Chronotype is an established concept designed to identify distinct phase relationships between the expression of circadian rhythms and external synchronizers in humans. Although it has been widely accepted that chronotype is subjected to ontogenetic modulation, there is no consensus on the interaction between age and gender. This study aimed to determine the relationship between age- and gender-related changes in the morningness-eveningness character in a large sample of people. A total of 14,650 volunteers were asked to complete the Brazilian version of the Horne and Östberg chronotype questionnaire. The data demonstrated that, on average, women were more morning-oriented than men until the age of 30 and there were no significant differences between men and women from 30 to 45 years of age. In contrast to the situation observed until the age of 30, women older than 45 years were more evening-oriented than men. These results suggest that the ontogenetic development of the circadian timekeeping system is more plastic in men, as represented by the larger amplitude of chronotype changes throughout their aging process. The phase delay of adolescence and phase advance of the elderly seem to be phenomena that are more markedly present in men than in women. Thus, our data, for the first time, provide support that sharply opposes the view that there is a single path toward morningness as a function of age, regardless of gender.

We have studied the in influence of the mean molecular length on the nature of the cholesteric (N*) – smectic A (A) liquid crystal phase transition for thermotropic compounds of cholesteryl myristate (C14), cholesteryl nonanoate (C9), and binary mixtures of C14 – C9 and cholesteryl caproate (C6) phase (dA), the mean molecular length (<img src="http:/img/fbpe/bjp/v32n2b/07eq01.gif">) in the N* domain, and the correlation length (epsilon), as well as changes along the N* – A phase transition, were determined from the X-ray diffraction data. The results show a decrease in A phase domain and an expansion of the N* – domain as the mean molecular length is diminished. Such effect induces a second order A – N* phase transition for a particular mixture of 63.1 mol% of C9 and 36.9 mol% of C6, evidenced by viscosity measurements in good agreement with previous density data.

Chronotype is an established concept designed to identify distinct phase relationships between the expression of circadian rhythms and external synchronizers in humans. Although it has been widely accepted that chronotype is subjected to ontogenetic modulation, there is no consensus on the interaction between age and gender. This study aimed to determine the relationship between age- and gender-related changes in the morningness-eveningness character in a large sample of people. A total of 14,650 volunteers were asked to complete the Brazilian version of the Horne and Östberg chronotype questionnaire. The data demonstrated that, on average, women were more morning-oriented than men until the age of 30 and there were no significant differences between men and women from 30 to 45 years of age. In contrast to the situation observed until the age of 30, women older than 45 years were more evening-oriented than men. These results suggest that the ontogenetic development of the circadian timekeeping system is more plastic in men, as represented by the larger amplitude of chronotype changes throughout their aging process. The phase delay of adolescence and phase advance of the elderly seem to be phenomena that are more markedly present in men than in women. Thus, our data, for the first time, provide support that sharply opposes the view that there is a single path toward morningness as a function of age, regardless of gender.

Winery hygiene is a key factor to wine quality. In this work the effectiveness of four sanitising commercial products over stainless steel tanks was evaluated at a pilot scale. To carry out the experiment a young, untreated red wine, with a very high microbial contamination was distributed by stainless steel tanks where it stood for 70 to 80 days. After that contact time, the tanks were cleaned with an alkaline detergent and sanitised with the four products under study in three concentrations (in triplicate). The monitoring of the process was performed by ATP bioluminescence and traditional plate counts for yeasts, lactic acid bacteria and acetic acid bacteria. Weak correlation was found between the results obtained by the two methodologies. Higher concentrations than the lower recommended for the two oxidising products (peroxyacetic acid and permanganate based) were necessary in order to achieve satisfactory cleanliness. Inferior concentration than the lower recommended was necessary for the products indicated to clean in one step, but it should be noted that in the present work a previous cleaning procedure was conducted.

Alcoholic fermentation of grape must is a dynamic process involving diverse yeast populations which play an important role in wine characteristics. In order to enable a permanent control by the oenologist rapid and low cost methodologies to identify the species of yeasts present during fermentation should be implemented. Single Strand Conformation Polymorphism technique (SSCP), targeting D1 and D2 domains of 26S rDNA, was tested to differentiate wine yeast species. SSCP profiles were produced for 17 collection strains belonging to 15 different wine related yeast species. The technique was further investigated for the identification of yeasts inoculated to sterile grape must as single or in mixtures of two different species. Identical SSCP profiles were obtained from yeasts grown in grape must and in conventional growth media. SSCP allowed obtaining species specific bands, and SSPC profiles from grape must inoculated with mixtures of two strains revealed the presence of specific bands of both species. Direct SSCP yeast analysis of a spontaneous fermenting must carried out after 48 and 192 h of fermentation, enabled to compare the yeast community at two different periods of fermentation. SSCP profiles showed the presence of bands from species associated with the beginning and the end of fermentation, respectively at 48 and 192 h of fermentation. We conclude that SSCP is a quite promising methodology to monitor yeast populations present during grape must fermentation, which revealed to be easy to implement and low-priced.