41,950 research outputs found
Measurement of the branching fractions for B--> D(*)+pi(-)l(-)(nu)over-bar(l) and (B)over-bar(0)-> D-(*)0 pi(+)l(-)(nu)over-bar(l)
No full textWe report on a measurement of the branching fractions for B- --> D(*)+ pi(-)l(-)(nu) over bar (l) and (B) over bar (0) --> D-(*)0 pi(+)l(-)(nu) over bar (l) with 275 x 10(6) B (B) over bar events collected at the Y(4S) resonance with the Belle detector at KEKB. Events are tagged by fully reconstructing one of the B mesons in hadronic modes. We obtain B(B- --> D(+)pi(-)l(-)(nu) over bar (l)) = (0.54 +/- 0.07 (stat) +/- 0.07(syst) +/- 0.06(BR)) x 10(-2), B(B- --> D*+pi(-) l(-) (nu) over bar (l)) (0.67 +/- 0.11 (stat) +/- 0.09(syst) +/- 0.03(BR)) x 10(-2), B((B) over bar (0) --> D(0)pi(+)l(-) (nu) over bar (l)) = (0.33 +/- 0.06(stat) +/- 0.06(syst) +/- 0.03(BR)) x 10(-2), B((B) over bar (0) -->D(*0)pi(+)l(-)(nu) over bar (l)) = (0.65 +/- 0.12(stat) +/- 0.08(syst) +/- 0.05(BR)) x 10(-2), where the third error comes from the error on (B) over bar --> D((*))l(-)(nu) over bar (l) decays. Contributions from B-0 --> D(*+)l(-)(nu) over bar (l) decays are excluded in the measurement of (B) over bar (0) --> D(0)pi(+)l-(nu) over bar (l).Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)0ARTICLE5null7
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Precision measurement of the D*(0) decay branching fractions
No full textUsing 482 pb(-1) of data taken at root s = 4.009 GeV, we measure the branching fractions of the decays of D*(0) into D-0 pi(0) and D-0 gamma to be B(D*(0) -> D-0 pi(0)) = (65.5 +/- 0.8 +/- 0.5)% and B(D*(0) -> D0 gamma) = (34.5 +/- 0.8 +/- 0.5)%, respectively, by assuming that the D*(0) decays only into these two modes. The ratio of the two branching fractions is B(D*(0) -> D-0 pi(0))/B(D*(0) -> D-0 gamma) = 1.90 +/- 0.07 +/- 0.05, which is independent of the assumption made above. The first uncertainties are statistical and the second ones systematic. The precision is improved by a factor of 3 compared to the present world average values
Measurements of the absolute branching fractions for D-s(+) -> eta e(+)nu(e) and D-s(+) -> eta ' e(+)nu(e)
No full textBy analyzing 482 pb(-1) of e(+)e(-) collision data collected at root s = 4.009 GeV with the BESIII detector at the BEPCII collider, we measure the absolute branching fractions for the semileptonic decays D-s(+) -> eta e(+)nu(e) and D-s(+) -> eta ' e(+)nu(e) to be B(D-s(+) -> eta e(+)nu(e)) = (2.30 +/- 0.31 +/- 0.08)% and B(D-s(+) -> eta ' e(+)nu(e)) = (0.93 +/- 0.30 +/- 0.05)%, respectively, and their ratio B(D-s(+) -> eta ' e(+)nu(e)) / B(D-s(+) -> eta ' e(+)nu(e)) = 0.40 +/- 0.14 +/- 0.02, where the first uncertainties are statistical and the second ones are systematic. The results are in good agreement with previous measurements within uncertainties; they can be used to determine the eta-eta' mixing angle and improve upon the D-s(+) semileptonic branching ratio precision
Understanding the D-sJ(+)(2317) and D-sJ(+)(2460) with sum rules in heavy quark effective theory
No full textIn the framework of heavy quark effective theory we use QCD sum rules to calculate the masses of the (c) over bars(0(+),1(+)) and (1(+),2(+)) excited states. The results are consistent with the states D-sJ(2317) and D-sJ(2460) observed by BABAR and CLEO being the 0(+) and 1(+) states in the j(l)=1/2(+) doublet.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)0ARTICLE11null6
Vitamin D supplementation and breast cancer prevention : a systematic review and meta-analysis of randomized clinical trials
No full textIn recent years, the scientific evidence linking vitamin D status or supplementation to breast cancer has grown notably. To investigate the role of vitamin D supplementation on breast cancer incidence, we conducted a systematic review and meta-analysis of randomized controlled trials comparing vitamin D with placebo or no treatment. We used OVID to search MEDLINE (R), EMBASE and CENTRAL until April 2012. We screened the reference lists of included studies and used the “Related Article” feature in PubMed to identify additional articles. No language restrictions were applied. Two reviewers independently extracted data on methodological quality, participants, intervention, comparison and outcomes. Risk Ratios and 95% Confident Intervals for breast cancer were pooled using a random-effects model. Heterogeneity was assessed using the I2 test. In sensitivity analysis, we assessed the impact of vitamin D dosage and mode of administration on treatment effects. Only two randomized controlled trials fulfilled the pre-set inclusion criteria. The pooled analysis included 5372 postmenopausal women. Overall, Risk Ratios and 95% Confident Intervals were 1.11 and 0.74–1.68. We found no evidence of heterogeneity. Neither vitamin D dosage nor mode of administration significantly affected breast cancer risk. However, treatment efficacy was somewhat greater when vitamin D was administered at the highest dosage and in combination with calcium (Risk Ratio 0.58, 95% Confident Interval 0.23–1.47 and Risk Ratio 0.93, 95% Confident Interval 0.54–1.60, respectively). In conclusions, vitamin D use seems not to be associated with a reduced risk of breast cancer development in postmenopausal women. However, the available evidence is still limited and inadequate to draw firm conclusions. Study protocol code: FARM8L2B5L
Preservice Teachers' Development of Effective Approaches to Text-based Discussion
No full textText-based discussion is a dialogic instructional practice to promote reading comprehension among students. To enact this practice, a teacher engages students in authentic conversation about text as students read it, to assist them in building understanding of text ideas as they are encountered. Text-based discussion has the potential to promote the development of both low-level and high-level comprehension skills among students, yet teachers need support in learning to enact it. Research has indicated that text-based discussion is not well-represented in classrooms today, likely because not many teachers have access to this support.
Recently, some teacher educators have focused on teaching preservice teachers (PSTs) to enact text-based discussions during teacher preparation programs, in an attempt to increase the presence of the practice in classrooms. Practice-based methods courses have been developed which attempt to provide preservice teachers with the knowledge and skill needed to enact text-based discussions successfully. This study investigated the ways in which six preservice teachers’ enactments of text-based discussion developed over the course of their one-year student teaching placements, after completing one such methods course in which they learned to enact the practice.
Data were collected at three time points during student teaching, and included transcripts of enactments of text-based discussion, lesson plans, interview transcripts, and assessments of lesson quality using the Instructional Quality Instrument (Junker et al., 2004). Analysis of the data suggested that the PSTs entered student teaching with the ability to enact text-based discussions with a moderate level of success, and that the quality of the discussions continued to improve over the course of the school year. The methods course seemed to support PSTs in learning to link student comments and press students for accuracy and reasoning. PSTs were more successful in eliciting student linking and recall of explicit text information than in eliciting elaborated responses from students; the participation structure enforced by the PST seemed to influence the extent to which students provided elaborated responses. This study supports the use of practice-based methods courses to teach PSTs to enact text-based discussions, and uncovers several areas that are in need of additional focus during these courses
Inclusive decays B->DX and B->D*X
No full textComplete Author List: Gibbons L, Johnson SD, Kwon Y, Roberts S, Thorndike EH, Jessop CP, Lingel K, Marsiske H, Perl ML, Schaffner SF, Ugolini D, Wang R, Zhou X, Coan TE, Fadeyev V, Korolkov I, Maravin Y, Narsky I, Shelkov V, Staeck J, Stroynowski R, Volobouev I, Ye J, Artuso M, Efimov A, Frasconi F, Gao M, Goldberg M, He D, Kopp S, Horwitz N, Moneti GC, Mountain R, Mukhin Y, Schuh S, Skwarnicki T, Stone S, Thulasidas M, Viehhauser G, Xing X, Bartelt J, Csorna SE, Jain V, Marka S, Freyberger A, Godang R, Kinoshita K, Lai IC, Pomianowski P, Schrenk S, Bonvicini G, Cinabro D, Greene R, Perera LP, Barish B, Chadha M, Chan S, Eigen G, Miller JS, OGrady C, Schmidtler M, Urheim J, Weinstein AJ, Wurthwein F, Asner DM, Bliss DW, Brower WS, Masek G, Paar HP, Sharma V, Gronberg J, Kutschke R, Lange DJ, Menary S, Morrison RJ, Nelson HN, Nelson TK, Qiao C, Richman JD, Roberts D, Ryd A, Witherell MS, Balest R, Behrens BH, Cho K, Ford WT, Park H, Rankin P, Roy J, Smith JG, Alexander JP, Bebek C, Berger BE, Berkelman K, Bloom K, Cassel DG, Cho HA, Coffman DM, Crowcroft DS, Dickson M, Drell PS, Ecklund KM, Ehrlich R, Elia R, Foland AD, Gaidarev P, Gittelman B, Gray SW, Hartill DL, Heltsley BK, Kandaswamy J, Katayama N, Kim PC, Kreinick DL, Lee T, Liu Y, Ludwig GS, Masui J, Mevissen J, Mistry NB, Ng CR, Nordberg E, Ogg M, Patterson JR, Peterson D, Riley D, Soffer A, Ward C, Athanas M, Avery P, Jones CD, Lohner M, Prescott C, Yang S, Yelton J, Zheng J, Brandenburg G, Briere RA, Gao YS, Kim DYJ, Wilson R, Yamamoto H, Browder TE, Li F, Li Y, Rodriguez JL, Bergfeld T, Eisenstein BI, Ernst J, Gladding GE, Gollin GD, Hans RM, Johnson E, Karliner I, Marsh MA, Palmer M, Selen M, Thaler JJ, Edwards KW, Bellerive A, Janicek R, MacFarlane DB, McLean KW, Patel PM, Sadoff AJ, Ammar R, Baringer P, Bean A, Besson D, Coppage D, Darling C, Davis R, Hancock N, Kotov S, Kravchenko I, Kwak N, Anderson S, Kubota Y, Lattery M, ONeill JJ, Patton S, Poling R, Riehle T, Savinov V, Smith A, Alam MS, Athar SB, Ling Z, Mahmood AH, Severini H, Timm S, Wappler F, Anastassov A, Blinov S, Duboscq JE, Fisher KD, Fujino D, Fulton R, Gan KK, Hart T, Honscheid K, Kagan H, Kass R, Lee J, Spencer MB, Sung M, Undrus A, Wanke R, Wolf A, Zoeller MM, Nemati B, Richichi SJ, Ross WR, Skubic P, Wood M, Bishai M, Fast J, Gerndt E, Hinson JW, Menon N, Miller DH, Shibata EI, Shipsey IPJ, Yurko M</p
Coauthor prediction for junior researchers
No full textResearch collaboration can bring in different perspectives and generate more productive results. However, finding an appropriate collaborator can be difficult due to the lacking of sufficient information. Link prediction is a related technique for collaborator discovery; but its focus has been mostly on the core authors who have relatively more publications. We argue that junior researchers actually need more help in finding collaborators. Thus, in this paper, we focus on coauthor prediction for junior researchers. Most of the previous works on coauthor prediction considered global network feature and local network feature separately, or tried to combine local network feature and content feature. But we found a significant improvement by simply combing local network feature and global network feature. We further developed a regularization based approach to incorporate multiple features simultaneously. Experimental results demonstrated that this approach outperformed the simple linear combination of multiple features. We further showed that content features, which were proved to be useful in link prediction, can be easily integrated into our regularization approach. © 2013 Springer-Verlag
HIV/AIDS in the Slums of Kenya: Intervening Through Effectively Utilizing Volunteers
No full textHIV/AIDS affects millions of people globally and has significantly impacted public health for decades. In Kenya, the effects of HIV/AIDS are widespread, but slum areas have an adult HIV prevalence rate twice as high as the national rate. Slums are characterized by scarce resources, making HIV prevention efforts extremely challenging. Many believe that the voluntary sector is best suited for the role of spearheading efforts to address HIV/AIDS through prevention programs. International volunteerism is growing in popularity, but the various projects that volunteers work on are sustainable and impactful only if the volunteers are properly trained. To examine this process, the author travelled to Kenya to work with Fadhili Community, a local NGO involved in HIV/AIDS prevention programs within Kibera and other slums. The objectives of this research study were to assess current volunteer HIV/AIDS programs, determine gaps in knowledge and skills among volunteers, and develop an HIV/AIDS training manual for incoming volunteers. The author, utilizing participant observation, visited eight
volunteer HIV/AIDS programs in different regions of Kenya to assess them for organizational capacity to utilize volunteers. The author discovered widespread assumptions prevalent among HIV programs and international volunteers that prevented effective utilization of volunteers. To address the gaps in knowledge common among volunteers and to address the expectations of HIV programs, the author created and introduced a HIV/AIDS manual to Fadhili Community
volunteers. Educating and training international volunteers in a concise yet effective way will positively impact HIV/AIDS programs in Kibera
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