MICROBIOLOGICAL STUDY ON ICE FROM A FISH STALL

The ice used for exposure of fish products could be a source of secondary contamination due to ice machine, due to not respected good manufacturing practices, particularly when ice is left on the fish stall and the next day the new layer is deposited over the old one. Aim of this study was the verification of the hygienic risk of this procedure through analyses of the liquid produced by the zones "thawed cephalopods" and "fresh whole fish". Almost the microorganisms found were Gram negative (in particular Pseudomonadaceae)

USE OF GASEOUS OZONE AS A DISINFECTANT IN MEAT INDUSTRY

The aim of this study was to investigate the possible use of gaseous ozone as a disinfectant for meat industry environments. Firstly microbial inactivation trials were conducted in laboratory conditions on Petri plates inoculated with some microorganisms of importance to the food industry. The treatment with 1 ppm of ozone resulted to be effective in 1 h on the strains in use. Then similar trials were conducted in a meat industry, 1 ppm of ozone was supplied for 3 h. The results confirmed the antimicrobial efficacy of ozone even if it was less active than in laboratory conditions. A different sensibility among the microorganisms was observed, the most resistant being P. fluorescens and B. thuringiensis. Our results confirm the suitability of gaseous ozone as a disinfectant for meat industry environments and underline the need to calibrate ozone treatment parameters on the real environmental conditions of work-room

CRITICAL ASPECTS IN SCRAPS OF COLD SMOKED SALMON PROCESSING

The aim of the paper was to summarize the critical aspects in the processing of smoked salmon scraps as resulted from seven different lots of samples through microbiological and chemical-physical analysis. Results demonstrate that this product has very variable salt content, high microbial counts influencing the shelf-life, rancidity problems depending on the raw material and is heavily contaminated by Listeria monocytogenes

Effect of Magnetic Fields on Drug Induced Contractility and Mortality in Spirostomum

The influence of homogeneous magnetic fields up to 5.5 T on contractile frequency and mortality in the ciliate protozoan spirostomum ambiguum stimulated by 2,2′ PDS is reported. Magnetic fields are observed to decrease contractile frequency and to significantly increase mortality

Quality of Imported Argentine Beef

A total of 8 lots of vacuum-packed bovine rump hearts (Gluteus medius muscle) imported in Italy from Argentina were submitted to microbiological (total bacterial count, Enterobacteriaceae, Pseudomonas spp., Lactobacilli, sulfite-reducing Clostridia, Listeria monocytogenes) and physicochemical analyses (pH, total volatile basic nitrogen, color measurement and shear force) after different storage times (35, 75 and 100 days). Lactobacilli were the predominant microbial population (about 6 log cfu/cm2), causing a microbial stabilization and acidification of meat. Seventy-three Lactobacilli isolates were submitted to random amplified polymorphic DNA-polymerase chain reaction and identified, showing a high prevalence of Lactobacillus sakei (in all the samples) and Lactobacillus curvatus (in samples stored for 75 or 100 days). We observed high total volatile basic nitrogen levels (>27 mgN/100 g) in all the samples and a discoloration of beef after the opening of the packs. Our results suggest the need for a higher standardization of production conditions. Practical Applications Vacuum-packed raw beef from Argentina is globally commercialized, and it is frequently shipped to European markets. Considering the perishability of this product and the very long shelf life assigned, the availability of microbiological and physicochemical data could be useful for quality evaluations purposes. Our data indicate that a long shelf life (3–4 months) is potentially achievable, but the application of the best hygienic practices during meat production and an optimal stabilization of microflora by the selection (or addition) of lactic acid bacteria must be assured. As protein degradation and microbial population showed to be stable during the shelf life, quality characteristics that are perceived by the consumer (such as color indexes) become important parameters for a proper evaluation of meat quality

Visual consequences of molecular changes in the guanylate cyclase activating protein

Purpose: In this study, we characterize and model changes in visual performance associated with a Tyr99Cys substitution in the guanylate cyclase activating protein (GCAP1) in four family members aged between 39 and 55 years. Guanylate cyclase and its activating protein are molecules in the visual transduction pathway that restore cyclic GMP (cGMP) following its light-activated hydrolysis. The mutation causes an excess of cGMP in the dark and results in progressive photoreceptor loss. Methods: L-cone temporal acuity was measured as a function of target irradiance; and L-cone temporal contrast-sensitivity was measured as a function of temporal frequency. Results: All four GCAP1-mutant family members show sensitivity or acuity losses relative to normal observers. The data for the youngest family member are consistent with an abnormal speeding up of the visual response relative to normals, but those for the older members show a progressive higher-frequency sensitivity loss consistent with a slowing down of their response. Conclusions: The speeding up of the visual response in the youngest observer is consistent with the Tyr99Cys-mutation resulting in the more rapid replacement of cGMP after light exposure, and thus in a reduction of temporal integration and relative improvement in high frequency sensitivity compared to normals. The high-frequency losses in the older observers are consistent with their vision being further limited by the interposition of some sluggish process. This might result from some residual or malfunctioning molecular process limiting transduction within damaged photoreceptors, or from an active or passive postreceptoral reorganization caused by the paucity of functioning photoreceptors

Are ring galaxies the ancestors of giant low surface brightness galaxies?

We simulate the collisional formation of a ring galaxy and we integrate its evolution up to 1.5 Gyr after the interaction. About 100-200 Myr after the collision, the simulated galaxy is very similar to observed ring galaxies (e.g. Cartwheel). After this stage, the ring keeps expanding and fades. Approximately 0.5-1 Gyr after the interaction, the disc becomes very large (∼100 kpc) and flat. Such extended discs have been observed only in giant low surface brightness galaxies (GLSBs). We compare various properties of our simulated galaxies (surface brightness profile, morphology, H i spectrum and rotation curve) with the observations of four well-known GLSBs (UGC 6614, Malin 1, Malin 2 and NGC 7589). The simulations match quite well the observations, suggesting that ring galaxies could be the progenitors of GLSBs. This result is crucial for the cold dark matter (CDM) model, as it was very difficult, so far, to explain the formation of GLSBs within the CDM scenari

Intermediate-mass black holes and ultraluminous X-ray sources in the Cartwheel ring galaxy

Chandra and XMM-Newton observations of the Cartwheel galaxy show ∼17 bright X-ray sources (≳5 × 1038erg s−1), all within the gas-rich outer ring. We explore the hypothesis that these X-ray sources are powered by intermediate-mass black holes (IMBHs) accreting gas or undergoing mass transfer from a stellar companion. To this purpose, we run N-body/smoothed particle hydrodynamics simulations of the galaxy interaction which might have led to the formation of Cartwheel, tracking the dynamical evolution of two different IMBH populations: halo and disc IMBHs. Halo IMBHs cannot account for the observed X-ray sources, as only a few of them cross the outer ring. Instead, more than half of the disc IMBHs are pulled in the outer ring as a consequence of the galaxy collision. However, also in the case of disc IMBHs, accretion from surrounding gas clouds cannot account for the high luminosities of the observed sources. Finally, more than 500 disc IMBHs are required to produce ≲15 X-ray sources via mass transfer from very young stellar companions. Such number of IMBHs is very large and implies extreme assumptions. Thus, the hypothesis that all the observed X-ray sources in Cartwheel are associated with IMBHs is hardly consistent with our simulations, even if it is still possible that IMBHs account for the few (≲1-5) brightest ultraluminous X-ray source

Blue straggler stars in dwarf spheroidal galaxies - II. Sculptor and Fornax

The existence of blue straggler stars (BSSs) in dwarf spheroidal galaxies (dSphs) is still an open question. In fact, many BSS candidates have been observed in the Local Group dSphs, but it is unclear whether they are real BSSs or young stars. Shedding light on the nature of these BSS candidates is crucial in order to understand the star formation history of dSphs. In this paper, we consider BSS candidates in Sculptor and Fornax. In Fornax, there are strong hints that the BSS population is contaminated by young stars, whereas in Sculptor there is no clear evidence of recent star formation. We derive the radial and luminosity distribution of BSS candidates from wide field imaging data extending beyond the nominal tidal radius of these galaxies. The observations are compared with the radial distribution of BSSs expected from dynamical simulations. In Sculptor, the radial distribution of BSS candidates is consistent with that of red horizontal branch (RHB) stars and is in agreement with theoretical expectations for BSSs generated via mass transfer in binaries. On the contrary, in Fornax, the radial distribution of BSS candidates is more concentrated than that of all the considered stellar populations. This result supports the hypothesis that most of BSS candidates in Fornax are young stars, and this is consistent with previous studie

Effect of Shot Peening on Oxidation and Precipitation in Inconel 718

In this study, the effect of the surface state on the behaviour of Inconel 718 alloy exposed to 640 ∘ C and 700 ∘ C environments for times varying between one and one hundred hours was investigated. In particular, the focus was set on the evolution of oxidation and precipitation phenomena during thermal exposure. Three surface states were considered: two generated through shot peening treatments featuring different coverage levels, while the third condition is a non-peened one. Shot peening treatments modify the surface condition and introduce higher residual stresses and microhardness values than in the non-treated condition. The morphology of the oxides appears to be different depending on the condition observed. Regarding the kinetics, over time the oxidation process follows a parabolic trend and appears to be influenced by the surface state; in particular, severe shot peening treatment is characterized by the highest intensity of the phenomenon. However, the order of magnitude of the weight gains measured suggests that the observed variations can be neglected, and that the positive effect of shot peening can be exploited without introducing oxidation problems. From the point of view of the microstructural evolution, an increase in the coarsening kinetics of γ ” phase was observed in the shot peened layer