Noisy metrology beyond the standard quantum limit.

Parameter estimation is of fundamental importance in areas from atomic spectroscopy and atomic clocks to gravitational wave detection. Entangled probes provide a significant precision gain over classical strategies in the absence of noise. However, recent results seem to indicate that any small amount of realistic noise restricts the advantage of quantum strategies to an improvement by at most a multiplicative constant. Here, we identify a relevant scenario in which one can overcome this restriction and attain superclassical precision scaling even in the presence of uncorrelated noise. We show that precision can be significantly enhanced when the noise is concentrated along some spatial direction, while the Hamiltonian governing the evolution which depends on the parameter to be estimated can be engineered to point along a different direction. In the case of perpendicular orientation, we find superclassical scaling and identify a state which achieves the optimum.

[Nonspecific adhesion of Staphylococcus aureus strains to solid surfaces]. / Niespecyficzna przyczepnosc komórek Staphylococcus aureus do powierzchni stalych.

Autoagregating strains of bacteria are characterised by high surface hydrophobicity, which determines their ability to adhesion. An assessment was done of non-specific adhesion to solid surfaces of S. aureus strains isolated from blood, pus and nasopharynx of hospitalised people. The method used made possible differentiation of strains, which were studied, on the basis of their surface characteristics. Their properties decide about the abilities of strains to the colonisation of host tissues and at the same time they influence their potential virulence. In the study attention was also paid to the participation of surface proteins in the processes of adhesion cells to glass surfaces.

[Protozoa as reservoirs for human bacterial pathogens]. / Pierwotniaki jako rezerwuary chorobotwórczych dla czlowieka bakterii.

The ability of bacterial pathogens to survive within the human host cells results from their evolutional adaptation of which the most important stage could be the development of parasitic relations between bacteria and free-living protozoa. This paper shows the bacterial species, pathogenic for man, surviving in protozoans cells.

Antibiotic resistance and phage types of faecal Klebsiella isolated from healthy zoo apes.

The isolated species of Klebsiella were characterized by biotyping and phage typing methods. The majority of strains were resistant to certain examined drugs. For epidemiological reasons these strains can be potentially dangerous to the population of zoo animals.

Effect of some quaternary benzylammonium salts on physiology of yeast.

In order to determine the biological activity of eight compounds belonging to a group of quaternary ammonium salts, their influence on the active methionine transport, the integrity of cell membranes, respiration, and viability of Saccharomyces cerevisiae and some other yeast species has been investigated. The earliest effect observed during ammonium salts action on yeast cells is an immediate methionine transport abolishment followed by its fast leakage, which indicates increasing cell membrane degradation. Gradual decline of other biological functions such as respiration and viability is thus a result of disintegration and lack of tightness of the cell membranes. The studied compounds are characterized by a rather unspecific spectrum of action on yeast resulting in irreversible damage of cell walls and cell membranes, which in consequence leads to cell death.

pif mutation blocks recombination between mitochondrial rho+ and rho- genomes having tandemly arrayed repeat units in Saccharomyces cerevisiae.

Three allelic nuclear mutants affected in the recombination of mtDNA have been characterized in Saccharomyces cerevisiae and assigned to the PIF locus. In the mutants, the general recombination measured by the recombination frequency between linked or unlinked alleles is normal. However, the pif mutations prevent the integration into the rho+ genome of the markers (oli1, oli2, diu1, ery, oxi1, oxi2) of those rho- genomes that have tandemly arrayed repeat units. Therefore, these rho- genomes characterize a PIF-dependent recombination system. The pif mutations have also revealed the existence of a PIF-independent recombination system used by those rho- genomes that have an inverted organization of their repeat units. The markers of such palindromic rho- genomes exhibit high integration frequency into the rho+ genome even in the presence of the pif mutation. In addition, the pif mutations greatly increase suppressiveness in crosses between pif rho+ strains and PIF-dependent as well as PIF-independent rho- clones. We conclude that the recombination between rho+ and rho- genomes involves at least two distinct systems that depend on the organization of the rho- genome.

Light effects in yeast: relation between the respiratory deficiency and light sensitivity in yeast.

Visible light of 5,000 lux intensity has been shown to photokill yeast cells at 12 degrees C. In the present report some of isogenic respiratory deficient mit- and nuclear mutants were compared for their sensitivity to light. No close correlation between the cytochromes spectra and light resistance was observed. Although, the nuclear and rho- mutants which lack cytochromes a + a3 and b are as a rule light resistant. Photokilling effect in yeast seems to be dependent both on the sufficiency of respiratory chain and on protein synthesis probably on cytoplasmic level.

The lethal effects of some onolophosphate insecticides on yeast Saccharomyces cerevisiae.

Thre enolophosphate insecticides (chlorphenvinphos: 0-/-/2',4'-dichlorophenyl/-2-chlorovinyl/diethyl phosphate, bromphenvinphos: 0-/1-/2',4'-dichlorophenyl/-2-bromovinyl/diethyl phosphate, mebromvinphos: 0-/1-/2',4'-dichlorophenyl/-2-bromovinyl/dimethyl phosphate) have been tested for their biological activity in baker's yeast. The results indicate that the chemicals exert an immediate hibitory effect on amino acid transport system, respiration, fermentation and ell growth. Consequently the effect of precipitous cell death also occurred. Furthermore the direct destroying action of the studied chemicals on protoplast as also observed. The main cause of cell death is the development of membrane leakiness. It was found that the loss of sugar transport activity parallels the loss of cell viability. All the studied insecticides showed negligible netic activity.

Comparison of some Shigella flexneri (Escherichia coli) hybrids in cross agglutination and agglutinin absorption tests.

Antigenic structure of Lac+ hybrids selected from Escherichia coli x Shigella flexneri crosses was compared in the cross agglutination and absorption tests. Identity of the hybrids from the recipients of serotype 2a and variant Y was proved, as well as from serotypes 1b and 4b. The latter hybrids were coupled with Shigella flexneri strains 3a, 3b and 3c. The hybrids appeared almost identical with serotype 3c.

Respiratory mutation and galactose metabolism in yeast Saccharomyces cerevisiae.

Restriction in growth on galactose as unique source of energy due to respiratory deficiency resulting from mutation in a gene gal probably different from gal 3 is described.

[Immunologic properties of various cell fractions of a wild strain and a mutant strain of Saccharomyces cerevisiae Hansen]. / Propriétés immunologiques de diverses fractions de la paroi d'une souche sauvage et d'une souche mutante de Saccharomyces cerevisiae Hansen.

Some fractions of the Saccharomyces cerevisiae cell wall have been prepared by the action of Helix pomatia juice on intact cells. Immunosera were obtained by injecting rabbits with these fractions. Immunofluorescence reactions, obtained with these sera, show that some fractions of mannopeptides when extracted from a "smooth-colony" mutant strain, have lost antigenic determinants.

Comparative serologic analysis of Lac+ recombinants of serotypes 2a, 2b, 5a and variant Y of Shigella flexneri.

The serologic structure of Lac+ recombinants of 2a, 2b, 5a and var. Y serotypes of Sh. flexneri was compared. Rec. 2a Lac+, rec. 2b Lac+ and rec. Y Lac+ were shown to be identified, and rec. 5a Lac+ was found to differ from those mentioned in that it was deficient in determinants for 3,4 group antigen complex. Furthermore, the paper discusses the presumable genetic mechanisms of the described variability.