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Various Layers (various + layer)

Distribution by Scientific Domains
Life Sciences25%
Engineering25%

Selected Abstracts

Impact of S100B on local field potential patterns in anesthetized and kainic acid-induced seizure conditions in vivo

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2007
Seiichi Sakatani
Abstract S100B is a calcium-binding protein predominantly expressed in astrocytes. Previous studies using gene-manipulated animals have suggested that the protein has a role in synaptic plasticity and learning. In order to assess the physiological roles of the protein in active neural circuitry, we recorded spontaneous neural activities from various layers of the neocortex and hippocampus in urethane-anesthetized S100B knockout (KO) and wildtype (WT) control mice. Typical local field oscillation patterns including the slow (0.5,2 Hz) oscillations in the neocortex, theta (3,8 Hz) and sharp wave-associated ripple (120,180 Hz) oscillations in the hippocampus were observed in both genotypes. Comparisons of the frequency, power and peak amplitude have shown that these oscillatory patterns were virtually indistinguishable between WT and KO. When seizure was induced by intraperitoneal injection of kainic acid, a difference between WT and KO appeared in the CA1 radiatum local field potential pattern, where seizure events were characterized by prominent appearance of hyper-synchronous gamma band (30,80 Hz) activity. Although both genotypes developed seizures within 40 min, the gamma amplitude was significantly smaller during the development of seizures in KO mice. Our results suggest that deficiency of S100B does not have a profound impact on spontaneous neural activity in normal conditions. However, when neural activity was sufficiently raised, activation of S100B-related pathways may take effect, resulting in modulation of neural activities. [source]

Desmocollin 1 expression and desmosomal remodeling during terminal differentiation of human anagen hair follicle: an electron microscopic study

EXPERIMENTAL DERMATOLOGY, Issue 5 2004
Elena Donetti
Abstract:, The terminal differentiation (TD) program of keratinocytes of the human hair follicle (HF) occurs with specific temporal and spatial features in the various layers of the inner root sheath (IRS) and in the innermost layer of the outer root sheath (companion layer). This process is characterized by complex nuclear and cytoplasmic morphological changes, accompanied by profound modifications in intercellular junctions. As no correlation exists between the structure and the molecular composition of desmosomes during TD of the IRS/companion unit, the aim of our study was to investigate by transmission electron microscopy the remodeling of desmosomes in keratinizing cells of these compartments. By immunogold post embedding technique, we studied in anagen HFs the modulation of the synthesis of desmocollin 1 (Dsc1), a transmembrane glycoprotein specifically synthesized in the IRS and in the companion layer. Dsc1 immunoreactivity was actually confined to these compartments and tended to increase just before the level of TD, particularly in the Henle's layer and in the IRS cuticle. In Huxley's layer, the immunolabeling was patchy and in the companion layer Dsc1 synthesis was detected above the level of keratinization of Huxley's layer. In the whole IRS, concomitantly with TD, there was an abrupt and almost complete disappearance of Dsc1 synthesis. An asymmetric distribution of Dsc1 was noticed (i) between cells at different stages of differentiation and (ii) between cells belonging to layers with different spatial/temporal features of TD. Our results show that the ultrastructural modifications of desmosomes during TD of HF are paralleled by the modulation of the synthesis of desmocollin 1. [source]

Multilayered Core/Shell Nanowires Displaying Two Distinct Magnetic Switching Events,

ADVANCED MATERIALS, Issue 22 2010
Yuen Tung Chong
Atomic layer deposition (ALD) and electrodeposition are combined with a porous template to create ordered arrays of nanowires in which a nickel core and an iron oxide shell are separated by a silica spacer layer. The switching of each magnetic component is distinct and occurs at a field that depends on the tunable thicknesses of the various layers. [source]

Exploration of communication models in the design of distributed embedded systems

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 3 2007
Kazutaka Kobayashi Non-member
Abstract Distributed embedded systems involve communication in various layers, and therefore their design is more difficult than of single embedded systems. This paper presents how communication exploration can be done in a design process of distributed embedded systems using an example of event-triggered and time-triggered communication. A design process begins from abstract specification without assuming any communication category, then explores the categories in a stepwise manner, followed by physical implementation synthesis. This encourages stepwise decision making, component and framework reuse, and early stage verification. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]

Layered view of QoS issues in IP-based mobile wireless networks

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2006
Haowei Bai
Abstract With the convergence of wireless communication and IP-based networking technologies, future IP-based wireless networks are expected to support real-time multimedia. IP services over wireless networks (e.g. wireless access to Internet) enhance the mobility and flexibility of traditional IP network users. Wireless networks extend the current IP service infrastructure to a mix of transmission media, bandwidth, costs, coverage, and service agreements, requiring enhancements to the IP protocol layers in wireless networks. Furthermore, QoS provisioning is required at various layers of the IP protocol stack to guarantee different types of service requests, giving rise to issues related to cross-layer design methodology. This paper reviews issues and prevailing solutions to performance enhancements and QoS provisioning for IP services over mobile wireless networks from a layered view. Copyright © 2006 John Wiley & Sons, Ltd. [source]

European Regional Structural Funds: How Large is the Influence of Politics on the Allocation Process?

JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 3 2010
FLORENCE BOUVET
The allocation of Structural Funds, the most important component of the European Union (EU) cohesion policy, is subject to intense bargaining between national governments and across layers of political governance. Using Structural Funds data for each cohesion objective over 1989,99, we examine which variables, economic and political, determine the actual funds allocation. We test our hypotheses with a Tobit model that accounts for the two-stage allocation process and our limited dependent variables. Our results indicate that economic criteria are not the only determinants of funds allocation. Indeed, we find that the political situation within a country and a region and the relations between various layers of governance influence the allocation process. This article is also the only study to measure the impact of additional funds provided by the region or the country itself, and to differentiate the analysis by cohesion objective. [source]

Use of the ecological information system SynBioSys for the analysis of large datasets

JOURNAL OF VEGETATION SCIENCE, Issue 4 2007
Joop H.J. Schaminée
Abstract The rapid developments in computer techniques and the availability of large datasets open new perspectives for vegetation analysis aiming at better understanding of the ecology and functioning of ecosystems and underlying mechanisms. Information systems prove to be helpful tools in this new field. Such information systems may integrate different biological levels, viz. species, community and landscape. They incorporate a GIS platform for the visualization of the various layers of information, enabling the analysis of patterns and processes which relate the individual levels. An example of a newly developed information system is SynBioSys Europe, an initiative of the European Vegetation Survey (EVS). For the individual levels of the system, specific sources are available, notably national and regional Turboveg databases for the community level and data from the recently published European Map of Natural Vegetation for the landscape level. The structure of the system and its underlying databases allow user-defined queries. With regard to its application, such information systems may play a vital role in European nature planning, such as the implementation the EU-program Natura 2000. To illustrate the scope and perspectives of the program, some examples from The Netherlands are presented. They are dealing with long-term changes in grassland ecosystems, including shifts in distribution, floristic composition, and ecological indicator values. [source]

Study of Epidermis Development in Sturgeon (Acipenser persicus) Larvae

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2010
Z. Saadatfar
With 10 figures Summary Fish skin is essential for survival, maintenance of body shape, and protection against the shock and infection. During week 1 of sturgeon larval development, the epidermis is thin and not differentiated in various layers yet, but by week 4,6 the thickness increases and various layers appear, depending upon the region of the body. Mucous cells differentiate early in development on the surface of epithelium and contain acid and neutral mucopolysaccharides. Primordial sensory buds are visible within the epithelia of the skin of the head in week 1 larvae, and become numerous during later larval development. Club cells are specialized epidermal cells that have an immune function and appear in the middle layer of the head and trunk epidermis on week 4. [source]