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Simple synthesis of gold-decorated silica nanoparticles by in situ precipitation method with new plasmonic properties
No full textWe describe a simple method for the preparation of gold-decorated silica (SiO2) nanoparticles (NPs) by the in situ precipitation method using simple BH4? ions reduction as a procedure, where BH4? ions are adsorbed onto PEI-functionalized SiO2 NPs for stabilizing and reducing gold ions onto PEI-SiO2 surface in water under ambient conditions. The result was 3-nm gold nanoshell NPs attached to SiO2 core (~ 75 nm) with a surface plasmon resonance (SPR) at ~ 680 nm. SPR band is associated with Au NP aggregates that arise from strong interparticle interaction. This is an alternative to the gold-seeding methods and the use of anionic gold species for the obtention of gold-decorated SiO2 NPs with an important red-shift in UV–Vis absorption and with potential applications in biosensors and photothermal therapy.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Monitoring versus prediction of the power of three different PV technologies in the coast of Lima-Peru
No full textThis article presents the benefits of two simple analytical models for estimating the outdoor performance of three different photovoltaic technologies in Lima, Peru. The Osterwald and the constant fill factor models are implemented to estimate the maximum power delivered by three photovoltaic module technologies: aluminum back surface field, heterojunction with intrinsic thin-layer and amorphous/microcrystalline thin-film tandem. A 12-months experimental campaign is carried out through measurements of current-voltage curves, irradiance and module temperature. The results show that both models overestimate the modelled power when compared to the measured one. In order to correct the maximum power predicted by both models, a correction factor is introduced. This correction factor allows us to estimate losses and a respective effective nominal power to minimize the prediction error on a monthly and yearly basis. These parameters demonstrate a unique behavior for each technology during different months implying different seasonal impacts of the ambient variables on the module performance. The effectiveness of this correction factor is demonstrated through accuracy measures. It enables the photovoltaic power prediction with an error < 1% for the particular climate in Lima, Peru. © 2021 Published under licence by IOP Publishing Ltd.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Changes in rocky intertidal communities after the 2015 and 2017 El Niño events along the Peruvian coast
No full textThe Peruvian coast experiences the largest interannual variability of sea surface temperature in the world due to the combined influence of the coastal upwelling and El Niño Southern Oscillation (ENSO). Although biological impacts of El Niño events have been widely reported, their effects on rocky intertidal communities remains largely unknown in Peru. Herein, we analyze the results of two biological surveys of rocky intertidal communities, conducted along 1400 km of the Peruvian coast. The first survey was conducted in 2015 yielding a snapshot of the distribution of rocky intertidal communities after 17 years of stable La Niña-like conditions. The second survey was carried in October 2017, after the 2015-16 and the 2017 El Niño events, which produced warm sea surface temperature (SST) anomalies up to 6 °C on the Peruvian coast. We find no changes throughout the latitudinal transect in taxonomic richness but an important turnover of species, especially marked in the transition zone (~4–8°S) between the Panamic and the Humboldt provinces. Temperature-related southward migration of species was evidenced in a few sites but did not explain the large-scale change in communities observed from 2015 to 2017, primarily driven by large changes in the distribution of a few ecologically important species across the Panamic and Humboldt provinces. A primary environmental impact on some ecologically key species likely triggered a chain of secondary impacts through ecological relationships which lead to a complex change independent from SST gradients. Further studies are needed to better characterize and disentangle the seasonal and interannual variability of the rocky intertidal communities and their drivers. When this interannual variability is integrated, the nine study sites show a highly persistent community structure determined by the latitudinal SST gradient along the Peruvian coast. © 2020 Elsevier LtdConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Trends and patterns of the double burden of malnutrition (DBM) in Peru: a pooled analysis of 129,159 mother–child dyads
No full textBackground: This study aims to evaluate trends of DBM in Peru over the last 20 years. Methods: Using individual-level data collected in nationally representative household surveys from Peru between 1996 and 2017, we analysed trends in the prevalence and patterning of the DBM. We classified the nutritional status of children and their mothers as undernourished (either underweight, stunted or wasted for children), normal, overweight or obese. Children classified as experiencing the DBM were those undernourished and living with an overweight or obese mother. We also fitted logistic regression models to evaluate the probability of children having an overweight/obese mother across subgroups of socioeconomic status, place of residence and education. Results: The overall percentage of children experiencing the DBM in 2016 was 7%, and constitutes ~203,600 children (90% of whom were stunted). Between 1996 and 2016, undernourished children have seen the largest relative increase in the risk of having an overweight mother (31% vs. 37%) or obese mother (6% vs. 17%); however, due to the substantial decrease in the absolute number of undernourished children, the DBM has not grown. Moreover, all children, irrespective of their own nutritional status, are now more likely to live with an overweight or obese mother, a consistent pattern across wealth, location and education subgroups, and all regions of Peru. Conclusions: DBM prevalence in Peru has decreased, although the number of DBM cases is estimated to be above 200,000. In addition, all children are now more likely to live with overweight or obese mothers. The basic pattern has shifted from one of undernourished children whose mothers have a ‘normal’ BMI, to one where now most children have a ‘normal’ or healthy anthropometric status, but whose mothers are overweight or obese. This suggest that Peru is on the cusp of a major public health challenge requiring significant action. © 2021, The Author(s).Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Surface processes at a polymetallic (Mn-Fe-Pb) sulfide subject to cyanide leaching under sonication conditions and with an alkaline pretreatment: Understanding differences in silver extraction with X-ray photoelectron spectroscopy (XPS)
No full textLeaching of polymetallic sulfides is often challenging due to the complexity of these systems. The main issues are related to the formation of surface by-products or to the presence of different metals that require a greater consumption of chemicals compared to that needed to extract the target metal during leaching. This latter case is followed in the present work using X-ray photoelectron spectroscopy (XPS) during the leaching of a silver-containing polymetallic (Mn-Fe-Pb) sulfide under three different cyanidation procedures: (1) conventional leaching, (2) ultrasound-assisted leaching, and (3) leaching of a sample pretreated in alkaline media. In all cases, leaching results in the build-up of Pb compounds (oxides/hydroxides) on the surface of the minerals, suggesting a mechanism in which Pb is first leached by hydroxide and cyanide and later is re-adsorbed as an external layer on the minerals. On the other hand, the effect of each process on Mn was quite distinct: 1) Conventional leaching leads to the oxidation of the sulfide (pyrite) surface and a slight increase of surface Mn species; 2) Ultrasound-assisted leaching decreases surface Mn by dissolving oxidized species, which exposes fresh sulfide surfaces and increases Ag extraction; and 3) An alkaline pretreatment at high temperature exposed fresh sulfide surfaces and decreased the surface concentration of Mn. The fact that ultrasound-assisted leaching and leaching after an alkaline pretreatment allow for a higher Ag extraction (60% and 75% of total Ag, respectively, as opposed to the 25% extracted via conventional leaching), indicates that leaching is more efficient if the surface is not oxidized and if Mn is removed from the samples, either before or during leaching. © 2020 Elsevier B.V.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Assessing near real-time satellite precipitation products for flood simulations at sub-daily scales in a sparsely gauged watershed in Peruvian andes
No full textThis study investigates the applicability of Satellite Precipitation Products (SPPs) in near real-time for the simulation of sub-daily runoff in the Vilcanota River basin, located in the south-eastern Andes of Peru. The data from rain gauge stations are used to evaluate the quality of Integrated Multi-satellite Retrievals for GPM–Early (IMERG-E), Global Satellite Mapping of Precipita-tion–Near Real-Time (GSMaP-NRT), Climate Prediction Center Morphing Method (CMORPH), and HydroEstimator (HE) at the pixel-station level; and these SPPs are used as meteorological inputs for the hourly hydrological modeling. The GR4H model is calibrated with the hydrometric station of the longest record, and model simulations are also verified at one station upstream and two stations downstream of the calibration point. Comparing the sub-daily precipitation data observed, the results show that the IMERG-E product generally presents higher quality, followed by GSMaP-NRT, CMORPH, and HE. Although the SPPs present positive and negative biases, ranging from mild to moderate, they do represent the diurnal and seasonal variability of the hourly precipitation in the study area. In terms of the average of Kling-Gupta metric (KGE), the GR4H_GSMaP-NRT’ yielded the best representation of hourly discharges (0.686), followed by GR4H_IMERG-E’ (0.623), GR4H_Ensemble-Mean (0.617) and GR4H_CMORPH’ (0.606), and GR4H_HE’ (0.516). Finally, the SPPs showed a high potential for monitoring floods in the Vilcanota basin in near real-time at the operational level. The results obtained in this research are very useful for implementing flood early warning systems in the Vilcanota basin and will allow the monitoring and short-term hydrological forecasting of floods by the Peruvian National Weather and Hydrological Service. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Agaricus bisporus mushroom as partial fat replacer improves the sensory quality maintaining the instrumental characteristics of beef burger
No full textIliani Patinho is grateful to CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil, for the master scholarship (process n° 1766129). Juan D. Rios-Mera received the support of the CIENCIACTIVA programme, PhD scholarship contract n° 238-2018-FONDECYT. The authors would also like to thank Zucca mushrooms Company, VPJ Foods, Ibrac Additives and Condiments and Sealed Air Brazil, for donating ingredients, raw materials and packaging.The effect of Agaricus bisporus (AB) mushroom as a fat replacer in beef burgers was evaluated. Four treatments were compared: control (0% AB, 20% fat) and 3 treatments with partial fat replacement: AB 5% (5% AB, 15% fat); AB 10% (10% AB, 10% fat); AB 15% (AB 15%, 5% fat). Mushroom addition increased moisture content and yield and decreased cooking loss and diameter reduction of the burgers. Formulations with the highest AB concentrations were lighter and redder than the control. AB incorporation affected texture, resulting in less hard and less chewy products. In general, lipid oxidation increased during the storage time, however the lowest values were observed in AB 15%, i.e. the lowest fat content and the presence of AB increased the oxidative stability. AB 10% and AB 15% had good overall liking and were sensorially characterized as juicy, tender and flavorsome burgers. The partial replacement of animal fat by AB is a promising strategy for developing a low-fat burger. © 2020 Elsevier LtdFondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Associations among household animal ownership, infrastructure, and hygiene characteristics with source attribution of household fecal contamination in Peri-urban communities of Iquitos, Peru
No full textUsing previously validated microbial source tracking markers, we detected and quantified fecal contamination from avian species and avian exposure, dogs, and humans on household cooking tables and floors. The association among contamination, infrastructure, and socioeconomic covariates was assessed using simple and multiple ordinal logistic regressions. The presence of Campylobacter spp. in surface samples was linked to avian markers. Using molecular methods, animal feces were detected in 75.0% and human feces in 20.2% of 104 households. Floors were more contaminated than tables as detected by the avian marker Av4143, dog marker Bactcan, and human marker Bachum. Wood tables were consistently more contaminated than non-wood surfaces, specifically with the mitochondrial avian markers ND5 and CytB, fecal marker Av4143, and canine marker Bactcan. Final multivariable models with socioeconomic and infrastructure characteristics included as covariates indicate that detection of avian feces and avian exposure was associated with the presence of chickens, maternal age, and length of tenancy, whereas detection of human markers was associated with unimproved water source. Detection of Campylobacter in surface samples was associated with the avian fecal marker Av4143. We highlight the critical need to detect and measure the burden of animal fecal waste when evaluating household water, hygiene, and sanitation interventions, and the possibility of decreasing risk of exposure through the modification of surfaces to permit more effective household disinfection practices. Animals may be a more important source of household fecal contamination than humans in many low-resource settings, although interventions have historically focused almost exclusively on managing human waste. © 2021 by The American Society of Tropical Medicine and HygieneFondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Comparison of learning management system platforms for choosing a suitable platform for users in research administration
No full textThe present paper is a comparison of three types of e-learning management systems. In the research administration of the University of Sciences and Humanities, a platform of online courses is aimed to achieve training and project courses that will be focused on the institution's researchers. For this purpose, it is necessary to use tools adapted to the way of working that are user-friendly and can be adapted to the users' requirements. Therefore, the three platforms' comparison was performed by measuring the following points: Description of the platforms' characteristics, description of the functionality, and the comparative analysis. This research is made to be implemented in the Image Processing Research Laboratory (INTI-Lab) server and to use the platform at the beginning of the year 2020. Online courses have become a tool that allows people to obtain knowledge rapidly, and as researchers, to adapt to these modalities makes the distribution of information faster and easier. © 2021 Seventh Sense Research Group®.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
I + D + i Perú: Innovación, Ciencia y Tecnología para un crecimiento sustentable (N° 1 / Mayo - Julio 2021)
No full textMuestra algunos resultados recientes del esfuerzo que el Estado realiza a través del Concytec, financiando proyectos de investigación con calidad y pertinencia para el desarrollo económico y social