Asymptotically idempotent aggregation operators for trust management in multi-agent systems

The study of trust management in multi-agent system, especially distributed, has grown over the last years. Trust is a complex subject that has no general consensus in literature, but has emerged the importance of reasoning about it computationally. Reputation systems takes into consideration the history of an entity’s actions/behavior in order to compute trust, collecting and aggregating ratings from members in a community. In this scenario the aggregation problem becomes fundamental, in particular depending on the environment. In this paper we describe a technique based on a class of asymptotically idempotent aggregation operators, suitable particulary for distributed anonymous environments

Axiomatization of residual income and generation of financial securities

This paper presents an axiomatization of residual income, aka excess profit, and illustrates how it may univocally engenders fixed-income or variable-income assets. In the first part it is shown that, depending on the relations between excess profit and the investor's excess wealth, a well-specified theory of residual income is generated: one is the standard theory, which historically traces back to Hamilton (1777) and Marshall (1890) and is a deep-rooted notion in economic theory, finance, and accounting. Another one is the systemic value added or lost-capital paradigm: introduced in Magni (2000, 2003), the theory is enfolded in Keynes's (1936) notion of user cost and is naturally generated by an arbitrage-theory perspective. In the second part, the paper reverts the usual analysis: instead of computing residual incomes profits from a pattern of cash flows, residual incomes are fixed first to derive vectors of cash flows. It is shown that variable- or fixed-income assets may be constructed on the basis of either theory starting from pre-determined growth rates for excess profit. In particular, zero-coupon bonds and coupon bonds traded in a capital market are shown to be deducted as equilibrium vectors of residual-income-based assets.Residual income, excess profit, capital, arbitrage, bond

Valutazione sull'uso dei sistemi di climatizzazione elio-assistiti in ambito di edifici per edilizia universitaria

Nell’ambito dell’impiantistica si sta diffondendo l’idea di utilizzare sistemi che facciano ricorso all’energia solare per coprire le esigenze legate alla climatizzazione estiva. Dato il rapido aumento della domanda, l’uso crescente di impianti di condizionamento con macchine frigorifere a compressione alimentate ad energia elettrica è causa dell’aumento del picco di potenza elettrica che spesso ha portato al raggiungimento della capacità limite delle reti. I sistemi di refrigerazione che si prestano meglio all’impiego di energia solare sono sia i sistemi ad assorbimento, che quelli ad adsorbimento. Delineata la strategia generale per la progettazione di tali sistemi, viene analizzato un possibile un caso test, un edificio in fase di ristrutturazione presso la Facoltà di Ingegneria dell’Università di Pisa. Dopo aver analizzato i metodi per valutare l’energia radiante e gli apporti termici sugli edifici, si analizzano i modelli per simulare il comportamento degli edifici in transitorio e gli effetti di sfasamento legati alla tipologia di involucro edilizio. Vengono infine riportate alcune conclusioni dove si evidenzia come l’utilizzazione di sistemi di climatizzazione elio-assistiti, fatta salva l’ottimizzazione delle macchine e dei sistemi, debba passare necessariamente attraverso una revisione delle metodologie progettuali che tendano a ridare valore ad alcuni aspetti talvolta considerati marginali nella progettazione di impianti convenzionali

Working memory tasks in interpreting studies - A meta-analysis

Studies about working memory (WM) and interpreting have used a variety of methods and results are often conflicting. There is therefore the need to analyse the cognitive tasks which have been used so far to assess their effectiveness in detecting WM performance differences. This paper presents the findings of a meta-analysis that compares the results of interpreters and interpreting students (study group) to the results of non-interpreters (control group) in four cognitive tasks (reading span, n-back task, listening span and dual tasks). Interpreters show a significant WM advantage of medium size over non-interpreters in tasks based on verbal stimuli, but not in tasks based on non-verbal stimuli. In addition, differences are larger when there is a wider gap in interpreting expertise between the two groups

SMC3 knockdown triggers genomic instability and p53-dependent apoptosis in human and zebrafish cells

BACKGROUND: The structural maintenance of chromosome 3 (SMC3) protein is a constituent of a number of nuclear multimeric protein complexes that are involved in DNA recombination and repair in addition to chromosomal segregation. Overexpression of SMC3 activates a tumorigenic cascade through which mammalian cells acquire a transformed phenotype. This has led us to examine in depth how SMC3 level affects cell growth and genomic stability. In this paper the effect of SMC3 knockdown has been investigated. RESULTS: Mammalian cells that are SMC3 deficient fail to expand in a clonal population. In order to shed light on the underlying mechanism, experiments were conducted in zebrafish embryos in which cell competence to undergo apoptosis is acquired at specific stages of development and affects tissue morphogenesis. Zebrafish Smc3 is 95% identical to the human protein, is maternally contributed, and is expressed ubiquitously at all developmental stages. Antisense-mediated loss of Smc3 function leads to increased apoptosis in Smc3 expressing cells of the developing tail and notocord causing morphological malformations. The apoptosis and the ensuing phenotype can be suppressed by injection of a p53-specific MO that blocks the generation of endogenous p53 protein. Results in human cells constitutively lacking p53 or BAX, confirmed that a p53-dependent pathway mediates apoptosis in SMC3-deficient cells. A population of aneuploid cells accumulated in zebrafish embryos following Smc3-knockdown whereas in human cells the transient downregulation of SMC3 level lead to the generation of cells with amplified centrosome number. CONCLUSION: Smc3 is required for normal embryonic development. Its deficiency affects the morphogenesis of tissues with high mitotic index by triggering an apoptotic cascade involving p53 and the downstream p53 target gene bax. Cells with low SMC3 level display centrosome abnormalities that can lead to or are the consequence of dysfunctional mitosis and/or aneuploidy. Collectively the data support the view that SMC3 deficiency affects chromosomal stability leading to the activation of p53-dependent mitotic checkpoint

A note on a Tarski type fixed-point theorem

AbstractIn this paper we propose a basic fixed-point theorem for correspondences inspired by Tarski's intersection point theorem. This result furnishes an efficient tool to prove the existence of pure strategy Nash equilibria for two player games with possibly discontinuous payoffs functions defined on compact real intervals

The Impact of Age and Duration of Cochlear Implant in a Congenital Deaf Population: An ERP Study

Objective: It is well known that patients with Cochlear Implant (CI) have a large inter-individual variability in linguistic and auditory performances. This can be related to individual auditory processing abilities and integrity of auditory system from auditory nerve to cerebral cortex. P300 can be used for the evaluation of central auditory functions in people with hearing loss and CI. No studies considered the P300 in the population of prelingually deafened adults that underwent CI in old age. The aim of this study is to assess Event Related Potential (ERP) in patients with congenital profound hearing loss with early or late implantation and evaluate these results respect to an age-matched normal hearing group. Methods: ERPs (N100, N200 and P300) and auditory benefit testing (pure tone average and speech audiometric test) and auditory perception testing (Categories of Auditory Performance\u2014CAP) were evaluated in all subjects with their device. Results: All mean latencies (N100, N200 and P300) were found greater in patients group compared to control group. When analyzing all measures in patient group, we did not find any significant differences according to age of implant while significant difference (p > 0.05) in N100 amplitude (p = 0.045) and P300 latency (p = 0.035) were found according to time of CI use. A linear correlation between N200 and P300 latency in control and patients groups was found. Conclusion: In summary, ERPs analysis in the evaluation of CI showed a great importance of long use of the device in addiction to an early time of implant

Faraway, so close. The comparative method and the potential of non-model animals in mitochondrial research

Inference from model organisms has been the engine for many discoveries in life science, but indiscriminate generalization leads to oversimplifications and misconceptions. Model organisms and inductive reasoning are irreplaceable: there is no other way to tackle the complexity of living systems. At the same time, it is not advisable to infer general patterns from a restricted number of species, which are very far from being representative of the diversity of life. Not all models are equal. Some organisms are suitable to find similarities across species, other highly specialized organisms can be used to focus on differences. In this opinion piece, we discuss the dominance of the mechanistic/reductionist approach in life sciences and make a case for an enhanced application of the comparative approach to study processes in all their various forms across different organisms. We also enlist some rising animal models in mitochondrial research, to exemplify how non-model organisms can be chosen in a comparative framework. These taxa often do not possess implemented tools and dedicated methods/resources. However, because of specific features, they have the potential to address still unanswered biological questions. Finally, we discuss future perspectives and caveats of the comparative method in the age of ‘big data’

Grid: From EGEE to EGI and from INFN-GRID to IGI

In the last fifteen years the approach of the “computational Grid” has changed the way to use computing resources. Grid computing has raised interest worldwide in academia, industry, and government with fast development cycles. Great efforts, huge funding and resources have been made available through national, regional and international initiatives aiming at providing Grid infrastructures, Grid core technologies, Grid middleware and Grid applications. The Grid software layers reflect the architecture of the services developed so far by the most important European and international projects. In this paper Grid e-Infrastructure story is given, detailing European, Italian and international projects such as EGEE, INFN-Grid and NAREGI. In addition the sustainability issue in the long-term perspective is described providing plans by European and Italian communities with EGI and IGI