Development of a real-time PCR assay for the detection of cow and donkey milk

A real-time PCR allelic discrimination TaqMan assay based on the analysis of a single nucleotide polymorphism enabling the differentiation of cow (Bos taurus) and donkey (Equus asinus) milk was developed. Specific primers and probes were designed on the mitochondrial cytochrome c oxidase subunit I gene. The primers were designed upstream and downstream the chosen diagnosis site in a conserved region. Two probes were designed to specifically hybridise to B. taurus and E. asinus sequences. The test allowed the discrimination of bovine and donkey DNA in all blood and pure milk samples giving an unambiguous result plot of rapid and easy interpretation. The detection threshold was 2?% of cow milk in donkey milk. The applicability of the method to matrices containing degraded DNA was demonstrated by analysing samples of raw donkey and cow milk autoclave-treated (121?°C for 15?min). Finally, the assay when applied to milk samples collected from the retail trade has confirmed the species indicated in the label. Furthermore, the assay represents a potentially valuable diagnostic tool for species identification in dairy products for allergic people.     

Influence of some environmental factors on drupe maturation and olive oil composition

BACKGROUND: Understanding the relationships between olive cultivars and the cultivation environment as well as optimising cultivation choices can lead to maximum expression of oil production in terms of both quantity and quality. For this purpose, samples of the Ortice olive cultivar grown in two different environments in southern Italy at altitudes of 500 and 50 m above sea level (a.s.l.) were harvested on various dates to monitor drupe maturation and determine the nutritional and chemical characteristics of the oils. RESULTS: Fruits grown at 50 m a.s.l. ripened about 10–15 days earlier than those grown at 500 m a.s.l. The oil obtained at 500 m a.s.l. was characterised by a higher content of total polyphenols and a higher content of oleic and stearic acids. CONCLUSION: The different heat accumulation related to the environment affected drupe development as well as the colouring trend and oil content. Consequently, the growth environment changed the content of Ortice oil fatty acids and polyphenols, while the flavour profile remained fairly stable in both environments, with the cultivar effect prevailing over the environment factor. © 2012 Society of Chemical Industry     

An apparatus for cyclic tests on cylindrical concrete specimens

An apparatus specifically designed for static and cyclic testing of concrete and rock cylindrical samples is described. A particular characteristic of this equipment is the possibility of cyclic variation of the confining pressure, in addition to variation of the vertical load. The technical features of the apparatus are illustrated, as well as those of the instruments used for measuring and recording the variation of loads and displacements during the tests, up to the failure of the specimens. Comments are also presented on the devices controlling the variation of load with time and on the characteristics of the load histories adopted in an experimental research aimed at investigating the behaviour of concrete under repeated triaxial loads.     

Convergence of the Kleiser Schumann method for the Navier-Stokes equations

Calcolo - We analyze the Kleiser-Schumann metho for the numerical approximation of Navier-Stokes' equations with two directions of periodicity. In these directions a pseudo-spectral Galerkin...     

Association of elongation factor 2 with ribosomes during growth of a murine ascitic tumor

The amount of elongation factor 2 (EF-2) associated with different ribosomal fractions (mono- and polyribosomes) isolated from a methylcholanthrene-induced sarcoma is estimated during tumor growth (exponential and plateau phase of growth). Direct EF-2 quantification is obtained by a modification of the method of the diphtheria toxin-catalyzed transfer of (14C)ADP-ribose from (14C)NAD+ to the enzyme. Data reported show that the amount of EF-2 associated with the monoribosomal fraction changes during tumor growth, and particularly, that this amount increases when the tumor cells enter into the plateau phase. In contrast, the EF-2 content of the polyribosomal fraction does not change during the different phases of tumor growth. Data also show that the amount of EF-2 bound to the monoribosomal fraction isolated from tumor cells is significantly and constantly lower than that of the corresponding fraction isolated from reticulocytes or hepatocytes. Moreover the tumor monoribosomes generated by the polyribosome breakdown induced by the "starvation" procedure did not show significant changes in their EF-2 content with respect to monoribosomes isolated from tumor cells maintained in physiological conditions. Besides, tumor monoribosomes generated by the polyribosome breakdown induced by puromycin or by running-off treatment exhibit a relevant increase of the EF-2 content. In these conditions the amount of EF-2 associated with the monoribosomes is similar to that associated with the monoribosomes of control cells (hepatocytes and reticulocytes). Results are discussed in view of a possible regulative role of the EF-2 enzyme in the ribosomal cycle of eukaryotic cells.     

An automatic pulsed laser microfluorometer with high spatial and temporal resolution

The paper describes an automatic pulsed laser microfluorometer with high spatial and temporal resolution, developed in our laboratories. The instrument consists of: (i) a nitrogen-laser-pumped dye-laser for the excitation of the fluorescence, (ii) a microscope with additional optics to focus the excitation beam on the sample and to collect the fluorescence, (iii) filters or monochromators to select the output wavelength, (iv) a fast photomultiplier tube to detect the signal, and (v) a dual time-scale microprocessor-controlled signal averager for the acquisition and processing of the signal. Examples are given that show the potential of the time-resolved fluorescence microscopy in studying, quantitatively and qualitatively, the properties of fluorescent molecules.     

Use of intelligent sensors and software radio technologies foroptimal design of reconfigurable multimedia surveillance networks

In these last years, the increasing request for security coming from civil society led to intensive exploitation of the most advanced technological tools for solving problems related to remote monitoring of public sites. New-generation multimedia surveillance systems will be characterized by such key topics as distribution of processing capabilities among intelligent sensor and central processing levels, and dynamic reconfigurability of the wireless links thanks to innovative software radio technologies. In this work a joint analysis of such aspects is presented in order to provide optimal design strategies for new-generation multimedia surveillance networks, able to take into account the trade-offs between available computing and communications resources and required performance in terms of correct event detection and real-time processing     

LDPE‐based blends and films stabilized with nonreleasing polymeric antioxidants for safer food packaging

Several novel random copolymers of ethylene and 1‐olefin counits bearing a highly efficient phenolic antioxidant moiety placed at different distances from the polymerizable double bond were prepared in the presence of a metallocene catalyst. These copolymers were melt‐blended with an antioxidant‐free LDPE in an internal batch mixer to obtain innovative materials containing nonreleasing polymeric antioxidants suitable for safer food packaging applications. Blends and films, obtained by compression molding, were tested for their thermal and thermo‐oxidative stability by thermogravimetric analysis both in dynamic and isothermal conditions. Films containing the macromolecular antioxidants showed a longer induction time before O₂ uptake starts and, consequently, a higher degradation temperature than neat LDPE or LDPE containing a low molecular weight commercial additive. Aging tests demonstrated that the new polymeric antioxidants also exert a valid protection against photo‐oxidation. Eventually, migration tests demonstrated the absence of any trace of products containing the antioxidant moiety when the films were kept in contact with a food simulant. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012