Access to preventive care by immigrant populations

Many immigrant populations lack access to primary health care. A recently published study on cholesterol screening among immigrant populations in the US found disparities in cholesterol screening in those originating from Mexico, largely due to limited access to healthcare. This inverse care affects immigrants in many destination countries despite their greater health need

Assessing survival in widowers, and controls -A nationwide, six- to nine-year follow-up

To access full text version of this article. Please click on the hyperlink "View/open" at the bottom of this pageThe aim of this study was to assess if widowers had an increased mortality rate during the first 6 to 9 years after the death of their wife, compared initially to an age-matched control group and also compared to the general population of Iceland. The study base was comprised of all 371 men born in 1924-1969 who were widowed in Iceland in 1999-2001 and 357 controls, married men, who were matched by age and residence.The widowers and controls were followed through the years 2002-2007 using information from Statistics Iceland. Mortality rates were compared between the groups and also with the general population. The mortality rate comparisons were: study group vs. control group, on the one hand, and study group vs. general population on the other. Causes of death were also compared between widowers and their wives. A statistically significant increase in mortality in the widowers' group, compared to controls, was observed.Lifestyle-related factors could not be excluded as contributing to cause of death in these cases. Being a widower was related to an increased risk of death for at least 9 years after the death of their wife.Landspitali - National University Hospital in Reykjavik Iceland, Rannis, the Icelandic Centre for Research (provides assistance to Icelandic science & technology, Reykjavik, Iceland), Utfararstofa Islands (a funeral home, Reykjavik, Iceland), Swedish Cancer Society (Cancerfonden), Styrktarsjodur Lifsins samtaka um liknarmedferd (Palliative Care Association, Iceland), Utfarastofa Kirkjugardanna (a funeral home, Reykjavik, Iceland

An open-source high-frequency lock-in amplifier

We present characterization of a lock-in amplifier based on a field programmable gate array capable of demodulation at up to 50 MHz. The system exhibits 90 nV/sqrt(Hz) of input noise at an optimum demodulation frequency of 500 kHz.The passband has a full-width half-maximum of 2.6 kHz for modulation frequencies above 100 kHz. Our code is opensource and operates on a commercially available platform

Infrapopliteal angioplasty using a combined angiosomal reperfusion strategy

Introduction Infra-popliteal angioplasty continues to be widely performed with minimal evidence to guide practice. Endovascular device selection is contentious and there is even uncertainty over which artery to treat for optimum reperfusion. Direct reperfusion (DR) targets the artery supplying the ischaemic tissue. Indirect reperfusion (IR) targets an artery supplying collaterals to the ischaemic area. Our unit practice for the last eight years has been to attempt to open all tibial arteries at the time of angioplasty. When successful, this results in both direct and indirect; or combined reperfusion (CR). The aim was to review the outcomes of CR and compare them with DR or IR alone. Methods An eight year retrospective review from a single unit of all infra-popliteal angioplasties was undertaken. Wound healing, limb salvage, amputation-free and overall survival data as well as re-intervention rates were captured for all patients. Subgroup analysis for diabetics was undertaken. Kaplan Meier curves are presented for survival outcomes. All odds and hazard ratios (HR) and p values were corrected for bias from confounders using multivariate analysis. Results 250 procedures were performed: 22 (9%) were CR; 115 (46%) DR and 113 (45%) IR. Amputation- free survival (HR 0.504, p = 0.039) and re-intervention and amputation-free survival (HR 0.414, p = 0.005) were significantly improved in patients undergoing CR compared to IR. Wound healing was similarly affected by reperfusion strategy (OR = 0.35, p = 0.047). Effects of CR over IR were similar when only diabetic patients were considered. Conclusions Combined revascularisation can only be achieved in approximately 10% of patients. However, when successful, it results in significant improvements in wound healing and amputation- free survival over simple indirect reperfusion techniques

Telomere disruption results in non-random formation of de novo dicentric chromosomes involving acrocentric human chromosomes

Copyright: © 2010 Stimpson et al.Genome rearrangement often produces chromosomes with two centromeres (dicentrics) that are inherently unstable because of bridge formation and breakage during cell division. However, mammalian dicentrics, and particularly those in humans, can be quite stable, usually because one centromere is functionally silenced. Molecular mechanisms of centromere inactivation are poorly understood since there are few systems to experimentally create dicentric human chromosomes. Here, we describe a human cell culture model that enriches for de novo dicentrics. We demonstrate that transient disruption of human telomere structure non-randomly produces dicentric fusions involving acrocentric chromosomes. The induced dicentrics vary in structure near fusion breakpoints and like naturally-occurring dicentrics, exhibit various inter-centromeric distances. Many functional dicentrics persist for months after formation. Even those with distantly spaced centromeres remain functionally dicentric for 20 cell generations. Other dicentrics within the population reflect centromere inactivation. In some cases, centromere inactivation occurs by an apparently epigenetic mechanism. In other dicentrics, the size of the alpha-satellite DNA array associated with CENP-A is reduced compared to the same array before dicentric formation. Extrachromosomal fragments that contained CENP-A often appear in the same cells as dicentrics. Some of these fragments are derived from the same alpha-satellite DNA array as inactivated centromeres. Our results indicate that dicentric human chromosomes undergo alternative fates after formation. Many retain two active centromeres and are stable through multiple cell divisions. Others undergo centromere inactivation. This event occurs within a broad temporal window and can involve deletion of chromatin that marks the locus as a site for CENP-A maintenance/replenishment.This work was supported by the Tumorzentrum Heidelberg/Mannheim grant (D.10026941)and by March of Dimes Research Foundation grant #1-FY06-377 and NIH R01 GM069514

Measurement and Modeling of Particle Radiation in Coal Flames

This work aims at developing a methodology that can provide information of in-flame particle radiation in industrial-scale flames. The method is based on a combination of experimental and modeling work. The experiments have been performed in the high-temperature zone of a 77 kWth swirling lignite flame. Spectral radiation, total radiative intensity, gas temperature, and gas composition were measured, and the radiative intensity in the furnace was modeled with an axisymmetric cylindrical radiation model using Mie theory for the particle properties and a statistical narrow-band model for the gas properties. The in-flame particle radiation was measured with a Fourier transform infrared (FTIR) spectrometer connected to a water-cooled probe via fiber optics. In the cross-section of the flame investigated, the particles were found to be the dominating source of radiation. Apart from giving information about particle radiation and temperature, the methodology can also provide estimates of the amount of soot radiation and the maximum contribution from soot radiation compared to the total particle radiation. In the center position in the flame, the maximum contribution from soot radiation was estimated to be less than 40% of the particle radiation. As a validation of the methodology, the modeled total radiative intensity was compared to the total intensity measured with a narrow angle radiometer and the agreement in the results was good, supporting the validity of the used approach

Proliferation of Ty3/gypsy-like retrotransposons in hybrid sunflower taxa inferred from phylogenetic data

<p>Abstract</p> <p>Background</p> <p>Long terminal repeat (LTR) retrotransposons are a class of mobile genetic element capable of autonomous transposition via an RNA intermediate. Their large size and proliferative ability make them important contributors to genome size evolution, especially in plants, where they can reach exceptionally high copy numbers and contribute substantially to variation in genome size even among closely related taxa. Using a phylogenetic approach, we characterize dynamics of proliferation events of <it>Ty3/gypsy</it>-like LTR retrotransposons that led to massive genomic expansion in three <it>Helianthus </it>(sunflower) species of ancient hybrid origin. The three hybrid species are independently derived from the same two parental species, offering a unique opportunity to explore patterns of retrotransposon proliferation in light of reticulate evolutionary events in this species group.</p> <p>Results</p> <p>We demonstrate that <it>Ty3/gypsy</it>-like retrotransposons exist as multiple well supported sublineages in both the parental and hybrid derivative species and that the same element sublineage served as the source lineage of proliferation in each hybrid species' genome. This inference is based on patterns of species-specific element numerical abundance within different phylogenetic sublineages as well as through signals of proliferation events present in the distributions of element divergence values. Employing methods to date paralogous sequences within a genome, proliferation events in the hybrid species' genomes are estimated to have occurred approximately 0.5 to 1 million years ago.</p> <p>Conclusion</p> <p>Proliferation of the same retrotransposon major sublineage in each hybrid species indicates that similar dynamics of element derepression and amplification likely occurred in each hybrid taxon during their formation. Temporal estimates of these proliferation events suggest an earlier origin for these hybrid species than previously supposed.</p

Regulation of Alr1 Mg Transporter Activity by Intracellular Magnesium

Mg homeostasis is critical to eukaryotic cells, but the contribution of Mg transporter activity to homeostasis is not fully understood. In yeast, Mg uptake is primarily mediated by the Alr1 transporter, which also allows low affinity uptake of other divalent cations such as Ni2+, Mn2+, Zn2+ and Co2+. Using Ni2+ uptake to assay Alr1 activity, we observed approximately nine-fold more activity under Mg-deficient conditions. The mnr2 mutation, which is thought to block release of vacuolar Mg stores, was associated with increased Alr1 activity, suggesting Alr1 was regulated by intracellular Mg supply. Consistent with a previous report of the regulation of Alr1 expression by Mg supply, Mg deficiency and the mnr2 mutation both increased the accumulation of a carboxy-terminal epitope-tagged version of the Alr1 protein (Alr1-HA). However, Mg supply had little effect on ALR1 promoter activity or mRNA levels. In addition, while Mg deficiency caused a seven-fold increase in Alr1-HA accumulation, the N-terminally tagged and untagged Alr1 proteins increased less than two-fold. These observations argue that the Mg-dependent accumulation of the C-terminal epitope-tagged protein was primarily an artifact of its modification. Plasma membrane localization of YFP-tagged Alr1 was also unaffected by Mg supply, indicating that a change in Alr1 location did not explain the increased activity we observed. We conclude that variation in Alr1 protein accumulation or location does not make a substantial contribution to its regulation by Mg supply, suggesting Alr1 activity is directly regulated via as yet unknown mechanisms

Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls

Background The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea. Methods We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up. Findings We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01–1.03), male (1.54, 1.16–2.04), neither obese nor severely obese (1.82, 1.06–3.13 and 4.19, 2.14–8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09–2.22) or cardiovascular disease (1.33, 1.00–1.79), and shorter hospital admission (1.01 per day, 1.00–1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission). Interpretation Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19. Funding PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care. COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders