Etude éco-biologique d’Artémia salina des zones humides de l’Ouest Algérien

L’Artémie (Artémia salina) est une espèce de crustacé vivant dans les lacs salés, les chotts et les marais salants .Elle est en abondance dans les salines de l’ouest Algérien. Ce genre de crustacé est très demandé dans le domaine d’exploitation des ressources hydriques et en aquaculture. Dans le présent travail on a étudié, en premier lieu l’aspect biologique et écologique de ce crustacé dans les salines de Bathioua (wilaya d’Oran) et Oued Djemaa (wilaya de Relizane), en deuxième lieu on a étudié son accommodation à différentes doses de salinité dans un milieu même quand les conditions de vie sont défavorables. L’Artémie salina est capable de produire des cystes qui ont la capacité de donner naissance à une larve appelée nauplius. La résistivité des cystes au stress du milieu en état de cryptobiose, leur permet de subsister à des températures extrêmes. Les nauplius sont distribués dès l’éclosion ou après 24 à 48 h d’enrichissement en protéines et en lipides. Les résultats obtenus lors de ce travail ont montré que le taux de reproduction varie en fonction des changements saisonniers des différents facteurs écologiques et des éléments physico chimiques de son environnement.Mots-clés: Artémia salina, aspect biologique, adaptation, salines, Ouest Algérien. Eco-biological study of Artemia salina wetlands of West AlgeriaThe Artemia (Artemia salina) is a species of crustacean living in salt lakes, chotts and salt marshes. It is in abundance in the salt mines of western Algeria. This kind of crustacean is highly demanded in the fields of water exploitation and aquaculture. In this study, the observation is drawn on the biological and ecological aspects of this crustacean in the salt mines of Bathioua (Oran wilaya) and Oued Djemaa (Relizane wilaya), according to the seasonal variations. Artemia salina is able to produce cysts that have the ability to give birth to a larva called nauplius. The resistivity of cysts at environment stress on cryptobiosis state allows them to survive in extreme temperatures. Nauplii begin hatching after 24 to 48 h enrichment in proteins and lipids. The results obtained in this work showed that the reproduction rate varies according to seasonal changes in different ecological factors and the physical and chemical elements of its environment.Keywords : Artemia salina, biological aspect, adaptation, salt, West Algeria

Mobility of Chromium and Tin Associated with Geochemical Dynamics in Groundwater in Meboudja Plain

AbstractIn the region of Sidi Amar Annaba South. Storage of industrial waste from the Arcelor-Mittal steel complex directly on the floor produced an infiltration of heavy metals to the under saturated and groundwater area. To know the exact origin of some pollutants and their evolution in time, monthly monitoring of water chemistry (potential hydrogen, potential of oxydo-reduction, temperature, conductivity, Oxygen, Calcium, Magnesium, Sodium, Potassium, Chlorine, sulfate, bicarbonate, Nitrate, Strontium, total Chrome, total Tin) was performed on wells for water cycle.Statistical analysis shows a common origin of chromium and tin that would be due to electroplating waste. The temporal evolution of these elements highlights the influence of several factors (potential hydrogen, potential of oxydo-reduction, rainfall and pumping) in the dissolution of these species and the evolution of the dominant aqueous species. There presentation of water points on the Eh-pH equilibrium diagram indicates that chromium may appear in the water table in two complex forms, trivalent and hexavalent by against the tin is in the hexavalent form

Phase appearance or disappearance in two-phase flows

This paper is devoted to the treatment of specific numerical problems which appear when phase appearance or disappearance occurs in models of two-phase flows. Such models have crucial importance in many industrial areas such as nuclear power plant safety studies. In this paper, two outstanding problems are identified: first, the loss of hyperbolicity of the system when a phase appears or disappears and second, the lack of positivity of standard shock capturing schemes such as the Roe scheme. After an asymptotic study of the model, this paper proposes accurate and robust numerical methods adapted to the simulation of phase appearance or disappearance. Polynomial solvers are developed to avoid the use of eigenvectors which are needed in usual shock capturing schemes, and a method based on an adaptive numerical diffusion is designed to treat the positivity problems. An alternate method, based on the use of the hyperbolic tangent function instead of a polynomial, is also considered. Numerical results are presented which demonstrate the efficiency of the proposed solutions

The Effect of the Stationary Phase on Resolution in the HPLC-Based Separation of Racemic Mixtures Using Vancomycin as a Chiral Selector: A Case Study with Profen Nonsteroidal Anti-Inflammatory Drugs

\ua9 2023 by the authors.Chiral resolution is a technique of choice, making it possible to obtain asymmetric and enantiomerically pure compounds from a racemic mixture. This study investigated the behavior of vancomycin when used as a chiral additive in high-performance liquid chromatography (HPLC) to separate enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), including ketoprofen, ibuprofen, flurbiprofen, and naproxen enantiomeric impurities. We compared two achiral stationary phases (C18 and NH2) to assess the impact of mobile phase composition and stationary phase on the vancomycin retention time in the racemic resolution of drug enantiomers. Our results demonstrated the successful enantioseparation of all drugs using vancomycin in the mobile phase (phosphate buffer 0.05 M/2-propanol, 50/50) with an NH2 column. This enhanced separation on the NH2 column resulted from the chromatography system’s efficiency and vancomycin dimers’ stereoselective interaction on the NH2 surface. This study underscores the importance of stationary phase selection in the chiral resolution of NSAIDs with vancomycin as a chiral additive. It offers valuable insights for future research and development of NSAID chiral separation methods, highlighting potential vancomycin applications in this context

Recommendations for economic evaluations of cell and gene therapies: a systematic literature review with critical appraisal

Objective: No consensus exists on the ideal methodology to evaluate the economic impact and value of new, potentially curative gene therapies. We aimed to identify and describe published methodologic recommendations for the economic evaluation of gene therapies and assess whether these recommendations have been applied in published evaluations. Methods: This study was conducted in three stages: a systematic literature review of methodologic recommendations for economic evaluation of gene therapies; an assessment of the appropriateness of recommendations; and a review to assess the degree to which the recommendations were applied in published evaluations. Results: A total of 2,888 references were screened, 83 articles were reviewed to assess eligibility, and 20 papers were included. Fifty recommendations were identified, and 21 reached consensus thresholds. Most evaluations were based on naive treatment comparisons and did not apply consensus recommendations. Innovative payment mechanisms for gene therapies were rarely considered. The only widely applied recommendations related to modeling choices and methods. Conclusions: Methodological recommendations for economic evaluations of gene therapies are generally not being followed. Assessing the applicability and impact of the recommendations from this study may facilitate the implementation of consensus recommendations in future evaluations

A diabetes risk score for Qatar utilizing a novel mathematical modeling approach to identify individuals at high risk for diabetes

We developed a diabetes risk score using a novel analytical approach and tested its diagnostic performance to detect individuals at high risk of diabetes, by applying it to the Qatari population. A representative random sample of 5,000 Qataris selected at different time points was simulated using a diabetes mathematical model. Logistic regression was used to derive the score using age, sex, obesity, smoking, and physical inactivity as predictive variables. Performance diagnostics, validity, and potential yields of a diabetes testing program were evaluated. In 2020, the area under the curve (AUC) was 0.79 and sensitivity and specificity were 79.0% and 66.8%, respectively. Positive and negative predictive values (PPV and NPV) were 36.1% and 93.0%, with 42.0% of Qataris being at high diabetes risk. In 2030, projected AUC was 0.78 and sensitivity and specificity were 77.5% and 65.8%. PPV and NPV were 36.8% and 92.0%, with 43.0% of Qataris being at high diabetes risk. In 2050, AUC was 0.76 and sensitivity and specificity were 74.4% and 64.5%. PPV and NPV were 40.4% and 88.7%, with 45.0% of Qataris being at high diabetes risk. This model-based score demonstrated comparable performance to a data-derived score. The derived self-complete risk score provides an effective tool for initial diabetes screening, and for targeted lifestyle counselling and prevention programs.Peer reviewe