A Study to Validate the Relevancy of V-Tecs Catalogue of Tasks for Masonry in the Tidewater Area

It was the intent of this study to seek answers to the following questions as they related to the masonry program at N.T.V.C., Norfolk, Virginia: 1. What specific occupational competencies were performed by he bricklayer in the Tidewater area masonry work force? 2. In what specific masonry skills must students be competent in order to be employable in the Tidewater area? 3. Were the tasks listed in V-Tecs catalogue relevant to entry-level skills of the Tidewater masonry work force

Droplet Dynamics in Cooling Tower Plumes

Large cooling towers are becoming more common as a means of disposing of large quantities of waste heat from steam electric generating stations. Increased attention is being focused on how the effluents from these towers affect the environment. This research is concerned with the determination of the paths and ultimate deposition of salt laden drift drops exiting from a cooling tower by analyzing the basic droplet dynamics governing the transport of these droplets. The equation of motion is developed for a liquid drift drop as it is transported through the atmosphere. A term appears in the equation of motion which has not been considered by previous authors. A finite difference technique is used to solve for the velocity and position of the drift drop at any time. Meteorological variables as well as cooling tower variables are considered in calculating the trajectory of the drift drop. A model is developed to account for the effects of dissolved chemicals on droplet evaporation rate. The concepts presented in this paper have been incorporated into a model which predicts chemical deposition from evaporative cooling towers. The results of the model study show better agreement with experimental data than previous models

Produtividade e níveis foliares de nutrientes em cultivares de café sob diferentes populações de plantas

Cultivares de cafeeiro (Coffea Arabica L.) adaptadas às regiões de cultivo, com população de plantas otimizada e adequado estado nutricional são premissas para a obtenção de produções elevadas de café. Estudou-se a produção trienal de café e o teor foliar de macronutrientes de cultivares de cafeeiro em função das densidades de plantio. Foram utilizados os cultivares Catuaí Amarelo (IAC 47), Obatã (IAC 1669-20), Acaiá (IAC 474-19) e Icatu Amarelo (IAC 2944) nas populações de 2.500 plantas ha-1 com duas plantas por cova; e, 5.000, 7.519 e 10.000 plantas ha-1 com uma planta por cova. As plantas foram adubadas de modo homogêneo, porém, sem calagem. À medida que a população de cafeeiros aumentou, a produtividade trienal de café aumentou, a produção de frutos por planta diminuiu e os teores foliares de fósforo (P), potássio (K) e enxofre (S) aumentaram. Nos cafeeiros sob adensamento encontrou-se igual ou maior teor de macronutrientes do que naqueles sob espaçamento convencional, sendo que os maiores teores foram observados nas cultivares de porte alto, e os menores, na cultivar Obatã, de porte baixo. Nos cafeeiros das covas com uma planta observou-se maior produção de café e menores concentrações de P, Ca e S do que naqueles das covas com duas plantas. No geral, os cultivares e as populações de cafeeiros estavam com teores de N e S acima dos limites de referência citados na literatura, mas com teores dos demais macronutrientes dentro da faixa adequada.Coffee (Coffea Arabica L.) plantations using adapted cultivars to regional environmental conditions with optimal plant population density and adequate nutrition are expected to show high yield responses. The triennial production and leaf macronutrient concentrations of four coffee cultivars were studied under different plant population densities. Catuaí Amarelo (IAC 47), Obatã (IAC 1669-20), Acaiá (IAC 474-19) and Icatu Amarelo (IAC 2944) were planted in densities of 2,500; 5,000; 7,519; and 10,000 plants ha-1 with one plant per hole and two plants per hole in the 2,500 plant ha-1. Plants were homogeneously fertilized without liming. As the population density increased the triennial coffee productivity increased, the yield per plant decreased, and leaf concentrations of phosphorus (P), potassium (K) and sulfur (S) increased. Coffee plants under dense systems presented equal or higher leaf macronutrient concentrations compared to the plants under conventional population. Taller cultivars presented the highest nutrient concentration values, and Obatã, a dwarf cultivar, the lowest values. Higher coffee yields and lower leaf P, Ca and S concentrations were observed in plots with one plant compared to the plots with two plants. In general, the coffee cultivars had leaf N and S concentrations above the reference limits reported in the literature, but leaf concentrations of other macronutrients were within adequate ranges

Design Rules for Self-Assembly of 2D Nanocrystal/Metal-Organic Framework Superstructures.

We demonstrate the guiding principles behind simple two dimensional self-assembly of MOF nanoparticles (NPs) and oleic acid capped iron oxide (Fe3 O4 ) NCs into a uniform two-dimensional bi-layered superstructure. This self-assembly process can be controlled by the energy of ligand-ligand interactions between surface ligands on Fe3 O4 NCs and Zr6 O4 (OH)4 (fumarate)6 MOF NPs. Scanning transmission electron microscopy (TEM)/energy-dispersive X-ray spectroscopy and TEM tomography confirm the hierarchical co-assembly of Fe3 O4 NCs with MOF NPs as ligand energies are manipulated to promote facile diffusion of the smaller NCs. First-principles calculations and event-driven molecular dynamics simulations indicate that the observed patterns are dictated by combination of ligand-surface and ligand-ligand interactions. This study opens a new avenue for design and self-assembly of MOFs and NCs into high surface area assemblies, mimicking the structure of supported catalyst architectures, and provides a thorough fundamental understanding of the self-assembly process, which could be a guide for designing functional materials with desired structure

VOSviewer and Bibliometrix

Non

Novel parvoviruses from wild and domestic animals in Brazil provide new insights into parvovirus distribution and diversity

Parvoviruses (family Parvoviridae) are small, single-stranded DNA viruses. Many parvoviral pathogens of medical, veterinary and ecological importance have been identified. In this study, we used high-throughput sequencing (HTS) to investigate the diversity of parvoviruses infecting wild and domestic animals in Brazil. We identified 21 parvovirus sequences (including twelve nearly complete genomes and nine partial genomes) in samples derived from rodents, bats, opossums, birds and cattle in Pernambuco, São Paulo, Paraná and Rio Grande do Sul states. These sequences were investigated using phylogenetic and distance-based approaches and were thereby classified into eight parvovirus species (six of which have not been described previously), representing six distinct genera in the subfamily Parvovirinae. Our findings extend the known biogeographic range of previously characterized parvovirus species and the known host range of three parvovirus genera (Dependovirus, Aveparvovirus and Tetraparvovirus). Moreover, our investigation provides a window into the ecological dynamics of parvovirus infections in vertebrates, revealing that many parvovirus genera contain well-defined sub-lineages that circulate widely throughout the world within particular taxonomic groups of hosts

GAS6 Induces Axl-mediated Chemotaxis of Vascular Smooth Muscle Cells

Atherosclerosis and arterial restenosis are disease processes involving the accumulation of vascular smooth muscle cells following vascular injury. Key events leading to these processes are migration and proliferation of these cells. Here, we demonstrate that GAS6, encoded by the growth arrest-specific gene 6, induces a directed migration (chemotaxis) of both rat and human primary vascular smooth muscle cells while showing only marginal mitogenic potential in human vascular smooth muscle cells. GAS6 stimulation induces Axl autophosphorylation in human vascular smooth muscle cells, indicating that specific GAS6-Axl interactions may be associated with GAS6-directed chemotaxis. To test this hypothesis, vascular smooth muscle cells overexpressing Axl were generated by gene transfer and assessed for their ability to migrate along a GAS6 gradient. These Axl overexpressors exhibited 2-5-fold increased sensitivity to GAS6-induced chemotaxis. Furthermore, vascular smooth muscle cells expressing the kinase dead mutant of Axl or exposure to the soluble Axl extracellular domain showed attenuated GAS6-induced migration. Taken together, these results suggest that GAS6 is a novel chemoattractant that induces Axl-mediated migration of vascular smooth muscle cells. The separation of mitogenesis from migration provided by this study may enhance the molecular dissection of cell migration in vascular damage

Desempenho de bezerros recebendo silagens de sorgo ou de cana-de-açúcar como únicos alimentos volumosos

Sorghum silage (SS) or sugar cane silage (SC) supplemented with cottonseed meal to adjust the diet’s crude protein concentration to 16%, were fed to black and white Holstein calves, to evaluate their performances concerning feed consumption, weight gains and food conversions. The animals presented 97.7kg +-1.0 kg liveweight at the beginning of the trial, which consisted of a 14 days adaptation period followed by a 70 days experimental period. Sorghum silage presented higher daily weight gains averages than sugar cane silage: 0.601 kg against 0.378 kg (p<0.05), feed conversion (kilograms of dry matter consumption by kilogram of liveweight gain) of 7.760 and 12.830 (p<0.05) and a protein conversion of 1.444 and 2.210 kg of ingested crude protein by kilogram of liveweight gain (p<0.05). Daily dry matter consumptions (4.638 kg and 4.671 kg); and daily protein consumption (0.798 kg and 0.805 kg) respectively for SS and SC, were not statistically different (p>;0.05).Silagens de sorgo granífero (tratamento SS) e de cana-de-açúcar (tratamento SC), suplementadas com farelo de algodão para ajustar o nível protéico das dietas a 16%, foram fornecidas a bezerros da raça Holandesa variedade malhada de preto, para avaliação de seus desempenhos em termos de consumo de alimentos, ganhos de peso e conversões alimentares. Os animais apresentaram média de peso de 97,7 ± 1,0 kg ao início do período de adaptação, de 14 dias, ao qual seguiu-se período experimental de 70 dias. Os resultados mostraram que o tratamento com silagem de sorgo granífero foi superior ao com cana-de-açúcar (p<0,01) em termos de ganhos diários de peso (0,601 kg contra 0,378 kg), conversão alimentar em quilogramas de matéria seca ingeridas por quilo de ganho de peso (7,760 kg contra 12,830 kg) e em quilogramas de proteína bruta ingeridas por quilo de ganho de peso (1,440 kg contra 2,210 kg). Os consumos diários de matéria seca (4,638 kg e 4,671 kg) e de proteína bruta (0,798 kg e 0,805 kg) para SS e SC, respectivamente, apresentaram semelhança estatística entre tratamentos (p>;0,05)

Sugar cane silage replacing sorghum silage for lactating cows

Doze vacas Holandesas e Schwyz foram utilizadas em um delineamento switch-back para avaliar os tratamentos constituídos das seguintes silagens, corrigidas para um mesmo nível protéico pela adição de proporções diferentes de farelo de algodão, de forma a garantir os nutrientes necessários para a mantença das fêmeas e ainda para a produção dos primeiros 8 quilogramas de leite por animal e por dia, havendo suplementação de mistura concentrada para as quantias de leite secretadas superiores a oito quilogramas: Tratamento A) silagem de sorgo granífero; Tratamento B) 50% de silagem de sorgo granífero e 50% de silagem de cana-de-açúcar; Tratamento C) silagem de cana-de-açúcar. As produções de leite por animal e por dia foram respectivamente 12,9 kg, 12,3 kg e 11,8 kg, sendo o tratamento A, significativamente superior ao C (p<0,05). O consumo de matéria seca total por 100 kg de peso vivo (3,0 kg, 3,0 kg e 2,8 kg), bem como o de nutrientes digestíveis totais (9,2 kg, 8,8 kg e 8,0 kg), respectivamente para os tratamentos A, B e C, não foram estatisticamente diferentes. Doze ovinos da raça Ideal prestaram-se para realizar prova de digestibilidade aparente com os mesmos tratamentos aplicados às vacas em lactação: os valores encontrados para digestibilidade da matéria seca foram 54,4%; 56,8% e 52,0%; para os tratamentos A, B e C, não sendo consideradas as diferenças estatisticamente significativas.Twelve Holstein and Schwyz lactating cows were used in a switch-back trial to evaluate the following silages corrected to a same nitrogen level by addiction of cottonseed meal, to supply the required nutrients for maintenance and production of the eight first kg of milk per cow by day, concentrate meals being used to supplement the milk produced above this level: Treatment A) grain sorghum silage; Treatment B) 50% grain sorghum silage and 50% sugar cane silage; Treatment C) sugar cane silage. Milk production per cow per day was respectively 12.9 kg, 12.3 kg and 11.8 kg and treatment A was superior to C (p<0.05). Total dry matter consumption by 100 kg of body live-weight (3.0kg, 3.0kg and 2.8kg), as the TDN consumptions (9.2kg, 8.8kg and 8.0kg) for treatments A,B and C respectively, presented no statistical differences. Twelve Ideal breed lambs were used to run an apparent digestibility trial with the same treatments applied to the lactating cows: the dry matter digestibility values were 54.4%, 56.8% and 52.0% respectively for A,B and C treatments, with no statistical differences among them