286 research outputs found
Modelagem e controle avançado não-linear multivariável por lógica nebulosa : aplicação para um processo de copolimerização
A obtenção de um modelo matemático confiável de um dado processo é um
pré-requisito fundamental para o projeto de controladores. Contudo, particularmente para sistemas poliméricos que são intrinsecamente caracterizados por dinâmicas complexas, o delineamento de uma aproximação a partir dos primeiros princípios é uma tarefa bastante
árdua e, por vezes, não realizável. Logo, representações matemáticas mais simples, porém reprodutivas das principais peculiaridades do sistema, são bem-vindas. Assim sendo, este trabalho apresenta o desenvolvimento e a implementação de dois esquemas de controle
preditivo não-linear multivariável baseado em modelo nebuloso para um processo de copolimerização. Modelos MISO (Multi-Input/Single-Output) lineares e exponenciais são construídos a partir da lógica nebulosa, combinados e aplicados para simulação e predição on-line. Os desempenhos das estruturas de controle propostas foram comparados
ao DMC (Dynamic Matrix Control) e a um típico NMPC (Nonlinear Model-based Predictive Control) para o problema servo. Os resultados obtidos comprovaram a eficácia das configurações projetadas
Variability of the prevalence of depression in function of sociodemographic and environmental factors: ecological model
Major depression etiopathogenesis is related to a wide variety of genetics, demographic and psychosocial factors, as well as to environmental factors. The objective of this study is to analyze sociodemographic and environmental variables that are related to the prevalence of depression through correlation analysis and to develop a regression model that explains the behavior of this disease from an ecological perspective. This is an ecological, retrospective, cross-sectional study. The target population was 1,148,430 individuals over the age of 16 who were registered in Aragon (Spain) during 2010, with electronic medical records in the community’s primary health care centers. The spatial unit was the Basic Health Area (BHA). The dependent variable was the diagnosis of Depression and the ecological independent variables were: Demographic variables (gender and age), population distribution, typology of the entity, population structure by sex and age, by nationality, by education, by work, by salary, by marital status, structure of the household by number of members, and state of the buildings. The results show moderate and positive correlations with higher rates of depression in areas having a higher femininity index, higher population density, areas with a higher unemployment rate and higher average salary. The results of the linear regression show that aging +75 and rural entities act as protective factors for depression, while urban areas and deficient buildings act as risk factors. In conclusion, the ecological methodology may be a useful tool which, together with the statistical epidemiological analysis, can help in the political decision making process
Disintegrins extracted from totonacan rattlesnake (Crotalus totonacus) venom and their anti-adhesive and anti-migration effects on MDA-MB-231 and HMEC-1 cells
Disintegrins are low molecular weight cysteine-rich proteins (4–14 kDa) that are isolated mainly from viperid
snake venom. Due to their potential as lead compounds for binding and blocking integrin receptors, snake venom
disintegrins have become one of the most studied venom protein families. The aim of this study was to obtain
disintegrins from C. totonacus venom and evaluate their capability to bind and block integrin receptors. The C.
totonacus disintegrin fraction (totonacin) represents two disintegrin isoforms obtained from C. totonacus venom.
These disintegrins showed extracellular-matrix (ECM) protein adhesion and migration inhibitory effects on
MDA-MB-231 and HMEC-1 cells. Totonacin (3 μM) inhibited MDA-MB-231 cell adhesion to the ECM proteins,
fibronectin, vitronectin, and laminin by 31.2, 44.0, and 32.1, respectively. Adhesion inhibition to fibronectin,
vitronectin, and laminin observed on HMEC-1 cells was 42.8, 60.8, and 51%, respectively. In addition, totonacin
(3 μM) significantly inhibited MDA-MB-231 and HMEC-1 cell migration (41.4 and 48.3%, respectively).
Totonacin showed more potent cell adhesion inhibitory activity toward vitronectin in both cell lines. These
results suggest a major affinity of totonacin toward αVβ3, α8β1, αVβ5, αVβ1, and αIIbβ3 integrins. In addition, the
inhibitory effect observed on MDA-MB-231 and HMEC-1 cell migration reinforces the evidence of an interaction
between these disintegrins and αVβ3 integrin, which plays a key role in migration and angiogenesis
Multivariable nonlinear advanced control of copolymerization processes
A reliable multivariable model of a process is a fundamental prerequisite for the design of an efficient control strategy. Though, such a model is often very hard to obtain via a first-principles approach. The development of two fuzzy model-based multivariable nonlinear predictive control schemes and their implementation on a copolymerization process are described in this paper. Multi-input/single-output models are developed using fuzzy logic and combined to form a parallel system model for simulation and online prediction. The behavior of the outlined controllers were compared to the dynamic matrix control (DMC) and to a typical nonlinear model-based predictive control (NMPC) for regulatory problem and the obtained results showed the effectiveness of the proposed structures
Estudio físico-químicos de los huevos de Iguana iguana Linnaeus, 1758
Iguana iguana eggs were physically and chemically characterized. the physical tests were performed by methods of spectrophotolorimetry, calibrator, tape measure, micrometer, flexometer and flotation and chemical tests according to the guidelines required by A.O.A.C. The results obtained showed with respect to the physical characteristics: On average, a weight of 14.78 (g); longitudinal diameter 39.70 mm (±0.49), cross-sectional diameter 26.41mm (±0.6), perimeter length 11.55 cm (±0.2), perimeter width 9.07 cm (±02), among other characteristics evaluated. Regarding the chemical composition, in shell 51.23% (±3.02) Inorganic Calcium; 20.17% (±1.56) Inorganic Phosphorus; in albumen 51.47% (±1.05) of crude protein, 17.02% (±1.33) of raw fat and in compact albumen a weight of 3.83 g (±0.21). Through multiple regressions, it was determined that the weight depends on the percentage of shell and the compact albumen in 87%. The specific gravity depends not only on the perimeter length but also on the percentage of shell and the thickness of this in the equatorial zone in a 86.3%. The percentage of shell, weight, specific gravity and thickness in the equatorial zone in 88.3%. The chromatic characterization determined its color between medium yellow and yellowish white.Caracterización físico-químicamente de huevos de Iguana iguana. Las pruebas físicas se realizaron por métodos de Espectrofotocolorimetría, calibrador, cinta métrica, micrómetro, flexómetro y flotación y las pruebas químicas acorde a los lineamientos exigidos por la A.O.A.C. Los resultados obtenidos mostraron con respecto a las características físicas: En promedio, un peso de 14,78 (g); diámetro longitudinal 39,70 mm (±0,49), diámetro transversal 26,41mm (±0,6), largo perimetral 11,55 cm (±0,2), ancho perimetral 9,07 cm (± 0,2), entre otras caractericticas evaluadas. Respecto a la composición química, en cáscara 51,23% (±3,02) Calcio Inorgánico; 20,17% (±1,56) Fósforo Inorgánico; en albumen 51,47% (±1,05) de proteína bruta, un 17,02% (±1,33) de grasa cruda y en albumen compacto un peso de 3,83 g (±0,21). Mediante regresiones múltiples se determinó que el peso depende del porcentaje de cáscara y del albumen compacto en un 87%. La gravedad específica depende no solo del largo perimetral sino también del porcentaje de cáscara y del grosor de ésta en la zona ecuatorial en un 86,3%. El porcentaje de cáscara, del peso, gravedad específica y grosor en la zona ecuatorial en 88,3%. La caracterización cromática determinó su color entre amarillo medio y blanco amarillento
Estudio físico-químicos de los huevos de Iguana iguana Linnaeus, 1758
Caracterización físico-químicamente de huevos de Iguana iguana. Las pruebas físicas se realizaron por métodos de Espectrofotocolorimetría, calibrador, cinta métrica, micrómetro, flexómetro y flotación y las pruebas químicas acorde a los lineamientos exigidos por la A.O.A.C. Los resultados obtenidos mostraron con respecto a las características físicas: En promedio, un peso de 14,78 (g); diámetro longitudinal 39,70 mm (±0,49), diámetro transversal 26,41mm (±0,6), largo perimetral 11,55 cm (±0,2), ancho perimetral 9,07 cm (± 0,2), entre otras caractericticas evaluadas. Respecto a la composición química, en cáscara 51,23% (±3,02) Calcio Inorgánico; 20,17% (±1,56) Fósforo Inorgánico; en albumen 51,47% (±1,05) de proteína bruta, un 17,02% (±1,33) de grasa cruda y en albumen compacto un peso de 3,83 g (±0,21). Mediante regresiones múltiples se determinó que el peso depende del porcentaje de cáscara y del albumen compacto en un 87%. La gravedad específica depende no solo del largo perimetral sino también del porcentaje de cáscara y del grosor de ésta en la zona ecuatorial en un 86,3%. El porcentaje de cáscara, del peso, gravedad específica y grosor en la zona ecuatorial en 88,3%. La caracterización cromática determinó su color entre amarillo medio y blanco amarillento
Estudio Preliminar Sobre La Decoloración Del Residual Líquido De La Producción De Papel Mediante Ozonización
Preliminarily, the relationship between Color Reduction (%RC), Total Suspended Solids concentration (SST), and as independent variable, the time of Ozone Oxidation Process, was evaluated with reference values of DQO of the black liquor adjusting its concentration from SST to 300 and 50mg/dm3. A batch reactor of 12,60dm3, an effective height of 3,2dm and an ozone generating device from SEFILTRA company (air flow of 2dm3/min, c(O3) of 9,50mg/dm3 with a O3(g) production 19mg/min) was used. The polynomic correlation was determined from 192 data sets with satisfactory adjustment level (R=0,92; p <0,001). Although, preliminarily, the DQO reduction (%RDQO) was not included in the polynomial relationship, it can be concluded that: a) The %RC and %RDQO is reduced when color and DQO increases from the ozonized sample at same time intervals; this reduction is greater when the SST levels of the ozonized sample increases. b) The %RC and %RDQO decrease when the SST level of the ozonized sample increases. c) Depending on the initial color, of the DQO and of the SST level of the sample, values from 10 to 53 %Rc were obtained after 10 min, and of 66 to 94 %Rc after 60 min
Detección de Leucoptera sinuella (Reutti) (Lepidoptera: Lyonetiidae) en Chile, con la identificación de algunos parasitoides asociados
En marzo del 2015 el Servicio Agrícola y Ganadero (SAG), a través de actividades de vigilancia forestal, detectó por primera vez en Chile la presencia de Leucoptera sinuella (Reutti), atacando follaje de álamos (Populus spp., Salicaceae), en la comuna de Talagante (Región Metropolitana de Santiago).
Actividades de prospección desarrolladas por el SAG han determinado que este microlepidóptero se encuentra distribuido en diversas comunas de las regiones de Valparaíso, Metropolitana de Santiago, Libertador General Bernardo O’Higgins, Maule, Ñuble y Biobío. Adicionalmente, fueron
identificadas siete especies de microhimenópteros parasitoides asociados a L. sinuella, pertenecientes a las familias Eulophidae (6 especies) y Chalcididae (1 especie)
Genomic insertion of a heterologous acetyltransferase generates a new lipopolysaccharide antigenic structure in brucella abortus and brucella melitensis
Brucellosis is a bacterial zoonosis of worldwide distribution caused by bacteria of the genus Brucella. In Brucella abortus and Brucella melitensis, the major species infecting domestic ruminants, the smooth lipopolysaccharide (S-LPS) is a virulence factor. This S-LPS carries a N-formyl-perosamine homopolymer O-polysaccharide that is the major antigen in serodiagnostic tests and is required for virulence. We report that the Brucella O-PS can be structurally and antigenically modified using wbdR, the acetyl-transferase gene involved in N-acetyl-perosamine synthesis in Escherichia coli O157:H7. Brucella constructs carrying plasmidic wbdR expressed a modified O-polysaccharide but were unstable, a problem circumvented by inserting wbdR into a neutral site of chromosome II. As compared to wild-type bacteria, both kinds of wbdR constructs expressed shorter O-polysaccharides and NMR analyses showed that they contained both N-formyl and N-acetyl-perosamine. Moreover, deletion of the Brucella formyltransferase gene wbkC in wbdR constructs generated bacteria producing only N-acetyl-perosamine homopolymers, proving that wbdR can replace for wbkC. Absorption experiments with immune sera revealed that the wbdR constructs triggered antibodies to new immunogenic epitope(s) and the use of monoclonal antibodies proved that B. abortus and B. melitensis wbdR constructs respectively lacked the A or M epitopes, and the absence of the C epitope in both backgrounds. The wbdR constructs showed resistance to polycations similar to that of the wild-type strains but displayed increased sensitivity to normal serum similar to that of a per R mutant. In mice, the wbdR constructs produced chronic infections and triggered antibody responses that can be differentiated from those evoked by the wild-type strain in S-LPS ELISAs. These results open the possibilities of developing brucellosis vaccines that are both antigenically tagged and lack the diagnostic epitopes of virulent field strains, thereby solving the diagnostic interference created by current vaccines against Brucella
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