1,721,036 research outputs found
Learning and discrimination of multimodal sensorial stimuli before and after hippocampal lesion.
No full textLearning and discrimination of multimodal sensorial stimuli before and after hippocampal lesion.
No full textA discrete-to-continuum approach to frequency bangaps in 1D biatomic metamaterials
No full textWe formulate a discrete-to-continuum approach to the dispersion relation of one-dimensional lattice metamaterials. With reference to a generic lattice structure that can be described as a biatomic mass-spring chain, we formulate a higher order gradient continuum theory of the competent dynamical problem using a homogenization approach. The proposed theory allows us to obtain an analytic description of the bandgap-type response of the homogenized chain, and to estimate the frequency boundary region that is affected by the full transmission of mechanical waves. Numerical applications of the proposed discrete-to-continuum approach are given with reference to tensegrity metamaterials, which exhibit a prestress-tunable bandgap response over a wide range of frequencies
A frugal printed electrochemical architecture to monitor dopamine release in mice brain: Organ-on-screen-printed approach
No full textDopamine (DA) is an important catecholamine neuromodulator that is present in the brain of mammal, and changes of its level can be related to some neurological diseases such as Parkinson, Huntington and Alzheimer. As a consequence, rapid, cost-effective and sensitive approaches are required to monitor the dopamine changes, especially in the brain. In this paper, we report the development of a frugal electrochemical platform for the development of an affordable organ-on-screen-printed strip to monitor the dopamine release from mice's brain. Coupling diagnostics, engineering and neuroscience, a flexible screen-printed platform has been applied to the determination of dopamine release from brain slice finely anchored onto the working area of the platform. After the experimental condition were optimized both in standard and PC-12 cell culture media, with a detection limit of ca. 1 μM and a linear range up to 160 μM (with a relative standard deviation of 9%), the platform was tested toward different areas of the brain, namely striatum and cerebellum. The printed strip was capable to monitor the release of dopamine following the stimulation with potassium chloride drop, highlighting the difference amount of dopamine in these areas. This work demonstrates how affordable facilities may produce frugal innovation to be used for low-cost organ-on-chip platforms
GIRK1-Mediated Inwardly Rectifying Potassium Current Is a Candidate Mechanism Behind Purkinje Cell Excitability, Plasticity, and Neuromodulation
No full textG-protein-coupled inwardly rectifying potassium (GIRK) channels contribute to the resting membrane potential of many neurons and play an important role in controlling neuronal excitability. Although previous studies have revealed a high expression of GIRK subunits in the cerebellum, their functional role has never been clearly described. Using patch-clamp recordings in mice cerebellar slices, we examined the properties of the GIRK currents in Purkinje cells (PCs) and investigated the effects of a selective agonist of GIRK1-containing channels, ML297 (ML), on PC firing and synaptic plasticity. We demonstrated that GIRK channel activation decreases the PC excitability by inhibiting both sodium and calcium spikes and, in addition, modulates the complex spike response evoked by climbing fiber stimulation. Our results indicate that GIRK channels have also a marked effect on synaptic plasticity of the parallel fiber-PC synapse, as the application of ML297 increased the expression of LTP while preventing LTD. We, therefore, propose that the recruitment of GIRK channels represents a crucial mechanism by which neuromodulators can control synaptic strength and membrane conductance for proper refinement of the neural network involved in memory storage and higher cognitive functions
Wave dispersion in thin-walled orthotropic waveguides using the first order shear deformation theory
No full textThe aim of this paper is to extract the dispersion parameters, i.e. phase velocity, energy velocity and attenuation, of orthotropic thin-walled waveguides with generic cross-section. To this end, a semi-analytical finite element (SAFE) formulation is presented, which is based on the Reissner-Mindlin theory of curved shells. Complex axial wavenumbers and mode shapes of guided wave modes are extracted from a second-order polynomial eigenvalue problem, while the energy velocity is post-processed using the computed eigensolutions and SAFE operators. Different numerical examples are proposed, for which the obtained results are in very good agreement with those computed using other well-stated SAFE formulations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Coupling local resonance with Bragg band gaps in single-phase mechanical metamaterials
Full text linkA.K. has received funding from the European Union’s Seventh Framework programme for research and innovation under the Marie Skłodowska-Curie Grant Agreement No. 609402-2020 researchers: Train to Move (T2M). M.M. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 658483. N.M.P. is supported by the European Research Council as the PI of the following active projects: ERC StG Ideas 2011 BIHSNAM No. 279985; ERC PoC 2015 SILKENE No. 693670, and by the European Commission under the Graphene Flagship (WP14 “Polymer Nanocomposites”, No. 604391). F.B. is supported by ERC StG Ideas 2011 BIHSNAM No. 279985. Computational resources were provided by HPC@POLITO (http://www.hpc.polito.it)
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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