Climate model genealogy Masson, D.; Knutti, R.
Geophysical research letters,
28 April 2011, Letnik:
38, Številka:
8
Journal Article
Recenzirano
Climate change projections are often given as equally weighted averages across ensembles of climate models, despite the fact that the sampling of the underlying ensembles is unclear. We show that a ...hierarchical clustering of a metric of spatial and temporal variations of either surface temperature or precipitation in control simulations can capture many model relationships across different ensembles. Strong similarities are seen between models developed at the same institution, between models sharing versions of the same atmospheric component, and between successive versions of the same model. A perturbed parameter ensemble of a model appears separate from other structurally different models. The results provide insight into intermodel relationships, into how models evolve through successive generations, and suggest that assuming model independence in such ensembles of opportunity is not justified.
Key Points
Models by the same institution behave similarly
Structural model uncertainty is important
Model development resembles an evolutionary process
Nous rapportons les attitudes et pratiques des soignants en Afrique francophone concernant l’annonce du statut VIH aux adolescents, et les témoignages de jeunes vivant avec le VIH (jvVIH). Lors d’un ...atelier de trois jours à Abidjan, Côte d’Ivoire, en novembre 2016, les soignants (médecins, psychologues, travailleurs sociaux) de 19 sites de prise en charge pédiatrique du VIH ont partagé leurs pratiques et difficultés et 4 jvVIH leur vécu de l’annonce. Au total, 35 participants de 8 pays d’Afrique de l’Ouest/centrale (Bénin, Burkina Faso, Côte d’Ivoire, Cameroun, Mali, République démocratique du Congo, Sénégal, Togo) ont contribué : 14 médecins, 8 psychologues, 6 conseillers, 3 travailleurs sociaux. L’expérience des centres était variable, mais l’âge à l’annonce restait tardif : 34 % des 1 296 adolescents âgés entre 10 et 12 ans connaissaient leur statut. L’âge médian à l’annonce était de 13 ans (étendue : 11-15 ans). La pratique de l’annonce s’avérait complexe, en raison de multiples facteurs (crainte des parents de la rupture du secret, manque de communication entre professionnels). L’annonce individuelle était la pratique majoritairement adoptée. Quatre centres pratiquaient une annonce en séances de groupe pour faciliter le soutien en miroir, et un avait recours à l’appui de pairs-adolescents. Les jvVIH ont plaidé pour une annonce plus précoce, dès 10 ans. En Afrique de l’Ouest/centrale francophone, le processus de l’annonce reste complexe pour parents et soignants, et l’annonce trop tardive. L’élaboration d’un guide de bonnes pratiques de l’annonce du VIH, adapté aux contextes socio-culturels devrait permettre d’améliorer ce processus.
Aluminum compounds are the most widely used adjuvants in veterinary and human vaccines. Despite almost a century of use and substantial advances made in recent decades about their fate and biological ...effects, the exact mechanism of their action has been continuously debated, from the initial "depot-theory" to the direct immune system stimulation, and remains elusive. Here we investigated the early in vitro response of primary human PBMCs obtained from healthy individuals to aluminum oxyhydroxide (the most commonly used adjuvant) and a whole vaccine, in terms of internalization, conventional and non-conventional autophagy pathways, inflammation, ROS production, and mitochondrial metabolism. During the first four hours of contact, aluminum oxyhydroxide particles, with or without adsorbed vaccine antigen, (1) were quickly recognized and internalized by immune cells; (2) increased and balanced two cellular clearance mechanisms, i.e. canonical autophagy and LC3-associated phagocytosis; (3) induced an inflammatory response with TNF-α production as an early event; (4) and altered mitochondrial metabolism as assessed by both decreased maximal oxygen consumption and reduced mitochondrial reserve, thus potentially limiting further adaptation to other energetic requests. Further studies should consider a multisystemic approach of the cellular adjuvant mechanism involving interconnections between clearance mechanism, inflammatory response and mitochondrial respiration.
We report the first experimental results on spin-dependent elastic weakly interacting massive particle (WIMP) nucleon scattering from the XENON1T dark matter search experiment. The analysis uses the ...full ton year exposure of XENON1T to constrain the spin-dependent proton-only and neutron-only cases. No significant signal excess is observed, and a profile likelihood ratio analysis is used to set exclusion limits on the WIMP-nucleon interactions. This includes the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3×10^{-42} cm^{2} at 30 GeV/c^{2} and 90% confidence level. The results are compared with those from collider searches and used to exclude new parameter space in an isoscalar theory with an axial-vector mediator.
Delayed single- and few-electron emissions plague dual-phase time projection chambers, limiting their potential to search for light-mass dark matter. This paper examines the origins of these events ...in the XENON1T experiment. Characterization of the intensity of delayed electron backgrounds shows that the resulting emissions are correlated, in time and position, with high-energy events and can effectively be vetoed. In this work we extend previous S2-only analyses down to a single electron. From this analysis, after removing the correlated backgrounds, we observe rates <30 events/(electron×kg×day) in the region of interest spanning 1 to 5 electrons. We derive 90% confidence upper limits for dark matter-electron scattering, first direct limits on the electric dipole, magnetic dipole, and anapole interactions, and bosonic dark matter models, where we exclude new parameter space for dark photons and solar dark photons.
Statistical models of the relationship between precipitation and topography are key elements for the spatial interpolation of rain-gauge measurements in high-mountain regions. This study investigates ...several extensions of the classical precipitation-height model in a direct comparison and within two popular interpolation frameworks, namely linear regression and kriging with external drift. The models studied include predictors of topographic height and slope at several spatial scales, a stratification by types of a circulation classification, and a predictor for wind-aligned topographic gradients. The benefit of the modeling components is investigated for the interpolation of seasonal mean and daily precipitation using leave-one-out cross-validation. The study domain is a north-south cross section of the European Alps (154 km 187 km) that is inclined towards dense rain-gauge measurements (approx. 440 stations, 1971-2008). The significance of the topographic predictors was found to strongly depend on the interpolation framework. In linear regression, predictors of slope and at multiple scales reduce interpolation errors substantially. But with as many as nine predictors, the resulting interpolation still poorly replicates the across-ridge variation of climatological mean precipitation. Kriging with external drift (KED) leads to much smaller interpolation errors than linear regression, but this is achieved with a single predictor (local topographic height), whereas the incorporation of more extended predictor sets brings only marginal further improvement. Furthermore, the stratification by circulation types and the wind-aligned gradient predictor do not improve over the single predictor KED model. As for daily precipitation, interpolation accuracy improves considerably with KED and the use of a single predictor field (the distribution of seasonal mean precipitation) as compared to ordinary kriging (i.e., without any predictor). Nonetheless, information from circulation types did not improve interpolation accuracy. Our results confirm that the consideration of topography effects is important for spatial interpolation of precipitation in high-mountain regions. But a single predictor may be sufficient and taking appropriate account of the spatial autocorrelation (by kriging) can be more effective than the development of elaborate predictor sets within a regression model. Our results also question a popular practice of using linear regression for predictor selection in spatial interpolation; however they support the common practice of using a climatological mean field as a background in the interpolation of daily precipitation.
Submarine landslides can generate sediment-laden flows whose scale is impressive. Individual flow deposits have been mapped that extend for 1,500 km offshore from northwest Africa. These are the ...longest run-out sediment density flow deposits yet documented on Earth. This contribution analyses one of these deposits, which contains ten times the mass of sediment transported annually by all of the world's rivers. Understanding how this type of submarine flow evolves is a significant problem, because they are extremely difficult to monitor directly. Previous work has shown how progressive disintegration of landslide blocks can generate debris flow, the deposit of which extends downslope from the original landslide. We provide evidence that submarine flows can produce giant debris flow deposits that start several hundred kilometres from the original landslide, encased within deposits of a more dilute flow type called turbidity current. Very little sediment was deposited across the intervening large expanse of sea floor, where the flow was locally very erosive. Sediment deposition was finally triggered by a remarkably small but abrupt decrease in sea-floor gradient from 0.05° to 0.01°. This debris flow was probably generated by flow transformation from the decelerating turbidity current. The alternative is that non-channelized debris flow left almost no trace of its passage across one hundred kilometres of flat (0.2° to 0.05°) sea floor. Our work shows that initially well-mixed and highly erosive submarine flows can produce extensive debris flow deposits beyond subtle slope breaks located far out in the deep ocean.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Background Long-term consequences of cancer treatments in young women, and especially fertility issues, are gaining attention as survival rates increase. Breast cancer is the most frequent ...malignancy in women of reproductive age. Aim The purpose of this review is to describe serum anti-müllerian hormone (AMH) level at diagnosis and its evolution during and after chemotherapy in women of reproductive age treated for breast cancer. Second, the impact of taxanes on AMH, the association between AMH and amenorrhea, and the comparison of AMH with other hormonal markers of ovarian reserve were studied. Methods A systematic PubMed search was conducted on all articles, published up to April 2016 and related to AMH in women suffering from breast cancer using the following key words: AMH, müllerian-inhibiting substance, ovarian reserve, ovarian function, breast cancer, gonadotoxicity, ovarian toxicity, amenorrhea, chemotherapy, and menopause. Results AMH levels rapidly fall down to undetectable levels in most women during chemotherapy and generally persist at very low levels in most women after the treatment. Taxanes seem to impact negatively ovarian function, but data on ovarian reserve are scarce. AMH is a predictor of the occurrence of chemotherapy-related amenorrhea and is the most relevant hormonal marker of ovarian reserve. Conclusion Serum AMH is a relevant tool for ovarian reserve assessment and follow-up during treatment in premenopausal women with breast cancer. Further large prospective studies are necessary to determine its predictive interest for post-treatment residual fertility, and eventually use it in fertility preservation counseling before treatment initiation.
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