The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging infection causing a widely spread pandemic of Coronavirus disease 2019 (COVID-19). The current COVID-2019 pandemic is ...prompting fear of falling sick, dying, helplessness and stigma, urgent and timely understanding of mental health status is needed to help the community. Our investigation designed to survey the general population in Saudi Arabia to assess the degree of psychological impact during the pandemic.
During the early stage of the outbreak, we conducted an online-based survey using a snowballing sample technique. The surveys collected data about several aspects of participant sociodemographic, knowledge, concerns, psychological impact, and mental health status. We assessed the psychological impact and mental health status using the Impact of Event Scale-Revised (IES-R), and the Depression, Anxiety, and Stress Scale (DASS-21).
Our survey recruited 1160 respondents of the general public of Saudi Arabia. Of them, 23.6% reported moderate or severe psychological impact of the outbreak, 28.3%,24%, and 22.3% reported moderate to severe depressive, anxiety, and stress symptoms, respectively. Females reported IES-R (B: 5.46, 95% CI: 3.61 to 7.31) and DASS subscales B coefficient ranged from 1.65 to 2.63, along with high-school students, working in the medical field, and poor self-reported health status was significantly associated with a high level of IES-R and DASS scales (p < .05). Experiencing breathing difficulty and dizziness showed a stronger association with higher IES-R and DASS subscales than other somatic symptoms (e.g., headache and fever);(p < .001). Respondents who practiced specific preventative measures (e.g., hand washing, social distancing) demonstrated a protective effect against stress, anxiety, and depression symptoms. Social distancing appeared to be protective on stress and anxiety subscales (B: -1.49, 95% CI: −2.79 to −0.19),(B: -1.53, 95% CI: −2.50 to −0.57),respectively; and hand hygiene on depression subscale (B: -2.43, 95% CI: −4.44 to −0.42).
Throughout the early stage of the COVID-19 outbreak in Saudi Arabia, the results showed that nearly one-fourth of the sampled general population experienced moderate to severe psychological impact. Following specific precautionary measures appeared to have a protective effect on the individual's mental health. Our findings can be used to construct psychological interventions directed toward vulnerable populations and to implement public mental health strategies in the early stages of the outbreak.
•There is Limited data about psychological impact during the COVID-19 pandemic in Saudi Arabia•Health care workers, females, were associated with higher levels of stress, anxiety, and depression symptoms.•Students and those with poor self-reported health status reported higher levels of stress, anxiety, and depression symptoms.•Participants with reported mental disorders (10.5%) showed high scores on all DASS and IER-S scales.•Preventative measures demonstrated a protective effect against, stress, anxiety, and depression symptoms
This paper extends the application of a frame-angle-based (FAB) direct torque controller (DTC) for permanent magnet synchronous motor (PMSM) drives to low and very low speeds. The FAB-DTC is intended ...for PMSM drives that are fed by <inline-formula><tex-math notation="LaTeX">3\phi</tex-math></inline-formula> six-pulse wavelet-modulated dc-ac converters. The foundations of the FAB-DTC are based on regulating the <inline-formula><tex-math notation="LaTeX">d\text{--}q</tex-math></inline-formula>-axis stator voltages, in response to variations in the load torque and/or drive speed. The adjustments in <inline-formula><tex-math notation="LaTeX">d\text{--}q</tex-math></inline-formula>-axis stator voltages are created by changing the angle <inline-formula><tex-math notation="LaTeX">\vartheta</tex-math></inline-formula> of the frame spanned by the <inline-formula><tex-math notation="LaTeX">d\text{--}q</tex-math></inline-formula>-axis stator voltages. In order to extend the FAB-DTC to low and very low speeds, the changes in <inline-formula><tex-math notation="LaTeX">\vartheta</tex-math></inline-formula> are accompanied by changes in the maximum scale. The values of maximum scale and <inline-formula><tex-math notation="LaTeX">d\text{--}q</tex-math></inline-formula>-axis stator voltages are used to update or change the reference signals employed by the wavelet modulation to generate switching pulses to operate a <inline-formula><tex-math notation="LaTeX">3\phi</tex-math></inline-formula> dc-ac converter. The complete PMSM drive system incorporating the modified FAB-DTC is implemented for a 10-hp PMSM drive system. The performance of the FAB-DTC is investigated for different changes in the command torque for various low and very low speeds. Performance results demonstrate stable, fast, dynamic, and accurate responses, which have minor sensitivity to variations in load torque and/or drive speed.
Abstract
The aggregate udder shape (Bowl, Round, Cup), udder measurements (udder width, UW, udder front depth, UFD, udder rear depth, URD, udder levelness, ULV, udder heights, UH) and teat ...measurements (teat diameters, TD, front teat length, FTL, rear teat length, RTL, distance between front teats, DFT and distance between rear teats, DRT) were measured on 1300 Friesian cows located in a commercial farm under subtropical conditions (Egypt) to appraise udder and teats status and to evaluate the possible relationships with some milk production characteristics in conjunction with udder shape, age at first calving, sire and inbreeding effects on udder morphological traits and milk production ability. For such an available sample size, parity had affected (
P
< 0.01) UFD, TD, FTL and RTL. In addition, udder shape affected (
P
< 0.01) UW, UFD, URD, ULV and DFT. None of the other studied factors affected milk production traits. The bowl udder shape (
P
< 0.01) yielded a high total milk yield (3267.19 kg), adjusted milk yield (2443.01 kg) and lactation length (480.70 d) compared to other udder shapes. The genetic correlations of UW with total milk yield and persistency were strongly positive (0.86 and 0.93, respectively). However, strong negative genetic correlations were found between UW with peak milk yield and lactation length (− 0.92 and − 0.80, respectively), between RTL with peak milk yield (− 0.92) and DRT with persistency (− 0.79). As found from the stepwise multiple regression, UW and URD can be used as good indicators for predicting milk yield and lactation length. Additionally, this study spotlights the genetic background of udder characteristics based on reliable studies and the QTL database for cattle as a first step toward applying this knowledge side by side with phenotypic traits to improve the productivity of the Holstein breed under subtropical conditions.
We investigated the potential relationship between endometriosis and risk of ovarian, endometrial, cervical, and breast cancers using the National Inpatient Sample (NIS) database.
We utilized the ...International Classification of Diseases (ICD-10) system to identify relevant codes from the NIS database (2016-2019). Univariate and multivariate regression analyses (adjusted for age, race, hospital region, hospital teaching status, income Zip score, smoking, alcohol use, and hormonal replacement therapy) were conducted to evaluate the association between endometriosis and gynecologic cancers and summarized as odds ratios (ORs) with 95% confidence intervals (CIs).
In the examined dataset, there were 1164 and 225,323 gynecologic cancer patients with and without endometriosis, respectively. Univariate analysis showed endometriosis was significantly associated with a higher risk of ovarian (OR = 3.42, 95% CI: 3.05-3.84,
< 0.001) and endometrial (OR = 3.35, 95% CI: 2.97-3.79,
< 0.001) cancers. There was no significant association between endometriosis and cervical cancer (OR = 1.05, 95% CI: 0.85-1.28,
= 0.663). Interestingly, endometriosis was significantly associated with a low risk of breast cancer (OR = 0.12, 95% CI: 0.10-0.17,
< 0.001). Multivariate analysis after Bonferroni correction (
< 0.006) showed that endometriosis was significantly associated with a high risk of ovarian (adjusted OR = 3.34, 95% CI: 2.97-3.75,
< 0.001) and endometrial (adjusted OR = 3.61, 95% CI: 3.12-4.08,
< 0.001) cancers. Conversely, there was no significant association between endometriosis and cervical cancer (OR = 0.80, 95% CI: 0.65-0.99,
= 0.036).
Patients with endometriosis exhibited unique gynecologic cancer risk profiles, with higher risks for ovarian and endometrial cancers, and no significant risk for cervical cancer. The observed connection between endometriosis and a reduced risk of breast cancer remains a perplexing phenomenon, which cannot be put into context to date.
The city of Jeddah (Saudi Arabia) has experienced two catastrophic flash flood events in 2009 and 2011. These flood events had catastrophic effect on human lives and livelihoods around the wadi ...Muraikh, wadi Qus, wadi Methweb, and wadi Ghulail in which 113 people were dead and with 10,000 houses and 17,000 vehicles were damaged. Thus, a comprehensive flood management is required. The flood management requires information on different aspects such as the hydrological, geotechnical, environmental, social, and economic aspects of flooding. Flood susceptibility mapping for any area helps the decision makers to understand the flood trends and can aid in appropriate planning and flood prevention. In this study, two models were used for the generation of flood susceptibility maps for the Jeddah region. The first model includes bivariate probability analysis (frequency ratio), and the second model uses the multivariate analysis. For the multivariate model, the acquired weights of the FR model were entered into the logistic regression model to evaluate the correlation between flood occurrence and each related factor. This integration will overcome some of the weakness of the logistic regression, and the performance the LR will be enhanced. A flood inventory map was prepared with a total of 127 flood locations. These flood locations were extracted from different sources including field investigation and high-resolution satellite image (IKONOS 1 m). These flood locations were randomly split into two groups, one dataset representing 70 % was used for training the models, and the remaining 30 % was used for models validation. Various independent flood-related factors such as slope, elevation, curvature, geology, landuse, soil drain, and distance from streams were included. The impact of each independent flood-related factors on flooding was evaluated by analyzing each independent factor with the historical flood inventory data. The training and validation datasets were used to evaluate the flood susceptibility maps using the success and the prediction rate methods. The results of the accuracy assessment showed a success rate of 90.4 and 91.6 % and a prediction rate of 89.6 and 91.3 % for FR and ensemble FR and LR models, respectively. In addition, a comparison has been made between real flood events in 2009 and the resultant susceptibility maps. Hence, it is concluded that the FR and ensemble Fr and LR models can provide an acceptable accuracy in the prediction of flood susceptibility in the Saudi Arabia. Our findings indicated that these flood susceptibility maps can assist planners, decision makers, and other agencies to deal with the flood management and planning in the area.
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•Synthesis of highly efficient photocatalysts Ce doped ZnO nanorods was achieved.•Polyamines triethylenetetraamine as the cross-linking agents was used.•The samples were evaluated by ...the determination of their photonic efficiencies.•All Ce doped samples exhibited superior photocatalytic activity than UV-100.•0.5% Ce doped ZnO nanorods exhibits the highest photocatalytic activity.
Here we successfully report the synthesis of highly efficient Ce doped ZnO nanorods photocatalysts under mild hydrothermal conditions utilizing polyamines triethylenetetraamine (TETA) as the cross-linking agents for the first time. The XRD patterns demonstrate that the ZnO nanorods are highly crystalline and Ce ions were successfully incorporated into the lattice position of ZnO. Presence of Ce3+, Ce4+ and Zn2+ ions cerium doped ZnO nanorods has been confirmed by XPS analysis. SEM images show that with increasing Ce doping, very thin fluffy or porous like structures on smooth ZnO nanorods were appeared. The lattice spacing between the adjacent lattice planes in the HRTEM images is measured to be approximately 0.52nm, confirming the ZnO nanorod grows along 0001 direction. Optical characterizations indicate that the Ce doping can shift the absorption edge of ZnO to the visible range and reduce the band gap. The prepared photocatalysts have been compared with commercial photocatalysts Hombikat UV-100 by the determination of their photonic efficiencies for degradation methylene blue. All Ce doped samples exhibited superior photocatalytic performance than either pure ZnO nanorods or Hombikat UV-100. 0.5% Ce doped ZnO exhibits highest photocatalytic activity among the prepared samples.
A simple, sensitive, low-cost, quick and reliable square-wave anodic stripping voltammetric method is described for the determination of the antidiabetic drug Linagliptin (LNG) in pure form, tablets, ...and spiked human urine and plasma samples. Using a pencil graphite electrode (PGE), cyclic voltammetry (CV) was applied to study the electrochemical behavior of LNG. In a Teorell–Stenhagen buffer (pH 5.5) containing 0.1 M NaClO4 as a supporting electrolyte, the LNG yields an irreversible well-defined oxidation peak at about 1.2 V vs. Ag/AgCl electrode. The various affecting factors, such as the pH, buffer type, supporting electrolyte, accumulation potential, scan rate and accumulation time, were tested and optimized. Also, square-wave adsorptive anodic stripping voltammetric (SWAdASV) studies show that the peak current various linearly over the LNG concentration range of 0.24 – 5.20 μg mL−1 (R2 = 0.9994). The detection and quantification limits were calculated to be 0.10 and 0.33 μg mL−1, respectively. The proposed procedure exhibits a good precision, selectivity, and stability and was applied successfully to determine the LNG in pharmaceutical formulations (tablets) and biological fluids (spiked human urine and plasma samples).
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•Recent advances in lipases and their use in combination with metal catalyst to access chiral intermediates in last decade.•Development of transition metal based racemization ...catalysts for utilization in DKR protocols.•Timelines and breakthroughs in the development of transition metal based racemization catalysts.•Widening of the range of chiral alcohols and amines that are employed as substrates in lipase catalyzed KR.•Applications of lipase and metal combination to access other chiral intermediates.
The importance of chiral organic intermediates in various industrial sectors cannot be underestimated. Lipases and their use in combination with metal catalysts is a promising and facile approach to obtain enantiomerically pure chiral intermediates like alcohols and amines. The area of lipase-mediated kinetic resolution (KR) and its dynamic counterpart (dynamic kinetic resolution, DKR) employing lipases and metal based racemization catalysts has shown extensive and stimulating advances in the recent years. The present review highlights the recent progress in this field pertaining to the development of transition metal based racemization catalysts for utilization in DKR protocols and also widening of the application for a range of chiral alcohols and amines that are employed as substrates in lipase catalyzed KR. In addition, the developments in the lipase catalyzed protocols to access other chiral intermediates such as esters, amides, aminoacids etc and their derivatives are also discussed.
Outbreaks of Middle East respiratory syndrome (MERS) raise questions about the prevalence and evolution of the MERS coronavirus (CoV) in its animal reservoir. Our surveillance in Saudi Arabia in 2014 ...and 2015 showed that viruses of the MERS-CoV species and a human CoV 229E–related lineage co-circulated at high prevalence, with frequent co-infections in the upper respiratory tract of dromedary camels. Including a betacoronavirus 1 species, we found that dromedary camels share three CoV species with humans. Several MERS-CoV lineages were present in camels, including a recombinant lineage that has been dominant since December 2014 and that subsequently led to the human outbreaks in 2015. Camels therefore serve as an important reservoir for the maintenance and diversification of the MERS-CoVs and are the source of human infections with this virus.
Soft robots provide a pathway to accurately mimic biological creatures and be integrated into their environment with minimal invasion or disruption to their ecosystem. These robots made from soft ...deforming materials possess structural properties and behaviors similar to the bodies and organs of living creatures. However, they are difficult to develop in terms of integrated actuation and sensing, accurate modeling, and precise control. This article presents a soft-rigid hybrid robotic fish inspired by the Pangasius fish. The robot employs a flexible fin ray tail structure driven by a servo motor, to act as the soft body of the robot and provide the undulatory motion to the caudal fin of the fish. To address the modeling and control challenges, reinforcement learning (RL) is proposed as a model-free control strategy for the robot fish to swim and reach a specified target goal. By training and investigating the RL through experiments on real hardware, we illustrate the capability of the fish to learn and achieve the required task.
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