92 research outputs found

    The stock exchange of influencers: a financial approach for studying fanbase variation trends

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    In many online social networks (OSNs), a limited portion of profiles emerges and reaches a large base of followers, i.e., the so-called social influencers. One of their main goals is to increase their fanbase to increase their visibility, engaging users through their content. In this work, we propose a novel parallel between the ecosystem of OSNs and the stock exchange market. Followers act as private investors, and they follow influencers, i.e., buy stocks, based on their individual preferences and on the information they gather through external sources. In this preliminary study, we show how the approaches proposed in the context of the stock exchange market can be successfully applied to social networks. Our case study focuses on 60 Italian Instagram influencers and shows how their followers short-term trends obtained through Bollinger bands become close to those found in external sources, Google Trends in our case, similarly to phenomena already observed in the financial market. Besides providing a strong correlation between these different trends, our results pose the basis for studying social networks with a new lens, linking them with a different domain

    Intrinsic charm in a matched general-mass scheme

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    The FONLL general-mass variable-flavour number scheme provides a framework for the matching of a calculation in which a heavy quark is treated as a massless parton to one in which the mass dependence is retained throughout. We describe how the usual formulation of FONLL can be extended in such a way that the heavy quark parton distribution functions are freely parameterized at some initial scale, rather than being generated entirely perturbatively. We specifically consider the case of deep-inelastic scattering, in view of applications to PDF determination, and the possible impact of a fitted charm quark distribution on F2cF_2^c is assessed.Comment: 16 pages, 5 figures. Final version, to be published in Physics Letters B. Typo in eq 13 corrected, minor clarifications adde

    Three Synchronous Head and Neck Cancers: A Multidisciplinary and Surgical Challenge.

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    Second primary cancer (SPC) is a term used to describe a new primary cancer occurring in patients who had formerly been diagnosed with tumor. Even though SPCs appear to be related to primary cancers, they are actually entities that have arisen independently and not as a result of recurrence. This report is of the first case in literature of a patient hospitalized for the surgical treatment of 3 synchronous Head and Neck Cancers. A 66-year-old male was admitted to our hospital (Ospedale Degli Infermi—Biella, Italy) complaining about pharyngodynia. Three different lesions were identified through endoscopic examination and narrow band imaging: the first one on left tonsil, the second one on epiglottis, and the third one on right aryepiglottic fold. The case was subject to a multidisciplinary team analysis due to its complexity, then the surgery consisted in (1) CO2 laser left tonsillectomy, associated with (2) CO2 laser excision of the lesion on epiglottis free edge, and (3) CO2 laser excision of right aryepiglottic fold lesion. Synchronous tumors are among the most defiant challenges for surgeons since no international guideline specifies differentiated strategies to be adopted in patients affected by synchronous Head and Neck Cancers, therefore surgical planning must be tailored differently from patient to patient, and many unsolved questions still concern clinical treatments to be adopted

    Parton distributions with threshold resummation

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    We construct a set of parton distribution functions (PDFs) in which fixed-order NLO and NNLO calculations are supplemented with soft-gluon (threshold) resummation up to NLL and NNLL accuracy respectively, suitable for use in conjunction with any QCD calculation in which threshold resummation is included at the level of partonic cross sections. These resummed PDF sets, based on the NNPDF3.0 analysis, are extracted from deep-inelastic scattering, Drell-Yan, and top quark pair production data, for which resummed calculations can be consistently used. We find that, close to threshold, the inclusion of resummed PDFs can partially compensate the enhancement in resummed matrix elements, leading to resummed hadronic cross-sections closer to the fixed-order calculation. On the other hand, far from threshold, resummed PDFs reduce to their fixed-order counterparts. Our results demonstrate the need for a consistent use of resummed PDFs in resummed calculations.Comment: 43 pages, 17 figures, accepted for publication in JHE

    Cyber-physical Threat Detection Platform Designed for Healthcare Systems

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    Hospitals are responsible for delivering healthcare services to patients in need. These services are large and complex and get affected by multiple interacting actors, such as doctors, nurses, patients, citizens, medical suppliers, health insurance providers. Lately, hospitals around the world are one of the main targets when it comes to terrorist attacks, the cyber realm being the principal source. The healthcare sector is particularly vulnerable due to heavy involvement in patient personal and health information, time constraints, and complex day-to-day operations. In addition to cyber-threats, physical threats are increasingly growing and even healthcare facilities are not immune to them. Malicious intended people created cyber threatening attacks with the purpose to systematically collect evidence against the healthcare system, to advocate for the end of such attacks, and to endanger people\u27s lives or to use the stolen personal data for bad intended actions. Henceforth it is necessary to build a platform that will get alerts and incidents at a fast pace in real-time to prevent any casualties at low cost. SAFECARE project aims to offer protection to hospitals and increase the compliance for the European regulations and security regarding ethics and privacy for health services. This paper presents a solution that will enhance security in hospitals. The primary platform will be built based on a BTMS (Building Threat Monitoring System) where events, incidents, and alerts will be transmitted by sensors from hospital rooms in real-time. Several scenarios were thought to simulate different types of attacks against hospitals and according to the scenarios, various prototypes will be built for assuring the security of the personal and patients from various hospitals.</p

    Searching for dark matter in X-rays: how to check the dark matter origin of a spectral feature

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    A signal from decaying dark matter (DM) can be unambiguously distinguished from spectral features of astrophysical or instrumental origin by studying its spatial distribution. We demonstrate this approach by examining the recent claim of 0912.0552 regarding the possible DM origin of the 2.5 keV line in Chandra observations of the Milky Way satellite known as Willman 1. Our conservative strategy is to adopt a relatively large dark mass for Willman 1 and relatively small dark masses for the comparison objects. We analyze archival observations by XMM-Newton of M31 and Fornax dwarf spheroidal galaxy (dSph) and Chandra observations of Sculptor dSph. By performing a conservative analysis of X-ray spectra, we show the absence of a DM decay line with parameters consistent with those of 0912.0552. For M31, the observations of the regions between 10 and 20 kpc from the center, where the uncertainties in the DM distribution are minimal, make a strong exclusion at the level above 10sigma. The minimal estimate for the amount of DM in the central 40 kpc of M31 is provided by the model of 0912.4133, assuming the stellar disk's mass to light ratio ~8 and almost constant DM density within a core of 28 kpc. Even in this case one gets an exclusion at 5.7sigma from central region of M31 whereas modeling all processed data from M31 and Fornax produces more than 14sigma exclusion. Therefore, despite possible systematic uncertainties, we exclude the possibility that the spectral feature at ~2.5 keV found in 0912.0552 is a DM decay line. We conclude, however, that the search for DM decay line, although demanding prolonged observations of well-studied dSphs, M31 outskirts and other similar objects, is rather promising, as the nature of a possible signal can be checked. An (expected) non-observation of a DM decay signal in the planned observations of Willman 1 should not discourage further dedicated observations.Comment: 16 pages, 8 figures; journal version; analysis of additional data from M31 outskirts and comments on arXiv:1001.4055 are adde

    Dark matter electron anisotropy: a universal upper limit

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    We study the dipole anisotropy in the arrival directions of high energy CR electrons and positrons (CRE) of Dark Matter (DM) origin. We show that this quantity is very weakly model dependent and offers a viable criterion to discriminate among CRE from DM or from local discrete sources, like e.g. pulsars. In particular, we find that the maximum anisotropy which DM can provide is to a very good approximation a universal quantity and, as a consequence, if a larger anisotropy is detected, this would constitute a strong evidence for the presence of astrophysical local discrete CRE sources, whose anisotropy, instead, can be naturally larger than the DM upper limit. We further find that the main source of anisotropy from DM is given by the fluctuation in the number density of DM sub-structures in the vicinity of the observer and we thus devote special attention to the study of the variance in the sub-structures realization implementing a dedicated Montecarlo simulation. Such scenarios will be probed in the next years by Fermi-LAT, providing new hints, or constraints, about the nature of DM.Comment: 23 pages, 7 figure

    Oscillating nonlinear large scale structure in growing neutrino quintessence

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    Growing Neutrino quintessence describes a form of dynamical dark energy that could explain why dark energy dominates the universe only in recent cosmological times. This scenario predicts the formation of large scale neutrino lumps which could allow for observational tests. We perform for the first time N-body simulations of the nonlinear growth of structures for cold dark matter and neutrino fluids in the context of Growing Neutrino cosmologies. Our analysis shows a pulsation - increase and subsequent decrease - of the neutrino density contrast. This could lead to interesting observational signatures, as an enhanced bulk flow in a situation where the dark matter density contrast only differs very mildly from the standard LCDM scenario. We also determine for the first time the statistical distribution of neutrino lumps as a function of mass at different redshifts. Such determination provides an essential ingredient for a realistic estimate of the observational signatures of Growing Neutrino cosmologies. Due to a breakdown of the non-relativistic Newtonian approximation our results are limited to redshifts z > 1.Comment: 17 pages, 1 table, 10 figures; MNRAS in pres

    S.A.A.C. - Sistema Automático de Asistencia al Cultivo

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    Este artículo presenta una experiencia realizada en el marco de un proyecto de transferencia desarrollado dentro de la cátedra Proyecto de Sistemas de la carrera Ingeniería en Sistemas de Información de la Universidad Católica Argentina de La Plata. El proyecto, denominado SAAC, Sistema Automático de Asistencia al Cultivo, describe un modelo experimental con una solución integral capaz de controlar de manera automática diferentes tipos de cultivos desde un dispositivo móvil Android. El resultado obtenido es una combinación eficaz de Hardware, Software e ideas innovadoras, que debido a una parametrización sencilla permite controlar y monitorear la temperatura, humedad, nivel de fertilizante en tierra e iluminación del cultivo, pudiendo modificar los parámetros censados de acuerdo a las necesidades propias definidas para cada tipo de cultivo y/o plantación y la situación climatológica imperante en el entorno.VIII Workshop Innovación en Sistemas de Software (WISS).Red de Universidades con Carreras en Informática (RedUNCI
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