| 1. |
- Abgrall, N., et al.
(författare)
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The large enriched germanium experiment for neutrinoless double beta decay (LEGEND)
- 2017
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Ingår i: AIP Conference Proceedings. - : Author(s). - 1551-7616 .- 0094-243X. ; 1894
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Konferensbidrag (refereegranskat)abstract
- The observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neu-trinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ∼0.1 count /(FWHM·t·yr) in the region of the signal. The current generation 76Ge experiments GERDA and the Majorana Demonstrator, utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ signal region of all 0νββ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76Ge experiment. The collaboration aims to develop a phased 0νββ experimental program with discovery potential at a half-life approaching or at 1028 years, using existing resources as appropriate to expedite physics results.
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| 2. |
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| 3. |
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| 4. |
- Abila, R., et al.
(författare)
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Oil extraction imperils Africa’s Great Lakes
- 2016
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 354:6312, s. 561-562
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- As the world's demands for hydrocarbons increase (1), remote areas previously made inaccessible by technological limitations are now being prospected for oil and gas deposits. Virtually unnoticed by the public, such activities are ongoing in the East African Great Lakes region, threatening these ecosystems famed for their hyper-diverse biota, including the unique adaptive radiations of cichlid fishes (2). Countries in the region see exploitation of hydrocarbon reserves as a vital economic opportunity. In the Lake Albert region of Uganda, for example, the government foresees a $3.6 billion oil profit per year starting in 2018—a sum almost as high as the country's current annual budget (3). However, oil extraction in the East African Great Lakes region poses grave risks to the environment and local communities.
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| 5. |
- Saunois, M., et al.
(författare)
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The global methane budget 2000–2012
- 2016
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Ingår i: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 8:2, s. 697-751
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Tidskriftsartikel (refereegranskat)abstract
- The global methane (CH4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH4 over the past decade. Emissions and concentrations of CH4 are continuing to increase, making CH4 the second most important human-induced greenhouse gas after carbon dioxide. Two major difficulties in reducing uncertainties come from the large variety of diffusive CH4 sources that overlap geographically, and from the destruction of CH4 by the very short-lived hydroxyl radical (OH). To address these difficulties, we have established a consortium of multi-disciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate research on the methane cycle, and producing regular (∼ biennial) updates of the global methane budget. This consortium includes atmospheric physicists and chemists, biogeochemists of surface and marine emissions, and socio-economists who study anthropogenic emissions. Following Kirschke et al. (2013), we propose here the first version of a living review paper that integrates results of top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models, inventories and data-driven approaches (including process-based models for estimating land surface emissions and atmospheric chemistry, and inventories for anthropogenic emissions, data-driven extrapolations). For the 2003–2012 decade, global methane emissions are estimated by top-down inversions at 558 Tg CH4 yr−1, range 540–568. About 60 % of global emissions are anthropogenic (range 50–65 %). Since 2010, the bottom-up global emission inventories have been closer to methane emissions in the most carbon-intensive Representative Concentrations Pathway (RCP8.5) and higher than all other RCP scenarios. Bottom-up approaches suggest larger global emissions (736 Tg CH4 yr−1, range 596–884) mostly because of larger natural emissions from individual sources such as inland waters, natural wetlands and geological sources. Considering the atmospheric constraints on the top-down budget, it is likely that some of the individual emissions reported by the bottom-up approaches are overestimated, leading to too large global emissions. Latitudinal data from top-down emissions indicate a predominance of tropical emissions (∼ 64 % of the global budget, < 30° N) as compared to mid (∼ 32 %, 30–60° N) and high northern latitudes (∼ 4 %, 60–90° N). Top-down inversions consistently infer lower emissions in China (∼ 58 Tg CH4 yr−1, range 51–72, −14 %) and higher emissions in Africa (86 Tg CH4 yr−1, range 73–108, +19 %) than bottom-up values used as prior estimates. Overall, uncertainties for anthropogenic emissions appear smaller than those from natural sources, and the uncertainties on source categories appear larger for top-down inversions than for bottom-up inventories and models. The most important source of uncertainty on the methane budget is attributable to emissions from wetland and other inland waters. We show that the wetland extent could contribute 30–40 % on the estimated range for wetland emissions. Other priorities for improving the methane budget include the following: (i) the development of process-based models for inland-water emissions, (ii) the intensification of methane observations at local scale (flux measurements) to constrain bottom-up land surface models, and at regional scale (surface networks and satellites) to constrain top-down inversions, (iii) improvements in the estimation of atmospheric loss by OH, and (iv) improvements of the transport models integrated in top-down inversions. The data presented here can be downloaded from the Carbon Dioxide Information Analysis Center (http://doi.org/10.3334/CDIAC/GLOBAL_METHANE_BUDGET_2016_V1.1) and the Global Carbon Project.
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| 6. |
- Campbell, William, et al.
(författare)
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Prediction impact curve is a new measure integrating intervention effects in the evaluation of risk models
- 2016
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Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 69, s. 89-95
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We propose a new measure of assessing the performance of risk models, the area under the prediction impact curve (auPIC), which quantifies the performance of risk models in terms of their average health impact in the population. Study Design and Setting: Using simulated data, we explain how the prediction impact curve (PIC) estimates the percentage of events prevented when a risk model is used to assign high-risk individuals to an intervention. We apply the PIC to the Atherosclerosis Risk in Communities (ARIC) Study to illustrate its application toward prevention of coronary heart disease. Results: We estimated that if the ARIC cohort received statins at baseline, 5% of events would be prevented when the risk model was evaluated at a cutoff threshold of 20% predicted risk compared to 1% when individuals were assigned to the intervention without the use of a model. By calculating the auPIC, we estimated that an average of 15% of events would be prevented when considering performance across the entire interval. Conclusion: We conclude that the PIC is a clinically meaningful measure for quantifying the expected health impact of risk models that supplements existing measures of model performance.
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| 7. |
- Fernandez-Martinez, M., et al.
(författare)
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Nutrient scarcity as a selective pressure for mast seeding
- 2019
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Ingår i: Nature Plants. - : Springer Science and Business Media LLC. - 2055-026X .- 2055-0278. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Mast seeding is one of the most intriguing reproductive traits in nature. Despite its potential drawbacks in terms of fitness, the widespread existence of this phenomenon suggests that it should have evolutionary advantages under certain circumstances. Using a global dataset of seed production time series for 219 plant species from all of the continents, we tested whether masting behaviour appears predominantly in species with low foliar nitrogen and phosphorus concentrations when controlling for local climate and productivity. Here, we show that masting intensity is higher in species with low foliar N and P concentrations, and especially in those with imbalanced N/P ratios, and that the evolutionary history of masting behaviour has been linked to that of nutrient economy. Our results support the hypothesis that masting is stronger in species growing under limiting conditions and suggest that this reproductive behaviour might have evolved as an adaptation to nutrient limitations and imbalances.
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| 8. |
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| 9. |
- Henneman, L., et al.
(författare)
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Responsible implementation of expanded carrier screening
- 2016
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Ingår i: Eur J Hum Genet. - : Springer Science and Business Media LLC. ; 24:6, s. E1-E12
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Tidskriftsartikel (refereegranskat)abstract
- This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines.
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| 10. |
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| 11. |
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| 12. |
- Saunois, M., et al.
(författare)
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Variability and quasi-decadal changes in the methane budget over the period 2000–2012
- 2017
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 17:18, s. 11135-11161
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Tidskriftsartikel (refereegranskat)abstract
- Following the recent Global Carbon Project (GCP) synthesis of the decadal methane (CH4) budget over 2000–2012 (Saunois et al., 2016), we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH4 emissions. The GCP dataset integrates results from top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models (including process-based models for estimating land surface emissions and atmospheric chemistry), inventories of anthropogenic emissions, and data-driven approaches. The annual global methane emissions from top-down studies, which by construction match the observed methane growth rate within their uncertainties, all show an increase in total methane emissions over the period 2000–2012, but this increase is not linear over the 13 years. Despite differences between individual studies, the mean emission anomaly of the top-down ensemble shows no significant trend in total methane emissions over the period 2000–2006, during the plateau of atmospheric methane mole fractions, and also over the period 2008–2012, during the renewed atmospheric methane increase. However, the top-down ensemble mean produces an emission shift between 2006 and 2008, leading to 22 [16–32] Tg CH4 yr−1 higher methane emissions over the period 2008–2012 compared to 2002–2006. This emission increase mostly originated from the tropics, with a smaller contribution from mid-latitudes and no significant change from boreal regions. The regional contributions remain uncertain in top-down studies. Tropical South America and South and East Asia seem to contribute the most to the emission increase in the tropics. However, these two regions have only limited atmospheric measurements and remain therefore poorly constrained. The sectorial partitioning of this emission increase between the periods 2002–2006 and 2008–2012 differs from one atmospheric inversion study to another. However, all top-down studies suggest smaller changes in fossil fuel emissions (from oil, gas, and coal industries) compared to the mean of the bottom-up inventories included in this study. This difference is partly driven by a smaller emission change in China from the top-down studies compared to the estimate in the Emission Database for Global Atmospheric Research (EDGARv4.2) inventory, which should be revised to smaller values in a near future. We apply isotopic signatures to the emission changes estimated for individual studies based on five emission sectors and find that for six individual top-down studies (out of eight) the average isotopic signature of the emission changes is not consistent with the observed change in atmospheric 13CH4. However, the partitioning in emission change derived from the ensemble mean is consistent with this isotopic constraint. At the global scale, the top-down ensemble mean suggests that the dominant contribution to the resumed atmospheric CH4 growth after 2006 comes from microbial sources (more from agriculture and waste sectors than from natural wetlands), with an uncertain but smaller contribution from fossil CH4 emissions. In addition, a decrease in biomass burning emissions (in agreement with the biomass burning emission databases) makes the balance of sources consistent with atmospheric 13CH4 observations. In most of the top-down studies included here, OH concentrations are considered constant over the years (seasonal variations but without any inter-annual variability). As a result, the methane loss (in particular through OH oxidation) varies mainly through the change in methane concentrations and not its oxidants. For these reasons, changes in the methane loss could not be properly investigated in this study, although it may play a significant role in the recent atmospheric methane changes as briefly discussed at the end of the paper.
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| 13. |
- Sigurdsson, Bjarni D., et al.
(författare)
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Geothermal ecosystems as natural climate change experiments : The ForHot research site in Iceland as a case study
- 2016
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Ingår i: Icelandic Agricultural Sciences. - 1670-567X. ; 29:1, s. 53-71
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Tidskriftsartikel (refereegranskat)abstract
- This article describes how natural geothermal soil temperature gradients in Iceland have been used to study terrestrial ecosystem responses to soil warming. The experimental approach was evaluated at three study sites in southern Iceland one grassland site that has been warm for at least 50 years (GO), and another comparable grassland site (GN) and a Sitka spruce plantation (FN) site that have both been warmed since an earthquake took place in 2008. Within each site type, five ca. 50 m long transects, with six permanent study plots each, were established across the soil warming gradients, spanning from unwarmed control conditions to gradually warmer soils. It was attempted to select the plots so the annual warming levels would be ca. +1, +3, +5, +10 and +20 °C within each transect. Results of continuous measurements of soil temperature (Ts) from 2013-2015 revealed that the soil warming was relatively constant and followed the seasonal Ts cycle of the unwarmed control plots. Volumetric water content in the top 5 cm of soil was repeatedly surveyed during 2013-2016. The grassland soils were wetter than the FN soils, but they had sometimes some significant warming-induced drying in the surface layer of the warmest plots, in contrast to FN. Soil chemistry did not show any indications that geothermal water had reached the root zone, but soil pH did increase somewhat with warming, which was probably linked to vegetation changes. As expected, the potential decomposition rate of organic matter increased significantly with warming. It was concluded that the natural geothermal gradients at the ForHot sites in Iceland offered realistic conditions for studying terrestrial ecosystem responses to warming with minimal artefacts.
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| 14. |
- Skoglundh, Magnus, 1965, et al.
(författare)
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Copper mobility in zeolite-based SCR catalysts
- 2017
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Ingår i: Presented at the 254th American Chemical Society National Meeting & Exposition, Washington D.C., USA, August 20-24, 2017.
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Konferensbidrag (refereegranskat)abstract
- Selective catalytic reduction with ammonia (NH3-SCR) is an effective, well-established method to eliminate nitrogen oxides (NOx) in oxygen excess for stationary and mobile applications. Titania-supported vanadia catalysts are traditionally used for NH3-SCR. This type of catalyst is effective in the range 300-450°C, but the NOx reduction efficiency decreases at both lower and higher temperatures. The efficiency of the NH3-SCR process can be improved significantly by using catalysts based on copper-exchanged zeolites and zeotypes, due to their high activity around 200°C. Solid-state ion-exchange in a mixture of copper oxide and zeolite is an efficient way to prepare such catalysts, but this process usually requires high (>700°C) temperatures. The ion-exchange can be considerably affected by appropriate choice of atmosphere during the process. It is shown that the copper-exchange is possible at unprecedented low temperatures, as low as 250°C, in presence of ammonia. The influence of the treatment conditions on the copper-exchange and the mechanism of the reaction-driven ion-exchange process will be presented and discussed. Such copper-exchanged zeolite structures with high copper loading are potentially interesting catalysts for a number of technical applications.Powder mixtures of Cu2O or CuO and zeolite with either CHA, MFI or *BEA framework structure were exposed to well-defined gas atmospheres at constant temperature. After the treatment, the SCR activity of the samples was determined by steady state and transient flow reactor experiments, and the physicochemical properties of the samples were characterized with bulk and surface sensitive characterization techniques. Furthermore, first-principles calculations were used to investigate the energetic conditions for the ion-exchange process.We show that in the presence of ammonia, copper becomes mobile at considerably lower temperatures,
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| 15. |
- Skoglundh, Magnus, 1965, et al.
(författare)
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Mobility of copper in zeolite-based SCR catalysts
- 2017
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Ingår i: Presented at the 25th North American Catalysis Society Meeting, Denver, Colorado, USA, June 4-9 2017.
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Konferensbidrag (refereegranskat)abstract
- Selective catalytic reduction with ammonia (NH3-SCR) is a well-established and effective method to eliminate nitrogen oxides (NOx) in oxygen excess for stationary and mobile applications. Vanadia supported on titania was the first NH3-SCR catalyst that was commercialized. This type of catalyst is effective around 300-450°C, however at lower or higher temperatures, the efficiency of the catalyst to reduce NOx decreases. To increase the overall NOx reduction, high SCR activity around 200°C is required and copper-exchanged zeolites are interesting candidates in this respect. Solid-state ion-exchange in a mixture of copper oxide and zeolite is an efficient method to prepare such catalysts, but the process usually requires high (>700°C) temperatures. The ion-exchange process with copper oxides and zeolites can be considerably affected inpresence of reactive atmospheres. It is shown that the copper-exchange is possible at unprecedented low temperatures, as low as 250°C, when facilitated by ammonia. The influence of the treatment conditions on the copper-exchange and the mechanism of the ion-exchange process will be presented and discussed. Such copper-exchanged zeolite structures with high copper loading are potentially interesting catalysts for a number of technical applications.Powder mixtures of CuO or Cu2O and zeolite with either the MFI, *BEA or CHA framework structure were exposed to well-defined gas atmospheres at constant temperature. After the treatment the SCR activity was determined by steady state and transient flow reactor experiments, and the physico-chemical properties of the samples were characterized with bulk and surface sensitive characterization techniques. Furthermore, density functional theory calculations were used to investigate the energetic conditions for the ion-exchange process. We show that copper in the presence of ammonia becomes mobile at considerably lower temperatures,
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| 16. |
- van Overbeeke, Eline, et al.
(författare)
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Design, Conduct, and Use of Patient Preference Studies in the Medical Product Life Cycle : A Multi-Method Study
- 2019
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Ingår i: Frontiers in Pharmacology. - : Frontiers Media SA. - 1663-9812. ; 10:1395
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate stakeholder perspectives on how patient preference studies (PPS) should be designed and conducted to allow for inclusion of patient preferences in decision-making along the medical product life cycle (MPLC), and how patient preferences can be used in such decision-making.Methods: Two literature reviews and semi-structured interviews (n = 143) with healthcare stakeholders in Europe and the US were conducted; results of these informed the design of focus group guides. Eight focus groups were conducted with European patients, industry representatives and regulators, and with US regulators and European/Canadian health technology assessment (HTA) representatives. Focus groups were analyzed thematically using NVivo.Results: Stakeholder perspectives on how PPS should be designed and conducted were as follows: 1) study design should be informed by the research questions and patient population; 2) preferred treatment attributes and levels, as well as trade-offs among attributes and levels should be investigated; 3) the patient sample and method should match the MPLC phase; 4) different stakeholders should collaborate; and 5) results from PPS should be shared with relevant stakeholders. The value of patient preferences in decision-making was found to increase with the level of patient preference sensitivity of decisions on medical products. Stakeholders mentioned that patient preferences are hardly used in current decision-making. Potential applications for patient preferences across industry, regulatory and HTA processes were identified. Four applications seemed most promising for systematic integration of patient preferences: 1) benefit-risk assessment by industry and regulators at the marketing-authorization phase; 2) assessment of major contribution to patient care by European regulators; 3) cost-effectiveness analysis; and 4) multi criteria decision analysis in HTA.Conclusions: The value of patient preferences for decision-making depends on the level of collaboration across stakeholders; the match between the research question, MPLC phase, sample, and preference method used in PPS; and the sensitivity of the decision regarding a medical product to patient preferences. Promising applications for patient preferences should be further explored with stakeholders to optimize their inclusion in decision-making.
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| 17. |
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