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In this work, a new Virtual Element Method (VEM) of arbitrary order k≥ 2 for the time dependent Navier–Stokes equations in stream-function form is proposed and analyzed. Using suitable projection operators, the bilinear and trilinear terms are discretized by only using the proposed degrees of freedom associated with the virtual space. Under certain assumptions on the computational domain, error estimations are derived and shown that the method is optimally convergent in both space and time variables. Finally, to justify the theoretical analysis, four benchmark examples are examined numerically.

In this article we propose and analyze a Virtual Element Method (VEM) to approximate the isolated solutions of the von Kármán equations, which describe the deformation of very thin elastic plates. We consider a variational formulation in terms of two variables: the transverse displacement of the plate and the Airy stress function. The VEM scheme is conforming in H2for both variables and has the advantages of supporting general polygonal meshes and is simple in terms of coding aspects. We prove that the discrete problem is well posed for hsmall enough and optimal error estimates are obtained. Finally, numerical experiments are reported illustrating the behavior of the virtual scheme on different families of meshes.

Tuberculosis is a principal mortality causes in world, and vaccination with BCG is a key for your prevention.

Tuberculosis is a principal mortality causes in world, and vaccination with BCG is a key for your prevention.

Bacteria have evolved a variety of signal transduction mechanisms that generate different outputs in response to external stimuli. Chemosensory pathways are widespread in bacteria and are among the most complex signaling mechanisms, requiring the participation of at least six proteins.

Amblyomma maculatumKoch sensu lato (s.l.) ticks are the vector of Rickettsia parkeriin Arizona, where nine cases of R. parkeririckettsiosis have been identified since the initial case in 2014. The current study sought to better define the geographic ranges of the vector and pathogen and to assess the potential public health risk posed by R. parkeriin this region of the southwestern United States. A total of 275 A. maculatums.l. ticks were collected from 34 locations in four counties in Arizona and one county in New Mexico and screened for DNA of Rickettsiaspecies. Rickettsia parkeriwas detected in 20.4% of the ticks, including one specimen collected from New Mexico, the first report of R. parkeriin A. maculatums.l. from this state. This work demonstrates a broader distribution of A. maculatums.l. ticks and R. parkeriin the southwestern United States than appreciated previously to suggest that R. parkeririckettsiosis is underrecognized in this region.

It is estimated that 71 million people live with chronic hepatitis C viral infection (HCV). Part of the comorbidities associated with cirrhosis is frailty. Remarkably, diet is highly important in the management of cirrhosis and liver diseases. Therefore, it is necessary to evaluate the quality of the diet in this population. In this context, we evaluated the frailty and quality of the diet in patients with chronic HCV infection with or without cirrhosis, as well as the association between demographic, clinical, and anthropometric variables.

Evaluar el efecto del plan de estudios de la Licenciatura en Medicina de la Universidad Guadalajara LAMAR sobre las competencias profesionales para la promoción de la salud y la participación social.

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La elección de qué prueba solicitar a un paciente así como su interpretación es un escenario diario con el cual el especialista debe enfrentarse y el endoscopista no es ajeno a ello. Es común que cuando se habla de una prueba diagnóstica (laboratorio o imagen) se escuche el comentario de parámetros como sensibilidad, especificidad y valores predictivos. Los parámetros mencionados reflejan las características de una prueba diagnóstica y sirven para decidir en qué momento debemos utilizarlas (sensibilidad y especificidad de una prueba) o qué significado tiene un resultado de una prueba en un paciente en particular.

This paper is devoted to the numerical analysis of an augmented finite element approximation of the axisymmetric Brinkman equations. Stabilization of the variational formulation is achieved by adding suitable Galerkin least-squares terms, allowing us to transform the original problem into a formulation better suited for performing its stability analysis. The sought quantities (here velocity, vorticity, and pressure) are approximated by Raviart−Thomas elements of arbitrary order k≥ 0, piecewise continuous polynomials of degree k+ 1, and piecewise polynomials of degree k, respectively. The well-posedness of the resulting continuous and discrete variational problems is rigorously derived by virtue of the classical Babuška–Brezzi theory. We further establish a priori error estimates in the natural norms, and we provide a few numerical tests illustrating the behavior of the proposed augmented scheme and confirming our theoretical findings regarding optimal convergence of the approximate solutions.

To evaluate a method for measuring the cylinder, sphere, and wavefront of progressive addition lenses (PALs) in eyeglass frames.

The aim of this paper is to develop a finite element method which allows computing the buckling coefficients and modes of a non-homogeneous Timoshenko beam. Studying the spectral properties of a non-compact operator, we show that the relevant buckling coefficients correspond to isolated eigenvalues of finite multiplicity. Optimal order error estimates are proved for the eigenfunctions as well as a double order of convergence for the eigenvalues using classical abstract spectral approximation theory for non-compact operators. These estimates are valid independently of the thickness of the beam, which leads to the conclusion that the method is locking-free. Numerical tests are reported in order to assess the performance of the method.

Se presenta el caso de una mujer de 69 años de edad con colangitis aguda, debido a la compresión extrínseca de las vías biliares por el desarrollo de mieloma. El involucro del páncreas secundario a mieloma múltiple es poco común. La paciente se manejó con radioterapia. La reducción del tamaño del tumor y sin recidiva de la colangitis se observaron después de 12 meses.

In this study, we present and analyze a virtual element discretization for a nonselfadjoint fourth-order eigenvalue problem derived from the transmission eigenvalue problem. Using suitable projection operators, the sesquilinear forms are discretized by only using the proposed degrees of freedom associated with the virtual spaces. Under standard assumptions on the polygonal meshes, we show that the resulting scheme provides a correct approximation of the spectrum and prove an optimal-order error estimate for the eigenfunctions and a double order for the eigenvalues. Finally, we present some numerical experiments illustrating the behavior of the virtual scheme on different families of meshes.

Gastronomy is a fundamental pillar of tourism for visitors to discover the cultural heritage of the place they visit, thus turning culinary pleasures into determining motivations for the choice of destination and, simultaneously, an essential variable for the tourist satisfaction conformation of the travelling experience. This research aims to study the gastronomic experiences of travellers in different destinations. The investigation is based on fieldwork with 445 replies to a survey, and the results reveal the positive influence of culinary experiences on gastronomic satisfaction and loyalty to the destination, as well as an influence of gastronomic motivations on the value perceived and culinary experiences. In summary, gastronomic experiences form the backbone of the motivations and subsequent satisfaction and loyalty of travellers in a tourist destination.

The genus Rickettsiaencompasses 35 valid species of intracellular, coccobacilli bacteria that can infect several eukaryotic taxa, causing multiple emerging and re-emerging diseases worldwide. This work aimed to gather and summarise the current knowledge about the genus Rickettsiain Mexico, updating the taxonomy of the bacteria and their hosts by including all the records available until 2020, to elucidate host-parasite relationships and determine the geographical distribution of each Rickettsiaspecies present in the country. Until now, 14 species of Rickettsiabelonging to four groups have been recorded in Mexico. These species have been associated with 26 arthropod species (14 hard ticks, three soft ticks, two sucking lice, and seven fleas) and 17 mammal species distributed over 30 states in Mexico. This work highlights the high biological inventory of rickettsias for Mexico and reinforces the need to approach the study of this group from a One Health perspective.

Equatorial and Andean climate has no extreme temperatures; however, the region has a high diurnal oscillation. The government seeks to contribute to the improvement of housing conditions, which is mainly reflected in the emblematic housing program "Plan Casa para Todos" (PCT). PCT that aims to cover the social demand and reduce the qualitative housing deficit. It has been widely discussed that habitability and the housing deficit cannot be improved if the thermal conditions of dwellings and passive designed strategies are ignored, thus passive design principles, active devices, and renewable energy (RE) offer a way forward. Based on the hypothesis to bring out the possibility of reaching Net-Zero Energy Buildings (NZEB) in Quito, the objective is to develop a roadmap towards possible NZEBs. Inspired by genetic algorithms, optimization models were used to obtain the ideal NZEB for Quito. Simulations were carried using Python software with the calculating engine Energy Plus. First results show that the relationship towards the urban grid, the internal and spatial layout, thickness of walls, roof's sealing, among other factors, significantly affect the energy-efficiency as well as the thermal comfort conditions. Further research is required from the science-policy interface to apply NZEBs effectively.

Nitrate is of central importance in bacterial physiology. Previous studies indicated that movements toward nitrate are due to energy taxis, which is based on the cytosolic sensing of consequences of nitrate metabolism. Here we present the first report on nitrate chemotaxis. This process is initiated by specific nitrate binding to the periplasmic ligand binding domain (LBD) of McpN. Nitrate chemotaxis is highly regulated and occurred only under nitrate starvation conditions, which is helpful information to explore nitrate chemotaxis in other bacteria. We present the three-dimensional structure of the McpN-LBD in complex with nitrate, which is the first structure of a chemoreceptor PilJ-type domain. This structure reveals striking similarities to that of the abundant 4-helix bundle domain but employs a different sensing mechanism. Since McpN homologues show a wide phylogenetic distribution, nitrate chemotaxis is likely a widespread phenomenon with importance for the life cycle of ecologically diverse bacteria.

Genome analyses indicate that many bacteria possess an elevated number of chemoreceptors, suggesting that these species are able to perform chemotaxis to a wide variety of compounds. The scientific community is now only beginning to explore this diversity and to elucidate the corresponding physiological relevance. The discovery of histamine chemotaxis in the human pathogen Pseudomonas aeruginosaprovides insight into tactic movements that occur within the host. Since histamine is released in response to bacterial pathogens, histamine chemotaxis may permit bacterial migration and accumulation at infection sites, potentially modulating, in turn, quorum-sensing-mediated processes and the expression of virulence genes. As a consequence, the modulation of histamine chemotaxis by signal analogues may result in alterations of the bacterial virulence. As the first report of bacterial histamine chemotaxis, this study lays the foundation for the exploration of the physiological relevance of histamine chemotaxis and its role in pathogenicity.