Generalized Complex Spectral Decomposition for a Quantum Decay Process

By extending the notion of mixed states to functionals acting on the space of observables with diagonal singularity we obtain a well-defined complex spectral decomposition of the time evolution for a quantum decaying system. In this formalism, generalized Gamow states are obtained with well-defined physical properties.     

The Effect of Speaking Sample Duration on Determination of Habitual Pitch

The purpose of this study was to investigate if there was an effect of duration of speaking on determination of habitual pitch. Five speaking periods commonly used to elicit habitual pitch in clinical voice evaluations were compared (1, 5, 15, 30, and 60 seconds). Thirty female speakers with normal voices participated. Results of a within-subject univariate F-test revealed a statistically significant (p < 0.001) difference in habitual pitch among the speaking periods. Habitual pitch for the 1-second and 60-second speaking periods were found to be statistically significantly (p < 0.05) different than all remaining speaking periods, and the habitual pitch for the 30-second speaking period was found to be statistically significantly (p < 0.05) different than 60-second speaking period. Implications for the use of various speaking durations when determining habitual pitch are discussed, as is the possibility of a speaking duration effect on determination of other pitch-related voice parameters.     

Fluorescent Probe ABM for Screening Gastrointestinal Patient’s Immune State

The fluorescent probe-aminoderivative of benzanthrone, ABM (developed at Riga Technical University, Riga, Latvia) was used to characterize the membranes of lymphocytes of cancer patients: 46 patients with gastrointestinal diseases, 13 patients having different primary localizations with massive metastases and intoxication. Patients were divided into three groups: (1) with decreased fluorescence intensity, (2) normal fluorescence intensity, (3) increased fluorescence intensity. The lymphocytes distribution among subsets differed between groups, in correspondence to the level of florescence intensity. Surgical treatment affected the main immunological parameters and elevated the functional activity of lymphocytes. In the advanced tumors group, fluorescence intensity correlates with the survival rate. Results suggest that determination of lymphocytes functional activity by ABM can aid evaluation of the immune status in cancer patients.     

Analyzing complex networks evolution through Information Theory quantifiers

A methodology to analyze dynamical changes in complex networks based on Information Theory quantifiers is proposed. The square root of the Jensen-Shannon divergence, a measure of dissimilarity between two probability distributions, and the MPR Statistical Complexity are used to quantify states in the network evolution process. Three cases are analyzed, the Watts-Strogatz model, a gene network during the progression of Alzheimer's disease and a climate network for the Tropical Pacific region to study the El Niño/Southern Oscillation (ENSO) dynamic. We find that the proposed quantifiers are able not only to capture changes in the dynamics of the processes but also to quantify and compare states in their evolution.     

Wavelength-agile H2O absorption spectrometer for thermometry of general combustion gases

Using a novel Fourier-domain mode-locking (FDML) laser scanning 1330-1380 nm, we have developed a gas thermometer based on absorption spectroscopy that is appropriate for combustion gases at essentially arbitrary conditions. The path-integrated measurements are particularly useful in homogeneous environments, and here we present measurements in a controlled piston engine and a shock tube. Engine measurements demonstrate a RMS temperature precision of ±3% at 1500 K and 200 kHz bandwidth; the precision is improved dramatically by averaging. Initial shock tube measurements place the absolute accuracy of the thermometer within ∼2% to 1000 K. The sensor performs best when significant H₂O vapor is present, but requires only at 300 K, at 1000 K, or at 3000 K for 2% accurate thermometry, assuming a 4 kHz measurement bandwidth (200 kHz scans with 50 averages). The sensor also provides H₂O mole fraction and shows potential for monitoring gas pressure based on the broadening of spectral features. To aid in designing other sensors based on high-temperature, high-pressure H₂O absorption spectroscopy, a database of measured spectra is included.     

Fluorescent Probe ABM and Estimation of Immune State in Patients with Different Pathologies (Review Article)

The fluorescent probe ABM (3-aminobenzanthrone derivative) one of the fluorescent probes synthesized in Riga Technical University proved to be an excellent, independent model for studying cell membranes. In our work we have investigated the possibility of using the fluorescent probe ABM for detection of immune state in patients with different pathologies. There is a strong correlation among all studied ABM spectral parameters, immunological characteristics, clinical and laboratory investigations of the all observed patients groups. The obtained results suggest that ABM spectral parameters in cell suspension reflect the alterations of the cellular mechanisms of immunity. Therefore fluorescent method could be used as preliminary screening test in immune diagnostics instead of more expensive, time consuming methods (subset detection, radioisotope method etc.) used as routine in clinics. Spectral parameters of ABM reflect a wide range of interrelated (interdependent) characteristics of cells (physico-chemical state and microviscosity of membrane, proliferating and lipid metabolic activity of cells, distribution of cells among subsets). The observed change of the studied parameters reflects alterations of the cellular mechanisms of immunity which is a main focus for its application as preliminary screening test in immune diagnostics. The fluorescence based method is sensitive, less expensive and time consuming, technically simple and convenient.