731 research outputs found
The World According to De Finetti
No full textBruno de Finetti is one of the founding fathers of the subjectivist school of probability, where probabilities are interpreted as rational degrees of belief. His work on the relation between the theorems of probability and rationality is among the corner stones of modern subjective probability theory. De Finetti maintained that rationality requires that degrees of belief be coherent, and he argued that the whole of probability theory could be derived from these coherence conditions. De Finetti’s interpretation of probability has been highly influential in science. This paper focuses on the application of this interpretation to quantum mechanics. We argue that de Finetti held that the coherence conditions of degrees of belief in events depend on their verifiability. Accordingly, the standard coherence conditions of degrees of belief that are familiar from the literature on subjective probability only apply to degrees of belief in events which could (in principle) be jointly verified; and the coherence conditions of degrees of belief in events that cannot be jointly verified are weaker. While the most obvious explanation of de Finetti’s verificationism is the influence of positivism, we argue that it could be motivated by the radical subjectivist and instrumental nature of probability in his interpretation; for as it turns out, in this interpretation it is difficult to make sense of the idea of coherent degrees of belief in, and accordingly probabilities of unverifiable events. We then consider the application of this interpretation to quantum mechanics, concentrating on the Einstein-Podolsky-Rosen experiment and Bell’s theorem
Symmetry of evidence without evidence of symmetry
No full textThe de Finetti Theorem is a cornerstone of the Bayesian approach. Bernardo (1996) writes that its "message is very clear: if a sequence of observations is judged to be exchangeable, then any subset of them must be regarded as a random sample from some model, and there exists a prior distribution on the parameter of such model, hence requiring a Bayesian approach." We argue that while exchangeability, interpreted as symmetry of evidence, is a weak assumption, when combined with subjective expected utility theory, it implies also complete confidence that experiments are identical. When evidence is sparse, and there is little evidence of symmetry, this implication of de Finetti's hypotheses is not intuitive. This motivates our adoption of multiple-priors utility as the benchmark model of preference. We provide two alternative generalizations of the de Finetti Theorem for this framework. A model of updating is also provided.Ambiguity, exchangeability, symmetry, updating, learning, multiple-priors
Emerging Roles of the Intraflagellar Transport System in the Orchestration of Cellular Degradation Pathways
No full textCiliated cells exploit a specific transport system, the intraflagellar transport (IFT) system, to ensure the traffic of molecules from the cell body to the cilium. However, it is now clear that IFT activity is not restricted to cilia-related functions. This is strikingly exemplified by the observation that IFT proteins play important roles in cells lacking a primary cilium, such as lymphocytes. Indeed, in T cells the IFT system regulates the polarized transport of endosome-associated T cell antigen receptors and signaling mediators during assembly of the immune synapse, a specialized interface that forms on encounter with a cognate antigen presenting cell and on which T cell activation and effector function crucially depend. Cellular degradation pathways have recently emerged as new extraciliary functions of the IFT system. IFT proteins have been demonstrated to regulate autophagy in ciliated cells through their ability to recruit the autophagy machinery to the base of the cilium. We have now implicated the IFT component IFT20 in another central degradation process that also controls the latest steps in autophagy, namely lysosome function, by regulating the cation-independent mannose-6-phosphate receptor (CI-MPR)-dependent lysosomal targeting of acid hydrolases. This involves the ability of IFT20 to act as an adaptor coupling the CI-MPR to dynein for retrograde transport to the trans-Golgi network. In this short review we will discuss the emerging roles of IFT proteins in cellular degradation pathways
“L’ospedale cresce con noi”. Luoghi di cura a misura di bambino nell’immaginario dei minori
No full textNonostante il crescente interesse per l’umanizzazione dei servizi l’ospedale soffre ancora di una parziale marginalità nella riflessione pedagogica. Dopo un’introduzione teorica sulle principali tematiche legate all’ospedalizzazione dei minori, questo lavoro dà voce a bambini e adolescenti in qualità di soggetti attivi e competenti in grado di suggerire risposte alle questioni che li riguardano e spunti utili anche per il mondo adulto. Lo studio è frutto dell’analisi di 3560 elaborati di minori del territorio piacentino, raccolti nel primo trimestre dell’anno 2014 grazie al progetto “L’ospedale cresce con noi”, propedeutico alla riprogettazione degli spazi ospedalieri. I contenuti emersi dagli elaborati sono stati analizzati e presentati seguendo le categorie fenomenologiche di spazio vissuto, corpo vissuto, tempo vissuto, la relazione di cura, esperienza vissuta: tra soggettività ed emozioni, narrare e narrarsi: alla ricerca di un senso. Si delineano direzioni interdisciplinari utili alla realizzazione di un ospedale che sia realmente amico dei minori, seguendo il loro autentico desiderio e immaginario, un vero contesto educativo in cui la malattia può essere affrontata come esperienza evolutiva e opportunità di crescita. Un progetto locale viene pertanto presentato come possibile apripista per nuovi percorsi di senso e valorizzazione esistenziale all’interno e all’esterno degli ospedali, nell’ottica di una solida cultura preventiva applicabile sia ai minori che agli adulti.Despite growing interest in the humanization of services, hospitals still suffer from partial marginality in pedagogical studies. After a theoretical introduction on the main themes related to the hospitalization of minors, this paper gives voice to children and adolescents as active and competent subjects able to propose answers to the questions that concern them and also useful suggestions for the adult world. This study is the result of the analysis of 3,560 contributions by minors, including papers, drawings and models, collected in the Piacenza area in the first quarter of the year 2014 as part of the project “L’ospedale cresce con noi” (the hospital grows with us), preparatory to the redesign of hospital spaces. These works were analyzed and presented according to phenomenological categories of lived space, lived body, lived time, care relationship, lived experience. The range covered subjectivity and emotions, narrating and narrating oneself in search of meaning. In line with the authentic desire and imagination expressed by the minors, interdisciplinary directions are outlined for the realization of a truly minor-friendly hospital, an educational context in which patients can experience disease as growth opportunity. A local project is therefore presented as a possible forerunner of new paths of meaning and existential enhancement inside and outside hospitals, with a view to a solid preventive culture for both children and adults
Sguardi internazionali sulla povertà educativa
No full textIl presente articolo esplora la multifattorialità del fenomeno dell’educational poverty fondandosi su una revisione della letteratura effettuata in database generalisti e socio-psico-pedagogici e sul dialogo con esperti internazionali. Cosa si intende con educational poverty? Ci sono nessi con il recente costrutto italiano di povertà educativa? Dapprincipio si rileva che il sintagma “educational poverty” sia perlopiù traducibile con “povertà di istruzione” e successivamente si riflette sui contesti ove ricorre e sulle componenti semantiche. Senza pretese di esaustività, sono presentati scenari in
cui si fa uso del costrutto, soffermandosi sulle aree di senso che ampliano gli orizzonti oltre la mera povertà di istruzione e sulle direzioni per prevenire e contrastare il fenomeno correlato.International Views on Educational Poverty. This paper explores the multifactorial nature of the educational poverty phenomenon founding on a literature review carried out in generalist and socio-psycho-pedagogical databases and on dialogues with international experts. What is meant by educational poverty? Are there links with the recent Italian construct of povertà educativa? Initially, it is noted that the phrase “educational poverty” usually corresponds to the Italian “povertà di istruzione” and subsequently one reflects on the contexts where it occurs and on its semantic components. Without claiming to be exhaustive, the author presents scenarios in which the construct is used, focusing on the areas of meaning that broaden the horizons beyond the mere “povertà di istruzione” and on directions to prevent and fight the related phenomenon
Sguardi internazionali sulla povertà educativa
No full textIl presente articolo esplora la multifattorialità del fenomeno dell’educational poverty fondandosi su una revisione della letteratura effettuata in database generalisti e socio-psico-pedagogici e sul dialogo con esperti internazionali. Cosa si intende con educational poverty? Ci sono nessi con il recente costrutto italiano di povertà educativa? Dapprincipio si rileva che il sintagma “educational poverty” sia perlopiù traducibile con “povertà di istruzione” e successivamente si riflette sui contesti ove ricorre e sulle componenti semantiche. Senza pretese di esaustività, sono presentati scenari in cui si fa uso del costrutto, soffermandosi sulle aree di senso che ampliano gli orizzonti oltre la mera povertà di istruzione e sulle direzioni per prevenire e contrastare il fenomeno correlato.International Views on Educational Poverty.
This paper explores the multifactorial nature of the educational poverty phenomenon founding on a literature review carried out in generalist and socio-psycho-pedagogical databases and on dialogues with international experts. What is meant by educational poverty? Are there links with the recent Italian construct of povertà educativa? Initially, it is noted that the phrase “educational poverty” usually corresponds to the Italian “povertà di istruzione” and subsequently one reflects on the contexts where it occurs and on its semantic components. Without claiming to be exhaustive, the author presents scenarios in which the construct is used, focusing on the areas of meaning that broaden the horizons beyond the mere “povertà di istruzione” and on directions to prevent and fight the related phenomenon
SU(p,q) coherent states and Gaussian de Finetti theorems
No full textInternational audienceWe prove a generalization of the quantum de Finetti theorem when the local space is an infinite-dimensional Fock space. In particular, instead of considering the action of the permutation group on n copies of that space, we consider the action of the unitary group U(n) on the creation operators of the n modes and define a natural generalization of the symmetric subspace as the space of states invariant under unitaries in U(n). Our first result is a complete characterization of this subspace, which turns out to be spanned by a family of generalized coherent states related to the special unitary group SU(p,q) of signature (p,q). More precisely, this construction yields a unitary representation of the noncompact simple real Lie group SU(p,q). We therefore find a dual unitary representation of the pair of groups U(n) and SU(p,q) on an n(p+q)-mode Fock space.The (Gaussian) SU(p,q) coherent states resolve the identity on the symmetric subspace, which implies a Gaussian de Finetti theorem stating that tracing over a few modes of a unitary-invariant state yields a state close to a mixture of Gaussian states. As an application of this de Finetti theorem, we show that the n×n upper-left submatrix of an n×n Haar-invariant unitary matrix is close in total variation distance to a matrix of independent normal variables if n3=O(m)
USE OF HYPERBARIC PRILOCAINE IN AMBULATORY SURGERY
No full textUSE OF HYPERBARIC PRILOCAINE IN AMBULATORY SURGERY
F. Troisi, A. Ferrara, P. Merlin, F. Sacco, E. Finetti, S. Collini
Anestesia e Ranimazione, Az Ospedaliera S Andrea, Roma, Italy
Background and aims: Data on prilocaine use for ambulatory intrathecal anaesthesia are limited. In this randomized study we compared 2% hyperbaric prilocaine and sufentanil with 2% hyperbaric bupivacaine and sufentanil for spinal anesthesia in outpatients undergoing elective anorectal surgery without increasing side - effects or delaying.
Methods: Patients ASA I-III were randomly allocated to receive 30mg hyperbaric prilocaine plus 5 microg sufentanyl (group PS,n=20) or 10 mg hyperbaric bupivacaine plus 5 microg sufentanyl (group BS, n=20) in sitting position. After sitting for 3 min (group PS) and 10 min (group BS), patients were positioned for surgery. Written informed consent was obtained from all subjects.
Results: There were no significant differences in intraoperative outcomes (hypotension, bradycardia, respirator depression) but mean recovery, discharge time, postoperative pain and urinary retention were significantly shorter in group PS.
Conclusions: This study demonstrates the superiority of the combination of low-dose hyperbaric prilocaine and sufenatnyl for spinal anaesthesia in ambulatory anorectal surgery. It is an excellent alternative to bupivacain because of faster attainment and resolution block, greater haemodynamic stability, earlier deambulation, reduced risk of urinary retention and early patients discharge.
Assigned speakers:
Dr. Fabiana Troisi, Az Ospedaliera S Andrea , Roma , Italy
Assigned in sessions:
06.09.2012, 08:00-18:30, Posters for Electronic Viewing, Posters for Electronic Viewing, Poster Area
07.09.2012, 08:00-18:30, Posters for Electronic Viewing, Posters for Electronic Viewing, Poster Are
Scanning tunneling microscopy and photoemission studies of self-organised Ag nanostructures on the N-modified Cu(001) surface
No full textThere has been a strong interest in methods of creating nanometer scale structures and in particular forming one and two-dimensional electron confinement structures. Self -organisation has been recognised as a promising way for growing large nanostructure domains with sufficiently regular size and spacing as required for the observation of quantum well states. We investigated the electronic properties and the morphology of Ag nano structures on c(2 x 2)-N/Cu(001) surface. This system is an example of epitaxial growth confined on nanoscale regions due to the occurrence of an adsorbate induced reconstruction. Using a combination of Scanning Tunneling Microscopy and Angle Resolved Photoemission Spectroscopy techniques we were able to determine the morphology and the growth mode of Ag on N -modified Cu(001) surface and the occurrence of quantum size effects in the electron properties of Ag nanostripes and nanoislands, evidenced in the observation of quantum well states
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