2,350 research outputs found
Information and Willingness to Pay in a Contingent Valuation Study: The Value of S. Erasmo in the Lagoon of Venice
This paper reports on a contingent valuation study eliciting willingness to pay for a public program for the preservation of lagoon, beach and infrastructure in the island of S. Erasmo in the Lagoon of Venice. A referendum dichotomous choice approach with a follow-up question is used to obtain information about willingness to pay from a sample of residents of the Veneto Region in Italy. We use split samples to investigate the effect of providing different levels of information to respondents before asking the payment questions. Our experimental treatment is a reminder of possible reasons for voting in favor or against the proposed program before the referendum question. We find that reminding respondents of the reasons for voting for or against the public works increases WTP among less highly educated respondents, and decreases WTP among more highly educated respondents.Contingent valuation, Effects of information
EFFECTS OF VISUAL EXPERIENCE ON FUNCTIONAL AND ANATOMICAL MEASURES OF VISUAL CORTEX PLASTICITY
EFFECTS OF VISUAL EXPERIENCE ON FUNCTIONAL AND ANATOMICAL MEASURES OF VISUAL CORTEX PLASTICITY
Much of the recent progress in examining how cortical circuits are influenced by experience has been achieved by using the measurement of Ocular Dominance (OD) plasticity in the visual cortex.
In this paradigm, altered retinal activity caused by unilateral eye-lid closureâmonocular deprivationâleads to dramatic shifts in the binocular response properties of neurons in the visual cortex. Although the phenomenology of OD shifts has been described in detail in several species, the mouse is the most useful model for identifying the cellular and molecular mechanisms underlying OD plasticity: pronounced plasticity has been revealed in mouse visual cortex throughout life using physiological, imaging and neuroanatomical methods, and important insights into factors controlling the critical period. Binocular visual function appears to be most sensitive to experiential changes early in life, between postnatal days 19 and 32âi.e. during the critical periodâdespite several studies reporting that OD shifts in mice can also be induced in adulthood through an extension of the time course of the critical period, which closure has been shown mostly related to the maturation of intracortical inhibition.
We measured the ocular dominance shift following monocular deprivation using Optical Imaging, which allows for detection of the size and the strength of response of the stimulated area in mouse visual cortex (V1) after viewing a specific visual stimulus on a screen. Moreover, the number of inhibitory cells and perineuronal nets were counted by immunohistochemistry to determine their involvement in neuronal plasticity during recovery from monocular deprivation.
Our experiments showed that 7 days of dark rearing after long-term monocular deprivation can enhance plasticity such that a normal OD is restored
EFFECTS OF VISUAL EXPERIENCE ON FUNCTIONAL AND ANATOMICAL MEASURES OF VISUAL CORTEX PLASTICITY
EFFECTS OF VISUAL EXPERIENCE ON FUNCTIONAL AND ANATOMICAL MEASURES OF VISUAL CORTEX PLASTICITY
Much of the recent progress in examining how cortical circuits are influenced by experience has been achieved by using the measurement of Ocular Dominance (OD) plasticity in the visual cortex.
In this paradigm, altered retinal activity caused by unilateral eye-lid closureâmonocular deprivationâleads to dramatic shifts in the binocular response properties of neurons in the visual cortex. Although the phenomenology of OD shifts has been described in detail in several species, the mouse is the most useful model for identifying the cellular and molecular mechanisms underlying OD plasticity: pronounced plasticity has been revealed in mouse visual cortex throughout life using physiological, imaging and neuroanatomical methods, and important insights into factors controlling the critical period. Binocular visual function appears to be most sensitive to experiential changes early in life, between postnatal days 19 and 32âi.e. during the critical periodâdespite several studies reporting that OD shifts in mice can also be induced in adulthood through an extension of the time course of the critical period, which closure has been shown mostly related to the maturation of intracortical inhibition.
We measured the ocular dominance shift following monocular deprivation using Optical Imaging, which allows for detection of the size and the strength of response of the stimulated area in mouse visual cortex (V1) after viewing a specific visual stimulus on a screen. Moreover, the number of inhibitory cells and perineuronal nets were counted by immunohistochemistry to determine their involvement in neuronal plasticity during recovery from monocular deprivation.
Our experiments showed that 7 days of dark rearing after long-term monocular deprivation can enhance plasticity such that a normal OD is restored
Enhancement of visual cortex plasticity by dark exposure
Dark rearing is known to delay the time course of the critical period for ocular dominance plasticity in the visual cortex. Recent evidence suggests that a period of dark exposure (DE) may enhance or reinstate plasticity even after closure of the critical period, mediated through modification of the excitatoryâinhibitory balance and/or removal of structural brakes on plasticity. Here, we investigated the effects of a week of DE on the recovery from a month of monocular deprivation (MD) in the primary visual cortex (V1) of juvenile mice. Optical imaging of intrinsic signals revealed that ocular dominance in V1 of mice that had received DE recovered slightly more quickly than of mice that had not, but the level of recovery after three weeks was similar in both groups. Two-photon calcium imaging showed no significant difference in the recovery of orientation selectivity of excitatory neurons between the two groups. Parvalbumin-positive (PV+) interneurons exhibited a smaller ocular dominance shift during MD but again no differences in subsequent recovery. The percentage of PV+ cells surrounded by perineuronal nets, a structural brake on plasticity, was lower in mice with than those without DE. Overall, DE causes a modest enhancement of mouse visual cortex plasticity
An advanced design approach to support urban transformations through multi-stakeholder collaborations
Urban transformations depend on the uses of the city by âoldâ and new citizens (residents, workers, migrants, refugees, students, seasonal, homeless individuals, tourists, city-users, commuters), and on their relation within urban spaces and resources, triggering regenerative opportunities, networking and empowerment processes. Considering the city and its heritage as a common good, in which each citizen could access and play for the knowledge, management, conservation and transformation of urban contexts, the contribute illustrates the results of experimental actions in Bologna (IT) finalized to test new stakeholder engagement processes and to develop new tools for participatory practices and new productions for the reactivation of the city. In the last years Bologna represents a field of experimentation for different forms of collaborative approaches with the aim to test and innovate tools and policies for the public space. The paper presents the results of specific projects linked to EU funding schemes (ROCK project) and local multi-stakeholder initiatives, such as the Bologna Design Week, which are part of the research and experimentation carried out by the research unit team. This article illustrates a model to improve the regenerative capacities of the city, by reinforcing local identity and culture, fostering participation through active engagement of all relevant stakeholders, allowing a diversity of responses of groups of actors with different roles and different strengths
Rethinking social housing: behavioural patterns and technological innovations
The building sector accounts for 40% of energy use and 25% of CO2 emissions, mainly due to inefficient building practices and energy consumption during the operational phase of buildings. Social housing accounts for a significant proportion of the European building stock and about 50% of the existing buildings are likely to require large-scale renovations in the coming years, meeting the current EPBD directive. This could represent an opportunity to renovate the affordable building stock, often characterized by premature disrepair, resulting in a bad perception from inhabitants and community. Significant European experiences have already shown the importance of an integrated approach finalized to the construction or renovation of social housing, leveraging on environmental sustainability, creating urban identity, adopting measures to face social disadvantage, offering at the same time quality housing standard. In this regard, it seems necessary to match technological advancements and knowledge in energy retrofitting with social needs and habits. The implementation of energy-efficiency improvements in social housing requests support and participation of the final energy consumer. The paper investigates how to deal with knowledge gaps in the relationship between retrofit technologies and users\u2019 behaviour and possible strategic measures to increase awareness between tenants through two case studies
PROPAGATION OF GRAVITY CURRENTS OF NON-NEWTONIAN POWER-LAW FLUIDS IN POROUS MEDIA
A comprehensive analytical and experimental framework is presented to
describe gravity-driven motions of rheologically complex fluids through
porous media. These phenomena are relevant in geophysical,
environmental, industrial and biological applications.
The fluid is characterized by an Ostwald-DeWaele constitutive equation with
behaviour index n. The flow is driven by the release of fluid at the origin of
an infinite porous domain. In order to represent several possible spreading
scenarios, we consider: i) different domain geometries: plane, radial, and
channelized, with the channel shape parameterized by ïą; ii) instantaneous
or continuous injection, depending on the time exponent of the volume of
fluid in the current, ïĄ; iii) horizontal or inclined impermeable boundaries.
Systematic heterogeneity along the streamwise and/or transverse direction
is added to the conceptualization upon considering a power-law
permeability variation governed by two additional parameters ï· and ïą.
Scalings for current length and thickness are derived in self similar form
coupling the modified Darcyâs law accounting for the fluid rheology with the
mass balance equation. The speed, thickness, and aspect ratio of the
current are studied as a function of model parameters; several different
critical values of ïĄ emerge and govern the type of dependency, as well as
the tendency of the current to accelerate or decelerate and become thicker
or thinner at a given point. The asymptotic validity of the solutions is limited
to certain ranges of model parameters.
Experimental validation is performed under constant volume, constant and
variable flux regimes in tanks/channels filled with transparent glass beads
of uniform or variable diameter, using shear-thinning suspensions and
Newtonian mixtures. The experimental results for the length and profile of
the current agree well with the self-similar solutions at intermediate and late
times
Porous gravity currents: A survey to determine the joint influence of fluid rheology and variations of medium properties
We develop a model to grasp the combined effect of rheology and spatial stratifications on two- dimensional non-Newtonian gravity-driven flow in porous media. We consider a power-law constitutive equation for the fluid, and a monomial variation of permeability and porosity along the vertical direction (transverse to the flow) or horizontal direction (parallel to the flow). Under these assumptions, similar- ity solutions are derived in semi-analytical form for thin gravity currents injected into a two-dimensional porous medium and having constant or time-varying volume. The extent and shape of the porous domain affected by the injection is significantly influenced by the interplay of model parameters. These describe the fluid (flow behaviour index n ), the spatial heterogeneity (coefficients ÎČ, Îł, ÎŽ, Ï for variations of per- meability and porosity in the horizontal or vertical direction), and the type of release (volume exponent α). Theoretical results are validated against two sets of experiments with α= 1 (constant inflow) con- ducted with a stratified porous medium (simulated by superimposing layers of glass beads of different diameter) and a Hele-Shaw analogue for power-law fluid flow, respectively. In the latter case, a recently established Hele-Shaw analogy is extended to the variation of properties parallel to the flow direction. Comparison with experimental results shows that the proposed model is able to capture the propagation of the current front and the current profile
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