366 research outputs found

    New precoding blind channel estimation and channel order estimation algorithm in OFDM systems with cyclic prefix

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    Using different precoding matrices, a new blind channel estimation in OFDM systems with cyclic prefix is presented in this paper. The proposed method employs one column of the correlation matrix directly, unlike the traditional precoding techniques where the elements of precoding matrix is been removed. Results show the impact of this method specially when using the type of precoding matrices which include the circulant property in its design. Since channel order estimation is an important task in blind methods, a new and simple algorithm is also investigated with no additional complexity been added to the system. A proof of diagonalizability property is mentioned which can be implemented for other investigations concerning this type of matrices

    Comment on `Electromagnetic force on a moving dipole'

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    Using the Lagrangian formalism, the electromagnetic force on a moving dipole derived by Kholmetskii, Missevitch and Yarman (2011, Eur. J. Phys. 32, 873) is found to be missing some important terms.Comment: The version as accepted by Eur. J. Phys.; 4 page

    Spin-orbit coupling and the conservation of angular momentum

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    In nonrelativistic quantum mechanics, the total (i.e. orbital plus spin) angular momentum of a charged particle with spin that moves in a Coulomb plus spin-orbit-coupling potential is conserved. In a classical nonrelativistic treatment of this problem, in which the Lagrange equations determine the orbital motion and the Thomas equation yields the rate of change of the spin, the particle's total angular momentum in which the orbital angular momentum is defined in terms of the kinetic momentum is generally not conserved. However, a generalized total angular momentum, in which the orbital part is defined in terms of the canonical momentum, is conserved. This illustrates the fact that the quantum-mechanical operator of momentum corresponds to the canonical momentum of classical mechanics.Comment: 10 pages, as published by Eur. J. Phy

    Relativistic Aharonov-Casher Phase in Spin One

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    The Aharonov-Casher (AC) phase is calculated in relativistic wave equations of spin one. The AC phase has previously been calculated from the Dirac-Pauli equation using a gauge-like technique \cite{MK1,MK2}. In the spin-one case, we use Kemmer theory (a Dirac-like particle theory) to calculate the phase in a similar manner. However the vector formalism, the Proca theory, is more widely known and used. In the presence of an electromagnetic field, the two theories are `equivalent' and may be transformed into one another. We adapt these transformations to show that the Kemmer theory results apply to the Proca theory. Then we calculate the Aharonov-Casher phase for spin-one particles directly in the Proca formalism.Comment: 12 page

    Effects of alginates on the growth, haematological, immunity, antioxidant and pro-inflammatory responses of rabbits under high temperature

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    Heat stress (HS) is one of the most severe hurdles impacting rabbit growth, immunity, homeostasis, and productivity. Alginate oligosaccharides (AOS) have considerable beneficial effects due to their plausible antioxidant and immune-stimulatory properties. This work was planned to explore the preventive function of AOS as a new bio-feed additive against the harmful effects caused by environmental HS on growing rabbits. Rabbits were allotted in four experimental groups (25 animals in each group) and fed on a basal diet supplemented with 0.0 (AOS0), 50 (AOS50), 100 (AOS100), and 150 (AOS150) mg AOS/kg diet reared under summer conditions. Dietary AOS supplementation improved significantly (P ≤ 0.001) feed conversion rate, while both AOS100 and AOS150 significantly (P ≤ 0.001) enhanced the final body weight and body weight gain. All AOS addition significantly increased nitric oxide and lysosome activity and significantly reduced interferon-gamma (IFNγ) compared with those in the control group. Tumor necrosis factor α (TNFα), interleukin1β (IL-1β), myeloperoxidase and protein carbonyl levels were significantly reduced in rabbits fed diets containing AOS (100 and 150 mg/kg) compared with those in the control group under heat stress conditions. In addition, glutathione (GSH) and catalase (CAT) were significantly (P ≤ 0.001) improved with increasing AOS dietary levels compared with the control group. Still, total antioxidant capacity (TAC), malondialdehyde (MDA), hematocrit, mean corpuscular volume (MCV), eosinophils, and lymphocytes did not change. Erythrocyte's indices improved significantly (P ≤ 0.001), while neutrophils and white blood cell counts were decreased by dietary AOS inclusion. Immunological (IgM and IgG) were markedly reduced in AOS-treated groups compared with the control group. The current investigation exemplified that AOS as a novel bio-feed additive that could be an effective strategy to extenuate prejudicial effects in heat-stressed rabbits via enhancing immunity, and antioxidant defence system, further regulating the inflammation cytokines.Universidad King Saud, Riad, Arabia Saudita | Ref. RSP2023R439Universidade de Vigo/CISU

    The Determinant of Subjective Well-Being among the adult individuals in the UAE

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    Background: Enhancing individual wellbeing is a national priority in the United Arab Emirates. Up to date, wellbeing at the country level was measured through the national wellbeing survey that is sector specific comprising of 122 questions. The “World Health Organization 5 items (WHO-5) Well-being Index” is a reliable instrument to assess Subjective Well-Being, yet was never tested at national level in the UAE. Aim: This study examined the association of socio-economic determinants of health with the subjective well-being (SWB) using WHO-5 Well-being Index to inform public health policy in the UAE. Method: A cross-sectional survey from adults (aged 18+ and above) was conducted. About 10,000 individuals were randomly selected across all the seven Emirates. A total of 7367 adults (18 years and above) took part in the survey (response rate was 74%). The WHO-5 instrument is a valid screening measure as it includes only 5 items, is freely available in at least thirty-one languages, and is tremendously easy to complete, interpret and score. The social support of the respondents was evaluated by using the Multidimensional Scale of Perceived Social Support. Results: The results of the study demonstrate that majority of the participants (79.27%) reported moderate - high (≥50) well-being scores showing the good quality of life/well-being, whereas, only 20.72% of the individual reported ill-being/likely depression in the future. Respondent’s age, gender, marital status, monthly income (AED- UAE dirham), employment status and reporting at least one or more morbidity were found to be significantly associated with the SWB variables (p < 0.05). A significant association was found between the comprehensive/emotional and /mental well-being and perceived social support. Conclusion: The WHO-5 index can be used as a reliable screening tool to identify wellbeing inequalities among adult individuals based on socio-economic determinants of health in the UAE. Addressing the socio- Hira Abdul Razzak1, Dr. Alya Harbi2, Ms. Mubarkah Jaber AlKarbi3, Dr. Amin Mohamed ElShamy4 , Dr. Lubna Al Shaali5, Dr. Rasha E Salama6 , Ms. Malaz Bakri7, Dr. Ahmed Alosi8, Ms. Amna AlDhmanie9 1678 © 2021 JPPW. All rights reserved economic determinants of health in the UAE can enhance subjective well-being (SWB) and help the UAE to achieve its strategic aspiration to make the UAE among the world leaders in quality of life

    Consanguinity and reproductive health among Arabs

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    Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity

    Assessment of burnout, resilience, and thriving among academic health professionals: findings from an international study

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    Introduction: Burnout, resilience, and thriving significantly impact academics, particularly in health professions, where responsibilities are extensive. This study aimed to explore these constructs among academic health professionals, examining sociodemographic and work-related factors influencing these outcomes.Methods: A cross-sectional study was conducted among academic health professionals via web-based professional networks from August 2022 to February 2023. Validated tools were used, and descriptive and inferential statistics were applied.Results: 505 participants were included, predominantly female (63%), with a mean age of 38.15 ± 9.6 years. High burnout was reported by 10.9%, 13.7% experienced exhaustion, and 6.3% were disengaged. Resilience and thriving were moderate at 59.2 and 51.9%, respectively. Age correlated negatively with burnout (r = −0.131, p = 0.003) but positively with resilience (r = 0.178, p < 0.001). Females reported higher exhaustion (p = 0.014), while males showed greater resilience (p = 0.016). Instructors exhibited lower resilience compared to assistant professors (p < 0.001) and associate professors (p < 0.001). Those at public universities reported higher exhaustion than those at private universities (p < 0.001).Conclusion: Variable levels of burnout, resilience, and thriving were observed among academic health professionals, influenced by sociodemographic and work-related factors. Interventions targeting resilience and thriving may mitigate burnout risk and enhance engagement among academics in health professions

    Potential of essential fatty acid deficiency with extremely low fat diet in lipoprotein lipase deficiency during pregnancy: A case report

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    BACKGROUND: Pregnancy in patients with lipoprotein lipase deficiency is associated with high risk of maternal pancreatitis and fetal death. A very low fat diet (< 10% of calories) is the primary treatment modality for the prevention of acute pancreatitis, a rare but potentially serious complication of severe hypertriglyceridemia. Since pregnancy can exacerbate hypertriglyceridemia in the genetic absence of lipoprotein lipase, a further reduction of dietary fat intake to < 1–2% of total caloric intake may be required during the pregnancy, along with the administration of a fibrate. It is uncertain if essential fatty acid deficiency will develop in the mother and fetus with this extremely low fat diet, or whether fibrates will cross the placenta and concentrate in the fetus. CASE PRESENTATION: A 23 year-old gravida 1 woman with primary lipoprotein lipase deficiency was seen at 7 weeks of gestation in the Lipid Clinic for management of severe hypertriglyceridemia that had worsened with pregnancy. While on her habitual fat intake of 10% of total calories, her pregnancy resulted in an exacerbation of the hypertriglyceridemia, which prompted further restriction of fat intake to < 2% of total calories, as well as administration of gemfibrozil at a lower than average dose. The level of gemfibrozil, as the active metabolite, in the venous and arterial fetal cord blood was within the expected therapeutic range for adults. The clinical signs and a biomarker of essential fatty acid deficiency, namely the ratio of 20:3 [n-9] to 20:4 [n-6] fatty acids, were closely monitored throughout her pregnancy. Despite her extremely low fat diet, the levels of essential fatty acids measured in the mother and in the fetal blood immediately postpartum were normal. Normal essential fatty acid levels may have been achieved by the topical application of sunflower oil. CONCLUSIONS: An extremely low fat diet in combination with topical sunflower oil and gemfibrozil administration was safely implemented in pregnancy associated with the severe hypertriglyceridemia of lipoprotein lipase deficiency
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