Vasculitides are a broad group of diseases that can involve any kind of vessel in any organ. These can be classified according to the size of the affected vessels. The most used classification categorizes them in small, medium, and large vessel vasculitis. Large vessel vasculitis can be further divided in Takayasu arteritis and giant cell arteritis which can sometimes be indistinguishable, even with biopsy. Radiology plays an important role identifying distribution patterns and disease extension18. Fluorine-Fluorodeoxyglucose (FDG) PET-CT shows increased vessel wall FDG uptake in patients with active large vessel vasculitis. Multiple studies show that FDG PET-CT helps to identify the anatomic structures with the disease, as well as evaluate its progression with a high sensibility and specificity in non-treated patients with large vessel vasculitis.

No dia 12/12/92, durante o experimento de campo TOGA-COARE (Tropical Ocean Global Atmosphere-Coupled Ocean-Atmosphere Response Experiment) uma missão foi efetuada, detectando uma região de convecção a NE da zona chamada de "Intensive Flux Array " (IFA: 1ºN-4ºS, 151-158ºE). Essa região caracterizava-se por apresentar uma circulação ciclônica nos baixos níveis e um fluxo divergente de NE em altitude, caracterizando a atividade convectiva do sistema. A análise das imagens no canal infravermelho do satélite GMS-4 indicava uma discreta propagação do sistema em direção a sudoeste. Os dois aviões WP-3D da "National Oceanic and Atmospheric Administration" (NOAA), utilizando a técnica de varredura FAST (Fore/Aft Scanning Technique), descreveram trajetórias paralelas coordenadas, primeiramente ao longo da linha convectiva e em seguida dentro da região estratiforme do sistema. Os dados de radares Doppler coletados durante essa missão mostravam a existência de células convectivas moderadas, localizadas dentro de uma área de precipitação estratiforme, e células convectivas mais intensas localizadas a sudoeste do sistema. A combinação das porções paralelas das trajetórias de cada avião foi utilizada para restituir o campo de vento 3D, usando a técnica variacional EODD (Extended Overdetermined Dual-Doppler). O campo de vento 3D, derivado dos dados de radar, serviu para estudar as características do sistema observado e para examinar a estrutura dos transportes de quantidade de movimento operado pelo sistema. A estrutura cinemática do sistema mostrou características clássicas, com um fluxo ascendente na frente do sistema que transporta o ar das camadas inferiores para o alto e um fluxo descendente atrás da linha convectiva. Os resultados para os transportes de quantidade de movimento também mostraram características similares a outros casos estudados anteriormente, tais como: (i) o transporte vertical de quantidade de movimento horizontal perpendicular à linha convectiva é amplificador do gradiente, resultando no aumento do seu cisalhamento vertical; (ii) para a componente paralela (v), a divergência vertical do fluxo v reduziu o seu cisalhamento vertical, gerando um transporte redutor do gradiente.

On December 12 1992, during TOGA-COARE (Tropical Ocean Global Atmosphere - Coupled Ocean-Atmosphere Response Experiment), enhanced convection was observed in the northeast of the COARE Intensive Flux Array (IFA: 1ºN-4ºS, 151-158ºE), occurring in a broad cyclonic flow at low levels and divergent northeasterly flow at upper levels. Satellite IR (Infra Red) pictures revealed scattered Class 2/3 convection, and indicated a discrete propagation toward southwest. Radar observations from two NOAA WP-3D aircrafts showed moderated convective cells, located in a stratiform precipitation region, and stronger convective cells in the southwest part of the system. During the two-plane mission, several "quad-Doppler" observations were obtained from the four-pattern legs described by each aircraft, first along the convective line and after in the stratiform part of the system. Combination of parallel portions of these aircraft flight tracks was made to synthesize the 3D wind fields, using the Extended Overdetermined Dual-Doppler technique (EODD). These radar-derived wind fields serve to highlight the main characteristics of the observed system and to examine the momentum transports occuring in the system. The derived airflow structure shows classical characteristics, with an updraft flow in front of the system transporting low-level air to high levels and a downdraft airflow in the rear. The results to the momentum transports reveals that this system presents similar features of previously observed ones, such as: (i) the vertical transport of horizontal momentum normal to the convective line is countergradient resulting in a increase of its vertical shear; (ii) the vertical transport of line-parallel wind (v) is downgradient because the vertical divergence of the vertical v-momentum flux decreases the v-shear.

Abstract Mexico City's air is highly contaminated by a mixture of gases (especially ozone) and particles. In 1994, the average of all emitted contaminants was about 7.3 tons/day/km2 . The high levels of air contamination can lead to the premature death of people, while causing alterations in a large portion of the exposed people and clearly lowering the quality of life. Adverse effects in the health of children and an increase of the cancer rate have been discussed. In 1994, traffic was responsible for 75% of the emitted pollutants in Mexico City. Consequently we propose and exemplify the introduction of an inductive tax and subsidy system to favor the purchase of electric cars with zero emission, while discouraging the purchase of gasoline cars. In this system, the government would not earn additional taxes, while correcting efficiently the market failure of not providing the non-market good "clean air".

Resumen El aire en la Ciudad de México se encuentra altamente contaminado con gases (especialmente ozono) y partículas. En 1994, el promedio de todos los contaminantes emitidos era alrededor de 7.3 toneladas/día/km2 . Los altos niveles de contaminación del aire pueden Ilevar a la muerte prematura a personas susceptibles, causan alteraciones en una gran parte de las personas expuestas, y claramente disminuyen la calidad de Vida. Se han discutido efectos adversos en la salud de los niños y el posible aumento de la tasa de cáncer. En 1994, 75% de la cantidad total de contaminantes en la Ciudad de México fue emitido por el transporte. Consecuentemente, proponemos y ejemplificamos la introducción de un sistema de impuestos y subsidios inductivos para favorecer la compra de autos eléctricos de emisión "cero", y para desincentivar la compra de autos de gasolina. En este sistema, el gobierno no ganaría impuestos adicionales; mientras corregiría de manera eficiente la falla del mercado libre de no proporcionar el valor no-comercial "aire limpio".