Portugal's Entry into the EC: The Challenge for Small Farmers

Portuguese farmers face price declines for several major enterprises because of the country's entrance into the European Economic Community (EC). The small farmers in Northwestern Portugal face some of the biggest adjustments. Price projections suggest that 1996 prices for their key enterprises may fall 15 to 30 percent below current levels, and their farm income may decline from 10 to 250 percent. Medium and large dairy farms will not be able to cover the fixed costs of the investments they were encouraged to make in recent years. Simulations of alternative scenarios were conducted for four farming systems in the region. Technological changes in existing enterprises will be adequate to recover the income lost on large farms. The smallest farms are not as affected by price declines because much of their income is earned off the farm. Medium farms face the greatest challenge. They cannot achieve the scale of large farms, and cannot earn as much off-farm income as small farms. Their future success will depend on the operation of the land market, and their ability to rent or buy more Iand

Chitosan-whey protein edible films produced in the absence or presence of transglutaminase: Analysis of their mechanical and barrier properties

Chitosan-whey protein edible films with different protein concentrations were prepared in the absence or presence of microbial transglutaminase as cross-linking agent. The films prepared in the presence of the enzyme showed low solubility at a wide range of pH, a lower degree of swelling, and good biodegradability following protease treatments. The presence of transglutaminase induced also an enhancement in film mechanical resistance and a reduction in their deformability. Finally, the barrier efficiency toward oxygen and carbon dioxide was found to be markedly improved in the cross-linked films which showed also a lower permeability to water vapor. Some potential practical applications of transglutaminase-treated chitosan-whey protein films are suggested

Utilizacao da embriogenese somatica no processo de melhoramento da tamareira.

A tamareira Phoenix dactilifera L. é uma palmeira do gênero Phoenix que produz frutos comestíveis que fazem parte de uma dieta básica de povos devários países do Oriente Médio (Bailey, 1944). Suas flores frescas são a base para uma bebida destilada (tora water). Uma goma medicional (kukm chil) é feita de seu palmito, sendo de comprovada eficácia em doenças do aparelho respiratório

Indução de calos embriogênicos em explantes de cupuacuzeiro.

Objetivou-se a indução de calos embriogênicos em cupuaçuzeiro, em função do tipo de explante e meio de cultura. Foram testados como explantes, segmentos cotiledonares e eixos embrionários divididos em três partes: região da plúmula, radícula e hipocótilo. Os explantes foram cultivados em 2 diferentes meios de cultura: 1) MS suplementado com 2,4-D (1 mg L-1) e Cinetina (0,25 mg L-1); 2) MS acrescido de ANA (5 mg L-1) e Cinetina (0,25 mg L-1). Constatou-se que a região do hipocótilo foi a parte mais responsiva do eixo embrionário, formando calos com aspecto branco e friável. As auxinas testadas nos meios não estimularam o processo embriogênico em calos de cupuaçuzeiro

Resposta de eixos embrionários de cupuaçu (Theobroma grandiflorum schum.) à concentração de sais, doses de sacarose e renovação do meio de cultivo.

Foram estudados os efeitos da concentração de sais, doses de sacarose e freqüência de renovação do meio de cultura para o desenvolvimento de eixos embrionários de cupuaçu (Theobroma grandiflorum Schum.). Testaram-se 2 concentrações de sais MS (100 e 50%), 2 níveis de sacarose (1,5 e 3%) e 3 freqüências de renovação dos meios (sem renovação, renovação aos 30 e aos 60 dias), com os meios acrescidos de ANA (0,5 mg/L) e BAP (0,3 mg/L.), semi-solidificados com ágar 0,7% e pH 5,7. Observou-se que a utilização do meio MS na concentração de sais completa, com a adição de 3% de sacarose e renovações do meio em intervalos de 30 dias, apresentou melhor desenvolvimento dos eixos embrionários

Re-carbonized vitreous carbon substrates for optical applications

Imaging optical systems components for satellites must have low specific mass and high stiffness, as weight is a problem for payloads and stiffness is essential to keep the substrate front surface shape. In this work, Re-carbonized Vitreous Carbon (RVC) was tested as a substrate material. The process to obtain RVC is different from the traditional process to obtain the Monolithic Vitreous Carbon (MVC). It is essential to understand the process to evaluate the surface roughness data. This work describes the process to obtain RVC, as a candidate for optical component substrate, and the results of its surface roughness measurements60523rd Congress of the International Commission for Optics (ICO

The mechanistic foundation of Weber’s law

[Abstract] Although Weber's law is the most firmly established regularity in sensation, no principled way has been identified to choose between its many proposed explanations. We investigated Weber's law by training rats to discriminate the relative intensity of sounds at the two ears at various absolute levels. These experiments revealed the existence of a psychophysical regularity, which we term time-intensity equivalence in discrimination (TIED), describing how reaction times change as a function of absolute level. The TIED enables the mathematical specification of the computational basis of Weber's law, placing strict requirements on how stimulus intensity is encoded in the stochastic activity of sensory neurons and revealing that discriminative choices must be based on bounded exact accumulation of evidence. We further demonstrate that this mechanism is not only necessary for the TIED to hold but is also sufficient to provide a virtually complete quantitative description of the behavior of the rats