Spectral/hp element methods: recent developments, applications, and perspectives

The spectral/hp element method combines the geometric flexibility of the classical h-type finite element technique with the desirable numerical properties of spectral methods, employing high-degree piecewise polynomial basis functions on coarse finite element-type meshes. The spatial approximation is based upon orthogonal polynomials, such as Legendre or Chebychev polynomials, modified to accommodate C0-continuous expansions. Computationally and theoretically, by increasing the polynomial order p, high-precision solutions and fast convergence can be obtained and, in particular, under certain regularity assumptions an exponential reduction in approximation error between numerical and exact solutions can be achieved. This method has now been applied in many simulation studies of both fundamental and practical engineering flows. This paper briefly describes the formulation of the spectral/hp element method and provides an overview of its application to computational fluid dynamics. In particular, it focuses on the use the spectral/hp element method in transitional flows and ocean engineering. Finally, some of the major challenges to be overcome in order to use the spectral/hp element method in more complex science and engineering applications are discussed

DEMON: a Proposal for a Satellite-Borne Experiment to study Dark Matter and Dark Energy

We outline a novel satellite mission concept, DEMON, aimed at advancing our comprehension of both dark matter and dark energy, taking full advantage of two complementary methods: weak lensing and the statistics of galaxy clusters. We intend to carry out a 5000 sqdeg combined IR, optical and X-ray survey with galaxies up to a redshift of z~2 in order to determine the shear correlation function. We will also find ~100000 galaxy clusters, making it the largest survey of this type to date. The DEMON spacecraft will comprise one IR/optical and eight X-ray telescopes, coupled to multiple cameras operating at different frequency bands. To a great extent, the technology employed has already been partially tested on ongoing missions, therefore ensuring improved reliability.Comment: 12 pages, 3 figures, accepted for publication in the SPIE conference proceeding

Surgical treatment in acromegaly: Experience in Córdoba

La acromegalia tiene una prevalencia de 35-70/millón. La cirugía transesfenoidales el tratamiento de elección, siendo la tasa de remisión del 80% en microadenomas y 50% en macroadenomas. Debido a la falta de registros, nos propusimos evaluar los resultados quirúrgicos en Córdoba y determinar factores predictivos de remisión.Métodos: Estudio retrospectivo-descriptivo de pacientes con cirugía como primera línea terapéutica. Criterios de remisión: normalización de IGF1 para edad/sexo, con GH ≤1,0 g/L.TestX2 y test exacto de Fisher y p<0,05.Resultados:Se incluyeron 38 pacientes: 61% mujeres y 39% hombres; edad promedio 45 años. Motivos de consulta más frecuentes: cefalea y crecimiento acral (26%), alteraciones visuales (20%). El 84% de los tumores fueron macroadenomas. De 37 pacientes, 54% se sometierona cirugía microscópica, 38% endoscópica y 8% transcraneal. El 29% evidenció complicaciones postquirúrgicas, siendo la diabetes insípida la más frecuente (10%). El porcentaje de las mismas fue: cirugía transcraneal el 33%, endoscópica 29% y microscópica 25% (p= 0,557). La remisión bioquímica a los 6 meses fue de 34% y a los 12 meses 55% (p=0,0001). Sin diferencias significativas entre la vía endoscópica y microscópica (p=0,071). De 36 pacientes el 31% evidenció resección tumoral completa. La mejoría clínicasubjetiva fue del 88%. No hubo factores predictivos de remisión bioquímica estadísticamente significativos. La remisión bioquímica con la cirugía fue similar a la bibliografía. No encontramos factores predictivos deremisión pero un número mayor de casos podría modificar estos resultadosAcromegaly prevalence is 35-70 / million. Transsphenoidal surgery is the first-line treatment, with a remission rate of 80% for microadenomas and 50% for macroadenomas. Our aim was to evaluate the surgical results in Córdoba and determine predictive remission factors due to the lack of records. Methods: Retrospective-descriptive study of patients with surgery as the first therapeutic line. Remission criteria: IGF1 normalization for age/sex, with GH ≤1.0 g/L. Test X2 and Fisher´s exact test with p<0.05. Results: 38 patients were included: 61% women and 39% men; Average age 45 years. Most frequent chief complaint: headache and acral growth (26%), visual disturbances (20%). Macroadenomas were the 84% of the tumors. Of 37 patients, 54% underwent microscopic surgery, 38% endoscopic and 8% transcranial. The 29% of patients showed post-operative complications and diabetes insipidus was the most frequent (10%). The percentage of them was: 33% transcranial surgery, 29% endoscopic and 25% microscopic (p = 0.557). The biochemical remission at 6 months was 34% and at 12 months 55% (p= 0.0001). No significant differences between the endoscopic and microscopic approach (p = 0.071). Of 36 patients, 31% showed complete tumor resection. The subjective clinical improvement was 88%. There weren´t predictive remission factors with significant differences. Conclusion: The surgical biochemical remission was similar to the bibliography. We didn´t find predictive remission factors but a larger number of patients could modify these results.Key words: acromegaly; neurosurgery; postoperative complications; remission inductionFil: Rendón, Matilde Inés. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Cecenarro, Laura Anahi. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Andrada, Marta Cecilia. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Barovero, Mariela Susana. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Bertolino, María Lorena. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Cagliolo, Mariela. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Carpentieri, Agata Rita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Damilano, Roxana Analía. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: De Battista, Juan Carlos. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Estario, Paula. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Fernández, Silvia. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Marquez, Maria Eugenia. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Monteserin, Natalia. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Quintero, María Lorena. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Sala, Claudia Susana. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Sosa, Gabriela Alejandra. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Surraco, María Elena. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: de Paul, Ana Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Szafryk de Mereshian, Paula Maria. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; ArgentinaFil: Fux Otta, Carolina. Departamento Neuroendocrinología. Sociedad de Endocrinología y Metabolismo de Córdoba; Argentin

Genotypes of Mycobacterium tuberculosis in patients at risk of drug resistance in Bolivia

Bolivia ranks among the 10 Latin American countries with the highest rates of tuberculosis (TB) and multidrug resistant (MDR) TB. In view of this, and of the lacking information on the population structure of Mycobacterium tuberculosis in the country, we explored genotype associations with drug resistance and clustering by analyzing isolates collected in 2010 from 100 consecutive TB patients at risk of drug resistance in seven of the nine departments in which Bolivia is divided. Fourteen isolates were MDR, 29 had other drug resistance profiles, and 57 were pansusceptible. Spoligotype family distribution was: Haarlem 39.4%, LAM 26.3%, T 22.2%, S 2.0%, X 1.0%, orphan 9.1%, with very low intra-family diversity and absence of Beijing genotypes. We found 66 different MIRU-VNTR patterns; the most frequent corresponded to Multiple Locus Variable Analysis (MLVA) MtbC15 patterns 860, 372 and 873. Twelve clusters, each with identical MIRU-VNTR and spoligotypes, gathered 35 patients. We found no association of genotype with drug resistant or MDR-TB. Clustering associated with SIT 50 and the H3 subfamily to which it belongs (p < 0.0001). The largest cluster involved isolates from three departments and displayed a genotype (SIT 50/MLVA 860) previously identified in Bolivian migrants into Spain and Argentina suggesting that this genotype is widespread among Bolivian patients. Our study presents a first overview of M. tuberculosis genotypes at risk of drug resistance circulating in Bolivia. However, results should be taken cautiously because the sample is small and includes a particular subset of M. tuberculosis population.Fil: Monteserin, Johana. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Camacho, Mirtha. Ministerio de Salud y Deportes. Instituto Nacional de Laboratorios de Salud. Laboratorio de Referencia Nacional de Vigilancia y Control de Tuberculosis; BoliviaFil: Barrera, Lucía. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; ArgentinaFil: Palomino, Juan Carlos. University of Ghent; BélgicaFil: Ritacco, Gloria Viviana. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martin, Anandi. University of Ghent; Bélgic

Combined approach to the identification of clinically infrequent non-tuberculous mycobacteria in Argentina

SETTING: Over 150 potentially pathogenic non-tuberculous mycobacteria (NTM) species have been described, posing an onerous challenge for clinical laboratory diagnosis. OBJECTIVE: To evaluate different approaches for the identification of 40 clinically relevant NTM isolates whose species were not reliably identified using our routine diagnostic workflow comprising phenotypic tests and hsp65 polymerase chain reaction restriction analysis. DESIGN: We used 1) sequencing analysis of four conserved gene targets: 16S rRNA, rpoB, hsp65 and sodA; 2) two commercial reverse hybridisation assays; and 3) protein analysis using matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF MS). RESULTS: Combined, but not individual, sequence analysis allowed reliable species identification for 30/ 40 (75%) isolates, including species previously unknown to be circulating in Argentina. Commercial kits outperformed our routine identification in only 5/35 isolates, and misclassified many more. MALDI-TOF MS accurately identified species in 22/36 (61%) isolates and did not misidentify any. CONCLUSIONS: Commercial kits did not resolve the problem of species of NTM isolates that elude identification. Combined DNA sequence analysis was the approach of choice. MALDI-TOF MS shows promise as a powerful, rapid and accessible tool for the rapid identification of clinically relevant NTM in the diagnostic laboratory, and its accuracy can be maximised by building up a customised NTM spectrum database