210,160 research outputs found
Measurement of the CKM angle gamma from a combination of B->Dh analyses
No full textA combination of three LHCb measurements of the CKM angle gamma is presented. The decays B->DK and B->Dpi are used, where D denotes an admixture of D0 and D0-bar mesons, decaying into K+K-, pi+pi-, K+-pi-+, K+-pi-+pi+-pi-+, KSpi+pi-, or KSK+K- final states. All measurements use a dataset corresponding to 1.0 fb-1 of integrated luminosity. Combining results from B->DK decays alone a best-fit value of gamma = 72.0 deg is found, and confidence intervals are set gamma in [56.4,86.7] deg at 68% CL, gamma in [42.6,99.6] deg at 95% CL. The best-fit value of gamma found from a combination of results from B->Dpi decays alone, is gamma = 18.9 deg, and the confidence intervals gamma in [7.4,99.2] deg or [167.9,176.4] deg at 68% CL, are set, without constraint at 95% CL. The combination of results from B->DK and B->Dpi decays gives a best-fit value of gamma = 72.6 deg and the confidence intervals gamma in [55.4,82.3] deg at 68% CL, gamma in [40.2,92.7] deg at 95% CL are set. All values are expressed modulo 180 deg, and are obtained taking into account the effect of D0-D0bar mixing
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Optimum projection angle for attaining maximum distance in a soccer punt kick
No full textCopyright @ Journal of Sports Science and Medicine 2011.This article has been made available through the Brunel Open Access Publishing Fund.To produce the greatest horizontal distance in a punt kick the ball must be projected at an appropriate angle. Here, we investigated the optimum projection angle that maximises the distance attained in a punt kick by a soccer goalkeeper. Two male players performed many maximum-effort kicks using projection angles of between 10 degrees and 90 degrees. The kicks were recorded by a video camera at 100 Hz and a 2-D biomechanical analysis was conducted to obtain measures of the projection velocity, projection angle, projection height, ball spin rate, and foot velocity at impact. The player's optimum projection angle was calculated by substituting mathematical equations for the relationships between the projection variables into the equations for the aerodynamic flight of a soccer ball. The calculated optimum projection angles were in agreement with the player's preferred projection angles (40 degrees and 44 degrees). In projectile sports even a small dependence of projection velocity on projection angle is sufficient to produce a substantial shift in the optimum projection angle away from 45 degrees. In the punt kicks studied here, the optimum projection angle was close to 45 degrees because the projection velocity of the ball remained almost constant across all projection angles. This result is in contrast to throwing and jumping for maximum distance, where the projection velocity the athlete is able to achieve decreases substantially with increasing projection angle and so the optimum projection angle is well below 45 degrees.This article is made available through the Brunel University Open Access Publishing Fund
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Importance of low-angle grain boundaries in YBa2Cu3O7-delta coated conductors
No full textOver the past ten years the perception of grain boundaries in YBa2Cu3O7−δ conductors has changed greatly. They are now not a problem to be eliminated, but an inevitable and potentially favourable part of the material. This change has arisen as a consequence of new manufacturing techniques which result in excellent grain alignment, reducing the spread of grain boundary misorientation angles. At the same time there is considerable recent evidence which indicates that the variation of properties of grain boundaries with mismatch angle is more complex than a simple exponential decrease in critical current. This is due to the fact that low-angle grain boundaries represent a qualitatively different system to high-angle boundaries. The time is therefore right for a targeted review of research into low-angle YBa2Cu3O7−δ grain boundaries. This article does not purport to be a comprehensive review of the physics of grain boundaries as found in YBa2Cu3O7−δ in general; for a broader overview we would recommend that the reader consult the comprehensive review of Hilgenkamp and Mannhart (2002 Rev. Mod. Phys. 74 485). The purpose of this article is to review the origin and properties of the low-angle grain boundaries found in YBa2Cu3O7−δ coated conductors both individually and as a collective system
Pain and discomfort during the first week of rapid maxillary expansion (RME) using two different RME appliances : A randomized controlled trial
No full textObjectives: To evaluate and compare perceived pain intensity, discomfort, and jaw function impairment during the first week with tooth-borne or tooth-bone-borne rapid maxillary expansion (RME) appliances. Materials and Methods: Fifty-four patients (28 girls and 26 boys) with a mean age of 9.8 years (SD 1.28 years) were randomized into two groups. Group A received a conventional hyrax appliance and group B a hybrid hyrax appliance anchored on mini-implants in the anterior palate. Questionnaires were used to assess pain intensity, discomfort, analgesic consumption, and jaw function impairment on the first and fourth days after RME appliance insertion. Results: Fifty patients answered both questionnaires. Overall median pain on the first day in treatment was 13.0 (range 0-82) and 3.5 (0-78) for groups A and B, respectively, with no significant differences in pain, discomfort, analgesic consumption, or functional jaw impairment between groups. Overall median pain on the fourth day was 9.0 (0-90) and 2.0 (0-71) for groups A and B, respectively, with no significant differences between groups. There were also no significant differences in pain levels within group A, while group B scored significantly lower concerning pain from molars and incisors and tensions from the jaw on day 4 than on the first day in treatment. There was a significant positive correlation between age and pain and discomfort on the fourth day in treatment. No correlations were found between sex and pain and discomfort, analgesic consumption, and jaw function impairment. Conclusions: Both tooth-borne and tooth-bone-borne RME were generally well tolerated by the patients during the first week of treatment
Optimum take-off angle in the long jump
No full textIn this study, we found that the optimum take-off angle for a long jumper may be predicted by combining the equation for the range of a projectile in free flight with the measured relations between take-off speed, take-off height and take-off angle for the athlete. The prediction method was evaluated using video measurements of three experienced male long jumpers who performed maximum-effort jumps over a wide range of take-off angles. To produce low take-off angles the athletes used a long and fast run-up, whereas higher take-off angles were produced using a progressively shorter and slower run-up. For all three athletes, the take-off speed decreased and the take-off height increased as the athlete jumped with a higher take-off angle. The calculated optimum take-off angles were in good agreement with the athletes' competition take-off angles
The effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle-closure glaucoma (EAGLE): study protocol for a randomized controlled trial
No full textGlaucoma is the leading cause of irreversible blindness. Although primary open-angle glaucoma is more common, primary angle-closure glaucoma (PACG) is more likely to result in irreversible blindness. By 2020, 5·3 million people worldwide will be blind because of PACG. The current standard care for PACG is a stepped approach of a combination of laser iridotomy surgery (to open the drainage angle) and medical treatment (to reduce intraocular pressure). If these treatments fail, glaucoma surgery (eg, trabeculectomy) is indicated. It has been proposed that, because the lens of the eye plays a major role in the mechanisms leading to PACG, early clear lens extraction will improve glaucoma control by opening the drainage angle. This procedure might reduce the need for drugs and glaucoma surgery, maintain good visual acuity, and improve quality of life compared with standard care.EAGLE aims to evaluate whether early lens extraction improves patient-reported, clinical outcomes, and cost-effectiveness, compared with standard care
Study of the decay mechanism for B+ -> p(p)over-barK(+) and B+ -> p(p)over-bar pi(+)
No full textWe study the characteristics of the low mass p (p) over bar enhancements near threshold in the three-body decays B+ -> p (p) over barK(+) and B+ -> p (p) over bar pi(+). We observe that the proton polar angle distributions in the p (p) over bar helicity frame in the two decays have the opposite polarity, and measure the forward-backward asymmetries as a function of the p mass for the p (p) over barK(+) mode. We also search for the intermediate two-body decays, B+ -> (p) over bar Delta(++) and B+ -> p (Delta) over bar (0), and set upper limits on their branching fractions. These results are obtained from a 414 fb(-1) data sample that contains 449 x 10(6) B (B) over bar events collected near the Gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. (c) 2007 Elsevier B.V. All rights reserved.IPE
Reliability of popliteal angle measurement: a study in cerebral palsy patients and healthy controls
No full textThe popliteal angle is a widely used clinical measure for hamstring contracture in cerebral palsy (CP) patients and in healthy individuals. The reliability of popliteal angle measurement is being questioned. The aim of this study is to determine the reliability of popliteal angle measurement by means of visual and goniometric assessment. METHODS: Three different observers measured the popliteal angle in 15 CP patients and 15 healthy volunteers. In each subject, popliteal angles were visually estimated and measured with a blinded goniometer twice by all observers with approximately 1 hour between measurement sessions. RESULTS: All intraclass correlation coefficients (ICCs) were lower in the CP group compared with healthy controls. The ICC for intraobserver differences was higher than 0.75 for both groups. The ICC for interobserver reliability of visual estimates and goniometric measurements was low for both groups. Intermethod ICC was higher than 0.75 for both groups. CONCLUSIONS: Measurements in the CP group seemed to be less reliable than measurements in the control group. Intraobserver reliability is reasonable for both groups, but lower in CP patients than in controls. Interobserver reliability of both visual estimates and goniometrical measurements is poor. No significant differences in reliability have been found between visual estimation and goniometric measurement. Because of poor interobserver reliability of popliteal angle measurement, this should not be the only variable in clinical decision making in CP patients
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