276 research outputs found

    A comparison of reflector antenna designs for wide-angle scanning

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    Conventional reflector antennas are typically designed for up to + or - 20 beamwidths scan. An attempt was made to stretch this scan range to some + or - 300 beamwidths. Six single and dual reflector antennas were compared. It is found that a symmetrical parabolic reflector with f/D = 2 and a single circular waveguide feed has the minimum scan loss (only 0.6 dB at Theta sub 0 = 8 deg, or a 114 beamwidths scan). The scan is achieved by tilting the parabolic reflector by an angle equal to the half-scan angle. The f/D may be shortened if a cluster 7 to 19 elements instead of one element is used for the feed. The cluster excitation is adjusted for each new beam scan direction to compensate for the imperfect field distribution over the reflector aperture. The antenna can be folded into a Cassegrain configuration except that, due to spillover and blockage considerations, the amount of folding achievable is small

    Establishment and characterization of two human breast carcinoma cell lines by spontaneous immortalization: Discordance between Estrogen, Progesterone and HER2/neu receptors of breast carcinoma tissues with derived cell lines

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    Background: Breast cancer is one of the most common cancers among women throughout the world. Therefore, established cell lines are widely used as in vitro experimental models in cancer research.Methods: Two continuous human breast cell lines, designated MBC1 and MBC2, were successfully established and characterized from invasive ductal breast carcinoma tissues of Malaysian patients. MBC1 and MBC2 have been characterized in terms of morphology analysis, population doubling time, clonogenic formation, wound healing assay, invasion assay, cell cycle, DNA profiling, fluorescence immunocytochemistry, Western blotting and karyotyping.Results: MBC1 and MBC2 exhibited adherent monolayer epithelial morphology at a passage number of 150. Receptor status of MBC1 and MBC2 show (ER+, PR+, HER2+) and (ER+, PR-, HER2+), respectively. These results are in discordance with histopathological studies of the tumoral tissues, which were triple negative and (ER-, PR-, HER2+) for MBC1 and MBC2, respectively. Both cell lines were capable of growing in soft agar culture, which suggests their metastatic potential. The MBC1 and MBC2 metaphase spreads showed an abnormal karyotype, including hyperdiploidy and complex rearrangements with modes of 52-58 chromosomes per cell.Conclusions: Loss or gain in secondary properties, deregulation and specific genetic changes possibly conferred receptor changes during the culturing of tumoral cells. Thus, we hypothesize that, among heterogenous tumoral cells, only a small minority of ER+/PR+/HER2+ and ER+/PR-/HER2+ cells with lower energy metabolism might survive and adjust easily to in vitro conditions. These cell lines will pave the way for new perspectives in genetic and biological investigations, drug resistance and chemotherapy studies, and would serve as prototype models in Malaysian breast carcinogenesis investigations. © 2012 Kamalidehghan et al.; licensee BioMed Central Ltd

    A comparison of reflector antenna designs for wide-angle scanning

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    Conventional reflector antennas are typically designed for up to + or - 20 beamwidths scan. An attempt was made to stretch this scan range to some + or - 300 beamwidths. Six single and dual reflector antennas were compared. It is found that a symmetrical parabolic reflector with f/D = 2 and a single circular waveguide feed has the minimum scan loss (only 0.6 dB at Theta sub 0 = 8 deg, or a 114 beamwidths scan). The scan is achieved by tilting the parabolic reflector by an angle equal to the half-scan angle. The f/D may be shortened if a cluster 7 to 19 elements instead of one element is used for the feed. The cluster excitation is adjusted for each new beam scan direction to compensate for the imperfect field distribution over the reflector aperture. The antenna can be folded into a Cassegrain configuration except that, due to spillover and blockage considerations, the amount of folding achievable is small

    Pfeiffer Type I Syndrome: A Genetically Proven Case Report

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    ObjectivePfeiffer Syndrome is as rare as Apert syndrome in the Western population. This condition is very rare in the Asian population. At the best of our knowledge this is the first genetically proven case report from Iran. The authors report with a review of literature, the case of a infant with Pfeiffer syndrome, manifested by Lacunar skull, ventriculomegaly, bicoronal craniosynostosis,frontal bossing, shallow orbits, parrot-like nose, umbilical hernia, broad and medially deviated great toes.

    Potential of oak acorn with and without polyethylene glycol as an alternative to corn in broiler diets

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    This study was conducted to investigate the potential for replacing corn with oak acorn (OA), a tannin-rich feedstuff, and the possible role of polyethylene glycol (PEG) in reducing detrimental effects of OA on broilers. A 3 × 2 factorial arrangement of treatments was used with three levels of OA (0, 150, and 200 g/kg diet), with and without 10 g/kg PEG. A total of 528 one-day-old male and female Cobb 500 broiler chicks were randomly assigned to one of six experimental treatments, with four replicates of 22 birds each. OA was included in the starter (days 1–21) and finisher (days 22–42) diets as a replacement for corn, without changing the dietary levels of other ingredients. The results indicated that dietary inclusion of OA, without PEG, significantly reduced bodyweight gain (BWG) overall (days 1–42) and resulted in worse finisher and overall feed conversion ratios (FCR). PEG had no significant effect on the performance of birds fed diets without OA, but improved overall the BWG of birds receiving 150 and 200 g/kg OA as well as finisher and overall the FCR of birds given 150 g/kg OA. Liver and pancreas weights were not significantly influenced by OA level, PEG or their interaction. Feeding with 200 g/kg OA had deleterious effects on some tibia traits. In conclusion, a significant interaction between OA level and PEG indicates that PEG has the potential to reduce the adverse effects of OA, leading to improved performance. Thus, up to 150 g/kg OA could be included in PEG-supplemented diets, without adverse effects on performance or the tibia traits of broilers.Keywords: High-tannin feedstuff, performance, poultry nutrition, tibia characteristi

    Quantitative trait loci associated with kernel weight and test weight in durum wheat

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    Tese de doutoramento em História, em Altos Estudos, apresentada à Faculdade de Letras da Universidade de CoimbraEntre 1943 e 1986, as relações diplomáticas luso-italianas caracterizaram-se por uma progressiva aproximação. Finda a II Guerra Mundial, a Itália, membro do Eixo até 1943, assinava, em 1947, o Tratado de Paz como país vencido. Em Portugal, os governantes portugueses temiam que a vitória dos Aliados levasse ao fim do Estado Novo, um regime antidemocrático e autoritário com características fascizantes. As incertezas e as expectativas internas e externas eram, pois, vividas em Lisboa e em Roma com nervosismo até ao final dos anos 40, quando os instrumentos principais das relações internacionais no Ocidente – como a ONU, a OECE, a NATO e a CECA – ficam delineados, permitindo aos dois países integrarem-se numa esfera de interacção comum e no âmbito da qual as relações luso-italianas ficavam reforçadas. Contudo, se a Itália garantia o seu lugar nos projectos de cooperação europeia, Portugal direccionava-se para o Ultramar. Também aqui as relações luso-italianas poderiam encontrar um ponto de reforço se ao anticolonialismo professado pelo Governo de Roma não se opusesse o acérrimo colonialismo do Governo de Lisboa, com a desconfiança do Governo português a acentuar-se com o início das guerras coloniais, a partir de 1961. Condenado na ONU, pressionado na NATO, Portugal buscava o apoio da Itália, cedido apenas dentro dos limites da solidariedade devida a um aliado no quadro da Aliança Atlântica. Caído o Estado Novo em Abril de 1974, Roma e Lisboa encetavam um período de maior identificação em termos de princípios políticos e de objectivos, com a primeira a ceder os seus préstimos para garantir o sucesso da transição democrática e para acelerar o processo da negociação da independência das colónias. Ao fazê-lo, pretendia não só solidificar as relações diplomáticas com Lisboa, mas também com os novos países surgidos do Ultramar, considerados altamente rentáveis para investir e alargar a presença da Itália na África. A Democracia de Abril veio também permitir o estreitamento das relações luso-italianas no campo multilateral, com a Itália a ter um papel de destaque no processo de adesão de Portugal à CEE não só ao impor um número de reformas a executar a nível comunitário para optimizar o funcionamento institucional e salvaguardar a economia italiana, produtora de produtos similares à portuguesa e com necessidades símiles em termos de financiamentos europeus, mas também ao acelerar a conclusão das negociações, em 1985.Between 1943 and 1986, a growing closeness characterizes the Portuguese – Italian diplomatic relations. After the World War II, while the Portuguese leaders feared the ruin of the Estado Novo, an antidemocratic and authoritarian regime with fascist characteristics, the Italian Government signed, in 1947, the Peace Treaty as a defeated ally of the Nazi Germany. The uncertainties and the expectations were, therefore, nervously felt in Lisbon and Rome till the end of the 40´s, when the two countries join the OEEC and the OTAN and assure their acceptance by the western partners. At the same time, the diplomatic relations between them were strengthened. However, while the Italians focused on the development of the European communities, the Portuguese focused on their Colonial Empire. By this time, the anti-colonialism of the Italian government, as opposed to the colonialism of the Portuguese government, created some difficulties in the relations between the two. The situation got worse with the beginning of the Portuguese colonial wars, in 1961. Condemned by the UN and pressured by the NATO, Portugal searched for Italy's support, which was given only sparingly. Simultaneously, the African nationalists and the political opposition to the Estado Novo enlarged their support base in Italy, mainly in the political sectors of the left, which had negative consequences in the relations between Lisbon and Rome. With the revolution of April 25th 1974, the Estado Novo disappeared without resistance. With the new democratic and anti-colonialist regime, the relations between Rome and Lisbon entered a new phase of greater cooperation. The Italian Government helped the new government with the democratic transition, the decolonization and the negotiation of the Portuguese entrance into the European Economic Community. By doing so, Italy attempted not only to strengthen the diplomatic relations with Portugal and with the new African countries, very appealing to the Italian capital, but also to fortify the role and influence of her own and that of the southern Europe in the European communities
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