Rigidity around Poisson Submanifolds

We prove a rigidity theorem in Poisson geometry around compact Poisson submanifolds, using the Nash-Moser fast convergence method. In the case of one-point submanifolds (fixed points), this immediately implies a stronger version of Conn's linearization theorem, also proving that Conn's theorem is, indeed, just a manifestation of a rigidity phenomenon; similarly, in the case of arbitrary symplectic leaves, it gives a stronger version of the local normal form theorem; another interesting case corresponds to spheres inside duals of compact semisimple Lie algebras, our result can be used to fully compute the resulting Poisson moduli space.Comment: 43 pages, v3: published versio

Patient-doctor continuity and diagnosis of cancer: electronic medical records study in general practice

This is the final version of the article. Available from Royal College of General Practitioners via the DOI in this record.BACKGROUND: Continuity of care may affect the diagnostic process in cancer but there is little research. AIM: To estimate associations between patient-doctor continuity and time to diagnosis and referral of three common cancers. DESIGN AND SETTING: Retrospective cohort study in general practices in England. METHOD: This study used data from the General Practice Research Database for patients aged ≥40 years with a diagnosis of breast, colorectal, or lung cancer. Relevant cancer symptoms or signs were identified up to 12 months before diagnosis. Patient-doctor continuity (fraction-of-care index adjusted for number of consultations) was calculated up to 24 months before diagnosis. Time ratios (TRs) were estimated using accelerated failure time regression models. RESULTS: Patient-doctor continuity in the 24 months before diagnosis was associated with a slightly later diagnosis of colorectal (time ratio [TR] 1.01, 95% confidence interval [CI] =1.01 to 1.02) but not breast (TR = 1.00, 0.99 to 1.01) or lung cancer (TR = 1.00, 0.99 to 1.00). Secondary analyses suggested that for colorectal and lung cancer, continuity of doctor before the index consultation was associated with a later diagnosis but continuity after the index consultation was associated with an earlier diagnosis, with no such effects for breast cancer. For all three cancers, most of the delay to diagnosis occurred after referral. CONCLUSION: Any effect for patient-doctor continuity appears to be small. Future studies should compare investigations, referrals, and diagnoses in patients with and without cancer who present with possible cancer symptoms or signs; and focus on 'difficult to diagnose' types of cancer.This work was funded by Cancer Research UK (C41384/A13266)

Blinded assessment of treatment effects utilizing information about the randomization block length

It is essential for the integrity of double-blind clinical trials that during the study course the individual treatment allocations of the patients as well as the treatment effect remain unknown to any involved person. Recently, methods have been proposed for which it was claimed that they would allow reliable estimation of the treatment effect based on blinded data by using information about the block length of the randomization procedure. If this would hold true, it would be difficult to preserve blindness without taking further measures. The suggested procedures apply to continuous data. We investigate the properties of these methods thoroughly by repeated simulations per scenario. Furthermore, a method for blinded treatment effect estimation in case of binary data is proposed, and blinded tests for treatment group differences are developed both for continuous and binary data. We report results of comprehensive simulation studies that investigate the features of these procedures. It is shown that for sample sizes and treatment effects which are typical in clinical trials, no reliable inference can be made on the treatment group difference which is due to the bias and imprecision of the blinded estimates

Interventions for treating anxiety after stroke

Background: Approximately 20% of stroke patients experience anxiety at some point after stroke. Objectives: To determine if any treatment for anxiety after stroke decreases the proportion of patients with anxiety disorders or symptoms, and to determine the effect of treatment on quality of life, disability, depression, social participation, risk of death or caregiver burden. Search methods: We searched the trials register of the Cochrane Stroke Group (October 2010), CENTRAL (The Cochrane Library 2010, Issue 4), MEDLINE (1950 to October 2010), EMBASE (1947 to October 2010), PsycINFO (1806 to October 2010), Allied and Complementary Medicine database (AMED) (1985 to October 2010), Cumulative Index to Nursing and Allied Health (CINAHL) (1982 to October 2010), Proquest Digital Dissertations (1861 to October 2010), and Psychological Database for Brain Impairment Treatment Efficacy (PsycBITE) (2004 to October 2010). In an effort to identify further published, unpublished and ongoing trials, we searched trial registries and major international stroke conference proceedings, scanned reference lists, and contacted select individuals known to the review team who are actively involved in psychological aspects of stroke research, and the Association of the British Pharmaceutical Industry. Selection criteria: Two review authors independently screened and selected titles and abstracts for inclusion in the review. Randomised trials of any intervention in patients with stroke where the treatment of anxiety was an outcome were eligible. Data collection and analysis: Two review authors independently extracted data for analysis. We performed a narrative review. A meta-analysis was planned but not carried out as studies were not of sufficient quality to warrant doing so. Main results: We included two trials (three interventions) involving 175 participants with co-morbid anxiety and depression in the review. Both trials used the Hamilton Anxiety Scale (HAM-A) to assess anxiety, and neither included a placebo control group. One trial randomised 81 patients to paroxetine, paroxetine plus psychotherapy or standard care. Mean level of anxiety severity scores were 58% and 71% lower in the paroxetine, and paroxetine plus psychotherapy groups respectively compared with those in standard care at follow-up (P < 0.01). The second trial randomised 94 stroke patients, also with co-morbid anxiety and depression, to receive buspirone hydrochloride or standard care. At follow-up, the mean level of anxiety was significantly lower for those receiving buspirone relative to controls (P < 0.01). Half of the participants receiving paroxetine experienced adverse events that included nausea, vomiting or dizziness; however, only 14% of those receiving buspirone experienced nausea or palpitations. No information was provided about the duration of symptoms associated with adverse events. Authors' conclusions: There is insufficient evidence to guide the treatment of anxiety after stroke. The data available suggest that pharmaceutical therapy (paroxetine and buspirone) may be effective in reducing anxiety symptoms in stroke patients with co-morbid anxiety and depression. No information was available for stroke patients with anxiety only. Randomised placebo controlled trials are needed

Mirtazapine Augmentation for Selective Serotonin Reuptake Inhibitor-Induced Sexual Dysfunction: A Retropective Investigation

The aim of the present study was to retrospectively identify sexual dysfunction changes in the patients under mirtazapine-augmented serotonin reuptake inhibito (SSRI) treatment. The study comprised medical records of 20 outpatients, under mirtazapine-augmented SSRI treatment for their major depressive disorder, who had been selected among the patients that had developed sexual dysfunction to previous treatment as monotherapy, with SSRI for at least six weeks. These drugs were maintained and mirtazapine were added (15-45 mg/day). There was a significant difference in scores between baseline and week 4 or week 8 on the both Hamilton Depression Rating and Arizona Sexual Experience Scale. According to Clinical Global Impression-Improvement, 68.4% of the patients were responders. The use of low-dose mirtazapine as an add-on treatment to SSRIs appears to be an effective and well-tolerated augmenttaion for sexual dysfunction caused by SSRIs

Probing the Sensitivity of Electron Wave Interference to Disorder-Induced Scattering in Solid-State Devices

The study of electron motion in semiconductor billiards has elucidated our understanding of quantum interference and quantum chaos. The central assumption is that ionized donors generate only minor perturbations to the electron trajectories, which are determined by scattering from billiard walls. We use magnetoconductance fluctuations as a probe of the quantum interference and show that these fluctuations change radically when the scattering landscape is modified by thermally-induced charge displacement between donor sites. Our results challenge the accepted understanding of quantum interference effects in nanostructures.Comment: 8 pages, 5 figures, Submitted to Physical Review

Run Scenarios for the Linear Collider

Scenarios are developed for runs at a Linear Collider, in the case that there is a rich program of new physics.Comment: 12 pages, 10 tables, Latex; Snowmass 2001 plenary repor