Development of reverse-transcription PCR techniques to analyse the density and sex ratio of gametocytes in genetically diverse Plasmodium chabaudi infections

We have developed cross-genotype and genotype-specific quantitative reverse-transcription PCR (qRT-PCR) assays to detect and quantify the number of parasites, transmission stages (gametocytes) and male gametocytes in blood stage Plasmodium chabaudi infections. Our cross-genotype assays are reliable, repeatable and generate counts that correlate strongly (R(2)s > 90%) with counts expected from blood smears. Our genotype-specific assays can distinguish and quantify different stages of genetically distinct parasite clones (genotypes) in mixed infections and are as sensitive as our cross-genotype assays. Using these assays we show that gametocyte density and gametocyte sex ratios vary during infections for two genetically distinct parasite lines (genotypes) and present the first data to reveal how sex ratio is affected when each genotype experiences competition in mixed-genotype infections. Successful infection of mosquito vectors depends on both gametocyte density and their sex ratio and we discuss the implications of competition in genetically diverse infections for transmission success

Astrophysical science metrics for next-generation gravitational-wave detectors

The second generation of gravitational-wave detectors are being built and tuned all over the world. The detection of signals from binary black holes is beginning to fulfill the promise of gravitational-wave astronomy. In this work, we examine several possible configurations for third-generation laser interferometers in existing km-scale facilities. We propose a set of astrophysically motivated metrics to evaluate detector performance. We measure the impact of detector design choices against these metrics, providing a quantitative cost-benefit analyses of the resulting scientific payoffs

Ectomycorrhizal fungal biodiversity from New Caledonian rainforests on ultramafic soils

Background: Ectomycorrhizal (ECM) fungi play key roles in ecosystems functioning, such as in plant community dynamic. However, very few studies have been undertaken in the tropics. New Caledonia is an archipelago located in the South West Pacific and is wellrecognized for its exceptional biodiversity, especially due to its geographical isolation and the presence of ultramafic soils. In this study, we present the first large molecular study on ECM fungal communities in New Caledonian rainforests from ultramafic soils. Method: We collected ECM root tips and fruit bodies from three sites located in the South of the main island. In each site, sampling was performed in two monodominant rainforests, with an upper canopy dominated by Nothofagus aequilateralis (Nothofagaceae) or Arillastrum gummiferum (Myrtaceae). Adjacent mixed rainforests were also studied. These formations might represent different successional stages of forest dynamic. Fungi were identified by sequencing the internal transcribed spacer (ITS) of the nuclear ribosomal genes, and host plant were identified as well using the same genomic region. Results: Out of the 587 ECM root tips and 2372 fruit bodies, 312 OTUs, belonging to at least 29 lineages, were delineated. The community was largely dominated by the /cortinarius lineage in the above- and below-ground communities. Furthermore, community structure analyses strongly suggested host preferences. Discussion - conclusion: This work increases our knowledge of ECM fungal biodiversity in the tropics, particularly in terms of diversity and dynamic. Indeed, the species diversity seems to be similar to the diversity observed in other tropical and temperate forests and most of the molecular species delineated might be unique to New Caledonia. We could also hypothesise that some fungal groups play major roles in the community dynamic as inoculums sources. Additionally, in the context of land disturbance, the results obtained will permit to develop biological indicators for further conservation and ecological restoration programs of New Caledonian ultramafic ecosystems. (Texte intégral

The Stony Brook / SMARTS Atlas of mostly Southern Novae

We introduce the Stony Brook / SMARTS Atlas of (mostly) Southern Novae. This atlas contains both spectra and photometry obtained since 2003. The data archived in this atlas will facilitate systematic studies of the nova phenomenon and correlative studies with other comprehensive data sets. It will also enable detailed investigations of individual objects. In making the data public we hope to engender more interest on the part of the community in the physics of novae. The atlas is on-line at \url{http://www.astro.sunysb.edu/fwalter/SMARTS/NovaAtlas/} .Comment: 11 figures; 5 table

Prospective cohort study to investigate the burden and transmission of acute gastroenteritis in care homes: a study protocol.

INTRODUCTION: Noroviruses are the leading cause of acute gastroenteritis in all age groups, but illness is more severe and causes excess mortality in the elderly, particularly those in long-term care. The total burden of norovirus disease in the elderly in the UK is poorly defined; no current surveillance programmes systematically or accurately quantify norovirus infection in those living in care homes. The aim of this study is to evaluate an enhanced surveillance system for acute gastroenteritis among the elderly in care homes. METHODS AND ANALYSIS: We will conduct this prospective cohort study in care homes in North West England; residents and staff at study care homes will be asked to participate. We will prospectively enrol a cohort of participants in an enhanced surveillance system to capture the incidence of acute gastroenteritis and use multiplex PCR to detect pathogens. We will sample symptomatic and non-symptomatic participants to understand characteristics of norovirus disease and susceptibility to infection. We will generate novel data on transmission dynamics by collecting data on the pattern of interactions within care homes using electronic proximity sensors. Comparisons of outbreak and non-outbreak periods will be used to quantify the impact of norovirus outbreaks on care homes. ETHICS AND DISSEMINATION: The study has been approved by the North West-Greater Manchester South NHS Research Ethics Committee (REC Reference: 16/NW/0541). Study outputs will be disseminated through scientific conferences and peer-reviewed publications. This study will provide detailed insight on the burden and aetiology of acute gastroenteritis in care homes, in addition to generating novel data on transmission dynamics and risks. The study will identify areas for improving infection control practice and allow more accurate modelling of the introduction of interventions such as vaccination

Special Issue Introduction: Writing Infrastructure

This article is the introduction to the second of two Communication and Design Quarterly special issues focused on conceptualizations of infrastructure. While there are more continuities than differences between the themes and methodologies of articles in the first and second issues, this second issue leans towards articles that have taken up infrastructure as it pertains to writing and rhetoric. This introduction frames the value of infrastructure as a metaphor for making visible how writing and rhetoric structure and enact much of our world, especially for writing pedagogy. In addition, this article concludes by introducing the six contributions in this issue

Virulence, drug sensitivity and transmission success in the rodent malaria, Plasmodium chabaudi.

Here, we test the hypothesis that virulent malaria parasites are less susceptible to drug treatment than less virulent parasites. If true, drug treatment might promote the evolution of more virulent parasites (defined here as those doing more harm to hosts). Drug-resistance mechanisms that protect parasites through interactions with drug molecules at the sub-cellular level are well known. However, parasite phenotypes associated with virulence might also help parasites survive in the presence of drugs. For example, rapidly replicating parasites might be better able to recover in the host if drug treatment fails to eliminate parasites. We quantified the effects of drug treatment on the in-host survival and between-host transmission of rodent malaria (Plasmodium chabaudi) parasites which differed in virulence and had never been previously exposed to drugs. In all our treatment regimens and in single- and mixed-genotype infections, virulent parasites were less sensitive to pyrimethamine and artemisinin, the two antimalarial drugs we tested. Virulent parasites also achieved disproportionately greater transmission when exposed to pyrimethamine. Overall, our data suggest that drug treatment can select for more virulent parasites. Drugs targeting transmission stages (such as artemisinin) may minimize the evolutionary advantage of virulence in drug-treated infections

Incidence of Hospitalization for Heart Failure and Case-Fatality Among 3.25 Million People With and Without Diabetes Mellitus

Background: Recent clinical trials of new glucose-lowering treatments have drawn attention to the importance of hospitalisation for heart failure as a complication of diabetes. However, the epidemiology is not well described, particularly for type 1 diabetes. We examined the incidence and case-fatality of heart failure hospitalisations in the entire population aged 30 and older resident in Scotland during 2004 to 2013. Methods: Date and type of diabetes diagnosis were linked to heart failure hospitalisations and deaths using the national Scottish registers. Incidence rates and case-fatality were estimated in regression models (quasi-Poisson and logistic regression respectively). All estimates are adjusted for age, sex, socio-economic status and calendar-year. Results: Over the 10-year period of the study, among 3.25 million people there were 91,429, 22,959 and 1,313 incident heart failure events among those without diabetes, with type 2, and type 1 diabetes respectively. The crude incidence rates of heart failure hospitalisation were therefore 2.4, 12.4 and 5.6 per 1000 person-years for these three groups. Heart failure hospitalisation incidence was higher in people with diabetes, regardless of type, than in people without. Relative differences were smallest for older men, in whom the difference was nonetheless large (men aged 80, rate ratio 1.78; 95% CI 1.45 to 2.19). Rates declined similarly, by 0.2% per calendar-year, in people with type 2 diabetes and without diabetes. Rates fell faster, however, in those with type 1 diabetes (2.2% per calendar-year, RR for type 1/calendar-year interaction 0.978; 95% CI 0.959 to 0.998). 30-day case-fatality was similar among people with type 2 diabetes and without diabetes, but was higher in type 1 diabetes for men (OR 0.96; 95% CI 0.95 to 0.96) and women (OR 0.98; 95% CI 0.97 to 0.98). Case-fatality declined over time for all groups (3.3% per calendar-year, OR per calendar-year 0.967; 95% CI 0.961 to 0.973). Conclusions: Despite falling incidence, particularly in type 1 diabetes, heart failure remains around 2-fold higher than in people without diabetes, with higher case-fatality in those with type 1 diabetes. These findings support the view that heart failure is an under-recognised and important complication in diabetes, particularly for type 1 disease

"Now he walks and walks, as if he didn't have a home where he could eat": food, healing, and hunger in Quechua narratives of madness

In the Quechua-speaking peasant communities of southern Peru, mental disorder is understood less as individualized pathology and more as a disturbance in family and social relationships. For many Andeans, food and feeding are ontologically fundamental to such relationships. This paper uses data from interviews and participant observation in a rural province of Cuzco to explore the significance of food and hunger in local discussions of madness. Carers’ narratives, explanatory models, and theories of healing all draw heavily from idioms of food sharing and consumption in making sense of affliction, and these concepts structure understandings of madness that differ significantly from those assumed by formal mental health services. Greater awareness of the salience of these themes could strengthen the input of psychiatric and psychological care with this population and enhance knowledge of the alternative treatments that they use. Moreover, this case provides lessons for the global mental health movement on the importance of openness to the ways in which indigenous cultures may construct health, madness, and sociality. Such local meanings should be considered by mental health workers delivering services in order to provide care that can adjust to the alternative ontologies of sufferers and carers