La Northern Avenue a Yerevan e il piano urbanistico di Tamanian

A differenza di molte altre capitali dei paesi dell'area, come la vicina Tbilisi, che in anni recenti ha ceduto alla fascinazione e alle suggestioni di architetture spettacolari, perlopiù estranee al contesto, alla geografia ed al tessuto urbano, o di Baku, dove il restauro della città vecchia ha aperto le porte alla realizzazione di un gran numero di cattedrali dell’architettura globalizzata, Yerevan sta perseguendo, autonomamente e in controtendenza rispetto ai vicini, un proprio modello di sviluppo urbano, non incentrato sull’alterità e il conflitto con l’esistente, ma basato in gran parte sugli indirizzi contenuti nel piano di Alexander Tamanian del 1924.In contrast with its neighbour Tbilisi, which in recent years has yielded to the fascination and charm of spectacular architecture, mostly out of context, geography and urban fabric, or from Baku, where the restoration of the Old Town has opened up the doors to the realization of a large number of archistar-made buildings, Yerevan is pursuing an own model of urban development, not focused on the conflict with the existing fabric, but largely based on the addresses contained in the 1924 plan by Alexander Tamanian

Diseño de hipertextos en matemática para estudiantes de ingeniería

En el presente reporte de investigación sintetizamos algunas reflexiones relativas al diseño de hipertextos sobre temas de matemática destinados a alumnos de primer año universitario, objeto de estudio de nuestra línea de investigación. Los puntos a analizar versan sobre la planificación de dos hipertextos, uno sobre funciones trascendentes y el otro sobre el método de Newton Raphson para el cálculo de raíces. Como colofón del reporte presentamos algunas reflexiones sobre el diseño de hipertextos para nivel educativo superior, surgida del análisis realizado y de nuestra experiencia investigativa

Actividades de cálculo diferencial con computadora: estudio de habilidades matemáticas desarrolladas

El presente artículo reporta un estudio transeccional descriptivo sobre el desarrollo de habilidades matemáticas así como la relación de éstas con actividades matemáticas y contenidos específicos. Analizamos producciones escritas de estudiantes de carreras de ingeniería que realizan su primer curso de Cálculo Diferencial. Para esta experiencia han trabajado en un taller usando el software Mathematica. Describimos los criterios considerados para la clasificación de las actividades y habilidades, los instrumentos para la evaluación y el procesamiento de los datos. En las conclusiones establecemos relaciones entre tipos de actividades y habilidades promovidas y nos referimos al rol del software en la enseñanza y en el aprendizaje de la introducción al Cálculo Diferencial. Finalmente mediante el análisis estadístico descriptivo y el de componentes principales reforzamos la hipótesis de que una habilidad debe medirse en estrecha dependencia con el contenido y la tarea realizada

Sol–gel synthesis and characterization of Co-doped LSGM perovskites

One of the major requirements for the development and commercialization of low-cost SOFCs is the reduction in the operating temperature. One of the methods to reach this aim is the use of solid electrolytes which exhibit superior ionic conductivity at intermediate temperatures (IT, T < 800 °C). Among these ionic conductors, doped LaGaO3 materials show high oxide ionic conductivity in the 600–800 °C range. These perovskites are usually prepared by time- and energy-consuming solid state reaction. In this paper, La0.8Sr0.2Ga0.8Mg0.2O2.8 (LSGM) and La0.8Sr0.20Ga0.8Mg0.2−xCoxO3−δ (LSGMC) powders containing different amounts of Co (x = 0.05, 0.085 and 0.10) were prepared from precursors synthesised by citrate sol–gel method. The precursors were calcined at 1000 °C (10 h) and dense high-purity pellets were obtained by pressing (300 MPa) and sintering in air at 1475 °C (5, 10 and 20 h). Sintered pellets of LSGM and LSGMC contained very small amounts (<1%) of SrLaGa3O7 and SrLaGaO4, respectively, as detected by X-ray diffraction (XRD) and by the combined use of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The data clearly showed the feasibility of sol–gel methods to produce Co-doped LSGM perovskite type oxides

Sol–gel synthesis, X-ray photoelectron spectroscopy and electrical conductivity of Co-doped (La, Sr)(Ga, Mg)O3−δ perovskites

La0.8Sr0.2Ga0.8Mg0.2−xCoxO3−δ (LSGMC) powders containing different amounts of Co (x = 0.05 and 0.085) were prepared by a citrate sol–gel method. The powders were used to prepare highly phase-pure LSGMC sintered pellets with controlled composition and fractional densities larger than 95%. For the first time, LSGMC materials were subjected to X-ray photoelectron spectroscopy (XPS) characterization. XPS data confirmed the presence of the dopants in the material and allowed to identify two different chemical states for Sr2+ and oxygen, both related to the oxygen-deficient perovskite structure of LSGMC. The conductivity of LSGMC sintered pellets containing different amounts of Co ions in the B sites of the perovskite lattice was assessed by electrochemical impedance spectroscopy (EIS) in the 250–750 °C temperature range. Conductivity values and apparent activation energies were in good agreement with previously published data referring to materials with same composition, but prepared by solid-state route. Therefore, the physicochemical and electrochemical characterization clearly demonstrated the ability of sol–gel methods to produce high-purity Co-doped LSGM perovskites, which represent promising solid electrolytes for intermediate-temperature SOFCs

Using Topological Data Analysis for diagnosis pulmonary embolism

Pulmonary Embolism (PE) is a common and potentially lethal condition. Most patients die within the first few hours from the event. Despite diagnostic advances, delays and underdiagnosis in PE are common.To increase the diagnostic performance in PE, current diagnostic work-up of patients with suspected acute pulmonary embolism usually starts with the assessment of clinical pretest probability using plasma d-Dimer measurement and clinical prediction rules. The most validated and widely used clinical decision rules are the Wells and Geneva Revised scores. We aimed to develop a new clinical prediction rule (CPR) for PE based on topological data analysis and artificial neural network. Filter or wrapper methods for features reduction cannot be applied to our dataset: the application of these algorithms can only be performed on datasets without missing data. Instead, we applied Topological data analysis (TDA) to overcome the hurdle of processing datasets with null values missing data. A topological network was developed using the Iris software (Ayasdi, Inc., Palo Alto). The PE patient topology identified two ares in the pathological group and hence two distinct clusters of PE patient populations. Additionally, the topological netowrk detected several sub-groups among healthy patients that likely are affected with non-PE diseases. TDA was further utilized to identify key features which are best associated as diagnostic factors for PE and used this information to define the input space for a back-propagation artificial neural network (BP-ANN). It is shown that the area under curve (AUC) of BP-ANN is greater than the AUCs of the scores (Wells and revised Geneva) used among physicians. The results demonstrate topological data analysis and the BP-ANN, when used in combination, can produce better predictive models than Wells or revised Geneva scores system for the analyzed cohortComment: 18 pages, 5 figures, 6 tables. arXiv admin note: text overlap with arXiv:cs/0308031 by other authors without attributio

Osservazioni sul paradigma dei learning object

No abstract availabl

Multidisciplinary approach to the forensic identification of a late discovery victim of a motorcycle accident

This paper presents a case of a late discovery of a motorcycle accident victim. The fact that the remains were almost skeletonized required the input of several disciplines in order to identify the victim. Therefore, anthropology, odontology, facial reconstruction, and genetics were employed. It was found that the victim was male, between the ages of 35 to 55 with a number of healed fractures. In addition, perimortem trauma with a pattern that was consistent with a motorcycle accident was found in the head and upper body regions. Dental findings included a tooth out of alignment with the rest of the dental arcade, as well as a heavily decayed tooth that was replaced by a dental bridge. Both of these findings were supported by ante mortem photographs of the victim. A two-dimensional facial reconstruction was carried out and produced a very good likeness of the deceased. The above findings were confirmed by DNA analysis that matched a bone sample to those of the family of the deceased. This case illustrates the benefits of combining several different methods to make an initial assessment of a case and narrow the list of potential candidates. This can help speed up the process of identification and save resources for law enforcement agencies

Avaliação do risco cardiovascular em pacientes obesos hipertensos com síndrome metabólica: estudo ARCOS

Weight loss improves metabolic abnormalities and reduces cardiovascular risk in obese hypertensive patients. To evaluate the impact of a sustained weight loss on coronary risk, 181 hypertensive patients with metabolic syndrome underwent to orlistat therapy, 120 mg, t.i.d., plus diet for 36 weeks. During therapy, Framingham risk scores (FRS) were calculated for determination of coronary heart disease risk in ten years. Body mass index decreased from 35.0 ± 4.2 to 32.6 ± 4.5 kg/m² (p 5% occurred in 64.6% of all patients, associated with improvement in glucose metabolism. Among those with abnormal glucose metabolism, 38 out 53 patients (71.7%) improved their glucose tolerance (p 5% em 64,6% de todos os pacientes, associada com melhora no metabolismo da glicose. Entre os 53 pacientes com metabolismo de glicose anormal, 38 (71,7%) melhoraram sua tolerância à glicose (p< 0,0005). Em conclusão, terapia de longa duração com orlistat auxilia a reduzir e manter mais baixo o peso corpóreo, reduzindo o risco de doença coronária e melhorando o metabolismo da glicose e protegendo, dessa maneira, contra o diabetes tipo 2.Federal University of São Paulo Divisions of EndocrinologyFederal University of São Paulo Division of NephrologyInstituto Dante Pazzaneze de Cardiologia Service of CardiologyRoche LaboratoriesUNIFESP, Divisions of EndocrinologyUNIFESP, Division of NephrologySciEL