Photonic Switching Techniques and Architecture for Next Generation Optical Networks

Currently, the growth in capacity demand is still increasing by the emergence of a large number of applications that dramatically increase bandwidth demand and generate a large number of resource requirements in the network. Since the emerging applications require increased bandwidth capacity, the vision of using optical technology in the communication channel, signal processing, and switching fabric is very promising. This article presents an overview of optical switching techniques currently under research investigations. It introduces enabling technologies that have been recently researched and then presents some newly proposed architectures. It describes the SKYLIGHT switch that has been recently developed by the author. The architecture design of the switch is based on a optical code division multiple access (OCDMA) technique. Performance evaluation of the switch fabric based on the analytical evaluation of the code and numerical simulations of the optical components used to implement the system is presented.     

Conditional visuo-motor learning in primates: a key role for the basal ganglia

Sensory guidance of behavior often involves standard visuo-motor mapping of body movements onto objects and spatial locations. For example, looking at and reaching to grasp a glass of wine requires the mapping of the eyes and hand to the location of the glass in space, as well as the formation of a hand configuration appropriate to the shape of the glass. But our brain is far more than just a standard sensorimotor mapping machine. Through evolution, the brain of advanced mammals, in particular human and non-human primates, has acquired a formidable capacity to construct non-standard, arbitrary mapping using associations between external events and behavioral responses that bear no direct relationship. For example, we have all learned to stop at a red traffic light and to go at a green one, or to wait for a specific tone before dialing a phone number and to hang up when hearing a busy signal. These arbitrary associations are acquired through experience, thereby providing primates with a rich and flexible sensorimotor repertoire. Understanding how they are learned, and how they are recalled and used when the context requires them, has been one of the challenging issues for cognitive neuroscience. Valuable insights have been gained over the last two decades through the convergence of multiple complementary approaches. Human neuropsychology and experimental lesions in monkeys have identified a network of brain structures important for conditional sensorimotor associations, whereas imaging studies in healthy human subjects and electrophysiological recordings in awake monkeys have sought to identify the different functional processes underlying the overall function. The present review focuses on the contribution of a network linking the prefrontal cortex, basal ganglia, and dorsal premotor cortex, with special emphasis on results from recording experiments in monkeys. We will first review data pointing to a specific contribution of each component of the network to the performance of well-learned arbitrary visuo-motor associations, as well as data suggesting how novel associations are formed. Then we will propose a model positing that each component of the fronto-striatal network makes a specific contribution to the formation and/or execution of sensorimotor associations. In this model, the basal ganglia are thought to play a key role in linking the sensory, motor, and reward information necessary for arbitrary mapping.     

Les ostracodes du Néogène supérieur du littoral nord-ouest marocain entre Tanger et Asilah

Ostracodes populations have been studied in 19 samples from the upper Neogene of the Atlantic coast of NW of Morocco, between Tangier and Asilah. One hundred and two species belonging to 53 genera have been indentified. Analysis of the species assemblages allowed to reconstruct the palaeoenvironmental evolution of these deposits. This begins with the transgression of the upper Tortonian which corresponds to a relatively deep circalittoral environment. The series continues by deposits showing a general regressive character, punctuated by few transgressives pulses. Shallowing starts at the end of the upper Tortonian with the deposition of calcarenites in massive banks, in an infralittoral exposed environment. This facies pass towards the top to a detrital facies, assigned to the Messinian and deposited under high energy conditions in a shallow-marine environment. The lower Pliocene transgression shows a more generalized character. The maximum deepening corresponds to the grey clay facies deposited in the external infralittoral environment, relatively protected and rich in phytal biotopes. The more recent deposits are shallower, from coastal environments, and show a more limited extension.     

Moderate walnut consumption improved lipid profile,steroid hormones and inflammation in trained elderly men: a pilot study with a randomized controlled trial

The present study aimed to investigate the effect of walnut consumption on lipid profile, steroid hormones and inflammation in trained elderly men performing concurrent (resistance and endurance) training. Twenty healthy elderly males were divided into two matched groups, in a randomized controlled trial, that trained three sessions per week: concurrent training + dietary walnut consumption (15 g/day for six weeks, CTW: n = 10); concurrent training + control diet (CT: n = 10). Fasting blood samples were taken 48 hours before and after intervention for biochemical assessments. levels of high-density lipoprotein (HDL) increased only in CTW compared to baseline (19.8%, p < 0.01). Total cholesterol (TC), low-density lipoprotein (LDL) and triglyceride (TG) levels significantly decreased only for CTW (i.e., 13%, 18%, and 18.5% at p < 0.01 for all). Testosterone (T) increased after the training compared to pre-training for CTW and CT (10.3%, p < 0.01, 4.27% p < 0.05, respectively), but the increase was significantly higher in CTW (p < 0.05). Serum cortisol (C) was lower for CTW compared to CT (p < 0.01). C-reactive protein (CRP) decreased in CTW in comparison with CT. The present study revealed that 6-week moderate walnut supplementation (15 g/day) improved lipid profile, steroid hormones and systematic inflammation in aged men performing concurrent training. These findings could be attributable to the potential effect of polyunsaturated fatty acids (PUFA) contained in walnut (linoleic acid, n-6; linolenic acid, n-3).