1,873 research outputs found
Primordial Power Spectra from Anisotropic Inflation
We examine cosmological perturbations in a dynamical theory of inflation in
which an Abelian gauge field couples directly to the inflaton, breaking
conformal invariance. When the coupling between the gauge field and the
inflaton takes a specific form, inflation becomes anisotropic and anisotropy
can persist throughout inflation, avoiding Wald's no-hair theorem. After
discussing scenarios in which anisotropy can persist during inflation, we
calculate the dominant effects of a small persistent anisotropy on the
primordial gravitational wave and curvature perturbation power spectra using
the "in-in" formalism of perturbation theory. We find that the primordial power
spectra of cosmological perturbations gain significant direction dependence and
that the fractional direction dependence of the tensor power spectrum is
suppressed in comparison to that of the scalar power spectrum.Comment: 25 pages, 2 figures; References added, typos corrected and some
discussion expanded; version submitted for publication in PR
Local Law Enforcement\u27s Ability to Transform Inputs Into Counterterrorism Outputs
Leadership within local police organizations should be able to, but do not, process information and create actionable strategies aimed toward proactive counterterrorism practices. This problem could lead to future terrorist attacks within the United States if police agencies do not adjust their tactics in response to growing terrorist threats. A possible cause of this problem is that leadership within local law enforcement agencies is reactive in nature and as a consequence, do not encourage officers to engage in proactive strategies. Using Easton\u27s conceptualization of systems theory as the foundation, the purpose of this case study of a single law enforcement agency in the southwest was to explore how police leadership influences counterterrorism strategies. Research questions focused on how police leadership processed information within their organization to develop counterterrorism tactics. Data were collected from interviews with police leadership and officers, observations of policing activities, and document review of policies, directives, and unclassified reports. These data were coded and analyzed following Yin\u27s procedure for schematic analysis. The results indicated that this agency has a successful counterterrorism strategy based on 6 organizational pillars of leading, proactive, learning, processing, policy, and communication. This study may promote positive social change by helping police leaders identify which system inputs provide the best detail for developing counterterrorism policy, and what community partnerships help police identify terrorism threats
A solid-reagent dispenser for use in the azocoll protease assay (and other insoluble substrate analyses).
A solid-reagent dispenser for use in the azocoll protease assay (and other insoluble substrate analyses)
Top A_FB at the Tevatron vs. charge asymmetry at the LHC in chiral U(1) flavor models with flavored Higgs doublets
We consider the top forward-backward (FB) asymmetry at the Tevatron and top
charge asymmetry at the LHC within chiral U(1)^\prime models with
flavor-dependent U(1)^\prime charges and flavored Higgs fields, which were
introduced in the ref. [65]. The models could enhance not only the top
forward-backward asymmetry at Tevatron, but also the top charge asymmetry at
LHC, without too large same-sign top pair production rates. We identify
parameter spaces for the U(1)^\prime gauge boson and (pseudo)scalar Higgs
bosons where all the experimental data could be accommodated, including the
case with about 125 GeV Higgs boson, as suggested recently by ATLAS and CMS.Comment: 11 pages, 6 figures, figures and discussion adde
Recommended from our members
Design of MARQUIS2: study protocol for a mentored implementation study of an evidence-based toolkit to improve patient safety through medication reconciliation.
BackgroundThe first Multi-center Medication Reconciliation Quality Improvement Study (MARQUIS1) demonstrated that implementation of a medication reconciliation best practices toolkit decreased total unintentional medication discrepancies in five hospitals. We sought to implement the MARQUIS toolkit in more diverse hospitals, incorporating lessons learned from MARQUIS1.MethodsMARQUIS2 is a pragmatic, mentored implementation QI study which collected clinical and implementation outcomes. Sites implemented a revised toolkit, which included interventions from these domains: 1) best possible medication history (BPMH)-taking; 2) discharge medication reconciliation and patient/caregiver counseling; 3) identifying and defining clinician roles and responsibilities; 4) risk stratification; 5) health information technology improvements; 6) improved access to medication sources; 7) identification and correction of real-time discrepancies; and, 8) stakeholder engagement. Eight hospitalists mentored the sites via one site visit and monthly phone calls over the 18-month intervention period. Each site's local QI team assessed opportunities to improve, implemented at least one of the 17 toolkit components, and accessed a variety of resources (e.g. implementation manual, webinars, and workshops). Outcomes to be assessed will include unintentional medication discrepancies per patient.DiscussionA mentored multi-center medication reconciliation QI initiative using a best practices toolkit was successfully implemented across 18 medical centers. The 18 participating sites varied in size, teaching status, location, and electronic health record (EHR) platform. We introduce barriers to implementation and lessons learned from MARQUIS1, such as the importance of utilizing dedicated, trained medication history takers, simple EHR solutions, clarifying roles and responsibilities, and the input of patients and families when improving medication reconciliation
Noether Symmetry Approach in "Cosmic Triad" Vector Field Scenario
To realize the accelerations in the early and late periods of our universe,
we need to specify potentials for the dominant fields. In this paper, by using
the Noether symmetry approach, we try to find suitable potentials in the
"cosmic triad" vector field scenario. Because the equation of state parameter
of dark energy has been constrained in the range of by observations, we derive the Noether conditions for the vector field
in quintessence, phantom and quintom models, respectively. In the first two
cases, constant potential solutions have been obtained. What is more, a fast
decaying point-like solution with power-law potential is also found for the
vector field in quintessence model. For the quintom case, we find an
interesting constraint on the field potentials,
where and are constants related to the Noether symmetry.Comment: 15 pages, no figures, accepted by Classical and Quantum Gravity
Top quark forward-backward asymmetry in R-parity violating supersymmetry
The interaction of bottom squark-mediated top quark pair production,
occurring in the R-parity violating minimal supersymmetric standard model
(MSSM), is proposed as an explanation of the anomalously large
forward-backward asymmetry (FBA) observed at the Tevatron. We find that this
model can give a good fit to top quark data, both the inclusive and invariant
mass-dependent asymmetries, while remaining consistent (at the 2-
level) with the total and differential production cross-sections. The scenario
is challenged by strong constraints from atomic parity violation (APV), but we
point out an extra diagram for the effective down quark-Z vertex, involving the
same coupling constant as required for the FBA, which tends to weaken the APV
constraint, and which can nullify it for reasonable values of the top squark
masses and mixing angle. Large contributions to flavor-changing neutral
currents can be avoided if only the third generation of sparticles is light.Comment: 24 pages, 7 figures. v3: included LHC top production cross section
data; model still consistent at 2 sigma leve
- …