Solution kinetics of gypsum

Two sets of six samples of crushed gypsum and demineralized water were prepared. One set contained crystals of a grain size between 125 and 250 microns, the other set between 500 and 1000 microns. Once a week one sample from each set was dried and weighed. The ion activity product was calculated from the final weight loss of both sets, and found to be 10????? for the larger-grain-sized samples at 25°c., and 10????? for the smaller-grain-sized samples at 25°c. Comparison with the solubility product 10????? suggests that the solutions were very near equilibrium. During the first weeks of the experiment, the samples of smaller grains dissolved at a slightly faster rate than those of larger grains, but the difference was reduced as the solutions approached equilibrium. The rate of solution was not constant for either set of samples, probably due to the presence of very fine particles of gypsum attached to the grains during grinding, whcich dissolved at a faster rate due to a higher surface-area-to-mass ratio.No embarg

What do kids with Acquired Brain Injury want? Mapping neuropsychological rehabilitation goals to the International Classification of Functioning, Disability and Health

Objective: To increase understanding of the community neuropsychological rehabilitation goals of young people with acquired brain injuries (ABIs). Method: Three hundred twenty-six neuropsychological rehabilitation goals were extracted from the clinical records of 98 young people with ABIs. The participants were 59% male, 2-19 years old, and 64% had a traumatic brain injury. Goals were coded using the International Classification of Functioning, Disability and Health: Children and Youth Version (ICF-CY). Descriptive statistical analysis was performed to assess the distribution of goals across the ICF-CY. Chi-squared and Cramer's V were used to identify demographic and injury-related associations of goal type. Results: The distribution of goals was 52% activities and participation (AP), 28% body functions (BF), 20% environmental factors (EF), and <1% body structures (BS). The number of EF goals increased with age at assessment (V =.14). Non-traumatic causes of ABIs were associated with more EF goals (V =.12). There was no association between sex or time post-injury and the distribution of goals across the ICF-CY. Conclusions: Young people with ABIs have a wide range of community neuropsychological rehabilitation goals that require an individualized, context-sensitive, and interdisciplinary approach. Community neuropsychological rehabilitation services may wish to ensure they are resourced to focus intervention on AP, with increasing consideration for EF as a young person progresses through adolescence. The findings of this research support models of community neuropsychological rehabilitation that enable wellness by combining direct rehabilitative interventions with attention to social context and systemic working across agencies

The relation between adult height and haemorrhagic and ischaemic stroke in the Renfrew/Paisley study

Adult height is a useful marker of fetal growth, growth and nutrition in childhood and childhood infections. Studies reporting inverse associations between height and stroke therefore provide support for the hypothesis that exposures acting in early life are important determinants of risk of stroke. However, few studies have been able to examine the association between height and stroke subtype. We recently showed that height is inversely related to ischaemic stroke, but because of small numbers it was not possible to robustly analyse the association between height and haemorrhagic stroke. A Norwegian study has shown a stronger inverse association with haemorrhagic compared with ischaemic stroke, but adjustment for socioeconomic position was not possible. We recently reported a significant inverse association between height and stroke mortality in both men and women in the Renfrew/Paisley cohort. Here we examine the association between height and subtype of incident stroke in this cohort