369 research outputs found

    Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The ascomycete fungus <it>Cercospora zeae-maydis </it>is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in <it>C. zeae-maydis </it>at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from <it>C. zeae-maydis </it>and evaluate their expression during vegetative, infectious, and reproductive growth.</p> <p>Results</p> <p>A total of 27,551 ESTs was obtained from five cDNA libraries constructed from vegetative and sporulating cultures of <it>C. zeae-maydis</it>. The ESTs, grouped into 4088 clusters and 531 singlets, represented 4619 putative unique genes. Of these, 36% encoded proteins similar (E value ≤ 10<sup>-05</sup>) to characterized or annotated proteins from the NCBI non-redundant database representing diverse molecular functions and biological processes based on Gene Ontology (GO) classification. We identified numerous, previously undescribed genes with potential roles in photoreception, pathogenesis, and the regulation of development as well as <it>Zephyr</it>, a novel, actively transcribed transposable element. Differential expression of selected genes was demonstrated by real-time PCR, supporting their proposed roles in vegetative, infectious, and reproductive growth.</p> <p>Conclusion</p> <p>Novel genes that are potentially involved in regulating growth, development, and pathogenesis were identified in <it>C. zeae-maydis</it>, providing specific targets for characterization by molecular genetics and functional genomics. The EST data establish a foundation for future studies in evolutionary and comparative genomics among species of <it>Cercospora </it>and other groups of plant pathogenic fungi.</p

    Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The ascomycete fungus <it>Cercospora zeae-maydis </it>is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in <it>C. zeae-maydis </it>at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from <it>C. zeae-maydis </it>and evaluate their expression during vegetative, infectious, and reproductive growth.</p> <p>Results</p> <p>A total of 27,551 ESTs was obtained from five cDNA libraries constructed from vegetative and sporulating cultures of <it>C. zeae-maydis</it>. The ESTs, grouped into 4088 clusters and 531 singlets, represented 4619 putative unique genes. Of these, 36% encoded proteins similar (E value ≤ 10<sup>-05</sup>) to characterized or annotated proteins from the NCBI non-redundant database representing diverse molecular functions and biological processes based on Gene Ontology (GO) classification. We identified numerous, previously undescribed genes with potential roles in photoreception, pathogenesis, and the regulation of development as well as <it>Zephyr</it>, a novel, actively transcribed transposable element. Differential expression of selected genes was demonstrated by real-time PCR, supporting their proposed roles in vegetative, infectious, and reproductive growth.</p> <p>Conclusion</p> <p>Novel genes that are potentially involved in regulating growth, development, and pathogenesis were identified in <it>C. zeae-maydis</it>, providing specific targets for characterization by molecular genetics and functional genomics. The EST data establish a foundation for future studies in evolutionary and comparative genomics among species of <it>Cercospora </it>and other groups of plant pathogenic fungi.</p

    Gender Inequity Norms Are Associated with Increased Male-Perpetrated Rape and Sexual Risks for HIV Infection in Botswana and Swaziland

    Get PDF
    There is limited empirical research on the underlying gender inequity norms shaping gender-based violence, power, and HIV risks in sub-Saharan Africa, or how risk pathways may differ for men and women. This study is among the first to directly evaluate the adherence to gender inequity norms and epidemiological relationships with violence and sexual risks for HIV infection.Data were derived from population-based cross-sectional samples recruited through two-stage probability sampling from the 5 highest HIV prevalence districts in Botswana and all districts in Swaziland (2004-5). Based on evidence of established risk factors for HIV infection, we aimed 1) to estimate the mean adherence to gender inequity norms for both men and women; and 2) to model the independent effects of higher adherence to gender inequity norms on a) male sexual dominance (male-controlled sexual decision making and rape (forced sex)); b) sexual risk practices (multiple/concurrent sex partners, transactional sex, unprotected sex with non-primary partner, intergenerational sex).A total of 2049 individuals were included, n = 1255 from Botswana and n = 796 from Swaziland. In separate multivariate logistic regression analyses, higher gender inequity norms scores remained independently associated with increased male-controlled sexual decision making power (AORmen = 1.90, 95%CI:1.09-2.35; AORwomen = 2.05, 95%CI:1.32-2.49), perpetration of rape (AORmen = 2.19 95%CI:1.22-3.51), unprotected sex with a non-primary partner (AORmen = 1.90, 95%CI:1.14-2.31), intergenerational sex (AORwomen = 1.36, 95%CI:1.08-1.79), and multiple/concurrent sex partners (AORmen = 1.42, 95%CI:1.10-1.93).These findings support the critical evidence-based need for gender-transformative HIV prevention efforts including legislation of women's rights in two of the most HIV affected countries in the world

    The Mechanisms of RNA SHAPE Chemistry

    Get PDF
    The biological functions of RNA are ultimately governed by the local environment at each nucleotide. Selective 2′-hydroxyl acylation analyzed by primer extension (SHAPE) chemistry is a powerful approach for measuring nucleotide structure and dynamics in diverse biological environments. SHAPE reagents acylate the 2′-hydroxyl group at flexible nucleotides because unconstrained nucleotides preferentially sample rare conformations that enhance the nucleophilicity of the 2′-hydroxyl. The critical corollary is that some constrained nucleotides must be poised for efficient reaction at the 2′-hydroxyl group. To identify such nucleotides, we performed SHAPE on intact crystals of the E. coli ribosome, monitored the reactivity of 1490 nucleotides in 16S ribosomal RNA, and examined those nucleotides that were hyper-reactive towards SHAPE and had well-defined crystallographic conformations. Analysis of these conformations revealed that 2′-hydroxyl reactivity is broadly facilitated by general base catalysis involving multiple RNA functional groups and by two specific orientations of the bridging 3′-phosphate group. Nucleotide analog studies confirmed the contributions of these mechanisms to SHAPE reactivity. These results provide a strong mechanistic explanation for the relationship between SHAPE reactivity and local RNA dynamics and will facilitate interpretation of SHAPE information in the many technologies that make use of this chemistry

    Small Grains and Rye Grass for Winter Pasture.

    Get PDF
    38 p

    Computer Simulation of the Effect of Cargo Shifting on Articulated Vehicles Performing Braking and Cornering Maneuvers, Volume 1, Executive Summary

    Get PDF
    P.0. 6-4-0118The effects of sloshing liquid cargo on the limit performance of articulated trucks have been investigated. The limit performances of four vehicle configurations in cornering and braking maneuvers were simulated using an augmented version of the vehicle simulation program, TDVS (Three Dimensional Vehicle Simulation). The vehicle configurations consisted of tractor with unbaffled, baffled, and compartmentalized tank trailers and a baseline van. Simulated maneuvers were lane change, cornering, straight-line braking, and braking-in-a-turn. Both vehicle configurations and maneuvers were modeled to correspond with the full-scale experiments, "Effect of Cargo Shifting on Vehicle Handling", (DOT-FH-11-9195), conducted by Dynamic Sciences, Inc. This report covers the validation of the augmented TDVS program, and the development and implementation of a methodology for conducting limit of performance simulations. Results are discussed and summarized in the context of the simulation program and in light of experimental data. Finally, recommendations are presented for vehicle dynamics analysis methodology and for future studies

    Endoskeletal structure in Cheirolepis (Osteichthyes, Actinopterygii), An early ray-finned fish

    Get PDF
    As the sister lineage of all other actinopterygians, the Middle to Late Devonian (Eifelian–Frasnian) Cheirolepis occupies a pivotal position in vertebrate phylogeny. Although the dermal skeleton of this taxon has been exhaustively described, very little of its endoskeleton is known, leaving questions of neurocranial and fin evolution in early ray‐finned fishes unresolved. The model for early actinopterygian anatomy has instead been based largely on the Late Devonian (Frasnian) Mimipiscis, preserved in stunning detail from the Gogo Formation of Australia. Here, we present re‐examinations of existing museum specimens through the use of high‐resolution laboratory‐ and synchrotron‐based computed tomography scanning, revealing new details of the neuro‐cranium, hyomandibula and pectoral fin endoskeleton for the Eifelian Cheirolepis trailli. These new data highlight traits considered uncharacteristic of early actinopterygians, including an uninvested dorsal aorta and imperforate propterygium, and corroborate the early divergence of Cheirolepis within actinopterygian phylogeny. These traits represent conspicuous differences between the endoskeletal structure of Cheirolepis and Mimipiscis. Additionally, we describe new aspects of the parasphenoid, vomer and scales, most notably that the scales display peg‐and‐socket articulation and a distinct neck. Collectively, these new data help clarify primitive conditions within ray‐finned fishes, which in turn have important implications for understanding features likely present in the last common ancestor of living osteichthyans

    Interpersonal violence: an important risk factor for disease and injury in South Africa

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Burden of disease estimates for South Africa have highlighted the particularly high rates of injuries related to interpersonal violence compared with other regions of the world, but these figures tell only part of the story. In addition to direct physical injury, violence survivors are at an increased risk of a wide range of psychological and behavioral problems. This study aimed to comprehensively quantify the excess disease burden attributable to exposure to interpersonal violence as a risk factor for disease and injury in South Africa.</p> <p>Methods</p> <p>The World Health Organization framework of interpersonal violence was adapted. Physical injury mortality and disability were categorically attributed to interpersonal violence. In addition, exposure to child sexual abuse and intimate partner violence, subcategories of interpersonal violence, were treated as risk factors for disease and injury using counterfactual estimation and comparative risk assessment methods. Adjustments were made to account for the combined exposure state of having experienced both child sexual abuse and intimate partner violence.</p> <p>Results</p> <p>Of the 17 risk factors included in the South African Comparative Risk Assessment study, interpersonal violence was the second leading cause of healthy years of life lost, after unsafe sex, accounting for 1.7 million disability-adjusted life years (DALYs) or 10.5% of all DALYs (95% uncertainty interval: 8.5%-12.5%) in 2000. In women, intimate partner violence accounted for 50% and child sexual abuse for 32% of the total attributable DALYs.</p> <p>Conclusions</p> <p>The implications of our findings are that estimates that include only the direct injury burden seriously underrepresent the full health impact of interpersonal violence. Violence is an important direct and indirect cause of health loss and should be recognized as a priority health problem as well as a human rights and social issue. This study highlights the difficulties in measuring the disease burden from interpersonal violence as a risk factor and the need to improve the epidemiological data on the prevalence and risks for the different forms of interpersonal violence to complete the picture. Given the extent of the burden, it is essential that innovative research be supported to identify social policy and other interventions that address both the individual and societal aspects of violence.</p

    Intimate partner violence against women in rural Vietnam - different socio-demographic factors are associated with different forms of violence: Need for new intervention guidelines?

    Get PDF
    Background: This population-based study investigated the different forms, magnitude and risk factors of men's violence against women in intimate relationships in a rural part of northern Vietnam and whether a difference in risk factors were at hand for the different forms of violence. Vietnam has undergone a rapid transition in the last 20 years, moving towards a more equal situation for men and women however, Confucian doctrine is still strong and little is known about men's violence against women within the Vietnamese family. Methods: This is a cross-sectional population-based study that used a questionnaire developed by the World Health Organisation for investigating women's health and violence against women in different settings. Face-to face structured interviewing was performed and 883 married women, aged 17 to 60 participated. Bi- and multivariate analyses was used for risk factor assessment. Results: The lifetime prevalence of physical violence was 30.9 percent and past year prevalence was 8.3 per cent, while the corresponding figures for physical and sexual violence combined was 32.7 and 9.2 percent. The lifetime prevalence was highest for psychological abuse ( 27.9 percent) as a single entity. In most cases the violence was of a severe nature and exercised as repeated acts over time. Woman's low educational level, husband's low education, low household income and the husband having more than one wife/partner were risk factors for lifetime and past year physical/sexual violence. The pattern of factors associated with psychological abuse alone was however different. Husband's low professional status and women's intermediate level of education appeared as risk factors. Conclusion: Men's violence against women in intimate relationships is commonly occurring in rural Vietnam. There is an obvious need of preventive and treatment activities. Our findings point at that pure psychological abuse is different from physical/sexual violence in terms of differing characteristics of the perpetrators and it might be that also different strategies are needed to reduce and prevent this violence
    corecore