Field trial of an automated batch chlorinator system at shared water points in an urban community of Dhaka, Bangladesh

Point-of-use water treatment with chlorine is underutilized in low-income households. The Zimba, an automated batch chlorinator, requires no electricity or moving parts, and can be installed at shared water points with intermittent flow. We conducted a small-scale trial to assess the acceptability and quality of Zimba-treated municipal water. Fieldworkers collected stored drinking water over a 10-week period from control (n = 24 households) and treatment (n = 30 households) compounds to assess levels of free chlorine and E. coli contamination. Overall, 80% of stored drinking water samples had a safe chlorine residual among treatment households, compared to 29% among control households (P &amp;lt; 0.001). Concentrations of E. coli were lower (mean difference = 0.4 log colony-forming units/100 mL, P = 0.004) in treatment compared to control households. Fifty-three percent of mothers (n = 17), thought the Zimba was easy to use and 76% were satisfied with the taste. The majority of mothers mentioned that collecting water from the Zimba took more time and created a long queue at the handpump. The Zimba successfully chlorinated household stored drinking water; however, further technology development is required to address user preferences. The Zimba may be a good option for point-of-collection water treatment in areas where queuing for water is uncommon.</jats:p

The impact of maternal separation on adult mouse behaviour and on the total neuron number in the mouse hippocampus

The maternal separation paradigm has been applied to C57BL/6J mice as an animal developmental model for understanding structural deficits leading to abnormal behaviour. A maternal separation (MS) model was used on postnatal day (PND) 9, where the pups were removed from their mother for 24 h (MS24). When the pups were 10 weeks old, the level of anxiety and fear was measured with two behavioural tests; an open field test and an elevated plus maze test. The Barnes platform maze was used to test spatial learning, and memory by using acquisition trials followed by reverse trial sessions. The MS24 mice spent more time in the open arms of the elevated plus maze compared to controls, but no other treatment differences were found in the emotional behavioural tests. However, in the reverse trial for the Barnes maze test there was a significant difference in the frequency of visits to the old goal, the number of errors made by the MS24 mice compared to controls and in total distance moved. The mice were subsequently sacrificed and the total number of neurons estimated in the hippocampus using the optical fractionator. We found a significant loss of neurons in the dentate gyrus in MS mice compared to controls. Apparently a single maternal separation can impact the number of neurons in mouse hippocampus either by a decrease of neurogenesis or as an increase in neuron apoptosis. This study is the first to assess the result of maternal separation combining behaviour and stereology

Xlr3b is a new imprinted candidate for X-linked parent-of-origin effects on cognitive function in mice

Imprinted genes show differential expression between maternal and paternal alleles as a consequence of epigenetic modification that can result in 'parent-of-origin' effects on phenotypic traits. There is increasing evidence from mouse and human studies that imprinted genes may influence behavior and cognitive functioning. Previous work in girls with Turner syndrome (45,XO) has suggested that there are X-linked parent-of-origin effects on brain development and cognitive functioning, although the interpretation of these data in terms of imprinted gene effects has been questioned. We used a 39,XO mouse model to examine the influence of the parental origin of the X chromosome on cognitive behaviors and expression of X-linked genes in brain. Our findings confirm the existence of X-linked imprinted effects on cognitive processes and identify a new maternally expressed imprinted gene candidate on the X chromosome, Xlr3b, which may be of importance in mediating the behavioral effects