Optical Tweezers as an Effective Tool for Spermatozoa Isolation from Mixed Forensic Samples

A single focus optical tweezer is formed when a laser beam is launched through a high numerical aperture immersion objective. This objective focuses the beam down to a diffraction-limited spot, which creates an optical trap where cells suspended in aqueous solutions can be held fixed. Spermatozoa, an often probative cell type in forensic investigations, can be captured inside this optical trap and dragged one by one across millimeter-length distances in order to create a cluster of cells which can be subsequently drawn up into a capillary for collection. Sperm cells are then ejected onto a sterile cover slip, counted, and transferred to a tube for DNA analysis workflow. The objective of this research was to optimize sperm cell collection for maximum DNA yield, and to determine the number of trapped sperm cells necessary to produce a full STR profile. A varying number of sperm cells from both a single-source semen sample and a mock sexual assault sample were isolated utilizing optical tweezers and processed using conventional STR analysis methods. Results demonstrated that approximately 50 trapped spermatozoa were required to obtain a consistently full DNA profile. A complete, single-source DNA profile was also achieved by isolating sperm cells via optical trapping from a mixture of sperm and vaginal epithelial cells. Based on these results, optical tweezers are a viable option for forensic applications such as separation of mixed populations of cells in forensic evidence

Burnout y educación en línea: adaptación y validación de escala durante la pandemia

During the COVID-19 pandemic, online education represented a serious alternative to continuing working life in higher education institutions (HEIs). Teachers around the world embraced a new role, adopting and using a wide range of technological and virtual tools to continue performing their activities and with the aim to interact with students and to continue teaching.  For this reason, research related to seek and identify factors for the teachers’ well-being is essential for educational leaders. Regarding these ideas, this paper aims to test the construct validity of a Mexican version of the Maslach Burnout Inventory-Educators Survey (MBI-ES) of Maslach et al. (1997), adapted to online education. Participants consisted of 406 Mexican university teachers who emergently switched from traditional to online educational practices during the SARS-CoV-2 virus outbreak. In order to test the factor structure of three alternative models based on Szigeti et al. (2016), the authors performed exploratory and confirmatory factor analyses (Ferrando & Lorenzo-Seva, 2018). Results showed that the model with three domain factors has the best fit. Besides, our findings show that the three-factor structure of the Mexican adaptation of MBI-ES is valid and reliable for the analysis of online education because the loading of all factors was representative.   Keywords: Burnout, Teacher, Online Education, COVID-19, Pandemic, Scale Adaptation.La educación en línea representa una alternativa a la continuidad de la vida laboral en las instituciones de educación superior (IES). Los docentes adoptaron un nuevo rol al disponer de una serie de herramientas tecnológicas y virtuales para realizar sus actividades e interactuar con los alumnos.  Por esta razón, la búsqueda e identificación de factores para el bienestar de los profesores es esencial para los líderes educativos. Este trabajo tiene como objetivo probar la validez de constructo de una versión mexicana de la escala Maslach Burnout Inventory-Educators Survey (MBI-ES) de Maslach et al. (1997), adaptada a la educación en línea.  Los participantes consisten en 406 profesores universitarios mexicanos que cambiaron las prácticas educativas tradicionales por prácticas en línea durante la pandemia de COVID-19. Para probar la estructura factorial de tres modelos alternativos tomando como base a Szigeti et al. (2016), se realizaron análisis factoriales exploratorio y confirmatorio (Ferrando y Lorenzo-Seva, 2018). Los resultados mostraron que el modelo con tres factores de dominio tiene el mejor ajuste. Además, nuestros hallazgos muestran que la estructura de tres factores de la adaptación mexicana de MBI-ES es válida y confiable para el análisis de la educación en línea porque todas las cargas de los factores fueron representativas.   Palabras clave: Burnout, Docente, Educación en línea, COVID-19, Pandemia, Adaptación de escala

Tolerância ao déficit hídrico em cultivares e/ou acesso de Brachiaria brizantha Stapf: alongamento foliar 1.

O alongamento foliar de cinco cultivares e/ou acesso de Brachiaria brizantha (cv. Marandu, cv. Xaraés, cv. Piatã e acesso BRA 003891) foi avaliado em experimento disposto no delineamento em blocos ao acaso em arranjo fatorial4x2 (quatro cultivares/acessos e duas condições hídricas) com quatros repetições, em casa-de-vegetação. As avaliações foram realizadas diariamente medindo-se o comprimento das folhas em expansão de dois perfi lhos por vaso. O cultivar Marandu teve a menor tolerância ao estresse por déficit hídrico, apresentando forte redução do seu crescimento já no terceiro dia (P<O,OS). O cultivar Piatã apresentou a maior resistência ao déficit hídrico (P<O,OS), reduzindo seu crescimento em relação à testemunha apenas no sexto dia (P<O,OS)

FrontEnd Sitio web sistema de monitoreo de sensores

El sitio web de Sistema de monitoreo de Sensores busca informar sobre el estado actual del aire en puntos estratégicos colocados dentro del ITESO y sobre el bosque de la primavera, asimismo buscamos brindar esta información a través de una la página web y su aplicación móvil, de esta manera podemos brindar todos estos datos a las personas sobre el estado actual de estas zonas verdes y así fomentar su cuidado. Se completó el desarrollo de un prototipo de sitio web más actual para el sistema de monitoreo de sensores, en este proyecto nos enfocaremos a la parte del FrontEnd. Se busca la mejora del sitio web, de mejorar la compatibilidad con distintas dimensiones según el dispositivo desde el cual se ingrese al sitio, sin sacrificar la funcionalidad de este. Utilizaremos los mismos aspectos técnicos utilizamos anteriormente en el prototipo (lenguaje HTML, CSS, JavaScript), junto con los respectivos Servicios Web proporcionados por el equipo de BackEnd, dando la funcionalidad buscada en los diferentes nodos.ITESO, A.C

The Relation of physical self-concept, anxiety, and BMI among mexicam university students

El propósito de la investigación es conocer y relacionar los resultados del autoconcepto físico, con diferentes tipos de ansiedad y el IMC en los estudiantes de enfermería y educación física dela península de Yucatán (México). La muestra estuvo formada por 264 participantes, de los cuales 91 eran varones y 173 mujeres, con edades comprendidas entre 18 y 25 años. Nuestros datos revelan que en el autoconcepto físico, los valores obtenidos por los estudiantes de educación física son superiores al de los estudiantes de enfermería. Los estudiantes de enfermería presentan mayores valores de ansiedad estado que los de educación física. La percepción que tienen los estudiantes de ciclos superiores en prácticamente todas las dimensiones del autoconcepto es superior a la del alumnado de ciclos inferiores. Los niveles de ansiedad disminuyen conforme pasan de ciclos inferiores a superioresThe purpose of this paper is to know and relate the results of the various dimensions formed by the physical self-concept with respect to the different types of anxiety and the BMI among nursing and physical education students in the area of the Yucatán peninsula in Mexico. The study is based on a sample of 264 people, being 91 men and 173 women between the ages of 18 and 25. The outcome shows that the values obtained by physical education students are higher than those obtained by nursing students regarding the physical selfconcept. Nursing students present a higher level of anxiety compared to physical education students. The perception showed by junior and senior students with regard to almost all dimensions of self-concept is higher than that of freshmen and sophomore students. Anxiety level among students decreases throughout the year

Visualization of the flow distribution inside the piston displacement of a gamma-type stirling engine

The dynamics of the confined flow inside the piston displacement of a Gamma-type Stirling engine operating as a heat pump is experimentally analyzed. The diameter of the piston is 30 mm; 2 mm smaller than the internal diameter of the cold cylinder. As the piston performs its reciprocating motion, the gas leaks around the gap between the piston and the cylinder wall, generating a continuous pulsating motion. In the first part of the cycle air is introduced and compressed by the piston motion, and then the second part of the cycle starts by expanding the air and ejecting it from the assembly chamber. Experimental observations were carried out at frequencies in the range 100 to 300 rpm. The flow was visualized using a vertical laser beam plane oriented in the same axial direction of the piston’s motion. The particles used as trackers are water drops condensed on carbon dioxide microcrystals. Images were taken with a high speed video camera with a frame rate of 1000 fps. PIV techniques were implemented to identify the flow main structures. For analysis purposes, fixed phase averages of the velocity fields are required, due to the turbulent regime observed in this phenomena and its oscillatory nature. Based on experimental measurements it can be demonstrated that the average flow involved is not axisymmetric, although very interestingly, specific inlet and exit regions of the piston-cylinder gap were identified.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

Practical implications of GPR investigation using 3D data reconstruction and transmission tomography

Non-destructive investigation using ground penetrating radar is becoming more popular in the inspection of civil structures. Currently, traditional 2D imaging is used as a preliminary tool to fi nd possible areas of interest for more detailed inspection, which can be accomplished by more advanced techniques like 3D image reconstruction or tomography. In this paper, a general overview of the work done at University of Minho regarding these techniques is presented, together with their limitations and advantages over typical radargrams, with implications for civil engineering applications. For this purpose, data acquisition on two large masonry walls and one large concrete specimen have been carried out, using refl ection mode, 3D reconstruction and transmission tomography. The specimens have been specially built for non-destructive inspection techniques testing, incorporating different materials and internal voids. Radar tomography and 3D image reconstruction techniques provided much more detailed information about structural integrity and shapes and location of the voids, when compared to 2D imaging originally used for potential target identification.Fundação para a Ciência e a Tecnologia (FCT) - POCTI SFRH/BD/6409/2001"Sustainable Bridges" European project - FP6-PLT-0165

NADPH Thioredoxin Reductase C and Thioredoxins Act Concertedly in Seedling Development

Thiol-dependent redox regulation of enzyme activity plays a central role in the rapid acclimation of chloroplast metabolism to ever-fluctuating light availability. This regulatory mechanism relies on ferredoxin reduced by the photosynthetic electron transport chain, which fuels reducing power to thioredoxins (Trxs) via a ferredoxin-dependent Trx reductase. In addition, chloroplasts harbor an NADPH-dependent Trx reductase, which has a joint Trx domain at the carboxyl terminus, termed NTRC. Thus, a relevant issue concerning chloroplast function is to establish the relationship between these two redox systems and its impact on plant development. To address this issue, we generated Arabidopsis (Arabidopsis thaliana) mutants combining the deficiency of NTRC with those of Trxs f, which participate in metabolic redox regulation, and that of Trx x, which has antioxidant function. The ntrc-trxf1f2 and, to a lower extent, ntrc-trxx mutants showed severe growth-retarded phenotypes, decreased photosynthesis performance, and almost abolished light-dependent reduction of fructose-1,6-bisphosphatase. Moreover, the combined deficiency of both redox systems provokes aberrant chloroplast ultrastructure. Remarkably, both the ntrc-trxf1f2 and ntrc-trxx mutants showed high mortality at the seedling stage, which was overcome by the addition of an exogenous carbon source. Based on these results, we propose that NTRC plays a pivotal role in chloroplast redox regulation, being necessary for the activity of diverse Trxs with unrelated functions. The interaction between the two thiol redox systems is indispensable to sustain photosynthesis performed by cotyledons chloroplasts, which is essential for early plant development.España Mineco BIO2013-43556-PEspaña, Junta de Andalucía CVI-591

CP Violation and Baryogenesis due to Heavy Majorana Neutrinos

We analyze the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy Majorana neutrinos and pay special attention to CP violation. Extending a recently proposed resummation formalism for two-fermion mixing to decay amplitudes, we calculate the resonant phenomenon of CP violation due to the mixing of two nearly degenerate heavy Majorana neutrinos. Solving numerically the relevant Boltzmann equations, we find that the isosinglet Majorana mass may range from 1 TeV up to the grand unification scale, depending on the mechanism of CP violation and/or the flavour structure of the neutrino mass matrix assumed. Finite temperature effects and possible constraints from the electric dipole moment of electron and other low-energy experiments are briefly discussed.Comment: 46 pages, LaTeX, 4 encapsulated figures include