1,028 research outputs found
Identifying Urban Sources as Cause of Elevated Grass Pollen Concentrations using GIS and Remote Sensing
We examine here the hypothesis that during flowering, the grass pollen concentrations at a specific site reflect the distribution of grass pollen sources within a few kilometres of this site.We perform this analysis on data from a measurement campaign in the city of Aarhus (Denmark) using three pollen traps and by comparing these observations with a novel inventory of grass pollen sources. The source inventory is based on a new methodology developed for urbanscale grass pollen sources. The new methodology is believed to be generally applicable for the European area, as it relies on commonly available remote sensing data combined with management information for local grass areas. The inventory has identified a number of grass pollen source areas present within the city domain. The comparison of the measured pollen concentrations with the inventory shows that the atmospheric concentrations of grass pollen in the urban zone reflect the source areas identified in the inventory, and that the pollen sources that are found to affect the pollen levels are located near or within the city domain. The results also show that during days with peak levels of pollen concentrations there is no correlation between the three urban traps and an operational trap located just 60 km away. This finding suggests that during intense flowering, the grass pollen concentration mirrors the local source distribution and is thus a local-scale phenomenon. Model simulations aimed at assessing population exposure to pollen levels are therefore recommended to take into account both local sources and local atmospheric transport, and not to rely only on describing regional to long-range transport of pollen. The derived pollen source inventory can be entered into local-scale atmospheric transport models in combination with other components that simulate pollen release in order to calculate urban-scale variations in the grass pollen load. The gridded inventory with a resolution of 14m is therefore made available as supplementary material to this paper, and the verifying grass pollen observations are additionally available in tabular form
Climate and site management as driving factors for the atmospheric greenhouse gas exchange of a restored wetland
The atmospheric greenhouse gas (GHG) budget of a restored wetland in western Denmark was established for the years 2009â2011 from eddy covariance measurements of carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>) fluxes. The water table in the wetland, which was restored in 2002, was unregulated, and the vegetation height was limited through occasional grazing by cattle and grass cutting. The annual net CO<sub>2</sub> uptake varied between 195 and 983 g m<sup>â2</sup> and the annual net CH<sub>4</sub> release varied between 11 and 17 g m<sup>â2</sup>. In all three years the wetland was a carbon sink and removed between 42 and 259 g C m<sup>â2</sup> from the atmosphere. However, in terms of the full annual GHG budget (assuming that 1 g CH<sub>4</sub> is equivalent to 25 g CO<sub>2</sub> with respect to the greenhouse effect over a time horizon of 100 years) the wetland was a sink in 2009, a source in 2010 and neutral in 2011. Complementary observations of meteorological factors and management activities were used to explain the large inter-annual variations in the full atmospheric GHG budget of the wetland. The largest impact on the annual GHG fluxes, eventually defining their sign, came from site management through changes in grazing duration and animal stocking density. These changes accounted for half of the observed variability in the CO<sub>2</sub> fluxes and about two thirds of the variability in CH<sub>4</sub> fluxes. An unusually long period of snow cover in 2010 had the second largest effect on the annual CO<sub>2</sub> flux, whose interannual variability was larger than that of the CH<sub>4</sub> flux. Since integrated CO<sub>2</sub> and CH<sub>4</sub> flux data from restored wetlands are still very rare, it is concluded that more long-term flux measurements are needed to quantify the effects of ecosystem disturbance, in terms of management activities and exceptional weather patterns, on the atmospheric GHG budget more accurately
Early psychosocial intervention in Alzheimerâs disease:Cost utility evaluation alongside the Danish Alzheimerâs Intervention Study (DAISY)
OBJECTIVE: To assess the cost utility of early psychosocial intervention for patients with Alzheimer's disease and their primary caregivers. DESIGN: Cost utility evaluation alongside a multicentre, randomised controlled trial with 3â
years of follow-up. SETTING: Primary care and memory clinics in five Danish districts. PARTICIPANTS: 330 community-dwelling patients and their primary caregivers. INTERVENTION: Psychosocial counselling and support lasting 8â12â
months after diagnosis and follow-up at 3, 6, 12 and 36â
months in the intervention group or follow-up only in the control group. MAIN OUTCOME MEASURES: The primary outcome measure was the cost of additional quality-adjusted life years (QALYs). Costs were measured from a societal perspective, including the costs of healthcare, social care, informal care and production loss. QALYs were estimated separately for the patient and the caregiver before aggregation for the main analysis. RESULTS: None of the observed cost and QALY measures were significantly different between the intervention and control groups, although a tendency was noted for psychosocial care leading to cost increases with informal care that was not outweighed by the tendency for cost savings with formal care. The probability of psychosocial intervention being cost-effective did not exceed 36% for any threshold value. The alternative scenario analysis showed that the probability of cost-effectiveness increased over the range of threshold values used if the cost perspective was restricted to formal healthcare. CONCLUSIONS: A multifaceted, psychosocial intervention programme was found unlikely to be cost-effective from a societal perspective. The recommendation for practice in settings that are similar to the Danish setting is to provide follow-up with referral to available local support programmes when needed, and to restrict large multifaceted intervention programmes to patients and caregivers with special needs until further evidence for cost-effectiveness emerges. TRIAL REGISTRATION: The study was registered in the Clinical Trial Database as ISRCTN74848736
Risk of Recurrent Venous Thromboembolism in Selected Subgroups of Men:A Danish Nationwide Cohort Study
Background âAlthough men are considered at high risk for recurrent venous thromboembolism (VTE), sex-specific data on prognostic factors are lacking. We estimated the cumulative recurrence risks associated with clinical characteristics and comorbidities known or suspected to be associated with the development of VTE recurrence: major surgery, trauma, history of cancer, rheumatic disorder, ischemic heart disease, congestive heart failure, chronic obstructive pulmonary disease, diabetes, chronic renal disease, varicose veins, alcohol-related diseases, and arterial hypertension. Methods âWe linked nationwide Danish health registries to identify all incident VTE in- and outpatients in men from 2008 through 2018. Recurrent VTE risk 2 years after anticoagulant discontinuation was calculated using the Aalen-Johansen estimator, stratified by age above/below 50 years. Results âThe study included 13,932 men with VTE, of whom 21% ( n â=â2,898) were aged <50 years. For men aged <50 years with at least one of the clinical characteristics, 2-year recurrence risk ranged from 6% (major surgery) to 16% (history of cancer). For men âĽ50 years with at least one of the characteristics, recurrence risk ranged from 7% (major surgery) to 12% (ischemic heart disease, chronic obstructive pulmonary disease, and chronic renal disease). Men aged <50 and âĽ50 years without the clinical characteristics all had a recurrence risk of 10%. Discussion âWe demonstrated a 2-year recurrence risk of at least 6%, regardless of age category and disease status, in this nationwide cohort of men with VTE. The recurrence risk must be balanced against bleeding risk. However, the high recurrence risk across all subgroups might ultimately lead to greater emphasis on male sex in future guidelines focusing on optimized secondary VTE prevention
Identification of 34 Novel Proinflammatory Proteins in a Genome-Wide Macrophage Functional Screen
Signal transduction pathways activated by Toll-like Receptors and the IL-1 family of cytokines are fundamental to mounting an innate immune response and thus to clearing pathogens and promoting wound healing. Whilst mechanistic understanding of the regulation of innate signalling pathways has advanced considerably in recent years, there are still a number of critical controllers to be discovered. In order to characterise novel regulators of macrophage inflammation, we have carried out an extensive, cDNA-based forward genetic screen and identified 34 novel activators, based on their ability to induce the expression of cxcl2. Many are physiologically expressed in macrophages, although the majority of genes uncovered in our screen have not previously been linked to innate immunity. We show that expression of particular activators has profound but distinct impacts on LPS-induced inflammatory gene expression, including switch-type, amplifier and sensitiser behaviours. Furthermore, the novel genes identified here interact with the canonical inflammatory signalling network via specific mechanisms, as demonstrated by the use of dominant negative forms of IL1/TLR signalling mediators
Modest de novo Reactivation of Single HIV-1 Proviruses in Peripheral CD4+ T Cells by Romidepsin
A cure for human immunodeficiency virus (HIV-1) is restricted by the continued presence of a latent reservoir of memory CD4+ T cells with proviruses integrated into their DNA despite suppressive antiretroviral therapy (ART). A predominant strategy currently pursued in HIV-1 cure-related research is the âkick and killâ approach, where latency reversal agents (LRAs) are used to reactivate transcription from integrated proviruses. The premise of this approach is that âkickingâ latent virus out of hiding allows the host immune system to recognize and kill infected cells. Clinical trials investigating the efficacy of LRAs, such as romidepsin, have shown that these interventions do induce transient spikes in viral RNA in HIV-1-infected individuals. However, since these trials failed to significantly reduce viral reservoir size or significantly delay time to viral rebound during analytical treatment interruptions, it is questioned how much each individual latent provirus is actually âkickedâ to produce viral transcripts and/or proteins by the LRA. Here, we developed sensitive and specific digital droplet PCR-based assays with single-provirus level resolution. Combining these assays allowed us to interrogate the level of viral RNA transcripts from single proviruses in individuals on suppressive ART with or without concomitant romidepsin treatment. Small numbers of proviruses in peripheral blood memory CD4+ T cells were triggered to become marginally transcriptionally active upon romidepsin treatment. These novel assays can be applied retrospectively and prospectively in HIV-1 cure-related clinical trials to gain crucial insights into LRA efficacy at the single provirus level
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