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Rapporto interno del Dipartimento di Matematica del Politecnico di Torino, N. 4, marzo 201

La mirada de Paul Beer a las casas modernas en Bogotá

El legado fotográfico de Paul Beer es un testimonio fundamental y fuente de investigación y de documentación de la arquitectura doméstica en Bogotá, en su mayoría inexistente en la actualidad. Gracias al trabajo del fotógrafo en Colombia entre 1948 y 1965, disponible en el archivo de Bogotá, se pueden identificar una serie de características de la imagen que se promovía de la arquitectura doméstica bogotana a mediados de siglo XX. A través de secuencias visuales que estructuran un recorrido por la casa desde la calle hasta el jardín, la “manera de ver” de Paul Beer permite analizar no sólo su espacialidad, sino los elementos suficientes para comprender la evolución y consolidación de un imaginario doméstico y el “lifestyle” que las firmas de arquitectos pretendían transmitir en un momento decisivo de modernización del país, mostrando la espacialidad, las aspiraciones y los valores formales que caracterizaron en este momento la casa moderna bogotana.The photographic legacy of Paul Beer is a fundamental source of testimony and documental research of domestic architecture in Bogota, mostly nonexistent today. Thanks to Beer’s work in Colombia between 1948 and 1965, available in “Archivo de Bogotá”, it can identify features in the image that was promoted by the Bogota domestic architecture in the midtwentieth century. Paul Beer’s “way of seeing” is a way to analyze not only the spatiality but enough elements to understand the evolution and consolidation of a domestic imaginary and the “lifestyle” promoted by the most prestigious firms of architects, through visual sequences that structure a tour of the house, from the street to the garden. It showed a decisive moment of modernization of the country, showing spatiality, aspirations and formal values that characterized the Bogota modern house

La ciudad desde el aire: vistas aéreas y “vedutas” del centro de Bogotá

El retrato de ciudad desde el aire, a vuelo de pájaro o a través del vedutismo, es un género de “fotografía urbana dibujada” que surge en Europa a principios del siglo XVI con la Tavola Strozzi de Nápoles de 1472. Las vedutas tendrán una época de esplendor con destacados pintores urbanos del siglo XVIII como Gaspar van Wittel (1653-1736), precursor de la tradición del Vedutismo y de pintores como Canaletto (1697-1768) o Francesco Guardi (1712-1793). Las representaciones urbanas de ciudad, panorámicas o parciales, han permitido mostrar según las distancias y alturas, las relaciones con la geografía y el paisaje, las estructuras, tramas, vida urbana, calles, edificios y habitantes. Con el tiempo, la fotografía ha ido complementando y también sustituyendo las vistas oblicuas, a vuelo de pájaro y las vedutas urbanas dibujadas, por la facilidad de capturar imágenes desde puntos altos a través de una ventana, desde una terraza, un globo, un avión, o incluso Google Earth. En Bogotá, las vistas realizadas por el Instituto Geográfico Agustín Codazzi (IGAG), las tomas de los fotógrafos-aviadores Saúl Ordúz y Rudolph, y las vedutas urbanas de fotógrafos como Armando Matiz, entre 1950 y 1970, conforman un conjunto de miradas desde el aire y a diferentes alturas. Una colección de “vistas y vedutas modernas”, que testimonian la evolución urbana y además revelan ante una mirada atenta, como la arquitectura moderna reconfiguro el centro de la ciudad, con transformaciones donde se agrupan nuevos edificios y espacios urbanos con históricos y emblemáticos. Un caso destacable de esto, son los espacios centrales a lo largo de la carrera Séptima: la Plaza de Bolívar, el Parque Santander y el Centro Internacional.Portrait city from aerial views, through “vedutismo”, is a genre of “urban photography drawn” that emerged in Europe in the early sixteenth century with the Strozzi Tavola city of Naples in 1472. The vedutas will have a heyday with outstanding urban eighteenth-century painters as Caspar van Wittel (1653-1736), forerunner of the tradition of vedutismo and painters such as Canaletto (1697-1768) and Francesco Guardi (1712-1793). Urban representations city, panoramic or partial, have enabled display for distances and heights, city relations with geography and landscape, structures and urban plots or urban life, the streets and buildings and its inhabitants. Over time, photography has been complementing and replacing the oblique views, a bird and urban vedutas drawn by the ability to capture images from high points through a window, a terrace, a balloon, a plane , and even Google Earth. In Bogota, the views held by the IGAC (Instituto Geográfico Agustín Codazzi), takes photographers-aviators Saul Orduz and Rudolph, and urban vedutas of photographers like Leo and Armando Matiz, between 1950 and 1970, make up a set of looks from the air at different heights. A collection of “modern vedutas” which testify to the urban evolution and also reveal to a careful look as modern architecture reconfigure the city center, with transformations where new buildings and urban spaces with historical and emblematic are grouped. A case of this are the central spaces along the Seventh race: Bolivar square, Santander Park and International Center

Electronic structure and ferroelectricity in SrBi2Ta2O9

The electronic structure of SrBi2Ta2O9 is investigated from first-principles, within the local density approximation, using the full-potential linearized augmented plane wave (LAPW) method. The results show that, besides the large Ta(5d)-O(2p) hybridization which is a common feature of the ferroelectric perovskites, there is an important hybridization between bismuth and oxygen states. The underlying static potential for the ferroelectric distortion and the primary source for ferroelectricity is investigated by a lattice-dynamics study using the Frozen Phonon approach.Comment: 17 pages, 7 figures. Phys. Rev. B, in pres

Hsa-miR-155-5p Up-Regulation in Breast Cancer and Its Relevance for Treatment With Poly[ADP-Ribose] Polymerase 1 (PARP-1) Inhibitors

miR-155-5p is a well-known oncogenic microRNA, showing frequent overexpression in human malignancies, including breast cancer. Here, we show that high miR-155-5p levels are associated with unfavorable prognostic factors in two independent breast cancer cohorts (CSS cohort, n = 283; and TCGA-BRCA dataset, n = 1,095). Consistently, miR-155-5p results as differentially expressed in the breast cancer subgroups identified by the surrogate molecular classification in the CSS cohort and the PAM50 classifier in TCGA-BRCA dataset, with the TNBC and HER2-amplified tumors carrying the highest levels. Since the analysis of TCGA-BC dataset also demonstrated a significant association between miR-155-5p levels and the presence of mutations in homologous recombination (HR) genes, we hypothesized that miR-155-5p might affect cell response to the PARP-1 inhibitor Olaparib. As expected, miR-155-5p ectopic overexpression followed by Olaparib administration resulted in a greater reduction of cell viability as compared to Olaparib administration alone, suggesting that miR-155-5p might induce a synthetic lethal effect in cancer cells when coupled with PARP-1-inhibition. Overall, our data point to a role of miR-155-5p in homologous recombination deficiency and suggest miR-155-5p might be useful in predicting response to PARP1 inhibitors in the clinical setting

Measurements of the reaction pˉp→ϕη\bar{p}p \to \phi \eta of antiproton annihilation at rest at three hydrogen target densities

The proton-antiproton annihilation at rest into the $\phi\eta$ final state was measured for three different target densities: liquid hydrogen, gaseous hydrogen at NTP and at a low pressure of 5 mbar. The yield of this reaction in the liquid hydrogen target is smaller than in the low-pressure gas target. The branching ratios of the $\phi\eta$ channel were calculated on the basis of simultaneous analysis of the three data samples. The branching ratio for annihilation into $\phi\eta$ from the $^3S_1$ protonium state turns out to be about ten times smaller as compared to the one from the $^1P_1$ state.Comment: 10 pages, 3 Postscript figures. Accepted by Physics Letters

New data on OZI rule violation in bar{p}p annihilation at rest

The results of a measurement of the ratio R = Y(phi pi+ pi-) / Y(omega pi+ pi-) for antiproton annihilation at rest in a gaseous and in a liquid hydrogen target are presented. It was found that the value of this ratio increases with the decreasing of the dipion mass, which demonstrates the difference in the phi and omega production mechanisms. An indication on the momentum transfer dependence of the apparent OZI rule violation for phi production from the 3S1 initial state was found.Comment: 11 pages, 3 PostScript figures, submitted to Physics Letter