Active packaging containing nisin and high pressure processing as post-processing listericidal treatments for convenience fermented sausages

Listeria monocytogenes was inoculated on the surface of sliced fermented sausages with no added sodium salt. The pathogen was progressively inactivated during the product shelf life (90 days). Antimicrobial packaging of fermented sausages with PVOH films containing nisin induced a more pronounced reduction of L. monocytogenes counts during refrigerated storage. HPP alone (600 MPa, 5 min, 12 °C) had no antimicrobial effect against L. monocytogenes at the studied conditions. Combination of HPP with antimicrobial packaging did not produce any extra protection against L. monocytogenes compared to antimicrobial packaging alone. The lack of effect of HPP on L. monocytogenes was attributed to a protective effect exerted by the low water activity of the product and its lactate content. These results reflect that antimicrobial packaging with the inclusion of nisin as a natural antimicrobial could be considered as an effective method to reduce the levels of L. monocytogenes in sliced fermented sausages with no added sodium salt

Evaluation of potential breath biomarkers for active smoking: assessment of smoking habits

Different compounds have been reported as biomarkers of a smoking habit, but, to date, there is no appropriate biomarker for tobacco-related exposure because the proposed chemicals seem to be nonspecific or they are only appropriate for short-term exposure. Moreover, conventional sampling methodologies require an invasive method because blood or urine samples are required. The use of a microtrap system coupled to gas chromatography–mass spectrometry analysis has been found to be very effective for the noninvasive analysis of volatile organic compounds in breath samples. The levels of benzene, 2,5-dimethylfuran, toluene, o-xylene, and m- p-xylene have been analyzed in breath samples obtained from 204 volunteers (100 smokers, 104 nonsmokers; 147 females, 57 males; ages 16 to 53 years). 2,5-Dimethylfuran was always below the limit of detection (0.005 ppbv) in the nonsmoker population and always detected in smokers independently of the smoking habits. Benzene was only an effective biomarker for medium and heavy smokers, and its level was affected by smoking habits. Regarding the levels of xylenes and toluene, they were only different in heavy smokers and after short-term exposure. The results obtained suggest that 2,5-dimethylfuran is a specific breath biomarker of smoking status independently of the smoking habits (e.g., short- and long-term exposure, light and heavy consumption), and so this compound might be useful as a biomarker of smoking exposure

Evaluation of potential breath biomarkers for active smoking: assessment of smoking habits

Different compounds have been reported as biomarkers of a smoking habit, but, to date, there is no appropriate biomarker for tobacco-related exposure because the proposed chemicals seem to be nonspecific or they are only appropriate for short-term exposure. Moreover, conventional sampling methodologies require an invasive method because blood or urine samples are required. The use of a microtrap system coupled to gas chromatography–mass spectrometry analysis has been found to be very effective for the noninvasive analysis of volatile organic compounds in breath samples. The levels of benzene, 2,5-dimethylfuran, toluene, o-xylene, and m- p-xylene have been analyzed in breath samples obtained from 204 volunteers (100 smokers, 104 nonsmokers; 147 females, 57 males; ages 16 to 53 years). 2,5-Dimethylfuran was always below the limit of detection (0.005 ppbv) in the nonsmoker population and always detected in smokers independently of the smoking habits. Benzene was only an effective biomarker for medium and heavy smokers, and its level was affected by smoking habits. Regarding the levels of xylenes and toluene, they were only different in heavy smokers and after short-term exposure. The results obtained suggest that 2,5-dimethylfuran is a specific breath biomarker of smoking status independently of the smoking habits (e.g., short- and long-term exposure, light and heavy consumption), and so this compound might be useful as a biomarker of smoking exposure

Probing quantum gravity using photons from a flare of the active galactic nucleus Markarian 501 observed by the MAGIC telescope

We analyze the timing of photons observed by the MAGIC telescope during a flare of the active galactic nucleus Mkn 501 for a possible correlation with energy, as suggested by some models of quantum gravity (QG), which predict a vacuum refractive index similar or equal to 1 + (E/M-QGn)(n), n = 1, 2. Parametrizing the delay between gamma-rays of different energies as Delta t = +/-tau E-1 or Delta t = +/-tau E-q(2), we find tau(1) = (0.030 +/- 0.012) s/GeV at the 2.5-sigma level, and tau(q) = (3.71 +/- 2.57) x 10(-6) s/GeV2, respectively. We use these results to establish lower limits M-QG1 > 0.21 X 10(18) GeV and M-QG2 > 0.26 x 10(11) GeV at the 95% C.L. Monte Carlo studies confirm the MAGIC sensitivity to propagation effects at these levels. Thermal plasma effects in the source are negligible, but we cannot exclude the importance of some other source effect.

Countervailing power? Collusion in markets with decentralized trade

We consider the collective incentives of buyers and sellers to form cartels in markets where trade is realized through decentralized pairwise bargaining. Cartels are coalitions of buyers or sellers that limit market participation and compensate inactive members for abstaining from trade. In a stable market outcome, cartels set Nash equilibrium quantities and cartel memberships are immune to defections. We prove that the set of stable market outcomes is non-empty and we provide its full characterization. Stable market outcomes are of two types: (i) at least one cartel actively restrains trade and the levels of market participation are balanced, or (ii) only one cartel, eventually the cartel that forms on the long side of the market, is active and it reduces trade slightly below the opponent's.

Evaluating active labor markets in Romania

We evaluate the presence of effects from joining one of four active labour market programs in Romania in the late 1990s compared to the no-program state. Using rich follow-up survey data and propensity score matching, we find that three programs (training and retraining, self-employment assistance, and employment and relocation services) had success in improving participants' economic outcomes and were cost-beneficial from society's perspective. In contrast, public employment was found detrimental for the employment prospects of its participants.