oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 3 )

2019 ( 360 )

2018 ( 541 )

2017 ( 533 )

Custom range...

Search Results: 1 - 10 of 449824 matches for " J.-C. Dauvin "
All listed articles are free for downloading (OA Articles)
Page 1 /449824
Display every page Item
Statistical analysis of polychaete population density: dynamics of dominant species and scaling properties in relative abundance fluctuations
B. Quiroz-Martinez, F. G. Schmitt,J.-C. Dauvin
Nonlinear Processes in Geophysics (NPG) , 2012,
Abstract: We consider here the dynamics of two polychaete populations based on a 20 yr temporal benthic survey of two muddy fine sand communities in the Bay of Morlaix, Western English Channel. These populations display high temporal variability, which is analyzed here using scaling approaches. We find that population densities have heavy tailed probability density functions. We analyze the dynamics of relative species abundance in two different communities of polychaetes by estimating in a novel way a "mean square drift" coefficient which characterizes their fluctuations in relative abundance over time. We show the usefulness of using new tools to approach and model such highly variable population dynamics in marine ecosystems.
ACTA MATHEMATICA UNIVERSITATIS COMENIANAE
J.-C. Puchta
ACTA MATHEMATICA UNIVERSITATIS COMENIANAE , 2001,
Abstract: . We improve bounds of A. Fujii concerning the distribution of zeros of Riemann's $\zeta$-function with respect to logarithms of prime numbers.
Organic synthesis applied to space sciences
Guillemin J.-C.
EPJ Web of Conferences , 2012, DOI: 10.1051/epjconf/20111806004
Abstract: About 160 molecules have been detected in the interstellar medium, the comae and the atmospheres of planets. The presence of these compounds leads to imagine a chemistry of these media to explain the formation of these species and to predict the possible presence of other ones. Many of them have never been synthesized or isolated in labs and their preparation can be challenging, up to necessitate news reactions or special equipments.
Le classement automatique des sceaux: solutions manuelles et problèmes d'informatique. Essai méthodologique appliqué à l'Orient Latin
J.-C. POUTIERS
Byzantina Symmeikta , 1981,
Abstract: No abstract
Selection of borehole temperature depth profiles for regional climate reconstructions
C. Chouinard ,J.-C. Mareschal
Climate of the Past (CP) & Discussions (CPD) , 2007,
Abstract: Borehole temperature depth profiles are commonly used to infer time variations in the ground surface temperature on centennial time scales. We compare different procedures to obtain a regional ground surface temperature history (GSTH) from an ensemble of borehole temperature depth profiles. We address in particular the question of selecting profiles that are not contaminated by non climatic surface perturbations and we compare the joint inversion of all the profiles with the average of individual inversions. Very few profiles of the Canadian data set meet the selection criteria (e.g. only 13 out of 73 profiles in Manitoba and Saskatchewan were retained). We show that the resolution and the stability of the inversion of selected profiles are much improved over those for a complete data set. When profiles have been selected, the average GSTH of individual inversions and the GSTH of the joint inversion are almost identical. This is not observed when the entire data set is inverted: the average of individual inversions is different from the joint inversion. We also show that the joint inversion of very noisy data sets does not improve the resolution but, on the contrary, causes strong instabilities in the inversion. When the profiles that are affected by noise can not be eliminated, averaging of the individual inversions yields the most stable result, but with very poor resolution.
Selection of borehole temperature depth profiles for regional climate reconstructions
C. Chouinard,J.-C. Mareschal
Climate of the Past Discussions , 2007,
Abstract: Borehole temperature depth profiles are commonly used to infer time variations in the ground surface temperature on centennial time scales. We compare different procedures to obtain a regional ground surface temperature history (GSTH) from an ensemble of borehole temperature depth profiles. We address in particular the question of selecting profiles that are not contaminated by non climatic surface perturbations and we compare the joint inversion of all the profiles with the average of individual inversions. We show that the resolution and the stability of the inversion of selected profiles are much improved over those for a complete data set. When profiles have been selected, the average GSTH of individual inversions and the GSTH of the joint inversion are almost identical. This is not observed when the entire data set is inverted: the average of individual inversions is different from the joint inversion. We also show that the joint inversion of very noisy data sets does not improve the resolution but, on the contrary, causes strong instabilities in the inversion. When the profiles that are affected by noise can not be eliminated, averaging of the individual inversions yields the most stable result, but with very poor resolution.
Wavelet ridge diagnosis of time-varying elliptical signals with application to an oceanic eddy
J. M. Lilly,J.-C. Gascard
Nonlinear Processes in Geophysics (NPG) , 2006,
Abstract: A method for diagnosing the physical properties of a time-varying ellipse is presented. This essentially involves extending the notion of instantaneous frequency to the bivariate case. New complications, and possibilities, arise from the fact that there are several meaningful forms in which a time-varying ellipse may be represented. A perturbation analysis valid for the near-circular case clarifies these issues. Diagnosis of the ellipse properties may then be performed using wavelet ridge analysis, and slowly-varying changes in the ellipse structure may be decoupled from the fast orbital motion through the use of elliptic integrals, without the need for additional explicit filtering. The theory is presented in parallel with an application to a position time series of a drifting subsurface float trapped in an oceanic eddy.
Logarithmic Adaptive Neighborhood Image Processing (LANIP): Introduction, Connections to Human Brightness Perception, and Application Issues
J.-C. Pinoli,J. Debayle
EURASIP Journal on Advances in Signal Processing , 2007, DOI: 10.1155/2007/36105
Abstract: A new framework for image representation, processing, and analysis is introduced and exposed through practical applications. The proposed approach is called logarithmic adaptive neighborhood image processing (LANIP) since it is based on the logarithmic image processing (LIP) and on the general adaptive neighborhood image processing (GANIP) approaches, that allow several intensity and spatial properties of the human brightness perception to be mathematically modeled and operationalized, and computationally implemented. The LANIP approach is mathematically, computationally, and practically relevant and is particularly connected to several human visual laws and characteristics such as: intensity range inversion, saturation characteristic, Weber’s and Fechner’s laws, psychophysical contrast, spatial adaptivity, multiscale adaptivity, morphological symmetry property. The LANIP approach is finally exposed in several areas: image multiscale decomposition, image restoration, image segmentation, and image enhancement, through biomedical materials and visual imaging applications.
Nephrotic Syndrome in Children: From Bench to Treatment
J.-C. Davin,N. W. Rutjes
International Journal of Nephrology , 2011, DOI: 10.4061/2011/372304
Abstract: Idiopathic nephrotic syndrome (INS) is the most frequent form of NS in children. INS is defined by the association of the clinical features of NS with renal biopsy findings of minimal changes, focal segmental glomerulosclerosis (FSGS), or mesangial proliferation (MP) on light microscopy and effacement of foot processes on electron microscopy. Actually the podocyte has become the favourite candidate for constituting the main part of the glomerular filtration barrier. Most cases are steroid sensitive (SSINS). Fifty percents of the latter recur frequently and necessitate a prevention of relapses by nonsteroid drugs. On the contrary to SSINS, steroid resistant nephrotic syndrome (SRINS) leads often to end-stage renal failure. Thirty to forty percents of the latter are associated with mutations of genes coding for podocyte proteins. The rest is due to one or several different circulating factors. New strategies are in development to antagonize the effect of the latter. 1. Introduction Nephrotic syndrome (NS) is an illness consisting in leakage of proteins in urine, resulting in life threatening conditions due hypovolemia, hypercoagulation, and infection. The annual incidence of NS in children in the USA and in Europe has been estimated to be 1–7 per 100,000 children, with a cumulative prevalence of 16 per 100,000 children [1–3]. Nephrotic syndrome in children can be classified according to 3 three groups [3]: secondary, congenital and infantile, and idiopathic. Secondary nephrotic syndrome is defined as nephrotic syndrome associated with well-defined diseases that are inflammatory (e.g., lupus nephritis, acute postinfectious glomerulonephritis, IgA nephropathy, Henoch-Sch?nlein purpura, etc.) or not (e.g., Alport syndrome, focal sclerosis due to reduced nephronic mass resulting from renal scarring, etc.). Congenital and infantile NSs are occurring before the age of one year and are mostly associated with infections (e.g., syphilis, toxoplasmosis, etc.) or with mutations of genes coding for podocytes proteins and are steroid resistant. Idiopathic nephrotic syndrome (INS) is the most frequent form of NS in children representing more than 90 percent of cases between 1 and 10 years of age and 50 percent after 10 years of age [1]. INS is defined by the association of the clinical features of NS with renal biopsy findings of diffuse foot process effacement on electron microscopy and minimal changes (called minimal change disease (MCD)), focal segmental glomerulosclerosis (FSGS), or diffuse mesangial proliferation (DMP) on light microscopy [4]. Most patients have
Formation Enthalpy of AlNi3-Based Alloys with Iron Additions by Calorimetric Solution and Direct Reaction Methods
K. Rzyman , J.-C. Gachon
Archives of Metallurgy and Materials , 2010, DOI: 10.2478/v10172-010-0004-6
Abstract: The enthalpies of formation of AlNi3-based alloys with iron additions were determined both by solution and direct reaction calorimetry. The results were analyzed in order to determine phase boundaries in the pseudo-binary AlNi3-FeNi3 system.
Page 1 /449824
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.