Reconstructing the Timing and Dispersion Routes of HIV-1 Subtype B Epidemics in The Caribbean and Central America: A Phylogenetic Story.

The Caribbean and Central America are among the regions with highest HIV-1B prevalence worldwide. Despite of this high virus burden, little is known about the timing and the migration patterns of HIV-1B in these regions. Migration is one of the major processes shaping the genetic structure of virus populations. Thus, reconstruction of epidemiological network may contribute to understand HIV-1B evolution and reduce virus prevalence. We have investigated the spatio-temporal dynamics of the HIV-1B epidemic in The Caribbean and Central America using 1,610 HIV-1B partial pol sequences from 13 Caribbean and 5 Central American countries. Timing of HIV-1B introduction and virus evolutionary rates, as well as the spatial genetic structure of the HIV-1B populations and the virus migration patterns were inferred. Results revealed that in The Caribbean and Central America most of the HIV-1B variability was generated since the 80 s. At odds with previous data suggesting that Haiti was the origin of the epidemic in The Caribbean, our reconstruction indicated that the virus could have been disseminated from Puerto Rico and Antigua. These two countries connected two distinguishable migration areas corresponding to the (mainly Spanish-colonized) Easter and (mainly British-colonized) Western islands, which indicates that virus migration patterns are determined by geographical barriers and by the movement of human populations among culturally related countries. Similar factors shaped the migration of HIV-1B in Central America. The HIV-1B population was significantly structured according to the country of origin, and the genetic diversity in each country was associated with the virus prevalence in both regions, which suggests that virus populations evolve mainly through genetic drift. Thus, our work contributes to the understanding of HIV-1B evolution and dispersion pattern in the Americas, and its relationship with the geography of the area and the movements of human populations.

Smart aeronautical structures: development and experimental validation of a structural health monitoring system for damage detection

En muchas ��reas de la ingenier��a, la integridad y confiabilidad de las estructuras son aspectos de extrema importancia. Estos son controlados mediante el adecuado conocimiento de danos existentes. T��picamente, alcanzar el nivel de conocimiento necesario que permita caracterizar la integridad estructural implica el uso de t��cnicas de ensayos no destructivos. Estas t��cnicas son a menudo costosas y consumen mucho tiempo. En la actualidad, muchas industrias buscan incrementar la confiabilidad de las estructuras que emplean. Mediante el uso de t��cnicas de ��ltima tecnolog��a es posible monitorizar las estructuras y en algunos casos, es factible detectar da��os incipientes que pueden desencadenar en fallos catastr��ficos. Desafortunadamente, a medida que la complejidad de las estructuras, los componentes y sistemas incrementa, el riesgo de la aparici��n de da��os y fallas tambi��n incrementa. Al mismo tiempo, la detecci��n de dichas fallas y defectos se torna m��s compleja. En a��os recientes, la industria aeroespacial ha realizado grandes esfuerzos para integrar los sensores dentro de las estructuras, adem��s de desarrollar algoritmos que permitan determinar la integridad estructural en tiempo real. Esta filosof��a ha sido llamada ���Structural Health Monitoring��� (o ���Monitorizaci��n de Salud Estructural��� en espa��ol) y este tipo de estructuras han recibido el nombre de ���Smart Structures��� (o ���Estructuras Inteligentes��� en espa��ol). Este nuevo tipo de estructuras integran materiales, sensores, actuadores y algoritmos para detectar, cuantificar y localizar da��os dentro de ellas mismas. Una novedosa metodolog��a para detecci��n de da��os en estructuras se propone en este trabajo. La metodolog��a est�� basada en mediciones de deformaci��n y consiste en desarrollar t��cnicas de reconocimiento de patrones en el campo de deformaciones. Estas ��ltimas, basadas en PCA (An��lisis de Componentes Principales) y otras t��cnicas de reducci��n dimensional. Se propone el uso de Redes de difracci��n de Bragg y medidas distribuidas como sensores de deformaci��n. La metodolog��a se valid�� mediante pruebas a escala de laboratorio y pruebas a escala real con estructuras complejas. Los efectos de las condiciones de carga variables fueron estudiados y diversos experimentos fueron realizados para condiciones de carga est��ticas y din��micas, demostrando que la metodolog��a es robusta ante condiciones de carga desconocidas. ABSTRACT In many engineering fields, the integrity and reliability of the structures are extremely important aspects. They are controlled by the adequate knowledge of existing damages. Typically, achieving the level of knowledge necessary to characterize the structural integrity involves the usage of nondestructive testing techniques. These are often expensive and time consuming. Nowadays, many industries look to increase the reliability of the structures used. By using leading edge techniques it is possible to monitoring these structures and in some cases, detect incipient damage that could trigger catastrophic failures. Unfortunately, as the complexity of the structures, components and systems increases, the risk of damages and failures also increases. At the same time, the detection of such failures and defects becomes more difficult. In recent years, the aerospace industry has done great efforts to integrate the sensors within the structures and, to develop algorithms for determining the structural integrity in real time. The ���philosophy��� has being called ���Structural Health Monitoring��� and these structures have been called ���smart structures���. These new types of structures integrate materials, sensors, actuators and algorithms to detect, quantify and locate damage within itself. A novel methodology for damage detection in structures is proposed. The methodology is based on strain measurements and consists in the development of strain field pattern recognition techniques. The aforementioned are based on PCA (Principal Component Analysis) and other dimensional reduction techniques. The use of fiber Bragg gratings and distributed sensing as strain sensors is proposed. The methodology have been validated by using laboratory scale tests and real scale tests with complex structures. The effects of the variable load conditions were studied and several experiments were performed for static and dynamic load conditions, demonstrating that the methodology is robust under unknown load conditions.

High power beam dump project for the accelerator prototype LIPAc: Cooling design and analysis

En el campo de la fusi��n nuclear y desarroll��ndose en paralelo a ITER (International Thermonuclear Experimental Reactor), el proyecto IFMIF (International Fusion Material Irradiation Facility) se enmarca dentro de las actividades complementarias encaminadas a solucionar las barreras tecnol��gicas que a��n plantea la fusi��n. En concreto IFMIF es una instalaci��n de irradiaci��n cuya misi��n es caracterizar materiales resistentes a condiciones extremas como las esperadas en los futuros reactores de fusi��n como DEMO (DEMOnstration power plant). Consiste de dos aceleradores de deuterones que proporcionan un haz de 125 mA y 40 MeV cada uno, que al colisionar con un blanco de litio producen un flujo neutr��nico intenso (1017 neutrones/s) con un espectro similar al de los neutrones de fusi��n [1], [2]. Dicho flujo neutr��nico es empleado para irradiar los diferentes materiales candidatos a ser empleados en reactores de fusi��n, y las muestras son posteriormente examinadas en la llamada instalaci��n de post-irradiaci��n. Como primer paso en tan ambicioso proyecto, una fase de validaci��n y dise��o llamada IFMIFEVEDA (Engineering Validation and Engineering Design Activities) se encuentra actualmente en desarrollo. Una de las actividades contempladas en esta fase es la construcci��n y operaci��n de una acelarador prototipo llamado LIPAc (Linear IFMIF Prototype Accelerator). Se trata de un acelerador de deuterones de alta intensidad id��ntico a la parte de baja energ��a de los aceleradores de IFMIF. Los componentes del LIPAc, que ser�� instalado en Jap��n, son suministrados por diferentes pa��ses europeos. El acelerador proporcionar�� un haz continuo de deuterones de 9 MeV con una potencia de 1.125 MW que tras ser caracterizado con diversos instrumentos deber�� pararse de forma segura. Para ello se requiere un sistema denominado bloque de parada (Beam Dump en ingl��s) que absorba la energ��a del haz y la transfiera a un sumidero de calor. Espa��a tiene el compromiso de suministrar este componente y CIEMAT (Centro de Investigaciones Energ��ticas Medioambientales y Tecnol��gicas) es responsable de dicha tarea. La pieza central del bloque de parada, donde se para el haz de iones, es un cono de cobre con un ��ngulo de 3.5o, 2.5 m de longitud y 5 mm de espesor. Dicha pieza est�� refrigerada por agua que fluye en su superficie externa por el canal que se forma entre el cono de cobre y otra pieza conc��ntrica con ��ste. Este es el marco en que se desarrolla la presente tesis, cuyo objeto es el dise��o del sistema de refrigeraci��n del bloque de parada del LIPAc. El dise��o se ha realizado utilizando un modelo simplificado unidimensional. Se han obtenido los par��metros del agua (presi��n, caudal, p��rdida de carga) y la geometr��a requerida en el canal de refrigeraci��n (anchura, rugosidad) para garantizar la correcta refrigeraci��n del bloque de parada. Se ha comprobado que el dise��o permite variaciones del haz respecto a la situaci��n nominal siendo el flujo cr��tico calor��fico al menos 2 veces superior al nominal. Se han realizado asimismo simulaciones fluidodin��micas 3D con ANSYS-CFX en aquellas zonas del canal de refrigeraci��n que lo requieren. El bloque de parada se activar�� como consecuencia de la interacci��n del haz de part��culas lo que impide cualquier cambio o reparaci��n una vez comenzada la operaci��n del acelerador. Por ello el dise��o ha de ser muy robusto y todas las hip��tesis utilizadas en la realizaci��n de ��ste deben ser cuidadosamente comprobadas. Gran parte del esfuerzo de la tesis se centra en la estimaci��n del coeficiente de transferencia de calor que es determinante en los resultados obtenidos, y que se emplea adem��s como condici��n de contorno en los c��lculos mec��nicos. Para ello por un lado se han buscado correlaciones cuyo rango de aplicabilidad sea adecuado para las condiciones del bloque de parada (canal anular, diferencias de temperatura agua-pared de decenas de grados). En un segundo paso se han comparado los coeficientes de pel��cula obtenidos a partir de la correlaci��n seleccionada (Petukhov-Gnielinski) con los que se deducen de simulaciones fluidodin��micas, obteniendo resultados satisfactorios. Por ��ltimo se ha realizado una validaci��n experimental utilizando un prototipo y un circuito hidr��ulico que proporciona un flujo de agua con los par��metros requeridos en el bloque de parada. Tras varios intentos y mejoras en el experimento se han obtenido los coeficientes de pel��cula para distintos caudales y potencias de calentamiento. Teniendo en cuenta la incertidumbre de las medidas, los valores experimentales concuerdan razonablemente bien (en el rango de 15%) con los deducidos de las correlaciones. Por motivos radiol��gicos es necesario controlar la calidad del agua de refrigeraci��n y minimizar la corrosi��n del cobre. Tras un estudio bibliogr��fico se identificaron los par��metros del agua m��s adecuados (conductividad, pH y concentraci��n de ox��geno disuelto). Como parte de la tesis se ha realizado asimismo un estudio de la corrosi��n del circuito de refrigeraci��n del bloque de parada con el doble fin de determinar si puede poner en riesgo la integridad del componente, y de obtener una estimaci��n de la velocidad de corrosi��n para dimensionar el sistema de purificaci��n del agua. Se ha utilizado el c��digo TRACT (TRansport and ACTivation code) adapt��ndalo al caso del bloque de parada, para lo cual se trabaj�� con el responsable (Panos Karditsas) del c��digo en Culham (UKAEA). Los resultados confirman que la corrosi��n del cobre en las condiciones seleccionadas no supone un problema. La Tesis se encuentra estructurada de la siguiente manera: En el primer cap��tulo se realiza una introducci��n de los proyectos IFMIF y LIPAc dentro de los cuales se enmarca esta Tesis. Adem��s se describe el bloque de parada, siendo el dise��o del sistema de rerigeraci��n de ��ste el principal objetivo de la Tesis. En el segundo y tercer cap��tulo se realiza un resumen de la base te��rica as�� como de las diferentes herramientas empleadas en el dise��o del sistema de refrigeraci��n. El cap��tulo cuarto presenta los resultados del relativos al sistema de refrigeraci��n. Tanto los obtenidos del estudio unidimensional, como los obtenidos de las simulaciones fluidodin��micas 3D mediante el empleo del c��digo ANSYS-CFX. En el quinto cap��tulo se presentan los resultados referentes al an��lisis de corrosi��n del circuito de refrigeraci��n del bloque de parada. El cap��tulo seis se centra en la descripci��n del montaje experimental para la obtenci��n de los valores de p��rdida de carga y coeficiente de transferencia del calor. Asimismo se presentan los resultados obtenidos en dichos experimentos. Finalmente encontramos un cap��tulo de ap��ndices en el que se describen una serie de experimentos llevados a cabo como pasos intermedios en la obtenci��n del resultado experimental del coeficiente de pel��cula. Tambi��n se presenta el c��digo inform��tico empleado para el an��lisis unidimensional del sistema de refrigeraci��n del bloque de parada llamado CHICA (Cooling and Heating Interaction and Corrosion Analysis). ABSTRACT In the nuclear fusion field running in parallel to ITER (International Thermonuclear Experimental Reactor) as one of the complementary activities headed towards solving the technological barriers, IFMIF (International Fusion Material Irradiation Facility) project aims to provide an irradiation facility to qualify advanced materials resistant to extreme conditions like the ones expected in future fusion reactors like DEMO (DEMOnstration Power Plant). IFMIF consists of two constant wave deuteron accelerators delivering a 125 mA and 40 MeV beam each that will collide on a lithium target producing an intense neutron fluence (1017 neutrons/s) with a similar spectra to that of fusion neutrons [1], [2]. This neutron flux is employed to irradiate the different material candidates to be employed in the future fusion reactors, and the samples examined after irradiation at the so called post-irradiative facilities. As a first step in such an ambitious project, an engineering validation and engineering design activity phase called IFMIF-EVEDA (Engineering Validation and Engineering Design Activities) is presently going on. One of the activities consists on the construction and operation of an accelerator prototype named LIPAc (Linear IFMIF Prototype Accelerator). It is a high intensity deuteron accelerator identical to the low energy part of the IFMIF accelerators. The LIPAc components, which will be installed in Japan, are delivered by different european countries. The accelerator supplies a 9 MeV constant wave beam of deuterons with a power of 1.125 MW, which after being characterized by different instruments has to be stopped safely. For such task a beam dump to absorb the beam energy and take it to a heat sink is needed. Spain has the compromise of delivering such device and CIEMAT (Centro de Investigaciones Energ��ticas Medioambientales y Tecnol��gicas) is responsible for such task. The central piece of the beam dump, where the ion beam is stopped, is a copper cone with an angle of 3.5o, 2.5 m long and 5 mm width. This part is cooled by water flowing on its external surface through the channel formed between the copper cone and a concentric piece with the latter. The thesis is developed in this realm, and its objective is designing the LIPAc beam dump cooling system. The design has been performed employing a simplified one dimensional model. The water parameters (pressure, flow, pressure loss) and the required annular channel geometry (width, rugoisty) have been obtained guaranteeing the correct cooling of the beam dump. It has been checked that the cooling design allows variations of the the beam with respect to the nominal position, being the CHF (Critical Heat Flux) at least twice times higher than the nominal deposited heat flux. 3D fluid dynamic simulations employing ANSYS-CFX code in the beam dump cooling channel sections which require a more thorough study have also been performed. The beam dump will activateasaconsequenceofthe deuteron beam interaction, making impossible any change or maintenance task once the accelerator operation has started. Hence the design has to be very robust and all the hypotheses employed in the design mustbecarefully checked. Most of the work in the thesis is concentrated in estimating the heat transfer coefficient which is decisive in the obtained results, and is also employed as boundary condition in the mechanical analysis. For such task, correlations which applicability range is the adequate for the beam dump conditions (annular channel, water-surface temperature differences of tens of degrees) have been compiled. In a second step the heat transfer coefficients obtained from the selected correlation (Petukhov- Gnielinski) have been compared with the ones deduced from the 3D fluid dynamic simulations, obtaining satisfactory results. Finally an experimental validation has been performed employing a prototype and a hydraulic circuit that supplies a flow with the requested parameters in the beam dump. After several tries and improvements in the experiment, the heat transfer coefficients for different flows and heating powers have been obtained. Considering the uncertainty in the measurements the experimental values agree reasonably well (in the order of 15%) with the ones obtained from the correlations. Due to radiological reasons the quality of the cooling water must be controlled, hence minimizing the copper corrosion. After performing a bibligraphic study the most adequate water parameters were identified (conductivity, pH and dissolved oxygen concentration). As part of this thesis a corrosion study of the beam dump cooling circuit has been performed with the double aim of determining if corrosion can pose a risk for the copper beam dump , and obtaining an estimation of the corrosion velocitytodimension the water purification system. TRACT code(TRansport and ACTivation) has been employed for such study adapting the code for the beam dump case. For such study a collaboration with the code responsible (Panos Karditsas) at Culham (UKAEA) was established. The work developed in this thesis has supposed the publication of three articles in JCR journals (���Journal of Nuclear Materials��� y ���Fusion Engineering and Design���), as well as presentations in more than four conferences and relevant meetings.

Business models in the Smart Grid: challenges, opportunities and proposals for prosumer profitability.

Considering that non-renewable energy resources are dwindling, the smart grid turns out to be one of the most promising and compelling systems for the future of energy. Not only does it combine efficient energy consumption with avant-garde technologies related to renewable energies, but it is also capable of providing several beneficial utilities, such as power monitoring and data provision. When smart grid end users turn into prosumers, they become arguably the most important value creators within the smart grid and a decisive agent of change in terms of electricity usage. There is a plethora of research and development areas related to the smart grid that can be exploited for new business opportunities, thus spawning another branch of the so-called ?green economy? focused on turning smart energy usage into a profitable business. This paper deals with emerging business models for smart grid prosumers, their strengths and weaknesses and puts forward new prosumer-oriented business models, along with their value propositions.

Human ��-aminobutyric acid type B receptors are differentially expressed and regulate inwardly rectifying K+ channels

��-Aminobutyric acid type B receptors (GABABRs) are involved in the fine tuning of inhibitory synaptic transmission. Presynaptic GABABRs inhibit neurotransmitter release by down-regulating high-voltage activated Ca2+ channels, whereas postsynaptic GABABRs decrease neuronal excitability by activating a prominent inwardly rectifying K+ (Kir) conductance that underlies the late inhibitory postsynaptic potentials. Here we report the cloning and functional characterization of two human GABABRs, hGABABR1a (hR1a) and hGABABR1b (hR1b). These receptors closely match the pharmacological properties and molecular weights of the most abundant native GABABRs. We show that in transfected mammalian cells hR1a and hR1b can modulate heteromeric Kir3.1/3.2 and Kir3.1/3.4 channels. Heterologous expression therefore supports the notion that Kir3 channels are the postsynaptic effectors of GABABRs. Our data further demonstrate that in principle either of the cloned receptors could mediate inhibitory postsynaptic potentials. We find that in the cerebellum hR1a and hR1b transcripts are largely confined to granule and Purkinje cells, respectively. This finding supports a selective association of hR1b, and not hR1a, with postsynaptic Kir3 channels. The mapping of the GABABR1 gene to human chromosome 6p21.3, in the vicinity of a susceptibility locus (EJM1) for idiopathic generalized epilepsies, identifies a candidate gene for inherited forms of epilepsy.

Chromophore-bearing NH2-terminal domains of phytochromes A and B determine their photosensory specificity and differential light lability.

In early seedling development, far-red-light-induced deetiolation is mediated primarily by phytochrome A (phyA), whereas red-light-induced deetiolation is mediated primarily by phytochrome B (phyB). To map the molecular determinants responsible for this photosensory specificity, we tested the activities of two reciprocal phyA/phyB chimeras in diagnostic light regimes using overexpression in transgenic Arabidopsis. Although previous data have shown that the NH2-terminal halves of phyA and phyB each separately lack normal activity, fusion of the NH2-terminal half of phyA to the COOH-terminal half of phyB (phyAB) and the reciprocal fusion (phyBA) resulted in biologically active phytochromes. The behavior of these two chimeras in red and far-red light indicates: (i) that the NH2-terminal halves of phyA and phyB determine their respective photosensory specificities; (ii) that the COOH-terminal halves of the two photoreceptors are necessary for regulatory activity but are reciprocally inter-changeable and thus carry functionally equivalent determinants; and (iii) that the NH2-terminal halves of phyA and phyB carry determinants that direct the differential light lability of the two molecules. The present findings suggest that the contrasting photosensory information gathered by phyA and phyB through their NH2-terminal halves may be transduced to downstream signaling components through a common biochemical mechanism involving the regulatory activity of the COOH-terminal domains of the photoreceptors.

Bosnia and Herzegovina: Building a Film/TV Production Industry to Boost its Economy and Unite its Divided Cultures

This paper discusses how Bosnia and Herzegovina (BiH) can boost its stalled economy by generating jobs and increasing film-tourism, while simultaneously helping unite its culturally divided nation, by building a film/TV production industry looking to Northern Ireland's successful model following its similarly violent history. Evidence is presented substantiating that BiH has the infrastructure and workforce from which to grow a film/TV production industry, but it must be built through large-scale foreign productions like Northern Ireland did with Game of Thrones. Examining studies conducted by industry experts, strategies are offered for building a competitive and sustainable film/TV production industry in BiH. Results reveal more research is needed evidencing film/TV production can unify people from different ethno-religious/political groups in post-conflict societies.

Reductive electrochemical formation of 6H-dibenzo[b,d]pyran-6-one and 2-benzopyran-1(1H)-one

In the present Letter several carbolactones (oxidative products) are obtained under aprotic cathodic conditions in the preparative scaled electrolysis of 1,2-quinones in a divided electrochemical cell and in the presence of oxygen. When 9,10-phenanthrenequinone is reduced 6H-dibenzo[b,d]pyran-6-one and [1,1���-biphenyl]-2,2���-dicarboxylic acid are obtained as major products. In the reduction of 1,2-naphthoquinone, 2-benzopyran-1(1H)-one, and 2-(2-carboxyethenyl)-benzoic acid were formed as main products. The proposed mechanism to explain the formation of these and other products, that involves an electron-transfer reaction to the oxygen in air, is now discussed.

Smart Monitoring Embedded Service for Energy-Efficient and Sustainable Management in Data Centers

Information technologies (IT) currently represent 2% of CO2 emissions. In recent years, a wide variety of IT solutions have been proposed, focused on increasing the energy efficiency of network data centers. Monitoring is one of the fundamental pillars of these systems, providing the information necessary for adequate decision making. However, today���s monitoring systems (MSs) are partial, specific and highly coupled solutions. This study proposes a model for monitoring data centers that serves as a basis for energy saving systems, offered as a value-added service embedded in a device with low cost and power consumption. The proposal is general in nature, comprehensive, scalable and focused on heterogeneous environments, and it allows quick adaptation to the needs of changing and dynamic environments. Further, a prototype of the system has been implemented in several devices, which has allowed validation of the proposal in addition to identification of the minimum hardware profile required to support the model.

Late Mogollon pottery types of the Reserve area / John B. Rinaldo, Assistant Curator, Archaeology, and Elaine A. Bluhm, Assistant, Archaeology.

v.36:no.7(1956)