Analisi Morfometrica dei Cromosomi del Coniglio (Oryctolagus Cuniculus L.)

RIASSUNTOSono stati studiati i cromosomi di coniglio (Oryctolagus cuniculus L.).Il numero diploide dei cromosomi in cellule somatiche e risultato di 2 n= 44. L'analisi morfologica e metrica di essi ha permesso la distinzione in gruppi di cromosomi affini. Una tale classificazione si pensa possa essere utile in ricerche di cariologia comparata nell'ambito dei Leporidae

Cellular-Automata model for dense-snow avalanches

This paper introduces a three-dimensional model for simulating dense-snow avalanches, based on the numerical method of cellular automata. This method allows one to study the complex behavior of the avalanche by dividing it into small elements, whose interaction is described by simple laws, obtaining a reduction of the computational power needed to perform a three-dimensional simulation. Similar models by several authors have been used to model rock avalanches, mud and lava flows, and debris avalanches. A peculiar aspect of avalanche dynamics, i.e., the mechanisms of erosion of the snowpack and deposition of material from the avalanche is taken into account in the model. The capability of the proposed approach has been illustrated by modeling three documented avalanches that occurred in Susa Valley (Western Italian Alps). Despite the qualitative observations used for calibration, the proposed method is able to reproduce the correct three-dimensional avalanche path, using a digital terrain model, and the order of magnitude of the avalanche deposit volume

Alterações do teor de nitrogênio na folha e pecíolo, na produção e composição da uva pela adubação nitrogenada em videiras no Planalto do Rio Grande do Sul.

O trabalho objetivou avaliar como a aplicação de N afeta o seu teor na folha inteira e pecíolo, usados para a recomendação de N à videira no RS e SC, e sobre a produção e composição da uva.bitstream/CNPUV/10104/1/cot087.pd

The Youthful Appearance of the 2003 EL61 Collisional Family

We present new solar phase curve observations of the 2003 EL61 collisional family showing that all the members have light-scattering properties similar to the bright icy satellites and dwarf planets. Compared to other Kuiper Belt objects, the five family members we observe (2003 EL61, 2002 TX300, 2003 OP32, 2005 RR43, and 1995 SM55) have conspicuously neutral color (V-I = 0.6-0.8 mag) and flat phase curves at small phase angles (phase coefficients of 0.0 - 0.1 mag deg-1). Comparing the phase curves we observe for other icy Kuiper Belt objects to the phase curves of icy satellites, we find that the flat phase curves of the 2003 EL61 family are an indication they have high albedo surfaces coated with fresh ice in the last ~100 Myr. We examine possible resurfacing processes and find none that are plausible. To avoid the influence of cosmic radiation that darkens and reddens most icy surfaces on times scales > ~100 Myr, the family members must be unusually depleted in carbon, or else the collision that created the family occurred so recently that the parent body and fragments have not had time to darken. We also find a rotation period of 4.845 (+/- 0.003) h with amplitude 0.26 (+/- 0.04) mags for 2003 OP32.Comment: 12 pages, 3 tables, 4 figure

A fully automated flow injection atomic absorption system for the determination of copper traces in waters with on-line pre-concentration in an ion-exchange column

The paper describes the development of an automatic on-line column pre-concentration technique using a time based-flow injection atomic absorption spectrometry system. A manifold incorporating a micro-column containing 25 mg of Dowex 50W-X8 was used with a time-based injector for the pre-concentration and determination of copper in natural and drinking waters. The system features depend on the alternate positions of a solenoid valve. The 3σ detection limits, enrichment factors, sampling frequency, relative standard deviations and linear calibration graphs were, respectively, in the range 0.6-1.5 μg/l, 25-60, 15-30 measurements/h, 1.0-3.1% and 1-65 μg/ml for pre-concentration times of 1 min. The procedure was successfully applied to a range of water samples and the accuracy was assessed through recovery experiments, the analysis of certified reference water samples and by independent analysis by atomic absorption spectrometry with electrothermal atomization

Algoritmo computacional para determinar o perfil mínimo de marcadores moleculares que discriminam um conjunto de cultivares.

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Phosphorus fractions in the vineyard soil of the Serra Gaúcha of Rio Grande do Sul, Brazil.

The study aimed to evaluate the accumulation of P fractions in a vineyard soil profile with successive applications of phosphate fertilizers. In January 2010 an area was selected of native forest and a vineyard at age 33 with a history of phosphate fertilizer application, in Bento Gonçalves, Rio Grande do Sul state. Soil samples were collected from 0-5, 5-10 and 10-20 cm layers, prepared and submitted to chemical fractionation of P. The excessive application of phosphate fertilizers during 33 years in the vineyard soil increased the levels of organic and inorganic P until the 20 cm layer in all P fractions. The highest levels of P in the vineyard soil were found mainly in the labile fractions extracted with anion exchange resin and NaHCO3, which indicates high nutrient availability to plants, but also indicates the potential of transfer of solution from soil to surface run-off or percolated through the soil profile, which represents greater potential for contamination of surface and subsurface waters

Altos teores de zinco no solo interferem o desenvolvimento de porta-enxertos de videira na Serra Gaúcha.

Em vinhedos é frequente e intenso o uso de fungicidas que possuem o zinco na sua composição, mas ainda existem poucos estudos sobre a interferência deste elemento sobre a videira. O objetivo deste trabalho é analisar a influência dos teores de zinco no solo em diferentes porta-enxertos de videiras cultivados em casa de vegetação na Serra Gaúcha. O trabalho foi conduzido em casa de vegetação na Embrapa Uva e Vinho, localizada na Serra Gaúcha do Rio Grande do Sul, Brasil. Utilizou-se solo coletado em Neossolo e cultivou-se, em vasos, cinco porta-enxertos (SO4, Paulsen1103, IAC572, IAC313 e 420A) em cinco doses de zinco (0, 20, 40, 80 e 160 mg kg-1 de Zn). Foram analisadas avaliações no crescimento, área foliar, matéria seca e índice de clorofila. O porta-enxerto IAC572 apresenta maior potencial de produção vegetativa e desta forma torna-se mais tolerante às doses altas de Zn no solo. Enquanto que o Paulsen 1103 e SO4 são mais sensíveis ao aumento de Zn no solo, identificados pela alteração dos índices de clorofila.Resumo expandido