8,997 research outputs found

    Neural Networks retrieving Boolean patterns in a sea of Gaussian ones

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    Restricted Boltzmann Machines are key tools in Machine Learning and are described by the energy function of bipartite spin-glasses. From a statistical mechanical perspective, they share the same Gibbs measure of Hopfield networks for associative memory. In this equivalence, weights in the former play as patterns in the latter. As Boltzmann machines usually require real weights to be trained with gradient descent like methods, while Hopfield networks typically store binary patterns to be able to retrieve, the investigation of a mixed Hebbian network, equipped with both real (e.g., Gaussian) and discrete (e.g., Boolean) patterns naturally arises. We prove that, in the challenging regime of a high storage of real patterns, where retrieval is forbidden, an extra load of Boolean patterns can still be retrieved, as long as the ratio among the overall load and the network size does not exceed a critical threshold, that turns out to be the same of the standard Amit-Gutfreund-Sompolinsky theory. Assuming replica symmetry, we study the case of a low load of Boolean patterns combining the stochastic stability and Hamilton-Jacobi interpolating techniques. The result can be extended to the high load by a non rigorous but standard replica computation argument.Comment: 16 pages, 1 figur

    Women's employment, children and transition: an empirical analysis on Poland

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    The effect of transition from centrally planned to market economies on female employment is unclear a-priori. Many studies have pointed out that the emergence of labour markets created obstacles to but also new opportunities for women’s employment. A frequently mentioned potential explanation of the lower female participation during the transition period is represented by the reduction of childcare facilities, which created a major constraint on the participation of women with dependent children. However, we must not forget the effect of forces of opposite sign, first of all the household necessity of having two earners during the turbulent transition period. The aim of this paper is to give an empirical assessment on how the transition to a market economy affected the relationship between motherhood and labour force outcomes in Poland. We estimate random effects probit models on two PACO panel datasets covering a four year period before the reform (1987-1990) and a three year period afterwards (1994-1996). Our findings indicate that during transition small children were much less of a deterrent to the employment probability of their mother than it was before transition

    Ethical and legal limits to the diffusion of self-produced autonomous weapons

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    The theme of self-produced weapons intertwines diversified ideas of an ethical, legal, engineering and data science nature. The critical starting point concerns the use of 3D or 4D printing for the self-production of weapons: the doctrinal and ethical discussion is open, while from a case law point of view no published decisions have been found. From a technical point of view it should be noted that, being produced with materials other than metal, the weapons in question would increase their danger, since it would not be possible to ascertain their possession through metal detectors.This possibility demonstrates how the combination of the application of 3D or 4D printing and AI can lead to further development of Autonomous Weapon Systems, especially drones, which are no longer confined to science fiction novels, but may appear on the market for goods and even available for mass consumption, and it stresses the need for the promotion of negotiations for the drafting of an international treaty banning the production and use of lethal autonomous weapons.The combination of such printers with biometric facial recognition algorithms raises concerns for the increasing issues of physical, individual and collective safety that may arise. In fact, the biometric recognition technology allows the identification of individuals through the measurement and analysis of the somatic or behavioural traits; it is based on intelligent software, modelled on the human ability to recognize and identify faces by collecting and analysing huge amounts of data, and it is able to evolve its skills beyond its programmer’s initial intention. It is clear that allowing self-production of such devices by non-expert users could produce more damages than benefits. The purpose of this contribution is to study how to regulate the effects of such self-made autonomous robots, since their use may have a devastating and disruptive effect on public integrity and social peace, especially in case of violent riots.<br/

    Therapeutic potential of bleomycin plus suicide or interferon-β gene transfer combination for spontaneous feline and canine melanoma

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    We originated and characterized melanoma cell lines derived from tumors of two feline and two canine veterinary patients. These lines reestablished the morphology, physiology and cell heterogeneity of their respective parental tumors. We evaluated the cytotoxicity of bleomycin (BLM) alone, or combined with interferon-β (IFN-β) or HSVtk/GCV suicide gene (SG) lipofection on these cells. Although the four animals presented stage III disease (WHO system), SG treated feline tumors displayed stable disease in vivo, while the canine ones exhibited partial response. Their derived cell lines reflected this behavior. Feline were significantly more sensitive than canine cells to IFN-β gene transfer. BLM improved the antitumor effects of both genes. The higher levels of reactive oxygen species (ROS) significantly correlated with membrane and DNA damages, emphasizing ROS intervention in apoptotic and necrotic cell death. After 3 days of BLM alone or combined with gene treatments, the colony forming capacity of two canine and one feline treatments survivor cells almost disappeared. Taken together, these results suggest that the treatments eradicated tumor initiating cells and support the clinical potential of the tested combinations.Fil: Agnetti, Lucrecia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Fondello, Chiara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Villaverde, Marcela Solange. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Glikin, Gerardo Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Finocchiaro, Liliana Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; Argentin

    Medieval Glassworks in the City of Ferrara (North Eastern Italy): The Case Study of Piazza Municipale

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    Compositional and structural characterization was carried out on transparent glass fragments found in a brick rubbish pit discovered in basal floor of the ducal palace of Ferrara, during the excavation of Piazza Municipale. This study aims to identify raw materials and glass-working techniques through X-Ray Fluorescence (XRF) quantitative chemical analyses and semi-quantitative Scanning Electron Microscopy (SEM) observations. The studied fragments were produced using siliceous-lime sands with natron as flux, and allowed us to better understand the production technologies in a historical period of great innovation for European glass art. The numerous findings of glass fragments discovered in brick underground cellars built for the specific purpose of household rubbish of wealthy complexes in Ferrara testify a consolidated system of separate discharge of solid waste into underground containers, which were closed and sealed once filled. The high volume of the finds indicates the absence of recycling of accumulated materials due to the well-being of the city. Compositional analysis confirmed the local production of glass shops in Ferrara during the late Middle Ages, characterized by differences with the glasses of the nearby city of Venice. Morphological analyses also defined the nature and relative abundance of the products, exploring the types and compositions of the Ferrara glass art

    Neurovisual training (TRIGRAM) in young patients with visual-perceptive dyslexia

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    Dyslexia is a language-based learning disability. Although this condition is characterized by anatomical malformation of the brain, it seems that the typical reading pattern of dyslexic may be also related to more complex sensory deficits. Among them, visual- perceptive deficits have been described in a subtype of dyslexia, called visual-perceptive dyslexia. The distinctive feature of a patient suffering from visual-perceptive dyslexia form is marked by effortlessly recognize the characteristics of each individual stimulus. The Tetra protocol is a visual-perceptual evaluation protocol that was introduced for the diagnostic phase and the rehabilitation of visual-perceptive dyslexia. The diagnostic tests include: the eidomorphometry test, designed to evaluate the perception of spatial relationships; the contrast sensitivity threshold test, especially at low spatial frequencies; and the REPORT TEST words, to assess the speed and the reading efficiency. In addition, the rehabilitation phase is carried out with the visual neuro-enhancement program TRIGRAM, a visual training proposal designed to reduce the lateral masking phenomenon in visual-perceptive dyslexic. Thus, in this study we used the diagnostic tests of TETRA® Protocol to determine presence of visual-perceptual abnormalities in children with dyslexia. Proven time the presence of these visual-perceptual alterations, the patients were also subjected to the rehabilitation sessions of TRIGRAM, in order to investigate whether this visual training may improve the pattern of reading. At the end of the program (t1) and after three months (t2), the same subjects underwent the same diagnostic tests of TETRA® Protocol to evaluate and confirm the results obtained during rehabilitation program. The results showed a significant increase in contrast sensitivity at low and high spatial frequencies. Moreover, the same improvements in the visual system's ability to discriminate the contours of an object within the field of view, have been maintained three months after the end of treatment. We also observed a significant improvement in the perception of spatial relationships, with reduction of SRA value. In conclusion, this study demonstrates that the visual rehabilitation training (TRIGRAM) is able to improve the perception of spatial relationships, and increase contrast sensitivity in young patients affected by "visual dyslexia". Nonetheless, these data need to be confirmed in larger cohort of subjects in order to establish whether these effects can also increase lexical ability (increased reading speed and reduce errors during the lexical task)

    I see you sharing thus I share with you: indirect reciprocity in toddlers, but not infants

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    Abstract Human societies are organised around cooperative interactions, the origins and development of which have become a timely topic. In this study, we investigated the development of indirect reciprocity in 18–24-month-old toddlers, and infants aged 6 months, on a two-phase sharing task with non-familiar individuals. In the first phase, we observed whether infants and toddlers differentiated and manifested a preference toward an individual altruistically sharing or acting selfishly. In the second phase, infants and toddlers interacted with the same prosocial and antisocial individuals seen in the first phase, and we observed whether they were willing to share with one of the two. Indirect reciprocity was assessed as the match between the preferences for the prosocial individual in phase one, and the first-person sharing in the second phase. Evidence showed that toddlers, but not infants, indirectly reciprocated the prosocial individual, suggesting that understanding of such a complex behaviour as indirect reciprocity may require prolonged experience in order to emerge

    Disability and work intensity in Italian households

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    The 2030 Agenda of the United Nations clearly sets the inclusion of persons with disabilities in the labour market as a main goal. However, especially in care welfare systems characterized by a low level of social services, disability not only impacts the labour market participation of disabled people themselves but may also affect the labour opportunities of other members of their household. Using EU-SILC data to compute individual work intensity-as a better measure of the actual level of labour attainment-this paper aims to disentangle direct and indirect correlations between disability and labour market participation in Italian households. In confirming the negative direct correlation between disability and labour market participation, the results also show a negative indirect correlation that depends on the family relationship between the disabled person and household members
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