The novel transcriptional regulator SczA mediates protection against Zn2+ stress by activation of the Zn2+-resistance gene czcD in Streptococcus pneumoniae

Maintenance of the intracellular homeostasis of metal ions is important for the virulence of many bacterial pathogens. Here, we demonstrate that the czcD gene of the human pathogen Streptococcus pneumoniae is involved in resistance against Zn2+, and that its transcription is induced by the transition-metal ions Zn2+, Co2+ and Ni2+. Upstream of czcD a gene was identified, encoding a novel TetR family regulator, SczA, that is responsible for the metal ion-dependent activation of czcD expression. Transcriptome analyses revealed that in a sczA mutant expression of czcD, a gene encoding a MerR-family transcriptional regulator and a gene encoding a zinc-containing alcohol dehydrogenase (adhB) were downregulated. Activation of the czcD promoter by SczA is shown to proceed by Zn2+-dependent binding of SczA to a conserved DNA motif. In the absence of Zn2+, SczA binds to a second site in the czcD promoter, thereby fully blocking czcD expression. This is the first example of a metalloregulatory protein belonging to the TetR family that has been described. The presence in S. pneumoniae of the Zn2+-resistance system characterized in this study might reflect the need for adjustment to a fluctuating Zn2+ pool encountered by this pathogen during infection of the human body

Toward a better understanding of the relation between music preference, listening behavior, and personality

Item does not contain fulltextPrevious research relating personality and music preferences has often measured such reported preferences according to genre labels. To support previous research, the current paper has expanded investigation of the relation between personality and music preferences to include direct measurement of music listening behavior. A study (N = 395) measured participants' personality, reported music preferences, and their listening behavior, which was tracked while using a music database for a minimum period of three months. Results indicated that reported music preferences were correlated to listening behavior, and indicated robust positive relations between Neuroticism and Classical music preference, and between Openness to Experience and Jazz music preference. Results also indicated issues when using genre labels to measure music preferences, which are discussed

Modelling firms propensity to continue service exporting: a cross-country analysis

The pivotal role of services in international business is now receiving widespread recognition. Furthermore, the global marketplace is being increasingly characterised by the speed and ease with which such services cross national boundaries. This exploratory study of Australian and Dutch service exporters provides, for the first time, an understanding of the factors that stimulate such exporters to continue on the internationalisation path. Our results confirm that the level of satisfaction/dissatisfaction with recent past export efforts, export revenue as a percentage of total sales (a measure of export commitment), as well as other more traditional motives for exporting, do explain a reasonable proportion of the variance in propensity to continue exporting. However, some interesting variations emerged between Australian and Dutch firms in their motives to continue exporting