Search results for "Persistence"
showing 10 items of 243 documents
Autocorrelation Metrics to Estimate Soil Moisture Persistence From Satellite Time Series: Application to Semiarid Regions
2021
Satellite-derived soil moisture (SM) products have become an important information source for the study of land surface processes in hydrology and land monitoring. Characterizing and estimating soil memory and persistence from satellite observations is of paramount relevance, and has deep implications in ecology, water management, and climate modeling. In this work, we address the problem of SM persistence estimation from microwave sensors using several autocorrelation metrics that, unlike traditional approaches, build on accurate estimates of the autocorrelation function from nonuniformly sampled time series. We show how the choice of the autocorrelation estimator can have a dramatic impac…
Persistence of C-reactive protein increased levels and high disease activity are predictors of cardiovascular disease in patients with axial spondylo…
2022
AbstractAn accurate prediction of cardiovascular (CV) risk in patients with Axial Spondyloarthritis (axSpA) is a strong unmet need, as CV risk algorithms poorly perform in these subjects. The aim of this study was to establish whether the persistence of high C-reactive protein (CRP) and high disease activity may be considered predictive factors of CVD in axSpA. 295 patients without personal history of CVD, were consecutively enrolled in this study. To evaluate the relationship between CV events occurrence (fatal and non-fatal) and the persistence of increased CRP levels, ASDAS (Ankylosing Spondylitis Disease Activity Score) > 2.1, and BASDAI (Bath Ankylosing Spondylitis Disease Activity)…
The genomic history of the Aegean palatial civilizations
2021
Summary The Cycladic, the Minoan, and the Helladic (Mycenaean) cultures define the Bronze Age (BA) of Greece. Urbanism, complex social structures, craft and agricultural specialization, and the earliest forms of writing characterize this iconic period. We sequenced six Early to Middle BA whole genomes, along with 11 mitochondrial genomes, sampled from the three BA cultures of the Aegean Sea. The Early BA (EBA) genomes are homogeneous and derive most of their ancestry from Neolithic Aegeans, contrary to earlier hypotheses that the Neolithic-EBA cultural transition was due to massive population turnover. EBA Aegeans were shaped by relatively small-scale migration from East of the Aegean, as e…
Factors associated with Pneumocystis colonization and circulating genotypes in chronic obstructive pulmonary disease patients with acute exacerbation…
2021
Abstract Pneumocystis jirovecii colonization is frequent during chronic obstructive pulmonary disease (COPD) and patients constitute potential contributors to its interhuman circulation. However, the existence of an environmental reservoir cannot be excluded. We assessed the prevalence and factors associated with Pneumocystis colonization during COPD, and studied circulation between patients and their domestic environment. Pneumocystis molecular detection and mtLSU genotyping were performed in oro-pharyngeal washes (OPW) sampled in 58 patients with COPD acute exacerbation, and in indoor dust, sampled in patients’ homes using electrostatic dust collectors (EDCs). Lung and systemic inflammati…
Understanding retention and metabolization of aroma compounds using an in vitro model of oral mucosa.
2020
International audience; The mechanism leading to aroma persistence during eating is not fully described. This study aims at better understanding the role of the oral mucosa in this phenomenon. Release of 14 volatile compounds from different chemical classes was studied after exposure to in vitro models of oral mucosa, at equilibrium by Gas-Chromatography-Flame Ionization Detection (GC-FID) and in dynamic conditions by Proton Transfer Reaction- Mass Spectrometry (PTR-MS). Measurements at equilibrium showed that mucosal hydration reduced the release of only two compounds, pentan-2-one and linalool (p < 0.05), and suggested that cells could metabolize aroma compounds from different chemical fa…
Topology-based goodness-of-fit tests for sliced spatial data
2023
In materials science and many other application domains, 3D information can often only be extrapolated by taking 2D slices. In topological data analysis, persistence vineyards have emerged as a powerful tool to take into account topological features stretching over several slices. In the present paper, we illustrate how persistence vineyards can be used to design rigorous statistical hypothesis tests for 3D microstructure models based on data from 2D slices. More precisely, by establishing the asymptotic normality of suitable longitudinal and cross-sectional summary statistics, we devise goodness-of-fit tests that become asymptotically exact in large sampling windows. We illustrate the test…
Computer Simulations for Polymer Dynamics
1991
In this paper we review recent work on the dynamics of polymeric systems using computer simulation methods. For a two-dimensional polymer melt, we show that the chains segregate and the dynamics can be described very well by the Rouse model. This simulation was carried out using the bond fluctuation Monte Carlo method. For three-dimensional (3d) melts and for the study of hydrodynamic effects, we use a molecular dynamics simulation. For 3d melts our results strongly support the concept of reptation. A detailed comparison to experiment shows that we can predict the time and length scales for the onset of reptation for a variety of polymeric liquids. For a single chain, we find the expected h…
Application of the Wood model to lactation curves of Comisana sheep
1997
Abstract Ninety-two ewes of the Comisana breed were used in a study to verify the forecasting capacity of the mathematical model proposed by Wood for fitting sheep data, and to evaluate the effect of the environmental factors affecting the parameters of the lactation curve. The Wood model underestimated the total lactation milk production with an error margin of 12.2 ± 7.8 kg of milk corresponding to 10.9 ± 6.6%. There was a strong influence of order of lambing × lambing season interaction on the lactation parameters. The curves for the winter lambing ewes demonstrated a higher peak production than autumn lambing ewes (1728.4 vs. 1082.6 g, P ≤ 0.05 for the second lambing ewes and 1772.8 vs.…
On the Asymmetric Recognition of Good and Bad News in France, Germany and the United Kingdom
2001
We investigate whether accounting systems recognise bad news more promptly in earnings than good news, where news is proxied by changes in share price. The analysis is based on a sample of firm/years drawn from France, Germany, and the UK during 1990 to 1998. These three countries are the originators of three distinct legal traditions. Previous studies have argued that asymmetric recognition, one manifestation of conservative accounting, is sensitive to legal background and history. We find that in all three countries the contemporaneous association between earnings and returns is much stronger for bad news (i.e. when price changes are negative) than for good news, and although the results …
Fiscal Policy Responsiveness, Persistence and Discretion
2008
This paper analyzes the different characteristics of fiscal policy using a two-step estimation procedure. First, we decompose both government spending and government revenue into three components: responsiveness, persistence and discretion. Second, we assess the determinants of these characteristics. Using data from 132 countries, our results show that fiscal policy is more persistent than responsive to economic conditions, which implies that the authorities may have less leeway in the short-run notably to curb spending behavior. In addition, countries characterized by greater fiscal persistence have less discretion and responsiveness. Finally, macroeconomic, institutional and geographic va…