4,187 research outputs found
Extracting Form Factors from Data
We extract ratios of form factors at low hadronic recoil from
recent data on decays in a model-independent way. The
presented method will improve in the future with further (angular) studies in
semileptonic rare B-decays and advance our understanding of form factors, which
are important inputs in precision tests of the Standard Model
Targeting a channel coating by using magnetic field and magnetic nanofluids
In this paper, the magnetic nanofluids and magnetic field are used to provide a coating around the wall of a channel. The magnetic field is induced by the direct current wire. Iron oxide is used as magnetic nanoparticles. A finite volume method is used to solve the Navier–Stokes equations, and the Eulerian–Lagrangian approach is employed to track the magnetic nanoparticles. The effects of magnetic strength, the position of current wire, and the diameter of magnetic nanoparticles on the trajectory of magnetic nanoparticles and coating efficiency are investigated by providing contours and diagrams. The results show that the length of coating decreases by about 55% with the increase in the particle diameter in the range of 500 nm to 1 μm. Further, the coating efficiency, defined as the ratio of the number of trapped particles on the wall to the number of injected particles at the inlet of the channel, improves by increasing the magnetic strength and decreasing the vertical position of the current wire
Sustainable use of winter Durum wheat landraces under Mediterranean conditions
This research expected to determine new durum wheat germplasm resistant to biotic and abiotic stress factors. Eighty durum wheat lines selected from eighteen diverse landraces were tested together with eight durum wheat cultivars under reliable yellow rust epidemic during two successive years. Average infection coefficient of populations and cultivars was 32.44 in 2003 and 26.24 in 2004, showing severe epidemic condition which occurred at adult plant stage in 2003. Because of this the number of selected resistant and moderately resistant plant material greatly reduced. According to the yield trial study in which twenty resistant lines selected out of 30 resistant and moderately from sixteen populations were included, only two checks outperformed grand mean (2.48 t ha -1) and two lines selected from landrace population followed these with slightly lower yield difference. On the other hand, there were several lines which performed better than the grand mean of protein content (13.24%), SDS sedimentation (28.40 ml) and semolina color (24.35) and they ranked in the first group including the two checks cultivars. Bi- plot analysis showed that some promising lines with reasonable grain yields, good quality parameters, winter hardiness and drought tolerances among yellow rust resistance durum wheat landraces can be selected for semiarid conditions of Mediterranean countries for sustainable production
Thrombotic gene polymorphisms and postoperative outcome after coronary artery bypass graft surgery
<p>Abstract</p> <p>Background</p> <p>Emerging perioperative genomics may influence the direction of risk assessment and surgical strategies in cardiac surgery. The aim of this study was to investigate whether single nucleotide polymorphisms (SNP) affect the clinical presentation and predispose to increased risk for postoperative adverse events in patients undergoing coronary artery bypass grafting surgery (CABG).</p> <p>Methods</p> <p>A total of 220 patients undergoing first-time CABG between January 2005 and May 2008 were screened for factor V gene G1691A (FVL), prothrombin/factor II G20210A (PT G20210A), angiotensin I-converting enzyme insertion/deletion (ACE-ins/del) polymorphisms by PCR and Real Time PCR. End points were defined as death, myocardial infarction, stroke, postoperative bleeding, respiratory and renal insufficiency and event-free survival. Patients were compared to assess for any independent association between genotypes for thrombosis and postoperative phenotypes.</p> <p>Results</p> <p>Among 220 patients, the prevalence of the heterozygous FVL mutation was 10.9% (n = 24), and 3.6% (n = 8) were heterozygous carriers of the PT G20210A mutation. Genotype distribution of ACE-ins/del was 16.6%, 51.9%, and 31.5% in genotypes I/I, I/D, and D/D, respectively. FVL and PT G20210A mutations were associated with higher prevalence of totally occluded coronary arteries (p < 0.001). Furthermore the risk of left ventricular aneurysm formation was significantly higher in FVL heterozygote group compared to FVL G1691G (<it>p </it>= 0.002). ACE D/D genotype was associated with hypertension (<it>p </it>= 0.004), peripheral vascular disease (p = 0.006), and previous myocardial infarction (<it>p </it>= 0.007).</p> <p>Conclusions</p> <p>FVL and PT G20210A genotypes had a higher prevalence of totally occluded vessels potentially as a result of atherothrombotic events. However, none of the genotypes investigated were independently associated with mortality.</p
Patterns of genetic diversity and linkage disequilibrium in a highly structured Hordeum vulgare association-mapping population for the Mediterranean basin
Population structure and genome-wide linkage disequilibrium (LD) were investigated in 192 Hordeum vulgare accessions providing a comprehensive coverage of past and present barley breeding in the Mediterranean basin, using 50 nuclear microsatellite and 1,130 DArT® markers. Both clustering and principal coordinate analyses clearly sub-divided the sample into five distinct groups centred on key ancestors and regions of origin of the germplasm. For given genetic distances, large variation in LD values was observed, ranging from closely linked markers completely at equilibrium to marker pairs at 50 cM separation still showing significant LD. Mean LD values across the whole population sample decayed below r 2 of 0.15 after 3.2 cM. By assaying 1,130 genome-wide DArT® markers, we demonstrated that, after accounting for population substructure, current genome coverage of 1 marker per 1.5 cM except for chromosome 4H with 1 marker per 3.62 cM is sufficient for whole genome association scans. We show, by identifying associations with powdery mildew that map in genomic regions known to have resistance loci, that associations can be detected in strongly stratified samples provided population structure is effectively controlled in the analysis. The population we describe is, therefore, shown to be a valuable resource, which can be used in basic and applied research in barle
A two-level temporal fair scheduler for multi-cell wireless networks
We propose a two-level scheduler for a frequency reuse-1 multi-cell wireless network satisfying inter-and intra-cell weighted temporal fairness constraints. As opposed to hard partitioning of the entire frequency band to different cell patterns in frequency reuse-M systems (M>1), we propose sharing this band opportunistically in time by these patterns. Through numerical examples, we show notable gains in overall network throughput due to improved multi-user diversity in comparison with a conventional frequency reuse-3 system. © 2012 IEEE
PTPN22 gene polymorphism in Takayasu's arteritis
Objective. Takayasu's arteritis (TA) is a chronic, rare granulomatous panarteritis of unknown aetiology involving mainly the aorta and its major branches. In this study, genetic susceptibility to TA has been investigated by screening the functional single nucleotide polymorphism (SNP) of PTPN22 gene encoding the lymphoid-specific protein tyrosine phosphatase. Methods. Totally, 181 patients with TA and 177 healthy controls are genotyped by PCR-RFLP method for the SNP rs2476601 (A/G) of PTPN22 gene. Polymorphic region was amplified by PCR and digested with Xcm I enzyme. Results. Detected frequencies of heterozygous genotype (AG) were 5.1% (9/177) in control group and 3.8% (7/181) in TA group (P = 0.61, odds ratio: 0.75, 95% CI: 0.3, 2.0). No association with angiographic type, vascular involvement or prognosis of TA was observed either. Conclusion. The distribution of PTPN22 polymorphism did not reveal any association with TA in Turkey. © The Author 2008. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved
Mapping adaptation of barley to droughted environments
Identifying barley genomic regions influencing the response of yield and its components to water deficits will aid in our understanding of the genetics of drought tolerance and the development of more drought tolerant cultivars. We assembled a population of 192 genotypes that represented landraces, old, and contemporary cultivars sampling key regions around the Mediterranean basin and the rest of Europe. The population was genotyped with a stratified set of 50 genomic and EST derived molecular markers, 49 of which were Simple Sequence Repeats (SSRs), which revealed an underlying population sub-structure that corresponded closely to the geographic regions in which the genotypes were grown. A more dense whole genome scan was generated by using Diversity Array Technology (DArT®) to generate 1130 biallelic markers for the population. The population was grown at two contrasting sites in each of seven Mediterranean countries for harvest 2004 and 2005 and grain yield data collected. Mean yield levels ranged from 0.3 to 6.2 t/ha, with highly significant genetic variation in low-yielding environments. Associations of yield with barley genomic regions were then detected by combining the DArT marker data with the yield data in mixed model analyses for the individual trials, followed by multiple regression of yield on markers to identify a multi-locus subset of significant markers/QTLs. QTLs exhibiting a pre-defined consistency across environments were detected in bins 4, 6, 6 and 7 on barley chromosomes 3H, 4H, 5H and 7H respectivel
Treatment Challenges in Pediatric Stroke Patients
Aim. In this study we presented our experience of 18 years on the etiology, risk factors, prophylactic and acute treatment, the effect of treatment to recurrence rate of patients with stroke. Methods. The population included 108 patients who had been treated for stroke at Pediatric Neurology Department of Ankara University with the diagnosis of arterial ischemic stroke and sinovenous thrombosis between January 1992 and
August 2010. Forty-one girls (38%) and 67 boys (62%) with mean symptom age 3.1 ± 4.04 years, (0–18 years old) were followed up with a mean period of 4.9 ± 3.78 years (0–17 years). Results. 30 patients had no risk factors, 34 patients had only one risk factor and 44 patients had multiple risk factors. Recurrence was seen in three patients. There was no any statistical correlation between the recurrence of stroke and the existence of risk factors (P = .961). Seventeen
patients received prophylactic treatment; 2 of them without any risk factors, 3 had one risk factor, 12 patients, who constituted the majority of our patients, had multiple risk factors (P = .024).
Conclusion. With this study we showed that the right prophylaxis for right patients reduces the rate of recurrence
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