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Este artículo tiene el objetivo de examinar los factores socioeconómicos que incidieron en los habitantes de un área natural protegida en Chiapas, México, para que adoptaran prácticas de reforestación en el marco de un proyecto interinstitucional que impulsó la restauración de sus predios forestales afectados por el huracán Bárbara en el año 2013. Con la información recopilada en el trabajo de campo entre 2014 y 2016, a través de observación directa y datos de 51 encuestas, se realizó un análisis cualitativo y estadístico con el apoyo de un modelo Logit. Los resultados muestran que la disposición de las personas a reforestar disminuye a medida que la ganadería representa su principal ocupación. Además, se revela que la población más proclive a reforestar es aquella que tiene mayor participación en actividades forestales, que es motivada por factores intrínsecos y reside de manera permanente en el lugar. Se concluye que los aspectos socioeconómicos ligados a las actividades productivas locales son factores que inciden en la decisión a reforestar.

The habitat fragmentation caused by reservoir construction in different aquatic systems in the Magdalena River basin is a latent threat to the diversity of fishes and aquatic environments in the Andean region of Colombia. Contributing to the knowledge about how fish assemblages are formed in these scenarios is fundamental for the management and decision-making on the aquatic resources of the basin. In this communication, we describe the results of a fish characterization in the area of influence of the Piedras Blancas reservoir, a high Andean reservoir built for hydroelectric power generation. Only three species of fish that make up the evaluated assemblage were captured, and two of them, Cyprinus carpio and Xiphophorus maculatus, are not native to the basin. Possibly, with a greater sampling effort, more species can be found. The native species Hemibrycon sp. is distributed mainly in a creek, while in the reservoir, the introduced species dominate. The environmental variables were in optimal ranges for the development of life in the evaluated environments. It is important to advance the knowledge about the distribution of the introduced and native species in the basin to generate recommendations that contribute to the management of these species in the aquatic systems of Colombian Andes.

Species diversity underpins all ecosystem services that support life. Despite this recognition and the great advances in detecting biodiversity, exactly how many and which species co-occur and interact, directly or indirectly in any ecosystem is unknown. Biodiversity accounts are incomplete; taxonomically, size, habitat, mobility or rarity biased. In the ocean, the provisioning of fish, invertebrates and algae is a fundamental ecosystem service. This extracted biomass depends on a myriad of microscopic and macroscopic organisms that make up the fabric of nature and which are affected by management actions. Monitoring them all and attributing changes to management policies is daunting. Here we propose that dynamic quantitative models of species interactions can be used to link management policy and compliance with complex ecological networks. This allows managers to qualitatively identify ‘interaction-indicator’ species, which are highly impacted by management policies through propagation of complex ecological interactions. We ground the approach in intertidal kelp harvesting in Chile and fishers' compliance with policies. Results allow us to identify sets of species that respond to management policy and/or compliance, but which are often not included in standardized monitoring. The proposed approach aids in the design of biodiversity programmes that attempt to connect management with biodiversity change. This article is part of the theme issue ‘Detecting and attributing the causes of biodiversity change: needs, gaps and solutions’.

There is a growing trend in using saliva for SARS-CoV-2 detection with reasonable accuracy. We have studied the responses of IgA, IgG, and IgM in human saliva by directly comparing disease with control analyzing two-trace two-dimensional correlation spectra (2T2D-COS) employing Fourier transform infrared (FTIR) spectra. The findings show the decrease of IgG and IgM salivary antibodies in the 50, 60, 65, and 75-years samples. Among the various COVID-19 populations studied, the female 30 years group reveal defence mechanisms exhibited by IgM and IgA. Lipids and fatty acids decrease, resulting in lipid oxidation due to the SARS-CoV-2 in the samples studied. Study shows salivary thiocyanate plays defence against SARS-CoV-2 in male population in 25 and 35 age groups. The receiver operation characteristics statistical method shows a sensitivity of 98% and specificity 94% for the samples studied. The measure of accuracy computed as F1 score and G score has a high value which supports the validation of our study. The 2T2D-COS analysis has the potential to monitor the progression of immunoglobulin’s response function of COVID-19 with good accuracy, which could help in diagnosing clinical trials.

Los Andes tropicales son una zona de alta biodiversidad, que constantemente se enfrenta a la presión del desarrollo hidroeléctrico. Sin embargo, los efectos de los embalses en los ecosistemas fluviales de la regióninfluenciados por cambios fisicoquímicos en la calidad del agua son poco conocidos. Colombia es el único país en América del Sur que gestiona bases de datos ambientales públicos y centralizados, allí se incluyen conjuntos de datos sobre la calidad de aguas superficiales asociados a la vigilancia medioambiental de las represas. Para evaluar las relaciones entre las condiciones de los ríos en Colombia con relación a las centrales hidroeléctricas, analizamos los datos de monitoreo asociados con 15 represas, enfocándonos en la disponibilidad de oxígeno, el régimen térmico y la pérdida de sedimentos; ya que estas propiedades están influenciadas directamente por la construcción de represas en los ríos, e imponen restricciones fundamentales en la estructura de los ecosistemas acuáticos aguas abajo de la presa. Encontramos que en la mayoría de los embalses en Colombia (7 de 10) se reducen estacionalmente grandes porcentajes de las concentraciones de sólidos suspendidos totales (50-99%) debido a la captura de sedimentos. Adicionalmente, la mayoría de los embalses (8 de 15), a través de la descarga de aguas superficiales a mayor temperatura, aumentan estacionalmente las temperaturas del río (entre 2 y 4 °C) con respecto a las condiciones aguas arriba. Un subconjunto de cuatro represas genera hipoxia aguas abajo (

El desarrollo de producción hidro-energética al norte de los Andes de Sudamérica se ha centrado en la cuenca Magdalena. Para esta cuenca se reporta que el 68 % de las especies de peces son endémicas y no se han estudiado los efectos que producen estas estructuras sobre sus ensamblajes en los ríos de alta montaña. Este trabajo responde preguntas asociadas a las características que describen el ensamblaje de peces y la influencia que ejercen algunas variables ambientales sobre su distribución en el transcurso de los periodos hidrológicos de sequía y lluvias en el área de influencia de dos embalses. Se capturaron siete especies de peces, cuatro de ellas no nativas de la cuenca. No se encontraron diferencias significativas de las abundancias entre los sistemas acuáticos y entre la temporalidad climática. La riqueza fue mayor en las quebradas y ríos. Los ensamblajes cambiaron según el sistema acuático, en embalses dominaron las especies no nativas Micropterus salmoides y Cyprinus carpio mientras que en las quebradas y ríos el ensamblaje estuvo conformado principalmente por Hemibrycon caucanus y Trichomycterus sp. Los ensamblajes no presentaron diferencias estadísticas entre periodos climáticos. Por otra parte, observamos que variables fisicoquímicas como el oxígeno y la transparencia, son importantes para la distribución de las especies no nativas en los embalses, y para las especies que se distribuyen en ríos y quebradas, la conductividad fue la variable más influyente. La información proporcionada en este estudio servirá de base para la gestión de la conservación de peces en los Andes.

Despite the fact that some parasitological reviews have recently been made in some groups of reptiles, such as snakes and lizards, the current knowledge about the parasitofauna and associated pathologies in reptiles is incomplete and scarce. Therefore, here we present the first record for the state of Querétaro, Mexico of the pentastomid Porocephalus crotali and the first record of the nematode Kalicephalus inermis parasitizing a specimen of Crotalus totonacus, as well as the first record of a fibroma in the mesentery.

Conventional spike sorting and motor intention decoding algorithms are mostly implemented on an external computing device, such as a personal computer. The innovation of high-resolution and high-density electrodes to record the brain’s activity at the single neuron level may eliminate the need for spike sorting altogether while potentially enabling in vivo neural decoding. This article explores the feasibility and efficient realization of in vivo decoding, with and without spike sorting. The efficiency of neural network-based models for reliable motor decoding is presented and the performance of candidate neural decoding schemes on sorted single-unit activity and unsorted multi-unit activity are evaluated. A programmable processor with a custom instruction set architecture, for the first time to the best of our knowledge, is designed and implemented for executing neural network operations in a standard 180-nm CMOS process. The processor’s layout is estimated to occupy 49 mm[Formula: see text] of silicon area and to dissipate 12 mW of power from a 1.8 V supply, which is within the tissue-safe operation of the brain.

The arrival of a non-native species to a new environment threatens local biological diversity, causing instability in the functioning of the ecosystem. The adverse ecological effects caused by these species have been scarcely documented for the Magdalena basin. By studying predator-prey interactions, we characterized the trophic niche of three non-native species (Micropterus salmoides, Oncorhynchus mykiss, and Cyprinus carpio) that dominate a high Andean reservoir in the Magdalena basin. To understand whether non-native species are preying on native fish, or if they present specific feeding behaviors that facilitate their establishment in lentic environments, we evaluated the diversity of the prey they consume, their feeding strategy, and possible differences in the feeding scheme. Forty individuals were analyzed, and twenty categories of prey were identified for these species. The consumed prey corresponds to the native biota; however, no native fish were found in the stomach contents evaluated. The diversity of prey consumed is similar amongst species, however, M. salmoides behaves like an important predator, as it consumes a larger amount of prey. We observed that the variation in diet composition amongst the non-native species is different, which favors their coexistence as it reduces the competition amongst them. Analyzing the type of diet of this non-native fish is a useful tool that provides a description of some trophic interactions in this aquatic environment. Our results contribute information on the existing interactions amongst non-native species to the Magdalena basin, which is important for the development of strategies to manage and promote impact mitigation.

The wide range of symptoms of the coronavirus disease 2019 (COVID-19) makes it challenging to predict the disease evolution using a single parameter. Therefore, to describe the pathophysiological response to SARS-CoV-2 infection in hospitalized patients with severe COVID-19, we compared according to survival or death, the sociodemographic and clinical characteristics, the biochemical and immunological attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra from saliva samples and their correlation with chemometric findings. Herein, we demonstrate that ATR-FTIR spectroscopy allows the description of the events related to cell damage, such as lipids biogenesis and the secondary structure of proteins associated with lactate dehydrogenase and albumin levels. Moreover, humoral (IgM) and cellular (IFN-γ, TNF-α, IL-10, and IL-6) responses were also increased in patients who died from COVID-19.

espanolEl bitcoin es una tecnologia originada en el ano 2009 que pretende implementar un sistema de pagos descentralizado entre personas. El presente trabajo se realiza con el fin de dar a conocer dicha tecnologia, la cual denota importancia debido a las funcionalidades y oportunidades que ofrece para todo tipo de individuos, desde aquellos que buscan un refugio de valor para su patrimonio, hasta los que desean invertir su dinero o simplemente entender su funcionamiento y utilizarla en el dia a dia. Este escrito expone los origenes del bitcoin, asi como sus principales caracteristi-cas y funcionamiento. Ademas, analiza sus ventajas y desventajas desde un punto de vista practico y hace un enfasis especial en la regulacion juridica existente alrededor de las criptomonedas en Colombia y Ecuador. A traves de una metodologia descriptiva y utilizando herramientas cualitativas y cuantitativas, se logro determinar un crecimiento progresivo del bitcoin durante los ultimos anos, no solo en terminos de valor, sino tambien de adopcion y de seguridad. Por este motivo, tanto Colombia como Ecuador deben adaptar sus re-gulaciones juridicas, con el fin de estar a la altura de la era digital en la que nos encontramos y aprovechar con ello los beneficios de este fenomeno en lugar de impedir su desarrollo. EnglishBitcoin is a technology originated in 2009 that aims to implement a decentralized payment system between people. The present work is carried out in order to pu-blicize this technology, which denotes importance due to the functionalities and opportunities it offers for all types of individuals, from those who seek a refuge of value for their assets, to those who wish to invest your money or simply unders-tand how it works and use it on a day-to-day basis.This writing exposes the origins of Bitcoin, as well as its main characteristics and operation. In addition, it analyzes its advantages and disadvantages from a prac-tical point of view and places special emphasis on the existing legal regulation around cryptocurrencies in Colombia and Ecuador.Through a descriptive methodology and using qualitative and quantitative tools, it was possible to determine a progressive growth of Bitcoin in recent years, not only in terms of value, but also of adoption and security. For this reason, both Co-lombia and Ecuador must adapt their legal regulations, in order to live up to the digital age in which we find ourselves and thereby take advantage of the benefits of this phenomenon instead of preventing its development.

espanolEl grafico de Poincare es un metodo no lineal que permite analizar la variabilidad de una senal, dibujando dicha senal contra ella misma retardada en el tiempo. Aunque este metodo ha sido aplicado al analisis del electroencefalograma (EEG) para la medicion de niveles de anestesia general, su aplicacion en la medicion de niveles de anestesia ligera aun no se ha abordado con profundidad. En este trabajo, se consideran varios tiempos de retardo en el grafico de Poincare para caracterizar el nivel de anestesia ligera en 110 pacientes sometidos a endoscopia digestiva. Los indices de Poincare son combinados con parametros espectrales de senales que contienen informacion del EEG y del EMG (electromiografia) para modelar los niveles de anestesia ligera, teniendo como referencia la escala de sedacion Ramsay. La mejor prediccion, utilizando indices del grafico de Poincare, del nivel de sedacion y analgesia (Pk = 0,711) se obtiene usando un retardo de 8 ms en el rango de frecuencia de 30-110 Hz y de 6 ms en el rango de frecuencia de 0,5 - 30 Hz, respectivamente. La combinacion de diferentes parametros permitio obtener valores de Pk = 0,799. EnglishPoincare plot is a non-linear method which allows analyzing the variability of a signal by plotting the signal against itself after a delay time. Although this method has been used to analyze the electroencephalogram (EEG) in order to assess general anesthesia, its application on light sedation has not been addressed in depth yet. In this work, several time-delays are considered in the Poincare plot to characterize levels of light anesthesia on 110 patients scheduled to digestive endoscopy. Poincare Plot indexes are mixed with parameters obtained from spectral analysis of signals with EEG and EMG (electromyography) information in order to model light anesthesia levels, according to Ramsay Sedation Scale. The best prediction, using indexes from Poincare plot, of sedation level and analgesia level (Pk = 0.711) is obtained with a time delay of 8ms in a frequency range from 30 Hz to 110 Hz and 6ms in a frequency range from 0.5 Hz to 30 Hz, respectively. Pk = 0.799 was obtained with a model mixing different parameters.

This article presents the design and efficient hardware implementation of binarized neural networks (BNNs) for brain-implantable neural spike sorting. In contrast to the conventional artificial neural networks (ANNs), in which the weights and activation functions of neurons are represented using real values, the BNNs utilize binarized weights and activation functions to dramatically reduce the memory requirement and computational complexity of the ANNs. The designed BNN is trained using several realistic neural datasets to verify its accuracy for neural spike sorting. The application-specific integrated circuit (ASIC) implementation of the designed BNN in a standard 0.18- $\mu \text{m}$ CMOS process occupies 0.33 mm 2 of silicon area. Power consumption estimation of the ASIC layout shows that the BNN dissipates $2.02~\mu \text{W}$ of power from a 1.8 V supply while operating at 24 kHz. The designed BNN-based spike sorting system is also implemented on a field-programmable gate array and is shown to reduce the required on-chip memory by 89% compared to those of the alternative state-of-the-art spike sorting systems. To the best of our knowledge, this is the first work employing BNNs for real-time in vivo neural spike sorting.

The Tropical Andes is a biodiversity hotspot facing pressure from planned and ongoing hydropower development. However, the effects of dams on the region's river ecosystems, as mediated by physicochemical changes in the water quality, are poorly known. Colombia is unique among its peers in South America with respect to managing central public environmental databases, including surface water quality data sets associated with the environmental monitoring of dams. To assess the relationship between hydropower and Colombian river conditions, we analyze monitoring data associated with 15 dams, focusing on oxygen availability, thermal regimes and sediment losses because these properties are influenced directly by river damming and impose fundamental constraints on the structure of downstream aquatic ecosystems. We find that most Colombian dams (7 of 10) seasonally reduce concentrations of total suspended solids by large percentages (50 %-99 %) through sediment trapping. Most dams (8 of 15) also, via the discharge of warm reservoir surface waters, seasonally increase river temperatures by 2 to 4 degrees C with respect to upstream conditions. A subset of four dams generate downstream hypoxia (< 4 mg L-1) and water that is 2 to 5 degrees C colder than inflows, with both processes driven by the turbination and discharge of cold and anoxic hypolimnetic waters during periods of reservoir stratification. Reliance on monitoring data likely leads us to under-detect impacts: many rivers are only sampled once or twice per year, which cannot capture temporal shifts across seasons and days (i.e., in response to hydropeaking). Despite these blind spots, the monitoring data point to some opportunities for planners and hydropower companies to mitigate downstream ecological impacts. These findings highlight the importance of implementing environmental monitoring schemes associated with hydrologic infrastructure in developing countries., Hydrology and Earth System Sciences, 27 (7), ISSN:1027-5606, ISSN:1607-7938

At the industrial level detect and compensate faults in the plant is important, to avoid irreparable damage and the increase of unproductive time, being necessary that the equipment has adequate sensors and the plant model analyzes the full operation of the system, among other requirements, to obtain under simulation the missing characteristics to diagnose faults. This paper works with the number of sensors in plant to reach diagnosability, for this the modelling is relationed with the acquired signals from the plant, it begins with an input/output identification method modelling by interpreted Petri net, then diagnosability general characteristics was determined, mathematically interrelated; and a sensor placement method for diagnosability was established. It uses matrix analysis to evaluate event-detectability and observability. The sensor placement method stablishes the plant operation points where additional sensors are needed; this process is explained with a simulation example. The investigation result is a minimal sensor set that makes the plant diagnosable, avoiding sensors redundancy and reducing related costs.

This article presents the design and implementation of an embedded programmable processor with a custom instruction set architecture for efficient realization of artificial neural networks (ANNs). The ANN processor architecture is scalable, supporting an arbitrary number of layers and number of artificial neurons (ANs) per layer. Moreover, the processor supports ANNs with arbitrary interconnect structures among ANs to realize both feed-forward and dynamic recurrent networks. The processor architecture is customizable in which the numerical representation of inputs, outputs, and signals among ANs can be parameterized to an arbitrary fixed-point format. An ASIC implementation of the designed programmable ANN processor for networks with up to 512 ANs and 262,000 interconnects is presented and is estimated to occupy 2.23 mm2 of silicon area and consume 1.25 mW of power from a 1.6 V supply while operating at 74 MHz in a standard 32-nm CMOS technology. In order to assess and compare the efficiency of the designed ANN processor, we have designed and implemented a dedicated reconfigurable hardware architecture for the direct realization of ANNs. Characteristics and implementation results of the designed programmable ANN processor and the dedicated ANN hardware on a Xilinx Artix-7 field-programmable gate array (FPGA) are presented and compared using two benchmarks, the MNIST benchmark using a feed-forward ANN and a movie review sentiment analysis benchmark using a recurrent neural network.

El Zamarrito canoso Haplophaedia lugens está distribuido en Ecuador y Colombia, donde es raro, localista y evaluado como Casi Amenazado. Detallamos observaciones a un nido con dos pichones de este colibrí, en Cerro Golondrinas, Carchi, en mayo de 2019.

We describe the change in the fish community of the Porce River in Magdalena River Basin, Colombia, following the construction of the Porce III hydropower reservoir based on 13 years of monitoring data. The results show a clear reduction of the number of native species, which have been supplanted by colonizing non-native species, especially in the reservoir. Four native species detected prior to dam construction have apparently disappeared, but 12 new species were registered post-construction. We analyzed spatial changes in beta diversity in the aquatic environments surrounding the dam. The new environment generated by the reservoir presents a unique species composition and contributes significantly to the total beta diversity of the system. Altogether three distinct new fish assemblages emerged following reservoir formation and there are now six assemblages where there had previously been three. This dramatic change, already visible within a decade of construction, highlights just how strong of an impact dam construction has on habitats and how rapidly fish communities react in this hotspot for endemic fish diversity. Our findings demonstrate the importance of monitoring fish communities for revealing the impact of damming on river ecosystems and informs potential complementary fish diversity inventories elsewhere in the Magdalena River basin., Neotropical Ichthyology, 20 (1)

Objective. Advances in brain–machine interfaces (BMIs) can potentially improve the quality of life of millions of users with spinal cord injury or other neurological disorders by allowing them to interact with the physical environment at their will. Approach. To reduce the power consumption of the brain-implanted interface, this article presents the first hardware realization of an in vivo intention-aware interface via brain-state estimation. Main Results. It is shown that incorporating brain-state estimation reduces the in vivo power consumption and reduces total energy dissipation by over 1.8× compared to those of the current systems, enabling longer better life for implanted circuits. The synthesized application-specific integrated circuit (ASIC) of the designed intention-aware multi-unit spike detection system in a standard 180 nm CMOS process occupies 0.03 mm2 of silicon area and consumes 0.63 µW of power per channel, which is the least power consumption among the current in vivo ASIC realizations. Significance. The proposed interface is the first practical approach towards realizing asynchronous BMIs while reducing the power consumption of the BMI interface and enhancing neural decoding performance compared to those of the conventional synchronous BMIs.

SARS-CoV-2 infection in hospital areas is of a particular concern, since the close interaction between health care personnel and patients diagnosed with COVID-19, which allows virus to be easily spread between them and subsequently to their families and communities. Preventing SARS-CoV-2 infection among healthcare personnel is essential to reduce the frequency of infections and outbreaks during the pandemic considering that they work in high-risk areas. In this research, silver nanoparticles (AgNPs) were tested in vitro and shown to have an inhibitory effect on SARS-CoV-2 infection in cultured cells. Subsequently, we assess the effects of mouthwash and nose rinse with ARGOVIT® silver nanoparticles (AgNPs), in the prevention of SARS-CoV-2 contagion in health workers consider as high-risk group of acquiring the infection in the General Tijuana Hospital, Mexico, a hospital for the exclusive recruitment of patients diagnosed with COVID-19. We present a prospective randomized study of 231 participants that was carried out for 9 weeks (during the declaration of a pandemic). The "experimental" group was instructed to do mouthwash and nose rinse with the AgNPs solution; the "control" group was instructed to do mouthwashes and nose rinse in a conventional way. The incidence of SARS-CoV-2 infection was significantly lower in the "experimental" group (two participants of 114, 1.8%) compared to the "control" group (thirty-three participants of 117, 28.2%), with an 84.8% efficiency. We conclude that the mouth and nasal rinse with AgNPs helps in the prevention of SARS-CoV-2 infection in health personnel who are exposed to patients diagnosed with COVID-19.

Thein vitroantiviral effect of AgNPs had been previously demonstrated as well as its toxicity in cells is known. Therefore, before studying its capacity to inhibit SARS-CoV-2, Vero E6 cell viability in the presence of AgNPs was studied. Two-fold serial dilutions of Argovit were added to Vero E6 monolayers and their viability was measured using a MTS Cell Proliferation Assay kit. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium) is a metabolic dye that relies on the conversion of soluble tetrazolium by bioreduction into a colored formazan product that is soluble in tissue culture medium. Once the concentration that is not toxic for Vero E6 cells was stablished, anin vitroinhibition assay was carried out, in which we confirmed that low non-toxic concentrations of AgNPs have an antiviral capacity against SARS-CoV-2.

In this paper, we investigate the use of monofacial PV models to simulate the production of bifacial PV systems over different albedos. Analytical and empirical models were evaluated using measured data obtained from three identical bifacial PV arrays: (1) with the backside covered by white plastic, (2) with normal albedo, and (3) with high albedo. The front-and rear-side irradiances were measured in order to integrate bifaciality of the modules into the models. The models showed good performance for non-real-time monitoring, especially under clear skies, and the analytical model was more accurate than the empirical model. The heatmap visualization technique was applied to six months of data in order to investigate the site conditions on the rear side of the modules as well as the accuracy of the models. The heatmap results of the rear- and front-sides irradiances showed that the installation conditions, such as the azimuth angles of the sun and the surrounding obstacles, had a strong impact on the energy received from the back of the modules. The heatmap results of the models validated the performance of the analytical model. The average daily errors for the analytical model were less than 1% and 3% for normal and high albedos, respectively. This work was supported by the SUDOKET SOE2/P1/E0677 project funded by FEDER of the EU under the Interreg-Sudoe program. The research leading to these results received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia.

Designers must carefully choose the best-suited fast Fourier transform (FFT) algorithm among various available techniques for the custom implementation that meets their design requirements, such as throughput, latency, and area. This article, to the best of authors' knowledge, is the first to present a compact and yet high-throughput parameterisable hardware architecture for implementing different FFT algorithms, including radix-2, radix-4, radix-8, mixed-radix, and split-radix algorithms. The designed architectures are fully parameterisable to support a variety of transform lengths and variable word-lengths. The FFT algorithms have been modelled and simulated in double-precision floating-point and fixed-point representations using authors' custom-developed library of numerical operations. The designed FFT architectures are modelled in Verilog hardware description language and their cycle-accurate and bit-true simulation results are verified against their fixed-point simulation models. The characteristics and implementation results of various FFT architectures on a Xilinx Virtex-7 FPGA are presented. Compared to recently published works, authors' memory-based FFT architectures utilise less reconfigurable resources while maintaining comparable or higher operating frequencies. The ASIC implementation results in a standard 45-nm CMOS technology are also presented for the designed memory-based FFT architectures. The execution times of FFTs on a workstation and a graphics processing unit are compared against authors' FPGA implementations.

Copper nanowires are widely used as on-chip interconnects due to their superior conductivity. However, with aggressive Cu interconnect scaling, surface scattering of electrons drastically increases the electrical resistivity. In this work, we have studied the electrical performance of Cu thin films deposited on different materials. By comparing the thickness dependence of Cu films' resistivity on MoS2 and SiO2, we have demonstrated that MoS2 can be used to enhance the electrical performance of ultrathin Cu films due to improved specular surface scattering by up to 40%. By fitting the experimental data with the theoretical Fuchs-Sondheimer (FS) model, we have determined the specularity parameter at the Cu/MoS2 interface to be p ≈ 0.4 at room temperature. Furthermore, first principle calculations based on density functional theory (DFT) indicate that the localized density of states (LDOS) at the Cu/amorphous SiO2 interface is larger than the LDOS at the Cu/MoS2 interface, which is believed to be responsible for the higher resistivity in the Cu thin films that are deposited on SiO2 substrates. Our results suggest that MoS2 may serve as a performance enhancer for future generations of Cu interconnects.

The present work reports the use of a flotation cell as a prospective reactor for ozonation and the intensification of ozonation (catalytic ozonation and photocatalytic ozonation). The effect of the pH, ozone concentration and loading catalyst was investigated. The performance of the flotation cell was compared with that of conventional reactors used in ozonation through the ozone utilized index (OUI), which was proposed in this work and relates the amount of ozone supplied to the system per milligram of degraded pollutant. The flotation cell has the lowest OUI, which indicates that the ozone supplied is highly consumed. It was found that the modified flotation cell is an efficient reactor for ozonation, catalytic ozonation and photocatalytic ozonation processes because total diclofenac degradation was achieved in a short time, mass transfer limitations were not found (Ha = 7.26), and it presented a relatively low energy consumption (1.15 kW h m−3).

Objective. The ability to reliably detect neural spikes from a relatively large population of neurons contaminated with noise is imperative for reliable decoding of recorded neural information. Approach. This article first analyzes the accuracy and feasibility of various potential spike detection techniques for in vivo realizations. Then an accurate and computationally-efficient spike detection module that can autonomously adapt to variations in recording channels’ statistics is presented. Main results. The accuracy of the chosen candidate spike detection technique is evaluated using both synthetic and real neural recordings. The designed detector also offers the highest decoding performance over two animal behavioral datasets among alternative detection methods. Significance. The implementation results of the designed 128-channel spike detection module in a standard 180 nm CMOS process is among the most area and power-efficient spike detection ASICs and operates within the tissue-safe constraints for brain implants, while offering adaptive noise estimation.

En la cuenca del río Magdalena, las actividades de rescate de peces son una medida de manejo ambiental utilizada para reducir su mortalidad en el área próxima a los embalses. Cuando se realiza la apertura y posterior cierre de compuertas del vertedero, producto de la operación de la central hidroeléctrica Porce III, aguas abajo de la presa se crean hábitats acuáticos temporales en forma de pozas marginales de lecho rocoso, en donde se presentan atrapamientos de peces. El objetivo del rescate es reubicarlos al canal principal del río para reducir su mortalidad. Entre los años 2013 y 2020 se capturaron 4927 individuos, representantes de 28 especies, 12 familias y cinco órdenes. Reubicamos a 4704 individuos nuevamente en el río Porce, siendo las especies de los géneros Chaetostoma, Andinoacara, Astyanax y Rhamdia los de mayor captura. También se capturaron especies potamodromas de la familia Pochilodontidae, cuya presencia próxima a la presa se debe posiblemente a migraciones que realizan para llevar a cabo su reproducción. Estas acciones de rescate y reubicación, producto de la operación de las centrales hidroeléctricas, deben ser replicadas en la cuenca como estrategia para mitigar los impactos ambientales ocasionados por la fragmentación del hábitat.

SARS-CoV-2 infection in hospital areas is of a particular concern, since the close interaction between health care personnel and patients diagnosed with COVID-19, which allows virus to be easily spread between them and subsequently to their families and communities. Preventing SARS-CoV-2 infection among healthcare personnel is essential to reduce the frequency of infections and outbreaks during the pandemic considering that they work in high-risk areas. In this research, silver nanoparticles (AgNPs) were tested in vitro and shown to have an inhibitory effect on SARS-CoV-2 infection in cultured cells. Subsequently, we assess the effects of mouthwash and nose rinse with ARGOVIT® silver nanoparticles (AgNPs), in the prevention of SARS-CoV-2 contagion in health workers consider as high-risk group of acquiring the infection in the General Tijuana Hospital, Mexico, a hospital for the exclusive recruitment of patients diagnosed with COVID-19. We present a prospective randomized study of 231 participants that was carried out for 9 weeks (during the declaration of a pandemic). The “experimental” group was instructed to do mouthwash and nose rinse with the AgNPs solution; the “control” group was instructed to do mouthwashes and nose rinse in a conventional way. The incidence of SARS-CoV-2 infection was significantly lower in the “experimental” group (two participants of 114, 1.8%) compared to the “control” group (thirty-three participants of 117, 28.2%), with a 84.8% efficiency. We conclude that the mouth and nasal rinse with AgNPs helps in the prevention of SARS-CoV-2 infection in health personnel who are exposed to patients diagnosed with COVID-19.

Since the first cases of human immunodeficiency virus (HIV), ocular manifestations secondary to infection have been known and these have been related to the CD4+ lymphocyte count.To describe the correlation between ocular manifestations in patients with HIV and the CD4+ lymphocyte count.Analytical cross-sectional study of patients with HIV whose CD4+ count was correlated with the presence of ophthalmological manifestations.21 patients between 26 and 67 years were studied. Only 3 patients were not on antiretroviral therapy. 67% of the patients presented some type of ocular manifestation, 42% presented non-infection related manifestations, 47% related manifestations and 24% both. Conjunctival microangiopathy was the most frequent ocular manifestation (35.7%). There was a statistically significant correlation (r = 0.76, p = 0.0001) between eye manifestations related to infection and CD4+ lymphocyte count.Patients with HIV frequently present ocular manifestations, the majority related to infection; there is a correlation between the presence of these with the CD4+ count. However, a similar number of manifestations not related to infection occurred without correlation with the count; therefore, HIV patients should have periodic ophthalmological examinations, independently of CD4+ count.desde los primeros casos de virus de inmunodeficiencia humana (VIH), se conocen manifestaciones oculares secundarias a la infección y estas se han relacionado con el conteo de linfocitos CD4+.describir la correlación entre las manifestaciones oculares en pacientes con VIH y el conteo de linfocitos CD4+.estudio transversal analítico de pacientes con VIH, en quienes se analizó la correlación entre conteo de CD4+ y manifestaciones oftalmológicas.se incluyeron 21 pacientes entre 26 y 67 años de edad. Solo tres no se encontraban en terapia antirretroviral. El 67% presentó algún tipo de manifestación ocular, 42% presentó manifestaciones no relacionadas con la infección, 47% manifestaciones relacionadas y 24% ambas. La microangiopatía de la conjuntiva fue la manifestación ocular más frecuente (35.7%). Hubo una correlación estadísticamente significativa (r = 0.76, p = 0.0001) entre las manifestaciones oculares relacionadas con la infección y el conteo de linfocitos CD4+.los pacientes con VIH presentan con frecuencia manifestaciones oculares, la mayoría asociadas a la infección. Existe correlación entre la presencia de estas con el conteo de CD4+; sin embargo, un número similar de manifestaciones no asociadas a la infección se presentaron sin correlación con el conteo, por lo que los pacientes con VIH deberían tener revisiones oftalmológicas periódicas, independientemente del conteo de CD4+.

Hay 43 especies introducidas en Colombia, todas ellas presentes en la cuenca del río Magdalena y repartidas así: 13 especies trasplantadas de una cuenca a otra (5 órdenes, 8 familias), incluyendo una especie identificada a nivel de género y una variedad; 30 especies exóticas u originarias de otros continentes (6 órdenes, 9 familias), incluyendo un híbrido y una variedad creada ex situ. Todas las especies consideradas son de interés para la acuicultura, pesca comercial, pesca deportiva y ornamento-acuariofilia. Se hace un análisis comparativo del estatus actual de estas especies en relación al 2012, fecha en la cual se realizó la última evaluación de las introducciones y se muestra la distribución actual de estas especies. De acuerdo a esto, se registraron 13 introducciones nuevas (siete especies trasplantadas y seis especies exóticas), de las cuales en 12 especies (una trasplantada más 11 exóticas), se amplió la distribución geográfica, prueba de su dispersión posterior a 2012. En la actualidad se cultivan 15 especies introducidas: seis especies exóticas en 121 municipios y nueve trasplantadas en 92 municipios, la mayoría policultivos (varias especies). La falta de controles de seguridad en estas instalaciones de cultivo, más la liberación intencionada, siembras y escapes, son las razones que explican la distribución actual de gran parte de las especies.

El uso de los peces y la relación con los ecosistemas acuáticos ha sido una constante en la historia del país, pero solo hasta la década de 1970 se vio la necesidad de llevar registro de las capturas y regular su uso para su conservación. Análisis de las categorías de amenaza de los peces de la cuenca indican que el Magdalena presenta el mayor número de especies amenazadas del país, siendo una de las más amenazadas de todos los Andes tropicales, con esfuerzos insuficientes por manejar sus especies o por conservarlas. Así, las medidas se han basado en el enfoque clásico de manejo de pesquerías monoespecíficas de zonas templadas, centrándose en las especies comerciales de consumo, y más recientemente ha incluido especies ornamentales y algunas medidas para los ecosistemas acuáticos, con un enfoque jerárquico que no incluye a los pescadores en la formulación de las medidas, y con falencias en el seguimiento y en la evaluación de sus objetivos. Se evidenció que las medidas cubren solo un cuarto de las especies de la cuenca y que es necesariocambiar al manejo de las pesquerías multiespecíficas tropicales, requiriéndose una estrategia a nivel nacional, de largo plazo, que integre y articule las diferentes medidas, instrumentos y órganos de manejo, ordenamiento e implementación de acciones para la conservación de la cuenca y sus recursos acuáticos. Todo esto debe estar enmarcado en una visión socioecosistémica incluyente y participativa de protección de los ecosistemas acuáticos, con soluciones basadas en la naturaleza a escala de cuenca.

Este libro nos pone al día en tres grandes bloques, uno inicial donde se aborda el estado del conocimiento tanto desde la perspectiva biótica como física de la cuenca, la geología, hidrología, sedimentología y su relación con los ecosistemas y la biodiversidad acuática; los peces, su diversidad taxonómica y genética, ecología e historias de vida y los servicios ecosistémicos que brindan como recursos pesqueros. En la segunda parte se consideran los conflictos ambientales en la cuenca, desde temas como la contaminación y la modificación del hábitat; los peces introducidos (exóticos y trasplantados y la “presión” de una demanda cada vez mayor de la pesca. En la sección tercera, tras una interpretación concienzuda de los capítulos anteriores y el conocimiento de los investigadores, se hace un análisis detallado de todas las amenazas, así como las estrategias de conservación y manejo del recurso íctico. Todo ello, sienta las bases para una serie de recomendaciones para la toma de decisiones que son recogidas al final de la obra.

The following is a description of the design, development, and implementation process of the SIMALL shopping mall simulator. Created in order to carry out a study of the behavior of shoppers inside a shopping mall in order to create a better distribution of warehouses in the mall. A short description showing how the simulator was implemented based on a Multi-agent System with an emotional BDI architecture is also included.

This work studied the physical-chemical characteristics of two lime-based stucco samples extracted from the “El Cerrito” archeological site in Querétaro, Mexico. Their compositional analyses are consistent with calcite, labradorite (clay mineral), sand size quartz and volcanic lithics, and organic compounds. Scanning Electron Microscopy (SEM) images confirmed the use of micro and submicron natural fibers. Energy Dispersive Spectroscopy semi-quantitative analysis (EDS-SEM) showed Al, Mg, Ca, C, Si, K, and O as the major element components. Inductively Coupled Plasma (ICP) quantitative analysis found Ca, Al, Fe, Mg, and K as the major components, and Ba, P, S, Sr, Mn, Cr, and V, as minor and trace elements that produce a compelling fingerprint. X-ray diffraction patterns reveal that these stuccoes are formed by calcite and labradorite crystalline phases. These analyses were used to develop and reproduce a new stucco formulation that can be used to conserve and restore archeological buildings and as modern wall finishing. The new stucco is a heterogeneous mixture of calcium hydroxide, pozzolan (alunite-kaolinite), fine quartz sand, and volcanic lithics as an aggregate, and soluble and insoluble natural fibers obtained from nopal pads as additives. A step-by-step methodology to prepare and apply the newly formulated stucco in a modern house as a wall finishing is reported. Pozzolan, calcium hydroxide, and water react to produce the pozzolanic effect acting as a non-hydraulic cement, while calcium hydroxide reacts with the atmospheric CO2 to form calcium carbonate. Portlandite conversion to calcite and the pozzolanic effect to obtain labradorite were shown by X-ray analysis and high-resolution SEM images of the newly applied stucco.

Bacterial ATP binding cassette (ABC) transporters mediate the influx of numerous substrates. The cluster A-I ABC transporters are responsible for the specific uptake of the essential metals zinc, manganese or iron, making them necessary for survival in metal-limited environments, which for pathogens include the animal host. In Paracoccus denitrificans, there are two zinc ABC transporter systems: ZnuABC and AztABCD with apparently redundant functions under zinc-limited conditions. The unusual presence of two zinc ABC transporter systems in the same organism allowed for the investigation of specificity in the interaction between the solute binding protein (SBP) and its cognate permease. We also assessed the role of flexible loop features in the SBP in permease binding and zinc transport. The results indicate that the SBP–permease interaction is highly specific and does not require the flexible loop features of the SBP. We also present an expanded table of the properties of characterized cluster A-I SBPs and a multiple sequence alignment highlighting the conserved features. Through this analysis, an apparently new family of binding proteins associated with ABC transporters was identified. The presence of homologues in several human pathogens raises the possibility of using it as a target for the development of new antimicrobial therapies.

This paper explains the modelling and simulation of we modeled and simulate the power output of bifacial PV modules installed over different albedos using monofacial PV performance models (analytical and empirical). The analytical model and empirical models were evaluated using experimental data obtained from the testbed consisting of three bifacial PV arrays mounted in the same configuration but with different rear irradiance conditions: (1) backside covered by white plastic, (2) over normal albedo, and (3) over high albedo. The models use the measured effective solar irradiances and the PV module temperatures to simulate the power output in a healthy condition; they were adapted to bifacial modules by introducing the irradiance bifacial gain in the models’ equations. The results of the comparison showed that both models achieved good performance to simulate the instantaneous output of the PV arrays. Daily energy relative errors during sunny days were much less than overcast days, or about 1% for both models, excluding the shading effect. However, compared to the empirical model, the analytical model achieved better performances considering the bifaciality of the PV modules. In addition, the error for the entire monitored period (74 days during March, April, and May 2020) was less than 1.5% for the analytical model, including sunny and cloudy days; such high accuracy in the energy output forecast shows that the analytical model can accurately predict the generation of bifacial PV modules under different skies conditions.

Objective: We aimed to describe the microbiological characteristics of infections in patients from an oncological center during 2.014-2.016. Methods: In this cross-sectional descriptive study, a total of 7.837 cultures corresponding to 1.216 patients were included. Microbiological and sociodemographic data were taken from cancer diagnosed patients admitted to Oncólogos de Occidente S.A. in Pereira, Armenia, Manizales and Cartago from January 2.014 to December 2.016. The bacterial resistance profiles were defined according to the CLSI guideline. Culture foci were blood, urine, tissue biopsies, skin and soft tissues, mucous membranes and feces. Results: The culture-positive rate was 27,94%. Amongst 2.190 isolates, Escherichia coli (22,42%) was the most frequent, followed by Klebsiella pneumonia (21,27%), Pseudomona aeruginosa (13,83%) and Staphylococcus aureus (5,11%). The most common mechanisms of antimicrobial resistance in Gram-negatives were Extended-Spectrum β-Lactamase (45,45%) and AmpC-type β-lactamases (37,71%). Discussion: Up to nearly one-third of our participants’ cultures were positive and a vast majority were gram-negatives, provided with ESBLs or AmpCs which in oncological patients it is a catastrophic outcome. We recommend to establish antibiotic dispensing policies thus achieving a microbiological risk control and improve the epidemiological surveillance. Empirical use of beta-lactams with extended spectrum or cephalosporins of 1 to 3 generation is not recommended due to the high resistance found. Resumen Objetivo: Describir las características microbiológicas de las infecciones en pacientes de un centro oncológico durante 2.014-2.016 Métodos: Estudio descriptivo, transversal. Incluyó 7.837 cultivos de 1.216 pacientes. Se recolectaron variables microbiológicas y sociodemográficas de pacientes diagnosticados con cáncer en las sedes de Pereira, Armenia, Manizales y Cartago de Oncólogos de Occidente S.A. durante 2.014 hasta 2.016. Los perfiles de resistencia bacteriana se definieron de acuerdo con la guía CLSI. Los focos de cultivo fueron sangre, orina, biopsias de tejidos, piel y tejidos blandos, membranas mucosas y heces. Resultados: La tasa de cultivo positivo fue del 27,94%. De 2.190 aislamientos, E. coli (22,42%) fue el más frecuente, seguido de K. pneumoniae (21,27%), P. aeruginosa (13,83%) y S. aureus (5,11%). Los principales mecanismos de resistencia identificados en Gram negativos fueron β-lactamasas de espectro extendido (45,45%) y β-lactamasa de tipo AmpC (37,71%). Discusión: Cerca de un tercio de los cultivos de los participantes fueron positivos y una vasta mayoría fueron gram negativos, provistos con ESBL o AmpC, lo que en pacientes oncológicos es un desenlace catastrófico. Recomendamos establecer políticas de dispensación de antibióticos, logrando así un control de riesgo microbiológico y mejorar la vigilancia epidemiológica. No se recomienda el uso empírico de betalactámicos con espectro extendido o cefalosporinas de 1 a 3 generación debido a la alta tasa de resistencia encontrada.