Improved Fletcher-Reeves Methods Based on New Scaling Techniques

This paper introduces a scaling parameter to the Fletcher-Reeves (FR) nonlinear conjugate gradient method. The main aim is to improve its theoretical and numerical properties when applied with inexact line searches to unconstrained optimization problems. We show that the sufficient descent and global convergence properties of Al-Baali for the FR method with a fairly accurate line search are maintained. We also consider the possibility of extending this result to less accurate line search for appropriate values of the scaling parameter. The reported numerical results show that several values for the proposed scaling parameter improve the performance of the FR method significantly

Some Aspects of Climate Variability and Increasing Aridity in Central Morocco over the Last Forty Years: Case of Tensift Basin (Marrakech-Morocco)

Morocco, due to its location in the Mediterranean circumference, is vulnerable to present and future climate variability and climate change. Its surface water resources are becoming ever more limited and difficult to exploit. It might be expected that the warming of the hot season and drought would result in an increase in arid and semi-arid regimes of the region. In this context, we are interested in the evolution of aridity through climate indexes, including precipitation, temperature and evapotranspiration over the last 40 years in the Tensift watershed (central Morocco). As preliminary results, in the Tensift basin, the temperature became higher during the last two decades. It diminishes paradoxally towards mountainous areas. A slight decrease of precipitation has been noticed in the foothill regions of the High Atlas and near the Haouz plain. The study of aridity evolutions by the aridity index of De Martonne and aridity index of UNEP takes into account respectively the ratio between the mean annual precipitation (P) and temperature (T) and the relationship between annual precipitation and evapotranspiration. Generally, the aridity is decreasing from downstream to upstream of the study area. But during the past two decades, the region of the Tensift knew a subtantial augmentation in arid land regime may be due to global warming and reduced precipitation measured. Typically, there is a coherence between UNEP index and the index of the De Martonne from point of view of increasing aridity, which adds robustness to the result. Keywords: Tensift watershed, De Martonne’s aridity index, UNEP index, aridity, spatial variability

Deficiency of Cks1 leads to learning and long-term memory defects and p27 dependentformation of neuronal cofilin aggregates

In mitotic cells, the cyclin-dependent kinase (CDK) subunit protein CKS1 regulates S phase entry by mediating degradation of the CDK inhibitor p27. Although mature neurons lack mitotic CDKs, we found that CKS1 was actively expressed in post-mitotic neurons of the adult hippocampus. Interestingly, Cks1 knockout (Cks1−/−) mice exhibited poor long-term memory, and diminished maintenance of long-term potentiation in the hippocampal circuits. Furthermore, there was neuronal accumulation of cofilin-actin rods or cofilin aggregates, which are associated with defective dendritic spine maturation and synaptic loss. We further demonstrated that it was the increased p27 level that activated cofilin by suppressing the RhoA kinase-mediated inhibitory phosphorylation of cofilin, resulting in the formation of cofilin aggregates in the Cks1−/− neuronal cells. Consistent with reports that the peptidyl-prolyl-isomerase PIN1 competes with CKS1 for p27 binding, we found that inhibition of PIN1 diminished the formation of cofilin aggregates through decreasing p27 levels, thereby activating RhoA and increasing cofilin phosphorylation. Our results revealed that CKS1 is involved in normal glutamatergic synapse development and dendritic spine maturation in adult hippocampus through modulating p27 stability

MADgazine: Advertising Design Showcase 2022

This magazine was consist of works created by the final year students of Bachelor of Multimedia Advertising Design programme. It is a compilation of all the final projects that executed by the students as part of their fulfilment for the undergraduate degree

Quantification de l’érosion hydrique par les méthodes USLE et RUSLE : Application aux sous-bassins versants du Bouregreg, Maroc

International audienceWater erosion is one of the major causes of soil degradation in the world. Among the most negative effects of water erosion is the accumulation of sedimentation in dam reservoirs, leading to a loss of their water storage potential and agro-pedological damage. In the northwest of Morocco, the Bouregreg watershed experiences soil losses every year, that cause a natural imbalance in the ecosystems of the basin and a slowdown in the region’s socio-economic development. These soil losses are reflected in the Sidi Mohamed Ben Abdellah Dam near the mouth of the Bouregreg, by silting up estimated, from a financial point of view, at several million dirhams/year. In order to help better understand and quantify this soil degradation phenomenon, we carried out an evaluation and quantification of the soil losses using empirical universal soil loss equations (USLE) and (RUSLE), by integrating into a Geographic Information System (GIS), layers of information of the main environmental factors involved in the erosive process of the Bouregreg sub-basins (climate, topography, soil, land use). The application of these empirical equations allowed us to identify in a general way, the main factors responsible for the soils water erosion in the Bouregreg watershed. Therefore, the results obtained from these equations show average values of soil loss estimated to 0.94 t/ha/yr and 1.07 t/ha/yr, by applying the USLE and RUSLE methods respectively. On the other hand, the comparison between the values of soil losses estimated in this work by USLE and RUSLE and those of previous works, show relatively small differences. The distribution of the different erosion classes highlights the combined effect of vegetation cover and topography on the variability of water erosion rates in the Bouregreg sub-watershedsL'érosion hydrique est l'une des causes majeures de la dégradation des sols dans le monde. La sédimentation dans les retenues des barrages est un des effets les plus négatifs de l'érosion hydrique, entrainant une perte de leur potentiel de stockage des eaux et des dégâts agropédologiques. Le bassin versant du Bouregreg, situé dans le Nord-Ouest du Maroc, connait chaque année des pertes de sol à l'origine d'un déséquilibre naturel des écosystèmes du bassin et d'un ralentissement du développement socio-économique de la région. Ces pertes de sols se traduisent au niveau du Barrage Sidi Mohamed Ben Abdellah proche de l'embouchure du Bouregreg, par un envasement estimé, de point de vue financier, à plusieurs millions de dirhams/an. Afin de quantifier et mieux comprendre ce phénomène de dégradation des sols, nous avons procédé à une évaluation et quantification des pertes en sol en utilisant les équations universelles empiriques (USLE) et (RUSLE), en intégrant sous forme de couches d'informations les principaux facteurs environnementaux impliqués dans le processus érosif (climat, topographie, sol, occupation du sol) relatives aux sous-bassins du Bouregreg dans un Système d'Information Géographique (SIG). L'application de ces équations empiriques nous a permis d'établir de façon générale les facteurs décisifs responsables de l'érosion hydrique des sols au niveau de ce bassin. Ainsi, les résultats obtenus montrent des valeurs moyennes des pertes en sol estimées à 0,94 t/ha/an et 1,07 t/ha/an par application des équations USLE et RUSLE respectivement. D'autre part, la comparaison entre les valeurs des pertes en sol estimées dans ce travail par USLE et RUSLE et celles des travaux antérieurs, montre des différences relativement faibles. La distribution des différentes classes d'érosion met en évidence l'effet conjugué notamment du couvert végétal et de la topographie sur la variabilité des taux d'érosion hydrique au niveau des quatre sous bassins de Bouregreg

Quantification de l’érosion hydrique par les méthodes USLE et RUSLE : Application aux sous-bassins versants du Bouregreg, Maroc

International audienceWater erosion is one of the major causes of soil degradation in the world. Among the most negative effects of water erosion is the accumulation of sedimentation in dam reservoirs, leading to a loss of their water storage potential and agro-pedological damage. In the northwest of Morocco, the Bouregreg watershed experiences soil losses every year, that cause a natural imbalance in the ecosystems of the basin and a slowdown in the region’s socio-economic development. These soil losses are reflected in the Sidi Mohamed Ben Abdellah Dam near the mouth of the Bouregreg, by silting up estimated, from a financial point of view, at several million dirhams/year. In order to help better understand and quantify this soil degradation phenomenon, we carried out an evaluation and quantification of the soil losses using empirical universal soil loss equations (USLE) and (RUSLE), by integrating into a Geographic Information System (GIS), layers of information of the main environmental factors involved in the erosive process of the Bouregreg sub-basins (climate, topography, soil, land use). The application of these empirical equations allowed us to identify in a general way, the main factors responsible for the soils water erosion in the Bouregreg watershed. Therefore, the results obtained from these equations show average values of soil loss estimated to 0.94 t/ha/yr and 1.07 t/ha/yr, by applying the USLE and RUSLE methods respectively. On the other hand, the comparison between the values of soil losses estimated in this work by USLE and RUSLE and those of previous works, show relatively small differences. The distribution of the different erosion classes highlights the combined effect of vegetation cover and topography on the variability of water erosion rates in the Bouregreg sub-watershedsL'érosion hydrique est l'une des causes majeures de la dégradation des sols dans le monde. La sédimentation dans les retenues des barrages est un des effets les plus négatifs de l'érosion hydrique, entrainant une perte de leur potentiel de stockage des eaux et des dégâts agropédologiques. Le bassin versant du Bouregreg, situé dans le Nord-Ouest du Maroc, connait chaque année des pertes de sol à l'origine d'un déséquilibre naturel des écosystèmes du bassin et d'un ralentissement du développement socio-économique de la région. Ces pertes de sols se traduisent au niveau du Barrage Sidi Mohamed Ben Abdellah proche de l'embouchure du Bouregreg, par un envasement estimé, de point de vue financier, à plusieurs millions de dirhams/an. Afin de quantifier et mieux comprendre ce phénomène de dégradation des sols, nous avons procédé à une évaluation et quantification des pertes en sol en utilisant les équations universelles empiriques (USLE) et (RUSLE), en intégrant sous forme de couches d'informations les principaux facteurs environnementaux impliqués dans le processus érosif (climat, topographie, sol, occupation du sol) relatives aux sous-bassins du Bouregreg dans un Système d'Information Géographique (SIG). L'application de ces équations empiriques nous a permis d'établir de façon générale les facteurs décisifs responsables de l'érosion hydrique des sols au niveau de ce bassin. Ainsi, les résultats obtenus montrent des valeurs moyennes des pertes en sol estimées à 0,94 t/ha/an et 1,07 t/ha/an par application des équations USLE et RUSLE respectivement. D'autre part, la comparaison entre les valeurs des pertes en sol estimées dans ce travail par USLE et RUSLE et celles des travaux antérieurs, montre des différences relativement faibles. La distribution des différentes classes d'érosion met en évidence l'effet conjugué notamment du couvert végétal et de la topographie sur la variabilité des taux d'érosion hydrique au niveau des quatre sous bassins de Bouregreg

Dual Functions of Nbs1 in the Repair of DNA Breaks and Proliferation Ensure Proper V(D)J Recombination and T-Cell Development ▿ †

Immunodeficiency and lymphoid malignancy are hallmarks of the human disease Nijmegen breakage syndrome (NBS; OMIM 251260), which is caused by NBS1 mutations. Although NBS1 has been shown to bind to the T-cell receptor alpha (TCRα) locus, its role in TCRβ rearrangement is unclear. Hypomorphic mutations of Nbs1 in mice and patients result in relatively mild T-cell deficiencies, raising the question of whether the truncated Nbs1 protein might have clouded a certain function of NBS1 in T-cell development. Here we show that the deletion of the entire Nbs1 protein in T-cell precursors (Nbs1T-del) results in severe lymphopenia and a hindrance to the double-negative 3 (DN3)-to-DN4 transition in early T-cell development, due to abnormal TCRβ coding and signal joints as well as the functions of Nbs1 in T-cell expansion. Chromatin immunoprecipitation (ChIP) analysis of the TCR loci reveals that Nbs1 depletion compromises the loading of Mre11/Rad50 to V(D)J-generated DNA double-strand breaks (DSBs) and thereby affects resection of DNA termini and chromatin conformation of the postcleavage complex. Although a p53 deficiency relieves the DN3→DN4 transition block, neither a p53 deficiency nor ectopic expression of TCRαβ rescues the major T-cell loss in Nbs1T-del mice. All together, these results demonstrate that Nbs1's functions in both repair of V(D)J-generated DSBs and proliferation are essential for T-cell development