Stability of an electroweak string with a fermion condensate

A solution of the standard electroweak theory with a single lepton family is constructed, consisting of a cosmic string and a fermion condensate within its core. The stability of this system to small perturbations is examined, and it is found that stability is not enhanced relative to the bare electroweak string. The presence of quark zero modes is shown to violate the existence criteria for embedded defects.Comment: 13 pages, preprint DAMTP 94-9, SWAT/2

Cost-Utility of Aspirin and Proton Pump Inhibitors for Primary Prevention

Aspirin reduces myocardial infarction but increases gastrointestinal bleeding. Proton pump inhibitors (PPIs) may reduce upper gastrointestinal bleed. We estimate the cost-utility of aspirin treatment with or without PPI for coronary heart disease (CHD) prevention among men at different risks for CHD and gastrointestinal bleed

A randomized trial comparing treatments for varicose veins

Supported by a grant from the Health Technology Assessment Programme of the National Institute for Health Research (06/45/02). The Health Services Research Unit is funded by the Chief Scientist Office of the Scottish Government Health Directorate. We thank Janice Cruden for her secretarial support and data management; Gladys McPherson and the programming team at the Centre for Healthcare Randomised Trials; Tracey Davidson, Lynda Constable, Jackie Ellington, Laura Elliott, and Yvonne Fernie for help with scoring the Aberdeen Varicose Vein Questionnaire; Luke Vale and Laura Ternent, our original economists in the group; members of the Project Management Group for their ongoing advice and support of the trial; members of the study team (Graeme MacLennan, Maria Prior, and Denise Bolsover) who contributed to the behavioral recovery component of the trial; the independent members of the trial steering committee (Alun Davies [chair], Ian Loftus, and Jane Nixon) and the data and safety monitoring committee (Gerry Stansby [chair], Winston Banya, and Marcus Flather); and the staff members at recruitment sites (see the Supplementary Appendix) who facilitated recruitment, treatment, and follow-up of trial participants.Peer reviewedPublisher PD

Transplantation of Adult Mouse iPS Cell-Derived Photoreceptor Precursors Restores Retinal Structure and Function in Degenerative Mice

This study was designed to determine whether adult mouse induced pluripotent stem cells (iPSCs), could be used to produce retinal precursors and subsequently photoreceptor cells for retinal transplantation to restore retinal function in degenerative hosts. iPSCs were generated using adult dsRed mouse dermal fibroblasts via retroviral induction of the transcription factors Oct4, Sox2, KLF4 and c-Myc. As with normal mouse ES cells, adult dsRed iPSCs expressed the pluripotency genes SSEA1, Oct4, Sox2, KLF4, c-Myc and Nanog. Following transplantation into the eye of immune-compromised retinal degenerative mice these cells proceeded to form teratomas containing tissue comprising all three germ layers. At 33 days post-differentiation a large proportion of the cells expressed the retinal progenitor cell marker Pax6 and went on to express the photoreceptor markers, CRX, recoverin, and rhodopsin. When tested using calcium imaging these cells were shown to exhibit characteristics of normal retinal physiology, responding to delivery of neurotransmitters. Following subretinal transplantation into degenerative hosts differentiated iPSCs took up residence in the retinal outer nuclear layer and gave rise to increased electro retinal function as determined by ERG and functional anatomy. As such, adult fibroblast-derived iPSCs provide a viable source for the production of retinal precursors to be used for transplantation and treatment of retinal degenerative disease

Five-Year Outcomes of a Randomized Trial of Treatments for Varicose Veins

BACKGROUND Endovenous laser ablation and ultrasound-guided foam sclerotherapy are recommended alternatives to surgery for the treatment of primary varicose veins, but their long-term comparative effectiveness remains uncertain. METHODS In a randomized, controlled trial involving 798 participants with primary varicose veins at 11 centers in the United Kingdom, we compared the outcomes of laser ablation, foam sclerotherapy, and surgery. Primary outcomes at 5 years were disease-specific quality of life and generic quality of life, as well as cost-effectiveness based on models of expected costs and quality-adjusted life-years (QALYs) gained that used data on participants’ treatment costs and scores on the EuroQol EQ-5D questionnaire. RESULTS Quality-of-life questionnaires were completed by 595 (75%) of the 798 trial participants. After adjustment for baseline scores and other covariates, scores on the Aberdeen Varicose Vein Questionnaire (on which scores range from 0 to 100, with lower scores indicating a better quality of life) were lower among patients who underwent laser ablation or surgery than among those who underwent foam sclerotherapy (effect size [adjusted differences between groups] for laser ablation vs. foam sclerotherapy, −2.86; 95% confidence interval [CI], −4.49 to −1.22; P<0.001; and for surgery vs. foam sclerotherapy, −2.60; 95% CI, −3.99 to −1.22; P<0.001). Generic quality-of-life measures did not differ among treatment groups. At a threshold willingness-to-pay ratio of £20,000 ($28,433 in U.S. dollars) per QALY, 77.2 CONCLUSIONS In a randomized trial of treatments for varicose veins, disease-specific quality of life 5 years after treatment was better after laser ablation or surgery than after foam sclerotherapy. The majority of the probabilistic cost-effectiveness model iterations favored laser ablation at a willingness-to-pay ratio of £20,000 ($28,433) per QALY. (Funded by the National Institute for Health Research; CLASS Current Controlled Trials number, ISRCTN51995477.

Interplay between Synaptonemal Complex, Homologous Recombination, and Centromeres during Mammalian Meiosis

The intimate synapsis of homologous chromosome pairs (homologs) by synaptonemal complexes (SCs) is an essential feature of meiosis. In many organisms, synapsis and homologous recombination are interdependent: recombination promotes SC formation and SCs are required for crossing-over. Moreover, several studies indicate that initiation of SC assembly occurs at sites where crossovers will subsequently form. However, recent analyses in budding yeast and fruit fly imply a special role for centromeres in the initiation of SC formation. In addition, in budding yeast, persistent SC–dependent centromere-association facilitates the disjunction of chromosomes that have failed to become connected by crossovers. Here, we examine the interplay between SCs, recombination, and centromeres in a mammal. In mouse spermatocytes, centromeres do not serve as SC initiation sites and are invariably the last regions to synapse. However, centromeres are refractory to de-synapsis during diplonema and remain associated by short SC fragments. Since SC–dependent centromere association is lost before diakinesis, a direct role in homolog segregation seems unlikely. However, post–SC disassembly, we find evidence of inter-centromeric connections that could play a more direct role in promoting homolog biorientation and disjunction. A second class of persistent SC fragments is shown to be crossover-dependent. Super-resolution structured-illumination microscopy (SIM) reveals that these structures initially connect separate homolog axes and progressively diminish as chiasmata form. Thus, DNA crossing-over (which occurs during pachynema) and axis remodeling appear to be temporally distinct aspects of chiasma formation. SIM analysis of the synapsis and crossover-defective mutant Sycp1−/− implies that SCs prevent unregulated fusion of homolog axes. We propose that SC fragments retained during diplonema stabilize nascent bivalents and help orchestrate local chromosome reorganization that promotes centromere and chiasma function

HIV Disclosure Anxiety:A Systematic Review and Theoretical Synthesis

HIV disclosure can help people living with HIV to access social support, enhance antiretroviral adherence, facilitate engagement in care and reduce unprotected sex. Given interpersonal risks associated with HIV disclosure, however, anxiety about sharing one’s status is common. To investigate anxiety about HIV disclosure in HIV-positive populations, we conducted a systematic review of qualitative and quantitative studies, with 119 studies included. The review demonstrated that perceived interpersonal risks are associated with HIV disclosure and outlined evidence of associations with anxiety, fear and worry. We present a new cognitive model of HIV disclosure anxiety adapted from clinical theories of health and social anxiety, consistent with evidence from the review. The model attempts to explain the development and maintenance of anxiety in individuals whose functioning is most affected by concerns about sharing their status. Implications for helping people living with HIV struggling with significant levels of anxiety about HIV disclosure are discussed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10461-016-1453-3) contains supplementary material, which is available to authorized users