360 research outputs found

    Quantum Google in a Complex Network

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    We investigate the behavior of the recently proposed quantum Google algorithm, or quantum PageRank, in large complex networks. Applying the quantum algorithm to a part of the real World Wide Web, we find that the algorithm is able to univocally reveal the underlying scale-free topology of the network and to clearly identify and order the most relevant nodes (hubs) of the graph according to their importance in the network structure. Moreover, our results show that the quantum PageRank algorithm generically leads to changes in the hierarchy of nodes. In addition, as compared to its classical counterpart, the quantum algorithm is capable to clearly highlight the structure of secondary hubs of the network, and to partially resolve the degeneracy in importance of the low lying part of the list of rankings, which represents a typical shortcoming of the classical PageRank algorithm. Complementary to this study, our analysis shows that the algorithm is able to clearly distinguish scale-free networks from other widespread and important classes of complex networks, such as Erd\H{o}s-R\'enyi networks and hierarchical graphs. We show that the ranking capabilities of the quantum PageRank algorithm are related to an increased stability with respect to a variation of the damping parameter α\alpha that appears in the Google algorithm, and to a more clearly pronounced power-law behavior in the distribution of importance among the nodes, as compared to the classical algorithm. Finally, we study to which extent the increased sensitivity of the quantum algorithm persists under coordinated attacks of the most important nodes in scale-free and Erd\H{o}s-R\'enyi random graphs

    Time-resolved photoluminescence of n-doped SrTiO_3

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    Following the recent surge of interest in n-doped strontium titanate as a possible blue light emitter, a time-resolved photoluminescence analysis was performed on nominally pure, Nb-doped and oxygen-deficient single-crystal SrTiO3 samples. The doping-effects on both the electronic states involved in the transition and the decay mechanism are respectively analyzed by comparing the spectral and dynamic features and the yields of the emission. Our time-resolved analysis, besides shedding some light on the basic recombination mechanisms acting in these materials, sets the intrinsic bandwidth limit of the proposed blue light emitting optoelectronic devices made of Ti-based perovskites heterostructures in the GHz range

    An Exploratory Study of Adult Baby-Diaper Lovers’ Characteristics in an Italian Online Sample

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    Background: Knowledge of the Adult Baby-Diaper Lovers (ABDL) phenomena is quite recent and there are, of yet, few studies on this phenomenon. Aim: This study was conceived to investigate the functions of ABDL behaviours and the characteristics of ABDL in an online Italian community sample. We hypothesized that ABDL phenomena were associated with general psychological maladjustment and with an experience of parental rejection during childhood. It was also assumed that there would be differences in ABDL profiles based on the age of appearance of their first Adult Baby-Diaper Lover (ABDL) fantasies. Method: An internet-based study was conducted and it involved 38 adults aged between 18 and 74 years (M = 34.95; SD = 12.25). Participants were first given an ad hoc questionnaire, which was devised to obtain information about the anamnestic variables related to ABDL. Then, the participants filled out the Cognitive Behaviour Assessment 2.0 battery to obtain anamnestic information regarding their psychological, medical, and personal history and to evaluate primary psychological dimensions in clinical practice. Finally, they filled out the Adult Parental Acceptance–Rejection Questionnaire, to evaluate their recollections of parental perceived rejection, and the Personality Assessment Questionnaire, to evaluate the primary psychological aspects related to parental rejection. Results: The data indicated that adults with ABDL showed the presence of anxious traits and recollections of parental rejection during childhood. Moreover, associations were observed between current or previous ABDL phenomena enuresis and negative mood states. Conclusion: Specific kinds of parental modes, anxiety traits, and enuresis seem to be the source of ABDL interests. Moreover, ADBL behaviours seem to assume different functions and meanings

    Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation

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    The so-called "polar catastrophe", a sudden electronic reconstruction taking place to compensate for the interfacial ionic polar discontinuity, is currently considered as a likely factor to explain the surprising conductivity of the interface between the insulators LaAlO3 and SrTiO3. We applied optical second harmonic generation, a technique that a priori can detect both mobile and localized interfacial electrons, to investigating the electronic polar reconstructions taking place at the interface. As the LaAlO3 film thickness is increased, we identify two abrupt electronic rearrangements: the first takes place at a thickness of 3 unit cells, in the insulating state; the second occurs at a thickness of 4-6 unit cells, i.e., just above the threshold for which the samples become conducting. Two possible physical scenarios behind these observations are proposed. The first is based on an electronic transfer into localized electronic states at the interface that acts as a precursor of the conductivity onset. In the second scenario, the signal variations are attributed to the strong ionic relaxations taking place in the LaAlO3 layer

    Multimodality imaging of chronic tophaceous gout

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    The diagnosis of gout is usually based on clinical presentation and laboratory findings. Imaging plays a role in the assessment and grading of articular damage related to chronic, long-standing disease, which is characterized by granulomatous synovitis, tophi, and erosions. Multimodality imaging of chronic tophaceous gout may be useful in clinical practice for a variety of purposes, including assessment of disease-related anatomical changes and monitoring of articular and soft-tissue lesions over time, especially in response to urate-lowering therapy. Radiography remains the primary imaging technique. Ultrasonography may detect monosodium urate crystals on cartilage, is helpful to assess small joint effusion, to guide to joint aspiration, and to evaluate the volume of tophi. Computed tomography is considered to be more sensitive than plain radiography in the detection and evaluation of cortical bone erosions associated with tophi. MRI represents the only imaging modality which provides visualization of bone marrow oedema associated with erosions and may be useful to characterize and distinguish tophi from other soft tissue nodules

    Thyroid autoimmune disorders and cancer

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    In the last decades, many studies conducted in vitro, and in vivo, have shown that thyroid autoimmunity and thyroid cancer (TC) (mainly papillary TC) can be concomitant, even if the exact mechanisms at the basis of this association are still not clear. Growing incidence of TC coincides with increased registration of autoimmune thyroid disorders (AITD) suggesting an association between those pathologies. Elevated TSH levels and thyroid autoimmunity were defined as independent risk factors for TC. However a lot of evidence suggests that autoimmunity and inflammation, per se, are risk factors for TC. The link between inflammation and TC involves multiple components of the immune system, extracellular matrix, stroma, and adipose tissue, with pro-tumoral activity of inflammation being opposed to anti-inflammatory effects, favoring protection against cancer progression. Within the tumor microenvironment, inflammatory cells, belonging both to innate (macrophages) and adaptive (lymphocytes) immune responses, are interconnected with fibroblasts, endothelial cells, adipocytes, and extracellular matrix through cytokines, chemokines and adipocytokines. Under the influence of transcriptional regulators (such as Nuclear Factor-kappa B, mitogen-activated protein kinases, or Phosphoinositide-3 kinase/protein kinase-B), oncogenes connected to the different subtypes of TC promote their farthermost proliferative effect on the tumor microenvironment. Future studies will be necessary to understand the connections between thyroid autoimmunity and cancer, also in order to design a tailored therapy for TC patients with AITD

    Tsunamis From Submarine Collapses Along the Eastern Slope of the Gela Basin (Strait of Sicily)

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    Geophysical surveys in the eastern slope of the Gela Basin (Strait of Sicily, central Mediterranean) contributed to the identification of several episodes of sediment mass transport, recorded by scars and deposits of various dimensions within the Pleistocene succession. In addition to a huge failure called Gela Slide with volume exceeding 600 km3, the most studied events show volumes estimated between 0.5 and 1.5 km3, which is common to many other submarine landslide deposits in this region and that can therefore be considered as a characteristic value. In this work, the tsunamigenic potential of two of such landslides, the so-called Northern Twin Slide and South Gela Basin Slide located about 50 km apart along the eastern slope of the Gela Basin, are investigated using numerical codes that describe the onset and motion of the slide, as well as the ensuing tsunami generation and propagation. The results provide the wave height of these tsunami events on the coast of southern Sicily and Malta and can be taken as representative of the tsunamigenic potential of typical landslides occurring along the slope of the Gela Basin

    Altered miR-193a-5p expression in children with cow's milk allergy

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    Cow's milk allergy (CMA) is one of the most common food allergies in children. Epigenetic mechanisms have been suggested to play a role in CMA pathogenesis. We shown that DNA methylation of Th1/Th2 cytokine genes and FoxP3 affects CMA disease course. Preliminary evidence suggest that also the miRNome could be implicated in the pathogenesis of allergy. Main study outcome was to comparatively evaluate miRNome in children with CMA and in healthy controls
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