3,428 research outputs found
Generalized Colonel Blotto Game
Competitive resource allocation between adversarial decision makers arises in
a wide spectrum of real-world applications such as in communication systems,
cyber-physical systems security, as well as financial, political, and electoral
competition. As such, developing analytical tools to model and analyze
competitive resource allocation is crucial for devising optimal allocation
strategies and anticipating the potential outcomes of the competition. To this
end, the Colonel Blotto game is one of the most popular game-theoretic
frameworks for modeling and analyzing such competitive resource allocation
problems. However, in many real-world competitive situations, the Colonel
Blotto game does not admit solutions in deterministic strategies and, hence,
one must rely on analytically complex mixed-strategies with their associated
tractability, applicability, and practicality challenges. In this paper, a
generalization of the Colonel Blotto game which enables the derivation of
deterministic, practical, and implementable equilibrium strategies is proposed
while accounting for the heterogeneity of the battlefields. In addition, the
proposed generalized game enables accounting for the consumed resources in each
battlefield, a feature that is not considered in the classical Blotto game. For
the generalized game, the existence of a Nash equilibrium in pure-strategies is
shown. Then, closed-form analytical expressions of the equilibrium strategies,
are derived and the outcome of the game is characterized; based on the number
of resources of each player as well as the valuation of each battlefield. The
generated results provide invaluable insights on the outcome of the
competition. For example, the results show that, when both players are fully
rational, the more resourceful player can achieve a better total payoff at the
Nash equilibrium, a result that is not mimicked in the classical Blotto game.Comment: 8 pages, 5 figure
Flux Discharge Cascades in Various Dimensions
We study the dynamics of electric flux discharge by charged particle pair or
spherical string or membrane production in various dimensions. When electric
flux wraps at least one compact cycle, we find that a single "pair" production
event can initiate a cascading decay in real time that "shorts out" the flux
and discharges many units of it. This process arises from local dynamics in the
compact space, and so is invisible in the dimensionally-reduced truncation. It
occurs in theories as simple as the Schwinger model on a circle, and has
implications for any theory with compact dimensions and electric flux,
including string theories and the string landscape.Comment: 19+8 pages, 3 figures, 3 appendice
Punica granatum (Pomegranate) juice provides an HIV-1 entry inhibitor and candidate topical microbicide
BACKGROUND: For ≈ 24 years the AIDS pandemic has claimed ≈ 30 million lives, causing ≈ 14,000 new HIV-1 infections daily worldwide in 2003. About 80% of infections occur by heterosexual transmission. In the absence of vaccines, topical microbicides, expected to block virus transmission, offer hope for controlling the pandemic. Antiretroviral chemotherapeutics have decreased AIDS mortality in industrialized countries, but only minimally in developing countries. To prevent an analogous dichotomy, microbicides should be: acceptable; accessible; affordable; and accelerative in transition from development to marketing. Already marketed pharmaceutical excipients or foods, with established safety records and adequate anti-HIV-1 activity, may provide this option. METHODS: Fruit juices were screened for inhibitory activity against HIV-1 IIIB using CD4 and CXCR4 as cell receptors. The best juice was tested for inhibition of: (1) infection by HIV-1 BaL, utilizing CCR5 as the cellular coreceptor; and (2) binding of gp120 IIIB and gp120 BaL, respectively, to CXCR4 and CCR5. To remove most colored juice components, the adsorption of the effective ingredient(s) to dispersible excipients and other foods was investigated. A selected complex was assayed for inhibition of infection by primary HIV-1 isolates. RESULTS: HIV-1 entry inhibitors from pomegranate juice adsorb onto corn starch. The resulting complex blocks virus binding to CD4 and CXCR4/CCR5 and inhibits infection by primary virus clades A to G and group O. CONCLUSION: These results suggest the possibility of producing an anti-HIV-1 microbicide from inexpensive, widely available sources, whose safety has been established throughout centuries, provided that its quality is adequately standardized and monitored
The simulation of action disorganisation in complex activities of daily living
Action selection in everyday goal-directed tasks of moderate complexity is known to be subject to breakdown following extensive frontal brain injury. A model of action selection in such tasks is presented and used to explore three hypotheses concerning the origins of action disorganisation: that it is a consequence of reduced top-down excitation within a hierarchical action schema network coupled with increased bottom-up triggering of schemas from environmental sources, that it is a more general disturbance of schema activation modelled by excessive noise in the schema network, and that it results from a general disturbance of the triggering of schemas by object representations. Results suggest that the action disorganisation syndrome is best accounted for by a general disturbance to schema activation, while altering the balance between top-down and bottom-up activation provides an account of a related disorder - utilisation behaviour. It is further suggested that ideational apraxia (which may result from lesions to left temporoparietal areas and which has similar behavioural consequences to action disorganisation syndrome on tasks of moderate complexity) is a consequence of a generalised disturbance of the triggering of schemas by object representations. Several predictions regarding differences between action disorganisation syndrome and ideational apraxia that follow from this interpretation are detailed
Spreading, Nonergodicity, and Selftrapping: a puzzle of interacting disordered lattice waves
Localization of waves by disorder is a fundamental physical problem
encompassing a diverse spectrum of theoretical, experimental and numerical
studies in the context of metal-insulator transitions, the quantum Hall effect,
light propagation in photonic crystals, and dynamics of ultra-cold atoms in
optical arrays, to name just a few examples. Large intensity light can induce
nonlinear response, ultracold atomic gases can be tuned into an interacting
regime, which leads again to nonlinear wave equations on a mean field level.
The interplay between disorder and nonlinearity, their localizing and
delocalizing effects is currently an intriguing and challenging issue in the
field of lattice waves. In particular it leads to the prediction and
observation of two different regimes of destruction of Anderson localization -
asymptotic weak chaos, and intermediate strong chaos, separated by a crossover
condition on densities. On the other side approximate full quantum interacting
many body treatments were recently used to predict and obtain a novel many body
localization transition, and two distinct phases - a localization phase, and a
delocalization phase, both again separated by some typical density scale. We
will discuss selftrapping, nonergodicity and nonGibbsean phases which are
typical for such discrete models with particle number conservation and their
relation to the above crossover and transition physics. We will also discuss
potential connections to quantum many body theories.Comment: 13 pages in Springer International Publishing Switzerland 2016 1 M.
Tlidi and M. G. Clerc (eds.), Nonlinear Dynamics: Materials, Theory and
Experiment, Springer Proceedings in Physics 173. arXiv admin note: text
overlap with arXiv:1405.112
Definitions, Criteria and Global Classification of Mast Cell Disorders with Special Reference to Mast Cell Activation Syndromes: A Consensus Proposal
Activation of tissue mast cells (MCs) and their abnormal growth and accumulation in various organs are typically found in primary MC disorders also referred to as mastocytosis. However, increasing numbers of patients are now being informed that their clinical findings are due to MC activation (MCA) that is neither associated with mastocytosis nor with a defined allergic or inflammatory reaction. In other patients with MCA, MCs appear to be clonal cells, but criteria for diagnosing mastocytosis are not met. A working conference was organized in 2010 with the aim to define criteria for diagnosing MCA and related disorders, and to propose a global unifying classification of all MC disorders and pathologic MC reactions. This classification includes three types of `MCA syndromes' (MCASs), namely primary MCAS, secondary MCAS and idiopathic MCAS. MCA is now defined by robust and generally applicable criteria, including (1) typical clinical symptoms, (2) a substantial transient increase in serum total tryptase level or an increase in other MC-derived mediators, such as histamine or prostaglandin D 2, or their urinary metabolites, and (3) a response of clinical symptoms to agents that attenuate the production or activities of MC mediators. These criteria should assist in the identification and diagnosis of patients with MCAS, and in avoiding misdiagnoses or overinterpretation of clinical symptoms in daily practice. Moreover, the MCAS concept should stimulate research in order to identify and exploit new molecular mechanisms and therapeutic targets. Copyright (C) 2011 S. Karger AG, Base
SIADH and hyponatraemia: why does it matter?
The vasopressin-receptor antagonists have received approval for the treatment of hyponatraemia secondary to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). It is therefore necessary that physicians encountering hyponatraemia focus on SIADH. Recent studies show that hyponatraemia is often poorly managed—insufficient diagnostic tests are ordered and patients are undertreated. At the same time, it has become clear that chronic hyponatraemia causes neurological symptoms such as gait disturbances and attention deficits. However, physicians often tolerate chronic hyponatraemia as if it were benign, or as if its treatment would cause significant morbidity. Therefore, physicians must reconsider the diagnostic and therapeutic approaches to hyponatraemia and SIADH
A survey of statistics in three UK general practice journal
Background
Many medical specialities have reviewed the statistical content of their journals. To our knowledge this has not been done in general practice. Given the main role of a general practitioner as a diagnostician we thought it would be of interest to see whether the statistical methods reported reflect the diagnostic process.
Methods
Hand search of three UK journals of general practice namely the British Medical Journal (general practice section), British Journal of General Practice and Family Practice over a one-year period (1 January to 31 December 2000).
Results
A wide variety of statistical techniques were used. The most common methods included t-tests and Chi-squared tests. There were few articles reporting likelihood ratios and other useful diagnostic methods. There was evidence that the journals with the more thorough statistical review process reported a more complex and wider variety of statistical techniques.
Conclusions
The BMJ had a wider range and greater diversity of statistical methods than the other two journals. However, in all three journals there was a dearth of papers reflecting the diagnostic process. Across all three journals there were relatively few papers describing randomised controlled trials thus recognising the difficulty of implementing this design in general practice
Recognizing Speech in a Novel Accent: The Motor Theory of Speech Perception Reframed
The motor theory of speech perception holds that we perceive the speech of
another in terms of a motor representation of that speech. However, when we
have learned to recognize a foreign accent, it seems plausible that recognition
of a word rarely involves reconstruction of the speech gestures of the speaker
rather than the listener. To better assess the motor theory and this
observation, we proceed in three stages. Part 1 places the motor theory of
speech perception in a larger framework based on our earlier models of the
adaptive formation of mirror neurons for grasping, and for viewing extensions
of that mirror system as part of a larger system for neuro-linguistic
processing, augmented by the present consideration of recognizing speech in a
novel accent. Part 2 then offers a novel computational model of how a listener
comes to understand the speech of someone speaking the listener's native
language with a foreign accent. The core tenet of the model is that the
listener uses hypotheses about the word the speaker is currently uttering to
update probabilities linking the sound produced by the speaker to phonemes in
the native language repertoire of the listener. This, on average, improves the
recognition of later words. This model is neutral regarding the nature of the
representations it uses (motor vs. auditory). It serve as a reference point for
the discussion in Part 3, which proposes a dual-stream neuro-linguistic
architecture to revisits claims for and against the motor theory of speech
perception and the relevance of mirror neurons, and extracts some implications
for the reframing of the motor theory
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