Evidence from stellar rotation of enhanced disc dispersal: (I) The case of the triple visual system BD-21 1074 in the β\beta Pictoris association

The early stage of stellar evolution is characterized by a star-disc locking mechanism. The disc-locking prevents the star to spin its rotation up, and its timescale depends on the disc lifetime. Some mechanisms can significantly shorten this lifetime, allowing a few stars to start spinning up much earlier than other stars. In the present study, we aim to investigate how the properties of the circumstellar environment can shorten the disc lifetime. We have identified a few multiple stellar systems, composed of stars with similar masses, which belong to associations with a known age. Since all parameters that are responsible for the rotational evolution, with the exception of environment properties and initial stellar rotation, are similar for all components, we expect that significant differences among the rotation periods can only arise from differences in the disc lifetimes. A photometric timeseries allowed us to measure the rotation periods of each component, while high-resolution spectra provided us with the fundamental parameters, $v\sin{i}$ and chromospheric line fluxes. The rotation periods of the components differ significantly, and the component B, which has a closer companion C, rotates faster than the more distant and isolated component A. We can ascribe the rotation period difference to either different initial rotation periods or different disc-locking phases arising from the presence of the close companion C. In the specific case of BD$-$21 1074, the second scenario seems to be more favored. In our hypothesis of different disc-locking phase, any planet orbiting this star is likely formed very rapidly owing to a gravitational instability mechanism, rather than core accretion. Only a large difference of initial rotation periods alone could account for the observed period difference, leaving comparable disc lifetimes.Comment: Accepted by Astronomy & Astrophysics on July 31, 2014; Pages 12, Figs.

Extracorporeal Blood Purification Therapies for Sepsis.

Extracorporeal blood purification is proposed as an adjuvant therapy for sepsis, aiming at controlling the associated dysregulation of the immune system, which is known to induce organ dysfunctions. Different therapies have been developed to address certain steps of the immune dysregulation. Most of the available blood purification devices focus on a single target, such as the endotoxin that triggers the immune cascade, or the cytokine storm that causes organ damages. However, the highly adsorptive membrane named oXiris® is a unique 4-in-1 device that combines cytokine and endotoxin removal properties, renal replacement function, and antithrombogenic properties. More recently, promising treatments that focus on the pathogen itself or the immune cells have been developed and are currently under investigation. In this review, we aim to summarize, according to their target, the different extracorporeal blood purification techniques that are already available for use. We will also briefly introduce the most recent techniques that are still under development. Because of its unique ability to remove both endotoxins and cytokines, we will particularly discuss the highly adsorptive preheparinized oXiris® membrane. We will present its properties, advantages, pitfalls, as well as therapeutic perspectives based on experimental and clinical data. Video Journal Club "Cappuccino with Claudio Ronco" at https://www.karger.com/Journal/ArticleNews/223997?sponsor=5

Photometric study of southern SU UMa-type dwarf novae and candidates -- III: NSV 10934, MM Sco, AB Nor, CAL 86

We photometrically observed four southern dwarf novae in outburst (NSV 10934, MM Sco, AB Nor and CAL 86). NSV 10934 was confirmed to be an SU UMa-type dwarf nova with a mean superhump period of 0.07478(1) d. This star also showed transient appearance of quasi-periodic oscillations (QPOs) during the final growing stage of the superhumps. Combined with the recent theoretical interpretation and with the rather unusual rapid terminal fading of normal outbursts, NSV 10934 may be a candidate intermediate polar showing SU UMa-type properties. The mean superhump periods of MM Sco and AB Nor were determined to be 0.06136(4) d and 0.08438(2) d, respectively. We suggest that AB Nor belongs to a rather rare class of long-period SU UMa-type dwarf novae with low mass-transfer rates. We also observed an outburst of the suspected SU UMa-type dwarf nova CAL 86. We identified this outburst as a normal outburst and determined the mean decline rate of 1.1 mag/d.Comment: 13 pages, 23 figures, to appear in MNRAS. For more information, see http://www.kusastro.kyoto-u.ac.jp/vsnet

On the class distribution labelling step sensitivity of co-training

Co-training can learn from datasets having a small number of labelled examples and a large number of unlabelled ones. It is an iterative algorithm where examples labelled in previous iterations are used to improve the classification of examples from the unlabelled set. However, as the number of initial labelled examples is often small we do not have reliable estimates regarding the underlying population which generated the data. In this work we make the claim that the proportion in which examples are labelled is a key parameter to co-training. Furthermore, we have done a series of experiments to investigate how the proportion in which we label examples in each step influences cotraining performance. Results show that co-training should be used with care in challenging domains.IFIP International Conference on Artificial Intelligence in Theory and Practice - Knowledge Acquisition and Data MiningRed de Universidades con Carreras en Informática (RedUNCI

Epidemiology and outcomes of early versus late septic acute kidney injury in critically ill patients: A retrospective cohort study.

It was recently proposed to distinguish early from late sepsis-associated acute kidney injury (SA-AKI). We aimed to determine the relative frequency of these entities in critically ill patients and to describe their characteristics and outcomes. We included in this retrospective cohort study all adult patients admitted for sepsis in a tertiary ICU between 2010 and 2020. We excluded those on chronic dialysis or without consent. We extracted serum creatinine, hourly urinary output, and clinical and socio-demographic data from medical records until day 7 or ICU discharge. AKI presence and characteristics were assessed daily using KDIGO criteria. We compared patients with early (occurring within 2 days of admission) or late (occurring between day 2 and day 7) SA-AKI. We conducted sensitivity analyses using different definitions for early/late SA-AKI. Among 1835 patients, 1660 (90%) fulfilled SA-AKI criteria. Of those, 1610 (97%) had early SA-AKI, and 50 (3%) had late SA-AKI. Similar proportions were observed when only considering AKI with elevated sCr (71% vs. 3%), severe AKI (67% vs. 6%), or different time windows for early SA-AKI. Compared with early SA-AKI patients, those with late SA-AKI were younger (median age [IQR] 59 [49-70] vs. 69 [58-76] years, p < 0.001), had lower Charlson comorbidity index (3 [1-5] vs. 5 [3-7], p < 0.001) and lower SAPSII scores (41 [34-50] vs. 53 [43-64], p < 0.001). They had similar (24% vs. 26%, p = 0.75) in-hospital mortality. AKI is almost ubiquitous in septic critically ill patients and present within two days of admission. The timing from ICU admission might not be relevant to distinguish different phenotypes of SA-AKI. Ethics Committee Vaud, Lausanne, Switzerland (n°2017-00008)

A hybrid wrapper/filter approach for feature subset selection

This work presents a hybrid wrapper/filter algorithm for feature subset selection that can use a combination of several quality criteria measures to rank the set of features of a dataset. These ranked features are used to prune the search space of subsets of possible features such that the number of times the wrapper executes the learning algorithm for a dataset with M features is reduced to O(M) runs. Experimental results using 14 datasets show that, for most of the datasets, the AUC assessed using the reduced feature set is comparable to the AUC of the model constructed using all the features. Furthermore, the algorithm archieved a good reduction in the number of features.Sociedad Argentina de Informática e Investigación Operativ

Mission conjointe NMA/PRIFAS d´étude et de prospective dans Le Sudeste du Bresil, du 27 octobre au 10 novembre 1990.

bitstream/item/116959/1/1589.pd