1,153 research outputs found
Seeing the Unseen: Plaster Reliefs in Middle Byzantine Constantinople
This paper discusses the scarce, but crucial evidence for plaster reliefs in Constantinople between the ninth and the thirteenth centuries. While many plaster reliefs survived in the Balkan peninsula, there is room to confirm that they were also used in the capital. Plaster reliefs were a quick substitution for marble, but could also answer aesthetic needs and architectural conventions that continued from Late Antiquity in to Middle and Late Byzantine architecture, even with some changes
Experimental constraints on amphibole stability in primitive alkaline and calc-alkaline magmas
Equilibrium crystallization experiments were carried out on two primitive basaltic
rocks (APR16: Na2O+K2O=4.40 wt%; CM42: Na2O+K2O=2.59 wt%) with the aim to
investigate the amphibole stability in the differentiation processes at deep crustal level,
of primitive alkaline (APR16) and calc-alkaline (CM42) magmas. The experiments were
performed with different initial H2O contents (0-5 wt%), at pressure of 800 MPa, in the
temperature range of 975-1225 °C. For the explored conditions, amphibole crystallization
occurs in both compositions at H2O in the melt >7wt% while the temperature of their
occurrence is lower in the alkaline composition (<1050 °C in APR16 and ≥1050 °C in
CM42). Moreover, amphibole crystallization seems to be influenced by the Na2O/K2O
ratio rather than the absolute Na2O content in the melt. This is evident when experimental
results on the APR16 and CM42 are compared with experimental data obtained from a
primitive ultrapotassic composition (leucite-basanite: Na2O+K2O=4.58 wt%) and with
thermodynamic modelling by the Rhyolite-MELTS algorithm. The comparison shows
that amphibole never saturates the leucite-basanite at any of the investigated/modelled
conditions, even when an extended crystallization increases the Na2O of melts up to
contents like those of calc-alkaline experimental glasses. We conclude that, at pressure
of 800 MPa and hydrous conditions, only primitive liquids with Na2O/K2O ratio ≥0.9
are more prone to crystallize amphibole
Absolute quantification of viruses by TaqMan real-time RT-PCR in grapevines.
The absolute quantification determines the absolute amount of a targeted nucleic acid expressed as a copy number or concentration. The knowledge of virus concentrations in commercial crops possesses high relevance to ensure a reliable diagnosis. The objective of this study was to perform an absolute quantification of five viruses in infected grapevines (Vitis spp.). Different known amounts of the standard sample (cloned viral cDNA or in vitro transcribed viral RNA) were quantified by TaqMan RT-qPCR. Based on these data, standard curves were generated plotting Ct values (threshold cycle) against the log of the standard sample amount. Infected grapevine samples were evaluated to determine virus titers, which were highly variable. This result may contribute to improve virus diagnosis by accurately quantifying virus titre variations in grapevines. Key words: RT-qPCR, GRSPaV, GVA, GVD, GLRaV-3 and -4. RESUMO: A quantificação absoluta determina a quantidade absoluta de um ácido nucleico alvo expressa como número de cópias ou concentração. O conhecimento das concentrações virais em culturas comerciais tem grande relevância para assegurar um diagnóstico confiável. O objetivo deste trabalho foi realizar uma quantificação absoluta de cinco vÃrus em videiras infectadas (Vitis spp.). Diferentes quantidades conhecidas da amostra padrão (cDNA viral clonado ou RNA viral transcrito in vitro) foram quantificadas por RT-qPCR TaqMan. A partir destes dados, curvas padrão foram geradas plotando-se os valores de Ct (ciclo limiar) contra o log da quantidade da amostra padrão. Amostras de videiras infectadas foram avaliadas visando-se determinar os tÃtulos virais que foram bastante variáveis. Este resultado contribui para melhorar o diagnóstico viral ao quantificar com precisão variações no tÃtulo viral em videiras. Palavras-chave: RT-qPCR, GRSPaV, GVA, GVD, GLRaV-3 e -4. A quantificação absoluta determina a quantidade absoluta de um ácido nucleico alvo expressa como número de cópias ou concentração. O conhecimento das concentrações virais em culturas comerciais tem grande relevância para assegurar um diagnóstico confiável. O objetivo deste trabalho foi realizar uma quantificação absoluta de cinco vÃrus em videiras infectadas (Vitis spp.). Diferentes quantidades conhecidas da amostra padrão (cDNA viral clonado ou RNA viral transcrito in vitro) foram quantificadas por RT-qPCR TaqMan. A partir destes dados, curvas padrão foram geradas plotando-se os valores de Ct (ciclo limiar) contra o log da quantidade da amostra padrão. Amostras de videiras infectadas foram avaliadas visando-se determinar os tÃtulos virais que foram bastante variáveis. Este resultado contribui para melhorar o diagnóstico viral ao quantificar com precisão variações no tÃtulo viral em videiras. Palavras-chave: RT-qPCR, GRSPaV, GVA, GVD, GLRaV-3 e -4
Exploring efficient imperative handover mechanisms for heterogeneous wireless networks
The Next Generation Internet will provide ubiquitous
computing by the seamless operation of heterogeneous
wireless networks. It will also provide support for quality-ofservice, QoS, fostering new classes of applications and will havea built-in multi-level security environment. A key requirement of this new infrastructure will be support for efficient vertical handover. Y-Comm is a new architecture that will meet the challenge of this new environment. This paper explores the design of efficient imperative handover mechanisms using the Y-Comm Framework. It first looks at different types of handovers, then examines the Y-Comm Framework and shows how Y-Comm maps unto current mobile infrastructure. It then explores support for different handover mechanisms using Y-Comm. Finally, it highlights the development of a new testbed to further investigate
the proposed mechanisms
Dbl oncogene expression in MCF-10 A epithelial cells disrupts mammary acinar architecture, induces EMT and angiogenic factor secretion.
The proteins of the Dbl family are guanine nucleotide exchange factors (GEFs) of Rho GTPases and are known to be involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders, neoplastic transformation, and tumor metastasis. We have previously demonstrated that expression of Dbl oncogene in lens epithelial cells modulates genes encoding proteins involved in epithelial-mesenchymal-transition (EMT) and induces angiogenesis in the lens. Our present study was undertaken to investigate the role of Dbl oncogene in epithelial cells transformation, providing new insights into carcinoma progression. To assess how Dbl oncogene can modulate EMT, cell migration, morphogenesis, and expression of pro-apoptotic and angiogenic factors we utilized bi- and three-dimensional cultures of MCF-10â–‘A cells. We show that upon Dbl expression MCF-10â–‘A cells undergo EMT. In addition, we found that Dbl overexpression sustain
Expressão de proteÃna capsÃdica recombinante do Apple stem pitting virus e produção de antissoro policlonal.
O objetivo deste trabalho foi a expressão do gene da proteÃna capsidÃca do ASPV em bactérias e a produção do antissoro policlonal contra a proteÃna expressada.Resumo
Numerical and Experimental Analysis of the Daughter Distribution in Liquid-Liquid Stirred Tanks
The drop size distributions (DSDs) of a dilute immiscible liquid-liquid mixture were measured in a fully turbulent stirred tank operating at different impeller speeds. The results were used to infer the best daughter distribution function (DDF) leading to the best reproduction of the shape of the DSD. Bell-shaped, U-shaped, M-shaped, and uniform statistical DDFs were studied, producing from two to four daughters from each breakup event. A simplified approach from the literature was adopted to solve the population balance equation that considers the spectrum of the turbulence inside the tank obtained from computational fluid dynamics simulations. The U-shaped distribution producing four fragments better reproduces the shape of the experimental DSD in the studied system
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