86 research outputs found
The Networked Common Goods Game
We introduce a new class of games called the networked common goods game
(NCGG), which generalizes the well-known common goods game. We focus on a
fairly general subclass of the game where each agent's utility functions are
the same across all goods the agent is entitled to and satisfy certain natural
properties (diminishing return and smoothness). We give a comprehensive set of
technical results listed as follows.
* We show the optimization problem faced by a single agent can be solved
efficiently in this subclass. The discrete version of the problem is however
NP-hard but admits an fully polynomial time approximation scheme (FPTAS).
* We show uniqueness results of pure strategy Nash equilibrium of NCGG, and
that the equilibrium is fully characterized by the structure of the network and
independent of the choices and combinations of agent utility functions.
* We show NCGG is a potential game, and give an implementation of best/better
response Nash dynamics that lead to fast convergence to an
-approximate pure strategy Nash equilibrium.
* Lastly, we show the price of anarchy of NCGG can be as large as
(for any ), which means selfish behavior
in NCGG can lead to extremely inefficient social outcomes
Ultrafast Optical Response of a High Reflectivity GaAs/AlAs Bragg Mirror
Quantum Matter and Optic
Observation of breather-like states in a single Josephson cell
We present experimental observation of broken-symmetry states in a
superconducting loop with three Josephson junctions. These states are generic
for discrete breathers in Josephson ladders. The existence region of the
breather-like states is found to be in good accordance with the theoretical
expectations. We observed three different resonant states in the
current-voltage characteristics of the broken-symmetry state, as predicted by
theory. The experimental dependence of the resonances on the external magnetic
field is studied in detail.Comment: 7 pages, 8 figure
A kinetic approach to eta' production from a CP-odd phase
The production of (eta,eta')- mesons during the decay of a CP-odd phase is
studied within an evolution operator approach. We derive a quantum kinetic
equation starting from the Witten-DiVecchia-Veneziano Lagrangian for
pseudoscalar mesons containing a U_A(1) symmetry breaking term. The non-linear
vacuum mean field for the flavour singlet pseudoscalar meson is treated as a
classical, self-interacting background field with fluctuations assumed to be
small. The numerical solution provides the time evolution of momentum
distribution function of produced eta'- mesons after a quench at the
deconfinement phase transition. We show that the time evolution of the momentum
distribution of the produced mesons depend strongly on the shape of the
effective potential at the end of the quench, exhibiting either parametric or
tachyonic resonances. Quantum statistical effects are essential and lead to a
pronounced Bose enhancement of the low momentum states.Comment: 10 pages, latex, epsfig, 6 figure
Research Review: Do parent ratings of infant negative emotionality and selfâregulation predict psychopathology in childhood and adolescence? A systematic review and metaâanalysis of prospective longitudinal studies
Background
Identifying lowâcost and easy to implement measures of infant markers of later psychopathology may improve targeting of early intervention for prevention. Because of their early manifestation, relative stability and overlap with constructs central to affectâbased dimensions of child and adolescent psychopathology, negative emotionality and selfâregulation have been the focus of this research. We conducted a metaâanalysis of longitudinal studies examining the prospective association between infant temperament measured with parent ratings and child/adolescent psychopathology.
Methods
A systematic literature search for prospective longitudinal studies, which included measures of questionnaireâassessed infant temperament (negative emotionality, selfâregulation, behavioural inhibition, surgency/extraversion, activity level) and symptoms of child or adolescent mental health (externalising, internalising) and neurodevelopmental problems (attention deficit/hyperactivity disorder [ADHD], autism spectrum disorder [ASD]), was conducted. Standardised estimates of association were calculated and pooled in metaâanalyses.
Results
Twentyâfive studies (n = 28,425) met inclusion criteria. Small associations were seen between psychopathology aggregated across all domains and infant negative emotionality (r = .15; p < .001) and selfâregulation (r = â.19; p = .007). Effects were also significant but weaker for behavioural inhibition (r = .10; p = .027) and activity level (r = .08; p = .016). Surgency/extraversion was not significantly associated with psychopathology in general (r = â.04; p = .094); however, it was negatively associated with ASD (r = â.10, p = .015). Significant correlations were observed with some outcomes isomorphic with predictors, internalising problems and behavioural inhibition (r = .10; p = .013), ADHD symptoms and activity level (r = .19; p = .009).
Conclusion
Questionnaireâbased assessments of infant negative emotionality may have transdiagnostic potential to contribute to a risk index of later childhood psychopathology. Behavioural inhibition, surgency/extraversion and activity ratings may provide more specific predictive power. More data from prospective studies are required before the potential of selfâregulation and surgency/extraversion can be properly gauged
Anogenital distance: A longitudinal evaluation of its variants and indices in boys and girls of Sonora, Mexico
Isolation of Elafin and Elastase-Specific Inhibitor (ESI) from Bronchial Secretions. Evidence of Sequence Homology and Immunological Cross-Reactivity
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