Effects on mobility training and de-adaptations in subjects with Spinal Cord Injury due to a Wearable Robot: A preliminary report

open7noopenSale, Patrizio; Russo, Emanuele Francesco; Russo, Michele; Masiero, Stefano; Piccione, Francesco; Calabrò, Rocco Salvatore; Filoni, SerenaSale, Patrizio; Russo, Emanuele Francesco; Russo, Michele; Masiero, Stefano; Piccione, Francesco; Calabrò, Rocco Salvatore; Filoni, Seren

Stratified stochastic variational inference for high-dimensional network factor model

There has been considerable recent interest in Bayesian modeling of high-dimensional networks via latent space approaches. When the number of nodes increases, estimation based on Markov Chain Monte Carlo can be extremely slow and show poor mixing, thereby motivating research on alternative algorithms that scale well in high-dimensional settings. In this article, we focus on the latent factor model, a widely used approach for latent space modeling of network data. We develop scalable algorithms to conduct approximate Bayesian inference via stochastic optimization. Leveraging sparse representations of network data, the proposed algorithms show massive computational and storage benefits, and allow to conduct inference in settings with thousands of nodes.Comment: 25 pages, 1 figures. Corrected compilation issues and minor typo

Characterizing growth instability: new evidence on unit roots and structural breaks in countries’ long run trajectories

In this paper we investigate whether long run time series of income per capita are better described by a trend-stationary model with few structural changes or by unit root processes in which permanent stochastic shocks are responsible for the observed growth discontinuities. For a group of advanced and developing countries in the Maddison database, we employ a unit root test that allows for an unspecified number of breaks under the alternative hypothesis (up to some ex ante determined maximum). Monte Carlo simulations studying the finite sample properties of the test are reported and discussed. When compared with previous findings in the literature, our results show less evidence against the unit root hypothesis. We find even fewer rejections when relaxing the assumption of Gaussian shocks. Our results are broadly consistent with the implications of evolutionary macro models which posit frequent growth shifts and fat-tailed distribution of aggregate shocks

Digitalization, copyright and innovation in the creative industries: an agent-based model

The ambiguity of the empirical results on the relationship between copyright and creativity calls for a better theoretical understanding of the issue, possibly enlarging the analysis to other factors such as technology and copyright enforcement. This paper addresses these complex policy issues by developing an agent-based model (ABM) to study how the interplay between digitization and copyright enforcement affects the production and access to cultural goods. The model includes creators who compete in different submarkets and invest in activities that might lead to the generation of creative outputs in existing submarkets, new (to the creators) submarkets, or in newly “invented†submarkets. Finally, the model features a copyright system that provides creators with the exclusive right to reproduce their original copies and a pirate market responsible for creating and distributing pirated copies

Do patents really foster innovation in the pharmaceutical sector? Results from an evolutionary, agent-based model

The role of the patent system in the pharmaceutical sector is highly debated also due to its strong public health implications. In this paper we develop an evolutionary, agent-based model of the pharmaceutical industry to explore the impact of different configurations of the patent system upon innovation and competition. The model is able to replicate the main stylized facts of the drug industry as emergent properties. We perform policy experiments to assess the impact of different IPR regimes changing the breadth and length of patents. Results suggest that enlarging the extent and duration of patents yields adverse effects in terms of innovation outcomes, as well as of market competition and consumer welfare. Such general conclusions hold even if one takes into account the possible positive effects on R&D intensity and information disclosure triggered by patents

Bio-responsive hydrogels for an in vitro brain cancer cell model: self-controlled inhibition of matrix metalloproteinase activity

In nature, an unbalanced level of enzyme activity (e.g. proteases) is correlated to various disease states, particularly cancer. Among them, several studies have established that medulloblastoma (MB), a brain cancer in children, is associated with an overexpression of matrix metalloproteases (MMPs) (predominantly MMP-2), which is the consequence of the downregulation of their natural inhibitors tissue inhibitors of matrix metalloproteases (TIMPs) (e.g. TIMP-2). Although MMP inhibition remains a relevant therapeutic approach, MMP synthetic inhibitors have not converted to clinical application due to their dose-limiting side effects following systemic administration. As a result, the controlled delivery of endogenous MMP inhibitors directly in situ, could therefore provide the re-establishment of the MMP/TIMP equilibrium. The main goal of this work is to develop a MMP-2 responsive hydrogel that could provide an on-demand controlled release of the recombinant tissue inhibitor of MMP-2 (rTIMP-2) in response to elevated MMP-2 activity. This could be beneficial to restore the enzyme/inhibitor equilibrium and provide reduction of tumour growth and metastasis. MMP-2 responsive hydrogels were fabricated through thiol-ene step-growth polymerization of multiarm PEG-norbornene (PEG4-NB) with a MMP-2 recognised peptide sequence. Hydrogels demonstrated their MMP-2 sensitivity through the release of an encapsulated fluorescent dextran probe, as crosslinks are degraded by the enzyme. Following mesh size optimisation using a model dithiothreitol (DTT) cross-linked PEG4-NB hydrogel, MMP-2 responsive hydrogels were found to proficiently encapsulate and retain rTIMP-2, a necessary condition to maintain an exclusively enzyme triggered release. rTIMP-2 loaded hydrogels demonstrated their ability to efficiently inhibit different levels of MMP-2 and to modulate enzyme activity on the basis of the different rTIMP-2 payloads. These outcomes were obtained by monitoring both the residual MMP-2 activity and the subsequent release of a co-encapsulated fluorescent dextran upon MMP-2 action. Lastly, in a preliminary study, rTIMP-2 containing hydrogels proved to be cell biocompatible and able to inhibit MMP-2 secreted by MB cells. These findings promote the potential ability of this bio-responsive hydrogel to promote the renewal of the imbalance between MMP-2 and TIMP-2, an essential condition to reduce medulloblastoma growth

Science and Values: A Two-way Direction

In the science and values literature, scholars have shown how science is influenced and shaped by values, often in opposition to the ‘value free’ ideal of science. In this paper, we aim to contribute to the science and values literature by showing that the relation between science and values flows not only from values into scientific practice, but also from (allegedly neutral) science to values themselves. The extant literature in the ‘science and values’ field focuses by and large on reconstructing, post hoc, how values have influenced science; our reconstruction of the case studies, instead, aims to show that scientific concepts and methods, because of specific identifiable characteristics, can promote some values rather than (or at the expense of) others. We explain this bidirectional relation in analogy to debates on the normativity of technical artifacts and on feminist approaches in science, and we illustrate our claims with cases from the health sciences and machine learning. While our arguments in this paper also draw on post hoc reconstructions, we intend to show where we should engage not only with the question of whether a practice is value-laden, but also how specific conceptual and methodological choices can influence values down the road. All in all, these considerations expand the ways in which philosophers can contribute to more value-aware scientific practices