Atom in a coherently controlled squeezed vacuum

A broadband squeezed vacuum photon field is characterized by a complex squeezing function. We show that by controlling the wavelength dependence of its phase it is possible to change the dynamics of the atomic polarization interacting with the squeezed vacuum. Such a phase modulation effectively produces a finite range temporal interaction kernel between the two quadratures of the atomic polarization yielding the change in the decay rates as well as the appearance of additional oscillation frequencies. We show that decay rates slower than the spontaneous decay rate can be achieved even for a squeezed bath in the classic regime. For linear and quadratic phase modulations the power spectrum of the scattered light exhibits narrowing of the central peak due to the modified decay rates. For strong phase modulations side lobes appear symmetrically around the central peak reflecting additional oscillation frequencies.Comment: 4 pages, 4 figure

To the modification of methods of nuclear chronometry in astrophysics and geophysics

In practically all known till now methods of nuclear chronometry there were usually taken into account the life-times of only fundamental states of $\alpha$-radioactive nuclei. But in the processes of nuclear synthesis in stars and under the influence of the constant cosmic radiation on surfaces of planets the excitations of the $\alpha$-radioactive nuclei are going on. Between them there are the states with the excited $\alpha$-particles inside the parent nuclei and so with much smaller life-times. And inside the large masses of stellar, terrestrial and meteoric substances the transitions between different internal conditions of radioactive nuclei are accompanied by infinite chains of the $\gamma$-radiations with the subsequent $\gamma$-absorptions, the further $\gamma$-radiations etc. For the description of the $\alpha$-decay evolution with considering of such excited states and multiple $\gamma$-radiations and $\gamma$-absorptions inside stars and under the influence of the cosmic radiation on the earth surface we present the quantum-mechanical approach, which is based on the generalized Krylov-Fock theorem. Some simple estimations are also presented. They bring to the conclusion that the usual (non-corrected) "nuclear clocks" do really indicate not to realistic values but to the \emph{upper limits} of the durations of the $\alpha$-decay stellar and planet processes.Comment: 6 pages, Standard LaTeX v.2

Retinal nerve fiber layer thickness in subgroups of multiple sclerosis, measured by optical coherence tomography and scanning laser polarimetry

Optical coherence tomography (OCT) and scanning laser polarimetry (GDx ECC) are non-invasive methods used to assess retinal nerve fiber layer (RNFL) thickness, which may be a reliable tool used to monitor axonal loss in multiple sclerosis (MS). The objectives of this study are (1) to compare OCT with the GDx ECC; (2) to assess and compare the RNFL thickness in subgroups of MS. Ophthalmologic examination and RNFL assessment by OCT and GDx were performed in 65 MS patients (26 relapsing-remitting (RRMS), ten secondary-progressive (SPMS), 29 primary-progressive (PPMS)). Twenty-eight patients (43%) had a history of optic neuritis (ON). Adjustments were made for age and disease duration. RNFL thickness was reduced in eyes with previous ON (p < 0.01). No differences were found between PPMS and relapse-onset MS. OCT and GDx ECC measurements were moderately correlated (rho = 0.73, p < 0.01). Visual field-mean deviation (MD) values correlated with OCT means (r = 0.44, p < 0.01) and GDx ECC TSNIT average (r = 0.41, p < 0.01). In patients without previous ON, EDSS correlated with MD (r = -0.36, p < 0.01), visual field-pattern standard deviation (PSD) (r = 0.30, p < 0.05), OCT means (r = -0.31-0.30, p < 0.05) and macular volume (r = -0.37, p < 0.01). For MSIS-29 physical impact score, significant correlations were found with MD (r = -0.48, p < 0.01) and PSD (r = 0.48, p < 0.01). Conclusions: No differences between PPMS and relapse-onset MS subgroups were found. RNFL thickness was reduced in eyes with previous ON. Although OCT and GDx ECC findings were moderately correlated and showed significant correlations with measures of visual function in patients without previous ON, EDSS correlated significantly with visual and OCT measures, but not with GDx ECC

Mapping the proton drip line from Z=31 to Z=49

The structure of proton drip line nuclei in the 60 < A < 100 mass range is studied with the Relativistic Hartree Bogoliubov (RHB) model. For the elements which determine the astrophysical rapid proton capture process path, the RHB model predicts the location of the proton drip-line, the ground-state quadrupole deformations and one-proton separation energies at and beyond the drip-line. The results of the present theoretical investigation are compared with available experimental data. For possible odd-Z ground state proton emitters, the calculated deformed single-particle orbitals occupied by the odd valence proton and the corresponding spectroscopic factors are compared with predictions of the macroscopic-microscopic mass model.Comment: 20 pages, LaTeX, 6 eps figs, submitted to Nucl. Phys.

FAST CARS: Engineering a Laser Spectroscopic Technique for Rapid Identification of Bacterial Spores

Airborne contaminants, e.g., bacterial spores, are usually analyzed by time consuming microscopic, chemical and biological assays. Current research into real time laser spectroscopic detectors of such contaminants is based on e.g. resonant Raman spectroscopy. The present approach derives from recent experiments in which atoms and molecules are prepared by one (or more) coherent laser(s) and probed by another set of lasers. The connection with previous studies based on "Coherent Anti-Stokes Raman Spectroscopy" (CARS) is to be noted. However generating and utilizing maximally coherent oscillation in macromolecules having an enormous number of degrees of freedom is much more challenging. This extension of the CARS technique is called FAST CARS (Femtosecond Adaptive Spectroscopic Techniques for Coherent Anti-Stokes Raman Spectroscopy), and the present paper proposes and analyses ways in which it could be used to rapidly identify pre-selected molecules in real time.Comment: 43 pages, 21 figures; replacement with references added. Submitted to the Proceedings of National Academy of Science

Control of Raman Lasing in the Nonimpulsive Regime

We explore coherent control of stimulated Raman scattering in the nonimpulsive regime. Optical pulse shaping of the coherent pump field leads to control over the stimulated Raman output. A model of the control mechanism is investigated.Comment: 4 pages, 5 figure

A monitor for Cellular Oxygen METabolism (COMET): monitoring tissue oxygenation at the mitochondrial level

After introduction of the protoporphyrin IX-triplet state lifetime technique as a new method to measure mitochondrial oxygen tension in vivo, the development of a clinical monitor was started. This monitor is the “COMET”, an acronym for Cellular Oxygen METabolism. The COMET is a non-invasive electrically powered optical device that allows measurements on the skin. The COMET is easy to transport, due to its lightweight and compact size. After 5-aminolevulinic acid application on the human skin, a biocompatible sensor enables detection of PpIX in the mitochondria. PpIX acts as a mitochondrially located oxygen-sensitive dye. Three measurement types are available in the touchscreen-integrated user interface, ‘Single’, ‘Interval’ and ‘Dynamic measurement’. COMET is currently used in several clinical studies in our institution. In this first description of the COMET device we show an incidental finding during neurosurgery. To treat persisting intraoperative hypertension a patient was administered clonidine, but due to rapid administration an initial phase of peripheral vasoconstriction occurred. Microvascular flow and velocity parameters measured with laser-doppler (O2C, LEA Medizintechnik) decreased by 44 and 16% respectively, but not the venous-capillary oxygen saturation. However, mitochondrial oxygen tension in the skin detected by COMET decreased from a steady state of 48 to 16 mmHg along with the decrease in flow and velocity. We conclude that COMET is ready for clinical application and we see the future for this bedside monitor on the intensive care, operating theater, and testing of mitochondrial effect of pharmaceuticals

Rape in prison: A hidden epidemic

America\u27s prisons are filled. The war on crime has created a bulging prison system. Inside the jails and prisons, crime -- especially rape -- occurs every day. Traditionally, the rape of prisoners in the American prison system was either ignored or the subject of bad jokes. Recently, serious inquiry has begun into the incidence of sexual assault behind prison walls. This study examines prison rape. Using data generated as a result of the Prison Rape Elimination Act, along with statistics from national databases and testimony from victims of prison rape and their advocates, this study suggests that the incidence of rape in prison in this country is significantly higher than the occurrence of sexual assault on the street; that prison rapists and victims are not defined by gender; that prison rape can be a serial crime; and that this epidemic has profound and enduring consequences for its victims - and society

High-yield production of completely linear dextrans and isomalto-oligosaccharides by a truncated dextransucrase from Ligilactobacillus animalis TMW 1.971

Several lactic acid bacteria are capable of producing water-soluble exopolysaccharides such as dextran from sucrose by using glucansucrases. Several recombinant glucansucrases were described, however, yields were often limited and most dextrans were branched at position O3. In this study, the dextransucrase from Ligilactobacillus animalis TMW 1.971 was recombinantly produced without its N-terminal variable region and used for dextran synthesis. The enzyme expressed well and showed very high total as well as transferase activities compared to other glucansucrases. It was able to transfer nearly all glucose from sucrose to oligo- and polymeric products under certain conditions (about 95 % of glucose transferred). The high efficiency of the enzyme made it possible to obtain absolute dextran yields of up to 214.9 g/L from a 1.5 M sucrose solution. Structural characterization of the products showed that the dextrans produced have a rather low molecular weight, a narrow size distribution, and are completely linear. Furthermore, we showed that various low molecular weight dextrans or 1,6-linked isomalto-oligosaccharides can be efficiently produced by acid hydrolysis. Overall, we demonstrated that Ligilactobacillus animalis TMW 1.971 dextransucrase can be used to efficiently synthesize dextrans with a quite unique structural composition. The dextrans produced have a high potential for further applications such as synthesis of copolymers or size standards with a very defined molecular structure

Screening of 14 lactic acid bacteria for fermentative isomalto/malto-polysaccharide synthesis

Some lactic acid bacteria such as Limosilactobacillus reuteri or Fructilactobacillus sanfranciscensis contain genes encoding 4,6-α-glucanotransferases. These enzymes convert starch and maltodextrins into isomalto/malto-polysaccharides (IMMPs). Many studies focused on the properties of recombinant glucanotransferases, but limited knowledge is available on fermentative synthesis. However, this aspect would be important for the in situ IMMP formation in fermented foods such as sourdough. Therefore, the aim of this study was to investigate the IMMP synthesis of 14 different lactic acid bacteria. We demonstrated that 11 of the investigated strains formed IMMPs with varying structural compositions from different maltodextrins. The portions of α-1,6-linkages depended on the bacterial strain and composition of the maltodextrin. By using different analytical approaches, it was demonstrated that linear chains of α-1,6-linked glucopyranoses with varying lengths were formed. Thus, the 11 IMMP-producing strains have high potential for an in situ synthesis of IMMPs in fermented foods such as sourdough