2,774 research outputs found
Le strutture narrative di Fenice in Iliade IX: il paradigma di Meleagro
La tesi si propone di analizzare da un punto di vista narratologico il racconto del mito di Meleagro narrato da Fenice in Il. 9.524-605. Si cercheranno di individuare le particolari strutture narrative che questo racconto presenta, e di mostrare come le soluzioni adottate dal suo narratore risultino funzionali allo scopo paradigmatico per il quale il racconto è stato introdotto. Si passerà successivamente ad un esame delle principali versioni del mito di Meleagro tramandateci dalle fonti arcaiche e classiche, che vuole essere propedeutico al discorso riguardante il rapporto fra tradizione e innovazione all’interno della versione omerica. Infine, si tenterà di mettere in luce il contributo che un’indagine di tipo narrativo può offrire all’interpretazione del paradigma di Meleagro
New sulfurated derivatives of cinnamic acids and rosmaricine as inhibitors of STAT3 and NF-kappa B transcription factors
A set of new sulfurated drug hybrids, mainly derived from caffeic and ferulic acids and rosmaricine, has been synthesized and their ability to inhibit both STAT3 and NF-kappa B transcription factors have been evaluated. Results showed that most of the new hybrid compounds were able to strongly and selectively bind to STAT3, whereas the parent drugs were devoid of this ability at the tested concentrations. Some of them were also able to inhibit the NF-kappa B transcriptional activity in HCT-116 cell line and inhibited HCT-116 cell proliferation in vitro with IC50 in micromolar range, thus suggesting a potential anticancer activity. Taken together, our study described the identification of new derivatives with dual STAT3/NF-kappa B inhibitory activity, which may represent hit compounds for developing multi-target anticancer agents
The chief financial officer (CFO) profile and R&D investment intensity: evidence from listed European companies
urpose – This study aims to investigate whether the characteristics of the chief financial officer (CFO) have an impact on the intensity of the corporate research and development (R&D) investment. Design/methodology/approach – Based on hand-collected data for the CFOs of a sample of the largest European listed companies for the period 2013–2016, this study uses regression analyses to test empirically the association of CFO education, CFO gender and CFO age with R&D investment intensity.
Findings – The presence of female CFOs, CFOs with a Master of Business Administration (MBA) or Doctor of Philosophy (PhD) degree and older CFOs is positively associated with the intensity of R&D investment. Research limitations/implications – This study relies on some observable characteristics of CFOs and focuses on large listed companies.
Practical implications – The results of this study may help investors, stakeholders and practitioners to understand better which type of CFO characteristics are more likely to result in higher firm-level R&D investment intensity.
Originality/value – This study offers the first insights into the impact of CFOs, as the most prominent C-suite executives, on the level of corporate investments in R&D activity
Determinants of financial instruments risk disclosure: An empirical analysis in the banking sector
This study investigates the effects of firm and country factors, considered as determinants of the financial instruments risk disclosure (FIRD) proxied by IFRS 7 in the European banking system. We select 582 banks-year observations based on the largest five European economies (France, Germany, Italy, Spain and the UK) as provided by the International Monetary Fund (IMF). Our analysis covers a period of 8 years (2007-2014) and adopts an OLS model. Results show that both firm (the type of auditor, board size and profitability) and country factors (financing environment, regulatory environment, and organizational status) affect FIRD. Limitations for this paper could relate to country selection, as well as on the breadth of the sample. Nevertheless, these aspects could unveil possible areas of future inquiry. The contribution of the study is twofold. It enriches the literature about firm and country determinants on financial instruments risk disclosure, as combined rather than single-standing variables. Yet, it draws the attention of banks' management and investors on what the crucial factors to reach an optimal level of FIRD are and gain the confidence of capital markets, reducing information asymmetries. This is the first empirical investigation on the determinants of FIRD, using IFRS 7, in the European banking sector that adopts firm and country factors in a combined effort
A selective alpha1D-adrenoreceptor antagonist inhibits human prostate cancer cell proliferation and motility "in vitro"
The progression of prostate cancer (PC) to a metastatic hormone refractory disease is the major contributor to the overall cancer mortality in men, mainly because the conventional therapies are generally ineffective at this stage. Thus, other therapeutic options are needed as alternatives or in addition to the classic approaches to prevent or delay tumor progression. Catecholamines participate to the control of prostate cell functions by the activation of alpha1-adrenoreceptors (alpha1-AR) and increased sympathetic activity has been linked to PC development and evolution. Molecular and pharmacological studies identified three alpha1-AR subtypes (A, B and D), which differ in tissue distribution, cell signaling, pharmacology and physiological role. Within the prostate, alpha1A-ARs mainly control stromal cell functions, while alpha1B- and alpha1D- subtypes seem to modulate glandular epithelial cell growth. The possible direct contribution of alpha1D-ARs in tumor biology is supported by their overexpression in PC. The studies here presented investigate the "in vitro" antitumor action of A175, a selective alpha1D-AR antagonist we have recently obtained by modifying the potent, but not subtype-selective alpha1-AR antagonist (S)-WB4101, in the hormone-refractory PC3 and DU145 PC cell lines. The results indicate that A175 has an alpha1D-AR-mediated significant and dose-dependent antiproliferative action that possibly involves the induction of G0/G1 cell cycle arrest, but not apoptosis. In addition, A175 reduces cell migration and adhesiveness to culture plates. In conclusion, our work clarified some cellular aspects promoted by alpha1D-AR activity modulation and supports a further pharmacological approach in the cure of hormone-refractory PC, by targeting specifically this AR subtype
Insulin secretory granules labelled with phogrin-fluorescent proteins show alterations in size, mobility and responsiveness to glucose stimulation in living β-cells
The intracellular life of insulin secretory granules (ISGs) from biogenesis to secretion depends on their structural (e.g. size) and dynamic (e.g. diffusivity, mode of motion) properties. Thus, it would be useful to have rapid and robust measurements of such parameters in living β-cells. To provide such measurements, we have developed a fast spatiotemporal fluctuation spectroscopy. We calculate an imaging-derived Mean Squared Displacement (iMSD), which simultaneously provides the size, average diffusivity, and anomalous coefficient of ISGs, without the need to extract individual trajectories. Clustering of structural and dynamic quantities in a multidimensional parametric space defines the ISGs’ properties for different conditions. First, we create a reference using INS-1E cells expressing proinsulin fused to a fluorescent protein (FP) under basal culture conditions and validate our analysis by testing well-established stimuli, such as glucose intake, cytoskeleton disruption, or cholesterol overload. After, we investigate the effect of FP-tagged ISG protein markers on the structural and dynamic properties of the granule. While iMSD analysis produces similar results for most of the lumenal markers, the transmembrane marker phogrin-FP shows a clearly altered result. Phogrin overexpression induces a substantial granule enlargement and higher mobility, together with a partial de-polymerization of the actin cytoskeleton, and reduced cell responsiveness to glucose stimulation. Our data suggest a more careful interpretation of many previous ISG-based reports in living β-cells. The presented data pave the way to high-throughput cell-based screening of ISG structure and dynamics under various physiological and pathological conditions
Thermal expansivity and degradation properties of PLA/HA and PLA/ bTCP in vitro conditioned composites
[EN] The objective of this study was to investigate the thermal expansivities and degradation properties for several in vitro
conditioned biodegradable poly(lactic acid)/hydroxyapatite (PLA/HA) and poly(lactic acid)/b-tricalcium phosphate (PLA/
bTCP) composites with different mass% of the particle reinforcements (i.e. 10, 20 and 30). The samples were prepared by
extrusion followed by injection moulding and incubated in a customized simulated body fluid at 37 C over 60, 90, 120,
150 and 180 days, respectively. Thermal expansion and degradation properties of in vitro conditioned samples, along with
dynamic mechanical properties of unconditioned ones, were systematically investigated through coefficients of linear
thermal expansion and thermal strain changes, decomposition temperatures, mass changes and per cent residues. The
results indicated that PLA/bTCP composites performed better than PLA/HA composites, irrespective of their filler mass%,
revealing high values of glass transition temperatures, around a mean value of 65 C, both on dynamic mechanical analysis
and on dilatation measurements but lower values on their degradation temperatures, such as 360 C. The results suggest the
feasibility of tailoring high-loaded osteoconductive fillers-reinforced PLA composites for various medical and engineering
applications.Ferri, JM.; Motoc, DL.; Ferrándiz Bou, S.; Balart, R. (2019). Thermal expansivity and degradation properties of PLA/HA and PLA/
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Time-varying information measures: an adaptive estimation of information storage with application to brain-heart interactions
Network Physiology is a rapidly growing field of study that aims to understand how physiological systems interact to maintain health. Within the information theory framework the information storage (IS) allows to measure the regularity and predictability of a dynamic process under stationarity assumption. However, this assumption does not allow to track over time the transient pathways occurring in the dynamical activity of a physiological system. To address this limitation, we propose a time-varying approach based on the recursive least squares algorithm (RLS) for estimating IS at each time instant, in non-stationary conditions. We tested this approach in simulated time-varying dynamics and in the analysis of electroencephalographic (EEG) signals recorded from healthy volunteers and timed with the heartbeat to investigate brain-heart interactions. In simulations, we show that the proposed approach allows to track both abrupt and slow changes in the information stored in a physiological system. These changes are reflected in its evolution and variability over time. The analysis of brain-heart interactions reveals marked differences across the cardiac cycle phases of the variability of the time-varying IS. On the other hand, the average IS values exhibit a weak modulation over parieto-occiptal areas of the scalp. Our study highlights the importance of developing more advanced methods for measuring IS that account for non-stationarity in physiological systems. The proposed time-varying approach based on RLS represents a useful tool for identifying spatio-temporal dynamics within the neurocardiac system and can contribute to the understanding of brain-heart interactions
Fabrication and testing of a high resolution extensometer based on resonant MEMS strain sensors
A novel type of linear extensometer with exceptionally high resolution of 4 nm based on MEMS resonant strain sensors bonded on steel and operating in a vacuum package is presented. The tool is implemented by means of a steel thin bar that can be pre-stressed in tension within two fixing anchors. The extension of the bar is detected by using two vacuum-packaged resonant MEMS double-ended tuning fork (DETF) sensors bonded on the bar with epoxy glue, one of which is utilized for temperature compensation. Both sensors are driven by a closed loop self-oscillating transresistance amplifier feedback scheme implemented on a PCB (Printed Circuit Board). On the same board, a microcontroller-based frequency measurement circuit is also implemented, which is able to count the square wave fronts of the MEMS oscillator output with a resolution of 20 nsec. The system provides a frequency noise of 0.2 Hz corresponding to an extension resolution of 4 nm for the extensometer. Nearly perfect temperature compensation of the frequency output is achieved in the temperature range 20-35°C using the reference sensor
Sources of variability in the set-up of an Indoor GPS
An increasing demand for an extended flexibility to model types and production volumes in the manufacture of large-size assemblies has generated a growing interest in the reduction of jigs and fixtures deployment during assembly operations. A key factor enabling and sustaining this reduction is the constantly expanding availability of instruments for dimensional measurement of large-size products. However, the increasing complexity of these measurement systems and their set-up procedures may hinder the final users in their effort to assess whether the performance of these instruments is adequate for pre-specified inspection tasks. In this paper, mixed-effects and fixed-effects linear statistical models are proposed as a tool to assess quantitatively the effect of set-up procedures on the uncertainty of measurement results. This approach is demonstrated on a Metris Indoor GPS system (iGPS). The main conclusion is that more than 99% of the variability in the considered measurements is accounted for by the number of points used in the bundle adjustment procedure during the set-up phase. Also, different regions of the workspace have significantly different error standard deviations and a significant effect on the transient duration of measurement. This is expected to affect adversely the precision and unbiasedness of measurements taken with Indoor GPS when tracking moving objects
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