305,419 research outputs found
Le opere del Filosofo Anepigrafo tra alchimia, neoplatonismo e filosofia naturale: edizione critica, traduzione e commento
No full textLa tesi è dedicata al Filosofo Anepigrafo, autore tràdito all’interno del corpus alchemico greco, ed è organizzata in tre sezioni, fra loro distinte ma strettamente comunicanti. La prima parte è dedicata allo studio della tradizione manoscritta del corpus. I testimoni sono analizzati da un duplice punto di vista: da un lato paleografico e codicologico, dall’altro in un’ottica di storia della scienze e delle idee, e dunque della ricezione materiale dei testi negli ambienti eruditi di epoca bizantina e poi rinascimentale. Apre la sezione una recensio di tutti i testimoni che tramandano opere attribuite all’autore; segue una serie di studi su alcuni punti individuati come salienti nella storia della trasmissione in un periodo compreso fra il X e il XVII secolo. La seconda parte è consacrata allo studio filologico della tradizione e comprende l’edizione critica, con traduzione italiana, delle tre opere all’autore. Lo studio dei rapporti fra i manoscritti, oltre a determinare i codici utili per la constitutio textus, ha permesso di evidenziare il carattere “fluido” della tradizione e al contempo di identificare sufficienti elementi per tracciare, per la prima volta, uno stemma codicum della trasmissione testuale di un autore del corpus alchemico. Chiude la sezione un commento filologico-testuale ai principali loci critici. La terza parte è configurata come una serie di saggi critici di carattere storico-filosofico al fine di riconoscere l’identità dell’autore, le sue influenze e il milieu in cui operò. Egli è identificato come un filosofo neoplatonico di VII/VIII secolo, la cui dottrina si configura come un’originale propaggine della metafisica della natura di matrice soprattutto procliana. Le conclusioni indagano ulteriormente il proposto Sitz im Leben dell’Anepigrafo, avanzando l’ipotesi dell’esistenza di una “chimica metafisica” sviluppatasi a partire dalla metafisica della natura neoplatonica, ed evidenziano l’inadeguatezza della corrente narratio vulgata sulla trasmissione del sapere filosofico e scientifico a questa altezza cronologica
To stay or to go? Paired associative stimulation highlights state-dependent causal interactions from right IFG to left M1 during a Go/NoGo task
No full textMotor inhibition requires suppressing inappropriate motor responses. Studies suggest that during motor inhibition tasks (e.g., Go/NoGo Task) the right inferior frontal gyrus (rIFG) exerts an indirect influence over the primary motor cortex (M1) via a cortico-subcortical route encompassing the basal ganglia. Here, we sought to investigate whether strengthening a direct cortico-cortical rIFG-to-M1 route affects behavioural and electrophysiological indices of motor inhibition. We used transcranial magnetic stimulation (TMS) to record motor-evoked potentials (MEPs) to left M1 (lM1) stimulation; and induce associative plasticity of the rIFG-lM1 pathway using cortico-cortical Paired Associative Stimulation (ccPAS). Motor inhibition was assessed with a Go/NoGo task. In 2 days/sessions, 28 healthy humans received a ccPAS protocol aimed either at strengthening (ccPASrIFG-M1) the rIFG-to-lM1 pathway and a control protocol (ccPASM1-rIFG). In each session, participants performed a simple Go/NoGo task before, immediately after and 30 minutes after the ccPAS. MEPs to single- (M1) and dual-coil TMS (rIFG-M1) during observation of Go and NoGo stimuli were recorded before and after ccPAS. Participants were divided into two groups: ccPAS-responding, i.e., displaying “online” MEP changes already during ccPASrIFG-M1 administration, and non ccPAS-responding. Both groups showed similar increase of commission errors, reduction of omission errors, and reduced response times, irrespective of the ccPAS session. Concerning the neurophysiological results, ccPASrIFG-M1 induced distinct changes of rIFG-lM1 interactions during Go and NoGo trials: relative to single-pulse MEPs, dual-coil MEPs were enhanced in Go trials and suppressed in NoGo trials. This effect was significant only in ccPAS-responding participants. The ccPASM1-rIFG protocol did not affect MEP amplitudes. These findings show that enhancing rIFG-to-lM1 connectivity in ccPAS-responding participants, results in an enhanced state-dependent causal influence of rIFG over lM1, dynamically shifting from facilitatory to inhibitory depending on task demands. Therefore, while prior work has shown that the cortico-subcortical rIFG-to-lM1 route is selective for motor inhibition, here we show that the cortico-cortical rIFG-to-lM1 route is functionally malleable by ccPAS, subject to interindividual differences in sensitivity to ccPAS and flexibly modulated according to learned visuo-motor associations. By driving associative plasticity into the rIFG-to-lM1 network, we induced task-dependent modulations of rIFG-lM1 interactions only in ccPAS-responding participants, calling for the need of personalized brain stimulation approaches: future research should elucidate which factors contribute to interindividual variability and how to optimize stimulation protocols. Finally, we provide novel insights into the malleability and modulatory role of the cortico-cortical route connecting rIFG to lM1 as a flexible state-dependent neural circuit
Probabilistic topic models for sequence data
No full textProbabilistic topic models are widely used in different contexts to uncover the hidden structure in large text corpora. One of the main (and perhaps strong) assumption of these models is that generative process follows a bag-of-words assumption, i.e. each token is independent from the previous one. We extend the popular Latent Dirichlet Allocation model by exploiting three different conditional Markovian assumptions: (i) the token generation depends on the current topic and on the previous token; (ii) the topic associated with each observation depends on topic associated with the previous one; (iii) the token generation depends on the current and previous topic. For each of these modeling assumptions we present a Gibbs Sampling procedure for parameter estimation. Experimental evaluation over real-word data shows the performance advantages, in terms of recall and precision, of the sequence-modeling approaches. © 2013 The Author(s)
Speaking with Emotions
No full textWe aim at the realization of an Embodied Conversational Agent able to interact naturally and emotionally with user(s). In previous work, we have elaborated a model that computes the nonverbal behaviors associated to a given set of communicative functions. Specifying for a given emotion, its corresponding facial expression will not produce the sensation of expressivity. To do so, one needs to specify parameters such as intensity, tension, movement property. Moreover, emotion affects also lip shapes during speech. Simply adding the facial expression of emotion to the lip shape does not produce lip readable movement. In this paper we present a model that adds expressivity to the animation of an agent at the level of facial expression as well as of the lip shape
Una nuova visione sulla relazione tra massa e metallicità stellare in galassie quiescenti: effetto delle abbondanze chimiche, della storia di formazione stellare ed dell'evoluzione in redshift
No full textThe star formation history of galaxies can be reconstructed from the properties of their stellar populations, like their age and metallicity. Observations of nearby quiescent, early-type galaxies (ETGs) picture a downsizing scenario, where the stellar content of the most massive ones formed early on, in a short and intense stellar burst, while that in lower-mass ETGs formed later on and over longer timescales. While the downsizing reflects a statistical probability of their formation, ETGs actually assembled their mass following different paths. The average trends, upon which current galaxy formation models are built, can then be limiting in describing the overall formation history of ETGs. Further, nearby galaxies are affected by cosmic evolution effects, like mergers and gas accretion, contaminating their observed properties and blurring the actual trends. To mitigate this effect, in this work, I study the stellar population properties of a large sample of quiescent ETGs at redshift 0.6 ≤ z ≤ 1. In particular, I propose a different outlook on the mass-metallicity relation by probing the existence of a flat upper limit to metallicity, and a lower limit that depends on the mass, and I study the effect of the SFH and redshift evolution. Finally, I present the spectral analysis of a massive quiescent galaxy observed with JWST at z ∼ 2, allowing, for the first time, to simulatenously measure the optical and NIR galaxy spectrum outside the local Universe.The star formation history of galaxies can be reconstructed from the properties of their stellar populations, like their age and metallicity. Observations of nearby quiescent, early-type galaxies (ETGs) picture a downsizing scenario, where the stellar content of the most massive ones formed early on, in a short and intense stellar burst, while that in lower-mass ETGs formed later on and over longer timescales. While the downsizing reflects a statistical probability of their formation, ETGs actually assembled their mass following different paths. The average trends, upon which current galaxy formation models are built, can then be limiting in describing the overall formation history of ETGs. Further, nearby galaxies are affected by cosmic evolution effects, like mergers and gas accretion, contaminating their observed properties and blurring the actual trends. To mitigate this effect, in this work, I study the stellar population properties of a large sample of quiescent ETGs at redshift 0.6 ≤ z ≤ 1. In particular, I propose a different outlook on the mass-metallicity relation by probing the existence of a flat upper limit to metallicity, and a lower limit that depends on the mass, and I study the effect of the SFH and redshift evolution. Finally, I present the spectral analysis of a massive quiescent galaxy observed with JWST at z ∼ 2, allowing, for the first time, to simulatenously measure the optical and NIR galaxy spectrum outside the local Universe
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
INFILTRAZIONI INTRADETRUSORIALI DI ONABOTULINUMTOXINA IN PAZIENTI AFFETTI DA SINDROME DELLA VESCICA IPERATTIVA: BEST- PRACTICE MANAGEMENT
No full textAim of the study L’obiettivo dello studio è stata la valutazione dei diversi protocolli di trattamento con infiltrazione intradetrusoriale di Onabotulinumtossina A in pazienti affetti da vescica iperattiva (OAB) refrattaria ai comuni anticolinergici. Materials and methods 87 pazienti di entrambi i sessi, di età superiore a 18 anni, affetti da OAB con o senza incontinenza urinaria, sono stati trattati con infiltrazioni intradetrusoriali di Onabot/A in regime di ricovero o in regime ambulatoriale. E’ stata valutata la durata della degenza ospedaliera e della permanenza in ambulatorio per l’espletamento della procedura, la frequenza della cateterizzazione post-infiltrazione, delle complicanze pre e post- operatorie e il grado di soddisfazione al trattamento (VAS al trattamento). I pazienti sono stati valutati prima e 15 giorni dopo il trattamento mediante compilazione del diario minzionale di 3 giorni consecutivi, uroflussometria con valutazione del residuo post- minzionale (RPM) e VAS sull’impatto dei sintomi urinari sulla qualità della vita (QoL). Results Riportiamo i risultati di 64 pazienti (59 donne e 5 uomini) sottoposti ad almeno due infiltrazioni consecutive di Onabot/A. 21 pazienti sono stati trattati in regime di ricovero ordinario e sottoposti ad infiltrazione con l’uso di anestesia generale; 43 pazienti sono stati trattati in regime ambulatoriale con anestesia locale. Nei pazienti trattati in regime di ricovero, la durata media di degenza e di cateterizzazione è stata rispettivamente 39.4±12.6 e 37.8±10.6 ore; i punteggi medi della VAS alla soddisfazione al trattamento e della VAS sull’impatto dei sintomi urinari sulla QoL sono stati 6.3±1.1 e 8.2±1.3. Il valore medio del RPM è stato 74.3±15.2 ml. La frequenza di infezioni urinarie (IVU), valutata nei sei mesi successivi al trattamento, è stata 2.4±1.6. Nei pazienti trattati ambulatorialmente, la durata media di cateterizzazione, di permanenza in ambulatorio e la frequenza media di IVU sono state inferiori a quelle dei pazienti trattati in regime di ricovero. In questo gruppo di pazienti, i valori medi della VAS al trattamento e della VAS sulla QoL sono stati .....rispettivamente. Discussion ll nostro studio dimostra che l’infiltrazione intradetrusoriale di Onabot/A è una procedura semplice eseguibile in regime ambulatoriale con l'uso di anestesia locale. La frequenza di IVU successiva al trattamento è risultata bassa rispetto ad altri studi. In nessun paziente è stato necessario ricorrere al cateterismo intermittente. Tali risultati possono essere dovuti all'impiego di una bassa dose di Onabot/A sin dall'inizio del trattamento. Conclusions L’infiltrazione intradetrusoriale di Onabot/A in pazienti affetti da OAB refrattaria è una semplice e ripetibile procedura, eseguibile in ambulatorio mediante anestesia locale. Rare sono le complicanze intra e post- operatorie. Tali risultati sono dovuti all’acquisizione di una maggiore esperienza nel tempo insieme con la disponibilità di un centro urologico dedicato a questa tipologia di pazienti
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The so-called "De generatione hominis" by Splenios: remarks on a Greek peculiar embryological treatise
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