The Emotional Facet of Subjective and Neural Indices of Similarity.

Emotional similarity refers to the tendency to group stimuli together because they evoke the same feelings in us. The majority of research on similarity perception that has been conducted to date has focused on non-emotional stimuli. Different models have been proposed to explain how we represent semantic concepts, and judge the similarity among them. They are supported from behavioural and neural evidence, often combined by using Multivariate Pattern Analyses. By contrast, less is known about the cognitive and neural mechanisms underlying the judgement of similarity between real-life emotional experiences. This review summarizes the major findings, debates and limitations in the semantic similarity literature. They will serve as background to the emotional facet of similarity that will be the focus of this review. A multi-modal and overarching approach, which relates different levels of neuroscientific explanation (i.e., computational, algorithmic and implementation), would be the key to further unveil what makes emotional experiences similar to each other

Action understanding requires the left inferior frontal cortex.

Numerous studies have established that inferior frontal cortex is active when hand actions are planned, imagined, remembered, imitated, and even observed. Furthermore, it has been proposed that these activations reflect a process of simulating the observed action to allow it to be understood and thus fully perceived. However, direct evidence for a perceptual role for left inferior frontal cortex is rare, and linguistic or motor contributions to the reported activations have not been ruled out. We used repetitive transcranial magnetic stimulation (rTMS) over inferior frontal gyrus during a perceptual weight-judgement task to test the hypothesis that this region contributes to action understanding. rTMS at this site impaired judgments of the weight of a box lifted by a person, but not judgements of the weight of a bouncing ball or of stimulus duration, and rTMS at control sites had no impact. This demonstrates that the integrity of left inferior frontal gyrus is necessary to make accurate perceptual judgments about other people's actions

DEPLOYMENT OF NATIVE IP MULTICAST ROUTING SERVICES ON THE ITALIAN ACADEMIC AND RESEARCH NETWORK

In 1993 the GARR (Italian Academic and Research Network) was connected to MBONE (worldwide IP multicast enabled network backbone). Since then, and especially in the last few years, this network has been used to test and develop new IP multicast routing protocols and applications. However it was a tunnel-based solution, not suitable for taking advantage of the new potential of IP multicast nor for use by a large community. This paper describes the work done for a migration to a native IP multicast routing deployment, highlighting the solutions adopted when dealing with the implementation problems and the complex wide area network management. The aim of this work is also to ensure a native IP multicast connection with the other Research Networks and the rest of Internet

The role of the anterior temporal lobes in the comprehension of concrete and abstract words: rTMS evidence

Conceptual knowledge allows us to bring meaning to our world. Studies of semantic dementia (SD) patients and some functional neuroimaging studies indicate that the anterior temporal lobes, bilaterally, are a core neural substrate for the formation of conceptual representations. The majority of SD patients (who have circumscribed atrophy of the anterior temporal lobes) have better comprehension of concrete than abstract words. However, this finding remains controversial, as some individual SD patients have exhibited reverse imageability effects, i.e., relative preservation of abstract knowledge. This would imply that the anterior temporal lobes are particularly crucial for processing sensory aspects of semantic knowledge, which are an important part of concrete but not abstract concepts. To adjudicate on this debate, we used offline, low-frequency, repetitive transcranial magnetic stimulation to disrupt neural processing temporarily in the left or right temporal poles (TPs). We examined this effect using a synonym judgement task, comprising high, medium and low imageability items, which we have previously employed with a case-series of SD patients. The time required to make semantic decisions was slowed considerably, particularly for low imageability items, consistent with the pattern we observed in SD. These results confirm that both TPs make a critical contribution to semantic processing, even for abstract concepts that do not have strong sensory representations

Conceptual knowledge is underpinned by the temporal pole bilaterally: Convergent evidence from rTMS

Conceptual knowledge provides the basis on which we bring meaning to our world. Studies of semantic dementia patients and some functional neuroimaging studies indicate that the anterior temporal lobes, bilaterally, are the core neural substrate for the formation of semantic representations. This hypothesis remains controversial, however, as traditional neurological models of comprehension do not posit a role for these regions. To adjudicate on this debate, we conducted 2 novel experiments that used off-line, low-frequency, repetitive transcranial magnetic stimulation to disrupt neural processing temporarily in the left or right temporal poles (TPs). The time required to make semantic decisions was slowed considerably, yet specifically, by this procedure. The results confirm that both TPs form a critical substrate within the neural network that supports conceptual knowledge

INTRODUCING TRANSPARENT WEB CACHING IN A LOCAL AREA NETWORK

The term \u27transparent web caching\u27 refers to cache technology in which web traffic is automatically intercepted and redirected toward one or more cache servers. The redirection of web data can be accomplished using L4 switches or routers. Being completely transparent to the user (no browser configuration is required) the service can be easily implemented and turns out to be scalable and fail-safe. This work presents the results of our experimental use of transparent caching technology in a simple network environment. We focus on the impact this technique could have on network performance, with all its benefits and problems, as well as its effects on end users. The analysis is based on data gathered in an operative network during a two-month period

Rete GARR-B: Piano di routing IP multicast

The IP multicast was introduced in the GARR network (Italian Network for University and Scientific Community) in 1993 with the connection to Mbone (worldwide virtual multicast network). Since then the Italian Mbone developed constantly allowing the test of protocols and applications. Nevertheless the original Mbone structure is not suitable for an efficient utilization of multicast potentialities and advantages, preventing from exploiting all the services on a large scale; moreover it doesn\u27t allow an interconnection with those ISP which are enabling multicast in their networks but with different technical solutions. This document, after a description of the limits of the present Mbone on GARR, proposes the steps for an updating plane: - IP multicast implementation on the production routers of the backbone, using the PIM-SM protocol; - choice and configuration of the Rendez-Vous Points; - definition of IP multicast boundary routers; - bandwidth limitation; - inter-domain routing (MSDP and MBGP); - international multicast connections. The document deals with some of IP multicast management tools, as well.L\u27introduzione del multicast IP sulla rete GARR (Rete per l\u27Universit? e la Ricerca Scientifica Italiana) risale al 1993 con la prima connessione a Mbone (rete virtuale multicast mondiale). Da allora c\u27e\u27 stato un costante sviluppo sulla Mbone italiana che ha reso possibile la sperimentazione di protocolli e applicativi. Tuttavia la struttura originaria di Mbone non consente un utilizzo efficace delle potenzialita\u27 e dei vantaggi del multicast, precludendo la possibilita\u27 di sfruttarne appieno i servizi su larga scala; cosi\u27 come non consente l\u27interconnessione con quegli ISP che stanno gia\u27 abilitando le loro reti al multicast con soluzioni tecniche diverse. Questo documento, dopo una descrizione dei limiti dell\u27attuale Mbone sul GARR, ne propone le fasi necessarie per un piano di aggiornamento: - implementazione di IP multicast sulla dorsale sui router di produzione con protocollo PIM-SM; - scelta e configurazione dei Rendez-Vous Point; - definizione delle frontiere amministrative (boundary router); - limitazioni di banda; - inter-domain routing (MSDP e MBGP); - connessioni multicast internazionali. Il documento contiene anche un accenno ad alcuni degli strumenti utilizzabili per la gestione dell?IP multicast