Direct Domino Synthesis of Azido-Dienoic Acids: Potential Linker Units

We report an atom-economical domino synthesis of functionalized and stereodefined dienes. This method hinges on an allylic alkylation–electrocyclic ring-opening sequence and allows direct access to doubly vinylogous azido-dienoic acids bearing challenging substitution patterns. This class of compounds re­presents useful linkers in chemical biology by virtue of the ortho­gonality between the azido and carboxylic acid moieties

An Atom-Economical and Stereoselective Domino Synthesis of Functionalised Dienes

Open sesame: A direct synthesis of functionalised and stereodefined dienes, relying on a domino allylic alkylation/electrocyclic ring-opening sequence, is reported. This method allows concise access to doubly vinylogous esters. A further systematic study of ring-opening rates of carbon-substituted cyclobutenes allowed the design of substrates amenable to sequential pericyclic reactions

Direct observation of homogeneous cavitation in nanopores

We report on the evaporation of hexane from porous alumina and silicon membranes. These membranes contain billions of independent nanopores tailored to an ink-bottle shape, where a cavity several tens of nanometers in diameter is separated from the bulk vapor by a constriction. For alumina membranes with narrow enough constrictions, we demonstrate that cavity evaporation proceeds by cavitation. Measurements of the pressure dependence of the cavitation rate follow the predictions of the bulk, homogeneous, classical nucleation theory, definitively establishing the relevance of homogeneous cavitation as an evaporation mechanism in mesoporous materials. Our results imply that porous alumina membranes are a promising new system to study liquids in a deeply metastable state.Comment: 14 pages , 4 figures. Source files also contain Supplemental Material (Doebele_HomogeneousCavitationMembranes_SM.pdf

Epidemiologic Relationship between Toscana Virus Infection and Leishmania infantum Due to Common Exposure to Phlebotomus perniciosus Sandfly Vector

Sand flies are recognised vectors of parasites in the genus Leishmania and a number of arthropod-borne viruses, in particular viruses within the genus Phlebovirus, family Bunyaviridae. In southern France, Toscana phlebovirus (TOSV) is recognized as a prominent cause of summer meningitis. Since Leishmania and TOSV have a common vector (Phlebotomus perniciosus), an epidemiologic link has been assumed for a long time. However, there is no scientific evidence of such a link between human leishmaniosis and phleboviral infections. To identify a possible link, we investigated the presence and distribution of antibodies against these two microorganisms (i) in individuals and (ii) at a spatial level in the city of Marseille (south-eastern France). Five hundred sera were selected randomly in the biobank of the Department of Parasitology of the Public Hospitals of Marseille. All sera were previously tested for IgG against Leishmania by Western Blotting, and TOSV IgG were detected by indirect immunofluorescence. The seropositivity rates were 21.4% for TOSV and 28% for Leishmania. Statistical analysis demonstrated that seropositivity for one pathogen was significantly associated with seropositivity to the other pathogen. This result provided the first robust evidence for the existence of an epidemiological relationship between Leishmania infantum and TOSV. Addresses of tested patients were geolocalized and integrated into Geographical Information System software, in order to test spatial relationship between the two pathogens. Spatial analysis did not allow to identify (i) specific patterns for the spatial distribution of positive serological results for TOSV or Leishmania, and (ii) a spatial relationship between Leishmania and TOSV positive serological results. This may reflect the fact that the sample studied was not powerful enough to demonstrate either a spatial clustering or co-location, i.e. that the actual risk exposure area is smaller than the mean of distance between patients in our study (245 m)

Is leadership a reliable concept in animals? An empirical study in the horse

International audienceLeadership is commonly invoked when accounting for the coordination of group movements in animals, yet it remains loosely defined. In parallel, there is increased evidence of the sharing of group decisions by animals on the move. How leadership integrates within this recent framework on collective decision-making is unclear. Here, we question the occurrence of leadership in horses, a species in which this concept is of prevalent use. The relevance of the three main definitions of leadership - departing first, walking in front travel position, and eliciting the joining of mates - was tested on the collective movements of two semi-free ranging groups of Przewalski horses (Equus ferus przewalskii). We did not find any leader capable of driving most group movements or recruiting mates more quickly than others. Several group members often displayed pre-departure behaviours at the same time, and the simultaneous departure of several individuals was common. We conclude that the decision-making process was shared by several group members a group movement (i.e., partially shared consensus) and that the leadership concept did not help to depict individual departure and leading behaviour across movements in both study groups. Rather, the different proxies of leadership produced conflicting information about individual contributions to group coordination. This study discusses the implications of these findings for the field of coordination and decision-making research

Evaluating parents’ decisions about next-generation sequencing for their child in the NC NEXUS (North Carolina Newborn Exome Sequencing for Universal Screening) study: a randomized controlled trial protocol

Abstract Background Using next-generation sequencing (NGS) in newborn screening (NBS) could expand the number of genetic conditions detected pre-symptomatically, simultaneously challenging current precedents, raising ethical concerns, and extending the role of parental decision-making in NBS. The NC NEXUS (Newborn Exome Sequencing for Universal Screening) study seeks to assess the technical possibilities and limitations of NGS-NBS, devise and evaluate a framework to convey various types of genetic information, and develop best practices for incorporating NGS-NBS into clinical care. The study is enrolling both a healthy cohort and a cohort diagnosed with known disorders identified through recent routine NBS. It uses a novel age-based metric to categorize a priori the large amount of data generated by NGS-NBS and interactive online decision aids to guide parental decision-making. Primary outcomes include: (1) assessment of NGS-NBS sensitivity, (2) decision regret, and (3) parental decision-making about NGS-NBS, and, for parents randomized to have the option of requesting them, additional findings (diagnosed and healthy cohorts). Secondary outcomes assess parents’ reactions to the study and to decision-making. Methods/design Participants are parents and children in a well-child cohort recruited from a prenatal clinic and a diagnosed cohort recruited from pediatric clinics that treat children with disorders diagnosed through traditional NBS (goal of 200 children in each cohort). In phase 1, all parent participants use an online decision aid to decide whether to accept NGS-NBS for their child and provide consent for NGS-NBS. In phase 2, parents who consent to NGS-NBS are randomized to a decision arm or control arm (2:1 allocation) and learn their child’s NGS-NBS results, which include conditions from standard (non-NGS) NBS plus other highly actionable childhood-onset conditions. Parents in the decision arm use a second decision aid to make decisions about additional results from their child’s sequencing. In phase 3, decision arm participants learn additional results they have requested. Online questionnaires are administered at up to five time points. Discussion NC NEXUS will use a rigorous interdisciplinary approach designed to collect rich data to inform policy, practice, and future research. Trial registration clinicaltrials.gov, NCT02826694 . Registered on 11 July, 2016

Contrasting Spatial Distribution and Risk Factors for Past Infection with Scrub Typhus and Murine Typhus in Vientiane City, Lao PDR

Scrub typhus and murine typhus are neglected but important treatable causes of fever, morbidity and mortality in South-East Asia. Epidemiological data suggests that scrub typhus would be more common in rural areas and murine typhus in urban areas but there are very few comparative data from places where both diseases occur, as is the case in Vientiane, the capital of the Lao PDR. We therefore determined the frequency of IgG antibody seropositivity against scrub typhus and murine typhus, as indices of prior exposure to these pathogens, in a randomly selected population of 2,002 adults living in different neighbourhoods in Vientiane. The overall prevalence of IgG against these two pathogens was ∼20%. However, within the city, the spatial distribution of IgG against these two diseases was radically different - past exposure to murine typhus being more frequent in urbanized areas while past exposure to scrub typhus more frequent in outlying areas. This study underscores the importance of ecological characteristics in improving the understanding of both scrub typhus and murine typhus transmission and epidemiology