Study of angular responses of mixed amplitude–phase holographic gratings: shifted Borrmann effect

We present theoretical results for angular responses of transmitted and diffracted beams in mixed amplitude–phase holographic gratings. Experimental results for gratings recorded in photographic emulsions and developed without a bleaching bath, with diffraction efficiencies of > 20%, are also presented. The model shows an angular shift between minimum transmittance and maximum diffraction efficiency when both index modulation and absorption coefficient modulation are present. Also, the Borrmann effect was found outside the Bragg angle. This method can be extended to a study of the mechanism of image formation in materials such as bacteriorhodopsin and azo-dye-doped polymers that exhibit both types of modulations (index and absorption)

Montaje y puesta a punto del evaporadador de película descendente por recompresión térmica de vapor, para la planta de secado de suero y leche en la Cooperativa Colanta sede San Pedro

RESUMEN : El proyecto busca ampliar la capacidad del proceso de filtración de suero de 300.000 L/día a 800.000 L/día, instalando una planta de filtración, evaporación y secado de suero parcialmente desmineralizado. Con dicha capacidad, además de disminuir la cantidad de agua tratada, ya que el inventario que no es procesado debe ser tratado antes de ser vertido al río, dadas sus características fisicoquímicas que generan contaminación a los afluentes e incumplen las regulaciones de vertimientos vigentes en Colombia (Res. 0631 de 2015). Dentro del alcance del proyecto está la adquisición de equipos para el proceso de pretratamiento, evaporación, cristalización y secado de suero parcialmente desmineralizado y construcción de edificios y obras civiles que conforman las plantas de tratamiento de suero. El proyecto para la planta de secado consta de cinco fases: Adquisición de equipos, montaje y puesta a punto de los equipos de pretratamiento, montaje y puesta a punto del evaporador de película descendente por recompresión térmica de vapor (TVR), construcción del edificio y obras civiles, montaje de los equipos de secado y cristalización de suero. La práctica empresarial se desarrollará en la fase de montaje y puesta a punto del evaporador TVR, el cual es un equipo que estaba en uso en una planta de producción de queso, razón por la cual será necesario llevarlo a las condiciones óptimas de funcionamiento para la aplicación específica de secado de suero en la que será empleado. Durante el viaje una de las calandrias sufrió una avería en el serpentín de calentamiento y deberá evaluarse su reparación o cambio para el correcto funcionamiento.ABSTRACT : The project seeks to expand the capacity of the filtration process of serum from 300,000 L/day to 800,000 L/day, installing a filtration, evaporation and drying plant for partially demineralized whey. With this capacity, in addition to reducing the amount of treated water, since the inventory that is not processed must be treated before being discharged into the river, given its physicochemical characteristics that generate pollution to the tributaries and break the regulations of shedding in force in Colombia (Res. 0631 of 2015). Within the scope of the project is the acquisition of equipment for the process of pretreatment, evaporation, crystallization and drying of partially demineralized serum and construction of buildings and civil works that make up the treatment plants of Suero. The project for the drying plant consists of five phases: Adquisition of equipments, Assembly and tuning of pretreatment equipment, Installation and commissioning of the falling film evaporator by thermal vapor recompression (TVR), Construction of the building and civil works, Assembly of serum drying and crystallization equipment. The business practice will be developed in the assembly and tuning phase of the TVR evaporator, which is a device that was in use in a cheese production plant, which is why it will be necessary to bring it to the optimal operating conditions for the specific application of whey drying in which it will be used. During the trip one of the calenders suffered a breakdown in the heating coil and its repair or change should be evaluated for proper operation

Shrub diversity in Mediterranean shrublands: Rescuer or victim of productivity?

[ENG]Aims: Unravelling the most prevalent causal direction between diversity and function in naturally recovered plant assemblages can greatly improve our understanding of the functional significance of diversity and its applications under the ongoing envi- ronmental changes. In this study, we apply a structural equation model framework to unravel the most plausible causal direction in the diversity–productivity relationship in subseral Mediterranean shrub-dominated communities. Methods: Total shrub cover (as a proxy of productivity when controlled by the time since land use cessation or the last wildfire), the number of species, and the number of functional types based on the dominant life forms (phanerophytes vs. chamaephytes), and the dominant foliar syndromes (deciduous vs. evergreen, needled vs. broad- leaved), were sampled in 195 circular plots distributed along an elevation gradient ranging from 400 to 1400 m a.s.l. in the Central Iberian Peninsula. We first explored the distribution of functional types along the elevation gradient using a non-metric multidimensional scaling (NMDS). Secondly, a structural equation model (SEM) frame- work using mixed-effects models was defined to unveil the prevalent causal direction between diversity (species and functional types) and productivity at the landscape scale. Results: Model selection using the Fisher's C information criterion supported a causal direction from total shrub cover to diversity in this landscape. Interestingly, the best supported model also supported a positive relationship between species richness and the number of functional types, which in turn is driven by the total shrub cover along the elevation gradient. Conclusions: Our results suggest that more species might not necessarily boost pro- ductivity. On the contrary, ongoing warming temperatures and aridity, which are characteristic of low elevations compared to highlands, might significantly reduce the number of species (victim rather than rescuer) through deleterious effects on productivity

Improving the Performance of a Named Entity Extractor by Applying a Stacking Scheme

In this paper we investigate the way of improving the performance of a Named Entity Extraction (NEE) system by applying machine learning techniques and corpus transformation. The main resources used in our experiments are the publicly available tagger TnT and a corpus of Spanish texts in which named entities occurrences are tagged with BIO tags. We split the NEE task into two subtasks 1) Named Entity Recognition (NER) that involves the identification of the group of words that make up the name of an entity and 2) Named Entity Classification (NEC) that determines the category of a named entity. We have focused our work on the improvement of the NER task, generating four different taggers with the same training corpus and combining them using a stacking scheme. We improve the baseline of the NER task (Fβ=1 value of 81.84) up to a value of 88.37. When a NEC module is added to the NER system the performance of the whole NEE task is also improved. A value of 70.47 is achieved from a baseline of 66.07

Digital light processing-3D printing of thermoset materials with high biodegradability from amino acid-derived acrylamide monomers

Six acrylamide resins, derived from l-phenylalanine and l-leucine, are designed for application in digital light processing (DLP) printers to obtain biodegradable thermoset polymers. The acrylamide copolymers are prepared under light irradiation at 405 nm and thermal post-curing processes. Low molecular weight poly(ethylene glycol)diacrylate (PEGDA) and N,N-dimethylacrylamide (DMAM), both liquid resins, are used as co-monomers and diluents for the amino acid-derived acrylamide solubilization. The presence of two phenylalanine units and two ester groups in the acrylamide monomer accuses a fast degradation rate in hydrolytic medium in 90 days. The residual products leached in the aqueous media prove to be non-cytotoxic, when 3D-printed samples are cultured with osteoblast cells (MG63), which represents an advantage for the safe disposal of printer waste materials. The scaled-up pieces derived from l-phenylalanine and diethylene glycol, as amino acid-derived acrylamide (named compound C), PEGDA and DMAM, present high dimensional stability after DLP printing of complex structures used as testing samples. Layers of 50 µm of thickness are well cohesive having isotropic behavior, as demonstrated with tensile-strain measurements performed in X–Y–Z (plane) directions. The compound C, which contains phenylalanine amino acid, reveals a promising potential to replace non-biodegradable acrylate polymers used in prototyping systems.Postprint (author's final draft

Applying Stacking and Corpus Transformation to a Chunking Task

In this paper we present an application of the stacking technique to a chunking task: named entity recognition. Stacking consists in applying machine learning techniques for combining the results of different models. Instead of using several corpus or several tagger generators to obtain the models needed in stacking, we have applied three transformations to a single training corpus and then we have used the four versions of the corpus to train a single tagger generator. Taking as baseline the results obtained with the original corpus (Fβ=1 value of 81.84), our experiments show that the three transformations improve this baseline (the best one reaches 84.51), and that applying stacking also improves this baseline reaching an Fβ=1 measure of 88.43

¿Cómo interpretamos el papel de la religión en las elecciones presidenciales CR 2018?: Conversatorio de la Red para el Diálogo entre Ciencia y Religión (REDICIRE) de la Universidad de Costa Rica

Participantes del conversatorio: Mariano Sáenz Vega, Alberto Rojas Rojas, Roberto Leiva Pacheco, Jeffry Chinchilla Madrigal, Luis Fernando Aragón Vargas, Alejandro Leal Esquivel, Miguel Gamboa Gamboa, Javier Tapia Balladares, Ligia Victoria Rodríguez Hernández, Ana María Serrano Alvarado, Stephanie Fallas Navarro, Efraín Calderón Guevara.Este es el resumen que Jeffry Chinchilla Madrigal y Mariano Sáenz Vega, rescataron del conversatorio del 27 de setiembre de 2018 (¡gracias colegas!). Se solicitó a cada uno de los participantes revisar el texto y editar su participación, pero hubo muy poca respuesta. De todos modos, se había explicado a los participantes que el objetivo era tener un resumen para los archivos de REDICIRE o, en el mejor de los casos, un manuscrito que subiríamos al repositorio institucional Kérwá de la Universidad de Costa Rica, así como al “DRIVE” de la Red. A pesar de ser posible que hayamos omitido algunas intervenciones que hubiera sido deseable rescatar, el tema se considera suficientemente importante a las vísperas de una nueva ronda electoral en Costa Rica como para ponerlo a disposición de los lectores.Universidad de Costa Rica/[245-B8-369]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigacoines PsicológicasUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Físic

Functional Divergence of the Arabidopsis Florigen-Interacting bZIP Transcription Factors FD and FDP.

Flowering of many plant species depends on interactions between basic leucine zipper (bZIP) transcription factors and systemically transported florigen proteins. Members of the genus Arabidopsis contain two of these bZIPs, FD and FDP, which we show have largely complementary expression patterns in shoot apices before and during flowering. CRISPR-Cas9-induced null mutants for FDP flower slightly earlier than wild-type, whereas fd mutants are late flowering. Identical G-box sequences are enriched at FD and FDP binding sites, but only FD binds to genes involved in flowering and only fd alters their transcription. However, both proteins bind to genes involved in responses to the phytohormone abscisic acid (ABA), which controls developmental and stress responses. Many of these genes are differentially expressed in both fd and fdp mutant seedlings, which also show reduced ABA sensitivity. Thus, florigen-interacting bZIPs have distinct functions in flowering dependent on their expression patterns and, at earlier stages in development, play common roles in phytohormone signaling

Determinación del Dímero D en pacientes con anticoagulante lúpico

La determinación del dímero D es de gran utilidad para establecer el diagnóstico de trombosis venosa profunda; sin embargo, en los pacientes que presentan anticoagulante lúpico su hallazgo e importancia todavía no ha sido claramente definidos. Se analizan 80 pacientes con cuadros sugestivos del síndrome antifosfolípidico. Todos los pacientes estuvieron comprendidos entre 20 y 40 años de edad , 13 (16%) casos mostraron alguna prueba positiva del citado síndrome, cinco de ellos, 4 mujeres y 1 varón presentaron anticoagulante lúpico positivo y 8 casos, 6 mujeres y 2 varones evidenciaron anticuerpos anticardiolipina positivos. a los 13 pacientes se les realizó el dímero D por dos métodos, así como, los niveles de fibrinógeno y la presencia de productos de degradación del fibrinógeno (PDF). Los métodos de dímero D que se utilizaron fueron: la técnica de aglutinación indirecta con partículas de látex y la técnica de ELISA. Los resultados obtenidos muestran que los pacientes con anticoagulante lúpico y/o anticuerpos anticardiolipina positivos y que presentan dímero D,muestran un cuadro de oclusión venosa que puede contribuir a la génesis de su problema trombótico.The determination of DImer-D has a great valué establishing the diagnosis of deepvenous thrombosis. However, in patients that present íupic anticoagulant, its importance and discovery are still not well defined. Because of these reasons, an investigation was planned to evalúate its presence in 80 patients with descriptions suggesting the antiphospholipid syndrome. Al! patients were aged 20 and 40 years. From the total sample síudied oniy 13 cases (16%), showeij a positive test forthe mentioned syndrome. Five cases (1 man and 4 women) had positive Iupic anticoagulant and 8 cases (2 men and 6 women ) had positive the anticardiolipin antibodies. To the whole group of 13 patients the determination of Dimer-D was made by 2 different methods. The levéis of fibrinogen and the presence of the fibrinogen degradation producís were aiso realizad.The methods used to determine DImer-D were: indirect agglutination with látex particles, and an Elisa test. The results obtained show that the patients with a positive iupic anticoagulant and/or a positive anticardiolipin antibodies, togeíherv^ith the presence of Dimer D, describes cases with venous oclussionwich contributesto the génesis of the thrombotic problem.Universidad de Costa Rica/[807-96-329]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Hematología y Trastornos Afines (CIHATA