1,749 research outputs found

    Neural Nets and Star/Galaxy Separation in Wide Field Astronomical Images

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    One of the most relevant problems in the extraction of scientifically useful information from wide field astronomical images (both photographic plates and CCD frames) is the recognition of the objects against a noisy background and their classification in unresolved (star-like) and resolved (galaxies) sources. In this paper we present a neural network based method capable to perform both tasks and discuss in detail the performance of object detection in a representative celestial field. The performance of our method is compared to that of other methodologies often used within the astronomical community.Comment: 6 pages, to appear in the proceedings of IJCNN 99, IEEE Press, 199

    AMPHIPHILIC, BIODEGRADABLE ANDBIOCOMPATIBLE POLYMERS FOR INDUSTRIALAPPLICATIONS

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    The aim of this PhD work was to establish the synthetic procedures for new families of biocompatible and biodegradable and/or bioeliminable biomaterials that can be differently processed to obtain nanoparticles, core-shell nanofibres and hydrogel slabs or conduits, respectively. Depending on composition, size and morphology, these biomaterials may be intended for applications as drug delivery systems and/or tissue regeneration. Specifically, the research project has been developed along two main lines: \u2022 Synthesis of poly(lactic-glycolic acid)-g-poly(1-vinylpyrrolidin-2-one) (PLGA-g-PVP) copolymers whose architecture consisted of a long PLGA backbone with oligomeric PVP pendants. These were obtained by the radical polymerisation of 1-vinylpyrrolidin-2-one in molten PLGA 50:50, acting as chain transfer agent. The procedure was a single pot - single step one. Copolymers were characterized by FTIR, 1H- and 13C-NMR and thermal analyses. They were saponified giving, besides PLGA degradation products, also un-degraded PVP. This was isolated and analysed by size exclusion chromatography, to evaluate the molecular weights of grafted PVP chains. MALDI-TOF analysis allowed identifying the chemical structure of PVP terminals and unambiguously establishing that PVP chains had been grafted onto PLGA backbone PLGA-g-PVP with different PVP content were formulated as drug nanocarriers by different procedures. Doxorubicin-loaded nanoparticles were prepared by the solvent diffusion method and fully characterised. In vitro drug release kinetics were studied and in vitro biological activity evaluated on several antitumoral cell lines. PLGA-g-PVP were also used as coatings of lipid nanocapsules for the delivery of curcumin and artemisinin as antimalarials. Drug loaded-lipid micro-dispersions were first prepared by oil in water emulsion. The lipid drops were converted into nanometric ones by high pressure homogenization and finally surface coated by adding a DMSO/acetone PLGA-g-PVP solution. Growth inhibition assay were conducted on plasmodium falciparum (3D7) cultures. Haemoltic assays were conducted on healthy red blood cells. PLGA-g-PVP- and PLGA-based scaffolds consisting of nanofibrous mats were produced by electrospinning. Starting materials were electrospun and their morphology was evaluated by scanning electron microscopy and wettability by contact angle measurements. Coaxial electrospinning of two materials, in which PLGA formed the core and PLGA-g-PVP the shell of fibres, were also conducted and compared with those obtained by mixed solutions of staritng materials. Chemical composition was evaluated by TGA, morphology by scanning electron microscopy and wettability by contact angle measurements. Nanofabric scaffold produced will be evaluated for drug release and tissue engineering applications. \u2022 Synthesis of a new classes of poly(saccharide)-poly(aminoamine)s 3D-network intended as scaffolds for the regeneration of liver. In particular, hyaluronic acid-polyamidoamine and hyaluronic acid-gelatin- polyamidoamine hydrogels were synthesised by amidation reaction between the carboxylic acid group of hyaluronic acid and amine groups of gelatin and or an NH2-functionalized PAA, promoted by 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as coupling agent. Chemical-physical characterization were carried out on hydrogels. In order to promote hepatic cell proliferation serotonin was bonded to both hydrogels, adding it to the initial recipe, exploiting the above reaction between carboxylic acid group of hyaluronic acid and amine group of serotonin. Serotonin-loaded hydrogels were tested in vitro to evaluate biological efficacy

    Editorial: Endocrine modulators of neurological processes: potential treatment targets of pediatric neurological diseases.

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    Editorial on the Research Topic Endocrine Modulators of Neurological Processes: Potential Treatment Targets of Pediatric Neurological Diseases

    Lossy Multi/Hyperspectral Compression HW Implementation at high data rate

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    Image compression is becoming more and more important, as new multispectral and hyperspectral instruments are going to generate very high data rates due to the increased spatial and spectral resolutions. Transmitting all the acquired data to the ground segment is a serious bottleneck, and compression techniques are a feasible solution to this problem. The CCSDS has established a working group (WG) on multispectral and Hyperspectral Data Compression (MHDC), which has the purpose of standardizing compression techniques to be used onboard. The WG has already standardized a lossless compression algorithm for multispectral and hyperspectral images, and has started working on a lossy compression algorithm. The complexity of lossless compression algorithms is typically larger than that of lossy ones, leading to potentially lower throughputs. Therefore, a careful assessment is required in order to identify techniques that are able to sustain very high data rates. The increased complexity can also lead to increased resource occupancy on a hardware device such as an FPGA. Lossy compression introduces information losses in the images, and these losses must be accurately characterized, and their effect on the applications investigated. For these reasons, developing a lossy algorithm requires a more elaborate process. Under an ESA contract primed by Politecnico of Torino, TSD is currently designing an IP core for FPGA and/or ASIC implementation of a lossy compression algorithm that is being proposed for CCSDS standardization. In addition to the IP core, TSD is developing a HW platform based on the Xilinx Virtex-5 XQR5VFX130, the industry's first high performance rad-hard reconfigurable FPGA for processing-intensive for space systems. Advanced results along with details of electronic platform design will be presented in this paper

    Chlamydophila pecorum in fetuses of mediterranean buffalo (bubalus bubalis) bred in Italy

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    In order to study the role played by the different species of Chlamydophila in causing abortions in Mediterranean buffalo, the Authors examined 164 fetuses from 80 different buffalo herds in Southern Italy. Three fetuses, came from two different herds, were positive. Our study confirms the pathogenic role of C. pecorum in buffalo, not only as a cause of neuropathology in calves but as an infectious abortive agent

    Stimulated single-fiber electromyography (sSFEMG) in Lambert-Eaton syndrome

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    Objective: To report the clinical features and the neurophysiological approach of a patient with Lambert-Eaton myasthenic syndrome (LEMS), highlighting the diagnostic role of the stimulated single fiber electromyography (sSFEMG). Case report: A 60-year-old woman presenting with the LEMS triad (proximal and axial weakness, autonomic dysfunction and areflexia) was evaluated by neurophysiological tests (electroneuromyography, repetitive stimulation test (TSR), voluntary and stimulated SFEMG). We reported: 1) increase of compound muscle action potential (CMAP) amplitude (>60%) following brief isometric exercise compared to the rest (baseline); 2) decremental/incremental response of CMAP amplitude at low- (3 Hz) and high-frequency (30 Hz) repetitive stimulation test (RST), respectively; 3) increased neuromuscular jitter and blocking at voluntary single-fiber electromyography (vSFEMG); 4) stimulation rate-dependent reduction of the neuromuscular jitter and blocking at sSFEMG. Diagnosis was confirmed by serological demonstration of circulating voltage gated calcium channels (VGCC) antibodies. Significance: The present case highlights the role of the sSFEMG in the diagnosis of LEMS, underling the stimulation rate-dependency of both neuromuscular jitter and blocks

    Extraction of phenolic compounds from 'Aglianico' and 'Uva di Troia' grape skins and seeds in model solutions: Influence of ethanol and maceration time

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    The effect of increasing concentration of ethanol (0, 4, 7.5 and 13 %) and contact time (respectively 1, 4, 7 and 10 days) on the extraction of phenolics from berry skins and seeds of the grape, Vitis vinifera 'Aglianico' and 'Uva di Troia', were examined. Two assays of post-fermentative maceration in two hydroalcoholic solutions at 11 and 13 % ethanol, were also performed. Chromatic properties and phenolics of medium were analyzed by HPLC and spectrophotometric methods. The extraction of total phenolics, anthocyanins, proanthocyanidins, and vanilline reactive flavans (VRF) from berry skins reached the maximum on the 4th day of maceration. Quercetin and gallic acid were gradually extracted from grape skins. The maximum release of flavan-3-ols from the skins was achieved on the first day of maceration. Total phenolics, tannins and VRF were gradually extracted from seeds. During the postfermentative maceration, higher the content of ethanol, higher the extraction of total polyphenols and tannins from 'Uva di Troia' skins and the extraction of total polyphenols and tannins from 'Aglianico' seeds. These results clearly indicate that the grape cultivar mainly influences the release of phenolic compounds from the solid parts of berry to the must especially during postfermentative maceration.

    The New Paradigms in Clinical Research: From Early Access Programs to the Novel Therapeutic Approaches for Unmet Medical Needs.

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    Despite several innovative medicines gaining worldwide approval in recent years, there are still therapeutic areas for which unsatisfied therapeutic needs persist. For example, high unmet clinical need was observed in patients diagnosed with type 2 diabetes mellitus and hemophilia, as well as in specific age groups, such as the pediatric population. Given the urgent need to improve the therapy of clinical conditions for which unmet clinical need is established, clinical testing, and approval of new medicines are increasingly being carried out through accelerated authorization procedures. Starting from 1992, the Food and Drug Administration and the European Medicines Agency have supported the so-called Early Access Programs (EAPs). Such procedures, which can be based on incomplete clinical data, allow an accelerated marketing authorization for innovative medicines. The growth in pharmaceutical research has also resulted in the development of novel therapeutic approaches, such as biotech drugs and advanced therapy medicinal products, including new monoclonal antibodies for the treatment of asthma, antisense oligonucleotides for the treatment of Duchenne muscular dystrophy and spinal muscular atrophy, and new anticancer drugs that act on genetic biomarkers rather than any specific type of cancer. Even though EAPs and novel therapeutic approaches have brought huge benefits for public health, their implementation is limited by several challenges, including the high risk of safety-related label changes for medicines authorized through the accelerated procedure, the high costs, and the reimbursement and access concerns. In this context, regulatory agencies should provide the best conditions for the implementation of the described new tools
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