Applications of the Ashtekar gravity to four dimensional hyperk\"ahler geometry and Yang-Mills Instantons

The Ashtekar-Mason-Newman equations are used to construct the hyperk\"ahler metrics on four dimensional manifolds. These equations are closely related to anti self-dual Yang-Mills equations of the infinite dimensional gauge Lie algebras of all volume preserving vector fields. Several examples of hyperk\"ahler metrics are presented through the reductions of anti self-dual connections. For any gauge group anti self-dual connections on hyperk\"ahler manifolds are constructed using the solutions of both Nahm and Laplace equations.Comment: 9pages, Figures are not include

Perfluorooctanoic Acid for Shotgun Proteomics

Here, we describe the novel use of a volatile surfactant, perfluorooctanoic acid (PFOA), for shotgun proteomics. PFOA was found to solubilize membrane proteins as effectively as sodium dodecyl sulfate (SDS). PFOA concentrations up to 0.5% (w/v) did not significantly inhibit trypsin activity. The unique features of PFOA allowed us to develop a single-tube shotgun proteomics method that used all volatile chemicals that could easily be removed by evaporation prior to mass spectrometry analysis. The experimental procedures involved: 1) extraction of proteins in 2% PFOA; 2) reduction of cystine residues with triethyl phosphine and their S-alkylation with iodoethanol; 3) trypsin digestion of proteins in 0.5% PFOA; 4) removal of PFOA by evaporation; and 5) LC-MS/MS analysis of the resulting peptides. The general applicability of the method was demonstrated with the membrane preparation of photoreceptor outer segments. We identified 75 proteins from 1 µg of the tryptic peptides in a single, 1-hour, LC-MS/MS run. About 67% of the proteins identified were classified as membrane proteins. We also demonstrate that a proteolytic 18O labeling procedure can be incorporated after the PFOA removal step for quantitative proteomic experiments. The present method does not require sample clean-up devices such as solid-phase extractions and membrane filters, so no proteins/peptides are lost in any experimental steps. Thus, this single-tube shotgun proteomics method overcomes the major drawbacks of surfactant use in proteomic experiments

Protein processing characterized by a gel-free proteomics approach

We describe a method for the specific isolation of representative N-terminal peptides of proteins and their proteolytic fragments. Their isolation is based on a gel-free, peptidecentric proteomics approach using the principle of diagonal chromatography. We will indicate that the introduction of an altered chemical property to internal peptides holding a free α-N-terminus results in altered column retention of these peptides, thereby enabling the isolation and further characterization by mass spectrometry of N-terminal peptides. Besides pointing to changes in protein expression levels when performing such proteome surveys in a differential modus, protease specificity and substrate repertoires can be allocated since both are specified by neo-N-termini generated after a protease cleavage event. As such, our gel-free proteomics technology is widely applicable and amenable for a variety of proteome-driven protease degradomics research

Modelado de sistemas supervisores distribuidos y abiertos usando redes de Petri y orientación a Objetos

El modelado de sistemas supervisores para ambientes automatizados puede ser visto como una tarea que involucra técnicas y métodos de dos áreas principales: ingeniería de control e ingeniería de software. En este contexto, el propósito de este trabajo es introducir un nuevo abordaje para el modelado de sistemas supervisores distribuidos y abiertos, basado en la unión de técnicas tradicionales de ingeniería de software (como la orientación a objetos) y con modelos formales de los sistemas dinámicos a eventos discretos (como las redes de Petri). En el primer nivel de abstracción, es usado el modelo de referencia de procesamiento distribuido y abierto (RM-ODP) como marco atquitectural estándar pata la construcción de un sistema distribuido y abierto. Basado en el modelo de referencia ODP, los diagramas en el lenguaje de modelado unificado UML son construidos como un segundo nivel de abstracción. Finalmente, las redes de Petri (el tercer nivel de abstracción) son usadas a través del proceso con la finalidad de garantizar la coherencia entre los modelos en UML desde el análisis de requerimientos hasta la implementación de manera a proveer modelos formales del sistema

Seleção de tamanho de partículas por bovinos Nelore em confinamento e sua relação com características de carcaça.

Pesquisas apresentam a existência de variação individual em relação ao comportamento alimentar de bovinos confinados, mesmo estando na mesma baia de confinamento. Objetivou-se avaliar se a seletividade por tamanho de partícula no cocho tem relação com as características de carcaça de bovinos Nelore Mocho. O experimento foi realizado na área de confinamento de junho a novembro de 2012. Foram utilizados 18 animais, com idade e peso médio iniciais de 21 meses e 335 kg, respectivamente, provenientes do rebanho da marca OB. Os animais foram abatidos com idade e o peso médio de 23 meses e 535 kg, e espessura de gordura mínima de 5 mm. Foi mantido um registro diário do ofertado e das sobras recolhidas, por animal. Avaliou-se o tamanho médio de partículas restantes no cocho pelo método Penn State a cada quatro horas diárias. Fez-se uso de análises de Cluster para agrupar os animais conforme seletividade por partículas consumidas. As médias foram ajustadas pelo método dos mínimos quadrados e comparadas por meio do teste de Tukey a 5% de probabilidade. Apesar do comportamento seletivo diferenciado, em relação ao tamanho de partículas, não houve diferença estatística significativa entre os grupos de seleção alimentar (p>0,05) para as características de carcaça dos animais. Conclui-se que a seletividade por tamanho de partículas no cocho não implicam em alterações nas características de carcaça de bovinos de corte em confinamento. Abstract: Studies with feedlot livestock have identified quantitative and qualitative differences as it relates to individual food intake. The objective of this study was to evaluate if the food selection based on particle size in the trough was associated carcass characteristics of Nelore Mocho cattle. The experiment was conducted in the confinement, from June to November 2012. Eighteen OB brand animals were studied, with respective baseline age and average weight of 21 months and 335 kg. The animals were slaughtered at an average age and weight of 23 months and 515 kg, and minimal subcutaneous thickness of 5 mm. A registry of the daily intake was kept. The Penn State method and leftover scores were used to analyze the average size of the particles at four hour a day of feeding. Cluster analysis was used to group animals according to particle size selectivity for food intake. Least square method was used to adjust averages and Tukey?s test was used for comparison at 5% probability level. Despite the different selective behavior related to particle sizes, there were no statistically significant differences (p>0.05) among carcass characteristics. It was concluded particle size selectivity not affect carcass characteristics of confined beef cattle

Multiple factor analysis to identify correlated variable among microclimate, thermal comfort and infrared thermography in agroforestry systems.

Goal was to use the Multiple Factor Analysis to reduce dimensionality of variables, to identify groups of correlated variables and to obtain a common assessment tool to evaluate microclimate, thermal comfort and infrared thermography in agroforestry systems. The experiment was conducted at the Embrapa Beef Cattle, Campo Grande, MS, from July 2015 to February 2016, corresponding to winter and summer seasons, in two agroforestry systems with different tree densities and spatial arrangements of native and planted trees. Readings were made from 8:00 a.m. to 4:00 p.m., for microclimate parameters (air temperature, dew point temperature, black globe temperature, relative humidity, wind speed, global solar radiation, photosynthetically active radiation and luminosity), thermal comfort (Temperature and Humidity Index, Black Globe and Humidity Index, Radiation Thermal Load), and infrared thermography (temperature and humidity of tree crown and soil surface), under full sun and shadow projection. Multiple Factor Analysis found three Synthetic Analytical Dimensions that explained 55.5% of the total observed variance. Strong and positive associations between infrared thermography, microclimate, thermal comfort and radiation were found. Thus, it is suggested that infrared thermography is a potential tool to be used for microclimate prediction and thermal comfort under agroforestry systems

Ultrafine-scale magnetostratigraphy of marine ferromanganese crust

http://geology.geoscienceworld.org/content/39/3/227.full.pdf+htmlHydrogenetic ferromanganese crusts are iron-manganese oxide chemical precipitates on the seafloor that grow over periods of tens of millions of years. Their secular records of chemical, mineralogical, and textural variations are archives of deep-sea environmental changes. However, environmental reconstruction requires reliable high-resolution age dating. Earlier chronological methods using radiochemical and stable isotopes provided age models for ferromanganese crusts, but have limitations on the millimeter scale. For example, the reliability of 10Be/9Be chronometry, commonly considered the most reliable technique, depends on the assumption that the production and preservation of 10Be are constant, and requires accurate knowledge of the 10Be half-life. To overcome these limitations, we applied an alternative chronometric technique, magnetostratigraphy, to a 50-mm-thick hydrogenetic ferromanganese crust (D96-m4) from the northwest Pacific. Submillimeter-scale magnetic stripes originating from approximately oppositely magnetized regions oriented parallel to bedding were clearly recognized on thin sections of the crust using a high-resolution magnetometry technique called scanning SQUID (superconducting quantum interference device) microscopy. By correlating the boundaries of the magnetic stripes with known geomagnetic reversals, we determined an average growth rate of 5.1 ± 0.2 mm/m.y., which is within 16% of that deduced from the 10Be/9Be method (6.0 ± 0.2 mm/m.y.). This is the finest-scale magnetostratigraphic study of a geologic sample to date. Ultrafine-scale magnetostratigraphy using SQUID microscopy is a powerful new chronological tool for estimating ages and growth rates for hydrogenetic ferromanganese crusts. It provides chronological constraints with the accuracy promised by the astronomically calibrated magnetostratigraphic time scale (1–40 k.y.).Japan Society for the Promotion of Science (Grant-in-Aid for Scientific Research (21654071))National Science Foundation (U.S.) (Collaboration in Mathematical Geosciences Program