45 research outputs found
An observational and Mendelian randomisation study on vitamin D and COVID-19 risk in UK Biobank
A growing body of evidence suggests that vitamin D deficiency has been associated with an increased susceptibility to viral and bacterial respiratory infections. In this study, we aimed to examine the association between vitamin D and COVID-19 risk and outcomes. We used logistic regression to identify associations between vitamin D variables and COVID-19 (risk of infection, hospitalisation and death) in 417,342 participants from UK Biobank. We subsequently performed a Mendelian Randomisation (MR) study to look for evidence of a causal effect. In total, 1746 COVID-19 cases (399 deaths) were registered between March and June 2020. We found no significant associations between COVID-19 infection risk and measured 25-OHD levels after adjusted for covariates, but this finding is limited by the fact that the vitamin D levels were measured on average 11 years before the pandemic. Ambient UVB was strongly and inversely associated with COVID-19 hospitalization and death overall and consistently after stratification by BMI and ethnicity. We also observed an interaction that suggested greater protective effect of genetically-predicted vitamin D levels when ambient UVB radiation is stronger. The main MR analysis did not show that genetically-predicted vitamin D levels are causally associated with COVID-19 risk (OR = 0.77, 95% CI 0.55–1.11, P = 0.160), but MR sensitivity analyses indicated a potential causal effect (weighted mode MR: OR = 0.72, 95% CI 0.55–0.95, P = 0.021; weighted median MR: OR = 0.61, 95% CI 0.42–0.92, P = 0.016). Analysis of MR-PRESSO did not find outliers for any instrumental variables and suggested a potential causal effect (OR = 0.80, 95% CI 0.66–0.98, p-val = 0.030). In conclusion, the effect of vitamin D levels on the risk or severity of COVID-19 remains controversial, further studies are needed to validate vitamin D supplementation as a means of protecting against worsened COVID-19
User requirements for monitoring the evolution of stratospheric ozone at high vertical resolution (‘Operoz’: Operational ozone observations using limb geometry)
The purpose of the Operoz study has been threefold:
(i) To establish the user requirements for an operational mission targeting ozone profiles at high vertical resolution,
(ii) To identify the observational gaps with respect to these user requirements taking into account planned operational missions and observational ground networks, and
(iii) To perform a reality check on the observational requirements based on proven concepts and present-day knowledge of potentially available measurement techniques and to identify options for a small to medium size satellite mission
Fresh air in the 21st century?
Ozone is an air quality problem today for much of the world's population. Regions can exceed the ozone air quality standards (AQS) through a combination of local emissions, meteorology favoring pollution episodes, and the clean-air baseline levels of ozone upon which pollution builds. The IPCC 2001 assessment studied a range of global emission scenarios and found that all but one projects increases in global tropospheric ozone during the 21st century. By 2030, near-surface increases over much of the northern hemisphere are estimated to be about 5 ppb (+2 to +7 ppb over the range of scenarios). By 2100 the two more extreme scenarios project baseline ozone increases of >20 ppb, while the other four scenarios give changes of -4 to +10 ppb. Even modest increases in the background abundance of tropospheric ozone might defeat current AQS strategies. The larger increases, however, would gravely threaten both urban and rural air quality over most of the northern hemisphere
Afstudeerwerk
Voorwoord bij een nieuwe rubriek met afstudeerwerk
Het Bulletin KNOB biedt een podium aan zowel ervaren onderzoekers als aanstormend talent. Met een zekere regelmaat publiceren afgestudeerden een artikel op basis van hun masterscriptie of ander onderzoek dat zij aan de universiteit deden. Maar dit is slechts een topje van de ijsberg. Er is immers veel meer werk van studenten dat de aandacht van de lezer verdient. Daarom starten wij in het Bulletin KNOB een rubriek met afstudeerwerk. Eens in de twee jaar vragen wij een aantal pas afgestudeerden van wie de masterthesis of eindopdracht goed is beoordeeld hiervan een synthese te maken. Voor de eerste aflevering van deze rubriek zijn dat degenen die meedongen naar de KNOB Stimuleringsprijs 2021. Het resultaat vindt u in dit nummer: zeventien bijdragen over uiteenlopende onderwerpen, van Cubex-keuken tot herbestemming van industrieel erfgoed en van klimaatverbetering in steden tot Antwerpse zeemanshuizen. De auteurs zijn alumni van universitaire opleidingen op het gebied van architectuur- en stadsgeschiedenis, erfgoed en (landschaps)architectuur in Nederland en België. Met deze rubriek laten wij onze lezers kennisnemen van door studenten verricht onderzoek en bieden wij beginnende onderzoekers en ontwerpers een gelegenheid hun werk in het Bulletin KNOB te presenteren. Onze dank gaat daarbij uit naar collega Jeroen Goudeau, die ons het idee voor een rubriek met afstudeerwerk aan de hand deed. Wij wensen u veel leesplezier en inspiratie toe.
De redactieVoorwoord bij een nieuwe rubriek met afstudeerwerk
Het Bulletin KNOB biedt een podium aan zowel ervaren onderzoekers als aanstormend talent. Met een zekere regelmaat publiceren afgestudeerden een artikel op basis van hun masterscriptie of ander onderzoek dat zij aan de universiteit deden. Maar dit is slechts een topje van de ijsberg. Er is immers veel meer werk van studenten dat de aandacht van de lezer verdient. Daarom starten wij in het Bulletin KNOB een rubriek met afstudeerwerk. Eens in de twee jaar vragen wij een aantal pas afgestudeerden van wie de masterthesis of eindopdracht goed is beoordeeld hiervan een synthese te maken. Voor de eerste aflevering van deze rubriek zijn dat degenen die meedongen naar de KNOB Stimuleringsprijs 2021. Het resultaat vindt u in dit nummer: zeventien bijdragen over uiteenlopende onderwerpen, van Cubex-keuken tot herbestemming van industrieel erfgoed en van klimaatverbetering in steden tot Antwerpse zeemanshuizen. De auteurs zijn alumni van universitaire opleidingen op het gebied van architectuur- en stadsgeschiedenis, erfgoed en (landschaps)architectuur in Nederland en België. Met deze rubriek laten wij onze lezers kennisnemen van door studenten verricht onderzoek en bieden wij beginnende onderzoekers en ontwerpers een gelegenheid hun werk in het Bulletin KNOB te presenteren. Onze dank gaat daarbij uit naar collega Jeroen Goudeau, die ons het idee voor een rubriek met afstudeerwerk aan de hand deed. Wij wensen u veel leesplezier en inspiratie toe.
De redacti
The global methane budget 2000–2017
Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. Atmospheric emissions and concentrations of CH4 continue to increase, making CH4 the second most important human-influenced greenhouse gas in terms of climate forcing, after carbon dioxide (CO2). The relative importance of CH4 compared to CO2 depends on its shorter atmospheric lifetime, stronger warming potential, and variations in atmospheric growth rate over the past decade, the causes of which are still debated. Two major challenges in reducing uncertainties in the atmospheric growth rate arise from the variety of geographically overlapping CH4 sources and from the destruction of CH4 by short-lived hydroxyl radicals (OH). To address these challenges, we have established a consortium of multidisciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate new research aimed at improving and regularly updating the global methane budget. Following Saunois et al. (2016), we present here the second version of the living review paper dedicated to the decadal methane budget, integrating results of top-down studies (atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up estimates (including process-based models for estimating land surface emissions and atmospheric chemistry, inventories of anthropogenic emissions, and data-driven extrapolations).
For the 2008–2017 decade, global methane emissions are estimated by atmospheric inversions (a top-down approach) to be 576 Tg CH4 yr−1 (range 550–594, corresponding to the minimum and maximum estimates of the model ensemble). Of this total, 359 Tg CH4 yr−1 or ∼ 60 % is attributed to anthropogenic sources, that is emissions caused by direct human activity (i.e. anthropogenic emissions; range 336–376 Tg CH4 yr−1 or 50 %–65 %). The mean annual total emission for the new decade (2008–2017) is 29 Tg CH4 yr−1 larger than our estimate for the previous decade (2000–2009), and 24 Tg CH4 yr−1 larger than the one reported in the previous budget for 2003–2012 (Saunois et al., 2016). Since 2012, global CH4 emissions have been tracking the warmest scenarios assessed by the Intergovernmental Panel on Climate Change. Bottom-up methods suggest almost 30 % larger global emissions (737 Tg CH4 yr−1, range 594–881) than top-down inversion methods. Indeed, bottom-up estimates for natural sources such as natural wetlands, other inland water systems, and geological sources are higher than top-down estimates. The atmospheric constraints on the top-down budget suggest that at least some of these bottom-up emissions are overestimated. The latitudinal distribution of atmospheric observation-based emissions indicates a predominance of tropical emissions (∼ 65 % of the global budget, < 30∘ N) compared to mid-latitudes (∼ 30 %, 30–60∘ N) and high northern latitudes (∼ 4 %, 60–90∘ N). The most important source of uncertainty in the methane budget is attributable to natural emissions, especially those from wetlands and other inland waters.
Some of our global source estimates are smaller than those in previously published budgets (Saunois et al., 2016; Kirschke et al., 2013). In particular wetland emissions are about 35 Tg CH4 yr−1 lower due to improved partition wetlands and other inland waters. Emissions from geological sources and wild animals are also found to be smaller by 7 Tg CH4 yr−1 by 8 Tg CH4 yr−1, respectively. However, the overall discrepancy between bottom-up and top-down estimates has been reduced by only 5 % compared to Saunois et al. (2016), due to a higher estimate of emissions from inland waters, highlighting the need for more detailed research on emissions factors. Priorities for improving the methane budget include (i) a global, high-resolution map of water-saturated soils and inundated areas emitting methane based on a robust classification of different types of emitting habitats; (ii) further development of process-based models for inland-water emissions; (iii) intensification of methane observations at local scales (e.g., FLUXNET-CH4 measurements) and urban-scale monitoring to constrain bottom-up land surface models, and at regional scales (surface networks and satellites) to constrain atmospheric inversions; (iv) improvements of transport models and the representation of photochemical sinks in top-down inversions; and (v) development of a 3D variational inversion system using isotopic and/or co-emitted species such as ethane to improve source partitioning
Archeologisch onderzoek Gemert-Bakel, Dorpsstraat 72-74 : inventariserend veldonderzoek-proefsleuven (waarderende fase)
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Archeologisch onderzoek Gemert-Bakel, Grotel 7 : inventariserend veldonderzoek-proefsleuven (waarderende fase)
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Archeologisch onderzoek Gemert-Bakel, Doonheide-Noord, deelgebied A : een legerkamp uit de achttiende eeuw? : inventariserend veldonderzoek-proefsleuven (waarderende fase)
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Trends and Inter-Annual Variability of Methane Emissions Derived from 1979-1993 Global CTM Simulations.
Abstract not availableJRC.H-Institute for environment and sustainability (Ispra