Showing papers by "University of Southern Denmark published in 1990"

(Tetrakis(2-pyridylmethyl)ethylenediamine)iron(II) perchlorate, the first rapidly interconverting ferrous spin-crossover complex

Abstract: The preparation and characterization of the first Fe II spin-crossover complex that interconverts between high- and low-spin states at a rate faster than the 57 Fe Mossbauer time scale is reported. [Fe(tpen)](ClO 4 ) 2 .2/3H 2 O crystallizes in the monoclinic space group C2/c.

The hok killer gene family in gram-negative bacteria.

Abstract: The seven members of the hok killer gene family in Gram-negative bacteria are described here. The members of this gene family have been sequenced and include hok/sok from plasmid R1, flm and srnB from plasmid F, pnd from plasmids R483 and R16, and gef and relF, which are located on the Escherichia coli chromosome. The killer proteins encoded by these loci are highly toxic polypeptides of 50 to 52 amino acids. The proteins kill the cells from the inside by interfering with a vital function in the cell membrane. On the basis of their relatedness, the killer proteins and their corresponding loci are divided into four subfamilies. The members of one subfamily, hok/sok and flm, mediate plasmid maintenance by killing plasmid-free cells. The pnd and srnB subfamilies were discovered through their abilities to cause membrane damage and degradation of stable RNA. gef and relF, which constitute the chromosomal subfamily, were found because of their sequence similarity at the DNA and protein levels with other members of the hok gene family. However, no function has been described for the proteins belonging to this subfamily. Although the four subfamilies are distantly related in terms of DNA and protein sequence similarity, the overall genetic organization of the different loci has been well conserved during evolution. The expression of all of the members of the hok gene family is regulated post-transcriptionally. Thus, the expression of the hok and flm genes is regulated by small antisense RNAs that inhibit the translation of the stable hok and flm mRNAs. On the basis of structural and functional similarities, we suggest that each of the related plasmid-encoded killer genes is regulated by antisense RNAs. The conservation of this widespread gene family in Gram-negative bacteria suggests that the genes are important to the genomes that carry them.

The hok killer gene family in Gram-negative bacteria

Abstract: The seven members of the hok killer gene family in Gram-negative bacteria are described here. The members of this gene family have been sequenced and include hok/sok from plasmid R1, flm and srnB from plasmid F, pnd from plasmids R483 and R16, and gef and relF, which are located on the Escherichia coli chromosome. The killer proteins encoded by these loci are highly toxic polypeptides of 50 to 52 amino acids. The proteins kill the cells from the inside by interfering with a vital function in the cell membrane. On the basis of their relatedness, the killer proteins and their corresponding loci are divided into four subfamilies. The members of one subfamily, hok/sok and flm, mediate plasmid maintenance by killing plasmid-free cells. The pnd and srnB subfamilies were discovered through their abilities to cause membrane damage and degradation of stable RNA. gef and relF, which constitute the chromosomal subfamily, were found because of their sequence similarity at the DNA and protein levels with other members of the hok gene family. However, no function has been described for the proteins belonging to this subfamily. Although the four subfamilies are distantly related in terms of DNA and protein sequence similarity, the overall genetic organization of the different loci has been well conserved during evolution. The expression of all of the members of the hok gene family is regulated post-transcriptionally. Thus, the expression of the hok and flm genes is regulated by small antisense RNAs that inhibit the translation of the stable hok and flm mRNAs. On the basis of structural and functional similarities, we suggest that each of the related plasmid-encoded killer genes is regulated by antisense RNAs. The conservation of this widespread gene family in Gram-negative bacteria suggests that the genes are important to the genomes that carry them.

Directionality of Blackbird vocalization. Implications for vocal communication and its further study

Abstract: Etude des emissions sonores chez Tur dus merula et plus particulierement des variations d'intensite d'une emission dans l'espace. Une comparaison des emissions artificielles a travers la carcasse d'un animal mort est realisee. Les distorsions sonores induites par l'utilisation d'un appareil enregistreur et emetteur sont analysees afin de determiner les problemes que pose l'utilisation de cette technique de restitution de sons

(Tetrakis(2-pyridylmethyl)ethylenediamine)iron(II) Perchlorate, the First Rapidly Interconverting Ferrous Spin-Crossover Complex.

Abstract: The preparation and characterization of the first Fe II spin-crossover complex that interconverts between high- and low-spin states at a rate faster than the 57 Fe Mossbauer time scale is reported. [Fe(tpen)](ClO 4 ) 2 .2/3H 2 O crystallizes in the monoclinic space group C2/c.

Performing Conjoint Analysis Using PROC TRANSREG

Abstract: Conjoint Analysis is a frequently used technique when analyzing concepts for new products and/or services. According to a recent review of 1000 commercial studies, more than 50% of the studies used OLS-regression (and about 10% Monotonic Analysis of Variance, LOGIT, and Linear Mapping respectively) with regard to the estimation procedure involved. The paper compares PROC REG and PROC TRANSREG as procedures for aggregating the data and estimating the conjoint-model. The aim of the empirical study involved was to help politicians to formulate appropriate political marketing strategies and the data were gathered prior to a political election.