Incidence of Trypanosoma cruzi infection in two Guatemalan communities.

The prevalence of human infection by Trypanosoma cruzi was assessed using an enzyme-linked immunosorbent assay (ELISA) in a serological survey in 1998 of 2 rural communities (SMH and PS) in Guatemala. In SMH (Department of Zacapa), where Rhodnius prolixus was the principal vector, the seroprevalence amongst 373 people tested was 38.8%. In PS (Department of Santa Rosa), where the main vector was Triatoma dimidiata, 8.9% of the 428 people tested were seropositive. The overall prevalence of seropositivity was higher in females than in males in both SMH (40% vs 36%) and PS (11.9% vs 4.9%), although this difference was significant only in PS. Historical seroconversion rates, estimated retrospectively by fitting a transmission model to the age-prevalence curves, were 3.8% per year in SMH and 0.5% per year in PS. There was some indication of a recent reduction in incidence in both villages. In PS, but not in SMH, both the observed prevalence and the estimated incidence rates were significantly higher in females than in males

Differential antifungal activity of human and cryptococcal melanins with structural discrepancies

Indexación: Scopus.Melanin is a pigment found in all biological kingdoms, and plays a key role in protection against ultraviolet radiation, oxidizing agents, and ionizing radiation damage. Melanin exerts an antimicrobial activity against bacteria, fungi, and parasites. We demonstrated an antifungal activity of synthetic and human melanin against Candida sp. The members of the Cryptococcus neoformans and C. gattii species complexes are capsulated yeasts, which cause cryptococcosis. For both species melanin is an important virulence factor. To evaluate if cryptococcal and human melanins have antifungal activity against Cryptococcus species they both were assayed for their antifungal properties and physico-chemical characters. Melanin extracts from human hair and different strains of C. neoformans (n = 4) and C. gattii (n = 4) were investigated. The following minimum inhibitory concentrations were found for different melanins against C. neoformans and C. gattii were (average/range): 13.7/(7.8-15.6) and 19.5/(15.6-31.2) μg/mL, respectively, for human melanin; 273.4/(125- > 500) and 367.2/(125.5- > 500) μg/mL for C. neoformans melanin and 125/(62.5-250) and 156.2/(62-250) μg/mL for C. gattii melanin. Using Scanning Electron Microscopy we observed that human melanin showed a compact conformation and cryptococcal melanins exposed an amorphous conformation. Infrared spectroscopy (FTIR) showed some differences in the signals related to C-C bonds of the aromatic ring of the melanin monomers. High Performance Liquid Chromatography established differences in the chromatograms of fungal melanins extracts in comparison with human and synthetic melanin, particularly in the retention time of the main compound of fungal melanin extracts and also in the presence of minor unknown compounds. On the other hand, MALDI-TOF-MS analysis showed slight differences in the spectra, specifically the presence of a minor intensity ion in synthetic and human melanin, as well as in some fungal melanin extracts. We conclude that human melanin is more active than the two fungal melanins against Cryptococcus. Although some physico-chemical differences were found, they do not explain the differences in the antifungal activity against Cryptococcus of human and cryptococcal melanins. More detailed studies on the structure should be considered to associate structure and antifungal activity.https://www.frontiersin.org/articles/10.3389/fmicb.2017.01292/ful

Mineralogical Characterization and Ceramic Aplication of Muds From Washing of Natural Detritic Deposits

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasFALSEpu

Built Environment Factors Affecting Bike Sharing Ridership: Data-Driven Approach for Multiple Cities

Identification of factors influencing ridership is necessary for policy-making, as well as, when examining transferability and aspects of performance and reliability. In this work, a data-driven method is formulated to correlate arrivals and departures of station-based bike sharing systems with built environment factors in multiple cities. Ridership data from stations of multiple cities are pooled in one data set regardless of their geographic boundaries. The method bundles the collection, analysis, and processing of data, as well as, the model’s estimation using statistical and machine learning techniques. The method was applied on a national level in six cities in Germany, and also on an international level in three cities in Europe and North America. The results suggest that the model’s performance did not depend on clustering cities by size but by the relative daily distribution of the rentals. Selected statistically significant factors were identified to vary temporally (e.g., nightclubs were significant during the night). The most influencing variables were related to the city population, distance to city center, leisure-related establishments, and transport-related infrastructure. This data-driven method can help as a support decision-making tool to implement or expand bike sharing systems

A Deep Learning based Generalized Ground Motion Model for the Chilean Subduction Seismic Environment

This paper proposes a deep learning-based generalized ground motion model (GGMM) for interface and inslab subduction earthquakes recorded in Chile. A total of ~7000 ground-motion records from ~1700 events are used to train the GGMM. Unlike common ground-motion models (GMM), which generally consider individual ground-motion intensity measures such as spectral acceleration at a given period, the proposed GGMM is a data-driven framework that coherently uses recurrent neural networks (RNN) and hierarchical mixed-effects regression to output a cross-dependent vector of 35 ground-motion intensity measures (IM). The IM vector includes geomean of Arias intensity, peak ground velocity, peak ground acceleration, and significant duration, and RotD50 spectral accelerations at 32 periods between 0.05 to 5 seconds (denoted as Sa(T)). The inputs to the GMM include six causal seismic source and site parameters. The statistical evaluation of the proposed GGMM shows that the proposed framework results in high prediction power with coefficient of determination R2 > 0.7 for most IMs while maintaining the cross-IM dependencies. Furthermore, it is observed that the proposed GGMM leads to better goodness of fit for all periods of Sa(T) compared to two state-of-the-art Chilean GMMs (on average 0.2 higher R2)

A recurrent-neural-network-based generalized ground-motion model for the Chilean subduction seismic environment

This paper proposes a deep learning-based generalized ground motion model (GGMM) for interface and intraslab subduction earthquakes recorded in Chile. A total of ∼7000 ground-motion records from ∼1700 events are used to train the proposed GGMM. Unlike common ground-motion models (GMMs), which generally consider individual ground-motion intensity measures such as peak ground acceleration and spectral accelerations at given structural periods, the proposed GGMM is based on a data-driven framework that coherently uses recurrent neural networks (RNNs) and hierarchical mixed-effects regression to output a cross-dependent vector of 35 ground-motion intensity measures (denoted as IM). The IM vector includes geometric mean of Arias intensity, peak ground velocity, peak ground acceleration, and significant duration (denoted as Iageom, PGVgeom, PGAgeom, and D5-95geom, respectively), and RotD50 spectral accelerations at 31 periods between 0.05 and 5 s for a 5 % damped oscillator (denoted as Sa(T)). The inputs to the GGMM include six causal seismic source and site parameters, including fault slab mechanism, moment magnitude, closest rupture distance, Joyne-Boore distance, soil shear-wave velocity, and hypocentral depth. The statistical evaluation of the proposed GGMM shows high prediction power with R2 > 0.7 for most IMs while maintaining the cross-IM dependencies. Furthermore, the GGMM is carefully compared against two state-of-the-art Chilean GMMs, showing that the proposed GGMM leads to better goodness of fit for all periods of Sa(T) compared to the two considered GMMs (on average 0.2 higher R2). Finally, the GGMM is implemented to select hazard-consistent ground motions for nonlinear time history analysis of a sophisticated finite-element model of a 20-story steel special moment-resisting frame. Results of this analysis are statistically compared against those for hazard-consistent ground motions selected based on the conditional mean spectrum (CMS) approach. In general, it is observed that the drift demands computed using the two approaches cannot be considered statistically similar and the GGMM leads to higher demands

Analysis of human physical vulnerability using static equilibrium techniques of a Hazard flood for the determination of unsafe areas in the city of Catacaos - Piura, Peru

Heavy rains and El Nio phenomenon are recurring natural phenomena at a national level. These can cause floods due to the overflowing of rivers, which, when close to cities, can cause both human and material losses. The district of Catacaos, located in the city of Piura, was the one with the highest number of injuries due to the flood caused by El Nio phenomenon in 2017. This phenomenon causes a large amounts of rainfalls due to the presence of abnormally warm waters along the northern coast of Peru [1]. It is for this reason that the need arose to carry out an analysis of the physical vulnerability due to instability of people through static equilibrium, in said district, in order to present maps of unsafe areas in the face of this phenomenon. In this investigation, flood hazard maps are generated simulating the one presented in 2017, using 2D hydraulic modeling. For the generation of vulnerability curves, the instability analysis is performed by moment and drag force. Finally, maps with unsafe areas are made using ArcGis software. Where the results obtained indicate that 29.37% of the city was flooded. Likewise, the vulnerability maps generated show us that women and men over 18 years of age in the city of Catacaos would be vulnerable to dragging and overturning in the face of floods in 16.54% and 13.21%, respectively, of the total studied area. This information will be useful for the development of future evacuation plans during floods, carried out by national entities. © Published under licence by IOP Publishing Ltd

Bouc émissaire, substitution sacrificielle, violence et corporalité

Este texto desarrolla una reflexión de la relación entre culto, celebración y sustituto sacrificial en la fundación del tiempo-espacio humano. Para ello, se recurre a la novela de D. H. Lawrence The Plumed Serpent (La Serpiente Emplumada), donde se retrata una corrida de toros. Para leer este fragmento de la novela, el argumento que articula el texto tiene como soporte enunciativo el concepto de chivo expiatorio de René Girard, el de fetiche desarrollado por Auguste Comte y el análisis de Michel Serres sobre el intercambio sacrificial que le da sustrato a toda práctica social humana.Este artigo desenvolve uma reflexão sobre a relação entre culto, celebração e substituto sacrificial na fundação do tempo-espaço humano. Para isso, o autor recorre ao romance de D. H. Lawrence´s, The Plumed Serpent, onde é representada uma tourada. Para ler este fragmento do romance, o argumento que articula o texto tem como suporte expositivo o conceito de bode expiatório de René Girad, o conceito de fetichismo desenvolvido por Auguste Comte, e a análise de Michel Serres sobre a troca sacrificial que sustenta a totalidade da prática social humana.This article develops a reflection on the relationship among between cult, celebration, and sacrificial substitution in the foundation of human time-space. For this purpose, the author resorts to D. H. Lawrence´s novel The Plumed Serpent, where a bullfight is depicted. For reading this fragment of the novel, the argument articulating the text has as an finds expository support in René Girad´s concept of the scapegoat, the concept of fetishism developed by Auguste Comte, and Michel Serres´ analysis on the of sacrificial exchange which supports the whole totality of human social practice.Cet article propose une réflexion sur la relation entre culte, célébration et substitution sacrificielle dans la fondation du temps-espace humain. L’auteur utilise pour cela le roman de D. H. Lawrence, Le Serpent à Plumes, où est décrite une corrida. Pour lire ce passage du roman, l’argument qui structure le texte s’appuie sur le concept de bouc émissaire de René Girad, le concept de fétichisme développé par Auguste Comte et l’analyse de Michel Serres sur la substitution sacrificielle à la base de toute la pratique sociale humaine