International Journal of Agricultural Research, Innovation and Technology (IJARIT)
International Journal of Agricultural Research, Innovation and Technology (IJARIT)Not a member yet
12720 research outputs found
Sort by
CovSegNet: An Automated COVID-19 lesion segmentation from CT scans using Deep Learning Techniques: CARI 2022
No full textsubmission to EpisciencesThe coronavirus disease (COVID-19) pandemic has led to a devastating effect on the global public health. Computed Tomography (CT) is an effective tool in the screening of COVID-19. It is of great importance to rapidly and accurately segment COVID-19 lesions from CT images to help diagnostic and patient monitoring. In this paper, we propose a U-net based segmentation network using attention mechanism. As not all the features extracted from the encoders are useful for segmentation, we propose to incorporate an efficient attention mechanism, to an U-Net architecture to re-weight the feature representation channel-wise to capture rich contextual relationships for better features representation while maintaining a better time complexity. In addition, a novel subsampling techniques for CNN is introduced to significantly increase the amount of information kept by feature maps through subsampling layers and we finally use a focal Tversky loss to deal with small lesion segmentation. The experiment results, evaluated on a COVID-19 CT scans segmentation dataset where 3250 CT slices are available, demonstrate the proposed method can achieve an accurate and rapid segmentation on COVID-19 segmentation. The method takes only a fraction of second to segment a single CT slice.La pandémie du coronavirus (COVID-19) a eu un effet dévastateur sur la santé publique à l'échelle mondiale. La tomodensitométrie (CT) est un outil efficace dans le dépistage du COVID-19. Il est d'une grande importance de segmenter rapidement et avec précision le COVID- 19 lésions d'images CT pour aider au diagnostic et au suivi des patients. Dans cet article, nous proposons un réseau de segmentation basé sur U-net utilisant un mécanisme d'attention. Puisque tous les features extraits des encodeurs ne sont pas utiles pour la segmentation, nous proposons d'incorporer un mécanisme d'attention efficace, à l’architecture U-Net pour repondérer la représentation des features afin de capturer des relations contextuelles riches pour une meilleure représentation des caractéristiques tout en maintenant une meilleure complexité. De plus, une nouvelle technique de sous-échantillonnage pour CNN est introduite pour augmenter considérablement la quantité d'informations conservées par les features maps à travers des couches de sous-échantillonnage et nous utilisons enfin la fonction de cout Focal Tversky(FTL) pour mieux prendre en compte la segmentation des petites lésions. Notre architecture est évaluée sur un jeu de données de segmentation de tomodensitogrammes COVID-19 où 3250 images CT sont disponibles. Les résultats démontrent que la méthode proposée peut réaliser une segmentation précise et rapide sur la segmentation COVID-19. La méthode ne prend qu'une fraction de seconde pour segmenter une image CT
Les séries congruo-harmoniques alternées Partie 2 -Accélérations de convergence
No full textInternational audienceFor every couple (p;q) of strictly positive integers, the « alternate congruo-harmonic » series parametrized by (p;q), whose general term is (-1)^k/(pk+q), converges infra-linearly and very slowly. On the basis of a generalized continued fraction expansion of the partial rest of the series, this paper elaborates a family of algorithms which accelerate its convergence. The convergence speed of the sequences generated by these algorithms are compared. A precise asymptotic analysis is conducted, which reveals the possibility to accelerate the convergence either infra-linearly (but with an infinite diversity of possible speeds), or linearly (with a convergence rate that appears universal relatively to (p;q)), or super-linearly, by means of sequences extractions. Several open problems are also discussed, which concern the relative « performance » of the algorithms thus built and the possible optimality of some of them
Connaissances des patients diabétiques de type 2 suivis depuis moins de 5 ans en soins primaires dans la région Ouest de l’île de La Réunion : une étude transversale
No full textBackground: In France, the prevalence of type 2 diabetes is highest on Reunion Island, where there is a high morbidity and mortality rate attributed to this disease. Although necessary for the improvement of education programmes and the control of the disease, the learning needs of diabetic patients followed up in medical offices in Reunion are unknown. The objective of this study was to describe the knowledge of type 2 diabetic patients followed for less than 5 years in primary care.Method: A cross-sectional study was carried out, using a self-questionnaire assessing patients' knowledge of diabetes, complications, follow-up, diet and physical activity. Patients were recruited from medical offices in the western region of Reunion Island.Results: From 23 April to 31 July 2021, 89 patients were included in the study. The knowledge level of the total sample was moderate (median score of 14 out of 20). The best knowledge levels were in the topics “generalities on diabetes” and “complications”, while the lowest levels were in the categories “follow-up” and “diet and physical activity”. Glycated haemoglobin, libido disorders, frequency of urinalysis and dental consultation, and the recommended diet for diabetics which is the same as for the general population, were the least known concepts. Conclusion: This study revealed gaps in patients' knowledge that could be used to improve education programmes which in turn could reduce or prevent diabetes complications.Introduction : En France, la prévalence du diabète de type 2 est la plus élevée à l’île de La Réunion, où il existe une forte morbi-mortalité imputée à cette pathologie. Pourtant nécessaire à l’amélioration des programmes d’éducation et au contrôle de la maladie, les besoins d’apprentissage des patients diabétiques suivis en ambulatoire à La Réunion sont inconnus. L’objectif de cette étude était de décrire les connaissances des patients diabétiques de type 2 suivis depuis moins de 5 ans, en soins primaires.Méthode : Une étude transversale a été réalisée, selon un auto-questionnaire évaluant les connaissances des patients sur le diabète, les complications, le suivi, l’alimentation et l’activité physique. Les patients ont été recrutés dans les cabinets médicaux de la région Ouest de La Réunion. Résultats : Du 23 avril au 31 juillet 2021, 89 patients ont été inclus. Le niveau de connaissances de l’échantillon total était « fragile » (note médiane de 14 sur 20). Les meilleurs niveaux de connaissances concernaient les thèmes « généralités » et « complications », tandis que les niveaux les plus bas intéressaient les catégories « suivi » et « alimentation et activité physique ». L’hémoglobine glyquée, les troubles de la libido, les fréquences d’analyse d’urines et de consultation d’un dentiste, l’alimentation recommandée aux diabétiques identique pour la population générale, étaient les notions les moins connues. Conclusion : Cette étude a révélé des lacunes dans les connaissances des patients, pouvant servir à l’amélioration des programmes d’éducation, qui pourraient réduire ou prévenir les complications du diabète
L’intubation face à face en position assise sur mannequin haute-fidélité avec l’Airtraq® et la lame Macintosh® : nouvelle approche de la rétention à long terme de l’apprentissage par la simulation
No full textIntroduction: Orotracheal intubation exposes to complications. The ideal intubation position is debated. Face-to-face intubation (FtFi) in a seated position may have advantages. Following a study that focused on the learning of FtFi on a high-fidelity manikin with the Macintosh blade (MB) and the Airtraq (AT), we conducted this study to assess the retention of this learning.Method: Participants performed FtFi under the same conditions as the previous study, namely a manikin set for a Cormack score of 2b-3 and a POGO score of 0-20%. They had to perform at least 5 FtFi then continue until stabilization of the intubation time with AT and MB. The intubation time (IT), success, complications, subjective difficulty of intubation and POGO were collected. The results were compared to those of the previous study to assess retention.Results: 18 participants were included; the retention period was 30 months. By comparing the ITs of the first 3 FtFi between the two studies, we found an improvement with AT (p < 0.001) and no improvement for MB (p = 0.92). Comparing the ITs of the last 5 FtFi between the two studies, there was no difference with AT (p=0.51) and a slight improvement for MB (p=0.045). The learning curves showed that half of the participants had a retraining profile from the 14th trial with AT and no retraining profile for MB.Conclusion: Long-term retention of FtFi is good for AT. For MB, the technique is being consolidated.Introduction : L’intubation orotrachéale expose à des complications. La position idéale d’intubation fait débat. L’intubation face à face (iFaF) en position assise peut présenter des avantages. À la suite d’une étude qui portait sur l’apprentissage de l’iFaF sur mannequin haute-fidélité avec la lame Macintosh (LM) et l’Airtraq (AT), nous avons conduit cette étude pour évaluer la rétention de cet apprentissageMéthode : Les participants ont réalisé des iFaF dans les mêmes conditions que l’étude antérieure, à savoir un mannequin réglé pour un score de Cormack de 2b-3 et un score de POGO à 0-20 %. Ils devaient réaliser au moins 5 iFaF puis poursuivre jusqu’à stabilisation du temps d’intubation avec l’AT et la LM. Il était recueilli le temps d’intubation (TI), le succès, les complications, la difficulté subjective d’intubation et le POGO. Les résultats étaient comparés à ceux de la précédente étude pour évaluer la rétention.Résultats : 18 participants ont été inclus, le délai de rétention était de 30 mois. En comparant les TI des 3 premières iFaF entre les deux études, nous retrouvions une amélioration avec l’AT (p < 0,001) et l’absence d’amélioration pour la LM (p=0,92). En comparant les TI des 5 dernières iFaF entre les deux études, il n’y avait pas de différence avec l’AT (p=0,51) et une légère amélioration pour la LM (p=0,045). Les courbes d’apprentissage montraient que la moitié des participants présentait un profil de réentraînement à partir du 14e essai avec l’AT et l’absence de profil réentraînement pour la LM. Le TI avec l’AT était inférieur.Conclusion : La rétention à long terme de l’iFaF est bonne pour l’AT. Pour la LM, la technique est en cours de consolidation
Fractional dynamics of a transmission model of Zika disease
No full textInternational audienceThe goal of this work is to study a ZIKA disease model using fractional derivatives in the Caputo sense. After formulating the model, we compute the basic reproduction number R 0 and give rigorous proof of the existence of equilibrium points as well as stability analysis of these equilibrium points. Then, we study the existence and the uniqueness of the solutions of the fractional model using the Banach fixed point theory. Numerical simulations are performed to validate our analytical results, as well as to see the impact of varying the fractional parameter on the disease dynamic
Tannin phenotyping of the Vitaceae reveals a phylogenetic linkage of epigallocatechin in berries and leaves
No full textInternational audienceBackground and AimsCondensed tannins, responsible for berry and wine astringency, may have been selected during grapevine domestication (Narduzzi et al., 2015). This work examines the phylogenetic distribution of condensed tannins throughout the Vitaceae phylogenetic tree.MethodsGreen berries and mature leaves of representative true-to-type members of the Vitaceae were collected before “véraison”, freeze-dried, pulverised, and condensed tannins measured following depolymerization by nucleophilic addition of 2-mercaptoethanol to the C4 of the flavan-3-ol units in an organic acidic medium. Reaction products were separated and quantitated by UPLC/DAD/MS.Key Results and ConclusionsThe original ability to incorporate epigallocatechin (EGC) into grapevine condensed tannins was lost independently in both the American and Eurasian/Asian branches of the Vitaceae, with exceptional cases of reversion to the ancestral EGC phenotype. This is particularly true in the genus Vitis, where we now find two radically distinct groups differing with respect to EGC content. While Vitis species from Asia are void of EGC, 50% of the New World Vitis harbour EGC. Interestingly, the presence of EGC is tightly coupled with the degree of leaf margin serration. Noticeably, the rare Asian EGC-forming species are phylogenetically close to Vitis vinifera, the only remnant representative of Vitis in Eurasia. Both the wild ancestral V. vinifera subsp. sylvestris as well as the domesticated V. vinifera subsp. sativa can accumulate EGC and activate galloylation biosynthesis that compete for photoassimilates and reductive power
Successive modes of carbonate precipitation in microbialites along the hydrothermal spring of La Salsa in Laguna Pastos Grandes (Bolivian Altiplano).
No full text29 pagesInternational audienceInterpreting the paleoecosystems of ancient microbialites relies on our understanding of how modern microbialites form in relation with the bio-physico-chemical conditions of their environment. In this study, we investigated the formation of modern carbonate microbialites in the hydrothermal system of La Salsa in Laguna Pastos Grandes (Bolivia), which spans a wide range of physicochemical conditions and associated microbial communities. By combining dissolved inorganic carbon (DIC) isotope mass balance modeling, analysis of carbonates solubility diagram, and imaging of the microorganisms–mineral assemblages within microbial mats, we found that several modes of carbonate precipitation dominate in distinct portions of the hydrothermal system. (1) In high-[DIC] waters, undersaturated to slightly saturated with respect to calcite, cyanobacterial calcification is promoted by CO2 degassing and photosynthetic activity within the microbial mats. (2) In alkaline waters undergoing sustained evaporation, the precipitation of an amorphous calcium carbonate phase seems to control the water a(Ca2+)/a(CO32−) ratio and to serve as a precursor to micritic calcite formation in microbial mats. (3) In saline ephemeral ponds, where the carbonate precipitation is the highest, calcite precipitation probably occurs through a different pathway, leading to a different calcite texture, i.e., aggregates of rhombohedral crystals
A 1.5Ma Marine Record of Volcanic Activity and Associated Landslides Offshore Martinique (Lesser Antilles): Sites U1397 and U1399 of IODP 340 Expedition
No full textInternational audienceThe products of eruptive and mass-wasting processes that built island arc volcanoes are better preserved in marine deposits than on land. Holes U1397A and U1399A drilled during IODP Expedition 340 provide a 1.5 Ma record of the volcanic history of Martinique. 14 C dating and δ 18 O patterns are used to reconstitute the chronostratigraphy of tephra, volcaniclastic turbidites, and mass-wasting events (traced by debris avalanches, debrites, and duplication and deformation of pre-existing sediments), leading to a new volcanic history of Montagne Pelée and Pitons du Carbet volcanoes. The top 50 m of core U1397A provides a continuous highresolution sedimentation record over the last ~130 ka. The sedimentation record deeper than 50 m in core U1397A and in the whole core U1399A is discontinuous because of the numerous sliding and deformation events triggered by debris avalanches related to flank collapses. Three successive activity periods are identified since ~190 ka: the "Old Pelée" until 50 ka, the "Grand Rivière" (50-20 ka), and the "Recent Pelée" (20 ka-present day). The first two periods have the highest volcanic deposition rates offshore but very little outcrop on land. The whole magmatic activity of Mt Pelée comprises silicic andesites, but mafic andesites were also emitted during the whole "Grand Rivière." At ~115 ka, a major flank collapse ("Le Prêcheur") produced a debris avalanche and submarine landslide that affected sea floor sediments by erosion and deformation up to ~70 km from the shore. The Pitons du Carbet volcano was active from 1.2 Ma to 260 ka with numerous large flank collapses at a mean rate of 1 event every 100 ka. The average deposition rate of tephra fall offshore is much less than that at Mt Pelée. Our data show that correlations between the timing of large landslides or emission of mafic magmas and rapid sea level rise or lowstands suggested by previous studies are not systematic. The reconstituted chronostratigraphy of cores U1397A and U1399A provides the framework necessary for further studies of the magma petrology and production rates and timing of the mechanisms triggering flank collapses and related submarine landslides of Mt Pelée and Pitons du Carbet
Les usages journalistiques de la notion 'd'islamophobie' dans la presse d'opinion portugaise (2010-2020)
No full textInternational audienc
Qualité nutritionnelle des aliments thérapeutiques prêts à l’emploi : composition lipidique et les teneurs en vitamines
No full textInternational audienceSevere Acute Malnutrition (SAM) is still a public health issue in many low-income and middle-income countries. Its management has changed with the development of Ready-to-Use Therapeutic Foods (RUTF) that are energy-dense, lipid-based, micronutrient-enriched foods. The purpose of the present study was to define some aspects of the nutritional profile (in particular, lipid content, fatty acids profile, lipophilic vitamin content), oxidative status, and mycotoxin content of three RUTF products (of which two manufactured in Asia and one in Europe), at different time points during their storage. All RUTF displayed good lipid stability, with peroxide values < 10 meqO 2 /kg lipids, acidity index < 0.6 g/100 g lipids, and very low amounts of secondary oxidation volatile compounds. Only the one produced in Europe complied with the international recommendations on vitamin A and E contents. Lipid content ranged from 28.7 ± 0.5 to 41.2 ± 2.4 g/100 g. Oleic acid, palmitic acid, and linoleic acid (47.2 ± 7.4%, 26.8 ± 2.1%, and 12.4 ± 3.9% of total lipids, respectively) were the main fatty acids. Only one of the samples made in Asia exceeded the regulatory limit of mycotoxins. The RUTF lipid phase was rather stable at ambient temperature from 9 to 12 months, and appropriate packaging may have contributed to a major stability.La malnutrition aiguë sévère (MAS) reste un problème de santé publique dans de nombreux pays à revenu faible ou intermédiaire. Sa prise en charge a changé avec le développement des aliments thérapeutiques prêts à l’emploi (ATPE) qui sont des aliments denses en énergie, à base de lipides et enrichis en micronutriments. L’objectif de la présente étude était de définir certains aspects du profil nutritionnel (en particulier, la teneur en lipides, le profil des acides gras, la teneur en vitamines lipophiles), le statut oxydatif et la teneur en mycotoxines de trois produits RUTF (dont deux fabriqués en Asie et un en Europe), et ce à différents moments de leur stockage. Tous les RUTF présentaient une bonne stabilité lipidique, avec des indices de peroxyde < 10 meqO 2 /kg de lipides, un indice d’acidité < 0,6 g/100 g de lipides, et de très faibles quantités de composés volatils d’oxydation secondaire. Seul celui produit en Europe était conforme aux recommandations internationales sur les teneurs en vitamines A et E. La teneur en lipides variait de 28,7 ± 0,5 à 41,2 ± 2,4 g/100 g. Les principaux acides gras étaient l’acide oléique, l’acide palmitique et l’acide linoléique (47,2 ± 7,4 %, 26,8 ± 2,1 % et 12,4 ± 3,9 % des lipides totaux, respectivement). Un seul des échantillons fabriqués en Asie dépassait la limite réglementaire des teneurs en mycotoxines. La phase lipidique des RUTF était plutôt stable à température ambiante de 9 à 12 mois, et un conditionnement approprié a pu contribuer à cette bonne stabilité