509 research outputs found

    Studies on wings symmetry and honey bee races discrimination by using standard and geometric morphometrics

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    Abstract: Morphometric is an essential tool for honey bee races discrimination and characterization. Such vital tool has been applied widely in honey bee researches. Unfortunately there is no available literature for confirming honey bee wings symmetry. Therefore, standard and geometric morphometric analyses were employed for investigating wings symmetry as well as for discriminating between Carniolan and Yemeni honey bees. Moreover, three angles of hind wings (H1, H2 and H3) were evaluated in the discrimination between the two races. Results of morphometric analyses strongly confirmed the symmetry of honey bee wings. Standard and geometric morphometric analyses successfully discriminate between the two races. Hind wing length and angle H3 could be incorporated in honey bee races discrimination

    10  Gbps Mobile Visible Light Communication System Employing Angle Diversity, Imaging Receivers, and Relay Nodes

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    Over the last decade, visible light communication (VLC) systems have typically operated between 50 Mbps and 3.4 Gbps. In this paper, we propose and evaluate mobile VLC systems that operate at 10 Gbps. The enhancements in channel bandwidth and data rate are achieved by the introduction of laser diodes (LDs), angle diversity receivers (ADR), imaging receivers, relay nodes and delay adaptation techniques. We propose three mobile VLC systems; an ADR relay assisted LD-VLC (ADRR-LD), an imaging relay assisted LD-VLC (IMGR-LD) and select-the-best imaging relay assisted LD-VLC (SBIMGR-LD). The ADR and imaging receiver are proposed for the VLC system to mitigate the intersymbol interference (ISI), maximise the signal to noise ratio (SNR) and reduce the impact of multipath dispersion due to mobility. The combination of IMGR-LD with a delay adaptation technique adds a degree of freedom to the link design, which results in a VLC system that has the ability to provide high data rates under mobility. The proposed IMGR-LD system achieves significant improvements in the SNR over other systems in the worst case scenario in the considered real indoor environment

    Survey and molecular detection of Melissococcus plutonius, the causative agent of European Foulbrood in honeybees in Saudi Arabia

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    AbstractA large-scale field survey was conducted to screen major Saudi Arabian beekeeping locations for infection by Melissococcus plutonius. M. plutonius is one of the major bacterial pathogens of honeybee broods and is the causative agent of European Foulbrood disease (EFB). Larvae from samples suspected of infection were collected from different apiaries and homogenized in phosphate buffered saline (PBS). Bacteria were isolated on MYPGP agar medium. Two bacterial isolates, ksuMP7 and ksuMP9 (16S rRNA GenBank accession numbers, KX417565 and KX417566, respectively), were subjected to molecular identification using M. plutonius -specific primers, a BLAST sequence analysis revealed that the two isolates were M. plutonius with more than 98% sequence identity. The molecular detection of M. plutonius from honeybee is the first recorded incidence of this pathogen in Saudi Arabia. This study emphasizes the need for official authorities to take immediate steps toward treating and limiting the spread of this disease throughout the country

    Insomnia in chronic renal patients on dialysis in Saudi Arabia

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    <p>Abstract</p> <p>Background</p> <p>Studies have shown that insomnia is a common sleep disorder among patients with end-stage renal disease (ESRD). This study aimed to assess the prevalence of insomnia in Saudi patients with ESRD who are on maintenance dialysis.</p> <p>Methods</p> <p>This was an observational cross-sectional study carried out over a period of five months in two hemodialysis centers in Saudi Arabia. To assess the prevalence of insomnia, we used the ICSD-2 definition. We also examined the association between insomnia and other sleep disorders, the underlying causes of renal failure, dialysis duration, dialysis shift, and other demographic data.</p> <p>Results</p> <p>Out of 227 enrolled patients, insomnia was reported by 60.8%. The mean patient age was 55.7 ± 17.2 years; 53.7% were male and 46.3% were female. Insomnia was significantly associated with female gender, afternoon hemodialysis, Restless Legs Syndrome, high risk for obstructive Sleep Apnea Syndrome and excessive daytime sleepiness (<it><b>P-values: </b></it>0.05, 0.01, < 0.0001, < 0.0001, and < 0.0001, respectively). No significant association was found between insomnia and other variables, including BMI, smoking habits, underlying etiology of renal failure, dialysis duration, association with hemoglobin, ferritin, and phosphorus or dialysis adequacy as measured by the Kt/V index.</p> <p>Conclusion</p> <p>Insomnia is common in dialysis patients and was significantly associated with other sleep disorders. Greater attention needs to be given to the care of dialysis patients with regard to the diagnosis and management of insomnia and associated sleep disorders.</p

    Impact of Knowledge and Attitude on Saudis’ Physical Activity Practice and Inactivity Barriers: A Questionnaire-based Study

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    BACKGROUND: Community participation in physical activity is considered a major public health preference of WHO. Saudi Arabia in the last decades faced many tremendous economic changes leading to adoption of western dietary habits associated with sedentary lifestyle. AIM: We aimed to study the relationship between both physical activity knowledge and attitude of community to the practice of individuals. METHODS: We used a questionnaire consists of a mixture of closed-ended questions. Participants were recruited through direct meetings in local markets, schools, and workplaces. Seven hundred and sixty six individuals agreed to participate. RESULTS: Overall correct answers to questions about importance of physical activity were 76.58%. The predominance of participants’ attitude was to establish public places for physical activity in each neighborhood (92.1%). Participants acknowledged that they exercise to improve their health (47.5%). Participants mainly perform light exercises (47.2%) on basis of 1–3 times weekly (48.9%). About 90.8% of participants admitted that they like to increase duration of their physical activity. CONCLUSIONS: Overall physical activity practice of participants’ needs encourage overcoming obstacles that prevent individuals from practicing especially lack of time

    Aberrant right subclavian artery in a cadaver: a case report of an aortic arch anomaly

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    In early embryogenesis, aortic anomalies occur as a consequence of disorders in the development of the primitive aortic arches system. Aberrant right subclavian artery, also known as arteria lusoria, is one of the important congenital anomalies of the aortic arch, in which the right subclavian artery arises from the arch of aorta instead of the brachiocephalic trunk. During routine dissection of a female cadaver, we observed retro-oesophageal aberrant right subclavian artery arising as the fourth branch from the aortic arch. In this case, the brachiocephalic trunk was absent. Early detection of aortic arch anomalies through diagnostic interventions is helpful to avoid complications during surgical procedures

    Biochemical and histological evidences for the antitumor potential of Teucrium Oliverianum and Rhazya stricta in chemically-induced hepatocellular carcinoma

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    Background: Teucrium oliverianum and Rhazya stricta are medicinal plants used in traditional and herbal medicine for the treatment of diabetes, liver diseases and inflammatory conditions. The present study was planned to investigate the antitumor efficacy of Teucrium oliverianum and Rhazya stricta in chemically-induced hepatocellular carcinoma (HCC) in rats.Materials and Methods: Forty adult male rats weighing 170-200 g were divided into four groups; each group was comprised of ten rats: (1): Normal healthy animals served as negative control group, (2):  Hepatocellular carcinoma (HCC) group in which the rats were orally administered Nnitrosodiethylamine (dissolved in 0.9% normal saline), in a dose of 20 mg/kg b.wt. five times a week for six weeks, (3): HCC group treated with Teucrium oliverianum extract in a dose of 600 mg/kg b.wt for two months and (4): HCC group treated with Rhazya stricta extract in a dose of 750 mg/kg b.wt for two months. Serum alanine  aminotransferase (ALT), asparatate aminotransferase (AST), alkaline phosphatase (ALP) and  gammaglutamyl transferase (γ-GT) activities were estimated. Serum  carcinoembyronic antigen (CEA), alpha-fetoprotein (AFP), alpha-L-fucosidase (AFU), glypican-3 (GPC-3), golgi protein 73 (Gp-73) and vascular endothelial growth factor (VEGF) levels were determined. Histopathological examination of liver tissue sections was also carried out.Results: The HCC group showed significant elevation in serum AST, ALT, ALP and γ-GT activities as well  as CEA, AFP, AFU, Gpc-3, Gp 73 and VEGF levels versus the negative control group. Photomicrograph of liver tissue sections of rats in HCC revealed hepatic parenchyma with foci of anaplastic hepatocellular carcinoma as well as other foci of cystic cholangio carcinoma associated with areas of telangictasis with haemorrhage as well as individual hepatocellular necrosis.Conclusion: Treatment of HCC groups with Teucrium oliverianum or Rhazya stricta extract experienced significant improvement in the measured biochemical parameters as well as in the structural  organization of the liver. In conclusion, the current study provided experimental evidences for the antitumor efficacy of Teucrium oliverianum and Rhazya stricta against hepatocellular carcinoma. Such effect could be attributed to hepatoprotective properties, antiproliferative activity and antiangiogenic potential.Keywords: Hepatocellular carcinoma, Teucrium oliverianum, Rhazya stricta, rat

    Hologram selection in realistic indoor optical wireless systems with angle diversity receivers

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    In this paper, we introduce a new adaptive optical wireless system that employs a finite vocabulary of stored holograms. We propose a fast delay, angle, and power adaptive holograms (FDAPA-Holograms) approach based on a divide and conquer (DandC) methodology and evaluate it with angle diversity receivers in a mobile optical wireless system. The ultimate goal is to increase the signal-to-noise ratio (SNR), reduce the effect of intersymbol interference, and eliminate the need to calculate the hologram at each transmitter and receiver location. A significant improvement is achieved in the presence of demanding background illumination noise, receiver noise, multipath propagation, mobility, and shadowing typical in a realistic indoor environment. The combination of beam delay, angle, and power adaptation offers additional degrees of freedom in the link design, resulting in a system that is able to achieve higher data rates (5 Gb/s). At a higher data rate of 5 Gb/s and under eye safety regulations, the proposed FDAPA-Holograms system offers around 13 dB SNR with full mobility in a realistic environment where shadowing exists. The fast search algorithm introduced that is based on a D&C algorithm reduces the computation time required to identify the optimum hologram. Simulation results show that the proposed system, FDAPA-Holograms, can reduce the time required to identify the optimum hologram position from 64 ms taken by a classic adaptive hologram to about 14 ms

    Fast and Efficient Adaptation Techniques for Visible Light Communication Systems

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    Beam steering visible light communication (VLC) systems have been shown to offer performance enhancements over traditional VLC systems. However, an increase in the computational cost is incurred. In this paper, we introduce fast computer-generated holograms to speed up the adaptation process. The new, fast, and efficient fully adaptive VLC system can improve the receiver signal-to-noise ratio (SNR) and reduce the required time to estimate the position of the VLC receiver. It can also adapt to environmental changes, providing a robust link against signal blockage and shadowing. In addition, an angle diversity receiver and a delay adaptation technique are used to reduce the effect of intersymbol interference and multipath dispersion. Significant enhancements in the SNR with VLC channel bandwidths of more than 26 GHz are obtained, resulting in a compact impulse response and a VLC system that is able to achieve higher data rates (25 Gbps) with full mobility in the considered realistic indoor environment
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