704 research outputs found
Shared genetic contribution of type 2 diabetes and cardiovascular disease: Implications for prognosis and treatment
Purpose of Review:
The increased cardiovascular disease (CVD) risk in subjects with type 2 diabetes (T2D) is well established. This review collates the available evidence and assesses the shared genetic background between T2D and CVD: the causal contribution of common risk factors to T2D and CVD and how genetics can be used to improve drug development and clinical outcomes.
Recent Findings:
Large-scale genome-wide association studies (GWAS) of T2D and CVD support a shared genetic background but minimal individual locus overlap.
Summary:
Mendelian randomisation (MR) analyses show that T2D is causal for CVD, but GWAS of CVD, T2D and their common risk factors provided limited evidence for individual locus overlap. Distinct but functionally related pathways were enriched for CVD and T2D genetic associations reflecting the lack of locus overlap and providing some explanation for the variable associations of common risk factors with CVD and T2D from MR analyses
Ground-based remote sensing of an elevated forest fire aerosol layer at Whistler, BC: implications for interpretation of mountaintop chemistry
On 30 August 2009, intense forest fires in interior British Columbia (BC)
coupled with winds from the east and northeast resulted in transport of a
broad forest fire plume across southwestern BC. The physico-chemical and
optical characteristics of the plume as observed from Saturna Island
(AERONET), CORALNet-UBC and the Whistler Mountain air chemistry facility
were consistent with forest fire plumes that have been observed elsewhere in
continental North America. However, the importance of three-dimensional
transport in relation to the interpretation of mountaintop chemistry
observations is highlighted on the basis of deployment of both a <i>CL31</i> ceilometer
and a single particle mass spectrometer (SPMS) in a mountainous setting. The
SPMS is used to identify the biomass plume based on levoglucosan and
potassium markers. Data from the SPMS are also used to show that the
biomass plume was correlated with nitrate, but not correlated with sulphate
or sodium. This study not only provides baseline measurements of biomass
burning plume physico-chemical characteristics in western Canada, but also
highlights the importance of lidar remote sensing methods in the
interpretation of mountaintop chemistry measurements
The High Arctic in Extreme Winters: Vortex, Temperature, and MLS and ACE-FTS Trace Gas Evolution
The first three Canadian Arctic Atmospheric Chemistry Experiment (ACE) Validation Campaigns at Eureka (80° N, 86° W) were during two extremes of Arctic winter variability: Stratospheric sudden warmings (SSWs) in 2004 and 2006 were among the strongest, most prolonged on record; 2005 was a record cold winter. New satellite measurements from ACE-Fourier Transform Spectrometer (ACE-FTS), Sounding of the Atmosphere using Broadband Emission Radiometry, and Aura Microwave Limb Sounder (MLS), with meteorological analyses and Eureka lidar and radiosonde temperatures, are used to detail the meteorology in these winters, to demonstrate its influence on transport and chemistry, and to provide a context for interpretation of campaign observations. During the 2004 and 2006 SSWs, the vortex broke down throughout the stratosphere, reformed quickly in the upper stratosphere, and remained weak in the middle and lower stratosphere. The stratopause reformed at very high altitude, above where it could be accurately represented in the meteorological analyses. The 2004 and 2006 Eureka campaigns were during the recovery from the SSWs, with the redeveloping vortex over Eureka. 2005 was the coldest winter on record in the lower stratosphere, but with an early final warming in mid-March. The vortex was over Eureka at the start of the 2005 campaign, but moved away as it broke up. Disparate temperature profile structure and vortex evolution resulted in much lower (higher) temperatures in the upper (lower) stratosphere in 2004 and 2006 than in 2005. Satellite temperatures agree well with Eureka radiosondes, and with lidar data up to 50–60 km. Consistent with a strong, cold upper stratospheric vortex and enhanced radiative cooling after the SSWs, MLS and ACE-FTS trace gas measurements show strongly enhanced descent in the upper stratospheric vortex during the 2004 and 2006 Eureka campaigns compared to that in 2005
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An electronic family health history tool to identify and manage patients at increased risk for colorectal cancer: protocol for a randomized controlled trial.
BackgroundColorectal cancer is the fourth most commonly diagnosed cancer in the United States. Approximately 3-10% of the population has an increased risk for colorectal cancer due to family history and warrants more frequent or intensive screening. Yet, < 50% of that high-risk population receives guideline-concordant care. Systematic collection of family health history and decision support may improve guideline-concordant screening for patients at increased risk of colorectal cancer. We seek to test the effectiveness of a web-based, systematic family health history collection tool and decision support platform (MeTree) to improve risk assessment and appropriate management of colorectal cancer risk among patients in the Department of Veterans Affairs primary care practices.MethodsIn this ongoing randomized controlled trial, primary care providers at the Durham Veterans Affairs Health Care System and the Madison VA Medical Center are randomized to immediate intervention or wait-list control. Veterans are eligible if assigned to enrolled providers, have an upcoming primary care appointment, and have no conditions that would place them at increased risk for colorectal cancer (such as personal history, adenomatous polyps, or inflammatory bowel disease). Those with a recent lower endoscopy (e.g. colonoscopy, sigmoidoscopy) are excluded. Immediate intervention patients put their family health history information into a web-based platform, MeTree, which provides both patient- and provider-facing decision support reports. Wait-list control patients access MeTree 12 months post-consent. The primary outcome is the risk-concordant colorectal cancer screening referral rate obtained via chart review. Secondary outcomes include patient completion of risk management recommendations (e.g. colonoscopy) and referral for genetic consultation. We will also conduct an economic analysis and an assessment of providers' experience with MeTree clinical decision support recommendations to inform future implementation efforts if the intervention is found to be effective.DiscussionThis trial will assess the feasibility and effectiveness of patient-collected family health history linked to decision support to promote risk-appropriate screening in a large healthcare system such as the Department of Veterans Affairs.Trial registrationClinicalTrials.gov, NCT02247336 . Registered on 25 September 2014
Static Scaling Behavior of High-Molecular-Weight Polymers in Dilute Solution: A Reexamination
Previous theories of dilute polymer solutions have failed to distinguish
clearly between two very different ways of taking the long-chain limit: (I) at fixed temperature , and (II) ,
with fixed. I argue that the modern
two-parameter theory (continuum Edwards model) applies to case II --- not case
I --- and in fact gives exactly the crossover scaling functions for
modulo two nonuniversal scale factors. A Wilson-type renormalization group
clarifies the connection between crossover scaling functions and continuum
field theories. [Also contains a general discussion of the connection between
the Wilson and field-theoretic renormalization groups. Comments solicited.]Comment: 10 pages including 1 figure, 181159 bytes Postscript
(NYU-TH-93/05/01
A fully autonomous ozone, aerosol and nighttime water vapor lidar: a synergistic approach to profiling the atmosphere in the Canadian oil sands region
Lidar technology has been rapidly advancing over the past several decades. It
can be used to measure a variety of atmospheric constituents at very high
temporal and spatial resolutions. While the number of lidars continues to
increase worldwide, there is generally a dependency on an operator,
particularly for high-powered lidar systems. Environment and Climate Change
Canada (ECCC) has recently developed a fully autonomous, mobile lidar system
called AMOLITE (Autonomous Mobile Ozone Lidar Instrument for Tropospheric
Experiments) to simultaneously measure the vertical profile of tropospheric
ozone, aerosol and water vapor (nighttime only) from near the ground to
altitudes reaching 10 to 15 km. This current system uses a dual-laser,
dual-lidar design housed in a single climate-controlled trailer. Ozone
profiles are measured by the differential absorption lidar (DIAL) technique
using a single 1 m Raman cell filled with CO2. The DIAL
wavelengths of 287 and 299 nm are generated as the second and third Stokes
lines resulting from stimulated Raman scattering of the cell pumped using the
fourth harmonic of a Nd:YAG laser (266 nm). The aerosol lidar transmits
three wavelengths simultaneously (355, 532 and 1064 nm) employing a detector
designed to measure the three backscatter channels, two nitrogen Raman
channels (387 and 607 nm) and one cross-polarization channel at 355 nm. In
addition, we added a water vapor channel arising from the Raman-shifted
355 nm output (407 nm) to provide nighttime water vapor profiles. AMOLITE
participated in a validation experiment alongside four other ozone DIAL
systems before being deployed to the ECCC Oski-ôtin ground site in the
Alberta oil sands region in November 2016. Ozone was found to increase
throughout the troposphere by as much as a factor of 2 from stratospheric
intrusions. The dry stratospheric air within the intrusion was measured to be
less than 0.2 g kg−1. A biomass burning event that impacted the region
over an 8-day period produced lidar ratios of 35 to 65 sr at 355 nm and 40
to 100 sr at 532. Over the same period the Ångström exponent
decreased from 1.56±0.2 to 1.35±0.2 in the 2–4 km smoke region.</p
Real-time in vivo Cherenkoscopy Imaging During External Beam Radiation Therapy
Cherenkov radiation is induced when charged particles travel through dielectric media (such as biological tissue) faster than the speed of light through that medium. Detection of this radiation or excited luminescence during megavoltage external beam radiotherapy (EBRT) can allow emergence of a new approach to superficial dose estimation, functional imaging, and quality assurance for radiation therapy dosimetry. In this letter, the first in vivo Cherenkov images of a real-time Cherenkoscopy during EBRT are presented. The imaging system consisted of a time-gated intensified charge coupled device (ICCD) coupled with a commercial lens. The ICCD was synchronized to the linear accelerator to detect Cherenkov photons only during the 3.25-μs radiation bursts. Images of a tissue phantom under irradiation show that the intensity of Cherenkov emission is directly proportional to radiation dose, and images can be acquired at 4.7 frames/s with SNR\u3c30 . Cherenkoscopy was obtained from the superficial regions of a canine oral tumor during planned, Institutional Animal Care and Use Committee approved, conventional (therapeutically appropriate) EBRT irradiation. Coregistration between photography and Cherenkoscopy validated that Cherenkov photons were detected from the planned treatment region. Real-time images correctly monitored the beam field changes corresponding to the planned dynamic wedge movement, with accurate extent of overall beam field, and expected cold and hot regions
Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) experiment: design, execution and science overview
We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned July 2010 deployment of the ARA, which was postponed by 12 months due to UK-based flights related to the dispersal of material emitted by the Eyjafjallajökull volcano, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 involved the same atmospheric measurements, but included the ARA, special satellite observations and a more comprehensive ground-based measurement suite. The high-frequency aircraft data provided a comprehensive chemical snapshot of pyrogenic plumes from wildfires, corresponding to photochemical (and physical) ages ranging from 45 sr 10 days, largely by virtue of widespread fires over Northwestern Ontario. Airborne measurements reported a large number of emitted gases including semi-volatile species, some of which have not been been previously reported in pyrogenic plumes, with the corresponding emission ratios agreeing with previous work for common gases. Analysis of the NOy data shows evidence of net ozone production in pyrogenic plumes, controlled by aerosol abundance, which increases as a function of photochemical age. The coordinated ground-based and sonde data provided detailed but spatially limited information that put the aircraft data into context of the longer burning season in the boundary layer. Ground-based measurements of particulate matter smaller than 2.5 μm (PM2.5) over Halifax show that forest fires can on an episodic basis represent a substantial contribution to total surface PM2.5
Genetic loci on chromosome 5 are associated with circulating levels of interleukin-5 and eosinophil count in a European population with high risk for cardiovascular disease
IL-5 is a Th2 cytokine which activates eosinophils and is suggested to have an atheroprotective role. Genetic variants in the IL5 locus have been associated with increased risk of CAD and ischemic stroke. In this study we aimed to identify genetic variants associated with IL-5 concentrations and apply a Mendelian randomisation approach to assess IL-5 levels for causal effect on intima-media thickness in a European population at high risk of coronary artery disease. We analysed SNPs within robustly associated candidate loci for immune, inflammatory, metabolic and cardiovascular traits. We identified 2 genetic loci for IL-5 levels (chromosome 5, rs56183820, BETA = 0.11, P = 6.73E−5 and chromosome 14, rs4902762, BETA = 0.12, P = 5.76E−6) and one for eosinophil count (rs72797327, BETA = −0.10, P = 1.41E−6). Both chromosome 5 loci were in the vicinity of the IL5 gene, however the association with IL-5 levels failed to replicate in a meta-analysis of 2 independent cohorts (rs56183820, BETA = 0.04, P = 0.2763, I2 = 24, I2 − P = 0.2516). No significant associations were observed between SNPs associated with IL-5 levels or eosinophil count and IMT measures. Expression quantitative trait analyses indicate effects of the IL-5 and eosinophil-associated SNPs on RAD50 mRNA expression levels (rs12652920 (r2 = 0.93 with rs56183820) BETA = −0.10, P = 8.64E−6 and rs11739623 (r2 = 0.96 with rs72797327) BETA = −0.23, P = 1.74E−29, respectively). Our data do not support a role for IL-5 levels and eosinophil count in intima-media thickness, however SNPs associated with IL-5 and eosinophils might influence stability of the atherosclerotic plaque via modulation of RAD50 levels
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