The role of seaweed extracts, Ascophyllum nodosum, in the reduction in fecundity of Meloidogyne javanica

Les effets d'extraits commerciaux de l'algue marine #Ascophyllum nodosum sur la fécondité du nématode #Meloidogyne javanica, élevé sur tomate (#Lycopersicon esculentum$ cv. Ailsa Craig) sont évalués. Après une génération, le nombre d'oeufs du nématode récupérés sur les plantes traitées diminue considérablement en comparaison avec les plantes témoins, traitées avec de l'eau pure. Un plus faible nombre d'oeufs sont récupérés sur les plantes infestées par des juvéniles ayant incubé dans des extraits d'algue en comparaison avec les plantes infestées par des juvéniles ayant incubé dans de l'eau pure. (Résumé d'auteur

HIV prevention policy and programme planning: What can mathematical modelling contribute?

This thesis explores the potential contribution of mathematical modelling to informed decision-making on policy and programme planning for novel HIV prevention tools. Its hypothesis is that, under certain conditions, modelling results can be a useful addition to the evidence and other factors that influence the HIV prevention policy and programme development process. The emerging HIV prevention tools that serve to illustrate this are voluntary medical male circumcision, systemic pre-exposure prophylaxis with antiretroviral drugs, HIV vaccines, and structural interventions for people who inject drugs. Comparing model structures and findings, including the results of sensitivity analyses, through consensus processes, systematic reviews, and other methodologies serves to strengthen the potential contribution that modelling can make to HIV prevention policy. Modelling will increasingly be useful to biomedical HIV prevention trial design, given the evolving standard of prevention being offered to all trial participants. Populating mathematical models with up-to-date, context-relevant, and accurate information will remain a key challenge, along with effective knowledge translation strategies. Engaging policy makers from the start can help ensure that modelling addresses relevant policy questions, is informed by the best available locally available information, and finds a receptive audience when results are presented. Modellers can play an important role by generating modelling results on questions of key importance that provide insights into the potential impact of competing HIV prevention scenarios in the context of constrained resources. In effect, they can paint pictures for policy makers of the paths that can lead to a future in which HIV transmission is increasingly rare

Supernova siblings and their parent galaxies in the Zwicky Transient Facility Bright Transient Survey

International audienceSupernova (SN) siblings – two or more SNe in the same parent galaxy – are useful tools for exploring progenitor stellar populations as well as properties of the host galaxies such as distance, star-formation rate, dust extinction, and metallicity. Since the average SN rate for a Milky Way-type galaxy is just one per century, a large imaging survey is required to discover an appreciable sample of SN siblings. From the wide-field Zwicky Transient Facility (ZTF) Bright Transient Survey (which aims for spectroscopic completeness for all transients which peak brighter than r < 18.5 mag) we present 10 SN siblings in five parent galaxies. For each of these families, we analyse the SN’s location within the host and its underlying stellar population, finding agreement with expectations that SNe from more massive progenitors are found nearer to their host core and in regions of more active star formation. We also present an analysis of the relative rates of core collapse and thermonuclear SN siblings, finding a significantly lower ratio than past SN sibling samples due to the unbiased nature of the ZTF