821 research outputs found

    <i>Albugo candida</i> race diversity, ploidy and host-associated microbes revealed using DNA sequence capture on diseased plants in the field

    Get PDF
    • Physiological races of the oomycete Albugo candida are biotrophic pathogens of diverse plant species, primarily the Brassicaceae, and cause infections that suppress host immunity to other pathogens. However, A. candida race diversity and the consequences of host immunosuppression are poorly understood in the field. • We report a method that enables sequencing of DNA of plant pathogens and plant-associated microbes directly from field samples (Pathogen Enrichment Sequencing: PenSeq). We apply this method to explore race diversity in A. candida and to detect A. candida-associated microbes in the field (91 A. candida-infected plants).• We show with unprecedented resolution that each host plant species supports colonization by one of 17 distinct phylogenetic lineages, each with an unique repertoire of effector candidate alleles. These data reveal the crucial role of sexual and asexual reproduction, polyploidy and host domestication in A. candida specialization on distinct plant species. Our bait design also enabled phylogenetic assignment of DNA sequences from bacteria and fungi from plants in the field.• This paper shows that targeted sequencing has a great potential for the study of pathogen populations while they are colonizing their hosts. This method could be applied to other microbes, especially to those that cannot be cultured

    Evaluating the successful implementation of evidence into practice using the PARiHS framework : theoretical and practical challenges

    Get PDF
    Background The PARiHS framework (Promoting Action on Research Implementation in Health Services) has proved to be a useful practical and conceptual heuristic for many researchers and practitioners in framing their research or knowledge translation endeavours. However, as a conceptual framework it still remains untested and therefore its contribution to the overall development and testing of theory in the field of implementation science is largely unquantified. Discussion This being the case, the paper provides an integrated summary of our conceptual and theoretical thinking so far and introduces a typology (derived from social policy analysis) used to distinguish between the terms conceptual framework, theory and model – important definitional and conceptual issues in trying to refine theoretical and methodological approaches to knowledge translation. Secondly, the paper describes the next phase of our work, in particular concentrating on the conceptual thinking and mapping that has led to the generation of the hypothesis that the PARiHS framework is best utilised as a two-stage process: as a preliminary (diagnostic and evaluative) measure of the elements and sub-elements of evidence (E) and context (C), and then using the aggregated data from these measures to determine the most appropriate facilitation method. The exact nature of the intervention is thus determined by the specific actors in the specific context at a specific time and place. In the process of refining this next phase of our work, we have had to consider the wider issues around the use of theories to inform and shape our research activity; the ongoing challenges of developing robust and sensitive measures; facilitation as an intervention for getting research into practice; and finally to note how the current debates around evidence into practice are adopting wider notions that fit innovations more generally. Summary The paper concludes by suggesting that the future direction of the work on the PARiHS framework is to develop a two-stage diagnostic and evaluative approach, where the intervention is shaped and moulded by the information gathered about the specific situation and from participating stakeholders. In order to expedite the generation of new evidence and testing of emerging theories, we suggest the formation of an international research implementation science collaborative that can systematically collect and analyse experiences of using and testing the PARiHS framework and similar conceptual and theoretical approaches. We also recommend further refinement of the definitions around conceptual framework, theory, and model, suggesting a wider discussion that embraces multiple epistemological and ontological perspectives

    Temporal and Individual Variation in Offspring Provisioning by Tree Swallows: A New Method of Automated Nest Attendance Monitoring

    Get PDF
    Studies of the ecology and evolution of avian nesting behavior have been limited by the difficulty and expense of sampling nest attendance behavior across entire days or throughout a substantial portion of the nestling period. Direct observation of nesting birds using human observers and most automated devices requires sub-sampling of the nestling period, which does not allow for the quantification of the duration of chick-feeding by parents within a day, and may also inadequately capture temporal variation in the rate at which chicks are fed. Here I describe an inexpensive device, the Automated Perch Recorder (APR) system, which collects accurate, long-term data on hourly rates of nest visitation, the duration of a pair's workday, and the total number of visits the pair makes to their nest across the entire period for which it is deployed. I also describe methods for verifying the accuracy of the system in the field, and several examples of how these data can be used to explore the causes of variation in and tradeoffs between the rate at which birds feed their chicks and the total length of time birds spend feeding chicks in a day

    Building resilience in contemporary nursing practice

    Get PDF
    YesThe nursing profession is being threatened by staff shortages. Catherine Best explains why building resilience from within the profession is vital to safeguarding its future, by keeping newly qualified nurses in the job and preventing emotional ‘burnout’ across disciplines Resilience in nursing has been critiqued and challenged throughout the nursing literature. Trends in nursing have led to many nurses leaving the profession early in their career, often due to the immense pressures that they work under. There are many opinions on how nurses can develop the resilience needed to maintain professional integrity and continue to provide safe and effective care, while attempting to shoulder the considerable impact of political and professional drivers. This not only leaves nurses exhausted but often without hope. By taking collective action, this article argues that nurses may benefit from sharing ideas and learning from others, and in so doing rekindle hope and a belief that things can change

    Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers

    Get PDF
    &lt;p&gt;&lt;b&gt;Purpose:&lt;/b&gt; Imprecise measurement of physical activity variables might attenuate estimates of the beneficial effects of activity on health-related outcomes. We aimed to compare the cardiometabolic risk factor dose-response relationships for physical activity and sedentary behaviour between accelerometer- and questionnaire-based activity measures.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; Physical activity and sedentary behaviour were assessed in 317 adults by 7-day accelerometry and International Physical Activity Questionnaire (IPAQ). Fasting blood was taken to determine insulin, glucose, triglyceride and total, LDL and HDL cholesterol concentrations and homeostasis model-estimated insulin resistance (HOMAIR). Waist circumference, BMI, body fat percentage and blood pressure were also measured.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; For both accelerometer-derived sedentary time (&#60;100 counts.min−1) and IPAQ-reported sitting time significant positive (negative for HDL cholesterol) relationships were observed with all measured risk factors – i.e. increased sedentary behaviour was associated with increased risk (all p&#8804;0.01). However, for HOMAIR and insulin the regression coefficients were &#62;50% lower for the IPAQ-reported compared to the accelerometer-derived measure (p&#60;0.0001 for both interactions). The relationships for moderate-to-vigorous physical activity (MVPA) and risk factors were less strong than those observed for sedentary behaviours, but significant negative relationships were observed for both accelerometer and IPAQ MVPA measures with glucose, and insulin and HOMAIR values (all p&#60;0.05). For accelerometer-derived MVPA only, additional negative relationships were seen with triglyceride, total cholesterol and LDL cholesterol concentrations, BMI, waist circumference and percentage body fat, and a positive relationship was evident with HDL cholesterol (p = 0.0002). Regression coefficients for HOMAIR, insulin and triglyceride were 43–50% lower for the IPAQ-reported compared to the accelerometer-derived MVPA measure (all p&#8804;0.01).&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion:&lt;/b&gt; Using the IPAQ to determine sitting time and MVPA reveals some, but not all, relationships between these activity measures and metabolic and vascular disease risk factors. Using this self-report method to quantify activity can therefore underestimate the strength of some relationships with risk factors.&lt;/p&gt

    Adaptation and validation of the Patient Expectations and Satisfaction with Prenatal Care instrument among Brazilian pregnant women

    Get PDF
    Objective: to adapt and validate the Patient Expectations and Satisfaction with Prenatal Care instrument for use in Brazil. It contains 41 items divided into two dimensions: expectations and satisfaction. The adapted version was submitted to analysis for stability, convergent construct validity, and internal consistency (Cronbach’s alpha) for distinct groups and dimensions. Method: 119 pregnant women receiving prenatal care were interviewed and 26 of these women answered the instrument twice (retest). Internal consistency was appropriate (Cronbach’s alpha ≥ 0.70); test-retest presented strong correlation (r=0.82; p<0.001) for the domain expectations and moderate correlation (r=0.66; p<0.001) for the satisfaction domain. The analysis confirmed that the instrument’s adapted version is valid in the studied group. Results: there is strong evidence for the validity and reliability of the instrument’s adaptation. Conclusion: the instrument needs to be tested in groups of pregnant women with different social characteristics.CAPESCAPE

    The Expanding Fireball of Nova Delphini 2013

    Full text link
    A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion. Studying the structure of novae during the earliest phases is challenging because of the high spatial resolution needed to measure their small sizes. Here we report near-infrared interferometric measurements of the angular size of Nova Delphini 2013, starting from one day after the explosion and continuing with extensive time coverage during the first 43 days. Changes in the apparent expansion rate can be explained by an explosion model consisting of an optically thick core surrounded by a diffuse envelope. The optical depth of the ejected material changes as it expands. We detect an ellipticity in the light distribution, suggesting a prolate or bipolar structure that develops as early as the second day. Combining the angular expansion rate with radial velocity measurements, we derive a geometric distance to the nova of 4.54 +/- 0.59 kpc from the Sun.Comment: Published in Nature. 32 pages. Final version available at http://www.nature.com/nature/journal/v515/n7526/full/nature13834.htm

    Circulating Zonulin, a Marker of Intestinal Permeability, Is Increased in Association with Obesity-Associated Insulin Resistance

    Get PDF
    Zonulin is the only physiological mediator known to regulate intestinal permeability reversibly by modulating intercellular tight junctions. To investigate the relationship between intestinal permeability and obesity-associated metabolic disturbances in humans, we aimed to study circulating zonulin according to obesity and insulin resistance. Circulating zonulin (ELISA) was measured in 123 caucasian men in association with inflammatory and metabolic parameters (including minimal model-measured insulin sensitivity). Circulating zonulin increased with body mass index (BMI), waist to hip ratio (WHR), fasting insulin, fasting triglycerides, uric acid and IL-6, and negatively correlated with HDL-cholesterol and insulin sensitivity. In multiple regression analysis, insulin sensitivity (p = 0.002) contributed independently to circulating zonulin variance, after controlling for the effects of BMI, fasting triglycerides and age. When circulating IL-6 was added to this model, only BMI (p = 0.01) contributed independently to circulating zonulin variance. In conclusion, the relationship between insulin sensitivity and circulating zonulin might be mediated through the obesity-related circulating IL-6 increase

    Different sex ratios of children born to Indian and Pakistani immigrants in Norway

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>A low female-to-male ratio has been observed in different Asian countries, but this phenomenon has not been well studied among immigrants living in Western societies. In this study, we investigated whether a low female-to-male ratio exists among Indian and Pakistani immigrants living in Norway. In particular, we investigated whether the determination of sex via ultrasound examination, a common obstetric procedure that has been used in Norway since the early 1980 s, has influenced the female-to-male ratio among children born to parents of Indian or Pakistani origin.</p> <p>Methods</p> <p>We performed a retrospective cohort study of live births in mothers of Indian (n = 1597) and Pakistani (n = 5617) origin. Data were obtained from "Statistics Norway" and the female-to-male (F/M) sex ratio was evaluated among 21,325 children born, in increasing birth order, during three stratified periods (i.e., 1969-1986, 1987-1996, and 1997-2005).</p> <p>Results</p> <p>A significant low female-to-male sex ratio was observed among children in the third and fourth birth order (sex ratio 65; 95% CI 51-80) from mothers of Indian origin who gave birth after 1987. Sex ratios did not deviate from the expected natural variation in the Indian cohort from 1969 to 1986, and remained stable in the Pakistani cohort during the entire study period. However, the female-to-male sex ratio seemed less skewed in recent years (i.e., 1997-2005).</p> <p>Conclusion</p> <p>Significant differences were observed in the sex ratio of children born to mothers of Indian origin compared with children born to mothers of Pakistani origin. A skewed number of female births among higher birth orders (i.e., third or later) may partly reflect an increase in sex-selective abortion among mothers of Indian origin, although the numbers are too small to draw firm conclusions. Further research is needed to explain the observed differences in the female-to-male ratio among members of these ethnic groups who reside in Norway.</p

    Association of Fecal Microbial Diversity and Taxonomy with Selected Enzymatic Functions

    Get PDF
    Few microbial functions have been compared to a comprehensive survey of the human fecal microbiome. We evaluated determinants of fecal microbial β-glucuronidase and β-glucosidase activities, focusing especially on associations with microbial alpha and beta diversity and taxonomy. We enrolled 51 healthy volunteers (26 female, mean age 39) who provided questionnaire data and multiple aliquots of a stool, from which proteins were extracted to quantify β-glucuronidase and β-glucosidase activities, and DNA was extracted to amplify and pyrosequence 16S rRNA gene sequences to classify and quantify microbiome diversity and taxonomy. Fecal β-glucuronidase was elevated with weight loss of at least 5 lb. (P = 0.03), whereas β-glucosidase was marginally reduced in the four vegetarians (P = 0.06). Both enzymes were correlated directly with microbiome richness and alpha diversity measures, directly with the abundance of four Firmicutes Clostridia genera, and inversely with the abundance of two other genera (Firmicutes Lactobacillales Streptococcus and Bacteroidetes Rikenellaceae Alistipes) (all P = 0.05–0.0001). Beta diversity reflected the taxonomic associations. These observations suggest that these enzymatic functions are performed by particular taxa and that diversity indices may serve as surrogates of bacterial functions. Independent validation and deeper understanding of these associations are needed, particularly to characterize functions and pathways that may be amenable to manipulation
    corecore