INVESTIGATING CHALLENGES FACED BY EFL TEACHERS AT BLIDA PRIMARY SCHOOLS IN ALGERIA

This study investigates the challenges faced by English as Foreign Language (EFL) primary school teachers in Algeria, specifically in Blida primary schools. The study uses a mixed-methods approach, including a questionnaire designed to gather information about various aspects of the teacher's professional experience and a Likert scale to measure the level of agreement or disagreement with statements related to challenges faced by primary school teachers when teaching EFL. The study finds that primary school English teachers in Blida face significant challenges due to limited access to resources and support from parents or school administration. Providing targeted professional development opportunities for classroom management training and support can help overcome these challenges effectively and improve EFL instruction at primary schools. The study also identified challenges with lesson planning and curriculum development, but most EFL primary school teachers in Blida do not feel restricted by inadequate access to instructional materials and resources necessary for effective classroom instruction. The study has several limitations, including a small sample size and the use of a questionnaire, but it makes an important contribution towards understanding how the best educators can overcome some of the obstacles they face while providing high-quality EFL instruction for their pupils.  Article visualizations

Removal of Triphenylmethane Dyes by Bacterial Consortium

A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50 mg/L) and malachite green (50 mg/L) dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD) removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes

Acquisition 3D et visualisation d'objets culturels pour les applications de la réalité augmentée

Au cours des dernières décennies, le domaine de la reconstruction 3D a connu une croissance rapide et de nombreuses techniques ont été présentées par les scientifiques. L'enveloppe visuelle et la stéréovision sont deux de ces techniques, et sont classées parmi les techniques IBMR. Les enveloppes visuelles utilisent la forme d'un objet dérivée des images prises sous différents angles pour créer un modèle 3D approximatif de l'objet. La stéréovision calcule la dimension 3D (profondeur) en comparant deux images de la même scène qui ont été prises sous deux angles différents. Les pixels correspondants dans les deux images sont ensuite calculés pour déduire une carte de disparité qui est utilisée pour déterminer les profondeurs. Les deux techniques présentent des inconvénients lorsqu'elles sont utilisées seules, et l'un des objectifs de cette recherche est de surmonter ces problèmes et de développer une technique de reconstruction 3D efficace et robuste. Notre étude a abouti à la proposition d’une méthode innovante pour estimer l'enveloppe visuelle. Deux approches ont été combinées, à savoir, « la correspondance de caractéristiques » et « l’approche par bloc ». Ce qui a permis de reconstruire des objets avec des gains considérables de temps et sans perte de qualité. Nous avons utilisé les informations géométriques présentes dans les images pour réduire l'espace de recherche des algorithmes stéréoscopiques, réduisant ainsi le temps d'exécution de plus de la moitié du temps initial. Dans le cadre de cette recherche, nous avons eu l’occasion de reconstruire des objets culturels réels et d’intégrer leur modèles 3D à des applications de réalité augmentée.

Novel Approach for Detection and Removal of Moving Cast Shadows Based on RGB, HSV and YUV Color Spaces

Cast shadow affects computer vision tasks such as image segmentation, object detection and tracking since objects and shadows share the same visual motion characteristics. This unavoidable problem decreases video surveillance system performance. The basic idea of this paper is to exploit the evidence that shadows darken the surface which they are cast upon. For this reason, we propose a simple and accurate method for detection of moving cast shadows based on chromatic properties in RGB, HSV and YUV color spaces. The method requires no a priori assumptions regarding the scene or lighting source. Starting from a normalization step, we apply canny filter to detect the boundary between self-shadow and cast shadow. This treatment is devoted only for the first sequence. Then, we separate between background and moving objects using an improved version of Gaussian mixture model. In order to remove these unwanted shadows completely, we use three change estimators calculated according to the intensity ratio in HSV color space, chromaticity properties in RGB color space, and brightness ratio in YUV color space. Only pixels that satisfy threshold of the three estimators are labeled as shadow and will be removed. Experiments carried out on various video databases prove that the proposed system is robust and efficient and can precisely remove shadows for a wide class of environment and without any assumptions. Experimental results also show that our approach outperforms existing methods and can run in real-time systems

Effect of passively aerated biological pretreatment on different biomasses with diverse lignocellulosic fiber profiles

Passively aerated biological pretreatment was applied to four different lignocellulosic biomasses with varying fiber content profiles: sugar beet pulp (SBP), brewery bagasse (BB), rice husk (RH), and orange peel (OP). In order to analyze the organic matter solubilization yield at 24 and 48 h, different percentages of activated sewage sludge (2.5–10%) were utilized as inoculum. The OP achieved the best organic matter solubilization yield in terms of soluble chemical oxygen demand (sCOD) and dissolved organic carbon (DOC) at 2.5% inoculation and 24 h: 58.6% and 20%, respectively, since some total reducing sugars (TRS) consumption was identified after 24 h. On the contrary, the worst organic matter solubilization yield was obtained with RH, the substrate with the highest lignin content among the tested, with percentages of 3.6% and 0.7% in terms of sCOD and DOC respectively. In fact, it could be considered that this pretreatment was not successful with RH. The optimum inoculation proportion was 7.5% (v/v) except for the OP (2.5% (v/v)). Finally, due to the counterproductive organic matter consumption at longer pretreatment durations, the optimal time for BB, SBP, and OP was 24 h

Farnesol, a Fungal Quorum-Sensing Molecule Triggers Candida Albicans Morphological Changes by Downregulating the Expression of Different Secreted Aspartyl Proteinase Genes

The aim of this study was to determine the effect of exogenous farnesol in yeast-to-hyphae morphogenesis, and Saps (2, 4, 5 and 6) mRNA expressions by a Candida strain that does not produce endogenous farnesol. C. albicans was cultured in the absence and presence of farnesol at various concentrations (10, 100, and 300 µM), in proteinase induction medium, and then used to determine yeast-to- hyphae changes, Candida ultrastructure and to determine Saps 2, 4, 5 and 6 expressions using q-TR-PCR and ELISA (for Sap2). Data demonstrated that farnesol greatly reduced the yeast-to-hyphae morphogenesis of a Candida strain that does not produce endogenous farnesol. Farnesol induced several ultrastructural alterations, including changes in the cell-wall shape, a visible disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, and the presence of electron-dense vacuoles. Tested on gene expressions, farnesol was able to significantly (p < 0.01) decrease Sap2 secretion and mRNA expression. Farnesol downregulated also Sap4-6 mRNA expression. These results demonstrated for the first time that farnesol modules Candida morphogenesis through a downregulation of Saps 2, 4, 5 and 6 expressions. Overall these data point to the potential use of farnesol as an antifungal molecul

Potential use of Bacillus paramycoides for the production of the biopolymer polyhydroxybutyrate from leftover carob fruit agro-waste

This study was designed to investigate, at a laboratory scale, the possibility of valorizing the leftover carob fruits to produce the eco-friendly biopolymer polyhydroxybutyrate (PHB) by using the bacterial strain Bacillus paramycoides, which has been isolated from the botanical garden of Skikda University in Algeria. The PHB production was tested under various conditions: a pH of 3-8, temperature range of 30-44 celcius, carob extracted molasses concentration of 2-8% v/v, an incubation time of 24-96 h and an agitation speed of 150-300 rpm. The effects of different nitrogen sources and carob extracted molasses treatment types were also investigated. The PHB concentration was determined quantitatively as crotonic acid by measuring the absorbance at 300 nm. Cell growth was quantified by measuring the density of the culture at 600 nm. The presence of PHB was confirmed by applying high-performance liquid chromatography (HPLC) using an Aminex HPX-87H and implementing gas chromatography analysis. The best yield of PHB synthesis was obtained by using 6% v/v of 5 M H2SO4 treated with carob molasses as a carbon source, with peptone as a nitrogen source; incubation was conducted at 37 degrees C for 96 hat an agitation speed of 300 rpm (114.95 mg/L). The HPLC analysis confirmed the synthesis of PHB by B. paramycoides to have a chromatogram retention time of 22.5 min. Carob waste was successfully valorized to PHB