Advantage of the Highly Restricted Odorant Receptor Expression Pattern in Chemosensory Neurons of Drosophila.

A fundamental molecular feature of olfactory systems is that individual neurons express only one receptor from a large odorant receptor gene family. While numerous theories have been proposed, the functional significance and evolutionary advantage of generating a sophisticated one-receptor-per neuron expression pattern is not well understood. Using the genetically tractable Drosophila melanogaster as a model, we demonstrate that the breakdown of this highly restricted expression pattern of an odorant receptor in neurons leads to a deficit in the ability to exploit new food sources. We show that animals with ectopic co-expression of odorant receptors also have a competitive disadvantage in a complex environment with limiting food sources. At the level of the olfactory system, we find changes in both the behavioral and electrophysiological responses to odorants that are detected by endogenous receptors when an olfactory receptor is broadly misexpressed in chemosensory neurons. Taken together these results indicate that restrictive expression patterns and segregation of odorant receptors to individual neuron classes are important for sensitive odor-detection and appropriate olfactory behaviors

Nonconventional Ca(OH) ₂ treatment of bamboo for the reinforcement of cement composites

This study compares the structural and morphological changes in Guadua angustifolia Kunth (GAK) fiber prepared in three different ways (chips, barkless and crushed) when non-conventional alkaline treatment is applied. Moreover, it shows the improvement of mechanical properties of cement composites reinforced with these treated fibers. The three different preparations of Guadua were treated with a saturated solution of calcium hydroxide (5%) at 125 °C and 1.25 kPa for 3 h to remove non-cellulosic compounds. Then, their chemical, morphological, and structural properties were examined. The fibers exhibiting the higher delignification rate were selected to prepare cement composite boards, whose mechanical properties were successively compared with those of composites reinforced with untreated G. angustifolia fibers. The water/cement ratios of the cement mixed with the Ca(OH)2-treated and the untreated fibers were, respectively, around 0.3 and 0.25. The flexural strength and toughness of the two composites were evaluated after 7, 28, and 90 days of curing. The calcium hydroxide treatment showed higher efficiency in removing non-cellulosic materials when performed on crushed bamboo; moreover, the mechanical properties of the composites reinforced with the treated fibers were higher than those mixed with the untreated ones. After 90 days of curing, the flexural strength increased by around 40% and the toughness became three times higher (p < 0.05). The mechanical improvement by the Ca(OH)2 treatment of G. angustifolia fibers demonstrates its potential for the fabrication of cement composites

Clinical Skills Abilities Development During COVID-19 Pandemic in Mexico City

Medical formation includes the development of several skills including clinical ones. Medical students have to learn how to build a healthy doctor – patient relationship in order to provide the best diagnosis, treatment and quality of attention. COVID-19 provide a new challenge for all students in Mexico to learn skills that traditionally have been learned in person and not through a computer

Revealing personal identity through conferences about short stories in low-ses preschoolers.

This paper reveals personal identity through conferences about short stories in low-SES (Socio Economic Status) preschoolers between four and five years old in a kindergarten from the ICBF (Instituto Colombiano de Bienestar Familiar) in Bogotá. This research project´s objective is to analyze low-Ses preschoolers´ personal identity through conferences about short stories, identify criteria that determine low-SES preschoolers´ personal identity and describe the relationship between personal identity criteria and low-SES preschoolers´ life experiences. To achieve this purpose, the researchers selected ten preschoolers between four and five years old, five girls and five boys. For the implementation there were seven sessions in total in which the researchers applied seven personal identity criteria by showing children different short stories. These stories were created by the researchers and tailored to be relevant to the children. Also, different reading comprehension strategies and activities were carried out, children then drew about their life experiences and answered multiple questions designed by the researchers which were called conferences. To collect the data, the researchers used field notes, children´s drawings and conferences. After the process, it was found that feeling like part of a family, building relationships, recognizing their bodies and abilities, absorbing their environment, using their imagination to solve problems and dreaming about their future were relevant aspects and are related to their personal identity

Fungal inoculation effect on post-harvest sugarcane residue decomposition under field conditions

Fungal inoculation effect on post-harvest sugarcane residue (SCR) decomposition in field conditions was studied. In vitro interaction between selected fungi was determined by direct confrontation. Mycelial growth response to different concentrations of herbicides and urea was also assessed. Fungal combinations did not show inhibitory effects. Bjerkandera sp. Y-HHM2 and Myrothecium sp. S-3.20 growth decreased in 2.4-D agar plates. However, Pleurotus sp. Y- RN3 showed a stimulation in 10 ppm 2.4-D agar plates. The biggest growth in ametrine supplemented cultures was observed in Pleurotus sp. Y-RN3. Evaluation of increasing urea concentrations on mycelial growth showed that 5,000 ppm significantly inhibits mycelial growth. The field assay under rainfed condition showed that post-harvest SCR decomposition rate significantly increases in Y-HHM2, Y-RN3 and Y-HHM2/Y-RN3/S-3.20 treatments. This is the first report on the capability of Bjerkandera sp. Y-HHM2 and Pleurotus sp. Y-RN3 to accelerate post-harvest SCR decomposition in rainfed conditions at field scale, suggesting that these fungi might be useful tools in the sugarcane crop system.Fil: Maza, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Investigación Animal del Chaco Semiárido; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Sanidad Vegetal. Cátedra Fitopatología; ArgentinaFil: Medina, M.. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Plasencia, Adriana María. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Yasem, Marta Graciela. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Sanidad Vegetal. Cátedra Fitopatología; Argentin

Obtención y caracterización de biodiesel a partir de aceite de semillas de Ricinus communis. (Higuerilla) modificadas genéticamente y cultivadas en el Eje Cafétero

En este trabajo se presenta una investigación experimental llevada a cabo con el fin de evaluar las características principales del biodiesel de aceite de semillas de higuerilla modificadas genéticamente como una fuente alternativa para la producción de biocombustible. Se realizó la caracterización física y química de la materia prima donde se analizaron los parámetros de densidad, índice de refracción, viscosidad cinemática, humedad y materia volátil, los índices de peróxido, acidez, yodo y saponificación. Posteriormente se obtuvo el biodiesel por medio de la reacción de transesterificación del aceite con metanol usando metóxido de sodio como catalizador. Se caracterizó el biodiesel obtenido evaluando sus características físicas tales como, la densidad, índice de refracción, viscosidad cinemática, humedad y materia volátil, punto de ignición, poder calorífico y sus propiedades químicas como los índices de peróxido, acidez y yodo, la corrosión a la lámina de cobre y contenido de metales. Finalmente, se analizaron cualitativa y cuantitativamente los metilésteres obtenidos (biodiesel) por medio de la técnica de Cromatografía de Gases. Todos los resultados de la caracterización fueron comparados con las especificaciones técnicas estipuladas en la Norma Técnica Colombiana NTC 5444 y la ASTM D6751 para biocombustibles, concluyéndose que se obtuvo un biocombustible que cumple con la mayoría de los lineamientos estipulados en dichas normas que puede ayudar a disminuir el impacto ambiental y la dependencia causados por los combustibles fósiles

El mapa mental como didáctica facilitadora para la comprensión lectora en estudiantes universitarios

Los espacios académicos universitarios están evidenciando una serie de falencias en los procesos de lecto-escritura de los y las estudiantes de pregrado. Este artículo presentará los rasgos generales de la comprensión lectora y la posibilidad de potenciar las capacidades lectoras de este tipo de estudiantes mediante el método de los Mapas Mentales de Tony Buzan, en relación con el objetivo de la interpretación de textos en un cambio de perspectiva de la sociedad actual y una conciencia sociopolítica, generada en la creatividad autónoma de esta población. Se ha logrado identificar la necesidad de una propuesta formativa que propenda por resultados más claros y modifique los hábitos de estudio en estudiantes universitarios, desde una apropiación de la didáctica propia de los ambientes académico