591 research outputs found

    Branched covers of the sphere and the prime-degree conjecture

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    To a branched cover between closed, connected and orientable surfaces one associates a "branch datum", which consists of the two surfaces, the total degree d, and the partitions of d given by the collections of local degrees over the branching points. This datum must satisfy the Riemann-Hurwitz formula. A "candidate surface cover" is an abstract branch datum, a priori not coming from a branched cover, but satisfying the Riemann-Hurwitz formula. The old Hurwitz problem asks which candidate surface covers are realizable by branched covers. It is now known that all candidate covers are realizable when the candidate covered surface has positive genus, but not all are when it is the 2-sphere. However a long-standing conjecture asserts that candidate covers with prime degree are realizable. To a candidate surface cover one can associate one Y -> X between 2-orbifolds, and in a previous paper we have completely analyzed the candidate surface covers such that either X is bad, spherical, or Euclidean, or both X and Y are rigid hyperbolic orbifolds, thus also providing strong supporting evidence for the prime-degree conjecture. In this paper, using a variety of different techniques, we continue this analysis, carrying it out completely for the case where X is hyperbolic and rigid and Y has a 2-dimensional Teichmueller space. We find many more realizable and non-realizable candidate covers, providing more support for the prime-degree conjecture

    A suspected case of hunting accident. Case report

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    Nowadays, the use of molecular biology in forensics has made it possible to identify human victim and sometimes even the circumstances under which the death occurred through. In our case, a corpse of a 50-years old man with a gunshot wound was found in the woods. The suspected murderer declared that it had been a hunting accident while he shot a wild boar. During the autopsy, a bullet (Borra-bullet Gualandi, 32 gr) was found in the abdomen of the victim. The authors investigated the presence of boar and victim blood both on the bullet, in order to substantiate the thesis of the hunting accident. Laboratory investigations underscored the presence of human cellular material on the bullet, which corresponds to profile of the victim and human and porcine ribosomal DNA. Through this investigation, the authors showed that it was a hunting accident, because the bullet passed through the body of the boar before hitting the victim

    Valproic acid determination by liquid chromatography coupled to mass spectrometry (LC–MS/MS) in whole blood for forensic purposes

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    Valproic acid (VPA) is a well-known drug prescribed as anti-epileptic. It has a narrow therapeutic range and shows great individual differences in pharmacodynamics and pharmacokinetics. Consequently, the therapeutical drug monitoring (TDM) in patient's plasma is of crucial importance. Liquid chromatography coupled to mass spectrometry (LC–MS/MS) has gained importance in TDM applications for its features of sensitivity, selectivity and rapidity. However, in case of VPA, the LC–MS/MS selectivity could be hampered by the lack of a sufficient number of multiple reaction monitoring (MRM) transitions describing the molecule. In fact, the product ion scan of deprotonated molecules of VPA does not produce any ion and thus most LC–MS/MS methods are based on the detection of the unique MRM transition m/z 143➔143. In this way, the advantages of selectivity in LC–MS cannot be effectively exploited. In the present method, stable analyte adducts were exploited for the determination of VPA in blood. An Acquity HSS C18 column and mobile phases consisting of 5-mM ammonium formate and acetonitrile both added 0.1% formic acid were used. Source worked in negative acquisition mode and parameters were optimized to increase the adduct (m/z 189) and dimer (m/z 287) stability, and their fragmentation were used to increase the selectivity of MRM detection. The method has been validated according to the toxicological forensic guidelines and successfully applied to 10 real blood samples. Finally, the present method showed suitable for the rapid LC–MS/MS detection of VPA in whole blood, demonstrating the possibility to increase specificity by exploiting stable in-source adducts. This should be considered of utmost importance in the case of forensic applications

    Signaling in natural killer cells: SHIP, 2B4 and the Kinome

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    The NK cell is a large granular lymphocyte that plays a key role in protecting the body against numerous pathogens including parasites, intracellular bacteria, viral infections, as well as showing anti-tumor activity and playing a role in the rejection of allogeneic BM. Unlike other lymphocytic cell types, that utilize rearranging receptors, NK cells are regulated by a complex array of germ line encoded activating and inhibitory receptors. NK cells are often described as a front line or rapid defense given their response to stimuli can be immediate, although they also maintain functions that extend their role well into the adaptive immune system. Inhibitory receptors that recognize MHC class I molecules regulate NK cell responses and self-tolerance. Recent evidence indicates self-ligands not present in the MHC locus can also modulate NK function. We previously demonstrated that the NK receptor repertoire is disrupted by SHIP-deficiency. Here we show that an inhibitory receptor, 2B4, that recognizes an MHC-independent ligand is over expressed in NK cells of SHIP-/- mice at all stages of NK development and differentiation. Overexpression of 2B4 compromises key cytolytic NK functions, including killing of allogeneic, tumor and viral targets. These results demonstrate that in SHIP-/- NK cell 2B4 is the dominant inhibitory receptor. We then furthered this finding by examining the molecular basis of 2B4 dominance. We show that in SHIP-/- NK cells there is increased 2B4 expression as well as a strong bias towards the 2B4L isoform. We have also identified a greater than tenfold increase in SHP1 recruitment to 2B4. Consistent with this SHP1 over recruitment,both a broad and a selective SHP1 inhibitor restore SHIP-/- NK killing of complex targets.Through this study we have identified the molecular mechanism of 2B4 receptor dominance as SHP1 over-recruitment.In addition we have utilized protein array technology to explore NK signaling through the determination of the NK kinome. To this end we have been able to identify multiple pathways that may mark crucial differences between the mature and immature NK cell

    1H NMR Spectroscopy and MVA Analysis of Diplodus sargus Eating the Exotic Pest Caulerpa cylindracea

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    6noThe green alga Caulerpa cylindracea is a non-autochthonous and invasive species that is severely affecting the native communities in the Mediterranean Sea. Recent researches show that the native edible fish Diplodus sargus actively feeds on this alga and cellular and physiological alterations have been related to the novel alimentary habits. The complex effects of such a trophic exposure to the invasive pest are still poorly understood. Here we report on the metabolic profiles of plasma from D. sargus individuals exposed to C. cylindracea along the southern Italian coast, using 1H NMR spectroscopy and multivariate analysis (Principal Component Analysis, PCA, Orthogonal Partial Least Square, PLS, and Orthogonal Partial Least Square Discriminant Analysis, OPLS-DA). Fish were sampled in two seasonal periods from three different locations, each characterized by a different degree of algal abundance. The levels of the algal bisindole alkaloid caulerpin, which is accumulated in the fish tissues, was used as an indicator of the trophic exposure to the seaweed and related to the plasma metabolic profiles. The profiles appeared clearly influenced by the sampling period beside the content of caulerpin, while the analyses also supported a moderate alteration of lipid and choline metabolism related to the Caulerpa-based diet.openopenS. A. De Pascali; L. Del Coco; S. Felline; E. Mollo; A. Terlizzi; F. P. FanizziS. A., De Pascali; L., Del Coco; S., Felline; E., Mollo; Terlizzi, Antonio; F. P., Fanizz

    Harvest year effects on Apulian EVOOs evaluated by (1)H NMR based metabolomics

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    none5noNine hundred extra virgin olive oils (EVOO) were extracted from individual olive trees of four olive cultivars (Coratina, Cima di Mola, Ogliarola, Peranzana), originating from the provinces of Bari and Foggia (Apulia region, Southern Italy) and collected during two consecutive harvesting seasons (2013/14 and 2014/15). Following genetic identification of individual olive trees, a detailed Apulian EVOO NMR database was built using 900 oils samples obtained from 900 cultivar certified single trees. A study on the olive oil lipid profile was carried out by statistical multivariate analysis (Principal Component Analysis, PCA, Partial Least-Squares Discriminant Analysis, PLS-DA, Orthogonal Partial Least-Squares Discriminant Analysis, OPLS-DA). Influence of cultivar and weather conditions, such as the summer rainfall, on the oil metabolic profile have been evaluated. Mahalanobis distances and J2 criterion have been measured to assess the quality of resulting scores clusters for each cultivar in the two harvesting campaigns. The four studied cultivars showed non homogeneous behavior. Notwithstanding the geographical spread and the wide number of samples, Coratina showed a consistent behavior of its metabolic profile in the two considered harvests. Among the other three Peranzana showed the second more consistent behavior, while Cima di Mola and Ogliarola having the biggest change over the two years.Girelli, Chiara R; Del Coco, Laura; Papadia, Paride; De Pascali, Sandra A; Fanizzi, Francesco PGirelli, CHIARA ROBERTA; DEL COCO, Laura; Papadia, Paride; DE PASCALI, SANDRA ANGELICA; Fanizzi, Francesco Paol

    Performance Evaluation of end-to-end security protocols in an Internet of Things

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    Wireless Sensor Networks are destined to play a fundamental role in the next-generation Internet, which will be characterized by the Machine-to-Machine paradigm, according to which, embedded devices will actively exchange information, thus enabling the development of innovative applications. It will contribute to assert the concept of Internet of Things, where end-to-end security represents a key issue. In such context, it is very important to understand which protocols are able to provide the right level of security without burdening the limited resources of constrained networks. This paper presents a performance comparison between two of the most widely used security protocols: IPSec and DTLS. We provide the analysis of their impact on the resources of embedded devices. For this purpose, we have modified existing implementations of both protocols to make them properly run on our hardware platforms, and we have performed an extensive experimental evaluation study. The achieved results are not a consequence of a classical simulation campaign, but they have been obtained in a real scenario that uses software and hardware typical of the current technological developments. Therefore, they can help network designers to identify the most appropriate secure mechanism for end-to-end IP communications involving constrained devices
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