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- Abbasi, R., et al.
(författare)
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An absence of neutrinos associated with cosmic-ray acceleration in gamma-ray bursts
- 2012
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 484:7394, s. 351-354
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Tidskriftsartikel (refereegranskat)abstract
- Very energetic astrophysical events are required to accelerate cosmic rays to above 10(18) electronvolts. GRBs (c-ray bursts) have been proposed as possible candidate sources(1-3). In the GRB 'fireball' model, cosmic-ray acceleration should be accompanied by neutrinos produced in the decay of charged pions created in interactions between the high-energy cosmic-ray protons and gamma-rays(4). Previous searches for such neutrinos found none, but the constraints were weak because the sensitivity was at best approximately equal to the predicted flux(5-7). Here we report an upper limit on the flux of energetic neutrinos associated with GRBs that is at least a factor of 3.7 below the predictions(4,8-10). This implies either that GRBs are not the only sources of cosmic rays with energies exceeding 10(18) electronvolts or that the efficiency of neutrino production is much lower than has been predicted.
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| 6. |
- Pascal, M, et al.
(författare)
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Assessing the public health impacts of urban air pollution in 25 European cities : Results of the Aphekom project
- 2013
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 449, s. 390-400
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The Aphekom project aimed to provide new, clear, and meaningful information on the health effects of air pollution in Europe. Among others, it assessed the health and monetary benefits of reducing short and long-term exposure to particulate matter (PM) and ozone in 25 European cities. METHOD: Health impact assessments were performed using routine health and air quality data, and a common methodology. Two scenarios were considered: a decrease of the air pollutant levels by a fixed amount and a decrease to the World Health Organization (WHO) air quality guidelines. Results were economically valued by using a willingness to pay approach for mortality and a cost of illness approach for morbidity. RESULTS: In the 25 cities, the largest health burden was attributable to the impacts of chronic exposure to PM2.5. Complying with the WHO guideline of 10μg/m3 in annual mean would add up to 22months of life expectancy at age 30, depending on the city, corresponding to a total of 19,000 deaths delayed. The associated monetary gain would total some €31billion annually, including savings on health expenditures, absenteeism and intangible costs such as well-being, life expectancy and quality of life. CONCLUSION: European citizens are still exposed to concentrations exceeding the WHO recommendations. Aphekom provided robust estimates confirming that reducing urban air pollution would result in significant health and monetary gains in Europe. This work is particularly relevant now when the current EU legislation is being revised for an update in 2013.
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| 7. |
- Beelen, Rob, et al.
(författare)
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Development of NO2 and NOx land use regression models for estimating air pollution exposure in 36 study areas in Europe : the ESCAPE project
- 2013
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Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 72, s. 10-23
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Tidskriftsartikel (refereegranskat)abstract
- Estimating within-city variability in air pollution concentrations is important. Land use regression (LUR) models are able to explain such small-scale within-city variations. Transparency in LUR model development methods is important to facilitate comparison of methods between different studies. We therefore developed LUR models in a standardized way in 36 study areas in Europe for the ESCAPE (European Study of Cohorts for Air Pollution Effects) project.Nitrogen dioxide (NO2) and nitrogen oxides (NOx) were measured with Ogawa passive samplers at 40 or 80 sites in each of the 36 study areas. The spatial variation in each area was explained by LUR modeling. Centrally and locally available Geographic Information System (GIS) variables were used as potential predictors. A leave-one out cross-validation procedure was used to evaluate the model performance.There was substantial contrast in annual average NO2 and NOx concentrations within the study areas. The model explained variances (R2) of the LUR models ranged from 55% to 92% (median 82%) for NO2 and from 49% to 91% (median 78%) for NOx. For most areas the cross-validation R2 was less than 10% lower than the model R2. Small-scale traffic and population/household density were the most common predictors. The magnitude of the explained variance depended on the contrast in measured concentrations as well as availability of GIS predictors, especially traffic intensity data were important. In an additional evaluation, models in which local traffic intensity was not offered had 10% lower R2 compared to models in the same areas in which these variables were offered.Within the ESCAPE project it was possible to develop LUR models that explained a large fraction of the spatial variance in measured annual average NO2 and NOx concentrations. These LUR models are being used to estimate outdoor concentrations at the home addresses of participants in over 30 cohort studies.
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| 8. |
- Vanden Berghe, T, et al.
(författare)
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Necroptosis, necrosis and secondary necrosis converge on similar cellular disintegration features
- 2010
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Ingår i: CELL DEATH AND DIFFERENTIATION. - : Nature Publishing Group. - 1350-9047 .- 1476-5403. ; 17:6, s. 922-930
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Tidskriftsartikel (refereegranskat)abstract
- Necroptosis, necrosis and secondary necrosis following apoptosis represent different modes of cell death that eventually result in similar cellular morphology including rounding of the cell, cytoplasmic swelling, rupture of the plasma membrane and spilling of the intracellular content. Subcellular events during tumor necrosis factor (TNF)-induced necroptosis, H2O2-induced necrosis and anti-Fas-induced secondary necrosis were studied using high-resolution time-lapse microscopy. The cellular disintegration phase of the three types of necrosis is characterized by an identical sequence of subcellular events, including oxidative burst, mitochondrial membrane hyperpolarization, lysosomal membrane permeabilization and plasma membrane permeabilization, although with different kinetics. H2O2-induced necrosis starts immediately by lysosomal permeabilization. In contrast, during TNF-mediated necroptosis and anti-Fas-induced secondary necrosis, this is a late event preceded by a defined signaling phase. TNF-induced necroptosis depends on receptor-interacting protein-1 kinase, mitochondrial complex I and cytosolic phospholipase A(2) activities, whereas H2O2-induced necrosis requires iron-dependent Fenton reactions.
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