Polymeric Piezoelectric Sensors and Remote Communication for Detection of Bruxism

Active materials are capable of responding in a controlled way to different external physical or chemical stimulus by changing some of their properties. These materials can be used to design and develop sensors, actuators and multifunctional systems with a large number of applications for developing medical devices (for both surgery and implants). On the other hand, Bruxism is a health problem consisting on grinding or tightly clenching the upper and lower teeth, and both phenomena lead to wear of the teeth and produce a noise during the night that is sufficiently loud to disturb the sleep of anyone sharing the bedroom. The tension produced also causes problems in the muscles, tissues and other structures surrounding the jaw, ear pain, headaches, lesions to the teeth and disorders in the jaw joints. For an early, rapid, effective and economical diagnosis of bruxism, we propose the use of instrumented splints based on the use of active materials, in order to detect and record the intensity and duration of interdentally pressure episodes. This paper introduces the design, manufacture and testing of using instrumented splint for diagnosing bruxism. The contribution of this work basically focus on using piezoelectric polymeric sensors, taking advantage of their reduced thickness, and avoiding the alteration of the patient¿s bite. In addition, the system allows a quantitative assessment of intraoral pressure that consequently allows the diagnosis of bruxism behaviour at an early stage, aiming to perform corrective actions before irreversible dental wear appears. The first trials performed allowed to demonstrate the feasibility of the system, which also includes wireless communication capabilities for improving telemedicine tasks

Shadow Analysis of Soil Surface Roughness Compared to the Chain Set Method and Direct Measurement of Micro-relief.

Erosion potential and the effects of tillage can be evaluated from quantitative descriptions of soil surface roughness. The present study therefore aimed to fill the need for a reliable, low-cost and convenient method to measure that parameter. Based on the interpretation of micro-topographic shadows, this new procedure is primarily designed for use in the field after tillage. The principle underlying shadow analysis is the direct relationship between soil surface roughness and the shadows cast by soil structures under fixed sunlight conditions. The results obtained with this method were compared to the statistical indexes used to interpret field readings recorded by a pin meter. The tests were conducted on 4-m2 sandy loam and sandy clay loam plots divided into 1-m2 subplots tilled with three different tools: chisel, tiller and roller. The highly significant correlation between the statistical indexes and shadow analysis results obtained in the laboratory as well as in the field for all the soil?tool combinations proved that both variability (CV) and dispersion (SD) are accommodated by the new method. This procedure simplifies the interpretation of soil surface roughness and shortens the time involved in field operations by a factor ranging from 12 to 20

Cursos virtuales como espacios para el intercambio de conocimiento

Introduction: as technological development advances by leaps and bounds, virtual and interactive spaces occupy more and more time in man's daily life. The use of information and communication technologies are necessary tools to cope with the high flow of information that is handled.Objective: to describe the impact of virtual pre-event courses belonging to CovidCien2021 on medical science students.Methods: an observational, descriptive and cross-sectional study was carried out. The universe consisted of 53 students. We worked with the entire universe; no sampling technique was used. Variables: number of courses and participants per course, age, sex, academic year, career and polytomous variables. Descriptive and percentage statistics were used.Results: 12 courses were given, with an average of 173 participants. The female sex stood out with 36 participants (67,92 %). The fourth academic year (19; 35,84 %) and the medical career (45; 84,90 %) stood out. The mean number of responses was 253,57; there was general satisfaction among the participants. The highest number of responses were in the category totally satisfied.Conclusions: the development of courses through virtual spaces offers notable alternatives and benefits. It is presented as a renovating alternative in the face of complex situations that guarantees the continuity of teacher training. Its organization and implementation should not be schematized to a specific sector or subject of knowledge, but should be diversified, without losing sight of the presence as a key element.Introducción: los espacios virtuales e interactivos ocupan, conforme el desarrollo tecnológico avanza a pasos agigantados, mayor tiempo en el quehacer diario del hombre. El uso de las tecnologías de la información y las comunicaciones constituyen herramientas necesarias para hacer frente al alto flujo de información que se maneja.Objetivo: describir el impacto de los cursos pre-eventos virtuales pertenecientes a CovidCien2021 en estudiantes de las ciencias médicas.Métodos: se realizó un estudio observacional, descriptivo y de corte trasversal. El universo se conformó por 53 estudiantes. Se trabajó con la totalidad del universo; no se empleó técnica de muestreo. Variables: cantidad de cursos y participantes por curso, edad, sexo, año académico, carrera y variables politómica. Se empeló la estadística descriptiva y porcentual.Resultados: se impartieron 12 cursos; con una media de 173 participantes. Sobresalió el sexo femenino con 36 participantes (67,92 %). Destacó el cuarto año   académico (19; 35,84 %) y la carrera de medicina (45; 84,90 %). La media de respuestas fue de 253,57; se evidenció satisfacción generalizada en los participantes. El mayor número de respuestas fueron en la categoría totalmente satisfecho.Conclusiones: el desarrollo de cursos mediante espacios virtuales ofrece alternativas y beneficios notables. Se presenta como una alternativa renovadora ante situaciones complejas que garantiza la continuidad de la formación docente. Su organización y puesta en práctica no debe esquematizarse a un sector o temática específica del saber, sino que debe diversificarse; sin perder de vista la presencialidad como elemento primordial

Shadow Analysis Field Measurements Related to Soil Surface Rougness

The present study aimed to fill the need for a reliable, low-cost and convenient method to measure soil surface roughness. Based on the interpretation of micro-topographic shadows, this procedure is primarily designed for use in the field. The principle underlying shadow analysis is the direct relationship between SSR and the shadows cast by soil structures under fixed sunlight conditions. The results obtained with this method were compared to the statistical indexes used to express field readings recorded by pin meter and chain set methods. The tests were conducted on 4-m 2 sandy clay loam plots divided into 1-m 2 subplots tilled with three different implements: chisel, tiller and roller. The highly significant correlation between the statistical indexes and shadow analysis results proved that both variability (CV) and dispersion (SD) are accommodated by the new method. The method also showed a good proportionality with the chain roughness (CR). The SSR obtained for the different methods is mainly related to the presence of aggregates. The shadow analysis simplifies the interpretation of soil surface roughness and shortens the time involved in field operations by a factor ranging from 4 to 2

Assessment of soil surface roughness decay at semiarid field conditions using the shadow analysis method

Soil surface roughness (SSR) is an excellent parameter to assess soil vulnerability to wind and water erosion. Several methods are used to measure SSR depending on specific field and climate conditions. The method based on the shadow analysis has shown to be the most convenient technique to characterize SSR in the field than existing procedures when used in arid and semi-arid regions of Spain. This convenience is due to climate and soil conditions prevailing and low development and maintenance costs and adaptability. Therefore, the present study aimed to assess the SSR decay using the shadow analysis method at field in eight controlled plots of 1 m2. The data were collected from beginning of fall 2009 to spring 2010. Half of the experimental plots were covered to be used as control, to avoid influence from wind and water erosion. The rest of the plots were uncovered to assure SSR decay and to evaluate the parameter as the result of the produced erosion. The results showed marked differences among the cover an uncover plots. The parameters demonstrated that the method can be used to study the influence of wind and water erosion on soil at field conditions, although some adjustments must be done on method since it presents some limitations, mainly related to weather conditions when used continuously at field condition

Extreme temperature events analyzed with Fast Fourier Transform

Extreme weather and climate events have received increased attention in the last few years, due to the often large loss of agriculture business and exponentially increasing costs associated with them and insurance planning. This increased attention raises the question as to whether extreme weather and climate events are truly increasing, whether this is only a perceived increase exacerbated by enhanced media coverage, or both. There are a number of ways extreme climate events can be defined, such as extreme daily temperatures, extreme daily rainfall amounts, and large areas experiencing unusually warm monthly temperatures, among others. In this study, we will focus our attention in frost and heatstroke events measuring it as the number of days under 0 ºC and number of days with daily maximum over 30ºC monthly respectively. We have studied the trends in these extreme events applying a Fast Fourier Transform to the series to clarify the tendency. Lack of long-term climate data suitable for analysis of extremes is the single biggest obstacle to quantifying whether extreme events have changed over the twentieth century, including high temporal and spatial resolution observations of temperatures. However, several series have been grouped in different ways: chosen the longest series independently, by provinces, by main watersheds and altitude. On the other hand, synthetic series generated by Luna and Balairón (AEMet) were also analyzed. The results obtained by different pooling data are discussed concluding the difficulties to assess the extreme events tendencies and high regional variation in the trends

Analysis of Hail and Temperature Series for Peninsular Spain

Hail is a serious concern for agriculture on the Iberian Peninsula. Hailstorms affect crop yield and/or quality to a degree that depends on the crop species and the phenological time. In Europe, Spain is one of the countries that experience relatively high agricultural losses related to hailstorms. It is of high interest to study models that can support calculations of the probabilities of economic losses due to hail damage and of the tendency over time for such losses. Some studies developed in France and the Netherdlands show that the summer mean temperature was highly correlated with a yearly hail severity index developed from hailrelated parameters obtained for insurance purposes. Meanwhile, other studies in the USA point out that a highly significant correlation between both is not possible to find due to high climatic variability. The aim of this work is to test the correlation between average minimum temperatures and hail damage intensity over the Spanish Iberian Peninsula. With this purpose, correlation analyses on both variables were performed for the 47 Spanish provinces (as individuals and single set) and for all crops and four individual crops: grapes, wheat, barley and winter grains. Suitable crop insurance data are available from 1981 until 2007 and based on this period, temperature data were obtained. This study does not confirm the results previously obtained for France and the Netherlands that relate observed hail damage to the average minimum temperature. The reason for this difference and the nature of the cases observed are discussed

Teoría de números en criptografía y su debilidad ante la posible era de las computadoras cuánticas

La principal aplicación de la criptografía es la de proteger información para evitar que sea accesible a observadores no autorizados. Sin embargo, también tiene otras aplicaciones, por ejemplo verificar que un mensaje no haya sido modificado intencionadamente por un tercero, verificar que alguien es quien realmente dice ser, etc. El objetivo del presente trabajo es mostrar cómo la matemática juega un papel importante en la criptografía moderna y como ésta aprovecha los problemas difíciles (en el sentido computacional) que existen en la teoría de números para desarrollar protocolos criptográficos. Asimismo se menciona lo que pasaría con los protocolos criptográficos basados en la teoría de números si existiera una computadora cuántica

Supercritical extraction of lyophilized strawberry anthocyanins with pulsed electric fields pretreatment

Anthocyanins from LSB and with a PEF pretreatment were extracted with ethanol + SCCO2. The extraction at 200 bar, 333.15, 3.3% wt. of ethanol as cosolvent and using LSB with a PEF pretreatment of 1 kV/cm, produced an extraction yield of 0.284 % and a TAC of 0.231 (g/100 g of ethanol + SCCO2). The individual effect of 1.0 kV/cm of PEF pretreatment increases the %EY by 25 % and the TAC by 29 %. The individual effect of the cosolvent increases the %EY by 32% and that of TAC by 36.4%. However, the combined effect of 1.0 kV cm-1 and 3.3 % ethanol, produced an increase of 78.2 % and 85.3% in the %EY and TAC, respectively. Therefore, these results suggest that there is a synergistic effect, which means that both the electroporation caused by PEF in the LSB and the increase in polarity due to the addition of ethanol produce a substantial improvement over %ET and TAC. Furthermore, the process of extracting anthocyanins from LSB using a mixture of ethanol + supercritical carbon dioxide can be satisfactorily described by a solubility-based model such as the Kumar and Johnston model.The lyophilized strawberry anthocyanins were extracted using a supercritical extraction (SE) process. The effect of pulsed electric fields (PEF) as pretreatment and the influence of the addition of ethanol as a cosolvent on the percentage of extraction yield (EY) and the total anthocyanin concentration (TAC) were analyzed. The effect of PEF was evaluated at 0.5 and 1.0 kV/cm, while the effect of the cosolvent was studied in mixtures of supercritical carbon dioxide - ethanol (SCCO2 + ethanol) at 1.6 and 3.3% by weight. The best results (% EY = 0.506, TAC = 0.428 g /100 g of lyophilized strawberry) were obtained with a PEF pretreatment of 1.0 kV cm-1, 3.3%wt. ethanol at 200 bar and 333.15 K. The experimental results of solubility were suitably adjusted with the Kumar and Johnston model. The maximum solubility (0.114 g/100 g of solvent mixture) was obtained at 300 bar and 313.15 K.The authors would like to thank the National Council of Science and Technology of Mexico (CONACyT) for the scholarship granted to the master’s student in chemical sciences Marco A. Ávila-Hernández

Monthly hail time series analysis related to agricultural insurance

Hail is one of the mos important crop insurance in Spain being more than the 50% of the total insurance in cereal crops. The purpose of the present study is to carry out a study about the hail in cereals. Four provinces have been chosen, those with the values of production are higher: Burgos and Zaragoza for the wheat and Cuenca and Valladolid for the barley. The data that we had available for the study of the evolution and intensity of the damages for hail includes an analysis of the correlation between the ratios of agricultural insurances provided by ENESA and the number of days of annual hail (from 1981 to 2007). At the same time, several weather station per province were selected by the longest more complete data recorded (from 1963 to 2007) to perform an analysis of monthly time series of the number of hail days (HD). The results of the study show us that relation between the ratio of the agricultural insurances and the number of hail days is not clear. Several observations are discussed to explain these results as well as if it is possible to determinte a change in tendency in the HD time serie