The effect of the repeated experience of aggression in daily confrontations on the individual and social behavior of male mice

The influence of repeated experience of aggression in daily intermale confrontations on individual and social behaviour was studied in male mice of C57BL/6J (C57) and CBA/Lac (CBA) strains. Repeated experience of aggression led to a decrease of emotionality in males of highly emotional CBA strain and increase in exploratory activity in the open field and exploratory activity tests, decrease of immobility time in Porsolt's test and pain sensitivity estimated by the "hot plate" test. Low emotional C57 males did not change their individual behaviour in different situations under the influence of repeated experience of aggression. However, aggressive C57 mice demonstrated anxiety-like behaviour estimated in the plus-maze test. In the partition test aggressive mice of both strains showed an increase in communicative level (as a reaction to a familiar male) in comparison with their behaviour before aggressive confrontations. Behavioural reaction to a receptive female under unfamiliar conditions decreased which testified to a decrease in sexual motivation. It is concluded that formation of the aggressive type of social behaviour is accompanied by changes in the individual and social behaviour of male mice. Characteristics of these changes are genetically determined and depend on the duration of confrontations.     

波希米亚官邸

建于上世纪60年代的波希米亚官邸,位于皇后西街,这里曾是一间充满着传奇色彩的咖啡屋,也是当时多伦多民歌文化和爵士文化一个非常重要的聚会地点.     

Mutation of the conserved Gly94 and Gly126 in elongation factor Tu from Escherichia coli. Elucidation of their structural and functional roles

All guanine-nucleotide-binding proteins cycle between an inactive, GDP-bound and an active, GTP-bound conformation whereby they function as molecular switches. Elongation factor Tu from Escherichia coli is used as a model for defining residues important in the switch mechanism. Gly94 and Gly126 were separately mutated to alanine residues to study their role in the switch mechanism. The mutant proteins are denoted [G94A]EF-Tu and [G126A]EF-Tu, respectively. Both mutations affect the affinities for guanine nucleotides considerably, resulting in a decrease in the characteristic preference for GDP over GTP. Furthermore the [G94A]EF-Tu mutant possesses an increased GTPase activity. The aminoacyl-tRNA affinity is much reduced for [G94A]EF-Tu, as reflected in an increase of the dissociation rate constant for the ternary complex by a factor of 40. Surprisingly, however, both mutants in their GDP forms have a low, but significant affinity for aminoacyl-tRNA, which is not seen for the wild-type elongation factor Tu. The mutants only exhibit minor changes compared to the wild type with respect to in vitro translation of a poly(U) messenger.     

The regional characteristics of the health of the population and policy in the public health field

We compared the antimicrobial activities of two rigid gas permeable (RGP) lens care systems, a one-step wetting and soaking system (0.005% chlorhexidine gluconate, 0.02% EDTA) and a conditioning solution (0.006% chlorhexidine gluconate, 0.05% EDTA). The formulations were individually inoculated with approximately 10(6) CFU/mL of a pathogenic organism. Both the one-step wetting and soaking system and the conditioning solution demonstrated good antimicrobial efficacy against Pseudomonas aeruginosa, Staphylococcus epidermidis, Serratia marcescens, and Aspergillus fumigatus. However, the one-step wetting and soaking system provides better disinfection against Candida albicans (1.2 log reduction in 4 hours) than the conditioning solution (0.39 log reduction in 4 hours). The one-step system also reduced S. marcescens by 5 logs in 1 hour, whereas the conditioning solution reduced S. marcescens by about 2 logs only in the same time interval. Although both RGP lens care systems use the same active preservative (chlorhexidine digluconate), the variation in disinfecting activities may be attributed to differences in formulation and buffer systems.     

The radiation therapy of skin cancer of the face

Results of three-year radiotherapy are assessed in 586 patients with skin cancer, with tumors localized on the skin of the face in 484 of these. The results of treatment were found to depend on the histological structure of the tumor and disease stage: 100% cure was attained in patients with basal-cell carcinomas and T1 stage, whereas only 7% of patients with T4 stage were cured; in patients with squamous-cell carcinoma these figures were, respectively, 96.2 and 10%.