Étude numérique de l'effet de la portance inverse pour un fluide de Bingham autour d'un obstacle

Ce travail porte sur la simulation numérique d'un écoulement de fluide non-Newtonien (Bingham) autour d'un obstacle en forme de profil hydrodynamique. La méthode des volumes finis avec un maillage orthogonale généralisée est utilisée. Les résultats du calcul montrent une portance inverse pour l'écoulement du fluide de Bingham en régime laminaire. Ceci est en accord avec des résultats expérimentaux concernant la portance inverse obtenus par B. Dollet et al. (Physical Review Letters, 2005) pour une solution mousseuse

Utilizing genotyping-by-sequencing to elucidate Neotropical army ant evolution

The articulation of science and humanism has been from the outset one of the keystones of our programmatic initiative on person centered medicine. This involves the notion that the scientific method is what gives science its foundations and at the same time represents one of the principal strategies and tools to understand, formulate and intervene in crucial and paramount human concerns and activities such as health. A scientific approach to health and health care, from the perspective of person centered medicine, involves not only attending to organs and diseases (preferential topics in much of contemporary medicine), but more broadly to the whole field of human health, including ill health and positive health, within which organs and diseases are inscribed. (aut.ref.

Anthropometry for WorldSID A World-Harmonized Midsize Male Side Impact Crash Dummy

The WorldSID project is a global effort to design a new generation side impact crash test dummy under the direction of the International Organization for Standardization (ISO). The first WorldSID crash dummy will represent a world-harmonized mid-size adult male. This paper discusses the research and rationale undertaken to define the anthropometry of a world standard midsize male in the typical automotive seated posture. Various anthropometry databases are compared region by region and in terms of the key dimensions needed for crash dummy design. The Anthropometry for Motor Vehicle Occupants (AMVO) dataset, as established by the University of Michigan Transportation Research Institute (UMTRI), is selected as the basis for the WorldSID mid-size male, updated to include revisions to the pelvis bone location. The proposed mass of the dummy is 77.3kg with full arms. The rationale for the selected mass is discussed. The joint location and surface landmark database is appended to this paper

Acceptance of Google Meet during the spread of Coronavirus by Arab university students

The COVID-19 pandemic not only affected our health and medical systems but also has created large disruption of education systems at school and universities levels. According to the United Nation’s report, COVID-19 has influenced more than 1.6 billion learners from all over the world (190 countries or more). To tackle this problem, universities and colleges have implemented various technologically based platforms to replace the physical classrooms during the spread of Coronavirus. The effectiveness of these technologies and their educational impact on the educational sector has been the concern of researchers during the spread of the pandemic. Consequently, the current study is an attempt to explore the effect of Google Meet acceptance among Arab students during the pandemic in Oman, UAE, and Jordan. The perceived fear factor is integrated into a hybrid model that combines crucial factors in TAM (Technology acceptance Model) and VAM (Value-based Adoption Model). The integration embraces perceived fear factor with other important factors in TAM perceived ease of use (PEOU) and perceived usefulness (PU) on the one hand and technically influential factor of VAM, which are perceived technicality (PTE) and perceived enjoyment (PE) on the other hand. The data, collected from 475 participants (49% males and 51% females students), were analyzed using the partial least squares-structural equation modelling (PLS-SEM). The results have shown that TAM hypotheses of usefulness and easy to use have been supported. Similarly, the results have supported the hypotheses related to VAM factors of being technically useful and enjoying, which helps in reducing the atmosphere of fear that is created due to the spread of Coronavirus

Addition of vardenafil into storage solution protects the endothelium in a hypoxia-reoxygenation model

OBJECTIVE: Based upon the well known protective effect of intracellular cyclic guanosine monophosphate (cGMP) accumulation, we tested the hypothesis that storage solution enriched with optimal concentration of the phosphodiestherase-5 inhibitor vardenafil could provide better protection of vascular grafts against reperfusion injury after long-term cold ischaemic storage. METHODS: Isolated thoracic aorta obtained from rats underwent 24-h cold ischaemic preservation in physiological saline or vardenafil (10(-11) M)-supplemented saline solution. Reperfusion injury was simulated by hypochlorite (200 muM) exposure for 30 minutes. Endothelium-dependent vasorelaxation was assessed, and histopathological and molecular-biological examination of the aortic tissue were performed. RESULTS: Compared with the control group, the saline group showed significantly attenuated endothelium-dependent maximal relaxation (Rmax) to acetylcholine after hypoxia-reoxygenation, which was significantly improved by vardenafil supplementation (Rmax control: 98 +/- 1%; saline: 48 +/- 6%; vardenafil: 75 +/- 4%; p < .05). Vardenafil treatment significantly reduced DNA strand breaks (control: 10.6 +/- 6.2%; saline: 72.5 +/- 4.0%; vardenafil: 14.2 +/- 5.2%; p < .05) and increased cGMP score in the aortic wall (control: 8.2 +/- 0.6; saline: 4.5 +/- 0.3; vardenafil: 6.7 +/- 0.6; p < .05). CONCLUSIONS: Our results support the view that impairment of intracellular cGMP signalling plays a role in the pathogenesis of the endothelial dysfunction induced by cold storage warm reperfusion, which can be effectively reversed by pharmacological phosphodiesterase-5 inhibition

Point-of-sale tobacco advertising in Beirut, Lebanon following a national advertising ban

Abstract Background The objective of this study was to conduct an audit of point-of-sale (POS) tobacco advertising and assess compliance with an advertising ban in a large district of Beirut, Lebanon. Methods The audit was conducted 3 months following the ban on tobacco advertising. Trained students observed all tobacco retail outlets (n = 100) and entered data into a web-based form using iPad® technology. Presence of tobacco advertisements was assessed to determine compliance with the national advertising ban. Results Among the 100 tobacco retail outlets, 62% had tobacco advertisements, including 7% with a tobacco brand logo as part of the main exterior store sign. Conclusions POS tobacco advertising is widespread in Beirut despite the national advertising ban. These findings point to an urgent need for the enforcement of the advertisement ban with tobacco retail outlets in Lebanon

Seeking and accessing professional support for child anxiety in a community sample

There is a lack of current data on help-seeking, and barriers to accessing professional support for child anxiety disorders. This study aimed to provide current data on the frequency and type of parental help-seeking, professional support received, and parent-reported barriers/facilitators in the context of child anxiety, and to explore factors associated with help-seeking, and parent-reported barriers among help-seekers and non help-seekers. We conducted a survey of help-seeking in parents of 222 children (aged 7-11) with elevated anxiety symptoms identified through screening in schools, 138 children of whom met diagnostic criteria for an anxiety disorder. Almost two-thirds (64.5%) of parents of children with an anxiety disorder reported seeking help from a professional; in 38.4% of cases parents reported that their child had received support from a professional to help manage and overcome their anxiety difficulties, and < 3% had received evidence-based treatment (CBT). Frequently reported parental barriers related to difficulties differentiating between developmentally appropriate and clinically significant anxiety, a lack of help-seeking knowledge, perceived negative consequences of help-seeking, and limited service provision. Non-help seekers were more likely than help seekers to report barriers related to thinking a child's anxiety may improve without professional support, and the absence of professional recognition. Findings identify the need for (i) tools for parents and primary school staff to help identify children who may benefit from professional support to overcome difficulties with anxiety; and (ii) increased evidence-based provision for child anxiety disorders, including delivery within schools and direct support for parents

Identification of potential transcription factors that enhance human iPSC generation

Although many factors have been identified and used to enhance the iPSC reprogramming process, its efficiency remains quite low. In addition, reprogramming efficacy has been evidenced to be affected by disease mutations that are present in patient samples. In this study, using RNA-seq platform we have identified and validated the differential gene expression of five transcription factors (TFs) (GBX2, NANOGP8, SP8, PEG3, and ZIC1) that were associated with a remarkable increase in the number of iPSC colonies generated from a patient with Parkinson's disease. We have applied different bioinformatics tools (Gene ontology, protein–protein interaction, and signaling pathways analyses) to investigate the possible roles of these TFs in pluripotency and developmental process. Interestingly, GBX2, NANOGP8, SP8, PEG3, and ZIC1 were found to play a role in maintaining pluripotency, regulating self-renewal stages, and interacting with other factors that are involved in pluripotency regulation including OCT4, SOX2, NANOG, and KLF4. Therefore, the TFs identified in this study could be used as additional transcription factors that enhance reprogramming efficiency to boost iPSC generation technology.This study was supported by QBRI internal grant (QB16) and the Qatar University Student grant (QUST-2-CMED-2019-1)

Measuring institutions’ adoption of artificial intelligence applications in online learning environments: integrating the innovation diffusion theory with technology adoption rate

Artificial intelligence applications (AIA) increase innovative interaction, allowing for a more interactive environment in governmental institutions. Artificial intelligence is user-friendly and embraces an effective number of features among the different services it offers. This study aims to investigate users’ experiences with AIA for governmental purposes in the Gulf area. The conceptual model comprises the adoption properties (namely trialability, observability, compatibility, and complexity), relative advantage, ease of doing business, and technology export. The novelty of the paper lies in its conceptual model that correlates with both personal characteristics and technology-based features. The results show that the variables of diffusion theory have a positive impact on the two variables of ease of doing business and technology export. The practical implications of the current study are significant. We urge the concerned authorities in the governmental sector to understand the significance of each factor and encourage them to make plans, according to the order of significance of the factors. The managerial implications provide insights into the implementation of AIA in governmental systems to enhance the development of the services they offer and to facilitate their use by all users