Search results for "value"
showing 10 items of 5321 documents
Rejection odds and rejection ratios: A proposal for statistical practice in testing hypotheses
2016
Much of science is (rightly or wrongly) driven by hypothesis testing. Even in situations where the hypothesis testing paradigm is correct, the common practice of basing inferences solely on p-values has been under intense criticism for over 50 years. We propose, as an alternative, the use of the odds of a correct rejection of the null hypothesis to incorrect rejection. Both pre-experimental versions (involving the power and Type I error) and post-experimental versions (depending on the actual data) are considered. Implementations are provided that range from depending only on the p-value to consideration of full Bayesian analysis. A surprise is that all implementations -- even the full Baye…
Experimental observations of upstream overdeepening
2005
The issue of morphodynamic influence in meandering streams is investigated through a series of laboratory experiments on curved and straight flumes. Both qualitative and quantitative observations confirm the suitability of the recent theoretical developments (Zolezzi & Seminara 2001) that indicate the occurrence of two distinct regimes of morphodynamic influence, depending on the value of the width ratio of the channel β. The threshold value βR separating the upstream from the downstream influence regimes coincides with the resonant value discovered by Blondeaux & Seminara (1985). Indeed it is observed that upstream influence may occur only in relatively wide channels, while narrower stream…
Influencia de los factores de contingencia en el desarrollo del cuadro de mando integral y su asociación con un rendimiento mejor. El caso de las emp…
2016
En este trabajo se analiza la relación entre algunos factores de contingencia, el nivel de uso del cuadro de mando integral (CMI) y el beneficio percibido gracias a su aplicación. El CMI es una herramienta capaz de ofrecer a los responsables de las organizaciones una visión completa de cómo a través de la integración de medidas financieras y no financieras se ejecuta la estrategia. Del análisis realizado sobre la base de los datos obtenidos de las sedes centrales de 61 empresas españolas de productos y servicios se deduce que el grado de formalización y estandarización en las empresas tiene una influencia directa y positiva en el desarrollo del CMI hacia niveles más integradores y orientado…
Trial Methods for Nonlinear Bernoulli Problem
1997
In this article we consider a free boundary problem which is related to formation of waves on a fluid surface (for example the ship waves). We study the possibility to construct ‘trial’ methods where one solves a sequence of standard flow problems formulated in different geometries that converge to the final free boundary. Furthermore, we use the shape optimization techniques to analyse the convergence of the fixed point iteration near a fixed point. For stream function case we conclude that the fast convergence can be obtained by using non-standard boundary conditions and we present numerical results to confirm the analysis.
Equations-of-motion approach to the spin-12Ising model on the Bethe lattice
2006
We exactly solve the ferromagnetic spin- 1/2 Ising model on the Bethe lattice in the presence of an external magnetic field by means of the equations of motion method within the Green's function formalism. In particular, such an approach is applied to an isomorphic model of localized Fermi particles interacting via an intersite Coulomb interaction. A complete set of eigenoperators is found together with the corresponding eigenvalues. The Green's functions and the correlation functions are written in terms of a finite set of parameters to be self-consistently determined. A procedure is developed that allows us to exactly fix the unknown parameters in the case of a Bethe lattice with any coor…
On Big Data: How should we make sense of them?
2020
The topic of Big Data is today extensively discussed, not only on the technical ground. This also depends on the fact that Big Data are frequently presented as allowing an epistemological paradigm shift in scientific research, which would be able to supersede the traditional hypothesis-driven method. In this piece, I critically scrutinize two key claims that are usually associated with this approach, namely, the fact that data speak for themselves, deflating the role of theories and models, and the primacy of correlation over causation. In so doing, I will also refer to a recent case history of data mining projects in the field of biomedicine, i.e. EXPOsOMICS. My intention is both to acknow…
Phase separation versus wetting: A mean field theory for symmetrical polymer mixtures confined between selectively attractive walls
1996
Partially compatible symmetrical (N A # N B = N) binary mixtures of linear flexible polymers (A, B) are considered in the presence of two equivalent walls a distance D apart, assuming that both walls preferentially adsorb the same component. Using a Flory-Huggins type mean field approach analogous to previous work studying wetting phenomena in the semi-infinite version of this model, where D → ∞, it is shown that a single phase transition occurs in this thin film geometry, namely a phase separation between an A-rich and a B-rich phase (both phases include the bulk of the film). The coexistence curve is shifted to smaller values of the inverse Flory-Huggins parameter x -1 with decreasing D, …
Combined heterologies for monoclonal antibody-based immunoanalysis of fluxapyroxad
2018
Nowadays, instrumental methodologies and rapid bioanalytical techniques complement each other for the analysis of toxic chemical compounds. Fluxapyroxad was commercialized a few years ago as a fungicide and today it is being used worldwide to control a variety of pests. In the present study, the development of monoclonal antibody-based immunochemical methods for the analysis of this chemical in food samples was evaluated for the first time. Novel haptens were synthesized and protein bioconjugates were prepared. High-affinity and specific monoclonal antibodies to fluxapyroxad were generated from two haptens with alternative linker tethering sites. Haptens with linker site heterology and a st…
The value of open-source clinical science in pandemic response
2021
International audience
Synthesis of calcium carbonate biological materials: how many proteins are needed?
2013
In Nature, calcium carbonate biomineralizations are the most abundant mineralized structures of biological origin. Because many exhibit remarkable characteristics, several attempts have been made to use them as substitution materials for bone reconstruction or as models for generating biomimetic composites that exhibit tailored properties. CaCO3biomineralizations contain small amounts of amalgamate of proteins and polysaccharides that are secreted during the calcification process. They contribute to control the morphology of the crystallites and to spatially organize them in well-defined microstructures. These macromolecules, collectively defined as the skeletal matrix, have been the focus …