Physical Layer Security of Large Reflecting Surface Aided Communications with Phase Errors

The physical layer security (PLS) performance of a wireless communication link through a large reflecting surface (LRS) with phase errors is analyzed. Leveraging recent results that express the \ac{LRS}-based composite channel as an equivalent scalar fading channel, we show that the eavesdropper's link is Rayleigh distributed and independent of the legitimate link. The different scaling laws of the legitimate and eavesdroppers signal-to-noise ratios with the number of reflecting elements, and the reasonably good performance even in the case of coarse phase quantization, show the great potential of LRS-aided communications to enhance PLS in practical wireless set-ups.Comment: This work has been submitted to the IEEE for publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Sexual and Reproductive Health for Young Adults in Colombia: Teleconsultation Using Mobile Devices

Background: Sexual risk behaviors associated with poor information on sexuality have contributed to major public health problems in the area of sexual and reproductive health in teenagers and young adults in Colombia. Objective: To report our experience with the use of DoctorChat Mobile to provide sexual education and information among university students in Bogota, Colombia, and knowledge about the sexual risk factors detected among them. Methods: A mobile app that allows patients to ask about sexual and reproductive health issues was developed. Sexual and reproductive risk behaviors in a sample of young adults were measured before and after the use of the app through the validated survey Family Health International (FHI) Behavioral Surveillance Survey (BSS) for Use With Adults Between 15 and 49 Years. A nonprobabilistic convenience recruitment was undertaken through the study´s webpage. After completing the first survey, participants were allowed to download and use the app for a 6-month period (intervention), followed by completion of the same survey once again. For the inferential analysis, data was divided into 3 groups (dichotomous data, discrete quantitative data, and ordinal data) to compare the results of the questions between the first and the second survey. The study was carried out with a sample of university students between 18 and 29 years with access to mobile phones. Participation in the study was voluntary and anonymous. Results: A total of 257 subjects met the selection criteria. The preintervention survey was answered by 232 subjects, and 127 of them fully answered the postintervention survey. In total, 54.3% (69/127) of the subjects completed the survey but did not use the app, leaving an effective population of 58 subjects for analysis. Of these subjects, 53% (31/58) were women and 47% (27/58) were men. The mean age was 21 years, ranging between 18 and 29 years. The differences between the answers from both surveys were not statistically significant. The main sexual risk behaviors identified in the population were homosexual intercourse, nonuse of condoms, sexual intercourse with nonregular and commercial partners, the use of psychoactive substances, and lack of knowledge on symptoms of sexually transmitted diseases and HIV transmission. Conclusions: Although there were no differences between the pre- and postintervention results, the study revealed different risk behaviors among the participating subjects. These findings highlight the importance of promoting high-impact educational strategies on this matter and the importance of providing teenagers and young adults with easily accessible tools with reliable health information, regardless of their socioeconomic status

Parasites in Mexican patients with irritable bowel syndrome: a case-control study

One hundred and fifteen patients with symptoms suggestive of irritable bowel syndrome (IBS) according to Rome III criteria and 209 patients with gastrointestinal symptoms different from IBS (control) were identified through medical records from the Gastroenterology Clinic of the "Dr. Manuel Gea Gonzalez General Hospital" from January 2008 to March 2010. No statistical differences in IBS data as compared with control groups were observed except in bloating, that was more frequent in the IBS group (P = 0.043). Although the pathogenicity of specific intestinal protozoa could not be demonstrated due to lack of association with the development of gastrointestinal symptoms, Blastocystis spp, in the IBS group, exhibited a trend of association to diarrhoea (odds ratio = 2.73, 95% confidence interval = 0.84-8.80, P = 0.053), while having any parasite and diarrhoea was significant (odds ratio = 3.38, 95% confidence interval = 1.33-8.57, P = 0.008). The association between Blastocystis and diarrhoea in IBS patients although not conclusive is an interesting finding; nonetheless more extensive case-controlled studies are required to clearly define the role of some "non-pathogenic" parasites in intestinal disease and IBS

The U.S.-Mexico Border Infectious Disease Surveillance Project: Establishing Binational Border Surveillance

In 1997, the Centers for Disease Control and Prevention, the Mexican Secretariat of Health, and border health officials began the development of the Border Infectious Disease Surveillance (BIDS) project, a surveillance system for infectious diseases along the U.S.-Mexico border. During a 3-year period, a binational team implemented an active, sentinel surveillance system for hepatitis and febrile exanthems at 13 clinical sites. The network developed surveillance protocols, trained nine surveillance coordinators, established serologic testing at four Mexican border laboratories, and created agreements for data sharing and notification of selected diseases and outbreaks. BIDS facilitated investigations of dengue fever in Texas-Tamaulipas and measles in California–Baja California. BIDS demonstrates that a binational effort with local, state, and federal participation can create a regional surveillance system that crosses an international border. Reducing administrative, infrastructure, and political barriers to cross-border public health collaboration will enhance the effectiveness of disease prevention projects such as BIDS

Servicio centralizado de proyección de material docente

[ES] En los últimos años las tecnologías TIC se han ido incorporando en los diferentes ámbitos de la enseñanza, desde las pizarras electrónicas para las clases magistrales hasta el uso de tabletas para la visualización de libros docentes en formato electrónico. De hecho, resulta cada vez más frecuente que los docentes empleen sus portátiles para presentar su material en formato de transparencias. No obstante, esto implica que los profesores deben llevar sus portátiles al aula y conectarlos a través de un cable, sea VGA o HDMI, al proyector. Esto resta movilidad al profesor, anclado a través del cable al proyector, además de requerir que disponga de un portátil que ha de llevar al aula. Dado que, en la actualidad, casi la totalidad de la población dispone de móviles inteligentes, este artículo presenta la solución propuesta en un proyecto de innovación docente desarrollado (PID 14-61) en la Universidad de Granada. En éste, se propone una solución en la que el profesor sólo deberá llevar su móvil (o alternativamente una tableta o un portátil) al aula. El material docente será subido a un servidor central desde su despacho, y la visualización en el proyector será controlada a través del móvil usando una interfaz muy amigable y sencillo.El presente trabajo ha sido financiado a traves del Programa de Innovacion y Buenas Prácticas Docentes del Secretariado de Innovacion Docente de la Universidad de Granada, Proyecto de Innovacion Docente 14-61 ”Servicio de Proyeccion de Material Docente”, dentro de la acción 1 (innovacion en la gestión on-line de los procesos de ensenanza-aprendizaje). Parte del presente trabajo ha sido ˜ desarrollado por los alumnos D. Juan Ramon Gutiérrez Martínez, D. Daniel Alvarez González y D. David Gallardo Jimenez, siendo estos dos últimos becarios del citado PID.Navarro Ortiz, J.; Sendra, S.; Ameigeiras, P.; Torre, ADL.; Garcia, L.; Gomez, A.; Lopez-Soler, J.... (2018). Servicio centralizado de proyección de material docente. En XIII Jornadas de Ingeniería telemática (JITEL 2017). Libro de actas. Editorial Universitat Politècnica de València. 330-336. https://doi.org/10.4995/JITEL2017.2017.6508OCS33033

Estudio de perfiles de difracción de rayos X de una aleación Ti-13Ta-3Sn obtenida por aleado mecánico

Las aleaciones Ti-β se han vuelto altamente demandadas en la industria, por sus buenas características físicas y químicas. En el presente trabajo, se sintetizó una aleación Ti-13Ta-3Sn (%at) por aleado mecánico con tiempos entre 2 y 100h. Las aleaciones se caracterizaron por difracción de rayos X (DRX) y los patrones se analizaron por el método Rietveld con el software MAUD. Se caracterizaron los cambios microestructurales y la evolución de las fases Ti-α y Ti-β. Se identificó la presencia una nueva fase metaestable fcc y la síntesis de una aleación con un 79,80% en peso de fase Ti-β, ambas con tamaño de cristalita nanométrico. Palabras clave: Aleado mecánico, aleación Ti-β, difracción de rayos X

Plasma miRNA profile at COVID-19 onset predicts severity status and mortality

BACKGROUND: MicroRNAs (miRNAs) have a crucial role in regulating immune response against infectious diseases, showing changes early in disease onset and before the detection of the pathogen. Thus, we aimed to analyze the plasma miRNA profile at COVID-19 onset to identify miRNAs as early prognostic biomarkers of severity and survival. METHODS AND RESULTS: Plasma miRNome of 96 COVID-19 patients that developed asymptomatic/mild, moderate and severe disease was sequenced together with a group of healthy controls. Plasma immune-related biomarkers were also assessed. COVID-19 patients showed 200 significant differentially expressed (SDE) miRNAs concerning healthy controls, with upregulated putative targets of SARS-CoV-2, and inflammatory miRNAs. Among COVID-19 patients, 75 SDE miRNAs were observed in asymptomatic/mild compared to symptomatic patients, which were involved in platelet aggregation and cytokine pathways, among others. Moreover, 137 SDE miRNAs were identified between severe and moderate patients, where miRNAs targeting the SARS CoV-2 genome were the most strongly disrupted. Finally, we constructed a mortality predictive risk score (miRNA-MRS) with ten miRNAs. Patients with higher values had a higher risk of 90-days mortality (hazard ratio = 4.60; p-value < 0.001). Besides, the discriminant power of miRNA-MRS was significantly higher than the observed for age and gender (AUROC = 0.970 vs. 0.881; p = 0.042). CONCLUSIONS: SARS-CoV-2 infection deeply disturbs the plasma miRNome from an early stage of COVID-19, making miRNAs highly valuable as early predictors of severity and mortality