Slow dynamics of a confined supercooled binary mixture II: Q space analysis

We report the analysis in the wavevector space of the density correlator of a Lennard Jones binary mixture confined in a disordered matrix of soft spheres upon supercooling. In spite of the strong confining medium the behavior of the mixture is consistent with the Mode Coupling Theory predictions for bulk supercooled liquids. The relaxation times extracted from the fit of the density correlator to the stretched exponential function follow a unique power law behavior as a function of wavevector and temperature. The von Schweidler scaling properties are valid for an extended wavevector range around the peak of the structure factor. The parameters extracted in the present work are compared with the bulk values obtained in literature.Comment: 8 pages with 8 figures. RevTeX. Accepted for publication in Phys. Rev.

Quantificação da arborização urbana viária de Campinas, SP.

A arborização urbana compreende parques, praças, jardins, bosques, fragmentos florestais, arborização particular e arborização viária, e é responsável por oferecer grandes benefícios à qualidade de vida da população das cidades. A arborização viária, em especial aquela que é disposta em calçadas, canteiros centrais e rotatórias, pode ser um grande entrave para o desenvolvimento sustentável das cidades caso não seja bem manejada. À medida que o adensamento urbano aumenta, o comércio se expande e a frota de automóveis atinge números astronômicos, calçadas são rebaixadas e as vias têm que ser ampliadas: reduz-se o espaço necessário à presença de árvores. Portanto, a gestão qualificada das árvores é primordial para a sustentabilidade das cidades.bitstream/item/82260/1/029-12.pd

Inventário quantitativo da arborização urbana viária de Campinas.

Pesquisas sobre arborização urbana têm se concentrado no inventário de árvores como forma de subsídio para os planos do governo. No entanto, um inventário total é extremamente trabalhoso de ser feito no campo. Para facilitar a observação das árvores, suas características e reduzir o tempo de busca, ferramentas de geoprocessamento estão permitindo obter resultados mais rápidos e confiáveis, criando possibilidades de exploração e conhecimento científico na análise ambiental e social. O objetivo desse trabalho foi o de propor uma nova metodologia para contar árvores nas cidades. Técnicas de geoprocessamento com imagens de alta resolução espacial foram utilizados para obter o número total de árvores do sistema viário da cidade de Campinas. O número de árvores, arbustos, palmeiras e mudas obtido foi validado em campo por meio de amostragem a partir de classes de densidade e frequência. O erro foi calculado e utilizado para estimar o número final. O total da arborização urbana do sistema viário em Campinas foi de 120.730 indivíduos, excluindo mudas. O erro encontrado foi de 16%, o que mostrou que a metodologia utilizada foi adequada para estimar a arborização total

Double dynamical regime of confined water

The Van Hove self correlation function of water confined in a silica pore is calculated from Molecular Dynamics trajectories upon supercooling. At long time in the $\alpha$ relaxation region we found that the behaviour of the real space time dependent correlators can be decomposed in a very slow, almost frozen, dynamics due to the bound water close to the substrate and a faster dynamics of the free water which resides far from the confining surface. For free water we confirm the evidences of an approach to a crossover mode coupling transition, previously found in Q space. In the short time region we found that the two dynamical regimes are overimposed and cannot be distinguished. This shows that the interplay between the slower and the faster dynamics emerges in going from early times to the $\alpha$ relaxation region, where a layer analysis of the dynamical properties can be performed.Comment: 6 pages with 9 figures. RevTeX. Accepted for pulbication in J. Phys. Cond. Mat

Iris extramedullary hematopoiesis in choroidal melanoma

PURPOSE: Extramedullary hematopoiesis (EMH) usually occurs in patients with loss of bone marrow hematopoietic function, and in a vast majority of cases, it involves the liver, the spleen, or the lymph nodes. We report EMH in the iris of patients enucleated for choroidal melanoma (CM). METHODS: We report a series of three patients with CM, two treated with primary enucleation and one with secondary enucleation. RESULTS: Histopathology revealed EMH in the iris of all patients. CONCLUSION: EMH of the iris can be associated with CM in the absence of any hematological or systemic disorders. To the best of our knowledge, our work is the first report of this abnormal histopathological finding

In vitro aflatoxins recovery after changing buffer or protozoa concentrations in the rumen fermentation fluid

This study simulates in vitro the effects of (i) rumen acidity and (ii) change in rumen protozoa numbers on the recovery of aflatoxins (AFs). Two 24-h fermentation experiments were carried out using the same batch in vitro fermentation systems and substrate (dried corn meal) containing 11.42, 2.42, 7.65 and 1.70 µg/kg of AFB1, AFB2, AFG1 and AFG2 respectively. In Experiment 1, two buffer concentrations (normal salts dosage or lowered to 25%) were tested. Buffer reduction decreased gas production (730 vs. 1101 mL, p < 0.05), volatile fatty acids (VFA) and NH3 concentrations in the fermentation liquid (39.8 vs. 46.3 mmol/L, and 31.7 vs. 46.5 mg/dL respectively, p < 0.01). Recovery of all four AFs types was higher (p < 0.01) in the reduced buffer fermentation fluid, both as a percentage of total AF incubated (73.6% vs. 62.5%, 45.9% vs. 38.1%, 33.6% vs. 17.9% and 18.9% vs. 6.24% for AFB1, AFB2, AFG1 and AFG2 respectively) and as amounts relative to VFA production (163.4 vs. 123.5, 22.1 vs. 15.7, 48.8 vs. 22.5 and 6.16 vs. 1.86 ng/100 mmol of VFA, for AFB1, AFB2, AFG1 and AFG2 respectively). In Experiment 2, Stevia rebaudiana Bertoni extracts (S) or a Camphor essential oil (Cam) were added to fermenters and compared to the control (no additives, C). S and Cam addition resulted in a 25% reduction (p < 0.05) and a 15% increase (p < 0.05) in protozoa counts respectively, when compared to C. Both plant additives slightly reduced (p < 0.05) AFB1 recovery as a percentage of total AFB1 incubated (68.5% and 67.7% vs. 74.9% for S, Cam and C respectively). Recoveries of all other AFs were unaffected by the additives. In conclusion, the rumen in vitro AFB1 recovery (63%–75%) was higher than other AFs (3%–46%) and the acidic fermentation environment increased it. In our conditions, changes in protozoa numbers did not affect AFs recovery