140 research outputs found

    Stigma associated with mental illness: perspectives of university students in Qatar

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    Stigma in relation to mental illness is one of the main factors inhibiting people from seeking help. Studies have been undertaken looking into the knowledge, attitudes, and beliefs (KAB) about mental illness among residents in Qatar; however, none have looked specifically at students in higher education. The aim of this study was to understand the KAB toward mental illness among students at a Qatari university and determine if there are any differences based on gender, nationality, and college type. A convenience sample of students from all genders, colleges, and nationalities was approached to participate in a survey that consisted of four sections: demographic, beliefs, attitudes, and help-seeking and treatment preferences associated with mental illness. Chi-square testing was performed to test for differences in the distribution of proportions of our primary outcomes (students' beliefs, attitudes, and help-seeking and treatment preferences). A total of 282 students completed the survey. The majority of the participating students were females (59.3%), non-Qataris (64.3%), and enrolled in science-based colleges (62.7%). Beliefs reflecting poor mental health literacy, such as "medications to treat mental illness can cause addiction", "mental illness is not like any other illness", or that "mental illness is a punishment from God", were reported by a majority of students (84.4%, 56.7%, and 50.2%, respectively). Stigmatizing attitudes that were endorsed by a majority of students included believing that people with mental illness cannot have regular jobs (60.2%), that people with mental illness are dangerous (65.7%), and that they would not marry someone with a mental illness (88.9%). Additionally, 33.6% of students indicated they would be ashamed to mention if someone in their family or they themself, had a mental illness. A vast majority of students (86.3%) indicated to prefer family and friend's support as treatment options. Significant differences in KAB about mental illness between genders, colleges, and college type were found only for a few items. The findings of this study suggest that a high percentage of students reported KAB about mental illness, that are considered stigmatizing. Students' KAB about mental illness was consistent with that reported by the general population in Qatar. Nevertheless, the sample was small and as such, larger studies from a randomly selected population are needed to confirm these findings

    The Consequences of COVID-19 Instigated Recommendations for Indoor Air Quality: A Literature Review

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    The spread of COVID-19, as an airborne virus, opened a vast set of investigations within the realm of indoor air quality (IAQ) management and control. These investigations resulted in the publication of a series of recommendations and addenda that complement currently active IAQ standards and guidelines to meet the growing health and safety concerns of building owners, operators, and users. The hypothesis stands that the airborne transmission of the COVID-19 virus implies that more stringent indoor air quality control measures should be applied. Through a systematic review of selected recently published academic journals, this article explores the intended and non-intended consequences of the indoor air quality recommendations, guidelines, and standards. Two main approaches of classifications are induced from the review. The first categorizes the consequences based on the intentionality (i.e., intended vs. unintended consequences) and temporal scope (i.e. short-term or long-term). The second categorizes consequences based on their area, namely, (1) spatial design, (2) occupants health, comfort and well-being (3) building performance and ventilation, (4) technology and energy efficiency (5) social equity, and (6) policy as well as building standards. This is one of the first reviews make explicit the consequences of COVID related of addenda and recommendations of IAQ standards and guidelines, providing new insights regarding the planned and unplanned consequences. The review also highlights some gaps in the available literature that researchers need to swiftly address before institutionalizing the current health recommendations in IAQ practices

    Effect of gamma rays absorbed doses and heat treatment on the optical absorption spectra of silver ion-exchanged silicate glass

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    International audienceSamples of a commercial silicate glass have been subjected to ion exchange at 320 °C in a molten mixture of AgNO 3 and NaNO 3 with molar ratio of 1:99 and 5:95 for 60 min. The ion exchange process was followed by gamma irradiation in the dose range of 1–250 kGy and heating at the temperature of 550 °C for different time periods ranging from 10 to 582 min. The spectral absorption in UV–Vis range of the Ag–Na ion exchanged glass was measured and used to determine the states of silver prevailing in the glass during the ion exchange, the gamma irradiation and the heat treatment. The gamma irradiation induced holes and electrons in the glass structure leading to the creation of a brown colour, and silver ions trapped electrons to form silver atoms. We observed the first stage of aggregation after irradiation, as well as after heating. The silver atoms diffused and then aggregated to form nanoclusters after heating at 550 °C. A characteristic band at about 430 nm was induced. The surface Plasmon absorption of silver nanoclusters in the glass indicated that the nanoclusters radius grew between 0.9 and 1.43 nm with increasing of annealing time from 10 to 242 min and then saturated. We also found that the size of aggregates depends on the value of gamma radiation absorbed dose. Contrary to what was expected, we found that 20 kGy is the optimal absorbed dose corresponding to the larger size of the aggregates which decreases for absorbed doses above 20 kGy

    Review: The effect of different nanofiller materials on the thermoelectric behavior of bismuth telluride

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    This review paper summarizes and discusses the effect of nanosized fillers on bismuth telluride nanocomposites for thermoelectric applications. Classified into various dimensions based on electron confinement in space, the nanofiller effect on the figure-of-merit value is studied. By combining experimental data with theoretical models, the mechanisms for enhancing the thermoelectric properties were proposed. The outcomes of this review paper suggest that doped bismuth telluride composites (doped with selenium for n-type or antinomy for p-type) offer better thermoelectric properties compared to undoped composites. Moreover, improvements in undoped bismuth telluride composites are exclusive for the n-type only. The figure-of-merit value for bismuth telluride composites is less than two, where the 2D nanofillers show optimum ZT improvements. Nevertheless, the inconsistency of reported data in the thermoelectric area is a problem that must be addressed to have more control over the precision of the reported results for a better understanding of the concepts in this field.This work was supported by Grant no. NPRP10–0206–170366 from Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors. Open access publication of this article was funded by the Qatar National Library

    Current Situation of Tetranychus urticae (Acari: Tetranychidae) in Northern Africa: The Sustainable Control Methods and Priorities for Future Research

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    In North Africa, Tetranychus urticae Koch, 1836 represents one of the most destructive generalists among mite herbivores. Unfortunately, it is a source of important annual casualties in crop production. It is a phytophagous mite that can feed on hundreds of host plants and produces significant damage. The control of T. urticae in North Africa has been principally based on acaricide sprays. However, new alternative methods have shown effective results, such as artificial ultraviolet-B, natural enemies, and the introduction of new genetic methods. This review aims to present a synthesis of information surrounding control methods of T. urticae in North Africa. We highlight the principal findings of previous studies. Then, we discuss current control methods and propose new innovative research and sustainable approaches to controlling this pest. The control method can potentially extrapolate in North African regions due to its positive ecological results. Further, studies proved the use of natural enemies, myco-metabolites, bacteria metabolites, and the introduction of a genetic method in an integrated long-term sustainable program that can successfully defeat the populations of T. urticae. We also discuss high-priority research guidelines to investigate new sustainable management strategies. Setting up an integrated long-term ecological monitoring program in different Northwest African countries and incorporating new technologies into monitoring programs is an urgent need to fight this devastating pest

    Current Situation of Tetranychus urticae (Acari: Tetranychidae) in Northern Africa: The Sustainable Control Methods and Priorities for Future Research

    Get PDF
    In North Africa, Tetranychus urticae Koch, 1836 represents one of the most destructive generalists among mite herbivores. Unfortunately, it is a source of important annual casualties in crop production. It is a phytophagous mite that can feed on hundreds of host plants and produces significant damage. The control of T. urticae in North Africa has been principally based on acaricide sprays. However, new alternative methods have shown effective results, such as artificial ultraviolet-B, natural enemies, and the introduction of new genetic methods. This review aims to present a synthesis of information surrounding control methods of T. urticae in North Africa. We highlight the principal findings of previous studies. Then, we discuss current control methods and propose new innovative research and sustainable approaches to controlling this pest. The control method can potentially extrapolate in North African regions due to its positive ecological results. Further, studies proved the use of natural enemies, myco-metabolites, bacteria metabolites, and the introduction of a genetic method in an integrated long-term sustainable program that can successfully defeat the populations of T. urticae. We also discuss high-priority research guidelines to investigate new sustainable management strategies. Setting up an integrated long-term ecological monitoring program in different Northwest African countries and incorporating new technologies into monitoring programs is an urgent need to fight this devastating pest

    Current Situation of Tetranychus urticae (Acari : Tetranychidae) in Northern Africa: The Sustainable Control Methods and Priorities for Future Research

    Get PDF
    In North Africa, Tetranychus urticae Koch, 1836 represents one of the most destructive generalists among mite herbivores. Unfortunately, it is a source of important annual casualties in crop production. It is a phytophagous mite that can feed on hundreds of host plants and produces significant damage. The control of T. urticae in North Africa has been principally based on acaricide sprays. However, new alternative methods have shown effective results, such as artificial ultraviolet-B, natural enemies, and the introduction of new genetic methods. This review aims to present a synthesis of information surrounding control methods of T. urticae in North Africa. We highlight the principal findings of previous studies. Then, we discuss current control methods and propose new innovative research and sustainable approaches to controlling this pest. The control method can potentially extrapolate in North African regions due to its positive ecological results. Further, studies proved the use of natural enemies, myco-metabolites, bacteria metabolites, and the introduction of a genetic method in an integrated long-term sustainable program that can successfully defeat the populations of T. urticae. We also discuss high-priority research guidelines to investigate new sustainable management strategies. Setting up an integrated long-term ecological monitoring program in different Northwest African countries and incorporating new technologies into monitoring programs is an urgent need to fight this devastating pest.Peer reviewe

    Cytokines Activate JAK-STAT Signaling Pathway in MG-63 Cells on Titanium and Zirconia.

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    Although titanium has been traditionally used as the gold standard for dental implants, recent years have seen the widespread application of zirconia implants given their superiority with regards to reduced bacterial adhesion, inflammation and cellular-interaction in terms of bio-compatibility. The JAK-STAT signaling pathway plays an important role in bone remodeling and formation. The aim of the study was to investigate the activation of the JAK-STAT pathway through different cytokines in osteoblast-like cells (MG-63) on zirconia in comparison to titanium discs. IFN-γ induced the very strong activation of STAT1 protein, IFN-α activated both STAT1 and STAT3 molecules, IL-6 activated STAT3 and IL-4 induced the activation of STAT6 on both surfaces. The activation of STAT proteins was confirmed by western blot, immunofluorescence and flow cytometry using phospho-specific anti-STAT antibodies, which recognize only phosphorylated STAT proteins. The incubation of MG-63 cells with IFN-γ caused the upregulation of MHC class I and class II proteins when MG-63 cells were grown on zirconia and titanium discs. In sum, the present study shows that the JAK-STAT pathway is activated in MG-63 cells when they are incubated on titanium or zirconia surfaces

    Experimental and modeling analysis of p-type Bi0.4Sb1.6Te3 and graphene nanocomposites

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    The state-of-the-art Bismuth-Telluride (Bi2Te3) based systems are promising thermoelectric materials for efficient thermoelectric applications. In this study, the effect of graphene nanosheets (GNS) integrity on thermoelectric properties of a p-type Bi0.4Sb1.6Te3 alloy has been studied using high-energy ball milling and SPS sintering techniques. The synthesized pristine Bi0.4Sb1.6Te3 and 0.05wt% GNS/Bi0.4Sb1.6Te3 nanocomposites at different addition times of GNS have exhibited a single-phase and artifact-free bulk nanocrystalline Bi0.4Sb1.6Te3 with nanocrystals size of 17 nm. The TEM analysis confirmed the mechanical exfoliation of graphene filler in 5m nanocomposite into a single-layered nanostructure with an interplanar spacing of 0.343 nm. The prominent Raman features of the monolayered graphene sheet have appeared in the synthesized 5m-GNS/Bi0.4Sb1.6Te3 nanocomposite. This highlighted the crucial rule of graphene addition time on its structure and morphology of the synthesized nanocomposites. The ZT profile of 5m nanocomposite reached 0.801 at 348 K till 398 K. This resulted in 65% of improvements to the pristine Bi0.4Sb1.6Te3 pellet at 323 K. The obtained results were used to simulate a thermoelectric (TE) device module using ANSYS Workbench. The GNS nanocomposites have shown an ultrahigh output power of 95.57 W compared to 89.96 W for the pristine module at ΔT of 150 °C. The GNS addition has increased the output power of pristine Bi0.4Sb1.6Te3 by 7%, leading to comparable TE performance to other simulated Bi2Te3 systems
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