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Evaluating the use of Beer's law for estimating light interception in canopy architectures with varying heterogeneity and anisotropy
Light interception in plant canopies is most commonly estimated using a simple one-dimensional turbid medium model (i.e., Beer's law). Inherent in this class of models are assumptions that vegetation is uniformly distributed in space (homogeneous) and in many cases that vegetation orientation is uniformly distributed (isotropic). It is known that these assumptions are violated in a wide range of canopies, as real canopies commonly have heterogeneity at multiple scales and almost always have highly anisotropic leaf angle distributions. However, it is not quantitatively known under what conditions these assumptions become problematic given the difficulty of robustly evaluating model results for a range of canopy architectures. In this study, assumptions of vegetation homogeneity and isotropy were evaluated under clear sky conditions for a range of virtually-generated crop canopies with the aid of a detailed three-dimensional, leaf-resolving radiation model. Results showed that Beer's law consistently over predicted light interception for all canopy configurations. For canopies where the plant spacing was comparable to the plant height, Beer's law performed poorly, and over predicted daily intercepted sunlight by up to ∼115%. For vegetation with a highly anisotropic leaf inclination distribution but a relatively isotropic leaf azimuth distribution, the assumption of canopy isotropy (i.e., G = 0.5) resulted in relatively small errors. However, if leaf elevation and azimuth were both highly anisotropic, the assumption of canopy isotropy could introduce significant errors depending on the orientation of the azimuthal anisotropy with respect to the sun's path
A three-by-three matrix spectral problem for AKNS hierarchy and its binary Nonlinearization
A three-by-three matrix spectral problem for AKNS soliton hierarchy is
proposed and the corresponding Bargmann symmetry constraint involved in Lax
pairs and adjoint Lax pairs is discussed. The resulting nonlinearized Lax
systems possess classical Hamiltonian structures, in which the nonlinearized
spatial system is intimately related to stationary AKNS flows. These
nonlinearized Lax systems also lead to a sort of involutive solutions to each
AKNS soliton equation.Comment: 21pages, in Late
High Performance Technology in Algorithmic Cryptography
Alan Turing’s article, “Computation and intelligence”, gives the preamble of the characteristics of guessing if it is a machine or another human being. Currently, the use of ubiquitous technologies, such as the use of firmware, allows direct access to analog data, however, we must find a way to secure the information. Analyzing cryptographic algorithms for the transfer of multimedia information. Raise the use of cryptarithmetic. Finite automata will be developed that will govern the logic of the cryptographic algorithms to be integrated into Firmware, performance tests and controls will be carried out to determine the best strategies for their performance and algorithmic complexity. Technologies are expressed that allow the creation of learning environments, such as neural networks, that support other processes as the recognition of patterns on images
Zooplankton Abundance and Diversity in the Tropical and Subtropical Ocean
The abundance and composition of zooplankton down to 3000 m depth was studied in
the subtropical and tropical latitudes across the Atlantic, Pacific and Indian Oceans (35 N–40 S).
Samples were collected from December 2010 to June 2011 during the Malaspina Circumnavigation
Expedition. Usually, low abundances were observed with the highest values found in the North
Pacific Ocean, Benguela, and o Mauritania, and the lowest in the South Pacific Ocean. No significant
di erences in abundance and zooplankton composition were found among oceans, with depth being
consistently the most important factor a ecting their distribution. Each depth strata were inhabited by
distinct copepod assemblages, which significantly di ered among the strata. The contribution
of copepods to the zooplankton community increased with the depth although, as expected,
their abundance strongly decreased. Among the copepods, 265 species were identified but 85%
were rare and contributed less than 1% in abundance. Clausocalanus furcatus and Nannocalanus minor
dominated the epipelagic strata. Pleuromamma abdominalis and Lucicutia clausi were of importance in
the mesopelagic layer, and Pareucalanus, Triconia, Conaea and Metridia brevicauda in the bathypelagic
layer. Our results provide a global-scale assessment of copepod biodiversity and distribution,
providing a contemporary benchmark to follow future ocean changes at low latitudes
HLA-C genotype and TCR vβ expression analysis in Mexican patients with Psoriasis
"Genetic background and T-cell expansion have been associated as the most important factors for psoriasis susceptibility in the Caucasian population. This study was performed to identify the T cell receptor Vβ repertoire and HLA-Cw genotype in two Mexican groups with severe chronic plaque-type psoriasis. HLA-C typing was performed to detect the allele pattern associated with the disease by sequence-specific primer-polymerase chain reaction. In parallel, RT-PCR and Western blot were used for the identification of the TCR Vβ repertoire. We found a wide variety of HLA-C alleles displayed with a preference to HLA-Cw *07 as the most representative allele in the group of patients. TCR Vβ-2 and Vβ-7 clone-type frequencies were statistically significant (p of 0.0280) when compared to other TCR Vβ expressed in the two groups. We found notable differences both in the HLA-C genotype and TCR Vβ repertoire in the groups of patients studied. Since Mexican individuals are genetically different from the Caucasian population, we suggest that due to these differences the susceptibility to disease and activation of T-cells for a proper immune response may be affected.
Cost-effectiveness study of oral hypoglycemic agents in the treatment of outpatients with type 2 diabetes attending a public primary care clinic in Mexico City
Estudios de mercado en las zonas productoras de amaranto en Valles Altos
El objetivo de esta investigación fue realizar un estudio de mercado en las zonas productoras de amaranto en la zona de los Valles Altos. Se diseñó la entrevista semiestructurada, la cual está integrada por preguntas cerradas y abiertas; la entrevista se dividió en información general del productor, destino, uso de la producción, costos, utilidad e ingresos. En Valles Altos se entrevistaron a 89 productores de amaranto para grano, localizados en 26 comunidades de 13 municipios y delegaciones de las principales regiones productoras de la semilla de los estados de Puebla (Cohuacan, Tochimilco Tecamachalco, Atlixco Caltepec), México (Amecameca y San Juan Teotihuacán), Tlaxcala (Nativitas), Morelos (Temoac) y Distrito Federal en las delegaciones Xochimilco, Tláhuac y Milpa Alta. El periodo de estudio fue 2009 a 2010; se visitaron los cultivos en las parcelas de algunos productores, en donde se observó el amaranto en la etapa del secado de la panoja, para lo cual se encuentra cortado y tirado en el terreno, para posteriormente trillarlo. En otros casos aún no se cortaba el amaranto y en otros ya se había trillado. También se realizaron entrevistas en la Feria de Alegría y del Olivo de Tulyehualco, en la Delegación Xochimilco, Distrito Federal, en las bodegas y en las casas de los productores
Metabolic syndrome, adiposity, diet, and emotional eating are associated with oxidative stress in adolescents
Background: Metabolic syndrome (MS), a condition related to adiposity and oxidative stress, can develop in adolescence, a critical stage in life that impacts health in adulthood. However, there is scarce scientific research about the relationship between lifestyle factors, emotion management, and oxidative stress in this phase of life.Aim: To analyze whether nutritional parameters, lifestyle factors, emotion management, and MS in adolescents are associated with oxidative stress measured by the biomarker 8-isoprostane.Methods: A cross-sectional study was carried out in 132 adolescents (48.5% girls, aged 12 ± 0.48 years) and data were collected on nutritional parameters (anthropometric measurements, biochemical analyzes, and blood pressure), lifestyle factors (physical activity, sleep, and diet), and emotion management (self-esteem, emotional eating, and mood). 8-isoprostane was analyzed in spot urine samples. The study population was categorized in three groups (healthy, at-risk, and with MS) using the International Diabetes Federation definition of MS in adolescents. To capture more complex interactions, a multiple linear regression was used to analyze the association between 8-isoprostane and the aforementioned variables.Results: Urinary 8-isoprostane levels were significantly higher in the MS group compared to the healthy group (1,280 ± 543 pg./mg vs. 950 ± 416 pg./mg respectively). In addition, univariable analysis revealed positive significant associations between 8-isoprostane and body mass index, waist circumference, waist-to-height ratio, body fat percentage, blood lipid profile and glucose, emotional eating, and refined cereal intake. Conversely, a negative significant association was found between 8-isoprostane and sleep duration and fish intake. The multiple linear regression analysis revealed associations between 8-isoprostane and LDL-c (β = 0.173 value of p = 0.049), emotional eating (low β = 0.443, value of p = 0.036; high β = 0.152, value of p = 0.470), refined cereal intake (β =0.191, value of p = 0.024), and fish intake (β = -0.187, value of p = 0.050).Conclusion: The MS group, LDL-c, emotional eating, and high refined cereals and low fish intakes were associated with higher levels of oxidative stress in an adolescent population.</p
Sistema para la Aplicación de Pruebas Psicológicas vía Web
In this work, we present a generic Web system for the application, capturing and editing ofany multiple-choice psychological test capable of storing data permanently (in order to makecomparative and longitudinal studies). Also, these data can be imported into other statisticalprograms such as Microsoft Excel, SPSS and Origin. The implementation and administrationof the tests can be done from any Internet-connected computer without installing specializedsoftware. To evaluate the potential of this system, the questionnaire Cuestionario Honey-Alonsode Estilos de Aprendizaje (C. H. A. E. A.) was captured and applied to 255 subjects. Theresults showed a significant reduction in time spent calculating the factor, in the same way,the total score for each test also prevented the occurrence of errors made by human interventionin the assessment manual (since this process was automated by the system).En este trabajo se presenta un sistema web para la aplicación, captura y edición de cualquier prueba psicológica de opción múltiple con capacidad para almacenar datos de forma permanente (dicha información permitirá llevar a cabo estudios comparativos y longitudinales). De la misma forma, los datos almacenados pueden ser importados por otros programas estadísticos, como por ejemplo Microsoft Excel, SPSS y Origin. La aplicación y administración de estas pruebas puede hacerse desde cualquier computadora conectada a la Internet sin necesidad de instalar programas especializados. Para evaluar el potencial de este sistema, se capturó el Cuestionario Honey-Alonso de Estilos de Aprendizaje (C. H. A. E. A.) y se aplicó a 255 sujetos. Los resultados obtenidos demuestran una reducción considerable en el tiempo invertido en el cálculo de las subescalas (factor) y en la puntuación total de cada prueba, además, se evitó la aparición de errores cometidos por la intervención humana en la evaluación manual (debido a que este proceso fue automatizado por el sistema).</span
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