4,198 research outputs found
Disentanglement and decoherence in a pair of qutrits under dephasing noise
We relate disentanglement and decoherence rates in a pair of three-level
atoms subjected to multi-local and collective pure dephasing noise acting in a
preferred basis. The bipartite entanglement decay rate, as bounded from above
by the negativity, is found to be greater than or equal to the
dephasing-decoherence rates characterized by the decay of off-diagonal elements
in the corresponding full density matrix describing the system or the reduced
density matrix describing either qutrit, extending previous results for qubit
pairs subject to such noise.Comment: 9 pages, submitted to J. Mod. Opt. 01/21/07, accepted 08/14/07
Version 2 corrections: 1) E and D operators in second-to-last paragraph of
Sec. 2. 2) matrix elements (8,6) and (9,1) in Eq.
Local-dephasing-induced entanglement sudden death in two-component finite-dimensional systems
Entanglement sudden death (ESD), the complete loss of entanglement in finite
time, is demonstrated to occur in a class of bipartite states of qu-d-it pairs
of any finite dimension d > 2, when prepared in so-called `isotropic states'
and subject to multi-local dephasing noise alone. This extends previous results
for qubit pairs [T. Yu, J. H. Eberly, Phys. Rev. Lett. 97, 140403 (2006)] to
all qu-d-it pairs with d > 2.Comment: 8 pages, to appear in Phys. Rev.
Pornography and erotica: Definitions and Prevalence
In this paper, we offer some observations regarding the sex industry, in particular the pornography and erotica sectors. Marketing literature observing pornography and erotica is scant. We find that following exponential growth of the sex industry (given use of the Internet) an evaluation of consumer behaviour and marketing practices is justified. In order to begin a study of these industry sectors, we find it necessary to define both pornography and erotica. Following the development of definitions, we consider these industries from a marketing perspective in the hope that we may encourage research into these areas
Reliability Testing of the PABS (Pedestrian and Bicycling Survey) Method
The Pedestrian and Bicycling Survey (PABS) is a questionnaire designed to be economical and straightforward to administer so that it can be used by local governments interested in measuring the amount and purposes of walking and cycling in their communities. In addition, it captures key sociodemographic characteristics of those participating in these activities. Methods: In 2009 and 2010 results from the 4-page mail-out/mail-back PABS were tested for reliability across 2 administrations (test-retest reliability). Two versions--early and refined--were tested separately with 2 independent groups of university students from 4 universities (N = 100 in group 1; N = 87 in group 2). Administrations were 7 to 9 days apart. Results: Almost all survey questions achieved adequate to excellent reliability. Conclusions: Transportation surveys have not typically been tested for reliability making the PABS questionnaire an important new option for improving information collection about travel behavior, particularly walking and cycling
Overcoming Challenges to Teamwork in Patient-Centered Medical Homes: A Qualitative Study
There is emerging consensus that enhanced inter-professional teamwork is necessary for the effective and efficient delivery of primary care, but there is less practical information specific to primary care available to guide practices on how to better work as teams. The purpose of this study was to describe how primary care practices have overcome challenges to providing team-based primary care and the implications for care delivery and policy
Disentanglement and decoherence in two-spin and three-spin systems under dephasing
We compare disentanglement and decoherence rates within two-spin and
three-spin entangled systems subjected to all possible combinations of local
and collective pure dephasing noise combinations. In all cases, the bipartite
entanglement decay rate is found to be greater than or equal to the
dephasing-decoherence rates and often significantly greater. This sharpens
previous results for two-spin systems [T. Yu and J. H. Eberly Phys. Rev. B 68,
165322 (2003)] and extends them to the three-spin context.Comment: 17 page
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The Use of Web-Based Support Groups Versus Usual Quit-Smoking Care for Men and Women Aged 21-59 Years: Protocol for a Randomized Controlled Trial (Preprint)
BACKGROUND
Existing smoking cessation treatments are challenged by low engagement and high relapse rates, suggesting the need for more innovative, accessible, and interactive treatment strategies. Twitter is a Web-based platform that allows people to communicate with each other throughout the day using their phone.
OBJECTIVE
This study aims to leverage the social media platform of Twitter for fostering peer-to-peer support to decrease relapse with quitting smoking. Furthermore, the study will compare the effects of coed versus women-only groups on women’s success with quitting smoking.
METHODS
The study design is a Web-based, three-arm randomized controlled trial with two treatment arms (a coed or women-only Twitter support group) and a control arm. Participants are recruited online and are randomized to one of the conditions. All participants will receive 8 weeks of combination nicotine replacement therapy (patches plus their choice of gum or lozenges), serial emails with links to Smokefree.gov quit guides, and instructions to record their quit date online (and to quit smoking on that date) on a date falling within a week of initiation of the study. Participants randomized to a treatment arm are placed in a fully automated Twitter support group (coed or women-only), paired with a buddy (matched on age, gender, location, and education), and encouraged to communicate with the group and buddy via daily tweeted discussion topics and daily automated feedback texts (a positive tweet if they tweet and an encouraging tweet if they miss tweeting). Recruited online from across the continental United States, the sample consists of 215 male and 745 female current cigarette smokers wanting to quit, aged between 21 and 59 years. Self-assessed follow-up surveys are completed online at 1, 3, and 6 months after the date they selected to quit smoking, with salivary cotinine validation at 3 and 6 months. The primary outcome is sustained biochemically confirmed abstinence at the 6-month follow-up.
RESULTS
From November 2016 to September 2018, 960 participants in 36 groups were recruited for the randomized controlled trial, in addition to 20 participants in an initial pilot group. Data analysis will commence soon for the randomized controlled trial based on data from 896 of the 960 participants (93.3%), with 56 participants lost to follow-up and 8 dropouts.
CONCLUSIONS
This study combines the mobile platform of Twitter with a support group for quitting smoking. Findings will inform the efficacy of virtual peer-to-peer support groups for quitting smoking and potentially elucidate gender differences in quit rates found in prior research.
CLINICALTRIAL
ClinicalTrials.gov NCT02823028; https://clinicaltrials.gov/ct2/show/NCT0282302
Electronic Health Records and Support For Primary Care Teamwork
This study examined primary care practices' experiences using electronic health records (EHRs) as they strive to function as teams in patientcentered medical homes (PCMHs). We identify how EHRs facilitate and pose challenges to teamwork and how practices overcame such challenges. We describe solutions and identify opportunities to improve care processes as well as EHR functionalities and policies, to support teamwork
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