A.C.Electroluminescent Lamps: Shedding some light on their mysteries

A.C.powder electroluminescent lamps have been known and used for many years, but their mechanism of operation is still debated. Many thousands of phosphors are known, but the vast majority are not electroluminescent. A number of materials do exhibit the effect. Of these, however, ZnS doped with Cu is absolutely in a class of its own, and is the only material from which viable lamps can be made. In this work studies have been made of the performance of devices under a range of pulsed and continuous excitation conditions and new hypotheses presented which attempt to explain the behavior of this unique material

Sequential induction of three recombination directionality factors directs assembly of tripartite integrative and conjugative elements

Tripartite integrative and conjugative elements (ICE3) are a novel form of ICE that exist as three separate DNA regions integrated within the genomes of Mesorhizobium spp. Prior to conjugative transfer the three ICE3 regions of M. ciceri WSM1271 ICEMcSym1271 combine and excise to form a single circular element. This assembly requires three coordinated recombination events involving three site-specific recombinases IntS, IntG and IntM. Here, we demonstrate that three excisionases–or recombination directionality factors—RdfS, RdfG and RdfM are required for ICE3 excision. Transcriptome sequencing revealed that expression of ICE3 transfer and conjugation genes was induced by quorum sensing. Quorum sensing activated expression of rdfS, and in turn RdfS stimulated transcription of both rdfG and rdfM. Therefore, RdfS acts as a “master controller” of ICE3 assembly and excision. The dependence of all three excisive reactions on RdfS ensures that ICE3 excision occurs via a stepwise sequence of recombination events that avoids splitting the chromosome into a non-viable configuration. These discoveries expose a surprisingly simple control system guiding molecular assembly of these novel and complex mobile genetic elements and highlight the diverse and critical functions of excisionase proteins in control of horizontal gene transfer

Conhecimento e prática sobre os fatores de risco para o câncer de mama entre mulheres de 40 a 69 anos Knowledge of and practices regarding risk factors for breast cancer in women aged between 40 and 69 years

OBJETIVO: investigar conhecimento e prática sobre os fatores de risco para o câncer de mama entre usuárias da Estratégia de Saúde da Família (ESF). MÉTODOS: estudo transversal com 393 mulheres com idades entre 40 e 69 anos usuárias da ESF na cidade de Dourados, MS. Realizou-se uma entrevista, por meio de um questionário semi-estruturado, investigando-se variáveis sociodemográficas, história familiar e conhecimento/prática sobre os fatores de risco para o câncer de mama. A descrição das variáveis foi feita através de frequência simples e porcentagem. A associação do conhecimento sobre os fatores de risco e as variáveis foram verificadas pelo teste exato de Fisher e qui-quadrado com nível de significância de 5%. RESULTADOS: a idade média foi de 52,5 ± 8,1 anos, o tempo médio de estudo foi de 4,4±3,6 anos, 52,4% das mulheres eram pardas/negras e 66,6% possuiam companheiro. Entre as mulheres, 86,5% receberam alguma informação sobre o câncer de mama. Os fatores de risco para a doença eram conhecidos por 54,2% das mulheres. O conhecimento sobre os fatores de risco associou-se com a história familiar (p=0,004) e anos de estudo (p=0,01). Diante dos fatores de risco conhecidos, a frequência de práticas preventivas entre as mulheres foi de 52,2%. CONCLUSÕES: a identificação de variáveis relacionadas a um menor conhecimento sobre a doença pode auxiliar na adoção de estratégias direcionadas aos grupos mais vulneráveis.<br>OBJECTIVES: to investigate knowledge of and practices regarding risk factors for breast cancer among users of the Family Health Strategy (FHS). METHODS: a cross-sectional study was carried out among 393 women aged between 40 and 69 years using the FHS in the city of Dourados, in the Brazilian State of Mato Grosso do Sul. An interview was conducted using a semi-structured questionnaire to investigate socio-demographic variables, family history and awareness/practices regarding the risk factors for breast cancer. The variables were described using simple frequency and a percentage. The association between awareness of the risk factors and the variables was confirmed using Fisher's exact test and the chi-square with a level of significance of 5%. RESULTS: the mean age was 52.5 ± 8.1 years, the mean years of schooling was 4.4±3.6 years, 52.4% of the women were black/colored and 66.6% had a partner. Of the women, 86.5% had received some information on breast cancer. The risk factors for the disease are known by 54.2% of the women. Awareness of the risk factors was associated with family history (p=0.004) and years of schooling (p=0.01). Where the risk factors were known, 52.2% of the women took preventive measures. CONCLUSION: the identification of variables related to greater awareness of the disease may facilitate the adoption of strategies aimed at the most vulnerable groups

Genetic dissection of grain yield in bread wheat. I. QTL analysis

Grain yield forms one of the key economic drivers behind a successful wheat (Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature, little is known regarding the genetic control of grain yield. A doubled-haploid population, comprising 182 individuals, produced from a cross between two cultivars ‘Trident’ and ‘Molineux’, was used to construct a linkage map based largely on microsatellite molecular makers. ‘Trident’ represents a lineage of wheat varieties from southern Australia that has achieved consistently high relative grain yield across a range of environments. In comparison, ‘Molineux’ would be rated as a variety with low to moderate grain yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range of environments across the southern Australian wheat belt. In total, grain yield data were recorded for the population at 18 site-year combinations. Grain yield components were also measured at three of these environments. Many loci previously found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence grain yield and grain yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated with grain yield. A QTL associated with grain yield on chromosome 1B, with no significant relationship with plant height, ear-emergence or rust resistance, was detected (LOD ≥2) at eight of the 18 environments. The mean yield, across 18 environments, of individuals carrying the ‘Molineux’ allele at the 1B locus was 4.8% higher than the mean grain yield of those lines carrying the ‘Trident’ allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain yield at six of the 18 environments. Of the nine grain yield QTL not shown to be associated with plant height, phenology or rust resistance, two were located near QTL associated with grain yield components. A third QTL, associated with grain yield components at each of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with grain yield at any of the environments. The implications of these findings on marker-assisted selection for grain yield are discussed.H. Kuchel, K. J. Williams, P. Langridge, H. A. Eagles and S. P. Jefferie