2,218 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
Length-dependent changes in contractile dynamics are blunted due to cardiac myosin binding protein-C ablation
Enhanced cardiac contractile function with increased sarcomere length (SL) is, in part, mediated by a decrease in the radial distance between myosin heads and actin. The radial disposition of myosin heads relative to actin is modulated by cardiac myosin binding protein-C (cMyBP-C), suggesting that cMyBP-C contributes to the length-dependent activation (LDA) in the myocardium. However, the precise roles of cMyBP-C in modulating cardiac LDA are unclear. To determine the impact of cMyBP-C on LDA, we measured isometric force, myofilament Ca2+-sensitivity (pCa50) and length-dependent changes in kinetic parameters of cross-bridge (XB) relaxation (krel), and recruitment (kdf) due to rapid stretch, as well as the rate of force redevelopment (ktr) in response to a large slack-restretch maneuver in skinned ventricular multicellular preparations isolated from the hearts of wild-type (WT) and cMyBP-C knockout (KO) mice, at SL’s 1.9µm or 2.1µm. Our results show that maximal force was not significantly different between KO and WT preparations but length-dependent increase in pCa50 was attenuated in the KO preparations. pCa50 was not significantly different between WT and KO preparations at long SL (5.82±0.02 in WT vs. 5.87±0.02 in KO), whereas pCa50 was significantly different between WT and KO preparations at short SL (5.71±0.02 in WT vs. 5.80±0.01 in KO; p<0.05). The ktr, measured at half-maximal Ca2+-activation, was significantly accelerated at short SL in WT preparations (8.74±0.56s-1at 1.9µm vs. 5.71±0.40s-1at 2.1µm, p<0.05). Furthermore, krel and kdf were accelerated by 32% and 50%, respectively at short SL in WT preparations. In contrast, ktr was not altered by changes in SL in KO preparations (8.03±0.54s-1at 1.9µm vs. 8.90±0.37s-1at 2.1µm). Similarly, KO preparations did not exhibit length-dependent changes in krel and kdf. Collectively, our data implicate cMyBP-C is an important regulator of LDA via its impact on dynamic XB behavior due to changes in SL
Treating Lennox–Gastaut syndrome in epileptic pediatric patients with third-generation rufinamide
Lennox–Gastaut syndrome (LGS) is a rare but debilitating pediatric epileptic encephalopathy characterized by multiple intractable seizure types. Treatment of LGS is challenging because of the small number of antiepileptic drugs (AEDs) which are effective for this syndrome, as well as the need for polytherapy in the majority of patients. This review focuses on the treatment of LGS with rufinamide, a recently approved third-generation AED with reported efficacy as adjunctive therapy for LGS. All relevant papers identified through a PubMed search on the treatment of LGS with rufinamide were reviewed. To date, the literature suggests improvements in seizure frequency for pediatric patients with LGS on rufinamide. Rufinamide appears to be especially effective for atonic or drop attack seizures. Rufinamide also displays a favorable adverse event profile compared with the older anticonvulsants, as well as a minimal number of drug interactions, making it a promising option for the adjunctive treatment of seizures associated with LGS
Astrophysical Observations of a Dark Matter-Baryon Fifth Force
We consider the effects of an attractive, long-range Yukawa interaction
between baryons and dark matter (DM), focusing in particular on temperature and
pulsar timing observations of neutron stars (NSs). We show that such a fifth
force, with strength modestly stronger than gravity at ranges greater than tens
of kilometers (corresponding to mediator masses less than ), can dramatically enhance dark matter kinetic heating, capture, and
pulsar timing Doppler shifts relative to gravity plus short range interactions
alone. Using the coldest observed NS and pulsar timing array (PTA) data, we
derive limits on fifth force strength over a DM mass range spanning light dark
matter up to order solar mass composite DM objects. We also consider an
indirect limit by combining bullet cluster limits on the DM self-interaction
with weak equivalence principle test limits on baryonic self-interactions. We
find the combined indirect limits are moderately stronger than kinetic heating
and PTA limits, except when considering a DM subcomponent.Comment: 40 pages, 6 figures, v2: updated with analysis using another PTA
dataset, figures updated, conclusions unchange
A principal component meta-analysis on multiple anthropometric traits identifies novel loci for body shape
Large consortia have revealed hundreds of genetic loci associated with anthropometric traits, one trait at a time. We examined whether genetic variants affect body shape as a composite phenotype that is represented by a combination of anthropometric traits. We developed an approach that calculates averaged PCs (AvPCs) representing body shape derived from six anthropometric traits (body mass index, height, weight, waist and hip circumference, waist-to-hip ratio). The first four AvPCs explain \u3e99% of the variability, are heritable, and associate with cardiometabolic outcomes. We performed genome-wide association analyses for each body shape composite phenotype across 65 studies and meta-analysed summary statistics. We identify six novel loci: LEMD2 and CD47 for AvPC1, RPS6KA5/C14orf159 and GANAB for AvPC3, and ARL15 and ANP32 for AvPC4. Our findings highlight the value of using multiple traits to define complex phenotypes for discovery, which are not captured by single-trait analyses, and may shed light onto new pathways
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
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