4,521 research outputs found

    Are Researchers Registering Systematic Reviews in ClinicalTrials.gov?

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    BACKGROUND: ClinicalTrials.gov (CT) is an increasingly important resource for systematic reviewers attempting to identify published and unpublished clinical studies. In addition to clinical studies, however, some searches of the CT database also return systematic reviews (SRs). When I inquired about the SRs appearing in the results, the NLM Help Desk responded that “We do not recommend that systematic reviews be entered in ClinicalTrials.gov, since we only want the results of a clinical trial entered once. However, we will not refuse them if they are entered.” I wanted to find out how many SRs are included, describe their characteristics, and suggest search strategies for those wishing to exclude them. METHODS: Conduct a CT search for “systematic review” without limiting by field in case an SR was not explicitly titled as such. Screen the results for those records representing SRs as opposed to, e.g., mentioning one in the background to a clinical trial. Identify the total number of SRs. Test strategies for their ability to exclude them and calculate sensitivity, precision and specificity. RESULTS: I ran a search for “systematic review” (in quotes) in the advanced search \u3e Search Terms (field) on July 14, 2016, and applying no other limits, downloaded 181 results for analysis from among the 220,113 total number of records in the CT database. Of the 181 records, 47 (26%) were systematic reviews. All 47 were listed as Study Type: Observational. The remaining 134 records that were not SRs included a mix of Observational (21, 15.7%) and Interventional (113, 84.3%) study types. Title searching offers an effective way to avoid SRs: all but two true SRs had “systematic review” or “meta-analysis” in the Brief or Official Title. So in the expert search you could add the filter: NOT ( systematic review [TITLES] OR metaanalysis [TITLES] ). This filter has a sensitivity of 94.8%, precision of 96.9%, and specificity of 91.5%. CONCLUSION: The number of systematic reviews registered in CT is small at this time. They can be accurately avoided if you are looking for interventional studies by using the Study Type field, but not if you are looking for observational studies. Using the proposed title searching filter offers an effective way to avoid them. Librarians should advise their teams to register systematic reviews in appropriate sources such as PROSPERO (http://www.crd.york.ac.uk/PROSPERO/), but not ClinicalTrials.gov

    Replacement for the 10 page paper? A pilot project using blogs and wikis for a collaborative EBM assignment in a 3rd year internal medical clerkship

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    Objective Pilot a group assignment using blogs and wikis to develop evidence-based medicine skills in third year medical students on an internal medicine clerkship. Instead of the clerkship’s previous individual ten-page paper assignment, the students were divided into four groups of sixteen. During the clerkship, students are on geographically dispersed rotations. The earlier ten-page paper had required the students to complete a patient history and physical write-up. With the pilot project, each group was assigned a librarian and a physician faculty mentor. Each student recorded on the blog a clinical scenario and question they encountered. They were encouraged to communicate with the librarian to construct a well formed clinical question. Each student group then came to consensus on which question to pursue and collaborated on a wiki including a list of citations to the best available evidence, a critique of the studies, and implications for the patient

    Discovery potential of top-partners in a realistic composite Higgs model with early LHC data

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    Composite Higgs models provide a natural, non-supersymmetric solution to the hierarchy problem. In these models, one or more sets of heavy top-partners are typically introduced. Some of these new quarks can be relatively light, with a mass of a few hundred GeV, and could be observed with the early LHC collision data expected to be collected during 2010. We analyse in detail the collider signatures that these new quarks can produce. We show that final states with two (same-sign) or three leptons are the most promising discovery channels. They can yield a 5 sigma excess over the Standard Model expectation already with the 2010 LHC collision data. Exotic quarks of charge 5/3 are a distinctive feature of this model. We present a new method to reconstruct their masses from their leptonic decay without relying on jets in the final state.Comment: 28 pages 11 Figures 7 Tables, minor changes, added references, matches published versio

    Search for the Elusive Higgs Boson Using Jet Structure at LHC

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    We consider the production of a light non-standard model Higgs boson of order 100~\GEV with an associated WW boson at CERN Large Hadron Collider. We focus on an interesting scenario that, the Higgs boson decays predominately into two light scalars χ\chi with mass of few GeV which sequently decay into four gluons, i.e. h2χ4gh\to 2\chi \to 4g. Since χ\chi is much lighter than the Higgs boson, it will be highly boosted and its decay products, the two gluons, will move close to each other, resulting in a single jet for χ\chi decay in the detector. By using electromagnetic calorimeter-based and jet substructure analyses, we show in two cases of different χ\chi masses that it is quite promising to extract the signal of Higgs boson out of large QCD background.Comment: 20 pages, 7 figure

    Supporting the Occupational Therapy Student in the Production and Dissemination of Systematic Reviews: An Interprofessional Collaboration among Librarians and Occupational Therapy Faculty

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    Objectives This poster describes the outcomes of a curriculum-based collaboration between librarians and OT faculty (‘collaboration’) to enhance graduate student skills for conducting a systematic review (SR); the collaboration included database instruction, bibliographic management software, and culminated in student presentations to healthcare practitioners for continuing education credit. Three outcome areas are discussed: impact of the collaboration on student satisfaction and perceived competence; characteristics of the included literature; and the dissemination of SR findings to healthcare practitioners. Methods Three librarians participated in the instruction and the institutional repository (Jefferson Digital Commons; JDC) deposits. A total of 132 students over a period of two years (2013-2014) completed the curriculum, engaging with librarians and OT faculty to iteratively build on skills. At the conclusion of their curriculum, the capstone presentations were recorded and made freely available through the JDC. Quantitative data were examined with descriptive statistics in SPSS, and qualitative data were thematically coded by hand: course evaluations, practitioner attendance, bibliographic evaluations of the systematic reviews, and download statistics from the institutional repository. Results Students reported on open-ended course evaluation questions that among the top three concepts learned was ‘how to conduct a replicable and effective search.’ On multiple answer questions 83.6% of students selected the ‘collaborative librarian-faculty lecture’ as among the most helpful lectures offered, and 78.2% selected ‘working with librarian staff and course mentors to develop a search strategy’ as highly rated among course activities. Bibliographic data were extracted from 22 of 28 capstone presentations available for analysis (2013-2014) in the institutional repository, which contained 305 citations from 157 journals. The average of age of included articles was 4.8 years (SD=4.2, Range=0-24). Among the top 10 cited journals were 2 occupational therapy, 5 rehabilitation, and 3 specialty. Overall health care practitioner attendance at student capstones from 2012-2014 was 323. JDC recordings (as of 1/6/2015) had been accessed from 25 different countries, and are located most frequently via Google, JDC, and GoogleScholar. The total number of views was 1,446, and the total number of hours viewed was 163 hours. Conclusions Librarian-faculty collaborations resulted in high student perception of competence to conduct systematic reviews, utilization of a broad variety of peer-reviewed journals, and enhanced dissemination of evidence

    Radiative Electroweak Symmetry Breaking in a Little Higgs Model

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    We present a new Little Higgs model, motivated by the deconstruction of a five-dimensional gauge-Higgs model. The approximate global symmetry is SO(5)0×SO(5)1SO(5)_0\times SO(5)_1, breaking to SO(5)SO(5), with a gauged subgroup of [SU(2)0L×U(1)0R]×O(4)1[SU(2)_{0L}\times U(1)_{0R}]\times O(4)_1, breaking to SU(2)L×U(1)YSU(2)_L \times U(1)_Y. Radiative corrections produce an additional small vacuum misalignment, breaking the electroweak symmetry down to U(1)EMU(1)_{EM}. Novel features of this model are: the only un-eaten pseudo-Goldstone boson in the effective theory is the Higgs boson; the model contains a custodial symmetry, which ensures that T^=0\hat{T}=0 at tree-level; and the potential for the Higgs boson is generated entirely through one-loop radiative corrections. A small negative mass-squared in the Higgs potential is obtained by a cancellation between the contribution of two heavy partners of the top quark, which is readily achieved over much of the parameter space. We can then obtain both a vacuum expectation value of v=246v=246 GeV and a light Higgs boson mass, which is strongly correlated with the masses of the two heavy top quark partners. For a scale of the global symmetry breaking of f=1f=1 TeV and using a single cutoff for the fermion loops, the Higgs boson mass satisfies 120 GeV MH150\lesssim M_H\lesssim150 GeV over much of the range of parameter space. For ff raised to 10 TeV, these values increase by about 40 GeV. Effects at the ultraviolet cutoff scale may also raise the predicted values of the Higgs boson mass, but the model still favors MH200M_H\lesssim 200 GeV.Comment: 32 pages, 10 figures, JHEP style. Version accepted for publication in JHEP. Includes additional discussion of sensitivity to UV effects and fine-tuning, revised Fig. 9, added appendix and additional references

    State of the Art on Prediction of Concrete Pumping

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    Large scale constructions needs to estimate a possibility for pumping concrete. In this paper, the state of the art on prediction of concrete pumping including analytical and experimental works is presented. The existing methods to measure the rheological properties of slip layer (or called lubricating layer) are first introduced. Second, based on the rheological properties of slip layer and parent concrete, models to predict concrete pumping (flow rate, pumping pressure, and pumpable distance) are explained. Third, influencing factors on concrete pumping are discussed with the test results of various concrete mixes. Finally, future need for research on concrete pumping is suggested.ope

    Bullying girls - Changes after brief strategic family therapy: A randomized, prospective, controlled trial with one-year follow-up

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    Background: Many girls bully others. They are conspicuous because of their risk-taking behavior, increased anger, problematic interpersonal relationships and poor quality of life. Our aim was to determine the efficacy of brief strategic family therapy (BSFT) for bullying-related behavior, anger reduction, improvement of interpersonal relationships, and improvement of health-related quality of life in girls who bully, and to find out whether their expressive aggression correlates with their distinctive psychological features. Methods: 40 bullying girls were recruited from the general population: 20 were randomly selected for 3 months of BSFT. Follow-up took place 12 months after the therapy had ended. The results of treatment were examined using the Adolescents' Risk-taking Behavior Scale (ARBS), the State-Trait Anger Expression Inventory (STAXI), the Inventory of Interpersonal Problems (IIP-D), and the SF-36 Health Survey (SF-36). Results: In comparison with the control group (CG) (according to the intent-to-treat principle), bullying behavior in the BSFT group was reduced (BSFT-G from n = 20 to n = 6; CG from n = 20 to n = 18, p = 0.05) and statistically significant changes in all risk-taking behaviors (ARBS), on most STAXI, IIP-D, and SF-36 scales were observed after BSFT. The reduction in expressive aggression (Anger-Out scale of the STAXI) correlated with the reduction on several scales of the ARBS, IIP-D, and SF-36. Follow-up a year later showed relatively stable events. Conclusions: Our findings suggest that bullying girls suffer from psychological and social problems which may be reduced by the use of BSFT. Expressive aggression in girls appears to correlate with several types of risk-taking behavior and interpersonal problems, as well as with health-related quality of life. Copyright (c) 2006 S. Karger AG, Basel

    Top Partner Discovery in the TtZT\to tZ channel at the LHC

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    In this paper we study the discovery potential of the LHC run II for heavy vector-like top quarks in the decay channel to a top and a ZZ boson. Despite the usually smaller branching ratio compared to charged-current decays, this channel is rather clean and allows for a complete mass reconstruction of the heavy top. The latter is achieved in the leptonic decay channel of the ZZ boson and in the fully hadronic top channel using boosted jet and jet substructure techniques. To be as model-independent as possible, a simplified model approach with only two free parameters has been applied. The results are presented in terms of parameter space regions for 3σ3\sigma evidence or 5σ5\sigma discovery for such new states in that channel.Comment: 24 pages, 8 figures, version 2 updated to JHEP 01 (2015) 08

    Discovering the composite Higgs through the decay of a heavy fermion

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    A possible composite nature of the Higgs could be revealed at the early stage of the LHC, by analyzing the channels where the Higgs is produced from the decay of a heavy fermion. The Higgs production from a singly-produced heavy bottom, in particular, proves to be a promising channel. For a value \lambda=3 of the Higgs coupling to a heavy bottom, for example, we find that, considering a 125 GeV Higgs which decays into a pair of b-quarks, a discovery is possible at the 8 TeV LHC with 30 fb^{-1} if the heavy bottom is lighter than roughly 530 GeV (while an observation is possible for heavy bottom masses up to 650 GeV). Such a relatively light heavy bottom is realistic in composite Higgs models of the type considered and, up to now, experimentally allowed. At \sqrt{s}=14 TeV the LHC sensitivity on the channel increases significantly. With \lambda=3 a discovery can occur, with 100 fb^{-1}, for heavy bottom masses up to 1040 GeV. In the case the heavy bottom was as light as 500 GeV, the 14 TeV LHC would be sensitive to the measure of the \lambda\ coupling in basically the full range \lambda>1 predicted by the theory.Comment: 25 pp. v2: Minor changes. v3: Version accepted for publication in JHEP. v4: typos fixe
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