502 research outputs found

    An Outbreak of Q fever in a prison in Italy

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    We observed an outbreak of Q fever in a prison population. Overall, 65 of the 600 prison inmates developed the disease. The location of the prison cells had no apparent effect on the risk of infection. The outbreak was probably due to exposure to dust contaminated by a passing flock of sheep, which at the time of the outbreak was engaged in lambing. These findings highlight the possible emergence of Q fever in settings and populations not normally thought of as being at risk of exposure to the infection

    First results on the use of a EDXRF scanner for 3D imaging of paintings

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    A 3D map of chemical elements distribution from energy-dispersive X-ray fluorescence (EDXRF) analysis would be a perfect conclusion in a detailed study of any type of artifact. This map can be easily achieved by using synchrotron light as source of radiation, and microoptics both at the source and at the detector. In such a manner a micro-voxel is irradiated and detected, which can be at any depth with respect to the surface of the artifact. This method is effective but needs a high-intensity X-ray source; therefore, its use in archaeometry is limited. An alternative method is proposed in the present paper, which uses a portable EDXRF-device to measure the altered Kα/Kβ or Lα/Lβ-ratios, which allow to locate the chemical elements. Several examples are described

    Measuring the presence of organized crime across Italian provinces: a sensitivity analysis

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    The existing literature identifies different indicators to construct organized crime indices and places equal importance to different concepts of organized crime. This paper examines the sensitivity of organized crime across Italian provinces when different set of indicators and weights are used to combine crime indicators. Our findings suggest that there is a remarkable variation in the distribution of organized crime across Italian provinces based on the choice of indicators and the importance given to different crime indicators. It is also found that the relationship of organized crime with socioeconomic and political factors varies depending on the normative choices made in the construction of an organized crime index

    Gold and Silver joining technologies in the Moche Tombs “Señor de Sipán” and “Señora de Cao jewelery

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    About 200 gold and silver funerary ornaments from the Moche tombs “Señor de Sipán” and “Señora de Cao” were analyzed to determine their metallurgic characteristics. Of particular interest was the question about the gold-silver joining process. To this aim, following methods were employed, all based on the use of X-rays: - energy dispersive X-ray fluorescence; - transmission of monoenergetic fluorescent X-rays; - radiography. At least three joining methods were possibly identified: - of gluing gold and silver sheets; - of brazing using a proper solder; - of using a mercury amalgam

    New Techniques in Diagnostic X-ray Imaging: A Simulation Tool and Experimental Findings

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    Abstract Absorption X-ray imaging is a well-established technique. However it is still a challenging task in its search for a compromise between the need for high spatial resolution and high contrast and the request to keep the dose delivered to the patient within acceptable values. New imaging techniques are under investigation, like the use of new X-ray sources, phase contrast imaging or K-edge imaging. Monte Carlo or analytic simulations are often the best way to test and predict the effectiveness of these techniques. A new simulation tool for X-ray imaging will be presented together with some applications to the characterization of new X-ray sources, in-line phase contrast effect and angiographic K-edge imaging. Simulation results will be compared also with experimental dat

    Testing the accuracy of the calculation of gold leaf thickness by MC simulations and MA-XRF scanning

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    The use of X-ray fluorescence (XRF) scanning systems has become a common practice in many application sectors. In multistratified and heterogeneous samples, the simple analysis of an XRF spectrum as a response of the entire sample is not reliable, so different spectral analysis techniques have been proposed to detect the presence of surface stratification. One commonly studied case is that of gilding, i.e., the presence of a superimposing gold-leaf layer. The observation of changes in the net peak ratios of a single element or of several elements in an XRF spectrum is a well-developed practice, but is still not used in the case of XRF scanning (macro-X-Ray fluorescence scanning, MA-XRF), a technique that can be described as the extrapolation of XRF spot analysis to a second dimension, scanning a sample surface instead. This practice can yield information on the overlaying layer thickness, if some properties of the sample are known—or estimated—beforehand, e.g., the overlapping layer’s chemical composition and the matrix effect contribution from the bulk material (thick ratio). This work proposes the use of an algorithm to calculate the thickness distribution of a superimposing gold layer accurately and automatically through the differential attenuation method by using MA-XRF datasets in a total noninvasive manner. This approach has the clear advantage over the traditional spot sampling of allowing the generation of a surface heightmap to better visualize and interpret the data, as well as a considerably larger sample space. Monte Carlo simulations were used to verify the influence of the medium used to adhere the gold leaves to the substrate and to generate known spectra to assess the algorithm’s accuracy

    UV radiation promotes flavonoid biosynthesis, while negatively affecting the biosynthesis and de-epoxidation of xanthophylls: consequence for photoprotection?

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    There is evidence that UV radiation may detrimentally affect the biosynthesis of carotenoids, particularly de-epoxided xanthophylls, while strongly promoting phenylpropanoid, particularly flavonoid biosynthesis in a range of taxa. Here we tested the hypothesis that mesophyll flavonoids might protect chloroplasts from UV-induced photo-oxidative damage, by partially compensating for the UV-induced depression of xanthophyll biosynthesis. To test this hypothesis we grew two members of the Oleaceae family, Ligustrum vulgare L. and Phillyrea latifolia L., under either partial shading or fully exposed to sunlight, in the presence or in the absence of UV radiation. The examined species, which display very similar flavonoid composition, largely differ in their ability to limit the transmission of UV and visible light through the leaf and, hence, in the accumulation of flavonoids in mesophyll cells. We conducted measurements of photosynthesis, chlorophyll a fluorescence kinetics, the concentrations of individual carotenoids and phenylpropanoids at the level of whole-leaf, as well as the content of epidermal flavonoids. We also performed multispectral fluorescence micro-imaging to unveil the intra-cellular distribution of flavonoids in mesophyll cells. UV radiation decreased the concentration of carotenoids, particularly of xanthophylls, while greatly promoting the accumulation of flavonoids in palisade parenchyma cells. These effects were much greater in L. vulgare than in P. latifolia. UV radiation significantly inhibited the de-epoxidation of xanthophyll cycle pigments, while enhancing the concentration of luteolin, and particularly of quercetin glycosides. Flavonoids accumulated in the vacuole and the chloroplasts in palisade cells proximal to the adaxial epidermis. We hypothesize that flavonoids might complement the photo-protective functions of xanthophylls in the chloroplasts of mesophyll cells exposed to the greatest doses of UV radiation. However, UV radiation might result in adaxial mesophyll cells being less effective in dissipating the excess of radiant energy, e.g., by decreasing their capacity of thermal dissipation of excess visible light in the chloroplast

    Real-time PCR detection of Toxoplasma gondii in tissue samples of wild boars (Sus scrofa) from southern Italy reveals high prevalence and parasite load.

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    Background: Toxoplasmosis is a zoonotic parasitic disease caused by Toxoplasma gondii, a widespread protozoan in the phylum Apicomplexa. In Europe, several studies have demonstrated the presence of the parasite in tissues of wild boars (Sus scrofa), but no data exists on the T. gondii load in tissues which in turn may be an useful way to assess the infection risk for the consumer of wild boar meat. Methods: We sampled and tested a total of 472 tissue samples of brain, heart and masseter muscle from 177 wild boars from the Campania region of southern Italy by real-time PCR analyses for detection and quantification of T. gondii. The sensitivity and specificity of the method were calculated by ROC analysis curves. Results: PCR analysis revealed the presence of T. gondii in tissue samples of 78 out of 177 (44%) wild boars. In general, the brain presented the highest PCR prevalence (31%), followed by the heart (28.3%) and the masseter muscle (24.2%), with the highest estimated parasite numbers observed in the brain followed by the heart and masseter muscle. The PCR method showed an excellent discriminating ability for each of the examined tissues. According to the ROC analysis curves, the respective sensitivity and specificity were 99 and 100% for masseter muscle, 98 and 98% for brain and 96 and 98% for heart samples. Conclusions: The high prevalence of infection here detected suggests a widespread distribution of the parasite in the wildlife of the Campania region of southern Italy. The T. gondii burdens detected may potentially represent a source of infection for humans
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