12 research outputs found

    Phytochemical Characterization and Antimicrobial Potentialities of Two Medicinal plants, Chamaemelum nobile (L.) All and Matricaria chamomilla (L.)

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    Objective of the study was to evaluate the phytochemical characterization and antimicrobial effectiveness of two medicinal plants belonging to the Asteraceae family, growing spontaneously in the region of Boumerdes (Northeast Algeria) namely Chamaemelum nobile (L.) All and Matricaria chamomilla (L.). For this purpose, it was proposed to optimize the extraction parameters of the phenolic compounds of the aerial parts of two chosen species. The first step was intended to study the effect of different extraction solvents (water, chloroform and methanol) on the contents of different metabolites of these species. The qualitative screening of the aerial part of chamomile allowed to highlight different families of chemical compounds namely%253B flavonoids, total tannins, condensed tannins, gallic tannins, alkaloids, saponosides, glucosides, mucilages and total absence of anthocyanins and starch. This was confirmed by a quantitative analysis based on the determination of total phenolic compounds by spectrophotometry in the presence of the Folin-Ciocalteu reagent determined from the calibration curve of gallic acid. The results showed that the water was the best extraction solvent. At the second stage of our study, antimicrobial activity of the extracts was determined on six microbial strains such as Staphylococcus aureus, Bacillus thuringiensis, Escherichia coli and Fusarium sp., according to the disk diffusion method, and gave zones of inhibition ranging from 7 to 15 mm. Thus, the extracts had a moderately inhibitory activity and have reacted positively on at least one of the microbial strains tested with the exception of the fungal flora. However, the methanolic extract of M. chamomilla revealed a strong activity against to Pseudomonas sp. with an inhibition zone estimated at 22.5 mm

    Epidemiological study and identification of Escherichia coli strains associated with clinical events in Avian farming

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    Avian pathogenic Escherichia coli (APEC) represents a major challenge for the poultry industry, causing significant economic losses. This problem is exacerbated by the misuse use of antibiotics in Veterinary Medicine, leading to the emergence of resistant strains and thus creating a significant risk to Public Health. This study, carried out on 38 poultry farms in Algeria, involved the collection of 200 samples for the isolation of E. coli strains. The resistance of these strains to frequently used antibiotics was assessed using the agar diffusion method. Multiple Correspondence Analysis (MCA) was used to determine potential risk factors. The obtained results revealed that E. coli was present in 30% of samples. Alarming levels of resistance were observed against Tetracycline (81.6%), Ampicillin (78.3%), Ciprofloxacin (68.3%) and Nalidixic acid (60%). Stressful environmental conditions in poultry houses, such as temperature variations, high humidity, poor ventilation and stocking density were identified as key factors in the development of avian colibacillosis. In conclusion, the current study highlights the urgent need to strictly monitor and regulate the use of antibiotics in Veterinary Medicine and improve animal welfare in order to minimize the risk it pose to Public Health originated in the farms. In addition, it is essential that farmers maintain optimal environmental conditions in chicken rearing

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

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    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

    Le corps efféminé ou la mort masquée

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    Der verweichlichte körper oder der maskierte tod Die gängigen Bilder, die das Weibliche, die schöne, schlanke, sexy oder mütterliche Frau in den Modezeitschriften, Werbespots, Fernsehserien, usw darstellen, verhindern das Tödliche und das Verweichlichte, den Tod und das Weibliche im Gegensatz zur Männlichkeit gleichzeitig zu verbinden. Sie ermöglichen zwar den modernen Gesellschaften, ihren Mitgliedern eine friedliche und wohl geordnete Vision der Welt zu geben, um sie in ihrem Dasein zu beruhigen, aber diese hedonistischen Bilder, die auf Körperzurückhaltung beruhen, zwingen hingegen riesige Opfer auf für das Weibliche, das sich radikal im •Prozess der Verweichlichung“ seines Aussehens und seiner Verhaltensweisen einfügt, um seine Geschlechtsidentität sozial zu beglaubigen, und zwar die eines jungen Mädchens.The effeminate body and the masked death The prevailing imageries which draw femininity as the beautiful, slim, sexy or motherly woman in the fashion magazines, commercials, television series… prevent from considering jointly the deadly and the effeminate, the death and feminine, contrary to the imagery of virility. If our modern societies can offer their members a pacified and organised vision of the world to reassure them in their selfawareness, these hedonist pictures focusing on the control of the body impose, on the other hand, great sacrifices to the woman radically involved in •the process of effeminacy” of her appearances and behaviours in order to socially authenticate her gender, the adolescent girl.Les imageries ambiantes qui dessinent la féminité, la femme belle, mince, sexy ou maternante des magazines de mode, des spots publicitaires, des séries télévisées, etc., empêchent de penser conjointement le mortifère et l’efféminé, la mort et le féminin, contrairement à celles de la virilité. Si elles permettent aux sociétés modernes d’offrir à leurs membres une vision du monde pacifiée et ordonnée pour les rassurer dans leur sentiment d’être, ces imageries hédonistes axées sur la retenue du corps imposent en revanche d’immenses sacrifices au féminin radicalement inscrit dans le «procès d’effémination» de ses apparences et de ses conduites afin d’authentifier socialement son identité de genre, l’adolescente.El cuerpo afeminado o la muerte enmascarada Las imaginerías ambientes que dibujan la feminidad, la mujer guapa, delgada, sexy o maternal de las revistas de moda, los anuncios publicitarios, series televisivas etc., impiden pensar simultáneamente lo mortífero y lo afeminado, la muerte y lo femenino, al contrario de aquellas de la virilidad. Si permiten a las sociedades modernas ofrecer a sus miembros una visión del mundo pacificada y ordenada para tranquilizarles en su sentimiento de ser, estas imaginerías hedonistas enfocadas en la reserva del cuerpo imponen al contrario inmensos sacrificios al femenino radicalmente inscrito en el •proceso de afeminación” de sus apariencias y sus conductas para autentificar socialmente su identidad de género, la adolescente.Ait El Cadi Hakima. Le corps efféminé ou la mort masquée. In: Agora débats/jeunesses, 34, 2003. Les jeunes face à la mort. pp. 70-83

    The irrational thoughts of the unemployed youth

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    تهدف الدراسة الحالية الى التعرف على مدى وجود أفكار لاعقلانية لدى الشباب البطال وتحديد درجتها ومعرفة إلى أي مدى قد يؤثر وجود مثل هذه الأفكار في الشاب البطال و التعــرف علــى الاخــتلاف في الأفكار اللاعقلانية  بــين البطــالين حســب متغيرات الجنس، السن، الحالة الاجتماعية والمستوى التعليمي باستعمال المنهج الوصفي على عينة تكونت من 701 شاب بطال من الجنسين و استعمال مقياس الأفكار اللاعقلانية المصمم من طرف Malouff  و: (Schutte سنة 1986 أسفرت نتائج الدراسة عن : - وجود مستوى مرتفع من الأفكار اللاعقلانية لدى الشباب البطال - لا توجد فروق في متوسط الأفكار اللاعقلانية بين الجنسين وحسب متغير فئات السن ولا باختلاف المستوى التعليمي للشاب البطال.The current study aims at identifying the existence of irrational thoughts among unemployed youth, and to determine the degree to what extent may affect the existence of irrational thoughts in the unemployed youth, also to identify the difference in irrational thoughts among the unemployed according to gender, age, social status and educational level.The descriptive method was used on a sample that consisted of 701 young men of both sexes.In addition, the irrational thoughts scale designed by Malouff and Schutte in 1986 was used to achieve the study goal.The results of the study indicated that:- There is a high level of irrational ideas among unemployed youth - There were no differences in the average of irrational ideas between both sexes, the age and the educational level of the unemployed youth

    Green Fabrication of ZnO Nanoparticles and ZnO/rGO Nanocomposites from Algerian Date Syrup Extract: Synthesis, Characterization, and Augmented Photocatalytic Efficiency in Methylene Blue Degradation

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    International audienceThis innovative article provides a detailed description of the successful biosynthesis of zinc nanoparticles (ZnO-NPs) using an aqueous extract of Algerian Date Syrup, also known as molasses. A meticulous process was carried out to determine the optimal calcination temperature for ZnO-NPs, a crucial step in the preparation of these nanoparticles. The study was further extended by creating ZnO/rGOx nanocomposites through a hydrothermal method, varying the concentrations of reduced graphene oxide (rGO) at 5%, 10%, and 15%. The characteristics of the nanocomposites were thoroughly explored, encompassing chemical, optical, and morphological aspects, using sophisticated analysis techniques such as scanning electron microscopy (SEM), UV-visible diffuse reflectance spectroscopy (UV DRS), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). These analyses provided an in-depth understanding of the structure and properties of the nanocomposites. The centerpiece of this study is the evaluation of the photocatalytic degradation capacity of ZnO-NPs and ZnO/rGOx nanocomposites. These materials have demonstrated their ability to act as cost-effective and environmentally friendly photocatalysts for wastewater treatment. Experiments on methylene blue degradation under UV irradiation were conducted, yielding impressive results: a degradation efficiency of 86.6% was achieved in 140 min using 1 g/L of ZnO-NPs, and this rate reached 100% with the ZnO/rGO catalyst in the same time frame, highlighting its superiority as a photocatalyst. Furthermore, this study examined the variables affecting the photocatalysis experiment, including the solution’s pH and the amount of catalyst. The results revealed that the ZnO/rGO photocatalyst reached its optimal efficiency under neutral pH conditions and at a concentration of 1 g/L, providing crucial information for practical use of these materials. This enriched article highlights the promising potential of ZnO-NPs and ZnO/rGOx nanocomposites as efficient photocatalysts for methylene blue degradation, paving the way for significant environmental applications in wastewater treatment

    A Suv39h-dependent mechanism for silencing S-phase genes in differentiating but not in cycling cells

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    The Rb/E2F complex represses S-phase genes both in cycling cells and in cells that have permanently exited from the cell cycle and entered a terminal differentiation pathway. Here we show that S-phase gene repression, which involves histone-modifying enzymes, occurs through distinct mechanisms in these two situations. We used chromatin immunoprecipitation to show that methylation of histone H3 lysine 9 (H3K9) occurs at several Rb/E2F target promoters in differentiating cells but not in cycling cells. Furthermore, phenotypic knock-down experiments using siRNAs showed that the histone methyltransferase Suv39h is required for histone H3K9 methylation and subsequent repression of S-phase gene promoters in differentiating cells, but not in cycling cells. These results indicate that the E2F target gene permanent silencing mechanism that is triggered upon terminal differentiation is distinct from the transient repression mechanism in cycling cells. Finally, Suv39h-depleted myoblasts were unable to express early or late muscle differentiation markers. Thus, appropriately timed H3K9 methylation by Suv39h seems to be part of the control switch for exiting the cell cycle and entering differentiation

    Differential Cooperation between Heterochromatin Protein HP1 Isoforms and MyoD in Myoblasts*S⃞

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    Mechanisms of transcriptional repression are important during cell differentiation. Mammalian heterochromatin protein 1 isoforms HP1α, HP1β, and HP1γ play important roles in the regulation of chromatin structure and function. We explored the possibility of different roles for the three HP1 isoforms in an integrated system, skeletal muscle terminal differentiation. In this system, terminal differentiation is initiated by the transcription factor MyoD, whose target genes remain mainly silent until myoblasts are induced to differentiate. Here we show that HP1α and HP1β isoforms, but not HP1γ, interact with MyoD in myoblasts. This interaction is direct, as shown using recombinant proteins in vitro. A gene reporter assay revealed that HP1α and HP1β, but not HP1γ, inhibit MyoD transcriptional activity, suggesting a model in which MyoD could serve as a bridge between nucleosomes and chromatin-binding proteins such as HDACs and HP1. Chromatin immunoprecipitation assays show a preferential recruitment of HP1 proteins on MyoD target genes in proliferating myoblasts. Finally, modulation of HP1 protein level impairs MyoD target gene expression and muscle terminal differentiation. Together, our data show a nonconventional interaction between HP1 and a tissue-specific transcription factor, MyoD. In addition, they strongly suggest that HP1 isoforms play important roles during muscle terminal differentiation in an isoform-dependent manner
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