La détection des adénopathies métastatiques est un point fondamental dans le bilan d’extension de la maladie cancéreuse. L’examen tomodensitométrique est en routine plus utilisé que l’IRM. Le ...diagnostic d’adénopathie métastatique est principalement basé sur le critère de taille, avec des performances modestes lorsque la taille des ganglions est dans les limites supérieures de la normale. L’imagerie par résonance magnétique (IRM) de diffusion offre de nouvelles perspectives.
Detecting metastatic pelvic lymph nodes is essential during the survey of a pelvic carcinoma. In routine clinical practice, CT scan is commonly used. However, its accuracy is quite low for small size lymph nodes. Diffusion-weighted imaging could be in the near future an efficient modality.
The P300 component of the event-related potential is a large positive waveform that can be extracted from the ongoing electroencephalogram using a two-stimuli oddball paradigm, and has been ...associated with cognitive information processing (e.g. memory, attention, executive function). This paper reviews the development of the auditory P300 across the lifespan.
A systematic review and meta-analysis on the P300 was performed including 75 studies (n = 2,811). Scopus was searched for studies using healthy subjects and that reported means of P300 latency and amplitude measured at Pz and mean age. These findings were validated in an independent, existing cross-sectional dataset including 1,572 participants from ages 6-87. Curve-fitting procedures were applied to obtain a model of P300 development across the lifespan. In both studies logarithmic Gaussian models fitted the latency and amplitude data best. The P300 latency and amplitude follow a maturational path from childhood to adolescence, resulting in a period that marks a plateau, after which degenerative effects begin. We were able to determine ages that mark a maximum (in P300 amplitude) or trough (in P300 latency) segregating maturational from degenerative stages. We found these points of deflection occurred at different ages.
It is hypothesized that latency and amplitude index different aspects of brain maturation. The P300 latency possibly indexes neural speed or brain efficiency. The P300 amplitude might index neural power or cognitive resources, which increase with maturation.
En France, les vétérinaires praticiens bien qu’exerçant tous la même profession n’exercent pas tous le même métier : on peut opposer notamment les vétérinaires des villes à ceux des campagnes. Pour ...ces derniers, des différences apparaissent aussi selon leur domicile professionnel. En montagne notamment, il existe des contraintes particulières pour l’exercice de la médecine et de la chirurgie des animaux qui sont décrites dans cet article. Ces zones sont victimes d’une intense désertification qui concerne aussi et malheureusement les vétérinaires. En réponse à cette situation, les vétérinaires ont dû s’adapter pour maintenir une offre de service aussi efficace et performante qu’en ville ou qu’en zone de plaine pour les éleveurs et les propriétaires d’animaux de compagnie. Le recrutement de jeunes vétérinaires est devenu essentiel à la survie des entreprises vétérinaires et donc pour le réseau sanitaire. En effet, la veille sanitaire permise par ces structures est très importante en montagne, sans doute plus qu’ailleurs étant donné les risques sanitaires liés à l’élevage dans ces régions. Les éleveurs, devenus très performants ici comme en plaine, exigent les meilleurs soins et conseils de la part de leur vétérinaire traitant. Mais l’implication du vétérinaire de montagne va bien souvent au-delà d’un simple contrat de soin et nécessite de sa part un investissement personnel particulier.
Although research has explained how plant roots mechanically stabilize soils, in this article we explore how root systems create networks of preferential flow and thus influence water pressures in ...soils to trigger landslides. Root systems may alter subsurface flow: Hydrological mechanisms that promote lower pore-water pressures in soils are beneficial to slope stability, whereas those increasing pore pressure are adverse. Preferential flow of water occurs in the following types of root channels: (a) channels formed by dead or decaying roots, (b) channels formed by decayed roots that are newly occupied by living roots, and (c) channels formed around live roots. The architectural analysis of root systems improves our understanding of how roots grow initially, develop, die, and interconnect. Conceptual examples and case studies are presented to illustrate how root architecture and diverse traits (e.g., diameter, length, orientation, topology, sinuosity, decay rate) affect the creation of root channels and thus affect preferential flow.
Rainfall-initiated landslides continue to inflict damages and loss of life throughout the world. Processes and mechanisms revealed from hydrological, geomorphic, geotechnical, pedological, ...geological, hydrochemical, and biological investigations have advanced our understanding of these effects on slope stability; however, the interactions amongst these processes and attributes as they affect the initiation and propagation of landslides are not as well understood. Too often landslide studies are conducted from only one, or at most, two of these perspectives. Moreover, while precipitation and hydrology are recognized as dynamic influences, the earth system and ecological effects are often assumed to be static. We assess the interplay of these processes related to landslides triggered by positive pore water accretion and loss of soil suction. Each of these conditions arguably requires a different view on the processes that cause slope failure and predictive approaches.
This review starts from the perspective of dynamic, adapting earth and ecological systems and discusses how these attributes relate to landslide initiation, mode, location, and timing. Specifically, the role that large- and small-scale preferential flow plays in both contributing to and mitigating instability is elucidated, including effects of bedrock exfiltration. We also examine how and under what conditions these pathways manifest in different soils, lithology, and landforms. The multiple effects of rhizosphere processes on slope stability are discussed, including root reinforcement, evaporation from canopies and litter layers, transpiration, and the role of root structure affecting preferential flow paths.
Rainfall-initiated landslides involve highly dynamic hydrologic, earth surface, and ecological processes that persist over a range of spatial and temporal scales; however, guidance for overcoming these challenges has been elusive. A conceptual framework is presented to shed light on these dynamic and interactive processes that should lend insights into why and when certain slopes fail during storms, while other seemingly similar slopes do not fail. Such advances will benefit landslide hazard assessments and disaster responsiveness protocols.
This report adds a new definition for mild periodontitis that allows for better descriptions of the overall prevalence of periodontitis in populations. In 2007, the Centers for Disease Control and ...Prevention in partnership with the American Academy of Periodontology developed and reported standard case definitions for surveillance of moderate and severe periodontitis based on measurements of probing depth (PD) and clinical attachment loss (AL) at interproximal sites. However, combined cases of moderate and severe periodontitis are insufficient to determine the total prevalence of periodontitis in populations.
The authors proposed a definition for mild periodontitis as ≥ 2 interproximal sites with AL ≥ 3 mm and ≥ 2 interproximal sites with PD ≥ 4 mm (not on the same tooth) or one site with PD ≥ 5 mm . The effect of the proposed definition on the total burden of periodontitis was assessed in a convenience sample of 456 adults ≥ 35 years old and compared with other previously reported definitions for similar categories of periodontitis.
Addition of mild periodontitis increases the total prevalence of periodontitis by ≈31% in this sample when compared with the prevalence of severe and moderate disease.
Total periodontitis using the case definitions in this study should be based on the sum of mild, moderate, and severe periodontitis.
We study the resonance fluorescence spectra of a driven quantum dot placed inside a high-Q semiconductor cavity and interacting with an acoustic phonon bath. The dynamics is calculated using a ...time-convolutionless master equation in the polaron frame. We predict pronounced spectral broadening of the Mollow sidebands through off-resonant cavity emission which, for small cavity-coupling rates, increases quadratically with the Rabi frequency in direct agreement with recent experiments using semiconductor micropillars S. M. Ulrich et al., preceding Letter, Phys. Rev. Lett. 106, 247402 (2011). We also demonstrate that, surprisingly, phonon coupling actually helps resolve signatures of the elusive second rungs of the Jaynes-Cummings ladder states via off-resonant cavity feeding. Both multiphonon and multiphoton effects are shown to play a qualitatively important role on the fluorescence spectra.
Predicting the birth of a spoken word Roy, Brandon C.; Frank, Michael C.; DeCamp, Philip ...
Proceedings of the National Academy of Sciences - PNAS,
10/2015, Letnik:
112, Številka:
41
Journal Article
Recenzirano
Odprti dostop
Children learn words through an accumulation of interactions grounded in context. Although many factors in the learning environment have been shown to contribute to word learning in individual ...studies, no empirical synthesis connects across factors. We introduce a new ultradense corpus of audio and video recordings of a single child’s life that allows us to measure the child’s experience of each word in his vocabulary. This corpus provides the first direct comparison, to our knowledge, between different predictors of the child’s production of individual words. We develop a series of new measures of the distinctiveness of the spatial, temporal, and linguistic contexts in which a word appears, and show that these measures are stronger predictors of learning than frequency of use and that, unlike frequency, they play a consistent role across different syntactic categories. Our findings provide a concrete instantiation of classic ideas about the role of coherent activities in word learning and demonstrate the value of multimodal data in understanding children’s language acquisition.
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