Search results for "structures"
showing 10 items of 4815 documents
Extraembryonic tissues as a source of stem cells.
2009
The placenta is a fetal organ, responsible for nutrient and gas exchange between the mother and fetus throughout pregnancy [1]. At day 6.5, gastrulation begins in the posterior region of the embryo...
Effectiveness of nonlinear optical loop mirrors in chirped fiber gratings compensated dispersion-managed transmission systems
2005
International audience; We show that nonlinear optical loop mirrors can dramatically suppress the side peaks induced by the group delay ripples in chirped fiber gratings compensated dispersion-managed systems and significantly improve the system performance.
Dissipative solitons for mode-locked lasers
2012
International audience; Dissipative solitons are localized formations of an electromagnetic field that are balanced through an energy exchange with the environment in presence of nonlinearity, dispersion and/or diffraction. Their growing use in the area of passively mode-locked lasers is remarkable: the concept of a dissipative soliton provides an excellent framework for understanding complex pulse dynamics and stimulates innovative cavity designs. Reciprocally, the field of mode-locked lasers serves as an ideal playground for testing the concept of dissipative solitons and revealing their unusual dynamics. This Review provides basic definitions of dissipative solitons, summarizes their imp…
Do laboratory exposures represent field exposures? Effects of sediments contaminated by wood industry on yolk-sac fry of rainbow trout (Oncorhynchus …
2015
Purpose. Risk assessment of contaminated sediments is routinely based on laboratory exposures. The purpose of this work was to study if sediments contaminated by the chemical wood industry cause developmental defects in fish fry and how well a laboratory exposure correlates with a field exposure. Materials and methods. Newly hatched yolk-sac fry of rainbow trout (Oncorhynchus mykiss) were exposed in the laboratory and in situ. In the laboratory, the fish were placed in contact with either clean or contaminated sediment in aquaria. In the field, half of the fish were placed in contact with the lake sediment and the other half were similarly caged 2 m above it, to discern the effects of the s…
ESB: Ext2 Split Block Device
2012
Solid State Disks (SSDs) start to replace rotating media (hard disks, HDD) in many areas, but are still not as cost efficient concerning capacity to completely replace them. One approach to use their superior performance properties is to use them as a cache for magnetic disks to speed up overall storage operations. In this paper, we present and evaluate a file system level optimization based on ext2. We split metadata and data and store the metadata on a SDD while the data remains on a common HDD. We evaluate our system with filebench under a file server, web server, and web proxy scenario and compare the results with flashcache. We find that many of the scenarios do not contain enough meta…
Numerical modelling of low velocity multi-impact test on different stacking sequences
2019
The use of composite materials in the industrial field has been growing significantly for many years. This increase is explained by the fact that the industry, especially aeronautics which was pioneering in this field, is interested in the lightening of structures in order to be able to take up the new environmental challenges. Whether in the aeronautical field or in the land transport sector, structural elements may undergo multi-impactsor impact. Even at low velocitypose a threat to the integrity of the material and the structure itself. The objective of this work is to propose a numerical model to determine the damage within a composite structure subjected to low energy multi-impact. The…
Finite elements for nonlinear free vibrations analysis of smart laminates subjected to in-plane loadings
2015
Advanced composites, able to provide multi-functional capabilities besides the traditional structural functions, has been gaining attention in many technological fields. This inherent coupling of different physical fields can be exploited in transducer applications, structural health monitoring, vibration control, energy harvesting and other applications. Magneto-electro-elastic (MEE) composite materials are attracting increasing consideration as they couple mechanical, electrical and magnetic fields and this makes them particularly suitable for smart applications. Generally, single-phase materials exhibit either piezoelectric or piezomagnetic behavior and no direct magneto-electric couplin…
Nanog Regulates Primordial Germ Cell Migration Through Cxcr4b
2010
Abstract Gonadal development in vertebrates depends on the early determination of primordial germ cells (PGCs) and their correct migration to the sites where the gonads develop. Several genes have been implicated in PGC specification and migration in vertebrates. Additionally, some of the genes associated with pluripotency, such as Oct4 and Nanog, are expressed in PGCs and gonads, suggesting a role for these genes in maintaining pluripotency of the germ lineage, which may be considered the only cell type that perpetually maintains stemness properties. Here, we report that medaka Nanog (Ol-Nanog) is expressed in the developing PGCs. Depletion of Ol-Nanog protein causes aberrant migration of …
Nanog Regulates Proliferation During Early Fish Development
2009
Abstract Nanog is involved in controlling pluripotency and differentiation of stem cells in vitro. However, its function in vivo has been studied only in mouse embryos and various reports suggest that Nanog may not be required for the regulation of differentiation. To better understand endogenous Nanog function, more animal models should be introduced to complement the murine model. Here, we have identified the homolog of the mammalian Nanog gene in teleost fish and describe the endogenous expression of Ol-Nanog mRNA and protein during medaka (Oryzias latipes) embryonic development and in the adult gonads. Using medaka fish as a vertebrate model to study Nanog function, we demonstrate that …
Heavy ion SEE studies on 4-Gbit NAND-Flash memories
2007
Heavy ion SEE studies on three 4-Gbit NAND-flash memory types were performed at the RADEF facility at the University of Jyvaskyla, Finland with particular emphasis on SEFI differentiation. An error classification for complex memory devices is introduced, and respective cross sections are reported.