Seismological models from Apollo missions provided the first records of the Moon inner structure with a decrease in seismic wave velocities at the core-mantle boundary. The resolution of these records prevents a strict detection of a putative lunar solid inner core and the impact of the lunar mantle overturn in the lowest part of the Moon is still discussed. Here we combine geophysical and geodesic constraints from Monte Carlo exploration and thermodynamical simulations for different Moon internal structures to show that only models with a low viscosity zone enriched in ilmenite and an inner core present densities deduced from thermodynamic constraints compatible with densities deduced from tidal deformations.
View Article and Find Full Text PDFTo infer eigenvalues of the infinite-dimensional Koopman operator, we study the leading eigenvalues of the autocovariance matrix associated with a given observable of a dynamical system. For any observable f for which all the time-delayed autocovariance exist, we construct a Hilbert space H_{f} and a Koopman-like operator K that acts on H_{f}. We prove that the leading eigenvalues of the autocovariance matrix has one-to-one correspondence with the energy of f that is represented by the eigenvectors of K.
View Article and Find Full Text PDFThere is no satisfactory model to explain the mean velocity profile of the whole turbulent layer in canonical wall-bounded flows. In this paper, a mean velocity profile expression is proposed for wall-bounded turbulent flows based on a recently proposed stochastic representation of fluid flows dynamics. This original approach, called modeling under location uncertainty, introduces in a rigorous way a subgrid term generalizing the eddy-viscosity assumption and an eddy-induced advection term resulting from turbulence inhomogeneity.
View Article and Find Full Text PDFThe damage to liver mitochondria is universally observed in both humans and animal models after excessive alcohol consumption. Acute alcohol treatment has been shown to stimulate calcium (Ca) release from internal stores in hepatocytes. The resultant increase in cytosolic Ca is expected to be accumulated by neighboring mitochondria, which could potentially lead to mitochondrial Ca overload and injury.
View Article and Find Full Text PDFCancer etiology is influenced by alterations in protein synthesis that are not fully understood. In this study, we took a novel approach to investigate the role of the eukaryotic translation initiation factor eIF5A in human cervical cancers, where it is widely overexpressed. eIF5A contains the distinctive amino acid hypusine, which is formed by a posttranslational modification event requiring deoxyhypusine hydroxylase (DOHH), an enzyme that can be inhibited by the drugs ciclopirox and deferiprone.
View Article and Find Full Text PDFBased on physical laws describing the multiscale structure of turbulent flows, this paper proposes a regularizer for fluid motion estimation from an image sequence. Regularization is achieved by imposing some scale invariance property between histograms of motion increments computed at different scales. By reformulating this problem from a Bayesian perspective, an algorithm is proposed to jointly estimate motion, regularization hyperparameters, and to select the most likely physical prior among a set of models.
View Article and Find Full Text PDFA recurrent paradigm in calcium signaling is the coordination of the target response of the calcium signal with activation of metabolic energy production to support that response. This occurs in many tissues, including cardiac and skeletal muscle where contractile activity and ATP production are coordinately regulated by the frequency and amplitude of calcium transients, endocrine and exocrine cells that use calcium to drive the secretory process, and hepatocytes where the downstream targets of calcium include both catabolic and anabolic processes. The primary mechanism by which calcium enhances the capacity for energy production is through calcium-dependent stimulation of mitochondrial oxidative metabolism, achieved by increasing NADH production and respiratory chain flux.
View Article and Find Full Text PDFIEEE Trans Image Process
April 2012
Selecting optimal models and hyperparameters is crucial for accurate optical-flow estimation. This paper provides a solution to the problem in a generic Bayesian framework. The method is based on a conditional model linking the image intensity function, the unknown velocity field, hyperparameters, and the prior and likelihood motion models.
View Article and Find Full Text PDFIEEE Trans Image Process
February 2012
In this paper, a stochastic formulation of the brightness consistency used in many computer vision problems involving dynamic scenes (for instance, motion estimation or point tracking) is proposed. Usually, this model, which assumes that the luminance of a point is constant along its trajectory, is expressed in a differential form through the total derivative of the luminance function. This differential equation linearly links the point velocity to the spatial and temporal gradients of the luminance function.
View Article and Find Full Text PDFIn contrast to normal prostatic cells, the transcriptional repressor Inducible cAMP Early Repressor (ICER) is undetected in the nuclei of prostate cancer cells. The molecular mechanisms for ICER abnormal expression in prostate cancer cells remained largely unknown. In this report data is presented demonstrating that ICER is phosphorylated by the mitotic kinase cdk1.
View Article and Find Full Text PDFAphasia is common in elderly patients in the context of vascular or neurodegenerative disorders. In some cases, aphasia is an isolated symptom, occurring suddenly after a stroke, or developing progressively as a primary progressive aphasia. The diagnosis and treatment are then very similar in older and younger patients.
View Article and Find Full Text PDFIEEE Trans Pattern Anal Mach Intell
July 2009
In this paper, we present a method for the temporal tracking of fluid flow velocity fields. The technique we propose is formalized within a sequential Bayesian filtering framework. The filtering model combines an Itô diffusion process coming from a stochastic formulation of the vorticity-velocity form of the Navier-Stokes equation and discrete measurements extracted from the image sequence.
View Article and Find Full Text PDFSemantic dementia (SD) is a syndrome of progressive loss of semantic knowledge for objects and people. International criteria propose that SD be included in the frontotemporal lobar degeneration syndromes, with progressive non-fluent aphasia and frontotemporal dementia (FTD). However, several related syndromes have been defined that clinically and conceptually share both similarities and differences with SD: fluent progressive aphasia, progressive prosopagnosia, temporal variant of FTD.
View Article and Find Full Text PDFIEEE Trans Image Process
June 2010
In this paper, we address the issue of recovering and segmenting the apparent velocity field in sequences of images. As for motion estimation, we minimize an objective function involving two robust terms. The first one cautiously captures the optical flow constraint, while the second (a priori) term incorporates a discontinuity-preserving smoothness constraint.
View Article and Find Full Text PDFIEEE Trans Image Process
May 2010
We present a method for fully automatic three-dimensional (3D) reconstruction from a pair of weakly calibrated images in order to deal with the modeling of complex rigid scenes. A two-dimensional (2D) triangular mesh model of the scene is calculated using a two-step algorithm mixing sparse matching and dense motion estimation approaches. The 2D mesh is iteratively refined to fit any arbitrary 3D surface.
View Article and Find Full Text PDFThis paper presents a novel non-rigid registration method. The main contribution of the method is the modeling of the vorticity (respectively divergence) of the deformation field using vortex (respectively sink and source) particles. Two parameters are associated with a particle: the vorticity (or divergence) strength and the influence domain.
View Article and Find Full Text PDFCyclin D2 (Ccnd2) is an essential gene for folliculogenesis, as null mutation in mice impairs granulosa cell proliferation in response to FSH. Ccnd2 mRNA is induced during the estrus cycle by FSH and is rapidly inhibited by LH. Yet, the responsive elements and transcription factors accounting for the gene expression of cyclin D2 in the ovary have not been fully characterized.
View Article and Find Full Text PDFRisk of dementia increases after stroke, and poststroke dementia (PSD) is an important cause of disability in the elderly. The prevalence rates of PSD vary from 12.2% to 31.
View Article and Find Full Text PDFIEEE Trans Image Process
January 2005
In this paper, a new conditional formulation of classical filtering methods is proposed. This formulation is dedicated to image sequence-based tracking. These conditional filters allow solving systems whose measurements and state equation are estimated from the image data.
View Article and Find Full Text PDFAnn Dermatol Venereol
March 2003
Background: Prostatic adenocarcinoma is exceptionally associated with cutaneous lesions. We describe a patient with cutaneous lymphangitis and paraneoplastic ichtyosis related to prostatic cancer.
Case Report: A 92 year-old man had been treated for five years for a prostatic carcinoma.
Background: Inducible cAMP early repressor (ICER) is an important mediator of cAMP antiproliferative activity that acts as a putative tumor suppressor gene product. ICER is a transcriptional repressor that negatively regulates cAMP-mediated gene expression. Here, we report the effect of ectopically increasing the expression of ICER on in vitro and in vivo proliferation of the highly metastatic and androgen-insensitive AT6.
View Article and Find Full Text PDFIncreases in both Ca(2+) and nitric oxide levels are vital for a variety of cellular processes; however, the interaction between these two crucial messengers is not fully understood. Here, we demonstrate that expression of inducible nitric-oxide synthase in hepatocytes, in response to inflammatory mediators, dramatically attenuates Ca(2+) signaling by the inositol 1,4,5-trisphosphate-forming hormone, vasopressin. The inhibitory effects of induction were reversed by nitric oxide inhibitors and mimicked by prolonged cyclic GMP elevation.
View Article and Find Full Text PDFInducible cAMP early repressor (ICER) has been shown to be an important mediator of cAMP antiproliferative activity. In this report, it was found that cAMP retards LNCaP cell growth; in contrast, cAMP inhibits the growth of PC-3 and DU-145 cells. ICER protein levels were markedly reduced in prostate cancer epithelial cells and undetectable and uninducible by cAMP in LNCaP and DU 145 cells.
View Article and Find Full Text PDFIEEE Trans Med Imaging
May 2001
A new method for medical image registration is formulated as a minimization problem involving robust estimators. We propose an efficient hierarchical optimization framework which is both multiresolution and multigrid. An anatomical segmentation of the cortex is introduced in the adaptive partitioning of the volume on which the multigrid minimization is based.
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