High-precision cavity-enhanced spectroscopy for studying the H2-Ar collisions and interactions.

Information about molecular collisions is encoded in the shapes of collision-perturbed molecular resonances. This connection between molecular interactions and line shapes is most clearly seen in simple systems, such as the molecular hydrogen perturbed by a noble gas atom. We study the H2-Ar system by means of highly accurate absorption spectroscopy and ab initio calculations. On the one hand, we use the cavity-ring-down-spectroscopy technique to record the shapes of the S(1) 3-0 line of molecular hydrogen perturbed by argon. On the other hand, we simulate the shapes of this line using ab initio quantum-scattering calculations performed on our accurate H2-Ar potential energy surface (PES). In order to validate the PES and the methodology of quantum-scattering calculations separately from the model of velocity-changing collisions, we measured the spectra in experimental conditions in which the influence of the latter is relatively minor. In these conditions, our theoretical collision-perturbed line shapes reproduce the raw experimental spectra at the percent level. However, the collisional shift, δ0, differs from the experimental value by 20%. Compared to other line-shape parameters, collisional shift displays much higher sensitivity to various technical aspects of the computational methodology. We identify the contributors to this large error and find the inaccuracies of the PES to be the dominant factor. With regard to the quantum scattering methodology, we demonstrate that treating the centrifugal distortion in a simple, approximate manner is sufficient to obtain the percent-level accuracy of collisional spectra.

The use of bioactive properties of sage preparations to improve the storage stability of low-pressure mechanically separated meat from chickens2.

The aim of this study was to determine the effect of Salvia officinalis L. (sage) preparations on the storage stability of vacuum-packed low-pressure mechanically separated meat (MSM) from chickens stored at -18°C for 9 mo. Chilled low-pressure MSM coming from 4 production batches was obtained from the plant located in north-eastern Poland. All sage preparations-a water extract, ethanol extracts, and an essential oil-were prepared and added to the MSM under laboratory conditions. Five samples of low-pressure MSM were prepared that differed in terms of the type of sage preparation added: control-without addition of sage, WE-2.0% addition of water extract from sage, E40-2.0% addition of 40% (vol/vol) ethanol extract from sage, E70-2.0% addition of 70% (vol/vol) ethanol extract from sage, and EOS-0.1% addition of essential oil from sage. The MSM samples were assessed immediately after arrival into the laboratory and after 1, 2, 3, 4, 6, and 9 mo of storage. The quality changes of MSM samples were determined on the basis of the thiobarbituric acid reactive substances (TBARS) index and microbial analyses. On the basis of the TBARS index it was proved that addition of essential oil and (40% and 70% (vol/vol)) as well as water extracts of sage significantly (P < 0.05) slowed down fat oxidation processes in low-pressure MSM from chickens. The growth of mesophilic aerobic bacteria and psychrotrophic bacteria, coliforms, and Enterobacteriaceae was significantly (P < 0.05) restricted by all sage preparations tested. The most effective inhibitory effect for groups of bacteria analyzed in this study was demonstrated by sage essential oil, despite insignificant (P > 0.05) differences between the preparations. In conclusion, it was found that sage preparations are rich in bioactive compounds. Due to their antioxidant and antibacterial properties, especially sage oil and ethanol extracts may be recommended as an auxiliary factor to prolong the storage stability of frozen, vacuum-packed low-pressure MSM from chickens.

Anthropogenic- and natural sources of dust in peatland during the Anthropocene.

As human impact have been increasing strongly over the last decades, it is crucial to distinguish human-induced dust sources from natural ones in order to define the boundary of a newly proposed epoch - the Anthropocene. Here, we track anthropogenic signatures and natural geochemical anomalies in the Mukhrino peatland, Western Siberia. Human activity was recorded there from cal AD 1958 (±6). Anthropogenic spheroidal aluminosilicates clearly identify the beginning of industrial development and are proposed as a new indicator of the Anthropocene. In cal AD 1963 (±5), greatly elevated dust deposition and an increase in REE serve to show that the geochemistry of elements in the peat can be evidence of nuclear weapon testing; such constituted an enormous force blowing soil dust into the atmosphere. Among the natural dust sources, minor signals of dryness and of the Tunguska cosmic body (TCB) impact were noted. The TCB impact was indirectly confirmed by an unusual occurrence of mullite in the peat.

Application of a computer vision system to classify beef as normal or dark, firm, and dry.

The purpose of this research was to evaluate the possibility of using computer vision systems (CVS) to detect DFD beef. The experimental material consisted of beef obtained from 60 carcasses (M. semimembranosus) that were 48 h postmortem. The beef was classified into 2 quality groups according to pH: normal (pH < 5.8) or DFD (pH ≥ 5.8). L*, a*, and b* color components were determined in the experimental materials using both CIELab and a CVS using 3 color models: RGB (red, green, blue), HSV (hue, saturation, value), and HSL (hue, saturation, lightness). The total heme pigment content also was determined. As determined by both CIELab and CVS, DFD meat was characterized by a darker color than normal beef. Color lightness, as determined using both CIELab and CVS, can also be used to detect DFD beef. A significant relationship was found between V (r = -0.79) and L (r = -0.77) using CVS and pH, which is an indicator of DFD beef. This finding indicates the possibility of using these color components to assess the pH level of beef.

[Daily fat consumption by the population of Warsaw]. / Spozycie tluszczu w codziennej diecie ludnosci Warszawy.

Fat intake with the diet has been assessed within screening Pol-MONICA--Warsaw Project in randomly selected sample of Warsaw inhabitants aged between 35 and 64 years. Altogether 2571 individuals have been screened. Fat intake in daily diet has been estimated by the 24-hour recall technique. In men, fat intake covered 38.4% of the total energy supply with the diet whereas in female population - 37.7%. Mean contribution of SFA and P/S ratio in both sex groups have been 15.8% and 0.285, respectively. Daily cholesterol intake has been 641 mg (224 mg/1000 kcal) in male and 456 mg (227/1000 kcal) in female population. These values did not change significantly with the age of the screened individuals. Such a diet may be considered atherogenic.