134 research outputs found
New Model for Discussing the Diffusion Phenomena Effect on a Thermoelastic Plate Associated With Three-phase Lag
Here, a new model was used to discuss the effect of a magnetic field on an isotropic, homogeneous, elastic material with generalized thermoelastic diffusion with two-temperature using a new technique. Most researchers in this domain discussed the behavior of the solution depending on two ways: the Laplace method and the normal mode method. Those two methods fail in explaining some of the physical meaning of the problems, especially the behavior of time. On the other hand, the separation of variables method solves the system of equations and gets the analytical solution directly. Copper material is used to discuss the results found in some magnetic field
New Model for Discussing the Diffusion Phenomena Effect on a Thermoelastic Plate Associated with Three-phase Lag
Here, a new model was used to discuss the effect of a magnetic field on an isotropic, homogeneous, elastic material with generalized thermoelastic diffusion with two-temperature using a new technique. Most researchers in this domain discussed the behavior of the solution depending on two ways: the Laplace method and the normal mode method. Those two methods fail in explaining some of the physical meaning of the problems, especially the behavior of time. On the other hand, the separation of variables method solves the system of equations and gets the analytical solution directly. Copper material is used to discuss the results found in some magnetic field
Influence of low doses of gamma irradiation on cowpea beetle Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae): Poster
Phytosanitary irradiation for food commodities has been widely accepted in recent years. Gamma irradiation has been used as a phytosanitary treatment against microbial diseases, insect infestation and food spoilage. The goal of the current study was to determine the lowest possible dose of gamma irradiation that will induce longterm sterility of insects through generations. The effect of four gamma irradiation doses examined were; 20,40, 50 and 70 Gy. Irradiated males were crossed with normal females. For the cowpea beetle Callosobruchus maculatus(F.), adult fecundity, hatchability, adult emergence, sterility% was investigated. 100% adult mortality was achieved by 70 Gy dose. Fecundity, hatchability, number of adults emerged, sterility% were significantly reduced when males exposed to 20, 40, and 50 Gy compared to the control. The effect of parental irradiated males exposed to 20 Gy on F2 generation was also studied. Fecundity, hatchability, number of adult emerged, sterility% were significantly reduced in F2 compared to F1 and control progeny. Interestingly, for F1 generation, the effect of gamma rays on adult emergence% exhibit a hermetic effect response although it was not significant. These results demonstrat that pulse irradiation relying on low-doses of gamma radiation induce inherited semi-sterility through generations and is a very promising phytosanitary food technology for postharvest treatments.Phytosanitary irradiation for food commodities has been widely accepted in recent years. Gamma irradiation has been used as a phytosanitary treatment against microbial diseases, insect infestation and food spoilage. The goal of the current study was to determine the lowest possible dose of gamma irradiation that will induce longterm sterility of insects through generations. The effect of four gamma irradiation doses examined were; 20,40, 50 and 70 Gy. Irradiated males were crossed with normal females. For the cowpea beetle Callosobruchus maculatus(F.), adult fecundity, hatchability, adult emergence, sterility% was investigated. 100% adult mortality was achieved by 70 Gy dose. Fecundity, hatchability, number of adults emerged, sterility% were significantly reduced when males exposed to 20, 40, and 50 Gy compared to the control. The effect of parental irradiated males exposed to 20 Gy on F2 generation was also studied. Fecundity, hatchability, number of adult emerged, sterility% were significantly reduced in F2 compared to F1 and control progeny. Interestingly, for F1 generation, the effect of gamma rays on adult emergence% exhibit a hermetic effect response although it was not significant. These results demonstrat that pulse irradiation relying on low-doses of gamma radiation induce inherited semi-sterility through generations and is a very promising phytosanitary food technology for postharvest treatments
Advancements in tetronic acid chemistry. Part 1: Synthesis and reactions
AbstractThe preparation and the properties of the elusive tetronic acid are reviewed, including its synthesis, chemical reactivity and reactions
Exogenously applied proline enhances Morph-Physiological responses and yield of Drought-Stressed maize plants grown under different irrigation systems
The exogenous application of osmoprotectants [e.g., proline (Pro)] is an important approach for alleviating the adverse effects of abiotic stresses on plants. Field trials were conducted during the summers of 2017 and 2018 to determine the effects of deficit irrigation and exogenous application of Pro on the productivity, morph-physiological responses, and yield of maize grown under two irrigation systems [surface irrigation (SI) and drip irrigation (DI)]. Three deficit irrigation levels (I100, I85, and I70, representing 100, 85, and 70% of crop evapotranspiration, respectively) and two concentrations of Pro (Pro1 = 2 mM and Pro2 = 4 mM) were used in this study. The plants exposed to drought stress showed a significant reduction in plant height, dry matter, leaf area, chlorophyll content [soil plant analysis development (SPAD)], quantum efficiency of photosystem II [Fv/Fm, Fv/F0, and performance index (PI)], water status [membrane stability index (MSI) and relative water content (RWC)], and grain yield. The DI system increased crop growth and yield and reduced the irrigation water input by 30% compared with the SI system. The growth, water status, and yield of plants significantly decreased with an increase in the water stress levels under the SI system. Under the irrigation systems tested in this study, Pro1 and Pro2 increased plant height by 16 and 18%, RWC by 7 and 10%, MSI by 6 and 12%, PI by 6 and 19%, chlorophyll fluorescence by 7 and 11%, relative chlorophyll content by 9 and 14%, and grain yield by 10 and 14%, respectively, compared with Pro0 control treatment (no Pro). The interaction of Pro2 at I100 irrigation level in DI resulted in the highest grain yield (8.42 t ha–1). However, under the DI or SI system, exogenously applied Pro2 at I85 irrigation level may be effective in achieving higher water productivity and yield without exerting any harmful effects on the growth or yield of maize under limited water conditions. Our results demonstrated the importance of the application of Pro as a tolerance inducer of drought stress in maize
Interet D’une Supplementation En Spiruline Chez Les Enfants Drepanocytaires Homozygotes A L’hopital National De Niamey. (Essai Clinique Randomise En Double Aveugle A Propos De 53 Cas)
Spirulina is a micro algae used for thousands of years due to its healing properties. We supplemented children suffering from sickle cell anemia in order to appreciate its impact on the anthropometrical and clinical parameters. It consisted of a randomized clinical double blind test which was carried during a period of 9 months. The study concerned 53 homozygotes children suffering from sickle cell anemia aged 6 months to 15 years. Also, they were visiting the National Hospital of Niamey for follow up. One group (28 children) received 5 g of spirulina daily, and the other group (25 children) received placebo. The aspects studied were: the number of hospitalizations and transfusions, the vaso-occlusive crisis, the body mass index, and the splenomegalia. We found that 84.90% of patients were hospitalized at least once and 45.3% of them have already been transfused. The average number of crisis has greatly decreased in the spirulina group from 2.75 before the study to 1.18 at the end of the study. This, thus, was observed when compared to 2.44 to 1.6 in the placebo group. We also noticed a decrease of the number of hospitalizations and the number of transfusions which is less important in the group supplemented with spirulina. In conclusion, this study showed that supplementation in spirulina had a significant impact on children suffering from sickle cell anemia. This is even despite the fact that the difference between the two groups is not significant in some cases
Assessment of patients after coronary artery bypass grafting by dobutamine stress echocardiography
Dobutamine stress echocardiography is an accurate method for the diagnosis and localization of vascular compromise in patients evaluated after coronary artery bypass graft surgery. The test provides useful data for selection of patients for whom coronary angiography may be indicated
Observed long-term land cover vs climate impacts on the West African hydrological cycle: lessons for the future ? [P-3330-65]
West Africa has experienced a long lasting, severe drought as from 1970, which seems to be attenuating since 2000. It has induced major changes in living conditions and resources over the region. In the same period, marked changes of land use and land cover have been observed: land clearing for agriculture, driven by high demographic growth rates, and ecosystem evolutions driven by the rainfall deficit. Depending on the region, the combined effects of these climate and environmental changes have induced contrasted impacts on the hydrological cycle. In the Sahel, runoff and river discharges have increased despite the rainfall reduction (“less rain, more water”, the so-called "Sahelian paradox "). Soil crusting and erosion have increased the runoff capacity of the watersheds so that it outperformed the rainfall deficit. Conversely, in the more humid Guinean and Sudanian regions to the South, the opposite (and expected) “less rain, less water” behavior is observed, but the signature of land cover changes can hardly be detected in the hydrological records. These observations over the past 50 years suggest that the hydrological response to climate change can not be analyzed irrespective of other concurrent changes, and primarily ecosystem dynamics and land cover changes. There is no consensus on future rainfall trend over West Africa in IPCC projections, although a higher occurrence of extreme events (rainstorms, dry spells) is expected. An increase in the need for arable land and water resources is expected as well, driven by economic development and demographic growth. Based on past long-term observations on the AMMA-CATCH observatory, we explore in this work various future combinations of climate vs environmental drivers, and we infer the expected resulting trends on water resources, along the west African eco-climatic gradient. (Texte intégral
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