The effect of mechanical harvesting on wines of Chenin blanc grapes in South Africa

Alternate rows of a Chenin blanc test vineyard in its 9th leaf on the experimental farm of the Oenological and Viticultural Research Institute, Stellenbosch, were harvested by hand and machine. The effects of harvesting temperature, MOG content and holding time of mechanically-harvested grapes on wine quality were evaluated; these wines were compared with wines from hand-harvested grapes. Results showed that increases in the MOG content, harvesting temperature and holding time singly or cumulatively caused an increase in the total polyphenols of the wines. Similarly, increases in MOG content, harvesting temperature and holding time were deleterious to wine quality and the effects were cumulative. Furthermore, a holding time of up to 4 h brought about no significant decrease in wine quality, provided the grapes were harvested at low temperatures. When grapes were harvested at high temperatures, the holding time had to be reduced to 3 h with a low MOG content in order to produce wines of similar quality. With high MOG content the quality significantly lower even with a holding time of only 1 h.Der Einfluß der maschinellen Traubenernte auf den Wein der Sorte Chenin blancin SüdafrikaIn einem Versuchsweinberg des Oenological and Viticultural Research Institute, Stellenbosch, wurden die Rebzeilen abwechselnd maschinell und von Hand gelesen. Der Einfluß der Lesetemperatur, der Wartezeit der Trauben zwischen Lese und Weinbereitung sowie der Verunreinigung (MOG) des maschinell geernteten Lesegutes auf die Weinqualität wurde untersucht; die so gewonnenen Weine wurden mit Weinen aus handgelesenen Trauben verglichen. Es zeigte sich, daß bei einer Steigerung von Lesetemperatur, Wartezeit der Trauben und MOG-Anteil der Gesamtpolyphenolgehalt in den Weinen zunahm. Diese Faktoren wirkten sich auch auf diesensorisch ermittelte Weinqualität nachteilig aus. Bei einer Wartezeit bis zu 4 h war bei niedrigem oder hohem MOG-Anteil kein ungünstiger Einfluß auf die Weinqualität nachweisbar, vorausgesetzt, daß die Trauben bei niedriger Temperatur gelesen wurden. Um bei höheren Lesetemperaturen Weine ähnlich guter Qualität zu erzielen, durfte die Wartezeit 3 h nicht überschreiten und mußte der MOG-Anteil niedrig sein. Bei hohem MOG-Anteil war die Weinqualität dagegen beträchtlich verringert, auch wenn die Wartezeit nur 1 h betrug

Heat sensitivity of the rat: heart rate conditioning with a thermal CS

Recent theoretical interpretations of the cutaneous sensory code may be categorized into non-specific temporal-spatial patterning explanations vs specific modality receptor mechanisms. Electrophysiological data based upon neurological responses of lower mammals to both mechanical and thermal stimulation support both positions

Experimental evidence of differences in the absorption spectra of clustered and isolated ions in erbium doped fibers

The absorption spectra of clustered and isolated ions in erbium-doped germanosilicate fibers have been experimentally studied. The ground state absorption spectra broaden as the degree of erbium-ion clustering increases, indicating that the absorption spectra of clustered ions is significantly different from that of the homogeneous ions. This is confirmed by comparing the broadened absorption spectra with the fibre unbleachable loss spectrum; a direct measurement of the clustered ions. This is the first experimental evidence indicating different absorption cross-sections for the two species of ions in germanosilicate glass, an assumption used in the theoretical description of self-pulsing in erbium doped fiber lasers, but in direct contradiction to the pair-induced quenching model widely used to characterise EDFAs

Normal-internal resonances in quasi-periodically forced oscillators: a conservative approach

We perform a bifurcation analysis of normal–internal resonances in parametrised families of quasi–periodically forced Hamiltonian oscillators, for small forcing. The unforced system is a one degree of freedom oscillator, called the ‘backbone’ system; forced, the system is a skew–product flow with a quasi–periodic driving with basic frequencies. The dynamics of the forced system are simplified by averaging over the orbits of a linearisation of the unforced system. The averaged system turns out to have the same structure as in the well–known case of periodic forcing ; for a real analytic system, the non–integrable part can even be made exponentially small in the forcing strength. We investigate the persistence and the bifurcations of quasi–periodic –dimensional tori in the averaged system, filling normal–internal resonance ‘gaps’ that had been excluded in previous analyses. However, these gaps cannot completely be filled up: secondary resonance gaps appear, to which the averaging analysis can be applied again. This phenomenon of ‘gaps within gaps’ makes the quasi–periodic case more complicated than the periodic case

Muckle-Wells syndrome in the setting of basal cell nevus syndrome.

Muckle-Wells syndrome (MWS) is a rare disorder inherited in an autosomal-dominant fashion that belongs to a group of hereditary periodic fever syndromes. It specifically belongs to the cryopyrin-associated periodic syndromes (CAPSs) in which there is a mutation in the NLR

Caffeine blocks disruption of blood brain barrier in a rabbit model of Alzheimer's disease

High levels of serum cholesterol and disruptions of the blood brain barrier (BBB) have all been implicated as underlying mechanisms in the pathogenesis of Alzheimer's disease. Results from studies conducted in animals and humans suggest that caffeine might be protective against Alzheimer's disease but by poorly understood mechanisms. Using rabbits fed a cholesterol-enriched diet, we tested our hypothesis that chronic ingestion of caffeine protects against high cholesterol diet-induced disruptions of the BBB. New Zealand rabbits were fed a 2% cholesterol-enriched diet, and 3 mg caffeine was administered daily in drinking water for 12 weeks. Total cholesterol and caffeine concentrations from blood were measured. Olfactory bulbs (and for some studies hippocampus and cerebral cortex as well) were evaluated for BBB leakage, BBB tight junction protein expression levels, activation of astrocytes, and microglia density using histological, immunostaining and immunoblotting techniques. We found that caffeine blocked high cholesterol diet-induced increases in extravasation of IgG and fibrinogen, increases in leakage of Evan's blue dye, decreases in levels of the tight junction proteins occludin and ZO-1, increases in astrocytes activation and microglia density where IgG extravasation was present. Chronic ingestion of caffeine protects against high cholesterol diet-induced increases in disruptions of the BBB, and caffeine and drugs similar to caffeine might be useful in the treatment of Alzheimer's disease