1,303 research outputs found
Anomalous Roughening in Experiments of Interfaces in Hele-Shaw Flows with Strong Quenched Disorder
We report experimental evidences of anomalous kinetic roughening in the
stable displacement of an oil-air interface in a Hele-Shaw cell with strong
quenched disorder. The disorder consists on a random modulation of the gap
spacing transverse to the growth direction (tracks). We have performed
experiments varying average interface velocity and gap spacing, and measured
the scaling exponents. We have obtained beta=0.50, beta*=0.25, alpha=1.0,
alpha_l=0.5, and z=2. When there is no fluid injection, the interface is driven
solely by capillary forces, and a higher value of beta around beta=0.65 is
measured. The presence of multiscaling and the particular morphology of the
interfaces, characterized by high slopes that follow a L\'evy distribution,
confirms the existence of anomalous scaling. From a detailed study of the
motion of the oil--air interface we show that the anomaly is a consequence of
different local velocities over tracks plus the coupling in the motion between
neighboring tracks. The anomaly disappears at high interface velocities, weak
capillary forces, or when the disorder is not sufficiently persistent in the
growth direction. We have also observed the absence of scaling when the
disorder is very strong or when a regular modulation of the gap spacing is
introduced.Comment: 14 pages, 17 figure
Scenario-based modeling in industrial information systems
This manuscript addresses the creation of scenario-based models to reason about the behavior of existing industrial information systems. In our approach the system behavior is modeled in two steps that gradually introduce detail and formality. This manuscript addresses the first step, where text-based descriptions, in the form of structured rules, are used to specify how the system is or should be regulated. Those rules can be used to create behavioral snapshots, which are collections of scenario-based descriptions that represent different
instances of the system behavior. Snapshots are specified in an intuitive and graphical notation that considers the elements from the problem domain and permit designers to discuss and validate the externally observable behavior, together with the domain experts. In the second step (not fully covered in this manuscript), the system behavior is formalized with an executable model. This formal model, which in our approach is specified using the Colored Petri Net (CP-nets) language, allows the system internal behavior to be animated, simulated, and optimized.
The insights gained by experimenting with the formal model can be subsequently used for reengineering the existing system
Immunoparasitological Diagnosis Of Strongyloides Stercoralis In Garbage Collectors In Uberlândia, Mg, Brazil
The objective of this study was to determine the presence of Strongyloides stercoralis in urban garbage collectors through the use of immunological and parasitological methods. A total of 92 individuals were evaluated from August, 1997, to June, 1998. For the parasitological diagnosis Baermann and Lutz' methods were applied. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA) to detect specific IgG antibodies. Of the 92 workers examined, six (6.5%) were infected with larvae of S. stercoralis. The IFAT detected 19 (16.3%) and the ELISA 17 (18.5%) positive serum samples. The differences between the results of parasitological and immunological methods were statistically significant (p<0.05). These results demonstrate that there is a need to improve the health conditions of this category of city employees.6203/04/15180182CONCHA, R., HARRINGTON, J.R.W., ROGERS, A.L., Intestinal strongyloidiasis: Recognition, management and determinants of outcome (2005) J Clin Gastroenterol, 39, pp. 203-211SIDDIQUI, A.A., BERK, S.L., Diagnosis of Strongyloides stercoralis infection (2001) Clin Infect Dis, 33, pp. 1040-1047FERREIRA, M., Strongyloidiasis and acquired immunodeficiency syndrome (2003) Enf Emerg, 5, pp. 18-26VADLAMUDI, R.S., CHI, D.S., KRISHANASWAMY, G., Intestinal strongyloidiasis and hyperinfection syndrome (2006) Clin Mol Allergy, 4, pp. 1-13BAERMANN G. Eine Einfache methode zur auffindung von Ankylostomum (Nematoden) larven in Erdproben. Mededeel mit h. Geneesk Lab Weltvreden Feestbundel, Batavia, 1917, p. 41-7LUTZ, A.V., Schistosoma mansoni e a schistosomose, Segundo observações feitas no Brasil. (1919) Mem Inst Oswaldo Cruz, 11, pp. 121-125COSTA-CRUZ, J.M., BULLAMAH, C.B., GONÇALVEZ-PIRES, M.R.F., Cryo-microtome sections of coproculture larvae of Strongyloides stercoralis and Strongyloides ratti as antigen sources for the immunodiagnosis of human strongyloidiasis (1997) Rev Inst Med Trop São Paulo, 39, pp. 313-317MACHADO, E.R., UETA, M.T., GONÇALVES-PIRES, M.R.F., Strongyloides venezuelensis alkaline extract for the diagnosis of human strongyloidiasis by enzyme-linked immunosorbent assay (2003) Mem Inst Oswaldo Cruz, 98, pp. 849-853MACHADO, E.R., COSTA-CRUZ, J.M., Strongyloides stercoralis and other enteroparasites in children at Uberlândia City, state of Minas Gerais, Brazil (1998) Mem Inst Oswaldo Cruz, 93, pp. 161-164PAULA, F.M., CASTRO, E., GONÇALVES-PIRES, M.R.F., Parasitological and immunological diagnoses of strongyloidiasis in immunocompromised and nonimmunocompromised children at Uberlândia City, state of Minas Gerais, Brazil (2000) Rev Inst Med Trop São Paulo, 42, pp. 51-55OLIVEIRA, L.C.M., RIBEIRO, C.T., MENDES, D.M., Frequency of Strongyloides stercoralis in alcoholics (2002) Mem Inst Oswaldo Cruz, 97, pp. 119-121LINDO, J.F., CONWAY, D.J., ATKINS, N.S., Prospective evaluation of enzyme-linked immunosorbent assay and immunoblot methods for the diagnosis of endemic Strongyloides stercoralis infection (1994) Am J Trop Med Hyg, 51, pp. 175-179CLARK, C.S., LINNEMANN Jr, C.C., CLARK, J.G., Enteric parasites in workers occupationally exposed to sewage (1984) J Occup Med, 26, pp. 273-275SCHLOSSER, O., RALL, D., LAURECEAU, M.-N., Intestinal parasite carriage in workers exposed to sewage (1999) Eur J Epidemiol, 15, pp. 261-265GOMES, T.C., ALMEIDA, M.F., MUIRA, L.A., Helmintoses intestinais em população de rua da cidade do Rio de Janeiro. (2002) Rev Soc Bras Med Trop, 35, pp. 531-53
Anatomical traits and structural components of peduncle associated with lodging in Avena sativa L.
Received: May 14th, 2020 ; Accepted: June 19th, 2020 ; Published: January 5th, 2021 ; Correspondence: [email protected] dramatically reduces the yield of cereals and increases the difficulty of
mechanical harvesting. Because it is a complex phenomenon, new cultivars with genetic
resistance to lodging is a sustainable alternative in agricultural production systems. This
resistance is associated with a combination of factors, such as stem thickness and stiffness, being
closely linked to anatomical traits and structural carbohydrates present in the stem. In the present
study we compared, under field conditions, eight contrasting oat cultivars in terms of lodging
resistance. Our aim in this study was to investigate the association of anatomical traits and
structural components of the peduncle with resistance to lodging, aiming to assist in the plant
selection process. In addition, a second objective was to understand the genetic dissimilarity
among oat cultivars according to the characters studied. Some characteristics for potential indirect
selection were studied in this work and if correlated with lodging can be used to identify superior
genotypes. From the anatomical point of view, the correlation obtained between the internal
vascular bundle and the lodging resistance factor allowed us to confirm that this trait can be used
in indirect selection to lodging resistance. The structural components of peduncle, in the two ways
explored in the present study, comparison of mean and correlation, did not demonstrate the
potential to be used exclusively as plant selection characters traits for lodging resistance. There
is noticeable variability in oat cultivars for most stem traits
Studying nonlinear effects on the early stage of phase ordering using a decomposition method
Nonlinear effects on the early stage of phase ordering are studied using
Adomian's decomposition method for the Ginzburg-Landau equation for a
nonconserved order parameter. While the long-time regime and the linear
behavior at short times of the theory are well understood, the onset of
nonlinearities at short times and the breaking of the linear theory at
different length scales are less understood. In the Adomian's decomposition
method, the solution is systematically calculated in the form of a polynomial
expansion for the order parameter, with a time dependence given as a series
expansion. The method is very accurate for short times, which allows to
incorporate the short-time dynamics of the nonlinear terms in a analytical and
controllable way.Comment: 11 pages, 1 figure, to appear in Phys Lett
Experiments of Interfacial Roughening in Hele-Shaw Flows with Weak Quenched Disorder
We have studied the kinetic roughening of an oil--air interface in a forced
imbibition experiment in a horizontal Hele--Shaw cell with quenched disorder.
Different disorder configurations, characterized by their persistence length in
the direction of growth, have been explored by varying the average interface
velocity v and the gap spacing b. Through the analysis of the rms width as a
function of time, we have measured a growth exponent beta ~= 0.5 that is almost
independent of the experimental parameters. The analysis of the roughness
exponent alpha through the power spectrum have shown different behaviors at
short (alpha_1) and long (alpha_2) length scales, separated by a crossover
wavenumber q_c. The values of the measured roughness exponents depend on
experimental parameters, but at large velocities we obtain alpha_1 ~= 1.3
independently of the disorder configuration. The dependence of the crossover
wavenumber with the experimental parameters has also been investigated,
measuring q_c ~ v^{0.47} for the shortest persistence length, in agreement with
theoretical predictions.Comment: 20 pages, 22 figure
The new automated daily mortality surveillance system in Portugal
The experience reported in an earlier Eurosurveillance issue on a fast method to evaluate the impact of the 2003 heatwave on mortality in Portugal, generated a daily mortality surveillance system (VDM) that has been operating ever since jointly with the Portuguese Heat Health Watch Warning System. This work describes the VDM system and how it evolved to become an automated system operating year-round, and shows briefly its potential using mortality data from January 2006 to June 2009 collected by the system itself. The new system has important advantages such as: rapid information acquisition, completeness (the entire population is included), lightness (very little information is exchanged, date of death, age, sex, place of death registration). It allows rapid detection of impacts (within five days) and allows a quick preliminary quantification of impacts that usually took several years to be done. These characteristics make this system a powerful tool for public health action. The VDM system also represents an example of inter-institutional cooperation, bringing together organisations from two different ministries, Health and Justice, aiming at improving knowledge about the mortality in the population
Los sistemas integrados de producción agropecuaria como alternativa agroecológica (experiencia Cubana)
Specialized production systems generally require exogenous flow of resources and their maintenance and stability does not depend on its ability to sustain itself. In contrast, agroecological production systems, facing processes, show greater carrying capacity, generating synergies that may enhance natural abilities to produce food of plant and animal origin and to restore balance productive, ecologically and economically, to the influence refusal of any internal or external factor. A system is considered the sum of its parts, but the result of all, made by the parties. In agroecological systems implanted rationality not only biological functioning of soil, plants and animals, but is related to man and their social, economic and political. Here is discarded anthropocentric view of the world and takes place biocentric vision, which explains the functioning and evolution of any changes. Another aspect to consider are the traditional techniques and local knowledge. The experience acquired traditional and local knowledge, including empirical, agricultural activity is transmitted from generation to generation and are very important to achieve productive and efficient results.Los sistemas especializados de producción requieren generalmente de un flujo exógeno de recursos y su mantenimiento y estabilidad no dependen de su capacidad propia de sustento. En cambio, los sistemas productivos agroecológicos, que miran hacia los procesos, muestran mayor capacidad de sostenimiento, generando sinergias que permiten potenciar las capacidades naturales de producir alimentos de origen vegetal y animal y de restaurar el equilibrio productivo, ecológico y económico, ante la influencia negativa de cualquier factor interno o externo. Un sistema no es considerado la suma de sus partes, sino el resultado del todo, formado por las partes. En los sistemas agroecológicos se implanta no solo la racionalidad biológica del funcionamiento del suelo, las plantas y los animales, sino que se relaciona con el hombre y su entorno social, económico y político. Aquí se desecha la visión antropocéntrica del mundo y toma lugar la visión biocéntrica, que explica el funcionamiento y evolución de cualquier cambio. Otro aspecto a tener en cuenta son las técnicas tradicionales y los conocimientos locales. Las experiencias acumuladas, los conocimientos tradicionales y locales, incluso los empíricos, en la actividad agropecuaria se trasmiten de generación en generación y son de mucha importancia para lograr resultados productivos y eficientes
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