2,775 research outputs found
Re:Association between biallelic and monoallelic germline MYH gene mutations and colorectal cancer risk
Frequency and type of toenail tumors in the dromedary camel
A total of 275 dromedary camels (16 males and 259 females) of local “Arabiyat” breed suffering from different types and degrees of severity of toenail tumors were surgically treated. Histopathological examination of the tissue samples removed from 50 tumor-like growths (2 males and 48 females) revealed three types of tumors; squamous cell carcinoma (70%), spiny keratoderma (22%) and fibroma (8%). An increased incidence of tumors was recorded in the medial when compared to the lateral toenails in both sexes. In females, the incidence in the medial toenails was 90/259 (34.75%) and 71/259 (27.41%) in the right and left forelimbs respectively when compared to the lateral toenails which was 25/259 (9.65%) and 5/259 (1.93%) for the respective right and left forelimbs. In the hind limbs, this ratio was 29/259 (11.20%) and 20/259 (7.72%) for right and left medial toenails respectively, whereas it was 17/259 (6.56%) and 2/259 (0.77%) for the right and left lateral toenails respectively. Similar to the observations in female camels, male camels also showed a higher incidence of these tumors in the medial when compared to the lateral toenails in both fore and hind limbs. Based on these findings, we conclude that in the dromedary camels, the medial toenails of the fore limbs are most commonly affected with tumors; with the most common tumor being the squamous cell carcinoma
The use of high throughput DNA sequence analysis to assess the endophytic microbiome of date palm roots grown under different levels of salt stress
Date palms are able to grow under diverse abiotic stress conditions including in saline soils, where microbial communities may be help in the plant’s salinity tolerance. These communities able to produce specific growth promoting substances can enhance date palm growth in a saline environment. However, these communities are poorly defined. In the work reported here, the date palm endophytic bacterial and fungal communities were identified using the pyrosequencing method, and the microbial differential abundance in the root upon exposure to salinity stress was estimated. Approximately 150,061 reads were produced from the analysis of six ribosomal DNA libraries, which were prepared from endophytic microorganisms colonizing date palm root tissues. DNA sequence analysis of these libraries predicted the presence of a variety of bacterial and fungal endophytic species, some known and others unknown. The microbial community compositions of 30% and 8% of the bacterial and fungal species, respectively, were significantly (p ≤ 0.05) altered in response to salinity stress. Differential enrichment analysis showed that microbe diversity indicated by the Chao, Shannon and Simpson indices were slightly reduced, however, the overall microbial community structures were not significantly affected as a consequence of salinity. This may reflect a buffering effect by the host plant on the internal environments that these communities are colonizing. Some of the endophytes identified in this study were strains that were previously isolated from saline and marine environments. This suggests possible interactions with the plant that are favorable to salinity tolerance in date palm. [Int Microbiol 19(3):143-155 (2016)]Keywords: Phoenix dactylifera · endophytes · salt stres
Optimisation of arsenic adsorption from water by carbon nanofibres grown on powdered activated carbon impregnated with nickel
Contamination of water due to arsenic (As) is increasing in many parts of the world. The removal of As from aqueous solution by using impregnated carbon nanofibres (CNFs) as the adsorbent is reported in this paper. The effects of pH, CNFs dosage, contact time and initial concentration of arsenic were studied at room temperature (±25°C). The interactions among the parameters were also investigated. The data obtained from the adsorption experiment were analysed using statistical software in order to develop a regression equation to represent the optimum operating conditions. The interactions of each parameters were considered during this analysis and the result indicated that the highest removal (97.25%) of As can be attained at pH 6, initial concentration of arsenic of 0.08 mg L-1, contact time of 60 min and CNF dosage of 200 mg L-1. Comparison between impregnated CNF and Powdered Activated Carbon (PAC) were also done and it is determined that impregnated CNF has better removal compared to PAC alone. The final concentration of As after the treatment using CNFs was about 8 ~ 10 times less than that of using PAC. Therefore, it can be concluded that CNFs are highly potential for the adsorption of As from water
Adaptive multi-polling scheduler for QoS support of video transmission in IEEE 802.11e WLANs
The 802.11E Task Group has been established to enhance quality of service (QoS) provision for time-bounded services in the current IEEE 802.11 medium access control protocol. The QoS is introduced throughout hybrid coordination function controlled channel access (HCCA) for the rigorous QoS provision. In HCCA, the station is allocated a fixed transmission opportunity (TXOP) based on its TSPEC parameters so that it is efficient for constant bit rate streams. However, as the profile of variable bit rate traffics is inconstant, they are liable to experience a higher delay especially in bursty traffic case. In this paper, we present a dynamic TXOP assignment algorithm called adaptive multi-polling TXOP scheduling algorithm (AMTXOP) for supporting the video traffics transmission over IEEE 802.11e wireless networks. This scheme invests a piggybacked information about the size of the subsequent video frames of the uplink streams to assist the hybrid coordinator accurately assign the TXOP according to actual change in the traffic profile. The proposed scheduler is powered by integrating multi-polling scheme to further reduce the delay and polling overhead. Extensive simulation experiments have been carried out to show the efficiency of the AMTXOP over the existing schemes in terms of the packet delay and the channel utilization
Sustainable Clinical Academic Training Pathways: A framework for implementation in Oman
Clinical academics—medical doctors with additional training in basic science or clinical research—play a pivotal role in translating biomedical research into practical bedside applications. However, international studies suggest that the proportion of clinical academics relative to the medical workforce is dwindling worldwide. Although efforts to reverse this trend are ongoing in many countries, there is little perceptible dialogue concerning these issues in Oman. This article explores the current status of clinical academic training pathways worldwide, concluding with a framework for the implementation of a dual-degree medical-research training programme in Oman in order to stimulate and develop a sustainable national clinical academic workforce.Keywords: Training Programs; Undergraduate Medical Education; Graduate Medical Education; Internship and Residency; Medical Students; Research; Oman
Prevalence and Spectrum of Coronary Anomalies Detected on Coronary Computed Tomography Angiography: A single centre experience in Oman
ABSTRACT: Objectives: Coronary artery anomalies (CAAs) are uncommon congenital abnormalities with a prevalence ranging from 0.2–2%. CAAs can be asymptomatic or less commonly present with life-threatening symptoms. This study aimed to investigate the prevalence and spectrum of CAAs in patients who underwent coronary computed tomography angiography (CCTA) in Oman. Methods: This retrospective study was conducted at the National Heart Centre, Muscat, Oman between September 2012 and August 2018. All consecutive patients who had undergone CCTA were included. Results: A total of 4,445 patients were included in this study. Of these, 59 patients (1.3%) were diagnosed with CAAs with a mean age of 52.6 years (range: 12–80 years) and an equal gender distribution. Among the patients with CAAs, the majority (69.5%) had anomalous origins from the opposite or non-coronary sinus. Right coronary artery arising from the left coronary sinus was the most common type (33.9%). Fewer patients (18.6%) had left circumflex arising from the right coronary sinus (RCS). Seven patients (11.9%) had left main arising from the RCS. Other CAAs were in the dual left anterior descending artery (8.5%), high coronary artery take-off (6.8%), single coronary ostia (6.8%) and coronary artery fistula (6.8%). Conclusion: The prevalence of CAAs was 1.3% which is similar to the literature.Keywords: Coronary Vessel Anomalies; Computed Tomography Angiography; Prevalence; Oman
Anti-cancer effects and mechanism of actions of aspirin analogues in the treatment of glioma cancer
INTRODUCTION: In the past 25 years only modest advancements in glioma treatment have been made, with patient prognosis and median survival time following diagnosis only increasing from 3 to 7 months. A substantial body of clinical and preclinical evidence has suggested a role for aspirin in the treatment of cancer with multiple mechanisms of action proposed including COX 2 inhibition, down regulation of EGFR expression, and NF-κB signaling affecting Bcl-2 expression. However, with serious side effects such as stroke and gastrointestinal bleeding, aspirin analogues with improved potency and side effect profiles are being developed. METHOD: Effects on cell viability following 24 hr incubation of four aspirin derivatives (PN508, 517, 526 and 529) were compared to cisplatin, aspirin and di-aspirin in four glioma cell lines (U87 MG, SVG P12, GOS – 3, and 1321N1), using the PrestoBlue assay, establishing IC50 and examining the time course of drug effects. RESULTS: All compounds were found to decrease cell viability in a concentration and time dependant manner. Significantly, the analogue PN517 (IC50 2mM) showed approximately a twofold increase in potency when compared to aspirin (3.7mM) and cisplatin (4.3mM) in U87 cells, with similar increased potency in SVG P12 cells. Other analogues demonstrated similar potency to aspirin and cisplatin. CONCLUSION: These results support the further development and characterization of novel NSAID derivatives for the treatment of glioma
Calibrating PIRLS Test in Sultanate of Oman Using Item Response Theory
The study aimed to calibrate Oman data of the PIRLS test using the graded response model and to examine the psychometric properties of it, as well as identify the fit and unfit of its items. PIRLS2011 test booklets were used, which consisted of 146 test items (74 dichotomous and 72 polytomous). Items were divided into 13 booklets; each with two blocks (one literary and one informational). PIRLS test booklets were administered to 13 groups of fourth grade students in Sultanate of Oman with a total sample of 10394 students. Assumptions of IRT (unidimensionality and local independence) were examined and supported. Also, item fit was examined and supported using Samejima’s graded response model. The data was analyzed by Multilog7.03 program to estimate both item and ability parameters. Results indicated that the assumptions of IRT were proved. Also, IRT analysis revealed that 8 items showed unfit which represents only 5% of the test items. So, this result confirms that the test has good psychometric properties under the IRT
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