Post deposition aging of bloodstains probed by steady-state fluorescence spectroscopy

Blood is one of the most common body fluids discovered at crime scenes involving violent actions. It is one of the most important types of forensic evidence since it allows for the identification of the individual providing that there is a match with a known DNA profile. Determining the time since deposition (TSD) can assist investigators in establishing when the crime occurred or if a bloodstain present is actually related to the investigated event. To develop a forensically sound method for determining the TSD of a bloodstain, it is necessary to understand the underlying biochemical mechanisms occurring during aging. As biochemical processes occurring in blood are necessary for the continued survival of living organisms, they are important subjects of human biology and biomedicine and are well understood. However, the biochemistry of bloodstain aging ex vivo is primarily of interest to forensic scientists and has not yet been thoroughly researched. This preliminary study utilizes steady-state fluorescence spectroscopy to probe the changes in fluorescence properties of peripheral and menstrual blood up to 24-h post deposition. Peripheral and menstrual blood exhibited similar kinetic changes over time, assigned to the presence of the fluorophores: tryptophan, nicotinamide adenine dinucleotide (NADH), and flavins in both biological fluids. The biochemical mechanism of blood aging ex vivo is discussed

Measurement of the η\eta -η′\eta' mixing angle in π−\pi^{-} and K−K^{-} beams with GAMS-4π4\pi Setup

The results of mixing angle measurement for $\eta'$, $\eta$ mesons generated in charge exchange reactions with $\pi^{-}$ and $K^{-}$ beams are preseneted. When the $\eta'$, $\eta$ mesons are described in nonstrange(NS)--strange(S) quark basis the $\pi^{-}$ and $K^{-}$ beams allow to study $|\eta_{q}>$ and $|\eta_{s}>$ parts of the meson wave function. The cross section ratio at $t'=0$ (GeV/c)$^{2}$ in the $\pi^{-}$ beam is $R_{\pi}(\eta'/\eta)= 0.56 \pm 0.04$, results in mixing angle $\phi_{P} = (36.8 \pm 1.)^{o}$. For $K^{-}$ beam the ratio is $R_{K}(\eta'/\eta)= 1.30 \pm 0.16$. It was found that gluonium content in $\eta'$ is $\sin^{2}\psi_{G}= 0.15 \pm 0.06$. The experiment was carried out with GAMS-4$\pi$ Setup.Comment: 6 pages, 4 figures, 1 table, to be submitted in European physical journal C. Minor changes, the Bibliography extende

Molecular gyroscopes and biological effects of weak ELF magnetic fields

Extremely-low-frequency magnetic fields are known to affect biological systems. In many cases, biological effects display `windows' in biologically effective parameters of the magnetic fields: most dramatic is the fact that relatively intense magnetic fields sometimes do not cause appreciable effect, while smaller fields of the order of 10--100 $\mu$T do. Linear resonant physical processes do not explain frequency windows in this case. Amplitude window phenomena suggest a nonlinear physical mechanism. Such a nonlinear mechanism has been proposed recently to explain those `windows'. It considers quantum-interference effects on protein-bound substrate ions. Magnetic fields cause an interference of ion quantum states and change the probability of ion-protein dissociation. This ion-interference mechanism predicts specific magnetic-field frequency and amplitude windows within which biological effects occur. It agrees with a lot of experiments. However, according to the mechanism, the lifetime $\Gamma^{-1}$ of ion quantum states within a protein cavity should be of unrealistic value, more than 0.01 s for frequency band 10--100 Hz. In this paper, a biophysical mechanism has been proposed that (i) retains the attractive features of the ion interference mechanism and (ii) uses the principles of gyroscopic motion and removes the necessity to postulate large lifetimes. The mechanism considers dynamics of the density matrix of the molecular groups, which are attached to the walls of protein cavities by two covalent bonds, i.e., molecular gyroscopes. Numerical computations have shown almost free rotations of the molecular gyros. The relaxation time due to van der Waals forces was about 0.01 s for the cavity size of 28 angstr\"{o}ms.Comment: 10 pages, 7 figure

Insight into resolution enhancement in generalized two-dimensional correlation spectroscopy

Generalized two-dimensional correlation spectroscopy (2D-COS) can be used to enhance spectral resolution in order to help differentiate highly overlapped spectral bands. Despite the numerous extensive 2D-COS investigations, the origin of the 2D spectral resolution enhancement mechanism(s) is not completely understood. In the work here, we studied the 2D-COS of simulated spectra in order to develop new insights into the dependence of 2D-COS spectral features on the overlapping band separations, their intensities and bandwidths, and their band intensity change rates. We found that the features in the 2D-COS maps that are derived from overlapping bands were determined by the spectral normalized half-intensities and the total intensity changes of the correlated bands. We identified the conditions required to resolve overlapping bands. In particular, 2D-COS peak resolution requires that the normalized half-intensities of a correlating band have amplitudes between the maxima and minima of the normalized half-intensities of the overlapping bands. © 2013 Society for Applied Spectroscopy

Development of university sports in Russia: Management and economics

The article is devoted to topical issues of the development of student sports in Russia, bearing in mind the issues of management of student sports and their financing. The experience of the development of student sports clubs of universities is summarized and possible prospects for the development of the economy of student sports are presented