Nomenclature for renal replacement therapy and blood purification techniques in critically ill patients: practical applications

This article reports the conclusions of the second part of a consensus expert conference on the nomenclature of renal replacement therapy (RRT) techniques currently utilized to manage acute kidney injury and other organ dysfunction syndromes in critically ill patients. A multidisciplinary approach was taken to achieve harmonization of definitions, components, techniques, and operations of the extracorporeal therapies. The article describes the RRT techniques in detail with the relevant technology, procedures, and phases of treatment and key aspects of volume management/fluid balance in critically ill patients. In addition, the article describes recent developments in other extracorporeal therapies, including therapeutic plasma exchange, multiple organ support therapy, liver support, lung support, and blood purification in sepsis. This is a consensus report on nomenclature harmonization in extracorporeal blood purification therapies, such as hemofiltration, plasma exchange, multiple organ support therapies, and blood purification in sepsis

Progettazione strutturale di un ponte a sezione mista acciaio - calcestruzzo con sistema di isolamento

La presente tesi ha carattere prevalentemente progettuale, ponendosi l’onere di trattare nel dettaglio le problematiche realizzative di un’opera d’arte qual è un ponte autostradale di 1° categoria, attraversante lo Scolmatore Reno, costituito da tre campate per una lunghezza complessiva di 240 mt, composto da una sezione a cassone monocellulare mista acciaio – calcestruzzo, dotato di un sistema di isolamento sismico posto all’interfaccia tra la sovra / sotto struttura e ivi assoggettata a carichi statici e sismici. Visto il contesto territoriale / operativo, i vincoli progettuali, le richieste da parte della committenza e le normative tecniche di riferimento, la strada maestra seguita porterà ad analizzare compiutamente ogni elemento strutturale, applicando teorie, metodi e modelli comportamentali propri degli elementi monodimensionali, definendo una valutazione sismica tramite un’analisi statica lineare equivalente con spettro di risposta. Il percorso terminerà analizzando, interpretando e commentando i risultati ottenuti al fine di comprendere se le scelte costruttive siano consone al contesto progettuale, se i modelli siano attendibili nel rappresentare la realtà comportamentale e se le ipotesi (campo di validità dei risultati) siano ottemperate in relazione ad opportuni accorgimenti costruttivi

The Attentional Bottleneck: Constraints, Neural Correlates and Reward-Dependent Plasticity

Attraverso questa serie di esperimenti, abbiamo presentato i principali fattori per la selezione di target e definito le caratteristiche che consentono a un target di vincere la competizione per le risorse attenzionali. Abbiamo poi rivelato i correlati elettrofisiologici (ERP) del bottleneck attenzionale. In seguito abbiamo provocato cambiamenti durevoli, indotti da ricompensa, nella priorit\ue0 attenzionale di specifiche posizioni spaziali e rivelato un'interessante influenza di caratteristiche individuali nella modulazione della performance mediata dalla ricompensa. Inizialmente abbiamo rilevato un'influenza generale di posizione del target nell\u2019array, con migliori prestazioni per le posizioni pi\uf9 laterali, risultando in un\u2019anisotropia del campo visivo. Abbiamo poi osservato un effetto di posizione relativa dei target, ovvero un significativo vantaggio nella performance quando i target sono presentati nei due emicampi. Infine abbiamo dimostrato che la relativa forza competitiva di due posizioni target in una coppia \ue8 fortemente predetta sulla base della performance misurata nella condizione di target singolo per le date posizioni. Nel secondo esperimento, abbiamo misurato i potenziali evento-correlati (ERP) al fine di svelare i correlati neurali del bottleneck attenzionale. L\u2019N2pc non era modulata dal numero di target presentati, ma solo dal numero di target consciamente identificati, nonch\ue9 dalla loro relativa posizione spaziale. Inoltre abbiamo dimostrato che la migliore performance a livello comportamentale (corrispondente al riportare entrambi i target, rispetto a solo uno, nella condizione di doppio target) potrebbe essere spiegata da un precoce impegno attenzionale nella data prova. Infine abbiamo rivelato una suggestiva modulazione dell'ampiezza dell\u2019N2pc a seconda del numero di target individuati. Abbiamo poi studiato l'influenza di un protocollo di apprendimento mediato dalla ricompensa monetaria sulla priorit\ue0 attenzionale delle posizioni nello spazio. Attraverso l'utilizzo di un protocollo di training basato su di una ricompensa, siamo stati in grado di produrre cambiamenti duraturi nelle mappe di priorit\ue0, che sono responsabili di dirigere l'attenzione spaziale e di mediare la selezione di target. In particolare, posizioni spaziali associate ad un risultato positivo durante il training hanno acquisito una priorit\ue0 maggiore rispetto alle posizioni spaziali associate ad un risultato meno positivo. La variazione descritta nella priorit\ue0 attenzionale di posizioni specifiche \ue8 risultata evidente solo in presenza di una competizione tra target. \uc8 importante sottolineare che i cambiamenti osservati in termini di prestazioni sono stati misurati dopo quattro giorni dalla fase di training, probabilmente riflettendo cambiamenti plastici durevoli nelle mappe di priorit\ue0 spaziali. Infine, abbiamo indagato se l'entit\ue0 del bias attenzionale derivato dalla ricompensa potesse dipendere da specifici attributi individuali e tratti di personalit\ue0. Un'interessante influenza di alcuni tratti \ue8 apparsa influenzare le prestazioni durante la fase di training. Specificamente, differenze di prestazioni (in termini di precisione e di tempi di reazione) nel riportare un target presentato in una posizione altamente ricompensata e un target presentato in una posizione scarsamente ricompensata erano predette da fattori riguardanti il profilo dei soggetti. In particolare, abbiamo identificato due principali tratti individuali aventi un\u2019influenza sulle prestazioni, ovvero il sesso dei soggetti e il punteggio ottenuto nella sottoscala Drive della scala Behavioral Activation System. Complessivamente, questa ricerca offre risultati interessanti per quanto riguarda le basi comportamentali e neurali del bottleneck attenzionale. Inoltre, aggiunge nuovi critici elementi di prova nel campo dell'apprendimento attenzionale mediato dalla ricompensa, dimostrando che le mappe di priorit\ue0 spaziali possono andare incontro a durevoli cambiamenti plastici.Through this series of experiments, we unveiled major determinants in multiple target selection and defined which critical features allow a target to win competition for attentional resources. We then revealed the electrophysiological correlates (ERPs) of the attentional bottleneck. Moreover, we induced durable reward-based changes in the attentional priority of specific spatial locations, resulting in an imbalanced probability to identify a target in one or the other of two critical spatial locations in a pair, and revealed an interesting influence of individual traits affecting performance during the training session. In the first experiment, a series of critical elements were found to influence competition for attentional resources and allow a target to enter the attentional bottleneck. Firstly, an influence of target position within the stimulus array was revealed, with the best performance for the most lateralized positions, resulting in a visual anisotropy. We then observed an effect of targets\u2019 relative position, namely a significant advantage when the targets were displayed across hemifields. Eventually, we demonstrated that the relative competitive strength of two target locations in a pair can be predicted on the basis of performance measured in the single target condition for the given locations. In the second experiment, we measured the Event-Related Potentials (ERPs) in order to directly unveil neural correlates of the attentional bottleneck. Interestingly, a number of critical factors appeared to affect the occurrence and amplitude of the N2pc component. Specifically, the N2pc was not modulated by the number of presented targets, but only by the number of consciously identified targets, as well as by their relative spatial position. Furthermore, we demonstrated that the better performance at the behavioral level (corresponding to correctly reporting both targets vs. one in the double target condition) could be explained by an earlier attentional engagement in the given trial. Finally, we revealed a suggestive modulation of the amplitude of the N2pc waveform depending on the number of identified targets. We then investigated the influence of a reward-based learning protocol on the attentional priority of locations in space. Specifically, through the use of a reward-based training protocol, we were able to produce enduring changes in priority maps that are responsible for directing spatial attention and for arbitrating target selection. In particular, spatial locations associated with an overall more positive outcome during training were prioritized with respect to spatial locations associated with an overall less positive outcome. Importantly, the observed changes in performance were measured after a four-day delay from the training phase, likely reflecting durable plastic changes in spatial priority maps. Finally, we investigated whether the entity of the acquired reward-based attentional bias could depend on specific individual attributes and personality traits. An interesting influence of individual traits appeared to affect performance during training. Specifically, differences in performance (in terms of accuracy and of reaction times) between reporting a target displayed at an 80Hh position vs. a target displayed at a 20Lh position appeared to be predicted by a series of factors concerning participant profile. In particular, we identified two main individual traits having an influence on performance, namely gender and individual scores at the Drive subscale of the Behavioral Activation System scale. Altogether, this research contributes interesting results with respect to the behavioral and neural basis of the attentional bottleneck that characterizes spatial directed attention. Moreover, it adds critical new evidence in the field of reward-mediated attentional learning, demonstrating that spatial priority maps can encounter durable plastic changes

Reward-based plasticity of spatial priority maps: Exploiting inter-subject variability to probe the underlying neurobiology

Recent evidence indicates that the attentional priority of objects and locations is altered by the controlled delivery of reward, reflecting reward-based attentional learning. Here, we take an approach hinging on intersubject variability to probe the neurobiological bases of the reward-driven plasticity of spatial priority maps. Specifically, we ask whether an individual's susceptibility to the reward-based treatment can be accounted for by specific predictors, notably personality traits that are linked to reward processing (along with more general personality traits), but also gender. Using a visual search protocol, we show that when different target locations are associated with unequal reward probability, different priorities are acquired by the more rewarded relative to the less rewarded locations. However, while males exhibit the expected pattern of results, with greater priority for locations associated with higher reward, females show an opposite trend. Critically, both the extent and the direction of reward-based adjustments are further predicted by personality traits indexing reward sensitivity, indicating that not only male and female brains are differentially sensitive to reward, but also that specific personality traits further contribute to shaping their learning-dependent attentional plasticity. These results contribute to a better understanding of the neurobiology underlying reward-dependent attentional learning and cross-subject variability in this domain

Are Two Threats Worse Than One? the Effects of Face Race and Emotion On Fear Conditioning

Facial cues of racial outgroup or anger mediate fear learning that is resistant to extinction. Whether this resistance is potentiated if fear is conditioned to angry, other race faces has not been established. Two groups of Caucasian participants were conditioned with two happy and two angry face conditional stimuli (CSs). During acquisition, one happy and one angry face were paired with an aversive unconditional stimulus whereas the second happy and angry faces were presented alone. CS face race (Caucasian, African American) was varied between groups. During habituation, electrodermal responses were larger to angry faces regardless of race and declined less to other race faces. Extinction was immediate for Caucasian happy faces, delayed for angry faces regardless of race, and slowest for happy racial outgroup faces. Combining the facial cues of other race and anger does not enhance resistance to extinction of fear

Altering spatial priority maps via reward-based learning.

Spatial priority maps are real-time representations of the behavioral salience of locations in the visual field, resulting from the combined influence of stimulus driven activity and top-down signals related to the current goals of the individual. They arbitrate which of a number of (potential) targets in the visual scene will win the competition for attentional resources. As a result, deployment of visual attention to a specific spatial location is determined by the current peak of activation (corresponding to the highest behavioral salience) across the map. Here we report a behavioral study performed on healthy human volunteers, where we demonstrate that spatial priority maps can be shaped via reward-based learning, reflecting long-lasting alterations (biases) in the behavioral salience of specific spatial locations. These biases exert an especially strong influence on performance under conditions where multiple potential targets compete for selection, conferring competitive advantage to targets presented in spatial locations associated with greater reward during learning relative to targets presented in locations associated with lesser reward. Such acquired biases of spatial attention are persistent, are nonstrategic in nature, and generalize across stimuli and task contexts. These results suggest that reward-based attentional learning can induce plastic changes in spatial priority maps, endowing these representations with the "intelligent" capacity to learn from experience

Le strutture dell'Arsenale di Venezia. Studi e Restauri

The Venice Arsenal, with its 48 acres of extension and a history that goes back more than 800 years, is an extraordinary subject of study of constructive techniques and of experimentation in the development of restoration methods.The wooden covering systems in particular are the most precious example we have of almost 700 years of building technology, that was strictly linked to and influenced by the development of the naval shipbuilding industry. Since 1983 the Venice Superintendency has been working and investing many resources on a program of study of the Arsenal, concentrating above all on the roof\u2019s structures. An important occasion of testing the results of our study has been given by the restoration works on the wooden structures of the \u201ctesa\u201d of the Isolotto, built in the 14th century. These are the oldest structures of the whole building, and still maintain the original constructive characteristics. The text is a brief summary of the restoration works carried out on the trusses of the Isolotto and of the relative study to develop a model in the preservation, diagnostics and individuation of the wooden structures. The text also illustrates the level of knowledge of the constructive characteristics of the trusses of the whole building, the dendrochronologic studies carried out in the last 20 years and the first results of a research aimed at understanding the static-structural behaviour of the covering system