A comparative single-evaluation cross-sectional study was performed to evaluate cognitive damage in post-COVID-19 patients. The psychophysics tests of Two-Alternative Forced Choice (2AFC) and Simple Reaction Time (SRT), under a designed virtual environment, were used to evaluate the cognitive processes of decision-making, visual attention, and information processing speed. The population under study consisted of 147 individuals, 38 controls, and 109 post-COVID patients. During the 2AFC test, an Emotiv EPOC+^® headset was used to obtain EEG signals to evaluate their Focus, Interest, and Engagement metrics. Results indicate that compared to healthy patients or recovered patients from mild-moderate COVID-19 infection, patients who recovered from a severe-critical COVID infection showed a poor performance in different cognitive tests: decision-making tasks required higher visual sensitivity (p = 0.002), Focus (p = 0.01) and information processing speed (p < 0.001). These results signal that the damage caused by the coronavirus on the central nervous and visual systems significantly reduces the cognitive processes capabilities, resulting in a prevalent deficit of 42.42% in information processing speed for mild-moderate cases, 46.15% for decision-making based on visual sensitivity, and 62.16% in information processing speed for severe-critical cases. A psychological follow-up for patients recovering from COVID-19 is recommended based on our findings.

The ripening process in bananas causes the waste of a significant part of the production of this fruit. The aim of this research is to find a new technique useful for identifying, registering, and quantifying the ripening process of a banana (Musa AAB Simmonds) at the seventh stage of the growing process. This quantification is proposed with a nondestructive technique based on processing multispectral images. This experiment used a set of multispectral imagery registered in a range of 270-1000 nm (from UV to IR) with the aid of a monochromatic camera and a set of 10 optical filters. Multispectral images were analyzed with three different techniques: Fourier fractal analysis, Hotelling transform, and homogeneity texture analysis based on cooccurrence matrix. First, a characteristic index was computed for each technique for a daily set of multispectral imagery. These indexes are slope index, for Fourier fractals; the average of the computed eigenvalues, with Hotelling transform; and the texture homogeneity value. These indexes were evaluated using the behavior of the resulting graphs for a seven-day period, being preferred those graphs with a tendency of decreasing values. Finally, the repeatability of each technique was evaluated by reproducing similar values for each day during the evaluation period. These three methods will be compared in this article in order to select the one with the best performance for measuring the ripening process in bananas. The obtained results show that it is possible to effectively isolate the brown spots from the banana peel with the Hotelling transform by using only 2 optical filters: visible (410-690 nm) and Near-IR (820-910 nm). With the resulting spectral image fusion it was possible to effectively describe the evolution of the brown spots present in the ripening process through the texture homogeneity criteria.

In Latin America and the Caribbean, the consumption of energy, that comes mainly from fossil resources, have carried an increase in the air pollution. Electricity generation and its consumption in residential sector contributes to this problem with a significant percentage. On the other hand, recent research has demonstrated that the use of smart energy meters in developed countries reduces the electricity consumption due the continuous feedback gave to the consumer. This research presents the developing and implementation of an electrical energy consumption monitoring system based on smart sensors with IoT technology. The system calculates the instant power and the electrical efficiency as well as the energy consumed and its cost. The information of these variables is processed and transferred trough a WIFI ESP8266 module to a ThingSpeak server that works like a cloud database. Also, an Android mobile application that interacts directly with the database was developed to users visualize the variables behavior. For validate the smart sensor accuracy its measures were compared with the measures of an oscilloscope and a multimeter. Relative errors between -2.34 and 1.92 % were observed.

Today, maintaining an Internet connection is indispensable; as an example, we can refer to IoT applications that can be found in fields such as environmental monitoring, smart manufacturing, healthcare, smart buildings, smart homes, transportation, energy, and others. The critical elements in IoT applications are both the Wireless Sensor Nodes (WSn) and the Wireless Sensor Networks. It is essential to state that designing an application demands a particular design of a WSn, which represents an important time consumption during the process. In line with this observation, our work describes the development of a modular WSn (MWSn) built with digital processing, wireless communication, and power supply subsystems. Then, we reduce the WSn-implementing process into the design of its modular sensing subsystem. This would allow the development and launching processes of IoT applications across different fields to become faster and easier. Our proposal presents a versatile communication between the sensing modules and the MWSn using one- or two-wired communication protocols, such as I²C. To validate the efficiency and versatility of our proposal, we present two IoT-based remote monitoring applications.

The use of DC microgrids (DC-µGs) offers a variety of environmental benefits; albeit, a successful implementation depends on the implementation of an Energy Management System (EMS). An EMS is broadly implemented with a hierarchical and centralized structure, where the communications layer presents as a key element of the system to achieve a successful operation. Additionally, the relatively low cost of wireless communication technologies and the advantages offered by remote monitoring have promoted the inclusion of the Internet of Things (IoT) and Wireless Sensor and Actuator Network (WSAN) technologies in the energy sector. In this article is presented the development of an IoT EMS based on a WSAN (IoT-EMS-WSAN) for the management of a DC-µG. The proposed EMS is composed of a WiFi-based WSAN that is interconnected to a DC-µG, a cloud server, and a User Web App. The proposed system was compared to a conventional EMS with a high latency wired communication layer. In comparison to the conventional EMS, the IoT-EMS-WSAN increased the updating time from 100 ms to 1200 ms; also, the bus of the DC-µG maintained its stability even though its variations increased; finally, the DC bus responded to an energy-outage scenario with a recovery time of 1 s instead of 150 ms, as seen with the conventional EMS. Despite the reduced latency, the developed IoT-EMS-WSAN was demonstrated to be a reliable tool for the management, monitoring, and remote controlling of a DC-µG.

As an alternative to confronting the actual challenges in the conventional agriculture, Controlled Environment Agriculture (CEA) and hydroponics arise as sustainable alternatives, allowing for an efficient use of resources during green-leaf crop production. Considering a Nutrient Film Technique (NFT) hydroponic wall-system and two different ranges of light spectra provided via LED technology, this study evaluated their impact on the yield and efficiency during the cultivation of Swiss Chard crops (Beta vulgaris var. cicla) based on an analysis of morphological and nutritional characteristics. The experiment was developed in a growth room chamber, which was monitored and controlled under an IoT scheme, mainly focusing on the lighting treatments; treatments T1 and T2 were defined with the LED Barina 42W and LED MURFURN 70W, correspondingly. The results show no significant differences between both treatments in most morphological cases; however, the foliar area was significantly larger in treatment T1 than in treatment T2. Additionally, the nutritional quality of treatment T1 showed higher concentrations of carbohydrates, proteins, minerals, Ca, and K. Conclusively, the light spectrum composition provided by the lighting system influences the chard physiology, favoring the nutrient concentration under red–blue spectrum combinations.