Implementation of a FFT/IFFT Module on FPGA: Comparison of Methodologies

In this work, we have compared three different methodologies for the implementation of a FFT/IFFT module on FPGA: VHDL coding (VC), System-level tools at RT level (STR), and System-level tools at macroblock level (STM). In terms of resource usage and operation frequency, STM has obtained interesting results, although it has an important restriction about internal data width which produces a mean output error of 2.1%. VC and STR become a more general alternative that yields to a lower mean error (1.0%). Thus, we propose to combine VC and STR in order to facilitate the design process as well as allow designers to maintain total control over the module internal architecture and obtain an efficient structure

Association between long-term air pollution exposure and COVID-19 mortality in Latin America

Recent studies have shown a relationship between air pollution and increased vulnerability and mortality due to COVID-19. Most of these studies have looked at developed countries. This study examines the relationship between long-term exposure to air pollution and COVID-19-related deaths in four countries of Latin America that have been highly affected by the pandemic: Brazil, Chile, Colombia, and Mexico. Our results suggest that an increase in long-term exposure of 1 μg/m3 of fine particles is associated with a 2.7 percent increase in the COVID-19 mortality rate. This relationship is found primarily in municipalities of metropolitan areas, where urban air pollution sources dominate, and air quality guidelines are usually exceeded. By focusing the analysis on Latin America, we provide a first glimpse on the role of air pollution as a risk factor for COVID-19 mortality within a context characterized by weak environmental institutions, limited health care capacity and high levels of inequality

Open Development Platform for Embedded Systems

Ministerio de Economía y Competitividad TEC2011-2793

Hepatitis C virus molecular evolution: Transmission, disease progression and antiviral therapy

Hepatitis C virus (HCV) infection represents an important public health problem worldwide. Reduction of HCV morbidity and mortality is a current challenge owned to several viral and host factors. Virus molecular evolution plays an important role in HCV transmission, disease progression and therapy outcome. The high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures (e.g., host immune responses and antiviral therapy). HCV molecular evolution is shaped by different mechanisms including a high mutation rate, genetic bottlenecks, genetic drift, recombination, temporal variations and compartmentalization. These evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging manner. Remarkable advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against HCV. As a result, superior sustained viral responses have been attained. The rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer, more potent antivirals, bringing us one step closer to the interferon-free era.Fil: Preciado, María Victoria. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Valva, Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños ; ArgentinaFil: Escobar Gutierrez, Alejandro. Instituto de Diagnóstico y Referencia Epidemiológicos; MéxicoFil: Rahal, Paula. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Ruiz Tovar, Karina. Instituto de Diagnóstico y Referencia Epidemiológicos; MéxicoFil: Yamasaki, Lilian. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Vazquez Chacon, Carlos. Instituto de Diagnóstico y Referencia Epidemiológicos; MéxicoFil: Martinez Guarneros, Armando. Instituto de Diagnóstico y Referencia Epidemiológicos; MéxicoFil: Carpio Pedroza, Juan Carlos. Instituto de Diagnóstico y Referencia Epidemiológicos; MéxicoFil: Fonseca Coronado, Salvador. Universidad Nacional Autónoma de México; MéxicoFil: Cruz Rivera, Mayra. Universidad Nacional Autónoma de México; Méxic

Aminopropyltransferases Involved in Polyamine Biosynthesis Localize Preferentially in the Nucleus of Plant Cells

Plant aminopropyltransferases consist of a group of enzymes that transfer aminopropyl groups derived from decarboxylated S-adenosyl-methionine (dcAdoMet or dcSAM) to propylamine acceptors to produce polyamines, ubiquitous metabolites with positive charge at physiological pH. Spermidine synthase (SPDS) uses putrescine as amino acceptor to form spermidine, whereas spermine synthase (SPMS) and thermospermine synthase (TSPMS) use spermidine as acceptor to synthesize the isomers spermine and thermospermine respectively. In previous work it was shown that both SPDS1 and SPDS2 can physically interact with SPMS although no data concerning the subcellular localization was reported. Here we study the subcellular localization of these enzymes and their protein dimer complexes with gateway-based Bimolecular Fluorescence Complementation (BiFC) binary vectors. In addition, we have characterized the molecular weight of the enzyme complexes by gel filtration chromatography with in vitro assembled recombinant enzymes and with endogenous plant protein extracts. Our data suggest that aminopropyltransferases display a dual subcellular localization both in the cytosol and nuclear enriched fractions, and they assemble preferably as dimers. The BiFC transient expression data suggest that aminopropyltransferase heterodimer complexes take place preferentially inside the nucleus

Mecanismo de desvitrificación No-Isotérmica de una aleación

RESUMEN: Los vidrios metálicos del tipo FeSiB exhiben características magnéticas blandas que los hacen atractivos para núcleos de transformadores, por sus bajas pérdidas por histéresis. Las muestras amorfas de aleación Fe0,75Si0,15B0,10 se obtuvieron por Melt spinning, en la Universidad de Antioquia, pionera en Colombia en la implementación de esta técnica. Las muestras cristalinas se obtuvieron a partir de las muestras amorfas por un tratamiento isotérmico a 600 °C durante una hora. Tanto las muestras amorfa y cristalina fueron evaluadas por las técnicas XRD, TGA, y VSM (magnetometría vibrante). El material amorfo mostró nula cristalinidad y su curva de histéresis muestra que es magnéticamente blando. Por otro lado, las muestras cristalinas exhiben mayor pérdidas por histéresis. El mecanismo propuesto de la transformación amorfa → cristalina en condiciones no isotérmicas, evidenciado por el ensayo DSC, plantea una secuencia de tres pasos: En la primera etapa se forman dos fases amorfas activadas (sin liberación apreciable de calor), una rica en silicio, la otra rica en boro, vía una reacción de primer orden, con un parámetro cinético k0. A medida que transcurre el calentamiento la fase rica en silicio precipita una primera fase cristalina, solución sólida de silicio en hierro, αI(Fe,Si), con estructura BCC, a temperaturas desde 520 a 540 °C, mediante el parámetro k1. Después, la fase rica en boro precipita simultáneamente el compuesto Fe2B y termina la precipitación de αII(Fe,Si), vía el parámetro cinético k2. Estos dos últimos eventos son exotérmicos y se correlacionan a los respectivos picos del diagrama DSC. La fracción en masa del compuesto Fe2B se deduce estequiométricamente de la aleación. A partir de los datos experimentales se deduce el calor de cristalización promedio de la fase α(Fe,Si). El mecanismo se aplica relativamente bien a tres composiciones Fe, Si, B cercanas a la obtenida en este estudio, extraídas de la bibliografía, corroborando los resultados obtenidos. Se plantea una interpretación del calor de cristalización a partir de los datos de entalpía de mezclado y la capacidad calórica de las aleaciones Fe-Si.ABSTRACT: FeSiB based metallic glasses show magnetic softness. This characteristic allows its use in high frequencies, core transformers applications. Amorphous samples of Fe0,75Si0,15B0,10 were obtained at Universidad de Antioquia, pioneering in to develop the Melt spinning technique in Colombia. The samples were annealed at 600 °C in argon atmosphere for 1 hour in order to achieve complete crystallization. The samples were evaluated by XRD, TGA and VSM. The hysteresis loop of the amorphous material demonstrate its magnetically softness characteristic but the crystalline material has bigger hysteresis losses. The DSC profiles at 20 C/min of the amorphous FeSiB alloys show clearly the Curie temperature (Tc) and two exothermic peaks: the first one is associated to the solid solution αI(Fe,Si) precipitation and the second peak is, related to the iron boride formation compound and a new formation of αII(Fe,Si) particles. These results were explained with an initial proposal of a non-isothermal devitrification mechanism of a Fe0,75Si0,15B0,10 amorphous alloy. The mechanism comprises three stages: Initially, the parent amorphous matrix was dissociated onto two amorphous silicon and boron rich zones, by means of a first order kinetic parameter, k0. Secondly, silicon rich zones are exothermally transformed into an αI(Fe,Si) crystalline matrix, via the kinetic parameter, k1, explaining the first peak event. Lastly, the boron rich zones were transformed into a Fe2B + αII(Fe,Si) crystalline compounds, by means of k2 parameter. The Fe2B crystalline was stoichiometry calculated from the initial metallic composition. The heat flux per unit mass and time, associated to the Fe2B compound was evaluated using thermodynamic values. The enthalpies associated of the α(Fe,Si) precipitation were deduced from experimental data

Desarrollo de una interfaz RS-232 para el manejo de un coche de radiocontrol desde el PC

Este trabajo presenta el desarrollo de un sistema de radiocontrol para un coche teledirigido. Se trata de un circuito que, conectado al interfaz serie de un PC, permite controlar el coche desde una aplicación en lenguaje G. Así, el proceso de desarrollo se plantea como una práctica de laboratorio muy interesante y atractiva para los alumnos que cubre materias como la programación de periféricos, la comunicación con equipos informáticos y el control de sistemas a nivel de software

Is ultra-violet radiation the main force shaping molecular evolution of varicella-zoster virus?

<p>Abstract</p> <p>Background</p> <p>Varicella (chickenpox) exhibits a characteristic epidemiological pattern which is associated with climate. In general, primary infections in tropical regions are comparatively less frequent among children than in temperate regions. This peculiarity regarding varicella-zoster virus (VZV) infection among certain age groups in tropical regions results in increased susceptibility during adulthood in these regions. Moreover, this disease shows a cyclic behavior in which the number of cases increases significantly during winter and spring. This observation further supports the participation of environmental factors in global epidemiology of chickenpox. However, the underlying mechanisms responsible for this distinctive disease behavior are not understood completely. In a recent publication, Philip S. Rice has put forward an interesting hypothesis suggesting that ultra-violet (UV) radiation is the major environmental factor driving the molecular evolution of VZV.</p> <p>Discussion</p> <p>While we welcomed the attempt to explain the mechanisms controlling VZV transmission and distribution, we argue that Rice's hypothesis takes lightly the circulation of the so called "temperate VZV genotypes" in tropical regions and, to certain degree, overlooks the predominance of such lineages in certain non-temperate areas. Here, we further discuss and present new information about the overwhelming dominance of temperate VZV genotypes in Mexico regardless of geographical location and climate.</p> <p>Summary</p> <p>UV radiation does not satisfactorily explain the distribution of VZV genotypes in different tropical and temperate regions of Mexico. Additionally, the cyclic behavior of varicella does not shown significant differences between regions with different climates in the country. More studies should be conducted to identify the factors directly involved in viral spreading. A better understanding of the modes of transmissions exploited by VZV and their effect on viral fitness is likely to facilitate the implementation of preventive measures for disease control.</p

Chronic Expanding Hematoma Secondary to Excision of Recurrent Myxomas in a Bitch

Background: Expanding chronic hematoma is a relatively common postoperative complication in humans, not in dogs, nevertheless, is important understand this condition because it may affect the animal's health. A hematoma could be formed within hours and usually stabilizes spontaneously with the reabsorption of its content. However, occasionally the hematoma slowly expands, becomes encapsulated and forms a mass, causing a chronic expanding hematoma. Possibly skin and adipose tissue are displaced secondary to trauma, causing the formation of blood-filled cysts surrounded by a fibrous capsule. The aim of this document is to present the first report of a postsurgical chronic expanding hematoma in dog. Case: A case of chronic expanding hematoma secondary to excision of recurrent myxoma in a bitch was described. Physical examination showed a hard, firm, non-mobile mass enclosed within the deep muscular layers. This mass was between the sternum and the cranial abdomen, similar to previous lesions excised by another veterinarian. Fine needle aspiration indicated the presence of blood. Radiology demonstrated that the bone-cartilage tissue was not involved. Due to the size of the mass, a skin stretching pre-suturing technique using self-adhesive tape was applied around the mass 48 h before surgery.  The mass was removed with wide excision margins and portions of the affected muscles, but a large wound with great tension was created; consequently, a parallel to the wound incision and the thoraco-lumbar vertebrae was made.  Six months after surgery, the animal presented recurrence of the same lesion, which was also removed. The bleeding times were within the normal range, but the animal was diagnosed with hyperadrenocorticism. After both surgeries histopathological exam revealed a hematoma, that had thrombosis and granulation tissue with fibrosis and severe panniculitis, in addition of multifocal, chronic, moderate lymphohistiocytic myositis; all these changes were compatible with a chronic expanding hematoma.  Discussion: Chronic expanding hematoma is a mass that grows slowly secondary to hemorrhage and does not exhibit elements of malignancy. However, it can occasionally be confused for a soft-tissue neoplasm. It has been reported frequently in humans but not in small animals. The first case was reported in 2002: 5 puppies with a cervical hematoma classified as a chronic expanding hematoma was described. In addition, 3 cases were reported: 1 cat with perirenal chronic expanding hematoma; 1 bitch with intra-abdominal presentation, and 1 cat with this pathology on the right pelvic limb after an intramuscular injection.  The etiology of chronic expansive hematoma is unidentified in dogs, nevertheless, it is stipulated that is not an inflammatory process as previously assumed, but rather a neoplastic process. As in other cases, it was difficult to determine the origin of the chronic expanding hematoma. The coagulation times and platelets count were within ranges. Similarly, it is very complicated to relate hyperadrenocorticism with chronic expanding hematoma because dogs with Cushing’s disease generally present hypercoagulopathies. Myxomas are associated with endocrinopathies in humans and dogs, therefore, hyperadrenocorticism is possibly related with this neoplasia. Myxomas have an expansive growth pattern, contrasting with myxosarcomas, which are infiltrating; Although in the present case the skin mass appeared to be invasive, both macroscopical and histopathological appearance of it corresponded to a well-shaped capsule compatible with chronic expanding hematoma. In summary, to the best of our knowledge, this is the first report of a post-surgical chronic expanding hematoma in a dog.    Keywords: dog, canine, surgery, expanding hematoma, postoperative complications, myxomas, small animal