Quantum gravitational contributions to quantum electrodynamics

Quantum electrodynamics describes the interactions of electrons and photons. Electric charge (the gauge coupling constant) is energy dependent, and there is a previous claim that charge is affected by gravity (described by general relativity) with the implication that the charge is reduced at high energies. But that claim has been very controversial with the situation inconclusive. Here I report an analysis (free from earlier controversies) demonstrating that that quantum gravity corrections to quantum electrodynamics have a quadratic energy dependence that result in the reduction of the electric charge at high energies, a result known as asymptotic freedom.Comment: To be published in Nature. 19 pages LaTeX, no figure

A rare association of crossed fused renal ectopia

BACKGROUND: Thrombocytopenia and absent radius syndrome (TAR) is a rare genetic disorder. It is an autosomal recessive disorder characterised by radial aplasia and thrombocytopenia that may have additional anomalies. We report a case of TAR syndrome with crossed fused renal ectopia. This anomaly has not been previously reported in association with TAR syndrome. CASE PRESENTATION: A 24 years old female with Thrombocytopenia and absent radius syndrome admitted with pelvic fracture was investigated for recurrent urinary tract infections. Abdominal ultrasonography could not visualise the kidney on right side. Further extensive investigations in the form of intravenous urography (IVU), Magnetic resonance imaging (MRI) and renal isotope scans revealed a crossed fused renal ectopia. CONCLUSION: This report describes the new finding of a crossed fused renal ectopia associated with TAR syndrome that has not been reported before in the literature. Ectopic kidneys have increased susceptibility to develop complications like urinary infections, urolithiasis, and abdominal mass. There is a reported case of TAR syndrome with renal anomaly that developed Wilm's tumor. Finding of crossed fused renal ectopia warrants complete urologic investigation to rule out surgically correctable pathology in the urinary tract

Genetic analysis of a major international collection of cultivated apple varieties reveals previously unknown historic heteroploid and inbred relationships

Domesticated apple (Malus x domestica Borkh.) is a major global crop and the genetic diversity held within the pool of cultivated varieties is important for the development of future cultivars. The aim of this study was to investigate the diversity held within the domesticated form, through the analysis of a major international germplasm collection of cultivated varieties, the UK National Fruit Collection, consisting of over 2,000 selections of named cultivars and seedling varieties. We utilised Diversity Array Technology (DArT) markers to assess the genetic diversity within the collection. Clustering attempts, using the software STRUCTURE revealed that the accessions formed a complex and historically admixed group for which clear clustering was challenging. Comparison of accessions using the Jaccard similarity coefficient allowed us to identify clonal and duplicate material as well as revealing pairs and groups that appeared more closely related than a standard parent-offspring or full-sibling relations. From further investigation, we were able to propose a number of new pedigrees, which revealed that some historically important cultivars were more closely related than previously documented and that some of them were partially inbred. We were also able to elucidate a number of parent-offspring relationships that had resulted in a number of important polyploid cultivars. This included reuniting polyploid cultivars that in some cases dated as far back as the 18th century, with diploid parents that potentially date back as far as the 13th century

Light hadron, Charmonium(-like) and Bottomonium(-like) states

Hadron physics represents the study of strongly interacting matter in all its manifestations and the understanding of its properties and interactions. The interest on this field has been revitalized by the discovery of new light hadrons, charmonium- and bottomonium-like states. I review the most recent experimental results from different experiments.Comment: Presented at Lepton-Photon 2011, Mumbai, India; 21 pages, 18 figures; add more references; some correctio

Cervical cancer screening: target age bracket, screening frequency and screening method: review of recent evidence and comparison with the Portuguese performance indicator

Esta revisão teve por objetivo avaliar a força de evidência do indicador de desempenho português relativo ao rastreio do Câncer do Colo do Útero (CCU): (1) limites etários das mulheres da população geral que o devem realizar, a (2) periodicidade com que deve ser realizado e (3) qual o melhor exame de rastreio. Foram pesquisados os seguintes termos MeSH: vaginal smears, age groups, periodicity, methods, uterine cervical cancer. Foram excluídos os artigos que não abordavam o objetivo da investigação ou que não fossem redigidos em Inglês, Português ou Espanhol. Para interpretar os artigos selecionados foi utilizada a classificação SORT. Foram encontrados 197 artigos, dos quais seleccionados 9: 1 revisão sistemática (RS), 1 estudo clínico controlado aleatorizado, 2 estudos observacionais retrospectivos e 5 normas de orientação clínica (NOC). Os autores optaram por incluir nesta revisão mais 4 NOCs e 2 RSs por considerarem ser relevantes para a população Portuguesa, apesar de não resultarem da pesquisa efectuada. Os estudos sugerem realização do rastreio entre os 21 e 25 até aos 65 anos, com uma periodicidade trienal usando a citologia convencional. Existe ainda controvérsia no que toca aos 3 objetivos deste artigo (limites etários, frequência e método).The scope of this review was to assess the strength of evidence of Portuguese performance indicators on Cervical Cancer screening: (1) age group of the women that should be screened for cervical cancer; (2) frequency of screening; and (3) the best method for screening. The following MeSH terms were searched: vaginal smears, age groups, periodicity, methods, uterine cervical cancer. Articles not reflecting the study objectives or not available in English, Portuguese or Spanish were excluded. The SORT classification was used to rate the articles selected.Of the 197 articles found, 9 that met all study criteria were selected for inclusion in this review. These included 1 systematic review, 1 randomized controlled clinical trial, 2 retrospective studies and 5 clinical guidelines. The authors also chose to include 4 clinical guidelines and two systematic reviews relevant to the Portuguese population even though they did not appear in the initial search of the literature. The studies suggest screening women between the ages of 21 to 25 years and 65 years of age, once every three years using conventional cytology. There is still controversy regarding the three objectives of this study (target age bracket, screening frequency and screening method)

HLA-Cw*0602 associates with a twofold higher prevalence of positive streptococcal throat swab at the onset of psoriasis: a case control study

<p>Abstract</p> <p>Background</p> <p>The influence of streptococcal infections in the pathogenesis of psoriasis is not yet understood. <it>In vitro </it>data suggest that streptococcal factors influence T-cell function in psoriasis in a HLA-dependent manner, but studies designed to measure the HLA-C/Streptococci interaction are lacking. In the present study, we hypothesized that there is a statistical interaction between the result of streptococcal throat cultures and the presence of the HLA-Cw*0602 allele in psoriasis patients.</p> <p>Methods</p> <p>We performed a case control study using the "Stockholm Psoriasis Cohort" consisting of patients consecutively recruited within 12 months of disease onset (Plaque psoriasis = 439, Guttate psoriasis = 143), matched to healthy controls (n = 454) randomly chosen from the Swedish Population Registry. All individuals underwent physical examination including throat swabs and DNA isolation for HLA-Cw*0602 genotyping.</p> <p>The prevalence of positive streptococcal throat swabs and HLA-Cw*0602 was compared between patients and controls and expressed as odds ratios with 95% confidence intervals. Associations were evaluated separately for guttate and plaque psoriasis by Fisher's exact test.</p> <p>Results</p> <p>Regardless of disease phenotype, the prevalence of positive streptococcal throat swabs in HLA-Cw*0602 positive patients was twice the prevalence among HLA-Cw*0602 negative patients (OR = 5.8 C.I. = 3.57–9.67, p < 0.001), while no difference was observed among Cw*0602 positive versus negative controls.</p> <p>The corresponding odds ratios for the guttate and plaque psoriasis phenotypes were 3.5 (CI = 1.5–8.7, p = 0.01) and 2.3 (CI = 1.0–5.1, p = 0.02) respectively.</p> <p>Conclusion</p> <p>These findings suggest that among HLA-Cw*0602 positive psoriasis patients, streptococci may contribute to the onset or exacerbation of the inflammatory process independent of the disease phenotype. However, studies on the functional interaction between HLA-C and streptococcal factors are needed.</p

Cytological Aspects of Pleural, Peritoneal and Pericardial Fluids From Patients With Systemic Lupus Erythematosus

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74778/1/j.1365-2303.1992.tb00014.x.pd

Proximity morality in medical school – medical students forming physician morality "on the job": Grounded theory analysis of a student survey

<p>Abstract</p> <p>Background</p> <p>The value of ethics education have been questioned. Therefore we did a student survey on attitudes about the teaching of ethics in Swedish medical schools.</p> <p>Methods</p> <p>Questionnaire survey on attitudes to ethics education with 409 Swedish medical students participating. We analyzed > 8000 words of open-ended responses and multiple-choice questions using classic grounded theory procedures.</p> <p>Results</p> <p>In this paper we suggest that medical students take a proximity morality stance towards their ethics education meaning that they want to form physician morality "on the job". This involves comprehensive ethics courses in which quality lectures provide "ethics grammar" and together with attitude exercises and vignette reflections nurture tutored group discussions. Goals of forming physician morality are to develop a professional identity, handling diversity of religious and existential worldviews, training students described as ethically naive, processing difficult clinical experiences, and desisting negative role modeling from physicians in clinical or teaching situations, some engaging in "ethics suppression" by controlling sensitive topic discussions and serving students politically correct attitudes.</p> <p>Conclusion</p> <p>We found that medical students have a proximity morality attitude towards ethics education. Rather than being taught ethics they want to form their own physician morality through tutored group discussions in comprehensive ethics courses.</p

Spacelike Singularities and Hidden Symmetries of Gravity

We review the intimate connection between (super-)gravity close to a spacelike singularity (the "BKL-limit") and the theory of Lorentzian Kac-Moody algebras. We show that in this limit the gravitational theory can be reformulated in terms of billiard motion in a region of hyperbolic space, revealing that the dynamics is completely determined by a (possibly infinite) sequence of reflections, which are elements of a Lorentzian Coxeter group. Such Coxeter groups are the Weyl groups of infinite-dimensional Kac-Moody algebras, suggesting that these algebras yield symmetries of gravitational theories. Our presentation is aimed to be a self-contained and comprehensive treatment of the subject, with all the relevant mathematical background material introduced and explained in detail. We also review attempts at making the infinite-dimensional symmetries manifest, through the construction of a geodesic sigma model based on a Lorentzian Kac-Moody algebra. An explicit example is provided for the case of the hyperbolic algebra E10, which is conjectured to be an underlying symmetry of M-theory. Illustrations of this conjecture are also discussed in the context of cosmological solutions to eleven-dimensional supergravity.Comment: 228 pages. Typos corrected. References added. Subject index added. Published versio