Journal of Next-Generation Research 5.0
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Uplisting of Malagasy precious woods critical for their survival
No full textInternational audienceIllegal timber trade is a global issue; highly prized rosewoods are mainly sourced from Africa and Madagascar. In Madagascar, where corruption and political instability are rampant, forest regulations have been issued during the last 15 years to facilitate illegal rosewood exploitation. The current situation precludes non-detriment findings (under which the exporting State ensures that a proposed action will not be detrimental to the survival of a species) intended to enable sustainable use of standing populations, but the Malagasy government, backed by the World Bank, is promoting the sale of massive stocks of confiscated precious wood. We argue that allowing the sale of these stocks would encourage further illegal harvest. No suitable tools are available to identify, control or monitor standing trees or cut timber, and there are substantial knowledge gaps regarding species limits, population sizes, distribution and abundance. When combined with taxonomic confusion and weak governance, these factors necessitate uplifting all of Madagascar's precious woods to Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)
Planetesimal formation in an evolving protoplanetary disk with a dead zone
No full textInternational audienceContext. When and where planetesimals form in a protoplanetary disk are highly debated questions. Streaming instability is considered the most promising mechanism, but the conditions for its onset are stringent. Disk studies show that the planet forming region is not turbulent because of the lack of ionization forming possibly dead zones (DZs).Aims. We investigate planetesimal formation in an evolving disk, including the DZ and thermal evolution.Methods. We used a 1D time-evolving stratified disk model with composite chemistry grains, gas and dust transport, and dust growth.Results. Accretion of planetesimals always develops in the DZ around the snow line, due to a combination of water recondensation and creation of dust traps caused by viscosity variations close to the DZ. The width of the planetesimal forming region depends on the disk metallicity. For Z = Z⊙, planetesimals form in a ring of about 1 au width, while for Z > 1.2 Z⊙ planetesimals form from the snow line up to the outer edge of the DZ ≃ 20 au. The efficiency of planetesimal formation in a disk with a DZ is due to the very low effective turbulence in the DZ and to the efficient piling up of material coming from farther away; this material accumulates in region of positive pressure gradients forming a dust trap due to viscosity variations. For Z = Z⊙ the disk is always dominated in terms of mass by pebbles, while for Z > 1.2 Z⊙ planetesimals are always more abundant than pebbles. If it is assumed that silicate dust is sticky and grows up to impact velocities ~10 m s−1, then planetesimals can form down to 0.1 au (close to the inner edge of the DZ). In conclusion the DZ seems to be a sweet spot for the formation of planetesimals: wide scale planetesimal formation is possible for Z > 1.2 Z⊙. If hot silicate dust is as sticky as ice, then it is also possible to form planetesimals well inside the snow line
Constantinople désorientée, une filiation de l'inconfort
No full textInternational audienceEn analysant la manière dont est traité dans la littérature un stéréotype européocentré –la ville de Constantinople à cheval entre Orient et Occident–, l'article interroge les conditions d’émergence et de développement d’une filiation poétique, esthétique et idéologique. L’enjeu principal est d’identifier le fil directeur qui unirait deux écrivains-voyageurs français de la seconde génération romantique : Gérard de Nerval (Voyage en Orient, 1851) et Théophile Gautier (Constantinople, 1853) à deux écrivains turcs des XXe et XXIe siècles exemplairement attachés à la représentation d’Istanbul: Ahmet Hamdi Tampïnar (1901-1962) et Orhan Pamuk (1952-). A travers une démarche comparative, nous avons voulu montrer de quelle manière un tel cliché avait migré et s’était enchâssé dans une conscience collective autochtone au prix d’un travail complexe de réappropriation identitaire, phénomène intertextuel impliquant sélection, occultation et transposition
Recul et persistance du paludisme en Union des Comores : une approche géographique pour déterminer l’importance des facteurs environnementaux et sociaux dans son maintien
No full textMalaria has been present in the Comoros archipelago since 1925, when a major epidemic was first recorded in Grande Comore. The islands have been favourable to the development of vectors causing malaria transmission (Anopheles gambiae and Anopheles funestus) due to the high tropical rainfall, high hydrographic density, the suitable environment with forests and wetlands, as well as the construction of water reservoirs in households. This disease has been endemic since the 1970s and a major public health problem until the 2000s. From the end of the 1990s, the Comorian government has decided to implement a strategy to control malaria by anti-malaria vector control and population protection against mosquito bites. In the last twenty years, malaria control efforts have been intensified and for a first time, mass treatment with Artequick has been carried out in Mohéli (2007-2009), Anjouan (2012-2013) and Grande Comore (2013). There has since been a dramatic decline in malaria on all the islands, as Mohéli and Anjouan have entered a pre-elimination phase and Grande Comore is in the control phase. In the first part, this thesis describes the spatial and temporal dynamics of malaria before and after mass treatment in order to understand the impact of different control actions. A mapping of hospital prevalence and incidence of malaria at the district and village levels shows its decline in Anjouan and Mohéli and its persistence in Grande Comore. Spatial autocorrelation tests have revealed a similarity in malaria transmission between neighbouring localities that are forming clusters in Grande Comore. In the second part, it was demonstrated that environmental factors have an influence on malaria transmission, despite the greater importance of control actions. At the district level, simple and multiple linear regression models have been established between the incidence of malaria and land cover / land use patterns of islands and landscape indicators at the village level in Grande Comore. A survey on people's knowledge, practices and vulnerabilities was conducted among 1,288 households in the Union of the Comoros to assess factors of vulnerability that contribute to malaria transmission. Beyond having water reservoirs in households, the waste disposal location would also have an impact on malaria in Grande Comore. The survey revealed that several households on the large island did not take the 2013 mass treatment. This thesis provides a better understanding of the human and environmental aspects of malaria maintenance and thus aims to better target future control actions.Le paludisme a sévi dans l’archipel des Comores depuis 1925 où une grande épidémie s’est déclenchée à la Grande Comore. Ces îles ont offert des conditions favorables au développement des vecteurs responsables de la transmission du paludisme (Anopheles gambiae et Anopheles funestus) avec un climat tropical humide, une forte densité hydrographique, un environnement forestier et marécageux et la construction de citernes de collecte d’eau de pluie dans les habitations. Cette maladie est devenue endémique stable depuis les années 70 et un problème de santé publique majeur jusqu’aux années 2000. Dès la fin des années 90, le gouvernement comorien a décidé de mettre en place une stratégie de lutte contre le paludisme par la lutte anti-vectorielle et la protection de la population contre les piqûres des moustiques. Ces vingt dernières années, ces actions de lutte contre le paludisme se sont intensifiées et, pour la première fois, un traitement de masse à base d’Artequick a été réalisé à Mohéli (2007-2009), à Anjouan (2012-2013) et à la Grande Comore (2013). Depuis, un recul spectaculaire du paludisme a été observé sur l’ensemble des îles, car Mohéli et Anjouan sont entrées en phase de pré-élimination et la Grande Comore en phase de contrôle. Cette thèse décrit, dans la première partie, l’évolution spatiale et temporelle du paludisme avant et après le traitement de masse pour appréhender l’impact des différentes actions de lutte. Une cartographie de la prévalence en milieu hospitalier et de l’incidence du paludisme à l’échelle des districts sanitaires et des villages montre son recul à Anjouan et Mohéli et son maintien à la Grande Comore. Les tests d’autocorrélation spatiale ont révélé une similitude de la transmission du paludisme entre des localités proches, qui forment des clusters à la Grande Comore. Nous avons démontré, dans la deuxième partie, qu’il existe bel et bien une influence des facteurs environnementaux sur la transmission du paludisme bien que les actions de lutte ont plus de poids. À l’échelle des districts sanitaires, des modèles de régressions linéaires simple et multiple ont été établis entre l’incidence du paludisme et les caractéristiques de l’occupation du sol des îles et les indicateurs paysagers à l’échelle des villages de la Grande Comore. Une enquête sur les connaissances, les pratiques et les vulnérabilités des populations a été menée sur 1288 ménages de l’Union des Comores pour appréhender les facteurs de vulnérabilité favorables à la transmission du paludisme. Au-delà de la présence des citernes dans les ménages, le lieu de dépôt de déchets ménagers favoriserait son maintien à la Grande Comore. L’enquête a révélé que plusieurs ménages de la grande île n’avaient pas pris le traitement de masse de 2013. Cette thèse permet de mieux comprendre les aspects humains et environnementaux du maintien du paludisme et vise ainsi à mieux cibler les futures actions de lutte
Keeping phase III tuberculosis trials relevant : adapting to a rapidly changing landscape
No full textInternational audience• The landscape of tuberculosis (TB) treatment has evolved considerably over the last 10 years, necessitating careful consideration of various trial design aspects to ensure that TB phase III trials are still impactful at trial completion, often more than 4–5 years after initial design.• The choice of control is guided by the specific trial objectives, weighing the relative merits of internal validity and external generalizability alongside randomization in making the correct inference. A particular challenge occurs when international or national guidelines change during the trial.• Improved execution and relevance of noninferiority trials for TB require greater emphasis on study quality, especially maximizing treatment adherence and minimizing missing outcome data; preferred use of intention-to-treat rather than per-protocol analyses; more careful justification of the margin of noninferiority; and consideration of recent innovations such as a Bayesian approach to noninferiority.• Many adaptive trial designs are well suited to optimization of TB treatment. A thorough understanding of type I error rates and biases in treatment effect estimates is critical for regulatory approval and consideration in establishing World Health Organization (WHO) guidelines.• Treatment stratification is an area of limited experience for TB trials, and trialists must learn from well-established methodology in other disease areas.• Explanatory trials are important for evaluating the efficacy of an intervention under close to ideal conditions. However, no single trial can address all relevant questions about a given therapeutic intervention at one time, and pragmatic trials will be essential for public health and policy decision-making purposes.• TB treatment trials today should favor bold and creative approaches that can produce high-quality evidence for effective, patient-centered care made accessible to all 10 million new TB patients, including the half-million with drug-resistant TB (DR-TB), each year
Whole genome sequence of Vibrio cholerae directly from dried spotted filter paper
No full textInternational audienceBACKGROUND:Global estimates for cholera annually approximate 4 million cases worldwide with 95,000 deaths. Recent outbreaks, including Haiti and Yemen, are reminders that cholera is still a global health concern. Cholera outbreaks can rapidly induce high death tolls by overwhelming the capacity of health facilities, especially in remote areas or areas of civil unrest. Recent studies demonstrated that stool specimens preserved on filter paper facilitate molecular analysis of Vibrio cholerae in resource limited settings. Specimens preserved in a rapid, low-cost, safe and sustainable manner for sequencing provides previously unavailable data about circulating cholera strains. This may ultimately contribute new information to shape public policy response on cholera control and elimination.METHODOLOGY/PRINCIPAL FINDINGS:Whole genome sequencing (WGS) recovered close to a complete sequence of the V. cholerae O1 genome with satisfactory genome coverage from stool specimens enriched in alkaline peptone water (APW) and V. cholerae culture isolates, both spotted on filter paper. The minimum concentration of V. cholerae DNA sufficient to produce quality genomic information was 0.02 ng/μL. The genomic data confirmed the presence or absence of genes of epidemiological interest, including cholera toxin and pilus loci. WGS identified a variety of diarrheal pathogens from APW-enriched specimen spotted filter paper, highlighting the potential for this technique to explore the gut microbiome, potentially identifying co-infections, which may impact the severity of disease. WGS demonstrated that these specimens fit within the current global cholera phylogenetic tree, identifying the strains as the 7th pandemic El Tor.CONCLUSIONS:WGS results allowed for mapping of short reads from APW-enriched specimen and culture isolate spotted filter papers. This provided valuable molecular epidemiological sequence information on V. cholerae strains from remote, low-resource settings. These results identified the presence of co-infecting pathogens while providing rare insight into the specific V. cholerae strains causing outbreaks in cholera-endemic areas
Un contre-pouvoir illustré : la bande dessinée et les dessins contre la pollution industrielle pendant la dictature et la transition démocratique (Espagne, 1960-1979)
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Joint use of the mean and median for multi criteria decision support: the 3MCD method
No full textInternational audienceMost multicriteria aggregation functions are designed in a mono-decision-maker context. Using them for multi-decision-maker problems requires a prior transformation of the individual data of each decision-maker into a collective datum. Recently a method for the aggregation of data in the context of social choices has been introduced by Ngoie et al. (2015a): The Mean-Median Compromise Method (MMCM). In this paper, we suggest an adaptation of the MMCM to multi-criteria multi-decision-maker problems: the Mean and Median for Multi-Criteria Decision (3MCD). We also examine some properties of this rule
Force balance in numerical geodynamo simulations: a systematic study
No full textInternational audienceS U M M A R Y Dynamo action in the Earth's outer core is expected to be controlled by a balance between pressure, Coriolis, buoyancy and Lorentz forces, with marginal contributions from inertia and viscous forces. Current numerical simulations of the geodynamo, however, operate at much larger inertia and viscosity because of computational limitations. This casts some doubt on the physical relevance of these models. Our work aims at finding dynamo models in a moderate computational regime which reproduce the leading-order force balance of the Earth. By performing a systematic parameter space survey with Ekman numbers in the range 10 −6 ≤ E ≤ 10 −4 , we study the variations of the force balance when changing the forcing (Rayleigh number, Ra) and the ratio between viscous and magnetic diffusivities (magnetic Prandtl number, Pm). For dipole-dominated dynamos, we observe that the force balance is structurally robust throughout the investigated parameter space, exhibiting a quasi-geostrophic (QG) balance (balance between Coriolis and pressure forces) at zeroth order, followed by a first-order Magneto-Archimedean-Coriolis (MAC) balance between the ageostrophic Coriolis, buoyancy and Lorentz forces. At second order, this balance is disturbed by contributions from inertia and viscous forces. Dynamos with a different sequence of the forces, where inertia and/or viscosity replace the Lorentz force in the first-order force balance, can only be found close to the onset of dynamo action and in the multipolar regime. To assess the agreement of the model force balance with that expected in the Earth's core, we introduce a parameter quantifying the distance between the first-and second-order forces. Analysis of this parameter shows that the strongest-field dynamos can be obtained close to the onset of convection (Ra close to critical) and in situations of reduced magnetic diffusivity (high Pm). Decreasing the Ekman number gradually expands this regime towards higher supercriticalities and lower values of Pm. Our study illustrates that most classical numerical dynamos are controlled by a QG-MAC balance, while cases where viscosity and inertia play a dominant role are the exception rather than the norm