662 research outputs found
Political trials and the suppression of popular radicalism in England, 1799-1820
This chapter examines the decision-making process between the Home Office and the government’s law officers in prosecuting individuals for sedition and treason in the period 1799–1820. The term state trial suggests a more centralised and government-led repression of popular radicalism than the process was in practice. Provincial reformers also faced the complex layers of their local justice system, which was more loyalist, committed to stamping out political radicalism. The trial of the “Thirty Eight” Manchester radicals in June 1812 demonstrates the mutable definitions of treason, sedition and processes of justice in the theatre of the court.Peer reviewe
Sequestered Dark Matter
We show that hidden-sector dark matter is a generic feature of the type IIB
string theory landscape and that its lifetime may allow for a discovery through
the observation of very energetic gamma-rays produced in the decay. Throats or,
equivalently, conformally sequestered hidden sectors are common in flux
compactifications and the energy deposited in these sectors can be calculated
if the reheating temperature of the standard model sector is known. Assuming
that throats with various warp factors are available in the compact manifold,
we determine which throats maximize the late-time abundance of sequestered dark
matter. For such throats, this abundance agrees with cosmological data if the
standard model reheating temperature was 10^10 - 10^11 GeV. In two distinct
scenarios, the mass of dark matter particles, i.e. the IR scale of the throat,
is either around 10^5 GeV or around 10^10 GeV. The lifetime and the decay
channels of our dark matter candidates depend crucially on the fact that the
Klebanov-Strassler throat is supersymmetric. Furthermore, the details of
supersymmetry breaking both in the throat and in the visible sector play an
essential role. We identify a number of scenarios where this type of dark
matter can be discovered via gamma-ray observations.Comment: 36 pages, 3 figures; v2: references added, v3: introduction extended
and typos correcte
The Universal Kaehler Modulus in Warped Compactifications
We construct the effective theory of the universal Kaehler modulus in warped
compactifications using the Hamiltonian formulation of general relativity. The
spacetime dependent 10d solution is constructed at the linear level for both
the volume modulus and its axionic partner, and nontrivial cancellations of
warping effects are found in the dimensional reduction. Our main result is that
the Kaehler potential is not corrected by warping, up to an overall shift in
the background value of the volume modulus. We extend the analysis beyond the
linearized approximation by computing the fully backreacted 10d metric
corresponding to a finite volume modulus fluctuation. Also, we discuss the
behavior of the modulus in strongly warped regions and show that there are no
mixings with light Kaluza-Klein modes. These results are important for the
phenomenology and cosmology of flux compactifications.Comment: 28 pages, 1 figure; v2. corrected typos, added refs & minor
clarification
Interviewer-driven Variability in Social Network Reporting: Results from Health and Aging in Africa: a Longitudinal Study of an INDEPTH community (HAALSI) in South Africa
Social network analysis depends on how social ties to others are elicited during interviews, a process easily affected by respondent and interviewer behaviors. We investigate how the number of self-reported important social contacts varied within a single data collection round. Our data come from Health and Aging in Africa: a Longitudinal Study of an INDEPTH community (HAALSI), a comprehensive population-based survey of individuals aged 40 years and older conducted over 13 months at the Agincourt health and demographic surveillance site in rural South Africa. As part of HAALSI, interviewers elicited detailed egocentric network data. The average number of contacts reported by the 5,059 respondents both varied significantly across interviewers and fell over time as the data collection progressed, even after adjusting for respondent, interviewer, and respondent–interviewer dyad characteristics. Contact numbers rose substantially after a targeted interviewer intervention. We conclude that checking (and adjusting) for interviewer effects, even within one data collection round, is critical to valid and reliable social network analysis.
Measurements of social networks depend on the number and type of social ties to others (Berkman et al. 2000; Smith and Christakis 2008). These ties are typically elicited through interviews, a process easily affected by respondent or interviewer characteristics and behaviors. Understanding social network structure and composition requires substantial amounts of information from respondents (“egos”) about the people (“alters”) they have relationships with (Marsden 1990). Notably, the survey burden associated with network data collection depends heavily on the number of alters elicited through “name generator” questions: Each alter named leads to the repetition of all follow-up questions characterizing the ego–alter relationship (“name interpreters”; Burt 1984).
Interviewers have been identified as a key source of variation in survey responses, particularly for questions that are attitudinal, ambiguous, or have complex skip patterns (West and Blom 2016). Several studies have previously identified interviewer effects on network size (Brüderl et al. 2013; Josten and Trappmann 2016; Marsden 2003; Paik and Sanchagrin 2013; van Tilburg 1998). These interviewer effects may arise from differential understanding of survey questions, and therefore how questions are presented to respondents. Interviewers can also affect which alters are elicited due to their own characteristics (e.g., sex, race, age, or experience), or the nature of the interviewer–respondent dyad (e.g., gender, race, or age homophily), leading to different lines of enquiry, levels of probing, or expectations of social acceptability (Collins 1980; Hox 1994; Marsden 2003; Phung et al. 2015).
Furthermore, if respondents or interviewers are aware that naming more alters substantially increases survey length, then either group may consciously or unconsciously seek to minimize the number of alters named (Eagle and Proeschold-Bell 2015; van der Zouwen and van Tilburg 2001). In cross-sectional surveys, the opportunities for respondents to learn are limited, but those for interviewers will increase as the survey period progresses. Interviewers may try to reduce survey burden, either for themselves or for respondents, by favoring language or probes that decrease the number of alters elicited. Indeed, past studies in Europe have found evidence of interviewers intentionally filtering out questions by entering fewer responses that would trigger more questions. Such filtering behavior has been seen in Europe for interviewers who are being compensated by the interview rather than by the hour (Josten and Trappmann 2016; Kosyakova et al. 2014), for interviewers with prior experience using the relevant screening tool (Matschinger et al. 2005), and where interviewers are under substantial pressure to complete more interviews (Schnell and Kreuter 2000).
We aim to extend this literature by assessing how the number of alters elicited systematically changed over the course of a cross-sectional social network survey of older adults in rural South Africa. We show a substantial drop in alter numbers over time, and a swift reversal following retraining, providing substantial evidence for interviewer effects
Zambian Peer Educators for HIV Self-Testing (ZEST) study: rationale and design of a cluster randomised trial of HIV self-testing among female sex workers in Zambia
BACKGROUND: HIV testing and knowledge of status are starting points for HIV treatment and prevention interventions. Among female sex workers (FSWs), HIV testing and status knowledge remain far from universal. HIV self-testing (HIVST) is an alternative to existing testing services for FSWs, but little evidence exists how it can be effectively and safely implemented. Here, we describe the rationale and design of a cluster randomised trial designed to inform implementation and scale-up of HIVST programmes for FSWs in Zambia. METHODS: The Zambian Peer Educators for HIV Self-Testing (ZEST) study is a 3-arm cluster randomised trial taking place in 3 towns in Zambia. Participants (N=900) are eligible if they are women who have exchanged sex for money or goods in the previous 1 month, are HIV negative or status unknown, have not tested for HIV in the previous 3 months, and are at least 18 years old. Participants are recruited by peer educators working in their communities. Participants are randomised to 1 of 3 arms: (1) direct distribution (in which they receive an HIVST from the peer educator directly); (2) fixed distribution (in which they receive a coupon with which to collect the HIVST from a drug store or health post) or (3) standard of care (referral to existing HIV testing services only, without any offer of HIVST). Participants are followed at 1 and 4 months following distribution of the first HIVST. The primary end point is HIV testing in the past month measured at the 1-month and 4-month visits. ETHICS AND DISSEMINATION: This study was approved by the Institutional Review Boards at the Harvard T.H. Chan School of Public Health in Boston, USA and ERES Converge in Lusaka, Zambia. The findings of this trial will be presented at local, regional and international meetings and submitted to peer-reviewed journals for publication. TRIAL REGISTRATION NUMBER: Pre-results; NCT02827240
Reaching for the 'first 95': a cross-country analysis of HIV self-testing in nine countries in sub-Saharan Africa
OBJECTIVES: HIV self-testing (HIVST) offers a promising approach to increase HIV diagnosis and advance progress towards the UNAIDS 95-95-95 targets. We aimed to understand patterns of HIVST awareness and utilization in nine sub-Saharan African (SSA) countries, with the goal of identifying populations to target in disseminating this technology. DESIGN: A cross-sectional study. METHODS: We pooled individual-level population-based data from nine Demographic and Health Surveys (DHS) in SSA conducted 2015-2019 (Burundi, Cameroon, Guinea, Malawi, Senegal, Sierra Leone, South Africa, Zambia, Zimbabwe). Primary outcomes were HIVST awareness and utilization. We used logistic regression with survey fixed effects to explore the relationship between sociodemographic characteristics and these outcomes. Models were adjusted for sex, age, rural/urban residence, education, wealth, and marital status. We accounted for complex survey design. RESULTS: The study sample included 177 572 people (66.0% women, mean age 29 ± 10 years), of whom 86.6% [95% confidence interval (95% CI) 86.4-86.7] were unaware of HIVST, 11.7% (95% CI 11.6-11.9) were aware of but never used HIVST, and 1.7% (95% CI 1.6-1.8) had used HIVST. In adjusted models, women were less likely to be aware of HIVST [odds ratio (OR) 0.75, 95% CI 0.71-0.79], but more likely to have used HIVST (OR 1.17, 95% CI 1.03-1.32) compared with men. Rural residents, those who were least educated, and poorest were less likely to have heard of or used HIVST. CONCLUSION: HIVST awareness and uptake were low. Rural, less educated, and lower income populations were least likely to have heard of or used HIVST. Efforts to scale-up HIVST in these settings should aim to reach these less advantaged groups
Energy Transfer between Throats from a 10d Perspective
Strongly warped regions, also known as throats, are a common feature of the
type IIB string theory landscape. If one of the throats is heated during
cosmological evolution, the energy is subsequently transferred to other throats
or to massless fields in the unwarped bulk of the Calabi-Yau orientifold. This
energy transfer proceeds either by Hawking radiation from the black hole
horizon in the heated throat or, at later times, by the decay of
throat-localized Kaluza-Klein states. In both cases, we calculate in a 10d
setup the energy transfer rate (respectively decay rate) as a function of the
AdS scales of the throats and of their relative distance. Compared to existing
results based on 5d models, we find a significant suppression of the energy
transfer rates if the size of the embedding Calabi-Yau orientifold is much
larger than the AdS radii of the throats. This effect can be partially
compensated by a small distance between the throats. These results are
relevant, e.g., for the analysis of reheating after brane inflation. Our
calculation employs the dual gauge theory picture in which each throat is
described by a strongly coupled 4d gauge theory, the degrees of freedom of
which are localized at a certain position in the compact space.Comment: 25 pages; a comment adde
Social inequalities in stage at diagnosis of rectal but not in colonic cancer: a nationwide study
We investigated stage at diagnosis in relation to socioeconomic status (SES) among 15 274 patients with colorectal adenocarcinoma diagnosed in 1996–2004 nationwide in Denmark. The effect of SES on the risk of being diagnosed with distant metastasis was analysed using logistic regression models. A reduction in the risk of being diagnosed with distant metastasis was seen in elderly rectal cancer patients with high income, living in owner–occupied housing and living with a partner. Among younger rectal cancer patients, a reduced risk was seen in those having long education. No social gradient was found among colon cancer patients. The social gradient found in rectal cancer patients was significantly different from the lack of association found among colon cancer patients. There are socioeconomic inequalities in the risk of being diagnosed with distant metastasis of a rectal, but not a colonic, cancer. The different risk profile of these two cancers may reflect differences in symptomatology
Warped Kaluza-Klein Dark Matter
Warped compactifications of type IIB string theory contain natural dark
matter candidates: Kaluza-Klein modes along approximate isometry directions of
long warped throats. These isometries are broken by the full compactification,
including moduli stabilization; we present a thorough survey of Kaluza-Klein
mode decay rates into light supergravity modes and Standard Model particles. We
find that these dark matter candidates typically have lifetimes longer than the
age of the universe. Interestingly, some choices for embedding the Standard
Model in the compactification lead to decay rates large enough to be observed,
so this dark matter sector may provide constraints on the parameter space of
the compactification.Comment: 37pp; v2. references, minor clarificatio
Decaying Hidden Dark Matter in Warped Compactification
The recent PAMELA and ATIC/Fermi/HESS experiments have observed an excess of
electrons and positrons, but not anti-protons, in the high energy cosmic rays.
To explain this result, we construct a decaying hidden dark matter model in
string theory compactification that incorporates the following two ingredients,
the hidden dark matter scenario in warped compactification and the
phenomenological proposal of hidden light particles that decay to the Standard
Model. In this model, on higher dimensional warped branes, various warped
Kaluza-Klein particles and the zero-mode of gauge field play roles of the
hidden dark matter or mediators to the Standard Model.Comment: 15 pages; v4, several clarifications added, update on Fermi/HESS
result
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