DSP based platform for an enhanced HF channel simulator

With the aim of improving existing tools for testing new HF transmission systems, this article describes a modification of the basic Watterson (1970) model which can be implemented without any extra added complexity with a general purpose DSP card running an a PC IBM compatible.Peer ReviewedPostprint (published version

Algoritmo para optimizacion de la transferencia de datos libres de errores en canales H.F

We present a research on error-free data transmission in H.F. radio communications. In concrete, a study on the C.C.I.T.T. recomendation V.42 and a evaluation of the optimal frame length vs. average b.e.r. of th H. F . channel are treated. In order to carry out this, we simulated the behaviour of the H.F. channel using a well-known discrete model called Fritchman's model, which was changed in different situations. The results are presented graphically, and it can be observed that there is always an optimum length, which maximizes the throughput, in different channel conditions. Finally, the variation of the length as a function of the average b. e. r . of the channels is presented.Peer ReviewedPostprint (published version

A flexible protocol communications approach for a supervisory system

This paper deals with the communication protocol intended to control up to 1016 devices of a new supervisory system. It has been conceived in two complementary phases. The first one (Cycle-A) is intended to inform the Central Station of any event detected by the installed devices in less than two seconds. The second one allows to set up a link between the Central Station and a selected Local Station in order to request more information or to act on its devices for command or programming purposes. The dialog between the Central Station and the Local Station takes place on a two wire communication channel, also used to supply de current from the Central to all Local Stations.This paper deals with the communication protocol intended to control up to 1016 devices of a new supervisory system. It has been conceived in two complementary phases. The first one (Cycle-A) is intended to inform the Central Station of any event detected by the installed devices in less than two seconds. The second one allows to set up a link between the Central Station and a selected Local Station in order to request more information or to act on its devices for command or programming purposes. The dialog between the Central Station and the Local Station takes place on a two wire communication channel, also used to supply de current from the Central to all Local Stations.Peer ReviewedPostprint (published version

Monitoring of a virtual infrastructure testbed

This paper presents a SNMP-based Monitoring Agents for Multi-Constrain Resource Scheduling in Grids (SBLOMARS) as an effective solution for resource usage monitoring in virtual network environments. SBLOMARS is different to current large-scale distributed monitoring systems in three essential aspects: Firstly, it reaches a high level of generality by the integration of the SNMP protocol and thus, facilitates to handle heterogeneous operating platforms. Secondly, it is able to self-configure the polling periods of the resources to be monitored depending of network context and finally, it makes use of dynamic software structures to interface with third parties, allowing to be deployed in a wide range of devices, from simple mobile access devices to robust multiprocessor systems or clusters with even multiple hard disks and storage partitions. SBLOMARS has been deployed in EmanicsLab, a virtual laboratory constituted by fourteen nodes distributed in seven European Universities. Although the research is not yet concluded, available results confirm its suitability to deal with the challenges of monitoring virtual networks.Postprint (published version

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 10

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 10, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada de acceso abierto a todas las áreas del conocimiento, que cuenta con el esfuerzo de investigadores de varios países del mundo, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico que consoliden la transformación del conocimiento en diferentes escenarios, tanto organizacionales como universitarios, para el desarrollo de habilidades cognitivas del quehacer diario. La gestión del conocimiento es un camino para consolidar una plataforma en las empresas públicas o privadas, entidades educativas, organizaciones no gubernamentales, ya sea generando políticas para todas las jerarquías o un modelo de gestión para la administración, donde es fundamental articular el conocimiento, los trabajadores, directivos, el espacio de trabajo, hacia la creación de ambientes propicios para el desarrollo integral de las instituciones

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

A flexible protocol communications approach for a supervisory system

This paper deals with the communication protocol intended to control up to 1016 devices of a new supervisory system. It has been conceived in two complementary phases. The first one (Cycle-A) is intended to inform the Central Station of any event detected by the installed devices in less than two seconds. The second one allows to set up a link between the Central Station and a selected Local Station in order to request more information or to act on its devices for command or programming purposes. The dialog between the Central Station and the Local Station takes place on a two wire communication channel, also used to supply de current from the Central to all Local Stations.This paper deals with the communication protocol intended to control up to 1016 devices of a new supervisory system. It has been conceived in two complementary phases. The first one (Cycle-A) is intended to inform the Central Station of any event detected by the installed devices in less than two seconds. The second one allows to set up a link between the Central Station and a selected Local Station in order to request more information or to act on its devices for command or programming purposes. The dialog between the Central Station and the Local Station takes place on a two wire communication channel, also used to supply de current from the Central to all Local Stations.Peer Reviewe

Algoritmo para optimizacion de la transferencia de datos libres de errores en canales H.F

We present a research on error-free data transmission in H.F. radio communications. In concrete, a study on the C.C.I.T.T. recomendation V.42 and a evaluation of the optimal frame length vs. average b.e.r. of th H. F . channel are treated. In order to carry out this, we simulated the behaviour of the H.F. channel using a well-known discrete model called Fritchman's model, which was changed in different situations. The results are presented graphically, and it can be observed that there is always an optimum length, which maximizes the throughput, in different channel conditions. Finally, the variation of the length as a function of the average b. e. r . of the channels is presented.Peer Reviewe