Amperometric enzyme sensor to check the total antioxidant capacity of several mixed berries. comparison with two other spectrophotometric and fluorimetric methods

The aim of this research was to test the correctness of response of a superoxide dismutase amperometric biosensor used for the purpose of measuring and ranking the total antioxidant capacity of several systematically analysed mixed berries. Several methods are described in the literature for determining antioxidant capacity, each culminating in the construction of an antioxidant capacity scale and each using its own unit of measurement. It was therefore endeavoured to correlate and compare the results obtained using the present amperometric biosensor method with those resulting from two other different methods for determining the total antioxidant capacity selected from among those more frequently cited in the literature. The purpose was to establish a methodological approach consisting in the simultaneous application of different methods that it would be possible to use to obtain an accurate estimation of the total antioxidant capacity of different mixed berries and the food product

Il recepimento italiano della Direttiva 2004/80/CE. Brevi note di carattere pratico relative all’indennizzo delle vittime di reato

La Direttiva 2004/80/CE stabilisce che gli Stati membri dell’Unione Europea mettano in atto sistemi normativi volti a prevedere forme di indennizzo a favore delle vittime di reati violenti e dolosi, quando l’autore del fatto criminale sia sconosciuto o insolvente. Il presente articolo pone l’attenzione sul recepimento nell’ordinamento italiano della norma europea, operato con la Legge n. 122 del 6 luglio 2016,evidenziando gli aspetti critici e le problematiche sollevati dalla dottrina e dalla giurisprudenza. Appare, infatti, concorde la dottrina nel ritenere che tale norma rappresenta una lettura riduzionistica della disciplina europea. I punti critici della legge italiana sono sintetizzabili in particolare: nella generale restrizione del concetto di indennizzo (inteso prevalentemente come rimborso spese), nella limitazione dei reati per i quali è prevista la possibilità di ottenere un ristoro e nelle condizioni previste in capo alla vittima per accedere al beneficio. La Directive n°2004/80/CE prévoit que les États membres mettent en vigueur les dispositions législatives, réglementaires et administratives nécessaires pour indemniser les victimes de délits violents et intentionnels lorsque le contrevenant ne peut pas être identifié ou est insolvable. Cet article porte sur l’intégration de cette Directive dans le système légal italien, par la Loi n°122 du 6 juillet 2016, mettant en relief les aspects les plus critiques et les problèmes envisagés par la littérature et la jurisprudence. La littérature sur le sujet semble, en effet, indiquer que cette loi est réductionniste en comparaison avec la Directive européenne. Les points critiques de la loi italienne peuvent être résumés comme suit : la restriction du concept d’indemnisation (dans la loi italienne il ne couvre que les dépenses) ; le nombre restreint de délits pour lesquels l’indemnisation est prévue ; les caractéristiques de la victime nécessaires à l’obtention de l’indemnisation. The Directive no. 2004/80/CE stipulates that Member States shall bring into force the laws about compensation to violent and intentional crime victims where the offender cannot be identified or is insolvent. This article focuses on the incorporation of this Directive into the Italian legal system, through the law no. 122 of 6 July 2016, highlighting the most critical aspects and the problems unveiled by literature and justice case-law. The literature seems to agree that such a law is reductionist in comparison with the European regulation. The critical points of the Italian law may be summarised as follows: the restriction of the concept of compensation (in the Italian law it is intended as a mere cover expenditure); the few number of crimes for which a compensation can be envisaged; the underlying conditions of the victims for asking for the compensation

Reaching law-based SMC for spacecraft applications with actuators constraints

This letter considers a robust sliding mode control method for a spacecraft attitude control. The design of the control law is based on the reaching law approach for continuous-time systems. A novel method is proposed to design the parameters of both the reaching law and the sliding surface. The reaching law ensures that during the reaching phase the states of the system remains bounded. Then, taking into account the parameters of the mathematical model, the bounds are defined so that the control law does not overload the actuator limits, whatever the initial conditions. Furthermore, a variable gain is considered for the control law, to provide chattering alleviation of the control input. Numerical simulations are performed to show the effectiveness of the proposed approach

Treatment decision-making capacity in children and adolescents hospitalized for an acute mental disorder: The role of cognitive functioning and psychiatric symptoms

OBJECTIVE: This study was conducted to assess treatment decision-making capacity (TDMC) in a child and adolescent psychiatric sample and to verify possible associations between TDMC, psychiatric symptom severity, and cognitive functioning. METHODS: Twenty-two consecutively recruited patients hospitalized for an acute mental disorder, aged 11-18 years, underwent measurement of TDMC by the MacArthur Competence Assessment Tool for Treatment (MacCAT-T). The MacCAT-T interview focused on patients' current treatment, which comprised second-generation antipsychotics (45.5%), first-generation antipsychotics (13.6%), antiepileptic drugs used as mood stabilizers or lithium carbonate (45.5%), selective serotonin reuptake inhibitors (32%), and benzodiazepines (18%). We moreover measured cognitive functioning (Wechsler Intelligence Scale for Children III) and psychiatric symptom severity (Brief Psychiatric Rating Scale v 4.0). RESULTS: Patients' TDMC varied within the sample, but MacCAT-T scores were good in the sample overall, suggesting that children and adolescents with severe mental disorders could be competent to consent to treatment. The TDMC proved independent of psychiatric diagnosis while being positively associated with cognitive functioning and negatively with excitement. CONCLUSION: The MacCAT-T proved feasible for measuring TDMC in a child and adolescent psychiatric sample. TDMC in minors with severe mental disorders was not necessarily impaired. These results deserve reconsidering the interplay between minors and surrogate decision-makers as concerning treatment decisions

Modulação in vitro da função de barreira epitelial e integridade da junção de oclusão, em linhagem celular MDCK

Orientador: Carla Beatriz Collares BuzatoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaMestrad

Possible mechanisms underlying tilt aftereffect in the primary visual cortex: A critical analysis with the aid of simple computational models

AbstractA mathematical model of orientation selectivity in a single hypercolumn of the primary visual cortex developed in a previous work [Ursino, M., & La Cara, G.-E. (2004). Comparison of different models of orientation selectivity based on distinct intracortical inhibition rules. Vision Research, 44, 1641–1658] was used to analyze the possible mechanisms underlying tilt aftereffect (TAE). Two alternative models are considered, based on a different arrangement of intracortical inhibition (an anti-phase model in which inhibition is in phase opposition with excitation, and an in-phase model in which inhibition has the same phase arrangement as excitation but wider orientation selectivity). Different combinations of parameter changes were tested to explain TAE: a threshold increase in excitatory and inhibitory cortical neurons (fatigue), a decrease in intracortical excitation, an increase or a decrease in intracortical inhibition, a decrease in thalamo-cortical synapses. All synaptic changes were calculated on the basis of Hebbian (or anti-Hebbian) rules. Results demonstrated that the in-phase model accounts for several literature results with different combinations of parameter changes requiring: (i) a depressive mechanism to neurons with preferred orientation close to the adaptation orientation (fatigue of excitatory cortical neurons, and/or depression of thalamo-cortical synapses directed to excitatory neurons, and/or depression of intracortical excitatory synapses); (ii) a facilitatory mechanism to neurons with preferred orientation far from the adaptation orientation (fatigue of inhibitory cortical neurons, and/or depression of thalamo-cortical synapses directed to inhibitory neurons, and/or depression of intracortical inhibitory synapses). By contrast, the anti-phase model appeared less suitable to explain experimental data

Neural Networks and Connectivity among Brain Regions

As is widely understood, brain functioning depends on the interaction among several neural populations, which are linked via complex connectivity circuits and work together (in antagonistic or synergistic ways) to exchange information, synchronize their activity, adapt plastically to external stimuli or internal requirements, and more generally to participate in solving multifaceted cognitive tasks [...]

Organization, Maturation, and Plasticity of Multisensory Integration: Insights from Computational Modeling Studies

In this paper, we present two neural network models – devoted to two specific and widely investigated aspects of multisensory integration – in order to evidence the potentialities of computational models to gain insight into the neural mechanisms underlying organization, development, and plasticity of multisensory integration in the brain. The first model considers visual–auditory interaction in a midbrain structure named superior colliculus (SC). The model is able to reproduce and explain the main physiological features of multisensory integration in SC neurons and to describe how SC integrative capability – not present at birth – develops gradually during postnatal life depending on sensory experience with cross-modal stimuli. The second model tackles the problem of how tactile stimuli on a body part and visual (or auditory) stimuli close to the same body part are integrated in multimodal parietal neurons to form the perception of peripersonal (i.e., near) space. The model investigates how the extension of peripersonal space – where multimodal integration occurs – may be modified by experience such as use of a tool to interact with the far space. The utility of the modeling approach relies on several aspects: (i) The two models, although devoted to different problems and simulating different brain regions, share some common mechanisms (lateral inhibition and excitation, non-linear neuron characteristics, recurrent connections, competition, Hebbian rules of potentiation and depression) that may govern more generally the fusion of senses in the brain, and the learning and plasticity of multisensory integration. (ii) The models may help interpretation of behavioral and psychophysical responses in terms of neural activity and synaptic connections. (iii) The models can make testable predictions that can help guiding future experiments in order to validate, reject, or modify the main assumptions

The Representation of Objects in the Brain, and Its Link with Semantic Memory and Language: a Conceptual Theory with the Support of a Neurocomputational Model

Recognition of objects, their representation and retrieval in memory and the link of this representation with words is a hard cognitive problem, which can be summarized with the term “lexico-semantic memory”. Several recent cognitive theories suggest that the semantic representation of objects is a distributed process, which engages different brain areas in the sensory and motor regions. A further common hypothesis is that each region is organized by conceptual features, that are highly correlated, and neurally contiguous. These theories may be useful to explain the results of clinical tests on patients with lesions of the brain, who exhibit deficits in recognizing objects from words or in evoking words from objects, or to explain the use of appropriate words in bilingual subjects. The study of the cognitive aspects of lexico-semantic memory representation may benefit from the use of mathematical models and computer simulations. Aim of this chapter is to describe a theoretical model of the lexico-semantic system, which can be used by cognitive neuroscientists to summarize conceptual theories into a rigorous quantitative framework, to test the ability of these theories to reproduce real pieces of behavior in healthy and pathological subjects, and to suggest new hypotheses for subsequent testing. The chapter is structured as follows: first the basic assumptions on cognitive aspects of the lexico-semantic memory model are clearly presented; the same aspects are subsequently illustrated via the results of computer simulations using abstract object representations as input to the model. Equations are then reported in an Appendix for readers interested to mathematical issues. The model is based on the following main assumptions: i) an object is represented as a collection of features, topologically ordered according to a similarity principle in different brain areas; ii) the features belonging to the same object are linked together via a Hebbian process during a phase in which objects are presented individually; iii) features are described via neural oscillators in the gamma band. As a consequence, different object representations can be maintained simultaneously in memory, via synchronization of the corresponding features (binding and segmentation problem); iv) words are represented in a lexical area devoted to recognition of words from phonemes; v) words in the lexical area and the features representing objects are linked together via a Hebbian mechanism during a learning phase in which a word is presented together with the corresponding object; vi) the same object representation can be associated to two alternative words (for instance to represent bilinguism). In this case, the two words are connected via inhibitory synapses, to implement a competition among them. vii) the choice of words is further selected by an external inhibitory control system, which suppresses words which do not correspond to the present objective (for instance to choose between alternative languages). Several exempla of model possibilities are presented, with the use of abstract words. These exempla comprehend: the possibility to retrieve objects and words even in case of incomplete or corrupted information on object features; the possibility to establish a semantic link between words with superimposed features; the process of learning a second language (L2) with the support of a language previously known (L1) to represent neurocognitive aspects of bilinguism

A Computational Model of the Lexical-Semantic System Based on a Grounded Cognition Approach

This work presents a connectionist model of the semantic-lexical system based on grounded cognition. The model assumes that the lexical and semantic aspects of language are memorized in two distinct stores. The semantic properties of objects are represented as a collection of features, whose number may vary among objects. Features are described as activation of neural oscillators in different sensory-motor areas (one area for each feature) topographically organized to implement a similarity principle. Lexical items are represented as activation of neural groups in a different layer. Lexical and semantic aspects are then linked together on the basis of previous experience, using physiological learning mechanisms. After training, features which frequently occurred together, and the corresponding word-forms, become linked via reciprocal excitatory synapses. The model also includes some inhibitory synapses: features in the semantic network tend to inhibit words not associated with them during the previous learning phase. Simulations show that after learning, presentation of a cue can evoke the overall object and the corresponding word in the lexical area. Moreover, different objects and the corresponding words can be simultaneously retrieved and segmented via a time division in the gamma-band. Word presentation, in turn, activates the corresponding features in the sensory-motor areas, recreating the same conditions occurring during learning. The model simulates the formation of categories, assuming that objects belong to the same category if they share some features. Simple exempla are shown to illustrate how words representing a category can be distinguished from words representing individual members. Finally, the model can be used to simulate patients with focalized lesions, assuming an impairment of synaptic strength in specific feature areas