5,981 research outputs found

    Preheating after Small-Field Inflation

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    Whereas preheating after chaotic and hybrid inflation models has been abundantly studied in the literature, preheating in small field inflation models, where the curvature of the inflaton potential is negative during inflation, remains less explored. In these models, a tachyonic instability at the end of inflation leads to a succession of exponentially large increases and \emph{decreases} of the inflaton fluctuations as the inflaton condensate oscillates around the minimum of its potential. The net effect is a competition between low-momentum modes which grow and decrease significantly, and modes with higher momenta which grow less but also decrease less. We develop an analytical description of this process, which is analogous to the quantum mechanical problem of tunneling through a volcano-shaped potential. Depending on the parameters, preheating may be so efficient that it completes in less than one oscillation of the inflaton condensate. Preheating after small field inflation may also be followed by a long matter-dominated stage before the universe thermalizes, depending on the energy scale of inflation and the details of the inflaton interactions. Finally, another feature of these models is that the spectrum of the inflaton fluctuations at the end of preheating may be peaked around the Hubble scale. In fact, because preheating starts when the second slow-roll parameter ∣η∣|\eta| becomes of order unity while the first slow-roll parameter ϵ\epsilon is still much smaller than one, the universe is still inflating during preheating and the modes amplified by the initial tachyonic instability leave the Hubble radius. This may lead to an abundant production of primordial black holes and gravitational waves with frequencies today which are naturally small enough to fall into the range accessible by high-sensitivity interferometric experiments.Comment: 34 pages, 16 figures. v2: 1 ref. added, accepted for publication in Phys.Rev.

    Entanglement between a diamond spin qubit and a photonic time-bin qubit at telecom wavelength

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    We report on the realization and verification of quantum entanglement between an NV electron spin qubit and a telecom-band photonic qubit. First we generate entanglement between the spin qubit and a 637 nm photonic time-bin qubit, followed by photonic quantum frequency conversion that transfers the entanglement to a 1588 nm photon. We characterize the resulting state by correlation measurements in different bases and find a lower bound to the Bell state fidelity of F = 0.77 +/- 0.03. This result presents an important step towards extending quantum networks via optical fiber infrastructure

    Development of the Persuasion Knowledge Scales of Sponsored Content (PKS-SC)

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    Despite the popularity of the Persuasion Knowledge Model, and its persistent relevance given the omnipresence of sponsored content (e.g. brand placement in TV programmes and video games, or paid product reviews in blogs), the way scholars measure persuasion knowledge varies widely. This study aims to develop valid and reliable scales for standardized measurement of consumers' persuasion knowledge of sponsored content. In three phases, we developed the Persuasion Knowledge Scales of Sponsored Content (PKS-SC) that measures nine components: (1) recognition of sponsored content, (2) understanding of selling and persuasive intent, (3) recognition of the commercial source of sponsored content, (4) understanding of persuasive tactics, (5) understanding of the economic model, (6) self-reflective awareness of the effectiveness of sponsored content, (7) skepticism toward sponsored content, (8) appropriateness of sponsored content, and (9) liking of sponsored content. All scales have good to appropriate validity and reliability. Recommendations for future research are discussed.</p

    Economic Impacts of Wild Pigs on Livestock Producers in 13 States

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    Wild pigs (Sus scrofa) are an invasive species in the mainland United States, where they are responsible for a wide range of negative impacts including damage to crops, livestock depredation as well as disease transmission, destruction of property and ecosystems, and depredation of wildlife. This manuscript summarizes a recent survey-based effort to estimate wild pig damage and control costs incurred by livestock producers by state and livestock type. The survey was distributed by the U.S. Department of Agriculture National Agricultural Statistical Service in the summer of 2021 to a sample of livestock producers in the 13-state region. Findings indicated that predation and disease-related damage can be substantial in certain states and for certain types of livestock. In particular, damage to livestock operations, specifically cattle (Bos taurus) operations, in Texas, USA, was substantially higher than damage in other states and types of livestock operations. However, these amounts are dwarfed by the expenditure incurred by damage to property and the rooting of pasture. When aggregating across the entire 13-state region, we estimated that damage and control costs to livestock producers summed in 2020 to an annual amount of \u3e650millionUSD,drivenbydamagetoproperty(650 million USD, driven by damage to property (375.5 million USD) and the rooting of pasture ($192.9 million USD). The findings from this survey provide valuable information to estimate the full scope of the economic impact of wild pigs in the United States

    A Long Way in a Short Time: States' Progress on Health Care Coverage and Access, 2013-2015

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    Issue: The Affordable Care Actís policy reforms sought to expand health insurance coverage and make health care more affordable. As the nation prepares for policy changes under a new administration, we assess recent gains and challenges.Goal: To compare access to affordable health care across the U.S. between 2013 and 2015. Methods: Analysis of most recent publicly available data from the U.S. Census Bureau and the Behavioral Risk Factor Surveillance System.Key findings and conclusions: Between 2013 and 2015, uninsured rates for adults ages 19 to 64 declined in all states and by at least 3 percentage points in 48 states and the District of Columbia. For children, uninsured rates declined by at least 2 percentage points in 28 states. The share of adults age 18 and older who reported forgoing a visit to the doctor when needed because of costs dropped by at least 2 percentage points in 38 states and D.C. In contrast, there was little progress in expanding access to dental care for adults, which is not a required benefit under the ACA. These findings illustrate the impact that policy can have on access to care and offer a focal point for assessing future policy changes

    Project Reach: Implementation of Evidence-Based Psychotherapy Within Integrated Healthcare for Hurricane Harvey Affected Individuals

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    Project Reach was established to deliver evidence-based mental healthcare services to children and adults affected by Hurricane Harvey and its aftermath. Through Project Reach, an innovative multi-component assessment and treatment service is utilized to identify and treat in integrated healthcare settings both children and adults exhibiting significant behavioral health concerns in Houston. The aim is to provide sustainable, integrated mental health services through primary care and school-based settings to post-Harvey affected individuals whose emotional needs remain unmet. This paper describes the design and implementation of Project Reach as well as special considerations for implementation. The overall goal of Project Reach is to form a platform for expanding integrated services for those affected by Harvey that will maximize behavioral health outcomes while reducing cost and improving access

    Concerns about medication and medication adherence in patients with chronic pain recruited from general practice

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    This study examines the concerns and beliefs about medication reported by patients with nonmalignant chronic pain encountered within general practice. Two hundred thirty-nine patients with chronic pain took part in this research. Patients completed the Pain Medication Attitudes Questionnaire, a measure of patient concerns and beliefs relating to addiction, withdrawal, side effects, mistrust in doctors, perceived need of medication, scrutiny from others, and tolerance. The data revealed that patient concerns and beliefs predicted general medication nonadherence. In addition, concerns were related to the direction of nonadherence: overuse of medication was related to increased perceived need for medication and greater concern over side effects; underuse was related to decreased concerns over withdrawal and increased mistrust in the prescribing doctor. Analyses also indicated that patient attitudes and concerns about medication were more predictive of nonadherence than both level of pain and the reported frequency of experienced side effects. This research contributes to the increasing evidence that patient attitudes and beliefs about pain medication are associated with adherence behavior. Training general practitioners to identify and address these concerns may reduce concerns, improve adherence, and facilitate the doctor-patient relationship
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