47,195 research outputs found
Asymptotic enumeration of correlation-immune boolean functions
A boolean function of boolean variables is {correlation-immune} of order
if the function value is uncorrelated with the values of any of the
arguments. Such functions are of considerable interest due to their
cryptographic properties, and are also related to the orthogonal arrays of
statistics and the balanced hypercube colourings of combinatorics. The {weight}
of a boolean function is the number of argument values that produce a function
value of 1. If this is exactly half the argument values, that is,
values, a correlation-immune function is called {resilient}.
An asymptotic estimate of the number of -variable
correlation-immune boolean functions of order was obtained in 1992 by
Denisov for constant . Denisov repudiated that estimate in 2000, but we will
show that the repudiation was a mistake.
The main contribution of this paper is an asymptotic estimate of
which holds if increases with within generous limits and specialises to
functions with a given weight, including the resilient functions. In the case
of , our estimates are valid for all weights.Comment: 18 page
libtissue - implementing innate immunity
In a previous paper the authors argued the case for incorporating ideas from
innate immunity into articficial immune systems (AISs) and presented an outline
for a conceptual framework for such systems. A number of key general properties
observed in the biological innate and adaptive immune systems were hughlighted,
and how such properties might be instantiated in artificial systems was
discussed in detail. The next logical step is to take these ideas and build a
software system with which AISs with these properties can be implemented and
experimentally evaluated. This paper reports on the results of that step - the
libtissue system.Comment: 8 pages, 4 tables, 5 figures, Workshop on Artificial Immune Systems
and Immune System Modelling (AISB06), Bristol, U
An Immune Inspired Approach to Anomaly Detection
The immune system provides a rich metaphor for computer security: anomaly
detection that works in nature should work for machines. However, early
artificial immune system approaches for computer security had only limited
success. Arguably, this was due to these artificial systems being based on too
simplistic a view of the immune system. We present here a second generation
artificial immune system for process anomaly detection. It improves on earlier
systems by having different artificial cell types that process information.
Following detailed information about how to build such second generation
systems, we find that communication between cells types is key to performance.
Through realistic testing and validation we show that second generation
artificial immune systems are capable of anomaly detection beyond generic
system policies. The paper concludes with a discussion and outline of the next
steps in this exciting area of computer security.Comment: 19 pages, 4 tables, 2 figures, Handbook of Research on Information
Security and Assuranc
Celebration Schedule 2015 (Friday)
Full presentation schedule for Celebration, Friday, May 1, 201
Ligand-induced monoubiquitination of BIK1 regulates plant immunity
The detection of microorganism-associated ligands by plant cells activates a signalling cascade in which the kinase BIK1 is monoubiquinated, released from the FLS2-BAK1 complex, and internalized by endocytosis.
Recognition of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) triggers the first line of inducible defence against invading pathogens(1-3). Receptor-like cytoplasmic kinases (RLCKs) are convergent regulators that associate with multiple PRRs in plants(4). The mechanisms that underlie the activation of RLCKs are unclear. Here we show that when MAMPs are detected, the RLCK BOTRYTIS-INDUCED KINASE 1 (BIK1) is monoubiquitinated following phosphorylation, then released from the flagellin receptor FLAGELLIN SENSING 2 (FLS2)-BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1 (BAK1) complex, and internalized dynamically into endocytic compartments. The Arabidopsis E3 ubiquitin ligases RING-H2 FINGER A3A (RHA3A) and RHA3B mediate the monoubiquitination of BIK1, which is essential for the subsequent release of BIK1 from the FLS2-BAK1 complex and activation of immune signalling. Ligand-induced monoubiquitination and endosomal puncta of BIK1 exhibit spatial and temporal dynamics that are distinct from those of the PRR FLS2. Our study reveals the intertwined regulation of PRR-RLCK complex activation by protein phosphorylation and ubiquitination, and shows that ligand-induced monoubiquitination contributes to the release of BIK1 family RLCKs from the PRR complex and activation of PRR signalling
Immunological basis of differences in disease resistance in the chicken
Genetic resistance to diseases is a multigenic trait governed mainly by the immune system and its interactions with many physiologic and environmental factors. In the adaptive immunity, T cell and B cell responses, the specific recognition of antigens and interactions between antigen presenting cells, T cells and B cells are crucial. It occurs through a network of mediator proteins such as the molecules of the major histocompatibility complex (MHC), T cell receptors, immunoglobulins and secreted proteins such as the cytokines and antibodies. The diversity of these proteins that mainly is due to an intrinsic polymorphism of the genes causes phenotypic variation in disease resistance. The well-known linkage of MHC polymorphism and Marek's disease resistance difference represents a classic model revealing immunological factors in resistance differences and diversity of mediator molecules. The molecular bases in any resistance variation to infectious pathogens are vaguely understood. This paper presents a review of the major immune mediators involved in resistance and susceptibility to infectious diseases and their functional mechanisms in the chicken. The genetic interaction of disease resistance with production traits and the environment is mentioned
Free energies of Boltzmann Machines: self-averaging, annealed and replica symmetric approximations in the thermodynamic limit
Restricted Boltzmann machines (RBMs) constitute one of the main models for
machine statistical inference and they are widely employed in Artificial
Intelligence as powerful tools for (deep) learning. However, in contrast with
countless remarkable practical successes, their mathematical formalization has
been largely elusive: from a statistical-mechanics perspective these systems
display the same (random) Gibbs measure of bi-partite spin-glasses, whose
rigorous treatment is notoriously difficult. In this work, beyond providing a
brief review on RBMs from both the learning and the retrieval perspectives, we
aim to contribute to their analytical investigation, by considering two
distinct realizations of their weights (i.e., Boolean and Gaussian) and
studying the properties of their related free energies. More precisely,
focusing on a RBM characterized by digital couplings, we first extend the
Pastur-Shcherbina-Tirozzi method (originally developed for the Hopfield model)
to prove the self-averaging property for the free energy, over its quenched
expectation, in the infinite volume limit, then we explicitly calculate its
simplest approximation, namely its annealed bound. Next, focusing on a RBM
characterized by analogical weights, we extend Guerra's interpolating scheme to
obtain a control of the quenched free-energy under the assumption of replica
symmetry: we get self-consistencies for the order parameters (in full agreement
with the existing Literature) as well as the critical line for ergodicity
breaking that turns out to be the same obtained in AGS theory. As we discuss,
this analogy stems from the slow-noise universality. Finally, glancing beyond
replica symmetry, we analyze the fluctuations of the overlaps for an estimate
of the (slow) noise affecting the retrieval of the signal, and by a stability
analysis we recover the Aizenman-Contucci identities typical of glassy systems.Comment: 21 pages, 1 figur
HiZELS: the High Redshift Emission Line Survey with UKIRT
In these proceedings we report on HiZELS, the High-z Emission Line Survey,
our successful panoramic narrow-band Campaign Survey using WFCAM on UKIRT to
detect and study emission line galaxies at z~1-9. HiZELS employs the H2(S1)
narrow-band filter together with custom-made narrow-band filters in the J and
H-bands, with the primary aim of delivering large, identically-selected samples
of H-alpha emitting galaxies at redshifts of 0.84, 1.47 and 2.23. Comparisons
between the luminosity function, the host galaxy properties, the clustering,
and the variation with environment of these H-alpha-selected samples are
yielding unique constraints on the nature and evolution of star-forming
galaxies, across the peak epoch of star-formation activity in the Universe. We
provide a summary of the project status, and detail the main scientific results
obtained so far: the measurement of the evolution of the cosmic star-formation
rate density out to z > 2 using a single star-formation indicator,
determination of the morphologies, environments and dust-content of the
star-forming galaxies, and a detailed investigation of the evolution of their
clustering properties. We also summarise the on-going work and future goals of
the project.Comment: To appear in proceedings of "UKIRT at 30: A British Success Story"
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