215 research outputs found

    How do Zimbabweans value health states?

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    Background Quality of life weights based on valuations of health states are often used in cost utility analysis and population health measures. This paper reports on an attempt to develop quality of life weights within the Zimbabwe context. Methods 2,384 residents in randomly selected small residential plots of land in a high-density suburb of Harare valued descriptors of 38 health states based on different combinations of the five domains of the EQ-5D (mobility, self-care, usual activities, pain or discomfort and anxiety or depression). The English version of the EQ-5D was used. The time trade-off method was used to determine the values, and 19,020 individual preferences for health states were analysed. A residual maximum likelihood linear mixed model was used to estimate a function for predicting the values of all possible combinations of levels on the five domains. The model was fit to a random subset of two-thirds of the observations, with the remaining observations reserved for analysis of predictive validity. The results were compared to a similar study undertaken in the United Kingdom. Results A credible model was developed to predict the values of states that were not valued directly. In the subset of observations reserved for validation, the mean absolute difference between predicted and observed values was 0.045. All domains of the EQ-5D were found to contribute significantly to the model, both at the moderate and severe levels. Severe pain was found to have the largest negative coefficient, followed by the inability to wash and dress oneself. Conclusion Despite a generally lower education level than their European counterparts, urban Zimbabweans appear to value health states in a consistent manner, and the determination of a global method of establishing quality of life weights may be feasible and valid. However, as the relative weightings of the different domains, although correlated, differed from the standard set of weights recommended by the EuroQol Group, the locally determined coefficients should be used within the Zimbabwean context

    Confirmation of the Chinese version of the Problematic Internet Use Questionnaire Short Form (PIUQ-SF)

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    Although an increasing number of studies have focused on problematic Internet use, numerous measures exist with only modest investigation into their reliability and validity, both within and across different cultures (Király et al. 2015). The most frequently used questionnaire is the Internet Addiction Test (Young 1998). However, its factor structure appears to be unstable (e.g., Fernandez-Villa et al. 2015; Pontesetal. 2014). Koronczai et al. (2011) suggested that a suitable measure should fit six basic requirements. More specifically, it should be (i) comprehensive, that is examining more, possibly all, aspects of problematic Internet use; (ii) as concise as possible, in order to be able to assess the more impulsive population, and to use in time-limited surveys (or having different forms with different length). Such a measure should be (iii) reliable and valid for different methods of data collection (e.g. online, paper-and-pencil self-rating, face-to-face); as well as (iv) for different age groups (e.g. adolescents and adults), and (v) in different cultural settings. Finally, (vi) cut-off scores should be defined on the basis of clinical examination. The Problematic Internet Use Questionnaire (PIUQ) (Demetrovics et al. 2008) fulfills several of the aforementioned criteria. The 18-item PIUQ is a comprehensive measure that assesses three basic aspects of problematic Internet use (i.e., obsession, neglect, and control disorder). The 18-item and the shorter 9-item versions of the PIUQ have a reliable structure, and are suitable for time-limited surveys and have proved to be valid across various methods of data collection (i.e., online as well as paper-pencil) and age groups (Demetrovics et al. 2008; Koronczai et al. 2011). However, its implementation has so far mostly taken place in Western individualistic cultures (Kelley and Gruber 2010, 2013; Koronczai et al. 2011; Zahodne et al. 2011. To date, the PIUQ has also been applied in a survey in Iran with good Cronbach’s alpha coefficients and subscales (Mazhari 2012a, 2012b). Consequently, validation of the questionnaire in a culture that is significantly different from the Western culture is needed. Accordingly, the aim of the present study was the validation of the 9-item PIUQ among the Chinese population

    The influence of a pre-exercise sports drink (PRX) on factors related to maximal aerobic performance

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    <p>Abstract</p> <p>Background</p> <p>Pre-exercise sports drinks (PRX) are commonly used as ergogenic aids in athletic competitions requiring aerobic power. However, in most cases, claims regarding their effectiveness have not been substantiated. In addition, the ingredients in PRX products must be deemed acceptable by the athletic governing bodies that regulate their use in training and competition. The purpose of this study was to examine the effects of a modified PRX formulation (known as EM·PACTℱ) from earlier investigations on factors related to maximal aerobic performance during a graded exercise test. The modification consisted of removing creatine to meet the compliance standards set forth by various athletic organizations that regulate the use of nutritional supplements.</p> <p>Methods</p> <p>Twenty-nine male and female college students varying in levels of aerobic fitness participated in a randomized crossover administration of PRX (containing 14 g/serving of fructose, medium-chain triglycerides, and amino acids mixed with 8 oz. of water) and placebo (PL) 30 minutes prior to performing a treadmill test with approximately one week separation between the trials. VO<sub>2</sub>max, maximal heart rate (HR), time to exhaustion (Time), and percentage estimated non-protein fat substrate utilization (FA) during two <it>a priori </it>submaximal stages of a graded exercise testing were evaluated.</p> <p>Results</p> <p>The VO<sub>2</sub>max mean value of the PRX trial was significantly greater than the PL trial (P < 0.01). The mean value for Time was also observed to be greater for the PRX trial compared to PL (P < 0.05). Additionally, percentage of FA during submaximal stages of the exercise test was greater for PRX trial in comparison to PL (P < 0.01).</p> <p>Conclusions</p> <p>The modified PRX formulation utilized in this investigation supports the findings of the previous investigation and its efficacy for enhancing indices of aerobic performance (specifically VO<sub>2</sub>max, Time, & FA) during graded exercise testing.</p

    Spanish Validation of the Flourishing Scale in the General Population

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    Well-being research and its measurement have grown in the last two decades. The objective of this study was to adapt and validate the Flourishing Scale in a sample of Spanish adults. This was a cross-sectional study using a non-probabilistic sample of 999 Spanish general adult population participants. The psychometric properties of the scale were analysed from an exploratory and confirmatory perspective. Exploratory factor analysis showed a one-factor solution explaining 42.3% of the variance; an internal consistency of .846; temporal reliability correlation of .749; convergent validity with the Satisfaction with Life Scale of .521 and criterion validity with positive and negative affect (PANAS), pessimism and optimism (LOT-R) ranging from .270 to .488. Confirmatory factor analysis testing the one-factor solution showed a χ2 of 65.57 df = 20; CFI of .982, RMSEA of .06, average variance extracted index of .518 and composite reliability index of .841. Results showed that the Spanish version of the FS is a reliable and valid method for measuring high levels of well-bein

    Soil water-holding capacity and monodominance in Southern Amazon tropical forests

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    Background and aims: We explored the hypothesis that low soil water-holding capacity is the main factor driving the monodominance of Brosimum rubescens in a monodominant forest in Southern Amazonia. Tropical monodominant forests are rare ecosystems with low diversity and high dominance of a single tree species. The causes of this atypical condition are still poorly understood. Some studies have shown a relationship between monodominance and waterlogging or soil attributes, while others have concluded that edaphic factors have little or no explanatory value, but none has accounted for soil-moisture variation other than waterlogging. This study is the first to explicitly explore how low soil water-holding capacity influences the monodominance of tropical forests. Methods: We conducted in situ measurements of vertical soil moisture using electrical resistance collected over 1 year at 0–5; 35–40 and 75–80 cm depths in a B. rubescens monodominant forest and in an adjacent mixed-species forest in the Amazon-Cerrado transition zone, Brazil. Minimum leaf water potential (ιmin) of the seven most common species, including B. rubescens, and soil water-holding capacity for both forests were determined. Results: The vertical soil moisture decay pattern was similar in both forests for all depths. However, the slightly higher water availability in the monodominant forest and ιmin similarity between B. rubescens and nearby mixed forest species indicate that low water-availability does not cause the monodominance. Conclusions: We reject the hypothesis that monodominance of B. rubescens is primarily determined by low soil water-holding capacity, reinforcing the idea that monodominance in tropical forests is not determined by a single factor

    Range Expansion Drives Dispersal Evolution In An Equatorial Three-Species Symbiosis

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    A-09-14International audienceBackground Recurrent climatic oscillations have produced dramatic changes in species distributions. This process has been proposed to be a major evolutionary force, shaping many life history traits of species, and to govern global patterns of biodiversity at different scales. During range expansions selection may favor the evolution of higher dispersal, and symbiotic interactions may be affected. It has been argued that a weakness of climate fluctuation-driven range dynamics at equatorial latitudes has facilitated the persistence there of more specialized species and interactions. However, how much the biology and ecology of species is changed by range dynamics has seldom been investigated, particularly in equatorial regions. Methodology/Principal Findings We studied a three-species symbiosis endemic to coastal equatorial rainforests in Cameroon, where the impact of range dynamics is supposed to be limited, comprised of two species-specific obligate mutualists –an ant-plant and its protective ant– and a species-specific ant parasite of this mutualism. We combined analyses of within-species genetic diversity and of phenotypic variation in a transect at the southern range limit of this ant-plant system. All three species present congruent genetic signatures of recent gradual southward expansion, a result compatible with available regional paleoclimatic data. As predicted, this expansion has been accompanied by the evolution of more dispersive traits in the two ant species. In contrast, we detected no evidence of change in lifetime reproductive strategy in the tree, nor in its investment in food resources provided to its symbiotic ants. Conclusions/Significance Despite the decreasing investment in protective workers and the increasing investment in dispersing females by both the mutualistic and the parasitic ant species, there was no evidence of destabilization of the symbiosis at the colonization front. To our knowledge, we provide here the first evidence at equatorial latitudes that biological traits associated with dispersal are affected by the range expansion dynamics of a set of interacting species

    Assessing the predictability of self-harm in a high-risk adult prisoner population: a prospective cohort study

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    Background: Prisoners are at increased risk of self-harm and when either intent is expressed, or an act of self-harm carried out, prisoners in the UK are subject to self-harm/suicide monitoring (referred to as “open ACCT” monitoring). However, there is a paucity of validated instruments to identify risk of self-harm in prisoner populations. In response to the need to support prison staff to determine who is at increased risk of self-harm or repeat self-harm, the aim of this study was to determine whether any pre-existing, standardised instruments could usefully identify future self-harm events in prisoners undergoing ACCT monitoring. Methods: A multi-stage prospective cohort study was conducted, where the Prison Screening Questionnaire (PriSnQuest), a modified Borderline Symptom List-23 (BSL-23), Self-Harm Inventory (SHI), Patient Health Questionnaire-9 (PHQ-9) and Clinical Outcomes in Routine Evaluation – Outcome Measure (CORE-OM) instruments were administered to prisoners aged 18 and above, who were judged to be at an increased risk of self-harm (on open ACCT monitoring) during the recruitment phase. A 6-month follow-up determined self-harm occurrence since baseline, and Area-Under-the-Curve (AUC) analysis examined the ability of the instruments to predict future self-harm. Results: Prison records established that 29.1% self-harmed during the follow up period, involving a total of 423 self-harm events reported from 126 individuals, followed up for 66,789 prisoner days (median 167 days; IQR 71–207.5 days). This translated to an ‘event incidence’ of 6.33 per 1000 prisoner days of those who had been placed upon an ACCT, or ‘prisoner incidence’ of 1.89 per 1000 days, with considerable variation for both gender and participating prisons. None of the summary scores derived from the selected instruments showed a meaningful ability to predict self-harm, however, exploratory logistic regression analysis of individual background and instrument items revealed gender-specific item sets which were statistically significant in predicting future self-harm. Conclusions: Prospective self-harm was not predicted by any of the pre-existing instruments that were under consideration. Exploratory logistic regression analysis did reveal gender-specific item sets, producing predictive algorithms which were statistically significant in predicting future self-harm; however, the operational functionality of these item sets may be limited
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