University of Paris

About: University of Paris is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Medicine. The organization has 102426 authors who have published 174180 publications receiving 5041753 citations. The organization is also known as: Sorbonne.

ENSO and greenhouse warming

Abstract: This Review looks at the state of knowledge on the El Nino/Southern Oscillation (ENSO), a natural climate phenomenon. It discusses recent advances and insights into how climate change will affect this natural climate varibility cycle. The El Nino/Southern Oscillation (ENSO) is the dominant climate phenomenon affecting extreme weather conditions worldwide. Its response to greenhouse warming has challenged scientists for decades, despite model agreement on projected changes in mean state. Recent studies have provided new insights into the elusive links between changes in ENSO and in the mean state of the Pacific climate. The projected slow-down in Walker circulation is expected to weaken equatorial Pacific Ocean currents, boosting the occurrences of eastward-propagating warm surface anomalies that characterize observed extreme El Nino events. Accelerated equatorial Pacific warming, particularly in the east, is expected to induce extreme rainfall in the eastern equatorial Pacific and extreme equatorward swings of the Pacific convergence zones, both of which are features of extreme El Nino. The frequency of extreme La Nina is also expected to increase in response to more extreme El Ninos, an accelerated maritime continent warming and surface-intensified ocean warming. ENSO-related catastrophic weather events are thus likely to occur more frequently with unabated greenhouse-gas emissions. But model biases and recent observed strengthening of the Walker circulation highlight the need for further testing as new models, observations and insights become available.

In the realm of the Hubble tension - a review of solutions

Abstract: The $\Lambda$CDM model provides a good fit to a large span of cosmological data but harbors areas of phenomenology. With the improvement of the number and the accuracy of observations, discrepancies among key cosmological parameters of the model have emerged. The most statistically significant tension is the $4-6\sigma$ disagreement between predictions of the Hubble constant $H_0$ by early time probes with $\Lambda$CDM model, and a number of late time, model-independent determinations of $H_0$ from local measurements of distances and redshifts. The high precision and consistency of the data at both ends present strong challenges to the possible solution space and demand a hypothesis with enough rigor to explain multiple observations--whether these invoke new physics, unexpected large-scale structures or multiple, unrelated errors. We present a thorough review of the problem, including a discussion of recent Hubble constant estimates and a summary of the proposed theoretical solutions. Some of the models presented are formally successful, improving the fit to the data in light of their additional degrees of freedom, restoring agreement within $1-2\sigma$ between {\it Planck} 2018, using CMB power spectra data, BAO, Pantheon SN data, and R20, the latest SH0ES Team measurement of the Hubble constant ($H_0 = 73.2 \pm 1.3{\rm\,km\,s^{-1}\,Mpc^{-1}}$ at 68\% confidence level). Reduced tension might not simply come from a change in $H_0$ but also from an increase in its uncertainty due to degeneracy with additional physics, pointing to the need for additional probes. While no specific proposal makes a strong case for being highly likely or far better than all others, solutions involving early or dynamical dark energy, neutrino interactions, interacting cosmologies, primordial magnetic fields, and modified gravity provide the best options until a better alternative comes along.[Abridged]

Hypothermia Therapy after Traumatic Brain Injury in Children

Abstract: A total of 225 children were randomly assigned to the hypothermia group or the normothermia group; the mean temperatures achieved in the two groups were 33.1±1.2°C and 36.9±0.5°C, respectively. At 6 months, 31% of the patients in the hypothermia group, as compared with 22% of the patients in the normothermia group, had an unfavorable outcome (relative risk, 1.41; 95% confidence interval [CI], 0.89 to 2.22; P = 0.14). There were 23 deaths (21%) in the hypothermia group and 14 deaths (12%) in the normothermia group (relative risk, 1.40; 95% CI, 0.90 to 2.27; P = 0.06). There was more hypotension (P = 0.047) and more vasoactive agents were administered (P<0.001) in the hypothermia group during the rewarming period than in the normothermia group. Lengths of stay in the intensive care unit and in the hospital and other adverse events were similar in the two groups. Conclusions In children with severe traumatic brain injury, hypothermia therapy that is initiated within 8 hours after injury and continued for 24 hours does not improve the neurologic outcome and may increase mortality. (Current Controlled Trials number, ISRCTN77393684.)

Introduction to Statistical Learning Theory

Abstract: The goal of statistical learning theory is to study, in a statistical framework, the properties of learning algorithms. In particular, most results take the form of so-called error bounds. This tutorial introduces the techniques that are used to obtain such results.

Evidence that the prevalence of childhood overweight is plateauing: Data from nine countries

Abstract: Until quite recently, there has been a widespread belief in the popular media and scientific literature that the prevalence of childhood obesity is rapidly increasing However, high quality evidence has emerged from several countries suggesting that the rise in the prevalence has slowed appreciably, or even plateaued This review brings together such data from nine countries (Australia, China, England, France, Netherlands, New Zealand, Sweden, Switzerland and USA), with data from 467,294 children aged 2-19 years The mean unweighted rate of change in prevalence of overweight and obesity was +000 (049)% per year across all age ×sex groups and all countries between 1995 and 2008 For overweight alone, the figure was +001 (056)%, and for obesity alone -001 (024)% Rates of change differed by sex, age, socioeconomic status and ethnicity While the prevalence of overweight and obesity appears to be stabilizing at different levels in different countries, it remains high, and a significant public health issue Possible reasons for the apparent flattening are hypothesised