22 research outputs found

    Locomotor loading mechanics in the hindlimbs of tegu lizards (Tupinambis merinae): comparitive and evolutionary implications

    Get PDF
    Skeletal elements are usually able to withstand several times their usual load before they yield, and this ratio is known as the bone\u27s safety factor. Limited studies on amphibians and non-avian reptiles have shown that they have much higher limb bone safety factors than birds and mammals. It has been hypothesized that this difference is related to the difference in posture between upright birds and mammals and sprawling ectotherms; however, limb bone loading data from a wider range of sprawling species are needed in order to determine whether the higher safety factors seen in amphibians and non-avian reptiles are ancestral or derived conditions. Tegus (family Teiidae) are an ideal lineage with which to expand sampling of limb bone loading mechanics for sprawling taxa, particularly for lizards, because they are from a different clade than previously sampled iguanas and exhibit different foraging and locomotor habits (actively foraging carnivore versus burst-activity herbivore). We evaluated the mechanics of locomotor loading for the femur of the Argentine black and white tegu (Tupinambus merianae) using three-dimensional measurements of the ground reaction force and hindlimb kinematics, in vivo bone strains and femoral mechanical properties. Peak bending stresses experienced by the femur were low (tensile: 10.4±1.1 MPa; compressive: –17.4±0.9 MPa) and comparable to those in other reptiles, with moderate shear stresses and strains also present. Analyses of peak femoral stresses and strains led to estimated safety factor ranges of 8.8–18.6 in bending and 7.8–17.5 in torsion, both substantially higher than typical for birds and mammals but similar to other sprawling tetrapods. These results broaden the range of reptilian and amphibian taxa in which high femoral safety factors have been evaluated and further indicate a trend for the independent evolution of lower limb bone safety factors in endothermic taxa

    Moving Forward in Fostering Humour: Towards Training Lighter Forms of Humour in Multicultural Contexts

    Full text link
    The following theoretical position paper has the aim to outline two important future directions of humour intervention research. Firstly, existing humour trainings have not differentiated explicitly between different uses of humour or humour that may be virtuous or not. Within the realm of Positive Psychology, all virtuous forms of humour need to be identified and interventions developed that aim at fostering these benevolent/lighter forms. Secondly, most humour trainings have been adapted and conducted in one cultural context. Future trainings should consider cross-cultural perspectives to allow for comparative research and practice. Thus, the current paper first gives an overview on the extant literature on the distinction between lighter and darker forms of humour, as well as showing how humour can serve the virtues proposed by Peterson and Seligman (2004). Then, we elaborate on the findings on humour and well-being, as well as findings on existing humour interventions. The second section starts with open questions and hypotheses on how a new generation of trainings targeting lighter forms of humour could look like. Then, we discuss (potential) cultural differences in humour and how this may affect the design of interventions. When aiming for cross-cultural adaptations of the same humour program, several challenges have to be overcome, such as the term “humour” not having the same meaning in every culture, and cultural rules on what can be laughed at

    Locomotor loading mechanics in the hindlimbs of tegu lizards (Tupinambis merianae): Comparative and evolutionary implications

    Get PDF
    Skeletal elements are usually able to withstand several times their usual load before they yield, and this ratio is known as the bone’s safety factor. Limited studies on amphibians and non-avian reptiles have shown that they have much higher limb bone safety factors than birds and mammals. It has been hypothesized that this difference is related to the difference in posture between upright birds and mammals and sprawling ectotherms; however, limb bone loading data from a wider range of sprawling species are needed in order to determine whether the higher safety factors seen in amphibians and non-avian reptiles are ancestral or derived conditions. Tegus (family Teiidae) are an ideal lineage with which to expand sampling of limb bone loading mechanics for sprawling taxa, particularly for lizards, because they are from a different clade than previously sampled iguanas and exhibit different foraging and locomotor habits (actively foraging carnivore versus burst-activity herbivore). We evaluated the mechanics of locomotor loading for the femur of the Argentine black and white tegu (Tupinambus merianae) using three- dimensional measurements of the ground reaction force and hindlimb kinematics, in vivo bone strains and femoral mechanical properties. Peak bending stresses experienced by the femur were low (tensile: 10.4±1.1MPa; compressive: –17.4±0.9MPa) and comparable to those in other reptiles, with moderate shear stresses and strains also present. Analyses of peak femoral stresses and strains led to estimated safety factor ranges of 8.8–18.6 in bending and 7.8–17.5 in torsion, both substantially higher than typical for birds and mammals but similar to other sprawling tetrapods. These results broaden the range of reptilian and amphibian taxa in which high femoral safety factors have been evaluated and further indicate a trend for the independent evolution of lower limb bone safety factors in endothermic taxa

    Dialysis facility staff perceptions of racial, gender, and age disparities in access to renal transplantation

    No full text
    Abstract Background Racial/ethnic, gender, and age disparities in access to renal transplantation among end-stage renal disease (ESRD) patients have been well documented, but few studies have explored health care staff attitudes towards these inequalities. Staff perceptions can influence patient care and outcomes, and identifying staff perceptions on disparities could aid in the development of potential interventions to address these health inequities. The objective of this study was to investigate dialysis staff (n = 509), primarily social workers and nurse managers, perceptions of renal transplant disparities in the Southeastern United States. Methods This is a mixed methods study that uses both deductive and inductive qualitative analysis of a dialysis staff survey conducted in 2012 using three open-ended questions that asked staff to discuss their perceptions of factors that may contribute to transplant disparities among African American, female, and elderly patients. Results Study results suggested that the majority of staff (n = 255, 28%) perceived patients’ low socioeconomic status as the primary theme related to why renal transplant disparities exist between African Americans and non-Hispanic whites. Staff cited patient perception of old age as a primary contributor (n = 188, 23%) to the disparity between young and elderly patients. The dialysis staff responses on gender transplant disparities suggested that staff were unaware of differences due to limited experience and observation (n = 76, 14.7%) of gender disparities. Conclusions These findings suggest that dialysis facilities should educate staff on existing renal transplantation disparities, particularly gender disparities, and collaboratively work with transplant facilities to develop strategies to actively address modifiable patient barriers for transplant

    Addition of estimated cardiorespiratory fitness to the clinical assessment of 10-year coronary heart disease risk in asymptomatic men

    No full text
    The Framingham Risk Score (FRS) was developed to quantify a patient's coronary heart disease (CHD) risk. Non-exercise estimated CRF (e-CRF) may provide a clinically practical method for describing cardiorespiratory fitness. We computed e-CRF and tested its association with the FRS and CHD. Male participants (n\ua0=\ua029,854) in the Aerobics Center Longitudinal Study (ACLS) who completed a baseline examination between 1979–2002 were followed for 12 years to determine incident CHD defined by self-report of myocardial infarction, revascularization, or CHD mortality. e-CRF was defined from a 7-item scale and categorized using age-specific tertiles. Multivariable survival analysis determined associations between FRS, e-CRF, and CHD. Interaction between e-CRF and FRS was tested by stratified analysis by ‘low’ and ‘moderate or high’ 10-year CHD risk. Men with high e-CRF were significantly (p-value\ua

    Association of Cardiorespiratory Fitness With Coronary Heart Disease in Asymptomatic Men

    No full text
    Objective To examine the association of cardiorespiratory fitness (CRF) with risk of coronary heart disease (CHD) while controlling for an individual's Framingham Risk Score (FRS)-predicted CHD risk. Patients and Methods The study included 29,854 men from the Aerobics Center Longitudinal Study, who received a baseline examination from January 1, 1979, to December 31, 2002. Coronary heart disease events included self-reported myocardial infarction or revascularization or CHD death. Multivariable survival analysis investigated the association between CRF, FRS, and CHD. Cardiorespiratory fitness was analyzed as both a continuous and a categorical variable. The population was stratified by "low" and "moderate or high" risk of CHD to test for differences in the FRS stratified by CRF. Results Compared with men without incident CHD, men with incident CHD were older (mean age, 51.6 years vs 44.6 years), had lower average maximally achieved fitness (10.9 metabolic equivalent of tasks vs 12.0 metabolic equivalent of tasks [METs]), and were more likely to have moderate or high 10-year CHD risk (

    A Randomized Controlled Trial of a Mobile Clinical Decision Aid to Improve Access to Kidney Transplantation: iChoose Kidney

    Get PDF
    Kidney transplantation is the preferred treatment for patients with end-stage renal disease, as it substantially increases a patient’s survival and is cost-saving compared to a lifetime of dialysis. However, transplantation is not universally chosen by patients with renal failure, and limited knowledge about the survival benefit of transplantation versus dialysis may play a role. We created a mobile application clinical decision aid called iChoose Kidney to improve access to individualized prognosis information comparing dialysis and transplantation outcomes. Methods: We describe the iChoose Kidney study, a randomized controlled trial designed to test the clinical efficacy of a mobile health decision aid among end-stage renal disease patients referred for kidney transplantation at 3 large, diverse transplant centers across the United States. Approximately 450 patients will be randomized to receive either (i) standard of care or “usual” transplantation education, or (ii) standard of care plus iChoose Kidney. Results: The primary outcome is change in knowledge about the survival benefit of kidney transplantation versus dialysis from baseline to immediate follow-up; secondary outcomes include change in treatment preferences, improved decisional conflict, and increased access to kidney transplantation. Analyses are also planned to examine effectiveness across subgroups of race, socioeconomic status, health literacy, and health numeracy. Discussion: Engaging patients in health care choices can increase patient empowerment and improve knowledge and understanding of treatment choices. If the effectiveness of iChoose Kidney has a greater impact on patients with low health literacy, lower socioeconomic status, and minority race, this decision aid could help reduce disparities in access to kidney transplantation
    corecore