74 research outputs found
Online Approval Committee Elections
Assume candidates need to be selected. The candidates appear over time.
Each time one appears, it must be immediately selected or rejected -- a
decision that is made by a group of individuals through voting. Assume the
voters use approval ballots, i.e., for each candidate they only specify whether
they consider it acceptable or not. This setting can be seen as a voting
variant of choosing secretaries. Our contribution is twofold. (1) We assess
to what extent the committees that are computed online can proportionally
represent the voters. (2) If a prior probability over candidate approvals is
available, we show how to compute committees with maximal expected score
A network of Rab GTPases controls phagosome maturation and is modulated by Salmonella enterica serovar Typhimurium
Members of the Rab guanosine triphosphatase (GTPase) family are key regulators of membrane traffic. Here we examined the association of 48 Rabs with model phagosomes containing a non-invasive mutant of Salmonella enterica serovar Typhimurium (S. Typhimurium). This mutant traffics to lysosomes and allowed us to determine which Rabs localize to a maturing phagosome. In total, 18 Rabs associated with maturing phagosomes, each with its own kinetics of association. Dominant-negative mutants of Rab23 and 35 inhibited phagosome–lysosome fusion. A large number of Rab GTPases localized to wild-type Salmonella-containing vacuoles (SCVs), which do not fuse with lysosomes. However, some Rabs (8B, 13, 23, 32, and 35) were excluded from wild-type SCVs whereas others (5A, 5B, 5C, 7A, 11A, and 11B) were enriched on this compartment. Our studies demonstrate that a complex network of Rab GTPases controls endocytic progression to lysosomes and that this is modulated by S. Typhimurium to allow its intracellular growth
Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study
Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Equité des systèmes de recommandation : les perspectives du choix social
Les algorithmes d'apprentissage automatique (machine learning) sont largement utilisés dans les systèmes de recommandation pour personnaliser les suggestions de contenu en fonction des préférences des utilisateurs. Cependant, ces algorithmes peuvent involontairement favoriser certains producteurs tout en négligeant d'autres, soulevant des préoccupations éthiques et sociétales concernant l'équité et la représentation. Ce travail vise à créer des algorithmes de recommandation plus équitable qui équilibrent les préférences des utilisateurs avec le bien-être des producteurs de contenu. En abordant les défis liés à la définition de l'équité et à l'efficacité computationnelle, nous proposons un cadre ancré dans la théorie du choix social. ce cadre guide le développement de nouvelles méthode de recommandation qui distribuent équitablement l'exposition aux producteurs de contenu sans compromettre la qualité des recommandations. Nos méthodes sont étayées par des garanties théoriques concernant l'équité, la convergence et l'efficacité computationnelle, ainsi que par des évaluations sur des jeux de données.Machine learning algorithms are widely used in the recommender systems for personalizing content recommendations based on user preferences. However, these algorithms can inadvertently promote certain producers while overlooking others, raising ethical and societal concerns about fairness and representation. This work aims to create fairer recommendation algorithms that balance user preferences with content producer welfare. Addressing the challenges of defining fairness for ranked recommendations and preserving computational efficiency, we propose a framework grounded in social choice theory. This framework guides the development of new recommendation methods that fairly distribute exposure to content producers without compromising rcommendation quality. Our methods are substantiated by theoretical guarantees of fairness, convergence and computational efficiency, as well as real-world dataset evaluations
Equité des systèmes de recommandation : les perspectives du choix social
Machine learning algorithms are widely used in the recommender systems for personalizing content recommendations based on user preferences. However, these algorithms can inadvertently promote certain producers while overlooking others, raising ethical and societal concerns about fairness and representation. This work aims to create fairer recommendation algorithms that balance user preferences with content producer welfare. Addressing the challenges of defining fairness for ranked recommendations and preserving computational efficiency, we propose a framework grounded in social choice theory. This framework guides the development of new recommendation methods that fairly distribute exposure to content producers without compromising rcommendation quality. Our methods are substantiated by theoretical guarantees of fairness, convergence and computational efficiency, as well as real-world dataset evaluations.Les algorithmes d'apprentissage automatique (machine learning) sont largement utilisés dans les systèmes de recommandation pour personnaliser les suggestions de contenu en fonction des préférences des utilisateurs. Cependant, ces algorithmes peuvent involontairement favoriser certains producteurs tout en négligeant d'autres, soulevant des préoccupations éthiques et sociétales concernant l'équité et la représentation. Ce travail vise à créer des algorithmes de recommandation plus équitable qui équilibrent les préférences des utilisateurs avec le bien-être des producteurs de contenu. En abordant les défis liés à la définition de l'équité et à l'efficacité computationnelle, nous proposons un cadre ancré dans la théorie du choix social. ce cadre guide le développement de nouvelles méthode de recommandation qui distribuent équitablement l'exposition aux producteurs de contenu sans compromettre la qualité des recommandations. Nos méthodes sont étayées par des garanties théoriques concernant l'équité, la convergence et l'efficacité computationnelle, ainsi que par des évaluations sur des jeux de données
Optimizing generalized Gini indices for fairness in rankings
There is growing interest in designing recommender systems that aim at being
fair towards item producers or their least satisfied users. Inspired by the
domain of inequality measurement in economics, this paper explores the use of
generalized Gini welfare functions (GGFs) as a means to specify the normative
criterion that recommender systems should optimize for. GGFs weight individuals
depending on their ranks in the population, giving more weight to worse-off
individuals to promote equality. Depending on these weights, GGFs minimize the
Gini index of item exposure to promote equality between items, or focus on the
performance on specific quantiles of least satisfied users. GGFs for ranking
are challenging to optimize because they are non-differentiable. We resolve
this challenge by leveraging tools from non-smooth optimization and projection
operators used in differentiable sorting. We present experiments using real
datasets with up to 15k users and items, which show that our approach obtains
better trade-offs than the baselines on a variety of recommendation tasks and
fairness criteria.Comment: Accepted to SIGIR 202
Le thalidomide dans le myélome de Kahler
AIX-MARSEILLE2-BU Pharmacie (130552105) / SudocSudocFranceF
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