193 research outputs found
Crowdfunding: The Case of Italy
Crowdfunding is a fundraising process from a large audience to launch a new venture or entrepreneurial project. It is mostly based on the use of Web and represents a unique category of fundraising, with different vehicles, processes and goals. It is very diffused in the global economic landscape and in Italy where a specific discipline for crowdfunding was introduced for the first time in Europe. The chapter, after a summary of the peculiarities, spread and regulation of crowdfunding, intends to analyze the characteristics of a platform operating on the Italian market (Produzioni dal Basso), highlighting its characteristics, strengths and weaknesses. The work also intends to carry out a simulation for the realization of a crowdfunding project by an Italian Foundation operating in the social sector of child and adolescent distress, to be implemented through the use of the same platform
Multiphysics Finite-Element Modeling of the Neuron/Electrode Electrodiffusive Interaction
Understanding the biological-electrical transduction mechanisms is essential for reliable neural signal recording and feature extraction. As an alternative to state-of-the-art lumped-element circuit models, here we adopt a multiscale-multiphysics finite-element modeling framework. The model couples ion transport with the Hodgkin-Huxley model and the readout circuit, and is used to investigate a few relevant case studies. This approach is amenable to explore ion transport in the extracellular medium otherwise invisible to circuit model analysis
Modelling Load Stochastic Jumps for Power Systems Dynamic Analysis
This letter proposes an approach to model power system loads as stochastic processes that incorporate both continuous and event-driven dynamics. The letter provides a brief theoretical background on the stochastic differential equations defining Ornstein-Uhlenbeck processes with jumps used for the stochastic modeling of power system voltage-dependent loads. The all-island 1479-bus Irish transmission system serves to illustrate and test the proposed jump-diffusion model
SDE-based wind speed models with Weibull distribution and exponential autocorrelation
This paper discusses three approaches to construct wind speed models based on Stochastic Differential Equations (SDEs). The methods are applied to construct models able to simulate wind speed trajectories that are statistically described by means of the Weibull distribution and the exponential autocorrelation. The ability of the three models to reproduce stochastic processes with the above indicated statistical properties is duly studied and compared. With this aim, wind speed measurements recorded in a weather station located in Ireland are analyzed. The parameters obtained in this analysis are used to set up the developed models. Finally, the statistical properties of the trajectories generated by the three models are compared with the statistical properties of the considered wind speed data set
Carbon Budget of an Agroforestry System after Being Converted from a Poplar Short Rotation Coppice
Poplar (Populus L. spp.) Short Rotation Coppice systems (SRCs) for bioenergy production
are being converted back to arable land. Transitioning to Alley Cropping Systems (ACSs) could be a
suitable strategy for integrating former tree rows and arable crops. A field trial (Pisa, Central Italy)
was set up with the aim of assessing the C storage of an ACS system based on hybrid poplar and
sorghum (Sorghum bicolor L. Moench) and comparing it with that of an SRC cultivation system.
The carbon budget at the agroecosystem scale was assessed in the first year of the transition using the
net biome production (NBP) approach with a simplified method. The overall NBP for the SRC was
positive (96 40 g C m2 year1), highlighting that the system was a net carbon sink (i.e., NBP > 0).
However, the ACS registered a net C loss (i.e., NBP < 0), since the NBP was 93 56 g C m2 year1.
In the first year of the transition, converting the SRC into an ACS counteracted the potential beneficial
eect of C storage in tree belowground biomass due to the high heterotrophic respiration rate recorded
in the ACS, which was fostered by the incorporation of residues and tillage disturbance in the alley.
Additional years of heterotrophic respiration measurements could allow for an estimate of the speed
and extent of C losses
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Carbon Budget of an Agroforestry System after Being Converted from a Poplar Short Rotation Coppice
Poplar (Populus L. spp.) Short Rotation Coppice systems (SRCs) for bioenergy production are being converted back to arable land. Transitioning to Alley Cropping Systems (ACSs) could be a suitable strategy for integrating former tree rows and arable crops. A field trial (Pisa, Central Italy) was set up with the aim of assessing the C storage of an ACS system based on hybrid poplar and sorghum (Sorghum bicolor L. Moench) and comparing it with that of an SRC cultivation system. The carbon budget at the agroecosystem scale was assessed in the first year of the transition using the net biome production (NBP) approach with a simplified method. The overall NBP for the SRC was positive (96 ± 40 g C m−2 year−1), highlighting that the system was a net carbon sink (i.e., NBP > 0). However, the ACS registered a net C loss (i.e., NBP < 0), since the NBP was −93 ± 56 g C m−2 year−1. In the first year of the transition, converting the SRC into an ACS counteracted the potential beneficial effect of C storage in tree belowground biomass due to the high heterotrophic respiration rate recorded in the ACS, which was fostered by the incorporation of residues and tillage disturbance in the alley. Additional years of heterotrophic respiration measurements could allow for an estimate of the speed and extent of C losses
Impact of Variability, Uncertainty and Frequency Regulation on Power System Frequency Distribution
This work originates from the observation of the frequency distribution of the Irish system as obtained from a Frequency Disturbance Recorder lent to the last author by the University of Tennessee. The probability density function of such a distribution appears to be bimodal. The paper first investigates how stochastic sources, in particular, load and wind power estimation errors, impact on the distribution of the frequency of a high-voltage transmission system. Then, possible routes to obtain a bimodal distribution of the frequency are explored and the most likely cause that leads to the observed behaviour of the Irish system is identified. Finally, the paper presents a comparison of different frequency regulation strategies and their impact on the distribution of the frequency. A sensitivity analysis of wind speed and load parameters is presented and discussed based on the IEEE-14 bus system
Exploring extra dimensions to capture saliva metabolite fingerprints from metabolically healthy and unhealthy obese patients by comprehensive two-dimensional gas chromatography featuring Tandem Ionization mass spectrometry
This study examines the information potential of comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC×GC-TOF MS) and variable ionization energy (i.e., Tandem Ionization™) to study changes in saliva metabolic signatures from a small group of obese individuals. The study presents a proof of concept for an effective exploitation of the complementary nature of tandem ionization data. Samples are taken from two sub-populations of severely obese (BMI > 40 kg/m2) patients, named metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). Untargeted fingerprinting, based on pattern recognition by template matching, is applied on single data streams and on fused data, obtained by combining raw signals from the two ionization energies (12 and 70 eV). Results indicate that at lower energy (i.e., 12 eV), the total signal intensity is one order of magnitude lower compared to the reference signal at 70 eV, but the ranges of variations for 2D peak responses is larger, extending the dynamic range. Fused data combine benefits from 70 eV and 12 eV resulting in more comprehensive coverage by sample fingerprints. Multivariate statistics, principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA) show quite good patient clustering, with total explained variance by the first two principal components (PCs) that increases from 54% at 70 eV to 59% at 12 eV and up to 71% for fused data. With PLS-DA, discriminant components are highlighted and putatively identified by comparing retention data and 70 eV spectral signatures. Within the most informative analytes, lactose is present in higher relative amount in saliva from MHO patients, whereas N-acetyl-D-glucosamine, urea, glucuronic acid γ-lactone, 2-deoxyribose, N-acetylneuraminic acid methyl ester, and 5-aminovaleric acid are more abundant in MUO patients. Visual feature fingerprinting is combined with pattern recognition algorithms to highlight metabolite variations between composite per-class images obtained by combining raw data from individuals belonging to different classes, i.e., MUO vs. MHO.Graphical abstract
Risk factors for hepatitis C virus infection among nonintravenous-drug-using heterosexuals attending a clinic for sexually transmitted disease in Italy
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ERK phosphorylation and miR-181a expression modulate activation of human memory TH17 cells
T helper (TH) cell polarization during priming is modulated by a number of signals, but whether polarization to a given phenotype also influences recall responses of memory TH cells is relatively unknown. Here we show that miR-181a is selectively induced in both human and mouse naive T cells differentiating into the TH17, but not TH1 or TH2 subset. In human memory TH17 cells, miR-181a regulates responses to cognate antigens through modulation of ERK phosphorylation. By enhancing the signalling cascade from the T-cell receptor, such molecular network reduces the threshold of TH17 cell activation. Moreover, at a late time point, the same network induces a self-regulatory mechanism dependent on ID3, a negative regulator of transcription factors that control RORC expression, thus modulating TH17 activity. Our results demonstrate that the phenotype acquired by TH cells during priming contributes to their threshold of activation to secondary antigenic stimulations, thus influencing memory responses
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