1,018 research outputs found
Comparison of System Call Representations for Intrusion Detection
Over the years, artificial neural networks have been applied successfully in
many areas including IT security. Yet, neural networks can only process
continuous input data. This is particularly challenging for security-related
non-continuous data like system calls. This work focuses on four different
options to preprocess sequences of system calls so that they can be processed
by neural networks. These input options are based on one-hot encoding and
learning word2vec or GloVe representations of system calls. As an additional
option, we analyze if the mapping of system calls to their respective kernel
modules is an adequate generalization step for (a) replacing system calls or
(b) enhancing system call data with additional information regarding their
context. However, when performing such preprocessing steps it is important to
ensure that no relevant information is lost during the process. The overall
objective of system call based intrusion detection is to categorize sequences
of system calls as benign or malicious behavior. Therefore, this scenario is
used to evaluate the different input options as a classification task. The
results show, that each of the four different methods is a valid option when
preprocessing input data, but the use of kernel modules only is not recommended
because too much information is being lost during the mapping process.Comment: 12 pages, 1 figure, submitted to CISIS 201
Identification of malaria hot spots for focused intervention in tribal state of India: a GIS based approach
<p>Abstract</p> <p>Background</p> <p>In India, presently malaria shows a declining trend whereas <it>Plasmodium falciparum (Pf) </it>cases show an up trend. In central India, specifically, Madhya Pradesh (M.P.) a forested and tribal area, control of malaria is logistically difficult and outbreaks are frequently recorded, reasons for this being inadequate surveillance, poor reporting, a time lag in reporting to decision makers and a lack of geo referenced information to pin point the trouble spots for a timely preventive action.</p> <p>Results</p> <p>An information management system based on Geographic Information System (GIS) using district and block wise malaria data, has been constructed for Madhya Pradesh for quick retrieval of info and dynamic generation of maps to highlight hot spots of malaria for formulating prompt and focused malaria control strategy. Out of total 48 districts consisting of 313 blocks, based on certain criteria GIS identified 58 blocks falling in 25 districts as Hot Spots. Malaria flares up from these pockets whenever favourable conditions for transmission occurs. It was suggested to National Vector Borne Disease Control Programme (NVBDCP) that focused malaria control in these hot pockets may be taken up on priority during the year 2007, it was implemented by State Health Authorities, M.P. under the directive of NVBDCP. Implementation of control measures were evaluated by NVBDCP.</p> <p>Conclusion</p> <p>GIS mapping would make it easy to update information instantly and to identify the trouble spots at the village level within the district which is the lowest unit equipped with computer facilities and the information can reach instantly to state and the policy makers to formulate focused and cost effective malaria control strategy. This is the first time when GIS has been used in national control programme for tribal malaria.</p
A Feynman integral in Lifshitz-point and Lorentz-violating theories in R<sup>D</sup> ⨁ R<i><sup>m</sup></i>
We evaluate a 1-loop, 2-point, massless Feynman integral ID,m(p,q) relevant for perturbative field theoretic calculations in strongly anisotropic d=D+m dimensional spaces given by the direct sum RD ⨁ Rm . Our results are valid in the whole convergence region of the integral for generic (noninteger) codimensions D and m. We obtain series expansions of ID,m(p,q) in terms of powers of the variable X:=4p2/q4, where p=|p|, q=|q|, p Є RD, q Є Rm, and in terms of generalised hypergeometric functions 3F2(−X), when X<1. These are subsequently analytically continued to the complementary region X≥1. The asymptotic expansion in inverse powers of X1/2 is derived. The correctness of the results is supported by agreement with previously known special cases and extensive numerical calculations
Regulation of Mouse Small Heat Shock Protein αb-Crystallin Gene by Aryl Hydrocarbon Receptor
The stress-inducible small heat shock protein (shsp)/αB-crystallin gene is expressed highly in the lens and moderately in other tissues. Here we provide evidence that it is a target gene of the aryl hydrocarbon receptor (AhR) transcription factor. A sequence (−329/−323, CATGCGA) similar to the consensus xenobiotic responsive element (XRE), called here XRE-like, is present in the αBE2 region of αB-crystallin enhancer and can bind AhR in vitro and in vivo. αB-crystallin protein levels were reduced in retina, lens, cornea, heart, skeletal muscle and cultured muscle fibroblasts of AhR−/− mice; αB-crystallin mRNA levels were reduced in the eye, heart and skeletal muscle of AhR−/− mice. Increased AhR stimulated αB-crystallin expression in transfection experiments conducted in conjunction with the aryl hydrocarbon receptor nuclear translocator (ARNT) and decreased AhR reduced αB-crystallin expression. AhR effect on aB-crystallin promoter activity was cell-dependent in transfection experiments. AhR up-regulated αB-crystallin promoter activity in transfected HeLa, NIH3T3 and COS-7 cells in the absence of exogenously added ligand (TCDD), but had no effect on the αB-crystallin promoter in C2C12, CV-1 or Hepa-1 cells with or without TCDD. TCDD enhanced AhR-stimulated αB-crystallin promoter activity in transfected αTN4 cells. AhR could bind to an XRE-like site in the αB-crystallin enhancer in vitro and in vivo. Finally, site-specific mutagenesis experiments showed that the XRE-like motif was necessary for both basal and maximal AhR-induction of αB-crystallin promoter activity. Our data strongly suggest that AhR is a regulator of αB-crystallin gene expression and provide new avenues of research for the mechanism of tissue-specific αB-crystallin gene regulation under normal and physiologically stressed conditions
Working Group Report: Heavy-Ion Physics and Quark-Gluon Plasma
This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09
which was part of Working Group-4. Discussion and work on some aspects of
Quark-Gluon Plasma believed to have created in heavy-ion collisions and in
early universe are reported.Comment: 20 pages, 6 eps figures, Heavy-ion physics and QGP activity report in
"IX Workshop on High Energy Physics Phenomenology (WHEPP-09)" held in
Institute of Physics, Bhubaneswar, India, during January 3-14, 2006. To be
published in PRAMANA - Journal of Physics (Indian Academy of Science
Acidic Extracellular pH Promotes Activation of Integrin αvβ3
Acidic extracellular pH is characteristic of the cell microenvironment in several important physiological and pathological contexts. Although it is well established that acidic extracellular pH can have profound effects on processes such as cell adhesion and migration, the underlying molecular mechanisms are largely unknown. Integrin receptors physically connect cells to the extracellular matrix, and are thus likely to modulate cell responses to extracellular conditions. Here, we examine the role of acidic extracellular pH in regulating activation of integrin [alpha]v[beta]3. Through computational molecular dynamics simulations, we find that acidic extracellular pH promotes opening of the [alpha]v[beta]3 headpiece, indicating that acidic pH can thereby facilitate integrin activation. This prediction is consistent with our flow cytometry and atomic force microscope-mediated force spectroscopy assays of integrin [alpha]v[beta]3 on live cells, which both demonstrate that acidic pH promotes activation at the intact cell surface. Finally, quantification of cell morphology and migration measurements shows that acidic extracellular pH affects cell behavior in a manner that is consistent with increased integrin activation. Taken together, these computational and experimental results suggest a new and complementary mechanism of integrin activation regulation, with associated implications for cell adhesion and migration in regions of altered pH that are relevant to wound healing and cancer.National Institute of Biomedical Imaging and Bioengineering (U.S.) (Award Number T32EB006348)Massachusetts Institute of Technology (Collamore-Rogers Fellowship)National Institutes of Health (U.S.) (NIH Cell Migration Consortium Grant U54-GM069668)National Science Foundation (U.S.) (CAREER Award)Singapore-MIT Alliance for Research and Technology (BioSystem and Micromechanics (BioSyM) Interdisciplinary Research Group
Investigating antimalarial drug interactions of emetine dihydrochloride hydrate using CalcuSyn-based interactivity calculations
The widespread introduction of artemisinin-based combination therapy has contributed to
recent reductions in malaria mortality. Combination therapies have a range of advantages,
including synergism, toxicity reduction, and delaying the onset of resistance acquisition.
Unfortunately, antimalarial combination therapy is limited by the depleting repertoire of
effective drugs with distinct target pathways. To fast-track antimalarial drug discovery, we
have previously employed drug-repositioning to identify the anti-amoebic drug, emetine
dihydrochloride hydrate, as a potential candidate for repositioned use against malaria.
Despite its 1000-fold increase in in vitro antimalarial potency (ED50 47 nM) compared with
its anti-amoebic potency (ED50 26±32 uM), practical use of the compound has been limited
by dose-dependent toxicity (emesis and cardiotoxicity). Identification of a synergistic partner
drug would present an opportunity for dose-reduction, thus increasing the therapeutic window.
The lack of reliable and standardised methodology to enable the in vitro definition of
synergistic potential for antimalarials is a major drawback. Here we use isobologram and
combination-index data generated by CalcuSyn software analyses (Biosoft v2.1) to define
drug interactivity in an objective, automated manner. The method, based on the median
effect principle proposed by Chou and Talalay, was initially validated for antimalarial application
using the known synergistic combination (atovaquone-proguanil). The combination was
used to further understand the relationship between SYBR Green viability and cytocidal versus
cytostatic effects of drugs at higher levels of inhibition. We report here the use of the
optimised Chou Talalay method to define synergistic antimalarial drug interactivity between
emetine dihydrochloride hydrate and atovaquone. The novel findings present a potential
route to harness the nanomolar antimalarial efficacy of this affordable natural product
Chiral plasmonics of self-assembled nanorod dimers
Chiral nanoscale photonic systems typically follow either tetrahedral or helical geometries that require four
or more different constituent nanoparticles. Smaller number of particles and different chiral geometries
taking advantage of the self-organization capabilities of nanomaterials will advance understanding of chiral
plasmonic effects, facilitate development of their theory, and stimulate practical applications of
chiroplasmonics. Here we show that gold nanorods self-assemble into side-by-side orientated pairs and
‘‘ladders’’ in which chiral properties originate from the small dihedral angle between them. Spontaneous
twisting of one nanorod versus the other one breaks the centrosymmetric nature of the parallel assemblies.
Two possible enantiomeric conformations with positive and negative dihedral angles were obtained with
different assembly triggers. The chiral nature of the angled nanorod pairs was confirmed by 4p full space
simulations and the first example of single-particle CD spectroscopy. Self-assembled nanorod pairs and
‘‘ladders’’ enable the development of chiral metamaterials, (bio)sensors, and new catalytic processes
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