Pesticide exposure and sprayer design: ergonomics evaluation to reduce pesticide exposure

Plant protection products are used in agriculture to improve yields, but this use can cause contamination of the environment and is also likely to have adverse short and long term effects on agricultural workers. This poster describes a systems approach to reducing the risk of operator exposure to plant protection products through the introduction of ergonomics to the design process of large agricultural sprayers.     

Water sources of urban trees in the Los Angeles metropolitan area

In semi-arid cities, urban trees are often irrigated, but may also utilize natural water sources such as groundwater. Consequently, the sources of water for urban tree transpiration may be uncertain, complicating efforts to efficiently manage water resources. We used a novel approach based on stable isotopes to determine tree water sources in the Los Angeles basin, where we hypothesized that trees would rely on irrigation water in the soil rather than develop deep roots to tap into groundwater. We evaluated the oxygen (δ¹⁸O) and hydrogen (δD) isotope ratios of xylem water, irrigation water, soil water, and groundwater in a study of temporal patterns in water sources at two urban sites, and a study of spatial patterns at nine urban sites and one “natural” riparian forest. Contrary to our hypothesis, we found that despite frequent irrigation, some trees tap into groundwater, although in most species this was a small water source. Some trees appeared to be using very shallow soil water at <30 cm depth, suggesting that these mature urban trees were quite shallowly rooted. In the natural site, trees appeared to be using urban runoff in addition to shallow soil water. We were able to identify tree uptake of precipitation at only 3 sites. The results show that some irrigated trees utilize groundwater and do not rely solely on irrigation water, which may make them able to withstand drought and/or water conservation measures. However, some irrigated trees may develop very shallow root systems, which may make them more susceptible.     

Schulman's urban lesbian: a hobosexual pedestrian rhetoric

The following article reads the protagonist in Sarah Schulman's Girls, Visions and Everything as not only lesbian, but as hobosexual-a concept representative of anti-capitalist practices in both sex and labor. The hobosexual is developed as an extension of the lesbian flaneur, as a concept that requires reading Schulman's urban lesbian at the intersection of class and sexuality. Lila Futuransky's sexual identity is suspended and complicated through an emphasis on her desire for queer mobility; her urban movements connect her to hobo history, but also expose the effects of capitalism that thwart her urban movement.     

Using Bayesian graphical models to model biases in observational studies and to combine multiple sources of data: application to low birth weight and water disinfection by-products

Summary.  Data in the social, behavioural and health sciences frequently come from observational studies instead of controlled experiments. In addition to random errors, observational data typically contain additional sources of uncertainty such as missing values, unmeasured confounders and selection biases. Also, the research question is often different from that which a particular source of data was designed to answer, and so not all relevant variables are measured. As a result, multiple sources of data are often necessary to identify the biases and to inform about different aspects of the research question. Bayesian graphical models provide a coherent way to connect a series of local submodels, based on different data sets, into a global unified analysis. We present a unified modelling framework that will account for multiple biases simultaneously and give more accurate parameter estimates than standard approaches. We illustrate our approach by analysing data from a study of water disinfection by-products and adverse birth outcomes in the UK.     

Measuring people's trust

Summary. We measure trust and trustworthiness in British society with a newly designed experiment using real monetary rewards and a sample of the British population. The study also asks the typical survey question that aims to measure trust, showing that it does not predict 'trust' as measured in the experiment. Overall, about 40% of people were willing to trust a stranger in our experiment, and their trust was rewarded half of the time. Analysis of variation in the trust behaviour in our survey suggests that trusting is more likely if people are older, their financial situation is either 'comfortable' or 'difficult' compared with 'doing alright' or 'just getting by', they are a homeowner or they are divorced, separated or never married compared with those who are married or cohabiting. Trustworthiness also is more likely among subjects who are divorced or separated relative to those who are married or cohabiting, and less likely among subjects who perceive their financial situation as 'just getting by' or 'difficult'. We also analyse the effect of attitudes towards risks on trust.     

Does mother’s employment conflict with child development? Multilevel analysis of British mothers born in 1958

Does maternal employment, while children are very young, affect their development? We link cognitive and behavioral scores of school-aged children to mothers’ employment during preschool years using virtually unique data for two generations in the 1958 British birth cohort. Our multivariate, multilevel model controls for mothers’ own cognitive and behavioral scores in childhood. Results are mixed and minor, confirming other British studies at mid-childhood. Reading is, significantly, slightly poorer where less educated mothers work in the child’s first year of life. We found few other interactions with employment but did detect intergenerational transmission of behavioral and cognitive characteristics.     

Child‐Care Instability and Behavior Problems: Does Parenting Stress Mediate the Relationship?

Child‐care instability is associated with more behavior problems in young children, but the mechanisms of this relationship are not well understood. Theoretically, this relationship is likely to emerge, at least in part, because care instability leads to increased parenting stress. Moreover, low socioeconomic status and single‐mother families may be more vulnerable to the effects of instability. This study tested these hypotheses using data from the Fragile Families and Child Wellbeing study (N = 1,675) and structural equation modeling. Three types of child‐care instability were examined: long‐term instability, multiplicity, and needing to use back‐up arrangements. Overall, findings showed little evidence that parenting stress mediated the associations between care instability and child behavior problems among the full sample. Among single‐mother and low‐income families, however, needing to use back‐up arrangements had small positive associations with parenting stress, which partially mediated the relationship between that type of care instability and child externalizing behavior problems.