Divergence of the dielectric constant in ultrathin granular metal films near the percolation threshold

We report on the electronic and optical properties of ultrathin granular films. We demonstrate that the static dielectric constant increases with thickness in the dielectric regime and diverges at the critical thickness, as predicted by classical percolation theory. However, for thicker samples, the dc conductivity does not obey scaling laws due to the presence of tunneling conduction. In this region the dielectric constant is positive, and the electronic transport is not metallic but can be described by Jonscher's universal power law, even though there is a Drude-like response indicating the presence of free charge carriers. Only for thicker films when the dielectric constant becomes negative is there metallic conduction

Swordfish growth pattern in the strait of Gibraltar; implications for mixing among Atlantic and Mediterranean stocks

A growth study of the swordfish in the Strait of Gibraltar was carried out, based on monthly size frequencies data collected from the Moroccan driftnet fishery during the period 2006-2011. The growth parameters were estimated by the modal progression analysis (MPA), using both the Bhattacharya and NORMSEP methods. The standard von Bertalanffy growth function (VBGF) for length was found to be: Lt =253.6 [1-exp (- 0.17(t + 1.30))]. The growth pattern of swordfish in the Strait of Gibraltar was found to be very similar to that obtained from past studies in various Mediterranean areas. Given the existing growth differences among Atlantic and Mediterranean swordfish, this suggests that the majority of fish caught in this area are most likely belonging to the Mediterranean stock. However, further studies are needed to identify the degree of mixing among stocks

A prototype node for wireless vision sensor network applications development

This paper presents a prototype vision-enabled sensor node based on a commercial vision system of reduced size and power consumption. The wireless infrastructure for the deployment of a distributed smart camera network based on these nodes is provided by commercial motes. The smart camera, based on a low-power bio-inspired processing scheme, enables in-node image processing and vision tools. This permits to elaborate a lighter representation of the scene, keeping the relevant information in terms of detected elements, features and events, alleviating the data transmission through the network. Therefore by passing only the relevant information to the neighboring sensor nodes, distributed and collaborative vision is possible with the limited data rates available in commercial wireless sensor networks. Communication between the different components of the system is supported by the available UARTs and GPIOs. Several examples of in-node image processing and feature detection has been tested in the prototype, and information at different abstraction levels has been broadcasted to the network.Junta de Andalucía 2006-TIC-2352Ministerio de Ciencia e Innovación TEC2009-1181

Sox9 and Sox8 protect the adult testis from male-to-female genetic reprogramming and complete degeneration.

The new concept of mammalian sex maintenance establishes that particular key genes must remain active in the differentiated gonads to avoid genetic sex reprogramming, as described in adult ovaries after Foxl2 ablation. Dmrt1 plays a similar role in postnatal testes, but the mechanism of adult testis maintenance remains mostly unknown. Sox9 and Sox8 are required for postnatal male fertility, but their role in the adult testis has not been investigated. Here we show that after ablation of Sox9 in Sertoli cells of adult, fertile Sox8(-/-) mice, testis-to-ovary genetic reprogramming occurs and Sertoli cells transdifferentiate into granulosa-like cells. The process of testis regression culminates in complete degeneration of the seminiferous tubules, which become acellular, empty spaces among the extant Leydig cells. DMRT1 protein only remains in non-mutant cells, showing that SOX9/8 maintain Dmrt1 expression in the adult testis. Also, Sox9/8 warrant testis integrity by controlling the expression of structural proteins and protecting Sertoli cells from early apoptosis. Concluding, this study shows that, in addition to its crucial role in testis development, Sox9, together with Sox8 and coordinately with Dmrt1, also controls adult testis maintenance

Study of Magnetic Superexchange in diluted Systems Znx Cd1-xCr2Se4 ( 0.35 ≤ x ≤ 0.58 )

The effects of cationic substitutions at different concentrations within the lattice Znx Cd1-xCr2Se4 (0.35≤x≤0.58) on the electronic transfer in chromium ions are investigated. For this propose, after taking into account the exchange integrals, we use the Anderson’s-Kanamori theory of superexchange to determine the transfer integrals bσσ and bπσ . With the use of the conventional molecular orbital model the covalency-mixing parameters, λσ and λπ, the electron spin transfer coefficients, ƒ i (i=σ, π, s ), and the total charge, C, transferred from ligand to the chromium ions, are evaluated. The variation of bσσ and bσπ with x agree with the passage of the system from ferromagnetic to antiferromagnetic order. For the compound presenting re-entrant behaviour (0.45≤x≤0.58), f s exhibits anomalous. The increasing in C with x is consistent with the expected decrease in covalency of the non magnetic cation in tetrahedral site.The effects of cationic substitutions at different concentrations within the lattice Znx Cd1-xCr2Se4 (0.35≤x≤0.58) on the electronic transfer in chromium ions are investigated. For this propose, after taking into account the exchange integrals, we use the Anderson’s-Kanamori theory of superexchange to determine the transfer integrals bσσ and bπσ . With the use of the conventional molecular orbital model the covalency-mixing parameters, λσ and λπ, the electron spin transfer coefficients, ƒ i (i=σ, π, s ), and the total charge, C, transferred from ligand to the chromium ions, are evaluated. The variation of bσσ and bσπ with x agree with the passage of the system from ferromagnetic to antiferromagnetic order. For the compound presenting re-entrant behaviour (0.45≤x≤0.58), f s exhibits anomalous. The increasing in C with x is consistent with the expected decrease in covalency of the non magnetic cation in tetrahedral site

Green approach to corrosion inhibition of mild steel in 1 M HCl solutions by Monosaccharides derivatives

Effect of new synthesized monosaccharide derivatives, namely: D-mannose (M1), D-gluconic acid-γ-lactone (M2), D-galactono-γ-lactone (M3), monoacetoneglucose (M4), diacetoneglucose (M5), on mild steel corrosion inhibition in an aerated acidic solution of 1 M HCl was investigated using weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy measurements. The results indicate that the type of inhibition depends on the type of compounds. Impedance measurements showed that the charge transfer resistance increased and double layer capacitance values decreased with inhibitor’s concentration. It is seen that the M2 performed excellently as a corrosion inhibitor which its efficiency reaches 91 % at 10-3 M. Adsorption of M2 molecules on mild steel surface was also studied to examine basic information on the interaction between the inhibitors and the metal surface. It is found that the inhibitor adsorb on the metal surface following the Langmuir isotherm model. The temperature effect on the performance of mild steel in 1 M HCl in the absence and presence of the best compound was studied in the temperature range from 293 to 323 K. Also, some thermodynamic data for the adsorption and dissolution processes are calculated and discussed

Thrombose de la veine ovarienne au post-partum, révélée par un syndrome appendiculaire: à propos d’un cas

Une patiente de 27 ans a présenté à J13 du post partum, suite à un accouchement eutocique non compliqué et sans anamnèse infectieuse, une douleur en fosse iliaque droite évoluant dans un contexte fébrile. Devant une suspicion clinique et biologique d'appendicite, nous avons réalisé une échographie abdominopelvienne qui était normale. Le complément par scanner abdominale, a objectivé une thrombose de la veine ovarienne (TVO) à droite remontant jusqu'à la veine cave inférieure. Le traitement médical était basé essentiellement sur les anticoagulants. L'évolution était favorable

Radio Frequency Energy Harvesting - Sources and Techniques

Energy harvesting technology is attracting huge attention and holds a promising future for generating electrical power. This process offers various environmentally friendly alternative energy sources. Especially, radio frequency (RF) energy has interesting key attributes that make it very attractive for low-power consumer electronics and wireless sensor networks (WSNs). Ambient RF energy could be provided by commercial RF broadcasting stations such as TV, GSM, Wi-Fi, or radar. In this study, particular attention is given to radio frequency energy harvesting (RFEH) as a green technology, which is very suitable for overcoming problems related to wireless sensor nodes located in harsh environments or inaccessible places. The aim of this paper is to review the progress achievements, the current approaches, and the future directions in the field of RF harvesting energy. Therefore, our aim is to provide RF energy harvesting techniques that open the possibility to power directly electronics or recharge secondary batteries. As a result, this overview is expected to lead to relevant techniques for developing an efficient RF energy harvesting system

Épidémiologie des accidents domestiques graves de l’enfant admis en réanimation pédiatrique polyvalente à l’hôpital d’enfants de Rabat-Maroc

Introduction: les accidents domestiques de l'enfant représentent un vrai problème de santé publique dans les pays industrialisés. Au Maroc, lapriorité en santé publique est toujours donnée aux pathologies   infectieuses, et bien qu'elle soit très peu décrite, la pathologie accidentelle de l'enfant devient de plus en plus fréquente dans notre pays avec une mortalité importante. L'objectif est de mettre le point sur la prévalence, lagravité, les aspects étiologiques, les facteurs de risque et les circonstances de survenue de ces accidents, ainsi que les moyens de préventionactive et passive. Méthodes: enquête rétrospective descriptive sur une période de douze mois portant sur tous les enfants pris en charge pour accident domestique grave au service de réanimation pédiatrique polyvalente de l'hôpital universitaire d'enfants de Rabat. Résultats: parmi 698 admissions, 108 cas d'accidents domestiques graves ont étaient colligés (soit 15,5%), L'âge moyen des enfants était de 04ans tout accident confondu, avec un sex-ratio de 1,08 en faveur des garçons. L'évolution générale était marquée par le décès de 16 enfants (soit 14,8%) parmi 164 décès toute pathologie confondue au cours de la même période d'étude (soit 9,75% des décès) avec une durée moyenne   d'hospitalisation de 04jours. les brûlures constituaient le premier accident dans notre série par 37cas, et elles étaient la première cause de mortalité par huit cas; par ailleurs, la population la plus à risque de brûlure était les nourrissons (67,6%). L'inhalation intrabronchique d'épingle à foulard  (accident particulier dans notre contexte islamique) à été retrouvée chez six cas. Conclusion: les accidents domestiques de l'enfant constituent rarement une préoccupation de premier plan dans la population alors qu'ils sont parfois très graves et source d'une mortalité importante. Le meilleur  traitement reste la prévention active et passive