The influence of non-imaging detector design on heralded ghost-imaging and ghost-diffraction examined using a triggered ICCD came

Ghost imaging and ghost diffraction can be realized by using the spatial correlations between signal and idler photons produced by spontaneous parametric down-conversion. If an object is placed in the signal (idler) path, the spatial correlations between the transmitted photons as measured by a single, non-imaging, “bucket” detector and a scanning detector placed in the idler (signal) path can reveal either the image or diffraction pattern of the object, whereas neither detector signal on its own can. The details of the bucket detector, such as its collection area and numerical aperture, set the number of transverse modes supported by the system. For ghost imaging these details are less important, affecting mostly the sampling time required to produce the image. For ghost diffraction, however, the bucket detector must be filtered to a single, spatially coherent mode. We examine this difference in behavour by using either a multi-mode or single-mode fibre to define the detection aperture. Furthermore, instead of a scanning detector we use a heralded camera so that the image or diffraction pattern produced can be measured across the full field of view. The importance of a single mode detection in the observation of ghost diffraction is equivalent to the need within a classical diffraction experiment to illuminate the aperture with a spatially coherent mode

Ruptures and repairs of group therapy alliance. an untold story in psychotherapy research

Although previous studies investigated the characteristics of therapeutic alliance in group treatments, there is still a dearth of research on group alliance ruptures and repairs. The model by Safran and Muran was originally developed to address therapeutic alliance in individual therapies, and the usefulness of this approach to group intervention needs to be demonstrated. Alliance ruptures are possible at member to therapist, member to member, member to group levels. Moreover, repairs of ruptures in group are quite complex, i.e., because other group members have to process the rupture even if not directly involved. The aim of the current study is to review the empirical research on group alliance, and to examine whether the rupture repair model can be a suitable framework for clinical understanding and research of the complexity of therapeutic alliance in group treatments. We provide clinical vignettes and commentary to illustrate theoretical and research aspects of therapeutic alliance rupture and repair in groups. Our colleague Jeremy Safran made a substantial contribution to research on therapeutic alliance, and the current paper illustrates the enduring legacy of this work and its potential application to the group therapy context

Intense myocyte formation from cardiac stem cells in human cardiac hypertrophy

It is generally believed that increase in adult contractile cardiac mass can be accomplished only by hypertrophy of existing myocytes. Documentation of myocardial regeneration in acute stress has challenged this dogma and led to the proposition that myocyte renewal is fundamental to cardiac homeostasis. Here we report that in human aortic stenosis, increased cardiac mass results from a combination of myocyte hypertrophy and hyperplasia. Intense new myocyte formation results from the differentiation of stem-like cells committed to the myocyte lineage. These cells express stem cell markers and telomerase. Their number increased >13-fold in aortic stenosis. The finding of cell clusters with stem cells making the transition to cardiogenic and myocyte precursors, as well as very primitive myocytes that turn into terminally differentiated myocytes, provides a link between cardiac stem cells and myocyte differentiation. Growth and differentiation of these primitive cells was markedly enhanced in hypertrophy, consistent with activation of a restricted number of stem cells that, through symmetrical cell division, generate asynchronously differentiating progeny. These clusters strongly support the existence of cardiac stem cells that amplify and commit to the myocyte lineage in response to increased workload. Their presence is consistent with the notion that myocyte hyperplasia significantly contributes to cardiac hypertrophy and accounts for the subpopulation of cycling myocytes

Imaging high-dimensional spatial entanglement with a camera

The light produced by parametric down-conversion shows strong spatial entanglement that leads to violations of EPR criteria for separability. Historically, such studies have been performed by scanning a single-element, single-photon detector across a detection plane. Here we show that modern electron-multiplying charge-coupled device cameras can measure correlations in both position and momentum across a multi-pixel field of view. This capability allows us to observe entanglement of around 2,500 spatial states and demonstrate Einstein-Podolsky-Rosen type correlations by more than two orders of magnitude. More generally, our work shows that cameras can lead to important new capabilities in quantum optics and quantum information science.Comment: 5 pages, 4 figure

DebtRank: Too central to fail? Financial networks, the FED and systemic risk

Systemic risk, here meant as the risk of default of a large portion of the financial system, depends on the network of financial exposures among institutions. However, there is no widely accepted methodology to determine the systemically important nodes in a network. To fill this gap, we introduce, DebtRank, a novel measure of systemic impact inspired by feedback-centrality. As an application, we analyse a new and unique dataset on the USD 1.2 trillion FED emergency loans program to global financial institutions during 2008g-2010. We find that a group of 22 institutions, which received most of the funds, form a strongly connected graph where each of the nodes becomes systemically important at the peak of the crisis. Moreover, a systemic default could have been triggered even by small dispersed shocks. The results suggest that the debate on too-big-to-fail institutions should include the even more serious issue of too-central-to-fail

Finanziare le infrastrutture : storia, innovazioni e teoria dalle "vie" romane al partenariato pubblico privato

La questione del finanziamento delle infrastrutture, da sempre centrale nell\u2019 agenda di ogni societ\ue0, risulta ad oggi ancora largamente inesplorata dal punto di vista storico. Questo volume ne propone quindi una ricostruzione di lungo periodo, ripercorrendo le modalit\ue0 attraverso cui si sono trovate e organizzate le risorse per costruire e gestire le infrastrutture in Europa dal medioevo ai giorni nostri. Dopo avere individuato nell\u2019et\ue0 romana l\u2019origine di due vie ancora oggi alla base della loro realizzazione e gestione (vale a dire la distribuzione dei costi sui frontisti e il principio del pay as you use), gli autori analizzano le specificit\ue0 dei contesti storici e degli attori coinvolti facendo emergere i diversi equilibri istituzionali da cui le varie soluzioni \u2013 tasse di scopo, debito pubblico e privato, equity-based finance, e partenariato pubblico privato \u2013 sono emerse nel corso dei secoli. Le molteplici forme di finanziamento sono poi riassunte in una tavola sinottica che ne rende chiaramente visibile l\u2019ordine d\u2019apparizione e la localizzazione, cos\uec come la coesistenza. Questa storia ci insegna infatti che, contrariamente a quanto spesso si sostiene, \ue8 impossibile identificare un modello unico che in ogni tempo e in ogni luogo si sia dimostrato superiore in termini di sostenibilit\ue0, crescita e ricaduta sociale; ci indica che le diverse combinazioni dei fattori istituzionali, tecnologici ed economici hanno dato origine a path-dependences spesso ignorate e invece cruciali nel determinare il successo o il fallimento di una soluzione; e ci suggerisce, infine, che il riferimento al passato deve essere visto come un richiamo alla realt\ue0, che evidenzia la complessit\ue0 di ci\uf2 che \ue8 stato e di ci\uf2 che \ue8, e ci fa capire il campo delle possibili soluzioni che si aprono in ogni determinato momento. Ad una di queste - che vanta radici molto lontane nel tempo - il partenariato pubblico privato \ue8 dedicata la seconda parte del volume, che ne affronta in maniera specifica e articolata gli aspetti teorici, normativi e operativi

Impact of perceived stress and immune status on decision-making abilities during COVID-19 pandemic lockdown

The ability to make risky decisions in stressful contexts has been largely investigated in experimental settings. We examined this ability during the first months of COVID-19 pandemic, when in Italy people were exposed to a prolonged stress condition, mainly caused by a rigid lockdown. Participants among the general population completed two cognitive tasks, an Iowa Gambling Task (IGT), which measures individual risk/reward decision-making tendencies, and a Go/No-Go task (GNG), to test impulsivity, together with two questionnaires, the Perceived Stress Scale and the Depression, Anxiety and Stress Scales. The Immune Status Questionnaire was additionally administered to explore the impact of the individual health status on decision making. The effect of the questionnaires scores on task performance was examined. The results showed that higher levels of perceived stress and a more self-reported vulnerable immune status were associated, separately, with less risky/more advantageous choices in the IGT in young male participants but with more risky/less advantageous choices in older male participants. These effects were not found in female participants. Impulsivity errors in the GNG were associated with more anxiety symptoms. These findings bring attention to the necessity of taking into account decision-making processes during stressful conditions, especially in the older and more physically vulnerable male population