Living in a cold and damp home: frameworks for understanding impacts on mental well-being.

OBJECTIVE: To carry out a review of recent studies that have explored relationships between mental well-being and how this may be affected by living in cold and damp homes. Attention is focused on intervention studies in which heating and insulation improvements were carried out and impacts on well-being assessed. STUDY DESIGN: Drawing mainly on a Cochrane Review published in 2013, nine studies of sound methodology are identified and significant effects discussed. METHODS: The review outlines the current frameworks for understanding mental well-being which prevail in psychology and psychiatry, describing the distinctions that can be made between mental well-being and its elements, namely positive mental health and negative mental health (the latter also known as mental disorder). The review then organizes findings from nine studies into the separate domains of positive and negative mental health, giving due consideration to the quality of the research, instruments used to measure mental health, methodological, and ethical issues. RESULTS: These first nine studies indicate early consensus. Living in cold and damp housing contributes to a variety of different mental health stressors, including persistent worry about debt and affordability, thermal discomfort, and worry about the consequences of cold and damp for health. Improvements to energy efficiency are often associated with significant improvements in mental well-being. CONCLUSIONS: Impacts affect both positive and negative mental health. A cumulative stress framework is hypothesized, within which the mental health impacts of improved energy efficiency can be better understood.

Dimer shape anisotropy: a nonspherical colloidal approach to omnidirectonal photonic band gaps.

Theoretical calculations of the photonic band gap forming properties are reported for a class of colloidal dimer-based structures with similarity to zinc blende and which map onto diamond or opalline face-centered cubic structures at the extrema in shape parameters. Inspired by the range of nonspherical building blocks for self-assembly synthesized using seeded emulsion polymerization and sol-gel techniques, we explore in particular the band structures as a function of dimer lobe symmetry and the degree of lobe interpenetration for tangent dimers. Complete photonic band gaps were observed between the second and third, fifth and sixth, or eighth and ninth bands for various shape classes. As well, select inverted and direct dimer-based structures showed two complete band gaps simultaneously.

Condom use in African adolescents: the role of individual and group factors.

This study set out to assess the ability of the Theory of Planned Behaviour (TPB) to predict and explain condom use in a traditional African context and in particular to assess the relative contributions of individual and normative constructs. A questionnaire survey was administered to 152 young adults (48% male, 52% female) at two points in time. Key constructs contained within the TPB were measured at Time 1. A short follow-up set of items was administered one week later at Time 2, thereby allowing for the measurement of actual behaviour. The results not only provide strong support for the predictive power of the TPB, since 67% of the variance in intention was explained, but also highlight the extent to which sexual behaviour in a rural location is governed by family/social influences. Subjective norm not only proved to be one of the most significant elements of the TPB model, together with self-efficacy (neither attitude nor perceived control were significantly involved), but 'my family' emerged as the most significant other. As such, the findings offer empirical evidence to support interventions that penetrate community networks.

Faecal calprotectin in the assessment of Crohn's disease activity.

BACKGROUND: Clinical and laboratory assessment of activity in Crohn's disease (CD) correlate poorly with endoscopic findings. Calprotectin is a calcium-binding protein abundant in neutrophil cytosol, and extremely stable in faeces. Faecal calprotectin (FC) is an excellent surrogate marker of neutrophil influx into the bowel lumen. AIM: To assess whether FC concentration from a spot stool sample reliably detects active inflammation in patients with CD. DESIGN: Cross-sectional comparative study. METHODS: Subjects had a previously confirmed diagnosis of CD and were suspected on clinical grounds to be in the midst of a relapse. Thirty-five entered the study; they underwent radiolabelled white cell scanning (WCS) and had a stool sample collected for calprotectin measurement on the same day. A Crohn's disease activity index (CDAI) was also calculated for each. The WCS scans were scored at six standard sites to give a mean total, 'extent', 'severity' and 'combined extent and severity' scores. RESULTS: FC was significantly and positively correlated with mean total (r = 0.73, p < 0.001), 'extent' (r = 0.71, p < 0.001), 'severity' (r = 0.64, p < 0.001) and combined 'extent and severity' WCS scores (r = 0.71, p < 0.001). A cut-off of faecal calprotectin > 100 microg/g gave a sensitivity of 80%, specificity of 67%, positive predictive value of 87% and a negative predictive value of 64% in identifying those with and without any inflammation on WCS. There was, however, no significant correlation between CDAI and mean total WCS score (r = 0.21, p = 0.24), nor between CDAI and FC (r = 0.33, p = 0.06). DISCUSSION: While the CDAI does not accurately reflect inflammatory activity in CD, a one-off FC reliably detects the presence or absence of intestinal inflammation in adult patients with CD, compared to WCS.

Nonspherical ZnS colloidal building blocks for three-dimensional photonic crystals.

The asymmetry introduced by a complex or nonspherical basis promotes photonic band gap formation in three-dimensional photonic crystals. However, relatively few techniques have been demonstrated to produce uniform nonspherical colloids for use as photonic crystal bases. Here we expand the menu of basis types with high refractive index by preparing nonspherical zinc sulfide colloids of uniform size and shape. Dimers, trimers, and planar tetramers were precipitated from aqueous solution by the thermal decomposition of thioacetamide in the presence of zinc nitrate, manganese nitrate, and nitric acid. The well-defined morphological types were obtained from suspensions aged for 4-6 h at 26-32 degrees C and then for 20-35 min at 85 degrees C. Stereological techniques were used to analyze SEM images and determine the percentage of each particle class. For example, the quantitative characterization of a particle population prepared at 29 degrees C for 6 h and 85 degrees C for 22 min had the composition 59+/-3% spheres, 31+/-2% dimers, 7+/-1% trimers, 0.4+/-0.2% tetramers, and 2.5+/-0.8% complex clusters (encompasses all other varieties of shape). X-ray diffraction and X-ray photoelectron spectroscopy confirmed the zinc blend crystal structure and the stoichiometric composition of the particles. The refractive index was estimated as 2.25 (413 nm) -2.09 (709 nm) by fitting experimental absorption spectra to curves derived from Mie scattering calculations. This indicated an average porosity approximately 24%. Such colloids offer the potential to form diamond-like lattices with large, stable photonic band gaps.

Pepper mottle virus Causing Disease in Chile Peppers in Southern New Mexico.

The primary pepper producing areas of southern New Mexico were surveyed to identify the viruses causing severe disease in chile peppers over a 2-year period. The survey included weeds commonly found in and around pepper fields. Using indirect enzyme-linked immunosorbent assay (ELISA), Pepper mottle virus (PepMoV) was associated with plants showing mosaic and distortion of foliage and fruit deformation. PepMoV and Cucumber mosaic virus (CMV) were determined based on ELISA to be infecting chile peppers and weeds singly or in combination. Four perennial plant species were infected with PepMoV and CMV, including Solanum elaeagnifolium (silverleaf nightshade), Convolvulus arvensis (field bindweed), and Chamysuraces sp. (small groundcherry), which had not previously been identified as hosts for PepMoV. Some peppers and weeds surveyed were also infected at a lower level by several other plant viruses.

Predicting early grade retention: a longitudinal investigation of primary school progress in a sample of rural South African children.

BACKGROUND: One hundred and fifty rural South African children, newly enrolled in Grade 2 in 1994, were retraced in 1998 when they were scheduled to have entered Grade 7. Only 39% of the cohort had progressed smoothly to Grade 7; more than a third (36%) had left their original primary school, and 25% had been retained at least once. AIMS: The present study investigated factors that were measurable at the start of Grade 2 which proved useful in predicting subsequent retention. METHOD: Details of children's academic progress from Grade 1 in 1993 through all subsequent years including 1998 were collected. Predictor variables included age at school entry, sex of child, nutritional status, academic achievement in Grade 1, cognitive test status at Grade 2, teacher assessments of children's behaviour, and biographical variables such as caregiver education and household size. RESULTS: Rural children's experience of primary school was relatively disrupted. For those who remained in the same school, a relatively good predictive model for retention was built, with Grade 1 academic achievement as well as caregiver education, and cognitive test scores being important predictors. CONCLUSIONS: Results corroborate those of developed world studies, in showing that early academic achievement is a strong predictor of retention. In addition, they highlight the importance of early curriculum mastery--rather than broader cognitive skills--for smooth progression through school.

Use of educational resource materials with South African children in day care.

The psychometric scores of black South African children (N = 248) in 16 day-care centers were assessed before (n = 119) and after (n = 129) the introduction of an enrichment package, which consisted of a range of educational toys and cost US $12 per child. Analysis indicated that the enrichment was associated with significant improvements on a number of psychometric measures. Results are critically examined in terms of methodological issues, the effects of a low-cost enrichment scheme, and aspects of the package which merited subsequent improvement.