Are Researchers Registering Systematic Reviews in ClinicalTrials.gov?

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(CT) is an increasingly important resource for systematic reviewers attempting to identify published and unpublished clinical studies.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

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

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

We consider the production of a light non-standard model Higgs boson of order 100~\GEV with an associated $W$ boson at CERN Large Hadron Collider. We focus on an interesting scenario that, the Higgs boson decays predominately into two light scalars $\chi$ with mass of few GeV which sequently decay into four gluons, i.e. $h\to 2\chi \to 4g$. Since $\chi$ 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 $\chi$ decay in the detector. By using electromagnetic calorimeter-based and jet substructure analyses, we show in two cases of different $\chi$ masses that it is quite promising to extract the signal of Higgs boson out of large QCD background.Comment: 20 pages, 7 figure

On the effect of resonances in composite Higgs phenomenology

We consider a generic composite Higgs model based on the coset SO(5)/SO(4) and study its phenomenology beyond the leading low-energy effective lagrangian approximation. Our basic goal is to introduce in a controllable and simple way the lowest-lying, possibly narrow, resonances that may exist is such models. We do so by proposing a criterion that we call partial UV completion. We characterize the simplest cases, corresponding respectively to a scalar in either singlet or tensor representation of SO(4) and to vectors in the adjoint of SO(4). We study the impact of these resonances on the signals associated to high-energy vector boson scattering, pointing out for each resonance the characteristic patterns of depletion and enhancement with respect to the leading-order chiral lagrangian. En route we derive the O(p^4) general chiral lagrangian and discuss its peculiar accidental and approximate symmetries.Comment: v3: a few typos corrected. Conclusions unchange

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

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

We present a new Little Higgs model, motivated by the deconstruction of a five-dimensional gauge-Higgs model. The approximate global symmetry is $SO(5)_0\times SO(5)_1$, breaking to $SO(5)$, with a gauged subgroup of $[SU(2)_{0L}\times U(1)_{0R}]\times O(4)_1$, breaking to $SU(2)_L \times U(1)_Y$. Radiative corrections produce an additional small vacuum misalignment, breaking the electroweak symmetry down to $U(1)_{EM}$. 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 $\hat{T}=0$ 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 $v=246$ 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 $f=1$ TeV and using a single cutoff for the fermion loops, the Higgs boson mass satisfies 120 GeV $\lesssim M_H\lesssim150$ GeV over much of the range of parameter space. For $f$ 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 $M_H\lesssim 200$ 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

Discovering the composite Higgs through the decay of a heavy fermion

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

State of the Art on Prediction of Concrete Pumping

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

Theoretical Constraints on the Higgs Effective Couplings

We derive constraints on the sign of couplings in an effective Higgs Lagrangian using prime principles such as the naturalness principle, global symmetries, and unitarity. Specifically, we study four dimension-six operators, O_H, O_y, O_g, and O_gamma, which contribute to the production and decay of the Higgs boson at the Large Hadron Collider (LHC), among other things. Assuming the Higgs is a fundamental scalar, we find: 1) the coefficient of O_H is positive except when there are triplet scalars, resulting in a reduction in the Higgs on-shell coupling from their standard model (SM) expectations if no other operators contribute, 2) the linear combination of O_H and O_y controlling the overall Higgs coupling to fermion is always reduced, 3) the sign of O_g induced by a new colored fermion is such that it interferes destructively with the SM top contribution in the gluon fusion production of the Higgs, if the new fermion cancels the top quadratic divergence in the Higgs mass, and 4) the correlation between naturalness and the sign of O_gamma is similar to that of O_g, when there is a new set of heavy electroweak gauge bosons. Next considering a composite scalar for the Higgs, we find the reduction in the on-shell Higgs couplings persists. If further assuming a collective breaking mechanism as in little Higgs theories, the coefficient of O_H remains positive even in the presence of triplet scalars. In the end, we conclude that the gluon fusion production of the Higgs boson is reduced from the SM rate in all composite Higgs models. Our study suggests a wealth of information could be revealed by precise measurements of the Higgs couplings, providing strong motivations for both improving on measurements at the LHC and building a precision machine such as the linear collider.Comment: 37 pages, one figure; v2: improved discussion on dispersion relation and other minor modifications; version accepted for publication