Search results for "models"

Predicting the age at natural menopause in middle-aged women

2021

Objective To predict the age at natural menopause (ANM). Methods Cox models with time-dependent covariates were utilized for ANM prediction using longitudinal data from 47 to 55-year-old women (n = 279) participating in the Estrogenic Regulation of Muscle Apoptosis study. The ANM was assessed retrospectively for 105 women using bleeding diaries. The predictors were chosen from the set of 32 covariates by using the lasso regression (model 1). Another easy-to-access model (model 2) was created by using a subset of 16 self-reported covariates. The predictive performance was quantified with c-indices and by studying the means and standard deviations of absolute errors (MAE ± SD) between the pre…

La recherche en finance d’entreprise:quel positionnement méthodologique ?

2008

(VF)Après avoir effectué, dans une première partie, un état des lieux permettant de préciser notamment la nature des questions que se posent les chercheurs en finance d’entreprise et les méthodes qu’ils emploient, la seconde partie est consacrée au positionnement de la recherche en finance d’entreprise et gouvernance sur le plan méthodologique. L’analyse fait ressortir tant l’importance de la modélisation sous ses différentes formes, qu’elle se rattache à la tradition de l’économie néoclassique ou à celle de l’économie néo-institutionnelle, que des travaux empiriques s’inscrivant dans le prolongement de cette modélisation. Sur le plan épistémologique, la recherche en finance d’entreprise se…

Empirical Study on the Relationship between the Cross-Correlation among Stocks and the Stocks' Volatility Clustering

2013

In this paper we discuss univariate and multivariate statistical properties of volatility with the aim of understanding how these two aspects are interrelated. Specifically, we focus on the relationship between the cross-correlation among stock's volatilities and the volatility clustering. Volatility clustering is related to the memory property of the volatility time-series and therefore to its predictability. Our results show that there exists a relationship between the level of predictability of any volatility time-series and the amount of its inter-dependence with other assets. In all considered cases, the more the asset is linked to other assets, the more its volatility keeps memory of …

Subjective financial situation and financial capability of young adults in Finland

2018

A key developmental task in young adulthood is acquiring financial capability (Serido, Shim, & Tang, 2013), meaning competent financial management skills and the responsibilities that these involve. This study extends previous research on the theoretical model of the development of financial capability, including financial confidence (or financial self-efficacy) and financial behavior as factors contributing to subjective and financial well-being. It is part of the Finnish Educational Transitions Studies (FinEdu) longitudinal research project. Participants were 418 young adults aged 24–25 at Time 1 and 26–27 at Time 2. Path and mediation models and Structural Equation Modeling followin…

Peak flow measurement in the Arno River by means of un steady-state water level data analysis

2008

Mechanics of invagination and folding: Hybridized instabilities when one soft tissue grows on another

2015

We address the folding induced by differential growth in soft layered solids via an elementary model that consists of a soft growing neo-Hookean elastic layer adhered to a deep elastic substrate. As the layer/substrate modulus ratio is varied from above unity towards zero we find a first transition from supercritical smooth folding followed by cusping of the valleys to direct subcritical cusped folding, then another to supercritical cusped folding. Beyond threshold the high amplitude fold spacing converges to about four layer thicknesses for many modulus ratios. In three dimensions the instability gives rise to a wide variety of morphologies, including almost degenerate zigzag and triple-ju…

Networking on advanced alternative models and analytical tools for risk assessment studies. Workshop - RiskTox

2022

Comunicacions científiques d'experts en seguretat alimentària: estratègies de mitigació, toxicitat de mescles. Scientific communications from food safety experts: mitigation strategies, toxicity of chemical mixtures and biomonitoring.

Mixtures of lecithin with polymerizable derivatives of cholesterol. A monolayer film balance study.

1986

One of the best investigated binary lipid mixtures is the lecithin-cholesterol system. We show here that it is possible to modify the cholesterol in such a way that it can be polymerized without changing its behaviour in mixtures with lecithin. The polymerizable derivatives exhibit a very similar phase diagram in the mixture with dipalmitoyl-phosphatidylcholine as the cholesterol itself. This is demonstrated by filmbalance measurements.

Phylogeny, biogeography and evolution of Triglochin L. (Juncaginaceae) – Morphological diversification is linked to habitat shifts rather than to gen…

2015

A species-level phylogeny is presented for Triglochin, the largest genus of Juncaginaceae (Alismatales) comprising about 30 species of annual and perennial herbs. Triglochin has an almost cosmopolitan distribution with Australia as centre of species diversity. Trans-Atlantic and trans-African disjunctions exist in the genus. Phylogenetic analyses were conducted based on molecular data obtained from nuclear (ITS, internal transcribed spacer) and chloroplast sequence data (psbA-trnH spacer, matK gene). Based on the phylogeny of the group divergence times were estimated and ancestral distribution areas reconstructed. Our data confirm the monophyly of Triglochin and resolve relationships betwee…

Bioaccesibility of Cylindrospermopsin from cooked fish muscle after the application of an in vitro digestion model and its bioavailability.

2017

Humans can be exposed to cyanotoxins through the ingestion of contaminated water, food or beverages. In the present work, the bioaccesibility of Cylindrospermopsin (CYN), one of the most relevant cyanotoxins, was evaluated in a pure CYN solution and cooked CYN-contaminated fish muscles (20 μg/mL). An in vitro digestion model including the salivar, gastric, duodenal and colonic phases was performed, being each fraction analyzed by HPLC-MS-MS to evaluate CYN degradation. Moreover, Caco-2/TC7 cells were exposed to the digested duodenal and colonic phases to elucidate the final bioavailability of CYN in an approximation to the real human exposure scenario. The results revealed that CYN bioacces…