Role of age, sex, and obesity in the higher prevalence of arthritis among lower socioeconomic groups: a population-based survey

Objective: To compare the prevalence of arthritis among population groups based on demographic, socioeconomic, and body mass index (BMI) characteristics; to investigate the combined influence of these factors on arthritis; and to assess the relationship between self-reported health and psychological distress and arthritis.

Methods: Data from the Victorian Population Health Survey (n = 7,500) were used in the study. Psychological distress was assessed using the Kessler Psychological Distress scale, and self-reported health was assessed by a single item. Multiple logistic regression was used to investigate the combined influence of demographic and socioeconomic factors and BMI on arthritis.

Results: Overall, 23% of Victorian adults (20% men and 26% women) reported having arthritis. The presence of arthritis was associated with high psychological distress (odds ratio [OR] 1.2; 95% confidence interval [95% CI] 1.1-1.4) and poor self-reported health (OR 1.9; 95% CI 1.7-2.1). Increased prevalence of arthritis was found in older age groups, lower education and income groups, and in people who were overweight or obese. Women had higher risk of arthritis, even after adjustment for age, residence, education, occupation, income, and BMI. Age and BMI independently predicted arthritis for men and women. For men, higher risk of arthritis was also associated with lower income.

Conclusion: Arthritis is a highly prevalent condition associated with poor health and high psychological distress. Prevalence of arthritis is disproportionately high among women and individuals from lower socioeconomic backgrounds. As the prevalence of arthritis is predicted to increase, careful consideration of causal factors, and setting priorities for resource allocation for the treatment and prevention of arthritis are required.

Severely compromised quality of life in women and those of lower socioeconomic status waiting for joint replacement surgery

Objective
To determine health-related quality of life (HRQOL), psychological distress, physical function, and self efficacy in persons waiting for lower-limb joint replacement surgery.

Methods
A total of 214 patients on a waiting list for unilateral primary total knee or hip replacement at a large Australian public teaching hospital completed questionnaires after entry to the list. HRQOL and psychological distress were compared with available population norms.

Results
Average HRQOL was extremely poor (mean ± SD 0.39 ± 0.24) and much lower (>2 SD) than the population norm. Near death-equivalent HRQOL or worse than death-equivalent HRQOL were reported by 15% of participants. High or very high psychological distress was up to 5 times more prevalent in the waiting list sample (relative risk 5.4 for participants ages 75 years and older; 95% confidence interval 3.3, 9.0). Women had significantly lower HRQOL, self efficacy, and physical function scores than men. After adjusting for age and sex, significant socioeconomic disparities were also found. Participants who received the lowest income had the poorest HRQOL; those with the least education or the lowest income had the highest psychological distress. Low self efficacy was moderately associated with poor HRQOL (r = 0.49, P < 0.001) and more strongly associated with high psychological distress (r = -0.55, P < 0.001).

Conclusion
Patients waiting for joint replacement have very poor HRQOL and high psychological distress, especially women and those from lower socioeconomic backgrounds. Lengthy waiting lists mean patients can experience extended and potentially avoidable morbidity. Interventions to address psychological distress and self efficacy could reduce this burden and should target women and lower socioeconomic groups.

Plasmodium falciparum possesses two GRASP proteins that are differentially targeted to the Golgi complex via a higher- and lower-eukaryote-like mechanism

Plasmodium falciparum, the causative agent of malaria, relies on a complex protein-secretion system for protein targeting into numerous subcellular destinations. Recently, a homologue of the Golgi re-assembly stacking protein (GRASP) was identified and used to characterise the Golgi organisation in this parasite. Here, we report on the presence of a splice variant that leads to the expression of a GRASP isoform. Although the first GRASP protein (GRASP1) relies on a well-conserved myristoylation motif, the variant (GRASP2) displays a different N-terminus, similar to GRASPs found in fungi. Phylogenetic analyses between GRASP proteins of numerous taxa point to an independent evolution of the unusual N-terminus that could reflect unique requirements for Golgi-dependent protein sorting and organelle biogenesis in P. falciparum. Golgi association of GRASP2 depends on the hydrophobic N-terminus that resembles a signal anchor, leading to a unique mode of Golgi targeting and membrane attachment.

Yagonia Roberts (brachiopoda : chonetidina) from the malimán formation, lower carboniferous of western Argentina : palaeobiogeographical implications

A new anoplid chonetid species, Yagonia furquei sp. nov., is described from the Lower Carboniferous (late Tournaisian–early Viséan) Malimán Formation of western Argentina. The associated temperate ‘Malimanian’ fauna is suggested to indicate an initial biotic segregation that took place in western Gondwana (southwestern South America), a palaeobiogeographic event that predated the late Viséan global cooling and associated major palaeolatitudinal biotic differentiation. Occurrences of Yagonia are here interpreted as evidence of a ‘south to north’ faunal migration pathway, here named the Austropanthalassic–Rheic oceanic corridor, established in western Gondwana during the late Early Carboniferous.

Nitric oxide control of lower vertebrate blood vessels

The gas, nitric oxide, plays a critical role in the control of the cardiovascular system of animals, and in particular blood pressure. This thesis demonstrated unique mechanisms by which nitric oxide regulates the blood vessels of various animals, which will alter our understanding of vascular regulation by peripheral nerves.

Effect of body tilt angle on fatigue and EMG activities in lower limbs during cycling

This study compared the rate of fatigue and lower limb EMG activities during high-intensity constantload cycling in upright and supine postures. Eleven active males performed seven cycling exercise tests: one upright graded test, four fatigue tests (two upright, two supine) and two EMG tests (one upright, one supine). During the fatigue tests participants initially performed a 10 s all-out effort followed by a constant-load test with 10 s all-out bouts interspersed every minute. The load for the initial two fatigue tests was 80% of the peak power (PP) achieved during the graded test and these continued until failure. The remaining two fatigue tests were performed at 20% PP and were limited to the times achieved during the 80% PP tests. During the EMG tests subjects performed a 10 s all-out effort followed by a constant-load test to failure at 80% PP. Normalised EMG activities (% maximum, NEMG) were assessed in five lower limb muscles. Maximum power and maximum EMG activity prior to each fatigue and EMG test were unaffected by posture. The rate of fatigue at 80% PP was significantly higher during supine compared with upright posture (-68 ± 14 vs. -26 ± 6 W min-1, respectively, P\0.05) and the divergence of the fatigue responses occurred by the second minute of exercise. NEMG responses were significantly higher in the supine posture by 1–4 min of exercise. Results show that fatigue is significantly greater during supine compared with upright high-intensity cycling and this effect is accompanied by a reduced activation of musculature that is active during cycling.

Chemical coding of vascular nitrergic nerves in lower vertebrates

Nitric oxide is an important regulator of blood pressure in mammals. This study provided new information on the role of nitric-oxide releasing sympathetic nerves in vascular regulation of lower vertebrates. The research outcomes advance knowledge on the potential role of these unique nerves in the control of the lower vertebrate cardiovascular system.

Bounded lower subdifferentiability optimization techniques : applications

In this article we develop a global optimization algorithm for quasiconvex programming where the objective function is a Lipschitz function which may have "flat parts". We adapt the Extended Cutting Angle method to quasiconvex functions, which reduces significantly the number of iterations and objective function evaluations, and consequently the total computing time. Applications of such an algorithm to mathematical programming problems inwhich the objective function is derived from economic systems and location problems are described. Computational results are presented.

Lower levels of physical activity in childhood associated with adult depression

Emerging evidence indicates that early life exposures influence adult health outcomes and there is cause to hypothesise a role for physical activity (PA) in childhood as a protective factor in adult depression. This study aimed to investigate the association between self-reported levels of PA in childhood and self-reported depressive illness. Lifetime depression and levels of physical activity (low/high) in childhood (<15 yr) were ascertained by self-report in 2152 adults (20–97 yr) participating in an ongoing epidemiological study in south-eastern Australia. Data were collected between 2000 and 2006. In this sample, 141 women (18.9%) and 169 men (12.0%) reported ever having a depressive episode. Low PA in childhood was associated with an increased risk of reporting depression in adulthood (OR = 1.70, 95%CI = 1.32–2.17, p < 0.001). Adjustment for age, gender and adult PA attenuated the relationship somewhat (OR = 1.35, 95%CI = 1.01–1.78, p = 0.04), however further adjustment for SES or country of birth did not affect this relationship. In this community-based study, lower levels of self-reported PA in childhood were associated with a 35% increase in odds for self-reported depression in adulthood. These results are consistent with the hypothesis that lower levels of PA in childhood may be a risk factor for adult depression.

Overweight children have a greater proportion of fat mass relative to muscle mass in the upper limbs than in the lower limbs : implications for bone strength at the distal forearm

Background: The influence of adiposity on upper-limb bone strength has rarely been studied in children, despite the high incidence of forearm fractures in this population.

Objective: The objective was to compare the influence of muscle and fat tissues on bone strength between the upper and lower limbs in prepubertal children.

Design: Bone mineral content, total bone cross-sectional area, cortical bone area (CoA), cortical thickness (CoTh) at the radius and tibia (4% and 66%, respectively), trabecular density (TrD), bone strength index (4% sites), cortical density (CoD), stress-strain index, and muscle and fat areas (66% sites) were measured by using peripheral quantitative computed tomography in 427 children (206 boys) aged 7–10 y.

Results: Overweight children (n = 93) had greater values for bone variables (0.3–1.3 SD; P < 0.0001) than did their normal-weight peers, except for CoD 66% and CoTh 4%. The between-group differences were 21–87% greater at the tibia than at the radius. After adjustment for muscle cross-sectional area, TrD 4%, bone mineral content, CoA, and CoTh 66% at the tibia remained greater in overweight children, whereas at the distal radius total bone cross-sectional area and CoTh were smaller in overweight children (P < 0.05). Overweight children had a greater fat-muscle ratio than did normal-weight children, particularly in the forearm (92 ± 28% compared with 57 ± 17%). Fat-muscle ratio correlated negatively with all bone variables, except for TrD and CoD, after adjustment for body weight (r = −0.17 to −0.54; P < 0.0001).

Conclusions: Overweight children had stronger bones than did their normal-weight peers, largely because of greater muscle size. However, the overweight children had a high proportion of fat relative to muscle in the forearm, which is associated with reduced bone strength.

Flexible multibody approach in forward dynamic simulation of locomotive strains in human skeleton with flexible lower body bones

A method for bone strain estimation is examined in this article. The flexibility of a single bone in an otherwise rigid human skeleton model has been studied previously by various authors. However, in the previous studies, the effect of the flexibility of multiple bones on the musculoskeletal model behavior was ignored. This study describes a simulation method that can be used to estimate the bone strains at both tibias and femurs of a 65-year old Caucasian male subject. The verification of the method is performed by the comparison of the results with other studies available in literature. The results of the study show good correlation with the results of previous empirical studies. A damping effect of the flexible bones on the model is also studied in this paper.