Exclusion of sunlight from Shiraz grapes alters wine colour, tannin and sensory properties

The aim of this study was to determine how changes in grape composition brought about by artificial shading (sunlight exclusion) influence wine properties including colour, flavonoid composition and sensory attributes. Prior to flowering, bunches of Shiraz grapes were enclosed in boxes designed to eliminate light without altering bunch temperature and humidity. This artificial bunch shading had little effect on berry ripening and accumulation of sugar but at harvest the shaded bunches had smaller berries and higher seed weight, juice pH and titratable acidity. The amount of anthocyanins in the fruit was not changed significantly but anthocyanin composition in the shaded berries was shifted towards dioxygenated anthocyanins (the glucosides of cyanidin and peonidin derivatives). Shaded fruit had increased seed tannins and decreased skin tannins but the largest relative change in flavonoids was a marked decrease in flavonols in the shaded fruit, similar to previous studies. Wines made from shaded fruit had lower wine colour density, total phenolics, anthocyanins and tannins when the wine was bottled and after ageing for up to three years. Analysis of potential flavour compounds following acid hydrolysis indicated that the wines made from shaded fruit had decreased levels of glycosides of β-damascenone and 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN). Sensory analysis of the wines indicated no significant difference in aroma attributes but the wines made from shaded fruit were rated lower for astringency, fruit flavour and flavour persistence in-mouth sensory attributes. The results indicate that extreme shading of Shiraz fruit can decrease wine colour, anthocyanins and tannins as well as altering sensory attributes.     

America Town: Planning the Outposts of Empire

The U. S. military is clearly a driving force in this era of American empire. Given this empire's global reach, what are its local impacts? Crimes and contamination are the most obvious and well-publicized ones. Less well known are the policies and projects that have contributed to the creation of sprawling bases scattered across the globe. Although there are obvious ideological critiques to the presence of overseas bases, this article offers a unique and particular spatial critique. Underlying superficial attempts at architectural compatibility are policies of fear and desires for identity that drastically increase the economic, cultural, and political costs of empire's reach.     

Macro and File Structure Preservation in Source-to-source Translation

This paper describes a strategy for translating macro definitions and uses in the context of performing automated source-to-source translation between high-level programming languages. This translation technology enables macros and other preprocessor structures to be preserved in the generated source. It is useful for generating readable and maintainable code.     

ACHIEVING FLEXIBLE AUTONOMY IN MULTIAGENT SYSTEMS USING CONSTRAINTS

Organizations influence many aspects of our lives. They exist for one reason: they can accomplish things that individuals cannot. While recent work in high-autonomy systems has shown that autonomy is a critical issue in artificial intelligence (AI) systems, these systems must also be able to cooperate with and rely on one another to deal with complex problems. The autonomy of such systems must be flexible, in order that agents may solve problems on their own as well as in groups. We have developed a model of distributed problem solving in which coordination of problem-solving agents is viewed as a multiagent constraint-satisfaction planning problem. This paper describes the experimental testbed that we are currently developing to facilitate the investigation of various constraint-based strategies for addressing the coordination issues inherent in cooperative distributed problem-solving domains.     

COOPERATIVE NAVIGATION AND THE FACULTY OF LANGUAGE

This paper presents an approach to simulating the evolution of language in which communication is viewed as an emerging phenomenon with both genetic and social components. A model is presented in which a population of agents is able to evolve a shared grammatical language from a purely lexical one, with critical elements of the faculty of language developed as a result of the need to navigate in and exchange information about the environment.     

MEASURING UNCERTAINTY IN ROUGH SET THEORY

A well justified measure of uncertainty for rough set theory is presented along with an axiomatic derivation. The connection between this measure and classical measures of uncertainty is provided.     

MEASURING GRANULARITY IN EVIDENCE THEORY

A new measure of uncertainty for evidence theory is presented. The measure of granularity is similar in form to the Shannon entropy but depends on set size as well as weight. It also has connections to the Hartley measure and the granularity measure of rough set theory.     

In situ measurement of white wine absorbance in clear and in coloured bottles using a modified laboratory spectrophotometer

In situ absorbance of visible light by white wine in bottles was determined with a modified spectrophotometer. A linear correlation was obtained between absorbance at 420 nm (A₄₂₀) measured in a cuvette (10 mm pathlength) and absorbance of that same wine measured in a 750 mL Flint bottle (colourless transparent glass). In addition, 5 types of coloured bottles, Emerald Green, Classic Green, French Green, Georgia Green and Cobalt Blue , also yielded strong correlations. A₄₂₀ of white wine in bottles of Antique Green or Amber glass could not be measured directly due to a strong absorbance of that wavelength by the glass. However, a strong correlation was established between measurement of A₄₂₀ (cuvette) and A₅₄₀ for white wine in Antique Green bottles and between A₄₂₀ (cuvette) and either A₅₄₀ or A₆₀₀ for white wine in Amber bottles. The method employed a standard UV-Visible spectrophotometer with an inexpensive modified sample port, and proved applicable to bottles with diameters ranging from 62 mm (375 mL capacity half bottles) up to 81 mm (750 mL capacity Burgundy bottles). In situ absorbance measurements plus subsequent chemical analysis and sensory assessment of a Chardonnay wine in Antique Green bottles showed that the method provided an estimate of oxidation in this white wine. Wine absorbance spectra over the full visible range were obtained in the Flint bottle. Measurements of the absorbance of visible light by the glass of empty bottles could also be obtained and used as a form of quality control for glass bottle manufacture.     

A review of potassium nutrition in grapevines with special emphasis on berry accumulation

Potassium (K) is essential for vine growth and yield. Grape berries are a strong sink for K, particularly during ripening. Excess K levels in grape berries may have a negative impact on wine quality, mainly because it decreases free tartaric acid resulting in an increase in the pH of grape juice, must and wine. In Australia, high K status is common in most vineyards, which reflects the high K and high pH values of most Australian grape juice. This necessitates pH adjustment during the vinification process, and tartaric acid addition is a common practice in most Australian wineries. High K concentration may also lead to excessive loss of the additional tartaric acid by precipitation as potassium bitartrate and, as a consequence, pH adjustment becomes more difficult and expensive. Ensuring naturally low K levels in the berry will help reduce costs of input and waste management at the winery. Potential vineyard management options to manipulate berry K accumulation include selective use of rootstock/scion combination, canopy management and irrigation strategies. However, the impact of these practices on determining the optimum K concentration requires careful calibration of production parameters and the desirable grape juice and wine quality in relation to tissue K concentration. This paper reviews and discusses the possible functions of K in grape berries, translocation of K into the berry, and genetic and cultural factors that may affect the accumulation of K in the berry. This will help to identify the key research and management strategies needed for controlling K concentrations in grape berries.