Strategy for Cost-Effective Reduction of the Sum of Health Risk Estimates for Exposures to Mixtures of Toxic Substances

The authors argue that a minimization approach can provide guidance for effective use of funds to reduce the sum of estimated risks or the upper limit of the sum of risk estimates for mixtures of chemicals

‘Going the Extra Miles’: Providing Itinerant Library Support to Graduate Distance Learners

Entering post-professional graduate students at the University of St. Augustine for Health Sciences must take courses in interprofessional studies, regardless of program affiliation. Each of these interprofessional courses has an optional face-to-face immersion session. Here students, faculty, and academic support staff converge on one of the university’s five campuses for a weekend of collaborative learning. Sessions include research presentations, peer-to-peer learning, group projects, and academic advisement. However, librarians identified one glaring omission – effective in-person library support. This presentation will show how librarians can use on-campus activities, such as immersion sessions or residencies, as opportunities to fill gaps in library literacy and improve outreach and engagement among distance learners and faculty. The presenter will incorporate personal reflection and student survey data to illustrate how ‘going the extra mile’ really impacts faculty collaboration and student success

Benchmark Calculations for Perchlorate from Three Human Cohorts

The presence of low concentrations of perchlorate in some drinking water sources has led to concern regarding potential effects on the thyroid. In a recently published report, the National Academy of Sciences indicated that the perchlorate dose required to cause hypothyroidism in adults would probably be > 0.40 mg/kg-day for months or longer. In this study, we calculated benchmark doses for perchlorate from thyroid-stimulating hormone (TSH) and free thyroxine (T(4)) serum indicators from two occupational cohorts with long-term exposure to perchlorate, and from a clinical study of volunteers exposed to perchlorate for 2 weeks. The benchmark dose for a particular serum indicator was defined as the dose predicted to cause an additional 5 or 10% of persons to have a serum measurement outside of the normal range. Using the data from the clinical study, we estimated the half-life of perchlorate in serum at 7.5 hr and the volume of distribution at 0.34 L/kg. Using these estimates and measurements of perchlorate in serum or urine, doses in the occupational cohorts were estimated and used in benchmark calculations. Because none of the three studies found a significant effect of perchlorate on TSH or free T(4), all of the benchmark dose estimates were indistinguishable from infinity. The lower 95% statistical confidence limits on benchmark doses estimated from a combined analysis of the two occupational studies ranged from 0.21 to 0.56 mg/kg-day for free T(4) index and from 0.36 to 0.92 mg/kg-day for TSH. Corresponding estimates from the short-term clinical study were within these ranges

Bioavailability of biosolids- and consumer product-associated polybrominated diphenyl ether (PBDE) flame retardants to terrestrial invertebrates

The primary objectives of this research were therefore to evaluate polybrominated diphenyl ether (PBDE) bioavailability to ecologically distinct soil invertebrates exposed to Penta-BDE-treated consumer polyurethane foam (PUF) products and biosolid products with incurred PBDEs. In laboratory bioassays, earthworms (Eisenia fetida) bioaccumulated SigmaPBDEs (47+99+100+183) up to 11,000 mug/kg lipid after 28 days from a mixture of artificial soil and anaerobically-digested sludge biosolid (ADB). Earthworms also bioaccumulated SigmaPBDEs (47+99+100+153+154+183) up to 13,500 and 838,000 mug/kg lipid after 28 d from a mixture of artificial soil and composted sludge biosolid (CB) and Penta-BDE-spiked artificial soil (SAS), respectively. No previous lab studies on bioaccumulation of PBDEs from sludge or sludge-amended soils have been published. Two publications, done by the same research group on the same sites in Sweden, do exist documenting incidental levels of PBDEs in worms collected from historically sludge-amended agricultural fields. In the current research, biota-soil accumulation factors (BSAFs) were appreciably higher (dependent upon dose) than those reported in these Swedish field studies. PBDE usage in Sweden has been much less intense than in North America. Increasing BSAFs with decreasing biosolids-amended soil burdens may indicate that PBDE constituents within these biosolid products may impact earthworms at relatively low levels in soil. The potential for a terrestrial arthropod, the house cricket ( Acheta domesticus) to take up PBDEs directly from consumer PUF was also evaluated in a laboratory bioassay. These insects frequent indoor spaces and discarded materials and hence may have increased access (and thus exposure) to PBDE-treated polymers. Cricket nymphs were reared in proximity to a commercially manufactured Penta-BDE-treated PUF. They accumulated SigmaPBDEs (47+85+99+100+153+154) up to 14,200 mug/kg lipid after 28 days. Non-depurated crickets ingested SigmaPBDE burdens up to 80,600 mug/kg lipid. Owing to the high PBDE content of the PUF (9% by weight) and the fact that much of it likely remained within the polymer matrix, cricket/PUF bioaccumulation factors (BAFs) were on the order of 10-4 to 10-3 for all PBDE congeners. to evaluate real-world biosolid-associated PBDE bioavailability in the soil-associated terrestrial environment, a food web bioaccumulation study was conducted within a Mid-Atlantic US agricultural soil ecosystem receiving long-term (\u3e20 years) sludge amendments. Patterns of those with most intimate contact and reliance on the soil (e.g. earthworms) most closely reflected the soil/biosolid/commercial Penta-BDE fingerprint. PBDEs were BQL in the herbivorous grasshopper, in contrast to the closely related cricket, an omnivorous scavenger. Surprisingly, PBDEs were largely BQL in predaceous wolf spiders regardless of size or trophic level. Penta-BDE constituent biota-soil accumulation factors (BSAFs) ranged from 0.006 (crickets) to 1.2 (earthworms), while BDE-209 BSAFs ranged from 0.07 (earthworms) to 10.5 (millipedes). Lipid and TOC normalized PBDE burdens were strongly correlated for earthworms and ground beetles, perhaps indicative of attainment of steady state accumulation. In general, PBDE burdens decreased in the invertebrates with trophic level at the sludge-amended field. The pattern of carbon (delta13C) and nitrogen (delta 15N) stable isotopes in the taxa sampled suggests different trophic interactions at the non-sludge and sludge-applied fields. However, as only two sites were surveyed, a more exhaustive data set is needed in order to draw more definitive conclusions. Results of these studies provide unequivocal evidence that PBDEs accumulate in soils where biosolids are applied. They also demonstrate that PUF- and biosolid-associated PBDEs are bioavailable and are accumulated to varying degrees by ecologically diverse soil-associated invertebrates. as such, they may become available for uptake by higher order terrestrial consumers, including reptiles, mammals and birds. (Abstract shortened by UMI.)

EXPERIENTIAL HIGH SCHOOL CAREER EDUCATION: RELATION TO SELF-EFFICACY AND MOTIVATION

Career education has become an integral part of high school programming in Canada (Gibbons, Borders, Wiles, Stephan & Davis, 2006). Research on school-based career interventions is on the rise throughout North America (Hiebert, 2010; Roest & Magnusson, 2005). The current study is intended to contribute to this growing area by examining the impact of an elective career education class offered in Saskatchewan public schools called Career and Work Exploration 30 (CWE30). CWE30 combines experiential classroom activities and work placements. Experiential learning has long been regarded as an effective way of increasing self-efficacy, as described in Social Cognitive Theory (SCT; e.g., Bandura, 1977), a factor shown to play a role in encouraging career exploration and confident career-related decision-making (e.g., Blustein, 1989). Another contributor to active career exploration is intrinsic motivation, described in Self-Determination Theory (SDT) as the innate desire to seek out knowledge and growth and to therefore engage in activities that foster this development (Deci & Ryan, 1985). Given the complex and relatively nascent nature of research in this area, the chosen methodology was a case study (Yin, 2014). Multiple types of data were collected. Fourteen grade 11 and 12 high school students from Saskatchewan completed the Career Decision-Making Self-Efficacy Scale - Short Form (CDMES-SF; Taylor & Betz, 1983) and a motivation questionnaire (adapted from Kerner et al., 2012) at the beginning and end of the second semester of the 2013-2014 school year. Two students and one teacher were interviewed. Further, the class curriculum, student attendance, blank copies of in-class activities, and homework that was assigned were collected. Results included significant differences in scores on the CDMSE-SF from pre to post testing and common themes on the qualitative measures such as frustration with assignments and placement time commitments; excitement about experiential learning; fears and uncertainties related to career decision-making; and suggestions for improvements emerged. Course documents provided further evidence as to the implementation of the CWE30 curriculum and the inclusion of factors thought to promote intrinsic motivation and self-efficacy as described in SDT and SCT respectively. Implications within the current literature as well as for future research are discussed

Embracing the Grey Zone: Navigating flexible boundaries at Welcome Inn Community Centre

This thesis is an exploration of relationships and issues of professional boundaries at Welcome Inn Community Centre, a faith-based community centre offering programs and services to address issues of poverty in Hamilton, Ontario. Data was gathered through semi-structured qualitative interviews with fifteen staff members, volunteers, and participants at Welcome Inn. A strengths-based perspective combined with mutual relationships and flexible boundaries were found to foster inclusion, acceptance, community building, and personal transformation at Welcome Inn Community Centre; Welcome Inn staff, volunteers, and program participants described these qualities positively. Mixed positive and negative comments were used to describe decision-making and boundaries at Welcome Inn. The need for increased intentionality and clarity around professional boundaries was identified. Using grounded theory methodology, a model, “Embracing the Grey Zone,’ and associated reflexive tools for navigating flexible boundaries were developed. The model and tools are presented here for use in social work community practice and education

Factors Influencing the Evolution of Chinese Disaster Relief Efforts

Disasters are life-altering events for any country. Every country around the world suffers from various kinds of disasters, whether produced by natural or human forces. The impact that these disasters have on people’s lives makes the topic of disaster relief and management a critical one for all governments around the globe; China is certainly no exception to the importance of disaster relief policy. As a country that has fallen victim to many disasters in recent memory, its disaster relief policy is one that has been analyzed at length by scholars around the world. In this piece, I seek to analyze the factors that contributed to the evolution of China’s disaster relief policies over the past few decades, in addition to the effects of these disasters on Chinese society. I argue that there are five main factors that have driven changes in this policy sector: institutional structure and centralization of power, media and technological advances in the realm of communication, international factors (foreign aid, pressures from the international community, and the Olympics), the historical concept of performance legitimation, and the development of civil society