Diversity and Ecology of Diatoms in Northwest of Algeria: case of El-Hammam stream and Estuary of Cheliff River

P. 37-52Ecological research on algae from Algeria and in particular on freshwater and estuarine diatoms remains insufficient. The aim of our work is to contribute to the taxonomy and ecology of benthic diatoms from freshwaters and estuaries in Algeria. For this purpose, we studied two sites of water courses in north-western Algeria: El-Hammam stream at Mascara and the estuary of Cheliff river at Mostaganem. Our inventory of benthic diatoms during dry season at the middle of El-Hammam stream during April, June and August 2010 led to the identification of 44 cosmopolitan species, while 30 species occurred at the mouth of Cheliff river. 10 taxa were recorded for the first time in Algeria. Diversity values (Species richness, Shannon's index and Equitability index) for the two study sites are generally medium to low. The results of the 17 diatom-based metrics tested show that ROTT trophic index (TID) and the Trophic Diatom Index (TDI) best mirrored water quality, but a revision of taxa autecological values is requiredS

Single Cell Analysis of Blood Mononuclear Cells Stimulated Through Either LPS or Anti-CD3 and Anti-CD28.

Immune cell activation assays have been widely used for immune monitoring and for understanding disease mechanisms. However, these assays are typically limited in scope. A holistic study of circulating immune cell responses to different activators is lacking. Here we developed a cost-effective high-throughput multiplexed single-cell RNA-seq combined with epitope tagging (CITE-seq) to determine how classic activators of T cells (anti-CD3 coupled with anti-CD28) or monocytes (LPS) alter the cell composition and transcriptional profiles of peripheral blood mononuclear cells (PBMCs) from healthy human donors. Anti-CD3/CD28 treatment activated all classes of lymphocytes either directly (T cells) or indirectly (B and NK cells) but reduced monocyte numbers. Activated T and NK cells expressed senescence and effector molecules, whereas activated B cells transcriptionally resembled autoimmune disease- or age-associated B cells (e.g., CD11c, T-bet). In contrast, LPS specifically targeted monocytes and induced two main states: early activation characterized by the expression of chemoattractants and a later pro-inflammatory state characterized by expression of effector molecules. These data provide a foundation for future immune activation studies with single cell technologies (https://czi-pbmc-cite-seq.jax.org/)

Contribution à la modélisation du flux de phosphore dans le barrage de Hammam Boughrara (province de Tlemcen, Algérie) : application à la gestion de l’eutrophisation

Dans la présente étude portant sur le barrage de Hammam Boughrara, mis en eau en 1999, nous avons appliqué plusieurs modèles de bilan du phosphore, à savoir les modèles de Vollenweider (1969), de Dillon & Rigler (1975), de Walker (1977), de Reckhow (1977) et d’Ostrofsky (1978). Afin de prendre en considération la vitesse de submersion graduelle des surfaces inondées, caractérisée ordinairement par un accroissement très important de l’état trophique résultant des apports endogènes du phosphore par lessivage, nous avons tenté d’adapter le modèle d’Ostrofsky (1978) à la réalité du réservoir étudié, et ce en ajoutant une nouvelle dimension. Les résultats obtenus montrent que le modèle proposé semble pertinent.In the present study, carried out on the Hammam Boughrara dam (impounded in 1999), a number of phosphorus balance models were applied, namely, Vollenweider (1969), Dillon & Rigler (1975), Walker (1977), Reckhow (1977) and Ostrofsky (1978) models. In order to take into account the rate of gradual submergence of flooded surfaces which is ordinarily characterized by an important increase in the trophic status as a result of endogenous inputs of phosphorus by leaching we have tried to adapt the Ostrofsky model (1978) to the reality of studied dam, by adding a new dimension. The obtained results show that the proposed model seems relevant

AMULET: a novel read count-based method for effective multiplet detection from single nucleus ATAC-seq data.

Detecting multiplets in single nucleus (sn)ATAC-seq data is challenging due to data sparsity and limited dynamic range. AMULET (ATAC-seq MULtiplet Estimation Tool) enumerates regions with greater than two uniquely aligned reads across the genome to effectively detect multiplets. We evaluate the method by generating snATAC-seq data in the human blood and pancreatic islet samples. AMULET has high precision, estimated via donor-based multiplexing, and high recall, estimated via simulated multiplets, compared to alternatives and identifies multiplets most effectively when a certain read depth of 25K median valid reads per nucleus is achieved

Sestrins induce natural killer function in senescent-like CD8(+) T cells

Aging is associated with remodeling of the immune system to enable the maintenance of life-long immunity. In the CD8⁺ T cell compartment, aging results in the expansion of highly differentiated cells that exhibit characteristics of cellular senescence. Here we found that CD27⁻CD28⁻CD8⁺ T cells lost the signaling activity of the T cell antigen receptor (TCR) and expressed a protein complex containing the agonistic natural killer (NK) receptor NKG2D and the NK adaptor molecule DAP12, which promoted cytotoxicity against cells that expressed NKG2D ligands. Immunoprecipitation and imaging cytometry indicated that the NKG2D-DAP12 complex was associated with sestrin 2. The genetic inhibition of sestrin 2 resulted in decreased expression of NKG2D and DAP12 and restored TCR signaling in senescent-like CD27⁻CD28⁻CD8⁺ T cells. Therefore, during aging, sestrins induce the reprogramming of non-proliferative senescent-like CD27⁻CD28⁻CD8⁺ T cells to acquire a broad-spectrum, innate-like killing activity

Characterizations of crystalline structure and catalytic activity of zwitterionic imidazole derivatives

International audienceThe zwitterion ligand L1 has been synthesized and characterized by single-crystal X-ray diffraction, and spectroscopic techniques (1H, 13C NMR, FT-IR, ESI-MS, and UV–Vis). The crystal structure shows that L1 molecules are planar and are connected via intermolecular N-H——O and intramolecular N-H——O interactions. The NMR analysis shows the presence of two mesomeric forms of L1 zwitterion and ketone-imidazolidine. The kinetic study of in situ complexes is followed by UV–vis spectroscopy and revealed a binuclear structure built from square base pyramidal geometry and octahedral one. In situ complexes obtained from L1 with different copper (II) salts are studied for their catecholase activities using 3,5-di-tert-butylcatechol. The obtained 3,5-di-tert-butylquinone was characterized by single-crystal X-ray diffraction,. The results show that the catalytic activity depends on the nature of the metal salt anion. From Michaelis-Menten model, we have evaluated the dissociation constant and the bond constant which are in good agreement with those of literature. The structure-activity relationship show that the high rate of catalytic oxidation depends on the presence of copper ion in the complex

Novel Synthesis of Histidine Derivative for Effective Treatment of Industrial Wastewater Containing Cadmium and Lead

International audienceIn this study, we evaluated the efficacy of ligand, 2-{[(2-hydroxy-3-methoxyphenyl)methyl]amino}-3-(1H-imidazol-4-yl)propanoic acid, in removing heavy metal ions from wastewater. To investigate the adsorption and/or complexation of Pb2+ and Cd2+ ions in aqueous solutions, we varied the conditions such as contact time, temperature, and pH. We characterized the ligand using different techniques such as FTIR, H-1 NMR, and single-crystal X-ray diffraction. We used atomic absorption spectrophotometry to determine the concentration of metal ions in the aqueous samples. The adsorption process was fast, with maximum adsorption achieved within 10 minutes for Pb2+ and Cd2+. The results revealed that at pH 2-8.92.62% of lead and 100% of cadmium were removed. Thermodynamic calculations suggest that physical forces predominantly drive the adsorption process of heavy metals onto the ligand. Our findings indicate that the ligand is capable of effectively reducing the concentration of the two heavy metals in wastewater to below 0.5 ppm, with an efficiency of 95.64% for lead and 100% for cadmium