246 research outputs found
Lower Bounds on Implementing Robust and Resilient Mediators
We consider games that have (k,t)-robust equilibria when played with a
mediator, where an equilibrium is (k,t)-robust if it tolerates deviations by
coalitions of size up to k and deviations by up to players with unknown
utilities. We prove lower bounds that match upper bounds on the ability to
implement such mediators using cheap talk (that is, just allowing communication
among the players). The bounds depend on (a) the relationship between k, t, and
n, the total number of players in the system; (b) whether players know the
exact utilities of other players; (c) whether there are broadcast channels or
just point-to-point channels; (d) whether cryptography is available; and (e)
whether the game has a k+t$ players, guarantees that every player gets a
worse outcome than they do with the equilibrium strategy
THE EROSION OF ETHICS AND MORALITY IN MEDICINE: PHYSICIAN PARTICIPATION IN LEGAL EXECUTIONS IN THE UNITED STATES
Colordag: An Incentive-Compatible Blockchain
We present Colordag, a blockchain protocol where following the prescribed
strategy is, with high probability, a best response as long as all miners have
less than 1/2 of the mining power. We prove the correctness of Colordag even if
there is an extremely powerful adversary who knows future actions of the
scheduler: specifically, when agents will generate blocks and when messages
will arrive. The state-of-the-art protocol, Fruitchain, is an epsilon-Nash
equilibrium as long as all miners have less than 1/2 of the mining power.
However, there is a simple deviation that guarantees that deviators are never
worse off than they would be by following Fruitchain, and can sometimes do
better. Thus, agents are motivated to deviate. Colordag implements a solution
concept that we call epsilon-sure Nash equilibrium and does not suffer from
this problem. Because it is an epsilon-sure Nash equilibrium, Colordag is an
epsilon Nash equilibrium and with probability (1 - epsilon) is a best response.Comment: To be published in DISC 202
Colordag: An Incentive-Compatible Blockchain
We present , a blockchain protocol where following the prescribed strategy is, with high probability, a best response as long as all miners have less than of the mining power. We prove the correctness of Colordag even if there is an extremely powerful adversary who knows future actions of the scheduler: specifically, when agents will generate blocks and when messages will arrive. The state-of-the-art protocol, Fruitchain, is an -Nash equilibrium as long as all miners have less than of the mining power. However, there is a simple deviation that guarantees that deviators are never worse off than they would be by following Fruitchain, and can sometimes do better. Thus, agents are motivated to deviate. Colordag implements a solution concept that we call and does not suffer from this problem. Because it is an -sure Nash equilibrium, Colordag is an -Nash equilibrium and with probability is a best response
The “Endless Trip” among the NPS Users: Psychopathology and Psychopharmacology in the Hallucinogen-Persisting Perception Disorder. A Systematic Review
Hallucinogen-persisting perception disorder (HPPD) is a syndrome characterized by prolonged or reoccurring perceptual symptoms, reminiscent of acute hallucinogen effects. HPPD was associated with a broader range of LSD (lysergic acid diethylamide)-like substances, cannabis, methylenedioxymethamphetamine (MDMA), psilocybin, mescaline, and psychostimulants. The recent emergence of novel psychoactive substances (NPS) posed a critical concern regarding the new onset of psychiatric symptoms/syndromes, including cases of HPPD. Symptomatology mainly comprises visual disorders (i.e., geometric pseudo-hallucinations, haloes, flashes of colors/lights, motion-perception deficits, afterimages, micropsia, more acute awareness of floaters, etc.), even though depressive symptoms and thought disorders may be comorbidly present. Although HPPD was first described in 1954, it was just established as a fully syndrome in 2000, with the revised fourth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). HPPD neural substrates, risk factors, and aetiopathogenesys still largely remain unknown and under investigation, and many questions about its pharmacological targets remain unanswered too. A critical mini review on psychopathological bases, etiological hypothesis, and psychopharmacological approaches toward HPPD, including the association with some novel substances, are provided here, by means of a literature search on PubMed/Medline, Google Scholar, and Scopus databases without time restrictions, by using a specific set of keywords. Pharmacological and clinical issues are considered, and practical psychopharmacological recommendations and clinical guidelines are suggested
Can long-term periodic variability and jet helicity in 3C 120 be explained by jet precession?
Optical variability of 3C 120 is discussed in the framework of jet
precession. Specifically, we assume that the observed long-term periodic
variability is produced by the emission from an underlying jet with a
time-dependent boosting factor driven by precession. The differences in the
apparent velocities of the different superluminal components in the
milliarcsecond jet can also be explained by the precession model as being
related to changes in the viewing angle. The evolution of the jet components
has been used to determine the parameters of the precession model, which also
reproduce the helical structure seen at large scales. Among the possible
mechanisms that could produce jet precession, we consider that 3C 120 harbours
a super-massive black hole binary system in its nuclear region and that torques
induced by misalignment between the accretion disc and the orbital plane of the
secondary black hole are responsible for this precession; we estimated upper
and lower limits for the black holes masses and their mean separation.Comment: 10 pages, 4 figures, accepted for publication in MNRA
Increasing condom use in heterosexual men: development of a theory-based interactive digital intervention
Increasing condom use to prevent sexually transmitted infections is a key public health goal. Interventions are more likely to be effective if they are theory- and evidence-based. The Behaviour Change Wheel (BCW) provides a framework for intervention development. To provide an example of how the BCW was used to develop an intervention to increase condom use in heterosexual men (the MenSS website), the steps of the BCW intervention development process were followed, incorporating evidence from the research literature and views of experts and the target population. Capability (e.g. knowledge) and motivation (e.g. beliefs about pleasure) were identified as important targets of the intervention. We devised ways to address each intervention target, including selecting interactive features and behaviour change techniques. The BCW provides a useful framework for integrating sources of evidence to inform intervention content and deciding which influences on behaviour to target
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