Root to Kellerer

We revisit Kellerer's Theorem, that is, we show that for a family of real probability distributions $(\mu_t)_{t\in [0,1]}$ which increases in convex order there exists a Markov martingale $(S_t)_{t\in[0,1]}$ s.t.\ $S_t\sim \mu_t$. To establish the result, we observe that the set of martingale measures with given marginals carries a natural compact Polish topology. Based on a particular property of the martingale coupling associated to Root's embedding this allows for a relatively concise proof of Kellerer's theorem. We emphasize that many of our arguments are borrowed from Kellerer \cite{Ke72}, Lowther \cite{Lo07}, and Hirsch-Roynette-Profeta-Yor \cite{HiPr11,HiRo12}.Comment: 8 pages, 1 figur

New electron source concept for single-shot sub-100 fs electron diffraction in the 100 keV range

We present a method for producing sub-100 fs electron bunches that are suitable for single-shot ultrafast electron diffraction experiments in the 100 keV energy range. A combination of analytical results and state-of-the-art numerical simulations show that it is possible to create 100 keV, 0.1 pC, 20 fs electron bunches with a spotsize smaller than 500 micron and a transverse coherence length of 3 nm, using established technologies in a table-top set-up. The system operates in the space-charge dominated regime to produce energy-correlated bunches that are recompressed by established radio-frequency techniques. With this approach we overcome the Coulomb expansion of the bunch, providing an entirely new ultrafast electron diffraction source concept

Multi-scale Renormalisation Group Improvement of the Effective Potential

Using the renormalisation group and a conjecture concerning the perturbation series for the effective potential, the leading logarithms in the effective potential are exactly summed for $O(N)$ scalar and Yukawa theories.Comment: 19 pages, DIAS STP 94-09. Expanded to check large N limit, typo's corrected, to appear in Phys Rev

Dallas with balls: televized sport, soap opera and male and female pleasures

Two of the most popular of television genres, soap opera and sports coverage have been very much differentiated along gender lines in terms of their audiences. Soap opera has been regarded very much as a 'gynocentric' genre with a large female viewing audience while the audiences for television sport have been predominantly male. Gender differentiation between the genres has had implications for the popular image of each. Soap opera has been perceived as inferior; as mere fantasy and escapism for women while television sports has been perceived as a legitimate, even edifying experience for men. In this article the authors challenge the view that soap opera and television sport are radically different and argue that they are, in fact, very similar in a number of significant ways. They suggest that both genres invoke similar structures of feeling and sensibility in their respective audiences and that television sport is a 'male soap opera'. They consider the ways in which the viewing context of each genre is related to domestic life and leisure, the ways in which the textual structure and conventions of each genre invoke emotional identification, and finally, the ways in which both genres re-affirm gender identities

Cardiovascular outcomes following a respiratory tract infection among adults with non-CF bronchiectasis: a general population based study

Rationale: Studies suggest that people with bronchiectasis are at increased risk of cardiovascular co-morbidities. Objectives: We aimed to quantify the relative risk of incident cardiovascular events following a respiratory tract infection amongst people with bronchiectasis. Methods: Using UK electronic primary care records, we conducted a within-person comparison using the self-controlled case series method. We calculated the relative risk of first time cardiovascular events (either first myocardial infarction [MI] or stroke) following a respiratory tract infection compared with the individual’s baseline risk. Results: Our cohort consisted of 895 individuals with non-CF bronchiectasis with a first MI or stroke and at least one respiratory tract infection. There was an increased rate of first time cardiovascular events in the 91 day period after a respiratory tract infection (Incidence Rate Ratio [IRR] 1.56; 95% CI 1.20 to 2.02). The rate of a first cardiovascular event was highest in the first three days following a respiratory tract infection (IRR 2.73, 95% CI 1.41 to 5.27). Conclusions: These data suggest that respiratory tract infections are strongly associated with a transient increased risk of first time MI or stroke amongst people with bronchiectasis. As respiratory tract infections are six times more common in people with bronchiectasis than the general population, the increased risk has a disproportionately greater impact in these individuals. These findings may have implications for including cardiovascular risk modifications in airway infection treatment pathways in this population

Determining the top-antitop and ZZZZ Couplings of a Neutral Higgs Boson of Arbitrary CP Nature at the NLC

The optimal procedure for extracting the coefficients of different components of a cross section which takes the form of unknown coefficients times functions of known kinematical form is developed. When applied to \epem\to t\anti t+Higgs production at \rts=1\tev and integrated luminosity of 200\fbi, we find that the t\anti t\toHiggs CP-even and CP-odd couplings and, to a lesser extent, the $ZZ\to$Higgs (CP-even) coupling can be extracted with reasonable errors, assuming the Higgs sector parameter choices yield a significant production rate. Indeed, the composition of a mixed-CP Higgs eigenstate can be determined with sufficient accuracy that a SM-like CP-even Higgs boson can be distinguished from a purely CP-odd Higgs boson at a high level of statistical significance, and vice versa.Comment: 8 pages, full postscript file also available via anonymous ftp at ftp://ucdhep.ucdavis.edu/gunion/eetottbh.p

Delivering a “Dose of Hope”: A Faith-Based Program to Increase Older African Americans’ Participation in Clinical Trials

Background: Underrepresentation of older-age racial and ethnic minorities in clinical research is a significant barrier to health in the United States, as it impedes medical research advancement of effective preventive and therapeutic strategies. Objective: The objective of the study was to develop and test the feasibility of a community-developed faith-based intervention and evaluate its potential to increase the number of older African Americans in clinical research. Methods: Using a cluster-randomized design, we worked with six matched churches to enroll at least 210 persons. We provided those in the intervention group churches with three educational sessions on the role of clinical trials in addressing health disparity topics, and those in the comparison group completed surveys at the same timepoints. All persons enrolled in the study received ongoing information via newsletters and direct outreach on an array of clinical studies seeking participants. We evaluated the short-, mid-, and longer-term effects of the interventional program on clinical trial-related outcomes (ie, screening and enrollment)

Comment on studying the corrections to factorization in B -> D(*) X

We propose studying the mechanism of factorization in exclusive decays of the form B->D(*)X by examining the differential decay rate as a function of the invariant mass of the light hadronic state X. If factorization works primarily due to the large N_c limit then its accuracy is not expected to decrease as the X invariant mass increases. However, if factorization is mostly a consequence of perturbative QCD then the corrections should grow with the X invariant mass. Combining data for hadronic tau decays and semileptonic B decays allows tests of factorization to be made for a variety of final states. We discuss the examples of B->D^*\pi^+\pi^-\pi^-\pi^0 and B->D^*\omega\pi^-. The mode B->D^*\omega\pi^- will allow a precision study of the dependence of the corrections to factorization on the invariant mass of the light hadronic state.Comment: 7 pages, minor clarifications to tex

The Kramers equation simulation algorithm II. An application to the Gross-Neveu model

We continue the investigation on the applications of the Kramers equation to the numerical simulation of field theoretic models. In a previous paper we have described the theory and proposed various algorithms. Here, we compare the simplest of them with the Hybrid Monte Carlo algorithm studying the two-dimensional lattice Gross-Neveu model. We used a Symanzik improved action with dynamical Wilson fermions. Both the algorithms allow for the determination of the critical mass. Their performances in the definite phase simulations are comparable with the Hybrid Monte Carlo. For the two methods, the numerical values of the measured quantities agree within the errors and are compatible with the theoretical predictions; moreover, the Kramers algorithm is safer from the point of view of the numerical precision.Comment: 20 pages + 1 PostScript figure not included, REVTeX 3.0, IFUP-TH-2