2,148 research outputs found
Building capacity for dissemination and implementation research: One university’s experience
Abstract Background While dissemination and implementation (D&I) science has grown rapidly, there is an ongoing need to understand how to build and sustain capacity in individuals and institutions conducting research. There are three inter-related domains for capacity building: people, settings, and activities. Since 2008, Washington University in St. Louis has dedicated significant attention and resources toward building D&I research capacity. This paper describes our process, challenges, and lessons with the goal of informing others who may have similar aims at their own institution. Activities An informal collaborative, the Washington University Network for Dissemination and Implementation Research (WUNDIR), began with a small group and now has 49 regular members. Attendees represent a wide variety of settings and content areas and meet every 6 weeks for half-day sessions. A logic model organizes WUNDIR inputs, activities, and outcomes. A mixed-methods evaluation showed that the network has led to new professional connections and enhanced skills (e.g., grant and publication development). As one of four, ongoing, formal programs, the Dissemination and Implementation Research Core (DIRC) was our first major component of D&I infrastructure. DIRC’s mission is to accelerate the public health impact of clinical and health services research by increasing the engagement of investigators in later stages of translational research. The aims of DIRC are to advance D&I science and to develop and equip researchers with tools for D&I research. As a second formal component, the Washington University Institute for Public Health has provided significant support for D&I research through pilot projects and a small grants program. In a third set of formal programs, two R25 training grants (one in mental health and one in cancer) support post-doctoral scholars for intensive training and mentoring in D&I science. Finally, our team coordinates closely with D&I functions within research centers across the university. We share a series of challenges and potential solutions. Conclusion Our experience in developing D&I research at Washington University in St. Louis shows how significant capacity can be built in a relatively short period of time. Many of our ideas and ingredients for success can be replicated, tailored, and improved upon by others
Multi-Scale Simulation of Viscoelastic Fiber-Reinforced Composites
This paper presents an effective algorithm to simulate the anisotropic viscoelastic behavior of a fiber-reinforced composite including the influence of the local geometric properties, like fiber-orientation and volume fraction. The considered composites consist of a viscoelastic matrix which is reinforced by elastic fibers. The viscoelastic composite behavior results anisotropic due to the local anisotropic fiber-orientations. The influence of the local time-dependent viscoelastic properties are captured within two elastic microscopic calculations for each fiberorientation in the composite part. These calculations can be performed within a preprocessing step, and thus no expensive, time-dependent viscoelastic multi-scale simulation has to be carried out to incorporate the local properties. The advantage of the presented approach is that the locally varying microscopic properties can be captured in a one-scale simulation within a commercial finite element tool like ABAQUS
Resurrecting light stops after the 125 GeV Higgs in the baryon number violating CMSSM
In order to accommodate the observed Higgs boson mass in the CMSSM, the stops
must either be very heavy or the mixing in the stop sector must be very large.
Lower stop masses, possibly more accessible at the LHC, still give the correct
Higgs mass only if the trilinear stop mixing parameter is in the
multi-TeV range. Recently it has been shown that such large stop mixing leads
to an unstable electroweak vacuum which spontaneously breaks charge or colour.
In this work we therefore go beyond the CMSSM and investigate the effects of
including baryon number violating operators on the stop and Higgs sectors. We find that for light stop masses as low as 220 GeV are consistent
with the observed Higgs mass as well as flavour constraints while allowing for
a stable vacuum. The light stop in this scenario is often the lightest
supersymmetric particle. We furthermore discuss the importance of the one-loop
corrections involving R-parity violating couplings for a valid prediction of
the light stop masses.Comment: 26 pages, 9 figures; v2: slightly extended discussion about bounds
from flavour observables; matches published versio
Coherent Acoustic Perturbation of Second-Harmonic-Generation in NiO
We investigate the structural and magnetic origins of the unusual ultrafast
second-harmonicgeneration (SHG) response of femtosecond-laser-excited nickel
oxide (NiO) previously attributed to oscillatory reorientation dynamics of the
magnetic structure induced by d-d excitations. Using time-resolved x-ray
diffraction from the (3/2 3/2 3/2) magnetic planes, we show that changes in the
magnitude of the magnetic structure factor following ultrafast optical
excitation are limited to = 1.5% in the first 30 ps. An
extended investigation of the ultrafast SHG response reveals a strong
dependence on wavelength as well as characteristic echoes, both of which give
evidence for an acoustic origin of the dynamics. We therefore propose an
alternative mechanism for the SHG response based on perturbations of the
nonlinear susceptibility via optically induced strain in a spatially confined
medium. In this model, the two observed oscillation periods can be understood
as the times required for an acoustic strain wave to traverse one coherence
length of the SHG process in either the collinear or anti-collinear geometries.Comment: 26 pages, 7 figure
Implication of the PAMELA antiproton data for dark matter indirect detection at LHC
Since the PAMELA results on the "anomalously" high positron fraction and the
lack of antiproton excess in our Galaxy, there has been a tremendous number of
studies advocating new types of dark matter, with larger couplings to electrons
than to quarks.
This raises the question of the production of dark matter particles (and
heavy associated coloured states) at LHC. Here, we explore a very simple
benchmark dark matter model and show that, in spite of the agreement between
the PAMELA antiproton measurements and the expected astrophysical secondary
background, there is room for large couplings of a WIMP candidate to heavy
quarks. Contrary to what could have been naively anticipated, the PAMELA pbar/p
measurements do not challenge dark matter model building, as far as the quark
sector is concerned. A quarkophillic species is therefore not forbidden.Owing
to these large couplings, one would expect that a new production channel opens
up at the LHC, through quark--quark and quark--gluon interactions. Alas, when
the PDF of the quark is taken into account, prospects for a copious production
fade away.Comment: 7 pages, 2 figures, captions of some figures modified, main
conclusion unchange
Direct neutron capture cross sections of 62Ni in the s-process energy range
Direct neutron capture on 62Ni is calculated in the DWBA and the cross
sections in the energy range relevant for s-process nucleosynthesis are given.
It is confirmed that the thermal value of the capture cross section contains a
subthreshold resonance contribution. Contrary to previous investigations it is
found that the capture at higher energies is dominated by p-waves, thus leading
to a considerably increased cross section at s-process energies and a modified
energy dependence.Comment: 10 pages, 1 figure, corrected typos in Eq. 6 and subsequent paragrap
A constrained supersymmetric left-right model
Abstract: We present a supersymmetric left-right model which predicts gauge coupling unification close to the string scale and extra vector bosons at the TeV scale. The subtleties in constructing a model which is in agreement with the measured quark masses and mixing for such a low left-right breaking scale are discussed. It is shown that in the constrained version of this model radiative breaking of the gauge symmetries is possible and a SM-like Higgs is obtained. Additional CP-even scalars of a similar mass or even much lighter are possible. The expected mass hierarchies for the supersymmetric states differ clearly from those of the constrained MSSM. In particular, the lightest down-type squark, which is a mixture of the sbottom and extra vector-like states, is always lighter than the stop. We also comment on the model’s capability to explain current anomalies observed at the LHC
Benchmarking with Spine Tango: potentials and pitfalls
The newly released online statistics function of Spine Tango allows comparison of own data against the aggregated results of the data pool that all other participants generate. This comparison can be considered a very simple way of benchmarking, which means that the quality of what one organization does is compared with other similar organizations. The goal is to make changes towards better practice if benchmarking shows inferior results compared with the pool. There are, however, pitfalls in this simplified way of comparing data that can result in confounding. This means that important influential factors can make results appear better or worse than they are in reality and these factors can only be identified and neutralized in a multiple regression analysis performed by a statistical expert. Comparing input variables, confounding is less of a problem than comparing outcome variables. Therefore, the potentials and limitations of automated online comparisons need to be considered when interpreting the results of the benchmarking procedur
Validity of the CMSSM interpretation of the diphoton excess
It has been proposed that the observed diphoton excess at 750 GeV could be explained within the constrained minimal supersymmetric standard model via resonantly produced stop bound states. We reanalyze this scenario critically and extend previous work to include the constraints from the stability of the electroweak vacuum and from the decays of the stoponium into a pair of Higgs bosons. It is shown that the interesting regions of parameter space with a light stop and Higgs of the desired mass are ruled out by these constraints. This conclusion is not affected by the presence of the bound states because the binding energy is usually very small in the regions of parameter space which can explain the Higgs mass. Thus, this also leads to strong constraints on the diphoton production cross section which is in general too small
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