654 research outputs found
Características de la mácula, nervio óptico y simetría interocular en pacientes prematuros medidas con tomografía de coherencia óptica
El parto prematuro se define como el nacimiento antes de las 37 semanas de edad gestacional (EG), encontrando mayor supervivencia hoy en día que hace unos 15-20 años, especialmente los recién nacidos muy prematuros (<32 semanas). El parto prematuro ocasiona un cambio en las condiciones fisiológicas del desarrollo del niño, privándole dela hipoxia fisiológica del útero o alterando las hormonas, factores de crecimiento o nutrientes maternos. Dentro de los órganos blanco de este proceso, se encuentran los ojos que pueden estar sujetos a trastornos que conducen a diferentes grados dedeterioro. Además de la retinopatía del prematuro, se han reportado datos sobre otras afecciones oftalmológicas relacionadas con la prematuridad, tales como el engrosamiento macular, o alteraciones sobre el nervio óptico, entre otras. Estas variaciones anatómicas podrían verse influenciadas por la inmadurez propia de la prematuridad o por los eventos adversos que se presentan después del nacimiento. Además, es posible que estos factores actúen como agravantes. Para estudiar las variaciones de la mácula y del nervio óptico, la tomografía de coherencia óptica (OCT) ha demostrado utilidad en población pediátrica. Este instrumento aporta mediciones casi histológicas de estas estructuras con alta fiabilidad y reproducibilidad..
Contribution of nitrogen from chicken manure to broccoli crop (Brassica oleracea L.)
Se evaluó a través de la técnica isotópica de 15N el aporte de nitrógeno (N) proveniente
de la pollinaza durante el desarrollo del cultivo de brócoli (Brassica oleracea L.). Se
establecieron seis tratamientos a una dosis de 300 kg N ha-1producto de la combinación de
fertilizante químico (N-fosfonitrato) y fertilizante orgánico (N-pollinaza): 1) 0 + 300; 2)
100 + 200; 3) 150 + 150; 4) 200 + 100; 5) 300 kg N-fosfonitrato ha−1 + 0 kg N-pollinaza ha−1; y
6) testigo sin fertilización N, en un diseño de bloques al azar con cinco repeticiones. Los
resultados mostraron el mayor rendimiento en los tratamientos 200 kg N-fosfonitrato
ha-1 + 100 kg N-pollinaza ha-1 y 300 kg N-fosfonitrato ha-1 (16 y 17 Mg ha-1, respectivamente).
El mayor rendimiento de N total (347 kg N ha-1) ocurrió a 150 kg N-pollinaza.
Los datos de 15N indican una baja asimilación de N-fertilizante, destacando los tratamientos
donde se aplicó pollinaza con los valores menores (3,2-4,1%) en comparación
con el tratamiento a base de N-fosfonitrato (28,7-48,0%). La absorción de N-pollinaza
fue aproximadamente 29,5%. Los datos sugieren un efecto sinérgico entre el fertilizante
químico y orgánico, ya que se observó una alta contribución del N del suelo dadas las
constantes aplicaciones de pollinaza al sistema de producción en Tepeaca, Puebla.The nitrogen (N) contribution from chicken manure to broccoli crop
(Brassica oleracea L.) was evaluate using the 15N isotopic technique. Six treatments
combining chemical fertilizer (N-phosphonitrate) and organic fertilizer (N-chicken
manure) at a total rate of 300 kg N ha-1 were established: 1) 0 + 300; 2) 100 + 200;
3) 150 + 150; 4) 200 + 100; 5) 300 kg N-phosphonitrate ha−1 + 0 kg N-chicken manure ha-1;
and 6) an unfertilized N control. Five replicates per treatment were established under a
statistical design of random blocks. The highest yield of broccoli (heads) corresponded
to treatments 200 kg N-phosphonitrate ha-1 + 100 kg N-chicken manure ha-1 and
300 kg N-phosphonitrate ha-1 yielding 16 and 17 Mg ha-1, respectively. The highest
value of total N-uptake (347 kg N ha-1) was observed in treatment corresponding to
150 kg N-phosphonitrate ha−1 + 150 kg N-chicken manure ha−1. The 15N data indicate low
values of N-fertilizer uptake (3.2-4.1%) when manure was applied. The N-phosphonitrate
alone treatment showed a higher value of N-fertilizer (28.7-48.0%) than treatment
200 kg N-phosphonitrate ha−1 + 100 kg N-chicken manure ha−1 (4.5-5.1%). The N uptake
by plants from manure was 29.5% average. The combination of chemical and organic
fertilizers resulted in a higher total N-uptake. The constant application of manure to soil
under broccoli production in Puebla region resulted in a significant contribution of soil
N to the broccoli crop.Fil: Daniel Torres Nava.
Colegio de Postgraduados. Campus Puebla (México)Fil: Engelberto Sandoval Castro.
Colegio de Postgraduados. Campus Puebla (México)Fil: Juan José Peña-Cabriales.
Centro de Investigación y Estudios Avanzados (Guanajuato, México)Fil: José Antonio Vera-Núñez.
Centro de Investigación y Estudios Avanzados (Guanajuato, México
Evaluation of resampling applied to UAV imagery for weed detection using OBIA
Los vehículos aéreos no tripulados (UAVs) son una tecnología emergente en el estudio de parámetros agrícolas por sus características y por portar sensores en diferente rango espectral. En este trabajo se ha detectado y cartografiado rodales de malas hierbas en fase temprana mediante análisis OBIA para elaborar mapas que optimicen el tratamiento herbicida localizado. Se ha aplicado resampling (resampleo) sobre imágenes tomadas en campo desde un UAV (UAV-I) para crear una nueva imagen con distinta resolución espacial. A las imágenes resampleadas (RS-I) se les evaluó la calidad espacial y espectral y la eficacia de nuestro análisis en la detección de malas hierbas. Los resultados de las imágenes RS-I muestran una precisión similar a las imágenes UAV-I siendo factible su utilización en tecnologías de manejo localizado de malas hierbas. Se discuten las ventajas del uso de la técnica de resampling en imágenes UAV.Unmanned aerial vehicles (UAV) are an emerging technology for the study of agriculture parameters due to its characteristics and the availability of embedding sensors with different spectral range. In our study, the detection and mapping of weeds in early phenological stage allowed to design a strategy for the optimizing of herbicide treatment. In this work, resampling is used to create a new version of an image with a different spatial resolution, using real UAV imagery. A spatial and spectral quality evaluation was carried out to resampled images (RS-I), and then, our workflow for weed detection applied. The results showed that RS-I and UAV-I showed similar accuracy on weed detection and thus could be used for site-specific weed management achieving a percentage of savings in the herbicide. Opportunities of using RS-I are discussed
El papel de la cultura en la evaluación de la felicidad entre países. Una aproximación fsQCA
The happiness of countries has important effects on their image, prestige, attraction of funds ortourism. Furthermore, there are rankings and models developed to try to explain what it dependson. This paper explores the possibility of improving the World Happiness Report model intwo ways: the inclusion of cultural variables and the analysis of possible interactions betweenvariables. To this end, the original database has been supplemented with Hofstede's culturaldimensions, replicating the original regression analyses and using an fsQCA. The results showthe need to include culture in this type of studies and the existence of three different models ofcountries with high happiness scoresLa felicidad de los países tiene importantes efectos en la imagen, prestigio, captación defondos o turismo de los mismos y se elaboran rakings y modelos que intentan explicar dequé depende la misma. En este trabajo se explora la posibilidad de mejorar el modelo delWorld Happiness Report mediante dos vías: la inclusión de variables culturales y el análisis deposibles interacciones entre las variables. Para ello, se ha completado la base de datos originalcon las dimensiones culturales del conocido modelo de Hofstede, replicando los análisis deregresión originales y utilizando un analisis fsQCA. Los resultados muestran la necesidad deincluir la cultura en este tipo de estudios y la existencia de tres modelos diferentes de países conaltas puntuaciones en felicidad
Qualitative operational risk software -development of a software tool for determining the root of operational risk
This article shows software that allows determining the statistical behavior of qualitative data originating surveys previously transformed with a Likert’s scale to quantitative data. The main intention is offer to users a useful tool to know statistics' characteristics and forecasts of financial risks in a fast and simple way. Additionally,this paper presents the definition of operational risk. On the other hand, the article explains different techniques to do surveys with a Likert’s scale (Avila, 2008) to
know expert’s opinion with the transformation of qualitative data to quantitative data. In addition, this paper will show how is very easy to distinguish an expert’s opinion
related to risk, but when users have a lot of surveys and matrices is very difficult to obtain results because is necessary to compare common data. On the other hand,
statistical value representative must be extracted from common data to get weight of each risk. In the end, this article exposes the development of “Qualitative
Operational Risk Software” or QORS by its acronym, which has been designed to determine the root of risks in organizations and its value at operational risk OpVaR
(Jorion, 2008; Chernobai et al, 2008) when input data comes from expert’s opinion and their associated matrices
Eye drop Self-medication: Comparative Questionnaire-based study of two Latin American cities.
A broad spectrum of ocular symptoms are treated by self-medication with commercial eye-drops. This behavior threatens individuals' visual health. In Latin America, evidence is poor.
Objective: To detect, characterize and compare patterns of ophthalmic self-medication between Córdoba (Argentina) and Barranquilla (Colombia).Design: Analytic, cross-sectional and comparative population-based study. Setting: Two private tertiary care ophthalmology centers from Córdoba, Argentina, and Barranquilla, Colombia.Participants: Patients 18 years of age or older who consulted for the first time in this two institutions duringAugust-November 2009, were included. A number of 570 patients were enrrolled.Methods: Data collected through a semi-structured questionnaire. Main outcome measure: To determine thefrequency of self-medication with eyedrops on a specific population of two cities in Latin America.Results: Comparable rates of ocular self-medication were found (25.6% and 25.7% for Cordoba and Barranquilla, respectively). The percentage of men and women who self-medicated was not significantly different between both samples. The major source of eye drops recommendation in the Argentineans patients was the pharmacist (31%); while the social source was predominant in Colombian individuals (53%). In Cordoba, the most frequently used product was a non-steroidal anti-inflammatory drop in combination with a vasoconstrictive agent (32%); while in Barranquilla, antibiotic eye drops were preferred (33%). Self-medication was higher between the ages of 31 and 50 years old in Argentinean citizens (28%) and between 18 to 31 years old in the Colombiancommunity (39%). This habit was found mostly in patients who completed university studies in Cordoba (33%); in Barranquilla, individuals with lower educational level practice more this behavior (36%).Conclusion: In both populations, patients commonly treat ocular conditions by self-medicating. Currently, anincreasing number of eye drops are obtainable without prescription and a high percentage of self-medicated patients in both samples ignore the possible side effects of the used medication.Fil: Marquez, Gabriel. Fundación VER; ArgentinaFil: Hildegard Piñeros-Heilbron. Fundación Oftalmológica del Caribe; ColombiaFil: Sanchez, Victoria M.. Fundación VER; ArgentinaFil: Torres, Victor Eduardo Roque. Fundación VER; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; ArgentinaFil: Gramajo, Ana L.. Fundación VER; ArgentinaFil: Juarez, Claudio P.. Fundación VER; Argentina. Fundación Oftalmológica del Caribe; ColombiaFil: Peña, Fernando. Fundación Oftalmológica del Caribe; ColombiaFil: Luna, José D.. Fundación VER; Argentin
El programa informático “Clustering Assessment IDL.IAS.1” para el agrupamiento e integración de píxeles contiguos en imágenes remotas
Contiene 7 documentos (1. Objetivos, alcance y publicaciones. 2. Registro y código) y 5 con el softwareA research group of the Institute for Sustainable Agriculture (CSIC, Cordoba, Spain) has
developed a procedure to spatially assess key agronomic and environmental characteristics of
tree orchards from remote sensing images through the software named Clustering Assessment®
(CLUAS).In the attached paper the CLUAS software development and the information generated by for
selected olive orchards and its validation with ground-truth data is shown. CLUAS works as an
add-on of ENVI®, and operates integrating the digital values (DV) of the neighboring pixels
within a defined range of DV. In the orchards plots trees, other vegetation cover and bare soil
were the land uses considered and the range of digital values (BDV) which best define each of
them determined. CLUAS provides parameters of each tree, such as the geometric centre, the
number of pixels or area, and the integrated digital values or relative potential yield. CLUAS
also characterizes key parameters of tree groves, such as the total area and the number, area and
the relative potential productivity of the whole trees; and similarly for the other land uses such
as vegetation cover and bare soil. Remote images with spatial resolution from 0.25 to 1.5m were
suitable for olive grove characterization.CLUAS can contribute to the site-specific management of tree groves, providing quantitative
information on each tree, small areas of an orchard, or whole orchards.Peer reviewe
Optimizing algorithms for thresholding segmentation applied to weed detection on UAV remote images.
En este trabajo se ha buscado la implementación de una alternativa al método de Otsu (1979) desarrollada por Hui-Fuang Ng (2006), el cual maximiza la diferencia entre varianzas espectrales y realiza una búsqueda multiumbral. En el estudio se emplearon imágenes procedentes de vehículos aéreos no tripulados (UAVs) tomadas en cultivos de maíz y girasol. Con una única ejecución del algoritmo en un entorno de análisis orientado a objetos, se discriminan aquellos objetos correspondientes a la fracción vegetal del suelo desnudo y se estima un umbral diferenciador entre cultivo y malas hierbas que contribuya a un subsiguiente proceso de clasificación. La técnica de Hui-Fuang detectó un mayor porcentaje de vegetación en todos los casos estudiados, oscilando el incremento entre un 3% y un 20%.This works aimed to implement an alternative to Otsu’s method (1979) developed by Hui- Fuang Ng (2006), which maximizes the difference between spectral variances and performs a multithreshold seeking. Unmanned aerial images taken in maize and sunflower crops were used in the research. In a single algorithm execution applied to an Object Based Image Analysis environment, the objects corresponding to both the vegetation fraction and bare soil are discriminated and a threshold to separate crop from weeds was also estimated, making easier a subsequent classification process. Fui-Huang’s technique provides a higher percentage of vegetation detection in all the cases, with an improvement which ranges from 3% to 20%
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