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Sensory and hedonic impact of the replacement of synthetic antioxidant for pink pepper residue extract in chicken burger
No full textThis study aimed to evaluate the sensory and hedonic perceptions of chicken burger manufactured with pink pepper residue extract (PPE) added to the meat and to the chitosan film. Five samples were manufactured: CT: control, without antioxidant; DP and FP: addition of PPE to the meat batter and to the film, respectively; C1 and C2: commercial brands of chicken burgers. Consumers characterized the samples using the overall liking test and Check-all-that-apply questions. The samples showed a medium–high level of acceptance and no significant differences were found between them. DP was the farthest sample from the ideal and FP showed positive results, since its characteristics were like the commercial samples. The direct extract application may lead to a reduction in the liking of chicken burgers, demonstrating that the technology of active films is a viable alternative to the use of natural antioxidant extracts in meat products. © 2019, Association of Food Scientists & Technologists (India).Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Arsenic in Peruvian rice cultivated in the major rice growing region of Tumbes river basin
No full textArsenic (As) exposure from surface and groundwater in Peru is being recognised as a potential threat but there are limited studies on As in the food-chain and none on As in Peruvian rice. In this study, we have determined the As content in rice cultivated in the Tumbes river basin located in the northern province of Peru, an area known for extensive rice cultivation. We collected rice and soil samples from agricultural fields, soil was collected using grid sampling technique while rice was collected from the heaps of harvested crop placed across the fields. The average total As concentration in rice was 167.94 ± 71 μg kg−1 (n = 29; range 68.39–345.31 μg kg−1). While the rice As levels were not highly elevated, the As content of few samples (n = 7) greater than 200 μg kg−1 could contribute negatively to human health upon chronic exposure. Average concentration of As in soil was 8.63 ± 7.8 mg kg−1 (n = 30) and soil to grain transfer factor was 0.025 ± 0.018 for 12 matched samples. Compared to our previous pilot study in 2006 (samples collected from the same agricultural fields but not from exact locations) there was a 41% decrease in As soil concentration in this study. Rice samples collected in 2006 (n = 5) had a mean concentration of 420 ± 109 μg kg−1. Our data provides a baseline of rice grain As concentrations in Peruvian province of Tumbes and warrants further studies on factors affecting uptake of As by the rice varieties cultivated in Peru and any potential human health risks. © 2019 Elsevier LtdConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Carbon-based perovskite solar cells by screen printing with preheating
No full textCarbon-based perovskite solar cells were manufactured by the screen-printing method using a triple mesoscopic layer of TiO2, ZrO2 and carbon. The perovskite solution was infiltrated at the TiO2/ZrO2 porous interface through the printed carbon layer on top of the ZrO2. Using a simple preheating of the substrates and the perovskite solution, a film deposited in air can be obtained. Using this method, an air-processed CPSC made under a humid atmosphere with 55% RH achieved a PCE of 10.35%. © Published under licence by IOP Publishing Ltd.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Forecast model of piura river flows calibrated with El Niño Costero 2017 [Pronóstico de caudales del río Piura calibrado con El Niño Costero 2017]
No full textThe extraordinary El Niño Costero of 2017 has affected the Peruvian coast, mainly in the Piura region, with the flooding of the Piura river, impacting rural and urban areas in the middle and lower basin. This paper analyses the situation from the perspective of hydrology. Since 2002, the basin has had an early warning system (EWS) made up of a hydrometeorological network and a forecast model, NAXOS. The EWS predicted flows at the Los Ejidos hydrometric station, located immediately upstream of Piura City. The hydrometeorological network has been gradually losing its operation and NAXOS has been left uncalibrated. Its inaccurate forecasts contributed to poor decision-making in disaster prevention in 2017. With the hydro-meteorological information of that year, three models of deterministic forecast of the flow in Los Ejidos have been adjusted by means of multiple linear regression, with 12 hours of anticipation for maximum events, starting from daily precipitation and upstream flows, coming from conventional and automatic stations. In moderate flows, it is even possible to have 18 hours of anticipation. The model provides an adequate approximation of the hydrographs of summer 2017. For the maximum flow, 3468 m3/s, forecast values were obtained with an error of less than 5%. The model has also been validated with data from the year 2019, obtaining satisfactory values. This model can be used by the authorities, in view of the possible occurrence of future events, for the timely adoption of preventive measures. © 2020 Latin American and Caribbean Consortium of Engineering Institutions. All rights reserved.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Determination of the maximum flows occurring in the Piura River during the El Niño 2017 [Determinación de los caudales máximos ocurridos en el río Piura durante el fenómeno El Niño 2017]
No full textIn the southern summer of 2017, the coastal El Niño phenomenon occurred in Peru. This type of event is recurrent in this region and due to its intensity, floods occurred in the city of Piura and in the Lower Piura Valley, due to the overflowing of the river of the same name. Scenarios like this put the structures within the riverbed at risk. In order to prevent and provide a warning system that allows timely evacuation of the areas at risk, it is necessary to know the flows that occur in the river. However, there are reasonable doubts about the reliability of the gauges in Los Ejidos Dam, located upstream of the city. This is because the basin's early warning system predicted maximum flows of 2900 m3/s on March 26, 2017, based on rainfall and flow data upstream of Los Ejidos, and finally the flow measured at the dam was 3468 m3/s. At that time the uncertainty was established as to whether the forecast model was out of balance or whether the measurements at the dam had calculation errors. This article presents the calculation of the flows in Los Ejidos Dam based on the collection of data recorded in the dam by the operator, Chira Piura Special Project (PECHP), during the period from January to May 2017, strictly following the existing literature, as well as the operation manuals. From the results obtained, it can be seen that the structure works alternately under a submerged and non-submerged regime, in addition to the fact that the greatest contribution to the flow comes from the free spillway, followed by the floodgate spillway and the cleaning channel. On the other hand, the flow obtained from the levels recorded during the El Niño 2016-2017 phenomenon differs by 16% from the maximum value reported. © 2020 Latin American and Caribbean Consortium of Engineering Institutions. All rights reserved.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Infrared and raman spectra of nanoporous SiO2 matrix filled with BaTiO3 nanoparticles
No full textNanocomposite in the form of a porous matrix SiO2 with average pore size of 320 nm filled with barium titanate nanoparticles in paraelectric cubic phase was obtained. Shift of the stretching vibration of Si-O-Si to higher frequencies caused by increased strengthening of the network in the matrices has been observed. Also demonstrated that decrease in the intensity of the absorption relating to Si-O(H) stretching vibration relative to Si-O(-Si) stretching vibration. Raman scattering spectra demonstrate the presence of both a cubic and a tetragonal ferroelectric crystalline phase in the filler nanoparticles. Thus, the mechanical deformation of nanoparticles in the pores of the matrix can lead to a change in the crystalline phase of the filler. © 2020 Trans Tech Publications Ltd, Switzerland.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
How the initiating ribosome copes with ppGpp to translate mRNAs
No full textDuring host colonization, bacteria use the alarmones (p)ppGpp to reshape their proteome by acting pleiotropically on DNA, RNA, and protein synthesis. Here, we elucidate how the initiating ribosome senses the cellular pool of guanosine nucleotides and regulates the progression towards protein synthesis. Our results show that the affinity of guanosine triphosphate (GTP) and the inhibitory concentration of ppGpp for the 30S-bound initiation factor IF2 vary depending on the programmed mRNA. The TufA mRNA enhanced GTP affinity for 30S complexes, resulting in improved ppGpp tolerance and allowing efficient protein synthesis. Conversely, the InfA mRNA allowed ppGpp to compete with GTP for IF2, thus stalling 30S complexes. Structural modeling and biochemical analysis of the TufA mRNA unveiled a structured enhancer of translation initiation (SETI) composed of two consecutive hairpins proximal to the translation initiation region (TIR) that largely account for ppGpp tolerance under physiological concentrations of guanosine nucleotides. Furthermore, our results show that the mechanism enhancing ppGpp tolerance is not restricted to the TufA mRNA, as similar ppGpp tolerance was found for the SETI-containing Rnr mRNA. Finally, we show that IF2 can use pppGpp to promote the formation of 30S initiation complexes (ICs), albeit requiring higher factor concentration and resulting in slower transitions to translation elongation. Altogether, our data unveil a novel regulatory mechanism at the onset of protein synthesis that tolerates physiological concentrations of ppGpp and that bacteria can exploit to modulate their proteome as a function of the nutritional shift happening during stringent response and infection. © 2020 Vinogradova et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Measurements of Hydrogen Peroxide and Oxidative DNA Damage in a Cell Model of Premature Aging
No full textReactive oxygen species (ROS) represent a number of highly reactive oxygen-derived by-products generated by the normal mitochondrial respiration and other cellular metabolic reactions. ROS can oxidize macromolecules including lipids, proteins, and nucleic acids. Under physiological condition, the cellular levels of ROS are controlled by several antioxidant enzymes. However, an imbalance between ROS production and detoxification results in oxidative stress, which leads to the accumulation of macromolecular damage and progressive decline in normal physiological functions. Oxidative deterioration of DNA can result in lesion that are mutagenic and contribute to aging and age-related diseases. Therefore, methods for the detection of ROS and oxidative deterioration of macromolecules such as DNA in cells provide important tool in aging research. Here, we described protocols for the detection of cytoplasmic and mitochondria pools of hydrogen peroxide, and the DNA modification 8-oxoguanine, a biomarker of oxidative damage, that are applicable to cell-based studies on aging and other related areas. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Metallochaperones are needed for mycobacterium tuberculosis and Escherichia coli nicotinamidase-pyrazinamidase activity
No full textMycobacterium tuberculosis nicotinamidase-pyrazinamidase (PZAse) is a metalloenzyme that catalyzes conversion of nicotinamide-pyrazinamide to nicotinic acid-pyrazinoic acid. This study investigated whether a metallochaperone is required for optimal PZAse activity. M. tuberculosis and Escherichia coli PZAses (PZAse-MT and PZAse-EC, respectively) were inactivated by metal depletion (giving PZAse-MT–Apo and PZAse-EC–Apo). Reactivation with the E. coli metallochaperone ZnuA or Rv2059 (the M. tuberculosis analog) was measured. This was repeated following proteolytic and thermal treatment of ZnuA and Rv2059. The CDC1551 M. tuberculosis reference strain had the Rv2059 coding gene knocked out, and PZA susceptibility and the pyrazinoic acid (POA) efflux rate were measured. ZnuA (200 M) achieved 65% PZAse-EC–Apo reactivation. Rv2059 (1 M) and ZnuA (1 M) achieved 69% and 34.3% PZAse-MT–Apo reactivation, respectively. Proteolytic treatment of ZnuA and Rv2059 and application of three (but not one) thermal shocks to ZnuA significantly reduced the capacity to reactivate PZAse-MT–Apo. An M. tuberculosis Rv2059 knockout strain was Wayne positive and susceptible to PZA and did not have a significantly different POA efflux rate than the reference strain, although a trend toward a lower efflux rate was observed after knockout. The metallochaperone Rv2059 restored the activity of metal-depleted PZAse in vitro. Although Rv2059 is important in vitro, it seems to have a smaller effect on PZA susceptibility in vivo. It may be important to mechanisms of action and resistance to pyrazinamide in M. tuberculosis. Further studies are needed for confirmation. IMPORTANCE Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis and remains one of the major causes of disease and death worldwide. Pyrazinamide is a key drug used in the treatment of tuberculosis, yet its mechanism of action is not fully understood, and testing strains of M. tuberculosis for pyrazinamide resistance is not easy with the tools that are presently available. The significance of the present research is that a metallochaperone-like protein may be crucial to pyrazinamide’s mechanisms of action and of resistance. This may support the development of improved tools to detect pyrazinamide resistance, which would have significant implications for the clinical management of patients with tuberculosis: drug regimens that are appropriately tailored to the resistance profile of a patient’s individual strain lead to better clinical outcomes, reduced onward transmission of infection, and reduction of the development of resistant strains that are more challenging and expensive to treat. Copyright © 2020 Sheen et al.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Chronic Pain Estimation Through Deep Facial Descriptors Analysis
No full textWorldwide, chronic pain has established as one of the foremost medical issues due to its 35% of comorbidity with depression and many other psychological problems. Traditionally, self-report (VAS scale) or physicist inspection (OPI scale) perform the pain assessment; nonetheless, both methods do not usually coincide [14]. Regarding self-assessment, several patients are not able to complete it objectively, like young children or patients with limited expression abilities. The lack of objectivity in the metrics draws the main problem of the clinical analysis of pain. In response, various efforts have tried concerning the inclusion of objective metrics, among which stand out the Prkachin and Solomon Pain Intensity (PSPI) metric defined by face appearance [5]. This work presents an in-depth learning approach to pain recognition considering deep facial representations and sequence analysis. Contrasting current state-of-the-art deep learning techniques, we correct rigid deformations caught since registration. A preprocessing stage is applied, which includes facial frontalization to untangle facial representations from non-affine transformations, perspective deformations, and outside noises passed since registration. After dealing with unbalanced data, we fine-tune a CNN from a pre-trained model to extract facial features, and then a multilayer RNN exploits temporal relation between video frames. As a result, we overcome state-of-the-art in terms of average accuracy at frames level (80.44%) and sequence level (84.54%) in the UNBC-McMaster Shoulder Pain Expression Archive Database.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte