379 research outputs found

    On the Chinese Exchange Rate Regime: an Attempt to Flexibility during 2015

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    This study will demonstrate, through an econometric and asset allocation approach, if and how the Chinese exchange rate regime was changing during 2015. Particularly, China to improve its exchange rate formation system implemented, during July and August 2015, three depreciation as a step toward a market-oriented exchange rate. This situation, along with the new right of the RMB to be an international currency in SDR should generate a loss of weight about the USD in the Chinese basket peg. For this reason, moving from Frankel-Wei’s basic econometric model - but with some appropriate changes - our objective is to verify if the Chinese monetary policy about the exchange rate has affected the inner balance of the Chinese basket-peg leading it towards a flexible exchange rate regime

    Risk factors for HBV/HIV/HCV in drug addicts: a survey of attendees of a Department of Pathological Dependence

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    Introduction. This study aims to determine risk factors for the acquisition of HIV, HBV and HCV infections among Injection Drug Users (IDUs) who attended the out-patient clinic of the Department of Pathological Dependence at Bari Hospital in Bari Province (Italy). Methods. The study was conducted in the year 2008 using the information available in the out-patient files of 291 drug addicts who were undergoing treatment. Results. Their average age was 29.3 and 133 (45.7%) of them were affected by HIV/ HBV/ HCV. The use of injected heroin, being separated or divorced, and having committed a crime were found to be risk factors for infection by HIV/ HBV/ HCV, while having a school diploma or a university degree and the use of cannabinoids were negatively associated with the infective diseases. Discussion and conclusions. While the data from the Italian Departments of Pathological Dependence concerning HIV diffusion in treated patients have been showing a reduction in the number of cases of seropositivity, drug addiction in industrialized countries is still the second most important risk factor, after promiscuous sexual behaviour, for infection by parenteral transmission. Correct risk assessment is essential for the planning of effective strategies for primary and secondary prevention

    Risk factors for HBV/HIV/HCV in drug addicts: a survey of attendees of a Department of Pathological Dependence

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    Introduction. This study aims to determine risk factors for the acquisition of HIV, HBV and HCV infections among Injection Drug Users (IDUs) who attended the out-patient clinic of the Department of Pathological Dependence at Bari Hospital in Bari Province (Italy). Methods. The study was conducted in the year 2008 using the information available in the out-patient files of 291 drug addicts who were undergoing treatment. Results. Their average age was 29.3 and 133 (45.7%) of them were affected by HIV/ HBV/ HCV. The use of injected heroin, being separated or divorced, and having committed a crime were found to be risk factors for infection by HIV/ HBV/ HCV, while having a school diploma or a university degree and the use of cannabinoids were negatively associated with the infective diseases. Discussion and conclusions. While the data from the Italian Departments of Pathological Dependence concerning HIV diffusion in treated patients have been showing a reduction in the number of cases of seropositivity, drug addiction in industrialized countries is still the second most important risk factor, after promiscuous sexual behaviour, for infection by parenteral transmission. Correct risk assessment is essential for the planning of effective strategies for primary and secondary prevention

    Structural Analysis and Photocurrent Spectroscopy of CCCs on 99.99% Aluminum

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    A characterization of chromate conversion coatings (CCCs) formed in the presence and in the absence of accelerator (ferro-ferricyanide redox couple) has been performed by various techniques (transmission electron microscopy, TEM, glow discharge optical emission spectrometry, GDOES, X-ray absorption near-end structure, XANES, and photon correlation spectroscopy). The results of a detailed investigation on morphological, compositional, and solid-state properties of freshly converted aluminum samples at different immersion times (30 s-90 min) are reported. The TEM and GDOES data suggest the presence of iron-cyanide species only in the external layer of CCC of nearly constant thickness. The XANES data suggest the presence of both Cr(VI) and Cr(III) species with a ratio Cr(VI)/Cr(III) close to 1:2. This ratio remains constant with the conversion time and seems slightly affected by the composition of conversion solution. The photoelectrochemical study suggests an insulating or slightly p-type behavior for CCC layers. A bandgap value of about 2.55 eV has been estimated, regardless of the conversion solution, although some differences in the photocurrent spectra have been observed for coatings formed in the presence or absence of accelerator. The location of electronic energy levels of the Al/CCC/electrolyte interface has been derived which could account for the different kinetics of coating formation in the presence of accelerator

    A nosocomial outbreak of 2009 pandemic influenza A(H1N1) in a paediatric oncology ward in Italy, October – November 2009

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    A nosocomial outbreak of 2009 pandemic influenza A(H1N1), with eight confirmed cases, occurred in a paediatric oncology ward in Italy, in October/November 2009. The fact that one case was infected despite being isolated and without contact to a symptomatic patient, hints towards potential transmission through a health care worker (HCW) and underlines the importance of vaccination of HCW who are involved in the care of critically ill patients

    Activation of FGF Signaling Mediates Proliferative and Osteogenic Differences between Neural Crest Derived Frontal and Mesoderm Parietal Derived Bone

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    BACKGROUND: As a culmination of efforts over the last years, our knowledge of the embryonic origins of the mammalian frontal and parietal cranial bones is unambiguous. Progenitor cells that subsequently give rise to frontal bone are of neural crest origin, while parietal bone progenitors arise from paraxial mesoderm. Given the unique qualities of neural crest cells and the clear delineation of the embryonic origins of the calvarial bones, we sought to determine whether mouse neural crest derived frontal bone differs in biology from mesoderm derived parietal bone. METHODS: BrdU incorporation, immunoblotting and osteogenic differentiation assays were performed to investigate the proliferative rate and osteogenic potential of embryonic and postnatal osteoblasts derived from mouse frontal and parietal bones. Co-culture experiments and treatment with conditioned medium harvested from both types of osteoblasts were performed to investigate potential interactions between the two different tissue origin osteoblasts. Immunoblotting techniques were used to investigate the endogenous level of FGF-2 and the activation of three major FGF signaling pathways. Knockdown of FGF Receptor 1 (FgfR1) was employed to inactivate the FGF signaling. RESULTS: Our results demonstrated that striking differences in cell proliferation and osteogenic differentiation between the frontal and parietal bone can be detected already at embryonic stages. The greater proliferation rate, as well as osteogenic capacity of frontal bone derived osteoblasts, were paralleled by an elevated level of FGF-2 protein synthesis. Moreover, an enhanced activation of FGF-signaling pathways was observed in frontal bone derived osteoblasts. Finally, the greater osteogenic potential of frontal derived osteoblasts was dramatically impaired by knocking down FgfR1. CONCLUSIONS: Osteoblasts from mouse neural crest derived frontal bone displayed a greater proliferative and osteogenic potential and endogenous enhanced activation of FGF signaling compared to osteoblasts from mesoderm derived parietal bone. FGF signaling plays a key role in determining biological differences between the two types of osteoblasts

    A geostatistical fusion approach using UAV data for probabilistic estimation of Xylella fastidiosa subsp. pauca infection in olive trees

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    Xylella fastidiosa is one of the most destructive plant pathogenic bacteria worldwide, affecting more than 500 plant species. In Apulia region (southeastern Italy), X. fastidiosa subsp. pauca (Xfp) is responsible for a severe disease, the olive quick decline syndrome (OQDS), spreading epidemically and with dramatic impact on the agriculture, the landscape, the tourism, and the cultural heritage of this region. An early detection of the infected plants would hinder the rapid spread of the disease. The main objective of this paper was to define a geostatistical approach of data fusion, which combines remote (radiometric), and proximal (geophysical) sensor data and visual inspections with plant diagnostic tests, to provide probabilistic maps of Xfp infection risk. The study site was an olive grove located at Oria (province of Brindisi, Italy), where at the time of monitoring (September 2017) only few plants showed initial symptoms of the disease. The measurements included: 1) acquisitions of reflected electromagnetic radiation with UAV (Unmanned Aerial Vehicle) equipped with a multi-spectral camera; 2) geophysical surveys on the trunks of 49 plants with Ground Penetrating Radar (GPR); 3) disease severity rating, by visual inspection of the proportion of canopy with symptoms; 4) qPCR (real time-quantitative Polymerase Chain Reaction) data from tests on 61 plants. The data were submitted to a set of processing techniques to define a “data fusion” procedure, based on non-parametric multivariate geostatistics. The approach allowed marking those areas where the risk of infection was higher, and identifying the possible infection entry routes into the field. The probability map of infection risk could be used as an effective tool for a preventive action and for a better organization of the monitoring plans

    Physicochemical Characterization of Passive Films and Corrosion Layers by Differential Admittance and Photocurrent Spectroscopy

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    Two different electrochemical techniques, differential admittance and photocurrent spectroscopy, for the characterization of electronic and solid state properties of passive films and corrosion layers are described and critically evaluated. In order to get information on the electronic properties of passive film and corrosion layers as well as the necessary information to locate the characteristic energy levels of the passive film/electrolyte junction like: flat band potential (Ufb), conduction band edge (EC) or valence band edge (EV), a wide use of Mott-Schottky plots is usually reported in corrosion science and passivity studies. It has been shown, in several papers, that the use of simple M-S theory to get information on the electronic properties and energy levels location at the film/electrolyte interface can be seriously misleading and/or conflicting with the physical basis underlying the M-S theory. A critical appraisal of this approach to the study of very thin and thick anodic passive film grown on base-metals (Cr, Ni, Fe, SS etc..) or on valve metals (Ta, Nb, W etc..) is reported in this work, together with possible alternative approach to overcome some of the mentioned inconsistencies. At this aim the theory of amorphous semiconductor Schottky barrier, introduced several years ago in the study of passive film/electrolyte junction, is reviewed by taking into account some of the more recent results obtained by the present authors. Future developments of the theory appears necessary to get more exact quantitative information on the electronic properties of passive films, specially in the case of very thin film like those formed on base metals and their alloys. The second technique described in this chapter, devoted to the physico-chemical characterization of passive film and corrosion layers, is a more recent technique based on the analysis of the photo-electrochemical answer of passive film/electrolyte junction under illumination with photons having suitable energy. Such a technique usually referred to as Photocurrent Spectroscopy (PCS) has been developed on the basis of the large research effort carried out by several groups in the 1970’s and aimed to investigate the possible conversion of solar energy by means of electrochemical cells. In this work the fundamentals of semiconductor/electrolyte junctions under illumination will be highlighted both for crystalline and amorphous materials. The role of amorphous nature and film thickness on the photo-electrochemical answer of passive film/solution interface is reviewed as well the use of PCS for quantitative analysis of the film composition based on a semi-empirical correlation between optical band gap and difference of electronegativity of film constituents previously suggested by the present authors. In this frame the results of PCS studies on valve metal oxides and valve metal mixed oxides will be discussed in order to show the validity of the proposed method. The results of PCS studies aimed to get information on passive film composition and carried out by different authors on base metals (Fe, Cr, Ni) and their alloys, including stainless steel, will be also compared with compositional analysis carried out by well-established surface analysis techniques

    Optical Characterization of Benign and Malignant Breast Lesions by Perturbative Model

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    The characterization of benign and malignant breast lesions was performed by the use of a perturbative model. Concentrations of blood, lipid, water and collagen were obtained. Differences between lesions and healthy tissue were observed

    Frequency of human papillomavirus infection and genotype distribution among women with known cytological diagnosis in a Southern Italian region

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    Introduction. In the Puglia region (South Italy) about 200 new hospitalizations for cervical cancer are registered every year. The study investigated the frequency of Human Papillomavirus (HPV) infection and the genotype distribution of HPV in a sample of women with known cytology attending the outpatient clinics of four Gynecological Departments of the University of Bari over a four-year period (2005-2008). Methods. Cervical samples from 1,168 women were analyzed for the presence of HPV-DNA through Polymerase Chain Reaction (PCR) in L1 region and reverse hybridization. The cytological results were associated with HPV positivity and type-specific prevalence. Results. Overall, HPV infection was found in 355 (30.4%) women. HPV-DNA was found in 34.4% of women with a cytological diagnosis of ASCUS, in 46.8% of women with Low-grade Squamous Intraepithelial Lesion (LSIL) and in 87.0% of women with High-grade Squamous Intraepithelial Lesion (HSIL)/carcinoma. Also 16.0% of women with normal Pap smear were found to be HPV-DNA positive. The most common HPV genotype was type 16 found in 27.3% of positives, followed by type 53 (11.5%), type 66 (9.2%) and type 31 (9.0%). HPV genotype 18 was found in 6.4% of positives. Types 16 or 18 were detected in about 34% (120/355) of all infected women, in about 33% of LSIL and in 60% of HSIL/ carcinoma HPV-positive women. Among low risk (LR) genotypes, type 61 was found in 10.7% of HPV positive women, type 62 in 8.4%, type 42 in 8.1% and type CP6108 in 7.8%. Discussion and conclusions. The findings of the study give evidence that HPV infection is frequent in the studied cohort of women. The most widespread genotypes found were 16 and 53. These data may represent a benchmark for future evaluation after the recent introduction of vaccination against HPV in 12-year-old girls
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