An Approach for Modeling Noncancer Dose Responses with an Emphasis on Uncertainty

This paper presents an approach for characterizing the probability of adverse effects occurring in a population exposed to dose rates in excess of the Reference Dose (RfD). The approach uses a linear threshold (hockey stick) model of response and is based on the current system of uncertainty factors used in setting RfDs. The approach requires generally available toxicological estimates such as No-Observed-Adverse-Effect Levels (NOAELs) or Benchmark Doses and doses at which adverse effects are observed in 50% of the test animals (ED₅₀s). In this approach, Monte Carlo analysis is used to characterize the uncertainty in the dose response slope based on the range and magnitude of the key sources of uncertainty in setting protective doses. The method does not require information on the shape of the dose response curve for specific chemicals, but is amenable to the inclusion of such data. The approach is applied to four compounds to produce estimates of response rates for dose rates greater than the RfD     

Management of Parkinson's disease in older women

Elderly women with Parkinson's disease (PD) represent a specific patient population that may benefit from individualized treatment strategies. PD has been shown to occur approximately twice as often in men than in women, resulting in theories regarding estrogen being protective against the disease and as a potential treatment strategy. Given women's longer life expectancy, they are more likely to reach an age where antiparkinsonian medications are associated with side-effects. This paper will review medical and surgical treatments as well as the relationship of gender and age with respect to the management of PD.     

Pond age and riparian zone proximity influence anuran occupancy of urban retention ponds

Urbanization is widespread throughout the United States and negatively affects many wildlife populations. However, certain urban features, such as retention ponds, may provide habitat for some species, such as amphibians. This study examines the influence of riparian zone proximity and pond age on retention pond occupancy by anurans. We identified and estimated the age of 25 retention ponds near Charlotte, North Carolina, USA and used a geographic information system to determine the distance to the nearest riparian zone. Occupancy modeling indicated that anuran presence decreased with increasing distance to riparian zone. Pond age also appeared to be an important factor, but the effect varied among species. Although the results of this study demonstrate the potential value of retention ponds to anurans, it is important to be conservative in estimating the ability of these ponds to sustain amphibian populations in urbanized regions.     

Between love and behaviour management: the psychodynamic reflective milieu at the Mulberry Bush School

ABSTRACT

This article presents findings from a qualitative research study of the Mulberry Bush School (MBS), a therapeutic residential primary school caring for children with severe social, emotional and behavioural difficulties. The article notes the challenges of working with children who have experienced traumatic relationship breakdown, and reviews ideas and practices developed at MBS to support the children’s development. There is a discussion of the research study’s methodology and main findings. The researchers argue that the therapeutic milieu at MBS maintains a creative tension between a secure, playful context and one where emotional disorder and disturbance are not suppressed. The study describes how a particular psychodynamic model of reflective practice has been successfully instituted at MBS to create a ‘staff therapeutic milieu’ supporting the group living and group learning through which therapy principally occurs. The article closes with comments on the applicability of this model to residential child care practice generally.     

Marriage and the economic status of women with children

Marriage is positively correlated with income, and women with children are much less likely to be in poverty if they are married. Selection into marriage makes it difficult to assess whether these correlations represent a causal effect of marriage. One instrument for marriage proposed in past research is the gender of a woman’s first child. We find that women who have a boy first are about 0.33 percentage points more likely to be married at any point in time. This effect operates through both increasing the probability that unmarried mothers marry the child’s father and reducing the probability of divorce. We also find that women whose first child is a boy experience higher levels of family income and are less likely to receive welfare income, be below the poverty line, and receive food stamps. Estimates using child gender as an instrumental variable for marriage suggest that marriage plays a large causal role in improving the economic well-being of women with children and that these effects are largest among women at the lower end of the income distribution.     

Life satisfaction and the economic and social characteristics of neighbourhoods

This paper uses data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey to investigate the association between neighbourhood effects and life satisfaction. We find that neighbourhood measures of social support and interaction and the absence of socio-economic deprivation are positively and significantly correlated with individual life satisfaction. Neighbourhood fixed effects, however, explain only an additional 1.5 to 2.5% of the variance in life satisfaction over the 14% explained by individual characteristics.