144 research outputs found

    Comparative physiology of Australian quolls (Dasyurus; Marsupialia)

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    Quolls (Dasyurus) are medium-sized carnivorous dasyurid marsupials. Tiger (3,840 g) and eastern quolls (780 g) are mesic zone species, northern quolls (516 g) are tropical zone, and chuditch (1,385 g) were once widespread through the Australian arid zone. We found that standard physiological variables of these quolls are consistent with allometric expectations for marsupials. Nevertheless, inter-specific patterns amongst the quolls are consistent with their different environments. The lower T ^sub b^ of northern quolls (34°C) may provide scope for adaptive hyperthermia in the tropics, and they use torpor for energy/water conservation, whereas the larger mesic species (eastern and tiger quolls) do not appear to. Thermolability varied from little in eastern (0.035°C °C^sup -1^) and tiger quolls (0.051°C ºC^sup -1^) to substantial in northern quolls (0.100°C ºC^sup -1^) and chuditch (0.146°C ºC^sup -1^), reflecting body mass and environment. Basal metabolic rate was higher for eastern quolls (0.662 ± 0.033 ml O^sub 2^ g^sup -1^ h^sup -1^), presumably reflecting their naturally cool environment. Respiratory ventilation closely matched metabolic demand, except at high ambient temperatures where quolls hyperventilated to facilitate evaporative heat loss; tiger and eastern quolls also salivated. A higher evaporative water loss for eastern quolls (1.43 ± 0.212 mg H^sub 2^O g^sup -1^ h^sup -1^) presumably reflects their more mesic distribution. The point of relative water economy was low for tiger (-1.3°C), eastern (-12.5°C) and northern (+3.3) quolls, and highest for the chuditch (+22.6°C). We suggest that these differences in water economy reflect lower expired air temperatures and hence lower respiratory evaporative water loss for the arid-zone chuditch relative to tropical and mesic quolls

    Data management for prospective research studies using SAS® software

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    <p>Abstract</p> <p>Background</p> <p>Maintaining data quality and integrity is important for research studies involving prospective data collection. Data must be entered, erroneous or missing data must be identified and corrected if possible, and an audit trail created.</p> <p>Methods</p> <p>Using as an example a large prospective study, the Missouri Lower Respiratory Infection (LRI) Project, we present an approach to data management predominantly using SAS software. The Missouri LRI Project was a prospective cohort study of nursing home residents who developed an LRI. Subjects were enrolled, data collected, and follow-ups occurred for over three years. Data were collected on twenty different forms. Forms were inspected visually and sent off-site for data entry. SAS software was used to read the entered data files, check for potential errors, apply corrections to data sets, and combine batches into analytic data sets. The data management procedures are described.</p> <p>Results</p> <p>Study data collection resulted in over 20,000 completed forms. Data management was successful, resulting in clean, internally consistent data sets for analysis. The amount of time required for data management was substantially underestimated.</p> <p>Conclusion</p> <p>Data management for prospective studies should be planned well in advance of data collection. An ongoing process with data entered and checked as they become available allows timely recovery of errors and missing data.</p

    Lateral wedge insoles for reducing biomechanical risk factors for medial knee osteoarthritis progression : a systematic review and meta-analysis

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    Objective Lateral wedge insoles are intended to reduce biomechanical risk factors of medial knee osteoarthritis (OA) progression, such as increased knee joint load; however, there has been no definitive consensus on this topic. The aim of this systematic review and meta-analysis was to establish the within-subject effects of lateral wedge insoles on knee joint load in people with medial knee OA during walking. Methods Six databases were searched from inception until February 13th 2015. Included studies reported on the acute biomechanical effects of lateral wedge insoles in people with medial knee osteoarthritis during walking. Primary outcomes of interest relating to the biomechanical risk of disease progression were the 1st and 2nd peak external knee adduction moment (EKAM) and knee adduction angular impulse (KAAI). Eligible studies were pooled using random-effects meta-analysis. Results Eighteen studies were included with a total of 534 participants. Lateral wedge insoles resulted in a small but statistically significant reduction in the 1st peak EKAM (SMD: -0.19; 95% CI -0.23 − -0.15) and 2nd peak EKAM (SMD: -0.25; 95% CI -0.32 − -0.19) with a low level of heterogeneity (I2 = 5% and 30%, respectively). There was a favourable but small reduction in the KAAI with lateral wedge insoles (SMD: -0.14; 95% CI -0.21 − -0.07, I2 =31%). Risk of methodological bias scores (Quality Index) ranged from 8 to 13 out of 16. Conclusions Lateral wedge insoles cause small reductions in the EKAM and KAAI in people with medial knee OA during walking. At present, they appear ineffective at attenuating structural changes in people with medial knee OA as a whole and may be better suited to targeted use in biomechanical phenotypes associated with larger reductions in knee load

    Does Cataract Surgery Alleviate Poverty? Evidence from a Multi-Centre Intervention Study Conducted in Kenya, the Philippines and Bangladesh

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    BACKGROUND: Poverty and blindness are believed to be intimately linked, but empirical data supporting this purported relationship are sparse. The objective of this study is to assess whether there is a reduction in poverty after cataract surgery among visually impaired cases. METHODOLOGY/PRINCIPAL FINDINGS: A multi-centre intervention study was conducted in three countries (Kenya, Philippines, Bangladesh). Poverty data (household per capita expenditure--PCE, asset ownership and self-rated wealth) were collected from cases aged ≥50 years who were visually impaired due to cataract (visual acuity<6/24 in the better eye) and age-sex matched controls with normal vision. Cases were offered free/subsidised cataract surgery. Approximately one year later participants were re-interviewed about poverty. 466 cases and 436 controls were examined at both baseline and follow-up (Follow up rate: 78% for cases, 81% for controls), of which 263 cases had undergone cataract surgery ("operated cases"). At baseline, operated cases were poorer compared to controls in terms of PCE (Kenya: 22versus£35p=0.02,Bangladesh:22 versus £35 p = 0.02, Bangladesh: 16 vs 24p=0.004,Philippines:24 p = 0.004, Philippines: 24 vs 32 p = 0.0007), assets and self-rated wealth. By follow-up PCE had increased significantly among operated cases in each of the three settings to the level of controls (Kenya: 30versus£36p=0.49,Bangladesh:30 versus £36 p = 0.49, Bangladesh: 23 vs 23p=0.20,Philippines:23 p = 0.20, Philippines: 45 vs $36 p = 0.68). There were smaller increases in self-rated wealth and no changes in assets. Changes in PCE were apparent in different socio-demographic and ocular groups. The largest PCE increases were apparent among the cases that were poorest at baseline. CONCLUSIONS/SIGNIFICANCE: This study showed that cataract surgery can contribute to poverty alleviation, particularly among the most vulnerable members of society. This study highlights the need for increased provision of cataract surgery to poor people and shows that a focus on blindness may help to alleviate poverty and achieve the Millennium Development Goals

    Sentinel Node Identification Rate and Nodal Involvement in the EORTC 10981-22023 AMAROS Trial

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    Background The randomized EORTC 10981-22023 AMAROS trial investigates whether breast cancer patients with a tumor-positive sentinel node biopsy (SNB) are best treated with an axillary lymph node dissection (ALND) or axillary radiotherapy (ART). The aim of the current substudy was to evaluate the identification rate and the nodal involvement. Methods The first 2,000 patients participating in the AMAROS trial were evaluated. Associations between the identification rate and technical, patient-, and tumor-related factors were evaluated. The outcome of the SNB procedure and potential further nodal involvement was assessed. Results In 65 patients, the sentinel node could not be identified. As a result, the sentinel node identification rate was 97% (1,888 of 1,953). Variables affecting the success rate were age, pathological tumor size, histology, year of accrual, and method of detection. The SNB results of 65% of the patients (n = 1,220) were negative and the patients underwent no further axillary treatment. The SNB results were positive in 34% of the patients (n = 647), including macrometastases (n = 409, 63%), micrometastases (n = 161, 25%), and isolated tumor cells (n = 77, 12%). Further nodal involvement in patients with macrometastases, micrometastases, and isolated tumor cells undergoing an ALND was 41, 18, and 18%, respectively. Conclusions With a 97% detection rate in this prospective international multicenter study, the SNB procedure is highly effective, especially when the combined method is used. Further nodal involvement in patients with micrometastases and isolated tumor cells in the sentinel node was similar—both were 18%

    Prevalence, Causes and Socio-Economic Determinants of Vision Loss in Cape Town, South Africa

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    PURPOSE: To estimate the prevalence and causes of blindness and visual impairment in Cape Town, South Africa and to explore socio-economic and demographic predictors of vision loss in this setting. METHODS: A cross sectional population-based survey was conducted in Cape Town. Eighty-two clusters were selected using probability proportionate to size sampling. Within each cluster 35 or 40 people aged 50 years and above were selected using compact segment sampling. Visual acuity of participants was assessed and eyes with a visual acuity less than 6/18 were examined by an ophthalmologist to determine the cause of vision loss. Demographic data (age, gender and education) were collected and a socio-economic status (SES) index was created using principal components analysis. RESULTS: Out of 3100 eligible people, 2750 (89%) were examined. The sample prevalence of bilateral blindness (presenting visual acuity <3/60) was 1.4% (95% CI 0.9-1.8). Posterior segment diseases accounted for 65% of blindness and cataract was responsible for 27%. The prevalence of vision loss was highest among people over 80 years (odds ratio (OR) 6.9 95% CI 4.6-10.6), those in the poorest SES group (OR 3.9 95% CI 2.2-6.7) and people with no formal education (OR 5.4 95% CI 1.7-16.6). Cataract surgical coverage was 68% in the poorest SES tertile (68%) compared to 93% in the medium and 100% in the highest tertile. CONCLUSIONS: The prevalence of blindness among people ≥50 years in Cape Town was lower than expected and the contribution of posterior segment diseases higher than previously reported in South Africa and Sub Saharan Africa. There were clear socio-economic disparities in prevalence of vision loss and cataract surgical coverage in this setting which need to be addressed in blindness prevention programs

    Costs of Reproduction and Terminal Investment by Females in a Semelparous Marsupial

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    Evolutionary explanations for life history diversity are based on the idea of costs of reproduction, particularly on the concept of a trade-off between age-specific reproduction and parental survival, and between expenditure on current and future offspring. Such trade-offs are often difficult to detect in population studies of wild mammals. Terminal investment theory predicts that reproductive effort by older parents should increase, because individual offspring become more valuable to parents as the conflict between current versus potential future offspring declines with age. In order to demonstrate this phenomenon in females, there must be an increase in maternal expenditure on offspring with age, imposing a fitness cost on the mother. Clear evidence of both the expenditure and fitness cost components has rarely been found. In this study, we quantify costs of reproduction throughout the lifespan of female antechinuses. Antechinuses are nocturnal, insectivorous, forest-dwelling small (20–40 g) marsupials, which nest in tree hollows. They have a single synchronized mating season of around three weeks, which occurs on predictable dates each year in a population. Females produce only one litter per year. Unlike almost all other mammals, all males, and in the smaller species, most females are semelparous. We show that increased allocation to current reproduction reduces maternal survival, and that offspring growth and survival in the first breeding season is traded-off with performance of the second litter in iteroparous females. In iteroparous females, increased allocation to second litters is associated with severe weight loss in late lactation and post-lactation death of mothers, but increased offspring growth in late lactation and survival to weaning. These findings are consistent with terminal investment. Iteroparity did not increase lifetime reproductive success, indicating that terminal investment in the first breeding season at the expense of maternal survival (i.e. semelparity) is likely to be advantageous for females

    Integration of modeling and simulation into hospital-based decision support systems guiding pediatric pharmacotherapy

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    <p>Abstract</p> <p>Background</p> <p>Decision analysis in hospital-based settings is becoming more common place. The application of modeling and simulation approaches has likewise become more prevalent in order to support decision analytics. With respect to clinical decision making at the level of the patient, modeling and simulation approaches have been used to study and forecast treatment options, examine and rate caregiver performance and assign resources (staffing, beds, patient throughput). There us a great need to facilitate pharmacotherapeutic decision making in pediatrics given the often limited data available to guide dosing and manage patient response. We have employed nonlinear mixed effect models and Bayesian forecasting algorithms coupled with data summary and visualization tools to create drug-specific decision support systems that utilize individualized patient data from our electronic medical records systems.</p> <p>Methods</p> <p>Pharmacokinetic and pharmacodynamic nonlinear mixed-effect models of specific drugs are generated based on historical data in relevant pediatric populations or from adults when no pediatric data is available. These models are re-executed with individual patient data allowing for patient-specific guidance via a Bayesian forecasting approach. The models are called and executed in an interactive manner through our web-based dashboard environment which interfaces to the hospital's electronic medical records system.</p> <p>Results</p> <p>The methotrexate dashboard utilizes a two-compartment, population-based, PK mixed-effect model to project patient response to specific dosing events. Projected plasma concentrations are viewable against protocol-specific nomograms to provide dosing guidance for potential rescue therapy with leucovorin. These data are also viewable against common biomarkers used to assess patient safety (e.g., vital signs and plasma creatinine levels). As additional data become available via therapeutic drug monitoring, the model is re-executed and projections are revised.</p> <p>Conclusion</p> <p>The management of pediatric pharmacotherapy can be greatly enhanced via the immediate feedback provided by decision analytics which incorporate the current, best-available knowledge pertaining to dose-exposure and exposure-response relationships, especially for narrow therapeutic agents that are difficult to manage.</p

    Linking Fearfulness and Coping Styles in Fish

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    Consistent individual differences in cognitive appraisal and emotional reactivity, including fearfulness, are important personality traits in humans, non-human mammals, and birds. Comparative studies on teleost fishes support the existence of coping styles and behavioral syndromes also in poikilothermic animals. The functionalist approach to emotions hold that emotions have evolved to ensure appropriate behavioral responses to dangerous or rewarding stimuli. Little information is however available on how evolutionary widespread these putative links between personality and the expression of emotional or affective states such as fear are. Here we disclose that individual variation in coping style predicts fear responses in Nile tilapia Oreochromis niloticus, using the principle of avoidance learning. Fish previously screened for coping style were given the possibility to escape a signalled aversive stimulus. Fearful individuals showed a range of typically reactive traits such as slow recovery of feed intake in a novel environment, neophobia, and high post-stress cortisol levels. Hence, emotional reactivity and appraisal would appear to be an essential component of animal personality in species distributed throughout the vertebrate subphylum

    Attachment, infidelity, and loneliness in college students involved in a romantic relationship: the role of relationship satisfaction, morbidity and prayer for partner

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    This study examined the mediating effects of relationship satisfaction, prayer for a partner, and morbidity in the relationship between attachment and loneliness, infidelity and loneliness, and psychological morbidity and loneliness, in college students involved in a romantic relationship. Participants were students in an introductory course on family development. This study examined only students (n = 345) who were involved in a romantic relationship. The average age of participants was 19.46 (SD = 1.92) and 25 % were males. Short-form UCLA Loneliness Scale (ULS-8), (Hays and DiMatteo in J Pers Assess 51:69–81, doi:10.1207/s15327752jpa5101_6, 1987); Relationship Satisfaction Scale (Funk and Rogge in J Fam Psychol 21:572–583, doi:10.1037/0893-3200.21.4.572, 2007); Rotterdam Symptom Checklist (De Haes et al. in Measuring the quality of life of cancer patients with the Rotterdam Symptom Checklist (RSCL): a manual, Northern Centre for Healthcare Research, Groningen, 1996); Prayer for Partner Scale, (Fincham et al. in J Pers Soc Psychol 99:649–659, doi:10.1037/a0019628, 2010); Infidelity Scale, (Drigotas et al. in J Pers Soc Psychol 77:509–524, doi:10.1037/0022-3514.77.3.509, 1999); and the Experiences in Close Relationship Scale-short form (Wei et al. in J Couns Psychol 52(4):602–614, doi:10.1037/0022-0167.52.4.602, 2005). Results showed that relationship satisfaction mediated the relationship between avoidance attachment and loneliness and between infidelity and loneliness. Physical morbidity mediated the relationship between anxious attachment and psychological morbidity. Psychological morbidity mediated the relationship between anxious attachment and physical morbidity. The present results expand the literature on attachment by presenting evidence that anxious and avoidant partners experience loneliness differently. Implications for couple’s therapy are addressed. Future research should replicate these results with older samples and married couples.Acknowledgments This research was supported by Grant Number 90FE0022 from the United States Department of Health and Human Services awarded to the last author
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