The construct validity of the work-related flow inventory in a sample of Australian workers

The purpose of this study was to examine the construct validity of the WOrk-reLated Flow inventory (WOLF; Bakker, 2008). This instrument was administered to 711 men and women who were working in Queensland, Australia. The results from the confirmatory factor analysis showed that the WOLF has moderately acceptable construct validity, with the three-factor model being a borderline fit to the data. Tests of the convergent validity of the WOLF yielded satisfactory results. However, the analysis of the discriminant validity of the WOLF showed that the instrument poorly discriminated between work enjoyment and intrinsic work motivation. Follow-up exploratory factor analysis, using recommended procedures for determining the number of factors to extract, revealed a two-factor solution, with the work enjoyment and intrinsic work motivation items loading on the same factor. Drawing on literature on psychological flow and motivation, as well as the findings of the present study, questions are raised over the adequacy of the conceptual basis of the three-factor model of work-related flow, the discriminant validity of the WOLF subscales, and the appropriateness of the wording of several of this measure's items. Using alternative methods and measures to investigate flow in work settings is recommended.

Predicting protein function using multiple kernels

High-throughput experimental techniques provide a wide variety of heterogeneous proteomic data sources. To exploit the information spread across multiple sources for protein function prediction, these data sources are transformed into kernels and then integrated into a composite kernel. Several methods first optimize the weights on these kernels to produce a composite kernel, and then train a classifier on the composite kernel. As such, these approaches result in an optimal composite kernel, but not necessarily in an optimal classifier. On the other hand, some approaches optimize the loss of binary classifiers and learn weights for the different kernels iteratively. For multi-class or multi-label data, these methods have to solve the problem of optimizing weights on these kernels for each of the labels, which are computationally expensive and ignore the correlation among labels. In this paper, we propose a method called Predicting Protein Function using Multiple K ernels (ProMK). ProMK iteratively optimizes the phases of learning optimal weights and reduces the empirical loss of multi-label classifier for each of the labels simultaneously. ProMK can integrate kernels selectively and downgrade the weights on noisy kernels. We investigate the performance of ProMK on several publicly available protein function prediction benchmarks and synthetic datasets. We show that the proposed approach performs better than previously proposed protein function prediction approaches that integrate multiple data sources and multi-label multiple kernel learning methods. The codes of our proposed method are available at https://sites.google.com/site/guoxian85/promk.

Validation of the Italian version of the Yale-Brown Obsessive Compulsive Scale-Second Edition (Y-BOCS-II) in a clinical sample

OBJECTIVE: The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is the most widely accepted measure of obsessive-compulsive disorder (OCD) symptom severity. Recently, the scale has been revised into a second edition (Y-BOCS-II) in order to improve its measurement properties. The present study aimed to evaluate the psychometric properties of the Italian version of the Y-BOCS-II Severity Scale (SS) in a large clinical sample. METHOD: The original version of the Y-BOCS-II was translated into Italian, which involved forward and back-translation procedures. The Italian Y-BOCS-II-SS was administered to one hundred twenty-five treatment-seeking adults with OCD, together with the original Y-BOCS-SS and a battery of self-report measures assessing OCD symptom severity and depressive and anxious symptomology. The factor structure, internal consistency, temporal stability, and construct validity were investigated on the whole sample, while inter-rater and test-retest reliability were assessed on a subsample of participants. RESULTS: Factor analyses revealed a two-factor structure different from those of the original scale, comprising (1) symptom severity; and (2) interference from symptoms. Internal consistency, test-retest reliability over a 2-week period and inter-rater reliability were satisfactory. The Y-BOCS-II-SS also showed excellent construct validity (and better than the Y-BOCS-SS), with good convergent and discriminant validity when assessed against other OCD symptom measures and measures of depression, anxiety and worry. CONCLUSIONS: These findings suggest that the Italian version of the Y-BOCS-II-SS retains the adequate psychometric properties of the original and that it can be confidently used as an assessment tool of OCD symptoms in both clinical and research settings.

Testing the focal species approach to making conservation decisions for species persistence

Aim: Most risk assessments and decisions in conservation are based on surrogate approaches, where a group of species or environmental indicators are selected as proxies for other aspects of biodiversity. In the focal species approach, a suite of species is selected based on life history characteristics, such as dispersal limitation and area requirements. Testing the validity of the focal species concept has proved difficult, due to a lack of theory justifying the underlying framework, explicit objectives and measures of success. We sought to understand the conditions under which the focal species concept has merit for conservation decisions. Location: Our model system comprised 10 vertebrate species in 39 patches of native forest embedded in pine plantation in New South Wales, Australia. Methods: We selected three focal species based on ecological traits. We used a multiple-species reserve selection method that minimizes the expected loss of species, by estimating the risk of extinction with a metapopulation model. We found optimal reserve solutions for multiple species, including all 10 species, the three focal species, for all possible combinations of three species, and for each species individually. Results: Our case study suggests that the focal species approach can work: the reserve system that minimized the expected loss of the focal species also minimized the expected species loss in the larger set of 10 species. How well the solution would perform for other species and given landscape dynamics remains unknown. Main conclusions: The focal species approach may have merit as a conservation short cut if placed within a quantitative decision-making framework, where the aspects of biodiversity for which the focal species act as proxies are explicitly defined, and success is determined by whether the use of the proxy results in the same decision. Our methods provide a framework for testing other surrogate approaches used in conservation decision-making and risk assessment. © 2013 John Wiley & Sons Ltd.

Organizational factors related to the confidence of workers in working with residents with dementia or depression in aged care facilities

OBJECTIVES: There has been limited research examining how organizational factors are associated with the level of confidence of residential aged care staff in managing both residents' depression and the behavioural and psychological symptoms of residents with dementia (BPSD). This study investigated this issue. METHOD: A cross-sectional study design was employed. In total, 255 aged care staff (131 senior staff, 124 junior staff) from 21 residential care facilities participated in the study. All staff completed measures of self-efficacy in managing BPSD as well as confidence in working with older people with depression. They also completed measures of organizational climate (autonomy, cohesion, trust, pressure, support, recognition, fairness and encouragement of innovation) and measures of workplace experience (job role, number of years working in aged care facilities), job stress and satisfaction, and knowledge of depression. RESULTS: The results demonstrated that autonomy, trust, support, and job stress were associated with confidence in managing BPSD, while the factors related to confidence in managing depression were autonomy, support, job stress, job satisfaction, and knowledge of depression. CONCLUSION: These findings highlight that organizational climate factors need to be addressed in order to increase staff confidence in managing BPSD and depression. In particular, the findings demonstrate the importance of fostering organizational environments in which autonomy is promoted and there is support and cooperation among aged care staff. Attention to these factors is likely to increase the confidence of staff as they carry out their carer role.

A new color space based on K-medoids clustering for fire detection

Pixel color has proven to be a useful and robust cue for detection of most objects of interest like fire. In this paper, a hybrid intelligent algorithm is proposed to detect fire pixels in the background of an image. The proposed algorithm is introduced by the combination of a computational search method based on a swarm intelligence technique and the Kemdoids clustering method in order to form a Fire-based Color Space (FCS), in fact, the new technique converts RGB color system to FCS through a 3*3 matrix. This algorithm consists of five main stages:(1) extracting fire and non-fire pixels manually from the original image. (2) using K-medoids clustering to find a Cost function to minimize the error value. (3) applying Particle Swarm Optimization (PSO) to search and find the best W components in order to minimize the fitness function. (4) reporting the best matrix including feature weights, and utilizing this matrix to convert the all original images in the database to the new color space. (5) using Otsu threshold technique to binarize the final images. As compared with some state-of-the-art techniques, the experimental results show the ability and efficiency of the new method to detect fire pixels in color images.

24-h urinary sodium excretion is associated with obesity in a cross-sectional sample of Australian schoolchildren

Emerging evidence indicates that dietary Na may be linked to obesity; however it is unclear whether this relationship is independent of energy intake (EI). The aim of this study was to assess the association between Na intake and measures of adiposity, including BMI z score, weight category and waist:height ratio (WHtR), in a sample of Australian schoolchildren. This was a cross-sectional study of schoolchildren aged 4-12 years. Na intake was assessed via one 24-h urine collection. BMI was converted to age- and sex-specific z scores, and WHtR was used to define abdominal obesity. In children aged ≥8 years, EI was determined via one 24-h dietary recall. Of the 666 children with valid urine samples 55 % were male (average age 9·3 (sd 1·8) years). In adjusted models an additional 17 mmol/d of Na was associated with a 0·10 higher BMI z score (95 % CI 0·07, 0·13), a 23 % (OR 1·23; 95 % CI 1·16, 1·31) greater risk of being overweight/obese and a 15 % (OR 1·15; 95 % CI 1·09, 1·23) greater risk of being centrally obese. In the subsample of 8-12-year-old children (n 458), adjustment for EI did not markedly alter the associations between Na and adiposity outcomes. Using a robust measure of daily Na intake we found a positive association between Na intake and obesity risk in Australian schoolchildren, which could not be explained by total energy consumption. To determine whether this is a causal relationship, longitudinal studies, with high-quality measures of Na and EI, are required.