476 research outputs found

    Enhancing Authentication in Online Distant Exams: A Proposed Method Utilizing Face and Voice Recognition

    Get PDF
    Due to COVID-19 pandemic, face-to-face teaching has been replaced by online education to reduce the risks of spreading the Coronavirus. Online examination is an important asset in the context of online learning to assess students, but observing students during testing and ensuring that they do not engage in misbehavior remains a major issue. Human observation is one of the most common methods when conducting an exam to ensure that students do not perform any unexpected behaviors, by entering the student in a laboratory or hall at the university and observing him throughout the exam period visually and soundly. However, this method is costly and labor-intensive. In this paper, a system is created that monitors students during an online test automatically based on face recognition and voice recognition using a machine learning algorithm. The camera on the students computer will be used to track the students facial movements, pupils, and lip movements, monitoring the students behavior throughout the test, and stopping any unexpected behavior. In this system, there are two parts: facial recognition and unexpected behavior detection. The face was recognized with an accuracy of 98.3%, and unexpected behavior was detected with an accuracy of 97.6%. There is also an opportunity to increase accuracy by improving the quality of the images in the dataset

    A Case of Pure Matrix Ureteral Stone: A rare type of urinary calculi that may be overlooked

    Get PDF
    Matrix stones are a rare form of urinary calculi with a low mineral content. We report a 63-year-old female patient who presented to the Sohar Hospital, Sohar, Oman, in 2018 with unexplained left flank pain and constipation. She had a history of chronic renal failure (CRF) and had previously undergone haemodialysis (HD). Non-contrast computed tomography (CT) did not show any renal or urinary stones. However, a left-sided ureteroscopy revealed a yellow-coloured stone that was soft in consistency occupying the proximal 5 cm section of the ureter. Many attempts at forceps extraction were required for complete clearance. A global quantitative composition analysis revealed the extracted stone to be composed entirely of protein-matrix material. Matrix stones require a high index of suspicion as they are sometimes radiolucent and cannot be visualised on CT scans. Risk factors include being female and a history of urinary tract infections, CRF and HD.Keywords: Urolithiasis; Ureteral Calculi; Diagnostic Imaging; Ureteroscopy; Case Report; Oman

    Phylogenetic characterization of two echinoid species of the southeastern Mediterranean, off Egypt

    Get PDF
    AbstractIn this study we investigated the phylogenetics of two sea urchin species, Arbacia lixula and Paracentrotus lividus from the Mediterranean Sea. Specimens were collected from the east coast of Alexandria City, Egypt. Pigmentation examination showed four sympatric color morphotypes (black, purple, reddish brown, and olive green). Mitochondrial DNA was extracted from specimens and mitochondrial cytochrome oxidase subunit I (COI) and 16S ribosomal RNA (16S) were sequenced. The results showed that all black specimens constituted the species A. lixula. All other colors belonged to P. lividus, with no apparent differentiation between color morphotypes. Moreover, P. lividus showed high haplotype diversity (COI; H=0.9500 and 16S; H=0.8580) and low values of nucleotide diversity (COI; π=0.0075 and 16S; π=0.0049), indicating a high degree of polymorphism within this species. This study represents the first attempt at DNA barcoding of echinoid species in the southeast Mediterranean off the Egyptian coast, and will provide a base for future phylogenetic analyses

    Multi-parametric arterial spin labelling and diffusion-weighted magnetic resonance imaging in differentiation of grade II and grade III gliomas

    Get PDF
    Purpose: To assess arterial spin labelling (ASL) perfusion and diffusion MR imaging (DWI) in the differentiation of grade II from grade III gliomas. Material and methods: A prospective cohort study was done on 36 patients (20 male and 16 female) with diffuse gliomas, who underwent ASL and DWI. Diffuse gliomas were classified into grade II and grade III. Calculation of tumoural blood flow (TBF) and apparent diffusion coefficient (ADC) of the tumoral and peritumoural regions was made. The ROC curve was drawn to differentiate grade II from grade III gliomas. Results: There was a significant difference in TBF of tumoural and peritumoural regions of grade II and III gliomas (p = 0.02 and p =0.001, respectively). Selection of 26.1 and 14.8 ml/100 g/min as the cut-off for TBF of tumoural and peritumoural regions differentiated between both groups with area under curve (AUC) of 0.69 and 0.957, and accuracy of 77.8% and 88.9%, respectively. There was small but significant difference in the ADC of tumoural and peritumoural regions between grade II and III gliomas (p = 0.02 for both). The selection of 1.06 and 1.36 × 10-3 mm2/s as the cut-off of ADC of tumoural and peritumoural regions was made, to differentiate grade II from III with AUC of 0.701 and 0.748, and accuracy of 80.6% and 80.6%, respectively. Combined TBF and ADC of tumoural regions revealed an AUC of 0.808 and accuracy of 72.7%. Combined TBF and ADC for peritumoural regions revealed an AUC of 0.96 and accuracy of 94.4%. Conclusion: TBF and ADC of tumoural and peritumoural regions are accurate non-invasive methods of differentiation of grade II from grade III gliomas

    Chemical Profiling of Significant Antioxidant and Phytotoxic Microwave-Extracted Essential Oil from Araucaria heterophylla Resin

    Get PDF
    Due to the various hazards of using synthetic chemical compounds in pharmaceutics, agriculture, and industry, scientists and researchers do their best to explore and assess new green natural compounds from natural resources with potent activity. The essential oil (EO) from the resin collected from Araucaria heterophylla Salisb. was extracted by the microwave technique and chemically characterized via GC-MS analysis. Furthermore, the extract EO was assessed for its antioxidant and phytotoxic activities. The EO has 33 compounds, mainly terpenes (98.23%), and the major compounds were α-pinene (62.57%), β-pinene (6.60%), germacrene D (5.88%), and β-caryophyllene (3.56%). The extracted EO showed substantial antioxidant activity, where it showed IC50 values of 142.42 and 118.03 mg L−1 for DPPH and ABTS, respectively. On the other hand, the EO revealed considerable phytotoxicity against the weed Chenopodium murale, where the EO showed IC50 values of 304.0, 230.1, and 147.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. Moreover, the EO showed the same pattern of allelopathic inhibition against the weed Sonchus oleraceus, where it showed IC50 values of 295.7, 224.5, and 106.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. The present study showed that the extraction technique affects the constituents of the EO, particularly the quantitative composition. The EO of A. heterophylla resin also revealed considerable antioxidant and phytotoxic activity against weeds. Therefore, it can be considered a promising natural resource that could be integrated into the weed management approach. However, further study is recommended for deep characterization of their authentic compounds and evaluation of their mode of action(s) on a wide spectrum of weeds

    Terretonin N: A New Meroterpenoid from Nocardiopsis sp.

    Get PDF
    Hamed A, Abdel-Razek AS, Frese M, et al. Terretonin N: A New Meroterpenoid from Nocardiopsis sp. Molecules. 2018;23(2): 299.Terretonin N (1), a new highly oxygenated and unique tetracyclic 6-hydroxymeroterpenoid, was isolated together with seven known compounds from the ethyl acetate extract of a solid-state fermented culture of Nocardiopsis sp. Their structures were elucidated by spectroscopic analysis. The structure and absolute configuration of 1 were unambiguously determined by X-ray crystallography. The isolation and taxonomic characterization of Nocardiopsis sp. is reported. The antimicrobial activity and cytotoxicity of the strain extract and compound 1 were studied using different microorganisms and a cervix carcinoma cell line, respectively

    Bacterial Diseases Affecting the Cultured Sepia Officinalis Leading to Increase Mortality Rates in The Laboratory

    Get PDF
    The early growth, mortality rates and bacterial infections of the cultured Sepia Officinalis were experimentally studied in the laboratory. Two hundred eighty-five sepia larvae were hatched and placed in a 100-liter capacity rectangular glass aquarium (filled with seawater) in the laboratory. The Sepia individuals (285 individuals) were divided into two groups the first fed on a mixture of amphipods, rotifers and artemia and the second group fed only on amphipods to follow their growth and mortality. The second group was observed to grow faster with length 6.76 ± 0.06mm and weight 0.11 ± 0.01gm than the first one. The survival rate was 100% by the end of the first week and decreased gradually by the end of the second week. The recorded mortality rate reached 49% by the day 15th, where they infected with bacterial disease of Vibrio alginolyticus. The clinical signs of the diseased S. Officinalis were lethargic condition, food fasting and multiple skin ulcers with white-gray discoloration were observed and appeared on the body. The main postmortem lesions were congestion of the internal organ, beside the presence of ascetic fluid. The mortality among the diseased Sepia was increased by age; however, it may cause death of most individuals by increasing time more than two weeks. The findings of antibiotic sensitivity test cleared that the isolated V. alginolyticus was sensitive to amoxiclav (amoxicillin-clavulanate), streptomycin, ciprofloxacin and chloramphenicol. Controversially, it was resistant to oxytetracycline, tobramycin, gentamycin and enrofloxacin

    Bacterial Diseases Affecting the Cultured Sepia Officinalis Leading to Increase Mortality Rates in The Laboratory

    Get PDF
    The early growth, mortality rates and bacterial infections of the cultured Sepia Officinalis were experimentally studied in the laboratory. Two hundred eighty five sepia larvae were hatched and placed in a 100 liter capacity rectangular glass aquarium (filled with seawater) in the laboratory. The Sepia individuals (285 individuals) were divided into two groups the first fed on a mixture of amphipods, rotifers and artemia and the second group fed only on amphipods to follow their growth and mortality. The second group was observed to grow faster with length 6.76 ± 0.06mm and weight 0.11 ± 0.01gm than the first one. The survival rate was 100% by the end of the first week and decreased gradually by the end of thesecond week. The recorded mortality rate reached 49% by the day 15th, where they infected with bacterial disease of Vibrio alginolyticus. The clinical signs of the diseased S. Officinalis were lethargic condition, food fasting and multiple skin ulcers with white-gray discoloration were observed and appeared on the body. The main post mortem lesions were congestion of the internal organ, beside the presence of ascetic fluid. The mortality among the diseased Sepia was increased by age; however it may causes death of most individuals by increasing time more than two weeks. The findings of antibiotic sensitivity test cleared that the isolated V. alginolyticus was sensitive to amoxiclav (amoxicillin-clavulanate), streptomycin, ciprofloxacin and chlormphinicol. Controversially, it was resistant to oxytetracycline, tobramycin, gentamycine and enrofloxacin.Keywords: Sepia Officinalis - growth rate - mortality rate - bacterial infection

    Impact of Folic Acid in Modulating Antioxidant Activity, Osmoprotectants, Anatomical Responses, and Photosynthetic Efficiency of Plectranthus amboinicus Under Salinity Conditions

    Get PDF
    Salinity is a major threat to the sustainability of agricultural production systems. Salt stress has unfavorable implications on various plant physio-morphological and biochemical reactions, causing osmotic and ionic stress. Exogenously applied folic acid (FA) may at least provide one mechanism to evade the injurious stress effects of saline irrigation water on Plectranthus amboinicus. In this regard, two pot trials were performed during the 2018–2019 and 2019–2020 seasons in an open greenhouse of an experimental farm (29°17'N; 30°53'E) in Fayoum, Egypt. We tested four levels of saline irrigation water (SW): 34, 68, and 102 mM NaCl, plus tap water as the control = 0), combined with FA at three concentrations (25 and 50 μM, plus spray with distilled water as the control = 0). The growth parameters, biochemistry, physiology, elemental leaf status, essential oil content, and anatomical responses were assessed. Salt markedly reduced photosynthetic productivity [Fv/Fm and performance index (PI)], total chlorophyll [soil plant analysis development (SPAD)], and leaf osmoprotectant compounds, i.e., total soluble sugars (TSS), free amino acids, proline, and total phenolics, thus hampering P. amboinicus growth and essential oil yield. However, the addition of FA as a foliar spray to P. amboinicus irrigated with saline water induced increases in Fv/Fm, SPAD, and PI. These were linked with enriched stem anatomical structures, leaf osmoprotectant compounds, and enhanced leaf enzymatic activity, e.g., superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, glutathione, ascorbic acid, and antioxidant content. Under salt stress, supplementation of 25 and 50 μM FA increased the growth and production of essential oil by 27.8 and 55.6%, respectively, compared with no applied FA. The highest growth characteristics and elemental leaf contents were obtained when P. amboinicus was irrigated with 0 mM saline water and treated foliarly with 50 μM of FA compared with non-treated plants. Overall, these data showed that foliar spraying with FA reduces the impact of salt stress on P. amboinicus irrigated with saline water
    corecore