282 research outputs found

    Attosecond transient absorption spectroscopy of helium above the N=2 ionization threshold

    Full text link
    Attosecond transient absorption spectroscopy (ATAS) allows for the study of electron dynamics in atoms and molecules with attosecond time resolution. Previous works reported in the literature have made use of ATAS to image and control such dynamics in the single-channel ionization continuum of helium; in particular, in the vicinity of the doubly excited autoionizing states lying between the N=1 and N=2 thresholds. In this work, we have extended these studies to autoionizing states lying above the N=2 threshold, where several ionization channels are open. From an accurate solution of the time-dependent Schrödinger equation, we predict the appearance of pronounced one-photon beatings between the 3snp states and the adjacent 1Se and 1De resonances, as well as, more surprisingly, two-photon beatings between the 3s3p doubly excited state and the 1Po nonresonant continuum. Both effects lead to a significant distortion of the 3snp Fano profiles and to a strong variation of these profiles with the pump-probe delay, thus demonstrating control of the corresponding multichannel two-electron correlated wave packets, in the same way as reported for resonances lying below the N=2 thresholdWe would like to acknowledge allocation of computer time at Mare Nostrum BSC and CCC-UAM. This work was supported by the European Research Council Advanced Grant No. XCHEM 290853, the MINECO Projects No. FIS2013-42002-R and No. FIS2016-77889-R, the European COST Action XLIC CM1204, and the CAM project NANOFRONTMAG. L.A. acknowledges support from the TAMOP NSF Grant No. 1607588, as well as UCF funding

    Inside-out and outside-in orientations: A meta-analysis of orientation's effects on innovation and firm performance

    Get PDF
    The inside-out and outside-in orientations place differing levels of emphasis on internal versus external resources and capabilities as sources of competitive advantage. While the inside-out orientation primarily considers organizational resources, followed by competitors and customers (implicitly), the outside-in orientation appears to reverse the order by first examining customers and competitors and then the degree to which the firm responds to them, implicitly addressing organizational resources. Existing empirical evidence does not clarify the comparative effects of inside-out and out-side in orientations on innovation performance. This paper draws on 232 independent studies (N = 38,051) analyzed systematically through a quantitative meta-analytic synthesis in order to develop a detailed contextualized elaboration of the relationships between the inside-out and outside-in orientations and innovation performance. Going beyond the direct effects, we also extend the literature by investigating the moderating effects of industry type (high-tech vs. low-tech), economic development (developed vs. developing countries), and cultural context (collectivist vs. individualist cultures). Our findings shed light on the relative value of inside-out and outside-in orientation for innovation performance, the direct and indirect effects of the two orientations on firm performance, and the conditions under which the effectiveness of each is enhanced

    Software Defined 5G Converged Access as a viable Techno-Economic Solution

    Get PDF
    Software Defined Converged Access represents a feasible solution to effectively address 5G traffic demands. This paper proposes an integrated mobile-optical control for wavelength and bandwidth allocation. Evaluations of bandwidth utilization and technoeconomic viability are provided.This work was partially supported by the Italian Government under CIPE resolution no. 135 (December 21, 2012), project INnovating City Planning through Information and Communication Technologies (INCIPICT) and by the EC through the H2020 5G-TRANSFORMER project (Project ID 761536)

    Software Defined 5G Converged Mobile Access Networks: Energy Efficiency Considerations

    Get PDF
    Software Defined Mobile Networks and Software Defined Access Networks bring programmability principle into mobile and optical domains. In this work we propose an integrated control approach and show the benefit in terms of energy efficiency.This work was partially supported by the Italian Government under CIPE resolution no. 135 (December 21, 2012), project INnovating City Planning through Information and Communication Technologies (INCIPICT) and by the EC through the H2020 5G-TRANSFORMER project (Project ID 761536)

    The assessment of hazelnut mechanical harvesting productivity

    Get PDF
    ArticleHazelnut cultivation represents a new opportunity for Calabrian mountainous and sloping areas (Southern Italy), where no alternative fruit crops, except forestry, could be settled. In this Region, hazelnut production doubled during the last fifty years, inciting the farmers to introduce mechanization in cropping practices such as harvesting in order to increase productivity and decrease production costs. Indeed, harvesting is currently one of the most expensive processes of the productive cycle, moreover to be time consuming if carried out manually. Mechanization degree depends significantly on the terrain topography: in sloping areas, rakes are often associated to aspirating machines to harvest the fallen fruit, while the employment of harvesting machines from the ground prevails in flat areas. In this context, the present paper aims to assess technical and economic aspects of harvesting operation, using a harvester from the ground model ‘Jolly 2800’ (GF s.r.l., Italy). Particularly, for technical purposes data about operational working time as well as working productivity were collected according to CIOSTA requirements, in two harvesting sites, whereas, for mechanical harvesting economic evaluation, an estimation model was applied to calculate machinery cost per hour. Moreover, the cost per kg of hazelnut in shell and the average cost per hectare were estimated also. The obtained results show a working productivity of 0.065 ha h-1 op-1 in the first harvesting site, while it was equal to 0.022 ha h -1 op-1 in the second one. Concerning the average cost per hectare, the second harvesting site showed the worst economic performances, with 550.76 € ha-1 against 182.54 € ha-1 obtained in the first one

    Tryptase as a marker of severity of aortic valve stenosis

    Get PDF
    Background: Severe aortic valve stenosis is one of the most common cause of mortality in adult patients affected with metabolic syndrome, a condition associated with an active inflammatory process involving also mast cells and their mediators, in particular tryptase. The aim of this study was to characterize the possible long-term prognostic role of tryptase in severe aortic valve stenosis. Case presentation: The baseline serum tryptase was measured in 5 consecutive patients admitted to our Hospital to undergo aortic valve replacement for severe acquired stenosis. Within 2years after, the patients were evaluated for the occurrence of major cardiovascular events (MACE). The tryptase measurements were higher in patients experiencing MACE (10.9, 11.7 and 9.32ng/ml) than in non-MACE ones (5.69 and 5.58ng/ml). Conclusions: In patients affected with severe aortic stenosis, baseline serum tryptase may predict occurence of MACE. Further studies are needed to demonstrate the long-term prognostic role of this biomarker

    Non-universal behaviour of helical two-dimensional three-component turbulence

    Get PDF
    The dynamics of two-dimensional three-component (2D3C) flows is relevant to describe the long-time evolution of strongly rotating flows and/or of conducting fluids with a strong mean magnetic field. We show that in the presence of a strong helical forcing, the out-of-plane component ceases to behave as a passive advected quantity and develops a nontrivial dynamics which deeply changes its large-scale properties. We show that a small-scale helicity injection correlates the input on the 2D component with the one on the out-of-plane component. As a result, the third component develops a nontrivial energy transfer. The latter is mediated by homochiral triads, confirming the strong 3D nature of the leading dynamical interactions. In conclusion, we show that the out-of-plane component in a 2D3C flow enjoys strong nonuniversal properties as a function of the degree of mirror symmetry of the small-scale forcing

    Behind the scenes of public funding for performing arts in Italy: hidden phenomena beyond the rhetoric of legislation

    Get PDF
    This paper focuses on how Italian performing arts organizations were funded between 2003 and 2005. How does policy regulate the financing system for performing arts? What are the underlying logics that govern financing choices? In this paper the authors move beyond the simple examination of formal policies by analysing the funding data and organizational routines of the ministerial offices responsible for the allocation of grants. The authors implemented a multi-method research methodology consisting of document analysis, in-depth interviews, and quantitative analysis of funding data. The main findings can be summarized as follows. First, funds are continuously allocated to the same group of organizations. Second, although rigid, the system is imbued by a 'rhetoric of the project'. Third, the system does not reward innovation. In conclusion, only by studying how the law is actually implemented can one capture the choices that underlie financing actions, and thus unravel unanticipated outcomes and inconsistencies between rhetoric and conduct

    Genotype-Phenotype Correlation in NF1: Evidence for a More Severe Phenotype Associated with Missense Mutations Affecting NF1 Codons 844–848

    Get PDF
    Neurofibromatosis type 1 (NF1), a common genetic disorder with a birth incidence of 1:2,000–3,000, is characterized by a highly variable clinical presentation. To date, only two clinically relevant intragenic genotype-phenotype correlations have been reported for NF1 missense mutations affecting p.Arg1809 and a single amino acid deletion p.Met922del. Both variants predispose to a distinct mild NF1 phenotype with neither externally visible cutaneous/plexiform neurofibromas nor other tumors. Here, we report 162 individuals (129 unrelated probands and 33 affected relatives) heterozygous for a constitutional missense mutation affecting one of five neighboring NF1 codons—Leu844, Cys845, Ala846, Leu847, and Gly848—located in the cysteine-serine-rich domain (CSRD). Collectively, these recurrent missense mutations affect ∼0.8% of unrelated NF1 mutation-positive probands in the University of Alabama at Birmingham (UAB) cohort. Major superficial plexiform neurofibromas and symptomatic spinal neurofibromas were more prevalent in these individuals compared with classic NF1-affected cohorts (both p < 0.0001). Nearly half of the individuals had symptomatic or asymptomatic optic pathway gliomas and/or skeletal abnormalities. Additionally, variants in this region seem to confer a high predisposition to develop malignancies compared with the general NF1-affected population (p = 0.0061). Our results demonstrate that these NF1 missense mutations, although located outside the GAP-related domain, may be an important risk factor for a severe presentation. A genotype-phenotype correlation at the NF1 region 844–848 exists and will be valuable in the management and genetic counseling of a significant number of individuals

    TERT promoter mutations are highly recurrent in SHH subgroup medulloblastoma

    Get PDF
    Telomerase reverse transcriptase (TERT) promoter mutations were recently shown to drive telomerase activity in various cancer types, including medulloblastoma. However, the clinical and biological implications of TERT mutations in medulloblastoma have not been described. Hence, we sought to describe these mutations and their impact in a subgroup-specific manner. We analyzed the TERT promoter by direct sequencing and genotyping in 466 medulloblastomas. The mutational distributions were determined according to subgroup affiliation, demographics, and clinical, prognostic, and molecular features. Integrated genomics approaches were used to identify specific somatic copy number alterations in TERT promoter-mutated and wild-type tumors. Overall, TERT promoter mutations were identified in 21 % of medulloblastomas. Strikingly, the highest frequencies of TERT mutations were observed in SHH (83 %; 55/66) and WNT (31 %; 4/13) medulloblastomas derived from adult patients. Group 3 and Group 4 harbored this alteration in <5 % of cases and showed no association wit
    • …
    corecore