29 research outputs found

    Development of a Survey to Assess Conceptual Understanding of Quantum Mechanics among Moroccan Undergraduates

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    We developed a Quantum Mechanics Conceptual Understanding Survey (QMCUS) in this study. The survey was conducted using a quantitative methodology. A multiple-choice survey of 35 questions was administered to 338 undergraduate students. Three experienced quantum mechanics instructors examined the validity of the survey. The reliability of our survey was measured using Cronbach's alpha, the Fergusson delta index, the discrimination index, and the point biserial correlation coefficient. These indices showed that the developed survey is reliable. The statistical analysis of the students' results using SPSS shows that the scores obtained by the students have a normal distribution, around the score of 7.14. The results of the t-test show that the students' scores are below the required threshold, which means that it is still difficult for the students to understand the concepts of quantum mechanics. The obtained results allow us to draw some conclusions. The students' difficulties in understanding the quantum concepts are due to the nature of these concepts; they are abstract and counterintuitive. In addition, the learners did not have frequent contact with the subatomic world, which led them to adopt misconceptions. Moreover, students find it difficult to imagine and conceptualize quantum concepts. Therefore, subatomic phenomena are still explained with classical paradigms. Another difficulty is the lack of prerequisites and the difficulties in using the mathematical formalism and its translation into Dirac notation

    Osteochondroma of the First Phalanx in Tbourida Horses

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    This study aimed at describing anatomo-histopathological and imaging features, using computed tomography and magnetic resonance imaging on six ex vivo forelimbs of Tbourida horses, that presented a particular bone exostosis on the dorsal and proximal part of the first phalanx, diagnosed by X-ray. Gross anatomy of the bone exostosis revealed an irregular surface with poly-lobulated tissue masses showing a cauliflower shape. The diameter/depth varied from 0.5 to 5.1 cm with a mean of 3.9 ± 0.9 cm. The capsule of the metacarpophalangeal joint was hypertrophic and showed many invaginations in the inner part, in contact with the bone exostosis. Computed tomography revealed cortical and medullary continuity of the bone exostosis, with the underlying bone, and remodeling of the cortical surface of the dorsal and proximal part of the first phalanx. Magnetic resonance imaging showed an increased signal intensity of the bone exostosis on the T1- and T2*-weighted gradient fast echo. Histological examination of the bone exostosis revealed a cap of hyaline cartilage, including large foci of endochondral ossification with a base of cancellous bone surrounding marrow spaces, which confirmed the diagnosis of osteochondroma. The capsule of the metacarpophalangeal joint showed a large amount of recently formed connective tissue fibers in its inner part, interspersed with mature connective tissue. The hyperextension of the metacarpophalangeal joint during a Tbourida show, which occurs on a hard ground surface, and the use of hobbles in horse stabling are most likely responsible for the outgrowth of an osteochondroma of different shapes and sizes, and fracture complications in some cases

    p(x)-Kirchhoff-type problem with no-flux boundary conditions and convection

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    This article establishes the existence of a weak solution for a class of p(x)p\left(x)-Kirchhoff-type problem under no-flux boundary conditions with a reaction term depending also on the gradient convection. The proof of the main result is constructed by utilizing the theory of topological degree and the theory of generalized Sobolev spaces

    Antibacterial Evaluation and Phytochemical Screening of eucalyptus gomphocephala DC against Pseudomonas aeruginosa

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      Objective: The aim was to evaluate the in vitro antibacterial activities of essential oil and extracts from Eucalyptus gomphocephala leaf on the growth of six strains of Pseudomonas aeruginosa. Methods: Aqueous, ethanol, hexane, petroleum ether extracts and essential oil of E. gomphocephala leaf were investigated on six strains of P. aeruginosa. The antibacterial activity was determined by agar-well diffusion method and expressed as the average diameter of the zone of inhibition of bacterial growth around the wells. The minimum inhibitory concentration (MIC) of active extracts was determined by microdilution assay. The preliminary phytochemical screening of the leaf was conducted using various standard methods.Results: The present study reveals that the essential oil does not show any activity against all strains. Extracts showed varying degrees of inhibition on the tested microorganisms. The petroleum ether and ethanol had a lower activity against strains. However, aqueous and hexane leaf extracts, of E. gomphocephala presented the highest anti P. aeruginosa activity against all strains tested. The MIC and minimum bactericidal concentration of the aqueous and hexane extracts ranged between 6.25 and 50 mg/ml. Qualitative analysis of E. gomphocephala revealed the presence of biological active compounds such as tannins, flavonoids, saponins and steroids/triterpenes.Conclusion: To conclude, extracts of E. gomphocephala leaf may be pursued as an antibacterial agent for the treatment of infections caused by P. aeruginosa. Keywords: Eucalyptus gomphocephala, Extracts, Antibacterial activity, Pseudomonas aeruginosa, Phytochemical screenin

    Proteomic Landscape and Deduced Functions of the Cardiac 14-3-3 Protein Interactome

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    Rationale: The 14-3-3 protein family is known to interact with many proteins in non-cardiac cell types to regulate multiple signaling pathways, particularly those relating to energy and protein homeostasis; and the 14-3-3 network is a therapeutic target of critical metabolic and proteostatic signaling in cancer and neurological diseases. Although the heart is critically sensitive to nutrient and energy alterations, and multiple signaling pathways coordinate to maintain the cardiac cell homeostasis, neither the structure of cardiac 14-3-3 protein interactome, nor potential functional roles of 14-3-3 protein–protein interactions (PPIs) in heart has been explored. Objective: To establish the comprehensive landscape and characterize the functional role of cardiac 14-3-3 PPIs. Methods and Results: We evaluated both RNA expression and protein abundance of 14-3-3 isoforms in mouse heart, followed by co-immunoprecipitation of 14-3-3 proteins and mass spectrometry in left ventricle. We identified 52 proteins comprising the cardiac 14-3-3 interactome. Multiple bioinformatic analyses indicated that more than half of the proteins bound to 14-3-3 are related to mitochondria; and the deduced functions of the mitochondrial 14-3-3 network are to regulate cardiac ATP production via interactions with mitochondrial inner membrane proteins, especially those in mitochondrial complex I. Binding to ribosomal proteins, 14-3-3 proteins likely coordinate protein synthesis and protein quality control. Localizations of 14-3-3 proteins to mitochondria and ribosome were validated via immunofluorescence assays. The deduced function of cardiac 14-3-3 PPIs is to regulate cardiac metabolic homeostasis and proteostasis. Conclusions: Thus, the cardiac 14-3-3 interactome may be a potential therapeutic target in cardiovascular metabolic and proteostatic disease states, as it already is in cancer therapy

    Reprogramming of cardiac phosphoproteome, proteome, and transcriptome confers resilience to chronic adenylyl cyclase-driven stress

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    Our prior study (Tarasov et al., 2022) discovered that numerous adaptive mechanisms emerge in response to cardiac-specific overexpression of adenylyl cyclase type 8 (TGAC8) which included overexpression of a large number of proteins. Here, we conducted an unbiased phosphoproteomics analysis in order to determine the role of altered protein phosphorylation in the adaptive heart performance and protection profile of adult TGAC8 left ventricle (LV) at 3–4 months of age, and integrated the phosphoproteome with transcriptome and proteome. Based on differentially regulated phosphoproteins by genotype, numerous stress-response pathways within reprogrammed TGAC8 LV, including PKA, PI3K, and AMPK signaling pathways, predicted upstream regulators (e.g. PDPK1, PAK1, and PTK2B), and downstream functions (e.g. cell viability, protein quality control), and metabolism were enriched. In addition to PKA, numerous other kinases and phosphatases were hyper-phosphorylated in TGAC8 vs. WT. Hyper-phosphorylated transcriptional factors in TGAC8 were associated with increased mRNA transcription, immune responses, and metabolic pathways. Combination of the phosphoproteome with its proteome and with the previously published TGAC8 transcriptome enabled the elucidation of cardiac performance and adaptive protection profiles coordinately regulated at post-translational modification (PTM) (phosphorylation), translational, and transcriptional levels. Many stress-response signaling pathways, i.e., PI3K/AKT, ERK/MAPK, and ubiquitin labeling, were consistently enriched and activated in the TGAC8 LV at transcriptional, translational, and PTM levels. Thus, reprogramming of the cardiac phosphoproteome, proteome, and transcriptome confers resilience to chronic adenylyl cyclase-driven stress. We identified numerous pathways/function predictions via gene sets, phosphopeptides, and phosphoproteins, which may point to potential novel therapeutic targets to enhance heart adaptivity, maintaining heart performance while avoiding cardiac dysfunction
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