Éditeur(s) : HAL CCSD Elsevier
Résumé : We report a preliminary analysis on the relationships between drainage basin structure and genetic structure of populations of the European vector of fasciolosis, Galba truncatula. In the study area, 251 snails belonging to 12 populations were collected along different ditches of a same river network. Each snail was genotyped at six variable microsatellite loci. Our results show that all sample sites are characterized by a low level of polymorphism and a very high and significant heterozygote deficiency. Our data reveal a significant genetic differentiation, even at a small scale, and failed to delimit clear patterns of isolation by euclidian distance. Our study shows that genetic differentiation significantly increases with hydrographic distance along the streams (p < 0.002), in consistence with the hypothesis that dispersion along the stream is dependent on the direction of water flow. This study shows that relationships can exist between the organization of the hydrological network and population biology of a disease vector, which has strong potential applications to drainage network management issues.
ISSN: 1567-1348

hal-00496374
https://hal.archives-ouvertes.fr/hal-00496374
DOI : 10.1016/j.meegid.2010.01.005

Éditeur(s) : Université des Antilles et de la Guyane CEREGMIA : Centre d'Etudes et de Recherche en Economie, Gestion et Modélisation Informatique Appliquée
Extrait de : "The changing world of coastal, island and tropical tourism" : conférence internationale, du 27 au 29 janvier 2011. Université des Antilles et de la Guyane
Description : The globalization process, accelerating in the last 20 years, has raised important developmental stakes : on the one hand, economic questions with the multiplication of exchanges and its concentration in certain regions of the world; on the other hand globalization has also raised important social issues, with the acceleration of demographic flux and the whole question of "inclusion" associated with this; the issues are also environmental, through increased needs and resource limitations. Tourism represents the ideal vector of this globalization and the stakes it represents. By focusing on international tourism in a country in the South, this article seeks to better understand the stakes involved in developing international tourism resources, by seeking an answer to the question : In what ways can ecotourism constitute a real strategy for economic development, poverty alleviation, and contribute to economic growth and the protection of natural resources ? We will be examining this question in the context the Ranomafana National Park in Madagascar.

Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Provenance : Université des Antilles et de la Guyane. Service commun de la documentation
Permalien : http://www.manioc.org/fichiers/HASH29f953af13018e4196aff5
HASH29f953af13018e4196aff5

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Sampling design is a key issue when establishing species inventories and characterizing habitats within highly heterogeneous landscapes. Sampling efforts in such environments may be constrained and many field studies only rely on subjective and/or qualitative approaches to design collection strategy. The region of Cacao, in French Guiana, provides an excellent study site to understand the presence and abundance of Anopheles mosquitoes, their species dynamics and the transmission risk of malaria across various environments. We propose an objective methodology to define a stratified sampling design. Following thorough environmental characterization, a factorial analysis of mixed groups allows the data to be reduced and non-collinear principal components to be identified while balancing the influences of the different environmental factors. Such components defined new variables which could then be used in a robust k-means clustering procedure. Then, we identified five clusters that corresponded to our sampling strata and selected sampling sites in each stratum. RESULTS: We validated our method by comparing the species overlap of entomological collections from selected sites and the environmental similarities of the same sites. The Morisita index was significantly correlated (Pearson linear correlation) with environmental similarity based on i) the balanced environmental variable groups considered jointly (p = 0.001) and ii) land cover/use (p-value<0.001). The Jaccard index was significantly correlated with land cover/use-based environmental similarity (p-value = 0.001). CONCLUSIONS: The results validate our sampling approach. Land cover/use maps (based on high spatial resolution satellite images) were shown to be particularly useful when studying the presence, density and diversity of Anopheles mosquitoes at local scales and in very heterogeneous landscapes.
BMC Ecology

pasteur-00914104
https://hal-riip.archives-ouvertes.fr/pasteur-00914104
https://hal-riip.archives-ouvertes.fr/pasteur-00914104/document
DOI : 10.1186/1472-6785-13-45
PUBMED : 24289184

Éditeur(s) : Université des Antilles et de la Guyane CEREGMIA : Centre d'études et de recherche en économie, gestion et modélisation informatique appliquée Université des Antilles et de la Guyane CEREGMIA : Centre d'études et de recherche en économie, gestion et modélisation informatique appliquée
Résumé : The globalization process, accelerating in the last 20 years, has raised important developmental stakes : on the one hand, economic questions with the multiplication of exchanges and its concentration in certain regions of the world; on the other hand globalization has also raised important social issues, with the acceleration of demographic flux and the whole question of "inclusion" associated with this; the issues are also environmental, through increased needs and resource limitations. Tourism represents the ideal vector of this globalization and the stakes it represents. By focusing on international tourism in a country in the South, this article seeks to better understand the stakes involved in developing international tourism resources, by seeking an answer to the question : In what ways can ecotourism constitute a real strategy for economic development, poverty alleviation, and contribute to economic growth and the protection of natural resources ? We will be examining this question in the context the Ranomafana National Park in Madagascar.

Droits : Document protégé par le droit d'auteur
fichiers:HASH29f953af13018e4196aff5

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triato-mines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance , diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Cha-gas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species.
ISSN: 1935-2727

Droits : http://creativecommons.org/licenses/by/
hal-01298091
https://hal-univ-perp.archives-ouvertes.fr/hal-01298091
https://hal-univ-perp.archives-ouvertes.fr/hal-01298091/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01298091/file/journal.pntd.0004427.PDF
DOI : 10.1371/journal.pntd.0004427

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon. We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections. The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3°C, mean incidence rates during epidemics could double. In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a step by step guide to model dengue spatial heterogeneity in other countries.
ISSN: 1935-2727

Droits : http://creativecommons.org/licenses/by/
pasteur-01247037
https://hal-riip.archives-ouvertes.fr/pasteur-01247037
https://hal-riip.archives-ouvertes.fr/pasteur-01247037/document
https://hal-riip.archives-ouvertes.fr/pasteur-01247037/file/journal.pntd.0004211.pdf
DOI : 10.1371/journal.pntd.0004211

Éditeur(s) : HAL CCSD Institute of Electrical and Electronics Engineers
Résumé : International audience
The state-space modeling of partially observed dynamical systems generally requires estimates of unknown parameters. The dynamic state vector together with the static parameter vector can be considered as an augmented state vector. Classical filtering methods, such as the extended Kalman filter (EKF) and the bootstrap particle filter (PF), fail to estimate the augmented state vector. For these classical filters to handle the augmented state vector, a dynamic noise term should be artificially added to the parameter components or to the deterministic component of the dynamical system. However, this approach degrades the estimation performance of the filters. We propose a variant of the PF based on convolution kernel approximation techniques. This approach is tested on a simulated case study.
ISSN: 0018-9251

inria-00459886
https://hal.inria.fr/inria-00459886
DOI : 10.1109/TAES.2009.5259183

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Local variation in the density of Anopheles mosquitoes and the risk of exposure to bites are essential to explain the spatial and temporal heterogeneities in the transmission of malaria. Vector distribution is driven by environmental factors. Based on variables derived from satellite imagery and meteorological observations, this study aimed to dynamically model and map the densities of Anopheles darlingi in the municipality of Saint-Georges de l’Oyapock (French Guiana). Longitudinal sampling sessions of An. darlingi densities were conducted between September 2012 and October 2014. Landscape and meteorological data were collected and processed to extract a panel of variables that were potentially related to An. darlingi ecology. Based on these data, a robust methodology was formed to estimate a statistical predictive model of the spatial-temporal variations in the densities of An. darlingi in Saint-Georges de l’Oyapock. The final cross-validated model integrated two landscape variables—dense forest surface and built surface—together with four meteorological variables related to rainfall, evapotranspiration, and the minimal and maximal temperatures. Extrapolation of the model allowed the generation of predictive weekly maps of An. darlingi densities at a resolution of 10-m. Our results supported the use of satellite imagery and meteorological data to predict malaria vector densities. Such fine-scale modeling approach might be a useful tool for health authorities to plan control strategies and social communication in a cost-effective, targeted, and timely manner.
ISSN: 1932-6203

hal-01383486
https://hal.archives-ouvertes.fr/hal-01383486
https://hal.archives-ouvertes.fr/hal-01383486/document
https://hal.archives-ouvertes.fr/hal-01383486/file/Adde_et_al_PlosONE_2016.pdf
DOI : 10.1371/journal.pone.0164685

Éditeur(s) : HAL CCSD Frontiers Media
Résumé : "Candidatus Liberibacter solanacearum" (Lso) has emerged as a serious threat world-wide. Five Lso haplotypes have been identified so far. Haplotypes A and B are present in the Americas and/or New Zealand, where they are vectored to solanaceous plants by the potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae). The fastidious nature of these pathogens has hindered the study of the interactions with their eukaryotic hosts (vector and plant). To understand the strategies used by these pathogens to infect their vector, the effects of each Lso haplotype (A or B) on psyllid fitness was investigated, and genome-wide transcriptomic and RT-qPCR analyses were performed to evaluate Lso gene expression in association with its vector. Results showed that psyllids infected with haplotype B had significantly lower percentage of nymphal survival compared to psyllids infected with haplotype A. Although overall gene expression across Lso genome was similar between the two Lso haplotypes, differences in the expression of key candidate genes were found. Among the 16 putative type IV effector genes tested, four of them were differentially expressed between Lso haplotypes, while no differences in gene expression were measured by qPCR or transcriptomic analysis for the rest of the genes. This study provides new information regarding the pathogenesis of Lso haplotypes in their insect vector.
ISSN: 2235-2988

hal-01512244
https://hal.archives-ouvertes.fr/hal-01512244
https://hal.archives-ouvertes.fr/hal-01512244/document
https://hal.archives-ouvertes.fr/hal-01512244/file/Yao%202016%20Frontiers%20in%20Cellular%20and%20Infection%20Microbiology_%7BD6ACF6EB-9794-4F27-AB84-9EF4099B6D78%7D.pdf
DOI : 10.3389/fcimb.2016.00062

Éditeur(s) : HAL CCSD SAGE Publications
Résumé : International audience
This work aims at developing a general methodology to determine the spatial changes in the basic reproduction number for vector-borne diseases. This requires a spatially explicit modeling system which will be based on a cellular automata (CA) approach and applied to the Chagas disease for both homogeneous and heterogeneous landscapes. Using an extension of the so-called next-generation matrix, we obtained an expression for the basic reproduction number Formula that characterizes the spatial heterogeneity of the risk of emergence of an outbreak. The performed simulation with the built CA model shows the effect of local vector dispersal in a heterogeneous landscape for Chagas disease transmission.
ISSN: 0037-5497

hal-01271476
https://hal-univ-perp.archives-ouvertes.fr/hal-01271476
DOI : 10.1177/0037549715626520

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Depuis désormais plus de deux décennies d’existence, le Parc National de la Guadeloupe connait un renouveau, mais surtout des bouleversements de tous ordres (sociaux, économiques, culturels, politiques et juridiques) avec la réforme du régime des parcs nationaux français. D’instrument de protection intégrale, il est devenu un instrument de protection intégrée, vecteur de développement durable. Malgré les critiques, les avancés dans le régime de conservation sont bien présentes. Dans la famille des parcs nationaux d’Outre-Mer, le Parc national de la Guadeloupe est le « frère ainé ». Pour lui, la réforme représente une évolution, mais dans quel sens ?
Since now more than two decades of its existence, after the reform of the legal regime of national parks, the National Park of Guadeloupe faces a renewal and challenges of all kinds (social, economic, cultural, political and legal). A tool for protection has become an instrument for integration, vector of the sustainable development. Despite the criticisms, progresses in the conservation regime are present. However, their efficacy may be limited, owing to its facultative applicability to France of the Overseas. In the family of National Parks from overseas, the National Park of Guadeloupe is the elder brother. For PNG this represents an improvement, but in what direction?
Guadeloupe

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.3587
http://journals.openedition.org/etudescaribeennes/3587

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
The spatio‐temporal dynamics of disease spread provide an area of acute scientific interest but substantial analytic challenges. Analytic approaches need to draw from current knowledge of disease systems yet be flexible enough to provide targeted inference without restrictive assumptions. We explore this balance in detail with respect to the observed pattern of spread of sugarcane yellow leaf virus, the causal agent of yellow leaf disease. This disease affects cultivated sugarcane plants and spreads via an aphid vector (Melanaphis sacchari). The system is of considerable economic interest, but presents several analytic complications. First, the plants begin as well separated individuals that grow into large plants with overlapping leaf canopies enabling increased vector access between neighbouring plants. The overlap between neighbouring plants first occurs within rows and then extends between rows, presenting another interesting spatial component to consider when modelling the propagation of infection. Second, the vector initially flies between plants but at some point sheds wings and shifts to walking between plants. We are particularly interested in how these two features of the system and their interrelation may impact the spatial spread of disease over time. In addition, we also explore the impact of potential immigration of infected vectors from outside of the study area. We treat our observed cane field as a spatial grid with regular spacing between rows and smaller spacing within rows. Our data consist of observed disease status of each of 1643 plants at each of six time points. We provide descriptive summaries of the temporal evolution of spatial pattern in infection, then propose hierarchical models to describe the pattern and capture the influence of the ecological and environmental factors listed above.
ISSN: 0143-9782

hal-00684235
https://hal.archives-ouvertes.fr/hal-00684235

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Malaria remains one of the most common vector-borne diseases in the world and the definition of novel control strategies can benefit from the modeling of transmission processes. However, data-driven models are often difficult to build, as data are very often incomplete, heterogeneous in nature and in quality, and/or biased. In this context, a knowledge-based approach is proposed to build a robust and general landscape-based hazard index for malaria transmission that is tailored to the Amazonian region. A partial knowledge-based model of the risk of malaria transmission in the Amazonian region, based on landscape features and extracted from a systematic literature review, was used. Spatialization of the model was obtained by generating land use and land cover maps of the cross-border area between French Guiana and Brazil, followed by computing and combining landscape metrics to build a set of normalized landscape-based hazard indices. An empirical selection of the best index was performed by comparing the indices in terms of adequacy with the knowledge-based model, intelligibility and correlation with P. falciparum incidence rates. The selected index is easy to interpret and successfully represents the current knowledge about the role played by landscape patterns in malaria transmission within the study area. It was significantly associated with P. falciparum incidence rates, using the Pearson and Spearman correlation coefficients (up to 0.79 and 0.75, respectively; p-value < 0.001), and the linear regression coefficient of determination (reaching 0.63; p-values < 0.001). This study establishes a spatial knowledge-driven, landscape-based hazard malaria index using remote sensing that can be easily produced on a regular basis and might be useful for malaria prediction, surveillance, and control. Keywords: remote sensing; land use and land cover; landscape metric; knowledge-based hazard modeling; malaria; cross-border area between French Guiana and Brazil
ISSN: 2072-4292

hal-01355255
https://hal.archives-ouvertes.fr/hal-01355255
https://hal.archives-ouvertes.fr/hal-01355255/document
https://hal.archives-ouvertes.fr/hal-01355255/file/010066865.pdf
IRD : fdi:010066865

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In this paper, we determine dislocation core structures and Peierls stresses of wadsleyite, a high-pressure mineral present in the Earth mantle. We use a Peierls-Nabarro model combined with a finite-element method in which we introduce two-dimensional generalized stacking fault energies. Several potential slip planes of wadsleyite are considered. The results show that dislocations in this mineral can exhibit complex dislocation cores with linear or non-collinear dissociation and even three-dimensional dislocation cores. The calculation of the Peierls stresses gives information on the potential activity of slip systems governing the plasticity of wadsleyite. Our study confirms experimental observations that 1/2 < 1 1 1 >{1 0 1} is the easiest slip system in this structure at high-pressure and that [1 0 0](0 1 0) is the second easiest. Both these easily slip systems have dislocations that dissociate into collinear partial dislocations. In contrast [0 1 0] dislocations with very large Burgers vector (11.2 angstrom) are stabilized by complex dissociations involving four partial dislocations.
ISSN: 1359-6454

hal-00475548
https://hal.archives-ouvertes.fr/hal-00475548
DOI : 10.1016/j.actamat.2009.10.047

Éditeur(s) : HAL CCSD Frontiers Media
Résumé : International audience
The Anopheles midgut hosts diverse bacterial communities and represents a complex ecosystem. Several evidences indicate that mosquito midgut microbiota interferes with malaria parasite transmission. However, the bacterial composition of salivary glands and ovaries, two other biologically important tissues, has not been described so far. In this study, we investigated the dynamics of the bacterial communities in the mosquito tissues from emerging mosquitoes until 8 days after a blood meal containing Plasmodium falciparum gametocytes and described the temporal colonization of the mosquito epithelia. Bacterial communities were identified in the midgut, ovaries, and salivary glands of individual mosquitoes using pyrosequencing of the 16S rRNA gene. We found that the mosquito epithelia share a core microbiota, but some bacteria taxa were more associated with one or another tissue at a particular time point. The bacterial composition in the tissues of emerging mosquitoes varied according to the breeding site, indicating that some bacteria are acquired from the environment. Our results revealed temporal variations in the bacterial community structure, possibly as a result of the mosquito physiological changes. The abundance of Serratia significantly correlated with P. falciparum infection both in the midgut and salivary glands of malaria challenged mosquitoes, which suggests that interactions occur between microbes and parasites. These bacteria may represent promising targets for vector control strategies. Overall, this study points out the importance of characterizing bacterial communities in malaria mosquito vectors.
ISSN: 1664-302X

hal-01546162
https://hal.archives-ouvertes.fr/hal-01546162
DOI : 10.3389/fmicb.2015.01500

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission.
ISSN: 1553-7366

hal-01546176
https://hal.archives-ouvertes.fr/hal-01546176
DOI : 10.1371/journal.ppat.1002742

Éditeur(s) : HAL CCSD
Résumé : International audience
Yellow leaf disease is a recent, important and widely spread disease of sugarcane (6), causing severe yield losses on susceptible cultivars. The disease is caused by Sugarcane Yellow Leaf Virus (SCLRV) of the genus Polerovirus in the family Luteoviridae. This virus is transmitted from plant to plant only by aphids in a persistent, circulative and non replicative manner. The epidemic of the SCYLV was little studied and there is a need for information on the spatial spread of the disease and on the role of the aphid in the disease spread. SCYLV was first identified in Guadeloupe in 1996 and Melanaphis sacchari has been the only SCYLV vector found in sugarcane fields. Even if the infection rate is relatively low (0% to 21%), disease may increase and cause damage to sugarcane in Guadeloupe. Even though disease free tissue cultured plants are used for sanitary control in Guadeloupe, understanding SCYLV spread by its vector may help determine additional management strategies against the virus.
IEW
New York, United States

hal-00684226
https://hal.archives-ouvertes.fr/hal-00684226

Éditeur(s) : HAL CCSD MAIK Nauka/Interperiodica
Résumé : International audience
The paper is concerned with the kinematics of the major faults, their pattern, and the time of occurrence of compression and extension deformations in the southeast of the Eastern Sayan. The geometry of the mountain ranges and the kinematics of the major faults exhibit northeast-oriented compression responsible for the current processes of relief formation, which corresponds to the direction of the vector of deformations associated with the Indo-Asian collision. The results obtained thus far may be indicative of the remote influence of collision on the orogenic activity and transpressional deformations in the Eastern Sayan since the end of the Miocene. Morphotectonic analysis has shown that the areas of Quaternary extension- related deformations in the Eastern Sayan are not a response to active rifting in the Baikal Rift Zone. The position and geometry of the subsided blocks and magma ruptures point to the fact that they form locally as extension structural elements near the strike-slip faults. The strike-slip and thrust faults are widespread and play the leading role in the development of the southeastern part of the Eastern Sayan.
ISSN: 0016-8521

insu-00667345
https://hal-insu.archives-ouvertes.fr/insu-00667345
DOI : 10.1134/S001685211101002X

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We study the geometrical properties of the subgroups of the multiplicative group of a finite extension of a finite field endowed with its vector space structure, and we show that in some cases the associated projective space has a natural groupe structure. We construct some cyclic codes related to Reed-Muller codes by evaluating polynomials on these subgroups. The geometrical properties of these groups give a fairly simple description of these codes of the Reed-Muller kind.
ISSN: 1071-5797

hal-00770256
https://hal.univ-antilles.fr/hal-00770256
DOI : 10.1006/ffta.1999.0268

Éditeur(s) : HAL CCSD American Society of Mechanical Engineers
Résumé : International audience
The isothermal flow in a model channel of plate-fin heat exchanger with periodically arranged embossed-like vortex generators is investigated. Velocity measurements are performed by LDA in the transitional regime (Reynolds number from 1000 up to 5000). Strong longitudinal vortices are observed downstream of each generator. The vortex roll-up process is highlighted by the evolution of the velocity vector field in the cross section of the flow. The modifications of the vortex characteristics after successively encountered generators are investigated. This work shows most of the flow features which are known to produce heat transfer enhancement, and shows that these smooth shaped vortex generators are very promising for enhanced heat exchangers.
ISSN: 0098-2202

hal-01582938
https://hal.archives-ouvertes.fr/hal-01582938
https://hal.archives-ouvertes.fr/hal-01582938/document
https://hal.archives-ouvertes.fr/hal-01582938/file/Dupont_heat_exchanger_JFE2002_preprint.pdf
DOI : 10.1115/1.1595675