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IntroductionDuring the COVID-19 lockdown, people's lifestyles have changed including their habits and physical activities. There has been an increase in anabolic hormones and nutritional supplement use among people who regularly do exercise in the MENA region. This study aims to assess knowledge, practice, and attitude toward the use of anabolic hormones and nutritional supplements among people who regularly exercise in the Middle East and North Africa (MENA) region and to compare their exercise habits and hormones and supplements usage between before and during COVID-19 lockdown.MethodsA self-administrated online Google form survey was carried out between February 2021 and April 2021. Five thousand eight hundred forty-five participants who regularly exercise and aged ≥18 years responded to the questionnaire. The questionnaire was distributed through social media platforms and included five sections: demographic, training characters, knowledge, practice, and attitude.ResultsThe participants mean age was 27.4 ± 8.6 years. Males represented 58.2 % of participants. 75.3% of the study participants had not used either hormones or supplements, and about 19% used supplements only. The mean percent score for knowledge, practice, and attitude were 39.3 ± 30.5, 1.1 ± 9.5, and 21.3 ± 23.8, respectively. Level of knowledge was higher among participants who worked in the medical field or as sports coaches. The practice was higher among male participants. The most commonly used anabolic hormones and nutritional supplements were steroids and proteins with bodybuilding being the most common purpose. Internet was the main source of information and pharmacy was the main source for procuring these substances. There was a significant decrease in proteins, carbohydrates, and sports drinks used during the COVID-19 lockdown compared to before the COVID-19 lockdown, while a statistically significant increase in vitamins used during the COVID-19 lockdown compared to before COVID-19 lockdown.DiscussionIn the MENA region, there has been an increase in the use of anabolic hormones and nutritional supplements. Most of the population has low knowledge of the harmful effect of uncontrolled, uninformed and unmonitored use of these substances Therefore, increasing the awareness level of participants and sports coaches should be a priority to limit the unsupervised use of hormones and supplements.

This article concerns the zero-Hopf bifurcation of a quadratic polynomial differential system in $\mathbb {R}^{4}$ . By using the averaging theory of third order, we provide that at most 25 limit cycles can bifurcate from one singularity with eigenvalues of the form ± bi, 0 and 0.

A magnetorheological is a new generation of smart materials in active mechanical vibration and shock control applications. This article is based on a comparative experimental study of the dynamic properties of magnetorheological elastomers (MRE) and magnetorheological fluids (MRF), whose damping and stiffness are controlled simultaneously by applying magnetic field intensity. The dynamic visco-analyser and rheometer were used to test the behaviour of MRE and MRF. The response of both materials depends on the amplitude due to shear strain. The experimental results clearly show the difference between the dynamic properties of MRE and MRF. More specifically, MFRs have high damping with low stiffness; on the other hand, the MRE has average damping with outstanding rigidity. These results help designers achieve more efficient and reliable structures in various engineering fields, such as buildings and mechanical applications.

EFTUD2 is mutated in patients with mandibulofacial dysostosis with microcephaly (MFDM). We generated a mutant mouse line with conditional mutation in Eftud2 and used Wnt1-Cre2 to delete it in neural crest cells. Homozygous deletion of Eftud2 causes brain and craniofacial malformations, affecting the same precursors as in MFDM patients. RNAseq analysis of embryonic heads revealed a significant increase in exon skipping and increased levels of an alternatively spliced Mdm2 transcript lacking exon 3. Exon skipping in Mdm2 was also increased in O9-1 mouse neural crest cells after siRNA knock-down of Eftud2 and in MFDM patient cells. Moreover, we found increased nuclear P53, higher expression of P53-target genes and increased cell death. Finally, overactivation of the P53 pathway in Eftud2 knockdown cells was attenuated by overexpression of non-spliced Mdm2, and craniofacial development was improved when Eftud2-mutant embryos were treated with Pifithrin-α, an inhibitor of P53. Thus, our work indicates that the P53-pathway can be targeted to prevent craniofacial abnormalities and shows a previously unknown role for alternative splicing of Mdm2 in the etiology of MFDM.

An efficient carcinogenic metal biosorbent was prepared by immobilizing microalgae Auxenochlorella protothecoides (AP) within Sugarcane Bagasse (SB) lignocellulosic matrix. The immobilization technique enhanced the biosorption of nickel by 32.25% at equilibrium compared with free Auxenochlorella protothecoides. The maximum metal biosorption capacity of free and immobilized Auxenochlorella protothecoides was calculated to be 42.08 and 62.1 mg /g, respectively. The removal efficiency of nickel ions was evaluated with Box-Behnken factorial design using three parameters: pH solution, contact time, and biosorbent concentration. Under optimum conditions, the RSM- DF platform determined the maximum metal elimination rate of 97.96% with the following optimal set of factors: pH 5.06, biosorbent concentration of 1.6 g/L, and contact time of 53.33 min. In the experimental design of the nickel bioprocess, the equilibrium adsorption isotherms were analyzed using sixteen models of two-, three-, and four –parameters. An evaluation of non-linear regression isotherms for choosing the goodness predicted fit elucidated that Fritz–Schlünder (IV) model was the more suitable model to present the equilibrium curves, identified based on the values of four error functions were as follow: the coefficient of determination (R²), the hybrid fractional error function (HYBRID), marquardt's percent standard deviation (MPSD), and the average relative error (ARE). The thermodynamic factors followed by the kinetics analyze demonstrated that the bioprocess was exothermic, favorable, and spontaneous at 298–318 K. Further, the biosorption of nickel ions towards the functional sites on the SB-AP was clarified by the proposal of four mechanisms on the network structure for cellulose, lignin, N-acetyl- β -d-glucosamine, and β-D-glucosamine unite. Finally, the functional groups, surface morphology, elemental compositions was analyzed using FTIR, SEM-EDX and ATG-DTG, respectively confirmed its ability to successfully treating the contaminants.

A numerical study of the natural convection of laminar heat transfers in the stationary state in a half-elliptic inclined cavity, which represents a continuation of the work done, we studied the influence of the tilt of the cavity by varying the angle — entered 0 degrees, which corresponds to the horizontal cavity, up to 15 degrees. For each value of δ we varied the Rayleigh number from 2.13 103 to 106. The system of equations governing the problem solved numerically by the fluent calculation code based on the finite volume method. Based on the Boussinesq approximation. Both bottom and upper walls maintained at a constant temperature. The interest of this study is to see the influence of the tilt of the half-elliptic cavity on the structure of the flow and the distribution of temperature. These results can exploited in semi-elliptic agricultural greenhouses that rest on sloping soils. We chose a Prandtl number 0.71 that corresponds to the air. Keywords: Heat transfer; half-elliptical; Natural convection; Laminar flow; Multicellular; CFD simulation

This paper deals with numerical investigation of a natural convective flow in a horizontal annular space between a heated square inner cylinder and a cold elliptical outer cylinder with a Newtonian fluid. Uniform temperatures are imposed along walls of the enclosure. The governing equations of the problem were solved numerically by the commercial code Fluent, based on the finite volume method and the Boussinesq approximation. The effects of Geometry Ratio GR and Rayleigh numbers on fluid flow and heat transfer performance are investigated. The Rayleigh number is varied from 103 to 106. Throughout the study the relevant results are presented in terms of isotherms, and streamlines. From the results, we found that the increase in the Geometry Ratio B leads to an increase of the heat transfer coefficient. The heat transfer rate in the annulus is translated in terms of the average Nusselt numbers along the enclosure’s sides. Tecplot 7 program was used to plot the curves which cleared these relations and isotherms and streamlines which illustrate the behavior of air through the channel and its variation with other parameters. The results for the streamlines, isotherms, local and average Nusselt numbers average Nusselt numbers are compared with previous works and show good agreement.

The present study evaluated the antioxidant and antibacterial activities of six aromatic plants, indigenous to the flora of the Algerian. The plants studied were Thymus vulgaris, Artemisia absinthium, scorzonena undulata, Malva Parviflora, Marrubium vulgare and Cotula cinerea. Extracts of these plants were analyzed for their total phenol compounds and antioxidant activity. The antimicrobial screening of the extracts was evaluated by agar disc diffusion method, the liquid broth microdilution was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Essential oil of A. absinthium possesses highest antioxidant activity among all extracts tested and phenolic extract of T. Vulgaris highest of DPPH radical. Among the plants screened, essential oil of A. absinthium and T. Vulgaris phenolic extract showed the best antibacterial activity. The mineral contents were determined by an atomic absorption spectrophotometer. Ca, K, Na, Mg, Fe and Cu were found to be the most abundant elements among the plants studied.

The species belonging to the genus Medicago are considered a very important genetic resource at global level both for planet’s food security and for sustainable rangelands management. The checklist of the Italian flora (2021) includes a total number of 40 Medicago species for Italy, and 27 for Campania region, with a number of doubtful records or related to species no more found in the wild. In this study, 10 Medicago species native to Campania region, and one archaeophyte (M. sativa), identified by means of morphological diagnostic characters, were analyzed in a blind test to assay the efficacy of nine microsatellite markers (five cp-SSRs and four n-SSRs). A total number of 33 individuals from 6 locations were sampled and genotyped. All markers were polymorphic, 40 alleles were obtained with n-SSRs ranging from 8–12 alleles per locus with an average of 10 alleles per marker, PIC values ranged from 0.672 to 0.847, and the most polymorphic SSR was MTIC 564. The cp-SSRs markers were highly polymorphic too; PIC values ranged from 0.644 to 0.891 with an average of 0.776, the most polymorphic cp-SSR was CCMP10. 56 alleles were obtained with cp-SSRs ranging from 7 to 17 alleles per locus with an average of 11. AMOVA analysis with n-SSR markers highlighted a great level of genetic differentiation among the 11 species, with a statistically significant fixation index (FST). UPGMA clustering and Bayesian-based population structure analysis assigned these 11 species to two main clusters, but the distribution of species within clusters was not the same for the two analyses. In conclusion, our results demonstrated that the combination of the used SSRs well distinguished the 11 Medicago species. Moreover, our results demonstrated that the use of a limited number of SSRs might be considered for further genetic studies on other Medicago species.

In the last decade, with the arrival of the 5G communication technology and the increasing numbers of vehicles being connected to the internet, conventional vehicle ad-hoc networks (VANETs) are evolving towards the internet of vehicles (IoV), which makes the co-existence of IEEE 802.11p and 5G-based technologies very important for the design of a heterogeneous IoV system that takes advantage of both. The IEEE 802.11p standard is still the best candidate to support direct communications for safety critical services. In fact, both the ETSI ITS-G5 and the IEEE 1609 standard families adopt the IEEE 802.11p standard as a medium access control (MAC) mechanism, and they require vehicles to exchange periodic awareness messages to avoid dangerous situations. When the density of vehicles increases, the MAC layer will suffer from radio channel congestion problems, and this may affect the various VANET applications, especially safety applications. Therefore, the decentralized congestion control (DCC) mechanism has been specified by ETSI to mitigate the channel congestion; this was achieved by adapting the transmission parameters, such as the transmit power and data-rate. However, many research studies have demonstrated limitations and a low performance of DCC, especially when the channel load is extremely high. To deal with this, in this paper, we investigate a new promising technique, called the transmission timing control (TTC), to control the channel load for periodic cooperative awareness. It consists of spreading the transmissions over time in order to avoid contention on the transmission channel. The objective of the paper is to propose an analytical study to calculate the probability of successful transmission using TTC. The demonstrated results show the efficiency of our timing control-enabled scheme to deal with the channel load on top of different conditions.

BackgroundThe Algerian COVID-19 vaccination campaign, which started at the end of January 2021, is marked by a slowly ascending curve despite the deployed resources. To tackle the issue, we assessed the levels and explored determinants of engagement toward the COVID-19 vaccine among the Algerian population.MethodsA nationwide, online-based cross-sectional study was conducted between March 27 and April 30, 2021. A two-stage stratified snowball sampling method was used to include an equivalent number of participants from the four cardinal regions of the country. A vaccine engagement scale was developed, defining vaccine engagement as a multidimensional parameter (5 items) that combined self-stated acceptance and willingness with perceived safety and efficacy of the vaccine. An Engagement score was calculated and the median was used to define engagement vs. non-engagement. Sociodemographic and clinical data, perceptions about COVID-19, and levels of adherence to preventive measures were analyzed as predictors for non-engagement.ResultsWe included 1,019 participants, 54% were female and 64% were aged 18–29 years. Overall, there were low rates of self-declared acceptance (26%) and willingness (21%) to take the vaccine, as well as low levels of agreement regarding vaccine safety (21%) and efficacy (30%). Thus, the vaccine engagement rate was estimated at 33.5%, and ranged between 29.6-38.5% depending on the region (p > 0.05). Non-engagement was independently associated with female gender (OR = 2.31, p < 0.001), low adherence level to preventive measures (OR = 6.93, p < 0.001), private-sector jobs (OR = 0.53, p = 0.038), perceived COVID-19 severity (OR = 0.66, p = 0.014), and fear from contracting the disease (OR = 0.56, p = 0.018). Concern about vaccine side effects (72.0%) and exigence for more efficacy and safety studies (48.3%) were the most commonly reported barrier and enabler for vaccine acceptance respectively; whereas beliefs in the conspiracy theory were reported by 23.4%.ConclusionsThe very low rates of vaccine engagement among the Algerian population probably explain the slow ascension of the vaccination curve in the country. Vaccine awareness campaigns should be implemented to address the multiple misconceptions and enhance the levels of knowledge and perception both about the disease and the vaccine, by prioritizing target populations and engaging both healthcare workers and the general population.

The use of crushed limestone sand in the concrete industry will be quite possible and imperative for environmental reasons. Many researchers around the world have found that concrete based on 50% substitution of river sand by limestone sand gives better physico-mechanical characteristics. The main objective of this investigation is to search for an optimal percentage of silica-limestone fines resulting from the substitution of half in quantity of alluvial sand by crushed limestone sand in ordinary concrete. The proportions of fines that were tested in this work are 6%, 8%, 10%, 12% and 14%. The obtained results revealed that concrete based on silica-limestone sand and containing 14% of the same type of fines strongly improves the different mechanical strengths and participates in the reduction of 10% and 13%, of the coefficient of capillary absorption and of the porosity accessible to water, respectively, compared to the control concrete. In addition, good statistical relationships between the studied parameters were also found

The interest of using combined sand of equal percentage of silica and limestone becomes evident in the formulation of compacted concrete in several previous works around the world, due to the formidable percentage of fines that improves the compactness and increases various mechanical resistances, which produces a more durable construction against different probable aggressions. This paper examines the effect of using this type of sand on workability, compressive strength, flexural strength, and splitting tensile strength. A durability test was consulted using infrared spectroscopy to assess diverse types of hydration products formed. Found results clearly show the advantages of using sand with silica and limestone grains (50/50)% in ordinary concrete infected by aggressive water. There is also an improvement in compactness, different mechanical resistances, and a reduction in the formation of harmful hydration products.

Antigen-specific T cell expansion

To obtain correctly, design of the structures under seismic loads, the methods of equivalent static and dynamic analyses are usually used. The assessment of the response of entire system soil-structure under seismic load is a fundamental step to anticipate losses and help to mitigate it. Some methods of the design of retaining walls under seismic loads require the knowledge of the maximum acceleration of seismic signal. The present work discusses these methods and a comparison with detailed analysis. Three confgurations of a retaining wall at diferent heights were considered under seismic loading: 10 signals from the 2003 Boumerdes earthquake and the 1999 Ain-Témouchent earthquake (in Algeria). Then it was assessed the dynamic thrust forces given by the approximate methods for maximum acceleration of the considered earthquakes. The approximate methods used are the pseudo-static method, the method of Seed and Whitman, the approach given in the Algerian seismic code RPA99 and the Mononobe–Okabe method. The results show that the integration of time history of seismic loading to evaluate the dynamic active earth pressure behind retaining walls is very important and can transmit higher values than the seismic force calculated by the simplifed methods. This demonstrates that an earthquake cannot be considered only by its maximum acceleration and to properly design the retaining structures, the developed energy during an earthquake must be taken into account. published