Search

Pathological processes often change the mechanical properties of cells. Increased rigidity could be a marker of cellular malfunction. Erythrocytes are a type of cell that deforms to squeeze through tiny capillaries; changes in their rigidity can dramatically affect their functionality. Furthermore, differences in the homeostatic elasticity of the cell can be used as a tool for diagnosis and even for choosing the adequate treatment for some illnesses. More accurate types of equipment needed to study biomechanical phenomena at the single-cell level are very costly and thus out of reach for many laboratories around the world. This study presents a simple and low-cost technique to study the rigidity of red blood cells (RBCs) through the application of electric fields in a hand-made microfluidic chamber that uses a capacitor principle. As RBCs are deformed with the application of voltage, cells are observed under a light microscope. From mechanical force vs. deformation data, the elastic constant of the cells is determined. The results obtained with the capacitor-based method were compared with those obtained using optical tweezers, finding good agreement. In addition, P. falciparum-infected erythrocytes were tested with the electric field applicator. Our technique provides a simple means of testing the mechanical properties of individual cells.

Malaria, which infected more than 240 million people and killed around six hundred thousand only in 2021, has reclaimed territory after the SARS-CoV-2 pandemic. Together with parasite resistance and a not-yet-optimal vaccine, the need for new approaches has become critical. While earlier, limited, studies have suggested that malaria parasites are affected by electromagnetic energy, the outcomes of this affectation vary and there has not been a study that looks into the mechanism of action behind these responses. In this study, through development and implementation of custom applicators for in vitro experimentation, conditions were generated in which microwave energy (MW) killed more than 90% of the parasites, not by a thermal effect but via a MW energy-induced programmed cell death that does not seem to affect mammalian cell lines. Transmission electron microscopy points to the involvement of the haemozoin-containing food vacuole, which becomes destroyed; while several other experimental approaches demonstrate the involvement of calcium signaling pathways in the resulting effects of exposure to MW. Furthermore, parasites were protected from the effects of MW by calcium channel blockers calmodulin and phosphoinositol. The findings presented here offer a molecular insight into the elusive interactions of oscillating electromagnetic fields with P. falciparum, prove that they are not related to temperature, and present an alternative technology to combat this devastating disease.

For decades, researchers have experimented with the possibility that machines can equal human linguistic capabilities. Recently, advances in the field of natural language processing (NLP) as well as a substantial increase in available naturally occurring linguistic data on social media platforms have made more advanced methodologies such as sentiment analysis (SA) gain substantial momentum on contemporary applications. This document compiles what the authors consider to be some of the most important concepts related to SA, as well as techniques and processes necessary for the various stages of its implementation. Furthermore, specific applications related to the extraction and classification of social media data using novel SA techniques are presented and quantified, with an emphasis on those used for the identification of mental health degradation during the COVID-19 pandemic. Finally, the authors present several conclusions highlighting the most prominent benefits and drawbacks of the methods discussed, followed by a brief discussion of possible future applications of certain methods of interest.

Hyperspectral imaging has become a valuable remote sensing tool due to the development of advanced remote acquisition systems with high spatial and spectral resolution, and the continuous developments on more efficient computing resources to handle the high volume of data. For this reason, hyperspectral image analysis has found important uses in precision agriculture, where the health status of crops in various stages of the production process can be assessed from their spectral signatures. This has similarly been the case for rice cultivation, which represents one of the most valuable crops worldwide in terms of gross production value, global consumption rates, and food security reserves. To maximize the productivity of this activity and minimize economic and food crop losses, various precision agriculture techniques to optimize yields by managing production inputs and monitoring plant health have been developed. Such applications include landcover classification, cultivar identification, nitrogen level assessment, chlorophyll content estimation and the identification of various factors, such as the presence of pests, weeds, disease or pollutants. The current work highlights and summarizes various aspects of interest of the main studies on hyperspectral imaging applications for rice cultivation. For instance, several tables summarize the most relevant work on the application of hyperspectral imaging for rice cultivation based on their acquisition methods, spectral region, rice species, and inferred magnitudes, among other parameters. In addition, we identify challenges across the field that limit the widespread deployment of hyperspectral imaging applications. Among these challenges, adequate modeling of various dynamic local factors and their influence on the analysis is a main concern. The main objective of this review is to provide a reference for future works that addresses the main challenges, and accelerate the development of deployable end user technologies to meet current global Sustainable Development Goals, in a manner that is resilient towards the increasingly dynamic growing conditions of rice plants expected by global climate change.

The target position information contained in scattering data is explored in the context of the scalar Helmholtz operator for the basic two-point scatterer system by means of the statistical estimation framework of the Fisher information and associated Cramér-Rao bound (CRB) relevant to unbiased position estimation. The CRB results are derived for the exact multiple scattering model and, for reference, also for the single scattering or first Born approximation model applicable to weak scatterers. The roles of the sensing configuration and the scattering parameters in target localization are analyzed. Blind spot conditions under which target localization is impossible are derived and discussed for both models. It is shown that the sets of sensing configuration and scattering parameters for which localization is impeded are different but equivalent (they have the same size) under the exact multiple scattering model and the Born approximation. Conditions for multiple scattering to be useful or detrimental to localization are derived.

La comunicación molecular permite el envío de información a través de moléculas u otras partículas a escala de nanómetros a micrómetros. La misma posee limitaciones como: degradación de las partículas en el medio acuoso durante la propagación y retardo de la señal de información recibida debido al movimiento browniano de las partículas. En este artículo se describen los fundamentos más relevantes de un sistema de comunicación molecular incluyendo retos, limitaciones y aplicaciones en la que esta tecnología tendría un impacto relevante. Se presentan los aspectos significativos del canal de comunicaciones, tipos de modulación y herramientas de modelaje de sistemas de comunicación molecular.

El incremento de la demanda de servicios interactivos de televisión, incluyendo programación de alta definición motivó la migración de transmisión SD analógica a digital. La transmisión digital de televisión ha sido un área de continua investigación e innovación, lo que se evidencia en el desarrollo tecnológico plural y la creación de nuevos estándares en años recientes. Este artículo brinda una breve reseña de los diferentes estándares para televisión digital usados alrededor del mundo, incluyendo sus características más importantes, los lugares donde han sido implementados, y los parámetros más destacados de cada estándar de televisión digital.

Las comunicaciones a través de líneas de potencia (PLC) se han convertido en una tecnología de interés para tener acceso a la red de Internet y otros servicios de Comunicación. PLC está siendo altamente competitiva con otras tecnologías para la extensión geográfica que cubre en la mayoría de las zonas que generarán grandes demandas de transmisión de datos. Para incorporar sistemas PLC es necesario conocer las características del medio (lineas de potencia) como canal de comunicación. Este artículo brinda una descripción detallada acerca de las propiedades y características de las redes eléctricas e interiores en cuanto a sus topologías, escenario de ruido, comportamiento del canal y finalmente un análisis acerca de los estudios y modelos actuales para la caracterización del canal.

Una red de sensores inalámbrica permite medir ciertos parámetros y cambios en características físicas como la temperatura y la humedad, así como también controlar, de cierta forma, estos parámetros con el fin de mejorar y facilitar el manejo de cualquier actividad a la que sean aplicadas, entre ellas, la agroindustria. Una de las grandes limitantes en estas redes son sus fuentes de energía, ya que los sensores deben ser dispositivos pequeños, por lo que existe un gran interés en buscar técnicas para el uso eficiente de la energía, uso de energías renovables como medio de alimentación en los sensores y aplicación del muestreo compresivo, el cual permite obtener suficiente información utilizando menos sensores que con los métodos convencionales.

El buen desempeño de una red de potencia inteligente, mejor conocida como Smart Grid, depende del sistema de comunicación empleado, de aquí la importancia de contar con la tecnología apropiada. En este artículo se presentan las tecnologías de comunicación usadas en los entornos de alta y media tensión, y el objetivo principal es documentar las características generales de cada una de ellas, sus aplicaciones, limitaciones y los estándares empleados. Para mayor comprensión, las mismas se han clasificado según su tipo, en cableadas e inalámbricas.

La Dra. Carmenza Spadafora estudió su doctorado en Bioquímica y Biología Molecular en la Universidad de Granada con el Consejo Superior de Investigaciones Científicas de España. Es egresada de la Universidad Eastern Michigan en Bioquímica Profesional y realizó dos formaciones postdoctorales en la Universidad Central de la Florida y en el Walter Reed Army Institute of Research en Estados Unidos. En el 2008 regresó a Panamá a incorporarse en el Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, INDICASAT AIP. Es coordinadora del Centro de Biología Celular y Molecular de las Enfermedades. Entre sus distinciones cuentan haber logrado el primer subsidio de Fase I de Panamá y el primero de Fase II de Latinoamérica del programa Exploraciones para los retos Globales, de la Fundación Bill y Melinda Gates. Carmenza ha sido galardonada por su excelencia en investigación en 2012 y 2014, premio otorgado por APANAC y SENACYT. Carmenza Spadafora forma parte del Sistema Nacional de Investigación, SNI, como Investigadora Distinguida.