145 research outputs found
The Great Increase in Relative Volatility of Real Wages in the United States
This paper documents that over the past 25 years, aggregate hourly real wages in the United States have become substantially more volatile relative to output. We use micro-data from the Current Population Survey (CPS) to show that this increase in relative volatility is predominantly due to increases in the relative volatility of hourly wages across different groups of workers. Compositional changes, by contrast, account for at most 12% of the increase in relative wage volatility. Using a Dynamic Stochastic General Equilibrium (DSGE) model, we show that the observed increase in relative wage volatility is unlikely to come from changes outside of the labor market (e.g. smaller exogenous shocks or more aggressive monetary policy). By contrast, increased flexibility in wage setting is capable of accounting for a large fraction of the observed increase in relative wage volatility. At the same time, increased wage flexibility generates a substantial decrease in the magnitude of business cycle fluctuations, which suggests a promising new explanation for the Great Moderation.Wage volatility, business cycles, great moderation, current population survey, dynamic stochastic general equilibrium models
La cyclicité des salaires réels agrégés aux États-Unis
Ce papier documente les caractéristiques cycliques divergentes des deux mesures de salaire réel agrégé les plus populaires aux États-Unis, soit le Average Hourly Earnings produit par le Bureau of Labor Statistics, et le salaire horaire moyen construit à l'aide des tables NIPA du Bureau of Economic Analysis. En analysant de plus près la mesure de salaire NIPA, on constate que le salaire réel agrégé aux États-Unis est acyclique et que sa volatilité relative par rapport au PIB augmente drastiquement après 1984. Nous montrons que cette augmentation de volatilité est due principalement à la hausse de la proportion de travailleurs avec plus d'habiletés (skilled) dans l'économie, ce type de travailleurs ayant une grande volatilité dans leurs salaires ainsi que dans leurs heures travaillées. Nous montrons aussi que la mesure agrégée de salaire provenant des tables NIPA est bien plus représentative de la population américaine que la mesure AHE, qui, quant à elle, n'a pas vu sa volatilité relative au PIB augmenter après 1984. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Salaires réels, Cycles économiques, Volatilité, Marché du travail
Vers un cinéma immatériel : réminiscences du cinématographique dans l’œuvre d'Olafur Eliasson
Il est désormais commun de reconnaître que le cinéma, aujourd’hui, s’émancipe de son dispositif médiatique traditionnel, adoptant maintes formes liées aux champs culturels qui l’accueillent : jeux vidéo, web, médias portatifs, etc. Toutefois, c’est peut-être le champ des arts visuels et médiatiques contemporains qui lui aura fait adopter, depuis la fin des années soixante, les formes les plus désincarnées, allant parfois jusqu’à le rendre méconnaissable. À cet effet, certaines œuvres sculpturales et installatives contemporaines uniquement composées de lumière et de vapeur semblent, par leurs moyens propres, bel et bien reprendre, tout en les mettant à l’épreuve, quelques caractéristiques du médium cinématographique. Basé sur ce constat, le présent mémoire vise à analyser, sur le plan esthétique, cette filiation potentielle entre le média-cinéma et ces œuvres au caractère immatériel. Pour ce faire, notre propos sera divisé en trois chapitres s’intéressant respectivement : 1) à l’éclatement médiatique du cinéma et à sa requalification vue par les théories intermédiales, 2) au processus d’évidement du cinéma – à la perte de ses images et de ses matériaux – dans les pratiques en arts visuels depuis une cinquantaine d’années, et 3) au corpus de l’artiste danois Olafur Eliasson, et plus spécialement à son œuvre Din Blinde Passager (2010), qui est intimement liée à notre problématique. Notre réflexion sera finalement, au long de ce parcours, principalement guidée par les approches esthétiques et philosophiques de Georges Didi-Huberman et de Jacques Rançière.It is now common to acknowledge that cinema, today, is emancipated from its traditional media figure, adopting various forms related to the cultural fields that welcome it : video games, web, portable medias, etc. However, it is perhaps the visual and media contemporary arts that have morphed it, since the late sixties, into the most disembodied forms, even sometimes beyond recognition. To this end, some contemporary sculptures and installations only composed of light and steam seem, by their own means, to have adopted, and simultaneously put to the test, some characteristics of the cinematographic medium. Based on this observation, this paper aims to analyze, on an aesthetic level, this relationship between media-cinema and the nature of these immaterial artworks. To do so, our analysis will be divided into three chapters focusing respectively on : 1) the expansion of the cinema and its requalification as seen by intermedial theories, 2) the cinema’s loss of its images and materials in some visual art practices since the last fifty years, and 3) the artistic corpus of Danish artist Olafur Eliasson, and more precisely his work entitled Din Blinde Passenger (2010), which is intimately related to our subject matter. Finally, our reflection will mainly be guided by the aesthetic and philosophical approaches of Georges Didi-Huberman and Jacques Rancière
Review of contemporary sound installation practices in Québec
Continuing a trend of publications investigating sound art within a specific geographical
context, this paper proposes an original view of the sound installation practice in Que´bec. This study is
part of a research project aiming at building new theoretical and practical tools for the documentation of
such artworks. In this paper we present the outcomes of the first phase and its connection with the bigger
picture of the project, which is the questioning of the relevance of spatial audio recordings with six degrees
of freedom (6DoF) for mediating the capture of knowledge relating to the sensory experience of a work.
During the first phase, we developed a conceptual descriptive framework based on a mixed-methods
approach, top-down and bottom-up, consisting in a systematic review of literature paralleled with
a categorization of contemporary sound art production in Que´bec based on publicly available
documentation. This process led to a formal and quantitative depiction of the Que´bec scene, which
aims to guide both the selection of case studies for the next phases but also to be part of the
conceptual tools for investigating the sensory experience of these works. This quantitative depiction of
the scene will thus foster a qualitative investigation of the sensory experience of sound art installations and
the knowledge that may be lost in standard written documentation practice with an original methodological
framework
Life in mine tailings: microbial population structure across the bulk soil, rhizosphere, and roots of boreal species colonizing mine tailings in northwestern Québec
Abstract
Purpose
Mining activities have negative effects on soil characteristics and can result in low pH, high heavy metal content, and limited levels of essential nutrients. A tailings storage area located in northwestern Québec showed natural colonization by plants from the adjacent natural environment. The objective of the study was to determine the main edaphic parameters that structured microbial populations associated with the indigenous woody plants that had naturally colonized the site.
Methods
Microbial populations were studied in the bulk soil, the rhizosphere, and inside plant roots using Illumina sequencing, ordination analysis (i.e., redundancy analysis (RDA) and principal coordinates analysis (PCoA)), ternary plotting, and statistical analysis (MANOVA).
Results
The main variables that drove the microbial community patterns were plant species and the tailings pH. Indeed, the main bacterial classes were Gammaproteobacteria and Deltaproteobacteria in both the rhizosphere and root endosphere. Analysis revealed that some dominant operational taxonomic units (e.g., Pseudomonas sp., Acinetobacter sp., and Delftia sp.) were present in increased proportions in roots for each plant species under study. This study also revealed that many of the most abundant fungal genera (e.g., Claussenomyces, Eupenicillium, and Trichoderma) were more abundant in the rhizosphere than in the root endosphere.
Conclusions
This comprehensive study of the microbial community dynamics in the bulk soil, rhizosphere, and root endosphere of boreal trees and shrubs could be beneficial in facilitating the rehabilitation of disturbed ecosystems
Usefulness and limitation of dobutamine stress echocardiography to predict acute response to cardiac resynchronization therapy.
peer reviewedBackground: It has been hypothesized that a long-term response to cardiac resynchronization therapy (CRT) could correlate with myocardial viability in patients with left ventricular (LV) dysfunction. Contractile reserve and viability in the region of the pacing lead have not been investigated in regard to acute response after CRT. Methods: Fifty-one consecutive patients with advanced heart failure, LV ejection fraction ≤ 35%, QRS duration > 120 ms, and intraventricular asynchronism ≥ 50 ms were prospectively included. The week before CRT implantation, the presence of viability was evaluated using dobutamine stress echocardiography. Acute responders were defined as a ≥15% increase in LV stroke volume. Results: The average of viable segments was 5.8 ± 1.9 in responders and 3.9 ± 3 in nonresponders (P = 0.03). Viability in the region of the pacing lead had an excellent sensitivity (96%), but a low specificity (56%) to predict acute response to CRT. Mitral regurgitation (MR) was reduced in 21 patients (84%) with acute response. The presence of MR was a poor predictor of response (sensibility 93% and specificity 17%). However, combining the presence of MR and viability in the region of the pacing lead yields a sensibility (89%) and a specificity (70%) to predict acute response to CRT. Conclusion: Myocardial viability is an important factor influencing acute hemodynamic response to CRT. In acute responders, significant MR reduction is frequent. The combined presence of MR and viability in the region of the pacing lead predicts acute response to CRT with the best accuracy
Post-traumatic stress among COVID-19 survivors: A descriptive study of hospitalized first-wave survivors
Introduction: The coronavirus Severe Acute Respiratory Syndrome Coronavirus Type 1 induces a severe respiratory disease, coronavirus disease 2019 (COVID-19). After Severe Acute Respiratory Syndrome Coronavirus Type 1 and Middle East Respiratory Syndrome infection, increased post-traumatic stress disorder (PTSD) rates were described.
Methods: This single-centred, prospective study aimed to evaluate the rates of PTSD in patients who were hospitalized for COVID-19. Inclusion criteria were COVID-19 patients hospitalized in the intensive care unit (ICU) or in a standard unit with at least 2 L/min oxygen. Six months post-hospitalization, subjects were assessed for PTSD using a validated screening tool, the Post-Traumatic Stress Checklist-5 (PCL-5).
Results: A total of 40 patients were included. No demographic differences between the ICU and non-ICU groups were found. The mean PCL-5 score for
the population was 8.85±10. The mean PCL-5 score was 6.7±8 in the ICU group and 10.5±11 in the non-ICU group (P=0.27). We screened one patient
with a positive PCL-5 score and one with a possible PCL-5 cluster score. Nine patients had a PCL-5 score of up to 15. Seven patients reported no symptoms.Seven patients accepted a psychological follow-up: one for PTSD, three for possible PTSD and three for other psychological problems.
Discussion: The PCL-5 tool can be used by lung physicians during consultations to identify patients for whom follow-up mental health assessment and treatment for PTSD are warranted.
Conclusion: Lung physicians should be aware of the risk of PTSD in patients hospitalized for COVID-19 and ensure appropriate screening and follow-up care
Usefulness of NT-pro BNP monitoring to identify echocardiographic responders following cardiac resynchronization therapy
<p>Abstract</p> <p>Background</p> <p>Cardiac resynchronization therapy (CRT) improves left ventricular (LV) volumes, mitral regurgitation (MR) severity and symptoms of patients with heart failure (HF). However, ≥ 30% of patients have no significant clinical or echocardiographic improvement following CRT. Reverse remodeling after CRT correlates with improved clinical outcomes. We hypothesized that in NT-pro BNP monitoring is accurate to identify responders following CRT.</p> <p>Methods</p> <p>42 consecutive patients (mean age 66 ± 12 years, male 68%) with HF undergoing CRT were prospectively enrolled. Responders at follow-up were defined by echocardiography (decrease in LV end systolic volume ≥ 15%). Echocardiography and NT-pro BNP measurement were performed at baseline and repeated 3 to 6 month after CRT.</p> <p>Results</p> <p>There was no significant difference between responders (n = 29, 69%) and non-responders (n = 13, 31%) regarding baseline NT-pro BNP level. Responders had significantly higher decrease in NT-pro BNP levels during follow-up than non-responders (absolute: -1428 ± 1333 pg.ml<sup>-1 </sup>vs. -61 ± 959 pg.ml<sup>-1</sup>, p = 0.002; relative: -45 ± 28% vs. 2 ± 28%, p < 0.0001). A decrease of ≥ 15% in NT-pro BNP 3–6 months after CRT identifies echocardiographic responders with a sensitivity of 90% and a specificity of 77%.</p> <p>Conclusion</p> <p>NT-pro BNP monitoring can accurately identify echocardiographic responders after CRT.</p
Tryptophan depletion results in tryptophan-to-phenylalanine substitutants
Activated T cells secrete interferon-γ, which triggers intracellular tryptophan shortage by upregulating the indoleamine 2,3-dioxygenase 1 (IDO1) enzyme1–4. Here we show that despite tryptophan depletion, in-frame protein synthesis continues across tryptophan codons. We identified tryptophan-to-phenylalanine codon reassignment (W>F) as the major event facilitating this process, and pinpointed tryptophanyl-tRNA synthetase (WARS1) as its source. We call these W>F peptides ‘substitutants’ to distinguish them from genetically encoded mutants. Using large-scale proteomics analyses, we demonstrate W>F substitutants to be highly abundant in multiple cancer types. W>F substitutants were enriched in tumours relative to matching adjacent normal tissues, and were associated with increased IDO1 expression, oncogenic signalling and the tumour-immune microenvironment. Functionally, W>F substitutants can impair protein activity, but also expand the landscape of antigens presented at the cell surface to activate T cell responses. Thus, substitutants are generated by an alternative decoding mechanism with potential effects on gene function and tumour immunoreactivity
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