International Nuclear Information System (INIS)
Guo Ya'nan; Jin Dapeng; Zhao Dixin; Liu Zhen'an; Qiao Qiao; Chinese Academy of Sciences, Beijing
2007-01-01
Due to the randomness of radioactive decay and nuclear reaction, the signals from detectors are random in time. But normal pulse generator generates periodical pulses. To measure the performances of nuclear electronic devices under random inputs, a random generator is necessary. Types of random pulse generator are reviewed, 2 digital random pulse generators are introduced. (authors)
Quantum random number generator
Pooser, Raphael C.
2016-05-10
A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.
Quantum random number generator
Soubusta, Jan; Haderka, Ondrej; Hendrych, Martin
2001-03-01
Since reflection or transmission of a quantum particle on a beamsplitter is inherently random quantum process, a device built on this principle does not suffer from drawbacks of neither pseudo-random computer generators or classical noise sources. Nevertheless, a number of physical conditions necessary for high quality random numbers generation must be satisfied. Luckily, in quantum optics realization they can be well controlled. We present an easy random number generator based on the division of weak light pulses on a beamsplitter. The randomness of the generated bit stream is supported by passing the data through series of 15 statistical test. The device generates at a rate of 109.7 kbit/s.
Uniform random number generators
Farr, W. R.
1971-01-01
Methods are presented for the generation of random numbers with uniform and normal distributions. Subprogram listings of Fortran generators for the Univac 1108, SDS 930, and CDC 3200 digital computers are also included. The generators are of the mixed multiplicative type, and the mathematical method employed is that of Marsaglia and Bray.
International Nuclear Information System (INIS)
Coveyou, R.R.
1974-01-01
The subject of random number generation is currently controversial. Differing opinions on this subject seem to stem from implicit or explicit differences in philosophy; in particular, from differing ideas concerning the role of probability in the real world of physical processes, electronic computers, and Monte Carlo calculations. An attempt is made here to reconcile these views. The role of stochastic ideas in mathematical models is discussed. In illustration of these ideas, a mathematical model of the use of random number generators in Monte Carlo calculations is constructed. This model is used to set up criteria for the comparison and evaluation of random number generators. (U.S.)
El-Hayek, Georges; Bangalore, Sripal; Casso Dominguez, Abel; Devireddy, Chandan; Jaber, Wissam; Kumar, Gautam; Mavromatis, Kreton; Tamis-Holland, Jacqueline; Samady, Habib
2017-03-13
The authors sought to perform a meta-analysis of randomized clinical trials (RCTs) comparing the safety and efficacy of biodegradable polymer drug-eluting stents (BP-DES) to second-generation durable polymer drug-eluting stents (DP-DES). Prior meta-analyses have established the superiority of BP-DES over bare-metal stents and first-generation DP-DES; however, their advantage compared with second-generation DP-DES remains controversial. The authors searched PubMed and Scopus databases for RCTs comparing BP-DES to the second-generation DP-DES. Outcomes included target vessel revascularization (TVR) as efficacy outcome and cardiac death, myocardial infarction (MI), and definite or probable stent thrombosis (ST) as safety outcomes. In addition, we performed landmark analysis for endpoints beyond 1 year of follow-up and a subgroup analysis based on the stent characteristics. The authors included 16 RCTs comprising 19,886 patients in the meta-analysis. At the longest available follow-up (mean duration 26 months), we observed no significant differences in TVR (p = 0.62), cardiac death (p = 0.46), MI (p = 0.98), or ST (risk ratio: 0.83, 95% confidence interval: 0.64 to 1.09; p = 0.19). Our landmark analysis showed that BP-DES were not associated with a reduction in the risk of very late ST (risk ratio: 0.87, 95% confidence interval: 0.49 to 1.53; p = 0.62). Similar outcomes were seen regardless of the eluting drug (biolimus vs. sirolimus), the stent platform (stainless steel vs. alloy), the kinetics of polymer degradation or drug release (6 months), the strut thickness of the BP-DES (thin 100 μm), or the DAPT duration (≥6 months vs. ≥12 months). BP-DES have similar safety and efficacy profiles to second-generation DP-DES. Published by Elsevier Inc.
[Intel random number generator-based true random number generator].
Huang, Feng; Shen, Hong
2004-09-01
To establish a true random number generator on the basis of certain Intel chips. The random numbers were acquired by programming using Microsoft Visual C++ 6.0 via register reading from the random number generator (RNG) unit of an Intel 815 chipset-based computer with Intel Security Driver (ISD). We tested the generator with 500 random numbers in NIST FIPS 140-1 and X(2) R-Squared test, and the result showed that the random number it generated satisfied the demand of independence and uniform distribution. We also compared the random numbers generated by Intel RNG-based true random number generator and those from the random number table statistically, by using the same amount of 7500 random numbers in the same value domain, which showed that the SD, SE and CV of Intel RNG-based random number generator were less than those of the random number table. The result of u test of two CVs revealed no significant difference between the two methods. Intel RNG-based random number generator can produce high-quality random numbers with good independence and uniform distribution, and solves some problems with random number table in acquisition of the random numbers.
Digital random-number generator
Brocker, D. H.
1973-01-01
For binary digit array of N bits, use N noise sources to feed N nonlinear operators; each flip-flop in digit array is set by nonlinear operator to reflect whether amplitude of generator which feeds it is above or below mean value of generated noise. Fixed-point uniform distribution random number generation method can also be used to generate random numbers with other than uniform distribution.
Philip, Femi; Stewart, Susan; Southard, Jeffrey A
2016-07-01
The relative safety of drug-eluting stents (DES) and bare-metal stents (BMS) in primary percutaneous coronary intervention (PPCI) in ST elevation myocardial infarction (STEMI) continues to be debated. The long-term clinical outcomes between second generation DES and BMS for primary percutaneous coronary intervention (PCI) using network meta-analysis were compared. Randomized controlled trials comparing stent types (first generation DES, second generation DES, or BMS) were considered for inclusion. A search strategy used Medline, Embase, Cochrane databases, and proceedings of international meetings. Information about study design, inclusion criteria, and sample characteristics were extracted. Network meta-analysis was used to pool direct (comparison of second generation DES to BMS) and indirect evidence (first generation DES with BMS and second generation DES) from the randomized trials. Twelve trials comparing all stents types including 9,673 patients randomly assigned to treatment groups were analyzed. Second generation DES was associated with significantly lower incidence of definite or probable ST (OR 0.59, 95% CI 0.39-0.89), MI (OR 0.59, 95% CI 0.39-0.89), and TVR at 3 years (OR 0.50: 95% CI 0.31-0.81) compared with BMS. In addition, there was a significantly lower incidence of MACE with second generation DES versus BMS (OR 0.54, 95% CI 0.34-0.74) at 3 years. These were driven by a higher rate of TVR, MI and stent thrombosis in the BMS group at 3 years. There was a non-significant reduction in the overall and cardiac mortality [OR 0.83, 95% CI (0.60-1.14), OR 0.88, 95% CI (0.6-1.28)] with the use of second generation DES versus BMS at 3 years. Network meta-analysis of randomized trials of primary PCI demonstrated lower incidence of MACE, MI, TVR, and stent thrombosis with second generation DES compared with BMS. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Object grammars and random generation
Directory of Open Access Journals (Sweden)
I. Dutour
1998-12-01
Full Text Available This paper presents a new systematic approach for the uniform random generation of combinatorial objects. The method is based on the notion of object grammars which give recursive descriptions of objects and generalize context-freegrammars. The application of particular valuations to these grammars leads to enumeration and random generation of objects according to non algebraic parameters.
Random number generation and creativity.
Bains, William
2008-01-01
A previous paper suggested that humans can generate genuinely random numbers. I tested this hypothesis by repeating the experiment with a larger number of highly numerate subjects, asking them to call out a sequence of digits selected from 0 through 9. The resulting sequences were substantially non-random, with an excess of sequential pairs of numbers and a deficit of repeats of the same number, in line with previous literature. However, the previous literature suggests that humans generate random numbers with substantial conscious effort, and distractions which reduce that effort reduce the randomness of the numbers. I reduced my subjects' concentration by asking them to call out in another language, and with alcohol - neither affected the randomness of their responses. This suggests that the ability to generate random numbers is a 'basic' function of the human mind, even if those numbers are not mathematically 'random'. I hypothesise that there is a 'creativity' mechanism, while not truly random, provides novelty as part of the mind's defence against closed programming loops, and that testing for the effects seen here in people more or less familiar with numbers or with spontaneous creativity could identify more features of this process. It is possible that training to perform better at simple random generation tasks could help to increase creativity, through training people to reduce the conscious mind's suppression of the 'spontaneous', creative response to new questions.
Microcomputer Unit: Generating Random Numbers.
Haigh, William E.
1986-01-01
Presents an activity, suitable for students in grades 6-12, on generating random numbers. Objectives, equipment needed, list of prerequisite experiences, instructional strategies, and ready-to-copy student worksheets are included. (JN)
Computer generation of random deviates
International Nuclear Information System (INIS)
Cormack, John
1991-01-01
The need for random deviates arises in many scientific applications. In medical physics, Monte Carlo simulations have been used in radiology, radiation therapy and nuclear medicine. Specific instances include the modelling of x-ray scattering processes and the addition of random noise to images or curves in order to assess the effects of various processing procedures. Reliable sources of random deviates with statistical properties indistinguishable from true random deviates are a fundamental necessity for such tasks. This paper provides a review of computer algorithms which can be used to generate uniform random deviates and other distributions of interest to medical physicists, along with a few caveats relating to various problems and pitfalls which can occur. Source code listings for the generators discussed (in FORTRAN, Turbo-PASCAL and Data General ASSEMBLER) are available on request from the authors. 27 refs., 3 tabs., 5 figs
LPTAU, Quasi Random Sequence Generator
International Nuclear Information System (INIS)
Sobol, Ilya M.
1993-01-01
1 - Description of program or function: LPTAU generates quasi random sequences. These are uniformly distributed sets of L=M N points in the N-dimensional unit cube: I N =[0,1]x...x[0,1]. These sequences are used as nodes for multidimensional integration; as searching points in global optimization; as trial points in multi-criteria decision making; as quasi-random points for quasi Monte Carlo algorithms. 2 - Method of solution: Uses LP-TAU sequence generation (see references). 3 - Restrictions on the complexity of the problem: The number of points that can be generated is L 30 . The dimension of the space cannot exceed 51
The MIXMAX random number generator
Savvidy, Konstantin G.
2015-11-01
In this paper, we study the randomness properties of unimodular matrix random number generators. Under well-known conditions, these discrete-time dynamical systems have the highly desirable K-mixing properties which guarantee high quality random numbers. It is found that some widely used random number generators have poor Kolmogorov entropy and consequently fail in empirical tests of randomness. These tests show that the lowest acceptable value of the Kolmogorov entropy is around 50. Next, we provide a solution to the problem of determining the maximal period of unimodular matrix generators of pseudo-random numbers. We formulate the necessary and sufficient condition to attain the maximum period and present a family of specific generators in the MIXMAX family with superior performance and excellent statistical properties. Finally, we construct three efficient algorithms for operations with the MIXMAX matrix which is a multi-dimensional generalization of the famous cat-map. First, allowing to compute the multiplication by the MIXMAX matrix with O(N) operations. Second, to recursively compute its characteristic polynomial with O(N2) operations, and third, to apply skips of large number of steps S to the sequence in O(N2 log(S)) operations.
Pseudo-Random Number Generators
Howell, L. W.; Rheinfurth, M. H.
1984-01-01
Package features comprehensive selection of probabilistic distributions. Monte Carlo simulations resorted to whenever systems studied not amenable to deterministic analyses or when direct experimentation not feasible. Random numbers having certain specified distribution characteristic integral part of simulations. Package consists of collector of "pseudorandom" number generators for use in Monte Carlo simulations.
USER S GUIDE FOR THE RANDOM DRUG SCREENING SYSTEM
Energy Technology Data Exchange (ETDEWEB)
McNeany, Karen I [ORNL
2013-12-01
The Random Drug Screening System (RDSS) is a desktop computing application designed to assign nongameable drug testing dates to each member in a population of employees, within a specific time line. The program includes reporting capabilities, test form generation, unique test ID number assignment, and the ability to flag high-risk employees for a higher frequency of drug testing than the general population.
Generating random networks and graphs
Coolen, Ton; Roberts, Ekaterina
2017-01-01
This book supports researchers who need to generate random networks, or who are interested in the theoretical study of random graphs. The coverage includes exponential random graphs (where the targeted probability of each network appearing in the ensemble is specified), growth algorithms (i.e. preferential attachment and the stub-joining configuration model), special constructions (e.g. geometric graphs and Watts Strogatz models) and graphs on structured spaces (e.g. multiplex networks). The presentation aims to be a complete starting point, including details of both theory and implementation, as well as discussions of the main strengths and weaknesses of each approach. It includes extensive references for readers wishing to go further. The material is carefully structured to be accessible to researchers from all disciplines while also containing rigorous mathematical analysis (largely based on the techniques of statistical mechanics) to support those wishing to further develop or implement the theory of rand...
Rabinowitz, Jonathan; Levine, Stephen Z.; Barkai, Orna; Davidov, Ori
2008-01-01
Dropout is often used as an outcome measure in clinical trials of antipsychotic medication. Previous research is inconclusive regarding (a) differences in dropout rates between first- and second-generation antipsychotic medications and (b) how trial design features reduce dropout. Meta-analysis of randomized controlled trials (RCTs) of antipsychotic medication was conducted to compare dropout rates for first- and second-generation antipsychotic drugs and to examine how a broad range of design...
Random Generators and Normal Numbers
Bailey, David H.; Crandall, Richard E.
2002-01-01
Pursuant to the authors' previous chaotic-dynamical model for random digits of fundamental constants, we investigate a complementary, statistical picture in which pseudorandom number generators (PRNGs) are central. Some rigorous results are achieved: We establish b-normality for constants of the form $\\sum_i 1/(b^{m_i} c^{n_i})$ for certain sequences $(m_i), (n_i)$ of integers. This work unifies and extends previously known classes of explicit normals. We prove that for coprime $b,c>1$ the...
A Model for Random Student Drug Testing
Nelson, Judith A.; Rose, Nancy L.; Lutz, Danielle
2011-01-01
The purpose of this case study was to examine random student drug testing in one school district relevant to: (a) the perceptions of students participating in competitive extracurricular activities regarding drug use and abuse; (b) the attitudes and perceptions of parents, school staff, and community members regarding student drug involvement; (c)…
A random number generator for continuous random variables
Guerra, V. M.; Tapia, R. A.; Thompson, J. R.
1972-01-01
A FORTRAN 4 routine is given which may be used to generate random observations of a continuous real valued random variable. Normal distribution of F(x), X, E(akimas), and E(linear) is presented in tabular form.
Zaccara, Gaetano; Giovannelli, Fabio; Maratea, Dario; Fadda, Valeria; Verrotti, Alberto
2013-09-01
Analysis of overall tolerability and neurological adverse effects (AEs) of eslicarbazepine acetate (ESL), lacosamide (LCM) and oxcarbazepine (OXC) from double-blind, placebo-controlled trials. Indirect comparisons of patients withdrawing because of AEs, and the incidence of some vestibulocerebellar AEs between these three antiepileptic dugs (AEDs). We searched MEDLINE for all randomized, double-blind, placebo-controlled trials investigating therapeutic effects of fixed oral doses of ESL, LCM and OXC in patients with drug resistant epilepsy. Withdrawal rate due to AEs, percentages of patients with serious AEs, and the proportion of patients experiencing any neurological AE, nausea and vomiting were assessed for their association with the experimental drug. Analyses were performed between recommended daily doses of each AED according to the approved summary of product characteristics (SPC). Risk differences were used to evaluate the association of any AE [99% confidence intervals (CIs)] or study withdrawals because of AEs (95% CIs) with the experimental drug. Indirect comparisons between withdrawal rate and AEs dizziness, coordination abnormal/ataxia and diplopia were estimated according to network meta-analysis (Net-MA). Eight randomized, placebo-controlled, double-blind trials (4 with ESL, 3 with LCM, and 1 with OXC) were included in our analysis. At high doses (OXC 1200mg, ESL 1200mg and LCM 400mg) there was an increased risk of AE-related study withdrawals compared to placebo for all drugs. Several AEs were associated with the experimental drug. Both number and frequency of AEs were dose-related. At high recommended doses, patients treated with OXC withdrew from the experimental treatment significantly more frequently than patients treated with ESL and LCM. Furthermore, the AEs coordination abnormal/ataxia and diplopia were significantly more frequently observed in patients treated with OXC compared to patients treated with LCM and ESL. The overall tolerability
The RANDOM computer program: A linear congruential random number generator
Miles, R. F., Jr.
1986-01-01
The RANDOM Computer Program is a FORTRAN program for generating random number sequences and testing linear congruential random number generators (LCGs). The linear congruential form of random number generator is discussed, and the selection of parameters of an LCG for a microcomputer described. This document describes the following: (1) The RANDOM Computer Program; (2) RANDOM.MOD, the computer code needed to implement an LCG in a FORTRAN program; and (3) The RANCYCLE and the ARITH Computer Programs that provide computational assistance in the selection of parameters for an LCG. The RANDOM, RANCYCLE, and ARITH Computer Programs are written in Microsoft FORTRAN for the IBM PC microcomputer and its compatibles. With only minor modifications, the RANDOM Computer Program and its LCG can be run on most micromputers or mainframe computers.
Generation of pseudo-random numbers
Howell, L. W.; Rheinfurth, M. H.
1982-01-01
Practical methods for generating acceptable random numbers from a variety of probability distributions which are frequently encountered in engineering applications are described. The speed, accuracy, and guarantee of statistical randomness of the various methods are discussed.
Self-correcting random number generator
Humble, Travis S.; Pooser, Raphael C.
2016-09-06
A system and method for generating random numbers. The system may include a random number generator (RNG), such as a quantum random number generator (QRNG) configured to self-correct or adapt in order to substantially achieve randomness from the output of the RNG. By adapting, the RNG may generate a random number that may be considered random regardless of whether the random number itself is tested as such. As an example, the RNG may include components to monitor one or more characteristics of the RNG during operation, and may use the monitored characteristics as a basis for adapting, or self-correcting, to provide a random number according to one or more performance criteria.
Analysis of android random number generator
Sarıtaş, Serkan
2013-01-01
Ankara : The Department of Computer Engineering and the Graduate School of Engineering and Science of Bilkent University, 2013. Thesis (Master's) -- Bilkent University, 2013. Includes bibliographical references leaves 61-65. Randomness is a crucial resource for cryptography, and random number generators are critical building blocks of almost all cryptographic systems. Therefore, random number generation is one of the key parts of secure communication. Random number generatio...
Song, J; Doucette, C; Hanniford, D; Hunady, K; Wang, N; Sherf, B; Harrington, J J; Brunden, K R; Stricker-Krongrad, A
2005-06-01
Target-based high-throughput screening (HTS) plays an integral role in drug discovery. The implementation of HTS assays generally requires high expression levels of the target protein, and this is typically accomplished using recombinant cDNA methodologies. However, the isolated gene sequences to many drug targets have intellectual property claims that restrict the ability to implement drug discovery programs. The present study describes the pharmacological characterization of the human histamine H3 receptor that was expressed using random activation of gene expression (RAGE), a technology that over-expresses proteins by up-regulating endogenous genes rather than introducing cDNA expression vectors into the cell. Saturation binding analysis using [125I]iodoproxyfan and RAGE-H3 membranes revealed a single class of binding sites with a K(D) value of 0.77 nM and a B(max) equal to 756 fmol/mg of protein. Competition binding studies showed that the rank order of potency for H3 agonists was N(alpha)-methylhistamine approximately (R)-alpha- methylhistamine > histamine and that the rank order of potency for H3 antagonists was clobenpropit > iodophenpropit > thioperamide. The same rank order of potency for H3 agonists and antagonists was observed in the functional assays as in the binding assays. The Fluorometic Imaging Plate Reader assays in RAGE-H3 cells gave high Z' values for agonist and antagonist screening, respectively. These results reveal that the human H3 receptor expressed with the RAGE technology is pharmacologically comparable to that expressed through recombinant methods. Moreover, the level of expression of the H3 receptor in the RAGE-H3 cells is suitable for HTS and secondary assays.
How random are random numbers generated using photons?
International Nuclear Information System (INIS)
Solis, Aldo; Angulo Martínez, Alí M; Ramírez Alarcón, Roberto; Cruz Ramírez, Hector; U’Ren, Alfred B; Hirsch, Jorge G
2015-01-01
Randomness is fundamental in quantum theory, with many philosophical and practical implications. In this paper we discuss the concept of algorithmic randomness, which provides a quantitative method to assess the Borel normality of a given sequence of numbers, a necessary condition for it to be considered random. We use Borel normality as a tool to investigate the randomness of ten sequences of bits generated from the differences between detection times of photon pairs generated by spontaneous parametric downconversion. These sequences are shown to fulfil the randomness criteria without difficulties. As deviations from Borel normality for photon-generated random number sequences have been reported in previous work, a strategy to understand these diverging findings is outlined. (paper)
Source-Independent Quantum Random Number Generation
Cao, Zhu; Zhou, Hongyi; Yuan, Xiao; Ma, Xiongfeng
2016-01-01
Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts—a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over 5 ×103 bit /s .
Source-Independent Quantum Random Number Generation
Directory of Open Access Journals (Sweden)
Zhu Cao
2016-02-01
Full Text Available Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts—a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over 5×10^{3} bit/s.
All-optical fast random number generator.
Li, Pu; Wang, Yun-Cai; Zhang, Jian-Zhong
2010-09-13
We propose a scheme of all-optical random number generator (RNG), which consists of an ultra-wide bandwidth (UWB) chaotic laser, an all-optical sampler and an all-optical comparator. Free from the electric-device bandwidth, it can generate 10Gbit/s random numbers in our simulation. The high-speed bit sequences can pass standard statistical tests for randomness after all-optical exclusive-or (XOR) operation.
Quality pseudo-random number generator
International Nuclear Information System (INIS)
Tarasiuk, J.
1996-01-01
The pseudo-random number generator (RNG) was written to match needs of nuclear and high-energy physics computation which in some cases require very long and independent random number sequences. In this random number generator the repetition period is about 10 36 what should be sufficient for all computers in the world. In this article the test results of RNG correlation, speed and identity of computations for PC, Sun4 and VAX computer tests are presented
Random Number Generation in Autism.
Williams, Mark A.; Moss, Simon A.; Bradshaw, John L.; Rinehart, Nicole J.
2002-01-01
This study explored the ability of 14 individuals with autism to generate a unique series of digits. Individuals with autism were more likely to repeat previous digits than comparison individuals, suggesting they may exhibit a shortfall in response inhibition. Results support the executive dysfunction theory of autism. (Contains references.)…
Random Item Generation Is Affected by Age
Multani, Namita; Rudzicz, Frank; Wong, Wing Yiu Stephanie; Namasivayam, Aravind Kumar; van Lieshout, Pascal
2016-01-01
Purpose: Random item generation (RIG) involves central executive functioning. Measuring aspects of random sequences can therefore provide a simple method to complement other tools for cognitive assessment. We examine the extent to which RIG relates to specific measures of cognitive function, and whether those measures can be estimated using RIG…
Quantifiers for randomness of chaotic pseudo-random number generators.
De Micco, L; Larrondo, H A; Plastino, A; Rosso, O A
2009-08-28
We deal with randomness quantifiers and concentrate on their ability to discern the hallmark of chaos in time series used in connection with pseudo-random number generators (PRNGs). Workers in the field are motivated to use chaotic maps for generating PRNGs because of the simplicity of their implementation. Although there exist very efficient general-purpose benchmarks for testing PRNGs, we feel that the analysis provided here sheds additional didactic light on the importance of the main statistical characteristics of a chaotic map, namely (i) its invariant measure and (ii) the mixing constant. This is of help in answering two questions that arise in applications: (i) which is the best PRNG among the available ones? and (ii) if a given PRNG turns out not to be good enough and a randomization procedure must still be applied to it, which is the best applicable randomization procedure? Our answer provides a comparative analysis of several quantifiers advanced in the extant literature.
Pseudo-random number generator based on asymptotic deterministic randomness
Wang, Kai; Pei, Wenjiang; Xia, Haishan; Cheung, Yiu-ming
2008-06-01
A novel approach to generate the pseudorandom-bit sequence from the asymptotic deterministic randomness system is proposed in this Letter. We study the characteristic of multi-value correspondence of the asymptotic deterministic randomness constructed by the piecewise linear map and the noninvertible nonlinearity transform, and then give the discretized systems in the finite digitized state space. The statistic characteristics of the asymptotic deterministic randomness are investigated numerically, such as stationary probability density function and random-like behavior. Furthermore, we analyze the dynamics of the symbolic sequence. Both theoretical and experimental results show that the symbolic sequence of the asymptotic deterministic randomness possesses very good cryptographic properties, which improve the security of chaos based PRBGs and increase the resistance against entropy attacks and symbolic dynamics attacks.
Pseudo-random number generator based on asymptotic deterministic randomness
International Nuclear Information System (INIS)
Wang Kai; Pei Wenjiang; Xia Haishan; Cheung Yiuming
2008-01-01
A novel approach to generate the pseudorandom-bit sequence from the asymptotic deterministic randomness system is proposed in this Letter. We study the characteristic of multi-value correspondence of the asymptotic deterministic randomness constructed by the piecewise linear map and the noninvertible nonlinearity transform, and then give the discretized systems in the finite digitized state space. The statistic characteristics of the asymptotic deterministic randomness are investigated numerically, such as stationary probability density function and random-like behavior. Furthermore, we analyze the dynamics of the symbolic sequence. Both theoretical and experimental results show that the symbolic sequence of the asymptotic deterministic randomness possesses very good cryptographic properties, which improve the security of chaos based PRBGs and increase the resistance against entropy attacks and symbolic dynamics attacks
RANDNA: a random DNA sequence generator.
Piva, Francesco; Principato, Giovanni
2006-01-01
Monte Carlo simulations are useful to verify the significance of data. Genomic regularities, such as the nucleotide correlations or the not uniform distribution of the motifs throughout genomic or mature mRNA sequences, exist and their significance can be checked by means of the Monte Carlo test. The test needs good quality random sequences in order to work, moreover they should have the same nucleotide distribution as the sequences in which the regularities have been found. Random DNA sequences are also useful to estimate the background score of an alignment, that is a threshold below which the resulting score is merely due to chance. We have developed RANDNA, a free software which allows to produce random DNA or RNA sequences setting both their length and the percentage of nucleotide composition. Sequences having the same nucleotide distribution of exonic, intronic or intergenic sequences can be generated. Its graphic interface makes it possible to easily set the parameters that characterize the sequences being produced and saved in a text format file. The pseudo-random number generator function of Borland Delphi 6 is used, since it guarantees a good randomness, a long cycle length and a high speed. We have checked the quality of sequences generated by the software, by means of well-known tests, both by themselves and versus genuine random sequences. We show the good quality of the generated sequences. The software, complete with examples and documentation, is freely available to users from: http://www.introni.it/en/software.
Generating equilateral random polygons in confinement III
International Nuclear Information System (INIS)
Diao, Y; Ernst, C; Montemayor, A; Ziegler, U
2012-01-01
In this paper we continue our earlier studies (Diao et al 2011 J. Phys. A: Math. Theor. 44 405202, Diao et al J. Phys. A: Math. Theor. 45 275203) on the generation methods of random equilateral polygons confined in a sphere. The first half of this paper is concerned with the generation of confined equilateral random walks. We show that if the selection of a vertex is uniform subject to the position of its previous vertex and the confining condition, then the distributions of the vertices are not uniform, although there exists a distribution such that if the initial vertex is selected following this distribution, then all vertices of the random walk follow this same distribution. Thus in order to generate a confined equilateral random walk, the selection of a vertex cannot be uniform subject to the position of its previous vertex and the confining condition. We provide a simple algorithm capable of generating confined equilateral random walks whose vertex distribution is almost uniform in the confinement sphere. In the second half of this paper we show that any process generating confined equilateral random walks can be turned into a process generating confined equilateral random polygons with the property that the vertex distribution of the polygons approaches the vertex distribution of the walks as the polygons get longer and longer. In our earlier studies, the starting point of the confined polygon is fixed at the center of the sphere. The new approach here allows us to move the starting point of the confined polygon off the center of the sphere. (paper)
On grey levels in random CAPTCHA generation
Newton, Fraser; Kouritzin, Michael A.
2011-06-01
A CAPTCHA is an automatically generated test designed to distinguish between humans and computer programs; specifically, they are designed to be easy for humans but difficult for computer programs to pass in order to prevent the abuse of resources by automated bots. They are commonly seen guarding webmail registration forms, online auction sites, and preventing brute force attacks on passwords. In the following, we address the question: How does adding a grey level to random CAPTCHA generation affect the utility of the CAPTCHA? We treat the problem of generating the random CAPTCHA as one of random field simulation: An initial state of background noise is evolved over time using Gibbs sampling and an efficient algorithm for generating correlated random variables. This approach has already been found to yield highly-readable yet difficult-to-crack CAPTCHAs. We detail how the requisite parameters for introducing grey levels are estimated and how we generate the random CAPTCHA. The resulting CAPTCHA will be evaluated in terms of human readability as well as its resistance to automated attacks in the forms of character segmentation and optical character recognition.
Generating equilateral random polygons in confinement II
International Nuclear Information System (INIS)
Diao, Y; Ernst, C; Montemayor, A; Ziegler, U
2012-01-01
In this paper we continue an earlier study (Diao et al 2011 J. Phys. A: Math. Theor. 44 405202) on the generation algorithms of random equilateral polygons confined in a sphere. Here, the equilateral random polygons are rooted at the center of the confining sphere and the confining sphere behaves like an absorbing boundary. One way to generate such a random polygon is the accept/reject method in which an unconditioned equilateral random polygon rooted at origin is generated. The polygon is accepted if it is within the confining sphere, otherwise it is rejected and the process is repeated. The algorithm proposed in this paper offers an alternative to the accept/reject method, yielding a faster generation process when the confining sphere is small. In order to use this algorithm effectively, a large, reusable data set needs to be pre-computed only once. We derive the theoretical distribution of the given random polygon model and demonstrate, with strong numerical evidence, that our implementation of the algorithm follows this distribution. A run time analysis and a numerical error estimate are given at the end of the paper. (paper)
Generating Realistic Labelled, Weighted Random Graphs
Directory of Open Access Journals (Sweden)
Michael Charles Davis
2015-12-01
Full Text Available Generative algorithms for random graphs have yielded insights into the structure and evolution of real-world networks. Most networks exhibit a well-known set of properties, such as heavy-tailed degree distributions, clustering and community formation. Usually, random graph models consider only structural information, but many real-world networks also have labelled vertices and weighted edges. In this paper, we present a generative model for random graphs with discrete vertex labels and numeric edge weights. The weights are represented as a set of Beta Mixture Models (BMMs with an arbitrary number of mixtures, which are learned from real-world networks. We propose a Bayesian Variational Inference (VI approach, which yields an accurate estimation while keeping computation times tractable. We compare our approach to state-of-the-art random labelled graph generators and an earlier approach based on Gaussian Mixture Models (GMMs. Our results allow us to draw conclusions about the contribution of vertex labels and edge weights to graph structure.
Physical Principle for Generation of Randomness
Zak, Michail
2009-01-01
A physical principle (more precisely, a principle that incorporates mathematical models used in physics) has been conceived as the basis of a method of generating randomness in Monte Carlo simulations. The principle eliminates the need for conventional random-number generators. The Monte Carlo simulation method is among the most powerful computational methods for solving high-dimensional problems in physics, chemistry, economics, and information processing. The Monte Carlo simulation method is especially effective for solving problems in which computational complexity increases exponentially with dimensionality. The main advantage of the Monte Carlo simulation method over other methods is that the demand on computational resources becomes independent of dimensionality. As augmented by the present principle, the Monte Carlo simulation method becomes an even more powerful computational method that is especially useful for solving problems associated with dynamics of fluids, planning, scheduling, and combinatorial optimization. The present principle is based on coupling of dynamical equations with the corresponding Liouville equation. The randomness is generated by non-Lipschitz instability of dynamics triggered and controlled by feedback from the Liouville equation. (In non-Lipschitz dynamics, the derivatives of solutions of the dynamical equations are not required to be bounded.)
Generating equilateral random polygons in confinement
International Nuclear Information System (INIS)
Diao, Y; Ernst, C; Montemayor, A; Ziegler, U
2011-01-01
One challenging problem in biology is to understand the mechanism of DNA packing in a confined volume such as a cell. It is known that confined circular DNA is often knotted and hence the topology of the extracted (and relaxed) circular DNA can be used as a probe of the DNA packing mechanism. However, in order to properly estimate the topological properties of the confined circular DNA structures using mathematical models, it is necessary to generate large ensembles of simulated closed chains (i.e. polygons) of equal edge lengths that are confined in a volume such as a sphere of certain fixed radius. Finding efficient algorithms that properly sample the space of such confined equilateral random polygons is a difficult problem. In this paper, we propose a method that generates confined equilateral random polygons based on their probability distribution. This method requires the creation of a large database initially. However, once the database has been created, a confined equilateral random polygon of length n can be generated in linear time in terms of n. The errors introduced by the method can be controlled and reduced by the refinement of the database. Furthermore, our numerical simulations indicate that these errors are unbiased and tend to cancel each other in a long polygon. (paper)
Miszczak, Jarosław Adam
2013-01-01
The presented package for the Mathematica computing system allows the harnessing of quantum random number generators (QRNG) for investigating the statistical properties of quantum states. The described package implements a number of functions for generating random states. The new version of the package adds the ability to use the on-line quantum random number generator service and implements new functions for retrieving lists of random numbers. Thanks to the introduced improvements, the new version provides faster access to high-quality sources of random numbers and can be used in simulations requiring large amount of random data. New version program summaryProgram title: TRQS Catalogue identifier: AEKA_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKA_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 18 134 No. of bytes in distributed program, including test data, etc.: 2 520 49 Distribution format: tar.gz Programming language: Mathematica, C. Computer: Any supporting Mathematica in version 7 or higher. Operating system: Any platform supporting Mathematica; tested with GNU/Linux (32 and 64 bit). RAM: Case-dependent Supplementary material: Fig. 1 mentioned below can be downloaded. Classification: 4.15. External routines: Quantis software library (http://www.idquantique.com/support/quantis-trng.html) Catalogue identifier of previous version: AEKA_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183(2012)118 Does the new version supersede the previous version?: Yes Nature of problem: Generation of random density matrices and utilization of high-quality random numbers for the purpose of computer simulation. Solution method: Use of a physical quantum random number generator and an on-line service providing access to the source of true random
Graphical analysis of some pseudo-random number generators
Lewis, Peter A. W.
1986-01-01
There exist today many 'good' pseudo-random number generators; the problem is to retrieve them. This document discusses three commonly used pseudo- random number generators, the first being RANDU, a notoriously bad generator, but one which is still occasionally used. The next is the widely used prime modulus, multiplicative congruential generator used in LL-RANDOMII, the Naval Postgraduate School random number package, and the last is the random number generator provided for microcomputers wi...
Standard random number generation for MBASIC
Tausworthe, R. C.
1976-01-01
A machine-independent algorithm is presented and analyzed for generating pseudorandom numbers suitable for the standard MBASIC system. The algorithm used is the polynomial congruential or linear recurrence modulo 2 method. Numbers, formed as nonoverlapping adjacent 28-bit words taken from the bit stream produced by the formula a sub m + 532 = a sub m + 37 + a sub m (modulo 2), do not repeat within the projected age of the solar system, show no ensemble correlation, exhibit uniform distribution of adjacent numbers up to 19 dimensions, and do not deviate from random runs-up and runs-down behavior.
Pharmacodynamics and common drug-drug interactions of the third-generation antiepileptic drugs.
Stefanović, Srđan; Janković, Slobodan M; Novaković, Milan; Milosavljević, Marko; Folić, Marko
2018-02-01
Anticonvulsants that belong to the third generation are considered as 'newer' antiepileptic drugs, including: eslicarbazepine acetate, lacosamide, perampanel, brivaracetam, rufinamide and stiripentol. Areas covered: This article reviews pharmacodynamics (i.e. mechanisms of action) and clinically relevant drug-drug interactions of the third-generation antiepileptic drugs. Expert opinion: Newer antiepileptic drugs have mechanisms of action which are not shared with the first and the second generation anticonvulsants, like inhibition of neurotransmitters release, blocking receptors for excitatory amino acids and new ways of sodium channel inactivation. New mechanisms of action increase chances of controlling forms of epilepsy resistant to older anticonvulsants. Important advantage of the third-generation anticonvulsants could be their little propensity for interactions with both antiepileptic and other drugs observed until now, making prescribing much easier and safer. However, this may change with new studies specifically designed to discover drug-drug interactions. Although the third-generation antiepileptic drugs enlarged therapeutic palette against epilepsy, 20-30% of patients with epilepsy is still treatment-resistant and need new pharmacological approach. There is great need to explore all molecular targets that may directly or indirectly be involved in generation of seizures, so a number of candidate compounds for even newer anticonvulsants could be generated.
Testing, Selection, and Implementation of Random Number Generators
National Research Council Canada - National Science Library
Collins, Joseph C
2008-01-01
An exhaustive evaluation of state-of-the-art random number generators with several well-known suites of tests provides the basis for selection of suitable random number generators for use in stochastic simulations...
A Method of Erasing Data Using Random Number Generators
井上,正人
2012-01-01
Erasing data is an indispensable step for disposal of computers or external storage media. Except physical destruction, erasing data means writing random information on entire disk drives or media. We propose a method which erases data safely using random number generators. These random number generators create true random numbers based on quantum processes.
Evidence of significant bias in an elementary random number generator
International Nuclear Information System (INIS)
Borgwaldt, H.; Brandl, V.
1981-03-01
An elementary pseudo random number generator for isotropically distributed unit vectors in 3-dimensional space has ben tested for bias. This generator uses the IBM-suplied routine RANDU and a transparent rejection technique. The tests show clearly that non-randomness in the pseudo random numbers generated by the primary IBM generator leads to bias in the order of 1 percent in estimates obtained from the secondary random number generator. FORTRAN listings of 4 variants of the random number generator called by a simple test programme and output listings are included for direct reference. (orig.) [de
A versatile programmable CAMAC random pulse generator
International Nuclear Information System (INIS)
Abdel-Aal, R.E.
1991-01-01
A new technique for generating linear pulses which can be random in both amplitude and time is described. With this technique, desired values for both pulse amplitude and spacing are set for the individual pulses by the software on a pulse-by-pulse basis. The versatility offered by this software programming allows a wide range of distributions to be obtained; with the user having close control on the distribution parameters. A number of such distributions may also be combined into a single output pulse stream. An implementation in a CAMAC module is presented. Both hardware and software aspects are described and typical performance results for amplitude and time distributions of the uniform and Gaussian type are given. Implications of using the pulser in a typical data acquisition environment on both the data acquisition and the pulser performance are considered. Typical applications are discussed together with some of the limitations. (orig.)
Long period pseudo random number sequence generator
Wang, Charles C. (Inventor)
1989-01-01
A circuit for generating a sequence of pseudo random numbers, (A sub K). There is an exponentiator in GF(2 sup m) for the normal basis representation of elements in a finite field GF(2 sup m) each represented by m binary digits and having two inputs and an output from which the sequence (A sub K). Of pseudo random numbers is taken. One of the two inputs is connected to receive the outputs (E sub K) of maximal length shift register of n stages. There is a switch having a pair of inputs and an output. The switch outputs is connected to the other of the two inputs of the exponentiator. One of the switch inputs is connected for initially receiving a primitive element (A sub O) in GF(2 sup m). Finally, there is a delay circuit having an input and an output. The delay circuit output is connected to the other of the switch inputs and the delay circuit input is connected to the output of the exponentiator. Whereby after the exponentiator initially receives the primitive element (A sub O) in GF(2 sup m) through the switch, the switch can be switched to cause the exponentiator to receive as its input a delayed output A(K-1) from the exponentiator thereby generating (A sub K) continuously at the output of the exponentiator. The exponentiator in GF(2 sup m) is novel and comprises a cyclic-shift circuit; a Massey-Omura multiplier; and, a control logic circuit all operably connected together to perform the function U(sub i) = 92(sup i) (for n(sub i) = 1 or 1 (for n(subi) = 0).
Generation and Analysis of Constrained Random Sampling Patterns
DEFF Research Database (Denmark)
Pierzchlewski, Jacek; Arildsen, Thomas
2016-01-01
Random sampling is a technique for signal acquisition which is gaining popularity in practical signal processing systems. Nowadays, event-driven analog-to-digital converters make random sampling feasible in practical applications. A process of random sampling is defined by a sampling pattern, which...... indicates signal sampling points in time. Practical random sampling patterns are constrained by ADC characteristics and application requirements. In this paper, we introduce statistical methods which evaluate random sampling pattern generators with emphasis on practical applications. Furthermore, we propose...... algorithm generates random sampling patterns dedicated for event-driven-ADCs better than existed sampling pattern generators. Finally, implementation issues of random sampling patterns are discussed....
Fast physical random bit generation with chaotic semiconductor lasers
Uchida, Atsushi; Amano, Kazuya; Inoue, Masaki; Hirano, Kunihito; Naito, Sunao; Someya, Hiroyuki; Oowada, Isao; Kurashige, Takayuki; Shiki, Masaru; Yoshimori, Shigeru; Yoshimura, Kazuyuki; Davis, Peter
2008-12-01
Random number generators in digital information systems make use of physical entropy sources such as electronic and photonic noise to add unpredictability to deterministically generated pseudo-random sequences. However, there is a large gap between the generation rates achieved with existing physical sources and the high data rates of many computation and communication systems; this is a fundamental weakness of these systems. Here we show that good quality random bit sequences can be generated at very fast bit rates using physical chaos in semiconductor lasers. Streams of bits that pass standard statistical tests for randomness have been generated at rates of up to 1.7 Gbps by sampling the fluctuating optical output of two chaotic lasers. This rate is an order of magnitude faster than that of previously reported devices for physical random bit generators with verified randomness. This means that the performance of random number generators can be greatly improved by using chaotic laser devices as physical entropy sources.
A pseudo-random number generator and its spectral test
International Nuclear Information System (INIS)
Wang Lai
1998-01-01
The author introduces a pseudo-random number generator and describes its algorithm and C language implementation. The performance of the generator is tested and compared with some well known LCG generators
Towards a high-speed quantum random number generator
Stucki, Damien; Burri, Samuel; Charbon, Edoardo; Chunnilall, Christopher; Meneghetti, Alessio; Regazzoni, Francesco
2013-10-01
Randomness is of fundamental importance in various fields, such as cryptography, numerical simulations, or the gaming industry. Quantum physics, which is fundamentally probabilistic, is the best option for a physical random number generator. In this article, we will present the work carried out in various projects in the context of the development of a commercial and certified high speed random number generator.
An integrable low-cost hardware random number generator
Ranasinghe, Damith C.; Lim, Daihyun; Devadas, Srinivas; Jamali, Behnam; Zhu, Zheng; Cole, Peter H.
2005-02-01
A hardware random number generator is different from a pseudo-random number generator; a pseudo-random number generator approximates the assumed behavior of a real hardware random number generator. Simple pseudo random number generators suffices for most applications, however for demanding situations such as the generation of cryptographic keys, requires an efficient and a cost effective source of random numbers. Arbiter-based Physical Unclonable Functions (PUFs) proposed for physical authentication of ICs exploits statistical delay variation of wires and transistors across integrated circuits, as a result of process variations, to build a secret key unique to each IC. Experimental results and theoretical studies show that a sufficient amount of variation exits across IC"s. This variation enables each IC to be identified securely. It is possible to exploit the unreliability of these PUF responses to build a physical random number generator. There exists measurement noise, which comes from the instability of an arbiter when it is in a racing condition. There exist challenges whose responses are unpredictable. Without environmental variations, the responses of these challenges are random in repeated measurements. Compared to other physical random number generators, the PUF-based random number generators can be a compact and a low-power solution since the generator need only be turned on when required. A 64-stage PUF circuit costs less than 1000 gates and the circuit can be implemented using a standard IC manufacturing processes. In this paper we have presented a fast and an efficient random number generator, and analysed the quality of random numbers produced using an array of tests used by the National Institute of Standards and Technology to evaluate the randomness of random number generators designed for cryptographic applications.
Generating random numbers by means of nonlinear dynamic systems
Zang, Jiaqi; Hu, Haojie; Zhong, Juhua; Luo, Duanbin; Fang, Yi
2018-07-01
To introduce the randomness of a physical process to students, a chaotic pendulum experiment was opened in East China University of Science and Technology (ECUST) on the undergraduate level in the physics department. It was shown chaotic motion could be initiated through adjusting the operation of a chaotic pendulum. By using the data of the angular displacements of chaotic motion, random binary numerical arrays can be generated. To check the randomness of generated numerical arrays, the NIST Special Publication 800-20 method was adopted. As a result, it was found that all the random arrays which were generated by the chaotic motion could pass the validity criteria and some of them were even better than the quality of pseudo-random numbers generated by a computer. Through the experiments, it is demonstrated that chaotic pendulum can be used as an efficient mechanical facility in generating random numbers, and can be applied in teaching random motion to the students.
The intermittency of vector fields and random-number generators
Kalinin, A. O.; Sokoloff, D. D.; Tutubalin, V. N.
2017-09-01
We examine how well natural random-number generators can reproduce the intermittency phenomena that arise in the transfer of vector fields in random media. A generator based on the analysis of financial indices is suggested as the most promising random-number generator. Is it shown that even this generator, however, fails to reproduce the phenomenon long enough to confidently detect intermittency, while the C++ generator successfully solves this problem. We discuss the prospects of using shell models of turbulence as the desired generator.
Pseudo-Random Number Generator Based on Coupled Map Lattices
Lü, Huaping; Wang, Shihong; Hu, Gang
A one-way coupled chaotic map lattice is used for generating pseudo-random numbers. It is shown that with suitable cooperative applications of both chaotic and conventional approaches, the output of the spatiotemporally chaotic system can easily meet the practical requirements of random numbers, i.e., excellent random statistical properties, long periodicity of computer realizations, and fast speed of random number generations. This pseudo-random number generator system can be used as ideal synchronous and self-synchronizing stream cipher systems for secure communications.
Quantum random number generation for loophole-free Bell tests
Mitchell, Morgan; Abellan, Carlos; Amaya, Waldimar
2015-05-01
We describe the generation of quantum random numbers at multi-Gbps rates, combined with real-time randomness extraction, to give very high purity random numbers based on quantum events at most tens of ns in the past. The system satisfies the stringent requirements of quantum non-locality tests that aim to close the timing loophole. We describe the generation mechanism using spontaneous-emission-driven phase diffusion in a semiconductor laser, digitization, and extraction by parity calculation using multi-GHz logic chips. We pay special attention to experimental proof of the quality of the random numbers and analysis of the randomness extraction. In contrast to widely-used models of randomness generators in the computer science literature, we argue that randomness generation by spontaneous emission can be extracted from a single source.
Truly random dynamics generated by autonomous dynamical systems
González, J. A.; Reyes, L. I.
2001-09-01
We investigate explicit functions that can produce truly random numbers. We use the analytical properties of the explicit functions to show that a certain class of autonomous dynamical systems can generate random dynamics. This dynamics presents fundamental differences with the known chaotic systems. We present real physical systems that can produce this kind of random time-series. Some applications are discussed.
Superparamagnetic perpendicular magnetic tunnel junctions for true random number generators
Parks, Bradley; Bapna, Mukund; Igbokwe, Julianne; Almasi, Hamid; Wang, Weigang; Majetich, Sara A.
2018-05-01
Superparamagnetic perpendicular magnetic tunnel junctions are fabricated and analyzed for use in random number generators. Time-resolved resistance measurements are used as streams of bits in statistical tests for randomness. Voltage control of the thermal stability enables tuning the average speed of random bit generation up to 70 kHz in a 60 nm diameter device. In its most efficient operating mode, the device generates random bits at an energy cost of 600 fJ/bit. A narrow range of magnetic field tunes the probability of a given state from 0 to 1, offering a means of probabilistic computing.
Program pseudo-random number generator for microcomputers
International Nuclear Information System (INIS)
Ososkov, G.A.
1980-01-01
Program pseudo-random number generators (PNG) intended for the test of control equipment and communication channels are considered. In the case of 8-bit microcomputers it is necessary to assign 4 words of storage to allocate one random number. The proposed economical algorithms of the random number generation are based on the idea of the ''mixing'' of such quarters of the preceeding random number to obtain the next one. Test results of the PNG are displayed for two such generators. A FORTRAN variant of the PNG is presented along with a program realizing the PNG made on the base of the INTEL-8080 autocode
Microcomputer-Assisted Discoveries: Generate Your Own Random Numbers.
Kimberling, Clark
1984-01-01
Having students try to generate their own random numbers can lead to much discovery learning as one tries to create 'patternlessness' from formulas. Developing an equidistribution test and runs test, plus other ideas for generating random numbers, is discussed, with computer programs given. (MNS)
New Trends in Pseudo-Random Number Generation
Gutbrod, F.
Properties of pseudo-random number generators are reviewed. The emphasis is on correlations between successive random numbers and their suppression by improvement steps. The generators under discussion are the linear congruential generators, lagged Fibonacci generators with various operations, and the improvement techniques combination, shuffling and decimation. The properties of the RANSHI generator are reviewed somewhat more extensively. The transition to 64-bit technology is discussed in several cases. The generators are subject to several tests, which look both for short range and for long range correlations. Some performance figures are given for a Pentium Pro PC. Recommendations are presented in the final chapter.
Generating and using truly random quantum states in Mathematica
Miszczak, Jarosław Adam
2012-01-01
The problem of generating random quantum states is of a great interest from the quantum information theory point of view. In this paper we present a package for Mathematica computing system harnessing a specific piece of hardware, namely Quantis quantum random number generator (QRNG), for investigating statistical properties of quantum states. The described package implements a number of functions for generating random states, which use Quantis QRNG as a source of randomness. It also provides procedures which can be used in simulations not related directly to quantum information processing. Program summaryProgram title: TRQS Catalogue identifier: AEKA_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKA_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 7924 No. of bytes in distributed program, including test data, etc.: 88 651 Distribution format: tar.gz Programming language: Mathematica, C Computer: Requires a Quantis quantum random number generator (QRNG, http://www.idquantique.com/true-random-number-generator/products-overview.html) and supporting a recent version of Mathematica Operating system: Any platform supporting Mathematica; tested with GNU/Linux (32 and 64 bit) RAM: Case dependent Classification: 4.15 Nature of problem: Generation of random density matrices. Solution method: Use of a physical quantum random number generator. Running time: Generating 100 random numbers takes about 1 second, generating 1000 random density matrices takes more than a minute.
Generating random walks and polygons with stiffness in confinement
International Nuclear Information System (INIS)
Diao, Y; Ernst, C; Saarinen, S; Ziegler, U
2015-01-01
The purpose of this paper is to explore ways to generate random walks and polygons in confinement with a bias toward stiffness. Here the stiffness refers to the curvature angle between two consecutive edges along the random walk or polygon. The stiffer the walk (polygon), the smaller this angle on average. Thus random walks and polygons with an elevated stiffness have lower than expected curvatures. The authors introduced and studied several generation algorithms with a stiffness parameter s>0 that regulates the expected curvature angle at a given vertex in which the random walks and polygons are generated one edge at a time using conditional probability density functions. Our generating algorithms also allow the generation of unconfined random walks and polygons with any desired mean curvature angle. In the case of random walks and polygons confined in a sphere of fixed radius, we observe that, as expected, stiff random walks or polygons are more likely to be close to the confinement boundary. The methods developed here require that the random walks and random polygons be rooted at the center of the confinement sphere. (paper)
Random Number Generation for High Performance Computing
2015-01-01
number streams, a quality metric for the parallel random number streams. * * * * * Atty. Dkt . No.: 5660-14400 Customer No. 35690 Eric B. Meyertons...responsibility to ensure timely payment of maintenance fees when due. Pagel of3 PTOL-85 (Rev. 02/11) Atty. Dkt . No.: 5660-14400 Page 1 Meyertons...with each subtask executed by a separate thread or process (henceforth, process). Each process has Atty. Dkt . No.: 5660-14400 Page 2 Meyertons
Image encryption using random sequence generated from generalized information domain
International Nuclear Information System (INIS)
Zhang Xia-Yan; Wu Jie-Hua; Zhang Guo-Ji; Li Xuan; Ren Ya-Zhou
2016-01-01
A novel image encryption method based on the random sequence generated from the generalized information domain and permutation–diffusion architecture is proposed. The random sequence is generated by reconstruction from the generalized information file and discrete trajectory extraction from the data stream. The trajectory address sequence is used to generate a P-box to shuffle the plain image while random sequences are treated as keystreams. A new factor called drift factor is employed to accelerate and enhance the performance of the random sequence generator. An initial value is introduced to make the encryption method an approximately one-time pad. Experimental results show that the random sequences pass the NIST statistical test with a high ratio and extensive analysis demonstrates that the new encryption scheme has superior security. (paper)
Unbiased All-Optical Random-Number Generator
Steinle, Tobias; Greiner, Johannes N.; Wrachtrup, Jörg; Giessen, Harald; Gerhardt, Ilja
2017-10-01
The generation of random bits is of enormous importance in modern information science. Cryptographic security is based on random numbers which require a physical process for their generation. This is commonly performed by hardware random-number generators. These often exhibit a number of problems, namely experimental bias, memory in the system, and other technical subtleties, which reduce the reliability in the entropy estimation. Further, the generated outcome has to be postprocessed to "iron out" such spurious effects. Here, we present a purely optical randomness generator, based on the bistable output of an optical parametric oscillator. Detector noise plays no role and postprocessing is reduced to a minimum. Upon entering the bistable regime, initially the resulting output phase depends on vacuum fluctuations. Later, the phase is rigidly locked and can be well determined versus a pulse train, which is derived from the pump laser. This delivers an ambiguity-free output, which is reliably detected and associated with a binary outcome. The resulting random bit stream resembles a perfect coin toss and passes all relevant randomness measures. The random nature of the generated binary outcome is furthermore confirmed by an analysis of resulting conditional entropies.
Mina, George S; Watti, Hussam; Soliman, Demiana; Shewale, Anand; Atkins, Jessica; Reddy, Pratap; Dominic, Paari
2018-01-05
Most data guiding revascularization of multivessel disease (MVD) and/or left main disease (LMD) favor coronary artery bypass grafting (CABG) over percutaneous coronary intervention (PCI). However, those data are based on trials comparing CABG to bare metal stents (BMS) or old generation drug eluting stents (OG-DES). Hence, it is essential to outcomes of CABG to those of new generation drug eluting stents (NG-DES). We searched PUBMED and Cochrane database for trials evaluating revascularization of MVD and/or LMD with CABG and/or PCI. A Bayesian network meta-analysis was performed to calculate odds ratios (OR) and 95% credible intervals (CrI). Primary outcome was major adverse cardiovascular events (MACE) at 3-5 years. Secondary outcomes were mortality, cerebrovascular accidents (CVA), myocardial infarction (MI) and repeat revascularization. We included 10 trials with a total of 9287 patients. CABG was associated with lower MACE when compared to BMS or OG-DES. However, MACE was not significantly different between CABG and NG-DES (OR 0.79, CrI 0.45-1.40). Moreover, there were no significant differences between CABG and NG-DES in mortality (OR 0.78, CrI 0.45-1.37), CVA (OR 0.93 CrI 0.35-2.2) or MI (OR 0.6, CrI 0.17-2.0). On the other hand, CABG was associated with lower repeat revascularization (OR 0.55, CrI 0.36-0.84). Our study suggests that NG-DES is an acceptable alternative to CABG in patients with MVD and/or LMD. However, repeat revascularization remains to be lower with CABG than with PCI. Copyright © 2018. Published by Elsevier Inc.
Pseudo-random number generator for the Sigma 5 computer
Carroll, S. N.
1983-01-01
A technique is presented for developing a pseudo-random number generator based on the linear congruential form. The two numbers used for the generator are a prime number and a corresponding primitive root, where the prime is the largest prime number that can be accurately represented on a particular computer. The primitive root is selected by applying Marsaglia's lattice test. The technique presented was applied to write a random number program for the Sigma 5 computer. The new program, named S:RANDOM1, is judged to be superior to the older program named S:RANDOM. For applications requiring several independent random number generators, a table is included showing several acceptable primitive roots. The technique and programs described can be applied to any computer having word length different from that of the Sigma 5.
A hybrid-type quantum random number generator
Hai-Qiang, Ma; Wu, Zhu; Ke-Jin, Wei; Rui-Xue, Li; Hong-Wei, Liu
2016-05-01
This paper proposes a well-performing hybrid-type truly quantum random number generator based on the time interval between two independent single-photon detection signals, which is practical and intuitive, and generates the initial random number sources from a combination of multiple existing random number sources. A time-to-amplitude converter and multichannel analyzer are used for qualitative analysis to demonstrate that each and every step is random. Furthermore, a carefully designed data acquisition system is used to obtain a high-quality random sequence. Our scheme is simple and proves that the random number bit rate can be dramatically increased to satisfy practical requirements. Project supported by the National Natural Science Foundation of China (Grant Nos. 61178010 and 11374042), the Fund of State Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications), China, and the Fundamental Research Funds for the Central Universities of China (Grant No. bupt2014TS01).
77 FR 2606 - Pipeline Safety: Random Drug Testing Rate
2012-01-18
... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket ID PHMSA-2012-0004] Pipeline Safety: Random Drug Testing Rate AGENCY: Pipeline and Hazardous Materials... pipelines and operators of liquefied natural gas facilities must select and test a percentage of covered...
75 FR 9018 - Pipeline Safety: Random Drug Testing Rate
2010-02-26
... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket ID PHMSA-2010-0034] Pipeline Safety: Random Drug Testing Rate AGENCY: Pipeline and Hazardous Materials... pipelines and operators of liquefied natural gas facilities must select and test a percentage of covered...
Pseudo-random bit generator based on Chebyshev map
Stoyanov, B. P.
2013-10-01
In this paper, we study a pseudo-random bit generator based on two Chebyshev polynomial maps. The novel derivative algorithm shows perfect statistical properties established by number of statistical tests.
Hardware implementation of a GFSR pseudo-random number generator
Aiello, G. R.; Budinich, M.; Milotti, E.
1989-12-01
We describe the hardware implementation of a pseudo-random number generator of the "Generalized Feedback Shift Register" (GFSR) type. After brief theoretical considerations we describe two versions of the hardware, the tests done and the performances achieved.
Random number generation based on digital differential chaos
Zidan, Mohammed A.; Radwan, Ahmed G.; Salama, Khaled N.
2012-01-01
In this paper, we present a fully digital differential chaos based random number generator. The output of the digital circuit is proved to be chaotic by calculating the output time series maximum Lyapunov exponent. We introduce a new post processing
Note on Marsaglia\\'s Xorshift Random Number Generators
Directory of Open Access Journals (Sweden)
Richard P. Brent
2004-08-01
Full Text Available Marsaglia (2003 has described a class of Xorshift random number generators (RNGs with periods 2n - 1 for n = 32, 64, etc. We show that the sequences generated by these RNGs are identical to the sequences generated by certain linear feedback shift register (LFSR generators using "exclusive or" (xor operations on n-bit words, with a recurrence defined by a primitive polynomial of degree n.
A Repetition Test for Pseudo-Random Number Generators
Gil, Manuel; Gonnet, Gaston H.; Petersen, Wesley P.
2017-01-01
A new statistical test for uniform pseudo-random number generators (PRNGs) is presented. The idea is that a sequence of pseudo-random numbers should have numbers reappear with a certain probability. The expectation time that a repetition occurs provides the metric for the test. For linear congruential generators (LCGs) failure can be shown theoretically. Empirical test results for a number of commonly used PRNGs are reported, showing that some PRNGs considered to have good statistical propert...
DuPont, Robert L.; Campbell, Michael D.; Campbell, Teresa G.; Shea, Corinne L.; DuPont, Helen S.
2013-01-01
Many schools implement random student drug testing (RSDT) programs as a drug prevention strategy. This study analyzes self-report surveys of students in eight secondary schools with well-established RSDT programs, comparing students who understood they were subject to testing and students who understood they were not subject to testing. Students…
Experimentally generated randomness certified by the impossibility of superluminal signals.
Bierhorst, Peter; Knill, Emanuel; Glancy, Scott; Zhang, Yanbao; Mink, Alan; Jordan, Stephen; Rommal, Andrea; Liu, Yi-Kai; Christensen, Bradley; Nam, Sae Woo; Stevens, Martin J; Shalm, Lynden K
2018-04-01
From dice to modern electronic circuits, there have been many attempts to build better devices to generate random numbers. Randomness is fundamental to security and cryptographic systems and to safeguarding privacy. A key challenge with random-number generators is that it is hard to ensure that their outputs are unpredictable 1-3 . For a random-number generator based on a physical process, such as a noisy classical system or an elementary quantum measurement, a detailed model that describes the underlying physics is necessary to assert unpredictability. Imperfections in the model compromise the integrity of the device. However, it is possible to exploit the phenomenon of quantum non-locality with a loophole-free Bell test to build a random-number generator that can produce output that is unpredictable to any adversary that is limited only by general physical principles, such as special relativity 1-11 . With recent technological developments, it is now possible to carry out such a loophole-free Bell test 12-14,22 . Here we present certified randomness obtained from a photonic Bell experiment and extract 1,024 random bits that are uniformly distributed to within 10 -12 . These random bits could not have been predicted according to any physical theory that prohibits faster-than-light (superluminal) signalling and that allows independent measurement choices. To certify and quantify the randomness, we describe a protocol that is optimized for devices that are characterized by a low per-trial violation of Bell inequalities. Future random-number generators based on loophole-free Bell tests may have a role in increasing the security and trust of our cryptographic systems and infrastructure.
Pseudo-random bit generator based on lag time series
García-Martínez, M.; Campos-Cantón, E.
2014-12-01
In this paper, we present a pseudo-random bit generator (PRBG) based on two lag time series of the logistic map using positive and negative values in the bifurcation parameter. In order to hidden the map used to build the pseudo-random series we have used a delay in the generation of time series. These new series when they are mapped xn against xn+1 present a cloud of points unrelated to the logistic map. Finally, the pseudo-random sequences have been tested with the suite of NIST giving satisfactory results for use in stream ciphers.
Analysis of random number generators in abnormal usage conditions
International Nuclear Information System (INIS)
Soucarros, M.
2012-01-01
Random numbers have been used through the ages for games of chance, more recently for secret codes and today they are necessary to the execution of computer programs. Random number generators have now evolved from simple dices to electronic circuits and algorithms. Accordingly, the ability to distinguish between random and non-random numbers has become more difficult. Furthermore, whereas in the past dices were loaded in order to increase winning chances, it is now possible to influence the outcome of random number generators. In consequence, this subject is still very much an issue and has recently made the headlines. Indeed, there was talks about the PS3 game console which generates constant random numbers and redundant distribution of secret keys on the internet. This thesis presents a study of several generators as well as different means to perturb them. It shows the inherent defects of their conceptions and possible consequences of their failure when they are embedded inside security components. Moreover, this work highlights problems yet to be solved concerning the testing of random numbers and the post-processing eliminating bias in these numbers distribution. (author) [fr
Ultrafast quantum random number generation based on quantum phase fluctuations.
Xu, Feihu; Qi, Bing; Ma, Xiongfeng; Xu, He; Zheng, Haoxuan; Lo, Hoi-Kwong
2012-05-21
A quantum random number generator (QRNG) can generate true randomness by exploiting the fundamental indeterminism of quantum mechanics. Most approaches to QRNG employ single-photon detection technologies and are limited in speed. Here, we experimentally demonstrate an ultrafast QRNG at a rate over 6 Gbits/s based on the quantum phase fluctuations of a laser operating near threshold. Moreover, we consider a potential adversary who has partial knowledge on the raw data and discuss how one can rigorously remove such partial knowledge with postprocessing. We quantify the quantum randomness through min-entropy by modeling our system and employ two randomness extractors--Trevisan's extractor and Toeplitz-hashing--to distill the randomness, which is information-theoretically provable. The simplicity and high-speed of our experimental setup show the feasibility of a robust, low-cost, high-speed QRNG.
Parallel random number generator for inexpensive configurable hardware cells
Ackermann, J.; Tangen, U.; Bödekker, B.; Breyer, J.; Stoll, E.; McCaskill, J. S.
2001-11-01
A new random number generator ( RNG) adapted to parallel processors has been created. This RNG can be implemented with inexpensive hardware cells. The correlation between neighboring cells is suppressed with smart connections. With such connection structures, sequences of pseudo-random numbers are produced. Numerical tests including a self-avoiding random walk test and the simulation of the order parameter and energy of the 2D Ising model give no evidence for correlation in the pseudo-random sequences. Because the new random number generator has suppressed the correlation between neighboring cells which is usually observed in cellular automaton implementations, it is applicable for extended time simulations. It gives an immense speed-up factor if implemented directly in configurable hardware, and has recently been used for long time simulations of spatially resolved molecular evolution.
Experimental nonlocality-based randomness generation with nonprojective measurements
Gómez, S.; Mattar, A.; Gómez, E. S.; Cavalcanti, D.; Farías, O. Jiménez; Acín, A.; Lima, G.
2018-04-01
We report on an optical setup generating more than one bit of randomness from one entangled bit (i.e., a maximally entangled state of two qubits). The amount of randomness is certified through the observation of Bell nonlocal correlations. To attain this result we implemented a high-purity entanglement source and a nonprojective three-outcome measurement. Our implementation achieves a gain of 27% of randomness as compared with the standard methods using projective measurements. Additionally, we estimate the amount of randomness certified in a one-sided device-independent scenario, through the observation of Einstein-Podolsky-Rosen steering. Our results prove that nonprojective quantum measurements allow extending the limits for nonlocality-based certified randomness generation using current technology.
The Reliability of Randomly Generated Math Curriculum-Based Measurements
Strait, Gerald G.; Smith, Bradley H.; Pender, Carolyn; Malone, Patrick S.; Roberts, Jarod; Hall, John D.
2015-01-01
"Curriculum-Based Measurement" (CBM) is a direct method of academic assessment used to screen and evaluate students' skills and monitor their responses to academic instruction and intervention. Interventioncentral.org offers a math worksheet generator at no cost that creates randomly generated "math curriculum-based measures"…
A Copula Based Approach for Design of Multivariate Random Forests for Drug Sensitivity Prediction.
Haider, Saad; Rahman, Raziur; Ghosh, Souparno; Pal, Ranadip
2015-01-01
Modeling sensitivity to drugs based on genetic characterizations is a significant challenge in the area of systems medicine. Ensemble based approaches such as Random Forests have been shown to perform well in both individual sensitivity prediction studies and team science based prediction challenges. However, Random Forests generate a deterministic predictive model for each drug based on the genetic characterization of the cell lines and ignores the relationship between different drug sensitivities during model generation. This application motivates the need for generation of multivariate ensemble learning techniques that can increase prediction accuracy and improve variable importance ranking by incorporating the relationships between different output responses. In this article, we propose a novel cost criterion that captures the dissimilarity in the output response structure between the training data and node samples as the difference in the two empirical copulas. We illustrate that copulas are suitable for capturing the multivariate structure of output responses independent of the marginal distributions and the copula based multivariate random forest framework can provide higher accuracy prediction and improved variable selection. The proposed framework has been validated on genomics of drug sensitivity for cancer and cancer cell line encyclopedia database.
Generation of Random Numbers and Parallel Random Number Streams for Monte Carlo Simulations
Directory of Open Access Journals (Sweden)
L. Yu. Barash
2012-01-01
Full Text Available Modern methods and libraries for high quality pseudorandom number generation and for generation of parallel random number streams for Monte Carlo simulations are considered. The probability equidistribution property and the parameters when the property holds at dimensions up to logarithm of mesh size are considered for Multiple Recursive Generators.
Brain potentials index executive functions during random number generation.
Joppich, Gregor; Däuper, Jan; Dengler, Reinhard; Johannes, Sönke; Rodriguez-Fornells, Antoni; Münte, Thomas F
2004-06-01
The generation of random sequences is considered to tax different executive functions. To explore the involvement of these functions further, brain potentials were recorded in 16 healthy young adults while either engaging in random number generation (RNG) by pressing the number keys on a computer keyboard in a random sequence or in ordered number generation (ONG) necessitating key presses in the canonical order. Key presses were paced by an external auditory stimulus to yield either fast (1 press/800 ms) or slow (1 press/1300 ms) sequences in separate runs. Attentional demands of random and ordered tasks were assessed by the introduction of a secondary task (key-press to a target tone). The P3 amplitude to the target tone of this secondary task was reduced during RNG, reflecting the greater consumption of attentional resources during RNG. Moreover, RNG led to a left frontal negativity peaking 140 ms after the onset of the pacing stimulus, whenever the subjects produced a true random response. This negativity could be attributed to the left dorsolateral prefrontal cortex and was absent when numbers were repeated. This negativity was interpreted as an index for the inhibition of habitual responses. Finally, in response locked ERPs a negative component was apparent peaking about 50 ms after the key-press that was more prominent during RNG. Source localization suggested a medial frontal source. This effect was tentatively interpreted as a reflection of the greater monitoring demands during random sequence generation.
Generating functionals for quantum field theories with random potentials
International Nuclear Information System (INIS)
Jain, Mudit; Vanchurin, Vitaly
2016-01-01
We consider generating functionals for computing correlators in quantum field theories with random potentials. Examples of such theories include cosmological systems in context of the string theory landscape (e.g. cosmic inflation) or condensed matter systems with quenched disorder (e.g. spin glass). We use the so-called replica trick to define two different generating functionals for calculating correlators of the quantum fields averaged over a given distribution of random potentials. The first generating functional is appropriate for calculating averaged (in-out) amplitudes and involves a single replica of fields, but the replica limit is taken to an (unphysical) negative one number of fields outside of the path integral. When the number of replicas is doubled the generating functional can also be used for calculating averaged probabilities (squared amplitudes) using the in-in construction. The second generating functional involves an infinite number of replicas, but can be used for calculating both in-out and in-in correlators and the replica limits are taken to only a zero number of fields. We discuss the formalism in details for a single real scalar field, but the generalization to more fields or to different types of fields is straightforward. We work out three examples: one where the mass of scalar field is treated as a random variable and two where the functional form of interactions is random, one described by a Gaussian random field and the other by a Euclidean action in the field configuration space.
Energy Technology Data Exchange (ETDEWEB)
Stipčević, Mario, E-mail: mario.stipcevic@irb.hr [Photonics and Quantum Optics Research Unit, Center of Excellence for Advanced Materials and Sensing Devices, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb (Croatia)
2016-03-15
In this work, a new type of elementary logic circuit, named random flip-flop (RFF), is proposed, experimentally realized, and studied. Unlike conventional Boolean logic circuits whose action is deterministic and highly reproducible, the action of a RFF is intentionally made maximally unpredictable and, in the proposed realization, derived from a fundamentally random process of emission and detection of light quanta. We demonstrate novel applications of RFF in randomness preserving frequency division, random frequency synthesis, and random number generation. Possible usages of these applications in the information and communication technology, cryptographic hardware, and testing equipment are discussed.
An investigation of the uniform random number generator
Temple, E. C.
1982-01-01
Most random number generators that are in use today are of the congruential form X(i+1) + AX(i) + C mod M where A, C, and M are nonnegative integers. If C=O, the generator is called the multiplicative type and those for which C/O are called mixed congruential generators. It is easy to see that congruential generators will repeat a sequence of numbers after a maximum of M values have been generated. The number of numbers that a procedure generates before restarting the sequence is called the length or the period of the generator. Generally, it is desirable to make the period as long as possible. A detailed discussion of congruential generators is given. Also, several promising procedures that differ from the multiplicative and mixed procedure are discussed.
Chaos-based Pseudo-random Number Generation
Barakat, Mohamed L.
2014-04-10
Various methods and systems related to chaos-based pseudo-random number generation are presented. In one example, among others, a system includes a pseudo-random number generator (PRNG) to generate a series of digital outputs and a nonlinear post processing circuit to perform an exclusive OR (XOR) operation on a first portion of a current digital output of the PRNG and a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output. In another example, a method includes receiving at least a first portion of a current output from a PRNG and performing an XOR operation on the first portion of the current PRNG output with a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output.
Chaos-based Pseudo-random Number Generation
Barakat, Mohamed L.; Mansingka, Abhinav S.; Radwan, Ahmed Gomaa Ahmed; Salama, Khaled N.
2014-01-01
Various methods and systems related to chaos-based pseudo-random number generation are presented. In one example, among others, a system includes a pseudo-random number generator (PRNG) to generate a series of digital outputs and a nonlinear post processing circuit to perform an exclusive OR (XOR) operation on a first portion of a current digital output of the PRNG and a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output. In another example, a method includes receiving at least a first portion of a current output from a PRNG and performing an XOR operation on the first portion of the current PRNG output with a permutated version of a corresponding first portion of a previous post processed output to generate a corresponding first portion of a current post processed output.
Random generation of RNA secondary structures according to native distributions
Directory of Open Access Journals (Sweden)
Nebel Markus E
2011-10-01
Full Text Available Abstract Background Random biological sequences are a topic of great interest in genome analysis since, according to a powerful paradigm, they represent the background noise from which the actual biological information must differentiate. Accordingly, the generation of random sequences has been investigated for a long time. Similarly, random object of a more complicated structure like RNA molecules or proteins are of interest. Results In this article, we present a new general framework for deriving algorithms for the non-uniform random generation of combinatorial objects according to the encoding and probability distribution implied by a stochastic context-free grammar. Briefly, the framework extends on the well-known recursive method for (uniform random generation and uses the popular framework of admissible specifications of combinatorial classes, introducing weighted combinatorial classes to allow for the non-uniform generation by means of unranking. This framework is used to derive an algorithm for the generation of RNA secondary structures of a given fixed size. We address the random generation of these structures according to a realistic distribution obtained from real-life data by using a very detailed context-free grammar (that models the class of RNA secondary structures by distinguishing between all known motifs in RNA structure. Compared to well-known sampling approaches used in several structure prediction tools (such as SFold ours has two major advantages: Firstly, after a preprocessing step in time O(n2 for the computation of all weighted class sizes needed, with our approach a set of m random secondary structures of a given structure size n can be computed in worst-case time complexity Om⋅n⋅ log(n while other algorithms typically have a runtime in O(m⋅n2. Secondly, our approach works with integer arithmetic only which is faster and saves us from all the discomforting details of using floating point arithmetic with
Secure self-calibrating quantum random-bit generator
International Nuclear Information System (INIS)
Fiorentino, M.; Santori, C.; Spillane, S. M.; Beausoleil, R. G.; Munro, W. J.
2007-01-01
Random-bit generators (RBGs) are key components of a variety of information processing applications ranging from simulations to cryptography. In particular, cryptographic systems require 'strong' RBGs that produce high-entropy bit sequences, but traditional software pseudo-RBGs have very low entropy content and therefore are relatively weak for cryptography. Hardware RBGs yield entropy from chaotic or quantum physical systems and therefore are expected to exhibit high entropy, but in current implementations their exact entropy content is unknown. Here we report a quantum random-bit generator (QRBG) that harvests entropy by measuring single-photon and entangled two-photon polarization states. We introduce and implement a quantum tomographic method to measure a lower bound on the 'min-entropy' of the system, and we employ this value to distill a truly random-bit sequence. This approach is secure: even if an attacker takes control of the source of optical states, a secure random sequence can be distilled
Efficient Raman generation in a waveguide: A route to ultrafast quantum random number generation
Energy Technology Data Exchange (ETDEWEB)
England, D. G.; Bustard, P. J.; Moffatt, D. J.; Nunn, J.; Lausten, R.; Sussman, B. J., E-mail: ben.sussman@nrc.ca [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada)
2014-02-03
The inherent uncertainty in quantum mechanics offers a source of true randomness which can be used to produce unbreakable cryptographic keys. We discuss the development of a high-speed random number generator based on the quantum phase fluctuations in spontaneously initiated stimulated Raman scattering (SISRS). We utilize the tight confinement and long interaction length available in a Potassium Titanyl Phosphate waveguide to generate highly efficient SISRS using nanojoule pulse energies, reducing the high pump power requirements of the previous approaches. We measure the random phase of the Stokes output using a simple interferometric setup to yield quantum random numbers at 145 Mbps.
On the Periods of the {ranshi} Random Number Generator
Gutbrod, F.
The stochastic properties of the pseudo-random number generator {ranshi} are discussed, with emphasis on the average period. Within a factor 2 this turns out to be the root of the maximally possible period. The actual set of periods depends on minor details of the algorithm, and the system settles down in one of only a few different cycles. These features are in perfect agreement with absolute random motion in phase space, to the extent allowed by deterministic dynamics.
Search for a perfect generator of random numbers
International Nuclear Information System (INIS)
Musyck, E.
1977-01-01
Theoretical tests have been carried out by COVEYOU and MAC PHERSON to verify the applications of the LEHMER algorithm. In a similar way, a theoretical method is proposed to evaluate in a rigorous way the random character of numbers generated by a shift register. This theory introduces the concept of ''degree of randomness'' of the elements, taken in a definite order, of a shift register. It permits making the judicious choice of the elements of the shift register which will produce the bits of the random numbers. On the other hand, a calculation method is developed in order to verify the primitive character of any shift register of high complexity. A new test, called ''slice test'', of empirical and theoretical use is also described; it constitutes a significant contribution to the understanding of certain properties of pseudo-random sequences. As a practical example, a random number generator structure formed with 32 bits, built out of a shift register with 61 elements and 60 modulo-2 adder circuits was made. The author is convinced that this generator can be considered to be practically perfect for all empirical applications of random numbers, particularly for the solution of Monte-Carlo problems. (author)
Analysis of entropy extraction efficiencies in random number generation systems
Wang, Chao; Wang, Shuang; Chen, Wei; Yin, Zhen-Qiang; Han, Zheng-Fu
2016-05-01
Random numbers (RNs) have applications in many areas: lottery games, gambling, computer simulation, and, most importantly, cryptography [N. Gisin et al., Rev. Mod. Phys. 74 (2002) 145]. In cryptography theory, the theoretical security of the system calls for high quality RNs. Therefore, developing methods for producing unpredictable RNs with adequate speed is an attractive topic. Early on, despite the lack of theoretical support, pseudo RNs generated by algorithmic methods performed well and satisfied reasonable statistical requirements. However, as implemented, those pseudorandom sequences were completely determined by mathematical formulas and initial seeds, which cannot introduce extra entropy or information. In these cases, “random” bits are generated that are not at all random. Physical random number generators (RNGs), which, in contrast to algorithmic methods, are based on unpredictable physical random phenomena, have attracted considerable research interest. However, the way that we extract random bits from those physical entropy sources has a large influence on the efficiency and performance of the system. In this manuscript, we will review and discuss several randomness extraction schemes that are based on radiation or photon arrival times. We analyze the robustness, post-processing requirements and, in particular, the extraction efficiency of those methods to aid in the construction of efficient, compact and robust physical RNG systems.
The random signal generator of imitated nuclear radiation pulse
International Nuclear Information System (INIS)
Li Dongcang; Yang Lei; Yuan Shulin; Yang Yinghui; Zang Fujia
2007-01-01
Based in pseudo-random uniformity number, it produces random numbers of Gaussian distribution and exponential distribution by arithmetic. The hardware is the single-chip microcomputer of 89C51. Program language makes use of Keil C. The output pulse amplitude is Gaussian distribution, exponential distribution or uniformity distribution. Likewise, it has two mode or upwards two. The time alternation of output pulse is both periodic and exponential distribution. The generator has achieved output control of multi-mode distribution, imitated random characteristic of nuclear pulse in amplitude and in time. (authors)
Study on random number generator in Monte Carlo code
International Nuclear Information System (INIS)
Oya, Kentaro; Kitada, Takanori; Tanaka, Shinichi
2011-01-01
The Monte Carlo code uses a sequence of pseudo-random numbers with a random number generator (RNG) to simulate particle histories. A pseudo-random number has its own period depending on its generation method and the period is desired to be long enough not to exceed the period during one Monte Carlo calculation to ensure the correctness especially for a standard deviation of results. The linear congruential generator (LCG) is widely used as Monte Carlo RNG and the period of LCG is not so long by considering the increasing rate of simulation histories in a Monte Carlo calculation according to the remarkable enhancement of computer performance. Recently, many kinds of RNG have been developed and some of their features are better than those of LCG. In this study, we investigate the appropriate RNG in a Monte Carlo code as an alternative to LCG especially for the case of enormous histories. It is found that xorshift has desirable features compared with LCG, and xorshift has a larger period, a comparable speed to generate random numbers, a better randomness, and good applicability to parallel calculation. (author)
DNA-based random number generation in security circuitry.
Gearheart, Christy M; Arazi, Benjamin; Rouchka, Eric C
2010-06-01
DNA-based circuit design is an area of research in which traditional silicon-based technologies are replaced by naturally occurring phenomena taken from biochemistry and molecular biology. This research focuses on further developing DNA-based methodologies to mimic digital data manipulation. While exhibiting fundamental principles, this work was done in conjunction with the vision that DNA-based circuitry, when the technology matures, will form the basis for a tamper-proof security module, revolutionizing the meaning and concept of tamper-proofing and possibly preventing it altogether based on accurate scientific observations. A paramount part of such a solution would be self-generation of random numbers. A novel prototype schema employs solid phase synthesis of oligonucleotides for random construction of DNA sequences; temporary storage and retrieval is achieved through plasmid vectors. A discussion of how to evaluate sequence randomness is included, as well as how these techniques are applied to a simulation of the random number generation circuitry. Simulation results show generated sequences successfully pass three selected NIST random number generation tests specified for security applications.
A fast random number generator for the Intel Paragon supercomputer
Gutbrod, F.
1995-06-01
A pseudo-random number generator is presented which makes optimal use of the architecture of the i860-microprocessor and which is expected to have a very long period. It is therefore a good candidate for use on the parallel supercomputer Paragon XP. In the assembler version, it needs 6.4 cycles for a real∗4 random number. There is a FORTRAN routine which yields identical numbers up to rare and minor rounding discrepancies, and it needs 28 cycles. The FORTRAN performance on other microprocessors is somewhat better. Arguments for the quality of the generator and some numerical tests are given.
Accelerating Pseudo-Random Number Generator for MCNP on GPU
Gong, Chunye; Liu, Jie; Chi, Lihua; Hu, Qingfeng; Deng, Li; Gong, Zhenghu
2010-09-01
Pseudo-random number generators (PRNG) are intensively used in many stochastic algorithms in particle simulations, artificial neural networks and other scientific computation. The PRNG in Monte Carlo N-Particle Transport Code (MCNP) requires long period, high quality, flexible jump and fast enough. In this paper, we implement such a PRNG for MCNP on NVIDIA's GTX200 Graphics Processor Units (GPU) using CUDA programming model. Results shows that 3.80 to 8.10 times speedup are achieved compared with 4 to 6 cores CPUs and more than 679.18 million double precision random numbers can be generated per second on GPU.
Nanosized Minicells Generated by Lactic Acid Bacteria for Drug Delivery
Directory of Open Access Journals (Sweden)
Huu Ngoc Nguyen
2017-01-01
Full Text Available Nanotechnology has the ability to target specific areas of the body, controlling the drug release and significantly increasing the bioavailability of active compounds. Organic and inorganic nanoparticles have been developed for drug delivery systems. Many delivery systems are through clinical stages for development and market. Minicell, a nanosized cell generated by bacteria, is a potential particle for drug delivery because of its size, safety, and biodegradability. Minicells produced by bacteria could drive therapeutic agents against cancer, microbial infection, and other diseases by targeting. In addition, minicells generated by lactic acid bacteria being probiotics are more interesting than others because of their benefits like safety, immunological improvement, and biodegradation. This review aims to highlight the stages of development of nanoparticle for drug delivery and discuss their advantages and limitations to clarify minicells as a new opportunity for the development of potential nanoparticle for drug delivery.
Solution-Processed Carbon Nanotube True Random Number Generator.
Gaviria Rojas, William A; McMorrow, Julian J; Geier, Michael L; Tang, Qianying; Kim, Chris H; Marks, Tobin J; Hersam, Mark C
2017-08-09
With the growing adoption of interconnected electronic devices in consumer and industrial applications, there is an increasing demand for robust security protocols when transmitting and receiving sensitive data. Toward this end, hardware true random number generators (TRNGs), commonly used to create encryption keys, offer significant advantages over software pseudorandom number generators. However, the vast network of devices and sensors envisioned for the "Internet of Things" will require small, low-cost, and mechanically flexible TRNGs with low computational complexity. These rigorous constraints position solution-processed semiconducting single-walled carbon nanotubes (SWCNTs) as leading candidates for next-generation security devices. Here, we demonstrate the first TRNG using static random access memory (SRAM) cells based on solution-processed SWCNTs that digitize thermal noise to generate random bits. This bit generation strategy can be readily implemented in hardware with minimal transistor and computational overhead, resulting in an output stream that passes standardized statistical tests for randomness. By using solution-processed semiconducting SWCNTs in a low-power, complementary architecture to achieve TRNG, we demonstrate a promising approach for improving the security of printable and flexible electronics.
BWIP-RANDOM-SAMPLING, Random Sample Generation for Nuclear Waste Disposal
International Nuclear Information System (INIS)
Sagar, B.
1989-01-01
1 - Description of program or function: Random samples for different distribution types are generated. Distribution types as required for performance assessment modeling of geologic nuclear waste disposal are provided. These are: - Uniform, - Log-uniform (base 10 or natural), - Normal, - Lognormal (base 10 or natural), - Exponential, - Bernoulli, - User defined continuous distribution. 2 - Method of solution: A linear congruential generator is used for uniform random numbers. A set of functions is used to transform the uniform distribution to the other distributions. Stratified, rather than random, sampling can be chosen. Truncated limits can be specified on many distributions, whose usual definition has an infinite support. 3 - Restrictions on the complexity of the problem: Generation of correlated random variables is not included
Device-independent randomness generation from several Bell estimators
Nieto-Silleras, Olmo; Bamps, Cédric; Silman, Jonathan; Pironio, Stefano
2018-02-01
Device-independent randomness generation and quantum key distribution protocols rely on a fundamental relation between the non-locality of quantum theory and its random character. This relation is usually expressed in terms of a trade-off between the probability of guessing correctly the outcomes of measurements performed on quantum systems and the amount of violation of a given Bell inequality. However, a more accurate assessment of the randomness produced in Bell experiments can be obtained if the value of several Bell expressions is simultaneously taken into account, or if the full set of probabilities characterizing the behavior of the device is considered. We introduce protocols for device-independent randomness generation secure against classical side information, that rely on the estimation of an arbitrary number of Bell expressions or even directly on the experimental frequencies of measurement outcomes. Asymptotically, this results in an optimal generation of randomness from experimental data (as measured by the min-entropy), without having to assume beforehand that the devices violate a specific Bell inequality.
Random number generators tested on quantum Monte Carlo simulations.
Hongo, Kenta; Maezono, Ryo; Miura, Kenichi
2010-08-01
We have tested and compared several (pseudo) random number generators (RNGs) applied to a practical application, ground state energy calculations of molecules using variational and diffusion Monte Carlo metheds. A new multiple recursive generator with 8th-order recursion (MRG8) and the Mersenne twister generator (MT19937) are tested and compared with the RANLUX generator with five luxury levels (RANLUX-[0-4]). Both MRG8 and MT19937 are proven to give the same total energy as that evaluated with RANLUX-4 (highest luxury level) within the statistical error bars with less computational cost to generate the sequence. We also tested the notorious implementation of linear congruential generator (LCG), RANDU, for comparison. (c) 2010 Wiley Periodicals, Inc.
Extensions of von Neumann's method for generating random variables
International Nuclear Information System (INIS)
Monahan, J.F.
1979-01-01
Von Neumann's method of generating random variables with the exponential distribution and Forsythe's method for obtaining distributions with densities of the form e/sup -G//sup( x/) are generalized to apply to certain power series representations. The flexibility of the power series methods is illustrated by algorithms for the Cauchy and geometric distributions
Algorithms for random generation and counting a Markov chain approach
Sinclair, Alistair
1993-01-01
This monograph studies two classical computational problems: counting the elements of a finite set of combinatorial structures, and generating them at random from some probability distribution. Apart from their intrinsic interest, these problems arise naturally in many branches of mathematics and the natural sciences.
RANDOMNUMBERS, Random Number Sequence Generated from Gas Ionisation Chamber Data
International Nuclear Information System (INIS)
Frigerio, N.A.; Sanathanan, L.P.; Morley, M.; Tyler, S.A.; Clark, N.A.; Wang, J.
1989-01-01
1 - Description of problem or function: RANDOM NUMBERS is a data collection of almost 2.7 million 31-bit random numbers generated by using a high resolution gas ionization detector chamber in conjunction with a 4096-channel multichannel analyzer to record the radioactive decay of alpha particles from a U-235 source. The signals from the decaying alpha particles were fed to the 4096-channel analyzer, and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts, 0 for an even count and 1 for and odd count, were then assembled in sequence to form 31-bit random numbers and transcribed onto magnetic tape. This cycle was repeated to obtain the random numbers. 2 - Method of solution: The frequency distribution of counts from the device conforms to the Brockwell-Moyal distribution which takes into account the dead time of the counter. The count data were analyzed and tests for randomness on a sample indicate that the device is a highly reliable source of truly random numbers. 3 - Restrictions on the complexity of the problem: The RANDOM NUMBERS tape contains 2,669,568 31-bit numbers
Random number generation based on digital differential chaos
Zidan, Mohammed A.
2012-07-29
In this paper, we present a fully digital differential chaos based random number generator. The output of the digital circuit is proved to be chaotic by calculating the output time series maximum Lyapunov exponent. We introduce a new post processing technique to improve the distribution and statistical properties of the generated data. The post-processed output passes the NIST Sp. 800-22 statistical tests. The system is written in Verilog VHDL and realized on Xilinx Virtex® FPGA. The generator can fit into a very small area and have a maximum throughput of 2.1 Gb/s.
DNA based random key generation and management for OTP encryption.
Zhang, Yunpeng; Liu, Xin; Sun, Manhui
2017-09-01
One-time pad (OTP) is a principle of key generation applied to the stream ciphering method which offers total privacy. The OTP encryption scheme has proved to be unbreakable in theory, but difficult to realize in practical applications. Because OTP encryption specially requires the absolute randomness of the key, its development has suffered from dense constraints. DNA cryptography is a new and promising technology in the field of information security. DNA chromosomes storing capabilities can be used as one-time pad structures with pseudo-random number generation and indexing in order to encrypt the plaintext messages. In this paper, we present a feasible solution to the OTP symmetric key generation and transmission problem with DNA at the molecular level. Through recombinant DNA technology, by using only sender-receiver known restriction enzymes to combine the secure key represented by DNA sequence and the T vector, we generate the DNA bio-hiding secure key and then place the recombinant plasmid in implanted bacteria for secure key transmission. The designed bio experiments and simulation results show that the security of the transmission of the key is further improved and the environmental requirements of key transmission are reduced. Analysis has demonstrated that the proposed DNA-based random key generation and management solutions are marked by high security and usability. Published by Elsevier B.V.
Uniqueness: skews bit occurrence frequencies in randomly generated fingerprint libraries.
Chen, Nelson G
2016-08-01
Requiring that randomly generated chemical fingerprint libraries have unique fingerprints such that no two fingerprints are identical causes a systematic skew in bit occurrence frequencies, the proportion at which specified bits are set. Observed frequencies (O) at which each bit is set within the resulting libraries systematically differ from frequencies at which bits are set at fingerprint generation (E). Observed frequencies systematically skew toward 0.5, with the effect being more pronounced as library size approaches the compound space, which is the total number of unique possible fingerprints given the number of bit positions each fingerprint contains. The effect is quantified for varying library sizes as a fraction of the overall compound space, and for changes in the specified frequency E. The cause and implications for this systematic skew are subsequently discussed. When generating random libraries of chemical fingerprints, the imposition of a uniqueness requirement should either be avoided or taken into account.
GASPRNG: GPU accelerated scalable parallel random number generator library
Gao, Shuang; Peterson, Gregory D.
2013-04-01
Graphics processors represent a promising technology for accelerating computational science applications. Many computational science applications require fast and scalable random number generation with good statistical properties, so they use the Scalable Parallel Random Number Generators library (SPRNG). We present the GPU Accelerated SPRNG library (GASPRNG) to accelerate SPRNG in GPU-based high performance computing systems. GASPRNG includes code for a host CPU and CUDA code for execution on NVIDIA graphics processing units (GPUs) along with a programming interface to support various usage models for pseudorandom numbers and computational science applications executing on the CPU, GPU, or both. This paper describes the implementation approach used to produce high performance and also describes how to use the programming interface. The programming interface allows a user to be able to use GASPRNG the same way as SPRNG on traditional serial or parallel computers as well as to develop tightly coupled programs executing primarily on the GPU. We also describe how to install GASPRNG and use it. To help illustrate linking with GASPRNG, various demonstration codes are included for the different usage models. GASPRNG on a single GPU shows up to 280x speedup over SPRNG on a single CPU core and is able to scale for larger systems in the same manner as SPRNG. Because GASPRNG generates identical streams of pseudorandom numbers as SPRNG, users can be confident about the quality of GASPRNG for scalable computational science applications. Catalogue identifier: AEOI_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOI_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: UTK license. No. of lines in distributed program, including test data, etc.: 167900 No. of bytes in distributed program, including test data, etc.: 1422058 Distribution format: tar.gz Programming language: C and CUDA. Computer: Any PC or
Programmable pseudo-random detector-pulse-pattern generator
International Nuclear Information System (INIS)
Putten, R. van der; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica
1990-01-01
This report discusses the design and realization of the digital part of the programmable pseudo-random detector pulse-pattern generator. For the design and realization use has been made of F-TTL and high speed special purpose ic's, in particular FAL's (15 ns). The design possibilities offered by the software for pro-gramming of the FAL's have been utilized as much as possible. In this way counters, registers and a state machine with extended control possibilities have been designed and an advanced 8 channel pulse generator has been developed which is controlled via the VME system bus. the generator possesses an internal clock oscillator of 16 MHZ. The moment when a pulse is generated can be adjusted with a step size of 250 ps. 2000 different periods (time windows) can be stored for generating a pattern. (author). 37 refs.; 6 figs
Testing random number generators for Monte Carlo applications
International Nuclear Information System (INIS)
Sim, L.H.
1992-01-01
Central to any system for modelling radiation transport phenomena using Monte Carlo techniques is the method by which pseudo random numbers are generated. This method is commonly referred to as the Random Number Generator (RNG). It is usually a computer implemented mathematical algorithm which produces a series of numbers uniformly distributed on the interval [0,1]. If this series satisfies certain statistical tests for randomness, then for practical purposes the pseudo random numbers in the series can be considered to be random. Tests of this nature are important not only for new RNGs but also to test the implementation of known RNG algorithms in different computer environments. Six RNGs have been tested using six statistical tests and one visual test. The statistical tests are the moments, frequency (digit and number), serial, gap, and poker tests. The visual test is a simple two dimensional ordered pair display. In addition the RNGs have been tested in a specific Monte Carlo application. This type of test is often overlooked, however it is important that in addition to satisfactory performance in statistical tests, the RNG be able to perform effectively in the applications of interest. The RNGs tested here are based on a variety of algorithms, including multiplicative and linear congruential, lagged Fibonacci, and combination arithmetic and lagged Fibonacci. The effect of the Bays-Durham shuffling algorithm on the output of a known bad RNG has also been investigated. 18 refs., 11 tabs., 4 figs. of
The additive congruential random number generator--A special case of a multiple recursive generator
Wikramaratna, Roy S.
2008-07-01
This paper considers an approach to generating uniformly distributed pseudo-random numbers which works well in serial applications but which also appears particularly well-suited for application on parallel processing systems. Additive Congruential Random Number (ACORN) generators are straightforward to implement for arbitrarily large order and modulus; if implemented using integer arithmetic, it becomes possible to generate identical sequences on any machine. Previously published theoretical analysis has demonstrated that a kth order ACORN sequence approximates to being uniformly distributed in up to k dimensions, for any given k. ACORN generators can be constructed to give period lengths exceeding any given number (for example, with period length in excess of 230p, for any given p). Results of empirical tests have demonstrated that, if p is greater than or equal to 2, then the ACORN generator can be used successfully for generating double precision uniform random variates. This paper demonstrates that an ACORN generator is a particular case of a multiple recursive generator (and, therefore, also a special case of a matrix generator). Both these latter approaches have been widely studied, and it is to be hoped that the results given in the present paper will lead to greater confidence in using the ACORN generators.
Quantum random number generator based on quantum tunneling effect
Zhou, Haihan; Li, Junlin; Pan, Dong; Zhang, Weixing; Long, Guilu
2017-01-01
In this paper, we proposed an experimental implementation of quantum random number generator(QRNG) with inherent randomness of quantum tunneling effect of electrons. We exploited InGaAs/InP diodes, whose valance band and conduction band shared a quasi-constant energy barrier. We applied a bias voltage on the InGaAs/InP avalanche diode, which made the diode works under Geiger mode, and triggered the tunneling events with a periodic pulse. Finally, after data collection and post-processing, our...
Generation of correlated finite alphabet waveforms using gaussian random variables
Jardak, Seifallah
2014-09-01
Correlated waveforms have a number of applications in different fields, such as radar and communication. It is very easy to generate correlated waveforms using infinite alphabets, but for some of the applications, it is very challenging to use them in practice. Moreover, to generate infinite alphabet constant envelope correlated waveforms, the available research uses iterative algorithms, which are computationally very expensive. In this work, we propose simple novel methods to generate correlated waveforms using finite alphabet constant and non-constant-envelope symbols. To generate finite alphabet waveforms, the proposed method map the Gaussian random variables onto the phase-shift-keying, pulse-amplitude, and quadrature-amplitude modulation schemes. For such mapping, the probability-density-function of Gaussian random variables is divided into M regions, where M is the number of alphabets in the corresponding modulation scheme. By exploiting the mapping function, the relationship between the cross-correlation of Gaussian and finite alphabet symbols is derived. To generate equiprobable symbols, the area of each region is kept same. If the requirement is to have each symbol with its own unique probability, the proposed scheme allows us that as well. Although, the proposed scheme is general, the main focus of this paper is to generate finite alphabet waveforms for multiple-input multiple-output radar, where correlated waveforms are used to achieve desired beampatterns. © 2014 IEEE.
Very high performance pseudo-random number generation on DAP
Smith, K. A.; Reddaway, S. F.; Scott, D. M.
1985-07-01
Since the National DAP Service began at QMC in 1980, extensive use has been made of pseudo-random numbers in Monte Carlo simulation. Matrices of uniform numbers have been produced by various generators: (a) multiplicative ( x+ 1 = 13 13xn mod 2 59); (b) very long period shift register ( x4423 + x271 + 1); (c) multiple shorter period ( x127 + x7 + 1) shift registers generating several matrices per iteration. The above uniform generators can also feed a normal distribution generator that uses the Box-Muller transformation. This paper describes briefly the generators, their implementation and speed. Generator (b) has been greatly speeded-up by re-implementation, and now produces more than 100 × 10 6 high quality 16-bit numbers/s. Generator (c) is under development and will achieve even higher performance, mainly due to producing data in greater bulk. High quality numbers are expected, and performance will range from 400 to 800 × 10 6 numbers/s, depending on how the generator is used.
Automatic generation of randomized trial sequences for priming experiments.
Ihrke, Matthias; Behrendt, Jörg
2011-01-01
In most psychological experiments, a randomized presentation of successive displays is crucial for the validity of the results. For some paradigms, this is not a trivial issue because trials are interdependent, e.g., priming paradigms. We present a software that automatically generates optimized trial sequences for (negative-) priming experiments. Our implementation is based on an optimization heuristic known as genetic algorithms that allows for an intuitive interpretation due to its similarity to natural evolution. The program features a graphical user interface that allows the user to generate trial sequences and to interactively improve them. The software is based on freely available software and is released under the GNU General Public License.
GRD: An SPSS extension command for generating random data
Directory of Open Access Journals (Sweden)
Bradley Harding
2014-09-01
Full Text Available To master statistics and data analysis tools, it is necessary to understand a number of concepts, manyof which are quite abstract. For example, sampling from a theoretical distribution can help individuals explore andunderstand randomness. Sampling can also be used to build exercises aimed to help students master statistics. Here, we present GRD (Generator of Random Data, an extension command for SPSS (version 17 and above. With GRD, it is possible to get random data from a given distribution. In its simplest use, GRD will return a set of simulated data from a normal distribution.With subcommands to GRD, it is possible to get data from multiple groups, over multiple repeated measures, and with desired effectsizes. Group sizes can be equal or unequal. With further subcommands, it is possible to sample from any theoretical population, (not simply the normal distribution, introduce non-homogeneous variances,fix or randomize subject effects, etc. Finally, GRD’s generated data are in a format ready to be analyzed.
Salvage Therapy of Multiple Myeloma: The New Generation Drugs
Directory of Open Access Journals (Sweden)
Alessandra Romano
2014-01-01
Full Text Available During the past decade, overall results of treatment of multiple myeloma (MM have been improved and survival curves are now significantly better with respect to those obtained with historical treatment. These improvements are linked to a deeper knowledge of the biology of disease and to the introduction in clinical practice of drugs with different mechanism of action such as proteasome inhibitors and immunomodulatory drugs (IMiDs. However, MM remains in most cases an incurable disease. For patients who relapse after treatment with novel agents, the prognosis is dismal and new drugs and therapeutic strategies are required for continued disease control. In this review, we summarize new insights in salvage therapy for relapsed/refractory MM as emerging from recent clinical trials exploring the activity of bendamustine, new generation proteasome inhibitors, novel IMiDs, monoclonal antibodies, and drugs interfering with growth pathways.
Salvage Therapy of Multiple Myeloma: The New Generation Drugs
Romano, Alessandra; Conticello, Concetta; Di Raimondo, Cosimo; Schinocca, Elena; La Fauci, Alessia; Parrinello, Nunziatina Laura; Chiarenza, Annalisa
2014-01-01
During the past decade, overall results of treatment of multiple myeloma (MM) have been improved and survival curves are now significantly better with respect to those obtained with historical treatment. These improvements are linked to a deeper knowledge of the biology of disease and to the introduction in clinical practice of drugs with different mechanism of action such as proteasome inhibitors and immunomodulatory drugs (IMiDs). However, MM remains in most cases an incurable disease. For patients who relapse after treatment with novel agents, the prognosis is dismal and new drugs and therapeutic strategies are required for continued disease control. In this review, we summarize new insights in salvage therapy for relapsed/refractory MM as emerging from recent clinical trials exploring the activity of bendamustine, new generation proteasome inhibitors, novel IMiDs, monoclonal antibodies, and drugs interfering with growth pathways. PMID:24967371
At least some errors are randomly generated (Freud was wrong)
Sellen, A. J.; Senders, J. W.
1986-01-01
An experiment was carried out to expose something about human error generating mechanisms. In the context of the experiment, an error was made when a subject pressed the wrong key on a computer keyboard or pressed no key at all in the time allotted. These might be considered, respectively, errors of substitution and errors of omission. Each of seven subjects saw a sequence of three digital numbers, made an easily learned binary judgement about each, and was to press the appropriate one of two keys. Each session consisted of 1,000 presentations of randomly permuted, fixed numbers broken into 10 blocks of 100. One of two keys should have been pressed within one second of the onset of each stimulus. These data were subjected to statistical analyses in order to probe the nature of the error generating mechanisms. Goodness of fit tests for a Poisson distribution for the number of errors per 50 trial interval and for an exponential distribution of the length of the intervals between errors were carried out. There is evidence for an endogenous mechanism that may best be described as a random error generator. Furthermore, an item analysis of the number of errors produced per stimulus suggests the existence of a second mechanism operating on task driven factors producing exogenous errors. Some errors, at least, are the result of constant probability generating mechanisms with error rate idiosyncratically determined for each subject.
PRIMITIVE MATRICES AND GENERATORS OF PSEUDO RANDOM SEQUENCES OF GALOIS
Directory of Open Access Journals (Sweden)
A. Beletsky
2014-04-01
Full Text Available In theory and practice of information cryptographic protection one of the key problems is the forming a binary pseudo-random sequences (PRS with a maximum length with acceptable statistical characteristics. PRS generators are usually implemented by linear shift register (LSR of maximum period with linear feedback [1]. In this paper we extend the concept of LSR, assuming that each of its rank (memory cell can be in one of the following condition. Let’s call such registers “generalized linear shift register.” The research goal is to develop algorithms for constructing Galois and Fibonacci generalized matrix of n-order over the field , which uniquely determined both the structure of corresponding generalized of n-order LSR maximal period, and formed on their basis Galois PRS generators of maximum length. Thus the article presents the questions of formation the primitive generalized Fibonacci and Galois arbitrary order matrix over the prime field . The synthesis of matrices is based on the use of irreducible polynomials of degree and primitive elements of the extended field generated by polynomial. The constructing methods of Galois and Fibonacci conjugated primitive matrices are suggested. The using possibilities of such matrices in solving the problem of constructing generalized generators of Galois pseudo-random sequences are discussed.
75 FR 79308 - Alcohol and Drug Testing: Determination of Minimum Random Testing Rates for 2011
2010-12-20
...-11213, Notice No. 14] Alcohol and Drug Testing: Determination of Minimum Random Testing Rates for 2011... random testing positive rates were .037 percent for drugs and .014 percent for alcohol. Because the... effective December 20, 2010. FOR FURTHER INFORMATION CONTACT: Lamar Allen, Alcohol and Drug Program Manager...
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2012-12-26
...-11213, Notice No. 16] Alcohol and Drug Testing: Determination of Minimum Random Testing Rates for 2013...., Washington, DC 20590, (telephone 202-493- 1342); or Kathy Schnakenberg, FRA Alcohol/Drug Program Specialist... from FRA's Management Information System, the rail industry's random drug testing positive rate has...
75 FR 1547 - Alcohol and Drug Testing: Determination of Minimum Random Testing Rates for 2010
2010-01-12
...-11213, Notice No. 13] RIN 2130-AA81 Alcohol and Drug Testing: Determination of Minimum Random Testing... percent for alcohol. Because the industry-wide random drug testing positive rate has remained below 1.0... effective upon publication. FOR FURTHER INFORMATION CONTACT: Lamar Allen, Alcohol and Drug Program Manager...
Primitive polynomials selection method for pseudo-random number generator
Anikin, I. V.; Alnajjar, Kh
2018-01-01
In this paper we suggested the method for primitive polynomials selection of special type. This kind of polynomials can be efficiently used as a characteristic polynomials for linear feedback shift registers in pseudo-random number generators. The proposed method consists of two basic steps: finding minimum-cost irreducible polynomials of the desired degree and applying primitivity tests to get the primitive ones. Finally two primitive polynomials, which was found by the proposed method, used in pseudorandom number generator based on fuzzy logic (FRNG) which had been suggested before by the authors. The sequences generated by new version of FRNG have low correlation magnitude, high linear complexity, less power consumption, is more balanced and have better statistical properties.
Generating Correlated QPSK Waveforms By Exploiting Real Gaussian Random Variables
Jardak, Seifallah
2012-11-01
The design of waveforms with specified auto- and cross-correlation properties has a number of applications in multiple-input multiple-output (MIMO) radar, one of them is the desired transmit beampattern design. In this work, an algorithm is proposed to generate quadrature phase shift- keying (QPSK) waveforms with required cross-correlation properties using real Gaussian random-variables (RV’s). This work can be considered as the extension of what was presented in [1] to generate BPSK waveforms. This work will be extended for the generation of correlated higher-order phase shift-keying (PSK) and quadrature amplitude modulation (QAM) schemes that can better approximate the desired beampattern.
A programmable Gaussian random pulse generator for automated performance measurements
International Nuclear Information System (INIS)
Abdel-Aal, R.E.
1989-01-01
This paper describes a versatile random signal generator which produces logic pulses with a Gaussian distribution for the pulse spacing. The average rate at the pulse generator output can be software-programmed, which makes it useful in performing automated measurements of dead time and CPU time performance of data acquisition systems and modules over a wide range of data rates. Hardware and software components are described and data on the input-output characteristics and the statistical properties of the pulse generator are given. Typical applications are discussed together with advantages over using radioactive test sources. Results obtained from an automated performance run on a VAX 11/785 data acquisition system are presented. (orig.)
Generating Correlated QPSK Waveforms By Exploiting Real Gaussian Random Variables
Jardak, Seifallah; Ahmed, Sajid; Alouini, Mohamed-Slim
2012-01-01
The design of waveforms with specified auto- and cross-correlation properties has a number of applications in multiple-input multiple-output (MIMO) radar, one of them is the desired transmit beampattern design. In this work, an algorithm is proposed to generate quadrature phase shift- keying (QPSK) waveforms with required cross-correlation properties using real Gaussian random-variables (RV’s). This work can be considered as the extension of what was presented in [1] to generate BPSK waveforms. This work will be extended for the generation of correlated higher-order phase shift-keying (PSK) and quadrature amplitude modulation (QAM) schemes that can better approximate the desired beampattern.
Cellular Automata-Based Parallel Random Number Generators Using FPGAs
Directory of Open Access Journals (Sweden)
David H. K. Hoe
2012-01-01
Full Text Available Cellular computing represents a new paradigm for implementing high-speed massively parallel machines. Cellular automata (CA, which consist of an array of locally connected processing elements, are a basic form of a cellular-based architecture. The use of field programmable gate arrays (FPGAs for implementing CA accelerators has shown promising results. This paper investigates the design of CA-based pseudo-random number generators (PRNGs using an FPGA platform. To improve the quality of the random numbers that are generated, the basic CA structure is enhanced in two ways. First, the addition of a superrule to each CA cell is considered. The resulting self-programmable CA (SPCA uses the superrule to determine when to make a dynamic rule change in each CA cell. The superrule takes its inputs from neighboring cells and can be considered itself a second CA working in parallel with the main CA. When implemented on an FPGA, the use of lookup tables in each logic cell removes any restrictions on how the super-rules should be defined. Second, a hybrid configuration is formed by combining a CA with a linear feedback shift register (LFSR. This is advantageous for FPGA designs due to the compactness of the LFSR implementations. A standard software package for statistically evaluating the quality of random number sequences known as Diehard is used to validate the results. Both the SPCA and the hybrid CA/LFSR were found to pass all the Diehard tests.
Generative Recurrent Networks for De Novo Drug Design.
Gupta, Anvita; Müller, Alex T; Huisman, Berend J H; Fuchs, Jens A; Schneider, Petra; Schneider, Gisbert
2018-01-01
Generative artificial intelligence models present a fresh approach to chemogenomics and de novo drug design, as they provide researchers with the ability to narrow down their search of the chemical space and focus on regions of interest. We present a method for molecular de novo design that utilizes generative recurrent neural networks (RNN) containing long short-term memory (LSTM) cells. This computational model captured the syntax of molecular representation in terms of SMILES strings with close to perfect accuracy. The learned pattern probabilities can be used for de novo SMILES generation. This molecular design concept eliminates the need for virtual compound library enumeration. By employing transfer learning, we fine-tuned the RNN's predictions for specific molecular targets. This approach enables virtual compound design without requiring secondary or external activity prediction, which could introduce error or unwanted bias. The results obtained advocate this generative RNN-LSTM system for high-impact use cases, such as low-data drug discovery, fragment based molecular design, and hit-to-lead optimization for diverse drug targets. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
Generation of correlated finite alphabet waveforms using gaussian random variables
Ahmed, Sajid
2016-01-13
Various examples of methods and systems are provided for generation of correlated finite alphabet waveforms using Gaussian random variables in, e.g., radar and communication applications. In one example, a method includes mapping an input signal comprising Gaussian random variables (RVs) onto finite-alphabet non-constant-envelope (FANCE) symbols using a predetermined mapping function, and transmitting FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The FANCE waveforms can be based upon the mapping of the Gaussian RVs onto the FANCE symbols. In another example, a system includes a memory unit that can store a plurality of digital bit streams corresponding to FANCE symbols and a front end unit that can transmit FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The system can include a processing unit that can encode the input signal and/or determine the mapping function.
Generation of correlated finite alphabet waveforms using gaussian random variables
Ahmed, Sajid; Alouini, Mohamed-Slim; Jardak, Seifallah
2016-01-01
Various examples of methods and systems are provided for generation of correlated finite alphabet waveforms using Gaussian random variables in, e.g., radar and communication applications. In one example, a method includes mapping an input signal comprising Gaussian random variables (RVs) onto finite-alphabet non-constant-envelope (FANCE) symbols using a predetermined mapping function, and transmitting FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The FANCE waveforms can be based upon the mapping of the Gaussian RVs onto the FANCE symbols. In another example, a system includes a memory unit that can store a plurality of digital bit streams corresponding to FANCE symbols and a front end unit that can transmit FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The system can include a processing unit that can encode the input signal and/or determine the mapping function.
Random Sequence for Optimal Low-Power Laser Generated Ultrasound
Vangi, D.; Virga, A.; Gulino, M. S.
2017-08-01
Low-power laser generated ultrasounds are lately gaining importance in the research world, thanks to the possibility of investigating a mechanical component structural integrity through a non-contact and Non-Destructive Testing (NDT) procedure. The ultrasounds are, however, very low in amplitude, making it necessary to use pre-processing and post-processing operations on the signals to detect them. The cross-correlation technique is used in this work, meaning that a random signal must be used as laser input. For this purpose, a highly random and simple-to-create code called T sequence, capable of enhancing the ultrasound detectability, is introduced (not previously available at the state of the art). Several important parameters which characterize the T sequence can influence the process: the number of pulses Npulses , the pulse duration δ and the distance between pulses dpulses . A Finite Element FE model of a 3 mm steel disk has been initially developed to analytically study the longitudinal ultrasound generation mechanism and the obtainable outputs. Later, experimental tests have shown that the T sequence is highly flexible for ultrasound detection purposes, making it optimal to use high Npulses and δ but low dpulses . In the end, apart from describing all phenomena that arise in the low-power laser generation process, the results of this study are also important for setting up an effective NDT procedure using this technology.
Random-Number Generator Validity in Simulation Studies: An Investigation of Normality.
Bang, Jung W.; Schumacker, Randall E.; Schlieve, Paul L.
1998-01-01
The normality of number distributions generated by various random-number generators were studied, focusing on when the random-number generator reached a normal distribution and at what sample size. Findings suggest the steps that should be followed when using a random-number generator in a Monte Carlo simulation. (SLD)
Quantum Statistical Testing of a Quantum Random Number Generator
Energy Technology Data Exchange (ETDEWEB)
Humble, Travis S [ORNL
2014-01-01
The unobservable elements in a quantum technology, e.g., the quantum state, complicate system verification against promised behavior. Using model-based system engineering, we present methods for verifying the opera- tion of a prototypical quantum random number generator. We begin with the algorithmic design of the QRNG followed by the synthesis of its physical design requirements. We next discuss how quantum statistical testing can be used to verify device behavior as well as detect device bias. We conclude by highlighting how system design and verification methods must influence effort to certify future quantum technologies.
Ghersi, Dario; Parakh, Abhishek; Mezei, Mihaly
2017-12-05
Four pseudorandom number generators were compared with a physical, quantum-based random number generator using the NIST suite of statistical tests, which only the quantum-based random number generator could successfully pass. We then measured the effect of the five random number generators on various calculated properties in different Markov-chain Monte Carlo simulations. Two types of systems were tested: conformational sampling of a small molecule in aqueous solution and liquid methanol under constant temperature and pressure. The results show that poor quality pseudorandom number generators produce results that deviate significantly from those obtained with the quantum-based random number generator, particularly in the case of the small molecule in aqueous solution setup. In contrast, the widely used Mersenne Twister pseudorandom generator and a 64-bit Linear Congruential Generator with a scrambler produce results that are statistically indistinguishable from those obtained with the quantum-based random number generator. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Pseudo random number generator based on quantum chaotic map
Akhshani, A.; Akhavan, A.; Mobaraki, A.; Lim, S.-C.; Hassan, Z.
2014-01-01
For many years dissipative quantum maps were widely used as informative models of quantum chaos. In this paper, a new scheme for generating good pseudo-random numbers (PRNG), based on quantum logistic map is proposed. Note that the PRNG merely relies on the equations used in the quantum chaotic map. The algorithm is not complex, which does not impose high requirement on computer hardware and thus computation speed is fast. In order to face the challenge of using the proposed PRNG in quantum cryptography and other practical applications, the proposed PRNG is subjected to statistical tests using well-known test suites such as NIST, DIEHARD, ENT and TestU01. The results of the statistical tests were promising, as the proposed PRNG successfully passed all these tests. Moreover, the degree of non-periodicity of the chaotic sequences of the quantum map is investigated through the Scale index technique. The obtained result shows that, the sequence is more non-periodic. From these results it can be concluded that, the new scheme can generate a high percentage of usable pseudo-random numbers for simulation and other applications in scientific computing.
Fully Digital Chaotic Oscillators Applied to Pseudo Random Number Generation
Mansingka, Abhinav S.
2012-05-01
adapted for pseudo random number generation by truncating statistically defective bits. Finally, a novel post-processing technique using the Fibonacci series is proposed and implemented with a non-autonomous driven hyperchaotic system to provide pseudo random number generators with high nonlinear complexity and controllable period length that enables full utilization of all branches of the chaotic output as statistically secure pseudo random output.
Random walk generated by random permutations of {1, 2, 3, ..., n + 1}
International Nuclear Information System (INIS)
Oshanin, G; Voituriez, R
2004-01-01
We study properties of a non-Markovian random walk X (n) l , l = 0, 1, 2, ..., n, evolving in discrete time l on a one-dimensional lattice of integers, whose moves to the right or to the left are prescribed by the rise-and-descent sequences characterizing random permutations π of [n + 1] = {1, 2, 3, ..., n + 1}. We determine exactly the probability of finding the end-point X n = X (n) n of the trajectory of such a permutation-generated random walk (PGRW) at site X, and show that in the limit n → ∞ it converges to a normal distribution with a smaller, compared to the conventional Polya random walk, diffusion coefficient. We formulate, as well, an auxiliary stochastic process whose distribution is identical to the distribution of the intermediate points X (n) l , l < n, which enables us to obtain the probability measure of different excursions and to define the asymptotic distribution of the number of 'turns' of the PGRW trajectories
Generative Learning Objects Instantiated with Random Numbers Based Expressions
Directory of Open Access Journals (Sweden)
Ciprian Bogdan Chirila
2015-12-01
Full Text Available The development of interactive e-learning content requires special skills like programming techniques, web integration, graphic design etc. Generally, online educators do not possess such skills and their e-learning products tend to be static like presentation slides and textbooks. In this paper we propose a new interactive model of generative learning objects as a compromise betweenstatic, dull materials and dynamic, complex software e-learning materials developed by specialized teams. We find that random numbers based automatic initialization learning objects increases content diversity, interactivity thus enabling learners’ engagement. The resulted learning object model is at a limited level of complexity related to special e-learning software, intuitive and capable of increasing learners’ interactivity, engagement and motivation through dynamic content. The approach was applied successfully on several computer programing disciplines.
Statistical evaluation of PACSTAT random number generation capabilities
Energy Technology Data Exchange (ETDEWEB)
Piepel, G.F.; Toland, M.R.; Harty, H.; Budden, M.J.; Bartley, C.L.
1988-05-01
This report summarizes the work performed in verifying the general purpose Monte Carlo driver-program PACSTAT. The main objective of the work was to verify the performance of PACSTAT's random number generation capabilities. Secondary objectives were to document (using controlled configuration management procedures) changes made in PACSTAT at Pacific Northwest Laboratory, and to assure that PACSTAT input and output files satisfy quality assurance traceability constraints. Upon receipt of the PRIME version of the PACSTAT code from the Basalt Waste Isolation Project, Pacific Northwest Laboratory staff converted the code to run on Digital Equipment Corporation (DEC) VAXs. The modifications to PACSTAT were implemented using the WITNESS configuration management system, with the modifications themselves intended to make the code as portable as possible. Certain modifications were made to make the PACSTAT input and output files conform to quality assurance traceability constraints. 10 refs., 17 figs., 6 tabs.
Random number generation as an index of controlled processing.
Jahanshahi, Marjan; Saleem, T; Ho, Aileen K; Dirnberger, Georg; Fuller, R
2006-07-01
Random number generation (RNG) is a functionally complex process that is highly controlled and therefore dependent on Baddeley's central executive. This study addresses this issue by investigating whether key predictions from this framework are compatible with empirical data. In Experiment 1, the effect of increasing task demands by increasing the rate of the paced generation was comprehensively examined. As expected, faster rates affected performance negatively because central resources were increasingly depleted. Next, the effects of participants' exposure were manipulated in Experiment 2 by providing increasing amounts of practice on the task. There was no improvement over 10 practice trials, suggesting that the high level of strategic control required by the task was constant and not amenable to any automatization gain with repeated exposure. Together, the results demonstrate that RNG performance is a highly controlled and demanding process sensitive to additional demands on central resources (Experiment 1) and is unaffected by repeated performance or practice (Experiment 2). These features render the easily administered RNG task an ideal and robust index of executive function that is highly suitable for repeated clinical use. ((c) 2006 APA, all rights reserved).
Generated effect modifiers (GEM's) in randomized clinical trials.
Petkova, Eva; Tarpey, Thaddeus; Su, Zhe; Ogden, R Todd
2017-01-01
In a randomized clinical trial (RCT), it is often of interest not only to estimate the effect of various treatments on the outcome, but also to determine whether any patient characteristic has a different relationship with the outcome, depending on treatment. In regression models for the outcome, if there is a non-zero interaction between treatment and a predictor, that predictor is called an "effect modifier". Identification of such effect modifiers is crucial as we move towards precision medicine, that is, optimizing individual treatment assignment based on patient measurements assessed when presenting for treatment. In most settings, there will be several baseline predictor variables that could potentially modify the treatment effects. This article proposes optimal methods of constructing a composite variable (defined as a linear combination of pre-treatment patient characteristics) in order to generate an effect modifier in an RCT setting. Several criteria are considered for generating effect modifiers and their performance is studied via simulations. An example from a RCT is provided for illustration. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Generated effect modifiers (GEM’s) in randomized clinical trials
Petkova, Eva; Tarpey, Thaddeus; Su, Zhe; Ogden, R. Todd
2017-01-01
In a randomized clinical trial (RCT), it is often of interest not only to estimate the effect of various treatments on the outcome, but also to determine whether any patient characteristic has a different relationship with the outcome, depending on treatment. In regression models for the outcome, if there is a non-zero interaction between treatment and a predictor, that predictor is called an “effect modifier”. Identification of such effect modifiers is crucial as we move towards precision medicine, that is, optimizing individual treatment assignment based on patient measurements assessed when presenting for treatment. In most settings, there will be several baseline predictor variables that could potentially modify the treatment effects. This article proposes optimal methods of constructing a composite variable (defined as a linear combination of pre-treatment patient characteristics) in order to generate an effect modifier in an RCT setting. Several criteria are considered for generating effect modifiers and their performance is studied via simulations. An example from a RCT is provided for illustration. PMID:27465235
78 FR 78275 - Alcohol and Drug Testing: Determination of Minimum Random Testing Rates for 2014
2013-12-26
...-11213, Notice No. 17] Alcohol and Drug Testing: Determination of Minimum Random Testing Rates for 2014... December 26, 2013. FOR FURTHER INFORMATION CONTACT: Jerry Powers, FRA Drug and Alcohol Program Manager, W38...-493-6313); or Sam Noe, FRA Drug and Alcohol Program Specialist, (telephone 615-719- 2951). Issued in...
76 FR 80781 - Alcohol and Drug Testing: Determination of Minimum Random Testing Rates for 2012
2011-12-27
...-11213, Notice No. 15] RIN 2130-AA81 Alcohol and Drug Testing: Determination of Minimum Random Testing...: Lamar Allen, Alcohol and Drug Program Manager, Office of Safety Enforcement, Mail Stop 25, Federal... Kathy Schnakenberg, FRA Alcohol/Drug Program Specialist, (telephone (719) 633-8955). Issued in...
About the problem of generating three-dimensional pseudo-random points.
Carpintero, D. D.
The author demonstrates that a popular pseudo-random number generator is not adequate in some circumstances to generate n-dimensional random points, n > 2. This problem is particularly noxious when direction cosines are generated. He proposes several soultions, among them a good generator that satisfies all statistical criteria.
The frequency of drugs in randomly selected drivers in Denmark
DEFF Research Database (Denmark)
Simonsen, Kirsten Wiese; Steentoft, Anni; Hels, Tove
is the Danish legal limit. The percentage of drivers positive for medicinal drugs above the Danish legal concentration limit was 0.4%; while, 0.3% of the drivers tested positive for one or more illicit drug at concentrations exceeding the Danish legal limit. Tetrahydrocannabinol, cocaine, and amphetamine were...... the most frequent illicit drugs detected above the limit of quantitation (LOQ); while, codeine, tramadol, zopiclone, and benzodiazepines were the most frequent legal drugs. Middle aged men (median age 47.5 years) dominated the drunk driving group, while the drivers positive for illegal drugs consisted......Introduction Driving under the influence of alcohol and drugs is a global problem. In Denmark as well as in other countries there is an increasing focus on impaired driving. Little is known about the occurrence of psychoactive drugs in the general traffic. Therefore the European commission...
An empirical test of pseudo random number generators by means of an exponential decaying process
International Nuclear Information System (INIS)
Coronel B, H.F.; Hernandez M, A.R.; Jimenez M, M.A.; Mora F, L.E.
2007-01-01
Empirical tests for pseudo random number generators based on the use of processes or physical models have been successfully used and are considered as complementary to theoretical tests of randomness. In this work a statistical methodology for evaluating the quality of pseudo random number generators is presented. The method is illustrated in the context of the so-called exponential decay process, using some pseudo random number generators commonly used in physics. (Author)
Novel pseudo-random number generator based on quantum random walks
Yang, Yu-Guang; Zhao, Qian-Qian
2016-02-01
In this paper, we investigate the potential application of quantum computation for constructing pseudo-random number generators (PRNGs) and further construct a novel PRNG based on quantum random walks (QRWs), a famous quantum computation model. The PRNG merely relies on the equations used in the QRWs, and thus the generation algorithm is simple and the computation speed is fast. The proposed PRNG is subjected to statistical tests such as NIST and successfully passed the test. Compared with the representative PRNG based on quantum chaotic maps (QCM), the present QRWs-based PRNG has some advantages such as better statistical complexity and recurrence. For example, the normalized Shannon entropy and the statistical complexity of the QRWs-based PRNG are 0.999699456771172 and 1.799961178212329e-04 respectively given the number of 8 bits-words, say, 16Mbits. By contrast, the corresponding values of the QCM-based PRNG are 0.999448131481064 and 3.701210794388818e-04 respectively. Thus the statistical complexity and the normalized entropy of the QRWs-based PRNG are closer to 0 and 1 respectively than those of the QCM-based PRNG when the number of words of the analyzed sequence increases. It provides a new clue to construct PRNGs and also extends the applications of quantum computation.
Novel pseudo-random number generator based on quantum random walks.
Yang, Yu-Guang; Zhao, Qian-Qian
2016-02-04
In this paper, we investigate the potential application of quantum computation for constructing pseudo-random number generators (PRNGs) and further construct a novel PRNG based on quantum random walks (QRWs), a famous quantum computation model. The PRNG merely relies on the equations used in the QRWs, and thus the generation algorithm is simple and the computation speed is fast. The proposed PRNG is subjected to statistical tests such as NIST and successfully passed the test. Compared with the representative PRNG based on quantum chaotic maps (QCM), the present QRWs-based PRNG has some advantages such as better statistical complexity and recurrence. For example, the normalized Shannon entropy and the statistical complexity of the QRWs-based PRNG are 0.999699456771172 and 1.799961178212329e-04 respectively given the number of 8 bits-words, say, 16Mbits. By contrast, the corresponding values of the QCM-based PRNG are 0.999448131481064 and 3.701210794388818e-04 respectively. Thus the statistical complexity and the normalized entropy of the QRWs-based PRNG are closer to 0 and 1 respectively than those of the QCM-based PRNG when the number of words of the analyzed sequence increases. It provides a new clue to construct PRNGs and also extends the applications of quantum computation.
Drug-eluting stents for acute coronary syndrome: a meta-analysis of randomized controlled trials.
Directory of Open Access Journals (Sweden)
Lishan Wang
Full Text Available Drug-eluting stents (DES are increasingly used for treatment of acute coronary syndrome (ACS. However, clinical efficacy and safety of various types of DES is not well established in these subjects. We therefore evaluated clinical utility of second-generation and first-generation DES in patients with ACS by conducting a meta-analysis.A search of Medline, Embase, the Cochrane databases, and Web of Science was made. Randomized controlled trials (RCTs which compared second-generation DES (everolimus-eluting stents [EES] or zotarolimus-eluting stents [ZES] versus first-generation DES (sirolimus-eluting stents [SES] or paclitaxe-eluting stents [PES] in patients with ACS and provided data on clinical efficacy or safety endpoints were included. Pooled estimates were calculated using random-effects model.A total of 2,757 participants with ACS in 6 RCTs were included. Compared with first-generation one, second-generation DES trended to be associated with the decreased incidence of definite or probable stent thrombosis in ACS patients (risk ratio [RR] = 0.60, 95% confidence intervals [CI] 0.33 to 1.07, p = 0.09. However, the rate of target lesion revascularization (TLR significantly increased in second-generation DES (RR = 2.08, 95%CI 1.25 to 3.47, p = 0.005. There were no significant differences in the incidence of major adverse cardiac events (MACEs, all-cause death, cardiac death, and recurrent myocardial infarction between the two arms (all p>0.10. The second-generation EES showed a tendency towards lower risk of MACEs (p = 0.06 and a beneficial effect on reducing stent thrombosis episodes (p = 0.009, while the second-generation ZES presented an increased occurrence of MACEs (p = 0.02 and TLR (p = 0.003.Second-generation DES, especially EES, appeared to present a lower risk of stent thrombosis, whereas second-generation ZES might increase the need for repeat revascularization in ACS patients. During coronary
Persaud, Navindra
2005-01-01
Computer algorithms can only produce seemingly random or pseudorandom numbers whereas certain natural phenomena, such as the decay of radioactive particles, can be utilized to produce truly random numbers. In this study, the ability of humans to generate random numbers was tested in healthy adults. Subjects were simply asked to generate and dictate random numbers. Generated numbers were tested for uniformity, independence and information density. The results suggest that humans can generate random numbers that are uniformly distributed, independent of one another and unpredictable. If humans can generate sequences of random numbers then neural networks or forms of artificial intelligence, which are purported to function in ways essentially the same as the human brain, should also be able to generate sequences of random numbers. Elucidating the precise mechanism by which humans generate random number sequences and the underlying neural substrates may have implications in the cognitive science of decision-making. It is possible that humans use their random-generating neural machinery to make difficult decisions in which all expected outcomes are similar. It is also possible that certain people, perhaps those with neurological or psychiatric impairments, are less able or unable to generate random numbers. If the random-generating neural machinery is employed in decision making its impairment would have profound implications in matters of agency and free will.
Pseudo-random number generation using a 3-state cellular automaton
Bhattacharjee, Kamalika; Paul, Dipanjyoti; Das, Sukanta
This paper investigates the potentiality of pseudo-random number generation of a 3-neighborhood 3-state cellular automaton (CA) under periodic boundary condition. Theoretical and empirical tests are performed on the numbers, generated by the CA, to observe the quality of it as pseudo-random number generator (PRNG). We analyze the strength and weakness of the proposed PRNG and conclude that the selected CA is a good random number generator.
Properties making a chaotic system a good Pseudo Random Number Generator
Falcioni, Massimo; Palatella, Luigi; Pigolotti, Simone; Vulpiani, Angelo
2005-01-01
We discuss two properties making a deterministic algorithm suitable to generate a pseudo random sequence of numbers: high value of Kolmogorov-Sinai entropy and high-dimensionality. We propose the multi dimensional Anosov symplectic (cat) map as a Pseudo Random Number Generator. We show what chaotic features of this map are useful for generating Pseudo Random Numbers and investigate numerically which of them survive in the discrete version of the map. Testing and comparisons with other generat...
25 CFR 547.14 - What are the minimum technical standards for electronic random number generation?
2010-04-01
... random number generation? 547.14 Section 547.14 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF... CLASS II GAMES § 547.14 What are the minimum technical standards for electronic random number generation...) Unpredictability; and (3) Non-repeatability. (b) Statistical Randomness.(1) Numbers produced by an RNG shall be...
Using Computer-Generated Random Numbers to Calculate the Lifetime of a Comet.
Danesh, Iraj
1991-01-01
An educational technique to calculate the lifetime of a comet using software-generated random numbers is introduced to undergraduate physiques and astronomy students. Discussed are the generation and eligibility of the required random numbers, background literature related to the problem, and the solution to the problem using random numbers.…
a Pseudo-Random Number Generator Employing Multiple RÉNYI Maps
Lui, Oi-Yan; Yuen, Ching-Hung; Wong, Kwok-Wo
2013-11-01
The increasing risk along with the drastic development of multimedia data transmission has raised a big concern on data security. A good pseudo-random number generator is an essential tool in cryptography. In this paper, we propose a novel pseudo-random number generator based on the controlled combination of the outputs of several digitized chaotic Rényi maps. The generated pseudo-random sequences have passed both the NIST 800-22 Revision 1a and the DIEHARD tests. Moreover, simulation results show that the proposed pseudo-random number generator requires less operation time than existing generators and is highly sensitive to the seed.
Exploiting Specific Interactions toward Next-Generation Polymeric Drug Transporters
Wieczorek, Sebastian; Krause, Eberhard; Hackbarth, Steffen; Roeder, Beate; Hirsch, Anna K. H.; Boerner, Hans G.
2013-01-01
A generic method describes advanced tailoring of polymer drug carriers based on polymer-block-peptides. Combinatorial means are used to select suitable peptide segments to specifically complex small-molecule drugs. The resulting specific drug formulation agents render insoluble drugs water-soluble
ACORN—A new method for generating sequences of uniformly distributed Pseudo-random Numbers
Wikramaratna, R. S.
1989-07-01
A new family of pseudo-random number generators, the ACORN ( additive congruential random number) generators, is proposed. The resulting numbers are distributed uniformly in the interval [0, 1). The ACORN generators are defined recursively, and the ( k + 1)th order generator is easily derived from the kth order generator. Some theorems concerning the period length are presented and compared with existing results for linear congruential generators. A range of statistical tests are applied to the ACORN generators, and their performance is compared with that of the linear congruential generators and the Chebyshev generators. The tests show the ACORN generators to be statistically superior to the Chebyshev generators, while being statistically similar to the linear congruential generators. However, the ACORN generators execute faster than linear congruential generators for the same statistical faithfulness. The main advantages of the ACORN generator are speed of execution, long period length, and simplicity of coding.
Quantum random-number generator based on a photon-number-resolving detector
International Nuclear Information System (INIS)
Ren Min; Wu, E; Liang Yan; Jian Yi; Wu Guang; Zeng Heping
2011-01-01
We demonstrated a high-efficiency quantum random number generator which takes inherent advantage of the photon number distribution randomness of a coherent light source. This scheme was realized by comparing the photon flux of consecutive pulses with a photon number resolving detector. The random bit generation rate could reach 2.4 MHz with a system clock of 6.0 MHz, corresponding to a random bit generation efficiency as high as 40%. The random number files passed all the stringent statistical tests.
Realization of a Quantum Random Generator Certified with the Kochen-Specker Theorem
Kulikov, Anatoly; Jerger, Markus; Potočnik, Anton; Wallraff, Andreas; Fedorov, Arkady
2017-12-01
Random numbers are required for a variety of applications from secure communications to Monte Carlo simulation. Yet randomness is an asymptotic property, and no output string generated by a physical device can be strictly proven to be random. We report an experimental realization of a quantum random number generator (QRNG) with randomness certified by quantum contextuality and the Kochen-Specker theorem. The certification is not performed in a device-independent way but through a rigorous theoretical proof of each outcome being value indefinite even in the presence of experimental imperfections. The analysis of the generated data confirms the incomputable nature of our QRNG.
Super fast physical-random number generation using laser diode frequency noises
Ushiki, Tetsuro; Doi, Kohei; Maehara, Shinya; Sato, Takashi; Ohkawa, Masashi; Ohdaira, Yasuo
2011-02-01
Random numbers can be classified as either pseudo- or physical-random in character. Pseudo-random numbers' periodicity renders them inappropriate for use in cryptographic applications, but naturally-generated physical-random numbers have no calculable periodicity, thereby making them ideally-suited to the task. The laser diode naturally produces a wideband "noise" signal that is believed to have tremendous capacity and great promise, for the rapid generation of physical-random numbers for use in cryptographic applications. We measured a laser diode's output, at a fast photo detector and generated physical-random numbers from frequency noises. We then identified and evaluated the binary-number-line's statistical properties. The result shows that physical-random number generation, at speeds as high as 40Gbps, is obtainable, using the laser diode's frequency noise characteristic.
A method for generating skewed random numbers using two overlapping uniform distributions
International Nuclear Information System (INIS)
Ermak, D.L.; Nasstrom, J.S.
1995-02-01
The objective of this work was to implement and evaluate a method for generating skewed random numbers using a combination of uniform random numbers. The method provides a simple and accurate way of generating skewed random numbers from the specified first three moments without an a priori specification of the probability density function. We describe the procedure for generating skewed random numbers from unifon-n random numbers, and show that it accurately produces random numbers with the desired first three moments over a range of skewness values. We also show that in the limit of zero skewness, the distribution of random numbers is an accurate approximation to the Gaussian probability density function. Future work win use this method to provide skewed random numbers for a Langevin equation model for diffusion in skewed turbulence
Systematic review of randomized trials on vasoconstrictor drugs for hepatorenal syndrome
DEFF Research Database (Denmark)
Gluud, Lise L; Christensen, Kurt; Christensen, Erik
2010-01-01
Vasoconstrictor drugs may improve renal function in hepatorenal syndrome (HRS), but the effect on mortality has not been established. We therefore performed a systematic review of randomized trials on vasoconstrictor drugs for type 1 or type 2 HRS. Mortality was the primary outcome measure...
2013-11-27
... PHMSA-2013-0248] Pipeline Safety: Random Drug Testing Rate; Contractor Management Information System Reporting; and Obtaining Drug and Alcohol Management Information System Sign-In Information AGENCY: Pipeline... Management Information System (MIS) Data; and New Method for Operators to Obtain User Name and Password for...
An X-ray CCD signal generator with true random arrival time
International Nuclear Information System (INIS)
Huo Jia; Xu Yuming; Chen Yong; Cui Weiwei; Li Wei; Zhang Ziliang; Han Dawei; Wang Yusan; Wang Juan
2011-01-01
An FPGA-based true random signal generator with adjustable amplitude and exponential distribution of time interval is presented. Since traditional true random number generators (TRNG) are resource costly and difficult to transplant, we employed a method of random number generation based on jitter and phase noise in ring oscillators formed by gates in an FPGA. In order to improve the random characteristics, a combination of two different pseudo-random processing circuits is used for post processing. The effects of the design parameters, such as sample frequency are discussed. Statistical tests indicate that the generator can well simulate the timing behavior of random signals with Poisson distribution. The X-ray CCD signal generator will be used in debugging the CCD readout system of the Low Energy X-ray Instrument onboard the Hard X-ray Modulation Telescope (HXMT). (authors)
A true random number generator based on mouse movement and chaotic cryptography
International Nuclear Information System (INIS)
Hu Yue; Liao Xiaofeng; Wong, Kwok-wo; Zhou Qing
2009-01-01
True random number generators are in general more secure than pseudo random number generators. In this paper, we propose a novel true random number generator which generates a 256-bit random number by computer mouse movement. It is cheap, convenient and universal for personal computers. To eliminate the effect of similar movement patterns generated by the same user, three chaos-based approaches, namely, discretized 2D chaotic map permutation, spatiotemporal chaos and 'MASK' algorithm, are adopted to post-process the captured mouse movements. Random bits generated by three users are tested using NIST statistical tests. Both the spatiotemporal chaos approach and the 'MASK' algorithm pass the tests successfully. However, the latter has a better performance in terms of efficiency and effectiveness and so is more practical for common personal computer applications.
Post-processing Free Quantum Random Number Generator Based on Avalanche Photodiode Array
International Nuclear Information System (INIS)
Li Yang; Liao Sheng-Kai; Liang Fu-Tian; Shen Qi; Liang Hao; Peng Cheng-Zhi
2016-01-01
Quantum random number generators adopting single photon detection have been restricted due to the non-negligible dead time of avalanche photodiodes (APDs). We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors' responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32 × 32 APD array is up to tens of Gbits/s. (paper)
Generating variable and random schedules of reinforcement using Microsoft Excel macros.
Bancroft, Stacie L; Bourret, Jason C
2008-01-01
Variable reinforcement schedules are used to arrange the availability of reinforcement following varying response ratios or intervals of time. Random reinforcement schedules are subtypes of variable reinforcement schedules that can be used to arrange the availability of reinforcement at a constant probability across number of responses or time. Generating schedule values for variable and random reinforcement schedules can be difficult. The present article describes the steps necessary to write macros in Microsoft Excel that will generate variable-ratio, variable-interval, variable-time, random-ratio, random-interval, and random-time reinforcement schedule values.
Problems with the random number generator RANF implemented on the CDC cyber 205
Kalle, Claus; Wansleben, Stephan
1984-10-01
We show that using RANF may lead to wrong results when lattice models are simulated by Monte Carlo methods. We present a shift-register sequence random number generator which generates two random numbers per cycle on a two pipe CDC Cyber 205.
Pseudo-random-number generators and the square site percolation threshold.
Lee, Michael J
2008-09-01
Selected pseudo-random-number generators are applied to a Monte Carlo study of the two-dimensional square-lattice site percolation model. A generator suitable for high precision calculations is identified from an application specific test of randomness. After extended computation and analysis, an ostensibly reliable value of p_{c}=0.59274598(4) is obtained for the percolation threshold.
Fast random-number generation using a diode laser's frequency noise characteristic
Takamori, Hiroki; Doi, Kohei; Maehara, Shinya; Kawakami, Kohei; Sato, Takashi; Ohkawa, Masashi; Ohdaira, Yasuo
2012-02-01
Random numbers can be classified as either pseudo- or physical-random, in character. Pseudo-random numbers are generated by definite periodicity, so, their usefulness in cryptographic applications is somewhat limited. On the other hand, naturally-generated physical-random numbers have no calculable periodicity, thereby making them ideal for the task. Diode lasers' considerable wideband noise gives them tremendous capacity for generating physical-random numbers, at a high rate of speed. We measured a diode laser's output with a fast photo detector, and evaluated the binary-numbers from the diode laser's frequency noise characteristics. We then identified and evaluated the binary-number-line's statistical properties. We also investigate the possibility that much faster physical-random number parallel-generation is possible, using separate outputs of different optical-path length and character, which we refer to as "coherence collapse".
Random Scenario Generation for a Multiple Target Tracking Environment Evaluation
DEFF Research Database (Denmark)
Hussain, Dil Muhammad Akbar
2006-01-01
, which were normally crossing targets, was to test the efficiency of the track splitting algorithm for different situations. However this approach only gives a measure of performance for a specific, possibly unrealistic, scenario and it was felt appropriate to develop procedures that would enable a more...... general performance assessment. Therefore, a random target motion scenario is adopted. Its implementation in particular for testing the track splitting algorithm using Kalman filters is used and a couple of tracking performance parameters are computed to investigate such random scenarios....
2010-12-07
... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Random Drug and Alcohol Testing... minimum random drug and alcohol testing percentage rates for the period January 1, 2011, through December... Regulations Title 14, section 120.109(b) (for drug testing), and 120.217(c) (for alcohol testing). Issued in...
10 CFR 26.67 - Random drug and alcohol testing of individuals who have applied for authorization.
2010-01-01
... 10 Energy 1 2010-01-01 2010-01-01 false Random drug and alcohol testing of individuals who have... PROGRAMS Granting and Maintaining Authorization § 26.67 Random drug and alcohol testing of individuals who... other entity relies on drug and alcohol tests that were conducted before the individual applied for...
2012-12-03
... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Random Drug and Alcohol Testing... the minimum random drug and alcohol testing percentage rates for the period January 1, 2013, through... Regulations Title 14, Sec. Sec. 120.109(b) (for drug testing), and 120.217(c) (for alcohol testing). Issued in...
2011-12-01
... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Random Drug and Alcohol Testing... the minimum random drug and alcohol testing percentage rates for the period January 1, 2012, through... Regulations Title 14, Sec. 120.109(b) (for drug testing), and 120.217(c) (for alcohol testing). Issued in...
2013-12-20
... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Random Drug and Alcohol Testing... the minimum random drug and alcohol testing percentage rates for the period January 1, 2014, through... Federal Regulations Title 14, section 120.109(b) (for drug testing), and 120.217(c) (for alcohol testing...
Evaluation of A Low-power Random Access Memory Generator
Kameswar Rao, Vaddina
2006-01-01
In this work, an existing RAM generator is analysed and evaluated. Some of the aspects that were considered in the evaluation are the optimization of the basic SRAM cell, how the RAM generator can be ported to newer technologys, automating the simulation process and the creation of the workflow for the energy model. One of the main focus of this thesis work is to optimize the basic SRAM cell. The SRAM cell which is used in the RAM generator is not optimized for area nor power. A compact layou...
An extended SPSS extension command for generating random data
Directory of Open Access Journals (Sweden)
Harding, Bradley
2015-10-01
Full Text Available The GRD extension command for SPSS (Harding & Cousineau, 2014 has been used in a variety of applications since its inception. Ranging from a teaching tool to demonstrate statistical analyses, to an inferential tool used to find critical values instead of looking into a z-table, GRD has been very well received. However, some users have requested other data generation components that would make GRD a more complete extension command: the possibility to add contaminants to the generated dataset as well as the ability to generate correlated variables. Another component we added is a graphical user interface (or GUI that makes GRD accessible through the drop-down menus in the SPSS Data Editor window. This GUI allows users to generate a simple dataset by entering parameters in dedicated fields rather than writing out the full script. Finally, we devised a small series of exercises to help users get acquainted with the new subcommands and GUI.
Generation of correlated finite alphabet waveforms using gaussian random variables
Jardak, Seifallah; Ahmed, Sajid; Alouini, Mohamed-Slim
2014-01-01
, the proposed scheme is general, the main focus of this paper is to generate finite alphabet waveforms for multiple-input multiple-output radar, where correlated waveforms are used to achieve desired beampatterns. © 2014 IEEE.
Generation of pseudo-random sequences for spread spectrum systems
Moser, R.; Stover, J.
1985-05-01
The characteristics of pseudo random radio signal sequences (PRS) are explored. The randomness of the PSR is a matter of artificially altering the sequence of binary digits broadcast. Autocorrelations of the two sequences shifted in time, if high, determine if the signals are the same and thus allow for position identification. Cross-correlation can also be calculated between sequences. Correlations closest to zero are obtained with large volume of prime numbers in the sequences. Techniques for selecting optimal and maximal lengths for the sequences are reviewed. If the correlations are near zero in the sequences, then signal channels can accommodate multiple users. Finally, Gold codes are discussed as a technique for maximizing the code lengths.
Autocatalytic polymerization generates persistent random walk of crawling cells.
Sambeth, R; Baumgaertner, A
2001-05-28
The autocatalytic polymerization kinetics of the cytoskeletal actin network provides the basic mechanism for a persistent random walk of a crawling cell. It is shown that network remodeling by branching processes near the cell membrane is essential for the bimodal spatial stability of the network which induces a spontaneous breaking of isotropic cell motion. Details of the phenomena are analyzed using a simple polymerization model studied by analytical and simulation methods.
Generation and monitoring of a discrete stable random process
Hopcraft, K I; Matthews, J O
2002-01-01
A discrete stochastic process with stationary power law distribution is obtained from a death-multiple immigration population model. Emigrations from the population form a random series of events which are monitored by a counting process with finite-dynamic range and response time. It is shown that the power law behaviour of the population is manifested in the intermittent behaviour of the series of events. (letter to the editor)
Efficient pseudo-random number generation for monte-carlo simulations using graphic processors
Mohanty, Siddhant; Mohanty, A. K.; Carminati, F.
2012-06-01
A hybrid approach based on the combination of three Tausworthe generators and one linear congruential generator for pseudo random number generation for GPU programing as suggested in NVIDIA-CUDA library has been used for MONTE-CARLO sampling. On each GPU thread, a random seed is generated on fly in a simple way using the quick and dirty algorithm where mod operation is not performed explicitly due to unsigned integer overflow. Using this hybrid generator, multivariate correlated sampling based on alias technique has been carried out using both CUDA and OpenCL languages.
Efficient pseudo-random number generation for Monte-Carlo simulations using graphic processors
International Nuclear Information System (INIS)
Mohanty, Siddhant; Mohanty, A K; Carminati, F
2012-01-01
A hybrid approach based on the combination of three Tausworthe generators and one linear congruential generator for pseudo random number generation for GPU programing as suggested in NVIDIA-CUDA library has been used for MONTE-CARLO sampling. On each GPU thread, a random seed is generated on fly in a simple way using the quick and dirty algorithm where mod operation is not performed explicitly due to unsigned integer overflow. Using this hybrid generator, multivariate correlated sampling based on alias technique has been carried out using both CUDA and OpenCL languages.
The new generation of antiepileptic drugs: advantages and disadvantages.
Perucca, E
1996-11-01
1. After a hiatus of over 20 years, several new antiepileptic drugs (vigabatrin, lamotrigine, gabapentin, oxcarbazepine, topiramate, felbamate, zonisamide and tiagabine) have reached or approached the registration phase. 2. Compared with older agents, many new drugs exhibit simpler pharmacokinetics. This is especially true for vigabatrin and gabapentin, which are renally eliminated and have a low interaction potential. 3. Unlike most of the older agents, vigabatrin, lamotrigine, gabapentin and tiagabine are devoid of significant enzyme inducing or inhibiting properties. Topiramate, oxcarbazepine and felbamate may induce the metabolism of steroid oral contraceptives. In addition, felbamate also acts as a metabolic inhibitor. 4. To date, the efficacy of new drugs has been evaluated extensively only under add-on conditions in patients with partial seizures (with or without secondary generalization) refractory to conventional treatment. However, there is evidence that lamotrigine, zonisamide, felbamate and, possibly, topiramate may also be effective in generalized epilepsies. 5. In placebo-controlled studies, typically between 15 and 40% of patients with difficult-to-treat partial epilepsy have shown an improvement (defined as a 50% or greater decrease in seizure frequency) after addition of a new drug. Only a small minority of these patients achieved complete seizure control. 6. Compared with older agents, some of the new drugs may have a better tolerability profile. Felbamate, however, has been associated with a high risk of aplastic anaemia and hepatotoxicity. 7. At present, the main use of the new agents is in patients refractory to first-line drugs such as carbamazepine or valproate, and further studies are required to characterize their activity spectrum as well as their potential value in monotherapy. In most patients, new drugs cannot be recommended for first-line use until evidence is obtained that potential advantages in tolerability or ease of use outweigh
Recommendations and illustrations for the evaluation of photonic random number generators
Hart, Joseph D.; Terashima, Yuta; Uchida, Atsushi; Baumgartner, Gerald B.; Murphy, Thomas E.; Roy, Rajarshi
2017-09-01
The never-ending quest to improve the security of digital information combined with recent improvements in hardware technology has caused the field of random number generation to undergo a fundamental shift from relying solely on pseudo-random algorithms to employing optical entropy sources. Despite these significant advances on the hardware side, commonly used statistical measures and evaluation practices remain ill-suited to understand or quantify the optical entropy that underlies physical random number generation. We review the state of the art in the evaluation of optical random number generation and recommend a new paradigm: quantifying entropy generation and understanding the physical limits of the optical sources of randomness. In order to do this, we advocate for the separation of the physical entropy source from deterministic post-processing in the evaluation of random number generators and for the explicit consideration of the impact of the measurement and digitization process on the rate of entropy production. We present the Cohen-Procaccia estimate of the entropy rate h (𝜖 ,τ ) as one way to do this. In order to provide an illustration of our recommendations, we apply the Cohen-Procaccia estimate as well as the entropy estimates from the new NIST draft standards for physical random number generators to evaluate and compare three common optical entropy sources: single photon time-of-arrival detection, chaotic lasers, and amplified spontaneous emission.
Recommendations and illustrations for the evaluation of photonic random number generators
Directory of Open Access Journals (Sweden)
Joseph D. Hart
2017-09-01
Full Text Available The never-ending quest to improve the security of digital information combined with recent improvements in hardware technology has caused the field of random number generation to undergo a fundamental shift from relying solely on pseudo-random algorithms to employing optical entropy sources. Despite these significant advances on the hardware side, commonly used statistical measures and evaluation practices remain ill-suited to understand or quantify the optical entropy that underlies physical random number generation. We review the state of the art in the evaluation of optical random number generation and recommend a new paradigm: quantifying entropy generation and understanding the physical limits of the optical sources of randomness. In order to do this, we advocate for the separation of the physical entropy source from deterministic post-processing in the evaluation of random number generators and for the explicit consideration of the impact of the measurement and digitization process on the rate of entropy production. We present the Cohen-Procaccia estimate of the entropy rate h(,τ as one way to do this. In order to provide an illustration of our recommendations, we apply the Cohen-Procaccia estimate as well as the entropy estimates from the new NIST draft standards for physical random number generators to evaluate and compare three common optical entropy sources: single photon time-of-arrival detection, chaotic lasers, and amplified spontaneous emission.
Brownian motion properties of optoelectronic random bit generators based on laser chaos.
Li, Pu; Yi, Xiaogang; Liu, Xianglian; Wang, Yuncai; Wang, Yongge
2016-07-11
The nondeterministic property of the optoelectronic random bit generator (RBG) based on laser chaos are experimentally analyzed from two aspects of the central limit theorem and law of iterated logarithm. The random bits are extracted from an optical feedback chaotic laser diode using a multi-bit extraction technique in the electrical domain. Our experimental results demonstrate that the generated random bits have no statistical distance from the Brownian motion, besides that they can pass the state-of-the-art industry-benchmark statistical test suite (NIST SP800-22). All of them give a mathematically provable evidence that the ultrafast random bit generator based on laser chaos can be used as a nondeterministic random bit source.
Ultra-fast quantum randomness generation by accelerated phase diffusion in a pulsed laser diode.
Abellán, C; Amaya, W; Jofre, M; Curty, M; Acín, A; Capmany, J; Pruneri, V; Mitchell, M W
2014-01-27
We demonstrate a high bit-rate quantum random number generator by interferometric detection of phase diffusion in a gain-switched DFB laser diode. Gain switching at few-GHz frequencies produces a train of bright pulses with nearly equal amplitudes and random phases. An unbalanced Mach-Zehnder interferometer is used to interfere subsequent pulses and thereby generate strong random-amplitude pulses, which are detected and digitized to produce a high-rate random bit string. Using established models of semiconductor laser field dynamics, we predict a regime of high visibility interference and nearly complete vacuum-fluctuation-induced phase diffusion between pulses. These are confirmed by measurement of pulse power statistics at the output of the interferometer. Using a 5.825 GHz excitation rate and 14-bit digitization, we observe 43 Gbps quantum randomness generation.
A Comparison of Three Random Number Generators for Aircraft Dynamic Modeling Applications
Grauer, Jared A.
2017-01-01
Three random number generators, which produce Gaussian white noise sequences, were compared to assess their suitability in aircraft dynamic modeling applications. The first generator considered was the MATLAB (registered) implementation of the Mersenne-Twister algorithm. The second generator was a website called Random.org, which processes atmospheric noise measured using radios to create the random numbers. The third generator was based on synthesis of the Fourier series, where the random number sequences are constructed from prescribed amplitude and phase spectra. A total of 200 sequences, each having 601 random numbers, for each generator were collected and analyzed in terms of the mean, variance, normality, autocorrelation, and power spectral density. These sequences were then applied to two problems in aircraft dynamic modeling, namely estimating stability and control derivatives from simulated onboard sensor data, and simulating flight in atmospheric turbulence. In general, each random number generator had good performance and is well-suited for aircraft dynamic modeling applications. Specific strengths and weaknesses of each generator are discussed. For Monte Carlo simulation, the Fourier synthesis method is recommended because it most accurately and consistently approximated Gaussian white noise and can be implemented with reasonable computational effort.
Anosov C-systems and random number generators
Savvidy, G. K.
2016-08-01
We further develop our previous proposal to use hyperbolic Anosov C-systems to generate pseudorandom numbers and to use them for efficient Monte Carlo calculations in high energy particle physics. All trajectories of hyperbolic dynamical systems are exponentially unstable, and C-systems therefore have mixing of all orders, a countable Lebesgue spectrum, and a positive Kolmogorov entropy. These exceptional ergodic properties follow from the C-condition introduced by Anosov. This condition defines a rich class of dynamical systems forming an open set in the space of all dynamical systems. An important property of C-systems is that they have a countable set of everywhere dense periodic trajectories and their density increases exponentially with entropy. Of special interest are the C-systems defined on higher-dimensional tori. Such C-systems are excellent candidates for generating pseudorandom numbers that can be used in Monte Carlo calculations. An efficient algorithm was recently constructed that allows generating long C-system trajectories very rapidly. These trajectories have good statistical properties and can be used for calculations in quantum chromodynamics and in high energy particle physics.
A generator for unique quantum random numbers based on vacuum states
DEFF Research Database (Denmark)
Gabriel, C.; Wittmann, C.; Sych, D.
2010-01-01
the purity of a continuous-variable quantum vacuum state to generate unique random numbers. We use the intrinsic randomness in measuring the quadratures of a mode in the lowest energy vacuum state, which cannot be correlated to any other state. The simplicity of our source, combined with its verifiably......Random numbers are a valuable component in diverse applications that range from simulations(1) over gambling to cryptography(2,3). The quest for true randomness in these applications has engendered a large variety of different proposals for producing random numbers based on the foundational...... unpredictability of quantum mechanics(4-11). However, most approaches do not consider that a potential adversary could have knowledge about the generated numbers, so the numbers are not verifiably random and unique(12-15). Here we present a simple experimental setup based on homodyne measurements that uses...
High-speed true random number generation based on paired memristors for security electronics
Zhang, Teng; Yin, Minghui; Xu, Changmin; Lu, Xiayan; Sun, Xinhao; Yang, Yuchao; Huang, Ru
2017-11-01
True random number generator (TRNG) is a critical component in hardware security that is increasingly important in the era of mobile computing and internet of things. Here we demonstrate a TRNG using intrinsic variation of memristors as a natural source of entropy that is otherwise undesirable in most applications. The random bits were produced by cyclically switching a pair of tantalum oxide based memristors and comparing their resistance values in the off state, taking advantage of the more pronounced resistance variation compared with that in the on state. Using an alternating read scheme in the designed TRNG circuit, the unbiasedness of the random numbers was significantly improved, and the bitstream passed standard randomness tests. The Pt/TaO x /Ta memristors fabricated in this work have fast programming/erasing speeds of ˜30 ns, suggesting a high random number throughput. The approach proposed here thus holds great promise for physically-implemented random number generation.
Does the placebo effect modulate drug bioavailability? Randomized cross-over studies of three drugs.
Hammami, Muhammad M; Yusuf, Ahmed; Shire, Faduma S; Hussein, Rajaa; Al-Swayeh, Reem
2017-05-23
Medication effect is the sum of its drug, placebo, and drug*placebo interaction effects. It is conceivable that the interaction effect involves modulating drug bioavailability; it was previously observed that being aware of caffeine ingestion may prolong caffeine plasma half-life. This study was set to evaluate such concept using different drugs. Balanced single-dose, two-period, two-group, cross-over design was used to compare the pharmacokinetics of oral cephalexin, ibuprofen, and paracetamol, each described by its name (overt) or as placebo (covert). Volunteers and study coordinators were deceived as to study aim. Drug concentrations were determined blindly by in-house, high performance liquid chromatography assays. Terminal-elimination half-life (t ½ ) (primary outcome), maximum concentration (C max ), C max first time (T max ), terminal-elimination-rate constant (λ), area-under-the-concentration-time-curve, to last measured concentration (AUC T ), extrapolated to infinity (AUC I ), or to T max of overt drug (AUC Overttmax ), and C max /AUC I were calculated blindly using standard non-compartmental method. Covert-vs-overt effect on drug pharmacokinetics was evaluated by analysis-of-variance (ANOVA, primary analysis), 90% confidence interval (CI) using the 80.00-125.00% bioequivalence range, and percentage of individual pharmacokinetic covert/overt ratios that are outside the +25% range. Fifty, 30, and 50 healthy volunteers (18%, 10%, and 6% females, mean (SD) age 30.8 (6.2), 31.4 (6.6), and 31.2 (5.4) years) participated in 3 studies on cephalexin, ibuprofen, and paracetamol, respectively. Withdrawal rate was 4%, 0%, and 4%, respectively. Eighteen blood samples were obtained over 6, 10, and 14 h in each study period of the three drugs, respectively. ANOVA showed no significant difference in any pharmacokinetic parameter for any of the drugs. The 90% CIs for AUC T , AUC I , C max , AUC Overttmax , and C max /AUC I were within the bioequivalence range, except
Shao, Naimin; Su, Yunzhang; Hu, Jingjing; Zhang, Jiahai; Zhang, Hongfeng; Cheng, Yiyun
2011-01-01
Background Polyamidoamine (PAMAM) and polypropylenimine (PPI) dendrimers are the commercially available and most widely used dendrimers in pharmaceutical sciences and biomedical engineering. In the present study, the loading and release behaviors of generation 3 PAMAM and generation 4 PPI dendrimers with the same amount of surface amine groups (32 per dendrimer) were compared using phenylbutazone as a model drug. Methods The dendrimer-phenylbutazone complexes were characterized by 1H nuclear magnetic resonance and nuclear Overhauser effect techniques, and the cytotoxicity of each dendrimer was evaluated. Results Aqueous solubility results suggest that the generation 3 PAMAM dendrimer has a much higher loading ability towards phenylbutazone in comparison with the generation 4 PPI dendrimer at high phenylbutazone-dendrimer feeding ratios. Drug release was much slower from the generation 3 PAMAM matrix than from the generation 4 PPI dendrimer. In addition, the generation 3 PAMAM dendrimer is at least 50-fold less toxic than generation 4 PPI dendrimer on MCF-7 and A549 cell lines. Conclusion Although the nuclear Overhauser effect nuclear magnetic resonance results reveal that the generation 4 PPI dendrimer with a more hydrophobic interior encapsulates more phenylbutazone, the PPI dendrimer-phenylbutazone inclusion is not stable in aqueous solution, which poses a great challenge during drug development. PMID:22267921
Three-dimensional pseudo-random number generator for implementing in hybrid computer systems
International Nuclear Information System (INIS)
Ivanov, M.A.; Vasil'ev, N.P.; Voronin, A.V.; Kravtsov, M.Yu.; Maksutov, A.A.; Spiridonov, A.A.; Khudyakova, V.I.; Chugunkov, I.V.
2012-01-01
The algorithm for generating pseudo-random numbers oriented to implementation by using hybrid computer systems is considered. The proposed solution is characterized by a high degree of parallel computing [ru
Note: Fully integrated 3.2 Gbps quantum random number generator with real-time extraction
International Nuclear Information System (INIS)
Zhang, Xiao-Guang; Nie, You-Qi; Liang, Hao; Zhang, Jun; Pan, Jian-Wei; Zhou, Hongyi; Ma, Xiongfeng
2016-01-01
We present a real-time and fully integrated quantum random number generator (QRNG) by measuring laser phase fluctuations. The QRNG scheme based on laser phase fluctuations is featured for its capability of generating ultra-high-speed random numbers. However, the speed bottleneck of a practical QRNG lies on the limited speed of randomness extraction. To close the gap between the fast randomness generation and the slow post-processing, we propose a pipeline extraction algorithm based on Toeplitz matrix hashing and implement it in a high-speed field-programmable gate array. Further, all the QRNG components are integrated into a module, including a compact and actively stabilized interferometer, high-speed data acquisition, and real-time data post-processing and transmission. The final generation rate of the QRNG module with real-time extraction can reach 3.2 Gbps.
Note: Fully integrated 3.2 Gbps quantum random number generator with real-time extraction
Energy Technology Data Exchange (ETDEWEB)
Zhang, Xiao-Guang; Nie, You-Qi; Liang, Hao; Zhang, Jun, E-mail: zhangjun@ustc.edu.cn; Pan, Jian-Wei [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhou, Hongyi; Ma, Xiongfeng [Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084 (China)
2016-07-15
We present a real-time and fully integrated quantum random number generator (QRNG) by measuring laser phase fluctuations. The QRNG scheme based on laser phase fluctuations is featured for its capability of generating ultra-high-speed random numbers. However, the speed bottleneck of a practical QRNG lies on the limited speed of randomness extraction. To close the gap between the fast randomness generation and the slow post-processing, we propose a pipeline extraction algorithm based on Toeplitz matrix hashing and implement it in a high-speed field-programmable gate array. Further, all the QRNG components are integrated into a module, including a compact and actively stabilized interferometer, high-speed data acquisition, and real-time data post-processing and transmission. The final generation rate of the QRNG module with real-time extraction can reach 3.2 Gbps.
Pseudo-random number generators for Monte Carlo simulations on ATI Graphics Processing Units
Demchik, Vadim
2011-03-01
Basic uniform pseudo-random number generators are implemented on ATI Graphics Processing Units (GPU). The performance results of the realized generators (multiplicative linear congruential (GGL), XOR-shift (XOR128), RANECU, RANMAR, RANLUX and Mersenne Twister (MT19937)) on CPU and GPU are discussed. The obtained speed up factor is hundreds of times in comparison with CPU. RANLUX generator is found to be the most appropriate for using on GPU in Monte Carlo simulations. The brief review of the pseudo-random number generators used in modern software packages for Monte Carlo simulations in high-energy physics is presented.
Fourth Generation Warfare in Chile: Illicit Drug Trafficking Threats
2011-03-21
effective tools, such as global marketing and communications beyond the borders, allow states and non-state actors to build a gigantic net of contacts...agencies57 to coordinate, articulate and promote public policies in drugs and implement programs of prevention, control, treatment and rehabilitation
Molotkov, S. N.
2017-03-01
Various methods for the clustering of photocounts constituting a sequence of random numbers are considered. It is shown that the clustering of photocounts resulting in the Fermi-Dirac distribution makes it possible to achieve the theoretical limit of the random number generation rate.
Beyond THC: the new generation of cannabinoid designer drugs
Directory of Open Access Journals (Sweden)
Liana eFattore
2011-09-01
Full Text Available Synthetic cannabinoids are functionally similar to delta9-tetrahydrocannabinol (THC, the psychoactive principle of cannabis, and bind to the same cannabinoid receptors in the brain and peripheral organs. From 2008, synthetic cannabinoids were detected in herbal smoking mixtures sold on websites and in head shops under the brand name of Spice Gold, Yucatan Fire, Aroma, and others. Although these products (also known as Spice drugs or legal highs do not contain tobacco or cannabis, when smoked they produce effects similar to THC. Intoxication, withdrawal, psychosis and death have been recently reported after consumption, posing difficult social, political and health challenges. More than 140 different Spice products have been identified to date. The ability to induce strong cannabis-like psychoactive effects, along with the fact that they are readily available on the Internet, still legal in many countries, marketed as natural safe substances, and undetectable by conventional drug screening tests, has rendered these drugs very popular and particularly appealing to young and drug-naïve individuals seeking new experiences. An escalating number of compounds with cannabinoid receptor activity are currently being found as ingredients of Spice, of which almost nothing is known in terms of pharmacology, toxicology and safety. Since legislation started to control the synthetic cannabinoids identified in these herbal mixtures, many new analogs have appeared on the market. New cannabimimetic compounds are likely to be synthesized in the near future to replace banned synthetic cannabinoids, leading to a dog chasing its tail situation. Spice smokers are exposed to drugs that are extremely variable in composition and potency, and are at risk of serious, if not lethal, outcomes. Social and health professionals should maintain a high degree of alertness for Spice use and its possible psychiatric effects in vulnerable people.
10 CFR 707.7 - Random drug testing requirements and identification of testing designated positions.
2010-01-01
... contractor, to have the potential to significantly affect the environment, public health and safety, or... evidence of the use of illegal drugs of employees in testing designated positions identified in this... section shall provide for random tests at a rate equal to 30 percent of the total number of employees in...
A Randomized Trial of Probation Case Management for Drug-Involved Women Offenders
Guydish, Joseph; Chan, Monica; Bostrom, Alan; Jessup, Martha A.; Davis, Thomas B.; Marsh, Cheryl
2011-01-01
This article reports findings from a clinical trial of a probation case management (PCM) intervention for drug-involved women offenders. Participants were randomly assigned to PCM (n = 92) or standard probation (n = 91) and followed for 12 months using measures of substance abuse, psychiatric symptoms, social support, and service utilization.…
Voluntary, Randomized, Student Drug-Testing: Impact in a Rural, Low-Income, Community
Barrington, Kyle D.
2008-01-01
Illegal drug use and abuse by the nation's secondary school students is a continuing public health issue and this is especially true for students living in rural, low-income areas where access to intervention and treatment services is often limited. To address this issue, some school districts have implemented voluntary, randomized, student …
Using pseudo-random number generator for making iterative algorithms of hashing data
International Nuclear Information System (INIS)
Ivanov, M.A.; Vasil'ev, N.P.; Kozyrskij, B.L.
2014-01-01
The method of stochastic data transformation made for usage in cryptographic methods of information protection has been analyzed. The authors prove the usage of cryptographically strong pseudo-random number generators as a basis for Sponge construction. This means that the analysis of the quality of the known methods and tools for assessing the statistical security of pseudo-random number generators can be used effectively [ru
High-Performance Pseudo-Random Number Generation on Graphics Processing Units
Nandapalan, Nimalan; Brent, Richard P.; Murray, Lawrence M.; Rendell, Alistair
2011-01-01
This work considers the deployment of pseudo-random number generators (PRNGs) on graphics processing units (GPUs), developing an approach based on the xorgens generator to rapidly produce pseudo-random numbers of high statistical quality. The chosen algorithm has configurable state size and period, making it ideal for tuning to the GPU architecture. We present a comparison of both speed and statistical quality with other common parallel, GPU-based PRNGs, demonstrating favourable performance o...
Waffenschmidt, Siw; Guddat, Charlotte
2015-01-01
Background: It is unclear which terms should be included in bibliographic searches for randomized controlled trials (RCTs) of drugs, and identifying relevant drug terms can be extremely laborious. The aim of our analysis was to determine whether a bibliographic search using only the generic drug name produces sufficient results for the generation…
Towards the generation of random bits at terahertz rates based on a chaotic semiconductor laser
International Nuclear Information System (INIS)
Kanter, Ido; Aviad, Yaara; Reidler, Igor; Cohen, Elad; Rosenbluh, Michael
2010-01-01
Random bit generators (RBGs) are important in many aspects of statistical physics and crucial in Monte-Carlo simulations, stochastic modeling and quantum cryptography. The quality of a RBG is measured by the unpredictability of the bit string it produces and the speed at which the truly random bits can be generated. Deterministic algorithms generate pseudo-random numbers at high data rates as they are only limited by electronic hardware speed, but their unpredictability is limited by the very nature of their deterministic origin. It is widely accepted that the core of any true RBG must be an intrinsically non-deterministic physical process, e.g. measuring thermal noise from a resistor. Owing to low signal levels, such systems are highly susceptible to bias, introduced by amplification, and to small nonrandom external perturbations resulting in a limited generation rate, typically less than 100M bit/s. We present a physical random bit generator, based on a chaotic semiconductor laser, having delayed optical feedback, which operates reliably at rates up to 300Gbit/s. The method uses a high derivative of the digitized chaotic laser intensity and generates the random sequence by retaining a number of the least significant bits of the high derivative value. The method is insensitive to laser operational parameters and eliminates the necessity for all external constraints such as incommensurate sampling rates and laser external cavity round trip time. The randomness of long bit strings is verified by standard statistical tests.
Towards the generation of random bits at terahertz rates based on a chaotic semiconductor laser
Kanter, Ido; Aviad, Yaara; Reidler, Igor; Cohen, Elad; Rosenbluh, Michael
2010-06-01
Random bit generators (RBGs) are important in many aspects of statistical physics and crucial in Monte-Carlo simulations, stochastic modeling and quantum cryptography. The quality of a RBG is measured by the unpredictability of the bit string it produces and the speed at which the truly random bits can be generated. Deterministic algorithms generate pseudo-random numbers at high data rates as they are only limited by electronic hardware speed, but their unpredictability is limited by the very nature of their deterministic origin. It is widely accepted that the core of any true RBG must be an intrinsically non-deterministic physical process, e.g. measuring thermal noise from a resistor. Owing to low signal levels, such systems are highly susceptible to bias, introduced by amplification, and to small nonrandom external perturbations resulting in a limited generation rate, typically less than 100M bit/s. We present a physical random bit generator, based on a chaotic semiconductor laser, having delayed optical feedback, which operates reliably at rates up to 300Gbit/s. The method uses a high derivative of the digitized chaotic laser intensity and generates the random sequence by retaining a number of the least significant bits of the high derivative value. The method is insensitive to laser operational parameters and eliminates the necessity for all external constraints such as incommensurate sampling rates and laser external cavity round trip time. The randomness of long bit strings is verified by standard statistical tests.
A fast ergodic algorithm for generating ensembles of equilateral random polygons
Varela, R.; Hinson, K.; Arsuaga, J.; Diao, Y.
2009-03-01
Knotted structures are commonly found in circular DNA and along the backbone of certain proteins. In order to properly estimate properties of these three-dimensional structures it is often necessary to generate large ensembles of simulated closed chains (i.e. polygons) of equal edge lengths (such polygons are called equilateral random polygons). However finding efficient algorithms that properly sample the space of equilateral random polygons is a difficult problem. Currently there are no proven algorithms that generate equilateral random polygons with its theoretical distribution. In this paper we propose a method that generates equilateral random polygons in a 'step-wise uniform' way. We prove that this method is ergodic in the sense that any given equilateral random polygon can be generated by this method and we show that the time needed to generate an equilateral random polygon of length n is linear in terms of n. These two properties make this algorithm a big improvement over the existing generating methods. Detailed numerical comparisons of our algorithm with other widely used algorithms are provided.
Quantum random number generator based on quantum nature of vacuum fluctuations
Ivanova, A. E.; Chivilikhin, S. A.; Gleim, A. V.
2017-11-01
Quantum random number generator (QRNG) allows obtaining true random bit sequences. In QRNG based on quantum nature of vacuum, optical beam splitter with two inputs and two outputs is normally used. We compare mathematical descriptions of spatial beam splitter and fiber Y-splitter in the quantum model for QRNG, based on homodyne detection. These descriptions were identical, that allows to use fiber Y-splitters in practical QRNG schemes, simplifying the setup. Also we receive relations between the input radiation and the resulting differential current in homodyne detector. We experimentally demonstrate possibility of true random bits generation by using QRNG based on homodyne detection with Y-splitter.
Quantum cryptography using coherent states: Randomized encryption and key generation
Corndorf, Eric
objectives of key generation and direct data-encryption, a new quantum cryptographic principle is demonstrated wherein keyed coherent-state signal sets are employed. Taking advantage of the fundamental and irreducible quantum-measurement noise of coherent states, these schemes do not require the users to measure the influence of an attacker. Experimental key-generation and data encryption schemes based on these techniques, which are compatible with today's WDM fiber-optic telecommunications infrastructure, are implemented and analyzed.
Creating, generating and comparing random network models with NetworkRandomizer.
Tosadori, Gabriele; Bestvina, Ivan; Spoto, Fausto; Laudanna, Carlo; Scardoni, Giovanni
2016-01-01
Biological networks are becoming a fundamental tool for the investigation of high-throughput data in several fields of biology and biotechnology. With the increasing amount of information, network-based models are gaining more and more interest and new techniques are required in order to mine the information and to validate the results. To fill the validation gap we present an app, for the Cytoscape platform, which aims at creating randomised networks and randomising existing, real networks. Since there is a lack of tools that allow performing such operations, our app aims at enabling researchers to exploit different, well known random network models that could be used as a benchmark for validating real, biological datasets. We also propose a novel methodology for creating random weighted networks, i.e. the multiplication algorithm, starting from real, quantitative data. Finally, the app provides a statistical tool that compares real versus randomly computed attributes, in order to validate the numerical findings. In summary, our app aims at creating a standardised methodology for the validation of the results in the context of the Cytoscape platform.
The generation of 68 Gbps quantum random number by measuring laser phase fluctuations
International Nuclear Information System (INIS)
Nie, You-Qi; Liu, Yang; Zhang, Jun; Pan, Jian-Wei; Huang, Leilei; Payne, Frank
2015-01-01
The speed of a quantum random number generator is essential for practical applications, such as high-speed quantum key distribution systems. Here, we push the speed of a quantum random number generator to 68 Gbps by operating a laser around its threshold level. To achieve the rate, not only high-speed photodetector and high sampling rate are needed but also a very stable interferometer is required. A practical interferometer with active feedback instead of common temperature control is developed to meet the requirement of stability. Phase fluctuations of the laser are measured by the interferometer with a photodetector and then digitalized to raw random numbers with a rate of 80 Gbps. The min-entropy of the raw data is evaluated by modeling the system and is used to quantify the quantum randomness of the raw data. The bias of the raw data caused by other signals, such as classical and detection noises, can be removed by Toeplitz-matrix hashing randomness extraction. The final random numbers can pass through the standard randomness tests. Our demonstration shows that high-speed quantum random number generators are ready for practical usage
High-Speed Device-Independent Quantum Random Number Generation without a Detection Loophole
Liu, Yang; Yuan, Xiao; Li, Ming-Han; Zhang, Weijun; Zhao, Qi; Zhong, Jiaqiang; Cao, Yuan; Li, Yu-Huai; Chen, Luo-Kan; Li, Hao; Peng, Tianyi; Chen, Yu-Ao; Peng, Cheng-Zhi; Shi, Sheng-Cai; Wang, Zhen; You, Lixing; Ma, Xiongfeng; Fan, Jingyun; Zhang, Qiang; Pan, Jian-Wei
2018-01-01
Quantum mechanics provides the means of generating genuine randomness that is impossible with deterministic classical processes. Remarkably, the unpredictability of randomness can be certified in a manner that is independent of implementation devices. Here, we present an experimental study of device-independent quantum random number generation based on a detection-loophole-free Bell test with entangled photons. In the randomness analysis, without the independent identical distribution assumption, we consider the worst case scenario that the adversary launches the most powerful attacks against the quantum adversary. After considering statistical fluctuations and applying an 80 Gb ×45.6 Mb Toeplitz matrix hashing, we achieve a final random bit rate of 114 bits /s , with a failure probability less than 10-5. This marks a critical step towards realistic applications in cryptography and fundamental physics tests.
True random number generation from mobile telephone photo based on chaotic cryptography
International Nuclear Information System (INIS)
Zhao Liang; Liao Xiaofeng; Xiao Di; Xiang Tao; Zhou Qing; Duan Shukai
2009-01-01
A cheap, convenient and universal TRNG based on mobile telephone photo for producing random bit sequence is proposed. To settle the problem of sequential pixels and comparability, three chaos-based approaches are applied to post-process the generated binary image. The random numbers produced by three users are tested using US NIST RNG statistical test software. The experimental results indicate that the Arnold cat map is the fastest way to generate a random bit sequence and can be accepted on general PC. The 'MASK' algorithm also performs well. Finally, comparing with the TRNG of Hu et al. [Hu Y, Liao X, Wong KW, Zhou Q. A true random number generator based on mouse movement and chaotic cryptography. Chaos, Solitons and Fractals 2007. doi: 10.1016/j.chaos.2007.10.022] which is presented by Hu et al., many merits of the proposed TRNG in this paper has been found.
The generation of random directed networks with prescribed 1-node and 2-node degree correlations
Energy Technology Data Exchange (ETDEWEB)
Zamora-Lopez, Gorka; Kurths, Juergen [Institute of Physics, University of Potsdam, PO Box 601553, 14415 Potsdam (Germany); Zhou Changsong [Department of Physics, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Zlatic, Vinko [Rudjer Boskovic Institute, PO Box 180, HR-10002 Zagreb (Croatia)
2008-06-06
The generation of random networks is a very common problem in complex network research. In this paper, we have studied the correlation nature of several real networks and found that, typically, a large number of links are deterministic, i.e. they cannot be randomized. This finding permits fast generation of ensembles of maximally random networks with prescribed 1-node and 2-node degree correlations. When the introduction of self-loops or multiple-links are not desired, random network generation methods typically reach blocked states. Here, a mechanism is proposed, the 'force-and-drop' method, to overcome such states. Our algorithm can be easily simplified for undirected graphs and reduced to account for any subclass of 2-node degree correlations.
The generation of random directed networks with prescribed 1-node and 2-node degree correlations
International Nuclear Information System (INIS)
Zamora-Lopez, Gorka; Kurths, Juergen; Zhou Changsong; Zlatic, Vinko
2008-01-01
The generation of random networks is a very common problem in complex network research. In this paper, we have studied the correlation nature of several real networks and found that, typically, a large number of links are deterministic, i.e. they cannot be randomized. This finding permits fast generation of ensembles of maximally random networks with prescribed 1-node and 2-node degree correlations. When the introduction of self-loops or multiple-links are not desired, random network generation methods typically reach blocked states. Here, a mechanism is proposed, the 'force-and-drop' method, to overcome such states. Our algorithm can be easily simplified for undirected graphs and reduced to account for any subclass of 2-node degree correlations
Robust random number generation using steady-state emission of gain-switched laser diodes
International Nuclear Information System (INIS)
Yuan, Z. L.; Lucamarini, M.; Dynes, J. F.; Fröhlich, B.; Plews, A.; Shields, A. J.
2014-01-01
We demonstrate robust, high-speed random number generation using interference of the steady-state emission of guaranteed random phases, obtained through gain-switching a semiconductor laser diode. Steady-state emission tolerates large temporal pulse misalignments and therefore significantly improves the interference quality. Using an 8-bit digitizer followed by a finite-impulse-response unbiasing algorithm, we achieve random number generation rates of 8 and 20 Gb/s, for laser repetition rates of 1 and 2.5 GHz, respectively, with a ±20% tolerance in the interferometer differential delay. We also report a generation rate of 80 Gb/s using partially phase-correlated short pulses. In relation to the field of quantum key distribution, our results confirm the gain-switched laser diode as a suitable light source, capable of providing phase-randomized coherent pulses at a clock rate of up to 2.5 GHz.
Strenge, Hans; Niederberger, Uwe
2008-06-01
The interference effect between Grooved Pegboard task with either hand and the executive task of cued verbal random number generation was investigated. 24 normal right-handed subjects performed each task under separate (single-task) and concurrent (dual-task) conditions. Articulatory suppression was required as an additional secondary task during pegboard performance. Analysis indicated an unambiguous distinction between the two hands. Comparisons of single-task and dual-task conditions showed an asymmetrical pattern of unidirectional interference with no practice effects during pegboard performance. Concurrent performance with nondominant hand but not the dominant hand of random number generation performance became continuously slower. There was no effect of divided attention on pegboard performance. Findings support the idea that the nondominant hand on the pegboard and random number tasks draw from the same processing resources but that for the executive aspect random number generation is more sensitive to changes in allocation of attentional resources.
Bisadi, Zahra; Acerbi, Fabio; Fontana, Giorgio; Zorzi, Nicola; Piemonte, Claudio; Pucker, Georg; Pavesi, Lorenzo
2018-02-01
A small-sized photonic quantum random number generator, easy to be implemented in small electronic devices for secure data encryption and other applications, is highly demanding nowadays. Here, we propose a compact configuration with Silicon nanocrystals large area light emitting device (LED) coupled to a Silicon photomultiplier to generate random numbers. The random number generation methodology is based on the photon arrival time and is robust against the non-idealities of the detector and the source of quantum entropy. The raw data show high quality of randomness and pass all the statistical tests in national institute of standards and technology tests (NIST) suite without a post-processing algorithm. The highest bit rate is 0.5 Mbps with the efficiency of 4 bits per detected photon.
On the design of henon and logistic map-based random number generator
Magfirawaty; Suryadi, M. T.; Ramli, Kalamullah
2017-10-01
The key sequence is one of the main elements in the cryptosystem. True Random Number Generators (TRNG) method is one of the approaches to generating the key sequence. The randomness source of the TRNG divided into three main groups, i.e. electrical noise based, jitter based and chaos based. The chaos based utilizes a non-linear dynamic system (continuous time or discrete time) as an entropy source. In this study, a new design of TRNG based on discrete time chaotic system is proposed, which is then simulated in LabVIEW. The principle of the design consists of combining 2D and 1D chaotic systems. A mathematical model is implemented for numerical simulations. We used comparator process as a harvester method to obtain the series of random bits. Without any post processing, the proposed design generated random bit sequence with high entropy value and passed all NIST 800.22 statistical tests.
Directory of Open Access Journals (Sweden)
Zahra Bisadi
2018-02-01
Full Text Available A small-sized photonic quantum random number generator, easy to be implemented in small electronic devices for secure data encryption and other applications, is highly demanding nowadays. Here, we propose a compact configuration with Silicon nanocrystals large area light emitting device (LED coupled to a Silicon photomultiplier to generate random numbers. The random number generation methodology is based on the photon arrival time and is robust against the non-idealities of the detector and the source of quantum entropy. The raw data show high quality of randomness and pass all the statistical tests in national institute of standards and technology tests (NIST suite without a post-processing algorithm. The highest bit rate is 0.5 Mbps with the efficiency of 4 bits per detected photon.
A portable high-quality random number generator for lattice field theory simulations
International Nuclear Information System (INIS)
Luescher, M.
1993-09-01
The theory underlying a proposed random number generator for numerical simulations in elementary particle physics and statistical mechanics is discussed. The generator is based on an algorithm introduced by Marsaglia and Zaman, with an important added feature leading to demonstrably good statistical properties. It can be implemented exactly on any computer complying with the IEEE-754 standard for single precision floating point arithmetic. (orig.)
Pseudo-Random Number Generators for Vector Processors and Multicore Processors
DEFF Research Database (Denmark)
Fog, Agner
2015-01-01
Large scale Monte Carlo applications need a good pseudo-random number generator capable of utilizing both the vector processing capabilities and multiprocessing capabilities of modern computers in order to get the maximum performance. The requirements for such a generator are discussed. New ways...
Matsumoto, Mari; Ohba, Ryuji; Yasuda, Shin-ichi; Uchida, Ken; Tanamoto, Tetsufumi; Fujita, Shinobu
2008-08-01
The demand for random numbers for security applications is increasing. A conventional random number generator using thermal noise can generate unpredictable high-quality random numbers, but the circuit is extremely large because of large amplifier circuit for a small thermal signal. On the other hand, a pseudo-random number generator is small but the quality of randomness is bad. For a small circuit and a high quality of randomness, we purpose a non-stoichiometric SixN metal-oxide-semiconductor field-effect transistor (MOSFET) noise source device. This device generates a very large noise signal without an amplifier circuit. As a result, it is shown that, utilizing a SiN MOSFET, we can attain a compact random number generator with a high generation rate near 1 Mbit/s, which is suitable for almost all security applications.
Probabilistic generation of random networks taking into account information on motifs occurrence.
Bois, Frederic Y; Gayraud, Ghislaine
2015-01-01
Because of the huge number of graphs possible even with a small number of nodes, inference on network structure is known to be a challenging problem. Generating large random directed graphs with prescribed probabilities of occurrences of some meaningful patterns (motifs) is also difficult. We show how to generate such random graphs according to a formal probabilistic representation, using fast Markov chain Monte Carlo methods to sample them. As an illustration, we generate realistic graphs with several hundred nodes mimicking a gene transcription interaction network in Escherichia coli.
Qin, Lan
2016-01-01
Objective: This meta-analysis was performed to compare radioiodine therapy with antithyroid drugs in terms of clinical outcomes, including development or worsening of ophthalmopathy, hyperthyroid cure rate, hypothyroidism, relapse rate and adverse events. Methods: Randomized controlled trials (RCTs) published in PubMed, Embase, Web of Science, SinoMed and National Knowledge Infrastructure, China, were systematically reviewed to compare the effects of radioiodine therapy with antithyroid drugs in patients with Graves' disease. Results were expressed as risk ratio with 95% confidence intervals (CIs) and weighted mean differences with 95% CIs. Pooled estimates were performed using a fixed-effects model or random-effects model, depending on the heterogeneity among studies. Results: 17 RCTs involving 4024 patients met the inclusion criteria and were included. Results showed that radioiodine treatment has increased risk in new ophthalmopathy, development or worsening of ophthalmopathy and hypothyroidism. Whereas, compared with antithyroid drugs, radioiodine treatment seems to have a higher hyperthyroid cure rate, lower recurrence rate and lower incidence of adverse events. Conclusion: Radioiodine therapy is associated with a higher hyperthyroid cure rate and lower relapse rate compared with antithyroid drugs. However, it also increases the risk of ophthalmopathy and hypothyroidism. Advances in knowledge: Considering that antithyroid drug treatment can be associated with unsatisfactory control of hyperthyroidism, we would recommend radioiodine therapy as the treatment of choice for patients with Graves' disease. PMID:27266544
Identifying co-targets to fight drug resistance based on a random walk model
Directory of Open Access Journals (Sweden)
Chen Liang-Chun
2012-01-01
Full Text Available Abstract Background Drug resistance has now posed more severe and emergent threats to human health and infectious disease treatment. However, wet-lab approaches alone to counter drug resistance have so far still achieved limited success due to less knowledge about the underlying mechanisms of drug resistance. Our approach apply a heuristic search algorithm in order to extract active network under drug treatment and use a random walk model to identify potential co-targets for effective antibacterial drugs. Results We use interactome network of Mycobacterium tuberculosis and gene expression data which are treated with two kinds of antibiotic, Isoniazid and Ethionamide as our test data. Our analysis shows that the active drug-treated networks are associated with the trigger of fatty acid metabolism and synthesis and nicotinamide adenine dinucleotide (NADH-related processes and those results are consistent with the recent experimental findings. Efflux pumps processes appear to be the major mechanisms of resistance but SOS response is significantly up-regulation under Isoniazid treatment. We also successfully identify the potential co-targets with literature confirmed evidences which are related to the glycine-rich membrane, adenosine triphosphate energy and cell wall processes. Conclusions With gene expression and interactome data supported, our study points out possible pathways leading to the emergence of drug resistance under drug treatment. We develop a computational workflow for giving new insights to bacterial drug resistance which can be gained by a systematic and global analysis of the bacterial regulation network. Our study also discovers the potential co-targets with good properties in biological and graph theory aspects to overcome the problem of drug resistance.
A revision of the subtract-with-borrow random number generators
Sibidanov, Alexei
2017-12-01
The most popular and widely used subtract-with-borrow generator, also known as RANLUX, is reimplemented as a linear congruential generator using large integer arithmetic with the modulus size of 576 bits. Modern computers, as well as the specific structure of the modulus inferred from RANLUX, allow for the development of a fast modular multiplication - the core of the procedure. This was previously believed to be slow and have too high cost in terms of computing resources. Our tests show a significant gain in generation speed which is comparable with other fast, high quality random number generators. An additional feature is the fast skipping of generator states leading to a seeding scheme which guarantees the uniqueness of random number sequences. Licensing provisions: GPLv3 Programming language: C++, C, Assembler
Random number generators in support of Monte Carlo problems in physics
International Nuclear Information System (INIS)
Dyadkin, I.G.
1993-01-01
The ability to support a modern users' expectations of random number generators to solve problems in physics is analyzed. The capabilities of the newest concepts and the old pseudo-random algorithms are compared. The author is in favor of multiplicative generators. Due to the 64-bit arithmetic of a modern PC, multiplicative generators have a sufficient number of periods (up to 2 62 ) and are quicker to generate and to govern independent sequences for parallel processing. In addition they are able to replicate sub-sequences (without storing their seeds) for each standard trial in any code and to simulate spatial and planar directions and EXP(-x) distributions often needed as ''bricks'' for simulating events in physics. Hundreds of multipliers for multiplicative generators have been tabulated and tested, and the required speeds have been obtained. (author)
Shete, Ganesh; Bansal, Arvind Kumar
2016-08-01
Drug nanocrystals have rapidly evolved into a mature drug delivery strategy in the last decade, with almost 16 products currently on the market. Several "top-down" technologies are available in the market for generation of nanocrystals. Despite several advantages, very few bottom-up technologies have been explored for commercial purpose. This short communication highlights a novel, bottom-up, spray drying based technology-NanoCrySP-to generate drug nanocrystals. Nanocrystals are generated in the presence of non-polymeric excipients that act as crystallization inducer for the drug. Excipients encourage crystallization of drug by plasticization, primary heterogeneous nucleation, and imparting physical barrier to crystal growth. Nanocrystals have shown significant improvement in dissolution and thereby oral bioavailability. NanoCrySP technology is protected through patents in India, the USA, and the European Union. NanoCrySP can be utilized for (i) pharmaceutical development of new chemical entities, (ii) differentiated products of existing molecules, and (iii) generic drug products. The aggregation of drug nanocrystals generated using NanoCrySP poses significant challenges in the nanocrystal-based product development. Addition of stabilizers either during spray drying or during dissolution has shown beneficial effects.
Zheng, Guanglou; Fang, Gengfa; Shankaran, Rajan; Orgun, Mehmet A; Zhou, Jie; Qiao, Li; Saleem, Kashif
2017-05-01
Generating random binary sequences (BSes) is a fundamental requirement in cryptography. A BS is a sequence of N bits, and each bit has a value of 0 or 1. For securing sensors within wireless body area networks (WBANs), electrocardiogram (ECG)-based BS generation methods have been widely investigated in which interpulse intervals (IPIs) from each heartbeat cycle are processed to produce BSes. Using these IPI-based methods to generate a 128-bit BS in real time normally takes around half a minute. In order to improve the time efficiency of such methods, this paper presents an ECG multiple fiducial-points based binary sequence generation (MFBSG) algorithm. The technique of discrete wavelet transforms is employed to detect arrival time of these fiducial points, such as P, Q, R, S, and T peaks. Time intervals between them, including RR, RQ, RS, RP, and RT intervals, are then calculated based on this arrival time, and are used as ECG features to generate random BSes with low latency. According to our analysis on real ECG data, these ECG feature values exhibit the property of randomness and, thus, can be utilized to generate random BSes. Compared with the schemes that solely rely on IPIs to generate BSes, this MFBSG algorithm uses five feature values from one heart beat cycle, and can be up to five times faster than the solely IPI-based methods. So, it achieves a design goal of low latency. According to our analysis, the complexity of the algorithm is comparable to that of fast Fourier transforms. These randomly generated ECG BSes can be used as security keys for encryption or authentication in a WBAN system.
A Bidirectional Generalized Synchronization Theorem-Based Chaotic Pseudo-random Number Generator
Directory of Open Access Journals (Sweden)
Han Shuangshuang
2013-07-01
Full Text Available Based on a bidirectional generalized synchronization theorem for discrete chaos system, this paper introduces a new 5-dimensional bidirectional generalized chaos synchronization system (BGCSDS, whose prototype is a novel chaotic system introduced in [12]. Numerical simulation showed that two pair variables of the BGCSDS achieve generalized chaos synchronization via a transform H.A chaos-based pseudo-random number generator (CPNG was designed by the new BGCSDS. Using the FIPS-140-2 tests issued by the National Institute of Standard and Technology (NIST verified the randomness of the 1000 binary number sequences generated via the CPNG and the RC4 algorithm respectively. The results showed that all the tested sequences passed the FIPS-140-2 tests. The confidence interval analysis showed the statistical properties of the randomness of the sequences generated via the CPNG and the RC4 algorithm do not have significant differences.
Modular Transformations, Order-Chaos Transitions and Pseudo-Random Number Generation
Bonelli, Antonio; Ruffo, Stefano
Successive pairs of pseudo-random numbers generated by standard linear congruential transformations display ordered patterns of parallel lines. We study the "ordered" and "chaotic" distribution of such pairs by solving the eigenvalue problem for two-dimensional modular transformations over integers. We conjecture that the optimal uniformity for pair distribution is obtained when the slope of linear modular eigenspaces takes the value n opt =maxint (p/√ {p-1}), where p is a prime number. We then propose a new generator of pairs of independent pseudo-random numbers, which realizes an optimal uniform distribution (in the "statistical" sense) of points on the unit square (0, 1] × (0, 1]. The method can be easily generalized to the generation of k-tuples of random numbers (with k>2).
Direct generation of all-optical random numbers from optical pulse amplitude chaos.
Li, Pu; Wang, Yun-Cai; Wang, An-Bang; Yang, Ling-Zhen; Zhang, Ming-Jiang; Zhang, Jian-Zhong
2012-02-13
We propose and theoretically demonstrate an all-optical method for directly generating all-optical random numbers from pulse amplitude chaos produced by a mode-locked fiber ring laser. Under an appropriate pump intensity, the mode-locked laser can experience a quasi-periodic route to chaos. Such a chaos consists of a stream of pulses with a fixed repetition frequency but random intensities. In this method, we do not require sampling procedure and external triggered clocks but directly quantize the chaotic pulses stream into random number sequence via an all-optical flip-flop. Moreover, our simulation results show that the pulse amplitude chaos has no periodicity and possesses a highly symmetric distribution of amplitude. Thus, in theory, the obtained random number sequence without post-processing has a high-quality randomness verified by industry-standard statistical tests.
Experimentally Generated Random Numbers Certified by the Impossibility of Superluminal Signaling
Bierhorst, Peter; Shalm, Lynden K.; Mink, Alan; Jordan, Stephen; Liu, Yi-Kai; Rommal, Andrea; Glancy, Scott; Christensen, Bradley; Nam, Sae Woo; Knill, Emanuel
Random numbers are an important resource for applications such as numerical simulation and secure communication. However, it is difficult to certify whether a physical random number generator is truly unpredictable. Here, we exploit the phenomenon of quantum nonlocality in a loophole-free photonic Bell test experiment to obtain data containing randomness that cannot be predicted by any theory that does not also allow the sending of signals faster than the speed of light. To certify and quantify the randomness, we develop a new protocol that performs well in an experimental regime characterized by low violation of Bell inequalities. Applying an extractor function to our data, we obtain 256 new random bits, uniform to within 10- 3 .
A universal algorithm to generate pseudo-random numbers based on uniform mapping as homeomorphism
International Nuclear Information System (INIS)
Fu-Lai, Wang
2010-01-01
A specific uniform map is constructed as a homeomorphism mapping chaotic time series into [0,1] to obtain sequences of standard uniform distribution. With the uniform map, a chaotic orbit and a sequence orbit obtained are topologically equivalent to each other so the map can preserve the most dynamic properties of chaotic systems such as permutation entropy. Based on the uniform map, a universal algorithm to generate pseudo random numbers is proposed and the pseudo random series is tested to follow the standard 0–1 random distribution both theoretically and experimentally. The algorithm is not complex, which does not impose high requirement on computer hard ware and thus computation speed is fast. The method not only extends the parameter spaces but also avoids the drawback of small function space caused by constraints on chaotic maps used to generate pseudo random numbers. The algorithm can be applied to any chaotic system and can produce pseudo random sequence of high quality, thus can be a good universal pseudo random number generator. (general)
A universal algorithm to generate pseudo-random numbers based on uniform mapping as homeomorphism
Wang, Fu-Lai
2010-09-01
A specific uniform map is constructed as a homeomorphism mapping chaotic time series into [0,1] to obtain sequences of standard uniform distribution. With the uniform map, a chaotic orbit and a sequence orbit obtained are topologically equivalent to each other so the map can preserve the most dynamic properties of chaotic systems such as permutation entropy. Based on the uniform map, a universal algorithm to generate pseudo random numbers is proposed and the pseudo random series is tested to follow the standard 0-1 random distribution both theoretically and experimentally. The algorithm is not complex, which does not impose high requirement on computer hard ware and thus computation speed is fast. The method not only extends the parameter spaces but also avoids the drawback of small function space caused by constraints on chaotic maps used to generate pseudo random numbers. The algorithm can be applied to any chaotic system and can produce pseudo random sequence of high quality, thus can be a good universal pseudo random number generator.
Thompson, J. R.; Taylor, M. S.
1982-01-01
Let X be a K-dimensional random variable serving as input for a system with output Y (not necessarily of dimension k). given X, an outcome Y or a distribution of outcomes G(Y/X) may be obtained either explicitly or implicity. The situation is considered in which there is a real world data set X sub j sub = 1 (n) and a means of simulating an outcome Y. A method for empirical random number generation based on the sample of observations of the random variable X without estimating the underlying density is discussed.
Scope of Various Random Number Generators in ant System Approach for TSP
Sen, S. K.; Shaykhian, Gholam Ali
2007-01-01
Experimented on heuristic, based on an ant system approach for traveling salesman problem, are several quasi- and pseudo-random number generators. This experiment is to explore if any particular generator is most desirable. Such an experiment on large samples has the potential to rank the performance of the generators for the foregoing heuristic. This is mainly to seek an answer to the controversial issue "which generator is the best in terms of quality of the result (accuracy) as well as cost of producing the result (time/computational complexity) in a probabilistic/statistical sense."
Pseudo-random properties of a linear congruential generator investigated by b-adic diaphony
Stoev, Peter; Stoilova, Stanislava
2017-12-01
In the proposed paper we continue the study of the diaphony, defined in b-adic number system, and we extend it in different directions. We investigate this diaphony as a tool for estimation of the pseudorandom properties of some of the most used random number generators. This is done by evaluating the distribution of specially constructed two-dimensional nets on the base of the obtained random numbers. The aim is to see how the generated numbers are suitable for calculations in some numerical methods (Monte Carlo etc.).
An efficient algorithm for generating random number pairs drawn from a bivariate normal distribution
Campbell, C. W.
1983-01-01
An efficient algorithm for generating random number pairs from a bivariate normal distribution was developed. Any desired value of the two means, two standard deviations, and correlation coefficient can be selected. Theoretically the technique is exact and in practice its accuracy is limited only by the quality of the uniform distribution random number generator, inaccuracies in computer function evaluation, and arithmetic. A FORTRAN routine was written to check the algorithm and good accuracy was obtained. Some small errors in the correlation coefficient were observed to vary in a surprisingly regular manner. A simple model was developed which explained the qualities aspects of the errors.
Fortran code for generating random probability vectors, unitaries, and quantum states
Directory of Open Access Journals (Sweden)
Jonas eMaziero
2016-03-01
Full Text Available The usefulness of generating random configurations is recognized in many areas of knowledge. Fortran was born for scientific computing and has been one of the main programming languages in this area since then. And several ongoing projects targeting towards its betterment indicate that it will keep this status in the decades to come. In this article, we describe Fortran codes produced, or organized, for the generation of the following random objects: numbers, probability vectors, unitary matrices, and quantum state vectors and density matrices. Some matrix functions are also included and may be of independent interest.
Molecular dynamics in drug design: new generations of compstatin analogs.
Tamamis, Phanourios; López de Victoria, Aliana; Gorham, Ronald D; Bellows-Peterson, Meghan L; Pierou, Panayiota; Floudas, Christodoulos A; Morikis, Dimitrios; Archontis, Georgios
2012-05-01
We report the computational and rational design of new generations of potential peptide-based inhibitors of the complement protein C3 from the compstatin family. The binding efficacy of the peptides is tested by extensive molecular dynamics-based structural and physicochemical analysis, using 32 atomic detail trajectories in explicit water for 22 peptides bound to human, rat or mouse target protein C3, with a total of 257 ns. The criteria for the new design are: (i) optimization for C3 affinity and for the balance between hydrophobicity and polarity to improve solubility compared to known compstatin analogs; and (ii) development of dual specificity, human-rat/mouse C3 inhibitors, which could be used in animal disease models. Three of the new analogs are analyzed in more detail as they possess strong and novel binding characteristics and are promising candidates for further optimization. This work paves the way for the development of an improved therapeutic for age-related macular degeneration, and other complement system-mediated diseases, compared to known compstatin variants. © 2012 John Wiley & Sons A/S.
Wall, Melanie; Cheslack-Postava, Keely; Hu, Mei-Chen; Feng, Tianshu; Griesler, Pamela; Kandel, Denise B
2018-01-01
This study sought to specify (1) the position of nonmedical prescription opioids (NMPO) in drug initiation sequences among Millennials (1979-96), Generation X (1964-79), and Baby Boomers (1949-64) and (2) gender and racial/ethnic differences in sequences among Millennials. Data are from the 2013-2014 National Surveys on Drug Use and Health (n = 73,026). We identified statistically significant drug initiation sequences involving alcohol/cigarettes, marijuana, NMPO, cocaine, and heroin using a novel method distinguishing significant sequences from patterns expected only due to correlations induced by common liability among drugs. Alcohol/cigarettes followed by marijuana was the most common sequence. NMPO or cocaine use after marijuana, and heroin use after NMPO or cocaine, differed by generation. Among successively younger generations, NMPO after marijuana and heroin after NMPO increased. Millennials were more likely to initiate NMPO than cocaine after marijuana; Generation X and Baby Boomers were less likely (odds ratios = 1.4;0.3;0.2). Millennials were more likely than Generation X and Baby Boomers to use heroin after NMPO (hazards ratios = 7.1;3.4;2.5). In each generation, heroin users were far more likely to start heroin after both NMPO and cocaine than either alone. Sequences were similar by gender. Fewer paths were significant among African-Americans. NMPOs play a more prominent role in drug initiation sequences among Millennials than prior generations. Among Millennials, NMPO use is more likely than cocaine to follow marijuana use. In all generations, transition to heroin from NMPO significantly occurs only when both NMPO and cocaine have been used. Delineation of drug sequences suggests optimal points in development for prevention and treatment efforts. Copyright © 2017 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Chakraborty, Brahmananda
2009-01-01
Random number plays an important role in any Monte Carlo simulation. The accuracy of the results depends on the quality of the sequence of random numbers employed in the simulation. These include randomness of the random numbers, uniformity of their distribution, absence of correlation and long period. In a typical Monte Carlo simulation of particle transport in a nuclear reactor core, the history of a particle from its birth in a fission event until its death by an absorption or leakage event is tracked. The geometry of the core and the surrounding materials are exactly modeled in the simulation. To track a neutron history one needs random numbers for determining inter collision distance, nature of the collision, the direction of the scattered neutron etc. Neutrons are tracked in batches. In one batch approximately 2000-5000 neutrons are tracked. The statistical accuracy of the results of the simulation depends on the total number of particles (number of particles in one batch multiplied by the number of batches) tracked. The number of histories to be generated is usually large for a typical radiation transport problem. To track a very large number of histories one needs to generate a long sequence of independent random numbers. In other words the cycle length of the random number generator (RNG) should be more than the total number of random numbers required for simulating the given transport problem. The number of bits of the machine generally limits the cycle length. For a binary machine of p bits the maximum cycle length is 2 p . To achieve higher cycle length in the same machine one has to use either register arithmetic or bit manipulation technique
Ultrasound-mediated drug delivery by gas bubbles generated from a chemical reaction.
Lee, Sungmun; Al-Kaabi, Leena; Mawart, Aurélie; Khandoker, Ahsan; Alsafar, Habiba; Jelinek, Herbert F; Khalaf, Kinda; Park, Ji-Ho; Kim, Yeu-Chun
2018-02-01
Highly echogenic and ultrasound-responsive microbubbles such as nitrogen and perfluorocarbons have been exploited as ultrasound-mediated drug carriers. Here, we propose an innovative method for drug delivery using microbubbles generated from a chemical reaction. In a novel drug delivery system, luminol encapsulated in folate-conjugated bovine serum albumin nanoparticles (Fol-BSAN) can generate nitrogen gas (N 2 ) by chemical reaction when it reacts with hydrogen peroxide (H 2 O 2 ), one of reactive oxygen species (ROS). ROS plays an important role in the initiation and progression of cancer and elevated ROS have been observed in cancer cells both in vitro and in vivo. High-intensity focussed ultrasound (HIFU) is used to burst the N 2 microbubbles, causing site-specific delivery of anticancer drugs such as methotrexate. In this research, the drug delivery system was optimised by using water-soluble luminol and Mobil Composition of Matter-41 (MCM-41), a mesoporous material, so that the delivery system was sensitive to micromolar concentrations of H 2 O 2 . HIFU increased the drug release from Fol-BSAN by 52.9 ± 2.9% in 10 minutes. The cytotoxicity of methotrexate was enhanced when methotrexate is delivered to MDA-MB-231, a metastatic human breast cancer cell line, using Fol-BSAN with HIFU. We anticipate numerous applications of chemically generated microbubbles for ultrasound-mediated drug delivery.
GenRGenS: Software for Generating Random Genomic Sequences and Structures
Ponty , Yann; Termier , Michel; Denise , Alain
2006-01-01
International audience; GenRGenS is a software tool dedicated to randomly generating genomic sequences and structures. It handles several classes of models useful for sequence analysis, such as Markov chains, hidden Markov models, weighted context-free grammars, regular expressions and PROSITE expressions. GenRGenS is the only program that can handle weighted context-free grammars, thus allowing the user to model and to generate structured objects (such as RNA secondary structures) of any giv...
A novel approach to generate random surface thermal loads in piping
Energy Technology Data Exchange (ETDEWEB)
Costa Garrido, Oriol, E-mail: oriol.costa@ijs.si; El Shawish, Samir; Cizelj, Leon
2014-07-01
Highlights: • Approach for generating continuous and time-dependent random thermal fields. • Temperature fields simulate fluid mixing thermal loads at fluid–wall interface. • Through plane-wave decomposition, experimental temperature statistics are reproduced. • Validation of the approach with a case study from literature. • Random surface thermal loads generation for future thermal fatigue analyses of piping. - Abstract: There is a need to perform three-dimensional mechanical analyses of pipes, subjected to complex thermo-mechanical loadings such as the ones evolving from turbulent fluid mixing in a T-junction. A novel approach is proposed in this paper for fast and reliable generation of random thermal loads at the pipe surface. The resultant continuous and time-dependent temperature fields simulate the fluid mixing thermal loads at the fluid–wall interface. The approach is based on reproducing discrete fluid temperature statistics, from experimental readings or computational fluid dynamic simulation's results, at interface locations through plane-wave decomposition of temperature fluctuations. The obtained random thermal fields contain large scale instabilities such as cold and hot spots traveling at flow velocities. These low frequency instabilities are believed to be among the major causes of the thermal fatigue in T-junction configurations. The case study found in the literature has been used to demonstrate the generation of random surface thermal loads. The thermal fields generated with the proposed approach are statistically equivalent (within the first two moments) to those from CFD simulations results of similar characteristics. The fields maintain the input data at field locations for a large set of parameters used to generate the thermal loads. This feature will be of great advantage in future sensitivity fatigue analyses of three-dimensional pipe structures.
A novel approach to generate random surface thermal loads in piping
International Nuclear Information System (INIS)
Costa Garrido, Oriol; El Shawish, Samir; Cizelj, Leon
2014-01-01
Highlights: • Approach for generating continuous and time-dependent random thermal fields. • Temperature fields simulate fluid mixing thermal loads at fluid–wall interface. • Through plane-wave decomposition, experimental temperature statistics are reproduced. • Validation of the approach with a case study from literature. • Random surface thermal loads generation for future thermal fatigue analyses of piping. - Abstract: There is a need to perform three-dimensional mechanical analyses of pipes, subjected to complex thermo-mechanical loadings such as the ones evolving from turbulent fluid mixing in a T-junction. A novel approach is proposed in this paper for fast and reliable generation of random thermal loads at the pipe surface. The resultant continuous and time-dependent temperature fields simulate the fluid mixing thermal loads at the fluid–wall interface. The approach is based on reproducing discrete fluid temperature statistics, from experimental readings or computational fluid dynamic simulation's results, at interface locations through plane-wave decomposition of temperature fluctuations. The obtained random thermal fields contain large scale instabilities such as cold and hot spots traveling at flow velocities. These low frequency instabilities are believed to be among the major causes of the thermal fatigue in T-junction configurations. The case study found in the literature has been used to demonstrate the generation of random surface thermal loads. The thermal fields generated with the proposed approach are statistically equivalent (within the first two moments) to those from CFD simulations results of similar characteristics. The fields maintain the input data at field locations for a large set of parameters used to generate the thermal loads. This feature will be of great advantage in future sensitivity fatigue analyses of three-dimensional pipe structures
Degli Stefani, Mario; Biasutti, Michele
2016-01-01
Objective: Framed in the patients’ engagement perspective, the current study aims to determine the effects of group music therapy in addition to drug care in comparison with drug care in addition to other non-expressive group activities in the treatment of psychiatric outpatients. Method: Participants (n = 27) with ICD-10 diagnoses of F20 (schizophrenia), F25 (schizoaffective disorders), F31 (bipolar affective disorder), F32 (depressive episode), and F60 (specific personality disorders) were randomized to receive group music therapy plus standard care (48 weekly sessions of 2 h) or standard care only. The clinical measures included dosages of neuroleptics, benzodiazepines, mood stabilizers, and antidepressants. Results: The participants who received group music therapy demonstrated greater improvement in drug dosage with respect to neuroleptics than those who did not receive group music therapy. Antidepressants had an increment for both groups that was significant only for the control group. Benzodiazepines and mood stabilizers did not show any significant change in either group. Conclusion: Group music therapy combined with standard drug care was effective for controlling neuroleptic drug dosages in adult psychiatric outpatients who received group music therapy. We discussed the likely applications of group music therapy in psychiatry and the possible contribution of music therapy in improving the psychopathological condition of adult outpatients. In addition, the implications for the patient-centered perspective were also discussed. PMID:27774073
An On-Demand Optical Quantum Random Number Generator with In-Future Action and Ultra-Fast Response.
Stipčević, Mario; Ursin, Rupert
2015-06-09
Random numbers are essential for our modern information based society e.g. in cryptography. Unlike frequently used pseudo-random generators, physical random number generators do not depend on complex algorithms but rather on a physical process to provide true randomness. Quantum random number generators (QRNG) do rely on a process, which can be described by a probabilistic theory only, even in principle. Here we present a conceptually simple implementation, which offers a 100% efficiency of producing a random bit upon a request and simultaneously exhibits an ultra low latency. A careful technical and statistical analysis demonstrates its robustness against imperfections of the actual implemented technology and enables to quickly estimate randomness of very long sequences. Generated random numbers pass standard statistical tests without any post-processing. The setup described, as well as the theory presented here, demonstrate the maturity and overall understanding of the technology.
International Nuclear Information System (INIS)
Goei, Reginald; Kessels, Alphons H.; Nix, Maarten; Knipschild, Paul G.
2000-01-01
Purpose: To assess the willingness of radiologists to change their practice when the results of a randomized clinical trial (RCT) on the use of antispasmodic drugs in barium enema are presented. Materials and Methods: During the years 1994 and 1995 two postal questionnaires were sent to 481 practicing radiologists who were all members of the Netherlands Society of Radiology. In the first questionnaire the respondents were asked to give the characteristics of their practices in performing daily barium enema. The data from this questionnaire was used as a reference. The second questionnaire was sent to the respondents together with an abstract on the randomized clinical trial supporting the use of antispasmodic drugs in barium enema. We also indicated a preference for Buscopan over Glucagon as the antispasmodic drug. The willingness to change prescription habits was measured by comparing the data of the two questionnaires. Results: Of 481 practicing radiologists, 312 responded to the first questionnaire and gave information of their prescription habits (response rate 64%). These 312 responders were sent an abstract of the RCT and were asked to fill out a second questionnaire to determine their willingness to change their practice. Two hundred and sixty-seven radiologists responded (response rate 86%). A significant number of 119 (51%) were willing to increase the use of antispasmodic drugs. A significant number of 128 (55%) chose to increase the use of Buscopan, while a significant number of 81 (32%) were willing to decrease the use of Glucagon. Conclusion: Direct exposure to the results of an RCT recommending the use of antispasmodic drugs in barium enema, especially Buscopan, is likely to increase its use by practicing radiologists
Minimal-post-processing 320-Gbps true random bit generation using physical white chaos.
Wang, Anbang; Wang, Longsheng; Li, Pu; Wang, Yuncai
2017-02-20
Chaotic external-cavity semiconductor laser (ECL) is a promising entropy source for generation of high-speed physical random bits or digital keys. The rate and randomness is unfortunately limited by laser relaxation oscillation and external-cavity resonance, and is usually improved by complicated post processing. Here, we propose using a physical broadband white chaos generated by optical heterodyning of two ECLs as entropy source to construct high-speed random bit generation (RBG) with minimal post processing. The optical heterodyne chaos not only has a white spectrum without signature of relaxation oscillation and external-cavity resonance but also has a symmetric amplitude distribution. Thus, after quantization with a multi-bit analog-digital-convertor (ADC), random bits can be obtained by extracting several least significant bits (LSBs) without any other processing. In experiments, a white chaos with a 3-dB bandwidth of 16.7 GHz is generated. Its entropy rate is estimated as 16 Gbps by single-bit quantization which means a spectrum efficiency of 96%. With quantization using an 8-bit ADC, 320-Gbps physical RBG is achieved by directly extracting 4 LSBs at 80-GHz sampling rate.
On a direct algorithm for the generation of log-normal pseudo-random numbers
Chamayou, J M F
1976-01-01
The random variable ( Pi /sub i=1//sup n/X/sub i//X/sub i+n/)/sup 1/ square root 2n/ is used to generate standard log normal variables Lambda (0, 1), where the X/sub i/ are independent uniform variables on (0, 1). (8 refs).
Bosch, Holger; Steinkamp, Fiona; Boller, Emil
2006-01-01
Seance-room and other large-scale psychokinetic phenomena have fascinated humankind for decades. Experimental research has reduced these phenomena to attempts to influence (a) the fall of dice and, later, (b) the output of random number generators (RNGs). The meta-analysis combined 380 studies that assessed whether RNG output correlated with human…
Digital-Analog Hybrid Scheme and Its Application to Chaotic Random Number Generators
Yuan, Zeshi; Li, Hongtao; Miao, Yunchi; Hu, Wen; Zhu, Xiaohua
2017-12-01
Practical random number generation (RNG) circuits are typically achieved with analog devices or digital approaches. Digital-based techniques, which use field programmable gate array (FPGA) and graphics processing units (GPU) etc. usually have better performances than analog methods as they are programmable, efficient and robust. However, digital realizations suffer from the effect of finite precision. Accordingly, the generated random numbers (RNs) are actually periodic instead of being real random. To tackle this limitation, in this paper we propose a novel digital-analog hybrid scheme that employs the digital unit as the main body, and minimum analog devices to generate physical RNs. Moreover, the possibility of realizing the proposed scheme with only one memory element is discussed. Without loss of generality, we use the capacitor and the memristor along with FPGA to construct the proposed hybrid system, and a chaotic true random number generator (TRNG) circuit is realized, producing physical RNs at a throughput of Gbit/s scale. These RNs successfully pass all the tests in the NIST SP800-22 package, confirming the significance of the scheme in practical applications. In addition, the use of this new scheme is not restricted to RNGs, and it also provides a strategy to solve the effect of finite precision in other digital systems.
Non-random mating for selection with restricted rates of inbreeding and overlapping generations
Sonesson, A.K.; Meuwissen, T.H.E.
2002-01-01
Minimum coancestry mating with a maximum of one offspring per mating pair (MC1) is compared with random mating schemes for populations with overlapping generations. Optimum contribution selection is used, whereby $\\\\\\\\Delta F$ is restricted. For schemes with $\\\\\\\\Delta F$ restricted to 0.25% per
A method for the generation of random multiple Coulomb scattering angles
International Nuclear Information System (INIS)
Campbell, J.R.
1995-06-01
A method for the random generation of spatial angles drawn from non-Gaussian multiple Coulomb scattering distributions is presented. The method employs direct numerical inversion of cumulative probability distributions computed from the universal non-Gaussian angular distributions of Marion and Zimmerman. (author). 12 refs., 3 figs
True random bit generators based on current time series of contact glow discharge electrolysis
Rojas, Andrea Espinel; Allagui, Anis; Elwakil, Ahmed S.; Alawadhi, Hussain
2018-05-01
Random bit generators (RBGs) in today's digital information and communication systems employ a high rate physical entropy sources such as electronic, photonic, or thermal time series signals. However, the proper functioning of such physical systems is bound by specific constrains that make them in some cases weak and susceptible to external attacks. In this study, we show that the electrical current time series of contact glow discharge electrolysis, which is a dc voltage-powered micro-plasma in liquids, can be used for generating random bit sequences in a wide range of high dc voltages. The current signal is quantized into a binary stream by first using a simple moving average function which makes the distribution centered around zero, and then applying logical operations which enables the binarized data to pass all tests in industry-standard randomness test suite by the National Institute of Standard Technology. Furthermore, the robustness of this RBG against power supply attacks has been examined and verified.
A robust random number generator based on differential comparison of chaotic laser signals.
Zhang, Jianzhong; Wang, Yuncai; Liu, Ming; Xue, Lugang; Li, Pu; Wang, Anbang; Zhang, Mingjiang
2012-03-26
We experimentally realize a robust real-time random number generator by differentially comparing the signal from a chaotic semiconductor laser and its delayed signal through a 1-bit analog-to-digital converter. The probability density distribution of the output chaotic signal based on the differential comparison method possesses an extremely small coefficient of Pearson's median skewness (1.5 × 10⁻⁶), which can yield a balanced random sequence much easily than the previously reported method that compares the signal from the chaotic laser with a certain threshold value. Moveover, we experimently demonstrate that our method can stably generate good random numbers at rates of 1.44 Gbit/s with excellent immunity from external perturbations while the previously reported method fails.
Quantum random bit generation using energy fluctuations in stimulated Raman scattering.
Bustard, Philip J; England, Duncan G; Nunn, Josh; Moffatt, Doug; Spanner, Michael; Lausten, Rune; Sussman, Benjamin J
2013-12-02
Random number sequences are a critical resource in modern information processing systems, with applications in cryptography, numerical simulation, and data sampling. We introduce a quantum random number generator based on the measurement of pulse energy quantum fluctuations in Stokes light generated by spontaneously-initiated stimulated Raman scattering. Bright Stokes pulse energy fluctuations up to five times the mean energy are measured with fast photodiodes and converted to unbiased random binary strings. Since the pulse energy is a continuous variable, multiple bits can be extracted from a single measurement. Our approach can be generalized to a wide range of Raman active materials; here we demonstrate a prototype using the optical phonon line in bulk diamond.
Experimental study of a quantum random-number generator based on two independent lasers
Sun, Shi-Hai; Xu, Feihu
2017-12-01
A quantum random-number generator (QRNG) can produce true randomness by utilizing the inherent probabilistic nature of quantum mechanics. Recently, the spontaneous-emission quantum phase noise of the laser has been widely deployed for quantum random-number generation, due to its high rate, its low cost, and the feasibility of chip-scale integration. Here, we perform a comprehensive experimental study of a phase-noise-based QRNG with two independent lasers, each of which operates in either continuous-wave (CW) or pulsed mode. We implement the QRNG by operating the two lasers in three configurations, namely, CW + CW, CW + pulsed, and pulsed + pulsed, and demonstrate their trade-offs, strengths, and weaknesses.
International Nuclear Information System (INIS)
Hall, Jim W.; Lawry, Jonathan
2004-01-01
Random set theory provides a convenient mechanism for representing uncertain knowledge including probabilistic and set-based information, and extending it through a function. This paper focuses upon the situation when the available information is in terms of coherent lower and upper probabilities, which are encountered, for example, when a probability distribution is specified by interval parameters. We propose an Iterative Rescaling Method (IRM) for constructing a random set with corresponding belief and plausibility measures that are a close outer approximation to the lower and upper probabilities. The approach is compared with the discrete approximation method of Williamson and Downs (sometimes referred to as the p-box), which generates a closer approximation to lower and upper cumulative probability distributions but in most cases a less accurate approximation to the lower and upper probabilities on the remainder of the power set. Four combination methods are compared by application to example random sets generated using the IRM
Generation of human pluripotent stem cell-derived hepatocyte-like cells for drug toxicity screening.
Takayama, Kazuo; Mizuguchi, Hiroyuki
2017-02-01
Because drug-induced liver injury is one of the main reasons for drug development failures, it is important to perform drug toxicity screening in the early phase of pharmaceutical development. Currently, primary human hepatocytes are most widely used for the prediction of drug-induced liver injury. However, the sources of primary human hepatocytes are limited, making it difficult to supply the abundant quantities required for large-scale drug toxicity screening. Therefore, there is an urgent need for a novel unlimited, efficient, inexpensive, and predictive model which can be applied for large-scale drug toxicity screening. Human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are able to replicate indefinitely and differentiate into most of the body's cell types, including hepatocytes. It is expected that hepatocyte-like cells generated from human ES/iPS cells (human ES/iPS-HLCs) will be a useful tool for drug toxicity screening. To apply human ES/iPS-HLCs to various applications including drug toxicity screening, homogenous and functional HLCs must be differentiated from human ES/iPS cells. In this review, we will introduce the current status of hepatocyte differentiation technology from human ES/iPS cells and a novel method to predict drug-induced liver injury using human ES/iPS-HLCs. Copyright © 2016 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.
Lawnik, Marcin
2018-01-01
The scope of the paper is the presentation of a new method of generating numbers from a given distribution. The method uses the inverse cumulative distribution function and a method of flattening of probabilistic distributions. On the grounds of these methods, a new construction of chaotic maps was derived, which generates values from a given distribution. The analysis of the new method was conducted on the example of a newly constructed chaotic recurrences, based on the Box-Muller transformation and the quantile function of the exponential distribution. The obtained results certify that the proposed method may be successively applicable for the construction of generators of pseudo-random numbers.
Generating log-normally distributed random numbers by using the Ziggurat algorithm
International Nuclear Information System (INIS)
Choi, Jong Soo
2016-01-01
Uncertainty analyses are usually based on the Monte Carlo method. Using an efficient random number generator(RNG) is a key element in success of Monte Carlo simulations. Log-normal distributed variates are very typical in NPP PSAs. This paper proposes an approach to generate log normally distributed variates based on the Ziggurat algorithm and evaluates the efficiency of the proposed Ziggurat RNG. The proposed RNG can be helpful to improve the uncertainty analysis of NPP PSAs. This paper focuses on evaluating the efficiency of the Ziggurat algorithm from a NPP PSA point of view. From this study, we can draw the following conclusions. - The Ziggurat algorithm is one of perfect random number generators to product normal distributed variates. - The Ziggurat algorithm is computationally much faster than the most commonly used method, Marsaglia polar method
Kanter, Ido; Butkovski, Maria; Peleg, Yitzhak; Zigzag, Meital; Aviad, Yaara; Reidler, Igor; Rosenbluh, Michael; Kinzel, Wolfgang
2010-08-16
Random bit generators (RBGs) constitute an important tool in cryptography, stochastic simulations and secure communications. The later in particular has some difficult requirements: high generation rate of unpredictable bit strings and secure key-exchange protocols over public channels. Deterministic algorithms generate pseudo-random number sequences at high rates, however, their unpredictability is limited by the very nature of their deterministic origin. Recently, physical RBGs based on chaotic semiconductor lasers were shown to exceed Gbit/s rates. Whether secure synchronization of two high rate physical RBGs is possible remains an open question. Here we propose a method, whereby two fast RBGs based on mutually coupled chaotic lasers, are synchronized. Using information theoretic analysis we demonstrate security against a powerful computational eavesdropper, capable of noiseless amplification, where all parameters are publicly known. The method is also extended to secure synchronization of a small network of three RBGs.
Theoretical and empirical convergence results for additive congruential random number generators
Wikramaratna, Roy S.
2010-03-01
Additive Congruential Random Number (ACORN) generators represent an approach to generating uniformly distributed pseudo-random numbers that is straightforward to implement efficiently for arbitrarily large order and modulus; if it is implemented using integer arithmetic, it becomes possible to generate identical sequences on any machine. This paper briefly reviews existing results concerning ACORN generators and relevant theory concerning sequences that are well distributed mod 1 in k dimensions. It then demonstrates some new theoretical results for ACORN generators implemented in integer arithmetic with modulus M=2[mu] showing that they are a family of generators that converge (in a sense that is defined in the paper) to being well distributed mod 1 in k dimensions, as [mu]=log2M tends to infinity. By increasing k, it is possible to increase without limit the number of dimensions in which the resulting sequences approximate to well distributed. The paper concludes by applying the standard TestU01 test suite to ACORN generators for selected values of the modulus (between 260 and 2150), the order (between 4 and 30) and various odd seed values. On the basis of these and earlier results, it is recommended that an order of at least 9 be used together with an odd seed and modulus equal to 230p, for a small integer value of p. While a choice of p=2 should be adequate for most typical applications, increasing p to 3 or 4 gives a sequence that will consistently pass all the tests in the TestU01 test suite, giving additional confidence in more demanding applications. The results demonstrate that the ACORN generators are a reliable source of uniformly distributed pseudo-random numbers, and that in practice (as suggested by the theoretical convergence results) the quality of the ACORN sequences increases with increasing modulus and order.
Kirtadze, Irma; Otiashvili, David; Tabatadze, Mzia; Vardanashvili, Irina; Sturua, Lela; Zabransky, Tomas; Anthony, James C
2018-06-01
Validity of responses in surveys is an important research concern, especially in emerging market economies where surveys in the general population are a novelty, and the level of social control is traditionally higher. The Randomized Response Technique (RRT) can be used as a check on response validity when the study aim is to estimate population prevalence of drug experiences and other socially sensitive and/or illegal behaviors. To apply RRT and to study potential under-reporting of drug use in a nation-scale, population-based general population survey of alcohol and other drug use. For this first-ever household survey on addictive substances for the Country of Georgia, we used the multi-stage probability sampling of 18-to-64-year-old household residents of 111 urban and 49 rural areas. During the interviewer-administered assessments, RRT involved pairing of sensitive and non-sensitive questions about drug experiences. Based upon the standard household self-report survey estimate, an estimated 17.3% [95% confidence interval, CI: 15.5%, 19.1%] of Georgian household residents have tried cannabis. The corresponding RRT estimate was 29.9% [95% CI: 24.9%, 34.9%]. The RRT estimates for other drugs such as heroin also were larger than the standard self-report estimates. We remain unsure about what is the "true" value for prevalence of using illegal psychotropic drugs in the Republic of Georgia study population. Our RRT results suggest that standard non-RRT approaches might produce 'under-estimates' or at best, highly conservative, lower-end estimates. Copyright © 2018 Elsevier B.V. All rights reserved.
Design of Probabilistic Random Forests with Applications to Anticancer Drug Sensitivity Prediction.
Rahman, Raziur; Haider, Saad; Ghosh, Souparno; Pal, Ranadip
2015-01-01
Random forests consisting of an ensemble of regression trees with equal weights are frequently used for design of predictive models. In this article, we consider an extension of the methodology by representing the regression trees in the form of probabilistic trees and analyzing the nature of heteroscedasticity. The probabilistic tree representation allows for analytical computation of confidence intervals (CIs), and the tree weight optimization is expected to provide stricter CIs with comparable performance in mean error. We approached the ensemble of probabilistic trees' prediction from the perspectives of a mixture distribution and as a weighted sum of correlated random variables. We applied our methodology to the drug sensitivity prediction problem on synthetic and cancer cell line encyclopedia dataset and illustrated that tree weights can be selected to reduce the average length of the CI without increase in mean error.
An adaptive random search for short term generation scheduling with network constraints.
Directory of Open Access Journals (Sweden)
J A Marmolejo
Full Text Available This paper presents an adaptive random search approach to address a short term generation scheduling with network constraints, which determines the startup and shutdown schedules of thermal units over a given planning horizon. In this model, we consider the transmission network through capacity limits and line losses. The mathematical model is stated in the form of a Mixed Integer Non Linear Problem with binary variables. The proposed heuristic is a population-based method that generates a set of new potential solutions via a random search strategy. The random search is based on the Markov Chain Monte Carlo method. The main key of the proposed method is that the noise level of the random search is adaptively controlled in order to exploring and exploiting the entire search space. In order to improve the solutions, we consider coupling a local search into random search process. Several test systems are presented to evaluate the performance of the proposed heuristic. We use a commercial optimizer to compare the quality of the solutions provided by the proposed method. The solution of the proposed algorithm showed a significant reduction in computational effort with respect to the full-scale outer approximation commercial solver. Numerical results show the potential and robustness of our approach.
Random Forest Segregation of Drug Responses May define Regions of Biological Significance
Directory of Open Access Journals (Sweden)
Qasim eBukhari
2016-03-01
Full Text Available The ability to assess brain responses in unsupervised manner based on fMRI measure has remained a challenge. Here we have applied the Random Forest (RF method to detect differences in the pharmacological MRI (phMRI response in rats to treatment with an analgesic drug (buprenorphine as compared to control (saline. Three groups of animals were studied: two groups treated with different doses of the opioid buprenorphine, low (LD and high dose (HD, and one receiving saline. PhMRI responses were evaluated in 45 brain regions and RF analysis was applied to allocate rats to the individual treatment groups. RF analysis was able to identify drug effects based on differential phMRI responses in the hippocampus, amygdala, nucleus accumbens, superior colliculus and the lateral and posterior thalamus for drug vs. saline. These structures have high levels of mu opioid receptors. In addition these regions are involved in aversive signaling, which is inhibited by mu opioids. The results demonstrate that buprenorphine mediated phMRI responses comprise characteristic features that allow an unsupervised differentiation from placebo treated rats as well as the proper allocation to the respective drug dose group using the RF method, a method that has been successfully applied in clinical studies.
Guidelines for random excitation forces due to cross flow in steam generators
Energy Technology Data Exchange (ETDEWEB)
Taylor, C.E.; Pettigrew, M.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)
1998-07-01
Random excitation forces can cause low-amplitude tube motion that will result in long-term fretting-wear or fatigue. To prevent these tube failures in steam generators and other heat exchangers, designers and trouble-shooters must have guidelines that incorporate random or turbulent fluid forces. Experiments designed to measure fluid forces have been carried out at Chalk River Laboratories and at other labs around the world. The data from these experiments have been studied and collated to determine suitable guidelines for random excitation forces. In this paper, a guideline for random excitation forces in single-phase cross flow is presented in the form of normalised spectra that are applicable to a wide range of flow conditions and tube frequencies. In particular, the experimental results used in this study were carried out over the full range of flow conditions found in a nuclear steam generator. The proposed guidelines are applicable to steam generators, condensers, reheaters and other shell-and-tube heat exchangers. They may be used for flow-induced vibration analysis of new or existing components, as input to vibration analysis computer codes and as specifications in procurement documents. (author)
Guidelines for random excitation forces due to cross flow in steam generators
International Nuclear Information System (INIS)
Taylor, C.E.; Pettigrew, M.J.
1998-01-01
Random excitation forces can cause low-amplitude tube motion that will result in long-term fretting-wear or fatigue. To prevent these tube failures in steam generators and other heat exchangers, designers and trouble-shooters must have guidelines that incorporate random or turbulent fluid forces. Experiments designed to measure fluid forces have been carried out at Chalk River Laboratories and at other labs around the world. The data from these experiments have been studied and collated to determine suitable guidelines for random excitation forces. In this paper, a guideline for random excitation forces in single-phase cross flow is presented in the form of normalised spectra that are applicable to a wide range of flow conditions and tube frequencies. In particular, the experimental results used in this study were carried out over the full range of flow conditions found in a nuclear steam generator. The proposed guidelines are applicable to steam generators, condensers, reheaters and other shell-and-tube heat exchangers. They may be used for flow-induced vibration analysis of new or existing components, as input to vibration analysis computer codes and as specifications in procurement documents. (author)
Li, Dongfang; Lu, Zhaojun; Zou, Xuecheng; Liu, Zhenglin
2015-10-16
Random number generators (RNG) play an important role in many sensor network systems and applications, such as those requiring secure and robust communications. In this paper, we develop a high-security and high-throughput hardware true random number generator, called PUFKEY, which consists of two kinds of physical unclonable function (PUF) elements. Combined with a conditioning algorithm, true random seeds are extracted from the noise on the start-up pattern of SRAM memories. These true random seeds contain full entropy. Then, the true random seeds are used as the input for a non-deterministic hardware RNG to generate a stream of true random bits with a throughput as high as 803 Mbps. The experimental results show that the bitstream generated by the proposed PUFKEY can pass all standard national institute of standards and technology (NIST) randomness tests and is resilient to a wide range of security attacks.
Directory of Open Access Journals (Sweden)
Dongfang Li
2015-10-01
Full Text Available Random number generators (RNG play an important role in many sensor network systems and applications, such as those requiring secure and robust communications. In this paper, we develop a high-security and high-throughput hardware true random number generator, called PUFKEY, which consists of two kinds of physical unclonable function (PUF elements. Combined with a conditioning algorithm, true random seeds are extracted from the noise on the start-up pattern of SRAM memories. These true random seeds contain full entropy. Then, the true random seeds are used as the input for a non-deterministic hardware RNG to generate a stream of true random bits with a throughput as high as 803 Mbps. The experimental results show that the bitstream generated by the proposed PUFKEY can pass all standard national institute of standards and technology (NIST randomness tests and is resilient to a wide range of security attacks.
Yu, Aifang; Chen, Xiangyu; Cui, Haotian; Chen, Libo; Luo, Jianjun; Tang, Wei; Peng, Mingzeng; Zhang, Yang; Zhai, Junyi; Wang, Zhong Lin
2016-12-27
Modern cryptography increasingly employs random numbers generated from physical sources in lieu of conventional software-based pseudorandom numbers, primarily owing to the great demand of unpredictable, indecipherable cryptographic keys from true random numbers for information security. Thus, far, the sole demonstration of true random numbers has been generated through thermal noise and/or quantum effects, which suffers from expensive and complex equipment. In this paper, we demonstrate a method for self-powered creation of true random numbers by using triboelectric technology to collect random signals from nature. This random number generator based on coupled triboelectric and electrostatic induction effects at the liquid-dielectric interface includes an elaborately designed triboelectric generator (TENG) with an irregular grating structure, an electronic-optical device, and an optical-electronic device. The random characteristics of raindrops are harvested through TENG and consequently transformed and converted by electronic-optical device and an optical-electronic device with a nonlinear characteristic. The cooperation of the mechanical, electrical, and optical signals ensures that the generator possesses complex nonlinear input-output behavior and contributes to increased randomness. The random number sequences are deduced from final electrical signals received by an optical-electronic device using a familiar algorithm. These obtained random number sequences exhibit good statistical characteristics, unpredictability, and unrepeatability. Our study supplies a simple, practical, and effective method to generate true random numbers, which can be widely used in cryptographic protocols, digital signatures, authentication, identification, and other information security fields.
Pseudo-Random Sequences Generated by a Class of One-Dimensional Smooth Map
Wang, Xing-Yuan; Qin, Xue; Xie, Yi-Xin
2011-08-01
We extend a class of a one-dimensional smooth map. We make sure that for each desired interval of the parameter the map's Lyapunov exponent is positive. Then we propose a novel parameter perturbation method based on the good property of the extended one-dimensional smooth map. We perturb the parameter r in each iteration by the real number xi generated by the iteration. The auto-correlation function and NIST statistical test suite are taken to illustrate the method's randomness finally. We provide an application of this method in image encryption. Experiments show that the pseudo-random sequences are suitable for this application.
Pseudo-Random Sequences Generated by a Class of One-Dimensional Smooth Map
International Nuclear Information System (INIS)
Wang Xing-Yuan; Qin Xue; Xie Yi-Xin
2011-01-01
We extend a class of a one-dimensional smooth map. We make sure that for each desired interval of the parameter the map's Lyapunov exponent is positive. Then we propose a novel parameter perturbation method based on the good property of the extended one-dimensional smooth map. We perturb the parameter r in each iteration by the real number x i generated by the iteration. The auto-correlation function and NIST statistical test suite are taken to illustrate the method's randomness finally. We provide an application of this method in image encryption. Experiments show that the pseudo-random sequences are suitable for this application. (general)
Konishi, Hirokazu; Miyauchi, Katsumi; Dohi, Tomotaka; Tsuboi, Shuta; Ogita, Manabu; Naito, Ryo; Kasai, Takatoshi; Tamura, Hiroshi; Okazaki, Shinya; Isoda, Kikuo; Daida, Hiroyuki
2016-04-01
The aim of this study is to compare first- and new-generation drug-eluting stents (DESs) which are implanted in long lesion. Stent length is known to be a predictor of adverse events after percutaneous coronary intervention (PCI), even with the first-generation DESs. The introduction of new-generation DESs has reduced the rates of adverse clinical events. However, the impact of stent length on long-term clinical outcomes is not well known. A total of 1181 consecutive patients who underwent PCI using either a first-generation DES (n = 885) or a new-generation DES (n = 296) between 2004 and 2011 were investigated. In each of the stent groups, the patients were divided into two groups by stent length (>32 and ≤32 mm) and compared. During the follow-up period, the incidence of major adverse cardiac events (MACEs) was significantly higher for patients with long stents implanted than with short stents (P stent groups in the new-generation DES group (P = 0.24; log-rank test). On multivariate Cox regression analysis, stent length was not associated with adverse events in the new-generation DES groups [hazard ratio (HR) 0.87; 95 % confidence interval (95 % CI) 0.71-1.04; P = 0.14]. Implanted stent length was significantly associated with a higher risk of MACEs in patients who received first-generation DESs, but not in patients who received the new-generation DESs.
Generation of pseudo-random numbers with the use of inverse chaotic transformation
Directory of Open Access Journals (Sweden)
Lawnik Marcin
2018-02-01
Full Text Available In (Lawnik M., Generation of numbers with the distribution close to uniform with the use of chaotic maps, In: Obaidat M.S., Kacprzyk J., Ören T. (Ed., International Conference on Simulation and Modeling Methodologies, Technologies and Applications (SIMULTECH (28-30 August 2014, Vienna, Austria, SCITEPRESS, 2014 Lawnik discussed a method of generating pseudo-random numbers from uniform distribution with the use of adequate chaotic transformation. The method enables the “flattening” of continuous distributions to uniform one. In this paper a inverse process to the above-mentioned method is presented, and, in consequence, a new manner of generating pseudo-random numbers from a given continuous distribution. The method utilizes the frequency of the occurrence of successive branches of chaotic transformation in the process of “flattening”. To generate the values from the given distribution one discrete and one continuous value of a random variable are required. The presented method does not directly involve the knowledge of the density function or the cumulative distribution function, which is, undoubtedly, a great advantage in comparison with other well-known methods. The described method was analysed on the example of the standard normal distribution.
40 CFR 761.308 - Sample selection by random number generation on any two-dimensional square grid.
2010-07-01
... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sample selection by random number... Â§ 761.79(b)(3) § 761.308 Sample selection by random number generation on any two-dimensional square... area created in accordance with paragraph (a) of this section, select two random numbers: one each for...
International Nuclear Information System (INIS)
De Menezes, Marcio Argollo; Brigatti, Edgardo; Schwämmle, Veit
2013-01-01
Microbiological systems evolve to fulfil their tasks with maximal efficiency. The immune system is a remarkable example, where the distinction between self and non-self is made by means of molecular interaction between self-proteins and antigens, triggering affinity-dependent systemic actions. Specificity of this binding and the infinitude of potential antigenic patterns call for novel mechanisms to generate antibody diversity. Inspired by this problem, we develop a genetic algorithm where agents evolve their strings in the presence of random antigenic strings and reproduce with affinity-dependent rates. We ask what is the best strategy to generate diversity if agents can rearrange their strings a finite number of times. We find that endowing each agent with an inheritable cellular automaton rule for performing rearrangements makes the system more efficient in pattern-matching than if transformations are totally random. In the former implementation, the population evolves to a stationary state where agents with different automata rules coexist. (paper)
Catalytic micromotor generating self-propelled regular motion through random fluctuation
Yamamoto, Daigo; Mukai, Atsushi; Okita, Naoaki; Yoshikawa, Kenichi; Shioi, Akihisa
2013-07-01
Most of the current studies on nano/microscale motors to generate regular motion have adapted the strategy to fabricate a composite with different materials. In this paper, we report that a simple object solely made of platinum generates regular motion driven by a catalytic chemical reaction with hydrogen peroxide. Depending on the morphological symmetry of the catalytic particles, a rich variety of random and regular motions are observed. The experimental trend is well reproduced by a simple theoretical model by taking into account of the anisotropic viscous effect on the self-propelled active Brownian fluctuation.
Distributed Pseudo-Random Number Generation and Its Application to Cloud Database
Chen, Jiageng; Miyaji, Atsuko; Su, Chunhua
2014-01-01
Cloud database is now a rapidly growing trend in cloud computing market recently. It enables the clients run their computation on out-sourcing databases or access to some distributed database service on the cloud. At the same time, the security and privacy concerns is major challenge for cloud database to continue growing. To enhance the security and privacy of the cloud database technology, the pseudo-random number generation (PRNG) plays an important roles in data encryptions and privacy-pr...
Pseudo-random number generator based on mixing of three chaotic maps
François, M.; Grosges, T.; Barchiesi, D.; Erra, R.
2014-04-01
A secure pseudo-random number generator three-mixer is proposed. The principle of the method consists in mixing three chaotic maps produced from an input initial vector. The algorithm uses permutations whose positions are computed and indexed by a standard chaotic function and a linear congruence. The performance of that scheme is evaluated through statistical analysis. Such a cryptosystem lets appear significant cryptographic qualities for a high security level.
Smoothing Brascamp-Lieb Inequalities and Strong Converses for Common Randomness Generation
Liu, Jingbo; Courtade, Thomas A.; Cuff, Paul; Verdu, Sergio
2016-01-01
We study the infimum of the best constant in a functional inequality, the Brascamp-Lieb-like inequality, over auxiliary measures within a neighborhood of a product distribution. In the finite alphabet and the Gaussian cases, such an infimum converges to the best constant in a mutual information inequality. Implications for strong converse properties of two common randomness (CR) generation problems are discussed. In particular, we prove the strong converse property of the rate region for the ...
Directory of Open Access Journals (Sweden)
Khvedelidze Arsen
2018-01-01
Full Text Available The generation of random mixed states is discussed, aiming for the computation of probabilistic characteristics of composite finite dimensional quantum systems. In particular, we consider the generation of random Hilbert-Schmidt and Bures ensembles of qubit and qutrit pairs and compute the corresponding probabilities to find a separable state among the states of a fixed rank.
Boonsathorn, Wasita; Charoen, Danuvasin; Dryver, Arthur L.
2014-01-01
E-Learning brings access to a powerful but often overlooked teaching tool: random number generation. Using random number generation, a practically infinite number of quantitative problem-solution sets can be created. In addition, within the e-learning context, in the spirit of the mastery of learning, it is possible to assign online quantitative…
Directory of Open Access Journals (Sweden)
Nicholas J. Sexton
2014-07-01
Full Text Available Random number generation (RNG is a complex cognitive task for human subjects, requiring deliberative control to avoid production of habitual, stereotyped sequences. Under various manipulations (e.g., speeded responding, transcranial magnetic stimulation, or neurological damage the performance of human subjects deteriorates, as reflected in a number of qualitatively distinct, dissociable biases. For example, the intrusion of stereotyped behaviour (e.g., counting increases at faster rates of generation. Theoretical accounts of the task postulate that it requires the integrated operation of multiple, computationally heterogeneous cognitive control ('executive' processes. We present a computational model of RNG, within the framework of a novel, neuropsychologically-inspired cognitive architecture, ESPro. Manipulating the rate of sequence generation in the model reproduced a number of key effects observed in empirical studies, including increasing sequence stereotypy at faster rates. Within the model, this was due to time limitations on the interaction of supervisory control processes, namely, task setting, proposal of responses, monitoring, and response inhibition. The model thus supports the fractionation of executive function into multiple, computationally heterogeneous processes.
Lee, Jeffrey S; Cleaver, Gerald B
2017-10-01
In this note, the Cosmic Microwave Background (CMB) Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n) random key matrix for a Vernam cipher is established.
International Nuclear Information System (INIS)
Phillips, Carolyn L.; Anderson, Joshua A.; Glotzer, Sharon C.
2011-01-01
Highlights: → Molecular Dynamics codes implemented on GPUs have achieved two-order of magnitude computational accelerations. → Brownian Dynamics and Dissipative Particle Dynamics simulations require a large number of random numbers per time step. → We introduce a method for generating small batches of pseudorandom numbers distributed over many threads of calculations. → With this method, Dissipative Particle Dynamics is implemented on a GPU device without requiring thread-to-thread communication. - Abstract: Brownian Dynamics (BD), also known as Langevin Dynamics, and Dissipative Particle Dynamics (DPD) are implicit solvent methods commonly used in models of soft matter and biomolecular systems. The interaction of the numerous solvent particles with larger particles is coarse-grained as a Langevin thermostat is applied to individual particles or to particle pairs. The Langevin thermostat requires a pseudo-random number generator (PRNG) to generate the stochastic force applied to each particle or pair of neighboring particles during each time step in the integration of Newton's equations of motion. In a Single-Instruction-Multiple-Thread (SIMT) GPU parallel computing environment, small batches of random numbers must be generated over thousands of threads and millions of kernel calls. In this communication we introduce a one-PRNG-per-kernel-call-per-thread scheme, in which a micro-stream of pseudorandom numbers is generated in each thread and kernel call. These high quality, statistically robust micro-streams require no global memory for state storage, are more computationally efficient than other PRNG schemes in memory-bound kernels, and uniquely enable the DPD simulation method without requiring communication between threads.
Chen, Lei; Liu, Tao; Zhao, Xian
2018-06-01
The anatomical therapeutic chemical (ATC) classification system is a widely accepted drug classification scheme. This system comprises five levels and includes several classes in each level. Drugs are classified into classes according to their therapeutic effects and characteristics. The first level includes 14 main classes. In this study, we proposed two network-based models to infer novel potential chemicals deemed to belong in the first level of ATC classification. To build these models, two large chemical networks were constructed using the chemical-chemical interaction information retrieved from the Search Tool for Interactions of Chemicals (STITCH). Two classic network algorithms, shortest path (SP) and random walk with restart (RWR) algorithms, were executed on the corresponding network to mine novel chemicals for each ATC class using the validated drugs in a class as seed nodes. Then, the obtained chemicals yielded by these two algorithms were further evaluated by a permutation test and an association test. The former can exclude chemicals produced by the structure of the network, i.e., false positive discoveries. By contrast, the latter identifies the most important chemicals that have strong associations with the ATC class. Comparisons indicated that the two models can provide quite dissimilar results, suggesting that the results yielded by one model can be essential supplements for those obtained by the other model. In addition, several representative inferred chemicals were analyzed to confirm the reliability of the results generated by the two models. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang. Copyright © 2017 Elsevier B.V. All rights reserved.
Phillips, Carolyn L.; Anderson, Joshua A.; Glotzer, Sharon C.
2011-08-01
Brownian Dynamics (BD), also known as Langevin Dynamics, and Dissipative Particle Dynamics (DPD) are implicit solvent methods commonly used in models of soft matter and biomolecular systems. The interaction of the numerous solvent particles with larger particles is coarse-grained as a Langevin thermostat is applied to individual particles or to particle pairs. The Langevin thermostat requires a pseudo-random number generator (PRNG) to generate the stochastic force applied to each particle or pair of neighboring particles during each time step in the integration of Newton's equations of motion. In a Single-Instruction-Multiple-Thread (SIMT) GPU parallel computing environment, small batches of random numbers must be generated over thousands of threads and millions of kernel calls. In this communication we introduce a one-PRNG-per-kernel-call-per-thread scheme, in which a micro-stream of pseudorandom numbers is generated in each thread and kernel call. These high quality, statistically robust micro-streams require no global memory for state storage, are more computationally efficient than other PRNG schemes in memory-bound kernels, and uniquely enable the DPD simulation method without requiring communication between threads.
Application of random number generators in genetic algorithms to improve rainfall-runoff modelling
Chlumecký, Martin; Buchtele, Josef; Richta, Karel
2017-10-01
The efficient calibration of rainfall-runoff models is a difficult issue, even for experienced hydrologists. Therefore, fast and high-quality model calibration is a valuable improvement. This paper describes a novel methodology and software for the optimisation of a rainfall-runoff modelling using a genetic algorithm (GA) with a newly prepared concept of a random number generator (HRNG), which is the core of the optimisation. The GA estimates model parameters using evolutionary principles, which requires a quality number generator. The new HRNG generates random numbers based on hydrological information and it provides better numbers compared to pure software generators. The GA enhances the model calibration very well and the goal is to optimise the calibration of the model with a minimum of user interaction. This article focuses on improving the internal structure of the GA, which is shielded from the user. The results that we obtained indicate that the HRNG provides a stable trend in the output quality of the model, despite various configurations of the GA. In contrast to previous research, the HRNG speeds up the calibration of the model and offers an improvement of rainfall-runoff modelling.
Directory of Open Access Journals (Sweden)
Lara Ortiz-Martin
2018-01-01
Full Text Available The proliferation of wearable and implantable medical devices has given rise to an interest in developing security schemes suitable for these systems and the environment in which they operate. One area that has received much attention lately is the use of (human biological signals as the basis for biometric authentication, identification and the generation of cryptographic keys. The heart signal (e.g., as recorded in an electrocardiogram has been used by several researchers in the last few years. Specifically, the so-called Inter-Pulse Intervals (IPIs, which is the time between two consecutive heartbeats, have been repeatedly pointed out as a potentially good source of entropy and are at the core of various recent authentication protocols. In this work, we report the results of a large-scale statistical study to determine whether such an assumption is (or not upheld. For this, we have analyzed 19 public datasets of heart signals from the Physionet repository, spanning electrocardiograms from 1353 subjects sampled at different frequencies and with lengths that vary between a few minutes and several hours. We believe this is the largest dataset on this topic analyzed in the literature. We have then applied a standard battery of randomness tests to the extracted IPIs. Under the algorithms described in this paper and after analyzing these 19 public ECG datasets, our results raise doubts about the use of IPI values as a good source of randomness for cryptographic purposes. This has repercussions both in the security of some of the protocols proposed up to now and also in the design of future IPI-based schemes.
Random generation of bubble sizes on the heated wall during subcooled boiling
International Nuclear Information System (INIS)
Koncar, B.; Mavko, B.
2003-01-01
In subcooled flow boiling, a locally averaged bubble diameter significantly varies in the transverse direction to the flow. From the experimental data of Bartel, a bent crosssectional profile of local bubble diameter with the maximum value shifted away from the heated wall may be observed. In the present paper, the increasing part of the profile (near the heated wall) is explained by a random generation of bubble sizes on the heated wall. The hypothesis was supported by a statistical analysis of different CFD simulations, varying by the size of the generated bubble (normal distribution) and the number of generated bubbles per unit surface. Local averaging of calculated void fraction distributions over different bubble classes was performed. The increasing curve of the locally averaged bubble diameter in the near-wall region was successfully predicted. (author)
Tlelo-Cuautle, Esteban; de la Fraga, Luis Gerardo
2016-01-01
This book offers readers a clear guide to implementing engineering applications with FPGAs, from the mathematical description to the hardware synthesis, including discussion of VHDL programming and co-simulation issues. Coverage includes FPGA realizations such as: chaos generators that are described from their mathematical models; artificial neural networks (ANNs) to predict chaotic time series, for which a discussion of different ANN topologies is included, with different learning techniques and activation functions; random number generators (RNGs) that are realized using different chaos generators, and discussions of their maximum Lyapunov exponent values and entropies. Finally, optimized chaotic oscillators are synchronized and realized to implement a secure communication system that processes black and white and grey-scale images. In each application, readers will find VHDL programming guidelines and computer arithmetic issues, along with co-simulation examples with Active-HDL and Simulink. Readers will b...
Mahr, Alfred; Golmard, Clara; Pham, Emilie; Iordache, Laura; Deville, Laure; Faure, Pierre
2017-07-01
Scarce studies analyzing adverse event (AE) data from randomized placebo-controlled clinical trials (RPCCTs) of selected illnesses suggested that a substantial proportion of collected AEs are unrelated to the drug taken. This study analyzed the nonspecific AEs occurring with active-drug exposure in RPCCTs for a large range of medical conditions. Randomized placebo-controlled clinical trials published in five prominent medical journals during 2006-2012 were searched. Only trials that evaluated orally or parenterally administered active drugs versus placebo in a head-to-head setting were selected. For AEs reported from ≥10 RPCCTs, Pearson's correlation coefficients (r) were calculated to determine the relationship between AE rates in placebo and active-drug recipients. Random-effects meta-analyses were used to compute proportions of nonspecific AEs, which were truncated at a maximum of 100%, in active-drug recipients. We included 231 trials addressing various medical domains or healthy participants. For the 88 analyzed AE variables, AE rates for placebo and active-drug recipients were in general strongly correlated (r > 0.50) or very strongly correlated (r > 0.80). The pooled proportions of nonspecific AEs for the active-drug recipients were 96.8% (95%CI: 95.5-98.1) for any AEs, 100% (97.9-100) for serious AEs, and 77.7% (72.7-83.2) for drug-related AEs. Results were similar for individual medical domains and healthy participants. The pooled proportion of nonspecificity of 82 system organ class and individual AE types ranged from 38% to 100%. The large proportion of nonspecific AEs reported in active-drug recipients of RPCCTs, including serious and drug-related AEs, highlights the limitations of clinical trial data to determine the tolerability of drugs. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Hall, Bruce W.; Bacon, Tina P.; Ferron, John M.
2013-01-01
Sixth graders participating in the "Too Good for Drugs" (TGFD) prevention program in comparison to 6th graders not participating show different results by student risk level. Sixth graders from 20 middle schools were randomly assigned to receive the intervention and those from 20 paired middle schools assigned to serve as controls (N =…
Chaotic oscillation and random-number generation based on nanoscale optical-energy transfer.
Naruse, Makoto; Kim, Song-Ju; Aono, Masashi; Hori, Hirokazu; Ohtsu, Motoichi
2014-08-12
By using nanoscale energy-transfer dynamics and density matrix formalism, we demonstrate theoretically and numerically that chaotic oscillation and random-number generation occur in a nanoscale system. The physical system consists of a pair of quantum dots (QDs), with one QD smaller than the other, between which energy transfers via optical near-field interactions. When the system is pumped by continuous-wave radiation and incorporates a timing delay between two energy transfers within the system, it emits optical pulses. We refer to such QD pairs as nano-optical pulsers (NOPs). Irradiating an NOP with external periodic optical pulses causes the oscillating frequency of the NOP to synchronize with the external stimulus. We find that chaotic oscillation occurs in the NOP population when they are connected by an external time delay. Moreover, by evaluating the time-domain signals by statistical-test suites, we confirm that the signals are sufficiently random to qualify the system as a random-number generator (RNG). This study reveals that even relatively simple nanodevices that interact locally with each other through optical energy transfer at scales far below the wavelength of irradiating light can exhibit complex oscillatory dynamics. These findings are significant for applications such as ultrasmall RNGs.
Thermodynamic method for generating random stress distributions on an earthquake fault
Barall, Michael; Harris, Ruth A.
2012-01-01
This report presents a new method for generating random stress distributions on an earthquake fault, suitable for use as initial conditions in a dynamic rupture simulation. The method employs concepts from thermodynamics and statistical mechanics. A pattern of fault slip is considered to be analogous to a micro-state of a thermodynamic system. The energy of the micro-state is taken to be the elastic energy stored in the surrounding medium. Then, the Boltzmann distribution gives the probability of a given pattern of fault slip and stress. We show how to decompose the system into independent degrees of freedom, which makes it computationally feasible to select a random state. However, due to the equipartition theorem, straightforward application of the Boltzmann distribution leads to a divergence which predicts infinite stress. To avoid equipartition, we show that the finite strength of the fault acts to restrict the possible states of the system. By analyzing a set of earthquake scaling relations, we derive a new formula for the expected power spectral density of the stress distribution, which allows us to construct a computer algorithm free of infinities. We then present a new technique for controlling the extent of the rupture by generating a random stress distribution thousands of times larger than the fault surface, and selecting a portion which, by chance, has a positive stress perturbation of the desired size. Finally, we present a new two-stage nucleation method that combines a small zone of forced rupture with a larger zone of reduced fracture energy.
Directory of Open Access Journals (Sweden)
Jack Xie
2010-08-01
Full Text Available The study evaluated substrate cleavage product(s generated by three botulinum neurotoxin serotype A (BoNT/A medicinal drug products utilizing a novel and highly specific, light-chain activity, high-performance liquid chromatography (LCA-HPLC method. Samples were reacted with a commercially available BoNT/A fluorescent substrate derived from the SNAP-25 sequence. Reaction products were separated by reversed-phase HPLC. The method detected an atypical cleavage pattern by one of the formulated drug products. IncobotulinumtoxinA produced two cleavage fragments rather than the single fragment typically generated by BoNT/A. Identification confirmed the secondary cleavage at a position corresponding to SNAP-25 Arg198–Ala199 (normal BoNT/A cleavage is Gln197–Arg198. Arg198–Ala199 is also the cleavage site for trypsin and serotype C toxin. Normal cleavage was observed for all other BoNT/A drug product samples, as well as 900-kD and 150-kD bulk toxin BoNT/A. The reason for this unexpected secondary cleavage pattern by one formulated BoNT/A drug product is unknown. Possible explanations include a contaminating protease and/or damage to the 150-kD type-A toxin causing nonspecific substrate recognition and subsequent cleavage uncharacteristic of type-A toxin. The BoNT/A drug products were also analyzed via the LCA-HPLC assay using a commercial BoNT/C fluorescent substrate derived from the syntaxin sequence. Cleavage of the serotype C substrate by incobotulinumtoxinA was also confirmed whilst neither of the other drug products cleaved the syntaxin substrate.
A comparison of alcohol and drug use by random motor vehicle drivers in Brazil and Norway.
Gjerde, Hallvard; Sousa, Tanara R; De Boni, Raquel; Christophersen, Asbjørg S; Limberger, Renata P; Zancanaro, Ivomar; Oiestad, Elisabeth L; Normann, Per T; Mørland, Jørg; Pechansky, Flavio
2014-05-01
A large proportion of road traffic crashes are related to driving under the influence (DUI) of alcohol or drugs. The aim of this study was to compare the use of alcohol, illegal drugs and psychoactive medicinal drugs among random drivers in Brazil and Norway, two countries with the same legal limit for drunk driving, but with marked differences in legislation history, enforcement and penalties for DUI, and to discuss any differences found. Roadside surveys were conducted on Fridays and Saturdays between noon and midnight. Samples of oral fluid were collected for analysis of drugs, whereas alcohol was determined by breath testing or by analysis of oral fluid. High participation rates of 94-97% were obtained in both countries. The weighted prevalence of driving with alcohol concentrations in breath or oral fluid equivalent to blood alcohol concentrations (BAC) above 0.2g/L was 2.7% (95% CI 2.2-3.3) in Brazil and 0.2% (95% CI 0.0-0.5) in Norway. Stimulants (amphetamines or cocaine) were found in samples from 1.0% (95% CI 0.7-1.4) of drivers in Brazil and 0.3% (95% CI 0.1-0.7) in Norway. The prevalence of amphetamines was highest among Brazilian truck drivers (3.6%; 95% CI 2.0-6.4). Tetrahydrocannabinol was found in samples from 0.5% (95% CI 0.3-0.8) of drivers in Brazil and 1.0% (95% CI 0.6-1.5) in Norway, whereas benzodiazepines or zopiclone were found in 1.0% (95% CI 0.7-1.4) and 1.7% (95% CI 1.2-2.4) of the samples from Brazil and Norway, respectively. The difference in the prevalence of alcohol may be related to the fact that Norway has implemented steps to reduce drunk driving since 1936, whereas Brazil has attempted to do the same for only a few years. Differences for drugs may be related to different patterns in the use of stimulants, cannabis and medicines. Copyright © 2014 Elsevier B.V. All rights reserved.
A proposal for a drug information database and text templates for generating package inserts
Directory of Open Access Journals (Sweden)
Okuya R
2013-07-01
Full Text Available Ryo Okuya,1 Masaomi Kimura,2 Michiko Ohkura,2 Fumito Tsuchiya3 1Graduate School of Engineering and Science, 2Faculty of Engineering, Shibaura Institute of Technology, Tokyo, 3School of Pharmacy, International University of Health and Welfare, Tokyo, Japan Abstract: To prevent prescription errors caused by information systems, a database to store complete and accurate drug information in a user-friendly format is needed. In previous studies, the primary method for obtaining data stored in a database is to extract drug information from package inserts by employing pattern matching or more sophisticated methods such as text mining. However, it is difficult to obtain a complete database because there is no strict rule concerning expressions used to describe drug information in package inserts. The authors' strategy was to first build a database and then automatically generate package inserts by embedding data in the database using templates. To create this database, the support of pharmaceutical companies to input accurate data is required. It is expected that this system will work, because these companies can earn merit for newly developed drugs to decrease the effort to create package inserts from scratch. This study designed the table schemata for the database and text templates to generate the package inserts. To handle the variety of drug-specific information in the package inserts, this information in drug composition descriptions was replaced with labels and the replacement descriptions utilizing cluster analysis were analyzed. To improve the method by which frequently repeated ingredient information and/or supplementary information are stored, the method was modified by introducing repeat tags in the templates to indicate repetition and improving the insertion of data into the database. The validity of this method was confirmed by inputting the drug information described in existing package inserts and checking that the method could
Security Flaws in an Efficient Pseudo-Random Number Generator for Low-Power Environments
Peris-Lopez, Pedro; Hernandez-Castro, Julio C.; Tapiador, Juan M. E.; Millán, Enrique San; van der Lubbe, Jan C. A.
In 2004, Settharam and Rhee tackled the design of a lightweight Pseudo-Random Number Generator (PRNG) suitable for low-power environments (e.g. sensor networks, low-cost RFID tags). First, they explicitly fixed a set of requirements for this primitive. Then, they proposed a PRNG conforming to these requirements and using a free-running timer [9]. We analyze this primitive discovering important security faults. The proposed algorithm fails to pass even relatively non-stringent batteries of randomness such as ENT (i.e. a pseudorandom number sequence test program). We prove that their recommended PRNG has a very short period due to the flawed design of its core. The internal state can be easily revealed, compromising its backward and forward security. Additionally, the rekeying algorithm is defectively designed mainly related to the unpractical value proposed for this purpose.
On the generation of log-Levy distributions and extreme randomness
International Nuclear Information System (INIS)
Eliazar, Iddo; Klafter, Joseph
2011-01-01
The log-normal distribution is prevalent across the sciences, as it emerges from the combination of multiplicative processes and the central limit theorem (CLT). The CLT, beyond yielding the normal distribution, also yields the class of Levy distributions. The log-Levy distributions are the Levy counterparts of the log-normal distribution, they appear in the context of ultraslow diffusion processes, and they are categorized by Mandelbrot as belonging to the class of extreme randomness. In this paper, we present a natural stochastic growth model from which both the log-normal distribution and the log-Levy distributions emerge universally-the former in the case of deterministic underlying setting, and the latter in the case of stochastic underlying setting. In particular, we establish a stochastic growth model which universally generates Mandelbrot's extreme randomness. (paper)
Precise algorithm to generate random sequential adsorption of hard polygons at saturation
Zhang, G.
2018-04-01
Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation" limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles and could thus determine the saturation density of spheres with high accuracy. In this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensional polygons. We also calculate the saturation density for regular polygons of three to ten sides and obtain results that are consistent with previous, extrapolation-based studies.
A randomized trial of employment-based reinforcement of cocaine abstinence in injection drug users.
Silverman, Kenneth; Wong, Conrad J; Needham, Mick; Diemer, Karly N; Knealing, Todd; Crone-Todd, Darlene; Fingerhood, Michael; Nuzzo, Paul; Kolodner, Kenneth
2007-01-01
High-magnitude and long-duration abstinence reinforcement can promote drug abstinence but can be difficult to finance. Employment may be a vehicle for arranging high-magnitude and long-duration abstinence reinforcement. This study determined if employment-based abstinence reinforcement could increase cocaine abstinence in adults who inject drugs and use cocaine during methadone treatment. Participants could work 4 hr every weekday in a workplace where they could earn about $10.00 per hour in vouchers; they were required to provide routine urine samples. Participants who attended the workplace and provided cocaine-positive urine samples during the initial 4 weeks were invited to work 26 weeks and were randomly assigned to an abstinence-and-work (n = 28) or work-only (n = 28) group. Abstinence-and-work participants had to provide urine samples showing cocaine abstinence to work and maintain maximum pay. Work-only participants could work independent of their urinalysis results. Abstinence-and-work participants provided more (p = .004; OR = 5.80, 95% CI = 2.03-16.56) cocaine-negative urine samples (29%) than did work-only participants (10%). Employment-based abstinence reinforcement can increase cocaine abstinence.
Czernik, Pawel
2013-10-01
The hardware random number generator based on the 74121 monostable multivibrators for applications in cryptographically secure distributed measurement and control systems with asymmetric resources was presented. This device was implemented on the basis of the physical electronic vibration generator in which the circuit is composed of two "loop" 74121 monostable multivibrators, D flip-flop and external clock signal source. The clock signal, witch control D flip-flop was generated by a computer on one of the parallel port pins. There was presented programmed the author's acquisition process of random data from the measuring system to a computer. The presented system was designed, builded and thoroughly tested in the term of cryptographic security in our laboratory, what there is the most important part of this publication. Real cryptographic security was tested based on the author's software and the software environment called RDieHarder. The obtained results was here presented and analyzed in detail with particular reference to the specificity of distributed measurement and control systems with asymmetric resources.
MODIFIED AES WITH RANDOM S BOX GENERATION TO OVERCOME THE SIDE CHANNEL ASSAULTS USING CLOUD
Directory of Open Access Journals (Sweden)
M. Navaneetha Krishnan
2017-01-01
Full Text Available Development of any communication system with secure and complex cryptographic algorithms highly depends on concepts of data security which is crucial in the current technological world. The security and complexity of the cryptography algorithms need to get increased by randomization of secret keys. To overcome the issues associated to data security and for improvising it during encryption and decryption process over the encrypting device, a novel Secure Side Channel Assault Prevention (SSCAP approach has been projected which will eliminate outflow of side channel messages and also provides effective security over the encrypting device. An effective Enriched AES (E-AES encryption algorithm is proposed to reduce the side channel attack; the modified algorithm in this research shows its improvement in the Generation of Random Multiple S - Box (GRM S-Box which makes it hard to the attacks to break the text which is in encrypted form. Our novel SSCAP approach also improves the security over the original information; it widely minimizes the leakage of the side channel information. Attackers cannot easily get a clue about the proposed S-Box Generation technique. Our E-AES algorithm will be implemented in cloud environment thereby improving the cloud security. The proposed SSCAP approach is judged against the existing security based algorithms on the scale of encryption and decryption time, time taken for generating the key, and performance. The proposed work proves to outperform over all other methods used in the past.
Maglennon, Gareth A; Cook, Beth S; Deeney, Alannah S; Bossé, Janine T; Peters, Sarah E; Langford, Paul R; Maskell, Duncan J; Tucker, Alexander W; Wren, Brendan W; Rycroft, Andrew N
2013-12-21
Mycoplasma hyopneumoniae is the cause of enzootic pneumonia in pigs, a chronic respiratory disease associated with significant economic losses to swine producers worldwide. The molecular pathogenesis of infection is poorly understood due to the lack of genetic tools to allow manipulation of the organism and more generally for the Mycoplasma genus. The objective of this study was to develop a system for generating random transposon insertion mutants in M. hyopneumoniae that could prove a powerful tool in enabling the pathogenesis of infection to be unraveled. A novel delivery vector was constructed containing a hyperactive C9 mutant of the Himar1 transposase along with a mini transposon containing the tetracycline resistance cassette, tetM. M. hyopneumoniae strain 232 was electroporated with the construct and tetM-expressing transformants selected on agar containing tetracycline. Individual transformants contained single transposon insertions that were stable upon serial passages in broth medium. The insertion sites of 44 individual transformants were determined and confirmed disruption of several M. hyopneumoniae genes. A large pool of over 10 000 mutants was generated that should allow saturation of the M. hyopneumoniae strain 232 genome. This is the first time that transposon mutagenesis has been demonstrated in this important pathogen and could be generally applied for other Mycoplasma species that are intractable to genetic manipulation. The ability to generate random mutant libraries is a powerful tool in the further study of the pathogenesis of this important swine pathogen.
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Pajaree Sriuttha
2018-01-01
Full Text Available Background. Nonsteroidal anti-inflammatory drugs (NSAIDs are the most widely used medication in several countries, including Thailand. NSAIDs have been associated with hepatic side effects; however, the frequency of these side effects is uncertain. Aim of the Review. To systematically review published literature on randomized, controlled trials that assessed the risk of clinically significant hepatotoxicity associated with NSAIDs. Methods. Searches of bibliographic databases EMBASE, PubMed, and the Cochrane Library were conducted up to July 30, 2016, to identify randomized controlled trials of ibuprofen, naproxen, diclofenac, piroxicam, meloxicam, mefenamic acid, indomethacin, celecoxib, and etoricoxib in adults with any disease that provide information on hepatotoxicity outcomes. Results. Among the 698 studies, 18 studies met the selection criteria. However, only 8 studies regarding three NSAIDs (celecoxib, etoricoxib, and diclofenac demonstrated clinically significant hepatotoxic evidence based on hepatotoxicity justification criteria. Of all the hepatotoxicity events found from the above-mentioned three NSAIDs, diclofenac had the highest proportion, which ranged from 0.015 to 4.3 (×10−2, followed by celecoxib, which ranged from 0.13 to 0.38 (×10−2, and etoricoxib, which ranged from 0.005 to 0.930 (×10−2. Conclusion. Diclofenac had higher rates of hepatotoxic evidence compared to other NSAIDs. Hepatotoxic evidence is mostly demonstrated as aminotransferase elevation, while liver-related hospitalization or discontinuation was very low.
Sarayani, Amir; Naderi-Behdani, Fahimeh; Hadavand, Naser; Javadi, Mohammadreza; Farsad, Fariborz; Hadjibabaie, Molouk; Gholami, Kheirollah
2015-01-01
Nurses' insufficient knowledge of adverse drug reactions is reported as a barrier to spontaneous reporting. Therefore, CE meetings could be utilized to enhance nurses' competencies. In a 3-armed randomized controlled trial, 496 nurses, working in a tertiary medical center, were randomly allocated to a didactic lecture, brainstorming workshop, or the control group (delayed education). Similar instructors (2 clinical pharmacists) prepared and delivered the educational content to all 3 groups. Outcomes were declarative/procedural knowledge (primary outcome), participation rate, and satisfaction. Knowledge was evaluated using a validated researcher-made questionnaire in 3 time points: immediately before, immediately after, and 3 months after each session. Participants' satisfaction was assessed immediately after each meeting via a standard tool. Data were analyzed using appropriate parametric and nonparametric tests. Rate of participation was 37.7% for the lecture group and 47.5% for the workshop group. The workshop participants were significantly more satisfied in comparison with the lecture group (p techniques. © 2015 The Alliance for Continuing Education in the Health Professions, the Society for Academic Continuing Medical Education, and the Council on Continuing Medical Education, Association for Hospital Medical Education.
Dalal, Krishna; Devarajan, Elanchezhiyan; Pandey, Ravindra Mohan; Subbiah, Vivekanandan; Tripathi, Manjari
2013-01-01
This report is based on the results of a randomized parallel controlled trial conducted to determine the efficacy of reflexology therapy in managing intractable epilepsy. Subjects who failed epilepsy surgery or were not candidates for epilepsy surgery or were non-responders of antiepileptic drugs (AEDs) took part in this study. The trial was completed by 77 subjects randomly assigned to 2 arms: control (AEDs) and reflexology (AEDs + reflexology therapy). The hypothesis was that hand reflexology therapy could produce results similar to those of vagus nerve stimulation, and foot reflexology therapy could maintain homeostasis in the functional status of individual body parts. Reflexology therapy was applied by family members. The follow-up period was 1.5 years. Quality of life in epilepsy patients was assessed with the QOLIE-31 instrument. In the reflexology group, the median baseline seizure frequency decreased from 9.5 (range 2-120) to 2 (range 0-110) with statistical significance (p reflexology group were 41.05 ± 7 and 43.6 ± 8, respectively. Posttherapy data were 49.07 ± 6 and 65.4 ± 9, respectively (p reflexology method allowed detection of knee pain in 85% of the reflexology group patients (p reflexology group patients reported nausea/vomiting (n = 1), change in voice (n = 2), and hoarseness (n = 1). Reflexology therapy together with AEDs may help reducing seizure frequency and improving quality of life in individuals with epilepsy. Copyright © 2013 S. Karger AG, Basel.
Directory of Open Access Journals (Sweden)
Gao XF
2017-05-01
Full Text Available Xiao-Fei Gao,1 Jun-Jie Zhang,1,2 Xiao-Min Jiang,1 Zhen Ge,1,2 Zhi-Mei Wang,1 Bing Li,1 Wen-Xing Mao,1 Shao-Liang Chen1,2 1Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 2Department of Cardiology, Nanjing Heart Center, Nanjing, People’s Republic of China Background: Pulmonary arterial hypertension (PAH is a devastating disease and ultimately leads to right heart failure and premature death. A total of four classical targeted drugs, prostanoids, endothelin receptor antagonists (ERAs, phosphodiesterase 5 inhibitors (PDE-5Is, and soluble guanylate cyclase stimulator (sGCS, have been proved to improve exercise capacity and hemodynamics compared to placebo; however, direct head-to-head comparisons of these drugs are lacking. This network meta-analysis was conducted to comprehensively compare the efficacy of these targeted drugs for PAH.Methods: Medline, the Cochrane Library, and other Internet sources were searched for randomized clinical trials exploring the efficacy of targeted drugs for patients with PAH. The primary effective end point of this network meta-analysis was a 6-minute walk distance (6MWD.Results: Thirty-two eligible trials including 6,758 patients were identified. There was a statistically significant improvement in 6MWD, mean pulmonary arterial pressure, pulmonary vascular resistance, and clinical worsening events associated with each of the four targeted drugs compared with placebo. Combination therapy improved 6MWD by 20.94 m (95% confidence interval [CI]: 6.94, 34.94; P=0.003 vs prostanoids, and 16.94 m (95% CI: 4.41, 29.47; P=0.008 vs ERAs. PDE-5Is improved 6MWD by 17.28 m (95% CI: 1.91, 32.65; P=0.028 vs prostanoids, with a similar result with combination therapy. In addition, combination therapy reduced mean pulmonary artery pressure by 3.97 mmHg (95% CI: -6.06, -1.88; P<0.001 vs prostanoids, 8.24 mmHg (95% CI: -10.71, -5.76; P<0.001 vs ERAs, 3.38 mmHg (95% CI: -6.30, -0.47; P=0.023 vs
Cassie state robustness of plasma generated randomly nano-rough surfaces
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Di Mundo, Rosa, E-mail: rosa.dimundo@poliba.it; Bottiglione, Francesco; Carbone, Giuseppe
2014-10-15
Graphical abstract: - Highlights: • Superhydrophobic randomly rough surfaces are generated by plasma etching. • Statistical analysis of roughness allows calculation of theWenzel roughness factor, r{sub W.} • A r{sub W} threshold is theoretically determined, above which superhydrophobicity is “robust”. • Dynamic wetting, e.g. with high speed impacting drops, confirms this prediction. - Abstract: Superhydrophobic surfaces are effective in practical applications provided they are “robust superhydrophobic”, i.e. able to retain the Cassie state, i.e. with water suspended onto the surface protrusions, even under severe conditions (high pressure, vibrations, high speed impact, etc.). We show that for randomly rough surfaces, given the Young angle, Cassie states are robust when a threshold value of the Wenzel roughness factor, r{sub W}, is exceeded. In particular, superhydrophobic nano-textured surfaces have been generated by self-masked plasma etching. In view of their random roughness, topography features, acquired by Atomic Force Microscopy, have been statistically analyzed in order to gain information on statistical parameters such as power spectral density, fractal dimension and Wenzel roughness factor (r{sub W}), which has been used to assess Cassie state robustness. Results indicate that randomly rough surfaces produced by plasma at high power or long treatment duration, which are also fractal self-affine, have a r{sub W} higher than the theoretical threshold, thus for them a robust superhydrophobicity is predicted. In agreement with this, under dynamic wetting conditionson these surfaces the most pronounced superhydrophobic character has been appreciated: they show the lowest contact angle hysteresis and result in the sharpest bouncing when hit by drops at high impact velocity.
International Nuclear Information System (INIS)
Prueksaritanont, Thomayant; Lin, Jiunn H.; Baillie, Thomas A.
2006-01-01
This paper aims to provide a scientifically based perspective on issues surrounding the proposed toxicology testing of synthetic drug metabolites as a means of ensuring adequate nonclinical safety evaluation of drug candidates that generate metabolites considered either to be unique to humans or are present at much higher levels in humans than in preclinical species. We put forward a number of theoretical considerations and present several specific examples where the kinetic behavior of a preformed metabolite given to animals or humans differs from that of the corresponding metabolite generated endogenously from its parent. The potential ramifications of this phenomenon are that the results of toxicity testing of the preformed metabolite may be misleading and fail to characterize the true toxicological contribution of the metabolite when formed from the parent. It is anticipated that such complications would be evident in situations where (a) differences exist in the accumulation of the preformed versus generated metabolites in specific tissues, and (b) the metabolite undergoes sequential metabolism to a downstream product that is toxic, leading to differences in tissue-specific toxicity. Owing to the complex nature of this subject, there is a need to treat drug metabolite issues in safety assessment on a case-by-case basis, in which a knowledge of metabolite kinetics is employed to validate experimental paradigms that entail administration of preformed metabolites to animal models
Sentiment Analysis of User-Generated Content on Drug Review Websites
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Na, Jin-Cheon
2015-03-01
Full Text Available This study develops an effective method for sentiment analysis of user-generated content on drug review websites, which has not been investigated extensively compared to other general domains, such as product reviews. A clause-level sentiment analysis algorithm is developed since each sentence can contain multiple clauses discussing multiple aspects of a drug. The method adopts a pure linguistic approach of computing the sentiment orientation (positive, negative, or neutral of a clause from the prior sentiment scores assigned to words, taking into consideration the grammatical relations and semantic annotation (such as disorder terms of words in the clause. Experiment results with 2,700 clauses show the effectiveness of the proposed approach, and it performed significantly better than the baseline approaches using a machine learning approach. Various challenging issues were identified and discussed through error analysis. The application of the proposed sentiment analysis approach will be useful not only for patients, but also for drug makers and clinicians to obtain valuable summaries of public opinion. Since sentiment analysis is domain specific, domain knowledge in drug reviews is incorporated into the sentiment analysis algorithm to provide more accurate analysis. In particular, MetaMap is used to map various health and medical terms (such as disease and drug names to semantic types in the Unified Medical Language System (UMLS Semantic Network.
Verger, Pierre; Rolland, Sophie; Paraponaris, Alain; Bouvenot, Julien; Ventelou, Bruno
2010-08-01
This study sought to identify the effect of drug reimbursability--a decision made in France by the National Authority for Health--on physicians' prescribing practices for a diet drug such as rimonabant, approved for obese or overweight patients with type-2 diabetes. A cross-sectional survey of French general practitioners (GPs) presented a case-vignette about a patient for whom this drug is indicated in two alternative versions, differing only in its reimbursability, to two separate randomized subsamples of GPs in early 2007, before any decision was made about reimbursement. The results indicate that (i) more than 20% of GPs in private practice would be willing to prescribe a non-reimbursed diet drug for patients with obesity complicated by type 2 diabetes; (ii) the number of GPs willing to prescribe it would increase by 47.6% if the drug were reimbursed, and (iii) such a drug would be adopted at a higher rate by GPs who have regular contacts with pharmaceutical sales representatives. In France, unlike most other countries, drug reimbursement status is a signal of quality. However, our results suggest that a significant proportion of GPs would spontaneously adopt anti-obesity drugs even if they were not reimbursed. Decisions about reimbursement of pharmaceutical products should be made taking into account that reimbursement is likely to intensify prescription.
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Liu R
2012-10-01
Full Text Available Rong Liu,1,2,* Yusi Lai,1,* Bin He,1 Yuan Li,1 Gang Wang,1 Shuang Chang,1 Zhongwei Gu1 1National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China; 2Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China*These authors contributed equally to this paperAbstract: A new approach of fabricating supramolecular nanoparticles generated by self-assembly polyrotaxanes for antitumor drug delivery has been reported. Cinnamic-acid-modified poly(ethylene glycol chains were threaded in a-cyclodextrins to form polyrotaxanes. The polyrotaxanes self-assembled supramolecular nanoparticles. The morphology of the nanoparticles was changed from nanovesicle to micelle after the antitumor drug, doxorubicin, was loaded. The release profile of the drug-loaded nanoparticles was investigated, and it was found that the sustaining release time could last for 32 hours. The drug-loaded nanoparticles were co-cultured with mouse 4T1 breast cancer cells with a drug concentration of 10 µg/mL; the cell survival rate was 3.3% after a 72-hour incubation. In an in vivo study of breast cancer in a mouse model, the drug-loaded nanoparticles were injected in the tail veins of mice with a dose of 5 mg/kg body weight. The tumor inhibition rate of drug-loaded nanoparticles was 53%, which was better than that of doxorubicin hydrochloride. The cardiac toxicity of doxorubicin was decreased greatly after the encapsulation into supramolecular polyrotaxane nanoparticles.Keywords: polyrotaxane, self-assembly, nanoparticle, doxorubicin, supermolecular
Reynolds, Maureen D; Tarter, Ralph E; Kirisci, Levent
2004-09-06
Men qualifying for substance use disorder (SUD) consequent to consumption of an illicit drug were compared according to recruitment method. It was hypothesized that volunteers would be more self-disclosing and exhibit more severe disturbances compared to randomly recruited subjects. Personal, demographic, family, social, substance use, psychiatric, and SUD characteristics of volunteers (N = 146) were compared to randomly recruited (N = 102) subjects. Volunteers had lower socioceconomic status, were more likely to be African American, and had lower IQ than randomly recruited subjects. Volunteers also evidenced greater social and family maladjustment and more frequently had received treatment for substance abuse. In addition, lower social desirability response bias was observed in the volunteers. SUD was not more severe in the volunteers; however, they reported a higher lifetime rate of opiate, diet, depressant, and analgesic drug use. Volunteers and randomly recruited subjects qualifying for SUD consequent to illicit drug use are similar in SUD severity but differ in terms of severity of psychosocial disturbance and history of drug involvement. The factors discriminating volunteers and randomly recruited subjects are well known to impact on outcome, hence they need to be considered in research design, especially when selecting a sampling strategy in treatment research.
Application of random number generators in genetic algorithms to improve rainfall-runoff modelling
Czech Academy of Sciences Publication Activity Database
Chlumecký, M.; Buchtele, Josef; Richta, K.
2017-01-01
Roč. 553, October (2017), s. 350-355 ISSN 0022-1694 Institutional support: RVO:67985874 Keywords : genetic algorithm * optimisation * rainfall-runoff modeling * random generator Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 3.483, year: 2016 https://ac.els-cdn.com/S0022169417305516/1-s2.0-S0022169417305516-main.pdf?_tid=fa1bad8a-bd6a-11e7-8567-00000aab0f27&acdnat=1509365462_a1335d3d997e9eab19e23b1eee977705
Randomly Generating Four Mixed Bell-Diagonal States with a Concurrences Sum to Unity
International Nuclear Information System (INIS)
Toh, S. P.; Zainuddin Hishamuddin; Foo Kim Eng
2012-01-01
A two-qubit system in quantum information theory is the simplest bipartite quantum system and its concurrence for pure and mixed states is well known. As a subset of two-qubit systems, Bell-diagonal states can be depicted by a very simple geometrical representation of a tetrahedron with sides of length 2√2. Based on this geometric representation, we propose a simple approach to randomly generate four mixed Bell decomposable states in which the sum of their concurrence is equal to one. (general)
Next generation human skin constructs as advanced tools for drug development.
Abaci, H E; Guo, Zongyou; Doucet, Yanne; Jacków, Joanna; Christiano, Angela
2017-11-01
Many diseases, as well as side effects of drugs, manifest themselves through skin symptoms. Skin is a complex tissue that hosts various specialized cell types and performs many roles including physical barrier, immune and sensory functions. Therefore, modeling skin in vitro presents technical challenges for tissue engineering. Since the first attempts at engineering human epidermis in 1970s, there has been a growing interest in generating full-thickness skin constructs mimicking physiological functions by incorporating various skin components, such as vasculature and melanocytes for pigmentation. Development of biomimetic in vitro human skin models with these physiological functions provides a new tool for drug discovery, disease modeling, regenerative medicine and basic research for skin biology. This goal, however, has long been delayed by the limited availability of different cell types, the challenges in establishing co-culture conditions, and the ability to recapitulate the 3D anatomy of the skin. Recent breakthroughs in induced pluripotent stem cell (iPSC) technology and microfabrication techniques such as 3D-printing have allowed for building more reliable and complex in vitro skin models for pharmaceutical screening. In this review, we focus on the current developments and prevailing challenges in generating skin constructs with vasculature, skin appendages such as hair follicles, pigmentation, immune response, innervation, and hypodermis. Furthermore, we discuss the promising advances that iPSC technology offers in order to generate in vitro models of genetic skin diseases, such as epidermolysis bullosa and psoriasis. We also discuss how future integration of the next generation human skin constructs onto microfluidic platforms along with other tissues could revolutionize the early stages of drug development by creating reliable evaluation of patient-specific effects of pharmaceutical agents. Impact statement Skin is a complex tissue that hosts various
Stochastic generation of explicit pore structures by thresholding Gaussian random fields
Energy Technology Data Exchange (ETDEWEB)
Hyman, Jeffrey D., E-mail: jhyman@lanl.gov [Program in Applied Mathematics, University of Arizona, Tucson, AZ 85721-0089 (United States); Computational Earth Science, Earth and Environmental Sciences (EES-16), and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Winter, C. Larrabee, E-mail: winter@email.arizona.edu [Program in Applied Mathematics, University of Arizona, Tucson, AZ 85721-0089 (United States); Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ 85721-0011 (United States)
2014-11-15
We provide a description and computational investigation of an efficient method to stochastically generate realistic pore structures. Smolarkiewicz and Winter introduced this specific method in pores resolving simulation of Darcy flows (Smolarkiewicz and Winter, 2010 [1]) without giving a complete formal description or analysis of the method, or indicating how to control the parameterization of the ensemble. We address both issues in this paper. The method consists of two steps. First, a realization of a correlated Gaussian field, or topography, is produced by convolving a prescribed kernel with an initial field of independent, identically distributed random variables. The intrinsic length scales of the kernel determine the correlation structure of the topography. Next, a sample pore space is generated by applying a level threshold to the Gaussian field realization: points are assigned to the void phase or the solid phase depending on whether the topography over them is above or below the threshold. Hence, the topology and geometry of the pore space depend on the form of the kernel and the level threshold. Manipulating these two user prescribed quantities allows good control of pore space observables, in particular the Minkowski functionals. Extensions of the method to generate media with multiple pore structures and preferential flow directions are also discussed. To demonstrate its usefulness, the method is used to generate a pore space with physical and hydrological properties similar to a sample of Berea sandstone. -- Graphical abstract: -- Highlights: •An efficient method to stochastically generate realistic pore structures is provided. •Samples are generated by applying a level threshold to a Gaussian field realization. •Two user prescribed quantities determine the topology and geometry of the pore space. •Multiple pore structures and preferential flow directions can be produced. •A pore space based on Berea sandstone is generated.
Random source generating far field with elliptical flat-topped beam profile
International Nuclear Information System (INIS)
Zhang, Yongtao; Cai, Yangjian
2014-01-01
Circular and rectangular multi-Gaussian Schell-model (MGSM) sources which generate far fields with circular and rectangular flat-topped beam profiles were introduced just recently (Sahin and Korotkova 2012 Opt. Lett. 37 2970; Korotkova 2014 Opt. Lett. 39 64). In this paper, a random source named an elliptical MGSM source is introduced. An analytical expression for the propagation factor of an elliptical MGSM beam is derived. Furthermore, an analytical propagation formula for an elliptical MGSM beam passing through a stigmatic ABCD optical system is derived, and its propagation properties in free space are studied. It is interesting to find that an elliptical MGSM source generates a far field with an elliptical flat-topped beam profile, being qualitatively different from that of circular and rectangular MGSM sources. The ellipticity and the flatness of the elliptical flat-topped beam profile in the far field are determined by the initial coherence widths and the beam index, respectively. (paper)
The determinants of cost efficiency of hydroelectric generating plants: A random frontier approach
International Nuclear Information System (INIS)
Barros, Carlos P.; Peypoch, Nicolas
2007-01-01
This paper analyses the technical efficiency in the hydroelectric generating plants of a main Portuguese electricity enterprise EDP (Electricity of Portugal) between 1994 and 2004, investigating the role played by increase in competition and regulation. A random cost frontier method is adopted. A translog frontier model is used and the maximum likelihood estimation technique is employed to estimate the empirical model. We estimate the efficiency scores and decompose the exogenous variables into homogeneous and heterogeneous. It is concluded that production and capacity are heterogeneous, signifying that the hydroelectric generating plants are very distinct and therefore any energy policy should take into account this heterogeneity. It is also concluded that competition, rather than regulation, plays the key role in increasing hydroelectric plant efficiency
Random number generators for large-scale parallel Monte Carlo simulations on FPGA
Lin, Y.; Wang, F.; Liu, B.
2018-05-01
Through parallelization, field programmable gate array (FPGA) can achieve unprecedented speeds in large-scale parallel Monte Carlo (LPMC) simulations. FPGA presents both new constraints and new opportunities for the implementations of random number generators (RNGs), which are key elements of any Monte Carlo (MC) simulation system. Using empirical and application based tests, this study evaluates all of the four RNGs used in previous FPGA based MC studies and newly proposed FPGA implementations for two well-known high-quality RNGs that are suitable for LPMC studies on FPGA. One of the newly proposed FPGA implementations: a parallel version of additive lagged Fibonacci generator (Parallel ALFG) is found to be the best among the evaluated RNGs in fulfilling the needs of LPMC simulations on FPGA.
On Generating Optimal Signal Probabilities for Random Tests: A Genetic Approach
Directory of Open Access Journals (Sweden)
M. Srinivas
1996-01-01
Full Text Available Genetic Algorithms are robust search and optimization techniques. A Genetic Algorithm based approach for determining the optimal input distributions for generating random test vectors is proposed in the paper. A cost function based on the COP testability measure for determining the efficacy of the input distributions is discussed. A brief overview of Genetic Algorithms (GAs and the specific details of our implementation are described. Experimental results based on ISCAS-85 benchmark circuits are presented. The performance of our GAbased approach is compared with previous results. While the GA generates more efficient input distributions than the previous methods which are based on gradient descent search, the overheads of the GA in computing the input distributions are larger.
Sheppard, David P; Woods, Steven Paul; Doyle, Katie L; Verduzco, Marizela
2017-02-01
HIV is associated with frontostriatal dysregulation and executive dysfunction. This study evaluated whether HIV-infected individuals evidence deficits in random number generation (RNG), which is a strategic task requiring paced, rule-guided production of digits. In total, 74 HIV+ adults and 54 seronegative comparison participants completed a comprehensive research neuropsychological battery. Participants produced a random digit sequence by avoiding any order and using numbers 1 through 10 for 100 s at a pace of 1 digit/s. Outcomes included intrusions, repetitions, seriation (1-2-3-4), and cycling (median length of gaps between repeating digits). HIV disease was associated with higher levels of seriation and cycling (ps .10). Among HIV+ individuals, higher seriation was associated with neuropsychological performance including poorer auditory attention, verbal learning, and delayed memory, whereas higher cycling scores were associated with poorer delayed memory and verbal fluency (ps random sequences, which showed medium associations with higher order verbal abilities and may contribute to greater declines in everyday functioning outcomes. Future studies might examine RNG's role in health behaviors such as medical decision-making or medication adherence. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Energy Technology Data Exchange (ETDEWEB)
Matthews, J O; Hopcraft, K I; Jakeman, E [Applied Mathematics Division, School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD (United Kingdom)
2003-11-21
Some properties of classical population processes that comprise births, deaths and multiple immigrations are investigated. The rates at which the immigrants arrive can be tailored to produce a population whose steady state fluctuations are described by a pre-selected distribution. Attention is focused on the class of distributions with a discrete stable law, which have power-law tails and whose moments and autocorrelation function do not exist. The separate problem of monitoring and characterizing the fluctuations is studied, analysing the statistics of individuals that leave the population. The fluctuations in the size of the population are transferred to the times between emigrants that form an intermittent time series of events. The emigrants are counted with a detector of finite dynamic range and response time. This is modelled through clipping the time series or saturating it at an arbitrary but finite level, whereupon its moments and correlation properties become finite. Distributions for the time to the first counted event and for the time between events exhibit power-law regimes that are characteristic of the fluctuations in population size. The processes provide analytical models with which properties of complex discrete random phenomena can be explored, and in addition provide generic means by which random time series encompassing a wide range of intermittent and other discrete random behaviour may be generated.
International Nuclear Information System (INIS)
Matthews, J O; Hopcraft, K I; Jakeman, E
2003-01-01
Some properties of classical population processes that comprise births, deaths and multiple immigrations are investigated. The rates at which the immigrants arrive can be tailored to produce a population whose steady state fluctuations are described by a pre-selected distribution. Attention is focused on the class of distributions with a discrete stable law, which have power-law tails and whose moments and autocorrelation function do not exist. The separate problem of monitoring and characterizing the fluctuations is studied, analysing the statistics of individuals that leave the population. The fluctuations in the size of the population are transferred to the times between emigrants that form an intermittent time series of events. The emigrants are counted with a detector of finite dynamic range and response time. This is modelled through clipping the time series or saturating it at an arbitrary but finite level, whereupon its moments and correlation properties become finite. Distributions for the time to the first counted event and for the time between events exhibit power-law regimes that are characteristic of the fluctuations in population size. The processes provide analytical models with which properties of complex discrete random phenomena can be explored, and in addition provide generic means by which random time series encompassing a wide range of intermittent and other discrete random behaviour may be generated
Das, Suman; Sadique Uz Zaman, J. K. M.; Ghosh, Ranjan
2016-06-01
In Advanced Encryption Standard (AES), the standard S-Box is conventionally generated by using a particular irreducible polynomial {11B} in GF(28) as the modulus and a particular additive constant polynomial {63} in GF(2), though it can be generated by many other polynomials. In this paper, it has been shown that it is possible to generate secured AES S-Boxes by using some other selected modulus and additive polynomials and also can be generated randomly, using a PRNG like BBS. A comparative study has been made on the randomness of corresponding AES ciphertexts generated, using these S-Boxes, by the NIST Test Suite coded for this paper. It has been found that besides using the standard one, other moduli and additive constants are also able to generate equally or better random ciphertexts; the same is true for random S-Boxes also. As these new types of S-Boxes are user-defined, hence unknown, they are able to prevent linear and differential cryptanalysis. Moreover, they act as additional key-inputs to AES, thus increasing the key-space.
Li, Xiayue; Curtis, Farren S.; Rose, Timothy; Schober, Christoph; Vazquez-Mayagoitia, Alvaro; Reuter, Karsten; Oberhofer, Harald; Marom, Noa
2018-06-01
We present Genarris, a Python package that performs configuration space screening for molecular crystals of rigid molecules by random sampling with physical constraints. For fast energy evaluations, Genarris employs a Harris approximation, whereby the total density of a molecular crystal is constructed via superposition of single molecule densities. Dispersion-inclusive density functional theory is then used for the Harris density without performing a self-consistency cycle. Genarris uses machine learning for clustering, based on a relative coordinate descriptor developed specifically for molecular crystals, which is shown to be robust in identifying packing motif similarity. In addition to random structure generation, Genarris offers three workflows based on different sequences of successive clustering and selection steps: the "Rigorous" workflow is an exhaustive exploration of the potential energy landscape, the "Energy" workflow produces a set of low energy structures, and the "Diverse" workflow produces a maximally diverse set of structures. The latter is recommended for generating initial populations for genetic algorithms. Here, the implementation of Genarris is reported and its application is demonstrated for three test cases.
Doufas, Anthony G; Panagiotou, Orestis A; Panousis, Periklis; Wong, Shane Shucheng; Ioannidis, John P A
2017-01-01
To determine whether drugs used to treat diverse conditions cause insomnia symptoms and whether their prescription information is concordant with this evidence. We conducted a survey of meta-analyses (Cochrane Database of Systematic Reviews) and comparisons with package inserts compiled in the Physicians' Desk Reference (PDR). We identified randomized controlled trials (RCTs) in which any drug had been evaluated vs placebo and sleep had been assessed. We collectively referred to insomnia-related outcomes as sleep disturbance. We also searched the PDR to identify any insomnia symptoms listed for drugs with RCT evidence available. Seventy-four Cochrane systematic reviews corresponding to 274 RCTs assessed 88 drugs in 27 different conditions, providing evidence on 109 drug-condition pairs. Of these 88 drugs, 5 decreased sleep problems and 19 increased sleep problems; 64 drugs had no nominally statistically significant effect on sleep. Acetylcholinesterase inhibitors, dopamine agonists, and selective serotonin reuptake inhibitors were the drug classes most importantly associated with sleep disturbance. Of 35 drugs that included disturbed sleep as an adverse effect in the PDR, only 14 had RCT evidence supporting such effect, and 2 had evidence of increasing and decreasing sleep problems in RCTs, although this was not shown in the PDR. We identified weak concordance between the PDR and RCTs (weighted κ=0.31; P<.001). The RCTs offer substantial evidence about the common effects of drugs on the risk of sleep disturbance; currently, prescription information only partially agrees with the available randomized evidence. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
Sullivan, Helen W; O'Donoghue, Amie C; Aikin, Kathryn J; Chowdhury, Dhuly; Moultrie, Rebecca R; Rupert, Douglas J
2016-05-01
To determine whether visual aids help people recall quantitative efficacy information in direct-to-consumer (DTC) prescription drug advertisements, and if so, which types of visual aids are most helpful. Individuals diagnosed with high cholesterol (n=2504) were randomized to view a fictional DTC print or television advertisement with no visual aid or one of four visual aids (pie chart, bar chart, table, or pictograph) depicting drug efficacy. We measured drug efficacy and risk recall, drug perceptions and attitudes, and behavioral intentions. For print advertisements, a bar chart or table, compared with no visual aid, elicited more accurate drug efficacy recall. The bar chart was better at this than the pictograph and the table was better than the pie chart. For television advertisements, any visual aid, compared with no visual aid, elicited more accurate drug efficacy recall. The bar chart was better at this than the pictograph or the table. Visual aids depicting quantitative efficacy information in DTC print and television advertisements increased drug efficacy recall, which may help people make informed decisions about prescription drugs. Adding visual aids to DTC advertising may increase the public's knowledge of how well prescription drugs work. Published by Elsevier Ireland Ltd.
Cross-generational effects on gender differences in psychoactive drug abuse and dependence.
Holdcraft, Laura C; Iacono, William G
2004-05-10
Studies of patients with cocaine and heroin use disorders have shown gender differences in prevalence, course, and outcome. These differences may be decreasing in successive generations. Less is known about gender differences in course and symptomatology for other illicit drug use disorders, especially in community samples. Participants (1323 men and 1384 women) who were biological or step-parents of twins and born in the 1940-1960s, from the Minnesota Twin-Family Study (MTFS) were divided into two cohorts based on the median birth year. A structured interview was used to assess DSM-III-R cannabis, amphetamine, cocaine and hallucinogen use disorders. There was a higher prevalence of each of these drug disorders and earlier onset of cannabis and amphetamine use disorders in later-born participants. For most drug use disorder categories, men and women were similar with respect to age of onset and severity of disorder but women had a shorter course of drug use disorders. Women with amphetamine disorders were atypical with respect to having a higher frequency of use but similar number of lifetime uses compared to men, and more emotional effects of amphetamine intoxication than men. In addition, women with amphetamine disorders were more likely to have anorexia nervosa than those without amphetamine disorders. These results have several implications for prevention, etiology and treatment.
Breusegem, Christophe; Spielberg, Leigh; Van Ginderdeuren, Rita; Vandewalle, Evelien; Renier, Charlotte; Van de Veire, Sara; Fieuws, Steffen; Zeyen, Thierry; Stalmans, Ingeborg
2010-07-01
To investigate the benefit of preoperative treatment with either topical nonsteroidal anti-inflammatory drug (NSAID) or steroid in terms of clinical outcomes following trabeculectomy. Prospective, randomized placebo-controlled trial. Sixty-one patients. Between July 2005 and October 2007, 61 consecutive medically uncontrolled glaucoma patients scheduled for first-time trabeculectomy were randomized to 1 of 3 study topical medication groups: nonsteroidal anti-inflammatory drugs (ketorolac), steroids (fluorometholone), or placebo (artificial tears). Patients instilled 1 drop 4 times daily for 1 month before the procedure and were examined on days 1 and 2, at weeks 1, 2, and 4, and at months 3, 6, 12, 18, and 24 after trabeculectomy. Incidence of postoperative surgical or medical interventions (needling, laser suture lysis, needling revision, and intraocular pressure [IOP]-lowering medication). Fifty-four patients (54 eyes) were entered for analysis. The mean number of preoperative medications was 2.3+/-0.9. The mean baseline IOP was 21.0+/-6.0 mmHg. The mean postoperative target IOP was 16.5+/-1.8 mmHg. The mean follow-up was 23.6+/-4.0 months. The percentage of patients requiring needling within the first year was 41% in the placebo group, 6% in the NSAID, and 5% in the steroid group (P = 0.006). The percentage of patients requiring IOP-lowering medication to reach the target IOP at 1 year was 24% in the placebo group, 18% in the NSAID group, and 0% in the steroid group (P = 0.054 overall; P = 0.038 for steroids vs. others). The log-rank test showed a significant (P = 0.019) difference in medication-free survival curves between the different groups. More specifically, patients in the steroid group needed significantly less medication over the total follow-up (P = 0.007). Topical ketorolac or fluorometholone for 1 month before surgery was associated with improved trabeculectomy outcomes in terms of likelihood of postoperative needling. In the steroid group, there was
Malmberg, M.; Kleinjan, M.; Overbeek, G.; Vermulst, A.; Monshouwer, K.; Lammers, J.; Vollebergh, W.A.M.; Engels, R.C.M.E.
2014-01-01
Aim: To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. Design: Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). Setting: General population of 11-15-year-old
Malmberg, Monique; Kleinjan, Marloes; Overbeek, Geertjan; Vermulst, Ad; Monshouwer, Karin; Lammers, Jeroen; Vollebergh, Wilma A M; Engels, Rutger C M E
2014-01-01
Aim: To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. Design: Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). Setting: General population of 11-15-year-old
Malmberg, M.; Kleinjan, M.; Overbeek, G.J.; Vermulst, A.A.; Monshouwer, K.; Lammers, J.; Vollebergh, W.A.M.; Engels, R.C.M.E.
2014-01-01
Aim To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. Design Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). Setting General population of 11-15-year-old adolescents
Adu, A; Armour, C L
1995-09-01
Six parenteral third generation cephalosporins have been introduced into clinical use in the past 10 years. The 3 most frequently available agents are cefotaxime, ceftriaxone and ceftazidime. These 3 third generation cephalosporins are characterised by a broad spectrum of activity and increased stability to beta-lactamases compared with the first and second generation cephalosporins. However, there are growing numbers of reports of resistance to these agents with increasing use. The major differences in the properties of the 3 agents are the long half-life of ceftriaxone and its dual route of elimination. Ceftazidime is best restricted to Pseudomonas aeruginosa infections where other agents are contraindicated or ineffective. Cefotaxime and ceftriaxone can be used in nosocomial Gram-negative infections where P. aeruginosa can be ruled out. The types and incidences of adverse drug reactions are not different for the 3 agents. A number of drug utilisation review (DUR) studies of these agents in the hospital setting have reported a considerable incidence of inappropriate use and substantial avoidable costs. There are methodological problems with most of the DUR studies, especially the criteria and the methods of cost estimation. The use of pharmacoeconomic methodology could ensure more realistic cost estimation; however, outcome data are, in most cases, not available.
The effect of hypnotic drug type on anesthetic depth and amnesia: a randomized clinical trial
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Amiri HR
2009-06-01
Full Text Available "n Normal 0 false false false EN-GB X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Bispectral index (BIS index shows the depth of anesthesia. The effects of drugs on BIS and amnesia are different. This study was performed to evaluate the association between two different sedative regimens on BIS and amnesia."n"nMethods: In this clinical trial, 60 patients who needed elective orthopedic surgery under regional anesthesia with intravenous sedation were elected. Patients divided in two equal groups based on sedation protocol by block randomization method: midazolam plus fentanyl group (MF group or propofol group (P group. Dose of sedative drugs were adjusted according to clinical findings of sedation. Depth of sedation in all patients, preserved in four based on modified Ramsey Sedation Score. Patients questioned about spontaneous recall after full awakening in recovery room. Recall of any event during operation considered as failed amnesia. Correlation of BIS index with recall was measured in two different groups separately."n"nResults: The frequency of recall was 2 (6.7% in P group and 10 (33.3% in MF group (p=0.01. The mean± SD of BIS in P group was 76±5 (68-91 and in MF group was 93.4±5 (77-98 (p<0.001. The difference of BIS in patients without amnesia (p=0.019 and with amnesia (p<0
Ossola, Giovanni; Sokal, Alan D
2004-08-01
We show that linear congruential pseudo-random-number generators can cause systematic errors in Monte Carlo simulations using the Swendsen-Wang algorithm, if the lattice size is a multiple of a very large power of 2 and one random number is used per bond. These systematic errors arise from correlations within a single bond-update half-sweep. The errors can be eliminated (or at least radically reduced) by updating the bonds in a random order or in an aperiodic manner. It also helps to use a generator of large modulus (e.g., 60 or more bits).
Directory of Open Access Journals (Sweden)
Jeffrey S. Lee
2017-10-01
Full Text Available In this note, the Cosmic Microwave Background (CMB Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n random key matrix for a Vernam cipher is established. Keywords: Particle physics, Computer science, Mathematics, Astrophysics
Parabiaghi, A; Tettamanti, M; D'Avanzo, B; Barbato, A
2016-01-01
To determine whether the prescription of aripiprazole, compared with olanzapine and haloperidol, was associated with a lower frequency of metabolic syndrome (MS) and treatment discontinuation at 1 year. Patients were randomly assigned to be treated open-label and according to usual clinical practice with either aripiprazole, olanzapine, or haloperidol and followed up for 1 year. Three hundred out-patients with persistent schizophrenia were recruited in 35 mental health services. The intention-to-treat (ITT) analysis found no significant differences in the rate of MS between aripiprazole (37%), olanzapine (47%), and haloperidol (42%). Treatment discontinuation for any cause was higher for aripiprazole (52%) than for olanzapine (33%; OR, 0.41; P = 0.004), or haloperidol (37%; OR, 0.51; P = 0.030). No significant difference was found between olanzapine and haloperidol. Time to discontinuation for any cause was longer for olanzapine than for aripiprazole (HR, 0.55; P haloperidol and aripiprazole, or between olanzapine and haloperidol. The prescription of aripiprazole did not significantly reduce the rates of MS, but its treatment retention was worse. Aripiprazole cannot be considered the safest and most effective drug for maintenance treatment of schizophrenia in routine care, although it may have a place in antipsychotic therapy. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Combining drug and music therapy in patients with moderate Alzheimer's disease: a randomized study.
Giovagnoli, Anna Rita; Manfredi, Valentina; Schifano, Letizia; Paterlini, Chiara; Parente, Annalisa; Tagliavini, Fabrizio
2018-06-01
Alzheimer's disease (AD) can impair language, but active music therapy (AMT) and memantine (M) can improve communication. This study aimed to clarify whether adding AMT to M may improve language in comparison with drugs alone in patients with moderate AD on stable therapy with acetylcholinesterase inhibitors (AchEI). Forty-five AD patients treated with stable dose of AchEI were randomized to receive AMT plus M 20 mg/day or M 20 mg/day for 24 weeks. The Severe Impairment Battery-Language (SIB-l), SIB, Mini Mental State Examination, Neuropsychiatric Inventory (NPI), Lubben Social Network Scale, Activities of Daily Living, and Instrumental Activities of Daily Living scores at baseline and 12 and 24 weeks assessed language (primary variable) and overall cognitive, psycho-behavior, social, and functional aspects (secondary variables). The SIB-l showed a stabilization of the baseline condition in both groups, in the absence of between-group differences. The NPI depression and appetite scores significantly improved in the M-AMT group. Moreover, significantly less patients in the M-AMT group than those in the M group showed worsening of the NPI total score. Daily activities, social relationships, and overall cognitive performance did not deteriorate. In patients with moderate AD, AMT added to pharmacotherapy has no further benefits for language in comparison with pharmacotherapy alone. However, this integrated treatment can improve the psycho-behavioral profile.
Generation of Polar Semi-Saturated Bicyclic Pyrazoles for Fragment-Based Drug Discovery Campaigns.
Luise, Nicola; Wyatt, Paul
2018-05-07
Synthesising polar semi-saturated bicyclic heterocycles can lead to better starting points for fragment-based drug discovery (FBDD) programs. This communication highlights the application of diverse chemistry to construct bicyclic systems from a common intermediate, where pyrazole, a privileged heteroaromatic able to bind effectively to biological targets, is fused to diverse saturated counterparts. The generated fragments can be further developed either after confirmation of their binding pose or early in the process, as their synthetic intermediates. Essential quality control (QC) for selection of small molecules to add to a fragment library is discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Marcin Piotr Pawlowski
2015-10-01
Full Text Available Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. In constrained devices of the Internet of Things ecosystem, high entropy random number generators are hard to achieve due to hardware limitations. For the purpose of the random number generation in constrained devices, this work proposes a solution based on the least-significant bits concatenation entropy harvesting method. As a potential source of entropy, on-board integrated sensors (i.e., temperature, humidity and two different light sensors have been analyzed. Additionally, the costs (i.e., time and memory consumption of the presented approach have been measured. The results obtained from the proposed method with statistical fine tuning achieved a Shannon entropy of around 7.9 bits per byte of data for temperature and humidity sensors. The results showed that sensor-based random number generators are a valuable source of entropy with very small RAM and Flash memory requirements for constrained devices of the Internet of Things.
Pawlowski, Marcin Piotr; Jara, Antonio; Ogorzalek, Maciej
2015-01-01
Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. In constrained devices of the Internet of Things ecosystem, high entropy random number generators are hard to achieve due to hardware limitations. For the purpose of the random number generation in constrained devices, this work proposes a solution based on the least-significant bits concatenation entropy harvesting method. As a potential source of entropy, on-board integrated sensors (i.e., temperature, humidity and two different light sensors) have been analyzed. Additionally, the costs (i.e., time and memory consumption) of the presented approach have been measured. The results obtained from the proposed method with statistical fine tuning achieved a Shannon entropy of around 7.9 bits per byte of data for temperature and humidity sensors. The results showed that sensor-based random number generators are a valuable source of entropy with very small RAM and Flash memory requirements for constrained devices of the Internet of Things. PMID:26506357
Pawlowski, Marcin Piotr; Jara, Antonio; Ogorzalek, Maciej
2015-10-22
Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. In constrained devices of the Internet of Things ecosystem, high entropy random number generators are hard to achieve due to hardware limitations. For the purpose of the random number generation in constrained devices, this work proposes a solution based on the least-significant bits concatenation entropy harvesting method. As a potential source of entropy, on-board integrated sensors (i.e., temperature, humidity and two different light sensors) have been analyzed. Additionally, the costs (i.e., time and memory consumption) of the presented approach have been measured. The results obtained from the proposed method with statistical fine tuning achieved a Shannon entropy of around 7.9 bits per byte of data for temperature and humidity sensors. The results showed that sensor-based random number generators are a valuable source of entropy with very small RAM and Flash memory requirements for constrained devices of the Internet of Things.
Li, Jiafu; Xiang, Shuiying; Wang, Haoning; Gong, Junkai; Wen, Aijun
2018-03-01
In this paper, a novel image encryption algorithm based on synchronization of physical random bit generated in a cascade-coupled semiconductor ring lasers (CCSRL) system is proposed, and the security analysis is performed. In both transmitter and receiver parts, the CCSRL system is a master-slave configuration consisting of a master semiconductor ring laser (M-SRL) with cross-feedback and a solitary SRL (S-SRL). The proposed image encryption algorithm includes image preprocessing based on conventional chaotic maps, pixel confusion based on control matrix extracted from physical random bit, and pixel diffusion based on random bit stream extracted from physical random bit. Firstly, the preprocessing method is used to eliminate the correlation between adjacent pixels. Secondly, physical random bit with verified randomness is generated based on chaos in the CCSRL system, and is used to simultaneously generate the control matrix and random bit stream. Finally, the control matrix and random bit stream are used for the encryption algorithm in order to change the position and the values of pixels, respectively. Simulation results and security analysis demonstrate that the proposed algorithm is effective and able to resist various typical attacks, and thus is an excellent candidate for secure image communication application.
Ti, Lianping; Richardson, Lindsey; DeBeck, Kora; Nguyen, Paul; Montaner, Julio; Wood, Evan; Kerr, Thomas
2014-08-01
Despite the growing prevalence of illicit stimulant drug use internationally, and the widespread involvement of people who inject drugs (IDU) within street-based drug markets, little is known about the impact of different types of street-based income generation activities on the cessation of stimulant use among IDU. Data were derived from an open prospective cohort of IDU in Vancouver, Canada. We used Kaplan-Meier methods and Cox proportional hazards regression to examine the effect of different types of street-based income generation activities (e.g., sex work, drug dealing, and scavenging) on time to cessation of stimulant use. Between December, 2005 and November, 2012, 887 IDU who use stimulant drugs (cocaine, crack cocaine, or crystal methamphetamine) were prospectively followed-up for a median duration of 47 months. In Kaplan-Meier analyses, compared to those who did not engage in street-based income generation activities, participants who reported sex work, drug dealing, scavenging, or more than one of these activities were significantly less likely to report stimulant drug use cessation (all pstreet-based income generation activity remained significantly associated with a slower time to stimulant drug cessation (all p<0.005). Our findings highlight the urgent need for strategies to address stimulant dependence, including novel pharmacotherapies. Also important, structural interventions, such as low-threshold employment opportunities, availability of supportive housing, legal reforms regarding drug use, and evidence-based approaches that reduce harm among IDU are urgently required. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Graphene resistive random memory — the promising memory device in next generation
International Nuclear Information System (INIS)
Wang Xue-Feng; Zhao Hai-Ming; Yang Yi; Ren Tian-Ling
2017-01-01
Graphene-based resistive random access memory (GRRAM) has grasped researchers’ attention due to its merits compared with ordinary RRAM. In this paper, we briefly review different types of GRRAMs. These GRRAMs can be divided into two categories: graphene RRAM and graphene oxide (GO)/reduced graphene oxide (rGO) RRAM. Using graphene as the electrode, GRRAM can own many good characteristics, such as low power consumption, higher density, transparency, SET voltage modulation, high uniformity, and so on. Graphene flakes sandwiched between two dielectric layers can lower the SET voltage and achieve multilevel switching. Moreover, the GRRAM with rGO and GO as the dielectric or electrode can be simply fabricated. Flexible and high performance RRAM and GO film can be modified by adding other materials layer or making a composite with polymer, nanoparticle, and 2D materials to further improve the performance. Above all, GRRAM shows huge potential to become the next generation memory. (topical reviews)
Macizo, Pedro; Bajo, Teresa; Soriano, Maria Felipa
2006-02-01
Working Memory (WM) span predicts subjects' performance in control executive tasks and, in addition, it has been related to the capacity to inhibit irrelevant information. In this paper we investigate the role of WM span in two executive tasks focusing our attention on inhibitory components of both tasks. High and low span participants recalled targets words rejecting irrelevant items at the same time (Experiment 1) and they generated random numbers (Experiment 2). Results showed a clear relation between WM span and performance in both tasks. In addition, analyses of intrusion errors (Experiment 1) and stereotyped responses (Experiment 2) indicated that high span individuals were able to efficiently use the inhibitory component implied in both tasks. The pattern of data provides support to the relation between WM span and control executive tasks through an inhibitory mechanism.
Treatments that generate higher number of adverse drug reactions and their symptoms
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Lucía Fernández-López
2015-12-01
Full Text Available Objectives: Adverse drug reactions (ADRs are an important cause of morbidity and mortality worldwide and generate high health costs. Therefore, the aims of this study were to determine the treatments which produce more ADRs in general population and the main symptoms they generate. Methods: An observational, cross-sectional study consisting in performing a self-rated questionnaire was carried out. 510 patients were asked about the treatments, illnesses and ADRs, they had suffered from. Results: 26.7% of patients had suffered from some ADR. Classifying patients according to the type of prescribed treatment and studying the number of ADR that they had, we obtained significant differences (p ≤ 0.05 for treatments against arthrosis, anemia and nervous disorders (anxiety, depression, insomnia. Moreover, determining absolute frequencies of these ADRs appearance in each treatment, higher frequencies were again for drugs against arthrosis (22.6% of patients treated for arthrosis suffered some ADR, anemia (14.28%, nerve disorders (13.44% and also asthma (16%. Regarding the symptoms produced by ADRs, the most frequent were gastrointestinal (60% of patients who suffered an ADR, had gastrointestinal symptoms and nervous alterations (dizziness, headache, sleep disturbances etc (24.6%. Conclusion: Therapeutic groups which produce more commonly ADRs are those for arthrosis, anemia, nervous disorders and asthma. In addition, symptoms which are generated more frequently are gastrointestinal and nervous problems. This is in accordance with the usual side effects of mentioned treatments. Health professionals should be informed about it, so that they would be more alert about a possible emergence of an ADR in these treatments. They also could provide enough information to empower patients and thus, they probably could detect ADR events. This would facilitate ADR detection and would avoid serious consequences generated to both patients' health and health economics.
Jahanshahi, M; Profice, P; Brown, R G; Ridding, M C; Dirnberger, G; Rothwell, J C
1998-08-01
Random number generation is an attention-demanding task that engages working memory and executive processes. Random number generation requires holding information 'on line', suppression of habitual counting, internally driven response generation and monitoring of responses. Evidence from PET studies suggests that the dorsolateral prefrontal cortex (DLPFC) is involved in the generation of random responses. We examined the effects of short trains of transcranial magnetic stimulation (TMS) over the left or right DLPFC or medial frontal cortex on random number generation in healthy normal participants. As in previous evidence, in control trials without stimulation participants performed poorly on the random number generation task, showing repetition avoidance and a tendency to count. Brief disruption of processing with TMS over the left DLPFC changed the balance of the individuals' counting bias, increasing the most habitual counting in ones and reducing the lower probability response of counting in twos. This differential effect of TMS over the left DLPFC on the balance of the subject's counting bias was not obtained with TMS over the right DLPFC or the medial frontal cortex. The results suggest that, with disruption of the left DLPFC with TMS, habitual counting in ones that has previously been suppressed is released from inhibition. From these findings a network modulation model of random number generation is proposed, whereby suppression of habitual responses is achieved through the modulatory influence of the left DLPFC over a number-associative network in the superior temporal cortex. To allow emergence of appropriate random responses, the left DLPFC inhibits the superior temporal cortex to prevent spreading activation and habitual counting in ones.
The Road from Host-Defense Peptides to a New Generation of Antimicrobial Drugs
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Alicia Boto
2018-02-01
Full Text Available Host-defense peptides, also called antimicrobial peptides (AMPs, whose protective action has been used by animals for millions of years, fulfill many requirements of the pharmaceutical industry, such as: (1 broad spectrum of activity; (2 unlike classic antibiotics, they induce very little resistance; (3 they act synergically with conventional antibiotics; (4 they neutralize endotoxins and are active in animal models. However, it is considered that many natural peptides are not suitable for drug development due to stability and biodisponibility problems, or high production costs. This review describes the efforts to overcome these problems and develop new antimicrobial drugs from these peptides or inspired by them. The discovery process of natural AMPs is discussed, as well as the development of synthetic analogs with improved pharmacological properties. The production of these compounds at acceptable costs, using different chemical and biotechnological methods, is also commented. Once these challenges are overcome, a new generation of versatile, potent and long-lasting antimicrobial drugs is expected.
Ondersma, Steven J; Svikis, Dace S; Thacker, Casey; Resnicow, Ken; Beatty, Jessica R; Janisse, James; Puder, Karoline
2018-04-01
Under-reporting of drug use in the perinatal period is well-documented, and significantly limits the reach of proactive intervention approaches. The Wayne Indirect Drug Use Screener (WIDUS) focuses on correlates of drug use rather than use itself. This trial tested a computer-delivered, brief intervention designed for use with indirect screen-positive cases, seeking to motivate reductions in drug use without presuming its presence. Randomized clinical trial with 500 WIDUS-positive postpartum women recruited between August 14, 2012 and November 19, 2014. Participants were randomly assigned to either a time control condition or a single-session, tailored, indirect brief intervention. The primary outcome was days of drug use over the 6-month follow-up period; secondary outcomes included urine and hair analyses results at 3- and 6-month follow-up. All outcomes were measured by blinded evaluators. Of the 500 participants (252 intervention and 248 control), 36.1% of participants acknowledged drug use in the 3 months prior to pregnancy, but 89% tested positive at the 6-month follow-up. Participants rated the intervention as easy to use (4.9/5) and helpful (4.4/5). Analyses revealed no between-group differences in drug use (52% in the intervention group, vs. 53% among controls; OR 1.03). Exploratory analyses also showed that intervention effects were not moderated by baseline severity, WIDUS score, or readiness to change. The present trial showed no evidence of efficacy for an indirect, single-session, computer-delivered, brief intervention designed as a complement to indirect screening. More direct approaches that still do not presume active drug use may be possible and appropriate. Copyright © 2018 Elsevier B.V. All rights reserved.
Young, Paul M; Traini, Daniela; Ong, Hui Xin; Granieri, Angelo; Zhu, Bing; Scalia, Santo; Song, Jie; Spicer, Patrick T
2017-10-01
Thickening polymers have been used as excipients in nasal formulations to avoid nasal run-off (nasal drip) post-administration. However, increasing the viscosity of the formulation can have a negative impact on the quality of the aerosols generated. Therefore, the study aims to investigate the use of a novel smart nano-cellulose excipient to generate suitable droplets for nasal drug delivery that simultaneously has only marginally increased viscosity while still reducing nasal drips. Nasal sprays containing nano-cellulose at different concentrations were investigated for the additive's potential as an excipient. The formulations were characterized for their rheological and aerosol properties. This was then compared to conventional nasal spray formulation containing the single-component hydroxyl-propyl methyl cellulose (HPMC) viscosity enhancing excipient. The HPMC-containing nasal formulations behave in a Newtonian manner while the nano-cellulose formulations have a yield stress and shear-thinning properties. At higher excipient concentrations and shear rates, the nano-cellulose solutions have significantly lower viscosities compared to the HPMC solution, resulting in improved droplet formation when actuated through conventional nasal spray. Nano-cellulose materials could potentially be used as a suitable excipient for nasal drug delivery, producing consistent aerosol droplet size, and enhanced residence time within the nasal cavity with reduced run-offs compared to conventional polymer thickeners.
Thongnopkoon, Thanu; Puttipipatkhachorn, Satit
2017-07-01
This study was aimed to examine the nanoparticle formation from redispersion of binary and ternary solid dispersions. Binary systems are composed of various ratios of glibenclamide (GBM) and polyvinylpyrrolidone K30 (PVP-K30), whereas a constant amount at 2.5%w/w of a surfactant, sodium lauryl sulfate (SLS) or Gelucire44/14 (GLC), was added to create ternary systems. GBM nanoparticles were collected after the systems were dispersed in water for 15 min. The obtained nanoparticles were characterized for size distribution, crystallinity, thermal behavior, molecular structure, and dissolution properties. The results indicated that GBM nanoparticles could be formed when the drug content of the systems was lower than 30%w/w in binary systems and ternary systems containing SLS. The particle size ranged from 200 to 500 nm in diameter with narrow size distribution. The particle size was increased with increasing drug content in the systems. The obtained nanoparticles were spherical and showed the amorphous state. Furthermore, because of being amorphous form and reduced particle size, the dissolution of the generated nanoparticles was markedly improved compared with the GBM powder. In contrast, all the ternary solid dispersions prepared with GLC anomalously provided the crystalline particles with the size ranging over 5 µm and irregular shape. Interestingly, this was irrelevant to the drug content in the systems. These results indicated the ability of GLC to destabilize the polymer network surrounding the particles during particle precipitation. Therefore, this study suggested that drug content, quantity, and type of surfactant incorporated in solid dispersions drastically affected the physicochemical properties of the precipitated particles.
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Yuthavong Yongyuth
2011-05-01
Full Text Available Abstract Background The prevalence of drug resistance amongst the human malaria Plasmodium species has most commonly been associated with genomic mutation within the parasites. This phenomenon necessitates evolutionary predictive studies of possible resistance mutations, which may occur when a new drug is introduced. Therefore, identification of possible new Plasmodium falciparum dihydrofolate reductase (PfDHFR mutants that confer resistance to antifolate drugs is essential in the process of antifolate anti-malarial drug development. Methods A system to identify mutations in Pfdhfr gene that confer antifolate drug resistance using an animal Plasmodium parasite model was developed. By using error-prone PCR and Plasmodium transfection technologies, libraries of Pfdhfr mutant were generated and then episomally transfected to Plasmodium berghei parasites, from which pyrimethamine-resistant PfDHFR mutants were selected. Results The principal mutation found from this experiment was S108N, coincident with the first pyrimethamine-resistance mutation isolated from the field. A transgenic P. berghei, in which endogenous Pbdhfr allele was replaced with the mutant PfdhfrS108N, was generated and confirmed to have normal growth rate comparing to parental non-transgenic parasite and also confer resistance to pyrimethamine. Conclusion This study demonstrated the power of the transgenic P. berghei system to predict drug-resistant Pfdhfr mutations in an in vivo parasite/host setting. The system could be utilized for identification of possible novel drug-resistant mutants that could arise against new antifolate compounds and for prediction the evolution of resistance mutations.
DeVito, Elise E; Kiluk, Brian D; Nich, Charla; Mouratidis, Maria; Carroll, Kathleen M
2018-02-01
Poor performance on Drug Stroop tasks, which could indicate attentional bias to drug-related cues, craving, poor cognitive control (including poor response inhibition), has been associated with substance use severity, treatment retention and substance use treatment outcomes. Cognitive Behavioral Therapy (CBT) focuses on training in appraisal and coping strategies, including strategies to minimize the negative impact of triggers and coping with drug-cue-induced craving. One mechanism of action of CBT may be the strengthening of cognitive control processes and reduction of attentional bias to drug-related stimuli. Methadone-maintained individuals with cocaine-use disorders, participating in a randomized controlled trial of treatment as usual (TAU) versus TAU plus access to computer-based CBT (CBT4CBT), completed a computerized Drug Stroop task at pre- and post-treatment. Analyses determined whether attentional bias toward drug-related stimuli changed differentially by treatment group or cocaine use outcomes across the treatment period and whether engagement in components of CBT4CBT or TAU treatment related to changes in attentional bias toward drug-related stimuli at post- versus pre-treatment. Participants achieving a longer duration of cocaine abstinence during treatment (3+ weeks) showed greater reductions in Drug Stroop Effect than those with shorter maximum continuous abstinence. Reductions in Drug Stroop Effect across treatment were associated with greater engagement with CBT4CBT-specific treatment components, but not TAU-specific treatment components. Reduction in attentional bias to drug-related cues and craving and/or improved executive cognitive control and response inhibition may contribute to the mechanism of action of CBT4CBT. Copyright © 2017 Elsevier B.V. All rights reserved.
Holtyn, August F; Koffarnus, Mikhail N; DeFulio, Anthony; Sigurdsson, Sigurdur O; Strain, Eric C; Schwartz, Robert P; Leoutsakos, Jeannie-Marie S; Silverman, Kenneth
2014-11-01
Determine if employment-based reinforcement can increase methadone treatment engagement and drug abstinence in out-of-treatment injection drug users. This study was conducted from 2008 to 2012 in a therapeutic workplace in Baltimore, MD. After a 4-week induction, participants (N=98) could work and earn pay for 26 weeks and were randomly assigned to Work Reinforcement, Methadone & Work Reinforcement, and Abstinence, Methadone & Work Reinforcement conditions. Work Reinforcement participants had to work to earn pay. Methadone & Work Reinforcement and Abstinence, Methadone, & Work Reinforcement participants had to enroll in methadone treatment to work and maximize pay. Abstinence, Methadone, & Work Reinforcement participants had to provide opiate- and cocaine-negative urine samples to maximize pay. Most participants (92%) enrolled in methadone treatment during induction. Drug abstinence increased as a graded function of the addition of the methadone and abstinence contingencies. Abstinence, Methadone & Work Reinforcement participants provided significantly more urine samples negative for opiates (75% versus 54%) and cocaine (57% versus 32%) than Work Reinforcement participants. Methadone & Work Reinforcement participants provided significantly more cocaine-negative samples than Work Reinforcement participants (55% versus 32%). The therapeutic workplace can promote drug abstinence in out-of-treatment injection drug users. Clinical trial registration number: NCT01416584. Copyright © 2014 Elsevier Inc. All rights reserved.
Okombo, John; Chibale, Kelly
2017-07-18
New, safe and effective drugs are urgently needed to treat and control malaria and tuberculosis, which affect millions of people annually. However, financial return on investment in the poor settings where these diseases are mostly prevalent is very minimal to support market-driven drug discovery and development. Moreover, the imminent loss of therapeutic lifespan of existing therapies due to evolution and spread of drug resistance further compounds the urgency to identify novel effective drugs. However, the advent of new public-private partnerships focused on tropical diseases and the recent release of large data sets by pharmaceutical companies on antimalarial and antituberculosis compounds derived from phenotypic whole cell high throughput screening have spurred renewed interest and opened new frontiers in malaria and tuberculosis drug discovery. This Account recaps the existing challenges facing antimalarial and antituberculosis drug discovery, including limitations associated with experimental animal models as well as biological complexities intrinsic to the causative pathogens. We enlist various highlights from a body of work within our research group aimed at identifying and characterizing new chemical leads, and navigating these challenges to contribute toward the global drug discovery and development pipeline in malaria and tuberculosis. We describe a catalogue of in-house efforts toward deriving safe and efficacious preclinical drug development candidates via cell-based medicinal chemistry optimization of phenotypic whole-cell medium and high throughput screening hits sourced from various small molecule chemical libraries. We also provide an appraisal of target-based screening, as invoked in our laboratory for mechanistic evaluation of the hits generated, with particular focus on the enzymes within the de novo pyrimidine biosynthetic and hemoglobin degradation pathways, the latter constituting a heme detoxification process and an associated cysteine
International Nuclear Information System (INIS)
Cornejo Diaz, N.; Vergara Gil, A.; Jurado Vargas, M.
2010-01-01
The Monte Carlo method has become a valuable numerical laboratory framework in which to simulate complex physical systems. It is based on the generation of pseudo-random number sequences by numerical algorithms called random generators. In this work we assessed the suitability of different well-known random number generators for the simulation of gamma-ray spectrometry systems during efficiency calibrations. The assessment was carried out in two stages. The generators considered (Delphi's linear congruential, mersenne twister, XorShift, multiplier with carry, universal virtual array, and non-periodic logistic map based generator) were first evaluated with different statistical empirical tests, including moments, correlations, uniformity, independence of terms and the DIEHARD battery of tests. In a second step, an application-specific test was conducted by implementing the generators in our Monte Carlo program DETEFF and comparing the results obtained with them. The calculations were performed with two different CPUs, for a typical HpGe detector and a water sample in Marinelli geometry, with gamma-rays between 59 and 1800 keV. For the Non-periodic Logistic Map based generator, dependence of the most significant bits was evident. This explains the bias, in excess of 5%, of the efficiency values obtained with this generator. The results of the application-specific assessment and the statistical performance of the other algorithms studied indicate their suitability for the Monte Carlo simulation of gamma-ray spectrometry systems for efficiency calculations.
Díaz, N Cornejo; Gil, A Vergara; Vargas, M Jurado
2010-03-01
The Monte Carlo method has become a valuable numerical laboratory framework in which to simulate complex physical systems. It is based on the generation of pseudo-random number sequences by numerical algorithms called random generators. In this work we assessed the suitability of different well-known random number generators for the simulation of gamma-ray spectrometry systems during efficiency calibrations. The assessment was carried out in two stages. The generators considered (Delphi's linear congruential, mersenne twister, XorShift, multiplier with carry, universal virtual array, and non-periodic logistic map based generator) were first evaluated with different statistical empirical tests, including moments, correlations, uniformity, independence of terms and the DIEHARD battery of tests. In a second step, an application-specific test was conducted by implementing the generators in our Monte Carlo program DETEFF and comparing the results obtained with them. The calculations were performed with two different CPUs, for a typical HpGe detector and a water sample in Marinelli geometry, with gamma-rays between 59 and 1800 keV. For the Non-periodic Logistic Map based generator, dependence of the most significant bits was evident. This explains the bias, in excess of 5%, of the efficiency values obtained with this generator. The results of the application-specific assessment and the statistical performance of the other algorithms studied indicate their suitability for the Monte Carlo simulation of gamma-ray spectrometry systems for efficiency calculations. Copyright 2009 Elsevier Ltd. All rights reserved.
Kleinman, Alan
2016-12-20
The random mutation and natural selection phenomenon act in a mathematically predictable behavior, which when understood leads to approaches to reduce and prevent the failure of the use of these selection pressures when treating infections and cancers. The underlying principle to impair the random mutation and natural selection phenomenon is to use combination therapy, which forces the population to evolve to multiple selection pressures simultaneously that invoke the multiplication rule of probabilities simultaneously as well. Recently, it has been seen that combination therapy for the treatment of malaria has failed to prevent the emergence of drug-resistant variants. Using this empirical example and the principles of probability theory, the derivation of the equations describing this treatment failure is carried out. These equations give guidance as to how to use combination therapy for the treatment of cancers and infectious diseases and prevent the emergence of drug resistance. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Directory of Open Access Journals (Sweden)
Bilan Stepan
2017-01-01
Full Text Available To date, there are many tasks that are aimed at studying the dynamic changes in physical processes. These tasks do not give advance known result. The solution of such problems is based on the construction of a dynamic model of the object. Successful structural and functional implementation of the object model can give a positive result in time. This approach uses the task of constructing artificial biological objects. To solve such problems, pseudo-random number generators are used, which also find wide application for information protection tasks. Such generators should have good statistical properties and give a long repetition period of the generated pseudo-random bit sequence. This work is aimed at improving these characteristics. The paper considers the method of forming pseudo-random sequences of numbers on the basis of aperiodic cellular automata with two active cells. A pseudo-random number generator is proposed that generates three bit sequences. The first two bit sequences are formed by the corresponding two active cells in the cellular automaton. The third bit sequence is the result of executing the XOR function over the bits of the first two sequences and it has better characteristics compared to them. The use of cellular automata with two active cells allowed to improve the statistical properties of the formed bit sequence, as well as its repetition period. This is proved by using graphical tests for generators built based on cellular automata using the neighborhoods of von Neumann and Moore. The tests showed high efficiency of the generator based on an asynchronous cellular automaton with the neighborhood of Moore. The proposed pseudo-random number generators have good statistical properties, which makes it possible to use them in information security systems, as well as for simulation tasks of various dynamic processes.
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M. Varchola
2009-12-01
Full Text Available This paper deals with an evaluation platform for cryptographic True Random Number Generators (TRNGs based on the hardware implementation of statistical tests for FPGAs. It was developed in order to provide an automatic tool that helps to speed up the TRNG design process and can provide new insights on the TRNG behavior as it will be shown on a particular example in the paper. It enables to test sufﬁcient statistical properties of various TRNG designs under various working conditions on the ﬂy. Moreover, the tests are suitable to be embedded into cryptographic hardware products in order to recognize TRNG output of weak quality and thus increase its robustness and reliability. Tests are fully compatible with the FIPS 140 standard and are implemented by the VHDL language as an IP-Core for vendor independent FPGAs. A recent Flash based Actel Fusion FPGA was chosen for preliminary experiments. The Actel version of the tests possesses an interface to the Actel’s CoreMP7 softcore processor that is fully compatible with the industry standard ARM7TDMI. Moreover, identical tests suite was implemented to the Xilinx Virtex 2 and 5 in order to compare the performance of the proposed solution with the performance of already published one based on the same FPGAs. It was achieved 25% and 65% greater clock frequency respectively while consuming almost equal resources of the Xilinx FPGAs. On the top of it, the proposed FIPS 140 architecture is capable of processing one random bit per one clock cycle which results in 311.5 Mbps throughput for Virtex 5 FPGA.
Tandjung, Kenneth; Basalus, Mounir W.Z.; Muurman, Esther; Louwerenburg, Hans W.; van Houwelingen, Gert K.; Stoel, Martin G.; de Man, Frits H.A.F.; Jansen, Hanneke; Huisman, Jennifer; Linssen, Gerard C.M.; Droste, Herman T.; Nienhuis, Mark B.; von Birgelen, Clemens
2012-01-01
Background: First- and second-generation drug-eluting stents (DES) differ in coating materials, which may influence the incidence of periprocedural myocardial infarction (PMI). Objective: To compare the incidence of PMI between first- and second-generation DES, using the current Academic Research
McGinty, Emma E; Goldman, Howard H; Pescosolido, Bernice; Barry, Colleen L
2015-02-01
Despite significant advances in treatment, stigma and discrimination toward persons with mental illness and drug addiction have remained constant in past decades. Prior work suggests that portraying other stigmatized health conditions (i.e., HIV/AIDS) as treatable can improve public attitudes toward those affected. Our study compared the effects of vignettes portraying persons with untreated and symptomatic versus successfully treated and asymptomatic mental illness and drug addiction on several dimensions of public attitudes about these conditions. We conducted a survey-embedded randomized experiment using a national sample (N = 3940) from an online panel. Respondents were randomly assigned to read one of ten vignettes. Vignette one was a control vignette, vignettes 2-5 portrayed individuals with untreated schizophrenia, depression, prescription pain medication addiction and heroin addiction, and vignettes 6-10 portrayed successfully treated individuals with the same conditions. After reading the randomly assigned vignette, respondents answered questions about their attitudes related to mental illness or drug addiction. Portrayals of untreated and symptomatic schizophrenia, depression, and heroin addiction heightened negative public attitudes toward persons with mental illness and drug addiction. In contrast, portrayals of successfully treated schizophrenia, prescription painkiller addiction, and heroin addiction led to less desire for social distance, greater belief in the effectiveness of treatment, and less willingness to discriminate against persons with these conditions. Portrayal of persons with successfully treated mental illness and drug addiction is a promising strategy for reducing stigma and discrimination toward persons with these conditions and improving public perceptions of treatment effectiveness. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Paul C Langley
2016-11-01
Full Text Available Next generation sequencing (NGS has the potential to disrupt not only the accepted process of drug development but also the hurdles a drug manufacturer would be expected to face in securing formulary approval and a possible premium price for the new compound. The purpose of this commentary is to consider the role of NGS in this process, one which is characterized as a process of creative destruction, where adoption of NGS in personalized medicine sets in train a mechanism of incessant product and process review. A mechanism driven by continuing modifications and extensions to NGS platforms as our understanding of the role of mutations and mutation load in therapy choice expands. At the same time this mechanism has significant implications for the continued revision of treatment guidelines and their adoption of NGS as integral parts of the treatment pathway. There are, however, a number of unresolved issues which have to be addressed. These include the choice of NGS platform, barriers to integrating evidence to support NGS-based therapy choices in treatment guidelines, the implications of NGS for drug development and the modification or rejection of current trial structures, the integration of comorbid disease states and the standards that formulary committees should adopt to evaluate NGS claims. The overarching theme, however, is the need to invest in a robust and credible evidence base. While we are a long way from achieving this, the focus must be on putting claims for therapy choice forward that are credible, evaluable and replicable. Type: Commentary
A high-speed on-chip pseudo-random binary sequence generator for multi-tone phase calibration
Gommé, Liesbeth; Vandersteen, Gerd; Rolain, Yves
2011-07-01
An on-chip reference generator is conceived by adopting the technique of decimating a pseudo-random binary sequence (PRBS) signal in parallel sequences. This is of great benefit when high-speed generation of PRBS and PRBS-derived signals is the objective. The design implemented standard CMOS logic is available in commercial libraries to provide the logic functions for the generator. The design allows the user to select the periodicity of the PRBS and the PRBS-derived signals. The characterization of the on-chip generator marks its performance and reveals promising specifications.
A high-speed on-chip pseudo-random binary sequence generator for multi-tone phase calibration
International Nuclear Information System (INIS)
Gommé, Liesbeth; Vandersteen, Gerd; Rolain, Yves
2011-01-01
An on-chip reference generator is conceived by adopting the technique of decimating a pseudo-random binary sequence (PRBS) signal in parallel sequences. This is of great benefit when high-speed generation of PRBS and PRBS-derived signals is the objective. The design implemented standard CMOS logic is available in commercial libraries to provide the logic functions for the generator. The design allows the user to select the periodicity of the PRBS and the PRBS-derived signals. The characterization of the on-chip generator marks its performance and reveals promising specifications
Tutubalina, Elena; Nikolenko, Sergey
2017-01-01
Adverse drug reactions (ADRs) are an essential part of the analysis of drug use, measuring drug use benefits, and making policy decisions. Traditional channels for identifying ADRs are reliable but very slow and only produce a small amount of data. Text reviews, either on specialized web sites or in general-purpose social networks, may lead to a data source of unprecedented size, but identifying ADRs in free-form text is a challenging natural language processing problem. In this work, we propose a novel model for this problem, uniting recurrent neural architectures and conditional random fields. We evaluate our model with a comprehensive experimental study, showing improvements over state-of-the-art methods of ADR extraction.
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Elena Tutubalina
2017-01-01
Full Text Available Adverse drug reactions (ADRs are an essential part of the analysis of drug use, measuring drug use benefits, and making policy decisions. Traditional channels for identifying ADRs are reliable but very slow and only produce a small amount of data. Text reviews, either on specialized web sites or in general-purpose social networks, may lead to a data source of unprecedented size, but identifying ADRs in free-form text is a challenging natural language processing problem. In this work, we propose a novel model for this problem, uniting recurrent neural architectures and conditional random fields. We evaluate our model with a comprehensive experimental study, showing improvements over state-of-the-art methods of ADR extraction.
Burke, Valerie; Beilin, Lawrie J; Cutt, Hayley E; Mansour, Jacqueline; Wilson, Amy; Mori, Trevor A
2005-06-01
To assess effects of multifactorial lifestyle modification on antihypertensive drug needs in treated hypertensive individuals. Randomized controlled trial. Research studies unit. Overweight hypertensive patients, receiving one or two antihypertensive drugs, were recruited by advertising, and allocated randomly to a usual care group (controls; n = 118) or a lifestyle modification group (programme group; n = 123). A 4-month programme of weight loss, a low-sodium 'Dietary Approaches to Stop Hypertension'-type diet with added fish, physical activity and moderation of alcohol intake. After 4 months, if mean 24-h ambulatory blood pressure (ABP) was less than 135/85 mmHg, antihypertensive drugs were withdrawn over 4 weeks and long-term home blood pressure monitoring was begun. Antihypertensive drug requirements, ABP, weight, waist girth at 4 months and 1-year follow-up. Ninety control group and 102 programme group participants completed the study. Mean 24-h ABP changed after 4 months by -1.0/-0.3 +/- 0.5/0.4 mmHg in controls and -4.1/-2.1 +/- 0.7/0.5 mmHg with the lifestyle programme (P lifestyle modification in patients with treated hypertension reduced blood pressure in the short-term. Decreased central obesity persisted 1 year later and could reduce overall cardiovascular risk.
López-Muñoz, Francisco; Sim, Kang; Shen, Winston Wu; Huelves, Lorena; Moreno, Raquel; Molina, Juan de Dios; Rubio, Gabriel; Noriega, Concha; Pérez-Nieto, Miguel Ángel; Alamo, Cecilio
2014-01-01
A bibliometric study was carried out to ascertain the volume and impact of scientific literature published on second-generation antipsychotic drugs (SGAs) in Singapore from 1997 to 2011. A search of the EMBASE and MEDLINE databases was performed to identify articles originating from Singapore that included the descriptors 'atypic* antipsychotic*', 'second-generation antipsychotic*', 'clozapine', 'risperidone', 'olanzapine', 'ziprasidone', 'quetiapine', 'sertindole', 'aripiprazole', 'paliperidone', 'amisulpride', 'zotepine', 'asenapine', 'iloperidone', 'lurasidone', 'perospirone' and 'blonanserin' in the article titles. Certain bibliometric indicators of production and dispersion (e.g. Price's Law on the increase of scientific literature, and Bradford's Law) were applied, and the participation index of various countries was calculated. The bibliometric data was also correlated with some social and health data from Singapore, such as the total per capita expenditure on health and gross domestic expenditure on research and development. From 1997 to 2011, a total of 51 articles on SGAs in Singapore were published. Our results suggested non-fulfilment of Price's Law (r = 0.0648 after exponential adjustment vs. r = 0.2140 after linear adjustment). The most widely studied drugs were clozapine (21 articles), risperidone (16 articles) and olanzapine (8 articles). Division into Bradford zones yielded a nucleus occupied by the Journal of Clinical Psychopharmacology (6 articles) and the Singapore Medical Journal(4 articles). The analysed material was published in a total of 30 journals, with the majority from six journals. Four of these six journals have an impact factor greater than 2. Publications on SGAs in Singapore are still too few to confirm an exponential growth of scientific literature.
Horimatsu, Takahiro; Sano, Yasushi; Tanaka, Shinji; Kawamura, Takuji; Saito, Shoichi; Iwatate, Mineo; Oka, Shiro; Uno, Koji; Yoshimura, Kenichi; Ishikawa, Hideki; Muto, Manabu; Tajiri, Hisao
2015-07-01
Previous studies have yielded conflicting results on the colonic polyp detection rate with narrow-band imaging (NBI) compared with white-light imaging (WLI). We compared the mean number of colonic polyps detected per patient for NBI versus WLI using a next-generation NBI system (EVIS LUCERA ELITE; Olympus Medical Systems) used with standard-definition (SD) colonoscopy and wide-angle (WA) colonoscopy. this study is a 2 × 2 factorial, prospective, multicenter randomized controlled trial. this study was conducted at five academic centers in Japan. patients were allocated to one of four groups: (1) WLI with SD colonoscopy (H260AZI), (2) NBI with SD colonoscopy (H260AZI), (3) WLI with WA colonoscopy (CF-HQ290), and (4) NBI with WA colonoscopy (CF-HQ290). the mean numbers of polyps detected per patient were compared between the four groups: WLI with/without WA colonoscopy and NBI with/without WA colonoscopy. Of the 454 patients recruited, 431 patients were enrolled. The total numbers of polyps detected by WLI with SD, NBI with SD, WLI with WA, and NBI with WA were 164, 176, 188, and 241, respectively. The mean number of polyps detected per patient was significantly higher in the NBI group than in the WLI group (2.01 vs 1.56; P = 0.032). The rate was not higher in the WA group than in the SD group (1.97 vs 1.61; P = 0.089). Although WA colonoscopy did not improve the polyp detection, next-generation NBI colonoscopy represents a significant improvement in the detection of colonic polyps.
Random mandatory drugs testing of prisoners: a biassed means of gathering information.
Gore, S M; Bird, A G; Strang, J S
1999-01-01
Our objective was to develop and test a methodology for inferring the percentage of prisoners currently using opiates from the percentage of prisoners testing positive for opiates in random mandatory drugs testing (rMDT). The study used results from Willing Anonymous Salivary HIV (WASH) studies (1994-6) in six adult Scottish prisons, and surveys (1994-5 and 1997) in 14 prisons in England and Wales. For Scottish prisons, the percentage of prisoners currently using opiates was determined by assuming, with varying empirical support, that: current users of opiates in prison were 1.5 times as many as current inside-injectors; and current inside-injectors were 0.75 times as many as ever injectors in prison. We also assumed that current inside-users' frequency of use of opiates (by any route) was equal to the frequency of inside-injecting by current inside-injectors in Aberdeen and Lowmoss Prisons in 1996, namely six times in 4 weeks. We assumed that some scheduling of heroin-use prior to weekends takes place, so that only 50% of current inside-users of opiates would test positive for opiates in rMDT: these assumptions allow us to arrive at WASH-based expectations for the total percentage of prisoners testing positive for opiates in rMDT. For England and Wales, a multiplier of 118/68 was applied which was derived from prisoners' interviews, to convert the results from ever inside-injectors, as determined by WASH studies, to the percentage of current inside users of opiates. We made the same assumptions on frequency of inside-use of opiates as in dealing with the Scottish results. We expected 202.7 opiate positive results in April to September 1997 in rMDTs at six adult prisons in Scotland, 226 were observed. We expected 227.0 at a set of 13 adult prisons and one other in England and Wales; 211 were observed. Further testing of the methodology for prisons in England and Wales will be possible when 1997 WASH data are released. So far, the methodology has performed well
Siebert, Johan N; Ehrler, Frederic; Lovis, Christian; Combescure, Christophe; Haddad, Kevin; Gervaix, Alain; Manzano, Sergio
2017-08-22
prescription by the physician to drug delivery by the nurse in each allocation group. TDD includes TDP. Stress level during the resuscitation scenario will be assessed for each participant by questionnaire and recorded by the heart rate monitor of a fitness watch. The study is formatted according to the Consolidated Standards of Reporting Trials Statement for Randomized Controlled Trials of Electronic and Mobile Health Applications and Online TeleHealth (CONSORT-EHEALTH) and the Reporting Guidelines for Health Care Simulation Research. Enrollment and data analysis started in March 2017. We anticipate the intervention will be completed in late 2017, and study results will be submitted in early 2018 for publication expected in mid-2018. Results will be reported in line with recommendations from CONSORT-EHEALTH and the Reporting Guidelines for Health Care Simulation Research . This paper describes the protocol used for a clinical trial assessing the impact of a mobile device app to reduce the rate of medication errors, time to drug preparation, and time to drug delivery during pediatric resuscitation. As research in this area is scarce, results generated from this study will be of great importance and might be sufficient to change and improve the pediatric emergency care practice. ClinicalTrials.gov NCT03021122; https://clinicaltrials.gov/ct2/show/NCT03021122 (Archived by WebCite at http://www.webcitation.org/6nfVJ5b4R). ©Johan N Siebert, Frederic Ehrler, Christian Lovis, Christophe Combescure, Kevin Haddad, Alain Gervaix, Sergio Manzano. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 22.08.2017.
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Katsanos, Konstantinos, E-mail: katsanos@med.upatras.gr [NHS Foundation Trust, King' s Health Partners, Department of Interventional Radiology, Guy' s and St. Thomas' Hospitals (United Kingdom); Spiliopoulos, Stavros [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece); Diamantopoulos, Athanasios [NHS Foundation Trust, King' s Health Partners, Department of Interventional Radiology, Guy' s and St. Thomas' Hospitals (United Kingdom); Karnabatidis, Dimitris [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece); Sabharwal, Tarun [NHS Foundation Trust, King' s Health Partners, Department of Interventional Radiology, Guy' s and St. Thomas' Hospitals (United Kingdom); Siablis, Dimitris [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece)
2013-06-15
IntroductionDrug-eluting stents (DES) have been proposed for the treatment of infrapopliteal arterial disease. We performed a systematic review to provide a qualitative analysis and quantitative data synthesis of randomized controlled trials (RCTs) assessing infrapopliteal DES.Materials and MethodsPubMed (Medline), EMBASE (Excerpta Medical Database), AMED (Allied and Complementary medicine Database), Scopus, CENTRAL (Cochrane Central Register of Controlled Trials), online content, and abstract meetings were searched in September 2012 for eligible RCTs according to the preferred reporting items for systematic reviews and meta-analyses selection process. Risk of bias was assessed using the Cochrane Collaboration's tool. Primary endpoint was primary patency defined as absence of {>=}50 % vessel restenosis at 1 year. Secondary outcome measures included patient survival, limb amputations, change of Rutherford-Becker class, target lesion revascularization (TLR) events, complete wound healing, and event-free survival at 1 year. Risk ratio (RRs) were calculated using the Mantel-Haenszel fixed effects model, and number-needed-to-treat values are reported.ResultsThree RCTs involving 501 patients with focal infrapopliteal lesions were analyzed (YUKON-BTX, DESTINY, and ACHILLES trials). All three RCTs included relatively short and focal infrapopliteal lesions. At 1 year, there was clear superiority of infrapopliteal DES compared with control treatments in terms of significantly higher primary patency (80.0 vs. 58.5 %; pooled RR = 1.37, 95 % confidence interval [CI] = 1.18-1.58, p < 0.0001; number-needed-to-treat (NNT) value = 4.8), improvement of Rutherford-Becker class (79.0 vs. 69.6 %; pooled RR = 1.13, 95 % CI = 1.002-1.275, p = 0.045; NNT = 11.1), decreased TLR events (9.9 vs. 22.0 %; pooled RR = 0.45, 95 % CI = 0.28-0.73, p = 0.001; NNT = 8.3), improved wound healing (76.8 vs. 59.7 %; pooled RR = 1.29, 95 % CI = 1.02-1.62, p = 0.04; NNT = 5.9), and better overall
International Nuclear Information System (INIS)
Katsanos, Konstantinos; Spiliopoulos, Stavros; Diamantopoulos, Athanasios; Karnabatidis, Dimitris; Sabharwal, Tarun; Siablis, Dimitris
2013-01-01
IntroductionDrug-eluting stents (DES) have been proposed for the treatment of infrapopliteal arterial disease. We performed a systematic review to provide a qualitative analysis and quantitative data synthesis of randomized controlled trials (RCTs) assessing infrapopliteal DES.Materials and MethodsPubMed (Medline), EMBASE (Excerpta Medical Database), AMED (Allied and Complementary medicine Database), Scopus, CENTRAL (Cochrane Central Register of Controlled Trials), online content, and abstract meetings were searched in September 2012 for eligible RCTs according to the preferred reporting items for systematic reviews and meta-analyses selection process. Risk of bias was assessed using the Cochrane Collaboration’s tool. Primary endpoint was primary patency defined as absence of ≥50 % vessel restenosis at 1 year. Secondary outcome measures included patient survival, limb amputations, change of Rutherford–Becker class, target lesion revascularization (TLR) events, complete wound healing, and event-free survival at 1 year. Risk ratio (RRs) were calculated using the Mantel–Haenszel fixed effects model, and number-needed-to-treat values are reported.ResultsThree RCTs involving 501 patients with focal infrapopliteal lesions were analyzed (YUKON-BTX, DESTINY, and ACHILLES trials). All three RCTs included relatively short and focal infrapopliteal lesions. At 1 year, there was clear superiority of infrapopliteal DES compared with control treatments in terms of significantly higher primary patency (80.0 vs. 58.5 %; pooled RR = 1.37, 95 % confidence interval [CI] = 1.18–1.58, p < 0.0001; number-needed-to-treat (NNT) value = 4.8), improvement of Rutherford–Becker class (79.0 vs. 69.6 %; pooled RR = 1.13, 95 % CI = 1.002–1.275, p = 0.045; NNT = 11.1), decreased TLR events (9.9 vs. 22.0 %; pooled RR = 0.45, 95 % CI = 0.28–0.73, p = 0.001; NNT = 8.3), improved wound healing (76.8 vs. 59.7 %; pooled RR = 1.29, 95 % CI = 1.02–1.62, p = 0.04; NNT = 5.9), and better
Halton, John H.
1989-09-01
A class of families of linear congruential pseudo-random sequences is defined, for which it is possible to branch at any event without changing the sequence of random numbers used in the original random walk and for which the sequences in different branches show properties analogous to mutual statistical independence. This is a hitherto unavailable, and computationally desirable, tool.
Can social capital be intentionally generated? a randomized trial from rural South Africa.
Pronyk, Paul M; Harpham, Trudy; Busza, Joanna; Phetla, Godfrey; Morison, Linda A; Hargreaves, James R; Kim, Julia C; Watts, Charlotte H; Porter, John D
2008-11-01
While much descriptive research has documented positive associations between social capital and a range of economic, social and health outcomes, there have been few intervention studies to assess whether social capital can be intentionally generated. We conducted an intervention in rural South Africa that combined group-based microfinance with participatory gender and HIV training in an attempt to catalyze changes in solidarity, reciprocity and social group membership as a means to reduce women's vulnerability to intimate partner violence and HIV. A cluster randomized trial was used to assess intervention effects among eight study villages. In this paper, we examined effects on structural and cognitive social capital among 845 participants and age and wealth matched women from households in comparison villages. This was supported by a diverse portfolio of qualitative research. After two years, adjusted effect estimates indicated higher levels of structural and cognitive social capital in the intervention group than the comparison group, although confidence intervals were wide. Qualitative research illustrated the ways in which economic and social gains enhanced participation in social groups, and the positive and negative dynamics that emerged within the program. There were numerous instances where individuals and village loan centres worked to address community concerns, both working through existing social networks, and through the establishment of new partnerships with local leadership structures, police, the health sector and NGOs. This is among the first experimental trials suggesting that social capital can be exogenously strengthened. The implications for community interventions in public health are further explored.
Implementation of a RANLUX Based Pseudo-Random Number Generator in FPGA Using VHDL and Impulse C
Agnieszka Dąbrowska-Boruch; Grzegorz Gancarczyk; Kazimierz Wiatr
2014-01-01
Monte Carlo simulations are widely used e.g. in the field of physics and molecular modelling. The main role played in these is by the high performance random number generators, such as RANLUX or MERSSENE TWISTER. In this paper the authors introduce the world's first implementation of the RANLUX algorithm on an FPGA platform for high performance computing purposes. A significant speed-up of one generator instance over 60 times, compared with a graphic card based solution, can be noticed. Compa...
Courtney, Colleen M; Goodman, Samuel M; Nagy, Toni A; Levy, Max; Bhusal, Pallavi; Madinger, Nancy E; Detweiler, Corrella S; Nagpal, Prashant; Chatterjee, Anushree
2017-10-01
The rise of multidrug-resistant (MDR) bacteria is a growing concern to global health and is exacerbated by the lack of new antibiotics. To treat already pervasive MDR infections, new classes of antibiotics or antibiotic adjuvants are needed. Reactive oxygen species (ROS) have been shown to play a role during antibacterial action; however, it is not yet understood whether ROS contribute directly to or are an outcome of bacterial lethality caused by antibiotics. We show that a light-activated nanoparticle, designed to produce tunable flux of specific ROS, superoxide, potentiates the activity of antibiotics in clinical MDR isolates of Escherichia coli , Salmonella enterica , and Klebsiella pneumoniae . Despite the high degree of antibiotic resistance in these isolates, we observed a synergistic interaction between both bactericidal and bacteriostatic antibiotics with varied mechanisms of action and our superoxide-producing nanoparticles in more than 75% of combinations. As a result of this potentiation, the effective antibiotic concentration of the clinical isolates was reduced up to 1000-fold below their respective sensitive/resistant breakpoint. Further, superoxide-generating nanoparticles in combination with ciprofloxacin reduced bacterial load in epithelial cells infected with S. enterica serovar Typhimurium and increased Caenorhabditis elegans survival upon infection with S. enterica serovar Enteriditis, compared to antibiotic alone. This demonstration highlights the ability to engineer superoxide generation to potentiate antibiotic activity and combat highly drug-resistant bacterial pathogens.
Analyzing user-generated online content for drug discovery: development and use of MedCrawler.
Helfenstein, Andreas; Tammela, Päivi
2017-04-15
Ethnopharmacology, or the scientific validation of traditional medicine, is a respected starting point in drug discovery. Home remedies and traditional use of plants are still widespread, also in Western societies. Instead of perusing ancient pharmacopeias, we developed MedCrawler, which we used to analyze blog posts for mentions of home remedies and their applications. This method is free and accessible from the office computer. We developed MedCrawler, a data mining tool for analyzing user-generated blog posts aiming to find modern 'traditional' medicine or home remedies. It searches user-generated blog posts and analyzes them for correlations between medically relevant terms. We also present examples and show that this method is capable of delivering both scientifically validated uses as well as not so well documented applications, which might serve as a starting point for follow-up research. Source code is available on GitHub at {{ https://github.com/a-hel/medcrawler }}. paivi.tammela@helsinki.fi. Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com
International Nuclear Information System (INIS)
Procassini, R J; Beck, B R
2004-01-01
It might be assumed that use of a ''high-quality'' random number generator (RNG), producing a sequence of ''pseudo random'' numbers with a ''long'' repetition period, is crucial for producing unbiased results in Monte Carlo particle transport simulations. While several theoretical and empirical tests have been devised to check the quality (randomness and period) of an RNG, for many applications it is not clear what level of RNG quality is required to produce unbiased results. This paper explores the issue of RNG quality in the context of parallel, Monte Carlo transport simulations in order to determine how ''good'' is ''good enough''. This study employs the MERCURY Monte Carlo code, which incorporates the CNPRNG library for the generation of pseudo-random numbers via linear congruential generator (LCG) algorithms. The paper outlines the usage of random numbers during parallel MERCURY simulations, and then describes the source and criticality transport simulations which comprise the empirical basis of this study. A series of calculations for each test problem in which the quality of the RNG (period of the LCG) is varied provides the empirical basis for determining the minimum repetition period which may be employed without producing a bias in the mean integrated results
Directory of Open Access Journals (Sweden)
R.-D. Hofheinz
2016-01-01
Full Text Available Background. In metastatic colorectal cancer (mCRC, continuing antiangiogenic drugs beyond progression might provide clinical benefit. We synthesized the available evidence in a meta-analysis. Patients and Methods. We conducted a meta-analysis of studies investigating the use of antiangiogenic drugs beyond progression. Eligible studies were randomized phase II/III trials. Primary endpoints were overall survival (OS and progression-free survival (PFS. Secondary endpoints were the impact of continuing antiangiogenic drugs (i in subgroups, (ii in different types of compounds targeting the VEGF-axis (monoclonal antibodies versus tyrosine kinase inhibitors, and (iii on remission rates and prevention of progression. Results. Eight studies (3,668 patients were included. Continuing antiangiogenic treatment beyond progression significantly improved PFS (HR 0.64; 95%-CI, 0.55–0.75 and OS (HR 0.83; 95%-CI, 0.76–0.89. PFS was significantly improved in all subgroups with comparable HR. OS was improved in all subgroups stratified by age, gender, and ECOG status. The rate of patients achieving at least stable disease was improved with an OR of 2.25 (95%-CI, 1.41–3.58. Conclusions. This analysis shows a significant PFS and OS benefit as well as a benefit regarding disease stabilization when using antiangiogenic drugs beyond progression in mCRC. Future studies should focus on the optimal sequence of administering antiangiogenic drugs.
Wang, Xiaojie; Zheng, Hong; Shou, Tao; Tang, Chunming; Miao, Kun; Wang, Ping
2017-03-29
Osteosarcoma is the most common malignant bone tumour. Due to the high metastasis rate and drug resistance of this disease, multi-drug regimens are necessary to control tumour cells at various stages of the cell cycle, eliminate local or distant micrometastases, and reduce the emergence of drug-resistant cells. Many adjuvant chemotherapy protocols have shown different efficacies and controversial results. Therefore, we classified the types of drugs used for adjuvant chemotherapy and evaluated the differences between single- and multi-drug chemotherapy regimens using network meta-analysis. We searched electronic databases, including PubMed (MEDLINE), EmBase, and the Cochrane Library, through November 2016 using the keywords "osteosarcoma", "osteogenic sarcoma", "chemotherapy", and "random*" without language restrictions. The major outcome in the present analysis was progression-free survival (PFS), and the secondary outcome was overall survival (OS). We used a random effect network meta-analysis for mixed multiple treatment comparisons. We included 23 articles assessing a total of 5742 patients in the present systematic review. The analysis of PFS indicated that the T12 protocol (including adriamycin, bleomycin, cyclophosphamide, dactinomycin, methotrexate, cisplatin) plays a more critical role in osteosarcoma treatment (surface under the cumulative ranking (SUCRA) probability 76.9%), with a better effect on prolonging the PFS of patients when combined with ifosfamide (94.1%) or vincristine (81.9%). For the analysis of OS, we separated the regimens to two groups, reflecting the disconnection. The T12 protocol plus vincristine (94.7%) or the removal of cisplatinum (89.4%) is most likely the best regimen. We concluded that multi-drug regimens have a better effect on prolonging the PFS and OS of osteosarcoma patients, and the T12 protocol has a better effect on prolonging the PFS of osteosarcoma patients, particularly in combination with ifosfamide or vincristine
Directory of Open Access Journals (Sweden)
Pavel Skok
2002-06-01
Full Text Available Background. The explanation of peptic ulcer etiology has changed significantly in the past decade after the clarification of the significance of Helicobacter pylori infection.Aim. To evaluate the effectiveness of Helicobacter pylori eradication in patients with hemorrhaging peptic ulcer and patients with peptic ulcer without complications.Study ethics. The study was approved in 1998 by the Medical Ethics Committee of the Republic of Slovenia (No. 90/09/98.Type of study. Prospective, controlled and randomized study, carried out between 1998–2000.Patients and methods. The study included 80 patients (50 male and 30 female, av.age 57.5 years, SD ± 17.1, range 22– 80 in which endoscopy confirmed hemorrhage from peptic ulcer of stomach or duodenum and Helicobacter pylori infection. In all cases endoscopic hemostasis was performed: injection sclerotherapy with diluted adrenalin 1:10,000 and 1% polidocanol or argon plasma coagulation. The control group was made up of 80 patients (50 male and 30 female, av.age 56.8 years, SD ± 16.8, range 19–80 with peptic ulcer of stomach or duodenum and Helicobacter pylori infection. Infection was confirmed by a rapid urease test and histologic investigation of the gastric mucosa. In all cases the recommended drug combinations were used in the treatment of the infection: a proton pump inhibitor, omeprazol (4 weeks, and combination of antibiotics, claritromycin and metronidazole or with regard to the antibiogram (1 week. The therapeutic success was ascertained endoscopically four weeks after inclusion in the study. Infection eradication was confirmed by the rapid urease test and histologic investigation of the gastric mucosa.Results. Four weeks after inclusion in the study the success of infection eradication was 92.5% in the study group, in the control group it was 91.3% (p > 0.05. In 6 patients (7.5%, 6/ 80 from the study group and in 7 (8.8%, 7/80 from the control group we introduced a replacement treatment
A Randomized Trial of Employment-Based Reinforcement of Cocaine Abstinence in Injection Drug Users
Silverman, Kenneth; Wong, Conrad J; Needham, Mick; Diemer, Karly N; Knealing, Todd; Crone-Todd, Darlene; Fingerhood, Michael; Nuzzo, Paul; Kolodner, Kenneth
2007-01-01
High-magnitude and long-duration abstinence reinforcement can promote drug abstinence but can be difficult to finance. Employment may be a vehicle for arranging high-magnitude and long-duration abstinence reinforcement. This study determined if employment-based abstinence reinforcement could increase cocaine abstinence in adults who inject drugs and use cocaine during methadone treatment. Participants could work 4 hr every weekday in a workplace where they could earn about $10.00 per hour in ...
DEFF Research Database (Denmark)
Petersen, Susanne G; Beyer, Nina; Hansen, Mette
2011-01-01
Petersen SG, Beyer N, Hansen M, Holm L, Aagaard P, Mackey AL, Kjaer M. Nonsteroidal anti-inflammatory drug or glucosamine reduced pain and improved muscle strength with resistance training in a randomized controlled trial of knee osteoarthritis patients.......Petersen SG, Beyer N, Hansen M, Holm L, Aagaard P, Mackey AL, Kjaer M. Nonsteroidal anti-inflammatory drug or glucosamine reduced pain and improved muscle strength with resistance training in a randomized controlled trial of knee osteoarthritis patients....
Lopez-Gonzalez, Elena; Herdeiro, Maria T; Piñeiro-Lamas, María; Figueiras, Adolfo
2015-02-01
The yellow-card scheme continues to be one of the principal methods for signal generation in pharmacovigilance. Nevertheless, under-reporting, one of its disadvantages, delays alert signals and has a negative influence on public health. Educational interventions in pharmacovigilance may have a positive impact on the spontaneous reporting of adverse drug reactions (ADRs). To assess the duration of the effect and effectiveness of an educational intervention in pharmacovigilance designed to improve ADR reporting in a robust pharmacovigilance system. A spatial, cluster randomized controlled trial was conducted covering all National Health System physicians in the northwest of Spain and targeting those who were actively engaged in clinical practice (n = 7,498). Of these, 2,120 were assigned in three spatial clusters to the intervention group (six hospitals and 138 primary care centers) and 3,614 in four clusters to the control group (seven hospitals and 267 primary care centers). The educational intervention consisted of two complementary approaches--one active (group sessions), the other passive (educational material, reporting form)-implemented from November 2007 to December 2008, with a follow-up period of 8 months. Intervention participation was 53.7 % in a hospital setting and 60.5 % in primary care settings. ADR reporting in the intervention group increased by 65.4 % (95 % confidence interval [CI]: 8.2-153.4) across the follow-up. The ADR reporting rate per 1,000 physicians/year in the intervention group rose from 28.1 to 39.6 following the intervention (51.7 and 27.4 in the first and second 4-month period, respectively). For the intervention group, relative risk (RR) was 2.31 (95 % CI: 1.46-3.68) and 1.04 (95 % CI: 0.61-1.77) in the first and second 4-month period, respectively adjusted to baseline values. There was an increase in unexpected ADR reporting (RR 2.06, 95 % CI 1.19-3.55). Pharmacovigilance educational interventions that have proved effective can be
Strenge, Hans; Lesmana, Cokorda Bagus Jaya; Suryani, Luh Ketut
2009-08-01
Verbal random number generation is a procedurally simple task to assess executive function and appears ideally suited for the use under diverse settings in cross-cultural research. The objective of this study was to examine ethnic group differences between young adults in Bali (Indonesia) and Kiel (Germany): 50 bilingual healthy students, 30 Balinese and 20 Germans, attempted to generate a random sequence of the digits 1 to 9. In Balinese participants, randomization was done in Balinese (native language L1) and Indonesian (first foreign language L2), in German subjects in the German (L1) and English (L2) languages. 10 of 30 Balinese (33%), but no Germans, were unable to inhibit habitual counting in more than half of the responses. The Balinese produced significantly more nonrandom responses than the Germans with higher rates of counting and significantly less occurrence of the digits 2 and 3 in L1 compared with L2. Repetition and cycling behavior did not differ between the four languages. The findings highlight the importance of taking into account culture-bound psychosocial factors for Balinese individuals when administering and interpreting a random number generation test.
Directory of Open Access Journals (Sweden)
Cecchini Marie A
2008-03-01
Full Text Available Abstract Background An estimated 13 million youths aged 12 to 17 become involved with alcohol, tobacco and other drugs annually. The number of 12- to 17-year olds abusing controlled prescription drugs increased an alarming 212 percent between 1992 and 2003. For many youths, substance abuse precedes academic and health problems including lower grades, higher truancy, drop out decisions, delayed or damaged physical, cognitive, and emotional development, or a variety of other costly consequences. For thirty years the Narconon program has worked with schools and community groups providing single educational modules aimed at supplementing existing classroom-based prevention activities. In 2004, Narconon International developed a multi-module, universal prevention curriculum for high school ages based on drug abuse etiology, program quality management data, prevention theory and best practices. We review the curriculum and its rationale and test its ability to change drug use behavior, perceptions of risk/benefits, and general knowledge. Methods After informed parental consent, approximately 1000 Oklahoma and Hawai'i high school students completed a modified Center for Substance Abuse Prevention (CSAP Participant Outcome Measures for Discretionary Programs survey at three testing points: baseline, one month later, and six month follow-up. Schools assigned to experimental conditions scheduled the Narconon curriculum between the baseline and one-month follow-up test; schools in control conditions received drug education after the six-month follow-up. Student responses were analyzed controlling for baseline differences using analysis of covariance. Results At six month follow-up, youths who received the Narconon drug education curriculum showed reduced drug use compared with controls across all drug categories tested. The strongest effects were seen in all tobacco products and cigarette frequency followed by marijuana. There were also significant
Latka, Mary H; Hagan, Holly; Kapadia, Farzana; Golub, Elizabeth T; Bonner, Sebastian; Campbell, Jennifer V; Coady, Micaela H; Garfein, Richard S; Pu, Minya; Thomas, Dave L; Thiel, Thelma K; Strathdee, Steffanie A
2008-05-01
We evaluated the efficacy of a peer-mentoring behavioral intervention designed to reduce risky distributive injection practices (e.g., syringe lending, unsafe drug preparation) among injection drug users with hepatitis C virus (HCV) infection. A randomized trial with a time-equivalent attention-control group was conducted among 418 HCV-positive injection drug users aged 18 to 35 years in 3 US cities. Participants reported their injection-related behaviors at baseline and at 3- and 6-month follow-ups. Compared with the control group, intervention-group participants were less likely to report distributive risk behaviors at 3 months (odds ratio [OR]=0.46; 95% confidence interval [CI]=0.27, 0.79) and 6 months (OR=0.51; 95% CI=0.31, 0.83), a 26% relative risk reduction, but were no more likely to cite their HCV-positive status as a reason for refraining from syringe lending. Effects were strongest among intervention-group participants who had known their HCV-positive status for at least 6 months. Peer mentoring and self-efficacy were significantly increased among intervention-group participants, and intervention effects were mediated through improved self-efficacy. This behavioral intervention reduced unsafe injection practices that may propagate HCV among injection drug users.
Abdolmaleki, Azizeh; Ghasemi, Jahan B
2017-01-01
Finding high quality beginning compounds is a critical job at the start of the lead generation stage for multi-target drug discovery (MTDD). Designing hybrid compounds as selective multitarget chemical entity is a challenge, opportunity, and new idea to better act against specific multiple targets. One hybrid molecule is formed by two (or more) pharmacophore group's participation. So, these new compounds often exhibit two or more activities going about as multi-target drugs (mtdrugs) and may have superior safety or efficacy. Application of integrating a range of information and sophisticated new in silico, bioinformatics, structural biology, pharmacogenomics methods may be useful to discover/design, and synthesis of the new hybrid molecules. In this regard, many rational and screening approaches have followed by medicinal chemists for the lead generation in MTDD. Here, we review some popular lead generation approaches that have been used for designing multiple ligands (DMLs). This paper focuses on dual- acting chemical entities that incorporate a part of two drugs or bioactive compounds to compose hybrid molecules. Also, it presents some of key concepts and limitations/strengths of lead generation methods by comparing combination framework method with screening approaches. Besides, a number of examples to represent applications of hybrid molecules in the drug discovery are included. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Ma, Li-xin; Wang, Yu-yi; Li, Xin-xue; Liu, Jian-ping
2012-03-01
Randomized controlled trial (RCT) is considered as the gold standard for the efficacy assessment of medicines. With the increasing number of Chinese patent drugs for treatment of type 2 diabetes, the methodology of post-marketing RCTs evaluating the efficacy and specific effect has become more important. To investigate post-marketing Chinese patent drugs for treatment of type 2 diabetes, as well as the methodological quality of post-marketing RCTs. Literature was searched from the books of Newly Compiled Traditional Chinese Patent Medicine and Chinese Pharmacopeia, the websites of the State Food and Drug Administration and the Ministry of Human Resources and Social Security of the People's Republic of China, China National Knowledge Infrastructure Database, Chongqing VIP Chinese Science and Technology Periodical Database, Chinese Biomedical Database (SinoMed) and Wanfang Data. The time period for searching ran from the commencement of each database to August 2011. RCTs of post-marketing Chinese patent drugs for treatment of type 2 diabetes with intervention course no less than 3 months. Two authors independently evaluated the research quality of the RCTs by the checklist of risk bias assessment and the data collection forms based on the CONSORT Statement. Independent double data-extraction was performed. The authors identified a total of 149 Chinese patent drugs for treatment of type 2 diabetes. According to different indicative syndromes, the Chinese patent drugs can be divided into the following types, namely, yin deficiency and interior heat (n=48, 32%), dual deficiency of qi and yin (n=58, 39%) and dual deficiency of qi and yin combined with blood stasis (n=22, 15%). A total of 41 RCTs meeting the inclusion criteria were included. Neither multicenter RCTs nor endpoint outcome reports were found. Risk bias analysis showed that 81% of the included studies reported randomization for grouping without sequence generation, 98% of these studies did not report
Franchi, Carlotta; Tettamanti, Mauro; Djade, Codjo Dgnefa; Pasina, Luca; Mannucci, Pier Mannuccio; Onder, Graziano; Gussoni, Gualberto; Manfellotto, Dario; Bonassi, Stefano; Salerno, Francesco; Nobili, Alessandro
2016-07-01
The aim of the study was to evaluate the effect of an e-learning educational program meant to foster the quality of drug prescription in hospitalized elderly patients. Twenty geriatric and internal medicine wards were randomized to intervention (e-learning educational program) or control (basic geriatric pharmacology notions). Logistic regression analysis was used in order to assess the effect of the intervention on the use of potentially inappropriate medication (PIM, primary outcome) at hospital discharge. Secondary outcomes were a reduced prevalence of at least one potential drug-drug interaction (DDI) and potentially severe DDI at discharge. Mortality rate and incidence of re-hospitalizations were other secondary outcomes assessed at the 12-month follow-up. A total of 697 patients (347 in the intervention and 350 in the control arms) were enrolled. No difference in the prevalence of PIM at discharge was found between arms (OR 1.29 95%CI 0.87-1.91). We also found no decrease in the prevalence of DDI (OR 0.67 95%CI 0.34-1.28) and potentially severe DDI (OR 0.86 95%CI 0.63-1.15) at discharge, nor in mortality rates and incidence of re-hospitalization at 12-month follow-up. This e-learning educational program had no clear effect on the quality of drug prescription and clinical outcomes in hospitalized elderly patients. Given the high prevalence of PIMs and potential DDIs recorded in the frame of this study, other approaches should be developed in order to improve the quality of drug prescription in this population. © 2016 The British Pharmacological Society.
Energy Technology Data Exchange (ETDEWEB)
Wang, Yonggang, E-mail: wangyg@ustc.edu.cn; Hui, Cong; Liu, Chong; Xu, Chao [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)
2016-04-15
The contribution of this paper is proposing a new entropy extraction mechanism based on sampling phase jitter in ring oscillators to make a high throughput true random number generator in a field programmable gate array (FPGA) practical. Starting from experimental observation and analysis of the entropy source in FPGA, a multi-phase sampling method is exploited to harvest the clock jitter with a maximum entropy and fast sampling speed. This parametrized design is implemented in a Xilinx Artix-7 FPGA, where the carry chains in the FPGA are explored to realize the precise phase shifting. The generator circuit is simple and resource-saving, so that multiple generation channels can run in parallel to scale the output throughput for specific applications. The prototype integrates 64 circuit units in the FPGA to provide a total output throughput of 7.68 Gbps, which meets the requirement of current high-speed quantum key distribution systems. The randomness evaluation, as well as its robustness to ambient temperature, confirms that the new method in a purely digital fashion can provide high-speed high-quality random bit sequences for a variety of embedded applications.
Pettigrew, Jonathan; Miller-Day, Michelle; Krieger, Janice L.; Zhou, Jiangxiu; Hecht, Michael L.
2014-01-01
Random assignment to groups is the foundation for scientifically rigorous clinical trials. But assignment is challenging in group randomized trials when only a few units (schools) are assigned to each condition. In the DRSR project, we assigned 39 rural Pennsylvania and Ohio schools to three conditions (rural, classic, control). But even with 13 schools per condition, achieving pretest equivalence on important variables is not guaranteed. We collected data on six important school-level variables: rurality, number of grades in the school, enrollment per grade, percent white, percent receiving free/assisted lunch, and test scores. Key to our procedure was the inclusion of school-level drug use data, available for a subset of the schools. Also, key was that we handled the partial data with modern missing data techniques. We chose to create one composite stratifying variable based on the seven school-level variables available. Principal components analysis with the seven variables yielded two factors, which were averaged to form the composite inflate-suppress (CIS) score which was the basis of stratification. The CIS score was broken into three strata within each state; schools were assigned at random to the three program conditions from within each stratum, within each state. Results showed that program group membership was unrelated to the CIS score, the two factors making up the CIS score, and the seven items making up the factors. Program group membership was not significantly related to pretest measures of drug use (alcohol, cigarettes, marijuana, chewing tobacco; smallest p>.15), thus verifying that pretest equivalence was achieved. PMID:23722619
Kwok, Charlotte S; Johnson, Emily L; Krauss, Gregory L
2017-11-01
Four "third-generation" antiepileptic drugs (AEDs) were approved for adjunctive treatment of refractory focal onset seizures during the past 10 years. Long-term efficacy and safety of the drugs were demonstrated in large extension studies and in reports of subgroups of patients not studied in pivotal trials. Reviewing extension study and post-marketing outcome series for the four newer AEDs-lacosamide, perampanel, eslicarbazepine acetate and brivaracetam-can guide clinicians in treating and monitoring patients. AED extension studies evaluate treatment retention, drug tolerability, and drug safety during individualized treatment with flexible dosing and thus provide information not available in rigid pivotal trials. Patient retention in the studies ranged from 75 to 80% at 1 year and from 36 to 68% at 2-year treatment intervals. Safety findings were generally similar to those of pivotal trials, with no major safety risks identified and with several specific adverse drug effects, such as hyponatremia, reported. The third-generation AEDs, some through new mechanisms and others with improved tolerability compared to related AEDs, provide new options in efficacy and tolerability.
Directory of Open Access Journals (Sweden)
Jong-Hwa Ahn
Full Text Available Limited data are available regarding the long-term clinical outcomes of second-generation drug-eluting stents (DES versus first-generation DES in patients with coronary chronic total occlusion (CTO who undergo percutaneous coronary intervention (PCI. The aim of this study was to compare the clinical outcomes of second-generation DES with those of first-generation DES for the treatment of CTO.Between March 2003 and February 2012, 1,006 consecutive patients with CTO who underwent successful PCI using either first-generation DES (n = 557 or second-generation DES (n = 449 were enrolled in a multicenter, observational registry. Propensity-score matching was also performed. The primary outcome was cardiac death over a 2-year follow-up period. No significant differences were observed between the two groups regarding the incidence of cardiac death (first-generation DES versus second-generation DES; 2.5% vs 2.0%; hazard ratio [HR]: 0.86; 95% confidence interval [CI]: 0.37 to 1.98; p = 0.72 or major adverse cardiac events (MACE, 11.8% vs 11.4%; HR: 1.00; 95% CI: 0.67 to 1.50; p = 0.99. After propensity score matching, the incidences of cardiac death (HR: 0.86; 95% CI: 0.35 to 2.06; p = 0.86 and MACE (HR: 0.93; 95% CI: 0.63 to 1.37; p = 0.71 were still similar in both groups. Furthermore, no significant differences were observed between sirolimus-eluting, paclitaxel-eluting, zotarolimus-eluting, and everolimus-eluting stents regarding the incidence of cardiac death or MACE.This study shows that the efficacy of second-generation DES is comparable to that of first-generation DES for treatment of CTO over 2 years of follow-up.
Using histograms to introduce randomization in the generation of ensembles of decision trees
Kamath, Chandrika; Cantu-Paz, Erick; Littau, David
2005-02-22
A system for decision tree ensembles that includes a module to read the data, a module to create a histogram, a module to evaluate a potential split according to some criterion using the histogram, a module to select a split point randomly in an interval around the best split, a module to split the data, and a module to combine multiple decision trees in ensembles. The decision tree method includes the steps of reading the data; creating a histogram; evaluating a potential split according to some criterion using the histogram, selecting a split point randomly in an interval around the best split, splitting the data, and combining multiple decision trees in ensembles.
Statistical analysis of the ratio of electric and magnetic fields in random fields generators
Serra, R.; Nijenhuis, J.
2013-01-01
In this paper we present statistical models of the ratio of random electric and magnetic fields in mode-stirred reverberation chambers. This ratio is based on the electric and magnetic field statistics derived for ideal reverberation conditions. It provides a further performance indicator for
Generating Random Samples of a Given Size Using Social Security Numbers.
Erickson, Richard C.; Brauchle, Paul E.
1984-01-01
The purposes of this article are (1) to present a method by which social security numbers may be used to draw cluster samples of a predetermined size and (2) to describe procedures used to validate this method of drawing random samples. (JOW)
Agarwal, G. S.; Dogariu, A.; Visser, T.D.; Wolf, E.
2005-01-01
The recently developed theory that unifies the treatments of polarization and coherence of random electro-magnetic beams is applied to study field correlations in Young's interference experiment. It is found that at certain pairs of points the transmitted field is spatially fully coherent,
Generation of triangulated random surfaces by the Monte Carlo method in the grand canonical ensemble
International Nuclear Information System (INIS)
Zmushko, V.V.; Migdal, A.A.
1987-01-01
A model of triangulated random surfaces which is the discrete analog of the Polyakov string is considered. An algorithm is proposed which enables one to study the model by the Monte Carlo method in the grand canonical ensemble. Preliminary results on the determination of the critical index γ are presented
Generating Variable and Random Schedules of Reinforcement Using Microsoft Excel Macros
Bancroft, Stacie L.; Bourret, Jason C.
2008-01-01
Variable reinforcement schedules are used to arrange the availability of reinforcement following varying response ratios or intervals of time. Random reinforcement schedules are subtypes of variable reinforcement schedules that can be used to arrange the availability of reinforcement at a constant probability across number of responses or time.…
Mbonye, Anthony K; Magnussen, Pascal; Chandler, Clare I R; Hansen, Kristian S; Lal, Sham; Cundill, Bonnie; Lynch, Caroline A; Clarke, Siân E
2014-07-29
An intervention was designed to introduce rapid diagnostics tests for malaria (mRDTs) into registered drug shops in Uganda to encourage rational and appropriate treatment of malaria with artemisinin-based combination therapy (ACT). We conducted participatory training of drug shop vendors and implemented supporting interventions to orientate local communities (patients) and the public sector (health facility staff and district officials) to the behavioral changes in diagnosis, treatment and referral being introduced in drug shops. The intervention was designed to be evaluated through a cluster randomized trial. In this paper, we present detailed design, implementation and evaluation experiences in order to help inform future studies of a complex nature. Three preparatory studies (formative, baseline and willingness-to-pay) were conducted to explore perceptions on diagnosis and treatment of malaria at drug shops, and affordable prices for mRDTs and ACTs in order to inform the design of the intervention and implementation modalities. The intervention required careful design with the intention to be acceptable, sustainable and effective. Critical components of intervention were: community sensitization and creating awareness, training of drug shop vendors to diagnose malaria with mRDTs, treat and refer customers to formal health facilities, giving pre-referral rectal artesunate and improved record-keeping. The primary outcome was the proportion of patients receiving appropriately-targeted treatment with ACT, evaluated against microscopy on a research blood slide. Introducing mRDTs in drug shops may seem simple, but our experience of intervention design, conduct and evaluation showed this to be a complex process requiring multiple interventions and evaluation components drawing from a combination of epidemiological, social science and health economics methodologies. The trial was conducted in phases sequenced such that each benefited from the other. The main challenges
Directory of Open Access Journals (Sweden)
Jimin Park
2015-01-01
Full Text Available Background. Atrial fibrillation (AF is the most common form of arrhythmia. Several trials have suggested that acupuncture may prevent AF. However, the efficacy of acupuncture for AF prevention has not been well investigated. Therefore, we designed a prospective, two-parallel-armed, participant and assessor blinded, randomized, sham-controlled clinical trial to investigate acupuncture in persistent AF (ACU-AF. Methods. A total of 80 participants will be randomly assigned to active acupuncture or sham acupuncture groups in a 1 : 1 ratio. Both groups will take the same antiarrhythmic medication during the study period. Patients will receive 10 sessions of acupuncture treatment once a week for 10 weeks. The primary endpoint is AF recurrence rate. Secondary endpoints are left atrium (LA and left atrial appendage (LAA changes in function and volume, and inflammatory biomarker changes. Ethics. This study protocol was approved by the institutional review boards (IRBs of Kyung Hee University Hospital (number 1335-04. This trial is registered with clinicaltrials.gov NCT02110537.
Beliakov, G.; Creighton, D.; Johnstone, M.; Wilkin, T.
2013-08-01
This paper describes an implementation of a Linear Congruential Generator (LCG) based on the binary representation of the normal number α, and of a combined generator based on that LCG. The base LCG with the modulus 333 provides a quality sequence with the period ≈3.7ṡ1015, which passes all but two statistical tests from BigCrush test suite. We improved on the original implementation by adapting Barrett's modular reduction method, which resulted in four-fold increase in efficiency. The combined generator has the period of ≈1023 and passes all tests from BigCrush suite.
GENERATION OF MULTI-LOD 3D CITY MODELS IN CITYGML WITH THE PROCEDURAL MODELLING ENGINE RANDOM3DCITY
Directory of Open Access Journals (Sweden)
F. Biljecki
2016-09-01
Full Text Available The production and dissemination of semantic 3D city models is rapidly increasing benefiting a growing number of use cases. However, their availability in multiple LODs and in the CityGML format is still problematic in practice. This hinders applications and experiments where multi-LOD datasets are required as input, for instance, to determine the performance of different LODs in a spatial analysis. An alternative approach to obtain 3D city models is to generate them with procedural modelling, which is – as we discuss in this paper – well suited as a method to source multi-LOD datasets useful for a number of applications. However, procedural modelling has not yet been employed for this purpose. Therefore, we have developed RANDOM3DCITY, an experimental procedural modelling engine for generating synthetic datasets of buildings and other urban features. The engine is designed to produce models in CityGML and does so in multiple LODs. Besides the generation of multiple geometric LODs, we implement the realisation of multiple levels of spatiosemantic coherence, geometric reference variants, and indoor representations. As a result of their permutations, each building can be generated in 392 different CityGML representations, an unprecedented number of modelling variants of the same feature. The datasets produced by RANDOM3DCITY are suited for several applications, as we show in this paper with documented uses. The developed engine is available under an open-source licence at Github at http://github.com/tudelft3d/Random3Dcity.
Neto, A I; Correia, C R; Oliveira, M B; Rial-Hermida, M I; Alvarez-Lorenzo, C; Reis, R L; Mano, J F
2015-04-01
We propose a novel hanging spherical drop system for anchoring arrays of droplets of cell suspension based on the use of biomimetic superhydrophobic flat substrates, with controlled positional adhesion and minimum contact with a solid substrate. By facing down the platform, it was possible to generate independent spheroid bodies in a high throughput manner, in order to mimic in vivo tumour models on the lab-on-chip scale. To validate this system for drug screening purposes, the toxicity of the anti-cancer drug doxorubicin in cell spheroids was tested and compared to cells in 2D culture. The advantages presented by this platform, such as feasibility of the system and the ability to control the size uniformity of the spheroid, emphasize its potential to be used as a new low cost toolbox for high-throughput drug screening and in cell or tissue engineering.
Simulated Performance Evaluation of a Selective Tracker Through Random Scenario Generation
DEFF Research Database (Denmark)
Hussain, Dil Muhammad Akbar
2006-01-01
performance assessment. Therefore, a random target motion scenario is adopted. Its implementation in particular for testing the proposed selective track splitting algorithm using Kalman filters is investigated through a number of performance parameters which gives the activity profile of the tracking scenario...... The paper presents a simulation study on the performance of a target tracker using selective track splitting filter algorithm through a random scenario implemented on a digital signal processor. In a typical track splitting filter all the observation which fall inside a likelihood ellipse...... are used for update, however, in our proposed selective track splitting filter less number of observations are used for track update. Much of the previous performance work [1] has been done on specific (deterministic) scenarios. One of the reasons for considering the specific scenarios, which were...
Raffaelli, Francesco; Ferranti, Giacomo; Mahler, Dylan H.; Sibson, Philip; Kennard, Jake E.; Santamato, Alberto; Sinclair, Gary; Bonneau, Damien; Thompson, Mark G.; Matthews, Jonathan C. F.
2018-04-01
Optical homodyne detection has found use as a characterisation tool in a range of quantum technologies. So far implementations have been limited to bulk optics. Here we present the optical integration of a homodyne detector onto a silicon photonics chip. The resulting device operates at high speed, up 150 MHz, it is compact and it operates with low noise, quantified with 11 dB clearance between shot noise and electronic noise. We perform on-chip quantum tomography of coherent states with the detector and show that it meets the requirements for characterising more general quantum states of light. We also show that the detector is able to produce quantum random numbers at a rate of 1.2 Gbps, by measuring the vacuum state of the electromagnetic field and applying off-line post processing. The produced random numbers pass all the statistical tests provided by the NIST test suite.
DEFF Research Database (Denmark)
Gøtzsche, P C; Hansen, M; Stoltenberg, M
1996-01-01
disease than the others. The patients felt worse on placebo than on active drug (p = 0.002). The mean differences in number of tender, painful and swollen joints after one month were 2.4 (p = 0.08), 3.0 (p = 0.12) and 2.2 (p = 0.03), respectively. Treatment failure occurred for 42 patients of whom 33......Patients with rheumatoid arthritis, in stable treatment with methotrexate, penicillamine, or sulfasalazine, were randomized in a double-blind fashion either to continuation of their usual treatment or to placebo. 112 patients were included; 52 patients who refused participation had no more severe...... received placebo (p = 0.000,001). There was no difference in the severity of side effects (p = 0.91). The patients guessed their treatment correctly more often than expected (p = 0.02) because of the perceived effect. None of the two observers guessed better than chance, and there were no differences...
DEFF Research Database (Denmark)
Gøtzsche, P C; Hansen, M; Stoltenberg, M
1996-01-01
Patients with rheumatoid arthritis, in stable treatment with methotrexate, penicillamine, or sulfasalazine, were randomized in a double-blind fashion either to continuation of their usual treatment or to placebo. 112 patients were included; 52 patients who refused participation had no more severe...... disease than the others. The patients felt worse on placebo than on active drug (p = 0.002). The mean differences in number of tender, painful and swollen joints after one month were 2.4 (p = 0.08), 3.0 (p = 0.12) and 2.2 (p = 0.03), respectively. Treatment failure occurred for 42 patients of whom 33...... received placebo (p = 0.000,001). There was no difference in the severity of side effects (p = 0.91). The patients guessed their treatment correctly more often than expected (p = 0.02) because of the perceived effect. None of the two observers guessed better than chance, and there were no differences...
Pseudo-Random Modulation of a Laser Diode for Generating Ultrasonic Longitudinal Waves
Madaras, Eric I.; Anatasi, Robert F.
2004-01-01
Laser generated ultrasound systems have historically been more complicated and expensive than conventional piezoelectric based systems, and this fact has relegated the acceptance of laser based systems to niche applications for which piezoelectric based systems are less suitable. Lowering system costs, while improving throughput, increasing ultrasound signal levels, and improving signal-to-noise are goals which will help increase the general acceptance of laser based ultrasound. One current limitation with conventional laser generated ultrasound is a material s damage threshold limit. Increasing the optical power to generate more signal eventually damages the material being tested due to rapid, high heating. Generation limitations for laser based ultrasound suggests the use of pulse modulation techniques as an alternate generation method. Pulse modulation techniques can spread the laser energy over time or space, thus reducing laser power densities and minimizing damage. Previous experiments by various organizations using spatial or temporal pulse modulation have been shown to generate detectable surface, plate, and bulk ultrasonic waves with narrow frequency bandwidths . Using narrow frequency bandwidths improved signal detectability, but required the use of expensive and powerful lasers and opto-electronic systems. The use of a laser diode to generate ultrasound is attractive because of its low cost, small size, light weight, simple optics and modulation capability. The use of pulse compression techniques should allow certain types of laser diodes to produce usable ultrasonic signals. The method also does not need to be limited to narrow frequency bandwidths. The method demonstrated here uses a low power laser diode (approximately 150 mW) that is modulated by controlling the diode s drive current and the resulting signal is recovered by cross correlation. A potential application for this system which is briefly demonstrated is in detecting signals in thick
Johnston, Nina; Bodegard, Johan; Jerström, Susanna; Åkesson, Johanna; Brorsson, Hilja; Alfredsson, Joakim; Albertsson, Per A; Karlsson, Jan-Erik; Varenhorst, Christoph
2016-08-01
Patients with myocardial infarction (MI) seldom reach recommended targets for secondary prevention. This study evaluated a smartphone application ("app") aimed at improving treatment adherence and cardiovascular lifestyle in MI patients. Multicenter, randomized trial. A total of 174 ticagrelor-treated MI patients were randomized to either an interactive patient support tool (active group) or a simplified tool (control group) in addition to usual post-MI care. Primary end point was a composite nonadherence score measuring patient-registered ticagrelor adherence, defined as a combination of adherence failure events (2 missed doses registered in 7-day cycles) and treatment gaps (4 consecutive missed doses). Secondary end points included change in cardiovascular risk factors, quality of life (European Quality of Life-5 Dimensions), and patient device satisfaction (System Usability Scale). Patient mean age was 58 years, 81% were men, and 21% were current smokers. At 6 months, greater patient-registered drug adherence was achieved in the active vs the control group (nonadherence score: 16.6 vs 22.8 [P = .025]). Numerically, the active group was associated with higher degree of smoking cessation, increased physical activity, and change in quality of life; however, this did not reach statistical significance. Patient satisfaction was significantly higher in the active vs the control group (system usability score: 87.3 vs 78.1 [P = .001]). In MI patients, use of an interactive patient support tool improved patient self-reported drug adherence and may be associated with a trend toward improved cardiovascular lifestyle changes and quality of life. Use of a disease-specific interactive patient support tool may be an appreciated, simple, and promising complement to standard secondary prevention. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Worthley, Stephen G; Wilkins, Gerard T; Webster, Mark W; Montarello, Joseph K; Delacroix, Sinny; Whitbourn, Robert J; Warren, Roderic J
2017-07-01
Catheter-based renal denervation for the treatment of drug-resistant hypertension has been intensively investigated in recent years. To date, only limited data have been published using multi-electrode radiofrequency ablation systems that can deliver lesions with a pre-determined pattern. This study was designed to evaluate the safety and performance of the second generation EnligHTN™ Renal Denervation System. This first-in-human, prospective, multi-center, non-randomized study included 39 patients (62% male, mean age 63 years, and mean baseline office blood pressure 174/93 mmHg) with drug-resistant hypertension. The primary safety and performance objectives were to characterize, from baseline to 6 months post procedure, the rate of serious procedural and device related adverse events, as adjudicated by an independent Clinical Events Committee, and the reduction of office systolic blood pressure. Renal artery denervation, using the second generation EnligHTN multi-electrode system significantly reduced office blood pressure from baseline to 1, 3, 6, 12, 18 and 24 months by 19/7, 26/9, 25/7, 23/7, 25/8 and 27/9 mmHg, respectively (p ≤ 0.0005). No serious device or procedure related adverse events affecting the renal arteries or renal function occurred through 24 months of follow-up. Renal sympathetic denervation using the second generation EnligHTN Renal Denervation System resulted in safe, rapid, and significant mean office blood pressure reduction that was sustained through 24 months. Future studies will need to address the utility of this system against an appropriate sham based comparator. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Hughes, Shannon; Cohen, David
2011-07-29
Ongoing initiatives to filter online health searches exclude consumer-generated content from search returns, though its inferiority compared with professionally controlled content is not demonstrated. The antidepressant escitalopram and the antipsychotic quetiapine have ranked over the last 5 years as top-selling agents in their respective drug classes. Both drugs have various off-label mental health and non-mental health uses, ranging from the relief of insomnia and migraines to the treatment of severe developmental disorders. Our objective was to describe the most frequently reported effects of escitalopram and quetiapine in online consumer reviews, to compare them with effects described in professionally controlled commercial health websites, and to gauge the usability of online consumer medication reviews. A stratified simple random sample of 960 consumer reviews was selected from all 6998 consumer reviews of the two drugs in 2 consumer-generated (www.askapatient.com and www.crazymeds.us) and 2 professionally controlled (www.webmd.com and www.revolutionhealth.com) health websites. Professional medication descriptions included all standard information on the medications from the latter 2 websites. All textual data were inductively coded for medication effects, and intercoder agreement was assessed. Chi-square was used to test for associations between consumer-reported effects and website origination. Consumers taking either escitalopram (n = 480) or quetiapine (n = 480) most frequently reported symptom improvement (30.4% or 146/480, 24.8% or 119/480) or symptom worsening (15.8% or 76/480, 10.2% or 49/480), changes in sleep (36% or 173/480, 60.6% or 291/480) and changes in weight and appetite (22.5% or 108/480, 30.8% or 148/480). More consumers posting reviews on consumer-generated rather than professionally controlled websites reported symptom worsening on quetiapine (17.3% or 38/220 versus 5% or 11/220, P concise yet comprehensive listing of drug effects, while
Drummond, Michael B; Astemborski, Jacquie; Lambert, Allison A; Goldberg, Scott; Stitzer, Maxine L; Merlo, Christian A; Rand, Cynthia S; Wise, Robert A; Kirk, Gregory D
2014-07-28
Even after quitting illicit drugs, tobacco abuse remains a major cause of morbidity and mortality in former injection drug users. An important unmet need in this population is to have effective interventions that can be used in the context of community based care. Contingency management, where a patient receives a monetary incentive for healthy behavior choices, and incorporation of individual counseling regarding spirometric "lung age" (the age of an average healthy individual with similar spirometry) have been shown to improve cessation rates in some populations. The efficacy of these interventions on improving smoking cessation rates has not been studied among current and former injection drug users. In a randomized, factorial design study, we recruited 100 active smokers from an ongoing cohort study of current and former injection drug users to assess the impact of contingency management and spirometric lung age on smoking cessation. The primary outcome was 6-month biologically-confirmed smoking cessation comparing contingency management, spirometric lung age or both to usual care. Secondary outcomes included differences in self-reported and biologically-confirmed cessation at interim visits, number of visits attended and quit attempts, smoking rates at interim visits, and changes in Fagerstrom score and self-efficacy. Six-month biologically-confirmed smoking cessations rates were 4% usual care, 0% lung age, 14% contingency management and 0% for combined lung age and contingency management (p = 0.13). There were no differences in secondary endpoints comparing the four interventions or when pooling the lung age groups. Comparing contingency management to non-contingency management, 6-month cessation rates were not different (7% vs. 2%; p = 0.36), but total number of visits with exhaled carbon monoxide-confirmed abstinence were higher for contingency management than non-contingency management participants (0.38 vs. 0.06; p = 0.03), and more contingency management
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Muetzell, S. (Univ. Hospital of Uppsala (Sweden). Dept. of Family Medicine)
1992-01-01
Computed tomography (CT) of the brain was performed in a random sample of a total of 195 men and 211 male alcoholic patients admitted for the first time during a period of two years from the same geographically limited area of Greater Stockholm as the sample. Laboratory tests were performed, including liver and pancreatic tests. Toxicological screening was performed and the consumption of hepatotoxic drugs was also investigated. The groups were then subdivided with respect to alcohol consumption and use of hepatotoxic drugs: group IA, men from the random sample with low or moderate alcohol consumption and no use of hepatotoxic drugs; IB, men from the random sample with low or moderate alcohol consumption with use of hepatotoxic drugs; IIA, alcoholic inpatients with use of alcohol and no drugs; and IIB, alcoholic inpatients with use of alcohol and drugs. Group IIB was found to have a higher incidence of cortical and subcortical changes than group IA. Group IB had a higher incidence of subcortical changes than group IA, and they differed only in drug use. Groups IIN and IIA only differed in drug use, and IIB had a higher incidence of brian damage except for anterior horn index and wide cerebellar sulci indicating vermian atrophy. Significantly higher serum levels of bilirubin, GGT, ASAT, ALAT, CK LD, and amylase were found in IIB. The results indicate that drug use influences the incidence of cortical and subcortical aberrations, except anterior horn index. It is concluded that the groups with alcohol abuse who used hepatotoxic drugs showed a picture of cortical changes (wide transport sulci and clear-cut of high-grade cortical changes) and also of subcortical aberrations, expressed as an increased widening on the third ventricle.
International Nuclear Information System (INIS)
Muetzell, S.
1992-01-01
Computed tomography (CT) of the brain was performed in a random sample of a total of 195 men and 211 male alcoholic patients admitted for the first time during a period of two years from the same geographically limited area of Greater Stockholm as the sample. Laboratory tests were performed, including liver and pancreatic tests. Toxicological screening was performed and the consumption of hepatotoxic drugs was also investigated. The groups were then subdivided with respect to alcohol consumption and use of hepatotoxic drugs: group IA, men from the random sample with low or moderate alcohol consumption and no use of hepatotoxic drugs; IB, men from the random sample with low or moderate alcohol consumption with use of hepatotoxic drugs; IIA, alcoholic inpatients with use of alcohol and no drugs; and IIB, alcoholic inpatients with use of alcohol and drugs. Group IIB was found to have a higher incidence of cortical and subcortical changes than group IA. Group IB had a higher incidence of subcortical changes than group IA, and they differed only in drug use. Groups IIN and IIA only differed in drug use, and IIB had a higher incidence of brian damage except for anterior horn index and wide cerebellar sulci indicating vermian atrophy. Significantly higher serum levels of bilirubin, GGT, ASAT, ALAT, CK LD, and amylase were found in IIB. The results indicate that drug use influences the incidence of cortical and subcortical aberrations, except anterior horn index. It is concluded that the groups with alcohol abuse who used hepatotoxic drugs showed a picture of cortical changes (wide transport sulci and clear-cut of high-grade cortical changes) and also of subcortical aberrations, expressed as an increased widening on the third ventricle
Jobet, E; Bougnoux, M E; Morand, S; Rivault, C; Cloarec, A; Hugot, J P
1998-03-01
Random amplified DNA markers (RAPD; Williams et al., 1990) were used to obtained specific RAPD fragments characterising different species of oxyuroids. We tested six species of worms parasitizing vertebrates or invertebrates: Passalurus ambiguus Rudolphi, 1819, parasite of Leporids; Syphacia obvelata (Rudolphi, 1802) Seurat, 1916, a parasite of rodents; Blatticola blattae (Graeffe, 1860) Chitwood, 1932 parasite of the cockroach Blattella germanica; Hammerschmidtiella diesingi (Hammerschmidt, 1838) Chitwood, 1932 and Thelastoma bulhoesi (Magalhaes, 1990) Travassos, 1929, parasites of the cockroach Periplaneta americana, and an undescribed parasite species of a passalid insect from New Caledonia. Among 15 oligonucleotides tested, nine produced several specific bands allowing the interspecific discrimination.
Swaminathan, Soumya; Pasipanodya, Jotam G; Ramachandran, Geetha; Hemanth Kumar, A K; Srivastava, Shashikant; Deshpande, Devyani; Nuermberger, Eric; Gumbo, Tawanda
2016-11-01
The role of drug concentrations in clinical outcomes in children with tuberculosis is unclear. Target concentrations for dose optimization are unknown. Plasma drug concentrations measured in Indian children with tuberculosis were modeled using compartmental pharmacokinetic analyses. The children were followed until end of therapy to ascertain therapy failure or death. An ensemble of artificial intelligence algorithms, including random forests, was used to identify predictors of clinical outcome from among 30 clinical, laboratory, and pharmacokinetic variables. Among the 143 children with known outcomes, there was high between-child variability of isoniazid, rifampin, and pyrazinamide concentrations: 110 (77%) completed therapy, 24 (17%) failed therapy, and 9 (6%) died. The main predictors of therapy failure or death were a pyrazinamide peak concentration <38.10 mg/L and rifampin peak concentration <3.01 mg/L. The relative risk of these poor outcomes below these peak concentration thresholds was 3.64 (95% confidence interval [CI], 2.28-5.83). Isoniazid had concentration-dependent antagonism with rifampin and pyrazinamide, with an adjusted odds ratio for therapy failure of 3.00 (95% CI, 2.08-4.33) in antagonism concentration range. In regard to death alone as an outcome, the same drug concentrations, plus z scores (indicators of malnutrition), and age <3 years, were highly ranked predictors. In children <3 years old, isoniazid 0- to 24-hour area under the concentration-time curve <11.95 mg/L × hour and/or rifampin peak <3.10 mg/L were the best predictors of therapy failure, with relative risk of 3.43 (95% CI, .99-11.82). We have identified new antibiotic target concentrations, which are potential biomarkers associated with treatment failure and death in children with tuberculosis. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.
On random number generators providing convergence more rapid than 1/√N
International Nuclear Information System (INIS)
Belov, V.A.
1982-01-01
To realize the simulation of processes in High Energy Physics a practical test of the efficiency in applying quasirandom numbers to check multiple integration with Monte-Karlo method is presented together with the comparison of the wellknown generators of quasirandom and pseudorandom numbers [ru
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Assaf, A. George [Isenberg School of Management, University of Massachusetts-Amherst, 90 Campus Center Way, Amherst 01002 (United States); Barros, Carlos Pestana [Instituto Superior de Economia e Gestao, Technical University of Lisbon, Rua Miguel Lupi, 20, 1249-078 Lisbon (Portugal); Managi, Shunsuke [Graduate School of Environmental Studies, Tohoku University, 6-6-20 Aramaki-Aza Aoba, Aoba-Ku, Sendai 980-8579 (Japan)
2011-04-15
This study analyses and compares the cost efficiency of Japanese steam power generation companies using the fixed and random Bayesian frontier models. We show that it is essential to account for heterogeneity in modelling the performance of energy companies. Results from the model estimation also indicate that restricting CO{sub 2} emissions can lead to a decrease in total cost. The study finally discusses the efficiency variations between the energy companies under analysis, and elaborates on the managerial and policy implications of the results. (author)
Generation of Multicellular Tumor Spheroids with Microwell-Based Agarose Scaffolds for Drug Testing.
Directory of Open Access Journals (Sweden)
Xue Gong
Full Text Available Three dimensional multicellular aggregate, also referred to as cell spheroid or microtissue, is an indispensable tool for in vitro evaluating antitumor activity and drug efficacy. Compared with classical cellular monolayer, multicellular tumor spheroid (MCTS offers a more rational platform to predict in vivo drug efficacy and toxicity. Nevertheless, traditional processing methods such as plastic dish culture with nonadhesive surfaces are regularly time-consuming, laborious and difficult to provide uniform-sized spheroids, thus causing poor reproducibility of experimental data and impeding high-throughput drug screening. In order to provide a robust and effective platform for in vitro drug evaluation, we present an agarose scaffold prepared with the template containing uniform-sized micro-wells in commercially available cell culture plates. The agarose scaffold allows for good adjustment of MCTS size and large-scale production of MCTS. Transparent agarose scaffold also allows for monitoring of spheroid formation under an optical microscopy. The formation of MCTS from MCF-7 cells was prepared using different-size-well templates and systematically investigated in terms of spheroid growth curve, circularity, and cell viability. The doxorubicin cytotoxicity against MCF-7 spheroid and MCF-7 monolayer cells was compared. The drug penetration behavior, cell cycle distribution, cell apoptosis, and gene expression were also evaluated in MCF-7 spheroid. The findings of this study indicate that, compared with cellular monolayer, MCTS provides a valuable platform for the assessment of therapeutic candidates in an in vivo-mimic microenvironment, and thus has great potential for use in drug discovery and tumor biology research.
Directory of Open Access Journals (Sweden)
Orla Doyle
Full Text Available This study examined the impact of a targeted Irish early intervention program on children's emotional and behavioral development using multiple methods to test the robustness of the results. Data on 164 Preparing for Life participants who were randomly assigned into an intervention group, involving home visits from pregnancy onwards, or a control group, was used to test the impact of the intervention on Child Behavior Checklist scores at 24-months. Using inverse probability weighting to account for differential attrition, permutation testing to address small sample size, and quantile regression to characterize the distributional impact of the intervention, we found that the few treatment effects were largely concentrated among boys most at risk of developing emotional and behavioral problems. The average treatment effect identified a 13% reduction in the likelihood of falling into the borderline clinical threshold for Total Problems. The interaction and subgroup analysis found that this main effect was driven by boys. The distributional analysis identified a 10-point reduction in the Externalizing Problems score for boys at the 90th percentile. No effects were observed for girls or for the continuous measures of Total, Internalizing, and Externalizing problems. These findings suggest that the impact of this prenatally commencing home visiting program may be limited to boys experiencing the most difficulties. Further adoption of the statistical methods applied here may help to improve the internal validity of randomized controlled trials and contribute to the field of evaluation science more generally.ISRCTN Registry ISRCTN04631728.
Generation of drugs coated iron nanoparticles through high energy ball milling
Energy Technology Data Exchange (ETDEWEB)
Radhika Devi, A.; Murty, B. S. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Chelvane, J. A. [Defence Metallurgical Research Laboratory, Hyderabad 500058 (India); Prabhakar, P. K.; Padma Priya, P. V.; Doble, Mukesh [Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036 (India)
2014-03-28
The iron nanoparticles coated with oleic acid and drugs such as folic acid/Amoxicillin were synthesized by high energy ball milling and characterized by X-ray diffraction, Transmission electron microscope, zeta potential, dynamic light scattering, Fourier Transform Infra red (FT-IR) measurements, and thermo gravimetric analysis (TGA). FT-IR and TGA measurements show good adsorption of drugs on oleic acid coated nanoparticles. Magnetic measurements indicate that saturation magnetization is larger for amoxicillin coated particles compared to folic acid coated particles. The biocompatibility of the magnetic nanoparticles prepared was evaluated by in vitro cytotoxicity assay using L929 cells as model cells.
Park, Boongik; Lee, Kihwan; Park, Jongjin; Kim, Jongmin; Kim, Ohyun
2013-03-01
A hybrid architecture consisting of an inverted organic photovoltaic device and a randomly-oriented electrospun PVDF piezoelectric device was fabricated as a highly-efficient energy generator. It uses the inverted photovoltaic device with coupled electrospun PVDF nanofibers as tandem structure to convert solar and mechanical vibrations energy to electricity simultaneously or individually. The power conversion efficiency of the photovoltaic device was also significantly improved up to 4.72% by optimized processes such as intrinsic ZnO, MoO3 and active layer. A simple electrospinning method with the two electrode technique was adopted to achieve a high voltage of - 300 mV in PVDF piezoelectric fibers. Highly-efficient HEG using voltage adder circuit provides the conceptual possibility of realizing multi-functional energy generator whenever and wherever various energy sources are available.
XIENCE V everolimus-eluting coronary stent system: a novel second generation drug-eluting stent
Beijk, Marcel A. M.; Piek, Jon J.
2007-01-01
Drug-eluting stents (DES) have been shown to be safe and significantly reduce clinical events and angiographic restenosis in the percutaneous treatment of coronary artery disease. Currently, three DES have been approved in Europe and Northern America: the sirolimus-eluting stent (SES), the
BINARY PARTICLE SWARM OPTIMIZATION APPROACH FOR RANDOM GENERATION OUTAGE MAINTENANCE SCHEDULING
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K. Suresh
2013-01-01
Full Text Available This paper presents a methodology for maintenance scheduling (MS of generators using binary particle swarm optimization (BPSO based probabilistic approach. The objective of this paper is to reduce the loss of load probability (LOLP for a power system. The capacity outage probability table (COPT is the initial step in creating maintenance schedule using the probabilistic levelized risk method. This paper proposes BPSO method which is used to construct the COPT. In order to mitigate the effects of probabilistic levelized risk method, BPSO based probabilistic levelized risk method is embarked on a MS problem. In order to validate the effectiveness of the proposed algorithm, case study results for simple five unit system can accomplish a significant levelization in the reliability indices that make possible to evaluate system generation system adequacy in the MS horizon of the power system. The proposed method shows better performance compared with other optimization methods and conventional method with improved search performance.
ANALYSIS AND VALIDATION OF GRID DEM GENERATION BASED ON GAUSSIAN MARKOV RANDOM FIELD
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F. J. Aguilar
2016-06-01
Full Text Available Digital Elevation Models (DEMs are considered as one of the most relevant geospatial data to carry out land-cover and land-use classification. This work deals with the application of a mathematical framework based on a Gaussian Markov Random Field (GMRF to interpolate grid DEMs from scattered elevation data. The performance of the GMRF interpolation model was tested on a set of LiDAR data (0.87 points/m2 provided by the Spanish Government (PNOA Programme over a complex working area mainly covered by greenhouses in Almería, Spain. The original LiDAR data was decimated by randomly removing different fractions of the original points (from 10% to up to 99% of points removed. In every case, the remaining points (scattered observed points were used to obtain a 1 m grid spacing GMRF-interpolated Digital Surface Model (DSM whose accuracy was assessed by means of the set of previously extracted checkpoints. The GMRF accuracy results were compared with those provided by the widely known Triangulation with Linear Interpolation (TLI. Finally, the GMRF method was applied to a real-world case consisting of filling the LiDAR-derived DSM gaps after manually filtering out non-ground points to obtain a Digital Terrain Model (DTM. Regarding accuracy, both GMRF and TLI produced visually pleasing and similar results in terms of vertical accuracy. As an added bonus, the GMRF mathematical framework makes possible to both retrieve the estimated uncertainty for every interpolated elevation point (the DEM uncertainty and include break lines or terrain discontinuities between adjacent cells to produce higher quality DTMs.
Zhang, Guang-He; Poon, Carmen C Y; Zhang, Yuan-Ting
2012-01-01
Wireless body sensor network (WBSN), a key building block for m-Health, demands extremely stringent resource constraints and thus lightweight security methods are preferred. To minimize resource consumption, utilizing information already available to a WBSN, particularly common to different sensor nodes of a WBSN, for security purposes becomes an attractive solution. In this paper, we tested the randomness and distinctiveness of the 128-bit biometric binary sequences (BSs) generated from interpulse intervals (IPIs) of 20 healthy subjects as well as 30 patients suffered from myocardial infarction and 34 subjects with other cardiovascular diseases. The encoding time of a biometric BS on a WBSN node is on average 23 ms and memory occupation is 204 bytes for any given IPI sequence. The results from five U.S. National Institute of Standards and Technology statistical tests suggest that random biometric BSs can be generated from both healthy subjects and cardiovascular patients and can potentially be used as authentication identifiers for securing WBSNs. Ultimately, it is preferred that these biometric BSs can be used as encryption keys such that key distribution over the WBSN can be avoided.
Lee, Joo Myung; Kang, Jeehoon; Lee, Euijae; Hwang, Doyeon; Rhee, Tae-Min; Park, Jonghanne; Kim, Hack-Lyoung; Lee, Sang Eun; Han, Jung-Kyu; Yang, Han-Mo; Park, Kyung Woo; Na, Sang-Hoon; Kang, Hyun-Jae; Koo, Bon-Kwon; Kim, Hyo-Soo
2016-10-24
The purpose of this study was to evaluate the clinical impact of chronic kidney disease (CKD) on clinical outcomes in contemporary practice of percutaneous coronary intervention (PCI) using second-generation drug-eluting stents (DES). Although second-generation DES have improved the safety and efficacy issues in PCI, data regarding the performance of second-generation DES in patients with CKD are still limited. We performed a patient-level pooled analysis on 12,426 patients undergoing PCI using second-generation DES from the Korean Multicenter Drug-Eluting Stent Registry. Endpoints were stent-oriented outcomes (target lesion failure [TLF]) and patient-oriented composite outcomes (POCO) during a median follow-up of 35 months. CKD patients were stratified by the estimated glomerular filtration rate (eGFR) from mild CKD to end-stage renal disease patients, and by the coexistence of diabetes mellitus (DM). A total of 2,927 patients had CKD (23.6%), who showed a significantly higher risk of TLF (adjusted hazard ratio [HR adjust ]: 1.50; 95% confidence interval [CI]: 1.21 to 1.86) and POCO (HR adjust 1.34; 95% CI: 1.17 to 1.55) compared to patients with preserved renal function. Stratified analysis by eGFR showed that TLF was not increased in the mild to moderate CKD, whereas severe CKD and dialysis-dependent patients showed significantly higher risk of TLF (HR adjust 2.44; 95% CI: 1.54 to 3.86; HR adjust 3.58; 95% CI: 2.52 to 5.08, respectively). The eGFR threshold of increased clinical events was 40 to 45 ml/min/1.73 m 2 . Among CKD patients, DM CKD patients showed a higher incidence of TLF compared to non-DM CKD patients (HR adjust : 1.82; 95% CI: 1.32 to 2.52), driven by the increase in target vessel-related events. In the era of second-generation DES, CKD patients were at a significantly higher risk of clinical outcomes only in severe CKD and end-stage renal disease patients. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All
Generation of pharmacophores and classification of drugs using protein-ligand complexes
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Eliana Velasquez
2014-04-01
Full Text Available Pharmacophore identification is a veryimportant step in de novo design, leadoptimization, chemogenomics, and virtualscreening of drugs. Unfortunately,the high cost of comercial software forpharmacophore detection is a commonlimiting factor for researchers with limitedfunding. This paper presents a set offreely available perl routines that weredesigned to help in the process of 3Dpharmacophore identification and QSARstudies. These routines also allowed theclassification of ligands based on theirtridimensional similarity and bindingmechanism. The family of phosphodiesterasesand their inhibitors were used astest model.
Comparative analysis of tumor spheroid generation techniques for differential in vitro drug toxicity
Raghavan, Shreya; Rowley, Katelyn R.; Mehta, Geeta
2016-01-01
Multicellular tumor spheroids are powerful in vitro models to perform preclinical chemosensitivity assays. We compare different methodologies to generate tumor spheroids in terms of resultant spheroid morphology, cellular arrangement and chemosensitivity. We used two cancer cell lines (MCF7 and OVCAR8) to generate spheroids using i) hanging drop array plates; ii) liquid overlay on ultra-low attachment plates; iii) liquid overlay on ultra-low attachment plates with rotating mixing (nutator plates). Analysis of spheroid morphometry indicated that cellular compaction was increased in spheroids generated on nutator and hanging drop array plates. Collagen staining also indicated higher compaction and remodeling in tumor spheroids on nutator and hanging drop arrays compared to conventional liquid overlay. Consequently, spheroids generated on nutator or hanging drop plates had increased chemoresistance to cisplatin treatment (20-60% viability) compared to spheroids on ultra low attachment plates (10-20% viability). Lastly, we used a mathematical model to demonstrate minimal changes in oxygen and cisplatin diffusion within experimentally generated spheroids. Our results demonstrate that in vitro methods of tumor spheroid generation result in varied cellular arrangement and chemosensitivity. PMID:26918944
Disease-responsive drug delivery: the next generation of smart delivery devices.
Wanakule, Prinda; Roy, Krishnendu
2012-01-01
With the advent of highly potent and cytotoxic drugs, it is increasingly critical that they be targeted and released only in cells of diseased tissues, while sparing physiologically normal neighbors. Simple ligand-based targeting of drug carriers, although promising, cannot always provide the required specificity to achieve this since often normal cells also express significant levels of the targeted receptors. Therefore, stimuli-responsive delivery systems are being explored to allow drug release from nano- and microcarriers and implantable devices, primarily in the presence of physiological or disease-specific pathophysiological signals. Designing smart biomaterials that respond to temperature or pH changes, protein and ligand binding, disease-specific degradation, e.g. enzymatic cleavage, has become an integral part of this approach. These strategies are used in combination with nano- and microparticle systems to improve delivery efficiency through several routes of administration, and with injectable or implantable systems for long term controlled release. This review focuses on recent developments in stimuli-responsive systems, their physicochemical properties, release profiles, efficacy, safety and biocompatibility, as well as future perspectives.
HIV drug resistance patterns in pregnant women using next generation sequence in Mozambique.
Rupérez, María; Noguera-Julian, Marc; González, Raquel; Maculuve, Sonia; Bellido, Rocío; Vala, Anifa; Rodríguez, Cristina; Sevene, Esperança; Paredes, Roger; Menéndez, Clara
2018-01-01
Few data on HIV resistance in pregnancy are available from Mozambique, one of the countries with the highest HIV toll worldwide. Understanding the patterns of HIV drug resistance in pregnant women might help in tailoring optimal regimens for prevention of mother to child transmission of HIV (pMTCT) and antenatal care. To describe the frequency and characteristics of HIV drug resistance mutations (HIVDRM) in pregnant women with virological failure at delivery, despite pMTCT or antiretroviral therapy (ART). Samples from HIV-infected pregnant women from a rural area in southern Mozambique were analysed. Only women with HIV-1 RNA >400c/mL at delivery were included in the analysis. HIVDRM were determined using MiSeq® (detection threshold 1%) at the first antenatal care (ANC) visit and at the time of delivery. Ninety and 60 samples were available at the first ANC visit and delivery, respectively. At first ANC, 97% of the women had HIV-1 RNA>400c/mL, 39% had CD4+ counts HIV-1 genotyping, less than 20% of women with detectable viremia at delivery had HIVDRM before initiating pMTCT or ART. This suggests that factors other than pre-existing resistance, such as lack of adherence or interruptions of the ANC chain, are also relevant to explain lack of virological suppression at the time of delivery in women receiving antiretrovirals drugs during pregnancy.
Arumugam, Jayavel; Bukkapatnam, Satish T S; Narayanan, Krishna R; Srinivasa, Arun R
2016-01-01
Current methods for distinguishing acute coronary syndromes such as heart attack from stable coronary artery disease, based on the kinetics of thrombin formation, have been limited to evaluating sensitivity of well-established chemical species (e.g., thrombin) using simple quantifiers of their concentration profiles (e.g., maximum level of thrombin concentration, area under the thrombin concentration versus time curve). In order to get an improved classifier, we use a 34-protein factor clotting cascade model and convert the simulation data into a high-dimensional representation (about 19000 features) using a piecewise cubic polynomial fit. Then, we systematically find plausible assays to effectively gauge changes in acute coronary syndrome/coronary artery disease populations by introducing a statistical learning technique called Random Forests. We find that differences associated with acute coronary syndromes emerge in combinations of a handful of features. For instance, concentrations of 3 chemical species, namely, active alpha-thrombin, tissue factor-factor VIIa-factor Xa ternary complex, and intrinsic tenase complex with factor X, at specific time windows, could be used to classify acute coronary syndromes to an accuracy of about 87.2%. Such a combination could be used to efficiently assay the coagulation system.
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Jayavel Arumugam
Full Text Available Current methods for distinguishing acute coronary syndromes such as heart attack from stable coronary artery disease, based on the kinetics of thrombin formation, have been limited to evaluating sensitivity of well-established chemical species (e.g., thrombin using simple quantifiers of their concentration profiles (e.g., maximum level of thrombin concentration, area under the thrombin concentration versus time curve. In order to get an improved classifier, we use a 34-protein factor clotting cascade model and convert the simulation data into a high-dimensional representation (about 19000 features using a piecewise cubic polynomial fit. Then, we systematically find plausible assays to effectively gauge changes in acute coronary syndrome/coronary artery disease populations by introducing a statistical learning technique called Random Forests. We find that differences associated with acute coronary syndromes emerge in combinations of a handful of features. For instance, concentrations of 3 chemical species, namely, active alpha-thrombin, tissue factor-factor VIIa-factor Xa ternary complex, and intrinsic tenase complex with factor X, at specific time windows, could be used to classify acute coronary syndromes to an accuracy of about 87.2%. Such a combination could be used to efficiently assay the coagulation system.
Smit, E.; Verdurmen, J.E.E.; Engels, R.C.M.E.
2015-01-01
In order to quantify the effectiveness of family interventions in preventing and reducing adolescent illicit drug use, we conducted a systematic review and meta-analysis of randomized controlled trials. We searched the Cochrane Database of Systematic Reviews, Educational Research Information Centre
Susukida, Ryoko; Crum, Rosa M; Stuart, Elizabeth A; Ebnesajjad, Cyrus; Mojtabai, Ramin
2016-07-01
To compare the characteristics of individuals participating in randomized controlled trials (RCTs) of treatments of substance use disorder (SUD) with individuals receiving treatment in usual care settings, and to provide a summary quantitative measure of differences between characteristics of these two groups of individuals using propensity score methods. Design Analyses using data from RCT samples from the National Institute of Drug Abuse Clinical Trials Network (CTN) and target populations of patients drawn from the Treatment Episodes Data Set-Admissions (TEDS-A). Settings Multiple clinical trial sites and nation-wide usual SUD treatment settings in the United States. A total of 3592 individuals from 10 CTN samples and 1 602 226 individuals selected from TEDS-A between 2001 and 2009. Measurements The propensity scores for enrolling in the RCTs were computed based on the following nine observable characteristics: sex, race/ethnicity, age, education, employment status, marital status, admission to treatment through criminal justice, intravenous drug use and the number of prior treatments. Findings The proportion of those with ≥ 12 years of education and the proportion of those who had full-time jobs were significantly higher among RCT samples than among target populations (in seven and nine trials, respectively, at P difference in the mean propensity scores between the RCTs and the target population was 1.54 standard deviations and was statistically significant at P different from individuals receiving treatment in usual care settings. Notably, RCT participants tend to have more years of education and a greater likelihood of full-time work compared with people receiving care in usual care settings. © 2016 Society for the Study of Addiction.
Zhang, Guo-Qiang; Tao, Shiqiang; Xing, Guangming; Mozes, Jeno; Zonjy, Bilal; Lhatoo, Samden D; Cui, Licong
2015-11-10
A unique study identifier serves as a key for linking research data about a study subject without revealing protected health information in the identifier. While sufficient for single-site and limited-scale studies, the use of common unique study identifiers has several drawbacks for large multicenter studies, where thousands of research participants may be recruited from multiple sites. An important property of study identifiers is error tolerance (or validatable), in that inadvertent editing mistakes during their transmission and use will most likely result in invalid study identifiers. This paper introduces a novel method called "Randomized N-gram Hashing (NHash)," for generating unique study identifiers in a distributed and validatable fashion, in multicenter research. NHash has a unique set of properties: (1) it is a pseudonym serving the purpose of linking research data about a study participant for research purposes; (2) it can be generated automatically in a completely distributed fashion with virtually no risk for identifier collision; (3) it incorporates a set of cryptographic hash functions based on N-grams, with a combination of additional encryption techniques such as a shift cipher; (d) it is validatable (error tolerant) in the sense that inadvertent edit errors will mostly result in invalid identifiers. NHash consists of 2 phases. First, an intermediate string using randomized N-gram hashing is generated. This string consists of a collection of N-gram hashes f1, f2, ..., fk. The input for each function fi has 3 components: a random number r, an integer n, and input data m. The result, fi(r, n, m), is an n-gram of m with a starting position s, which is computed as (r mod |m|), where |m| represents the length of m. The output for Step 1 is the concatenation of the sequence f1(r1, n1, m1), f2(r2, n2, m2), ..., fk(rk, nk, mk). In the second phase, the intermediate string generated in Phase 1 is encrypted using techniques such as shift cipher. The result
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Malmberg Monique
2010-09-01
Full Text Available Abstract Background Substance use is highly prevalent among Dutch adolescents. The Healthy School and Drugs program is a nationally implemented school-based prevention program aimed at reducing early and excessive substance use among adolescents. Although the program's effectiveness was tested in a quasi-experimental design before, many program changes were made afterwards. The present study, therefore, aims to test the effects of this widely used, renewed universal prevention program. Methods/Design A randomized clustered trial will be conducted among 3,784 adolescents of 23 secondary schools in The Netherlands. The trial has three conditions; two intervention conditions (i.e., e-learning and integral and a control condition. The e-learning condition consists of three digital learning modules (i.e., about alcohol, tobacco, and marijuana that are sequentially offered over the course of three school years (i.e., grade 1, grade 2, and grade 3. The integral condition consists of parental participation in a parental meeting on substance use, regulation of substance use, and monitoring and counseling of students' substance use at school, over and above the three digital modules. The control condition is characterized as business as usual. Participating schools were randomly assigned to either an intervention or control condition. Participants filled out a digital questionnaire at baseline and will fill out the same questionnaire three more times at follow-up measurements (8, 20, and 32 months after baseline. Outcome variables included in the questionnaire are the percentage of binge drinking (more than five drinks per occasion, the average weekly number of drinks, and the percentage of adolescents who ever drunk a glass of alcohol and the percentage of adolescents who ever smoked a cigarette or a joint respectively for tobacco and marijuana. Discussion This study protocol describes the design of a randomized clustered trial that evaluates the
Basta, Dietmar; Borsellino, Liliana; Ernst, Arne
2017-12-01
Vestibular rehabilitation using individualized vibrotactile neurofeedback training (IVNT) can lead to significant improvement in the postural stability of patients with vestibular symptoms of different origins. However, some of these patients have complex, severe dizziness, meaning that a pharmacological pretreatment or parallel (to vestibular rehabilitation) treatment can help them perform the rehabilitation exercises. Hence, the present study investigated the influence of a pharmacological treatment on the efficacy of vibrotactile neurofeedback training in patients with chronic, noncompensated vestibulopathies. All participants performed IVNT for ∼10 min each day for 2 weeks. In addition, every second participant was selected randomly to receive oral medication (20 mg cinnarizine and 40 mg dimenhydrinate per tablet), taking three tables per day. Trunk and ankle sway and postural stability were measured. In addition, the dizziness handicap inventory was evaluated immediately before training on the last day of training and 6 months after training. After the 10-day period of IVNT, both groups showed a statistically significant improvement in all parameters tested. A follow-up analysis after 6 months showed a long-term efficacy for the IVNT, that is, the patients remained significantly improved in their postural stability. The antivertiginous therapy did not hinder the efficacy of the IVNT. The present results indicate that IVNT even in combination with an antivertiginous drug therapy is an effective treatment regime for patients with disabling vertigo of different origins.
Plazomicin is a next-generation aminoglycoside with a potentially improved safety profile compared to other aminoglycosides. This study assessed plazomicin MICs and MBCs in four Brucella spp. reference strains. Like other aminoglycosides and aminocyclitols, plazomicin MBC values equaled MIC values ...
Next generation drug-eluting stents: focus on bioabsorbable platforms and polymers
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Brendan Doyle
2009-11-01
Full Text Available Brendan Doyle, David R Holmes JrDivision of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USAAbstract: The success of drug-eluting stents in preventing restenosis has shifted the focus of new stent development toward enhancing long term safety and efficacy of these devices, while simultaneously eliminating the need for indefinite dual antiplatelet therapy. A technical advance fulfilling these aims would hold tremendous potential to reduce morbidity, mortality and economic costs associated with the percutaneous treatment of coronary artery disease. An attractive approach is the use of bioabsorbable stent designs. These may include stents with different bioabsorbable drugs, bioabsorbable polymers or even bioabsorbable metallic backbones. A device that could achieve excellent acute and long-term results, but disappear completely within months (thereby avoiding the need for prolonged dual antiplatelet therapy, would be a tremendous advance. Too good to be true? We explore here the scientific rationale and prospects for success with this exciting concept.Keywords: percutaneous coronary intervention, biodegradable, bioabsorbable, polymer, stent
Carrascosa, J M; Del-Alcazar, E
2018-04-01
Biologic drugs have revolutionized the treatment of moderate to severe psoriasis in recent years because of their high efficacy and low risk of toxicity. However, even within the group of biologic therapies, there are differences related to the different mechanisms of action. Areas covered: We review the main adverse events associated with the biologic agents currently available for the treatment of psoriasis and the new inhibitors targeting the p19 subunit of interleukin (IL) 23 and the IL-17A receptor. This review covers injection site reactions, infections, cardiovascular events, demyelinating disorders, tumours, class effects secondary adverse events, immunogenicity, safety in pregnancy and vaccines efficacy. Expert commentary: More than a decade after the first approval of biologic drugs for use in psoriasis, the good safety profile of these drugs is one of the main justifications and incentives for their long-term use. The emergence of new pharmacological groups has made it possible to avoid some of the class effects of first-generation biologic agents and the new therapies appear to pose less risk of reactivation of latent infections, such as hepatitis B virus and tuberculosis. However, they are associated with new adverse effects related to their mechanism of action, including candidiasis and the risk of exacerbation or onset of inflammatory bowel disease.
Tada, Tomohisa; Byrne, Robert A; Simunovic, Iva; King, Lamin A; Cassese, Salvatore; Joner, Michael; Fusaro, Massimiliano; Schneider, Simon; Schulz, Stefanie; Ibrahim, Tareq; Ott, Ilka; Massberg, Steffen; Laugwitz, Karl-Ludwig; Kastrati, Adnan
2013-12-01
This study sought to compare the risk of stent thrombosis among patients treated with bare-metal stents (BMS), first-generation drug-eluting stents (G1-DES), and second-generation drug-eluting stents (G2-DES) for a period of 3 years. In patients undergoing coronary stenting, there is a scarcity of long-term follow-up data on cohorts large enough to compare rates of stent thrombosis across the stent generations. A total of 18,334 patients undergoing successful coronary stent implantation from 1998 to 2011 at 2 centers in Munich, Germany, were included in this study. Patients were stratified into 3 groups according to treatment with BMS, G1-DES, and G2-DES. The cumulative incidence of definite stent thrombosis at 3 years was 1.5% with BMS, 2.2% with G1-DES, and 1.0% with G2-DES. On multivariate analysis, G1-DES compared with BMS showed a significantly higher risk of stent thrombosis (odds ratio [OR]: 2.05; 95% confidence interval [CI]: 1.47 to 2.86; p stent thrombosis compared with BMS (OR: 0.82; 95% CI: 0.56 to 1.19; p = 0.30). Beyond 1 year, the risk of stent thrombosis was significantly increased with G1-DES compared with BMS (OR: 4.72; 95% CI: 2.01 to 11.1; p stenting, compared with BMS, there was a significant excess risk of stent thrombosis at 3 years with G1-DES, driven by an increased risk of stent thrombosis events beyond 1 year. G2-DES were associated with a similar risk of stent thrombosis compared with BMS. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
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Wouter eOomens
2015-06-01
Full Text Available The concept of executive functions plays a prominent role in contemporary experimental and clinical studies on cognition. One paradigm used in this framework is the random number generation (RNG task, the execution of which demands aspects of executive functioning, specifically inhibition and working memory. Data from the RNG task are best seen as a series of successive events. However, traditional RNG measures that are used to quantify executive functioning are mostly summary statistics referring to deviations from mathematical randomness. In the current study, we explore the utility of recurrence quantification analysis (RQA, a nonlinear method that keeps the entire sequence intact, as a better way to describe executive functioning compared to traditional measures. To this aim, 242 first- and second-year students completed a non-paced RNG task. Principal component analysis of their data showed that traditional and RQA measures convey more or less the same information. However, RQA measures do so more parsimoniously and have a better interpretation.
Morse, Melvin L; Beem, Lance W
2011-12-01
Reiki therapy is documented for relief of pain and stress. Energetic healing has been documented to alter biologic markers of illness such as hematocrit. True random number generators are reported to be affected by energy healers and spiritually oriented conscious awareness. The patient was a then 54-year-old severely ill man who had hepatitis C types 1 and 2 and who did not improve with conventional therapy. He also suffered from obesity, the metabolic syndrome, asthma, and hypertension. He was treated with experimental high-dose interferon/riboviron therapy with resultant profound anemia and neutropenia. Energetic healing and Reiki therapy was administered initially to enhance the patient's sense of well-being and to relieve anxiety. Possible effects on the patient's absolute neutrophil count and hematocrit were incidentally noted. Reiki therapy was then initiated at times of profound neutropenia to assess its possible effect on the patient's absolute neutrophil count (ANC). Reiki and other energetic healing sessions were monitored with a true random number generator (RNG). Statistically significant relationships were documented between Reiki therapy, a quieting of the electronically created white noise of the RNG during healing sessions, and improvement in the patient's ANC. The immediate clinical result was that the patient could tolerate the high-dose interferon regimen without missing doses because of absolute neutropenia. The patient was initially a late responder to interferon and had been given a 5% chance of clearing the virus. He remains clear of the virus 1 year after treatment. The association between changes in the RNG, Reiki therapy, and a patient's ANC is the first to the authors' knowledge in the medical literature. Future studies assessing the effects of energetic healing on specific biologic markers of disease are anticipated. Concurrent use of a true RNG may prove to correlate with the effectiveness of energetic therapy.
Andrade, Jason G; Dubuc, Marc; Guerra, Peter G; Landry, Evelyn; Coulombe, Nicolas; Leduc, Hugues; Rivard, Léna; Macle, Laurent; Thibault, Bernard; Talajic, Mario; Roy, Denis; Khairy, Paul
2013-06-01
Optimal cryoballoon ablation parameters for pulmonary vein (PV) isolation remain to be defined. We conducted a randomized preclinical trial to compare 2- versus 4-minute ablation lesions and assess the safety of active (forced) cryoballoon deflation. Thirty-two dogs underwent PV isolation with a second-generation 23 mm cryoballoon catheter. The left superior (LSPV) and inferior (LIPV) PVs were randomized in a factorial design to (1) a single 2- versus 4-minute cryoapplication, and (2) passive versus active cryoballoon deflation. Animals were survived for 30 days, after which histopathologic analysis was performed. Acute PV isolation was attained in 89.8% of PVs after a single application (93.8% LSPV, 85.2% LIPV; P = 0.2823). Mean time to PV isolation was 29.5 ± 18.5 seconds. Although 4-minute lesions were associated with a thicker neointima than 2-minute lesions (223.8 μm versus 135.6 μm; P = 0.007), no differences were observed in procedural characteristics (freezing temperature, rewarming time), rates of acute PV isolation, or the achievement of complete circumferentially transmural lesions at 30 days (78.7% overall; 86.2% for 2 minutes vs 70.0% for 4 minutes; P = 0.285). Active deflation was associated with faster balloon rewarming but not with significant differences in mean or maximum neointimal thickness. A single application with the second-generation cryoballoon catheter results in a high rate of PV isolation. The degree of vascular injury was not increased by active balloon deflation and no differences in acute efficacy or mature transmural circumferential lesions were observed with 2- versus 4-minute applications. © 2013 Wiley Periodicals, Inc.
Quorum sensing inhibitory drugs as next generation antimicrobials: worth the effort?
DEFF Research Database (Denmark)
Bjarnsholt, Thomas; Givskov, M.
2008-01-01
as biofilms are more tolerant to antibiotics than their planktonic counterparts. Therefore, research should identify new antimicrobial agents and their corresponding targets to decrease the biofilm-forming capability or persistence of the infectious bacteria. Here, we review one such drug target: bacterial......Bacterial resistance poses a major challenge to the development of new antimicrobial agents. Conventional antibiotics have an inherent obsolescence because they select for development of resistance. Bacterial infections have again become a serious threat in developed countries. Particularly......, elderly, immunocompromised, and hospitalized patients are susceptible to infections caused by bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. These bacteria form chronic, biofilm-based infections, which are challenging because bacterial cells living...
Usher, Kim; Park, Tanya; Foster, Kim; Buettner, Petra
2013-07-01
To test the effect of a nurse-led intervention on weight gain in people with serious mental illness prescribed and taking second generation antipsychotic medication. Weight gain and obesity has reached epidemic proportions in the general population with the prevalence of Metabolic Syndrome reaching 20-25% of the global population. People with serious mental illness are at even higher risk, particularly those taking second generation antipsychotic medication. An experimental randomized controlled trial was undertaken. The control group received a 12-week healthy lifestyle booklet. In addition to the booklet, the intervention group received weekly nutrition and exercise education, exercise sessions, and nurse support. Participants (n = 101) were assessed at baseline and 12 weeks. Data were collected between March 2008-December 2010. Seven outcome measures were used: body measurements included girth (cm), weight (kg), height (cm), and body mass index (kg/m(2) ); questionnaires included the medication compliance questionnaire, the Drug Attitude Inventory, the Liverpool University Neuroleptic Side Effect Rating Scale, and the Medical Outcomes Study Short Form 36. Differences in primary outcome measures between baseline and 12 weeks follow-up were compared between intervention and control groups using standard bi-variate statistical tests. The study was conducted between 2008-2010. The analysis of outcome measures for the control group (n = 50) and intervention group (n = 51) was not statistically significant. There was a mean weight change of -0·74 kg at 12 weeks for the intervention group (n = 51), while the control group (n = 50) had a mean weight change of -0·17 kg at 12 weeks. The results were not statistically significant. © 2012 Blackwell Publishing Ltd.
Liu, Yanfeng; Wang, Ying; Gao, Yongxing; Forbes, Jessica A; Qayyum, Rehan; Becker, Lewis; Cheng, Linzhao; Wang, Zack Z
2015-04-01
Megakaryocytes (MKs) are rare hematopoietic cells in the adult bone marrow and produce platelets that are critical to vascular hemostasis and wound healing. Ex vivo generation of MKs from human induced pluripotent stem cells (hiPSCs) provides a renewable cell source of platelets for treating thrombocytopenic patients and allows a better understanding of MK/platelet biology. The key requirements in this approach include developing a robust and consistent method to produce functional progeny cells, such as MKs from hiPSCs, and minimizing the risk and variation from the animal-derived products in cell cultures. In this study, we developed an efficient system to generate MKs from hiPSCs under a feeder-free and xeno-free condition, in which all animal-derived products were eliminated. Several crucial reagents were evaluated and replaced with Food and Drug Administration-approved pharmacological reagents, including romiplostim (Nplate, a thrombopoietin analog), oprelvekin (recombinant interleukin-11), and Plasbumin (human albumin). We used this method to induce MK generation from hiPSCs derived from 23 individuals in two steps: generation of CD34(+)CD45(+) hematopoietic progenitor cells (HPCs) for 14 days; and generation and expansion of CD41(+)CD42a(+) MKs from HPCs for an additional 5 days. After 19 days, we observed abundant CD41(+)CD42a(+) MKs that also expressed the MK markers CD42b and CD61 and displayed polyploidy (≥16% of derived cells with DNA contents >4N). Transcriptome analysis by RNA sequencing revealed that megakaryocytic-related genes were highly expressed. Additional maturation and investigation of hiPSC-derived MKs should provide insights into MK biology and lead to the generation of large numbers of platelets ex vivo. ©AlphaMed Press.
Directory of Open Access Journals (Sweden)
Nattagit Jiteurtragool
2018-02-01
Full Text Available The search for generation approaches to robust chaos has received considerable attention due to potential applications in cryptography or secure communications. This paper is of interest regarding a 1-D sigmoidal chaotic map, which has never been distinctly investigated. This paper introduces a generic form of the sigmoidal chaotic map with three terms, i.e., xn+1 = ∓AfNL(Bxn ± Cxn ± D, where A, B, C, and D are real constants. The unification of modified sigmoid and hyperbolic tangent (tanh functions reveals the existence of a “unified sigmoidal chaotic map” generically fulfilling the three terms, with robust chaos partially appearing in some parameter ranges. A simplified generic form, i.e., xn+1 = ∓fNL(Bxn ± Cxn, through various S-shaped functions, has recently led to the possibility of linearization using (i hardtanh and (ii signum functions. This study finds a linearized sigmoidal chaotic map that potentially offers robust chaos over an entire range of parameters. Chaos dynamics are described in terms of chaotic waveforms, histogram, cobweb plots, fixed point, Jacobian, and a bifurcation structure diagram based on Lyapunov exponents. As a practical example, a true random bit generator using the linearized sigmoidal chaotic map is demonstrated. The resulting output is evaluated using the NIST SP800-22 test suite and TestU01.
Nyamathi, Adeline M; Shin, Sanghyuk S; Smeltzer, Jolene; Salem, Benissa E; Yadav, Kartik; Ekstrand, Maria L; Turner, Susan F; Faucette, Mark
Homeless female ex-offenders (homeless female offenders) exiting jail and prison are at a critical juncture during reentry and transitioning into the community setting. The purpose of the study was to compare the effect of a dialectical behavioral therapy-case management (DBT-CM) program with a health promotion (HP) program on achieving drug and alcohol abstinence among female parolees/probationers residing in the community. We conducted a multicenter parallel randomized controlled trial with 130 female parolees/probationers (aged 19-64 years) residing in the community randomly assigned to either DBT-CM (n = 65) or HP (n = 65). The trial was conducted in four community-based partner sites in Los Angeles and Pomona, California, from February 2015 to November 2016. Treatment assignment was carried out using a computer-based urn randomization program. The primary outcome was drug and alcohol use abstinence at 6-month follow up. Analysis was based on data from 116 participants with complete outcome data. Multivariable logistic regression revealed that the DBT-CM program remained an independent positive predictor of decrease in drug use among the DBT-CM participants at 6 months (p = .01) as compared with the HP program participants. Being non-White (p < .05) and having higher depressive symptom scores (p < .05) were associated with lower odds of drug use abstinence (i.e., increased the odds of drug use) at 6 months. DBT-CM increased drug and alcohol abstinence at 6-month follow-up, compared to an HP program.
Smeets, Claudia H. W.; Smalbrugge, Martin; Gerritsen, Debby L.; Nelissen-Vrancken, Marjorie H. J. M. G.; Wetzels, Roland B.; van der Spek, Klaas; Zuidema, Sytse U.; Koopmans, Raymond T. C. M.
2013-01-01
Background: Neuropsychiatric symptoms are highly prevalent in nursing home patients with dementia. Despite modest effectiveness and considerable side effects, psychotropic drugs are frequently prescribed for these neuropsychiatric symptoms. This raises questions whether psychotropic drugs are
Energy Technology Data Exchange (ETDEWEB)
Coronel B, H.F.; Hernandez M, A.R.; Jimenez M, M.A. [Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, A.P. 475, Xalapa, Veracruz (Mexico); Mora F, L.E. [CIMAT, A.P. 402, 36000 Guanajuato (Mexico)]. e-mail: hcoronel@uv.mx
2007-07-01
Empirical tests for pseudo random number generators based on the use of processes or physical models have been successfully used and are considered as complementary to theoretical tests of randomness. In this work a statistical methodology for evaluating the quality of pseudo random number generators is presented. The method is illustrated in the context of the so-called exponential decay process, using some pseudo random number generators commonly used in physics. (Author)
Navarese, E.P.; Kowalewski, M.; Kandzari, D.; Lansky, A.; Gorny, B.; Koltowski, L.; Waksman, R.; Berti, S.; Musumeci, G.; Limbruno, U.; Schaaf, R.J. van der; Kelm, M.; Kubica, J.; Suryapranata, H.
2014-01-01
BACKGROUND: First-generation drug-eluting stents (DES) have become the most widely used devices worldwide for management of coronary artery disease. As remote follow-up data were becoming available, concerns emerged in regard to their long-term safety. Second-generation DES were designed to overcome
Khandelwal, Nitin; Chander, Yogesh; Rawat, Krishan Dutt; Riyesh, Thachamvally; Nishanth, Chikkahonnaiah; Sharma, Shalini; Jindal, Naresh; Tripathi, Bhupendra N; Barua, Sanjay; Kumar, Naveen
2017-08-01
At a noncytotoxic concentration, emetine was found to inhibit replication of DNA viruses [buffalopoxvirus (BPXV) and bovine herpesvirus 1 (BHV-1)] as well as RNA viruses [peste des petits ruminants virus (PPRV) and Newcastle disease virus (NDV)]. Using the time-of-addition and virus step-specific assays, we showed that emetine treatment resulted in reduced synthesis of viral RNA (PPRV and NDV) and DNA (BPXV and BHV-1) as well as inhibiting viral entry (NDV and BHV-1). In addition, emetine treatment also resulted in decreased synthesis of viral proteins. In a cell free endogenous viral polymerase assay, emetine was found to significantly inhibit replication of NDV, but not BPXV genome, suggesting that besides directly inhibiting specific viral polymerases, emetine may also target other factors essentially required for efficient replication of the viral genome. Moreover, emetine was found to significantly inhibit BPXV-induced pock lesions on chorioallantoic membrane (CAM) along with associated mortality of embryonated chicken eggs. At a lethal dose 50 (LD 50 ) of 126.49 ng/egg and at an effective concentration 50 (EC 50 ) of 3.03 ng/egg, the therapeutic index of the emetine against BPXV was determined to be 41.74. Emetine was also found to significantly delay NDV-induced mortality in chicken embryos associated with reduced viral titers. Further, emetine-resistant mutants were not observed upon long-term (P = 25) sequential passage of BPXV and NDV in cell culture. Collectively, we have extended the effective antiviral activity of emetine against diverse groups of DNA and RNA viruses and propose that emetine could provide significant therapeutic value against some of these viruses without inducing an antiviral drug-resistant phenotype. Copyright © 2017 Elsevier B.V. All rights reserved.
DEFF Research Database (Denmark)
Mangione, Fernanda Marinho; Biering-Sørensen, Tor; Nochioka, Kotaro
2017-01-01
OBJECTIVES: To compare mid-term outcomes between patients undergoing proximal left anterior descending artery (LAD) percutaneous coronary intervention (PCI) with second generation drug-eluting stent (DES) or bare-metal stent (BMS). BACKGROUND: PCI with BMS and first-generation DES have shown to b...
Blow, Frederic C; Walton, Maureen A; Bohnert, Amy S B; Ignacio, Rosalinda V; Chermack, Stephen; Cunningham, Rebecca M; Booth, Brenda M; Ilgen, Mark; Barry, Kristen L
2017-08-01
To examine efficacy of drug brief interventions (BIs) among adults presenting to a low-income urban emergency department (ED). Randomized controlled trial on drug use outcomes at 3, 6 and 12 months. Participants were assigned to (1) computer-delivered BI (Computer BI), (2) therapist-delivered, computer-guided BI (Therapist BI) or (3) enhanced usual care (EUC-ED) for drug-using adults. Participants were re-randomized after the 3-month assessment to either adapted motivational enhancement therapy (AMET) booster or enhanced usual care booster (EUC-B). Patients recruited from low-income urban emergency departments (ED) in Flint, Michigan, USA. A total of 780 ED patients reporting recent drug use, 44% males, mean age = 31 years. Computer BI consisted of an interactive program guided by a virtual health counselor. Therapist BI included computer guidance. The EUC-ED conditions included review of community health and HIV prevention resources. The BIs and boosters were based on motivational interviewing, focusing on reduction of drug use and HIV risk behaviors. Primary outcome was past 90 days using drugs at 6 and 12 months and secondary outcomes were weighted drug-days and days of marijuana use. Percentage changes in mean days used any drug from baseline to 12 months were: Computer BI + EUC-B: -10.9%, P = 0.0844; Therapist BI + EUC-B: -26.7%, P = 0.0041, for EUC-ED + EUC-B: -20.9, P = 0.0011. In adjusted analyses, there was no significant interaction between ED intervention and booster AMET for primary and secondary outcomes. Compared with EUC-ED, Therapist BI reduced number of days using any drug [95% confidence interval (CI) = -0.41, -0.07, P = 0.0422] and weighted drug-days (95% CI = -0.41, -0.08, P = 0.0283). Both Therapist and Computer BI had significantly fewer number of days using marijuana compared to EUC-ED (Therapist BI: 95% CI = -0.42, -0.06, P = 0.0104, Computer BI: 95% CI = -0.34, -0.01, P = 0.0406). Booster effects were not
Wade, Lucie; Forlini, Cynthia; Racine, Eric
2014-05-12
Donepezil, an acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease, has been widely cited in media and bioethics literature on cognitive enhancement (CE) as having the potential to improve the cognitive ability of healthy individuals. In both literatures, this claim has been repeatedly supported by the results of a small study published by Yesavage et al. in 2002 on non-demented pilots (30-70 years old). The factors contributing to this specific interpretation of this study's results are unclear. We examined print media and interdisciplinary bioethics coverage of this small study, aiming to provide insight into how evidence from research may be shaped within different discourses, potentially influencing important policy, ethics, and clinical decisions. Systematic qualitative content analysis was used to examine how this study was reported in 27 media and 22 bioethics articles. Articles were analyzed for content related to: (1) headlines and titles; (2) colloquialisms; and, (3) accuracy of reporting of the characteristics and results of the study. In media and bioethics articles referencing this small study, strong claims were made about donepezil as a CE drug. The majority of headlines, titles, and colloquialisms used enhancement language and the majority of these suggest that donepezil could be used to enhance intellectual ability. Further, both literatures moved between reporting the results of the primary study and magnifying the perceived connection between these results and the CE debate that was alluded to in the primary study. Specific descriptions of the results overwhelmingly reported an improvement in performance on a flight simulator, while more general statements claimed donepezil enhanced cognitive performance. Further, a high level of reporting accuracy was found regarding study characteristics of the original study, but variable levels of accuracy surrounded the presentation of complex characteristics (i.e., methods) or
Kooijman, D.G.; Balau, A.E.; Wilkins, S.; Ligterink, N.; Cuelenaere, R.
2015-01-01
European light duty vehicle emission legislation is gradually shifting the focus from test procedures with merely static test cycles, towards procedures including Real Driving Emissions (RDE), as they are a mean to achieve the European (NOx) emission reduction target. Hence a RDE trip must represent
Kooijman, D.G.; Balau, A.E.; Wilkins, S.; Ligterink, N.; Cuelenaere, R.
2015-01-01
European light duty vehicle emission legislation is gradually shifting the focus from test procedures with merely static test cycles, towards procedures including Real Driving Emissions (RDE), as they are a mean to achieve the European (NOx) emission reduction target. Hence a RDE trip must represent
Safety concerns and hidden agenda behind HPV vaccines: another generation of drug-dependent society?
Khatami, Mahin
2016-12-01
Analyses of data and hidden agenda behind repeated failed outcomes of cancer research and therapy, status of American health, safety concerns for HPV vaccines and future research considerations are summarized in this commentary. A closer look at cancer science reveals that highly power structure (system) in medical establishment vs. anti-system and chaos in cancer research ('medical/scientific ponzi schemes') is potent recipe for failed therapeutics that kills patients but generates huge corporate profit. American health status ranks last among other developed nations despite the highest amount that USA invests in healthcare. This is a wake-up call to make sure that the evil part of human being does not prevent the health services that the public deserves. Otherwise, 'it does not matter how many resources you have, if you don't know, or don't want to know, how to use them, they will never be enough'. Answer to cancer and improved public health is possible only by switching the current corruptive and abusive culture of 'who you know' to a culture of 'what you know'. Policy makers and professionals in decision making roles are urged to return to common sense and logics that our Forefathers used to serve the public.
Sadeek, Sadeek A.; El-Shwiniy, Walaa H.
2010-08-01
Three metal complexes of the fourth generation quinolone antimicrobial agent gatifloxacin (GFLX) with Y(ΙΙΙ), Zr(ΙV) and U(VΙ) have been prepared and characterized with physicochemical and spectroscopic techniques. In these complexes, gatifloxacin acts as a bidentate deprotonated ligand bound to the metal through the ketone oxygen and a carboxylato oxygen. The complexes are six-coordinated with distorted octahedral geometry. The kinetic parameters for gatifloxacin and the three prepared complexes have been evaluated from TGA curves by using Coats-Redfern (CR) and Horowitz-Metzeger (HM) methods. The calculated bond length and force constant, F(U dbnd O), for the UO 2 bond in uranyl complex are 1.7522 Å and 639.46 N m -1. The antimicrobial activity of the complexes has been tested against microorganisms, three bacterial species, such as Staphylococcus aureus ( S. aureus), Escherichia coli ( E. coli) and Pseudomonas aeruginosa ( P. aeruginosa) and two fungi species, penicillium ( P. rotatum) and trichoderma ( T. sp.), showing that they exhibit higher activity than free ligand.
Crawford, Natalie D; Amesty, Silvia; Rivera, Alexis V; Harripersaud, Katherine; Turner, Alezandria; Fuller, Crystal M
2013-09-01
Structural interventions may help reduce racial/ethnic disparities in HIV. In 2009 to 2011, we randomized pharmacies participating in a nonprescription syringe access program in minority communities to intervention (pharmacy enrolled and delivered HIV risk reduction information to injection drug users [IDUs]), primary control (pharmacy only enrolled IDUs), and secondary control (pharmacy did not engage IDUs). Intervention pharmacy staff reported more support for syringe sales than did control staff. An expanded pharmacy role in HIV risk reduction may be helpful.
Li, Zhanguo; An, Yuan; Su, Houheng; Li, Xiangpei; Xu, Jianhua; Zheng, Yi; Li, Guiye; Kwok, Kenneth; Wang, Lisy; Wu, Qizhe
2018-01-01
Abstract Aim Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We assess the effect of tofacitinib + conventional synthetic disease‐modifying anti rheumatic drugs (csDMARDs) on patient‐reported outcomes in Chinese patients with RA and inadequate response to DMARDs. Methods This analysis of data from the Phase 3 study ORAL Sync included Chinese patients randomized 4 : 4 : 1 : 1 to receive tofacitinib 5 mg twice daily, tofacitinib 10 mg twice daily, p...
Directory of Open Access Journals (Sweden)
Ikeda H
2015-10-01
Full Text Available Hiroshi Ikeda,1 Kazuya Ishiguro,1 Tetsuyuki Igarashi,1 Yuka Aoki,1 Toshiaki Hayashi,1 Tadao Ishida,1 Yasushi Sasaki,1,2 Takashi Tokino,2 Yasuhisa Shinomura1 1Department of Gastroenterology, Rheumatology and Clinical Immunology, 2Medical Genome Sciences, Research Institute for Frontier Medicine, Sapporo Medical University, Sapporo, Japan Abstract: A 69-year-old man was diagnosed with IgG λ-type multiple myeloma (MM, Stage II in October 2010. He was treated with one cycle of high-dose dexamethasone. After three cycles of bortezomib, the patient exhibited slow elevations in the free light-chain levels and developed a significant new increase of serum M protein. Bone marrow cytogenetic analysis revealed a complex karyotype characteristic of malignant plasma cells. To better understand the molecular pathogenesis of this patient, we sequenced for mutations in the entire coding regions of 409 cancer-related genes using a semiconductor-based sequencing platform. Sequencing analysis revealed eight nonsynonymous somatic mutations in addition to several copy number variants, including CCND1 and RB1. These alterations may play roles in the pathobiology of this disease. This targeted next-generation sequencing can allow for the prediction of drug resistance and facilitate improvements in the treatment of MM patients. Keywords: multiple myeloma, drug resistance, genome-wide sequencing, semiconductor sequencer, target therapy
Jang, Hun-jae; Park, Mi-ae; Sirotkin, Fedir V.; Yoh, Jack J.
2013-12-01
The expansion of the laser-induced bubble is the main mechanism in the developed microjet injector. In this study, Nd:YAG and Er:YAG lasers are used as triggers of the bubble formation. The impact of the laser parameters on the bubble dynamics is studied and the performance of the injector is evaluated. We found that the main cause of the differences in the bubble behavior comes from the pulse duration and wavelength. For Nd:YAG laser, the pulse duration is very short relative to the bubble lifetime making the behavior of the bubble close to that of the cavitation bubble, while in Er:YAG case, the high absorption in the water and long pulse duration change the initial behavior of the bubble making it close to a vapor bubble. The contraction and subsequent rebound are typical for cavitation bubbles in both cases. The results show that the laser-induced microjet injector generates velocity which is sufficient for the drug delivery for both laser beams of different pulse duration. We estimate the typical velocity within 30-80 m/s range and the breakup length to be larger than 1 mm suitable for trans-dermal drug injection.
Maru, Duncan Smith-Rohrberg; Kozal, Michael J; Bruce, R Douglas; Springer, Sandra A; Altice, Frederick L
2007-12-15
Directly administered antiretroviral therapy (DAART) is an effective intervention that improves clinical outcomes among HIV-infected drug users. Its effects on antiretroviral drug resistance, however, are unknown. We conducted a community-based, prospective, randomized controlled trial of DAART compared with self-administered therapy (SAT). We performed a modified intention-to-treat analysis among 115 subjects who provided serum samples for HIV genotypic resistance testing at baseline and at follow-up. The main outcomes measures included total genotypic sensitivity score, future drug options, number of new drug resistance mutations (DRMs), and number of new major International AIDS Society (IAS) mutations. The adjusted probability of developing at least 1 new DRM did not differ between the 2 arms (SAT: 0.41 per person-year [PPY], DAART: 0.49 PPY; adjusted relative risk [RR] = 1.04; P = 0.90), nor did the number of new mutations (SAT: 0.76 PPY, DAART: 0.83 PPY; adjusted RR = 0.99; P = 0.99) or the probability of developing new major IAS new drug mutations (SAT: 0.30 PPY, DAART: 0.33 PPY; adjusted RR = 1.12; P = 0.78). On measures of GSS and FDO, the 2 arms also did not differ. In this trial, DAART provided on-treatment virologic benefit for HIV-infected drug users without affecting the rate of development of antiretroviral medication resistance.