Science & Mathematics

Lorsqu’un bâtiment d’un centre de production d’électricité est frappé par la foudre, il se produit une dangereuse circulation de courants dans tous les composants connectés au bâtiment: les murs, le réseau de terre, et les câbles sortant du bâtiment. L’intérêt du présent travail est d’étudier les tensions transitoires aux extrémités de ces câbles, en particulier des câbles contrôle mesure, dans la mesure où ces câbles sont connectés à des équipements électroniques susceptibles d’être endommagés par des perturbations électromagnétiques engendrées par la foudre. Une approche basée sur la résolution numérique des équations de Maxwell via une méthode FDTD est adoptée. Notamment le formalisme de Holland et Simpson est utilisé pour modéliser toutes les structures constituées d’un réseau de fils minces: l’armature métallique du bâtiment, la grille en cuivre du réseau de terre, la galerie de béton et le câble coaxial de contrôle mesure. Une validation des modèles électromagnétiques développés pour chaque composant du site industriel est présentée. Une analyse de sensibilité est conduite pour déterminer l’influence des paramètres du système. En outre, la technique des plans d’expérience est utilisée pour générer un méta-modèle qui prédit la tension maximale induite aux extrémités du câble en fonction des paramètres les plus influents. Cela représentent un outil de calcul précis et informatiquement efficace pour évaluer la performance foudre des câbles de contrôle et de mesure.

A total of 26 models that estimate the relationship between height and diameter in terms of stand variables (basal area, quadratic mean diameter, maximum diameter, dominant diameter, dominant height, arithmetic mean height, age, number of trees per hectare and site index), were fitted to data corresponding to 9686 trees, using linear and non-linear regression procedures. The precision of the models was then evaluated by cross-validation. The data were collected during two inventories of 182 permanent plots of radiata pine (Pinus radiata D. Don) situated throughout Galicia, in the Northwest of Spain. Comparison of the models was carried out by studying the coefficient of determination, bias, mean square error, Akaike's information criterion and by using a F-test to compare predicted and observed values. Best results were obtained with those models that included any independent variable related to the height of the stand (mean or dominant height), although this implies a greater sampling effort for its application. The model of Tomé gave the best height estimates.

Dendritic spines are morphing structures believed to provide a cellular substrate for synaptic plasticity. It has been suggested that the actin cytoskeleton is the target of molecular mechanisms regulating spine morphology. Here we hypothesized that acidic calponin, an actin-binding protein, is one of the key regulators of actin filaments during spine plasticity. Our data showed that the overexpression of acidic calponin-GFP (green fluorescent protein) in primary cultures of rat hippocampal neurons causes an elongation of spines and an increase of their density as compared with those of GFP-expressing neurons. These effects required the actin-binding domains of acidic calponin. The close apposition of the presynatic marker synaptophysin to these long spines and the presence of specific postsynaptic markers actin, PSD-95, NR1, and GluR1 suggested the existence of functional excitatory synaptic contacts. Indeed, electrophysiological data showed that the postsynaptic overexpression of acidic calponin enhanced the frequency of miniature excitatory postsynaptic currents as compared with that of GFP-expressing neurons, but did not affect their properties such as amplitude, rise time, and half width. Studies in heterologous cells revealed that acidic calponin reorganized the actin filaments and stabilized them. Taken together, these findings show that acidic calponin regulates dendritic spine morphology and density, likely via regulation of the actin cytoskeleton reorganization and dynamic. Furthermore, the acidic calponin-induced spines are able to establish functional glutamatergic synapses. Such data suggest that acidic calponin is a key factor in the regulation of spine plasticity and synaptic activity.

24x36 mm, gélatine plan-film.

On étudie l'effet de thermogravitation dans une colonne verticale rectangulaire de faible épaisseur par la méthode aux différences finies. Dans un modèle à deux dimensions et à l'état stationnaire on tient compte des effets de bord et on obtient le profil des vitesses et les variations de concentration en tout point de la colonne pour différents écarts de température et différentes valeurs du coefficient Soret positif.

Among the various analytical dimensions purporting to an appraisal of the replication potential of eParticipation projects, institutional factors deserve considerably more attention by theorists and practitioners alike. This paper introduces a "process oriented" definition of sustainable eParticipation, based on five key attributes: juridical compliance, legitimacy, social value, efficiency, and productivity. These can be used to assess the level of potential integration of a participatory practice or trial within the legal, political, social and organisational contexts of the public sector institutions involved. We posit that sustainable participation will emerge whenever these five dimensions are not jeopardised, compromised, or are left unaltered, by the introduction of participatory elements into any decision-making process regarding issues of public relevance. Empirical investigation is recommended to assess the impact of specific Preparatory Actions on eParticipation by using the five propositions introduced.

A mathematical reconstruction of Maritime pine (Pinus pinaster Ait.) was produced using the WoodCim$^{\ooalign{\hfil\hbox{\textsc{r}}\hfil\crcr\mathhexbox20D}}$ software based on input information obtained by image scanning of twenty 83 years old stems sampled in Portugal. The application of the reconstruction software resulted in 3D and 2D representations for logs and trees that allowed the visual appraisal of external shape as well as of the internal knot architecture. Information on tree geometry (i.e. taper) and knot parameters (i.e. knot length, diameter and volume) and on their variation with tree height could be obtained from the reconstructed logs and stems and may be incorporated in sawing yield studies through simulation as well as in raw material characterisation studies. In the studied trees, the average volume percentage of knots varied from 0.07% for butt logs to 1.95% for top logs. The knot core represented, in % of the tree radius, from 28% at the stem bottom to 84% at 70% of total tree height.

As a main actor in humoral immunity, B cells participate in various antibody-related disorders. However, a deeper understanding of B-cell differentiation and function is needed in order to decipher their immune-modulatory roles, notably with the recent highlighting of regulatory B cells. microRNAs (miRNAs), key factors in various biological and pathological processes, have been shown to be essential for B-cell homeostasis, and therefore understanding their participation in B-cell biology could help identify biomarkers and contribute toward curing B-cell-related immune disorders. This review aims to report studies casting light on the roles played by miRNAs in B-cell lineage and function and B-cell-related immune pathologies.

The development of "logistics" in Europe since the 1980's has been leading to a complete integration of transport operations in a global approach of physical flows management. Freight transport has strongly been changing to get appropriate goods to the right place, at the right time and the lower total cost. Introduction of informatics, one of the technologies involved in "advanced logistics systems", is for sure one of the most relevant evolutions. The purposes of the present paper are to give an understandable view of the current state of informatics systems in use in freight transport, to provide an overview of their incoming evolutions and to evaluate the key-role they will play in this sector. The paper begins in section 1 with a definition of the logistics concept. It presents its integration in European firms management and shows how information and communication systems are important in logistics. Section 2 presents the characteristics of logistics organizations in manufacturing, distribution, and logistics supplying and points out the main trends of logistics evolutions. In section 3, the paper focuses on today's advanced information and communication systems in freight transport management. It points out the so-called "driving forces" that have been leading European firms to develop such systems and outlines the most interesting ones. As a conclusion, it forecasts the impacts of advanced systems on the freight transport sector.

(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.

Abeillia Bonaparte, 1850aAbeillia abeillei (De Lattre & Lesson, 1839)

(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.

Esta contribución tiene por objeto examinar la normativa que regula la restricción de movimientos y los controles por parte de las autoridades policiales conforme a la Ley Orgánica 4/2015, de Protección de la Seguridad Ciudadana y, en concreto, sus artículos 17 y 18. Se plantean dudas en torno a la constitucionalidad de ambos, debido a su imprevisibilidad o a su falta de precisión, al limitar derechos fundamentales como la libertad ambulatoria o, incluso, la intimidad por los registros en vehículos y el derecho de manifestación. Aquella norma contempla conceptos jurídicos indeterminados como seguridad ciudadana o riesgo para las personas que otorgan un amplio margen de apreciación a la policía y no permite comprender en qué casos las personas pueden ser objeto de registros o intervenciones. Por una parte, la restricción de movimientos puede producirse cuando puede alterarse la seguridad ciudadana o la convivencia pacífica, aun tratándose de una manifestación en el espacio público. El capítulo del libro propone ciertos criterios de actuación, que se han construido partiendo de la doctrina y la jurisprudencia. El eje principal de todos ellos es el principio de proporcionalidad y la necesidad de ponderar en cada caso los derechos que entran en conflicto, justificando el peso que se le concede a uno u otro de acuerdo con las circunstancias de hecho. Los controles deben tener presente la existencia de indicios previos en torno a una posible actividad criminal, lo que nuevamente plantea problemas de seguridad jurídica. ¿En qué casos el indicio es suficientemente significativo para practicar el control? Podemos deducir la respuesta de la casuística de los tribunales, pero el problema estriba en que será muy complicado probar la ausencia de peligro para la seguridad ciudadana, al margen de que la jurisprudencia se ha pronunciado de forma favorable cuando efectivamente la policía ha descubierto la existencia de actividad delictiva. El gran problema que suscita este tipo de intervención policial es la fina línea entre una actuación preventiva y unas diligencias propias de la vía penal. Así, cabe preguntarse si, a tenor de la LOPSC, pueden practicarse controles o registros en casos en que se cometan infracciones administrativas, lo que supondría restricción de la libertad de movimientos por la supuesta comisión de una infracción, y todo ello está vedado por el art. 25.2 CE. Por otro lado, cuando se lleve a cabo la diligencia policial, las pruebas que se obtengan no son preconstituidas, debido a que no hay presencia letrada y, además, cualquier tipo de interrogatorio o declaración de la persona afectada por la intervención no podrá emplearse sin la previa lectura de derechos. De lo contrario, debe reputarse nula. Los protocolos policiales deben tomar en consideración las garantías de defensa desde el momento en que la persona puede ser imputada por la comisión de un delito.

(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.