1,899 research outputs found

    Double Parton Scatterings in High-Energy Proton-Nucleus Collisions and Partonic Correlations

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    The joint study of Double Parton Scatterings, in high energy proton-proton and proton-nucleus collisions, can provide a lot of information on multi-parton correlations. The multi-parton structure is in fact probed in a different way by DPS, in pp-pp and in pp-AA collisions. In pp-AA collisions the interpretation of the experimental results may be however complicated by the presence of interference terms, which are missing in pp-pp. A suitable reaction channel, where interference terms are absent, is WJJWJJ production. By studying WJJWJJ production in pp-PbPb collisions, we estimate that the fraction of events due to DPS may be larger by a factor 3 or 4, as compared to pp-pp, while the amount of the increased fraction can give a direct indication on the importance of different correlation terms.Comment: 27 pages, 9 figure

    Gender quotas or girls’ networks? Towards an understanding of recruitment in the research profession in Italy

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    This article investigates the role of the gender composition of selection committees and networks in promoting women in research activities. We exploit a novel data set on recruitment processes at entry-level research positions in a leading Italian research centre that mainly operates in hard science. We find some evidence of discrimination against women at non-tenured entry levels, which is attenuated (or even reversed) by the presence of a woman on the selection committee. However, the most important predictor for recruitment seems to be previous connections with the research centre, which also serves as an important mechanism for women to enter the research profession. We conclude that quotas could be a solution for gender-biased preferences towards same-sex candidates in selection committees for non-tenure-track positions. Moreover, more gender-neutral networks would be another mechanism to bring more equality between men and women in research

    Double Parton Interactions in pp and pA Collisions

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    As a consequence of the increasingly large flux of partons at small x , Double Parton Interactions (DPI) play an increasingly important role at high energies. A detail understanding of DPI dynamics is therefore mandatory, for a reliable subtraction of the background in the search of new physics. On the other hand, DPI are an interesting topic of research by themselves, as DPI probe the hadron structure in a rather different way, as compared with the large pt processes usually considered. In this note we will make a short illustration of some of the main features characterizing DPI in pp and in pA collisions

    A Quantitative Version of Simple Types

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    This work introduces a quantitative version of the simple type assignment system, starting from a suitable restriction of non-idempotent intersection types. The resulting system is decidable and has the same typability power as the simple type system; thus, assigning types to terms supplies the very same qualitative information given by simple types, but at the same time can provide some interesting quantitative information. It is well known that typability for simple types is equivalent to unification; we prove a similar result for the newly introduced system. More precisely, we show that typability is equivalent to a unification problem which is a non-trivial extension of the classical one: in addition to unification rules, our typing algorithm makes use of an expansion operation that increases the cardinality of multisets whenever needed

    Potential biomarkers and novel pharmacological targets in protein aggregation-related neurodegenerative diseases

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    The aggregation of specific proteins plays a pivotal role in the etiopathogenesis of several neurodegenerative diseases (NDs). β-Amyloid (Aβ) peptide-containing plaques and intraneuronal neurofibrillary tangles composed of hyperphosphorylated protein tau are the two main neuropathological lesions in Alzheimer's disease. Meanwhile, Parkinson's disease is defined by the presence of intraneuronal inclusions (Lewy bodies), in which α-synuclein (α-syn) has been identified as a major protein component. The current literature provides considerable insights into the mechanisms underlying oligomeric-related neurodegeneration, as well as the relationship between protein aggregation and ND, thus facilitating the development of novel putative biomarkers and/or pharmacological targets. Recently, α-syn, tau and Aβ have been shown to interact each other or with other "pathological proteins" to form toxic heteroaggregates. These latest findings are overcoming the concept that each neurodegenerative disease is related to the misfolding of a single specific protein. In this review, potential opportunities and pharmacological approaches targeting α-syn, tau and Aβ and their oligomeric forms are highlighted with examples from recent studies. Protein aggregation as a biomarker of NDs, in both the brain and peripheral fluids, is deeply explored. Finally, the relationship between biomarker establishment and assessment and their use as diagnostics or therapeutic targets are discussed

    Low frequency follow up of radio halos and relics in the GMRT Radio Halo Cluster Survey

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    We performed GMRT low frequency observations of the radio halos, relics and new candidates belonging to the GMRT Radio Halo Cluster Sample first observed at 610 MHz. High sensitivity imaging was performed using the GMRT at 325 MHz and 240 MHz. The properties of the diffuse emission in each cluster were compared to our 610 MHz images and/or literature information available at other frequencies, in order to derive the integrated spectra over a wide frequency range.Beyond the classical radio halos, whose spectral index α\alpha is in the range 1.2÷1.3\sim1.2\div1.3 (Sνα\propto\nu^{-\alpha}), we found sources with α1.6÷1.9\alpha\sim1.6\div1.9. This result supports the idea that the spectra of the radiating particles in radio halos is not universal, and that inefficient mechanisms of particle acceleration are responsible for their origin. We also found a variety of brightness distributions, i.e. centrally peaked as well as clumpy halos. Even though the thermal and relativistic plasma tend to occupy the same cluster volume, in some cases a positional shift between the radio and X-ray peaks of emission is evident. Our observations also revealed the existence of diffuse cluster sources which cannot be easily classified either as halos or relics. New candidate relics were found in A1300 and in A1682, and in some clusters "bridges" of radio emission have been detected, connecting the relic and radio halo emission. Combining our new data with literature information, we derived the LogLX_{\rm X}-LogP325MHz_{\rm 325 MHz} correlation for radio halos, and investigated the possible trend of the spectral index of radio halos with the temperature of the intracluster medium.Comment: 19 pages, 10 figures, 5 tables, accepted for publication on A&

    Brightest Cluster Galaxies in the Extended GMRT radio halo cluster sample. Radio properties and cluster dynamics

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    Brightest Cluster Galaxies (BCGs) show exceptional properties over the whole electromagnetic spectrum. Their special location at the centres of galaxy clusters raises the question of the role of the environment on their radio properties. To decouple the effect of the galaxy mass and of the environment in their statistical radio properties, we investigate the possible dependence of the occurrence of radio loudness and of the fractional radio luminosity function on the dynamical state of the hosting cluster. We studied the radio properties of the BCGs in the Extended GMRT Radio Halo Survey (EGRHS). We obtained a statistical sample of 59 BCGs, which was divided into two classes, depending on the dynamical state of the host cluster, i.e. merging (M) and relaxed (R). Among the 59 BCGs, 28 are radio-loud, and 31 are radio--quiet. The radio-loud sources are located favourably located in relaxed clusters (71\%), while the reverse is true for the radio-quiet BCGs, mostly located in merging systems (81\%). The fractional radio luminosity function (RLF) for the BCGs is considerably higher for BCGs in relaxed clusters, where the total fraction of radio loudness reaches almost 90\%, to be compared to the \sim30\% in merging clusters. For relaxed clusters, we found a positive correlation between the radio power of the BCGs and the strength of the cool core, consistent with previous studies on local samples. Our study suggests that the radio loudness of the BCGs strongly depends on the cluster dynamics, their fraction being considerably higher in relaxed clusters. We compared our results with similar investigations, and briefly discussed them in the framework of AGN feedback.Comment: 12 pages, 6 figures, 3 tables, A&A accepte

    Screening of endocrine organ-specific humoral autoimmunity in 47,XXY Klinefelter's syndrome reveals a significant increase in diabetes-specific immunoreactivity in comparison with healthy control men.

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    The aim of this study was to evaluate the frequency of humoral endocrine organ-specific autoimmunity in 47,XXY Klinefelter’s syndrome (KS) by investigating the autoantibody profile specific to type 1 diabetes (T1DM), Addison’s disease (AD), Hashimoto thyroiditis (HT), and autoimmune chronic atrophic gastritis (AG). Sixty-one adult Caucasian 47,XXY KS patients were tested for autoantibodies specific to T1DM (Insulin Abs, GAD Abs, IA-2 Abs, Znt8 Abs), HT (TPO Abs), AD (21-OH Abs), and AG (APC Abs). Thirty-five of these patients were not undergoing testosterone replacement therapy TRT (Group 1) and the remaining 26 patients started TRT before the beginning of the study (Group 2). KS autoantibody frequencies were compared to those found in 122 control men. Six of 61 KS patients (9.8 %) were positive for at least one endocrine autoantibody, compared to 6.5 % of controls. Interestingly, KS endocrine immunoreactivity was directed primarily against diabetes-specific autoantigens (8.2 %), with a significantly higher frequency than in controls (p = 0.016). Two KS patients (3.3 %) were TPO Ab positive, whereas no patients were positive for AD- and AG-related autoantigens. The autoantibody endocrine profile of untreated and treated KS patients was not significantly different. Our findings demonstrate for the first time that endocrine humoral immunoreactivity is not rare in KS patients and that it is more frequently directed against type 1 diabetes-related autoantigens, thus suggesting the importance of screening for organ-specific autoimmunity in clinical practice. Follow-up studies are needed to establish if autoantibody-positive KS patients will develop clinical T1D

    Criticalities in the NZEB retrofit of scholastic buildings: analysis of a secondary school in Centre Italy

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    Abstract In Italy, the recast of the European Directive on Energy Performance of Buildings (2010/31/EU) is implemented with specific definitions and deadlines for Nearly Zero Energy Buildings. We focus our attention on schools, not only for their social importance and high visibility, but also because in the next future a significant share of these buildings is likely to undergo refurbishment for different purposes than the energetic one. We start to analyze the criticalities associated with the current Italian legislation on NZEBs by means of a bottom-up approach: we choose a benchmark secondary school (located in Pisa, hosting about 750 students) and perform an accurate energy audit of the building system, together with an energy and economic simulation of an NZEB retrofit. More in detail, we present the case study and explain its choice as an appropriate representative of the existing scholastic buildings in Centre Italy; besides, we build two concurrent energy models, based on tailored and asset rating methods, we propose technically-feasible actions for deep renovation, and simulate, for both models, the associated energy and economic savings after 20 years of use. We observe long payback periods of the retrofit measures, due to low yearly energy uses in the existing configuration. Based on these results, we attempt to extend to a more general level the considerations on strengths and weaknesses encountered in the present application of the Italian regulation on NZEBs

    Discovery of a radio relic in the low mass, merging galaxy cluster PLCK G200.9-28.2

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    Radio relics at the peripheries of galaxy clusters are tracers of the elusive cluster merger shocks. We report the discovery of a single radio relic in the galaxy cluster PLCK G200.9-28.2 (z=0.22z=0.22, M500=2.7±0.2×1014MM_{500} = 2.7\pm0.2 \times 10^{14} M_{\odot}) using the Giant Metrewave Radio Telescope at 235 and 610 MHz and the Karl G. Jansky Very Large Array at 1500 MHz. The relic has a size of 1×0.28\sim 1 \times 0.28 Mpc, an arc-like morphology and is located at 0.9 Mpc from the X-ray brightness peak in the cluster. The integrated spectral index of the relic is 1.21±0.151.21\pm0.15. The spectral index map between 235 and 610 MHz shows steepening from the outer to the inner edge of the relic in line with the expectation from a cluster merger shock. Under the assumption of diffusive shock acceleration, the radio spectral index implies a Mach number of 3.3±1.83.3\pm1.8 for the shock. The analysis of archival XMM Newton data shows that PLCK G200.9-28.2 consists of a northern brighter sub-cluster, and a southern sub-cluster in a state of merger. This cluster has the lowest mass among the clusters hosting single radio relics. The position of the Planck Sunyaev Ze'ldovich effect in this cluster is offset by 700 kpc from the X-ray peak in the direction of the radio relic, suggests a physical origin for the offset. Such large offsets in low mass clusters can be a useful tool to select disturbed clusters and to study the state of merger.Comment: 10 pages, 7 figures, 4 tables. Accepted for publication in MNRA
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