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Assessment of Intra-Seasonal Variability and Trends of Precipitations in a Climate Change Framework in West Africa

Atmospheric and Climate Sciences 2022年第1期12卷 150-171页

作者： Daniel Bio Tore Adechina Eric Alamou ezéchiel obada Eliezer Iboukoun Biao Esdras B. Josué Zandagba Laboratoire de Géosciences de l’Environnement et Applications Université Nationale des Sciences Technologies Ingénierie et Mathématiques (UNSTIM) Abomey Benin Laboratoire d’Hydrologie Appliquée (LHA) Institut National de l’Eau Université d’Abomey-Calavi (UAC) Godomey Benin école Nationale Supérieure des Travaux Publics (ENSTP/UNSTIM) Abomey Benin école Nationale Supérieure de Génie Mathématique et Modélisation (ENSGMM/UNSTIM) Abomey Benin

Climate change has led human beings to take an interest in the study of meteorological and climatic phenomena. In fact, the main impact of climate change on different sectors of society is caused by extreme events since the occurrence of extreme events leads to more impact related to change in mean climate. Unfortunately, the West African region is vulnerable to extreme rainfall impact because its economy is based on rain-fed agriculture. This study examined the seasonal variability of extreme rainfall in West Africa. Eight (8) climate indices were chosen from among the 27 defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). The nonparametric Mann-Kendall test was used to assess the seasonal trends. The indices of the same types (frequency or intensity) were compared to assess the intra-seasonal variation of extreme precipitation. The results indicate that, regardless of the season, the Gulf of Guinea receives more rainfall than the Sahel. This phenomenon is due to the fact that the coastal part of West Africa is under the influence of evaporation which is observed at the Atlantic Ocean and during the monsoon, while the other part is dominated by the desert. Mann-Kendall’s test revealed upward and downward trends during each season. The increase in extreme rainfall trends in the number of consecutive dry days suggests that droughts, due to global warming, could be observed and could have severe consequences in terms of water availability, energy supply, agricultural yields and ecosystems in West Africa. In addition, it can lead to the loss of biodiversity and health issues. It is therefore essential for policymakers or decisions makers to determine strategies and mitigation measures against climate change and its impacts on populations.

关键词： Extreme Precipitation Indices Variability Trend Mann Kendall West Africa

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Extreme Temperature Trends in the Beninese Niger River Basin (Benin)

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American Journal of Climate Change 2021年第4期10卷 371-385页

作者： Yarou Halissou Alamou Adéchina Eric obada ezéchiel Biao Ibukun Eliézer Chaire Internationale de Physique Mathématique et Application (CIPMA—CHAIRE UNESCO) Université d’Abomey-Calavi (UAC) Cotonou Benin Laboratoire de Géoscience de l’Environnement et Application (LaGEA/UNSTIM) Abomey Benin Ecole Nationale Supérieure des Travaux Publics (ENSTP) Université Nationale des Sciences Technologies Ingénierie et Mathématiques (UNSTIM) Abomey Benin Ecole Nationale Supérieure de Génie Mathématique et Modélisation Université Nationale des Sciences Technologies Ingénierie et Mathématiques (UNSTIM) Abomey Benin

In the context of climate change, the study of the variability of the climatic extremes in several regions of the world is of capital importance. This study has as main objective to analyze the variability of extreme temperature events in the Beninese basin of the Niger River for the recent and the near future. To achieve this objective, seven (07) extreme temperature indices based on historical daily temperature observations (1976 to 2019) and REMO RCM simulation outputs of RCP4.5 and RCP8.5 scenarios (2021-2050) were calculated. The obtained results were represented by calculating the means for each index and analyzing the trends and their significance by the Mann-Kendall method. The results show that the indices of extreme temperature intensity (TNn, TXx, and DTR), and those related to the frequency of warm sequences (WSDI, TN90p and TX90p) have experienced a significant increase in the past. This increase will continue until 2050. In contrast, the cold sequence frequency index (CSDI) decrease over the historical period as well as over the future period. These indices show much more change with the RCP8.5 scenario than with the RCP4.5 of the REMO climate model. Only the TXx and CSDI indices show statistically significant changes at all stations.

关键词： Temperatures Extreme Climatic Variations Beninese Niger River Basin

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An Automatic Optimization Technique for the Calibration of a Physically Based Hydrological Rainfall-Runoff Model

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Journal of Geoscience and Environment Protection 2021年第3期9卷 1-20页

作者： Zohou Pierre Jérôme Alamou Adéchina Eric obada ezéchiel Biao Iboukoun Eliézer Eugène C. ezin Université d’Abomey-Calavi (UAC) Abomey-Calavi Bénin Laboratoire de Recherche en Sciences Informatiques et Applications (LRSIA) UAC Abomey-Calavi Bénin Laboratoire d’Hydrologie Appliquée (LHA) UAC Abomey-Calavi Bénin Université Nationale des Sciences Technologies Ingénierie et Mathématiques (UNSTIM) Abomey Bénin

Models are tools widely used in the prediction of hydrological phenomena. The present study aims to contribute to the implementation of an automatic optimization strategy of parameters for the calibration of a hydrological model based on the least action principle (HyMoLAP). The Downhill Simplex method is also known as the Nelder-Mead algorithm, which is a heuristic research method, is used to optimize the cost function on a given domain. The performance of the model is evaluated by the Nash Stucliffe Efficiency Index (NSE), the Root Mean Square Error (RMSE), the coefficient of determination (R2), the Mean Absolute Error (MAE). A comparative estimation is conducted using the Nash-Sutcliffe Modeling Efficiency Index and the mean relative error to evaluate the performance of the optimization method. It appears that the variation in water balance parameter values is acceptable. The simulated optimization method appears to be the best in terms of lower variability of parameter values during successive tests. The quality of the parameter sets obtained is good enough to impact the performance of the objective functions in a minimum number of iterations. We have analyzed the algorithm from a technical point of view, and we have carried out an experimental comparison between specific factors such as the model structure and the parameter’s values. The results obtained confirm the quality of the model (NSE = 0.90 and 0.75 respectively in calibration and validation) and allow us to evaluate the efficiency of the Nelder-Mead algorithm in the automatic calibration of the HyMoLAP model. The developed hybrid automatic calibration approach is therefore one of the promising ways to reduce computational time in rainfall-runoff modeling.

关键词： Optimization HyMoLAP Automatic Calibration Validation Nelder-Mead Algorithm

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New Aspects of Field Entropy Squeezing as an Indicator for Mixed State Entanglement in an Effective Two-Level System with Stark Shift

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Chinese Physics Letters 2011年第12期28卷 24-27页

作者： S.Abdel-Khalek M.M.A.Ahmed A-S F.obada Department of Mathematics Faculty of ScienceSohag University82524 SohagEgypt Department of Mathematics Faculty of ScienceTaif University21974 TaifSaudi Arabia Department of Mathematics Faculty of ScienceAl-Azhar UniversityNasr City11884 CairoEgypt

We present an effective two-level system in interaction through two-photon processes with a single mode quantized electromagnetic field,initially prepared in a coherent *** entropy squeezing as an indicator of the entanglement in a mixed state system is *** temporal evolution of the negativity,Wehrl entropy,Wehrl phase distribution and field entropy squeezing are *** results highlight the important roles played by both the Stark shift parameters and the mixed state setting in the dynamics of the Wehrl entropy,Wehrl phase distribution and field entropy squeezing.

关键词： state entropy system

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Control of purity and entanglement for two spatially two-separated qubits via phase damping

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Chinese Physics B 2012年第10期21卷 115-121页

作者： A.S.F.obada H.A.Hessian A.B.A.Mohamed M.Hashem Faculty of Science Al-Azhar UniversityNasr CityCairoEgypt Faculty of Science Assiut UniversityAssiutEgypt Faculty of Science Al-Baha UniversityAl-BahaSaudi Arabia Al-Aflaj Community College Salman Bin Abdulaziz University Al-AflajSaudi Arabia

Control of purity and entanglement of two two-qubits dispersively coupled to a field with a reservoir are *** the qubits are entangled,while the field is either in a coherent state or a statistical mixture of two coherent *** an alternative entanglement measure we calculate the negativity of the eigenvalues of the partially transposed density matrix.A measure related to the mutual entropy,namely the index of entropy,is employed to measure the *** results agree well with the *** is found that the entanglement and purity have strong sensitivity to phase *** asymptotic behaviour of the states of the field,the two two-qubits,and the total system fall into mixed states.

关键词： entanglement phase damping purity separated qubits

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History and Projection of Hydrological Droughts in the Benin Basin of the Niger River (Benin)

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Journal of Atmospheric Science Research 2022年第2期5卷 33-51页

作者： Yarou Halissou Alamou Adéchina Eric Biao Iboukoun Eliézer obada ezéchiel Tore Daniel Bio Afouda Abel International Chair of Mathematical Physics and Applications(ICMPA-UNESCO CHAIRE) University of Abomey-Calavi(UAC)CotonouBenin National School of Public Works(ENSTP) National University of SciencesTechnologiesEngineering and Mathematics(UNSTIM)AbomeyBenin National School of Mathematical Engineering and Modeling(ENSGMM) National University of SciencesTechnologiesEngineering and Mathematics(UNSTIM)AbomeyBenin Laboratory of Environmental Geoscience and Application(LaGEA/UNSTIM) Benin Applied Hydrology Laboratory(LHA) University of Abomey-Calavi(UAC)CotonouBP4521Benin West African Science Service Center on Climate Change and Adapted Land Use(WASCAL) GRP Climate Change and Water ResourcesUniversity of Abomey-Calavi(UAC)Abomey-CalaviBP2008Benin

In the context of a changing climate,the Beninese Niger River basin has been the focus of several research studies for the quantification,planning,and modeling of water and related resources for sustainable *** research aims to characterize the historical(1976-2019)and projected(2021-2050)hydrological drought of the Beninese Niger River *** study used daily observations of rainfall,maximum and minimum temperatures,runoff rates and simulations of HIRHAM and REMO RCMs from fifteen(15)rainfall stations installed around the *** uses standardized streamflow indices(SDI)at 12-month and 36-month time *** results show that the calculated SDI indices show,on average,for all the model scenarios used,chronological trends of *** increases are not significant(are of the order of 0.00001 per year).The analysis of the SDI indices shows that,on average,the hydrological droughts in the Beninese basin of the Niger River will increase at 36 months and decrease at 12 months of the *** fact,these small variations of hydrological droughts will be accompanied by the increase of their duration and the decrease of their mag*** droughts detected in the Benin basin of the Niger River during the historical period will continue until 2050 in the same range but with more extended drought *** should be noted that most of the changes observed in the calculated and analyzed indices are not significant.

关键词： Hydrological Drought SDI Beninese Niger river basin

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Inflammatory model in patients with primary open angle glaucoma and diabetes

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International Journal of Ophthalmology(English edition) 2019年第5期12卷 795-801页

作者： Anca Pantalon Otilia obada Daniela Constantinescu Crenguta Feraru Dorin Chiselita Ophthalmology Department "St. Spiridon" University Hospital Ophthalmology Department "Gr.T.Popa" University of Medicine and Pharmacy Immunology Department "Gr.T.Popa" University of Medicine and Pharmacy

AIM: To assess the inflammatory cytokines expression in aqueous humor in diabetic primary open angle glaucoma(POAG) patients. METHODS: A cross-sectional study on 87 eyes, distributed as following: 26 eyes from diabetic patients, 16 eyes with POAG and 21 eyes from diabetic POAG patients; healthy controls(24 eyes) were recruited from patients undergoing conventional cataract surgery. A volume of 100 μL of aqueous humor(AH) was collected during phacoemulsification and 21 inflammatory markers were quantified using a Luminex~? cytometric bead assay: IL-1 Ra, IL-1α, IL-1β, IL-5, IL-6, IL-10, IL-17, GM-CSF, IFNγ, CCL2, CCL3, CCL4, CXCL5, CXCL8, bFGF, VEGF, TNFα. Main changes in cytokine profile were analyzed and compared between groups. Data on demographics, duration of glaucoma, intraocular pressure(IOP), number of anti-glaucoma substances were recorded for correlation analysis and prediction models. RESULTS: Significant differences in cytokine expression between groups were detected for CXCL5(P<0.001), CXCL8(P=0.004), IL-1α(P<0.001), IL-2(P<0.001), CCL4(P=0.003), CCL5(P<0.001) and TNFα(P=0.05). Post-hoc analysis identified IL-2(P=0.009) and CXCL5(P<0.001) as "separation markers" between POAG and diabetic POAG eyes. In POAG patients, the "separation markers" could highly predict the TNFα levels F(1, 16)=14.639, P<0.001, whereas in diabetic patients F(1, 24)=4.844, P=0.006 and diabetic POAG patients F(1, 19)=2.358, P=0.05 the level of prediction was ***: Our results reveal an inflammatory model based on increased TNFα levels in POAG *** co-stimulatory molecules and additional inflammatory pathways need to be further explored in diabetic POAG cases, since the prediction model could only partially explain the increased TNFα level in this category of patients.

关键词： primary open angle glaucoma cytokines inflammation diabetes

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Combined Effect of Dissipation and Thermal Mixed State on Entanglement in the Dispersive Limit

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Chinese Physics Letters 2008年第3期25卷 949-952页

作者： obada A. -S. F. HESSIAN H. A. MOHAMED A. -B. A. Faculty of Science Al-Azhar University Nasr City Cairo Egypt Faculty of Science Assiut University Assiut Egypt

We investigate the entanglement in the interacting system of a single mode thermal field and a single qubit with dissipation in the dispersive limit. The influence of initial temperature of thermal field and atoms on ... 详细信息

关键词： JAYNES-CUMMINGS MODEL QUANTUM-MECHANICS CURRENT SITUATION 2-LEVEL ATOM DECOHERENCE FIELD GENERATION DYNAMICS ENTROPY APPROXIMATION

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Entanglement of the Thermal State of an Anisotropic XYZ Spin Chain in an Inhomogeneous Constant Magnetic Field

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Chinese Physics Letters 2012年第3期29卷 9-12页

作者： A.-S.F.obada G.M.Abd Al-Kadar F.K.Faramawy A.A.Youssef Mathematics Department Faculty of ScienceAl-Azhar UniversityNasr City 11884CairoEgypt

A system of a two-qubit Heisenberg anisotropic XYZ spin chain in an inhomogeneous constant magnetic field with the Dzyaloshinskii-Moriya interaction is *** energy eigenvalues,the corresponding eigenstates and the thermal states of the system are *** entanglement is investigated according to Wootter's *** concurrence is studied against temperature for different values of the parameters involved.

关键词： system concurrence states

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Desmoid type fibromatosis: A case report with an unusual etiology

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World Journal of Gastrointestinal Oncology 2017年第9期9卷 385-389页

作者： Syed Faisal Jafri obada Obaisi Gerardo G Vergara Joe Cates Jaswinder Singh Jennifer Feeback Harathi Yandrapu Gastroenterology Research Medical CenterKansas City School of Medicine University of Missouri in Kansas City Pathology Research Medical CenterKansas City General and Vascular Surgery Research Medical CenterKansas City Hematology/Oncology Research Medical CenterKansas City Clinical Research Research Medical CenterKansas City Internal Medicine Department of Research Medical Center and Research Department of Kansas City Veterans Affairs Medical Center

Desmoid type fibromatosis(DTF) is a rare, locally invasive, non-metastasizing soft tissue tumor. We report an interesting case of DTF involving the pancreatic head of a 54-year-old woman. She presented with intermittent dysphagia and significant weight loss within a 3-mo period. Laboratory findings showed mild elevation of transaminases, significant elevation of alkaline phosphatase and direct hyperbilirubinemia, indicating obstructive jaundice. Computerized tomography of the abdomen revealed a mass in the head of the pancreas, dilated common bile duct, and dilated pancreatic duct. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound showed a large hypoechoic massin the head of the pancreas causing extrahepatic biliary obstruction and pancreatic ductal dilation. The patient underwent a successful partial pancreatico-duodenectomy and cholecystectomy. She received no additional therapy after surgery, and liver function tests were normalized within nine days after surgery. Currently, surgical resection is the recommended first line treatment. The patient will be followed for any recurrence.

关键词： Desmoid type fibromatosis Desmoid tumor Aggressive fibromatosis Pancreas Painless jaundice

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