97 research outputs found
Particle Physics from Almost Commutative Spacetimes
Our aim in this review article is to present the applications of Connes'
noncommutative geometry to elementary particle physics. Whereas the existing
literature is mostly focused on a mathematical audience, in this article we
introduce the ideas and concepts from noncommutative geometry using physicists'
terminology, gearing towards the predictions that can be derived from the
noncommutative description. Focusing on a light package of noncommutative
geometry (so-called 'almost commutative manifolds'), we shall introduce in
steps: electrodynamics, the electroweak model, culminating in the full Standard
Model. We hope that our approach helps in understanding the role noncommutative
geometry could play in describing particle physics models, eventually unifying
them with Einstein's (geometrical) theory of gravity.Comment: 104 pages, 5 figures, version 2 (minor changes and some additional
references
A survey of spectral models of gravity coupled to matter
This is a survey of the historical development of the Spectral Standard Model
and beyond, starting with the ground breaking paper of Alain Connes in 1988
where he observed that there is a link between Higgs fields and finite
noncommutative spaces. We present the important contributions that helped in
the search and identification of the noncommutative space that characterizes
the fine structure of space-time. The nature and properties of the
noncommutative space are arrived at by independent routes and show the
uniqueness of the Spectral Standard Model at low energies and the Pati-Salam
unification model at high energies.Comment: An appendix is added to include scalar potential analysis for a
Pati-Salam model. 58 Page
Locational memory of macrovessel vascular cells is transcriptionally imprinted
Vascular pathologies show locational predisposition throughout the body; further insights into the transcriptomics basis of this vascular heterogeneity are needed. We analyzed transcriptomes from cultured endothelial cells and vascular smooth muscle cells from nine adult canine macrovessels: the aorta, coronary artery, vena cava, portal vein, femoral artery, femoral vein, saphenous vein, pulmonary vein, and pulmonary artery. We observed that organ-specific expression patterns persist in vitro, indicating that these genes are not regulated by blood flow or surrounding cell types but are likely fixed in the epigenetic memory. We further demonstrated the preserved location-specific expression of GATA4 protein in cultured cells and in the primary adult vessel. On a functional level, arterial and venous endothelial cells differed in vascular network morphology as the arterial networks maintained a higher complexity. Our findings prompt the rethinking of the extrapolation of results from single-origin endothelial cell systems
Incidence and prevalence of dementia in linked administrative health data in Saskatchewan, Canada: a retrospective cohort study.
Determining the epidemiology of dementia among the population as a whole in specific jurisdictions - including the long-term care population-is essential to providing appropriate care. The objectives of this study were to use linked administrative databases in the province of Saskatchewan to determine the 12-month incidence and prevalence of dementia for the 2012/13 period (1) among individuals aged 45 and older in the province of Saskatchewan, (2) according to age group and sex, and (3) according to diagnosis code and other case definition criteria
Survival of atraumatic restorative treatment (ART) sealants and restorations: a meta-analysis
The purpose of this study is to perform a systematic investigation plus meta-analysis into survival of atraumatic restorative treatment (ART) sealants and restorations using high-viscosity glass ionomers and to compare the results with those from the 2005 ART meta-analysis. Until February 2010, four databases were searched. Two hundred four publications were found, and 66 reported on ART restorations or sealant survival. Based on five exclusion criteria, two independent reviewers selected the 29 publications that accounted for the meta-analysis. Confidence intervals (CI) and or standard errors were calculated and the heterogeneity variance of the survival rates was estimated. Location (school/clinic) was an independent variable. The survival rates of single-surface and multiple-surface ART restorations in primary teeth over the first 2 years were 93% (CI, 91–94%) and 62% (CI, 51–73%), respectively; for single-surface ART restorations in permanent teeth over the first 3 and 5 years it was 85% (CI, 77–91%) and 80% (CI, 76–83%), respectively and for multiple-surface ART restorations in permanent teeth over 1 year it was 86% (CI, 59–98%). The mean annual dentine lesion incidence rate, in pits and fissures previously sealed using ART, over the first 3 years was 1%. No location effect and no differences between the 2005 and 2010 survival rates of ART restorations and sealants were observed. The short-term survival rates of single-surface ART restorations in primary and permanent teeth, and the caries-preventive effect of ART sealants were high. Clinical relevance: ART can safely be used in single-surface cavities in both primary and permanent teeth. ART sealants have a high caries preventive effect
Systematic analysis of chromatin interactions at disease associated loci links novel candidate genes to inflammatory bowel disease
Cerebral ultrasound abnormalities in preterm infants caused by late-onset sepsis
INTRODUCTION:This study describes cerebral ultrasound abnormalities caused by late-onset sepsis (LOS) in very preterm infants with a gestational age of < 32 weeks and/or birthweight < 1500 grams. METHODS:The prospective study ("INFANT study") included 117 preterm infants with suspected LOS. Proven LOS was defined as a positive blood culture after 72 hours of life. In case of coagulase-negative staphylococci an elevated C-reactive protein was additionally required to establish proven LOS. Patients were identified as proven LOS and patients with only clinical symptoms of LOS. Cerebral ultrasound images were obtained in the first week after birth, during/after LOS and before discharge. Cerebral findings were divided in no/minor and major abnormalities. RESULTS:Eighty-six preterm infants had proven LOS and 31 preterm infants had only clinical signs of LOS. Four infants were excluded because pre-existing major brain abnormalities. No significant differences (p = 0.624) for incidence of major brain abnormalities on cerebral ultrasound were found. CONCLUSION:No differences were revealed in prevalence of major brain abnormalities between the groups with proven LOS and with clinical signs of LOS. Both infants with a gram negative sepsis developed major brain abnormalities, whereas only two of 66 preterm infants coagulase-negative staphylococci sepsis developed major brain abnormalities
Fatal case of influenza B virus pneumonia in a preterm neonate
Influenza B infection typically has low mortality. A 1020-g neonate had a septic clinical picture and pneumonia. Influenza B virus was isolated from nasopharyngeal and tracheal aspirates. The infant die
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