Validation of landslide susceptibility using a GIS-based statistical model and Remote Sensing Data in the Amzaz watershed in northern Morocco

The main objective of this research is to examine and validate the landslide susceptibility assessment (LSA)results of the spatial probability of landslide occurrence in the Amzaz watershed area in Northern Morocco,setting out to create a helpful agent for the decision-makers of land-use policies. In order to reach the maingoal of this study, two sub-objectives were defined: the presenting of the physiography and the cartographyof the geographical components of the study area, and the analysis of the LSA using a statistical-basedmethod, Information Value Method (IVM), as a criteria required by the Model. Lastly, the validation of theresults through the prediction and success rates was carried out. Landslide susceptibility is the probabilitythat landslides will be generated in the predicted zone depending on local terrain characteristics.Several methods are proposed for landslide susceptibility assessment worldwide. IVM has been applied toprepare the landslide susceptibility map. This paper envisages the definition of the settings of the study areaas well as the geophysical characteristics by means of the acquisition and preparation of predisposing factors,such as the geology, land use and climate and the application of the IVM on LSA using a statistically basedmethod for each subset of the landslide inventory.This study is aimed at a prediction vision for sustainability as an alternative and this is not limited todegradation processes. It also concerns the efforts made to adapt to the impacts and even those of mitigatingchange. The promotion of sustainable development in risk areas requires an effort to analyze and evaluatelocal practices and approaches. This is what we are trying to do through this work, which starts from amethodological basis to validate a model for predicting landslides affecting the Moroccan Central Rif area

Datation des carbonates impurs au Maroc à l’aide de la méthode de déséquilibre radioactif 230Th/234U

Au cours de ce travail, nous avons entrepris une série de mesures uranium, thorium sur des carbonates impurs en utilisant la méthode de dissolution totale (TSD). La correction des âges des dépôts, témoin d’une/des phase(s) humide(s) durant laquelle (lesquelles) la précipitation des carbonates a eu lieu, a été effectuée au moyen des techniques isochrones. Les résultats isotopiques obtenus montrent que: (1) le Plateau Central Marocain a connu au moins, deux phases humides, la première antérieure à 350 ka et la dernière récente au cours de l'épisode climatique Holocène, (2) la région d'Abda Doukalla a connu plusieurs épisodes de précipitations des carbonates qui datent respectivement de >350 ka, 229 ka, 140 ka, 98 ka, 42 ka et 20 ka.Mots-clés : dépôts quaternaires, déséquilibres radioactifs, spectrométrie alpha, carbonates impurs, travertin, plateau central marocain, Abda-Doukkala

Spinsterhood and its impact on disease features in women with rheumatoid arthritis

<p>Abstract</p> <p>Objective</p> <p>To evaluate the impact of spinsterhood on disease characteristics and quality of life (QoL) in Moroccan women with rheumatoid arthritis (RA).</p> <p>Methods</p> <p>185 women with RA were recruited in this study. Marital status was specified as follow: 1. Spinsterhood (never-married woman aged 38 or over), 2. Distressed marriage; 3. Nondistressed marriage and 4. Divorced or widowed. Marital distress was assessed by a self-report concerning coping efficacy and burden caring of husbands. Assessment criteria included the evaluation of: age at onset (years), diagnosis delay (months), disease duration (years), disease activity (evaluated by physical examination, biological inflammatory tests; and disease activity score (DAS 28)), pain intensity (measured with a visual analogue scale (VAS)); and radiographic damage (evaluated by the Sharp's method as modified by van der Heijde). Treatments (doses and duration) were specified. The Health Assessment Questionnaire (HAQ) was used to evaluate functional disability. QoL was measured using the Arabic version of the generic instrument SF-36.</p> <p>Results</p> <p>In our data, spinsterhood was detected in 42 (22.7%) patients vs. 88 (47.5%) with distressed marriage, 28 (15.1%) with nondistressed marriage and 27 (14.6%) divorced or widowed. Comparing the 4 groups, we found that QoL in never-married women was damaged in a significant way comparing to the other groups. Mental as well as physical aspects were affected. Also, we found that spinsterhood was associated to an early age at onset (p = 0.009), pain intensity (p < 0.001); clinical (p < 0.001) and biological disease activity (C-reactive protein; p = 0.02) and functional disability (p < 0.001). Logistic regression analysis revealed a significant relationship between spinsterhood and early age at onset and severe functional disability (for all p ≤ 0.01).</p> <p>Conclusion</p> <p>This study suggests that spinsterhood in our RA patients was associated with an altered QoL even compared with distressed married women. Also, we state that spinsterhood was associated with an early age at onset, severe joint pain; higher disease activity and with altered functional ability. It seems important to consider not only disease-related parameters but also social status as a determinant factor of poor course in RA.</p

FORMULATION, OPTIMIZATION AND CHARACTERIZATION OF IBUPROFEN LOADED MICROEMULSION SYSTEM USING D-OPTIMAL MIXTURE DESIGN

Objective: The purpose of this study was to develop, optimize and characterize a stable microemulsion, with an improvement of the solubility of a poorly aqueous soluble drug, ibuprofen. Methods: Various oils (oleic acid, cottonseed oil, olive oil, argan oil, and labrafac® WL 1349), surfactants (tween® 80, tween® 40, tween® 20) and co-surfactants including polyethylene glycol 400, ethanol, 1-butanol, and propylene glycol were selected after solubility studies. Then, pseudo-ternary phase diagrams with surfactant/co-surfactant ratio of 1:2, 1:1, 2:1 and 3:1 were constructed and a D-optimal mixture design method was used to optimize the ibuprofen loaded microemulsion. The optimized microemulsion was evaluated for several characteristics including globule size, zeta potential, pH, conductivity, refractive index and stability studies. Results: Optimized microemulsion obtained was composed of oleic acid (6.88% w/w), tween® 80/1-butanol (3:1, 63.11% w/w) and water (30.00% w/w). The results obtained showed an average globule size of 117.5 nm, a zeta potential of-6.47 mV and a transmittance of 96.95±0.77%. The optimized formulation showed an improvement in the solubility of ibuprofen with unchanged characteristics for one month. Conclusion: The use of pseudo-ternary phase diagrams and mathematical modeling allows to obtain an optimal microemulsion with perfect stability for 1 mo and a better solubilization capacity of ibuprofen

SOLUBILIZATION OF CELECOXIB USING ORGANIC COSOLVENT AND NONIONIC SURFACTANTS OPTIMIZED BY EXPERIMENTAL DESIGN

Objective: The solubility of drug substances in water is one of the major factors taken into account in the formulation of oral solutions and parenteral forms. The present study aims to evaluate the utility of a mixture design in improving water solubility of celecoxib through a micellar system by the use of organic co solvent and nonionic surfactants that are well tolerated by the parenteral route.Methods: In our study, a design of experiments approach was tested using a mixture design of nonionic surfactants (Tween® 80 and Solutol®HS 15), an organic cosolvent (ethanol) and celecoxib. Solubility determination was based on the analysis of samples absorbance at 215 nm. A particles size measurement was conducted using a Dynamic Light Scattering at the point showing the maximum of solubility.Results: The results showed a significant solubility increase in most of tested mixtures. The analysis of the design space showed that the solubility of celecoxib varies very closely with the concentration of Tween® 80 associated with ethanol and Solutol®HS 15 in water. Run 19 containing 0.8% of celecoxib, 10% of ethanol, 2% of Tween® 80, 2% of Solutol®HS 15 and water q. s. for 100% w/w improved celecoxib solubility by about 90 %, and showed an average particles size of 9.67 nm.Conclusion: Micellar solubilisation associating a cosolvent and nonionic surfactants seems to improve celecoxib solubility significantly. Mixture design provides maximum information about the effects and the proportions of each component from a limited number of experiments.Keywords: Solubility, Celecoxib, Mixture design, Cosolvent, SurfactantsÂ

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Antibacterial activity, structure and CMC relationships of alkanediyl α,ω-bis(dimethylammonium bromide) surfactants

Some alpha,omega-alkanediyl bis-dimethylammonium bromide compounds (gemini surfactants) referred as "m-s-m" have been synthesized, purified and characterized by usual spectroscopic methods. These compounds have been screened for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Their activity was compared. The compounds tested showed excellent in vitro antibacterial activity against Staphylococcus aureus ranging from 1.5 to 20 microg/ml and had variable activity against E. coli with minimum minimum inhibitory concentration (MIC) of 50 microg/ml. These compounds are less active against P. aeruginosa. On the other hand, contrary to the antibacterial activity of these products against S. aureus, a relation between the MIC and the critical micellar concentration (CMC) was found and relationship between chain's Length and antibacterial activity was found.This work was supported by the CNRPRT (Project research: PARS Chimie 008).Peer reviewe