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- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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- Copello, J A, et al.
(författare)
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Differential activation by Ca2+, ATP and caffeine of cardiac and skeletal muscle ryanodine receptors after block by Mg2+.
- 2002
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Ingår i: Journal of Membrane Biology. - : Springer Science and Business Media LLC. - 0022-2631 .- 1432-1424. ; 187:1, s. 51-64
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Tidskriftsartikel (refereegranskat)abstract
- The block of rabbit skeletal ryanodine receptors (RyR1) and dog heart RyR2 by cytosolic [Mg2+], and its reversal by agonists Ca2+, ATP and caffeine was studied in planar bilayers. Mg2+ effects were tested at submaximal activating [Ca2+] (5 microM). Approximately one third of the RyR1s had low open probability ("LA channels") in the absence of Mg2+. All other RyR1s displayed higher activity ("HA channels"). Cytosolic Mg2+ (1 mM) blocked individual RyR1 channels to varying degrees (32 to 100%). LA channels had residual P(o) <0.005 in 1 mM Mg2+ and reactivated poorly with [Ca2+] (100 microM), caffeine (5 mM), or ATP (4 mM; all at constant 1 mM Mg2+). HA channels had variable activity in Mg2+ and variable degree of recovery from Mg2+ block with Ca2+, caffeine or ATP application. Nearly all cardiac RyR2s displayed high activity in 5 microM [Ca2+]. They also had variable sensitivity to Mg2+. However, the RyR2s consistently recovered from Mg2+ block with 100 microM [Ca2+] or caffeine application, but not when ATP was added. Thus, at physiological [Mg2+], RyR2s behaved as relatively homogeneous Ca2+/caffeine-gated HA channels. In contrast, RyR1s displayed functional heterogeneity that arises from differential modulatory actions of Ca2+ and ATP. These differences between RyR1 and RyR2 function may reflect their respective roles in muscle physiology and excitation-contraction coupling.
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- Tranvik, Lars J., et al.
(författare)
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Lakes and reservoirs as regulators of carbon cycling and climate
- 2009
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Ingår i: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 54:6:2, s. 2298-2314
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Forskningsöversikt (refereegranskat)abstract
- We explore the role of lakes in carbon cycling and global climate, examine the mechanisms influencing carbon pools and transformations in lakes, and discuss how the metabolism of carbon in the inland waters is likely to change in response to climate. Furthermore, we project changes as global climate change in the abundance and spatial distribution of lakes in the biosphere, and we revise the estimate for the global extent of carbon transformation in inland waters. This synthesis demonstrates that the global annual emissions of carbon dioxide from inland waters to the atmosphere are similar in magnitude to the carbon dioxide uptake by the oceans and that the global burial of organic carbon in inland water sediments exceeds organic carbon sequestration on the ocean floor. The role of inland waters in global carbon cycling and climate forcing may be changed by human activities, including construction of impoundments, which accumulate large amounts of carbon in sediments and emit large amounts of methane to the atmosphere. Methane emissions are also expected from lakes on melting permafrost. The synthesis presented here indicates that (1) inland waters constitute a significant component of the global carbon cycle, (2) their contribution to this cycle has significantly changed as a result of human activities, and (3) they will continue to change in response to future climate change causing decreased as well as increased abundance of lakes as well as increases in the number of aquatic impoundments.
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5. |
- Hiesmayr, M., et al.
(författare)
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Decreased food intake is a risk factor for mortality in hospitalised patients : the NutritionDay survey 2006
- 2009
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Ingår i: Clinical Nutrition. - : Elsevier BV. - 0261-5614 .- 1532-1983. ; 28:5, s. 484-491
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Malnutrition is a known risk factor for the development of complications in hospitalised patients. We determined whether eating only fractions of the meals served is an independent risk factor for mortality. METHODS: The NutritionDay is a multinational one-day cross-sectional survey of nutritional factors and food intake in 16,290 adult hospitalised patients on January 19th 2006. The effect of food intake and nutritional factors on death in hospital within 30 days was assessed in a competing risk analysis. RESULTS: More than half of the patients did not eat their full meal provided by the hospital. Decreased food intake on NutritionDay or during the previous week was associated with an increased risk of dying, even after adjustment for various patient and disease related factors. Adjusted hazard ratio for dying when eating about a quarter of the meal on NutritionDay was 2.10 (1.53-2.89); when eating nothing 3.02 (2.11-4.32). More than half of the patients who ate less than a quarter of their meal did not receive artificial nutrition support. Only 25% patients eating nothing at lunch receive artificial nutrition support. CONCLUSION: Many hospitalised patients in European hospitals eat less food than provided as regular meal. This decreased food intake represents an independent risk factor for hospital mortality.
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- Post, Eric, et al.
(författare)
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Ecological Dynamics Across the Arctic Associated with Recent Climate Change
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 325:5946, s. 1355-1358
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Forskningsöversikt (refereegranskat)abstract
- At the close of the Fourth International Polar Year, we take stock of the ecological consequences of recent climate change in the Arctic, focusing on effects at population, community, and ecosystem scales. Despite the buffering effect of landscape heterogeneity, Arctic ecosystems and the trophic relationships that structure them have been severely perturbed. These rapid changes may be a bellwether of changes to come at lower latitudes and have the potential to affect ecosystem services related to natural resources, food production, climate regulation, and cultural integrity. We highlight areas of ecological research that deserve priority as the Arctic continues to warm.
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7. |
- Schidler, S, et al.
(författare)
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Performance Targets in Production Processes (PT-PRO) - final report
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- One of the main actions of the European Environmental Technologies Action Plan (ETAP) is: "Setting ambitious targets to improve the environmental performance of technologies within a given timeframe. This should encourage technological development while preparing the markets to accept and prepare for these high standard environmental technologies". On request of DG Environment, the JRC-IPTS launched a project on Performance Targets for Industry Processes (PT-PRO project), with the objective to further define concepts and to identify the conditions necessary to implement the concept of Performance Targets. The project was carried out with the help of ITA, ÖAW, GMV/IVL, FEA and TNO. This report provides a definition of the main elements of Performance Targets and an overview of the general principles for their implementation. Based on four case study sectors (the iron & steel, cement, pulp & paper and the textile industries), an illustration of these different elements is provided in relation with a range of industry sectors and their environmental challenges, existing regulations, technical potentials, market situations and organisational structure. The report also discusses the best conditions and limitations of setting Performance Targets for the industry and the possible value-added.
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