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
Pleistocene Tectono-magmato-volcanic events recorded east of Mayotte - insights for the ongoing seismo-volcanic crisis
No full textInternational audienceThe offshore eastern Mayotte area has been extensively studied since the outbreak of the seismo-volcanic crisis in May 2018. Several oceanographic surveys have been carried out by REVOSIMA – https://doi.org/10.18715/MAYOTTE.REVOSIMA (MAYOBS cruises -https://doi.org/10.18142/291) for monitoring purpose, or for academic research (SISMAORE - https://doi.org/10.17600/18001331 and SCRATCH cruises - https://doi.org/10.17600/18002274). They offer a complete coverage of the eastern slope and abyssal plain with multibeam bathymetry and backscatter imagery, sub-bottom profiler (SBP), and several sediment cores. This set of data offers the opportunity to describe the morphology of the area and details the first tens of meters of the sedimentary succession on the abyssal plain.We discover several features including faults, domes and massive chaotic deposits that developed or occurred during Quaternary in the vicinity of the new Fani Maore Volcano. Domes are interpreted as forced folds related to the intrusion of a large sill at depth. The main fault crossing the largest forced fold is a succession of en-echelon segments with vertical throws of up to 8 meters and a preferential N130° strike compatible with the present day regional dextral context. Analysis of the SBP profiles reveals that faulting and doming associated to sill intrusion occurred simultaneously, and together with the deposition of two massive (several km3) and chaotic lobes at the foot of the Mayotte slope. Sediment cores collected over or close to the massive deposits indicate a mixed bioclastic-volcanoclastic content with a large amount of pumices, whose aspect and chemical composition are identical to volcanic edifices located on the upper slope (Horseshoe Volcano) or onshore (Petite-Terre). Backscatter imagery also reveals streaks that cover the lobes and trace back to the same upper slope area. Analysis of bioclasts from a core catcher stopped in the upper part of the deposit shows a large variety of foraminifers, shells fragments, with a little proportion originating from the upper-slope and shelf. We propose that these massive lobe deposits might have occurred as the pumice-dominated material ejected at HV or PT flows downslope, thus reworking and incorporating a substantial amount of hemipelagic deposits along the slope and over the abyssal plain. These observations suggests that a tectono-magmato-volcanic event occurred during recent geological time (Late Pleistocene according to early estimations). At least one comparable set of similar and synchronous features appears on our dataset thus implying the occurrence of a similar event, earlier in the Pleistocene. The correlations between these events and the activity at HV and PT volcanic centers are critical, as it would provide a recurring scenario to compare with present day seismo-volcanic crisis at Mayotte.This work is funded by REVOSIMA, ANR funded COYOTES project, and internal BRGM Project PDEV MAYOTTE
Deciphering the Origins of Transient Seismic Moment Accelerations by Realistic Dynamic Rupture Simulations
No full textInternational audienceABSTRACT Properties of earthquake source physics can be inferred from the comparison between seismic observations and results of dynamic rupture models. Although simple self-similar rupture models naturally explain the space and time observations at the scale of the whole earthquake, several observational studies based on the analysis of source time functions (STFs) suggest that they are unable to reproduce the initial accelerating phases of the rupture. We here propose to reproduce the observed transient moment accelerations, without affecting the global self-similarity of the rupture, to constrain their possible physical origins. Simulated STFs are generated from dynamic simulations with heterogeneous slip-weakening distance Dc. Heterogeneity is introduced on the fault plane through a fractal number-size distribution of circular patches, in which Dc takes a value proportional to their radius. As a consequence of the stochastic spatial distribution of the patches, rupture development exhibits a large variability, and delays between initiation and main rupture activation frequently occur. This variability, together with the dynamic correlation between rupture velocity and slip velocity inside each broken patch, successfully perturbs the self-similar properties: rather than growing quadratically with time, STFs have an higher apparent time exponent, close to the observed value of 2.7. In a broader perspective, our simulations show that to respect observed STF shapes, realistic dynamic models should generate bursts of seismic moment, most likely by episodes where slip and rupture velocity are correlated. Such a behavior appears to emerge more naturally when considering heterogeneities in the friction parameters rather than in the initial stress
Increased metabolic fluxes in tomato stems infected by Botrytis cinerea
No full textInternational audienc
Prevalence and factors associated to gestational diabetes mellitus among pregnant women in Libreville: a cross-sectional study
No full textInternational audienceIntroduction: mainly occurring in low and middle income countries, gestational diabetes mellitus (GDM) represents 84% of hyperglycemia during pregnancy throughout the world. Moreover, being black is a risk factor to develop the disease. Our objective was to determine the prevalence and the associated factors of GDM in Libreville (Gabon).Methods: a cross-sectional study was carried out. Known diabetic women were excluded from the study and we had submitted asymptomatic pregnant women to a 2 steps 75g oral glucose tolerance test (T0-T2H), regardless of the stage of pregnancy at the moment of recruitment. The threshold for positivity was set at blood glucose level ≥ 8.5mmol/L World Health Organization (WHO 2013 threshold) and ≥ 7.8mmol/L (WHO 1999 threshold). Data were analyzed using Statview® for descriptive statistics, for both bivariate and multivariate analysis.Results: among 245 participants, we have found a GDM prevalence of 10.2% according to WHO 1999 threshold and 4.5% according to WHO 2013 threshold. Applying the WHO 1999 threshold, the associated factors were high maternal weight (p= 0.0498), overweight at recruitment (p=0.0246), personal history of GDM (p< 0.0001), age becomes an associated factor only if it is combined with high parity (p=0.0061). ceaserian-section and macrosomia were the two outcomes of GDM.Conclusion: Libreville has a high prevalence of GDM when the WHO 1999 criteria is compared to the WHO 2013 criteria. Discordance is also found with the identified associated factors. Further studies are needed to better appreciate gestational diabetes in Gabon
Production orale et anxiété langagière : comment favoriser la prise de parole en classe de LVE anglais ?
No full textThis research thesis focuses on language anxiety during oral production among students during English classes, a phenomenon that we can still observe among some students, although educational approaches are more and more benevolent. Through our research, our experiments and analyses, we try to understand the causes, in order to find solutions while taking into account the students’ socio-emotional aspect and the educational methods of the teachers. Thus, this research thesis suggests ways to think about educational methods a teacher can offer in order to make the students confident and to promote an easier oral production from them.Ce mémoire de recherche porte sur l'anxiété langagière lors de la production orale chez les élèves en classe d'anglais, une spécificité encore souvent observée chez certains élèves bien que les approches pédagogiques soient de plus en plus bienveillantes. À travers nos recherches, nos expérimentations et analyses, nous tentons de comprendre les causes afin d'y remédier tout en prenant en compte l'aspect socio-affectif des élèves et les méthodes pédagogiques des enseignants. Ainsi, ce mémoire propose des pistes de réflexions quant aux approches pédagogiques qu'un enseignant peut avoir afin de mettre en confiance ses élèves et favoriser une production orale la plus décomplexée possible
Ruthenium(II) Polypyridyl Complexes Containing Simple Dioxo Ligands: a Structure‐Activity Relationship Study Shows the Importance of the Charge
No full textInternational audienceCancer is one of the main causes of death worldwide. Platinum complexes (i.e., cisplatin, carboplatin, and others) are currently heavily used for the treatment of different types of cancer, but unwanted effects occur. Ruthenium complexes have been shown to be potential promising alternatives to these metal-based drugs. In this work, we performed a structure-activity relationship (SAR) study on two small series of Ru(II) polypyridyl complexes of the type [Ru(L1)2(O^O)]Cln (3-8), where L1 is 4,7-diphenyl-1,10-phenantroline (DIP) or 1,10phenantroline (phen), and O^O is a symmetrical anionic dioxo ligand: oxalate (ox, n = 0), malonate (mal, n = 0), or acetylacetonate (acac, n = 1). These two self-consistent series of compounds allowed us to perform a systematic investigation for establishing how the nature of the ligands and the charge affect the anticancer properties of the complexes. Cytotoxicity tests on different cell lines demonstrated that some of the six compounds 3-8 have a promising anticancer activity. More specifically, the cationic complex [Ru(DIP)2(η 2-acac)]Cl (4) has IC50 values in the mid-nanomolar concentration range, lower than those of cisplatin on the same cell lines. Interestingly, [Ru(DIP)2(η 2-acac)]Cl was found to localize mainly in the mitochondria, whereas a smaller fraction was detected in the nucleus. Overall, our SAR investigation demonstrates the importance of combining the positive charge of the complex with the highly lipophilic diimine ligand DIP
An aqueous extract of Syzygium cumini protects against kainate-induced status epilepticus and amnesia: evidence for antioxidant and anti-inflammatory intervention
No full textInternational audienc
Caractérisation phénotypique et morphobiométrique des poules locales (Gallus gallus) élevées en périphérie de Lubumbashi, République Démocratique du Congo
No full textInternational audienceThis study, with a main goal to characterise the local chicken at phenotypic and morphobiometric level, was conducted from September 2019 to January 2020 in three outlying districts of Lubumbashi city in the Democratic Republic of Congo (DRC). A total of 116 adult females and 64 adult males were photographed, described, and measured individually. The main results indicated that the phenotypic traits of the local chicken studied were very heterogeneous. Indeed, four main types of feather distribution were observed – normal feathering (80.56%), crested head (17.22%), naked-neck (1.67%), and feathered shank (0.56%). For feather morphology, normal plumage (98.33%) dominated frizzled plumage (1.67%). Plumage colouring varied with the predominance of black (15.00%), millefiori (10.56%), salmon pink (9.44%), and fawn (8.89%) colours. The single comb was the most common (96.67%) having usually the red (51.67%) or pink (35.56%) colour. The colour of wattles was dominated by red (58.89%) followed by pink (33.89%), while the predominant earlobe colour was red (32.78%) followed by red-white (23.33%) and white (21.67%). Among the eye colours, orange-red predominated (73.33%) followed by dark-brown (11.11%) and yellow-brown (9.44%). Most of the birds were having white skin colour (56.67%) followed by pink (22.22%) and yellow (21.11%). The shank colour was predominantly white (34.44%) followed by yellow (23.89%), grey (19.44%), black (16.67%), and green (5.56%). Regarding morphobiometric traits, the average live body weight of the local peri-urban chicken of Lubumbashi was 1.25 ± 0.52 kg in males and 1.06 ± 0.29 kg in females. Body weight and other body measurements vary significantly (p<0.001) depending on sex and in favour of males. Body weight was strongly and significantly correlated with shank circumference and chest circumference with a coefficient of 0.86 and 0.80, respectively.Cette étude, dont l'objectif principal était de caractériser la poule locale au niveau phénotypique et morphobiométrique, a été menée de septembre 2019 à janvier 2020 dans trois quartiers périphériques de la ville de Lubumbashi en République Démocratique du Congo (RDC). Au total, 116 femelles adultes et 64 mâles adultes ont été photographiés, décrits et mesurés individuellement. Les principaux résultats ont indiqué que les caractères phénotypiques des poules locales étudiées étaient très hétérogènes. En effet, quatre principaux types de répartition des plumes ont été observés : plumage normal (80,56 %), tête huppée (17,22 %), cou nu (1,67 %) et tarse emplumé (0,56 %). Pour la structure des plumes, le plumage normal (98,33 %) dominait le plumage frisé (1,67 %). La coloration du plumage variait avec la prédominance des couleurs noir (15,00%), mille-fleurs (10,56%), saumon (9,44%) et fauve (8,89%). La crête simple était la plus courante (96,67 %) avec généralement une couleur rouge (51,67 %) ou rose (35,56 %). La couleur des barbillons était dominée par le rouge (58,89 %) suivi du rose (33,89 %), tandis que la couleur prédominante des oreillons était le rouge (32,78 %) suivi du rouge-blanc (23,33 %) et du blanc (21,67 %). En ce qui concerne la coloration des yeux, le rouge orangé prédominait (73,33 %) suivi du brun foncé (11,11 %) et du brun jaune (9,44 %). La plupart des oiseaux avaient une peau de couleur blanche (56,67 %), suivie de rose (22,22 %) et de jaune (21,11 %). La couleur du tarse était principalement blanche (34,44 %), suivie du jaune (23,89 %), du gris (19,44 %), du noir (16,67 %) et du vert (5,56 %). Pour ce qui est des caractères morphobiométriques, le poids vif moyen de la locale périurbaine de Lubumbashi était de 1,25 ± 0,52 kg chez les mâles et de 1,06 ± 0,29 kg chez les femelles. Le poids vif et les autres mensurations corporelles varient significativement (p<0,001) selon le sexe en faveur des mâles. Le poids vif était fortement et significativement corrélé au diamètre du tarse et au périmètre thoracique avec un coefficient de 0,86 et 0,80, respectivement
Four-splitting based coarse-grained multicomputer parallel algorithm for the optimal binary search tree problem
No full textInternational audienc
La production orale en LVE au cycle 3 : la compétence plurilingue et la prononciation
No full textReunion island is a multilingual area inhabited by plurilingual individuals. Due to the familial and academic spheres, its inhabitants speak at least two languages, usually French and Creole. We want to use the children’s mother tongues to encourage the learning of English as a foreign language. This experiment focuses on improving the pronunciation of English. The line of argument is the following one: How to use the plurilingual competence in order to improve the learning of English and more precisely the pronunciation of our pupils ? In order to answer that question, we will begin by presenting the historical and linguistic background of Reunion Island before focusing on the works of researchers on plurilingualism. During our experiment, our classes were invested in the research of the vocabulary to rely on similar sounds between the French, Creole and English. The recreational activities used have encouraged children to be more united and meticulous allowing them to be focused and to improve their pronunciation. The decompartmentalization of the language has pushed the pupils to use the language thus giving sense to their learning.La Réunion est un territoire multilingue dans lequel évoluent des individus plurilingues. Par leur environnement, les habitants sont confrontés a minima à deux langues. Nous souhaitons utiliser les langues des élèves afin d'améliorer l’apprentissage de l’anglais. La problématique est la suivante : comment utiliser la compétence plurilingue pour améliorer la prononciation des élèves en anglais ? Pour répondre à cette question, nous évoquerons brièvement le paysage réunionnais, puis nous procéderons à une revue de la littérature des recherches entreprises sur le plurilinguisme. Durant l’expérimentation, nos deux classes se sont investies dans la recherche de vocabulaire pour s’appuyer sur la ressemblance de sons entre le français, le créole et l’anglais. Les situations ludiques utilisées ont favorisé l’entraide et la rigueur chez les élèves leur permettant de se concentrer pour améliorer leur prononciation. Le décloisonnement a favorisé l’utilisation de la langue par les élèves qui a donné du sens à leurapprentissage