priori has a number of consequences. First, the usual definitions of randomness depend on a causal structure and turn meaningless. So motivated, we propose an intrinsic, physically motivated measure for the randomness of a string of bits: its length minus its normalized work value, a quantity we closely relate to its Kolmogorov complexity (the length of the shortest program making a universal Turing machine output this string). We test this alternative concept of randomness for the example of non-local correlations, and we end up with a reasoning that leads to similar conclusions as in, but is conceptually more direct than, the probabilistic view since only the outcomes of measurements that can actually all be carried out together are put into relation to each other. In the same context-free spirit, we connect the logical reversibility of an evolution to the second law of thermodynamics and the arrow of time. Refining this, we end up with a speculation on the emergence of a space-time structure on bit strings in terms of data-compressibility relations. Finally, we show that logical consistency, by which we replace the abandoned causality, it strictly weaker a constraint than the latter in the multi-party case.Comment: 17 pages, 16 figures, small correction

Dietary protein safety and resistance exercise: what do we really know?

Resistance trainers continue to receive mixed messages about the safety of purposely seeking ample dietary protein in their quest for stimulating protein synthesis, improving performance, or maintaining health. Despite protein's lay popularity and the routinely high intakes exhibited by strength athletes, liberal and purposeful protein consumption is often maligned by "experts". University textbooks, instructors, and various forms of literature from personal training groups and athletic organizations continue to use dissuasive language surrounding dietary protein. Due to the widely known health benefits of dietary protein and a growing body of evidence on its safety profile, this is unfortunate. In response, researchers have critiqued unfounded educational messages. As a recent summarizing example, the International Society of Sports Nutrition (ISSN) Position Stand: Protein and Exercise reviewed general literature on renal and bone health. The concluding remark that "Concerns that protein intake within this range [1.4 – 2.0 g/kg body weight per day] is unhealthy are unfounded in healthy, exercising individuals." was based largely upon data from non-athletes due to "a lack of scientific evidence". Future studies were deemed necessary. This assessment is not unique in the scientific literature. Investigators continue to cite controversy, debate, and the lack of direct evidence that allows it. This review discusses the few existing safety studies done specific to athletes and calls for protein research specific to resistance trainers. Population-specific, long term data will be necessary for effective education in dietetics textbooks and from sports governing bodies

Lipid-soluble Vitamins A, D, and E in HIV-Infected Pregnant women in Tanzania.

There is limited published research examining lipid-soluble vitamins in human immunodeficiency virus (HIV)-infected pregnant women, particularly in resource-limited settings. This is an observational analysis of 1078 HIV-infected pregnant women enrolled in a trial of vitamin supplementation in Tanzania. Baseline data on sociodemographic and anthropometric characteristics, clinical signs and symptoms, and laboratory parameters were used to identify correlates of low plasma vitamin A (<0.7 micromol/l), vitamin D (<80 nmol/l) and vitamin E (<9.7 micromol/l) status. Binomial regression was used to estimate risk ratios and 95% confidence intervals. Approximately 35, 39 and 51% of the women had low levels of vitamins A, D and E, respectively. Severe anemia (hemoglobin <85 g/l; P<0.01), plasma vitamin E (P=0.02), selenium (P=0.01) and vitamin D (P=0.02) concentrations were significant correlates of low vitamin A status in multivariate models. Erythrocyte Sedimentation Rate (ESR) was independently related to low vitamin A status in a nonlinear manner (P=0.01). The correlates of low vitamin D status were CD8 cell count (P=0.01), high ESR (ESR >81 mm/h; P<0.01), gestational age at enrollment (nonlinear; P=0.03) and plasma vitamins A (P=0.02) and E (P=0.01). For low vitamin E status, the correlates were money spent on food per household per day (P<0.01), plasma vitamin A concentration (nonlinear; P<0.01) and a gestational age <16 weeks at enrollment (P<0.01). Low concentrations of lipid-soluble vitamins are widely prevalent among HIV-infected women in Tanzania and are correlated with other nutritional insufficiencies. Identifying HIV-infected persons at greater risk of poor nutritional status and infections may help inform design and implementation of appropriate interventions

Associations of baseline use of biologic or targeted synthetic DMARDs with COVID-19 severity in rheumatoid arthritis: Results from the COVID-19 Global Rheumatology Alliance physician registry.

OBJECTIVE: To investigate baseline use of biologic or targeted synthetic (b/ts) disease-modifying antirheumatic drugs (DMARDs) and COVID-19 outcomes in rheumatoid arthritis (RA). METHODS: We analysed the COVID-19 Global Rheumatology Alliance physician registry (from 24 March 2020 to 12 April 2021). We investigated b/tsDMARD use for RA at the clinical onset of COVID-19 (baseline): abatacept (ABA), rituximab (RTX), Janus kinase inhibitors (JAKi), interleukin 6 inhibitors (IL-6i) or tumour necrosis factor inhibitors (TNFi, reference group). The ordinal COVID-19 severity outcome was (1) no hospitalisation, (2) hospitalisation without oxygen, (3) hospitalisation with oxygen/ventilation or (4) death. We used ordinal logistic regression to estimate the OR (odds of being one level higher on the ordinal outcome) for each drug class compared with TNFi, adjusting for potential baseline confounders. RESULTS: Of 2869 people with RA (mean age 56.7 years, 80.8% female) on b/tsDMARD at the onset of COVID-19, there were 237 on ABA, 364 on RTX, 317 on IL-6i, 563 on JAKi and 1388 on TNFi. Overall, 613 (21%) were hospitalised and 157 (5.5%) died. RTX (OR 4.15, 95% CI 3.16 to 5.44) and JAKi (OR 2.06, 95% CI 1.60 to 2.65) were each associated with worse COVID-19 severity compared with TNFi. There were no associations between ABA or IL6i and COVID-19 severity. CONCLUSIONS: People with RA treated with RTX or JAKi had worse COVID-19 severity than those on TNFi. The strong association of RTX and JAKi use with poor COVID-19 outcomes highlights prioritisation of risk mitigation strategies for these people

Proteomics of Buccal Cavity Mucus in Female Tilapia Fish (Oreochromis spp.): A Comparison between Parental and Non-Parental Fish

Mouthbrooding is an elaborate form of parental care displayed by many teleost species. While the direct benefits of mouthbrooding such as protection and transportation of offsprings are known, it is unclear if mouthbrooding offers additional benefits to embryos during incubation. In addition, mouthbrooding could incur negative costs on parental fish, due to limited feeding opportunities. Parental tilapia fish (Oreochromis spp.) display an elaborated form of parental care by incubating newly hatched embryos in oral buccal cavity until the complete adsorption of yolk sac. In order to understand the functional aspects of mouthbrooding, we undertake a proteomics approach to compare oral mucus sampled from mouthbrooders and non-mouthbrooders, respectively. Majority of the identified proteins have also been previously identified in other biological fluids or mucus-rich organs in different organisms. We also showed the upregulation of 22 proteins and down regulation of 3 proteins in mucus collected from mouthbrooders. Anterior gradient protein, hemoglobin beta-A chain and alpha-2 globin levels were lower in mouthbrooder samples. Mouthbrooder oral mucus collectively showed increase levels of proteins related to cytoskeletal properties, glycolytic pathway and mediation of oxidative stress. Overall the findings suggest cellular stress response, probably to support production of mucus during mouthbrooding phase

Managing Spoilers in a Hybrid War: The Democratic Republic of Congo (1996-2010)

Scholarship on the management of spoilers in a hybrid type of conflict is almost non-existent. Through an examination of the recent Congolese wars and peace efforts (1996–2010), we develop an understanding of how spoilers are managed in a conflict characterised by both interstate and intrastate dynamics. Certainly, more strategies of dealing with spoiler behaviours in this type of conflict are likely to emerge as similar cases are investigated, but our discussion recommends these non-related, but strongly interacting principles: the practice of inclusivity, usually preferred in the management of spoilers, is more complex, and in fact ineffective, particularly when concerned groups’ internal politics and supportive alliances are unconventional. Because holding elections is often deemed indispensable in peacemaking efforts, it is vital that total spoilers be prevented from winning or disrupting them. The toughest challenge is the protection of civilians, especially when the state lacks a monopoly on the use of violence and governance remains partitioned across the country

Monitoring activities of teenagers to comprehend their habits: study protocol for a mixed-methods cohort study

Abstract: Background: Efforts to increase physical activity in youth need to consider which activities are most likely to be sustained over time in order to promote lifelong participation in physical activity. The Monitoring Activities of Teenagers to Comprehend their Habits (MATCH) study is a prospective cohort study that uses quantitative and qualitative methods to develop new knowledge on the sustainability of specific physical activities. Methods/design: Eight hundred and forty-three grade 5 and 6 students recruited from 17 elementary schools in New Brunswick, Canada, are followed-up three times per year. At each survey cycle, participants complete self-report questionnaires in their classroom under the supervision of trained data collectors. A sub-sample of 24 physically active students is interviewed annually using a semi-structured interview protocol. Parents (or guardians) complete telephone administered questionnaires every two years, and a health and wellness school audit is completed for each school. Discussion: MATCH will provide a description of the patterns of participation in specific physical activities in youth, and enable identification of the determinants of maintenance, decline, and uptake of participation in each activity. These data will inform the development of interventions that take into account which activities are the most likely to be maintained and why activities are maintained or dropped