209 research outputs found
A Resolved Millimeter Emission Belt in the AU Mic Debris Disk
We present imaging observations at 1.3 millimeters of the debris disk
surrounding the nearby M-type flare star AU Mic with beam size 3 arcsec (30 AU)
from the Submillimeter Array. These data reveal a belt of thermal dust emission
surrounding the star with the same edge-on geometry as the more extended
scattered light disk detected at optical wavelengths. Simple modeling indicates
a central radius of ~35 AU for the emission belt. This location is consistent
with the reservoir of planetesimals previously invoked to explain the shape of
the scattered light surface brightness profile through size-dependent dust
dynamics. The identification of this belt further strengthens the kinship
between the debris disks around AU Mic and its more massive sister star beta
Pic, members of the same ~10 Myr-old moving group.Comment: 10 pages, 2 figures. Accepted for publication in ApJ Letter
Assigning function to genome wide association study variants associated with complex gastrointestinal disease
PhDThe genome‐wide association study era has identified numerous loci associated with many
common polygenic diseases. The next challenge is to identify the functional consequences
of these variants and elicit how they impact on disease risk. Using a combination of protein
based assays, large scale microarrays and high‐throughput generation sequencing
platforms this thesis aims to identify the functional effects of disease loci, with particular
focus on Crohn’s disease and coeliac disease, two common complex gastrointestinal
diseases.
Variants located within the Interleukin 23 receptor are associated with both susceptibility
and protection from Crohn’s disease, a debilitating chronic inflammatory disease of the
bowel. A study was undertaken to investigate the effect of these variants, at the mRNA as
well as the protein level, on both cytokine and receptor levels.
Coeliac disease is a dietary intolerance to the gluten component of wheat, barley and rye
and has an estimated prevalence of approximately 1%. Genome‐wide association studies
have identified eight genomic different loci as associated with coeliac disease but none
have been functionally characterised. To investigate the effect that genotype has on gene
transcript levels, a genetical genomics study was undertaken in patients with coeliac
disease generating results with relevance to a range of autoimmune disorders.
Before disease based effects can be identified, it is first important to fully characterise the
normal human transcriptome and methylome. To this end CD4
+ T cells were studied using
novel high‐throughput sequencing techniques, with the aim of providing some insight into
novel genomic properties that may illuminate current and future disease associated loci.
Given the base pair resolution approach of high‐throughput sequencing, a novel method of
assaying for SNP effects on gene expression was developed. This allele specific method,
using whole transcriptome sequencing, is capable of identifying alterations in transcript
expression on a genome‐wide scale
A Submillimetre Search for Cold Extended Debris Disks in the Beta Pictoris Moving Group
The Beta Pictoris Moving Group is a nearby stellar association of young
(12Myr) co-moving stars including the classical debris disk star beta Pictoris.
Due to their proximity and youth they are excellent targets when searching for
submillimetre emission from cold, extended, dust components produced by
collisions in Kuiper-Belt-like disks. They also allow an age independent study
of debris disk properties as a function of other stellar parameters. We
observed 7 infrared-excess stars in the Beta Pictoris Moving Group with the
LABOCA bolometer array, operating at a central wavelength of 870 micron at the
12-m submillimetre telescope APEX. The main emission at these wavelengths comes
from large, cold dust grains, which constitute the main part of the total dust
mass, and hence, for an optically thin case, make better estimates on the total
dust mass than earlier infrared observations. Fitting the spectral energy
distribution with combined optical and infrared photometry gives information on
the temperature and radial extent of the disk. From our sample, beta Pic,
HD181327, and HD172555 were detected with at least 3-sigma certainty, while all
others are below 2-sigma and considered non-detections. The image of beta Pic
shows an offset flux density peak located near the south-west extension of the
disk, similar to the one previously found by SCUBA at the JCMT. We present SED
fits for detected sources and give an upper limit on the dust mass for
undetected ones. We find a mean fractional dust luminosity f_dust=11x10^{-4} at
t=12Myr, which together with recent data at 100Myr suggests an f_dust propto
t^{-alpha} decline of the emitting dust, with alpha > 0.8.Comment: 11 pages, 3 figures, 3 tables; accepted for publication in Astronomy
  & Astrophysic
Technical Review: Analysis and Appraisal of Four-Dimensional Building Information Modeling Usability in Construction and Engineering Projects
Building information modeling (BIM) fundamentally requires the importation of a three-dimensional (3D) model with a series of repository data. Numerous studies have been conducted to clarify the philosophy of BIM and promote its adoption in construction and engineering projects. The primary contributions of this research to the construction engineering and management body of knowledge are the technical review, analysis, and appraisal of various issues concerning the usability of four-dimensional (4D) BIM. The research aims to determine the readiness and development of 4D BIM. A technical literature review was conducted of various BIM software websites, journal articles, brochures, and videos about required 4D elements. A comparative analysis was conducted to compare the technical (TECA) and project-planning functionality (PPFA) aspects of developing 4D models with features provided by available BIM software. This analysis yielded matrices that can be used to guide decision making on which BIM software to invest in. The results reveal that all of the software packages in their way serve the purpose of developing a 4D BIM model
The Formation and Evolution of the First Massive Black Holes
The first massive astrophysical black holes likely formed at high redshifts
(z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations.
These black holes grow by mergers and gas accretion, evolve into the population
of bright quasars observed at lower redshifts, and eventually leave the
supermassive black hole remnants that are ubiquitous at the centers of galaxies
in the nearby universe. The astrophysical processes responsible for the
formation of the earliest seed black holes are poorly understood. The purpose
of this review is threefold: (1) to describe theoretical expectations for the
formation and growth of the earliest black holes within the general paradigm of
hierarchical cold dark matter cosmologies, (2) to summarize several relevant
recent observations that have implications for the formation of the earliest
black holes, and (3) to look into the future and assess the power of
forthcoming observations to probe the physics of the first active galactic
nuclei.Comment: 39 pages, review for "Supermassive Black Holes in the Distant
  Universe", Ed. A. J. Barger, Kluwer Academic Publisher
Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.
Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition
The effect of increasing the supply of skilled health providers on pregnancy and birth outcomes: evidence from the midwives service scheme in Nigeria
Background:
Limited availability of skilled health providers in developing countries is thought to be an important barrier to achieving maternal and child health-related MDG goals. Little is known, however, about the extent to which scaling-up supply of health providers will lead to improved pregnancy and birth outcomes. We study the effects of the Midwives Service Scheme (MSS), a public sector program in Nigeria that increased the supply of skilled midwives in rural communities on pregnancy and birth outcomes.
Methods:
We surveyed 7,104 women with a birth within the preceding five years across 12 states in Nigeria and compared changes in birth outcomes in MSS communities to changes in non-MSS communities over the same period.
Results:
The main measured effect of the scheme was a 7.3-percentage point increase in antenatal care use in program clinics and a 5-percentage point increase in overall use of antenatal care, both within the first year of the program. We found no statistically significant effect of the scheme on skilled birth attendance or on maternal delivery complications.
Conclusion:
This study highlights the complexity of improving maternal and child health outcomes in developing countries, and shows that scaling up supply of midwives may not be sufficient on its own
Association of Genetic Variants in NUDT15 with Thiopurine-Induced Myelosuppression in Patients with Inflammatory Bowel Disease
Funding Information: reported serving as a consultant for AbbVie UK; receiving honoraria from Falk and AbbVie UK; receiving grants from Crohn’s & Colitis UK and Tillott’s Pharmaceuticals; having a fellowship from the UK National Institute for Health Research; and receiving travel reimbursement from Merck Sharp & Dohme and Norgine. Dr Heap reported receiving travel reimbursement from AbbVie; and being a current employee of AbbVie and owning stock in the company. Dr Andersen reported receiving personal fees from Merck Sharp & Dohme and Janssen. Dr Ananthakrishnan reported receiving a grant from Pfizer; and receiving personal fees from Takeda. Dr Beaugerie reported receiving advisory board fees from Allergan, Janssen, and Pfizer; receiving a grant from Hospira; and receiving grants and honoraria from AbbVie, Merck Sharp & Dohme, Ferring, Takeda, and Tillott’s Pharmaceuticals. Dr Cummings reported receiving personal fees from AbbVie, Takeda, Biogen, Janssen, Merck Sharp & Dohme, Amgen, Hakim Pharmaceuticals, and Pfizer/Hospira; and receiving grants from Takeda, Biogen, AstraZeneca, and Pfizer/Hospira. Dr Halfvarson reported receiving personal fees from AbbVie, Hospira, Janssen, Medivir, Merck Sharp & Dohme, Pfizer, RenapharmaVifor, Takeda, Tillott’s Pharmaceuticals, Celgene, Sandoz, and Shire; and receiving grants from Janssen, Merck Sharp & Dohme, and Takeda. Dr Hart reported receiving advisory board fees from AbbVie, Atlantic, Bristol-Myers Squibb, Celltrion, Janssen, Merck Sharp & Dohme, Pfizer, Shire, and Takeda; receiving honoraria from Falk and Ferring; and receiving a grant from Takeda. Dr Irving reported receiving personal fees from Janssen, AbbVie, Takeda, Ferring, Pfizer, Lilly, Merck Sharp & Dohme, Samsung, and Sandoz; and receiving grants from Takeda and Merck Sharp & Dohme. Dr Lindsay reported receiving advisory board fees from Atlantic Health, AbbVie UK/global, Merck Sharp & Dohme, Shire UK, Vifor Pharma, Ferring International, Celltrion, Takeda, Napp, Pfizer, and Janssen; serving as a consultant for AbbVie UK/global, Takeda, and Pfizer; receiving grants from Shire UK, AbbVie UK/global, Warner Chilcott, Funding Information: Takeda, Hospira, Ferring International, and Merck Sharp & Dohme; receiving honoraria from Takeda, Cornerstones US, Tillott’s Pharmaceuticals, Napp, Shire International, Janssen, AbbVie, and Pfizer; and receiving travel reimbursement from AbbVie UK, Merck Sharp & Dohme, Warner Chilcott, Takeda, and Shire International. Dr McGovern reported receiving grants from the National Institutes of Health, Helmsley Charitable Trust, and Janssen; and serving as a consultant for Pfizer, Q Biologics, Cidara, Gilead, and Janssen. Dr Seksik reported receiving advisory board fees from Astellas; receiving honoraria from Takeda, AbbVie, and Ferring; and receiving grants from Merck Sharp & Dohme and Biocodex. Dr Sokol reported receiving grants from Biocodex, Danone, and BiomX; serving as a consultant for Enterome, Takeda, AbbVie, Roche, Amgen, Danone, BiomX, Ferring, Bristol-Myers Squibb, Astellas, Merck Sharp & Dohme, Novartis, Tillott’s Pharmaceuticals, and Biose; and being the co-founder of Nextbiotix. Dr Annese reported receiving advisory board fees from Takeda, AbbVie, and Medtronic; and receiving honoraria from Janssen, Takeda, AbbVie, and Medtronic. Dr Weersma reported receiving grants from Takeda, Ferring, and Tramedico; and receiving personal fees from AbbVie. Dr Goodhand reported receiving honoraria from Falk, AbbVie, and Shield Therapeutics. Dr Kennedy reported serving as a consultant for Falk; receiving honoraria from Falk, Allergan, Pharmacosmos, and Takeda; and being a deputy editor of Alimentary Pharmacology & Therapeutics. Dr Ahmad reported receiving unrestricted grants, advisory board fees, speaker honoraria, and support to attend international meetings from AbbVie, Merck Sharp & Dohme, Janssen, Takeda, Ferring, Tillott’s Pharmaceuticals, Ferring, Pfizer, Napp, Celltrion, and Hospira. No other disclosures were reported. Funding Information: Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California), Alistair McNair, PhD (Queen Elizabeth Hospital, London, UK), Anita Modi, MD (Luton and Dunstable University Hospital, Luton, UK), Kevin Monahan, PhD (West Middlesex University Hospital, Middlesex, UK), Alex Moran, MD (Northern Devon Healthcare Trust, Barnstaple, UK), Mary-Anne Morris, MD (Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK), Marianne Mortimore, MBBS (Mater Research Institute, University of Queensland, South Brisbane, Australia), Craig Mowat, MD (Ninewells Hospital, NHS Tayside, Dundee, UK), Rafeeq Muhammed, MD (Birmingham Children's Hospital, Birmingham, UK), Charles D. R. Murray, PhD (Royal Free Hospital, Royal Free London NHS Foundation Trust, London, UK), Hanlie Olivier (IBD Pharmacogenetics Group, University of Exeter, Exeter, UK), Timothy R. Orchard, DM (Imperial College Healthcare NHS Trust, London, UK), Simon Panter, MD (South Tyneside District Hospital, South Tyneside, UK), Vinod Patel, MBBS (Tameside and Glossop Integrated Care NHS Foundation Trust, Ashton-under-Lyne, UK), Rosemary Phillips, MD (Princess Alexandra Hospital, Essex, UK), Neeraj Prasad, MSc (Wrightington Hospital, Wrightington, UK), Cathryn Preston, MBChB (Bradford Royal Infirmary, Bradford, UK), Graham Radford-Smith, PhD (Royal Brisbane and Women’s Hospital, Brisbane, Australia), Praveen Rajasekhar, MD (Northumbria NHS Trust, Tyne and Wear, UK), Dipak Roy, PhD (Tameside and Glossop Integrated Care NHS Foundation Trust, Ashton-under-Lyne, UK), Rebecca Saich, PhD (Basingstoke and North Hampshire Hospital, Basingstoke, UK), Jack Satsangi, PhD (Western General Hospital, NHS Lothian, Edinburgh, UK), Stefan Schreiber, PhD (Kiel University, Kiel, Germany), Sandip Sen, MD (Royal Stoke University Hospital, Stoke-on-Trent, UK), Neil Shah, MD (Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK), Richard Shenderay, MBBS (Airedale NHS Foundation Trust, Keighley, UK), Acuth Shenoy, MD (Colchester Hospital University NHS Foundation Trust, Colchester, UK), James Shutt, DM (Dorset County Hospital NHS Foundation Trust, Dorchester, UK), Mark Silverberg, PhD (Mount Sinai Hospital, Toronto, Ontario, Canada), Alison Simmons, PhD (Oxford University Hospitals, Oxford, UK), Jonathan Simmons, DM (Royal Berkshire Hospital, Royal Berkshire NHS Foundation Trust, Reading, UK), Salil Singh, PhD (Bolton NHS Foundation Trust, Bolton, UK), Malcolm Smith, MBChB (Aberdeen Royal Infirmary, Aberdeen, UK), Mark Smith, MD (Shrewsbury and Telford Hospital NHS Trust, Shrewsbury, UK), Melissa Smith, MB (Royal Sussex County Hospital, Brighton, UK), Jonathon A. Snook, DPhil (Poole Hospital NHS Foundation Trust, Poole, UK), Sunil Sonwalker, MD (Calderdale Royal Hospital, Halifax, UK), Christine R. Stevens, PhD (Broad Institute, Harvard University, Cambridge, Massachusetts), Giacomo Sturniolo, PhD (Univerita di Padova, Padova, Italy), Sreedhar Subramanian, MD (Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, UK), Amanda Thomas, MBBS (Department of Gastroenterology, Royal Devon and Exeter Hospital NHS Foundation Trust, Exeter, UK), Mark Tighe, BM (Poole Hospital NHS Foundation Trust, Poole, UK), Franco Torrente, MD (Department of Gastroenterology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK), Mark Tremelling, MD (Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK), Epameinondas Tsianos, PhD (University Hospital of Ioannina, Ioannina, Greece), Deven Vani, MD (Mid Yorkshire Hospitals NHS Trust, Wakefield, UK), Alissa Walsh, MBBS (St Vincent’s Hospital, Sydney, Australia), Gillian Watermeyer, MBChB (Groote Schuur Hospital, Cape Town, South Africa), David Watts, MBChB (Forth Valley Royal Hospital, Larbert, UK), Gill Watts, MD (Wythenshawe Hospital, South Manchester, UK), Sean Weaver, PhD (Royal Bournemouth General Hospital, Bournemouth, UK), Emma Wesley, MBBS (Musgrove Park Hospital, Taunton and Somerset NHS Hospitals, Taunton, UK), Anne Willmott, MBChB (Leicester Royal Infirmary-Paediatric, Leicester, UK), Karen Yearsley, BM (Nevill Hall Hospital, Abergavenny, UK), Veena Zambar, MBBS (Leeds General Infirmary, Leeds, UK), and Sebastian Zeissig, MD (University Medical Center Schleswig-Hostein, Kiel, Germany). These individuals identified and recruited patient s to the study and provided comments on a draft of the manuscript. Funding Information: Adverse Events Consortium funded the sample collection and genotyping at the Broad Institute. The UK National Institute for Health Research provided research nurse support to facilitate recruitment at all UK research sites. Crohn’s & Colitis UK and forCrohns provided funding support and publicized this study to their members. The Exeter National Institute for Health Research Clinical Research Facility provided DNA storage and management. Institutional strategic support award WT097835MF from Wellcome Trust supported the management of the study. Samples from Cedars-Sinai were collected and processed through the MIRIAD biobank that was funded by grant P01DK046763 from the National Institutes of Health. Publisher Copyright: © 2019 American Medical Association. All rights reserved.IMPORTANCE Use of thiopurines may be limited by myelosuppression. TPMT pharmacogenetic testing identifies only 25% of at-risk patients of European ancestry. Among patients of East Asian ancestry, NUDT15 variants are associated with thiopurine-induced myelosuppression (TIM). OBJECTIVE To identify genetic variants associated with TIM among patients of European ancestry with inflammatory bowel disease (IBD). DESIGN, SETTING, AND PARTICIPANTS Case-control study of 491 patients affected by TIM and 679 thiopurine-tolerant unaffected patients who were recruited from 89 international sites between March 2012 and November 2015. Genome-wide association studies (GWAS) and exome-wide association studies (EWAS) were conducted in patients of European ancestry. The replication cohort comprised 73 patients affected by TIM and 840 thiopurine-tolerant unaffected patients. EXPOSURES Genetic variants associated with TIM. MAIN OUTCOMES AND MEASURES Thiopurine-induced myelosuppression, defined as a decline in absolute white blood cell count to 2.5 x 10(9)/L or less or a decline in absolute neutrophil cell count to 1.0 x 10(9)/L or less leading to a dose reduction or drug withdrawal. RESULTS Among 1077 patients (398 affected and 679 unaffected; median age at IBD diagnosis, 31.0 years [interquartile range, 21.2 to 44.1 years]; 540 [50%] women; 602 [56%] diagnosed as having Crohn disease), 919 (311 affected and 608 unaffected) were included in the GWAS analysis and 961 (328 affected and 633 unaffected) in the EWAS analysis. The GWAS analysis confirmed association of TPMT (chromosome 6, rs11969064) with TIM (30.5% [95/311] affected vs 16.4% [100/608] unaffected patients; odds ratio [OR], 2.3 [95% CI, 1.7 to 3.1], P = 5.2 x 10(-9)). The EWAS analysis demonstrated an association with an in-frame deletion in NUDT15 (chromosome 13, rs746071566) and TIM (5.8% [19/328] affected vs 0.2% [1/633] unaffected patients; OR, 38.2 [95% CI, 5.1 to 286.1], P = 1.3 x 10(-8)), which was replicated in a different cohort (2.7% [2/73] affected vs 0.2% [2/840] unaffected patients; OR, 11.8 [95% CI, 1.6 to 85.0], P = .03). Carriage of any of 3 coding NUDT15 variants was associated with an increased risk (OR, 27.3 [95% CI, 9.3 to 116.7], P = 1.1 x 10(-7)) of TIM, independent of TPMT genotype and thiopurine dose. CONCLUSIONS AND RELEVANCE Among patients of European ancestry with IBD, variants in NUDT15 were associated with increased risk of TIM. These findings suggest that NUDT15 genotyping may be considered prior to initiation of thiopurine therapy; however, further study including additional validation in independent cohorts is required.Peer reviewe
Orbital Constraints on the beta Pic Inner Planet Candidate with Keck Adaptive Optics
A point source observed 8 AU in projection from beta Pictoris in L' (3.8
micron) imaging in 2003 has been recently presented as a planet candidate. Here
we show the results of L'-band adaptive optics imaging obtained at Keck
Observatory in 2008. We do not detect beta Pic b beyond a limiting radius of
0.29 arcsec, or 5.5 AU in projection, from the star. If beta Pic b is an
orbiting planet, then it has moved >=0.12 arcsec (2.4 AU in projection) closer
to the star in the five years separating the two epochs of observation. We
examine the range of orbital parameters consistent with the observations,
including likely bounds from the locations of previously inferred planetesimal
belts. We find a family of low-eccentricity orbits with semimajor axes ~8-9 AU
that are completely allowed, as well as a broad region of orbits with e<~0.2,
a>~10 AU that are allowed if the apparent motion of the planet was towards the
star in 2003. We compare this allowed space with predictions of the planetary
orbital elements from the literature. Additionally, we show how similar
observations in the next several years can further constrain the space of
allowed orbits. Non-detections of the source through 2013 will exclude the
interpretation of the candidate as a planet orbiting between the 6.4 and 16 AU
planetesimal belts.Comment: 6 pages, 4 figures, pdflatex, ApJL accepte
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