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Integrating reinforcement learning, equilibrium points and minimum variance to understand the development of reaching: a computational model
Get PDFDespite the huge literature on reaching behaviour we still lack a clear idea about the motor control processes underlying its development in infants. This article contributes to overcome this gap by proposing a computational model based on three key hypotheses: (a) trial-anderror learning processes drive the progressive development of reaching; (b) the control of the movements based on equilibrium points allows the model to quickly find the initial approximate solution to the problem of gaining contact with the target objects; (c) the request of precision of the end-movement in the presence of muscular noise drives the progressive refinement of the reaching behaviour. The tests of the model, based on a two degrees of freedom simulated dynamical arm, show that it is capable of reproducing a large number of empirical findings, most deriving from longitudinal studies with children: the developmental trajectory of several dynamical and kinematic variables of reaching movements, the time evolution of submovements composing reaching, the progressive development of a bell-shaped speed profile, and the evolution of the management of redundant degrees of freedom. The model also produces testable predictions on several of these phenomena. Most of these empirical data have never been investigated by previous computational models and, more importantly, have never been accounted for by a unique model. In this respect, the analysis of the model functioning reveals that all these results are ultimately explained, sometimes in unexpected ways, by the same developmental trajectory emerging from the interplay of the three mentioned hypotheses: the model first quickly learns to perform coarse movements that assure a contact of the hand with the target (an achievement with great adaptive value), and then slowly refines the detailed control of the dynamical aspects of movement to increase accuracy
The Norm-Signaling Effects of Group Punishment: Combining Agent-Based Simulation and Laboratory Experiments
No full textPunishment plays a crucial role in favoring and maintaining social order. Recent studies emphasize the effect of the norm-signaling function of punishment. However, very little attention has been paid so far to the potential of group punishment. We claim that when inflicted by an entire group, the recipient of punishment views it as expressing norms. The experiments performed in this work provide evidence that humans are motivated not only by material incentives that punishment imposes but also by normative information that it conveys. The same material incentive has a different effect on the individuals\u27 future compliance depending on the way it is implemented, having a stronger effect when it also conveys normative information. We put forward the hypothesis that by inflicting equal material incentives, group punishment is more effective in enhancing compliance than uncoordinated punishment, because it takes advantage of the norm-signaling function of punishment. In support of our hypothesis, we present cross-methodological data, that is, data obtained through agent-based simulation and laboratory experiments with human subjects. The combination of these two methods allows us to provide an explanation for the proximate mechanisms generating the cooperative behavior observed in the laboratory experiment
Indagine sul Fiume Toce: sedimenti, campionatori passivi e bioaccumulo. Campionamento e datazione delle carote di sedimento
No full textNot availableIndagini su DDT e sostanze pericolose nell\u27ecosistema del Lago Maggiore. Programma 2013-2015. Rapporto annuale 2013 - Indagine sul Fiume Toce: sedimenti, campionatori passivi e bioaccumulo. Campionamento e datazione delle carote di sediment
The composting process from a waste management method to a remediation procedure
Get PDFComposting is a controlled technology to enhance the natural aerobic process of organic wastes degradation. The resulting product is a humified material that is principally recyclable for agricultural purpose. The composting process is one of the most important tools for waste management, by the European Community legislation. In recent years composting has been increasingly used as a remediation technology to remove biodegradable contaminants from soil, and to modulate heavy metals bioavailability in phytoremediation strategies. An optimization in the recovery of resources from wastes through composting could enhance soil fertility and promote its use in the remediation biotechnologies of contaminated soils
Water Framework Directive Intercalibration Technical Report. Mediterranean Lake Phytoplankton ecological assessment methods
No full textOne of the key actions identified by the Water Framework Directive (WFD; 2000/60/EC) is to develop ecological assessment tools and carry out a European intercalibration (IC) exercise. The aim of the Intercalibration is to ensure that the values assigned by each Member State to the good ecological class boundaries are consistent with the Directive\u27s generic description of these boundaries and comparable to the boundaries proposed by other MS. In total, 83 lake assessment methods were submitted for the 2nd phase of the WFD intercalibration (2008-2012) and 62 intercalibrated and included in the EC Decision on Intercalibration (EC 2013). The intercalibration was carried out in the 13 Lake Geographical Intercalibration Groups according to the ecoregion and biological quality element. In this report we describe how the intercalibration exercise has been carried out in the Mediterranean Lake Phytoplankton group
Exploring the functional soil-microbe interface and exoenzymes through soil metaexoproteomics
Get PDFFunctionally important proteins at the interface of cell and soil are of potentially low abundance when compared with commonly recovered intracellular proteins. A novel approach was developed and used to extract the metaexoproteome, the subset of proteins found outside the cell, in the context of a soil enriched with the nitrogen-containing recalcitrant polymer chitin. The majority of proteins recovered was of bacterial origin and localized to the outer membrane or extracellular milieu. A wide variety of transporter proteins were identified, particularly those associated with amino-acid and phosphate uptake. The metaexoproteome extract retained chitinolytic activity and we were successful in detecting Nocardiopsis-like chitinases that correlated with the glycoside hydrolase family 18 (GH18) chi gene data and metataxonomic analysis. Nocardiopsis-like chitinases appeared to be solely responsible for chitinolytic activity in soil. This is the first study to detect and sequence bacterial exoenzymes with proven activity in the soil enzyme pool
Comparing aspirations: intercalibration of ecological status concepts across European lakes for littoral diatoms
No full textEleven European countries participated in an exercise to harmonise diatom-based methods used for status assessment in lakes. Lakes were divided into low, medium and high alkalinity types for this exercise. However, it was not possible to perform a full intercalibration on low alkalinity lakes due to the short gradient and confounding factors. Values of the Trophie Index were computed for all samples in order that national datasets could all be expressed on a common scale. Not all participants had reference sites against which national methods could be standardised and, therefore, a Generalised Linear Modelling approach was used to control the effect of national differences in datasets. This enabled the high/good and good/moderate status boundaries to be expressed on a common scale and for deviations beyond ?0.25 class widths to be identified. Those countries which had relaxed boundaries were required to adjust these to within ?0.25 class widths whilst the intercalibration rules allowed those countries with more stringent boundaries to retain these. Despite biogeographical and typological differences between countries, there was broad agreement on the characteristics of high, good and moderate status diatom assemblages, and the exercise has ensured consistent application of Water Framework Directive assessments around Europe
Registro Toscano Difetti Congeniti. Rapporto 2014 Dati 2012. Rilevazione dei difetti congeniti nel periodo prenatale, alla nascita, nel primo anno di vita
No full textThe data presented cover the birth year 2012 covering a population of 30,015 births residing in Tuscany. Cases include congenital defects diagnosed in the prenatal period, at birth and within the first year of life, in women residing in Tuscany. Cases are recorded among live births, fetal deaths of 20 weeks gestation or more and induced abortions following prenatal diagnosis of congenital anomaly of any gestational age.Vengono presentati i dati dell\u27anno 2012 relativi ai casi con difetti congeniti diagnosticati in periodo prenatale, alla nascita ed entro il primo anno di vita, rilevati da donne residenti nella Regione Toscana. I casi registrati comprendono i nati vivi, le morti fetali con et? gestazionale di 20 o pi? settimane e gli aborti indotti a seguito di diagnosi prenatale di difetto congenito a qualsiasi et? gestazionale
ESITI RIPRODUTTIVI IN UNA COORTE DI NATI DA MADRI RESIDENTI NELLE VICINANZE DIUN INCENERITORE DI RIFIUTI SOLIDI URBANI
No full text.Introduzione La letteratura fornisce evidenze limitate sull\u27associazione tra esposizione a Inceneritore di Rifiuti Solidi Urbani (IRSU) e Esiti Avversi della Riproduzione (EAR). Il dominio dello studio ? rappresentato dall\u27area di San Zeno in provincia di Arezzo, nella quale sono presenti un IRSU attivo dal 2000 e altre sorgenti di inquinamento. Obiettivi Valutare in una coorte di nati l\u27associazione tra gli EAR e l\u27esposizione a IRSU, tenendo conto dell\u27esposizione ad altre fonti di emissione presenti nell\u27area in studio, delle caratteristiche socio-demografiche e di altre covariate materne. Metodi Lo studio ha utilizzato un approccio retrospettivo di coorte. I nati, selezionati dai Certificati di Assistenza al Parto nel periodo 2001-2010, sono stati associati alle madri residenti nell\u27area durante il periodo di gestazione e opportunamente georeferenziate. Le esposizioni all\u27IRSU e alle altre fonti (industrie e autostrada) sono state stimate mediante le mappe di diffusione del PM10 e Cadmio (modelli ADMS-URBAN). ? stata inoltre stimata l\u27esposizione ad altre strade principali mediante la distanza. Sono state definite tre classi di esposizione utilizzando il 50? el\u2780? percentile della distribuzione delle concentrazioni. Sono stati analizzati i principali EAR: sexratio, nascite pretermine, basso peso alla nascita, basso peso per et? gestazionale. Le associazioni con l\u27esposizione all\u27IRSU sono state stimate con Odds Ratio (OR) aggiustato per le altre esposizioni ambientali, stato socioeconomico e variabili materne (et?, nazionalit?, ordine di gravidanza, sesso del neonato), utilizzando come riferimento la classe di esposizione pi? bassa. ? stato inoltre stimato il Trend (Tr) dei rischi all\u27aumentare della classe di esposizione. Risultati La coorte analizzata ? costituita da 3069 nati. ? stato riscontrato un eccesso di nascite pretermine nella classe di alta esposizione rispetto a quella a minore esposizione (OR=1,61; p=0,12) e un trend statisticamente significativo (Tr=1,28; p=0,099). Si segnala in oltre un eccesso, seppur non statisticamente significativo, di nati piccoli per et? gestazionale nella classe di alta esposizione (OR=1,31; p=0,144) e un Trend positivo (Tr=1,145; p=0,141). Non sono stati riscontrati eccessi relativamente agli altri EAR analizzati. Conclusioni L\u27evidenza di associazione tra esposizione a Inceneritore di Rifiuti Solidi Urbani e nascite pretermine trova riscontro in altri studi similari (Candelaet al.) e merita approfondimenti specifici anche attraverso studi multicentrici che consentirebbero di aumentare la precisione delle stime
Mitral regurgitation changes after LVAD implantation: a numerical study.
No full textAim: Although the left ventricular (LV) unloading due to LVAD, in some patients (PTs) with severe mitral regurgitation (MR) and severe LV and left atrium dilation,a suboptimal results of LVAD implantation, characterized by persistent relevant MR, elevated left atrial and pulmonary pressure and low cardiac output was observed. The aim of this work is the use of the numerical simulator of the cardiovascular system (NM) to simulate PTs candidate to LVAD implantation with severe MR to assess if NM can predict in advance which PTs will be responder to LVAD therapy and which PTs need a mitral valvuloplasty (MV). Methods: Baseline and acute data after LVAD implantation of 5 PTs with severe MR were collected. PTs baseline were reproduced by the NM and then the effect of LVAD implantation was simulated with and without MV. Simulations results were compared to acute measured data. Results: Comparing measured and simulated data, it can be deduced that the NM can well reproduce PTs baseline and predict the haemodynamic effects of LVAD implantation in all 5 PTs. Moreover the model was able to identify the PTs in which the LVAD implantation did not improve haemodynamic significantly due to severe MR and persistent high LV volumes. Finally the NM can predict the effect of LVAD implantation and MV performed in one of the 5 PTs. Conclusions: NM could be useful to support clinicians in LVAD PTs selection and to optimize and personalize LVAD therapy