Listeria monocytogenes survey in cubed cooked ham packaged in modified atmosphere and bioprotective effect of selected lactic acid bacteria

The aim of this work was to study the presence of Listeria monocytogenes, as well as the potential activity of two bioprotective cultures (Lyocarni BOX-74 and Lyocarni BOX-57), versus a mix of three L. monocytogenes strains that were intentionally inoculated in cooked cubed ham, packaged in Modified Atmosphere Packaging and stored at different temperatures. The bioprotective cultures limit L. monocytogenes growth in cubed cooked ham stored either at 4\u25e6 C for 60 days and at 4\u25e6 C for 20 days and at 8\u25e6 C for 40 days. The inhibition at 8\u25e6 C is particularly useful for industrial cooked meat products, considering there are often thermal abuse conditions (8\u25e6 C) in the supermarkets. Both the starters can eliminate L. monocytogenes risk and maintain the products safe, despite the thermal abuse conditions. In addition, both culture starters grew without producing perceptible sensory variations in the samples, as demonstrated by the panel of the untrained tasters. The bioprotective LAB produced neither off-odours and off-flavours, nor white/viscous patinas, slime, discoloration or browning. Therefore, according to the obtained data, and despite the fact that cooked cubed ham did not show pH 64 4.4 or aw 64 0.92, or pH 64 5.0 and aw 64 0.94, as cited in the EC Regulation 2073/2005. It can be scientifically stated that cubes of cooked ham with the addition of bioprotective starters cultures do not constitute a favourable substrate for L. monocytogenes growth. Consequently, these products can easily fall into category 1.3 (ready-to-eat foods that are not favourable to L. monocytogenes growth, other than those for infants and for special medical purposes), in which a maximum concentration of L. monocytogenes of 100 CFU g 121 is allowed

Draft Genome Sequences of Eight Bacilli Isolated from an Ancient Roman Amphora

Paleomicrobiology, the study of ancient microbiological material, allows us to understand different evolutionary phenomena in bacteria. In this study, eight bacilli isolated from an ancient Roman amphora, which dates to the IV to V sec. AD, were sequenced and functionally annotated

Beam Test Results of the BTeV Silicon Pixel Detector

The results of the BTeV silicon pixel detector beam test carried out at Fermilab in 1999-2000 are reported. The pixel detector spatial resolution has been studied as a function of track inclination, sensor bias, and readout threshold.Comment: 8 pages of text, 8 figures, Proceedings paper of Pixel 2000: International Workshop on Semiconductor Pixel Detectors for Particles and X-Rays, Genova, June 5-8, 200

Performance of prototype BTeV silicon pixel detectors in a high energy pion beam

The silicon pixel vertex detector is a key element of the BTeV spectrometer. Sensors bump-bonded to prototype front-end devices were tested in a high energy pion beam at Fermilab. The spatial resolution and occupancies as a function of the pion incident angle were measured for various sensor-readout combinations. The data are compared with predictions from our Monte Carlo simulation and very good agreement is found.Comment: 24 pages, 20 figure

The duplicated Y-specific amhy gene is conserved and linked to maleness in silversides of the genus Odontesthes

Sex-determining genes have been successively isolated in several teleosts. In Odontesthes hatcheri and O. bonariensis, the amhy gene has been identified as a master sex-determining gene. However, whether this gene is conserved along related species is still unknown. In this study, the presence of amhy and its association with phenotypic sex was analyzed in 10 species of Odontesthes genus. The primer sets from O. hatcheri that amplify both amhs successfully generated fragments that correspond to amha and amhy in all species. The full sequences of amhy and amha isolated for four key species revealed higher identity values among presumptive amhy, including the 0.5 Kbp insertion in the third intron and amhy-specific insertions/deletions. Amha was present in all specimens, regardless of species and sex, whereas amhy was amplified in most but not all phenotypic males. Complete association between amhy-homologue with maleness was found in O. argentinensis, O. incisa, O. mauleanum, O. perugiae, O. piquava, O. regia, and O. smitti, whereas O. humensis, O. mirinensis, and O. nigricans showed varied degrees of phenotypic/genotypic sex mismatch. The conservation of amhy gene in Odontesthes provide an interesting framework to study the evolution and the ecological interactions of genotypic and environmental sex determination in this group.Fil: Hattori, Ricardo Shohei. Sao Paulo Fisheries Institue. Unidade de Pesquisa e Desenvolvimento de Campos do Jordão; BrasilFil: Somoza, Gustavo Manuel. Universidad Nacional de San Martin. Instituto Tecnológico de Chascomús - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Tecnológico de Chascomús; ArgentinaFil: Fernandino, Juan Ignacio. Universidad Nacional de San Martin. Instituto Tecnológico de Chascomús - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Tecnológico de Chascomús; ArgentinaFil: Colautti, Dario César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Miyoshi, Kaho. Tokyo University of Marine Science and Technology; JapónFil: Gong, Zhuang. Zhejiang Ocean University; ChinaFil: Yamamoto, Yoji. Tokyo University of Marine Science and Technology; JapónFil: Strüssmann, Carlos A.. Tokyo University of Marine Science and Technology; Japó

Beam Test of BTeV Pixel Detectors

The silicon pixel vertex detector is one of the key elements of the BTeV spectrometer. Detector prototypes were tested in a beam at Fermilab. We report here on the measured spatial resolution as a function of the incident angles for different sensor-readout electronics combinations. We compare the results with predictions from our Monte Carlo simulation.Comment: 7 pages, 5 figures, Invited talk given by J.C. Wang at "Vertex 2000, 9th International Workshop on Vertex Detectors", Michigan, Sept 10-15, 2000. To be published in NIM

Mullen, Carol A. (2005). Mentorship.

Rezensio

Variaciones estacionales e históricas de las especies ícticas de la laguna Chascomús

In the last five decades the ictiofauna of Chascomús Shallow lake has been studied in quite detail. Between 1999 and 2000 monthly samples of fish with fyke nets were taken. Thus obtaining the cuali-quantitative composition of each sample taken. These were used to assess the variations between sites and seasons of the year. Among the 17 species caught Porteño, pejerrey and sabalito were present in all the samples taken, wichwere dominant and wich represented 51%, 24% and 14% of the total number respectively, and 28% 10% and 37% in weight. Their composition was similar in all stations sampling at every date. Notwithstanding this differences between abundance (CPUEn) and the extracted biomass (CPUEw) were observed. The capture by unit of total effort decreased from winter to autumn. The average (CPUEw) for Chascomús was above the values corresponding to 47 samples taken in different water bodies from Buenos Aires pampas. Comparing the results with the obtained historical data throughout 40 years it was observed that the percentage of the planctophagous species, pejerrey and mandufia marked a declining tendency. On the other handthe biomass of the porteño and sabalito showed a market increase. Significant correlations between these changes and the antropogénic impact were observed.In the last five decades the ictiofauna of Chascomús shallow lake has been studied in quite detail. Between 1999 and 2000 monthly samples of fish with fyke nets were taken. Thus obtaining the cuali-quantitative composition of each sample taken. These were used to assess the variations between sites and seasons of the year. Among the 17 species caught Porteño, pejerrey and sabalito were present in all the samples taken, wichwere dominant and wich represented 51%, 24% and 14% of the total number respectively, and 28% 10% and 37% in weight. Their composition was similar in all stations sampling at every date. Notwithstanding this differences between abundance (CPUEn) and the extracted biomass (CPUEw) were observed. The capture by unit of total effort decreased from winter to autumn. The average (CPUEw) for Chascomús was above the values corresponding to 47 samples taken in different water bodies from Buenos Aires pampas. Comparing the results with the obtained historical data throughout 40 years it was observed that the percentage of the planctophagous species, pejerrey and mandufia marked a declining tendency. On the other handthe biomass of the porteño and sabalito showed a market increase. Significant correlations between these changes and the antropogénic impact were observed

Variaciones estacionales e históricas de las especies ícticas de la laguna Chascomús

In the last five decades the ictiofauna of Chascomús Shallow lake has been studied in quite detail. Between 1999 and 2000 monthly samples of fish with fyke nets were taken. Thus obtaining the cuali-quantitative composition of each sample taken. These were used to assess the variations between sites and seasons of the year. Among the 17 species caught Porteño, pejerrey and sabalito were present in all the samples taken, wichwere dominant and wich represented 51%, 24% and 14% of the total number respectively, and 28% 10% and 37% in weight. Their composition was similar in all stations sampling at every date. Notwithstanding this differences between abundance (CPUEn) and the extracted biomass (CPUEw) were observed. The capture by unit of total effort decreased from winter to autumn. The average (CPUEw) for Chascomús was above the values corresponding to 47 samples taken in different water bodies from Buenos Aires pampas. Comparing the results with the obtained historical data throughout 40 years it was observed that the percentage of the planctophagous species, pejerrey and mandufia marked a declining tendency. On the other handthe biomass of the porteño and sabalito showed a market increase. Significant correlations between these changes and the antropogénic impact were observed.Instituto de Limnología "Dr. Raúl A. Ringuelet

Microdosimetry on nanometric scale with a new low-pressure avalanche-confinement TEPC

The tissue equivalent proportional counter (TEPC) is the most accurate device for measuring the microdosimetric properties of a particle beam, nevertheless no detailed information on the track structure of the impinging particles can be obtained, since the lower operation limit of common TEPCs is about 0.3 μm. On the other hand, the pattern of particle interactions is measured by track-nanodosimetry, which derives the single-event distribution of ionization cluster size at the nanometric scale. Anyway, only three nanodosimeters are available worldwide. A feasibility study for extending the performances of TEPC down to the nanometric region was performed and a novel avalanche-confinement TEPC was designed and constructed. This detector is constituted by a cylindrical chamber, based on a three-electrode structure, connected to a vacuum and gas flow system to ensure a continuous replacement of the tissue equivalent gas, thus allowing to simulate different biological site sizes in the range 300-25 nm. This TEPC can be calibrated by exploiting a built-in alpha source and a miniaturized solid-state detector as a trigger. Irradiations with photons, fast neutrons and two hadron beams demonstrated the good performances of the device. A satisfactory agreement with FLUKA simulations was obtained