321 research outputs found

    Searching for diversity. An overview on board of Italian Cultural Organizations.

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    Diversity takes on different meanings and synonymous; actually, the theme has been strongly debated in the era of globalization, migration and because of the affirmation of human rights and gender policies. Many studies are related to the analysis of board diversity within the forprofit organizations. Indeed, there is paucity of studies that linked the topic to the role of demographic and non-demographic diversity among cultural organizations and NPOs sector. Italian cultural institutions have been grouped together in a website by the private association AICI. The website was used in the present study in order to map organizations and their boards in terms of multiple diversity variables such visible and invisible parameters. Hereby, diversity is explored among board members of 102 private foundations and associations, including dimensions like age, gender, nationality, educational and professional background. One of the main finds of the research highlights how Italian cultural organizations have a low degree of diversity within the boards of directors

    Moddicom: a Complete and Easily Accessible Library for Prognostic Evaluations Relying on Image Features

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    Decision Support Systems (DSSs) are increasingly exploited in the area of prognostic evaluations. For predicting the effect of therapies on patients, the trend is now to use image features, i.e. information that can be automatically computed by considering images resulting by analysis. The DSSs application as predictive tools is particularly suitable for cancer treatment, given the peculiarities of the disease –which is highly localised and lead to significant social costs– and the large number of images that are available for each patient. At the state of the art, there exists tools that allow to handle image features for prognostic evaluations, but they are not designed for medical experts. They require either a strong engineering or computer science background since they do not integrate all the required functions, such as image retrieval and storage. In this paper we fill this gap by proposing Moddicom, a user-friendly complete library specifically designed to be exploited by physicians. A preliminary experimental analysis, performed by a medical expert that used the tool, demonstrates the efficiency and the effectiveness of Moddicom

    Eicosapentaenoic acid induces DNA demethylation in carcinoma cells through a TET1-dependent mechanism

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    In cancer cells, global genomic hypomethylation is found together with localized hypermethylation of CpG islands within the promoters and regulatory regions of silenced tumor suppressor genes. Demethylating agents may reverse hypermethylation, thus promoting gene re-expression. Unfortunately, demethylating strategies are not efficient in solid tumor cells. DNA demethylation is mediated by ten-eleven translocation enzymes (TETs). They sequentially convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), which is associated with active transcription; 5-formylcytosine; and finally, 5-carboxylcytosine. Although α-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid, the major n-3 polyunsaturated fatty acids, have anti-cancer effects, their action, as DNA-demethylating agents, has never been investigated in solid tumor cells. Here, we report that EPA demethylates DNA in hepatocarcinoma cells. EPA rapidly increases 5hmC on DNA, inducing p21Waf1/Cip1 gene expression, which slows cancer cell-cycle progression. We show that the underlying molecular mechanism involves TET1. EPA simultaneously binds peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor α (RXRα), thus promoting their heterodimer and inducing a PPARγ-TET1 interaction. They generate a TET1-PPARγ-RXRα protein complex, which binds to a hypermethylated CpG island on the p21 gene, where TET1 converts 5mC to 5hmC. In an apparent shuttling motion, PPARγ and RXRα leave the DNA, whereas TET1 associates stably. Overall, EPA directly regulates DNA methylation levels, permitting TET1 to exert its anti-tumoral function.-Ceccarelli, V., Valentini, V., Ronchetti, S., Cannarile, L., Billi, M., Riccardi, C., Ottini, L., Talesa, V. N., Grignani, F., Vecchini, A., Eicosapentaenoic acid induces DNA demethylation in carcinoma cells through a TET1-dependent mechanism

    Fast 3D-EM reconstruction using Planograms for stationary planar positron emission mammography camera

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    Summary At the University of Pisa we are building a PEM prototype, the YAP–PEM camera, consisting of two opposite 6×6×3 cm 3 detector heads of 30×30 YAP:Ce finger crystals, 2×2×30 mm 3 each. The camera will be equipped with breast compressors. The acquisition will be stationary. Compared with a whole body PET scanner, a planar Positron Emission Mammography (PEM) camera allows a better, easier and more flexible positioning around the breast in the vicinity of the tumor: this increases the sensitivity and solid angle coverage, and reduces cost. To avoid software rejection of data during the reconstruction, resulting in a reduced sensitivity, we adopted a 3D-EM reconstruction which uses all of the collected Lines Of Response (LORs). This skips the PSF distortion given by data rebinning procedures and/or Fourier methods. The traditional 3D-EM reconstruction requires several times the computation of the LOR-voxel correlation matrix, or probability matrix { p ij }; therefore is highly time-consuming . We use the sparse and symmetry properties of the matrix { p ij } to perform fast 3D-EM reconstruction. Geometrically, a 3D grid of cubic voxels (FOV) is crossed by several divergent 3D line sets (LORs). The symmetries occur when tracing different LORs produces the same p ij value. Parallel LORs of different sets cross the FOV in the same way, and the repetition of p ij values depends on the ratio between the tube and voxel sizes. By optimizing this ratio, the occurrence of symmetries is increased. We identify a nucleus of symmetry of LORs: for each set of symmetrical LORs we choose just one LOR to be put in the nucleus , while the others lie outside. All of the possible p ij values are obtainable by tracking only the LORs of this nucleus . The coordinates of the voxels of all of the other LORs are given by means of simple translation rules. Before making the reconstruction, we trace the LORs of the nucleus to find the intersecting voxels, whose p ij values are computed and stored with their voxel coordinates on a hard disk. Only the non-zero p ij are considered and their computation is performed just once. During the reconstruction, the stored values are loaded and are available in the random access memory for all of the operations of normalization, backprojection and projection: these are now performed rapidly, because the application of the translation rules is much faster than the probability computations. We tested the algorithm on Monte Carlo data fully simulating the typical YAP–PEM clinical condition. The adopted algorithm gives an excellent positioning capability for hot spots in the camera FOV. To use all of the possible skew LORs in the FOV avoids the software rejection of collected data. Reconstructed images indicate that a 5 mm diameter tumor of 37 kBq/cm 3 , in an active breast with a 10:1 Tissue to Background ratio (T/B), with a 10 min acquisition, for a head distance of 5 cm, can be detected by the YAP–PEM with a SNR of 8.7±1.0. The obtained SNR values depend linearly on the tumor volume. The algorithm allows one to discriminate between two hot sources of 5.0 mm diameter if they do not lie on the same axis. The YAP–PEM is now in the assembly stage

    Discrimination of tropical forest types, dominant species, and mapping of functional guilds by hyperspectral and simulated multispectral Sentinel-2 data

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    To answer new scientific and ecological questions and monitor multiple forest changes, a fine scale characterization of these ecosystems is needed, and could imply the mapping of specific species, of detailed forest types, and of functional composition. This characterization can be now provided by the novel Earth Observation tools. This study aims to contribute to understanding the innovation in forest and ecological research that can be brought in by advanced remote sensing instruments, and proposes the guild mapping approach as a tool to efficiently monitor the varied tropical forest resources. We evaluated, in tropical Ghanaian forests, the ability of airborne hyperspectral and simulated multispectral Sentinel-2 data, and derived vegetation indices and textures, to: distinguish between two different forest types; to discriminate among selected dominant species; and to separate trees species grouped according to their functional guilds: Pioneer, Non Pioneer Light Demanding, and Shade Bearer. We then produced guild classification maps for each area using hyperspectral data. Our results showed that with both hyperspectral and simulated Sentinel-2 data these discrimination tasks can be successfully accomplished. Results also stressed the importance of texture features, especially if using the lower spectral and spatial Sentinel-2 resolution data, and highlighted the important role of the new Sentinel-2 data for ecological monitoring. Classification results showed a statistically significant improvement in overall accuracy using Support Vector Machine, over Maximum Likelihood approach. We proposed the functional guilds mapping as an innovative approach to: (i) monitor compositional changes, especially with respect to the effects of global climate change on forests, and particularly in the tropical biome where the occurrence of hundreds of species prevents mapping activities at species level; (ii) support large-scale forest inventories. The imminent Sentinel-2 data could serve to open the road for the development of new concepts and methods in forestry and ecological research

    Customising excitation properties of polycyclic aromatic hydrocarbons by rational positional heteroatom doping: the peri-xanthenoxanthene (PXX) case

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    In this paper we tackle the challenge of gaining control of the photophysical properties of PAHs through a site-specific N-doping within the structural aromatic framework. By developing a simple predictive tool that identifies C(sp2)-positions that if substituted with a heteroatom would tailor the changes in the absorption and emission spectral envelopes, we predict optimal substitutional patterns for the model peri-xanthenoxanthene (PXX) PAH. Specifically, TDDFT calculations of the electron density difference between the S1 excited state and S0 ground state of PXX allowed us to identify the subtleties in the role of sites i.e., electron donating or withdrawing character on excitation. The replacement of two C(sp2)-atoms with two N-atoms, in either electron donating or withdrawing positions, shifts the electronic transitions either to low or high energy, respectively. This consequently shifts the PXX absorption spectral envelop bathochromically or hypsochromically, as demonstrated by steady-state absorption spectroscopic measurements. Within the series of synthesised N-doped PXX, we tune the optical band gap within an interval of ∌0.4 eV, in full agreement with the theoretical predictions. Relatedly, measurements show the more blueshifted the absorption/emission energies, the greater the fluorescence quantum yield value (from ∌45% to ∌75%). On the other hand, electrochemical investigations suggested that the N-pattern has a limited influence on the redox properties. Lastly, depending on the N-pattern, different supramolecular organisations could be obtained at the solid-state, with the 1,7-pattern PXX molecule forming multi-layered, graphene-like, supramolecular sheets through a combination of weak H-bonding and π–π stacking interactions. Supramolecular striped patterned sheets could also be formed with the 3,9- and 4,10-congeners when co-crystallized with a halogen-bond donor molecule

    Perfluorooctanesulfonate and perfluorooctanoic acid exposures of the Italian general population

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    The serum concentrations of perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) were determined in 230 subjects of the Italian general population. Participants were enrolled in 2008 in two Italian towns (Brescia, Northern Italy, and Rome, Central Italy) and belonged to the three age ranges: 20-35. years, 36-50. years, and 51-65. years.PFOS and PFOA were quantified by HPLC interfaced to a mass spectrometer operating in the electrospray negative mode. Data were acquired using multiple reaction monitoring (MRM). The isotope dilution technique was applied throughout.The median serum concentrations of all participants were 6.31ngg-1 and 3.59ngg-1 for PFOS and PFOA, respectively, and the pertinent 90th percentiles were 12.38 and 6.92.Men had higher concentrations of PFOS and PFOA than women, regardless of age. The differences were statistically significant in the 20-35 and 36-50. years groups, but not in the 51-65 group.An increase of PFOS and PFOA serum concentrations with age was observed. The Median test showed a statistically significant difference (pâ‰Ș0.01) between the three age groups for both PFOS and PFOA when applied to the entire dataset (males and females). When the test was applied to the groups of males and females separately, a significant difference was observed for females (pâ‰Ș0.005) but not for males (p>0.1).The observed strong correlation between PFOS and PFOA concentrations suggests same or similar exposure routes. © 2010 Elsevier Ltd
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