Medium access control messaging scheme for cognitive radio networks

Los sistemas de radio cognitivos son una solución a la deficiente distribución del espectro inalámbrico de frecuencias. Usando acceso dinámico al medio, los usuarios secundarios pueden comunicarse en canales de frecuencia disponibles, mientras los usuarios asignados no están usando dichos canales. Un buen sistema de mensajería de control es necesario para que los usuarios secundarios no interfieran con los usuarios primarios en las redes de radio cognitivas. Para redes en donde los usuarios son heterogéneos en frecuencia, es decir, no poseen los mismos canales de frecuencia para comunicarse, el grupo de canales utilizado para transmitir información de control debe elegirse cuidadosamente. Por esta razón, en esta tesis se estudian las ideas básicas de los esquemas de mensajería de control usados en las redes de radio cognitivas y se presenta un esquema adecuado para un control adecuado para usuarios heterogéneos en canales de frecuencia. Para ello, primero se presenta una nueva taxonomía para clasificar las estrategias de mensajería de control, identificando las principales características que debe cumplir un esquema de control para sistemas heterogéneos en frecuencia. Luego, se revisan diversas técnicas matemáticas para escoger el mínimo número de canales por los cuales se transmite la información de control. Después, se introduce un modelo de un esquema de mensajería de control que use el mínimo número de canales y que utilice las características de los sistemas heterogéneos en frecuencia. Por último, se comparan diversos esquemas de mensajería de control en términos de la eficiencia de transmisión.

Incidence of liver damage of uncertain origin in HIV patients not co-infected with HCV/HBV.

BACKGROUND AND AIMS Several studies have reported that a significant number of HIV patients not co-infected with HCV/HBV develop liver damage of uncertain origin (LDUO). The objective of our study was to evaluate the incidence of and risk factors for the development of LDUO in HIV infected patients not co-infected with HCV/HBV. METHODS Prospective longitudinal study that included HIV-infected patients free of previous liver damage and viral hepatitis B or C co-infections. Patients were followed up at 6-monthly intervals. Liver stiffness was measured at each visit. Abnormal liver stiffness (ALS) was defined as a liver stiffness value greater than 7.2 kPa at two consecutive measurements. For patients who developed ALS, a protocol was followed to diagnose the cause of liver damage. Those patients who could not be diagnosed with any specific cause of liver disease were diagnosed as LDUO and liver biopsy was proposed. RESULTS 210 patients matched the inclusion criteria and were included. 198 patients completed the study. After a median (Q1-Q3) follow-up of 18 (IQR 12-26) months, 21 patients (10.6%) developed ALS. Of these, fifteen patients were diagnosed as LDUO. The incidence of LDUO was 7.64 cases/100 patient-years. Histological studies were performed on ten (66.6%) patients and all showed liver steatosis. A higher HOMA-IR value and body mass index were independently associated with the development of LDUO. CONCLUSION We found a high incidence of LDUO in HIV-infected patients associated with metabolic risk factors. The leading cause of LDUO in our study was non-alcoholic fatty liver disease.

Role of mental disorders in nosocomial infections after hip fracture treatment.

The association between mental disorders (MDs) and iatrogenic complications after hip fracture surgery has been poorly studied. Among iatrogenic complications, nosocomial infections (NIs) are a major factor in hip fracture surgery. The aim of this paper was to determine whether patients with a MD and a hip fracture develop more NIs after hip surgery than patients with no MD. We studied 912 patients who underwent surgery for a hip fracture (223 patients with a MD who underwent surgery for a hip fracture and 689 control patients without a MD who also underwent surgery for a hip fracture) and followed them after surgery. Univariable and multivariable analyses were performed using simple and multiple logistic regression analysis (confidence interval, crude and adjusted odds ratios, and P value). We found that MDs, gender, and comorbidities were not associated with a higher risk of developing a NI after surgery for a hip fracture. Only age increases the risk of a NI.

Fractura de cadera : proceso asistencial integrado

Este proceso asistencial reemplaza al anterior "Fractura de cadera en el anciano", publicado en 2002 (http://www.repositoriosalud.es/handle/10668/1533). Publicado en la página web de la Consejería de Igualdad, Salud y Políticas Sociales: www.juntadeandalucia.es/salud (Consejería de Igualdad, Salud y Políticas Sociales/ Profesionales / Nuestro Compromiso por la Calidad / Procesos Asistenciales Integrados)

Artrodesis de tobillo: resultados comparativos de diferentes técnicas

INTRODUCTION: Ankle arthrodesis in an intervention that may be performed using a variety of surgical approaches. The joint may be stabilized using diferent systems, with or without bone graft. MATERIAL AND METHODS: Retrospective study that collected the results of 40 patients who underwent ankle arthrodesis; the complications that arose were analyzed, results according to the AOFAS clinical rating system, global patient satisfaction and the relationship with the articular approach route, the !xation system or the usage of grafts.RESULTS: 55% of the patients presented one or more complication that motivated a total of 12 re-interventions in 10 patients (excludes removal of osteosynthesis material). The absence of consolidation, which required a new arthrodesis was more frequent in patients where osteosynthesis was not used (two out of three cases) than in those using screws (four out of 24 cases), while there was no register of this in 13 patients in which intramedullary pin. The use of the distal extreme of the fibula or the iliac crest as bone graft has failed to improve the consolidation. Arthroscopic approaches avoid the appearance of soft tissue complications, although the consolidation disorders were more frequent. The average score on the AOFAS clinical rating system was 56.4±21.2 and 55% of the patients were satisfied. CONCLUSIONS: Although the case histories fail to provide significant results, it is a demanding intervention, with an elevated complication rate. Intramedullary pins seem to favor improved consolidation.

Adaptación y validación al español del cuestionario 4CornerSAT para la medida de la satisfacción profesional del personal médico de atención especializada.

BACKGROUND Satisfaction of physicians is a concern in the healthcare sector, and it requires a multi-dimensional questionnaire in Spanish which studies their high-order needs. The objectives of this study are to adapt the 4CornerSAT Questionnaire to measure career satisfaction of physicians and to evaluate its validity in our context. METHOD The 4CornerSAT Questionnaire was adapted into Spanish, validating it among physicians of hospitals in Andalusia, Spain. A confirmatory factor analysis (CFA) was performed to corroborate the a priori model, and it was evaluated the internal consistency and the construct validity through the Cronbach's alpha and the correlation between the scale and the global item, respectively. RESULTS The adapted questionnaire was administrated to 121 specialist physicians. The CFA corroborated the four dimensions of the questionnaire (χ2=114.64, df=94, p<0.07; χ2/df=1.22; RMSEA=0.04). The internal consistency obtained an α=0.92 and the correlation between the summed scale and the global item verified the construct validity (r=0.77; p<0.001). CONCLUSIONS The 4CornerSAT questionnaire was adapted to Spanish, identifying an adequate construct validity and internal consistency.

Could radiotherapy effectiveness be enhanced by electromagnetic field treatment?

One of the main goals in radiobiology research is to enhance radiotherapy effectiveness without provoking any increase in toxicity. In this context, it has been proposed that electromagnetic fields (EMFs), known to be modulators of proliferation rate, enhancers of apoptosis and inductors of genotoxicity, might control tumor recruitment and, thus, provide therapeutic benefits. Scientific evidence shows that the effects of ionizing radiation on cellular compartments and functions are strengthened by EMF. Although little is known about the potential role of EMFs in radiotherapy (RT), the radiosensitizing effect of EMFs described in the literature could support their use to improve radiation effectiveness. Thus, we hypothesized that EMF exposure might enhance the ionizing radiation effect on tumor cells, improving the effects of RT. The aim of this paper is to review reports of the effects of EMFs in biological systems and their potential therapeutic benefits in radiotherapy.

Evolution of Trypanosoma cruzi: clarifying hybridisations, mitochondrial introgressions and phylogenetic relationships between major lineages

Several different models of Trypanosoma cruzi evolution have been proposed. These models suggest that scarce events of genetic exchange occurred during the evolutionary history of this parasite. In addition, the debate has focused on the existence of one or two hybridisation events during the evolution of T. cruzi lineages. Here, we reviewed the literature and analysed available sequence data to clarify the phylogenetic relationships among these different lineages. We observed that TcI, TcIII and TcIV form a monophyletic group and that TcIII and TcIV are not, as previously suggested, TcI-TcII hybrids. Particularly, TcI and TcIII are sister groups that diverged around the same time that a widely distributed TcIV split into two clades (TcIVS and TcIVN). In addition, we collected evidence that TcIII received TcIVSkDNA by introgression on several occasions. Different demographic hypotheses (surfing and asymmetrical introgression) may explain the origin and expansion of the TcIII group. Considering these hypotheses, genetic exchange should have been relatively frequent between TcIII and TcIVS in the geographic area in which their distributions overlapped. In addition, our results support the hypothesis that two independent hybridisation events gave rise to TcV and TcVI. Consequently, TcIVS kDNA was first transferred to TcIII and later to TcV and TcVI in TcII/TcIII hybridisation events.

Identification of the nicotinamide mononucleotide adenylyltransferase of Trypanosoma cruzi

The intracellular parasite Trypanosoma cruzi is the aetiological agent of Chagas disease, a public health concern with an increasing incidence rate. This increase is due, among other reasons, to the parasite’s drug resistance mechanisms, which require nicotinamide adenine dinucleotide (NAD+). Furthermore, this molecule is involved in metabolic and intracellular signalling processes necessary for the survival of T. cruzi throughout its life cycle. NAD+ biosynthesis is performed by de novo and salvage pathways, which converge on the step that is catalysed by the enzyme nicotinamide mononucleotide adenylyltransferase (NMNAT) (enzyme commission number: 2.7.7.1). The identification of the NMNAT of T. cruzi is important for the development of future therapeutic strategies to treat Chagas disease. In this study, a hypothetical open reading frame (ORF) for NMNAT was identified in the genome of T. cruzi. The corresponding putative protein was analysed by simulating structural models. The ORF was amplified from genomic DNA by polymerase chain reaction and was further used for the construction of a corresponding recombinant expression vector. The expressed recombinant protein was partially purified and its activity was evaluated using enzymatic assays. These results comprise the first identification of an NMNAT in T. cruzi using bioinformatics and experimental tools and hence represent the first step to understanding NAD+ metabolism in these parasites.

Adipose tissue concentrations of persistent organic pollutants and total cancer risk in an adult cohort from Southern Spain: preliminary data from year 9 of the follow-up.

There is an increasing trend in the incidence of cancer worldwide, and it has been accepted that environmental factors account for an important proportion of the global burden. The present paper reports preliminary findings on the influence of the historical exposure to a group of persistent organic pollutants on total cancer risk, at year 9 in the follow-up of a cohort from Southern Spain. A cohort of 368 participants (median age 51 years) was recruited in 2003. Their historical exposure was estimated by analyzing residues of persistent organic pollutants in adipose tissue. Estimation of cancer incidence was based on data from a population-based cancer registry. Statistical analyses were performed using multivariable Cox-regression models. In males, PCB 153 concentrations were positively associated with total cancer risk, with an adjusted hazard ratio (95% confidence interval) of 1.20 (1.01-1.41) for an increment of 100 ng/g lipid. Our preliminary findings suggest a potential relationship between the historical exposure to persistent organic pollutants and the risk of cancer in men. However, these results should be interpreted with caution and require verification during the future follow-up of this cohort.

Adaptive business intelligence for an open negotiation environment

Engineering of negotiation model allows to develop effective heuristic for business intelligence. Digital ecosystems demand open negotiation models. To define in advance effective heuristics is not compliant with the requirement of openness. The new challenge is to develop business intelligence in advance exploiting an adaptive approach. The idea is to learn business strategy once new negotiation model rise in the e-market arena. In this paper we present how recommendation technology may be deployed in an open negotiation environment where the interaction protocol models are not known in advance. The solution we propose is delivered as part of the ONE Platform, open source software that implements a fully distributed open environment for business negotiation

A Negotiation Style Recommender Based on Computational Ecology in Open Negotiation Environments

The system described herein represents the first example of a recommender system in digital ecosystems where agents negotiate services on behalf of small companies. The small companies compete not only with price or quality, but with a wider service-by-service composition by subcontracting with other companies. The final result of these offerings depends on negotiations at the scale of millions of small companies. This scale requires new platforms for supporting digital business ecosystems, as well as related services like open-id, trust management, monitors and recommenders. This is done in the Open Negotiation Environment (ONE), which is an open-source platform that allows agents, on behalf of small companies, to negotiate and use the ecosystem services, and enables the development of new agent technologies. The methods and tools of cyber engineering are necessary to build up Open Negotiation Environments that are stable, a basic condition for predictable business and reliable business environments. Aiming to build stable digital business ecosystems by means of improved collective intelligence, we introduce a model of negotiation style dynamics from the point of view of computational ecology. This model inspires an ecosystem monitor as well as a novel negotiation style recommender. The ecosystem monitor provides hints to the negotiation style recommender to achieve greater stability of an open negotiation environment in a digital business ecosystem. The greater stability provides the small companies with higher predictability, and therefore better business results. The negotiation style recommender is implemented with a simulated annealing algorithm at a constant temperature, and its impact is shown by applying it to a real case of an open negotiation environment populated by Italian companies

Natalizumab-related anaphylactoid reactions in MS patients are associated with HLA class II alleles.

OBJECTIVES We aimed to investigate potential associations between human leukocyte antigen (HLA) class I and class II alleles and the development of anaphylactic/anaphylactoid reactions in patients with multiple sclerosis (MS) treated with natalizumab. METHODS HLA class I and II genotyping was performed in patients with MS who experienced anaphylactic/anaphylactoid reactions and in patients who did not develop infusion-related allergic reactions following natalizumab administration. RESULTS A total of 119 patients with MS from 3 different cohorts were included in the study: 54 with natalizumab-related anaphylactic/anaphylactoid reactions and 65 without allergic reactions. HLA-DRB1*13 and HLA-DRB1*14 alleles were significantly increased in patients who developed anaphylactic/anaphylactoid reactions (p M-H = 3 × 10(-7); odds ratio [OR]M-H = 8.96, 95% confidence interval [CI] = 3.40-23.64), with a positive predictive value (PPV) of 82%. In contrast, the HLA-DRB1*15 allele was significantly more represented in patients who did not develop anaphylactic/anaphylactoid reactions to natalizumab (p M-H = 6 × 10(-4); ORM-H = 0.2, 95% CI = 0.08-0.50), with a PPV of 81%. CONCLUSIONS HLA-DRB1 genotyping before natalizumab treatment may help neurologists to identify patients with MS at risk for developing serious systemic hypersensitivity reactions associated with natalizumab administration.

Les associacions de veïns i veïnes de Barcelona i el programari lliure

Aquest és un treball que s'ha desenvolupat en dues parts: una enquesta per saber l'estat de l'art en temes de l'aplicació de les TIC en les associacions de veïns i veïnes de Barcelona i un cas pràctic focalitzat en una associació.

Disseny i implementació d'un conjunt de perifèrics de comunicació per a la seva incorporació en nous dissenys hardware del grup de robòtica i visió per computador

El grupo de robòtica i Visió fabricó la tarjeta gráfica MAGCL para el tratamiento de imágenes en tiempo real, en la que se incluyó un conector IDC20 proveniente de parte del bus de datos, de la FPGA que contiene, destinado a futuras aplicaciones. Con este proyecto se quiere aprovechar este conector para la comunicación de la placa con un PC, y se desarrollarán los puertos de comunicación serie RS232 y USB, Universal Serial Bus.El objetivo de este proyecto es establecer la comunicación de la tarjeta gráfica con un PC a través de estos dos tipos de puerto. Una vez conseguida la comunicación, quedan una serie de librerías hardware que pueden ayudar en la realización de futuros proyectos. La placa posee una FPGA (field programable gate array) destinada al desarrollo, pero programando esas librerías sobre otros componentes, se pueden utilizar estos puertos de forma permanente o exclusiva