4,221 research outputs found

    An isovelocity dynamometer method to determine monoarticular and biarticular muscle parameters

    Get PDF
    This study aimed to determine whether subject-specific individual muscle models for the ankle plantar flexors could be obtained from single joint isometric and isovelocity maximum torque measurements in combination with a model of plantar flexion. Maximum plantar flexion torque measurements were taken on one subject at six knee angles spanning full flexion to full extension. A planar three-segment (foot, shank and thigh), two muscle (soleus and gastrocnemius) model of plantar flexion was developed. Seven parameters per muscle were determined by minimizing a weighted root mean square difference (wRMSD) between the model output and the experimental torque data. Valid individual muscle models were obtained using experimental data from only two knee angles giving a wRMSD score of 16 N m, with values ranging from 11 to 17 N m for each of the six knee angles. The robustness of the methodology was confirmed through repeating the optimization with perturbed experimental torques (±20%) and segment lengths (±10%) resulting in wRMSD scores of between 13 and 20 N m. Hence, good representations of maximum torque can be achieved from subject-specific individual muscle models determined from single joint maximum torque measurements. The proposed methodology could be applied to muscle-driven models of human movement with the potential to improve their validity

    Decadal Trends In Age Structure And Recruitment Patterns Of Ocean Quahogs Arctica Islandica From The Mid-Atlantic Bight In Relation To Water Temperature

    Get PDF
    Occan quahogs (Arctica islandica) are long-lived bivalves. Distributionl patterns and biology of ocean quahogs ill the Mid-Atlantic Bight (MAB) off the cast coast of North America are directly related to bottom water temperatures. We examined long term recruitment patterns for ocean quahogs across temporal (decadal) and spatial (latitudinal. bathymetric) scales Using a spatially defined (Long Island Sound to Chesapeake Bay mouth) population encompassing a broad size (age) range of animals that had not yet recruited to the commercial fishery [(SL)], An age-at-length relationship for quahogs less than 80 mm SL is described using a power function. Quahog age did not vary significantly with depth or region, nor were any interaction terms between age and length with depth or region significant. An age-length key was developed for ocean quahogs to generate age frequencies for each station. Principal components analysis (PCA) oil the resulting age-frequency distributions standardized per low enabled construction of characteristic age-frequency distributions for similar stations identified by the PCA factor scores. These characteristic age-frequency distributions identified quahog cohorts with modal ages corresponding to recruitment during the 1948-1950. 1954-1959 1972-1980 and 1978-1983 time periods. Observed recruitment patterns in MA B ocean quahogs are strongly related to bottom water temperature patterns. Years it) Which the number of months with water temperatures averaging 6 degrees C to 10 degrees C exceeds the number of months with water temperatures less than 6 degrees C by at least two months are also years that contriute Strongly to the modal year classes in the population age-frequency distributions. In general. years with above average bottom water temperatures during January, February. and March lend to produce year classes that are distinct in the age-frequency distributions front the MAB (quahog populations. The observed time series of quahog recruitment Operates at a different time scale than stock surveys and most estimates of fishery dynamics. The 50-60-y lag between quahog recruitment to the benthos and recruitment to the fishery presents challenges for fishery forecasting in that changes in adult biomass and subsequent effects oil stock-recruit relationships will only become evident oil this this scale

    Viral infections in interferon-gamma receptor deficiency.

    Get PDF
    Interferon-gamma receptor deficiency is a recently described immunodeficiency that is associated with onset of severe mycobacterial infections in childhood. We describe the occurrence of symptomatic and often severe viral infections in 4 patients with interferon-gamma receptor deficiency and mycobacterial disease. The viral pathogens included herpes viruses, parainfluenza virus type 3, and respiratory syncytial virus. We conclude that patients with interferon-gamma receptor deficiency and mycobacterial disease have increased susceptibility to some viral pathogens

    Cranial osteopathy: its fate seems clear

    Get PDF
    BACKGROUND: According to the original model of cranial osteopathy, intrinsic rhythmic movements of the human brain cause rhythmic fluctuations of cerebrospinal fluid and specific relational changes among dural membranes, cranial bones, and the sacrum. Practitioners believe they can palpably modify parameters of this mechanism to a patient's health advantage. DISCUSSION: This treatment regime lacks a biologically plausible mechanism, shows no diagnostic reliability, and offers little hope that any direct clinical effect will ever be shown. In spite of almost uniformly negative research findings, "cranial" methods remain popular with many practitioners and patients. SUMMARY: Until outcome studies show that these techniques produce a direct and positive clinical effect, they should be dropped from all academic curricula; insurance companies should stop paying for them; and patients should invest their time, money, and health elsewhere

    Process evaluation of integrated diabetes management at primary healthcare facilities in Pakistan: a mixed-methods study

    Get PDF
    Background: Integrated care for diabetes and associated conditions at primary level health facilities can make care available to a much larger population, especially in rural areas. Aim: This process evaluation was to understand how the authors' integrated care was implemented and experienced by the care providers and patients, and to inform modifications prior to province-wide scale-up. Design & setting: The mixed-method study was conducted as part of a cluster randomised trial on integrated diabetes care at 14 public health facilities. Method: The care practices were assessed by analysing the routine clinical records of 495 registered patients with diabetes. Then semi-structured interviews with service providers and patients were used to understand their respective care experiences. A framework approach was applied to analyse and interpret the qualitative data. Results: The intervention and the study were implemented as intended under routine conditions in rural health centres. Key service processes effectively delivered included: skill-based training; screening and diagnostic tests; treatment card records; and the additional case management as per desk guide, including monitoring progress in glucose and weight at follow-up consultations, and mobile phone calls to help adherence. However, social and cultural factors affected clients' ability to change lifestyles, especially for women. The intervention effect was limited by the short study follow-up of only 9 months. Conclusion: Integrated diabetes care was feasible, both for providers and patients, and potentially scalable at primary care facilities under routine conditions in Pakistan. Additional operational interventions are required for sustained drug supplies, supervision, in-service training, and to address the social challenges to healthy activity and eating, especially for women

    Evaluation of the health-related quality of life of children in Schistosoma haematobium-endemic communities in Kenya: a cross-sectional study.

    Get PDF
    BACKGROUND: Schistosomiasis remains a global public health challenge, with 93% of the ~237 million infections occurring in sub-Saharan Africa. Though rarely fatal, its recurring nature makes it a lifetime disorder with significant chronic health burdens. Much of its negative health impact is due to non-specific conditions such as anemia, undernutrition, pain, exercise intolerance, poor school performance, and decreased work capacity. This makes it difficult to estimate the disease burden specific to schistosomiasis using the standard DALY metric. METHODOLOGY/PRINCIPAL FINDINGS: In our study, we used Pediatric Quality of Life Inventory (PedsQL), a modular instrument available for ages 2-18 years, to assess health-related quality of life (HrQoL) among children living in a Schistosoma haematobium-endemic area in coastal Kenya. The PedsQL questionnaires were administered by interview to children aged 5-18 years (and their parents) in five villages spread across three districts. HrQoL (total score) was significantly lower in villages with high prevalence of S. haematobium (-4.0%, p<0.001) and among the lower socioeconomic quartiles (-2.0%, p<0.05). A greater effect was seen in the psychosocial scales as compared to the physical function scale. In moderate prevalence villages, detection of any parasite eggs in the urine was associated with a significant 2.1% (p<0.05) reduction in total score. The PedsQL reliabilities were generally high (Cronbach alphas ≥0.70), floor effects were acceptable, and identification of children from low socioeconomic standing was valid. CONCLUSIONS/SIGNIFICANCE: We conclude that exposure to urogenital schistosomiasis is associated with a 2-4% reduction in HrQoL. Further research is warranted to determine the reproducibility and responsiveness properties of QoL testing in relation to schistosomiasis. We anticipate that a case definition based on more sensitive parasitological diagnosis among younger children will better define the immediate and long-term HrQoL impact of Schistosoma infection

    Emergence of heat extremes attributable to anthropogenic influences

    Get PDF
    Climate scientists have demonstrated that a substantial fraction of the probability of numerous recent extreme events may be attributed to human-induced climate change. However, it is likely that for temperature extremes occurring over previous decades a fraction of their probability was attributable to anthropogenic influences. We identify the first record-breaking warm summers and years for which a discernible contribution can be attributed to human influence. We find a significant human contribution to the probability of record-breaking global temperature events as early as the 1930s. Since then, all the last 16 record-breaking hot years globally had an anthropogenic contribution to their probability of occurrence. Aerosol-induced cooling delays the timing of a significant human contribution to record-breaking events in some regions. Without human-induced climate change recent hot summers and years would be very unlikely to have occurred.111411Ysciescopu

    Delivering integrated hypertension care at private health facilities in urban Pakistan: a process evaluation

    Get PDF
    Background: In Pakistan about 18% of all adults are affected by hypertension, and only one in eight of the prevalent cases have their hypertension controlled. As in many other low-middle income countries, a public–private partnership approach is being considered for delivering non-communicable disease care in urban areas. Aim: This process evaluation was undertaken to understand how an integrated care intervention was experienced by the care providers and patients, and to inform modifications before possible scaling. Design & setting: The mixed-methods study was conducted as part of a cluster randomised trial on integrated hypertension care at 26 private clinics. Method: The care practices were assessed by analysing the clinical records of 1138 registered patients with hypertension. Then semi-structured interviews with service providers and patients were used to understand their respective care experiences. A framework approach was applied to analyse and interpret the qualitative data. Results: District-led objective selection and context-sensitive staff training helped to get the clinics engaged in partnership working. About one-third of patients with hypertension had associated diabetes or renal compromise. The prescription of drugs is influenced by multiple non-clinical considerations of providers and patients. Many doctors allowed the use of home-based remedies as supplements to the prescribed allopathic drugs. Female patients faced more challenges in managing lifestyle changes. The intervention improved adherence to follow-up visits, but patient attrition remained a challenge. Conclusion: The integrated hypertension care intervention at private clinics is feasible, and leads to improved diagnosis and treatment in low-income country urban setting. The authors recommend continued implementation research and informed scaling of hypertension care at private clinics
    corecore