A perspective on using experiment and theory to identify design principles in dye-sensitized solar cells

Dye-sensitized solar cells (DSCs) have been the subject of wide-ranging studies for many years because of their potential for large-scale manufacturing using roll-to-roll processing allied to their use of earth abundant raw materials. Two main challenges exist for DSC devices to achieve this goal; uplifting device efficiency from the 12 to 14% currently achieved for laboratory-scale ‘hero’ cells and replacement of the widely-used liquid electrolytes which can limit device lifetimes. To increase device efficiency requires optimized dye injection and regeneration, most likely from multiple dyes while replacement of liquid electrolytes requires solid charge transporters (most likely hole transport materials – HTMs). While theoretical and experimental work have both been widely applied to different aspects of DSC research, these approaches are most effective when working in tandem. In this context, this perspective paper considers the key parameters which influence electron transfer processes in DSC devices using one or more dye molecules and how modelling and experimental approaches can work together to optimize electron injection and dye regeneration. This paper provides a perspective that theory and experiment are best used in tandem to study DSC device

Survey of Infectious Etiologies of Bovine Abortion during Mid- to Late Gestation in Dairy Herds.

Bovine abortion of unknown infectious etiology still remains a major economic problem. Thus, we investigated whether Brucella spp., Listeria monocytogenes, Salmonella spp., Campylobacter spp. and Coxiella burnetii are associated with abortion and/or stillbirth in Tunisian dairy cattle. Using a pan-Chlamydiales PCR, we also investigated the role of Chlamydiaceae, Waddlia chondrophila, Parachlamydia acanthamoebae and other members of the Chlamydiales order in this setting. Veterinary samples taken from mid to late-term abortions from twenty dairy herds were tested. From a total of 150 abortion cases collected, infectious agents were detected by PCR in 73 (48.66%) cases, 13 (8.66%) of which represented co-infections with two infectious agents. Detected pathogens include Brucella spp (31.3%), Chlamydiaceae (4.66%), Waddlia chondrophila (8%), Parachlamydia acanthamoebae (5.33%), Listeria monocytogenes (4.66%) and Salmonella spp. (3.33%). In contrast, Campylobacter spp. and Coxiella burnetii DNA were not detected among the investigated veterinary samples. This demonstrates that different bacterial agents may cause bovine abortion in Tunisia. This is the first report suggesting the role of Parachlamydia acanthamoebae in bovine abortion in Africa. Further studies with a larger number of samples are necessary to confirm whether this emerging pathogen is directly linked to abortion in cattle

Principles and application of an in vivo swine assay for the determination of arsenic bioavailability in contaminated matrices

The assessment of arsenic (As) bioavailability from contaminated matrices is a crucial parameter for reducing the uncertainty when estimating exposure for human health risk assessment. In vivo assessment of As utilising swine is considered an appropriate model for human health risk assessment applications as swine are remarkably similar to humans in terms of physiology and As metabolism. While limited in vivo As bioavailability data is available in the literature, few details have been provided regarding technical considerations for performing in vivo assays. This paper describes, with examples, surgical, experimental design and analytical issues associated with performing chronic and acute in vivo swine assays to determine As bioavailability in contaminated soil and food.Matthew Rees, Lloyd Sansom, Allan Rofe, Albert L. Juhasz, Euan Smith, John Weber, Ravi Naidu and Tim Kuche

Avaliação da aplicação do protocolo de triagem pré-natal para toxoplasmose em Belo Horizonte, Minas Gerais, Brasil: estudo transversal em puérperas de duas maternidades Evaluation of prenatal screening for toxoplasmosis in Belo Horizonte, Minas Gerais State, Brazil: a cross-sectional study of postpartum women in two maternity hospitals

Foi realizado estudo transversal, em duas maternidades públicas de Belo Horizonte, Minas Gerais, Brasil, com entrevista de 420 puérperas, de agosto de 2004 a maio de 2005, para avaliar a aplicação do protocolo de triagem pré-natal para toxoplasmose implantado, e as orientações oferecidas às gestantes suscetíveis. A cobertura do pré-natal foi de 98%, e da primeira triagem sorológica de 97%. O início do pré-natal e a realização da primeira sorologia ocorreram em média com 16 semanas. Foram identificadas 163 gestantes suscetíveis à toxoplasmose: 44% não repetiram a sorologia, e 42% alegaram não ter recebido orientações para prevenção da toxoplasmose. O início precoce do pré-natal e um maior número de consultas foram associados à repetição da sorologia e ao recebimento de orientações. As informações oferecidas foram: evitar contato com gatos (95%), não ingerir ou manipular carne crua (70%) e lavar cuidadosamente as hortaliças (53%). Concluiu-se que a adesão inadequada ao protocolo de triagem pré-natal de toxoplasmose encontrada no estudo pode gerar gastos financeiros sem melhoria na qualidade do cuidado perinatal.<br>This cross-sectional study of 420 women in two public maternity hospitals from August 2004 to May 2005 evaluated the application of a prenatal toxoplasmosis serological screening protocol in Belo Horizonte, Minas Gerais State, Brazil, and the information provided to susceptible pregnant women. Ninety-eight percent of women received prenatal care and 97% underwent the initial serological screening test, at an average of 16 weeks gestational age. The initial testing identified 163 women as susceptible to toxoplasmosis: 44% of these did not undergo repeat serological testing, and 42% of them did not remember having received information on the prevention of toxoplasmosis infection. Early prenatal care and a high number of prenatal visits were associated with repeat serological testing and orientation regarding its implications. Orientation on risk factors included: avoiding contact with cats (95%), not handling or eating raw meat (70%), and washing vegetables carefully before consumption (53%). Inadequate adherence to the prenatal screening protocol for toxoplasmosis, as detected in this study, may be generating health system costs without a corresponding improvement in the quality of perinatal care