Primal-dual stability in continuous linear optimization

Any linear (ordinary or semi-infinite) optimization problem, and also its dual problem, can be classified as either inconsistent or bounded or unbounded, giving rise to nine duality states, three of them being precluded by the weak duality theorem. The remaining six duality states are possible in linear semi-infinite programming whereas two of them are precluded in linear programming as a consequence of the existence theorem and the non-homogeneous Farkas Lemma. This paper characterizes the linear programs and the continuous linear semi-infinite programs whose duality state is preserved by sufficiently small perturbations of all the data. Moreover, it shows that almost all linear programs satisfy this stability property.This research was supported by DGES and FEDER, Grant MTM2005-08572-C03-01 and partially supported by CONACyT of MX.Grant 44003

Imagem em tuberculose pulmonar Pulmonary tuberculosis imaging

A tuberculose é uma doença de alta incidência e prevalência no Brasil. Sinais sugestivos de atividade ou seqüela da tuberculose podem ser obtidos através dos métodos de imagem. Na radiografia de tórax, a tuberculose pulmonar ativa pode manifestar-se sob a forma de consolidações, cavitações, padrões intersticiais (reticulares/retículo-nodulares), linfonodomegalias hilares ou mediastinais e derrame pleural. Imagens compatíveis com doença ativa, como nódulos centrolobulares de distribuição segmentar, cavidades de paredes espessas, espessamento de parede brônquica ou bronquiolar, bronquiectasias e linfonodomegalias, podem ser observadas pela tomografia computadorizada do tórax; cavidades de paredes finas, bronquiectasias de tração e estrias são imagens sugestivas de seqüela da doença, assim como o enfisema e o aspecto em mosaico do parênquima pulmonar. A cintilografia com o citrato de gálio-67 é um método complementar útil na detecção de processos infecciosos, incluindo a tuberculose, especialmente em pacientes imunossuprimidos. Estudos de inalação e perfusão pulmonar são utilizados na avaliação pré-operatória de pacientes com seqüelas de tuberculose ou tuberculose multirresistente. A tomografia por emissão de pósitrons utilizando a deoxiglicose marcada com o flúor-18 permite a detecção do processo inflamatório que ocorre na fase ativa da tuberculose e que pode persistir, em menor intensidade, após o término do tratamento. Métodos de imagem constituem importantes recursos para o diagnóstico e acompanhamento da tuberculose pulmonar.<br>Tuberculosis is a disease of high incidence and prevalence in Brazil. Imaging methods can reveal signs suggestive of tuberculosis activity or sequelae. Chest radiographs can reveal active lung tuberculosis through consolidations, cavitations, interstitial patterns (nodular and reticulo-nodular), mediastinal or hilar lymphadenopathy and pleural effusions. Images compatible with the active disease, such as centrilobular nodules segmentarily distributed, thick-walled cavities, thickened bronchial or bronchiolar walls, bronchiectasis and lymphadenopathy can be observed by computerized tomography. Thin-walled cavities, traction bronchiectasis, parenchymal bands, emphysema and mosaic pattern are signs suggestive of inactive disease. Gallium-67 citrate scyntigraphy is a complementary method useful in the detection of infectious diseases, including tuberculosis, especially in immunocompromised patients. Inhalation / perfusion analyses are used in the pre-operative assessment of patients carrying tuberculosis sequelaes and multiresistant tuberculosis. Positron emission tomography with fluorine-18 labeled deoxyglucose allows the detection of the inflammatory process that takes place during the active stage of tuberculosis and may persist, not so intense, after specific treatment is over. Imaging methods are valuable tools to be used in the diagnosis and follow up of pulmonary tuberculosis

Endovascular treatment of cerebral aneurysms: a retrospective study of 163 embolized aneurysms Tratamento endovascular de aneurismas cerebrais: estudo de 163 aneurismas embolizados

OBJECTIVE: To present the results of cerebral aneurysms treated by endovascular technique. METHOD: Retrospective analysis of patient files of Hospital Geral de Fortaleza, Brazil. RESULTS: We report the results of 163 cerebral aneurysms treated by endovascular techniques from January 2002 to October 2005. Patients with ruptured aneurysms (87.2%), according to Hunt-Hess scale were: 33.7% HH I, 28.4% HH II, 24.1% HH III, 13.8% HH IV. The Fisher scale grade IV was the most common (39.7%). Remodeling, coil embolization, arterial occlusion and histoacryl embolization were the techniques employed. Effective occlusion was achieved in 87.7%, partial occlusion in 5.3% and non-effective occlusion in 7.0% of the patients. Glasgow outcome scale results were: 76.3% GOS 5, 5.0% GOS 4, 5.8% GOS 3, 1.4% GOS 2 and 11.5% GOS 1. CONCLUSION: Endovascular treatment seems to be feasible within Brazilian public health system, with results as good as those obtained in larger international centers.<br>OBJETIVO: Apresentar os resultados de aneurismas tratados pela técnica endovascular. MÉTODO: Análise retrospectiva de prontuários do Hospital Geral de Fortaleza, Brasil. RESULTADOS: Apresentamos os resultados de 163 aneurismas cerebrais tratados por técnicas endovasculares de Janeiro de 2002 a Outubro de 2005. Os pacientes com aneurismas rotos (87,2%) eram, segundo a escala de Hunt-Hess: 33,7% HH1; 28.4% HH II, 24.1% HH III, 13.8% HH IV. O Grau IV da escala de Fisher foi o mais comum (39,7%). Empregaram-se as técnicas de remodeling, espiras metálicas, oclusão arterial e embolização com histoacryl. Foi obtida oclusão efetiva em 87,7%, oclusão parcial em 5,3% e oclusão não-efetiva em 7,0% dos casos. De acordo com a Glasgow outcome scale, os resultados foram: 76,3% GOS 5, 5,0% GOS 4, 5,8% GOS 3, 1,4% GOS 2 e 11,5% GOS 1. CONCLUSÃO: A aplicação de técnica endovasculares mostra-se viável na rede pública brasileira, com resultados comparáveis aos de grandes centros mundiais

The associated microflora to the larvae of human bot fly Dermatobia hominis L. Jr. (Diptera: Cuterebridae) and its furuncular lesions in cattle

The microflora associated to furuncular lesions, larvae and pupae of Dermatobia hominis, as well as the relationships between parasite, host and microflora associated, as a comprehensive microsystem, has been studied. One hundred and two furuncular myiasis due to D. hominis larvae in several breeds of cattle were studied and the following bacterial species were significant: Staphylococcus aureus, S. epidermidis, S. warneri, Bacillus subtilis and Escherichia coli. Closely related, the microflora associated to 141 samples from first, second, third instar larva and both external surface and larval cavities has been studied. The representative associated microflora to the larvae were: S. aureus, B. subtilis, S. hycus and Moraxella phenylpiruvica, Moerella wisconsiensis, Proteus mirabilis and P. vulgaris, M. phenylpiruvica, M. wisconsiensis, P. mirabilis and P. rettgeri were the representative microflora associated to 64 pupae of D. hominis