Is there such a thing as free government data?

The recently-amended European Public Sector Information (PSI) Directive rests on the assumption that government data is a valuable input for the knowledge economy. As a default principle, the directive sets marginal costs as an upper bound for charging PSI. This article discusses the terms under which the 2013 consultation on the implementation of the PSI Directive addresses the calculation criteria for marginal costs, which are complex to define, especially for internet-based services. What is found is that the allowed answers of the consultation indirectly lead the responder to reason in terms of the average incremental cost of allowing reuse, instead of the marginal cost of reproduction, provision and dissemination. Moreover, marginal-cost pricing (or zero pricing) is expected to lead to economically efficient results, while aiming at recouping the average incremental cost of allowing re-use may lead to excessive fees

Collaborative Open Data versioning: a pragmatic approach using Linked Data

Most Open Government Data initiatives are centralised and unidirectional (i.e., they release data dumps in CSV or PDF format). Hence for non trivial applications reusers make copies of the government datasets to curate their local data copy. This situation is not optimal as it leads to duplication of efforts and reduces the possibility of sharing improvements. To improve the usefulness of publishing open data, several authors recommeded to use standard formats and data versioning. Here we focus on publishing versioned open linked data (i.e., in RDF format) because they allow one party to annotate data released independently by another party thus reducing the need to duplicate entire datasets. After describing a pipeline to open up legacy-databases data in RDF format, we argue that RDF is suitable to implement a scalable feedback channel, and we investigate what steps are needed to implement a distributed RDFversioning system in production

The use of x-ray CT and MRI in the study of sacroiliac joints in patients with Behcet disease and acute anterior uveitis

Objective: It's controversial if Behcet Disease (BD) must be included in the group of seronegative spondyloarthropathy (SpA). Our aim was to establish the prevalence of sacroiliitis (SI) in patients with BD using X-Ray, CT and MRI, in comparison with patients with Acute Anterior Uveitis (AAU), that is known to belong to the subgroups of SpA. Methods: We considered, in the period from 04/2006 to 04/2009, 21 consecutive patients with BD, positive for HLA B51 and 28 consecutive patients with AAU, positive for HLA B27. These patients were previously selected by our Rheumatological Ward. Altogether we evaluated 98 sacroiliac joints (SIJ); each side of any patient was graded separately. Results: X-ray of the pelvis showed advanced SI (grade 4) in 14% of the cases in patients with AAU; in BD group only 7% CT showed advanced SI in 14% within AAU patients versus 6-12% of advanced SI (right to left) within BD patients. MR showed 14% of advanced SI (bilateral) within AAU versus 6-11% of advanced SI (right to left) in BD patients. Conclusions: This study supports the trend to not consider BD within the SpA, being the prevalence of SI in BD patients not very different from general population and anyway lower than that observed in patients with AAU. On the other side the prevalence of SI in AAU patients is higher than in BD patients and very similar to the one observed in patients with seronegative arthritis, and anyway high enough to consider joint involvement as an important feature of the disease

Risultati del trattamento chirurgico del varicocele nella infertilità maschile

To evaluate the results of surgical treatment of varicocele on infertile men, especially regarding sperm count, 245 patients, surgically treated from 1993 to 2003, were evaluated. Patients underwent to ligature and section of the pampiniform plexus, throught the subinguinal approach and local anaesthesia. At the follow-up (3-6-12 months) an improvement of sperm count was relieved in 79.5% of patients and the incidence of complications and relapses was of 3.7% and 1.2%, respectively. The Authors stress the efficacy of surgical treatment of varicocele in male infertility and hold the subinguinal approach as an effective treatment, minimally invasive and low cost

Three scales asymptotic homogenization and its application to layered hierarchical hard tissues

In the present work a novel multiple scales asymptotic homogenization approach is proposed to study the effective properties of hierarchical composites with periodic structure at different length scales. The method is exemplified by solving a linear elastic problem for a composite material with layered hierarchical structure. We recover classical results of two-scale and reiterated homogenization as particular cases of our formulation. The analytical effective coefficients for two phase layered composites with two structural levels of hierarchy are also derived. The method is finally applied to investigate the effective mechanical properties of a single osteon, revealing its practical applicability in the context of biomechanical and engineering applications

An Exploratory Empirical Assessment of Italian Open Government Data Quality With an eye to enabling linked open data

Context The diffusion of Linked Data and Open Data in recent years kept a very fast pace. However evidence from practitioners shows that disclosing data without proper quality control may jeopardize datasets reuse in terms of apps, linking, and other transformations. Objective Our goals are to understand practical problems experienced by open data users in using and integrating them and build a set of concrete metrics to assess the quality of disclosed data and better support the transition towards linked open data. Method We focus on Open Government Data (OGD), collecting problems experienced by developers and mapping them to a data quality model available in literature. Then we derived a set of metrics and applied them to evaluate a few samples of Italian OGD. Result We present empirical evidence concerning the common quality problems experienced by open data users when using and integrating datasets. The measurements effort showed a few acquired good practices and common weaknesses, and a set of discriminant factors among datasets. Conclusion The study represents the first empirical attempt to evaluate the quality of open datasets at an operational level. Our long-term goal is to support the transition towards Linked Open Government Data (LOGD) with a quality improvement process in the wake of the current practices in Software Qualit

Julearn: an easy-to-use library for leakage-free evaluation and inspection of ML models

The fast-paced development of machine learning (ML) methods coupled with its increasing adoption in research poses challenges for researchers without extensive training in ML. In neuroscience, for example, ML can help understand brain-behavior relationships, diagnose diseases, and develop biomarkers using various data sources like magnetic resonance imaging and electroencephalography. The primary objective of ML is to build models that can make accurate predictions on unseen data. Researchers aim to prove the existence of such generalizable models by evaluating performance using techniques such as cross-validation (CV), which uses systematic subsampling to estimate the generalization performance. Choosing a CV scheme and evaluating an ML pipeline can be challenging and, if used improperly, can lead to overestimated results and incorrect interpretations. We created julearn, an open-source Python library, that allow researchers to design and evaluate complex ML pipelines without encountering in common pitfalls. In this manuscript, we present the rationale behind julearn's design, its core features, and showcase three examples of previously-published research projects that can be easily implemented using this novel library. Julearn aims to simplify the entry into the ML world by providing an easy-to-use environment with built in guards against some of the most common ML pitfalls. With its design, unique features and simple interface, it poses as a useful Python-based library for research projects.Comment: 13 pages, 5 figure

The influence of anisotropic growth and geometry on the stress of solid tumors

Solid stresses can affect tumor patho-physiology in at least two ways: directly, by compressing cancer and stromal cells, and indirectly, by deforming blood and lymphatic vessels. In this work, we model the tumor mass as a growing hyperelastic material. We enforce a multiplicative decomposition of the deformation gradient to study the role of anisotropic tumor growth on the evolution and spatial distribution of stresses. Specifically, we exploit radial symmetry and analyze the response of circumferential and radial stresses to (a) degree of anisotropy, (b) geometry of the tumor mass (cylindrical versus spherical shape), and (c) different tumor types (in terms of mechanical properties). According to our results, both radial and circumferential stresses are compressive in the tumor inner regions, whereas circumferential stresses are tensile at the periphery. Furthermore, we show that the growth rate is inversely correlated with the stresses’ magnitudes. These qualitative trends are consistent with experimental results. Our findings therefore elucidate the role of anisotropic growth on the tumor stress state. The potential of stress-alleviation strategies working together with anticancer therapies can result in better treatments

Energy efficiency improvement by the application of nanostructured coatings on axial piston pump slippers

Axial piston pumps and motors are widely used in heavy-duty applications and play a fundamental role in hydrostatic and power split drives. The mechanical power losses in hydraulic piston pumps come from the friction between parts in relative motion. The improvement, albeit marginal, in overall efficiency of these components may significantly impact the global efficiency of the machine. The friction between slipper and swash plate is a functional key in an axial piston pump, especially when the pump (at low rotational speed or at partial displacement) works in the critical areas where the efficiency is low. The application of special surface treatments have been exploited in pioneering works in the past, trying different surface finishing or adding ceramic or heterogeneous metallic layers. The potential of structured coatings at nanoscale, with superhydrophobic and oleophobic characteristics, has never been exploited. Due to the difficulty to reproduce the real working conditions of axial piston pump slippers, it has been made a hydraulic test bench properly designed in order to compare the performance of nano-coated slippers with respect to standard ones. The nano-coated and standard slippers have been subjected to the following working conditions: a test at variable pressure and constant rotational speed, a test at constant pressure and variable rotational speed. The comparison between standard and nanocoated slippers, for both working conditions, shows clearly that more than 20% of friction reduction can be achieved using the proposed nano-coating methodology

GPU optimization of electroencephalogram analysis

Nowadays, with the advent of new non-invasive techniques of brain imaging, researchers have access to neural processes underlying the cognition in humans. One of the main challenges in this techniques is the detection of patterns in brain signals, generally very noisy and with artifacts inserted by vital signs. One of the most successful techniques for this is Independent Component Analysis which detects statistically independent components that are produced from different sources. These methods are very expensive in computational time, with many hours of processing for a single experiment. We analyzed this algorithm and detect two main types of operations: vector-matrix and matrix-matrix. We implemented an ad-hoc solution that executes on GPU and compared this with the original and CUBLAS versions. We obtained a 4x and 40x of performance increase of vector-matrix and matrix-matrix operations, respectively. These results are the first step towards real-time EEG processing which may produce a significant advance into BCI applications.Sociedad Argentina de Informática e Investigación Operativ