Despite efforts to contain and manage the SARS-CoV-2 outbreak which was declared a public health emergency of international concern in January 2020 by the World Health Organization (WHO), the COVID-19 pandemic still remains a major global challenge. Patients who display the classical symptoms of the infection are easily identified, tested, isolated and monitored. However, many cases of infected asymptomatic patients have been documented. These patients are not easily identified even though many evidences suggest that they can spread the virus to others. How and why these COVID-19 asymptomatic presentations occur remain unclear. The many theories and views are conjectural, and supporting evidences are still needed. In this review, we described the trend in SARS-CoV-2 viral shedding and susceptibility, providing perspectives on gender differences and asymptomatic patients. We further discussed how genetics, gender, viral inoculum, and pre-existing immunity may influence asymptomatic presentations in COVID-19 infections. We hope that this article improves our understanding of asymptomatic SAR-CoV-2 infection and it sheds light on some salient areas that should be considered as the search for a potent vaccine continues.
Computer systems and networks are increasingly used for many types of applications; as a result the security threats to computers and networks have also increased significantly. Traditionally, password user authentication is widely used to authenticate legitimate user, but this method has many loopholes such as password sharing, brute force attack, dictionary attack and more. The aim of this paper is to improve the password authentication method using Probabilistic Neural Networks (PNNs) with three types of distance include Euclidean Distance, Manhattan Distance and Euclidean Squared Distance and four features of keystroke dynamics including Dwell Time (DT), Flight Time (FT), mixture of (DT) and (FT), and finally Up-Up Time (UUT). The resul
... Show MoreHydrocarbon displacement at the pore scale is mainly controlled by the wetness properties of the porous media. Consequently, several techniques including nanofluid flooding were implemented to manipulate the wetting behavior of the pore space in oil reservoirs. This study thus focuses on monitoring the displacement of oil from artificial glass porous media, as a representative for sandstone reservoirs, before and after nanofluid flooding. Experiments were conducted at various temperatures (25 – 50° C), nanoparticles concentrations (0.001 – 0.05 wt% SiO2 NPs), salinity (0.1 – 2 wt% NaCl), and flooding time. Images were taken via a high-resolution microscopic camera and analyzed to investigate the displacement of the oil
... Show MoreIn this Paper, we proposed two new predictor corrector methods for solving Kepler's equation in hyperbolic case using quadrature formula which plays an important and significant rule in the evaluation of the integrals. The two procedures are developed that, in two or three iterations, solve the hyperbolic orbit equation in a very efficient manner, and to an accuracy that proves to be always better than 10-15. The solution is examined with and with grid size , using the first guesses hyperbolic eccentric anomaly is and , where is the eccentricity and is the hyperbolic mean anomaly.
The research include a pulsed Nd: YAG Laser with (300µs) pulse duration in the TEM00 mode at (1.06µm) wavelength for energies between (0.5-3) J was employed to drill Brass material which is use in industrial applications. The process of drill was assisted by an electric field. This resulted in an increase in the hole aspect ratio by the value (45%) and decrease in the hole taper by the value (25%) of its value under ordinary drilling conditions using the same input energy.
The National Charter for Education and Training in 1999 defined the principles, pillars and main objectives of the Moroccan education system, building on the various reforms of the early twenty-first century and the attempt to breathe new life into this reference document. Through partial and incremental changes, a total inability to tackle the root causes of the Moroccan education system and training has been revealed. This research has been conducted to answer the questions of education in the foreground national concerns and priorities in the discourse of the main political actors in Morocco that have been raised and remain interesting and can be expressed in the following question: Morocco still fails to meet the challenge of educati
... Show MoreBackground: The Covid-19 pandemic changed the world; its most important achievement for education was changing the approach from traditional to virtual education. The present study aimed to investigate the role of virtual education networks on mental health of students including personality, beliefs, scientific, and cultural dimensions, in selected countries.Methods: This was an exploratory and applied study. According to the phenomenology strategy, theoretical saturation occurred after 24 semi-structured and targeted qualitative interviews with teachers from Iran, Iraq, Syria and Lebanon, in 2023. Quantitative data was collected through a researcher-made online questionnaire with 423 participants. Teachers with at least a Bachelor’s degr
... Show MoreThe present study aimed to investigate effect of Pregabalin (PGB) on ovary tissue and number of follicles in female albino rats. Three groups of healthy adult female albino rats, fifteen rats in each group were used in current study. The rats of groups, G2 and G3 were administered orally with two doses 150 mg and 300mg/kg b.wt/day of pregabalin, respectively. The doses were given daily for 1 month, 2 months, and 3 months. Animals of group G1 (Control) were given saline alone. After the experimental periods, the rats were sacrificed and the isolated ovaries were histologically examined. The results of histological analysis of the ovaries in treated rats (G2, and G3) showed a significant (P≤0.05) decrease in the number of preantral, antral,
... Show MoreBac kground:: Septal deviation is one of the commonest anatomical deformities of the nasal skeleton, this deviation is usually accompanied by compensatory hypertrophy of the inferior turbinate on the concave side that will accentuate the severity of nasal obstruction.
Objectives: To evaluate the effect of septoplasty on the size of the inferior turbinate in patients with nasal septum deviation.
Methods: This is a prospective study of 25 patients attending the otolaryngological department at Al-Jirahat teaching hospital from September 2011 to November 2013, complaining mainly of nasal obstruction. Otolaryngological examination had shown nasal septum deviation. The cross sectional areas of inferior turbinates were measured with compu