Modelling survival : exposure pattern, species sensitivity and uncertainty

The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans

A prospective cohort study to assess seroprevalence, incidence, knowledge, attitudes and practices, willingness to pay for vaccine and related risk factors in dengue in a high incidence setting

Abstract Background Dengue is one of the most important vector-borne diseases in the world, causing significant morbidity and economic impact. In Colombia, dengue is a major public health problem. Departments of La Guajira, Cesar and Magdalena are dengue endemic areas. The objective of this research is to determine the seroprevalence and the incidence of dengue virus infection in the participating municipalities from these Departments, and also establish the association between individual and housing factors and vector indices with seroprevalence and incidence. We will also assess knowledge, attitudes and practices, and willingness-to-pay for dengue vaccine. Methods A cohort study will be assembled with a clustered multistage sampling in 11 endemic municipalities. Approximately 1000 homes will be visited to enroll people older than one year who living in these areas, who will be followed for 1 year. Dengue virus infections will be evaluated using IgG indirect ELISA and IgM and IgG capture ELISA. Additionally, vector indices will be measured, and adult mosquitoes will be captured with aspirators. Ovitraps will be used for continuous estimation of vector density. Discussion This research will generate necessary knowledge to design and implement strategies with a multidimensional approach that reduce dengue morbidity and mortality in La Guajira and other departments from Colombian Caribbean

Adoption and correlates of Postgraduate Hospital Educational Environment Measure (PHEEM) in the evaluation of learning environments – A systematic review^*

<p><b>Background:</b> The Postgraduate Hospital Educational Environment Measure (PHEEM) is a highly reliable and valid instrument to measure the educational environment during post graduate medical training. This review extends earlier reports by evaluating the extant adoption of PHEEM in various international clinical training sites, and its significant correlations in order to expand our understanding on the use of PHEEM and facilitate future applications and research.</p> <p><b>Method:</b> A systematic literature review was conducted on all articles between 2005 and October 2015 that adopted and reported data using the PHEEM.</p> <p><b>Results:</b> Overall 30 studies were included, encompassing data from 14 countries internationally. Notable differences in the PHEEM scores were found between different levels of training, disciplines, and clinical training sites. Common strengths and weaknesses in learning environments were observed and there were significant correlations between PHEEM scores and In-Training Exam (ITE) performance (positive correlation) and level of burnout (negative correlation), respectively.</p> <p><b>Conclusions:</b> PHEEM is widely adopted in different learning settings, and is a useful tool to identify the strengths and weaknesses of an educational environment. Future research can examine other correlates of PHEEM and longitudinal changes in interventional studies.</p

A Comparative Analysis of the Effect of Various Denture Adhesives Available in Market on the Retentive Ability of the Maxillary Denture: An In Vivo Study

“Every human being has a divine right to enjoy the health to its fullest.” Oral and Dental health is not an exception to this dictum. The speciality of Prosthodontics has emerged as a science to provide replacement of missing dentition for its form and functions along with associated structures. Any successful complete denture treatment combines exemplary technique, effective patient rapport, patient education, and familiarity with all possible management options in order to provide maximum satisfaction to patient. There are some forcing situations where providing desirable (optimal) retention may be a problem. In such types of patients use of denture adhesives is recommended for enhancing the quality of retention. The use of denture adhesive provides comfort and additional confidence not only by increasing the adhesive and cohesive but also eliminating voids between the denture base and the basal seat. This study is undertaken to evaluate the enhancement of retentive quality of complete denture with the use of denture adhesives available in Indian markets for the use by denture wearers