Galerkin, Least-Squares and GLS numerical approaches for advective-diffussive transport problems in engineering

European Congress on Computational Methods in Applied Sciences and Engineering, Barcelona 11-14 september 2000[Abstract] In this paper, a study of three FE numerical formulations (Galerkin, Least Squares and Galerkin/Least Squares) applied to the convective-diffuse problem is presented, focusing our attention in high Péclet-number problems. The election of these three approaches is not arbitrary, but based on the relations among them. First, we review the causes of appearance of numerical oscillations when a Galerkin formulation is used. Contrasting with the nature of the Galerkin method, the Least Squares methos has a rigorous foundation on the basis of minimizing the square residual, which ensures best numerical results. However, this improvement in the numerical solution implies an increment of the computational cost, wich normally becomes unaffordable in practice. The last one, know as GLS, is based on a stabilization of the Galerkin Method. GLS can be interpreted as a combination of the last two methods, being one to solve convective problems, because it unifies the advantages of the Galerkin and Least Squares Methods and cancels its disadventages. For each numerical method, a brief review is presented, the continuity and derivability requirements on the trial functions are stablished, and the reasons of its behavior when the method is applied to the convection-diffusion problem with high velocity fields are examined. Furthermore, special attention will be devoted to the consequences of relaxing the variational requirements in the LS and GLS methods. Finally, several 1D and 2D examples are presented

Petrov-Galerkin and Galerkin/Least Squares stabilized approaches for advectivediffusive transport problems

[Abstract] The Finite Element method with a Galerkin type weighting is a straight-forward weighted residual method that has been sucessfuly used in many engineering applications, specially in Solid Mechanics. However, this method yields oscillatory solutions when it is applied to high-advective problems in Fluid Mechanics. Several stabilized numerical formulations have been proposed in the last years to overcome these inestabilities. The common methodology of most of these approaches is based on the addition of a term to the Galerkin formulation, in order to enhance the estability behaviour while preserving the weighting residual scheme. In this paper, we focus our attention in the Stream Upwind/Petrov Galerkin method (SUPG), and the Galerkin/least-squares method (GLS). We will review the mathematical formulation of both of them, as well as the key concept of their respective fundamentals and derivations, i.e. the exact artificial diffusion method for the SUPG and the Least Squares Finite Element method for the GLS. Finally, we will present a comparision between both methods, pointing out important coincidences and estabishing their mutual relations.Xunta de Galicia; PGDIT99MAR1180

Factores predictores del abandono de la intervención psicológica grupal en una muestra de pacientes con cáncer de mama

Analizar las variables socioeconómicas, médicas y de afrontamiento que predicen el abandono del tratamiento psicológico grupal en una muestra de pacientes recién diagnosticadas de cáncer de mama. La muestra consistió en 62 pacientes con cáncer de mama, que estaban realizando tratamiento oncológico y que fueron incorporadas a un programa de intervención psicológica grupal. En la entrevista previa a la incorporación se recogió información socioeconómica, médica y durante la primera sesión, se administró una batería de cuestionarios a las participantes (COPE, GHQ-12, EORTC-QLQ-C-3.0). A lo largo de las sesiones se registró la asistencia de las pacientes. Una vez finalizado el tratamiento, se dividió la muestra en dos grupos: pacientes que habían completado el grupo (asistencia de un mínimo del 60% de las sesiones), y pacientes que no lo habían completado. Se analizaron las diferencias entre los dos grupos y las variables que resultaron significativas en el análisis bivariante fueron introducidas en el modelo de regresión logística. La tasa de abandono obtenida en nuestro estudio fue del 27,5%. Las variables predoctoras del cumplimiento del tratamiento psicológico en el modelo de regresión logística fueron el emplear la planificación como estrategia de afrontamiento al estrés, y un mayor nivel educativo. La edad, el estado psicopatológico y la calidad de vida no resultaron variables relevantes en la predicción del abandono del tratamiento. El nivel educativo y el estilo de afrontamiento son variables importantes a tener en cuenta en los estudios sobre abandono en intervenciones psicológicas grupales dirigidas a pacientes con cáncer.Between these To examine the socioeconomic, medical and coping factors that may predict dropping out of group psychotherapy in a sample of women recently diagnosed of breast cancer. 62 breast cancer patients undergoing oncologic treatment and attended a group psychotherapy program were included in the study. In the assessment interview we obtained information about their socioeconomic and clinical situation. During the first group session, a battery of questionnaires (COPE, GHQ-12, EORTC-QLQ-C-3.0) we administered to the participants. Patient assistance to the sessions was registered throughout the treatment. The sample was divided into 2 groups at the end of treatment: patients who had completed the therapy (assistance to a minimum of 60% of the sessions) and those who did not reach this threshold of assistance. The differences 2 groups were analysed and logistic regression with significant variables in bivariant analysis was performed. Drop out rate observed in the study was 27’5%. Higher educational level and the use of planning as a coping strategy were associated with better psychotherapy compliance in the logistic regression model. Age, psychopathological state and quality of life did not show significance as predictors of dropping out of treatment. Educational level and coping strategies are important factors to take into account in further studies about drop out rates in group psychotherapies for cancer patients

Imported eosinophilic fever with myositis: A diagnostic challenge

A 39-year-old caucasian man presented to our hospital in Barcelona with fever, dry cough, headache and weight loss of 4 kg. Symptoms started 5 days after returning from a 21-day travel to Malaysia. His physical examination was unremarkable except for a splenomegaly. Laboratory tests showed mild elevation of transaminases, elevated levels of lactate dehydrogenase (468 UI/L) and a normal blood cell count. Blood cultures, thick and thin blood smear and serologic tests for dengue, chikungunya, HIV, cytomegalovirus, Epstein-Barr virus, herpes virus 6, parvovirus B19, Toxoplasma spp and Rickettsia conorii were negative

Factores predictores del abandono de la intervención psicológica grupal en una muestra de pacientes con cáncer de mama

Analizar las variables socioeconómicas, médicas y de afrontamiento que predicen el abandono del tratamiento psicológico grupal en una muestra de pacientes recién diagnosticadas de cáncer de mama. La muestra consistió en 62 pacientes con cáncer de mama, que estaban realizando tratamiento oncológico y que fueron incorporadas a un programa de intervención psicológica grupal. En la entrevista previa a la incorporación se recogió información socioeconómica, médica y durante la primera sesión, se administró una batería de cuestionarios a las participantes (COPE, GHQ-12, EORTC-QLQ-C-3.0). A lo largo de las sesiones se registró la asistencia de las pacientes. Una vez finalizado el tratamiento, se dividió la muestra en dos grupos: pacientes que habían completado el grupo (asistencia de un mínimo del 60% de las sesiones), y pacientes que no lo habían completado. Se analizaron las diferencias entre los dos grupos y las variables que resultaron significativas en el análisis bivariante fueron introducidas en el modelo de regresión logística. La tasa de abandono obtenida en nuestro estudio fue del 27,5%. Las variables predoctoras del cumplimiento del tratamiento psicológico en el modelo de regresión logística fueron el emplear la planificación como estrategia de afrontamiento al estrés, y un mayor nivel educativo. La edad, el estado psicopatológico y la calidad de vida no resultaron variables relevantes en la predicción del abandono del tratamiento. El nivel educativo y el estilo de afrontamiento son variables importantes a tener en cuenta en los estudios sobre abandono en intervenciones psicológicas grupales dirigidas a pacientes con cáncer

Positive direct antiglobulin test in post-artesunate delayed haemolysis: more than a coincidence?

Background: Delayed haemolysis is a frequent adverse event after treatment with artesunate (AS). Removing onceinfected “pitted” erythrocytes by the spleen is the most accepted mechanism of haemolysis in these cases. However, an increasing number of cases with positive direct antiglobulin test (DAT) haemolysis after AS have been reported. Methods: All malaria cases seen at Hospital Clinic of Barcelona between 2015 and 2017 were retrospectively reviewed. Clinical, parasitological and laboratory data from patients treated with intravenous artesunate—specifcally looking for delayed haemolysis and DAT—was collected. Results: Among the 36 severe malaria patients treated with artesunate at the hospital, 10 (27.8%) developed postartesunate delayed haemolysis. Out of these, DAT was performed in six, being positive in four of them (at least 40%). DAT was positive only for complement—without IgG—suggesting drug-dependent immune-haemolytic anaemia of the immune-complex type. Three of the four patients were treated with corticosteroids and two also received blood transfusion, with a complete recovery. Conclusions: Drug-induced auto-immune phenomena in post-artesunate delayed haemolysis may be underre‑ ported and must be considered. The role of corticosteroids should be reassessed

Positive direct antiglobulin test in post-artesunate delayed haemolysis: more than a coincidence?

BACKGROUND: Delayed haemolysis is a frequent adverse event after treatment with artesunate (AS). Removing once-infected 'pitted' erythrocytes by the spleen is the most accepted mechanism of haemolysis in these cases. However, an increasing number of cases with positive direct antiglobulin test (DAT) haemolysis after AS have been reported. METHODS: All malaria cases seen at Hospital Clinic of Barcelona between 2015 and 2017 were retrospectively reviewed. Clinical, parasitological and laboratory data from patients treated with intravenous artesunate-specifically looking for delayed haemolysis and DAT-was collected. RESULTS: Among the 36 severe malaria patients treated with artesunate at the hospital, 10 (27.8%) developed post-artesunate delayed haemolysis. Out of these, DAT was performed in six, being positive in four of them (at least 40%). DAT was positive only for complement-without IgG-suggesting drug-dependent immune-haemolytic anaemia of the immune-complex type. Three of the four patients were treated with corticosteroids and two also received blood transfusion, with a complete recovery. CONCLUSIONS: Drug-induced auto-immune phenomena in post-artesunate delayed haemolysis may be underreported and must be considered. The role of corticosteroids should be reassessed

Post-splenectomy acute glomerulonephritis due to a chronic infection with Plasmodium falciparum and malariae

A 38-year-old Senegalese man with no previous medical history and living in Spain since 2004 was admitted due to fever, hypotension and edemas. The patient had not traveled to malaria endemic areas for the last 2 years, and 43 days before this episode he underwent an elective splenectomy in order to rule out a hematologic neoplasm due to a 27-cm splenomegaly and pancytopenia

Sporotrichoid dissemination of cutaneous leishmaniasis possibly triggered by a diagnostic puncture

Case report: A 31 year old Spanish woman attended Hospital Clinic in Barcelona in August 2018, after working in La Paz (Bolivia) for six months. She remembered an insect bite on her right thigh, during a trip to Beni (Brazilian border) with progression to a papule with a central crater within one month. Treatment with oral moxicillin/clavulanic acid yielded no improvement. Thereupon, a diagnostic puncture of the ulcer was performed, with a positive result of polymerase chain eaction (PCR) for Leishmania spp. without bacterial isolates in the culture. She then decided to return to Spain for management

Mirroring the Zika epidemics in Cuba: The view from a European imported diseases clinic

Dear Editor, the changing epidemiology of Zika virus infection has been described before and in this letter we would like to show how the local epidemiology of Zika in Cuba is reflected in imported cases in returning travellers to Barcelona. The spread of the 2015 Zika epidemic was mostly reported in South America and the Caribbean. While increasing numbers of cases raised in South-America, Cuba was still free of cases. On 2nd March 2016 the first imported case from Cuba (Artemisa province) was reported. The first autochthonous case was reported on 16th March 2016 in La Habana. Onwards, cases were reported in Camagüey, Cienfuegos, Guantánamo, Havana and Santiago. During 2017 transmission has been reported in municipalities of Arroyo Naranjo and Regla in the province of Havana