IDENTIFICACIÓN DE POLINIZADORES NATURALES DE Vanilla planifolia Jacks. ex Andrews

La producción de los frutos de vainilla (Vanilla planifolia Jacks. ex Andrews) se asegura a través de la polinización manual de las flores, debido a que el rostelo en la flor impide que el polen de la antera del órgano masculino llegue al estigma del órgano femenin

A Digital Predistortion Technique Based on a NARX Network to Linearize GaN Class F Power Amplifiers (poster)

This work presents a novel Digital Predistortion (DPD) scheme based on a NARX network, suitable for linearizing power amplifiers (PAs). The NARX network is a Recurrent Neural Network (RNN) with embedded memory that allows efficient modeling of nonlinear systems. Its neural architecture is very effective to model long term dependencies, such as the typical memory effects of PAs. To demonstrate the feasibility of the NARX network as a DPD system, a GaN class F PA with two LTE signals with 5 MHz of bandwidth is used. Experimental results show a distortion correction better than 10 dB

Volviéndonos mejores: necesidad de acción inmediata ante el reto de la obesidad. Una postura de profesionales de la salud.

La creciente epidemia de obesidad ha sido uno de los retos más importantes de salud pública en México durante los últimos años. Con apoyo de la Federación Mundial de Obesidad, en 2021 formamos un grupo de profesionales para identificar y resumir las acciones prioritarias en las que puede enfocarse nuestro país para hacer frente a esta epidemia. Al proceso de desarrollo y discusión de este grupo se sumaron más de 1 000 profesionales de la salud para retomar recomendaciones de documentos y guías de alto nivel previamente publicados. En conmemoración del Día Mundial de la Obesidad, en este 2022 se presenta esta postura como insumo para el desarrollo de acciones en el ámbito profesional y de los diferentes sectores, en la que se incluyen 10 recomendaciones de acción, desde la perspectiva poblacional hasta la atención individualizada, y se enfatiza en la importancia de la participación social, de las intervenciones integrales con visión centrada en la persona y de la sostenibilidad planetaria, además de mejorar la educación y las campañas de difusión, propiciar un ambiente promotor de entornos activos y blindar de conflictos de interés los esfuerzos de prevención y control. La postura hace un llamado para abordar la obesidad de manera seria, con base en la evidencia científica, oportuna e integral, con enfoque de curso de vida, de forma ética y sensible, y sin perpetuar las barreras del estigma de peso en la sociedad

Extinction risk of Mesoamerican crop wild relatives

Ensuring food security is one of the world's most critical issues as agricultural systems are already being impacted by global change. Crop wild relatives (CWR)—wild plants related to crops—possess genetic variability that can help adapt agriculture to a changing environment and sustainably increase crop yields to meet the food security challenge. Here we report the results of an extinction risk assessment of 224 wild relatives of some of the world's most important crops (i.e. chilli pepper, maize, common bean, avocado, cotton, potato, squash, vanilla and husk tomato) in Mesoamerica—an area of global significance as a centre of crop origin, domestication and of high CWR diversity. We show that 35% of the selected CWR taxa are threatened with extinction according to The International Union for Conservation of Nature (IUCN) Red List demonstrates that these valuable genetic resources are under high anthropogenic threat. The dominant threat processes are land use change for agriculture and farming, invasive and other problematic species (e.g. pests, genetically modified organisms) and use of biological resources, including overcollection and logging. The most significant drivers of extinction relate to smallholder agriculture—given its high incidence and ongoing shifts from traditional agriculture to modern practices (e.g. use of herbicides)—smallholder ranching and housing and urban development and introduced genetic material. There is an urgent need to increase knowledge and research around different aspects of CWR. Policies that support in situ and ex situ conservation of CWR and promote sustainable agriculture are pivotal to secure these resources for the benefit of current and future generations

Un tributo a Roberto Caldeyro-Barcia, considerado el pionero de la Perinatología

Roberto Caldeyro-Barcia nació en Montevideo en 1921, estudió Medicina graduándose como médico cirujano en 1947. Fue aceptado como investigador asociado en el Instituto de Fisiología bajo la supervisión del profesor Hermógenes Álvarez, quien estaba trabajando sobre el efecto de la actividad uterina en el pulso cardiaco fetal durante el parto. La presión amniótica se registró con el uso de un pequeño catéter introducido dentro de la cavidad amniótica, por lo que Caldeyro-Barcia propuso introducir un microcatéter directamente en el músculo uterino para obtener información más específica de la contracción uterina y su efecto sobre la actividad cardiaca fetal. Se observó que la frecuencia cardiaca disminuía en los casos de hipoxia fetal. Dichos descensos fueron llamados DIP I y II. Así, se confirmó que la hipoxia durante el parto tiene una deletérea acción en la oxigenación fetal, lo cual fue registrado y graduado como unidades montevideo. Dos años después, Edward H. Hon, quien trabajaba en la Universidad de Yale, confirmó estos hallazgos, lo que fue el inicio de la monitorización fetal durante el trabajo de parto en todo el mundo. Caldeyro-Barcia fue galardonado por muchas asociaciones académicas internacionales; asimismo fue designado director del Centro Sudamericano de Perinatología y presidente de la Federación Internacional de Ginecología y Obstetricia. Se consideró un amigo de México, país que visitó muchas veces, por lo que tuvo una relación académica muy cercana con Luis Castelazo-Ayala

Application of the NARX neural network as a digital predistortion technique for linearizing microwave power amplifiers

This work presents a digital predistortion (DPD) scheme to linearize power amplifiers (PAs) using a recurrent neural network called Nonlinear AutoRegressive with eXogenous input model (NARX) neural network (NARXNN). The architecture of the NARXNN is based on a class of discrete-time nonlinear system named NARX. Its topology has embedded memory at the input and output of the neural architecture, which allows an efficient linearization of PAs. To show the benefits of the DPD with NARXNN, a commercial PA is fed with a long term evolution signal at 2.0 GHz with 10 MHz of bandwidth. Our experimental results show an adjacent channel leakage ratio improvement of 24 dB.ITESO, A.C.Cinvestav GuadalajaraCICES

Wild orchids: A framework for identifying and improving sustainable harvest

Worldwide, thousands of orchid species are harvested from the wild. Widespread legal and illegal unsustainable trade has contributed to the decline of many species. However, there is also evidence of long-term, sustainable wild harvest of some orchid species that contribute to local livelihoods and cultural traditions. There is a clear need to help guide harvesters and resource managers towards sustainability. However, there is currently no appropriate framework to guide local harvest decisions, which is especially problematic given huge data limitations, variations in on-the-ground capacity to monitor and manage resources, and considering that the potential for sustainable harvest is context-specific. We reviewed the literature on orchid harvest, ecology and demography; assessed information on the life history of 27 harvested species; and drew on our experience with diverse orchid taxa to identify characteristics expected to influence harvest sustainability. We identified 23 characteristics within four themes: abundance and distribution; species traits related to growth and reproduction; local management practices; and demand. We selected 12 characteristics for which information was available for many species and observable in the field, and used an iterative process to develop a decision-making dichotomous key. The key identifies if and how the harvest of a given population at a given time can be conducted more sustainably, offering sets of considerations that harvesters and managers can use and adapt to local contexts. Critical research gaps include techniques for partial plant harvest and for augmentation; and investigation into the traits and protocols that have permitted long-term persistence and that can increase current sustainability

A digital predistortion technique based on a NARX network to linearize GaN class F power amplifiers

This work presents a novel Digital Predistortion (DPD) scheme based on a NARX network, suitable for linearizing power amplifiers (PAs). The NARX network is a Recurrent Neural Network (RNN) with embedded memory that allows efficient modeling of nonlinear systems. Its neural architecture is very effective to model long term dependencies, such as the typical memory effects of PAs. To demonstrate the feasibility of the NARX network as a DPD system, a GaN class F PA with two LTE signals with 5 MHz of bandwidth is used. Experimental results show a distortion correction better than 10 dB. © 2014 IEEE

Fungal Screening on Olive Oil for Extracellular Triacylglycerol Lipases: Selection of a Trichoderma harzianum Strain and Genome Wide Search for the Genes

A lipolytic screening with fungal strains isolated from lignocellulosic waste collected in banana plantation dumps was carried out. A Trichoderma harzianum strain (B13-1) showed good extracellular lipolytic activity (205 UmL−1). Subsequently, functional screening of the lipolytic activity on Rhodamine B enriched with olive oil as the only carbon source was performed. The successful growth of the strain allows us to suggest that a true lipase is responsible for the lipolytic activity in the B13-1 strain. In order to identify the gene(s) encoding the protein responsible for the lipolytic activity, in silico identification and characterization of triacylglycerol lipases from T. harzianum is reported for the first time. A survey in the genome of this fungus retrieved 50 lipases; however, bioinformatic analyses and putative functional descriptions in different databases allowed us to choose seven lipases as candidates. Suitability of the bioinformatic screening to select the candidates was confirmed by reverse transcription polymerase chain reaction (RT-PCR). The gene codifying 526309 was expressed when the fungus grew in a medium with olive oil as carbon source. This protein shares homology with commercial lipases, making it a candidate for further applications. The success in identifying a lipase gene inducible with olive oil and the suitability of the functional screening and bioinformatic survey carried out herein, support the premise that the strategy can be used in other microorganisms with sequenced genomes to search for true lipases, or other enzymes belonging to large protein families