A new approach to modelling the shelf life of Gilthead seabream (Sparus aurata)

A total of 217 Gilthead seabreams were subdivided in four groups, according to four different storage conditions. All fish were evaluated by both Quality Index Method (QIM) and microbiological analysis, sampling skin, gills and flesh, separately. A QIM score predictive system was set by modelling the growth of microflora of skin, gills and flesh and coupling these predictions to each related partial QIM score (QIMSkin, QIMGills, QIMFlesh). The expression of QIM score as a function of bacterial behaviour was carried out by the employment of two coefficients. The predicted mean bacterial concentrations corresponding to the QIM score at 14 days were always near to Log 8 CFU g^{ -1} in the case of 'S' (skin) and 'G' (gills) series. Moreover, predicted QIM scores were in a good agreement with observed data, reproducing the observed mean time of rejection as well as the bacterial spoilage level (Log 8 CFU g^{ -1}), for all kinds of storage condition

EFFECT OF SIDEROPHORES AGAINST E. COLI O157:H7

In this study, the inhibiting activity of siderophores produced by Pseudomonas fluorescens against Escherichia coli O157:7 was assayed. Siderophores were extracted from P. fluorescens cultures and preliminarily tested by C.A.S. reagent and UV. The siderophores activity against E. coli O157:H7 was characterised by the determination of Minimal Inhibiting Concentration (MIC). Furthermore, E. coli O157:H7 growth tests with and without siderophores were prepared at 12°C, pH 7 and 5, aw 0.997 and 0,988. The MIC was assessed at 7 μg/ml whereas the growth test showed a high inhibiting activity with the exception of tests at pH 5

Modelling Bacterial Dynamics in Food Products: Role of Environmental Noise and Interspecific Competition

In this paper we review some results obtained within the context of the predictive microbiology, which is a specific field of the population dynamics. In particular we discuss three models, which exploit tools of statistical mechanics, for bacterial dynamics in food of animal origin. In the first model, the random fluctuating behaviour, experimentally meas- ured, of the temperature is considered. In the second model stochastic differential equations are introduced to take into account the influence of physical and chemical variables, such as temperature, pH and activity water, subject to deter- ministic and random variations. The third model, which is an extended version of the second one, neglects the environ- mental fluctuations, and concentrates on the role of the interspecific bacterial interactions. The comparison between expected results and observed data indicates that the presence of noise sources and interspecific bacterial interactions improves the predictive features of the models analyzed

BEHAVIOUR OF Aeromonas hydrophila IN SALTED SWORDFISH SAMPLES

A challenge test for Aeromonas hydrophila in salted swordfish samples was carried out. Particularly, 24 samples (250g) were experimentally contaminated, salted and stored at two different temperature regimes (fluctuating – F group - and non fluctuating – NF group – regime). The count of A. hydrophila, Enterobacteria and Lactic acid bacteria (LAB) as well as the determination of pH and aw were performed at 0, 19 43, 163, 187, 230, 320 and 368 hours whereas the temperature was monitored continuously by using 6 data-loggers. In both group, the mean concentrations of A. hydrophila did not exceed Log 3 cfu/g and decreased below the mean value of Log 1 cfu/g after 368 hours. However in the F group the A. hydrophila growth was slower and the decrease appeared slightly higher than NF group and this suggests the temperature fluctuations induces a more pronounced behaviour variability of A. hydrophila under stressing conditions

Whole-body magnetic resonance imaging in the diagnosis and follow-up of multicentric infantile myofibromatosis: A case report

Myofibromatosis is an uncommon disorder of infancy, characterized by proliferation of myofibroblasts in solitary or multiple nodules. The clinical characteristics depend on the involved sites: Myofibromatosis may develop as a musculoskeletal form, with non-painful swellings and eventual mass effect symptoms, or as a generalized form with visceral involvement and organ failure. Prognosis and therapy vary between the abovementioned patterns. When there is no visceral involvement, the tumors may regress spontaneously; however, the visceral form may represent a lifethreatening condition with poor outcome and it requires aggressive management. Imaging assessment of disease spread is mandatory to determine diagnosis, prognosis and therapy. Due to the young age of the patients, a radiation-free evaluation is recommended. We herein describe a case of musculoskeletal myofibromatosis diagnosed in a 3-month-old male infant, investigated by serial wholebody magnetic resonance imaging (MRI) examination. The histological analysis and MRI characteristics enabled a correct diagnosis and organ involvement assessment with no radiation exposure. Moreover, whole-body MRI sequences provided a detailed evaluation of the disease within a short time frame, reducing the time of sedation, which is required to perform MRI in very young patients. Therefore, whole-body MRI was found to be accurate and safe in the diagnosis and follow-up of multicentric infantile myofibromatosis.Myofibromatosis is an uncommon disorder of infancy, characterized by proliferation of myofibroblasts in solitary or multiple nodules. The clinical characteristics depend on the involved sites: Myofibromatosis may develop as a musculoskeletal form, with non-painful swellings and eventual mass effect symptoms, or as a generalized form with visceral involvement and organ failure. Prognosis and therapy vary between the abovementioned patterns. When there is no visceral involvement, the tumors may regress spontaneously; however, the visceral form may represent a lifethreatening condition with poor outcome and it requires aggressive management. Imaging assessment of disease spread is mandatory to determine diagnosis, prognosis and therapy. Due to the young age of the patients, a radiation-free evaluation is recommended. We herein describe a case of musculoskeletal myofibromatosis diagnosed in a 3-month-old male infant, investigated by serial wholebody magnetic resonance imaging (MRI) examination. The histological analysis and MRI characteristics enabled a correct diagnosis and organ involvement assessment with no radiation exposure. Moreover, whole-body MRI sequences provided a detailed evaluation of the disease within a short time frame, reducing the time of sedation, which is required to perform MRI in very young patients. Therefore, whole-body MRI was found to be accurate and safe in the diagnosis and follow-up of multicentric infantile myofibromatosis

A new approach to predict the fish fillet shelf-life in presence of natural preservative agents

Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS) were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets

Shape Invariant Potential and Semi-Unitary Transformations (SUT) for Supersymmetric Harmonic Oscillator in T4-Space

Constructing the Semi - Unitary Transformation (SUT) to obtain the supersymmetric partner Hamiltonians for a one dimensional harmonic oscillator, it has been shown that under this transformation the supersymmetric partner loses its ground state in T^{4}- space while its eigen functions constitute a complete orthonormal basis in a subspace of full Hilbert space. Keywords: Supersymmetry, Superluminal Transformations, Semi Unitary Transformations. PACS No: 14.80L