29 research outputs found

    Interests Diffusion in Social Networks

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    Understanding cultural phenomena on Social Networks (SNs) and exploiting the implicit knowledge about their members is attracting the interest of different research communities both from the academic and the business side. The community of complexity science is devoting significant efforts to define laws, models, and theories, which, based on acquired knowledge, are able to predict future observations (e.g. success of a product). In the mean time, the semantic web community aims at engineering a new generation of advanced services by defining constructs, models and methods, adding a semantic layer to SNs. In this context, a leapfrog is expected to come from a hybrid approach merging the disciplines above. Along this line, this work focuses on the propagation of individual interests in social networks. The proposed framework consists of the following main components: a method to gather information about the members of the social networks; methods to perform some semantic analysis of the Domain of Interest; a procedure to infer members' interests; and an interests evolution theory to predict how the interests propagate in the network. As a result, one achieves an analytic tool to measure individual features, such as members' susceptibilities and authorities. Although the approach applies to any type of social network, here it is has been tested against the computer science research community. The DBLP (Digital Bibliography and Library Project) database has been elected as test-case since it provides the most comprehensive list of scientific production in this field.Comment: 30 pages 13 figs 4 table

    A rare case of endometriosis in Turner's syndrome

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    Endometriosis is defined by the presence of functional endometrial tissue outside the uterine cavity and musculature. It has a prevalence rate as high as 35e50% in women experiencing pain or infertility [1] and sometimes has a peculiar and rare onset [2,3]. Endometriosis is a common disease in menstruating women [4,5] but has also been reported in postmenopausal or surgically castrated women on hormone replacement therapy (HRT) [6]. The common denominator of all such cases is exposure to female hormones [7]. However, endometriosis, a common and important clinical problem in women of reproductive age, has rarely been described in prepubertal girls. In patients with Turner's syndrome or other ovarian dysgenesis, endometriosis is very rare. Some cases are subclinical, and endometriosis is an incidental finding during routine examination. Although endometriosis was described in the medical literature at the end of the 19th century, and the first theories regarding its hystogenesis were developed at the beginning of the 20th century, the real pathogenesis of endometriosis remains unknown. Most studies about the etiology of endometriosis claim that the main possible causes of endometriosis are probably multifactorial. Three theories of histogenesis have been proposed. (1) The metastatic theory [8] proposes the transplantation of endometrial tissue via retrograde menstrual implantation, vascular/lymphatic spread, and intraoperative implantation. (2) The coelomic metaplastic theory [9] suggests that the germinal epithelium of the ovary can be transformed by metaplasia into endometrium. This theory, which initially explained only ovarian endometriosis, has since been extended to the peritoneal serosa, as embryologic studies have indicated that Mullerian ducts, th

    The Virgo 3 km interferometer for gravitational wave detection

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    Virgo, designed, constructed and developed by the French-Italian VIRGO collaboration located in Cascina (Pisa, Italy) and aiming to detect gravitational waves, is a ground-based power recycled Michelson interferometer, with 3 km long suspended Fabry-Perot cavities. The first Virgo scientific data-taking started in mid-May 2007, in coincidence with the corresponding LIGO detectors. The optical scheme of the interferometer and the various optical techniques used in the experiment, such as the laser source, control, alignment, stabilization and detection strategies are outlined. The future upgrades that are planned for Virgo from the optical point of view, especially concerning the evolution of the Virgo laser, are presented. Finally, the next generation of the gravitational wave detector (advanced Virgo) is introduced from the point of view of the laser system

    Risk factors associated with adverse fetal outcomes in pregnancies affected by Coronavirus disease 2019 (COVID-19): a secondary analysis of the WAPM study on COVID-19.

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    Objectives To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Methods Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Results Mean gestational age at diagnosis was 30.6+/-9.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; pPeer reviewe

    Role of prenatal magnetic resonance imaging in fetuses with isolated mild or moderate ventriculomegaly in the era of neurosonography: international multicenter study

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    Objectives To assess the role of fetal magnetic resonance imaging (MRI) in detecting associated anomalies in fetuses presenting with mild or moderate isolated ventriculomegaly (VM) undergoing multiplanar ultrasound evaluation of the fetal brain. Methods This was a multicenter, retrospective, cohort study involving 15 referral fetal medicine centers in Italy, the UK and Spain. Inclusion criteria were fetuses affected by isolated mild (ventricular atrial diameter, 10.0–11.9 mm) or moderate (ventricular atrial diameter, 12.0–14.9 mm) VM on ultrasound, defined as VM with normal karyotype and no other additional central nervous system (CNS) or extra‐CNS anomalies on ultrasound, undergoing detailed assessment of the fetal brain using a multiplanar approach as suggested by the International Society of Ultrasound in Obstetrics and Gynecology guidelines for the fetal neurosonogram, followed by fetal MRI. The primary outcome of the study was to report the incidence of additional CNS anomalies detected exclusively on prenatal MRI and missed on ultrasound, while the secondary aim was to estimate the incidence of additional anomalies detected exclusively after birth and missed on prenatal imaging (ultrasound and MRI). Subgroup analysis according to gestational age at MRI (< 24 vs ≄ 24 weeks), laterality of VM (unilateral vs bilateral) and severity of dilatation (mild vs moderate VM) were also performed. Results Five hundred and fifty‐six fetuses with a prenatal diagnosis of isolated mild or moderate VM on ultrasound were included in the analysis. Additional structural anomalies were detected on prenatal MRI and missed on ultrasound in 5.4% (95% CI, 3.8–7.6%) of cases. When considering the type of anomaly, supratentorial intracranial hemorrhage was detected on MRI in 26.7% of fetuses, while polymicrogyria and lissencephaly were detected in 20.0% and 13.3% of cases, respectively. Hypoplasia of the corpus callosum was detected on MRI in 6.7% of cases, while dysgenesis was detected in 3.3%. Fetuses with an associated anomaly detected only on MRI were more likely to have moderate than mild VM (60.0% vs 17.7%; P < 0.001), while there was no significant difference in the proportion of cases with bilateral VM between the two groups (P = 0.2). Logistic regression analysis showed that lower maternal body mass index (adjusted odds ratio (aOR), 0.85 (95% CI, 0.7–0.99); P = 0.030), the presence of moderate VM (aOR, 5.8 (95% CI, 2.6–13.4); P < 0.001) and gestational age at MRI ≄ 24 weeks (aOR, 4.1 (95% CI, 1.1–15.3); P = 0.038) were associated independently with the probability of detecting an associated anomaly on MRI. Associated anomalies were detected exclusively at birth and missed on prenatal imaging in 3.8% of cases. Conclusions The incidence of an associated fetal anomaly missed on ultrasound and detected only on fetal MRI in fetuses with isolated mild or moderate VM undergoing neurosonography is lower than that reported previously. The large majority of these anomalies are difficult to detect on ultrasound. The findings from this study support the practice of MRI assessment in every fetus with a prenatal diagnosis of VM, although parents can be reassured of the low risk of an associated anomaly when VM is isolated on neurosonography

    A state observer for the Virgo inverted pendulum

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    International audienceWe report an application of Kalman filtering to the inverted pendulum (IP) of the Virgo gravitational wave interferometer. Using subspace method system identification techniques, we calculated a linear mechanical model of Virgo IP from experimental transfer functions. We then developed a Kalman filter, based on the obtained state space representation, that estimates from open loop time domain data, the state variables of the system. This allows the observation (and eventually control) of every resonance mode of the IP mechanical structure independently

    Discovering opportunities in content-based social networks

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    La principale attivitĂ  di un imprenditore Ăš quella di scoprire e prendere al volo "opportunitĂ ", le quali sono definite come situazioni che possono essere sfruttate in modo da ottenerne dei vantaggi di qualche tipo. Lungi dall'essere un'attivitĂ  semplice, questo tipo di lavoro puĂČ richiedere creativitĂ , esperienza, conoscenza del dominio ed una miriade di altri ingredienti. In questo lavoro presentiamo una formalizzazione della nozione di scoperta di opportunitĂ  all'interno di una rete; le "reti di opportunitĂ " sono costituite da un multigrafo diretto con attributi, uno sfruttatore di probabilitĂ , un insieme di pattern di opportunitĂ  e da funzioni di ranking delle opportunitĂ  scoperte

    Open domain knowledge extraction: Inference on a web scale

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    Though ontologies are considered central to foster the Semantic Web effort, their practical application on a Web scale is limited by the difficulty of building and maintaining high-coverage ontologies, for any of the almost unbounded number of social and technical domains mirrored on the Web. In this paper we present Open Knowledge Extraction (Open KE), a novel paradigm that creates a bridge between information retrieval, taxonomy learning and automated reasoning. Open KE builds on recently published algorithms for Open Information Extraction (Open IE) and automated taxonomy learning, which were shown able to extract information on a Web scale basis in an unsupervised manner. The key idea of Open KE is to generalize Open IE's lexicalized extractions with an automatically learned taxonomy. Lexicalized extractions are transformed in logic predicates, and used to populate a Semantic Model. An inference engine is then used to perform inductions and deductions. In this paper we describe the knowledge extraction workflow in its entirety, and apply it to a large-scale experiment in the domains of Artificial Intelligence and Virology

    A new content-based model for social network analysis

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    This paper presents a novel model for social network analysis in which, rather than analyzing the quantity of relationships (co-authorships, business relations, friendship, etc.), we analyze their communicative content. Text mining and clustering techniques are used to capture the content of communication and to identify the most popular themes. The social analyst is then able to perform a study of the network evolution in terms of the relevant themes of collaboration, the detection of new concepts gaining popularity, and the existence of popular themes that could benefit from better cooperation. The methodology is experimented in the domain of a Network of Excellence on enterprise interoperability, INTEROP. © 2008 IEEE

    Phases of Italian Industrial Development and the Relationship between the Public and Private Sectors

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    This essay describes the phases of postwar Italian industrial development with particular focus on the interaction between public- and private-sector firms. Four phases are analysed: postwar Reconstruction and the economic miracle (1950-64), State intervention (1964-75), crisis and Restructuring (1975-83) and Innovations, Profits and Finance (1983-90). Details on major transactions performed by the principal State.owned industrial agencies (IRI, ENI, EFIM) and by Principal Private-Sector industrial Groups (Fiat, Montedison, Olivetti, Pirelli, Pesenti) are provided
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