8,176 research outputs found
How to Reform the Italian Domestic Adoptions System Through a Centralized Market Design
Using an innovative variation of the standard Matching Market Design framework, this draft aims to provide inputs useful to drive the reform of the current Italian Domestic Adoption System (Italian families that desire to adopt an Italian child). The problem addressed in this draft, concern how to match the relative small number of waiting children to the large number of waiting families in the most rational and efficient way: each year, the adoptions system is not able to place the 20% of the children in foster care, despite the fact that the number of children (supply side) is very small respect the total amount of families (demand side) willing to adopt. This project is oriented to solve the inefficiencies characterizing the current adoption program, substituting the actual decentralized setup with a more efficient centralized matching market criteriaMatching Market Design, Adoptions System, Matching Algorithm
Fractional exclusion statistics and shot noise in ballistic conductors
We study the noise properties of ballistic conductors with carriers
satisfying fractional exclusion statistics. To test directly the nature of
exclusion statistics we found that systems under weakly degenerate conditions
should be considered. Typical of these systems is that the chemical potential,
is in the thermal range . In these conditions the noise
properties under current saturation are found to depend upon the statistical
parameter , displaying suppressed shot noise for , and
enhanced shot noise for , according to the attractive or repulsive
nature of the carrier exclusion statistics.Comment: 6 pages, 5 figures, accepted for publication in Phys. Rev.
Charge transport in bacteriorhodopsin monolayers: The contribution of conformational change to current-voltage characteristics
When moving from native to light activated bacteriorhodopsin, modification of
charge transport consisting of an increase of conductance is correlated to the
protein conformational change. A theoretical model based on a map of the
protein tertiary structure into a resistor network is implemented to account
for a sequential tunneling mechanism of charge transfer through neighbouring
amino acids. The model is validated by comparison with current-voltage
experiments. The predictability of the model is further tested on bovine
rhodopsin, a G-protein coupled receptor (GPCR) also sensitive to light. In this
case, results show an opposite behaviour with a decrease of conductance in the
presence of light.Comment: 6 pages, 4 figure
Mechanosensing in myosin filament solves a 60 years old conflict in skeletal muscle modeling between high power output and slow rise in tension
Almost 60 years ago Andrew Huxley with his seminal paper \cite{Huxley1957}
laid the foundation of modern muscle modeling, linking chemical events to
mechanical performance. He described mechanics and energetics of muscle
contraction through the cyclical attachment and detachment of myosin motors to
the actin filament with ad hoc assumptions on the dependence of the rate
constants on the strain of the myosin motors. That relatively simple hypothesis
is still present in recent models, even though with several modifications to
adapt the model to the different experimental constraints which became
subsequently available. However, already in that paper, one controversial
aspect of the model became clear. Relatively high attachment and detachment
rates of myosin to the actin filament were needed to simulate the high power
output at intermediate velocity of contraction. However, these rates were
incompatible with the relatively slow rise in tension after activation, despite
the rise should be generated by the same rate functions. This discrepancy has
not been fully solved till today, despite several hypotheses have been
forwarded to reconcile the two aspects. Here, using a conventional muscle
model, we show that the recently revealed mechanosensing mechanism of
recruitment of myosin motors \cite{Linarietal2015} can solve this long standing
problem without any further ad-hoc hypotheses
Opsin vs opsin: new materials for biotechnological applications
The need of new diagnostic methods satisfying, as an early detection, a low
invasive procedure and a cost-efficient value, is orienting the technological
research toward the use of bio-integrated devices, in particular bio-sensors.
The set of know-why necessary to achieve this goal is wide, from biochemistry
to electronics and is summarized in an emerging branch of electronics, called
\textit{proteotronics}. Proteotronics is here here applied to state a
comparative analysis of the electrical responses coming from type-1 and type-2
opsins. In particular, the procedure is used as an early investigation of a
recently discovered family of opsins, the proteorhodopsins activated by blue
light, BPRs. The results reveal some interesting and unexpected similarities
between proteins of the two families, suggesting the global electrical response
are not strictly linked to the class identity.Comment: 10 pages, 8 figures revised version with more figure
Oligopolistic Non-Linear Pricing and Size Economies
The effects of non-linear pricing are determined by the relationship between the demand and the technological structure of the market. This paper focuses on a model in which firms supply a homogeneous product in two different sizes. Information about consumers' reservation prices is incomplete and the production technology is characterized by size economies. Four equilibrium regions are identified depending on the relative intensity of size economies with respect to consumers' evaluation of a second unit of the good. The desirability of non-linear pricing varies across different equilibrium regions.non-linear pricing, size economies, supply technology.
Size effects on generation recombination noise
We carry out an analytical theory of generation-recombination noise for a two
level resistor model which goes beyond those presently available by including
the effects of both space charge fluctuations and diffusion current. Finite
size effects are found responsible for the saturation of the low frequency
current spectral density at high enough applied voltages. The saturation
behaviour is controlled essentially by the correlations coming from the long
range Coulomb interaction. It is suggested that the saturation of the current
fluctuations for high voltage bias constitutes a general feature of
generation-recombination noise.Comment: 3 pages, 1 figure. To appear in Applied Physics Letters (2 December
2002 issue
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