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Sample records for base dependent dna-carbon

  1. Paper-based electrochemiluminescence origami device for protein detection using assembled cascade DNA-carbon dots nanotags based on rolling circle amplification.

    Science.gov (United States)

    Wu, Ludan; Ma, Chao; Zheng, Xiaoxiao; Liu, Haiyun; Yu, Jinghua

    2015-06-15

    In this work, we developed a cascade signal amplification strategy for detection of IgG antigen by combining the rolling circle amplification (RCA) technique with oligonucleotide functionalized carbon dots (CDs), based on a paper-based electrochemiluminescence (ECL) origami device (PECLOD) for the first time. In this PECLOD, three-dimensional (3D) macroporous Au-paper electrode was fabricated and employed as the working electrode for specific and efficient antibodies capture. The RCA product containing tandem-repeat sequences could serve as an excellent template for periodic assembly of CDs, which presented per protein recognition event to numerous CDs tags for ECL readout. Under the optimal conditions, the proposed strategy showed remarkable amplification efficiency, very little nonspecific adsorption with good stability, reproducibility, and accuracy. Using human IgG (H-IgG) as a model protein, the designed strategy was successfully demonstrated for the ultrasensitive detection of protein target. The results revealed that the strategy exhibited a dynamic response to H-IgG range from 1.0 fM to 25 pM with a limit of detection as low as 0.15 fM. Importantly, the methodology can be further extended to the detection of other proteins or biomarkers.

  2. Measuring Class Cohesion Based on Dependence Analysis

    Institute of Scientific and Technical Information of China (English)

    Zhen-Qiang Chen; Bao-Wen Xu; Yu-Ming Zhou

    2004-01-01

    Classes are the basic modules in object-oriented (OO) software, which consist of attributes and methods. Thus, in OO environment, the cohesion is mainly about the tightness of the attributes and methods of classes. This paper discusses the relationships between attributes and attributes, attributes and methods, methods and methods of a class based on dependence analysis. Then the paper presents methods to compute these dependencies. Based on these, the paper proposes a method to measure the class cohesion, which satisfies the properties that a good measurement should have. The approach overcomes the limitations of previous class cohesion measures, which consider only one or two of the three relationships in a class.

  3. Learning Dependency-Based Compositional Semantics

    CERN Document Server

    Liang, Percy; Klein, Dan

    2011-01-01

    Suppose we want to build a system that answers a natural language question by representing its semantics as a logical form and computing the answer given a structured database of facts. The core part of such a system is the semantic parser that maps questions to logical forms. Semantic parsers are typically trained from examples of questions annotated with their target logical forms, but this type of annotation is expensive. Our goal is to learn a semantic parser from question-answer pairs instead, where the logical form is modeled as a latent variable. Motivated by this challenging learning problem, we develop a new semantic formalism, dependency-based compositional semantics (DCS), which has favorable linguistic, statistical, and computational properties. We define a log-linear distribution over DCS logical forms and estimate the parameters using a simple procedure that alternates between beam search and numerical optimization. On two standard semantic parsing benchmarks, our system outperforms all existing...

  4. Chinese Statistical Parser Based on Semantic Dependencies

    Institute of Scientific and Technical Information of China (English)

    李涓子; 王作英

    2002-01-01

    A new tagging method is presented to build a Chinese semantic corpus. The method characterizes the sentence meaning as a linear sequence of dependency relationships which are the semantic or syntactic relationships between words in the sentence. This representation method is used to build a Chinese statistical parser model to understand the sentence meaning. Specific experiments on automatic telephone switchboard conversations show that the proposed parser has a precision of 80%. This work provides a foundation for building a large-scale Chinese semantic corpus and for research on understanding modeling of the Chinese language.

  5. Scale-Dependent Representations of Relief Based on Wavelet Analysis

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Automatic generalization of geographic information is the core of multi-scale representation of spatial data,but the scale-dependent generalization methods are far from abundant because of its extreme complicacy.This paper puts forward a new consistency model about scale-dependent representations of relief based on wavelet analysis,and discusses the thresholds in the model so as to acquire the continual representations of relief with different details between scales.The model not only meets the need of automatic generalization but also is scale-dependent completely.Some practical examples are given.

  6. Valley-dependent beam manipulators based on photonic graphene

    Science.gov (United States)

    Deng, Fu-Sheng; Sun, Yong; Dong, Li-Juan; Liu, Yan-Hong; Shi, Yun-Long

    2017-02-01

    Trigonal warping distortion in energy band lifts the degeneracy of two valleys (K and K' points) of graphene. In this situation, electron transport becomes valley dependent, which can be used to design the valley beam splitter, collimator, or guiding device. Here, valley-dependent beam manipulators are designed based on artificial photonic graphene. In this scheme, the finite-size artificial photonic graphene is intentionally designed to realize the novel device functionalities. This kind of valley-dependent beam manipulators can work at an arbitrary range of electromagnetic waves from microwave to visible light. It potentially paves the way for the application of photonic graphene in future integrated photonic devices.

  7. Model-Based Dependability Analysis of Physical Systems with Modelica

    Directory of Open Access Journals (Sweden)

    Andrea Tundis

    2017-01-01

    Full Text Available Modelica is an innovative, equation-based, and acausal language that allows modeling complex physical systems, which are made of mechanical, electrical, and electrotechnical components, and evaluates their design through simulation techniques. Unfortunately, the increasing complexity and accuracy of such physical systems require new, more powerful, and flexible tools and techniques for evaluating important system properties and, in particular, the dependability ones such as reliability, safety, and maintainability. In this context, the paper describes some extensions of the Modelica language to support the modeling of system requirements and their relationships. Such extensions enable the requirement verification analysis through native constructs in the Modelica language. Furthermore, they allow exporting a Modelica-based system design as a Bayesian Network in order to analyze its dependability by employing a probabilistic approach. The proposal is exemplified through a case study concerning the dependability analysis of a Tank System.

  8. Least Dependent Component Analysis Based on Mutual Information

    CERN Document Server

    Stögbauer, H; Astakhov, S A; Grassberger, P; St\\"ogbauer, Harald; Kraskov, Alexander; Astakhov, Sergey A.; Grassberger, Peter

    2004-01-01

    We propose to use precise estimators of mutual information (MI) to find least dependent components in a linearly mixed signal. On the one hand this seems to lead to better blind source separation than with any other presently available algorithm. On the other hand it has the advantage, compared to other implementations of `independent' component analysis (ICA) some of which are based on crude approximations for MI, that the numerical values of the MI can be used for: (i) estimating residual dependencies between the output components; (ii) estimating the reliability of the output, by comparing the pairwise MIs with those of re-mixed components; (iii) clustering the output according to the residual interdependencies. For the MI estimator we use a recently proposed k-nearest neighbor based algorithm. For time sequences we combine this with delay embedding, in order to take into account non-trivial time correlations. After several tests with artificial data, we apply the resulting MILCA (Mutual Information based ...

  9. A New Statistical Parser Based on Bigram Lexical Dependencies

    CERN Document Server

    Collins, M

    1996-01-01

    This paper describes a new statistical parser which is based on probabilities of dependencies between head-words in the parse tree. Standard bigram probability estimation techniques are extended to calculate probabilities of dependencies between pairs of words. Tests using Wall Street Journal data show that the method performs at least as well as SPATTER (Magerman 95, Jelinek et al 94), which has the best published results for a statistical parser on this task. The simplicity of the approach means the model trains on 40,000 sentences in under 15 minutes. With a beam search strategy parsing speed can be improved to over 200 sentences a minute with negligible loss in accuracy.

  10. Energy based model for temperature dependent behavior of ferromagnetic materials

    Science.gov (United States)

    Sah, Sanjay; Atulasimha, Jayasimha

    2017-03-01

    An energy based model for temperature dependent anhysteretic magnetization curves of ferromagnetic materials is proposed and benchmarked against experimental data. This is based on the calculation of macroscopic magnetic properties by performing an energy weighted average over all possible orientations of the magnetization vector. Most prior approaches that employ this method are unable to independently account for the effect of both inhomogeneity and temperature in performing the averaging necessary to model experimental data. Here we propose a way to account for both effects simultaneously and benchmark the model against experimental data from 5 K to 300 K for two different materials in both annealed (fewer inhomogeneities) and deformed (more inhomogeneities) samples. This demonstrates that this framework is well suited to simulate temperature dependent experimental magnetic behavior.

  11. Node-Dependence-Based Dynamic Incentive Algorithm in Opportunistic Networks

    Directory of Open Access Journals (Sweden)

    Ruiyun Yu

    2014-01-01

    Full Text Available Opportunistic networks lack end-to-end paths between source nodes and destination nodes, so the communications are mainly carried out by the “store-carry-forward” strategy. Selfish behaviors of rejecting packet relay requests will severely worsen the network performance. Incentive is an efficient way to reduce selfish behaviors and hence improves the reliability and robustness of the networks. In this paper, we propose the node-dependence-based dynamic gaming incentive (NDI algorithm, which exploits the dynamic repeated gaming to motivate nodes relaying packets for other nodes. The NDI algorithm presents a mechanism of tolerating selfish behaviors of nodes. Reward and punishment methods are also designed based on the node dependence degree. Simulation results show that the NDI algorithm is effective in increasing the delivery ratio and decreasing average latency when there are a lot of selfish nodes in the opportunistic networks.

  12. Sleep-dependent consolidation of value-based learning.

    Science.gov (United States)

    Baran, Bengi; Daniels, Dasha; Spencer, Rebecca M C

    2013-01-01

    It has been suggested that sleep selectively enhances memories with future relevance. Given that sleep's benefits can vary by item within a learning context, the present study investigated whether the amount of sleep-dependent consolidation may vary across items based on the value of the to-be-learned material. For this purpose, we used a value-based learning paradigm in which participants studied words paired with point values. There were two groups; participants either studied the words in the evening and were tested after a 12 hr interval containing a full night of sleep, or studied the words in the morning and were tested after 12 hr of continuous daytime wake. Free recall (F(1,36) = 19.35, pvalue for sleep and wake groups (p = .74). Thus, while encoding may vary with the value of the to-be-learned item, sleep-dependent consolidation does not.

  13. Dependence Analysis Based on Dynamic Slicing for Debugging

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Dynamic program slicing is an effective technique for narrowingthe errors to t h e relevant parts of a program when debugging. Given a slicing criterion, the dyn amic slice contains only those statements that actually affect the variables in the slicing criterion. This paper proposes a dynamic slicing method based on sta tic dependence analysis. It uses the program dependence graph and other static i nformation to reduce the information needed to be traced during program executio n. Thus, the efficiency is dramatically improved while the precision is not depr e ssed. The slicing criterion is modified to fit for debugging. It consists of fil e-name and the line number at which the statement is.

  14. Dependability modeling and assessment in UML-based software development.

    Science.gov (United States)

    Bernardi, Simona; Merseguer, José; Petriu, Dorina C

    2012-01-01

    Assessment of software nonfunctional properties (NFP) is an important problem in software development. In the context of model-driven development, an emerging approach for the analysis of different NFPs consists of the following steps: (a) to extend the software models with annotations describing the NFP of interest; (b) to transform automatically the annotated software model to the formalism chosen for NFP analysis; (c) to analyze the formal model using existing solvers; (d) to assess the software based on the results and give feedback to designers. Such a modeling→analysis→assessment approach can be applied to any software modeling language, be it general purpose or domain specific. In this paper, we focus on UML-based development and on the dependability NFP, which encompasses reliability, availability, safety, integrity, and maintainability. The paper presents the profile used to extend UML with dependability information, the model transformation to generate a DSPN formal model, and the assessment of the system properties based on the DSPN results.

  15. Unveiling Stability Criteria of DNA-Carbon Nanotubes Constructs by Scanning Tunneling Microscopy and Computational Modeling

    Directory of Open Access Journals (Sweden)

    Svetlana Kilina

    2011-01-01

    Full Text Available We present a combined approach that relies on computational simulations and scanning tunneling microscopy (STM measurements to reveal morphological properties and stability criteria of carbon nanotube-DNA (CNT-DNA constructs. Application of STM allows direct observation of very stable CNT-DNA hybrid structures with the well-defined DNA wrapping angle of 63.4° and a coiling period of 3.3 nm. Using force field simulations, we determine how the DNA-CNT binding energy depends on the sequence and binding geometry of a single strand DNA. This dependence allows us to quantitatively characterize the stability of a hybrid structure with an optimal π-stacking between DNA nucleotides and the tube surface and better interpret STM data. Our simulations clearly demonstrate the existence of a very stable DNA binding geometry for (6,5 CNT as evidenced by the presence of a well-defined minimum in the binding energy as a function of an angle between DNA strand and the nanotube chiral vector. This novel approach demonstrates the feasibility of CNT-DNA geometry studies with subnanometer resolution and paves the way towards complete characterization of the structural and electronic properties of drug-delivering systems based on DNA-CNT hybrids as a function of DNA sequence and a nanotube chirality.

  16. Bases neurofisiológicas da dependência do tabaco Neurophysiological basis of tobacco dependence

    Directory of Open Access Journals (Sweden)

    Cleopatra S. Planeta

    2005-10-01

    Full Text Available A maioria dos estudos pré-clínicos e clínicos aponta a nicotina como o principal agente responsável pelo desenvolvimento da dependência ao tabaco. Muitos trabalhos têm demonstrado que as bases neurais da dependência à nicotina são semelhantes àquelas das outras drogas de abuso. A nicotina induz preferência condicionada por lugar e auto-administração e, portanto, atua como reforçador positivo, esse efeito parece ser mediado pelo sistema dopaminérgico mesolímbico. A nicotina também induz à sensibilização comportamental que é provavelmente resultante de alterações da expressão gênica do núcleo acumbens induzidas pela exposição prolongada a essa substância. A suspensão do uso de nicotina resulta em síndrome de abstinência. As evidências indicam que esses sinais e sintomas sejam mediados por receptores colinérgicos nicotínicos centrais e periféricos. Outros neurotransmissores, como por exemplo a serotonina e os peptídeos opióides, também podem estar envolvidos na mediação da dependência e síndrome de abstinência à nicotina. A revisão da literatura mostra a complexidade dos efeitos da nicotina no organismo. A integração entre as abordagens comportamental, neuroquímica e molecular possibilitará a compreensão dos mecanismos neurais da dependência ao tabaco e fornecerá as bases para o desenvolvimento racional de agentes terapêuticos que possam ser utilizados para o tratamento da dependência e síndrome de abstinência ao tabaco.It is generally accepted that nicotine is the major component in tobacco smoke responsible for addiction. Several studies have demonstrated that the neural mechanisms underlying nicotine addiction have much in common with those underlying the mechanisms of addiction to other drugs. Thus, it has been shown that nicotine induces conditioning place preference and self-administration across many species. Repeated treatment with nicotine also induces behavioral sensitization in

  17. SA BASED SOFTWARE DEPLOYMENT RELIABILITY ESTIMATION CONSIDERING COMPONENT DEPENDENCE

    Institute of Scientific and Technical Information of China (English)

    Su Xihong; Liu Hongwei; Wu Zhibo; Yang Xiaozong; Zuo Decheng

    2011-01-01

    Reliability is one of the most critical properties of software system.System deployment architecture is the allocation of system software components on host nodes.Software Architecture (SA)based software deployment models help to analyze reliability of different deployments.Though many approaches for architecture-based reliability estimation exist,little work has incorporated the influence of system deployment and hardware resources into reliability estimation.There are many factors influencing system deployment.By translating the multi-dimension factors into degree matrix of component dependence,we provide the definition of component dependence and propose a method of calculating system reliability of deployments.Additionally,the parameters that influence the optimal deployment may change during system execution.The existing software deployment architecture may be ill-suited for the given environment,and the system needs to be redeployed to improve reliability.An approximate algorithm,A*_D,to increase system reliability is presented.When the number of components and host nodes is relative large,experimental results show that this algorithm can obtain better deployment than stochastic and greedy algorithms.

  18. Force transducers based on the stress dependence of coercive force

    Science.gov (United States)

    Garshelis, I. J.

    1993-05-01

    An alternative measurement regime for magnetoelastic force transducers, based on variations in coercive field, is described. Hc is shown to be more directly related to the primary magnetic influence of stress, namely, the orientation of effective anisotropy, than conventionally used magnetization related parameters. The stress dependence of Hc is shown to generally reflect opposing factors associated with rotational and wall displacement magnetization reversal processes. In materials wherein Hc≪K/Ms wall motion dominates and if the product of λs/K and yield stress is high enough, large monotonic reductions of Hc with positive (tensile) stress are shown to be possible. A more complex variation of Hc with increasing compression is similarly expected. Experimental results from a transducer having an 18% Ni maraging steel core support these expectations.

  19. Spin-dependent terahertz oscillator based on hybrid graphene superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Díaz, E.; Miralles, K.; Domínguez-Adame, F. [GISC, Departamento Física de Materiales, Universidad Complutense, E-28040 Madrid (Spain); Gaul, C., E-mail: cgaul@pks.mpg.de [Max Planck Institute for the Physics of Complex Systems, 01187 Dresden (Germany)

    2014-09-08

    We theoretically study the occurrence of Bloch oscillations in biased hybrid graphene systems with spin-dependent superlattices. The spin-dependent potential is realized by a set of ferromagnetic insulator strips deposited on top of a gapped graphene nanoribbon, which induce a proximity exchange splitting of the electronic states in the graphene monolayer. We numerically solve the Dirac equation and study Bloch oscillations in the lowest conduction band of the spin-dependent superlattice. While the Bloch frequency is the same for both spins, we find the Bloch amplitude to be spin dependent. This difference results in a spin-polarized ac electric current in the THz range.

  20. Speaker-dependent Dictionary-based Speech Enhancement for Text-Dependent Speaker Verification

    DEFF Research Database (Denmark)

    Thomsen, Nicolai Bæk; Thomsen, Dennis Alexander Lehmann; Tan, Zheng-Hua

    2016-01-01

    The problem of text-dependent speaker verification under noisy conditions is becoming ever more relevant, due to increased usage for authentication in real-world applications. Classical methods for noise reduction such as spectral subtraction and Wiener filtering introduce distortion and do...

  1. Dependency Modeling of a SOA Based System Through Colored Petri Nets

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    2016-09-01

    Full Text Available Dependency relationships play an important role in testing, maintenance and configuration management of software systems. The informal dependency representations fail to observe behavioral connections among subsystems and cause ambiguity in representing different types of dependency relationships. Therefore, dependency in a software system requires a formal and unambiguous representation so that its correct effects can be visualized. In this paper, we present a Colored Petri Net based dependency analysis of a Service Oriented Architecture (SOA based system that represents specification of dependency relationships and models the dependencies in a SOA based system at conceptual level. Different types of dependency relations are represented in a formal manner by using Service Algebra. A module SOA based system ‘Online Bookshop’ has been developed and used for the purpose of modeling and example demonstration. Such modeling can help in identification of inconsistency among services, and web services can be verified for safety and reliability.

  2. DNA-carbon dots function as fluorescent vehicles for drug delivery.

    Science.gov (United States)

    Ding, Han; Du, Feiyue; Liu, Pengchang; Chen, Zhijun; Shen, Jiacong

    2015-04-01

    Carbon dots (CDs) are a new representative in the carbon-based material family, attracting tremendous interest in a large variety of fields, including biomedicine. In this report, we described a facile and green system for synthesizing DNA-CDs using genomic DNA isolated from Escherichia coli. DNA-CDs can be purified using a simple column centrifugation-based system. During DNA-CD synthesis, ribose was collapsed, accompanied by the release of nitrogen, and several new bonds (C-OH, N-O, and N-P) were formed, while the other covalent bonds of DNA were largely maintained. The presence of abundant chemical groups, such as amino or hydroxyl groups on DNA-CDs, may facilitate their future functionalization. These highly biocompatible DNA-CDs can serve as a new type of fluorescent vehicle for cell imaging and drug delivery studies. Our research may hasten the development of CDs for prominent future biomedical applications.

  3. Research on Dependable Ionizing Radiation Protection based on Model i*

    Directory of Open Access Journals (Sweden)

    Tan Hai

    2013-07-01

    Full Text Available The software’s unreliability mostly attributes to an erroneous analysis on the requirements done at the beginning. In this paper, we apply the tool of i* frame requirement modeling and build early requirement model against ionizing radiation. After finding out possible risks and corresponding solutions during the process of modeling analysis, we propose reasoning models against ionizing radiation. The radiation protection system  with  the  above models  can  figure out  the  purpose  of agents  related  to radiant source and provide normal service even when the environment software system is being interfered. It can serve the ecological and economical society with stability and development.  The model is divided into several sections. Section 1 gives the outline of the dependant software. Section 2 illustrates the  i* frame  technology. Section 3, 4 and 5 cover the topic of dependant security requirement analysis, SD&SR model on ionizing radiation respectively. Section 6 gives the conclusion.

  4. DEM Based Modeling: Grid or TIN? The Answer Depends

    Science.gov (United States)

    Ogden, F. L.; Moreno, H. A.

    2015-12-01

    The availability of petascale supercomputing power has enabled process-based hydrological simulations on large watersheds and two-way coupling with mesoscale atmospheric models. Of course with increasing watershed scale come corresponding increases in watershed complexity, including wide ranging water management infrastructure and objectives, and ever increasing demands for forcing data. Simulations of large watersheds using grid-based models apply a fixed resolution over the entire watershed. In large watersheds, this means an enormous number of grids, or coarsening of the grid resolution to reduce memory requirements. One alternative to grid-based methods is the triangular irregular network (TIN) approach. TINs provide the flexibility of variable resolution, which allows optimization of computational resources by providing high resolution where necessary and low resolution elsewhere. TINs also increase required effort in model setup, parameter estimation, and coupling with forcing data which are often gridded. This presentation discusses the costs and benefits of the use of TINs compared to grid-based methods, in the context of large watershed simulations within the traditional gridded WRF-HYDRO framework and the new TIN-based ADHydro high performance computing watershed simulator.

  5. Porphyrin-based Nanostructure-Dependent Photodynamic and Photothermal Therapies

    Science.gov (United States)

    Jin, Cheng S.

    This thesis presents the investigation of nanostructure-dependent phototherapy. We reviewed the liposomal structures for delivery of photosensitizers, and introduced a novel class of phototransducing liposomes called "porphysomes". Porphysomes are self-assembled from high packing density of pyropheophorbide alpha-conjugated phospholipids, resulting in extreme self-quenching of porphyrin fluorescence and comparable optical absorption to gold nanoparticles for high photothermal efficiency. We demonstrated this self-assembly of porphyrin-lipid conjugates converts a singlet oxygen generating mechanism (photodynamic therapy PDT activity) of porphyrin to photothermal mechanism (photothermal therapy PTT activity). The efficacy of porphysome-enhanced PTT was then evaluated on two pre-clinical animal models. We validated porphysome-enabled focal PTT to treat orthotopic prostate cancer using MRI-guided focal laser placement to closely mimic the current clinic procedure. Furthermore, porphysome-enabled fluorescence-guided transbronchial PTT of lung cancer was demonstrated in rabbit orthotopic lung cancer models, which led to the development of an ultra-minimally invasive therapy for early-stage peripheral lung cancer. On the other hand, the nanostructure-mediated conversion of PDT to PTT can be switched back by nanoparticle dissociation. By incorporating folate-conjugated phospholipids into the formulation, porphysomes were internalized into cells rapidly via folate receptor-mediated endocytosis and resulted in efficient disruption of nanostructures, which turned back on the photodynamic activity of densely packed porphyrins, making a closed loop of conversion between PDT and PTT. The multimodal imaging and therapeutic features of porphysome make it ideal for future personalized cancer treatments.

  6. Optical fiber temperature sensor based on wavelength-dependent detection

    Institute of Scientific and Technical Information of China (English)

    Zhigang Li(李志刚); Zhenhui Du(杜振辉); Baoguang Wang(王宝光); Chengzhi Jiang(蒋诚志)

    2004-01-01

    Semiconductor fiber temperature sensors have been used widely in many fields, but most of them pick up temperature by measuring the optical intensity of certain fixed narrow-band in absorption spectrum.Furthermore, they are sensitive to the loss of optical intensity and the fluctuation of light source power.The novel temperature measurement system proposed in this paper is based on the semiconductor absorption theory and the spectral analysis of method. To measure temperature, the sensor model detects not the certain narrow-band spectrum but the most spectra of the optical absorption edge. Therefore the measurement accuracy and the stability can be improved greatly. Experimental results are in agreement with theoretical analysis results perfectly.

  7. Time dependent mechanical modeling for polymers based on network theory

    Science.gov (United States)

    Billon, Noëlle

    2016-05-01

    Despite of a lot of attempts during recent years, complex mechanical behaviour of polymers remains incompletely modelled, making industrial design of structures under complex, cyclic and hard loadings not totally reliable. The non linear and dissipative viscoelastic, viscoplastic behaviour of those materials impose to take into account non linear and combined effects of mechanical and thermal phenomena. In this view, a visco-hyperelastic, viscoplastic model, based on network description of the material has recently been developed and designed in a complete thermodynamic frame in order to take into account those main thermo-mechanical couplings. Also, a way to account for coupled effects of strain-rate and temperature was suggested. First experimental validations conducted in the 1D limit on amorphous rubbery like PMMA in isothermal conditions led to pretty goods results. In this paper a more complete formalism is presented and validated in the case of a semi crystalline polymer, a PA66 and a PET (either amorphous or semi crystalline) are used. Protocol for identification of constitutive parameters is described. It is concluded that this new approach should be the route to accurately model thermo-mechanical behaviour of polymers using a reduced number of parameters of some physicl meaning.

  8. Micro-RNA detection based on fluorescence resonance energy transfer of DNA-carbon quantum dots probes.

    Science.gov (United States)

    Khakbaz, Faeze; Mahani, Mohamad

    2017-04-15

    Carbon quantum dots have been proposed as an effective platform for miRNA detection. Carbon dots were synthesized by citric acid. The synthesized dots were characterized by dynamic light scattering, UV-Vis spectrophotometry, spectrofluorimetry, transmission electron microscopy and FT-IR spectrophotometry. The fluorescence quantum yield of the synthesized dots was determined using quinine sulfate as the standard. The FAM-labeled single stranded DNA, as sensing element, was adsorbed on dots by π-π interaction. The quenching of the dots fluorescence due to fluorescence resonance energy transfer (FRET) was used for mir 9-1 detection. In the presence of the complementary miRNA, the FRET did not take place and the fluorescence was recovered.

  9. Nicotine Dependence as a Moderator of a Quitline-Based Message Framing Intervention

    OpenAIRE

    Fucito, Lisa M.; Latimer, Amy E.; Carlin-Menter, Shannon; Salovey, Peter; Cummings, K. Michael; Makuch, Robert W.; Toll, Benjamin A.

    2010-01-01

    High nicotine dependence is a reliable predictor of difficulty quitting smoking and remaining smoke-free. Evidence also suggests that the effectiveness of various smoking cessation treatments may vary by nicotine dependence level. Nicotine dependence, as assessed by Heaviness of Smoking Index baseline total scores, was evaluated as a potential moderator of a message-framing intervention provided through the New York State Smokers’ Quitline (free telephone based service). Smokers were exposed ...

  10. Irradiance and Temperature Dependence of Photo-Induced Orientation in Two Azobenzene-Based Polymers

    Science.gov (United States)

    1998-06-23

    and Almeria Natansohn* Department of Chemistry, Queen’s University, Kingston, Ontario, K7L 3N6 Paul Rochon Department of Physics, Royal Military...1. IRRADIANCE AND TEMPERATURE DEPENDENCE OF PHOTO-INDUCED ORIENTATION IN TWO AZOBENZENE-BASED POLYMERS Dennis Hore and Almeria Natansohn...IRRADIANCE AND TEMPERATURE DEPENDENCE OF PHOTO-INDUCED ORIENTATION IN TWO AZOBENZENE-BASED POLYMERS Dennis Hore and Almeria Natansohn Department of

  11. A Shortest Dependency Path Based Convolutional Neural Network for Protein-Protein Relation Extraction

    OpenAIRE

    2016-01-01

    The state-of-the-art methods for protein-protein interaction (PPI) extraction are primarily based on kernel methods, and their performances strongly depend on the handcraft features. In this paper, we tackle PPI extraction by using convolutional neural networks (CNN) and propose a shortest dependency path based CNN (sdpCNN) model. The proposed method (1) only takes the sdp and word embedding as input and (2) could avoid bias from feature selection by using CNN. We performed experiments on sta...

  12. Dependency Syntactic Tree Similarity Computation Based on Predicate-Argument Structures

    Institute of Scientific and Technical Information of China (English)

    Shuyuan Liu; Jianliang Xu; Feng liu

    2012-01-01

      In all fields of Natural Language Process,sentence similarity computation acts an important role. This paper introduces a dependency syntactic tree similarity computation method based on predicate-argument structures. The method treats predicate-argument structures as the research object and studies many features of dependency syntactic tree including word and word`s POS of each node and the dependency type between them. Then the similarity algorithm is proposed after comprehensively analyzing all the features of the predicate-argument structures. The experiment result is satisfied as this method describes dependency syntactic tree more comprehensively and accurately.

  13. Interactive and Symbolic Data Dependence AnalysisBased on Ranges of Expressions

    Institute of Scientific and Technical Information of China (English)

    杨博; 郑丰宙; 王鼎兴; 郑纬民

    2002-01-01

    Traditional data dependence testing algorithms have become very accurate and efficient for simple subscript expressions, but they cannot handle symbolic expressions because of the complexity of data-flow and lack of the semantic information of variables in programs. In this paper, a range-based testing and query approach, called DDTQ, is proposed to eliminate data dependence between array references with symbolic subscripts. DDTQ firstly extracts data dependence information from the symbolic subscripts, a testing algorithm is then used to disprove the dependence based on the ranges of expressions. The assumed dependence that cannot be handled by the disprover will be converted into simple questions by a question engine so that the compiler can solve them by user interaction in a friendly way. The experiment on perfect benchmarks indicates that DDTQ is effective in improving the parallelizing capability of the compiler.

  14. Experimental evaluation of optimal Vehicle Dynamic Control based on the State Dependent Riccati Equation technique

    NARCIS (Netherlands)

    Alirezaei, M.; Kanarachos, S.A.; Scheepers, B.T.M.; Maurice, J.P.

    2013-01-01

    Development and experimentally evaluation of an optimal Vehicle Dynamic Control (VDC) strategy based on the State Dependent Riccati Equation (SDRE) control technique is presented. The proposed nonlinear controller is based on a nonlinear vehicle model with nonlinear tire characteristics. A novel ext

  15. Using Necessary Information to Identify Item Dependence in Passage-Based Reading Comprehension Tests

    Science.gov (United States)

    Baldonado, Angela Argo; Svetina, Dubravka; Gorin, Joanna

    2015-01-01

    Applications of traditional unidimensional item response theory models to passage-based reading comprehension assessment data have been criticized based on potential violations of local independence. However, simple rules for determining dependency, such as including all items associated with a particular passage, may overestimate the dependency…

  16. Modeling of Rate-Dependent Hysteresis Using a GPO-Based Adaptive Filter.

    Science.gov (United States)

    Zhang, Zhen; Ma, Yaopeng

    2016-02-06

    A novel generalized play operator-based (GPO-based) nonlinear adaptive filter is proposed to model rate-dependent hysteresis nonlinearity for smart actuators. In the proposed filter, the input signal vector consists of the output of a tapped delay line. GPOs with various thresholds are used to construct a nonlinear network and connected with the input signals. The output signal of the filter is composed of a linear combination of signals from the output of GPOs. The least-mean-square (LMS) algorithm is used to adjust the weights of the nonlinear filter. The modeling results of four adaptive filter methods are compared: GPO-based adaptive filter, Volterra filter, backlash filter and linear adaptive filter. Moreover, a phenomenological operator-based model, the rate-dependent generalized Prandtl-Ishlinskii (RDGPI) model, is compared to the proposed adaptive filter. The various rate-dependent modeling methods are applied to model the rate-dependent hysteresis of a giant magnetostrictive actuator (GMA). It is shown from the modeling results that the GPO-based adaptive filter can describe the rate-dependent hysteresis nonlinear of the GMA more accurately and effectively.

  17. Copula-EVT Based Tail Dependence Structure of Financial Markets in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Tail dependence structure model based on Copula theory and extreme value theory (EVT) is constructed to picture the tail correlation of financial time series more exact. The empirical research results show that the Gumbel Copula can fit the upper and lower tail dependence structures of Shanghai A share index and Shenzhen A share index, and correlation of upper tails of both indices is stronger than that of lower-tails.

  18. Seismic dynamic monitoring in CO2 flooding based on characterization of frequency-dependent velocity factor

    Science.gov (United States)

    Zhang, Jun-Hua; Li, Jun; Xiao, Wen; Tan, Ming-You; Zhang, Yun-Ying; Cui, Shi-Ling; Qu, Zhi-Peng

    2016-06-01

    The phase velocity of seismic waves varies with the propagation frequency, and thus frequency-dependent phenomena appear when CO2 gas is injected into a reservoir. By dynamically considering these phenomena with reservoir conditions it is thus feasible to extract the frequency-dependent velocity factor with the aim of monitoring changes in the reservoir both before and after CO2 injection. In the paper, we derive a quantitative expression for the frequency-dependent factor based on the Robinson seismic convolution model. In addition, an inversion equation with a frequency-dependent velocity factor is constructed, and a procedure is implemented using the following four processing steps: decomposition of the spectrum by generalized S transform, wavelet extraction of cross-well seismic traces, spectrum equalization processing, and an extraction method for frequency-dependent velocity factor based on the damped least-square algorithm. An attenuation layered model is then established based on changes in the Q value of the viscoelastic medium, and spectra of migration profiles from forward modeling are obtained and analyzed. Frequency-dependent factors are extracted and compared, and the effectiveness of the method is then verified using a synthetic data. The frequency-dependent velocity factor is finally applied to target processing and oil displacement monitoring based on real seismic data obtained before and after CO2 injection in the G89 well block within Shengli oilfield. Profiles and slices of the frequency-dependent factor determine its ability to indicate differences in CO2 flooding, and the predicting results are highly consistent with those of practical investigations within the well block.

  19. Static Dependency Pair Method based on Strong Computability for Higher-Order Rewrite Systems

    CERN Document Server

    Kusakari, Keiichirou; Sakai, Masahiko; Blanqui, Frédéric

    2011-01-01

    Higher-order rewrite systems (HRSs) and simply-typed term rewriting systems (STRSs) are computational models of functional programs. We recently proposed an extremely powerful method, the static dependency pair method, which is based on the notion of strong computability, in order to prove termination in STRSs. In this paper, we extend the method to HRSs. Since HRSs include \\lambda-abstraction but STRSs do not, we restructure the static dependency pair method to allow \\lambda-abstraction, and show that the static dependency pair method also works well on HRSs without new restrictions.

  20. Spin-dependent thermoelectric effects in graphene-based superconductor junctions

    Science.gov (United States)

    Beiranvand, Razieh; Hamzehpour, Hossein

    2017-02-01

    Using the Bogoliubov-de Gennes formalism, we investigate the charge and spin-dependent thermoelectric effects in graphene-based superconductor junctions. The results demonstrate that despite normal-superconductor junctions, there is a temperature-dependent spin thermopower in both the graphene-based ferromagnetic-superconductor and ferromagnetic-Rashba spin-orbit region-superconductor junctions. It is also shown that in the presence of Rashba spin-orbit interaction, the charge and spin-dependent Seebeck coefficients reach their maximum up to 3.5 k B / e and 2.5 k B / e , respectively. Remarkably, these coefficients have a zero-point critical value with respect to the magnetic exchange field and chemical potential. This effect disappears when the Rashba coupling is absent. These results suggest that graphene-based superconductors can be used in spin-caloritronic devices.

  1. Dependent Neyman type A processes based on common shock Poisson approach

    Science.gov (United States)

    Kadilar, Gamze Özel; Kadilar, Cem

    2016-04-01

    The Neyman type A process is used for describing clustered data since the Poisson process is insufficient for clustering of events. In a multivariate setting, there may be dependencies between multivarite Neyman type A processes. In this study, dependent form of the Neyman type A process is considered under common shock approach. Then, the joint probability function are derived for the dependent Neyman type A Poisson processes. Then, an application based on forest fires in Turkey are given. The results show that the joint probability function of the dependent Neyman type A processes, which is obtained in this study, can be a good tool for the probabilistic fitness for the total number of burned trees in Turkey.

  2. Investigation on magnetic field dependent modulus of epoxidized natural rubber based magnetorheological elastomer

    Science.gov (United States)

    Yunus, N. A.; Mazlan, S. A.; Ubaidillah; Aziz, S. A. A.; Khairi, M. H. Ahmad; Wahab, N. A. A.; Shilan, S. T.

    2016-11-01

    This paper presents an investigation on the use of epoxidized natural rubber (ENR) as a matrix of magnetorheological elastomers (MREs). Isotropic ENR-based MRE samples were synthesized by homogeneously mixed the ENR compound with carbonyl iron particles (CIPs). The microstructure of the sample was observed, and the magnetic field-dependent moduli were analyzed using rheometer. The influences of excitation frequency, CIPs content and magnetic field on the field-dependent moduli of ENR-based MREs were evaluated through dynamic shear test. The microstructure of MRE samples demonstrated the dispersed CIPs in the ENR matrix. The remarkable increment of storage and loss moduli of the ENR-based MREs has exhibited the magnetically controllable storage and loss moduli of the samples when exposed to the magnetic field. Consequently, the CIPs content, frequency and magnetic field were significantly influenced the dynamic moduli of the ENR-based MREs.

  3. PRESSURE AND TEMPERATURE DEPENDENT DEFLAGRATION RATE MEASUREMENTS OF LLM-105 AND TATB BASED EXPLOSIVES

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, E A; Tan, N; Koerner, J; Lorenz, K T; Maienschein, J L

    2009-11-10

    The pressure dependent deflagration rates of LLM-105 and TATB based formulations were measured in the LLNL high pressure strand burner. The role of binder amount, explosive type, and thermal damage and their effects on the deflagration rate will be discussed. Two different formulations of LLM-105 and three formulations of TATB were studied and results indicate that binder amount and type play a minor role in the deflagration behavior. This is in sharp contrast to the HMX based formulations which strongly depend on binder amount and type. The effect of preheating these samples was considerably more dramatic. In the case of LLM-105, preheating the sample appears to have little effect on the deflagration rate. In contrast, preheating TATB formulations causes the deflagration rate to accelerate and become erratic. The thermal and mechanical properties of these formulations will be discussed in the context of their pressure and temperature dependent deflagration rates.

  4. Condition-dependent expression of melanin-based coloration in the Eurasian kestrel

    NARCIS (Netherlands)

    Piault, Romain; van den Brink, Valentijn; Roulin, Alexandre

    2012-01-01

    Melanin is the most common pigment in animal integuments and is responsible for some of the most striking ornaments. A central tenet of sexual selection theory states that melanin-based traits can signal absolute individual quality in any environment only if their expression is condition-dependent.

  5. An electroplating topography model based on layout-dependent variation of copper deposition rate

    Institute of Scientific and Technical Information of China (English)

    Wang Qiang; Chen Lan; Li Zhigang; Ruan Wenbiao

    2011-01-01

    A layout-pattern-dependent electroplating model is developed based on the physical mechanism of the electroplating process.Our proposed electroplating model has an advantage over former ones due to a consideration of the variation of copper deposition rate with different layout parameters during the process.The simulation results compared with silicon data demonstrate the improvement in accuracy.

  6. Simulation of biochemical reactions with time-dependent rates by the rejection-based algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Thanh, Vo Hong, E-mail: vo@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Priami, Corrado, E-mail: priami@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Department of Mathematics, University of Trento, Trento (Italy)

    2015-08-07

    We address the problem of simulating biochemical reaction networks with time-dependent rates and propose a new algorithm based on our rejection-based stochastic simulation algorithm (RSSA) [Thanh et al., J. Chem. Phys. 141(13), 134116 (2014)]. The computation for selecting next reaction firings by our time-dependent RSSA (tRSSA) is computationally efficient. Furthermore, the generated trajectory is exact by exploiting the rejection-based mechanism. We benchmark tRSSA on different biological systems with varying forms of reaction rates to demonstrate its applicability and efficiency. We reveal that for nontrivial cases, the selection of reaction firings in existing algorithms introduces approximations because the integration of reaction rates is very computationally demanding and simplifying assumptions are introduced. The selection of the next reaction firing by our approach is easier while preserving the exactness.

  7. A Shortest Dependency Path Based Convolutional Neural Network for Protein-Protein Relation Extraction

    Directory of Open Access Journals (Sweden)

    Lei Hua

    2016-01-01

    Full Text Available The state-of-the-art methods for protein-protein interaction (PPI extraction are primarily based on kernel methods, and their performances strongly depend on the handcraft features. In this paper, we tackle PPI extraction by using convolutional neural networks (CNN and propose a shortest dependency path based CNN (sdpCNN model. The proposed method (1 only takes the sdp and word embedding as input and (2 could avoid bias from feature selection by using CNN. We performed experiments on standard Aimed and BioInfer datasets, and the experimental results demonstrated that our approach outperformed state-of-the-art kernel based methods. In particular, by tracking the sdpCNN model, we find that sdpCNN could extract key features automatically and it is verified that pretrained word embedding is crucial in PPI task.

  8. A Shortest Dependency Path Based Convolutional Neural Network for Protein-Protein Relation Extraction.

    Science.gov (United States)

    Hua, Lei; Quan, Chanqin

    2016-01-01

    The state-of-the-art methods for protein-protein interaction (PPI) extraction are primarily based on kernel methods, and their performances strongly depend on the handcraft features. In this paper, we tackle PPI extraction by using convolutional neural networks (CNN) and propose a shortest dependency path based CNN (sdpCNN) model. The proposed method (1) only takes the sdp and word embedding as input and (2) could avoid bias from feature selection by using CNN. We performed experiments on standard Aimed and BioInfer datasets, and the experimental results demonstrated that our approach outperformed state-of-the-art kernel based methods. In particular, by tracking the sdpCNN model, we find that sdpCNN could extract key features automatically and it is verified that pretrained word embedding is crucial in PPI task.

  9. Nicotine dependence as a moderator of a quitline-based message framing intervention.

    Science.gov (United States)

    Fucito, Lisa M; Latimer, Amy E; Carlin-Menter, Shannon; Salovey, Peter; Cummings, K Michael; Makuch, Robert W; Toll, Benjamin A

    2011-04-01

    High nicotine dependence is a reliable predictor of difficulty quitting smoking and remaining smoke-free. Evidence also suggests that the effectiveness of various smoking cessation treatments may vary by nicotine dependence level. Nicotine dependence, as assessed by Heaviness of Smoking Index baseline total scores, was evaluated as a potential moderator of a message-framing intervention provided through the New York State Smokers' Quitline (free telephone based service). Smokers were exposed to either gain-framed (n=810) or standard-care (n=1222) counseling and printed materials. Those smoking 10 or more cigarettes per day and medically eligible were also offered a free 2-week supply of nicotine patches, gum, or lozenge. Smokers were contacted for follow-up interviews at 3 months by an independent survey group. There was no interaction of nicotine dependence scores and message condition on the likelihood of achieving 7-day point prevalence smoking abstinence at the 3-month follow-up contact. Among continuing smokers at the 3-month follow-up, smokers who reported higher nicotine dependence scores were more likely to report smoking more cigarettes per day and this effect was greater in response to standard-care messages than gain-framed messages. Smokers with higher dependence scores who received standard-care messages also were less likely to report use of nicotine medications compared with less dependent smokers, while there was no difference in those who received gain-framed messages. These findings lend support to prior research demonstrating nicotine dependence heterogeneity in response to message framing interventions and suggest that gain-framed messages may result in less variable smoking outcomes than standard-care messages.

  10. Delay-dependent observer-based stabilizing controller design for linear multiple state-delayed systems

    Institute of Scientific and Technical Information of China (English)

    Dejin WANG

    2003-01-01

    This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our proposed delay-dependent coupled LMIs criterion lies in that: (1) it can optimize one of multiple time delays with others selected properly, and at the same time, the feedback-gain and observer-gain can be obtained, respectively. (2) it is less conservative than the existing delay-independent ones in the literature. Algorithm to solve the coupled LMIs is also given. Numerical examples illustrate the effectiveness of our method.

  11. Vibrationally resolved UV/Vis spectroscopy with time-dependent density functional based tight binding

    CERN Document Server

    Rüger, Robert; van Lenthe, Erik; Heine, Thomas; Visscher, Lucas

    2016-01-01

    We report a time-dependent density functional based tight-binding (TD-DFTB) scheme for the calculation of UV/Vis spectra, explicitly taking into account the excitation of nuclear vibrations via the harmonic approximation. The theory of vibrationally resolved UV/Vis spectroscopy is first summarized from the viewpoint of TD-DFTB. The method is benchmarked against time-dependent density functional theory (TD-DFT) calculations for strongly dipole allowed excitations in various aromatic and polar molecules. Using the recent 3ob:freq parameter set of Elstner's group, excellent agreement with TD-DFT calculations using local functionals was achieved.

  12. A Method Based on Intuitionistic Fuzzy Dependent Aggregation Operators for Supplier Selection

    Directory of Open Access Journals (Sweden)

    Fen Wang

    2013-01-01

    Full Text Available Recently, resolving the decision making problem of evaluation and ranking the potential suppliers have become as a key strategic factor for business firms. In this paper, two new intuitionistic fuzzy aggregation operators are developed: dependent intuitionistic fuzzy ordered weighed averaging (DIFOWA operator and dependent intuitionistic fuzzy hybrid weighed aggregation (DIFHWA operator. Some of their main properties are studied. A method based on the DIFHWA operator for intuitionistic fuzzy multiple attribute decision making is presented. Finally, an illustrative example concerning supplier selection is given.

  13. Leucine-based receptor sorting motifs are dependent on the spacing relative to the plasma membrane

    DEFF Research Database (Denmark)

    Geisler, C; Dietrich, J; Nielsen, B L;

    1998-01-01

    amino acid, is constitutively active. In this study, we have investigated how the spacing relative to the plasma membrane affects the function of both types of leucine-based motifs. For phosphorylation-dependent leucine-based motifs, a minimal spacing of 7 residues between the plasma membrane...... and the phospho-acceptor was required for phosphorylation and thereby activation of the motifs. For constitutively active leucine-based motifs, a minimal spacing of 6 residues between the plasma membrane and the acidic residue was required for optimal activity of the motifs. In addition, we found that the acidic...

  14. Cigarette smoking, nicotine dependence and anxiety disorders: a systematic review of population-based, epidemiological studies

    Directory of Open Access Journals (Sweden)

    Moylan Steven

    2012-10-01

    Full Text Available Abstract Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective, the population assessed (random sample versus clinical population and diagnostic instrument utilized. Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM or International Classification of Diseases (ICD for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders. Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder, although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified. Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as

  15. Childhood ADHD and risk for substance dependence in adulthood: a longitudinal, population-based study.

    Directory of Open Access Journals (Sweden)

    Sharon Levy

    Full Text Available Adolescents with attention-deficit/hyperactivity disorder (ADHD are known to be at significantly greater risk for the development of substance use disorders (SUD compared to peers. Impulsivity, which could lead to higher levels of drug use, is a known symptom of ADHD and likely accounts, in part, for this relationship. Other factors, such as a biologically increased susceptibility to substance dependence (addiction, may also play a role.This report further examines the relationships between childhood ADHD, adolescent- onset SUD, and substance abuse and substance dependence in adulthood.Individuals with childhood ADHD and non-ADHD controls from the same population-based birth cohort were invited to participate in a prospective outcome study. Participants completed a structured neuropsychiatric interview with modules for SUD and a psychosocial questionnaire. Information on adolescent SUD was obtained retrospectively, in a previous study, from medical and school records. Associations were summarized using odds ratios (OR and 95% CIs estimated from logistic regression models adjusted for age and gender.A total of 232 ADHD cases and 335 non-ADHD controls participated (mean age, 27.0 and 28.6 years, respectively. ADHD cases were more likely than controls to have a SUD diagnosed in adolescence and were more likely to have alcohol (adjusted OR 14.38, 95% CI 1.49-138.88 and drug (adjusted OR 3.48, 95% CI 1.38-8.79 dependence in adulthood. The subgroup of participating ADHD cases who did not have SUD during adolescence were no more likely than controls to develop new onset alcohol dependence as adults, although they were significantly more likely to develop new onset drug dependence.Our study found preliminary evidence that adults with childhood ADHD are more susceptible than peers to developing drug dependence, a disorder associated with neurological changes in the brain. The relationship between ADHD and alcohol dependence appears to be more complex.

  16. Context-dependent feature selection using unsupervised contexts applied to GPR-based landmine detection

    Science.gov (United States)

    Ratto, Christopher R.; Torrione, Peter A.; Collins, Leslie M.

    2010-04-01

    Context-dependent classification techniques applied to landmine detection with ground-penetrating radar (GPR) have demonstrated substantial performance improvements over conventional classification algorithms. Context-dependent algorithms compute a decision statistic by integrating over uncertainty in the unknown, but probabilistically inferable, context of the observation. When applied to GPR, contexts may be defined by differences in electromagnetic properties of the subsurface environment, which are due to discrepancies in soil composition, moisture levels, and surface texture. Context-dependent Feature Selection (CDFS) is a technique developed for selecting a unique subset of features for classifying landmines from clutter in different environmental contexts. In past work, context definitions were assumed to be soil moisture conditions which were known during training. However, knowledge of environmental conditions could be difficult to obtain in the field. In this paper, we utilize an unsupervised learning algorithm for defining contexts which are unknown a priori. Our method performs unsupervised context identification based on similarities in physics-based and statistical features that characterize the subsurface environment of the raw GPR data. Results indicate that utilizing this contextual information improves classification performance, and provides performance improvements over non-context-dependent approaches. Implications for on-line context identification will be suggested as a possible avenue for future work.

  17. Formalizing dependency directed backtracking and explanation based learning in refinement search

    Energy Technology Data Exchange (ETDEWEB)

    Kambhampati, S. [Arizona State Univ., Tempe, AZ (United States)

    1996-12-31

    The ideas of dependency directed backtracking (DDB) and explanation based learning (EBL) have developed independently in constraint satisfaction, planning and problem solving communities. In this paper, I formalize and unify these ideas under the task-independent framework of refinement search, which can model the search strategies used in both planning and constraint satisfaction. I show that both DDB and EBL depend upon the common theory of explaining search failures, and regressing them to higher levels of the search tree. The relevant issues of importance include (a) how the failures are explained and (b) how many failure explanations are remembered. This task-independent understanding of DDB and EBL helps support cross-fertilization of ideas among Constraint Satisfaction, Planning and Explanation-Based Learning communities.

  18. Dependent component analysis based approach to robust demarcation of skin tumors

    Science.gov (United States)

    Kopriva, Ivica; Peršin, Antun; Puizina-Ivić, Neira; Mirić, Lina

    2009-02-01

    Method for robust demarcation of the basal cell carcinoma (BCC) is presented employing novel dependent component analysis (DCA)-based approach to unsupervised segmentation of the red-green-blue (RGB) fluorescent image of the BCC. It exploits spectral diversity between the BCC and the surrounding tissue. DCA represents an extension of the independent component analysis (ICA) and is necessary to account for statistical dependence induced by spectral similarity between the BCC and surrounding tissue. Robustness to intensity fluctuation is due to the scale invariance property of DCA algorithms. By comparative performance analysis with state-of-the-art image segmentation methods such as active contours (level set), K-means clustering, non-negative matrix factorization and ICA we experimentally demonstrate good performance of DCA-based BCC demarcation in demanding scenario where intensity of the fluorescent image has been varied almost two-orders of magnitude.

  19. A Comparison of Dependent Primary Care Utilization Rates Based on Deployments

    Science.gov (United States)

    2009-03-09

    Healthcare System (MHS), Dependents, Automated Staffing Model ( ASAM ), Primary Care 16. SECURITY CLASSIFICATION OF: a. REPORT U b. ABSTRACT U c. THIS...enrollees based on the Automated Staffing Assessment Model ( ASAM ) that the Army Medical Command (MEDCOM) uses to determine staffing requirements of...deployment. While the ASAM model helps to figure out the number of provider and support staff needed within the MEDCOM with an expected utilization

  20. Mechanism-based medication development for the treatment of nicotine dependence

    OpenAIRE

    Xi, Zheng-Xiong; Spiller, Krista; Gardner, Eliot L.

    2009-01-01

    Tobacco use is a global problem with serious health consequences. Though some treatment options exist, there remains a great need for new effective pharmacotherapies to aid smokers in maintaining long-term abstinence. In the present article, we first discuss the neural mechanisms underlying nicotine reward, and then review various mechanism-based pharmacological agents for the treatment of nicotine dependence. An oversimplified hypothesis of addiction to tobacco is that nicotine is the major ...

  1. Sulfuric acid nucleation: power dependencies, variation with relative humidity, and effect of bases

    Directory of Open Access Journals (Sweden)

    J. H. Zollner

    2012-01-01

    Full Text Available Nucleation of particles composed of sulfuric acid, water, and nitrogen base molecules was studied using a continuous flow reactor. The particles formed from these vapors were detected with an ultrafine condensation particle counter, while vapors of sulfuric acid and nitrogen bases were detected by chemical ionization mass spectrometry. Variation of particle numbers with sulfuric acid concentration yielded a power dependency on sulfuric acid of 5 ± 1 for relative humidities of 14–68% at 296 K; similar experiments with varying water content yielded power dependencies on H2O of ~7. The critical cluster contains about 5 H2SO4 molecules and a new treatment of the power dependency for H2O suggests about 12 H2O molecules for these conditions. Addition of 2-to-45 pptv of ammonia or methyl amine resulted in up to millions of times more particles than in the absence of these compounds. Particle detection efficiencies, sulfuric acid and nitrogen base detection, wall losses, and the extent of particle growth are discussed with the help of a recent computational fluid dynamics study that simulated the flow and chemistry in the flow reactor. Results are compared to previous laboratory nucleation studies and they are also discussed in terms of atmospheric nucleation scenarios.

  2. Observation of diameter dependent carrier distribution in nanowire-based transistors

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, A; Hantschel, T; Eyben, P; Verhulst, A S; Rooyackers, R; Vandooren, A; Mody, J; Nazir, A; Leonelli, D; Vandervorst, W, E-mail: Andreas.Schulze@imec.be [IMEC, Kapeldreef 75, 3001 Leuven (Belgium)

    2011-05-06

    The successful implementation of nanowire (NW) based field-effect transistors (FET) critically depends on quantitative information about the carrier distribution inside such devices. Therefore, we have developed a method based on high-vacuum scanning spreading resistance microscopy (HV-SSRM) which allows two-dimensional (2D) quantitative carrier profiling of fully integrated silicon NW-based tunnel-FETs (TFETs) with 2 nm spatial resolution. The key elements of our characterization procedure are optimized NW cleaving and polishing steps, the use of in-house fabricated ultra-sharp diamond tips, measurements in high vacuum and a dedicated quantification procedure accounting for the Schottky-like tip-sample contact affected by surface states. In the case of the implanted TFET source regions we find a strong NW diameter dependence of conformality, junction abruptness and gate overlap, quantitatively in agreement with process simulations. In contrast, the arsenic doped drain regions reveal an unexpected NW diameter dependent dopant deactivation. The observed lower drain doping for smaller diameters is reflected in the device characteristics by lower TFET off-currents, as measured experimentally and confirmed by device simulations.

  3. The relationship between reward-based learning and nicotine dependence in smokers with schizophrenia

    Science.gov (United States)

    AhnAllen, Christopher G.; Liverant, Gabrielle I.; Gregor, Kristin L.; Kamholz, Barbara W.; Levitt, James J.; Gulliver, Suzy Bird; Pizzagalli, Diego A.; Koneru, Vamsi K.; Kaplan, Gary B.

    2011-01-01

    Cigarette smoking rates remain remarkably high in schizophrenia relative to smoking in other psychiatric groups. Impairments in the reward system may be related to elevated rates of nicotine dependence and lower cessation rates in this psychiatric group. Smokers with schizophrenia and schizoaffective disorder (SWS; n = 15; M age = 54.87, SD = 6.51, 100% male) and a non-psychiatric control group of smokers (NCL; n = 16; M age = 50.38, SD = 11.52; 93.8% male) were administered a computerized signal detection task to measure reward-based learning. Performance on the signal detection task was assessed by response bias, discriminability, reaction time, and hit rate. Clinician-assessed and self-reported measures of smoking and psychiatric symptoms were completed. SWS exhibited similar patterns of reward-based learning compared to control smokers. However, decreased reward-based learning was associated with increased levels of nicotine dependence in SWS, but not among control smokers. Nicotine withdrawal and urge to smoke were correlated with anhedonia within the SWS group. Among SWS, reduced reward responsiveness and increased anhedonia were associated with and may contribute to greater co-occurring nicotine dependence. These findings emphasize the importance of targeting reward system functioning in smoking cessation treatment for individuals with schizophrenia. PMID:22342123

  4. A GIS-based time-dependent seismic source modeling of Northern Iran

    Science.gov (United States)

    Hashemi, Mahdi; Alesheikh, Ali Asghar; Zolfaghari, Mohammad Reza

    2017-01-01

    The first step in any seismic hazard study is the definition of seismogenic sources and the estimation of magnitude-frequency relationships for each source. There is as yet no standard methodology for source modeling and many researchers have worked on this topic. This study is an effort to define linear and area seismic sources for Northern Iran. The linear or fault sources are developed based on tectonic features and characteristic earthquakes while the area sources are developed based on spatial distribution of small to moderate earthquakes. Time-dependent recurrence relationships are developed for fault sources using renewal approach while time-independent frequency-magnitude relationships are proposed for area sources based on Poisson process. GIS functionalities are used in this study to introduce and incorporate spatial-temporal and geostatistical indices in delineating area seismic sources. The proposed methodology is used to model seismic sources for an area of about 500 by 400 square kilometers around Tehran. Previous researches and reports are studied to compile an earthquake/fault catalog that is as complete as possible. All events are transformed to uniform magnitude scale; duplicate events and dependent shocks are removed. Completeness and time distribution of the compiled catalog is taken into account. The proposed area and linear seismic sources in conjunction with defined recurrence relationships can be used to develop time-dependent probabilistic seismic hazard analysis of Northern Iran.

  5. Soluble Human Intestinal Lactoferrin Receptor: Ca(2+)-Dependent Binding to Sepharose-Based Matrices.

    Science.gov (United States)

    Oshima, Yuta; Seki, Kohei; Shibuya, Masataka; Naka, Yuki; Yokoyama, Tatsuya; Sato, Atsushi

    2016-01-01

    A soluble form of human intestinal lactoferrin receptor (shLFR) is identical to human intelectin-1 (hITLN-1), a galactofuranose-binding protein that acts as a host defense against invading pathogenic microorganisms. We found that recombinant shLFR, expressed in mammalian cells (CHO DG44, COS-1, and RK13), binds tightly to Sepharose 4 Fast Flow (FF)-based matrices in a Ca(2+)-dependent manner. This binding of shLFR to Sepharose 4 FF-based matrices was inhibited by excess D-galactose, but not by D-glucose, suggesting that shLFR recognizes repeating units of α-1,6-linked D-galactose in Sepharose 4 FF. Furthermore, shLFR could bind to both Sepharose 4B- and Sepharose 6B-based matrices that were not crosslinked in a similar manner as to Sepharose 4 FF-based matrices. Therefore, shLFR (hITLN-1) binds to Sepharose-based matrices in a Ca(2+)-dependent manner. This binding property is most likely related to the ability, as host defense lectins, to recognize sepharose (agarobiose)-like structures present on the surface of invading pathogenic microorganisms.

  6. Microbial composition during Chinese soy sauce koji-making based on culture dependent and independent methods.

    Science.gov (United States)

    Yan, Yin-zhuo; Qian, Yu-lin; Ji, Feng-di; Chen, Jing-yu; Han, Bei-zhong

    2013-05-01

    Koji-making is a key process for production of high quality soy sauce. The microbial composition during koji-making was investigated by culture-dependent and culture-independent methods to determine predominant bacterial and fungal populations. The culture-dependent methods used were direct culture and colony morphology observation, and PCR amplification of 16S/26S rDNA fragments followed by sequencing analysis. The culture-independent method was based on the analysis of 16S/26S rDNA clone libraries. There were differences between the results obtained by different methods. However, sufficient overlap existed between the different methods to identify potentially significant microbial groups. 16 and 20 different bacterial species were identified using culture-dependent and culture-independent methods, respectively. 7 species could be identified by both methods. The most predominant bacterial genera were Weissella and Staphylococcus. Both 6 different fungal species were identified using culture-dependent and culture-independent methods, respectively. Only 3 species could be identified by both sets of methods. The most predominant fungi were Aspergillus and Candida species. This work illustrated the importance of a comprehensive polyphasic approach in the analysis of microbial composition during soy sauce koji-making, the knowledge of which will enable further optimization of microbial composition and quality control of koji to upgrade Chinese traditional soy sauce product.

  7. Addressing dependability by applying an approach for model-based risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Gran, Bjorn Axel [Institutt for energiteknikk, OECD Halden Reactor Project, NO-1751 Halden (Norway)]. E-mail: bjorn.axel.gran@hrp.no; Fredriksen, Rune [Institutt for energiteknikk, OECD Halden Reactor Project, NO-1751 Halden (Norway)]. E-mail: rune.fredriksen@hrp.no; Thunem, Atoosa P.-J. [Institutt for energiteknikk, OECD Halden Reactor Project, NO-1751 Halden (Norway)]. E-mail: atoosa.p-j.thunem@hrp.no

    2007-11-15

    This paper describes how an approach for model-based risk assessment (MBRA) can be applied for addressing different dependability factors in a critical application. Dependability factors, such as availability, reliability, safety and security, are important when assessing the dependability degree of total systems involving digital instrumentation and control (I and C) sub-systems. In order to identify risk sources their roles with regard to intentional system aspects such as system functions, component behaviours and intercommunications must be clarified. Traditional risk assessment is based on fault or risk models of the system. In contrast to this, MBRA utilizes success-oriented models describing all intended system aspects, including functional, operational and organizational aspects of the target. The EU-funded CORAS project developed a tool-supported methodology for the application of MBRA in security-critical systems. The methodology has been tried out within the telemedicine and e-commerce areas, and provided through a series of seven trials a sound basis for risk assessments. In this paper the results from the CORAS project are presented, and it is discussed how the approach for applying MBRA meets the needs of a risk-informed Man-Technology-Organization (MTO) model, and how methodology can be applied as a part of a trust case development.

  8. A time-dependent vector field topology based on streak surfaces.

    Science.gov (United States)

    Uffinger, Markus; Sadlo, Filip; Ertl, Thomas

    2013-03-01

    It was shown recently how the 2D vector field topology concept, directly applicable to stationary vector fields only, can be generalized to time-dependent vector fields by replacing the role of stream lines by streak lines. The present paper extends this concept to 3D vector fields. In traditional 3D vector field topology separatrices can be obtained by integrating stream lines from 0D seeds corresponding to critical points. We show that in our new concept, in contrast, 1D seeding constructs are required for computing streak-based separatrices. In analogy to the 2D generalization we show that invariant manifolds can be obtained by seeding streak surfaces along distinguished path surfaces emanating from intersection curves between codimension-1 ridges in the forward and reverse finite-time Lyapunov exponent (FTLE) fields. These path surfaces represent a time-dependent generalization of critical points and convey further structure in time-dependent topology of vector fields. Compared to the traditional approach based on FTLE ridges, the resulting streak manifolds ease the analysis of Lagrangian coherent structures (LCS) with respect to visual quality and computational cost, especially when time series of LCS are computed. We exemplify validity and utility of the new approach using both synthetic examples and computational fluid dynamics results.

  9. The DEP-6D, a new preference-based measure to assess health states of dependency.

    Science.gov (United States)

    Rodríguez-Míguez, E; Abellán-Perpiñán, J M; Alvarez, X C; González, X M; Sampayo, A R

    2016-03-01

    In medical literature there are numerous multidimensional scales to measure health states for dependence in activities of daily living. However, these scales are not preference-based and are not able to yield QALYs. On the contrary, the generic preference-based measures are not sensitive enough to measure changes in dependence states. The objective of this paper is to propose a new dependency health state classification system, called DEP-6D, and to estimate its value set in such a way that it can be used in QALY calculations. DEP-6D states are described as a combination of 6 attributes (eat, incontinence, personal care, mobility, housework and cognition problems), with 3-4 levels each. A sample of 312 Spanish citizens was surveyed in 2011 to estimate the DEP-6D preference-scoring algorithm. Each respondent valued six out of the 24 states using time trade-off questions. After excluding those respondents who made two or more inconsistencies (6% out of the sample), each state was valued between 66 and 77 times. The responses present a high internal and external consistency. A random effect model accounting for main effects was the preferred model to estimate the scoring algorithm. The DEP-6D describes, in general, more severe problems than those usually described by means of generic preference-based measures. The minimum score predicted by the DEP-6D algorithm is -0.84, which is considerably lower than the minimum value predicted by the EQ-5D and SF-6D algorithms. The DEP-6D value set is based on community preferences. Therefore it is consistent with the so-called 'societal perspective'. Moreover, DEP-6D preference weights can be used in QALY calculations and cost-utility analysis.

  10. Inverse Temperature Dependence of Nuclear Quantum Effects in DNA Base Pairs

    CERN Document Server

    Fang, Wei; Rossi, Mariana; Feng, Yexin; Li, Xin-Zheng; Michaelides, Angelos

    2016-01-01

    Despite the inherently quantum mechanical nature of hydrogen bonding, it is unclear how nuclear quantum effects (NQEs) alter the strengths of hydrogen bonds. With this in mind, we use ab initio path integral molecular dynamics to determine the absolute contribution of NQEs to the binding in DNA base pair complexes, arguably the most important hydrogen-bonded systems of all. We find that depending on the temperature, NQEs can either strengthen or weaken the binding within the hydrogen-bonded complexes. As a somewhat counterintuitive consequence, NQEs can have a smaller impact on hydrogen bond strengths at cryogenic temperatures than at room temperature. We rationalize this in terms of a competition of NQEs between low-frequency and high-frequency vibrational modes. Extending this idea, we also propose a simple model to predict the temperature dependence of NQEs on hydrogen bond strengths in general.

  11. Wavelength-dependent polarization absorber based on multi-cladding fiber with gold coating

    Science.gov (United States)

    Weng, Sijun; Pei, Li; Liu, Chao; Wang, Jianshuai; Li, Jing; Ning, Tigang

    2016-12-01

    The wavelength-dependent polarization absorber based on multi-cladding fiber (MCF) with surface plasmon resonance (SPR) is proposed and demonstrated. In order to obtain the SPR effect both in the x- and y- polarized direction, the MCF is polished in two sides. The numerical simulations show that the polarization absorber with the wavelengths of 980/1550 nm and 1310/1550 nm can be obtained by adjusting the parameters of dielectric layer. Each wavelength only transmits a single polarization in the wavelength-dependent polarization absorber, and the loss of unwanted polarized mode is more than 95 dB/cm. In addition, when the length of fiber is only 550 μm, the bandwidths of polarization absorber are 29 nm at 980 nm and 413 nm at 1550 nm, respectively; meanwhile, the bandwidth of 1310/1550 nm polarization absorber reaches 102 nm and 302 nm, respectively.

  12. Observer-Based Controller Design for Singular Stochastic Markov Jump Systems with State Dependent Noise

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yong; ZHANG Weihai

    2016-01-01

    This paper is concerned with the problem of observer-based controller design for singular stochastic Markov jump systems with state-dependent noise.Two concepts called "non-impulsiveness" and "mean square admissibility" are introduced,which are different from previous ones.Sufficient conditions for the open-and closed-loop singular stochastic Markov jump systems with state-dependent noise to be mean square admissible are provided in terms of strict LMIs.The controller gain and the observer gain which guarantee the resulting closed-loop error system to be mean square admissible are obtained in turn by solving the strict LMIs.A numerical example is presented to show the efficiency of the design approach.

  13. Vibrationally resolved UV/Vis spectroscopy with time-dependent density functional based tight binding

    Science.gov (United States)

    Rüger, Robert; Niehaus, Thomas; van Lenthe, Erik; Heine, Thomas; Visscher, Lucas

    2016-11-01

    We report a time-dependent density functional based tight-binding (TD-DFTB) scheme for the calculation of UV/Vis spectra, explicitly taking into account the excitation of nuclear vibrations via the adiabatic Hessian Franck-Condon method with a harmonic approximation for the nuclear wavefunction. The theory of vibrationally resolved UV/Vis spectroscopy is first summarized from the viewpoint of TD-DFTB. The method is benchmarked against time-dependent density functional theory (TD-DFT) calculations for strongly dipole allowed excitations in various aromatic and polar molecules. Using the recent 3ob:freq parameter set of Elstner's group, very good agreement with TD-DFT calculations using local functionals was achieved.

  14. Modeling dependence based on mixture copulas and its application in risk management

    Institute of Scientific and Technical Information of China (English)

    OUYANG Zi-sheng; LIAO Hui; YANG Xiang-qun

    2009-01-01

    This paper is concerned with the statistical modeling of the dependence structure of multivariate financial data using the copula, and the application of copula functions in VaR valuation. After the introduction of the pure copula method and the maximum and minimum mixture copula method, authors present a new algorithm based on the more generalized mixture copula functions and the dependence measure, and apply the method to the portfolio of Shanghai stock composite index and Shenzhen stock component index. Comparing with the results from various methods, one can find that the mixture copula method is better than the pure Gaussia copula method and the maximum and minimum mixture copula method on different VaR level.

  15. Steganalysis for LSB Matching Based on the Dependences Between Neighboring Pixels

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2012-10-01

    Full Text Available It is hard to detect LSB matching steganography, especially in low embedding rate. However there are still some chances to attack it since the data embedding alters the dependences between neighboring pixels.  Based on this fact, this paper proposes a novel steganalysis method by modeling the dependences. The neighboring pixels are divided into three groups: horizontal, vertical, and diagonal.  Then, the prediction errors of the central pixel are calculated by each group respectively. Finally, the empirical probability matrices among these prediction errors are computed and used as features for steganalysis. Experimental results show the proposed method has better performance than SPAM scheme, which currently is the most sensitive detector for LSB Matching. Furthermore, combined with the SPAM features, the method achieves the best accuracy.

  16. Condition-dependence, pleiotropy and the handicap principle of sexual selection in melanin-based colouration.

    Science.gov (United States)

    Roulin, Alexandre

    2016-05-01

    The signalling function of melanin-based colouration is debated. Sexual selection theory states that ornaments should be costly to produce, maintain, wear or display to signal quality honestly to potential mates or competitors. An increasing number of studies supports the hypothesis that the degree of melanism covaries with aspects of body condition (e.g. body mass or immunity), which has contributed to change the initial perception that melanin-based colour ornaments entail no costs. Indeed, the expression of many (but not all) melanin-based colour traits is weakly sensitive to the environment but strongly heritable suggesting that these colour traits are relatively cheap to produce and maintain, thus raising the question of how such colour traits could signal quality honestly. Here I review the production, maintenance and wearing/displaying costs that can generate a correlation between melanin-based colouration and body condition, and consider other evolutionary mechanisms that can also lead to covariation between colour and body condition. Because genes controlling melanic traits can affect numerous phenotypic traits, pleiotropy could also explain a linkage between body condition and colouration. Pleiotropy may result in differently coloured individuals signalling different aspects of quality that are maintained by frequency-dependent selection or local adaptation. Colouration may therefore not signal absolute quality to potential mates or competitors (e.g. dark males may not achieve a higher fitness than pale males); otherwise genetic variation would be rapidly depleted by directional selection. As a consequence, selection on heritable melanin-based colouration may not always be directional, but mate choice may be conditional to environmental conditions (i.e. context-dependent sexual selection). Despite the interest of evolutionary biologists in the adaptive value of melanin-based colouration, its actual role in sexual selection is still poorly understood.

  17. An Individual Based Model of Arctic cod ( Boreogadus saida) early life in Arctic polynyas: II. Length-dependent and growth-dependent mortality

    Science.gov (United States)

    Thanassekos, Stéphane; Robert, Dominique; Fortier, Louis

    2012-05-01

    A bioenergetics individual based model (IBM) of early growth is used to investigate the relative importance of length-dependent and growth-dependent mortality during the early life (0-45 d) of Arctic cod in the Northeast Water (NEW) in 1993 and the North Water (NOW) in 1998. In the model, individual growth is forced by the observed temperature and prey concentration histories as prescribed by the hatch date of a larva. The IBM reproduced well the observed length-at-age and revealed large ontogenetic and interregional fluctuations in instantaneous growth. Four mortality scenarios were compared for each population: (1) constant mortality (estimated from catch-at-age data); (2) length-dependent mortality; (3) growth-dependent mortality; and (4) combined length- and growth-dependent mortality. Scenarios 2, 3, and 4 were parameterized to achieve the final survival produced by the constant mortality rates estimated from observations (scenario 1). Scenario 2 accounted well for declining mortality with size but not for the large variations in growth-dependent mortality. Scenario 3 failed to capture the decreasing vulnerability of surviving larvae to predation. Only scenario 4 accounted for both the large fluctuations in growth-dependent mortality and the progressive shift in dominance from length-dependent to growth-dependent mortality as the survivors increased in size. Sub-sampling the model output to reproduce the limited temporal resolution of sampling at sea improved the fit between observed and modeled frequencies-at-age, and pointed to the under-sampling of the smallest larvae as a major sampling bias.

  18. Structure Dependence of Lysosomal Transit of Chitosan-Based Polyplexes for Gene Delivery.

    Science.gov (United States)

    Thibault, Marc; Lavertu, Marc; Astolfi, Mélina; Buschmann, Michael D

    2016-10-01

    Chitosan-based polyplexes are known to traffic through lysosomes for a relatively long time, independent of the degree of deacetylation (DDA) and the number average molecular weight (Mn) of the polymer, even though both of these parameters have profound effects on polyplex stability and transfection efficiency. A better understanding of the lysosomal barrier is paramount to the rational design of vectors capable of overcoming obstacles to transgene expression. The aim of the present study was to investigate if lysosomal transit affects chitosan-based polyplex transfection efficiency in a structure-dependent (DDA, Mn) manner. Toward this end, we analyzed the effects of intracellular trafficking modifying agents on transfection efficiency and intracellular vesicular trafficking of polyplexes with different structural properties and stabilities or nucleic acid binding affinity. The use of agents that modify endosome/lysosome acidification and transit processes by distinct mechanisms and their effect on cell viability, polyplex uptake, vesicular trafficking, and transfection efficiency revealed novel and strong chitosan structure-dependent consequences of lysosomal transit. Inhibiting lysosomal transit using chloroquine significantly increased the efficiency of unstable polyplexes, while having minimal effects for polyplexes with intermediate or high stability. In parallel, specifically inhibiting the acidification of vesicles abrogated transfection for all formulations, suggesting that vesicular acidification is essential to promote transfection, most probably by facilitating lysosomal escape. These results provide novel insights into the structure-performance relationship of chitosan-based gene delivery systems.

  19. Constraint-based modeling and kinetic analysis of the Smad dependent TGF-beta signaling pathway.

    Directory of Open Access Journals (Sweden)

    Zhike Zi

    Full Text Available BACKGROUND: Investigation of dynamics and regulation of the TGF-beta signaling pathway is central to the understanding of complex cellular processes such as growth, apoptosis, and differentiation. In this study, we aim at using systems biology approach to provide dynamic analysis on this pathway. METHODOLOGY/PRINCIPAL FINDINGS: We proposed a constraint-based modeling method to build a comprehensive mathematical model for the Smad dependent TGF-beta signaling pathway by fitting the experimental data and incorporating the qualitative constraints from the experimental analysis. The performance of the model generated by constraint-based modeling method is significantly improved compared to the model obtained by only fitting the quantitative data. The model agrees well with the experimental analysis of TGF-beta pathway, such as the time course of nuclear phosphorylated Smad, the subcellular location of Smad and signal response of Smad phosphorylation to different doses of TGF-beta. CONCLUSIONS/SIGNIFICANCE: The simulation results indicate that the signal response to TGF-beta is regulated by the balance between clathrin dependent endocytosis and non-clathrin mediated endocytosis. This model is useful to be built upon as new precise experimental data are emerging. The constraint-based modeling method can also be applied to quantitative modeling of other signaling pathways.

  20. Designing Structure-Dependent MPC-Based AGC Schemes Considering Network Topology

    Directory of Open Access Journals (Sweden)

    Young-Sik Jang

    2015-04-01

    Full Text Available This paper presents the important features of structure-dependent model predictive control (MPC-based approaches for automatic generation control (AGC considering network topology. Since power systems have various generators under different topologies, it is necessary to reflect the characteristics of generators in power networks and the control system structures in order to improve the dynamic performance of AGC. Specifically, considering control system structures is very important because not only can the topological problems be reduced, but also a computing system for AGC in a bulk-power system can be realized. Based on these considerations, we propose new schemes in the proposed controller for minimizing inadvertent line flows and computational burden, which strengthen the advantages of MPC-based approach for AGC. Analysis and simulation results in the IEEE 39-bus model system show different dynamic behaviors among structure-dependent control schemes and possible improvements in computational burden via the proposed control scheme while system operators in each balancing area consider physical load reference ramp constraints among generators.

  1. Implementation of an analogue model of a memristor based on a light-dependent resistor

    Institute of Scientific and Technical Information of China (English)

    Wang Xiao-Yuan; Andrew L. Fitch; Herbert H. C. Iu; Victor Sreeram; Qi Wei-Gui

    2012-01-01

    In this paper,an analogue model of a memristor using a light-dependent resistor (LDR) is presented.This model can be simplified into two parts:a control circuit and a variable resistor.It can be used to easily verify theoretical presumptions about the switching properties of memristors.This LDR-based memristor model can also be used in both simulations and experiments for future research into memristor applications.The paper includes mathematical models,simulations,and experimental results.

  2. Microstructure-dependent piezoelectric beam based on modified strain gradient theory

    Science.gov (United States)

    Li, Y. S.; Feng, W. J.

    2014-09-01

    A microstructure-dependent piezoelectric beam model was developed using a variational formulation, which is based on the modified strain gradient theory and the Timoshenko beam theory. The new model contains three material length scale parameters and can capture the size effect, unlike the classical beam theory. To illustrate the new piezoelectric beam model, the static bending and the free vibration problems of a simply supported beam are numerically solved. These results may be useful in the analysis and design of smart structures that are constructed from piezoelectric materials.

  3. Sub-Half-Wavelength Atom Localization Based on Phase-Dependent Electromagnetically Induced Transparency

    Institute of Scientific and Technical Information of China (English)

    GONG cheng; HU Xiang-Ming; PENG Yan-Dong

    2008-01-01

    We present a realistic and efficient scheme for sub-half-wavelength atom localization.This scheme is based on the phase-dependent elecaromagnetically induced transparency in a four-level system in the double-Λ configuration.We use a strong bichromatic field(one component of which is standing-wave field)as the driving components,and a weak bichromatic field as the probe components.By choosing the collective phase of the four applied components,the atom js localized in either of the two half-wavelength regions with 50% detecting probability when the absorption to the probe fields is detected.

  4. Designing a multiple dependent state sampling plan based on the coefficient of variation.

    Science.gov (United States)

    Yan, Aijun; Liu, Sanyang; Dong, Xiaojuan

    2016-01-01

    A multiple dependent state (MDS) sampling plan is developed based on the coefficient of variation of the quality characteristic which follows a normal distribution with unknown mean and variance. The optimal plan parameters of the proposed plan are solved by a nonlinear optimization model, which satisfies the given producer's risk and consumer's risk at the same time and minimizes the sample size required for inspection. The advantages of the proposed MDS sampling plan over the existing single sampling plan are discussed. Finally an example is given to illustrate the proposed plan.

  5. A Self-Optimization Method for System Service Dependability based on Autonomic Computing

    Directory of Open Access Journals (Sweden)

    Qingtao Wu

    2012-11-01

    Full Text Available Under the intrusion or abnormal attacks, how to supply system service dependability autonomously, without being degraded, is the essential requirement to network system service. Autonomic Computing can overcome the heterogeneity and complexity of computing system, has been regarded as a novel and effective approach to implementing autonomous systems to address system security issues. To cope with the problem of declining network service dependability caused by safety threats, we proposed an autonomic method for optimizing system service performance based on Q-learning from the perspective of autonomic computing. First, we get the operations by utilizing the nonlinear mapping relations of the feedforward neural network. Then, we obtain the executive action by perceiving the state parameter changes of the network system in the service performance. Thirdly, we calculate the environment-rewarded function value integrated the changes of the system service performance and the service availability. Finally, we use the self-learning characteristics and prediction ability of the Q-learning to make the system service to achieve optimal performance. Simulation results show that this method is effective for optimizing the overall dependability and service utility of a system.

  6. Estimating the Probability of Vegetation to Be Groundwater Dependent Based on the Evaluation of Tree Models

    Directory of Open Access Journals (Sweden)

    Isabel C. Pérez Hoyos

    2016-04-01

    Full Text Available Groundwater Dependent Ecosystems (GDEs are increasingly threatened by humans’ rising demand for water resources. Consequently, it is imperative to identify the location of GDEs to protect them. This paper develops a methodology to identify the probability of an ecosystem to be groundwater dependent. Probabilities are obtained by modeling the relationship between the known locations of GDEs and factors influencing groundwater dependence, namely water table depth and climatic aridity index. Probabilities are derived for the state of Nevada, USA, using modeled water table depth and aridity index values obtained from the Global Aridity database. The model selected results from the performance comparison of classification trees (CT and random forests (RF. Based on a threshold-independent accuracy measure, RF has a better ability to generate probability estimates. Considering a threshold that minimizes the misclassification rate for each model, RF also proves to be more accurate. Regarding training accuracy, performance measures such as accuracy, sensitivity, and specificity are higher for RF. For the test set, higher values of accuracy and kappa for CT highlight the fact that these measures are greatly affected by low prevalence. As shown for RF, the choice of the cutoff probability value has important consequences on model accuracy and the overall proportion of locations where GDEs are found.

  7. Directed sample interrogation utilizing an accurate mass exclusion-based data-dependent acquisition strategy (AMEx).

    Science.gov (United States)

    Rudomin, Emily L; Carr, Steven A; Jaffe, Jacob D

    2009-06-01

    The ability to perform thorough sampling is of critical importance when using mass spectrometry to characterize complex proteomic mixtures. A common approach is to reinterrogate a sample multiple times by LC-MS/MS. However, the conventional data-dependent acquisition methods that are typically used in proteomics studies will often redundantly sample high-intensity precursor ions while failing to sample low-intensity precursors entirely. We describe a method wherein the masses of successfully identified peptides are used to generate an accurate mass exclusion list such that those precursors are not selected for sequencing during subsequent analyses. We performed multiple concatenated analytical runs to sample a complex cell lysate, using either accurate mass exclusion-based data-dependent acquisition (AMEx) or standard data-dependent acquisition, and found that utilization of AMEx on an ESI-Orbitrap instrument significantly increases the total number of validated peptide identifications relative to a standard DDA approach. The additional identified peptides represent precursor ions that exhibit low signal intensity in the sample. Increasing the total number of peptide identifications augmented the number of proteins identified, as well as improved the sequence coverage of those proteins. Together, these data indicate that using AMEx is an effective strategy to improve the characterization of complex proteomic mixtures.

  8. Wavelet based deseasonalization for modelling and forecasting of daily discharge series considering long range dependence

    Directory of Open Access Journals (Sweden)

    Szolgayová Elena

    2014-03-01

    Full Text Available Short term streamflow forecasting is important for operational control and risk management in hydrology. Despite a wide range of models available, the impact of long range dependence is often neglected when considering short term forecasting. In this paper, the forecasting performance of a new model combining a long range dependent autoregressive fractionally integrated moving average (ARFIMA model with a wavelet transform used as a method of deseasonalization is examined. It is analysed, whether applying wavelets in order to model the seasonal component in a hydrological time series, is an alternative to moving average deseasonalization in combination with an ARFIMA model. The one-to-ten-steps-ahead forecasting performance of this model is compared with two other models, an ARFIMA model with moving average deseasonalization, and a multiresolution wavelet based model. All models are applied to a time series of mean daily discharge exhibiting long range dependence. For one and two day forecasting horizons, the combined wavelet - ARFIMA approach shows a similar performance as the other models tested. However, for longer forecasting horizons, the wavelet deseasonalization - ARFIMA combination outperforms the other two models. The results show that the wavelets provide an attractive alternative to the moving average deseasonalization.

  9. Single-molecule derivation of salt dependent base-pair free energies in DNA

    CERN Document Server

    Huguet, J M; Forns, N; Smith, S B; Bustamante, C; Ritort, F; 10.1073/pnas.1001454107

    2010-01-01

    Accurate knowledge of the thermodynamic properties of nucleic acids is crucial to predicting their structure and stability. To date most measurements of base-pair free energies in DNA are obtained in thermal denaturation experiments, which depend on several assumptions. Here we report measurements of the DNA base-pair free energies based on a simplified system, the mechanical unzipping of single DNA molecules. By combining experimental data with a physical model and an optimization algorithm for analysis, we measure the 10 unique nearest-neighbor base-pair free energies with 0.1 kcal mol-1 precision over two orders of magnitude of monovalent salt concentration. We find an improved set of standard energy values compared with Unified Oligonucleotide energies and a unique set of 10 base-pair-specific salt-correction values. The latter are found to be strongest for AA/TT and weakest for CC/GG. Our new energy values and salt corrections improve predictions of DNA unzipping forces and are fully compatible with melt...

  10. The Influence of Web- Versus Paper-based Formats on the Assessment of Tobacco Dependence: Evaluating the Measurement Invariance of the Dimensions of Tobacco Dependence Scale

    OpenAIRE

    Richardson, Chris G; Johnson, Joy L; Ratner, Pamela A; Bruno D Zumbo

    2009-01-01

    The purpose of this study was to examine the influence of mode of administration (internet-based, web survey format versus pencil-and-paper format) on responses to the Dimensions of Tobacco Dependence Scale (DTDS). Responses from 1,484 adolescents that reported using tobacco (mean age 16 years) were examined; 354 (23.9%) participants completed a web-based version and 1,130 (76.1%) completed a paper-based version of the survey. Both surveys were completed in supervised classroom environments. ...

  11. Synthesis, spectroscopic characterization and pH dependent photometric and electrochemical fate of Schiff bases.

    Science.gov (United States)

    Rauf, Abdur; Shah, Afzal; Abbas, Saghir; Rana, Usman Ali; Khan, Salah Ud-Din; Ali, Saqib; Zia-Ur-Rehman; Qureshi, Rumana; Kraatz, Heinz-Bernhard; Belanger-Gariepy, Francine

    2015-03-05

    A new Schiff base, 1-((4-bromophenylimino) methyl) naphthalen-2-ol (BPIMN) was successfully synthesized and characterized by (1)H NMR, (13)C NMR, FTIR and UV-Vis spectroscopy. The results were compared with a structurally related Schiff base, 1-((4-chlorophenylimino) methyl) naphthalen-2-ol (CPIMN). The photometric and electrochemical fate of BPIMN and CPIMN was investigated in a wide pH range. The experimental findings were supported by quantum mechanical approach. The redox mechanistic pathways were proposed on the basis of results obtained electrochemical techniques. Moreover, pH dependent UV-Vis spectroscopy of BPIMN and CPIMN was carried out and the appearance of isosbestic points indicated the existence of these compounds in different tautomeric forms.

  12. A class-based link prediction using Distance Dependent Chinese Restaurant Process

    Science.gov (United States)

    Andalib, Azam; Babamir, Seyed Morteza

    2016-08-01

    One of the important tasks in relational data analysis is link prediction which has been successfully applied on many applications such as bioinformatics, information retrieval, etc. The link prediction is defined as predicting the existence or absence of edges between nodes of a network. In this paper, we propose a novel method for link prediction based on Distance Dependent Chinese Restaurant Process (DDCRP) model which enables us to utilize the information of the topological structure of the network such as shortest path and connectivity of the nodes. We also propose a new Gibbs sampling algorithm for computing the posterior distribution of the hidden variables based on the training data. Experimental results on three real-world datasets show the superiority of the proposed method over other probabilistic models for link prediction problem.

  13. Optimized distance-dependent atom-pair-based potential DOOP for protein structure prediction.

    Science.gov (United States)

    Chae, Myong-Ho; Krull, Florian; Knapp, Ernst-Walter

    2015-05-01

    The DOcking decoy-based Optimized Potential (DOOP) energy function for protein structure prediction is based on empirical distance-dependent atom-pair interactions. To optimize the atom-pair interactions, native protein structures are decomposed into polypeptide chain segments that correspond to structural motives involving complete secondary structure elements. They constitute near native ligand-receptor systems (or just pairs). Thus, a total of 8609 ligand-receptor systems were prepared from 954 selected proteins. For each of these hypothetical ligand-receptor systems, 1000 evenly sampled docking decoys with 0-10 Å interface root-mean-square-deviation (iRMSD) were generated with a method used before for protein-protein docking. A neural network-based optimization method was applied to derive the optimized energy parameters using these decoys so that the energy function mimics the funnel-like energy landscape for the interaction between these hypothetical ligand-receptor systems. Thus, our method hierarchically models the overall funnel-like energy landscape of native protein structures. The resulting energy function was tested on several commonly used decoy sets for native protein structure recognition and compared with other statistical potentials. In combination with a torsion potential term which describes the local conformational preference, the atom-pair-based potential outperforms other reported statistical energy functions in correct ranking of native protein structures for a variety of decoy sets. This is especially the case for the most challenging ROSETTA decoy set, although it does not take into account side chain orientation-dependence explicitly. The DOOP energy function for protein structure prediction, the underlying database of protein structures with hypothetical ligand-receptor systems and their decoys are freely available at http://agknapp.chemie.fu-berlin.de/doop/.

  14. Dynamic analysis of fault rockburst based on gradient-dependent plasticity and energy criterion

    Institute of Scientific and Technical Information of China (English)

    Xuebin Wang; Xiaobin Yang; Zhihui Zhang; Yishan Pan

    2004-01-01

    Fault rockburst is treated as a strain localization problem under dynamic loading condition considering strain gradient and strain rate. As a kind of dynamic fracture phenomena, rockburst has characteristics of strain localization, which is considered as a one-dimensional shear problem subjected to normal compressive stress and tangential shear stress. The constitutive relation of rock material is bilinear (elastic and strain softening) and sensitive to shear strain rate. The solutions proposed based on gradientdependent plasticity show that intense plastic strain is concentrated in fault band and the thickness of the band depends on the characteristic length of rock material. The post-peak stiffness of the fault band was determined according to the constitutive parameters of rock material and shear strain rate. Fault band undergoing strain softening and elastic rock mass outside the band constitute a system and the instability criterion of the system was proposed based on energy theory. The criterion depends on the constitutive relation of rock material, the structural size and the strain rate. The static result regardless of the strain rate is the special case of the present analytical solution. High strain rate can lead to instability of the system.

  15. Dependency-based algorithms for vector processing of sparse matrix forward/backward substitutions

    Energy Technology Data Exchange (ETDEWEB)

    Vuong, G.T.; Chahine, R. [Hydro-Quebec, Montreal, Quebec (Canada); Granelli, G.P.; Montagna, M. [Univ. di Pavia (Italy)

    1996-02-01

    In this paper two algorithms for forward/backward substitutions and their implementation on vector computers are considered. A dependency-based substitution algorithm (DBSA) is proposed and compared with the well known W-matrix method. According to DBSA, the non-zero entries of the factor matrices are rearranged in groups of elements (slices) leading to independent operations. In the implementation of the W-matrix method, the non-zero elements of the inverse factors are grouped in sets (pseudocolumns) to overcome the problem of dependency between addition operations. Test cases, performed on a CRAY X-MP2/216 and a CRAY Y-MP8/464 vector computer, are taken from real life power system problems and consist in the solution of linear systems with up to 12,000 equations. The maximum speed-ups achieved (with respect to a code based on standard sparsity programming) are near to 7 for complex arithmetic and to 11 for real arithmetic.

  16. A suppository-base-matrix tablet for time-dependent colon-specific delivery system

    Directory of Open Access Journals (Sweden)

    Meijuan Zou

    2014-09-01

    Full Text Available Our research has focused on the main design features and release performances of time-dependent colon-specific (TDCS delivery tablets, which relies on the relative constancy that is observed in the small intestinal transit time of dosage forms. But inflammatory bowel disease(IBD)can affect the transit time, and usually results in watery stool. Compared to the TDCS and wax-matrix TDCS tablet, a promising time-dependent colon-specific delivery system was investigated. In our study, a suppository-base-matrix coated tablet was evaluated. Water soluble suppository-base helps the expansion of tablet, facilitates uniform film dissolution and achives high osmotic pressure. Combining the expansion of carboxymethyl starch sodium (CMS-Na and the moisture absorption of NaCl, the coated TDCS tablet obtained a burst and targeted drug delivery system. A very good correlation between in vitro drug release and in vivo outcome was observed. This TDCS coated tablet provides a promising strategy to control drug release to the desired lower gastrointestinal region.

  17. NMR-based microbial metabolomics and the temperature-dependent coral pathogen Vibrio coralliilyticus.

    Science.gov (United States)

    Boroujerdi, Arezue F B; Vizcaino, Maria I; Meyers, Alexander; Pollock, Elizabeth C; Huynh, Sara Lien; Schock, Tracey B; Morris, Pamela J; Bearden, Daniel W

    2009-10-15

    Coral bleaching occurs when the symbioses between coral animals and their zooxanthellae is disrupted, either as part of a natural cycle or as the result of unusual events. The bacterium Vibrio coralliilyticus (type strain ATCC BAA-450) has been linked to coral disease globally (for example in the Mediterranean, Red Sea, Indian Ocean, and Great Barrier Reef) and like many other Vibrio species exhibits a temperature-dependent pathogenicity. The temperature-dependence of V. corallillyticus in regard to its metabolome was investigated. Nuclear magnetic resonance (NMR) spectra were obtained of methanol-water extracts of intracellula rmetabolites (endometabolome) from multiple samples of the bacteria cultured into late stationary phase at 27 degrees C (virulent form) and 24 degrees C (avirulent form). The spectra were subjected to principal components analysis (PCA), and significant temperature-based separations in PC1, PC2, and PC3 dimensions were observed. Betaine, succinate, and glutamate were identified as metabolites that caused the greatest temperature-based separations in the PC scores plots. With increasing temperature, betaine was shown to be down regulated, while succinate and glutamate were up regulated.

  18. Effectiveness of Mindfulness-Based Group Therapy Compared to the Usual Opioid Dependence Treatment

    Directory of Open Access Journals (Sweden)

    Saeed Imani

    2015-11-01

    Full Text Available  Objective: This study investigated the effectiveness of mindfulness-based group therapy (MBGT compared to the usual opioid dependence treatment (TAU.Thirty outpatients meeting the DSM-IV-TR criteria for opioid dependence from Iranian National Center for Addiction Studies (INCAS were randomly assigned into experimental (Mindfulness-Based Group Therapy and control groups (the Usual Treatment.The experimental group undertook eight weeks of intervention, but the control group received the usual treatment according to the INCAS program.  Methods:The Five Factor Mindfulness Questionnaire (FFMQ and the Addiction Sevier Index (ASI were administered at pre-treatment and post-treatment assessment periods. Thirteen patients from the experimental group and 15 from the control group completed post-test assessments. Results:The results of MANCOVA revealed an increase in mean scores in observing, describing, acting with awareness, non-judging, non-reacting, and decrease in mean scores of alcohol and opium in MBGT patient group. Conclusion:The effectiveness of MBGT, compared to the usual treatment, was discussed in this paper as a selective protocol in the health care setting for substance use disorders.

  19. Performance analysis of a dependable scheduling strategy based on a fault-tolerant grid model

    Institute of Scientific and Technical Information of China (English)

    WANG Yuanzhuo; LIN Chuang; YANG Yang; SHAN Zhiguang

    2007-01-01

    The grid provides an integrated computer platform composed of differentiated and distributed systems.These resources are dynamic and heterogeneous.In this paper,a novel fault-tolerant grid-scheduling model is pre sented based on Stochastic Petri Nets (SPN) to assure the heterogeneity and dynamism of the grid system.Also,a new grid-scheduling strategy,the dependable strategy for the shortest expected accomplishing time (DSEAT),is put forward,in which the dependability factor is introduced in the task-dispatching strategy.In the end,the performance of the scheduling strategy based on the fault-tolerant gridscheduling model is analyzed by an software package,named SPNP.The numerical results show that dynamic resources will increase the response time for all classes of tasks in differing degrees.Compared with shortest expected accomplishing time (SEAT) strategy,the DSEAT strategy can reduce the negative effects of dynamic and autonomic resources to some extent so as to guarantee a high quality of service (QoS).

  20. Hierarchical Clustering Algorithm based on Attribute Dependency for Attention Deficit Hyperactive Disorder

    Directory of Open Access Journals (Sweden)

    J Anuradha

    2014-05-01

    Full Text Available Attention Deficit Hyperactive Disorder (ADHD is a disruptive neurobehavioral disorder characterized by abnormal behavioral patterns in attention, perusing activity, acting impulsively and combined types. It is predominant among school going children and it is tricky to differentiate between an active and an ADHD child. Misdiagnosis and undiagnosed cases are very common. Behavior patterns are identified by the mentors in the academic environment who lack skills in screening those kids. Hence an unsupervised learning algorithm can cluster the behavioral patterns of children at school for diagnosis of ADHD. In this paper, we propose a hierarchical clustering algorithm to partition the dataset based on attribute dependency (HCAD. HCAD forms clusters of data based on the high dependent attributes and their equivalence relation. It is capable of handling large volumes of data with reasonably faster clustering than most of the existing algorithms. It can work on both labeled and unlabelled data sets. Experimental results reveal that this algorithm has higher accuracy in comparison to other algorithms. HCAD achieves 97% of cluster purity in diagnosing ADHD. Empirical analysis of application of HCAD on different data sets from UCI repository is provided.

  1. Temperature dependence of the light yield of the LAB-based and mesitylene-based liquid scintillators

    CERN Document Server

    DongMei, Xia; XiaoBo, Li; XiLei, Sun; YaYun, Ding; Li, Zhou; Jun, Cao; Wei, Hu; XingCheng, Ye; HaiTao, Chen; XueFeng, Ding; Bing, Du

    2014-01-01

    We studied the temperature dependence of the light yield of the linear alkyl benzene (LAB)-based and mesitylene-based liquid scintillators. The light yield increases by 23% for both liquid scintillators when the temperature is lowered from $26\\;^{\\circ}$C to $-40\\;^{\\circ }$C, correcting for the temperature response of the photomultiplier tube. The measurements help to understand the energy response of the liquid scintillator detectors. Especially, the next generation reactor neutrino experiments for neutrino mass hierarchy, such as the Jiangmen Underground Neutrino Observatory (JUNO), require very high energy resolution. As no apparent degradation on the liquid scintillator transparency was observed, lowering the operation temperature of the detector to $\\sim4\\;^\\circ$C will increase the photoelectron yield of the detector by 13%, combining the light yield increase of the liquid scintillator and the quantum efficiency increase of the photomultiplier tubes.

  2. Statistical mechanics-based method to extract atomic distance-dependent potentials from protein structures.

    Science.gov (United States)

    Huang, Sheng-You; Zou, Xiaoqin

    2011-09-01

    In this study, we have developed a statistical mechanics-based iterative method to extract statistical atomic interaction potentials from known, nonredundant protein structures. Our method circumvents the long-standing reference state problem in deriving traditional knowledge-based scoring functions, by using rapid iterations through a physical, global convergence function. The rapid convergence of this physics-based method, unlike other parameter optimization methods, warrants the feasibility of deriving distance-dependent, all-atom statistical potentials to keep the scoring accuracy. The derived potentials, referred to as ITScore/Pro, have been validated using three diverse benchmarks: the high-resolution decoy set, the AMBER benchmark decoy set, and the CASP8 decoy set. Significant improvement in performance has been achieved. Finally, comparisons between the potentials of our model and potentials of a knowledge-based scoring function with a randomized reference state have revealed the reason for the better performance of our scoring function, which could provide useful insight into the development of other physical scoring functions. The potentials developed in this study are generally applicable for structural selection in protein structure prediction.

  3. Flagellin Encoded in Gene-Based Vector Vaccines Is a Route-Dependent Immune Adjuvant.

    Science.gov (United States)

    Rady, Hamada F; Dai, Guixiang; Huang, Weitao; Shellito, Judd E; Ramsay, Alistair J

    2016-01-01

    Flagellin has been tested as a protein-based vaccine adjuvant, with the majority of studies focused on antibody responses. Here, we evaluated the adjuvant activity of flagellin for both cellular and humoral immune responses in BALB/c mice in the setting of gene-based immunization, and have made several novel observations. DNA vaccines and adenovirus (Ad) vectors were engineered to encode mycobacterial protein Ag85B, with or without flagellin of Salmonella typhimurium (FliC). DNA-encoded flagellin given IM enhanced splenic CD4+ and CD8+ T cell responses to co-expressed vaccine antigen, including memory responses. Boosting either IM or intranasally with Ad vectors expressing Ag85B without flagellin led to durable enhancement of Ag85B-specific antibody and CD4+ and CD8+ T cell responses in both spleen and pulmonary tissues, correlating with significantly improved protection against challenge with pathogenic aerosolized M. tuberculosis. However, inclusion of flagellin in both DNA prime and Ad booster vaccines induced localized pulmonary inflammation and transient weight loss, with route-dependent effects on vaccine-induced T cell immunity. The latter included marked reductions in levels of mucosal CD4+ and CD8+ T cell responses following IM DNA/IN Ad mucosal prime-boosting, although antibody responses were not diminished. These findings indicate that flagellin has differential and route-dependent adjuvant activity when included as a component of systemic or mucosally-delivered gene-based prime-boost immunization. Clear adjuvant activity for both T and B cell responses was observed when flagellin was included in the DNA priming vaccine, but side effects occurred when given in an Ad boosting vector, particularly via the pulmonary route.

  4. Flagellin Encoded in Gene-Based Vector Vaccines Is a Route-Dependent Immune Adjuvant.

    Directory of Open Access Journals (Sweden)

    Hamada F Rady

    Full Text Available Flagellin has been tested as a protein-based vaccine adjuvant, with the majority of studies focused on antibody responses. Here, we evaluated the adjuvant activity of flagellin for both cellular and humoral immune responses in BALB/c mice in the setting of gene-based immunization, and have made several novel observations. DNA vaccines and adenovirus (Ad vectors were engineered to encode mycobacterial protein Ag85B, with or without flagellin of Salmonella typhimurium (FliC. DNA-encoded flagellin given IM enhanced splenic CD4+ and CD8+ T cell responses to co-expressed vaccine antigen, including memory responses. Boosting either IM or intranasally with Ad vectors expressing Ag85B without flagellin led to durable enhancement of Ag85B-specific antibody and CD4+ and CD8+ T cell responses in both spleen and pulmonary tissues, correlating with significantly improved protection against challenge with pathogenic aerosolized M. tuberculosis. However, inclusion of flagellin in both DNA prime and Ad booster vaccines induced localized pulmonary inflammation and transient weight loss, with route-dependent effects on vaccine-induced T cell immunity. The latter included marked reductions in levels of mucosal CD4+ and CD8+ T cell responses following IM DNA/IN Ad mucosal prime-boosting, although antibody responses were not diminished. These findings indicate that flagellin has differential and route-dependent adjuvant activity when included as a component of systemic or mucosally-delivered gene-based prime-boost immunization. Clear adjuvant activity for both T and B cell responses was observed when flagellin was included in the DNA priming vaccine, but side effects occurred when given in an Ad boosting vector, particularly via the pulmonary route.

  5. A distance-dependent metal-enhanced fluorescence sensing platform based on molecular beacon design.

    Science.gov (United States)

    Zhou, Zhenpeng; Huang, Hongduan; Chen, Yang; Liu, Feng; Huang, Cheng Zhi; Li, Na

    2014-02-15

    A new metal-enhanced fluorescence (MEF) based platform was developed on the basis of distance-dependent fluorescence quenching-enhancement effect, which combined the easiness of Ag-thiol chemistry with the MEF property of noble-metal structures as well as the molecular beacon design. For the given sized AgNPs, the fluorescence enhancement factor was found to increase with a d(6) dependency in agreement with fluorescence resonance energy transfer mechanism at shorter distance and decrease with a d(-3) dependency in agreement with plasmonic enhancement mechanism at longer distance between the fluorophore and the AgNP surface. As a proof of concept, the platform was demonstrated by a sensitive detection of mercuric ions, using thymine-containing molecular beacon to tune silver nanoparticle (AgNP)-enhanced fluorescence. Mercuric ions were detected via formation of a thymine-mercuric-thymine structure to open the hairpin, facilitating fluorescence recovery and AgNP enhancement to yield a limit of detection of 1 nM, which is well below the U.S. Environmental Protection Agency regulation of the Maximum Contaminant Level Goal (10nM) in drinking water. Since the AgNP functioned as not only a quencher to reduce the reagent blank signal but also an enhancement substrate to increase fluorescence of the open hairpin when target mercuric ions were present, the quenching-enhancement strategy can greatly improve the detection sensitivity and can in principle be a universal approach for various targets when combined with molecular beacon design.

  6. Coulometric bioelectrocatalytic reactions based on NAD-dependent dehydrogenases in tricarboxylic acid cycle

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Jun [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Tsujimura, Seiya [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: seiya@kais.kyoto-u.ac.jp; Kano, Kenji [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: kkano@kais.kyoto-u.ac.jp

    2008-12-30

    This paper describes the characterization of mediated electro-enzymatic electrolysis systems based on NAD-dependent dehydrogenase reactions in the tricarboxylic acid (TCA) cycle. A micro-bulk electrolysis system with a carbon felt anode immersed in an electrolysis solution with a value of about 10 {mu}L was constructed for coulometric analysis of the substrate oxidation. Diaphorase (DI) was used to couple the NAD-dependent dehydrogenase reaction with the anode reaction of a suitable redox mediator. We focused on three types of NAD-dependant dehydrogenases reactions in this research: (1) isocitrate oxidation, in which the standard Gibbs energy change ({delta}G{sup o}') is negative; (2) {alpha}-ketoglutarate oxidation, which involves an electrochemically active coenzyme A (CoA); and (3) malate oxidation, which is thermodynamically unfavorable because of a large positive {delta}G{sup o}' value. The complete electrolysis of isocitrate was easily achieved, supporting the effective re-oxidation of NADH in the diaphorase-catalyzed electrochemical reaction. CoA was unfavorably oxidized at the electrodes in the presence of some mediators. The electrocatalytic oxidation of CoA was suppressed and the quantitative electrochemical oxidation of {alpha}-ketoglutarate was achieved by selecting a suitable mediator with negligibly slow electron transfer kinetics with CoA. The uphill malate oxidation was susceptible to product inhibition in the bioelectrochemical system, although NADH generated in the malate dehydrogenase reaction was immediately oxidized in the electrochemical system. The inhibition was successfully suppressed by linking citrate synthase to quench oxaloacetate and to make the total {delta}G{sup o}' value negative.

  7. Hubbard interactions in iron-based pnictides and chalcogenides: Slater parametrization, screening channels, and frequency dependence

    Science.gov (United States)

    van Roekeghem, Ambroise; Vaugier, Loïg; Jiang, Hong; Biermann, Silke

    2016-09-01

    We calculate the strength of the frequency-dependent on-site electronic interactions in the iron pnictides LaFeAsO, BaFe2As2 , BaRu2As2 , and LiFeAs and the chalcogenide FeSe from first principles within the constrained random phase approximation. We discuss the accuracy of an atomiclike parametrization of the two-index density-density interaction matrices based on the calculation of an optimal set of three independent Slater integrals, assuming that the angular part of the Fe d localized orbitals can be described within spherical harmonics as for isolated Fe atoms. We show that its quality depends on the ligand-metal bonding character rather than on the dimensionality of the lattice: it is excellent for ionic-like Fe-Se (FeSe) chalcogenides and a more severe approximation for more covalent Fe-As (LaFeAsO, BaFe2As2 ) pnictides. We furthermore analyze the relative importance of different screening channels, with similar conclusions for the different pnictides but a somewhat different picture for the benchmark oxide SrVO3: the ligand channel does not appear to be dominant in the pnictides, while oxygen screening is the most important process in the oxide. Finally, we analyze the frequency dependence of the interaction. In contrast to simple oxides, in iron pnictides its functional form cannot be simply modeled by a single plasmon, and the actual density of modes enters the construction of an effective Hamiltonian determining the low-energy properties.

  8. Calculation of temperature distribution in adiabatic shear band based on gradient-dependent plasticity

    Institute of Scientific and Technical Information of China (English)

    王学滨

    2004-01-01

    A method for calculation of temperature distribution in adiabatic shear band is proposed in terms of gradient-dependent plasticity where the characteristic length describes the interactions and interplaying among microstructures. First, the increment of the plastic shear strain distribution in adiabatic shear band is obtained based on gradient-dependent plasticity. Then, the plastic work distribution is derived according to the current flow shear stress and the obtained increment of plastic shear strain distribution. In the light of the well-known assumption that 90% of plastic work is converted into the heat resulting in increase in temperature in adiabatic shear band, the increment of the temperature distribution is presented. Next, the average temperature increment in the shear band is calculated to compute the change in flow shear stress due to the thermal softening effect. After the actual flow shear stress considering the thermal softening effect is obtained according to the Johnson-Cook constitutive relation, the increment of the plastic shear strain distribution, the plastic work and the temperature in the next time step are recalculated until the total time is consumed. Summing the temperature distribution leads to rise in the total temperature distribution. The present calculated maximum temperature in adiabatic shear band in titanium agrees with the experimental observations. Moreover, the temperature profiles for different flow shear stresses are qualitatively consistent with experimental and numerical results. Effects of some related parameters on the temperature distribution are also predicted.

  9. Orientation-dependent fiber-optic accelerometer based on grating inscription over fiber cladding.

    Science.gov (United States)

    Rong, Qiangzhou; Qiao, Xueguang; Guo, Tuan; Bao, Weijia; Su, Dan; Yang, Hangzhou

    2014-12-01

    An orientation-sensitive fiber-optic accelerometer based on grating inscription over fiber cladding has been demonstrated. The sensor probe comprises a compact structure in which a short section of thin-core fiber (TCF) stub containing a "cladding" fiber Bragg grating (FBG) is spliced to another single-mode fiber (SMF) without any lateral offset. A femtosecond laser side-illumination technique was utilized to ensure that the grating inscription remains close to the core-cladding interface of the TCF. The core mode and the cladding mode of the TCF are coupled at the core-mismatch junction, and two well-defined resonances in reflection appear from the downstream FBG, in which the cladding resonance exhibits a strong polarization and bending dependence due to the asymmetrical distribution of the cladding FBG along the fiber cross section. Strong orientation dependence of the vibration (acceleration) measurement has been achieved by power detection of the cladding resonance. Meanwhile, the unwanted power fluctuations and temperature perturbations can be referenced out by monitoring the fundamental core resonance.

  10. Size-dependent structure and magnetocaloric properties of Fe-based glass-forming alloy powders

    Directory of Open Access Journals (Sweden)

    Qiang Luo

    2016-04-01

    Full Text Available We investigated the influence of particle size on the microstructure and magnetocaloric effect of Fe-based alloy powders (11 μm to 100 μm in diameter. The degree of structure order varies with the powder size. The 11 μm to 18 μm powders show the largest peak magnetic entropy change (MEC. Increasing the degree of structure order tends to decrease the maximum MEC. Nevertheless, enhancement of refrigerant capacity and MEC (above 70 K is achieved when the crystalline phase content is ∼50% (above 75 μm in the 75 μm to 100 μm powders. Exponent n of the field dependence of MEC increases with the decrease in powder size above 22.5 K. The size dependence of the structure and properties is associated with the fact that a larger particle has a slower cooling rate and takes a longer time to form medium-to-long range ordered structures.

  11. Applications of the DA based normal form algorithm on parameter-dependent perturbations

    Science.gov (United States)

    Weisskopf, Adrian

    Many advanced models in physics use a simpler system as the foundation upon which problemspecific perturbation terms are added. There are many mathematical methods in perturbation theory which attempt to solve or at least approximate the solution for the advanced model based on the solution of the unperturbed system. The analytical approaches have the advantage that their approximation is an algebraic expression relating all involved quantities in the calculated solution up to a certain order. However, the complexity of the calculation often increases drastically with the number of iterations, variables, and parameters considered. On the other hand, the computer-based numerical approaches are fast once implemented, but their results are only numerical approximations without a symbolic form. A numerical integrator, for example, takes the initial values and integrates the ordinary differential equation up to the requested final state and yields the result as specific numbers. Therefore, no algebraic expression, much less a parameter dependence within the solution is given. The method presented in this work is based on the differential algebra (DA) framework, which was first developed to its current extent by Martin Berz et. al [3, 4, 5]. The used DA Normal Form Algorithm is an advancement by Martin Berz from the first arbitrary order algorithm by Forest, Berz, and Irwin [13], which was based on an DA-Lie approach. Both structures are already implemented in COSY INFINITY [18] documented in [7, 16, 17]. The result of the presented method is a numerically calculated algebraic expression of the solution up to an arbitrary truncation order. This method combines the effectiveness and automatic calculation of a computer-based numerical approximation and the algebraic relation between the involved quantities.

  12. Compositional-dependent lead borate based glasses doped with Eu3+ ions: Synthesis and spectroscopic properties

    Science.gov (United States)

    Pisarski, W. A.; Pisarska, J.; Dominiak-Dzik, G.; Mączka, M.; Ryba-Romanowski, W.

    2006-12-01

    New multicomponent lead borate based glasses with various PbO/B2O3 weight ratio were prepared. The glass samples were analyzed in detail by using Raman and IR absorption spectroscopy. Optical properties of Eu3+ ions have been investigated in lead borate based systems, in which PbO/B2O3 weight ratios were changed from 1:2 to 8:1 in glass composition. The values of the phonon energy of the host and 5D0 lifetime of Eu3+ decrease, whereas absorption and emission intensities, as well as bonding parameter increase with increasing PbO concentration. Additionally, spectral lines are shifted in direction to the lower frequency region. Non-monotonic dependence of the fluorescence intensity ratio R (5D0 7F2/5D0 7F1) upon PbO/B2O3 content has been observed in contrast to bonding parameter that is also non-linear but monotonic. Some structural and spectroscopic aspects for Eu-doped lead borate based glasses are presented.

  13. A Novel Filter Dependent CFR Scheme with Waterfilling Based Code Domain Compensation

    Science.gov (United States)

    Chang, Hyung Min; Lee, Won Cheol

    This paper proposes a novel crest factor reduction (CFR) algorithm applicable to currently deployed W-CDMA base stations. The peak-to-average ratio (PAR) reduction of the multiple carrier mixed signal, namely CFR, has been an issue in order to convey the benefit of using low-cost power amplifiers. The simple final clipping method (SFCM) as a conventional method has been widely utilized due to its simplicity and effectiveness. However, the SFCM degrades the adjacent channel leakage ratio (ACLR) characteristic as well as the signal quality indicated by either the error vector magnitude (EVM) or the peak code domain error (PCDE). Conventionally, in order to alleviate this undesired deterioration, extra channel filtering and signal quality enhancement followed by CFR might be processed in an open-loop style. Alternatively, to perform CFR by maintaining the PAR as low as possible subject to satisfying the prescribed ACLR and EVM/PCDE performance, this paper introduces the prediction filter dependent peak reduction (PFDPR) process collaboratively working with dynamic waterfilling-based code domain compensation (DWCDC). To verify the superiority of the proposed CFR algorithm, tentative simulations are conducted while maintaining the rules of legitimate W-CDMA base station test specifications.

  14. Dependencies among Architectural Views Got from Software Requirements Based on a Formal Model

    Directory of Open Access Journals (Sweden)

    Osis Janis

    2014-12-01

    Full Text Available A system architect has software requirements and some unspecified knowledge about a problem domain (e.g., an enterprise as source information for assessment and evaluation of possible solutions and getting the target point, a preliminary software design. The solving factor is architect’s experience and expertise in the problem domain (“AS-IS”. A proposed approach is dedicated to assist a system architect in making an appropriate decision on the solution (“TO-BE”. It is based on a formal mathematical model, Topological Functioning Model (TFM. Compliant TFMs can be transformed into software architectural views. The paper demonstrates and discusses tracing dependency links from the requirements to and between the architectural views.

  15. Artificial topological models based on a one-dimensional spin-dependent optical lattice

    Science.gov (United States)

    Zheng, Zhen; Pu, Han; Zou, Xubo; Guo, Guangcan

    2017-01-01

    Topological matter is a popular topic in both condensed matter and cold-atom research. In the past decades, a variety of models have been identified with fascinating topological features. Some, but not all, of the models can be found in materials. As a fully controllable system, cold atoms trapped in optical lattices provide an ideal platform to simulate and realize these topological models. Here we present a proposal for synthesizing topological models in cold atoms based on a one-dimensional spin-dependent optical lattice potential. In our system, features such as staggered tunneling, staggered Zeeman field, nearest-neighbor interaction, beyond-near-neighbor tunneling, etc. can be readily realized. They underlie the emergence of various topological phases. Our proposal can be realized with current technology and hence has potential applications in quantum simulation of topological matter.

  16. The Home Care Crew Scheduling Problem: Preference-based visit clustering and temporal dependencies

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Justesen, Tor Fog; Dohn, Anders Høeg

    2012-01-01

    branch-and-price solution algorithm, as this method has previously given solid results for classical vehicle routing problems. Temporal dependencies are modelled as generalised precedence constraints and enforced through the branching. We introduce a novel visit clustering approach based on the soft...... preference constraints. The algorithm is tested both on real-life problem instances and on generated test instances inspired by realistic settings. The use of the specialised branching scheme on real-life problems is novel. The visit clustering decreases run times significantly, and only gives a loss...... of quality for few instances. Furthermore, the visit clustering allows us to find solutions to larger problem instances, which cannot be solved to optimality....

  17. Growth dependence of conjugation explains limited plasmid invasion in biofilms: an individual‐based modelling study

    DEFF Research Database (Denmark)

    Merkey, Brian; Lardon, Laurent; Seoane, Jose Miguel;

    2011-01-01

    . By extending an individual‐based model of microbial growth and interactions to include the dynamics of plasmid carriage and transfer by individual cells, we were able to conduct in silico tests of this and other hypotheses on the dynamics of conjugal plasmid transfer in biofilms. For a generic model plasmid...... and scan speed) and spatial reach (EPS yield, conjugal pilus length) are more important for successful plasmid invasion than the recipients' growth rate or the probability of segregational loss. While this study identifies one factor that can limit plasmid invasion in biofilms, the new individual......Plasmid invasion in biofilms is often surprisingly limited in spite of the close contact of cells in a biofilm. We hypothesized that this poor plasmid spread into deeper biofilm layers is caused by a dependence of conjugation on the growth rate (relative to the maximum growth rate) of the donor...

  18. Adjoint-Based a Posteriori Error Estimation for Coupled Time-Dependent Systems

    KAUST Repository

    Asner, Liya

    2012-01-01

    We consider time-dependent parabolic problem s coupled across a common interface which we formulate using a Lagrange multiplier construction and solve by applying a monolithic solution technique. We derive an adjoint-based a posteriori error representation for a quantity of interest given by a linear functional of the solution. We establish the accuracy of our error representation formula through numerical experimentation and investigate the effect of error in the adjoint solution. Crucially, the error representation affords a distinction between temporal and spatial errors and can be used as a basis for a blockwise time-space refinement strategy. Numerical tests illustrate the efficacy of the refinement strategy by capturing the distinctive behavior of a localized traveling wave solution. The saddle point systems considered here are equivalent to those arising in the mortar finite element technique for parabolic problems. © 2012 Society for Industrial and Applied Mathematics.

  19. Temperature Dependence of Particle Size Distribution in Transformer Oil-Based Ferrofluid

    Science.gov (United States)

    Józefczak, Arkadiusz; Hornowski, Tomasz; Skumiel, Andrzej

    2011-04-01

    The temperature dependence of the particle size distribution (PSD) of a transformer oil-based ferrofluid was studied using an ultrasound method. The measurements of the ultrasound velocity and attenuation were carried out in the absence of an external magnetic field as a function of the volume concentration of magnetite particles at temperatures ranging from 10 °C to 80 °C. The experimental results of ultrasound measurements were analyzed within the framework of the Vinogradov-Isakovich theory which takes into account contributions to acoustical parameters due to friction and heat exchange between magnetic particles and the surrounding carrier liquid. From the best fit of the experimental results and theoretical predictions, the parameters characterizing the PSD at different temperatures were determined. In order to analyze ultrasonic data, the density and viscosity of ferrofluid samples and the transformer oil were also measured.

  20. An ERK-dependent pathway to Noxa expression regulates apoptosis by platinum-based chemotherapeutic drugs.

    Science.gov (United States)

    Sheridan, C; Brumatti, G; Elgendy, M; Brunet, M; Martin, S J

    2010-12-09

    Cisplatin is a widely used cancer chemotherapeutic that promotes DNA damage-associated apoptosis. Although platinum compounds are known to form DNA adducts and provoke DNA damage, the molecular mechanism of cisplatin-induced cell death remains unclear. In this article, we show that the BH3-only protein Noxa is strongly transcriptionally upregulated in response to cisplatin and related platinum compounds. Cisplatin-induced Noxa expression was ERK dependent, but p53 independent, and inhibition of ERK activation markedly attenuated cisplatin-induced cell death, as well as Noxa expression. Furthermore, siRNA-mediated ablation of Noxa expression also inhibited cisplatin-induced cell death and permitted clonogenic survival. These observations reveal a novel ERK-regulated route to Noxa expression that is important for the cell killing activity of platinum-based chemotherapeutic drugs.

  1. Temperature Dependence of Characteristics for Multimode Interference Based 3-dB Coupler in SOI

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The temperature dependence of characteristics for multimode interference(MMI) based 3-dB coupler in silicon-on-insulator is analyzed, which originates from the relatively high thermo-optic coefficient of silicon. For restricted interference 3-dB MMI coupler, the output power uniformity is ideally 0 at room temperature and becomes 0.32dB when temperature rises up to 550K.For symmetric interference 3-dB MMI coupler, the power uniformity keeps ideally 0 due to its intrinsic symmetric interference mechanism. With the temperature rising, the excess loss of the both devices increases. The performance deterioration due to temperature variety is more obvious to restricted interference MMI 3-dB coupler, comparing with that of symmetric interference MMI 3-dB coupler.

  2. Left-handed properties dependence versus the interwire distance in Fe-based microwires metastructures

    Directory of Open Access Journals (Sweden)

    Gabriel Ababei

    2016-05-01

    Full Text Available Experimental and theoretical investigations on the left-handed properties dependence versus the interwire distance of three new proposed Fe77.5Si7.5B15 glass coated microwires-based metastructures are presented. The left-handed characteristics of the metastructures were determined in the frequency range 8.2 ÷ 12 GHz and external d.c. magnetic fields ranging from 0 to 32 kA/m. The experimental results show that the electromagnetic losses of the metastructures increase with the decreasing of the interwire distance due to the increasing of the long-range dynamic dipole-dipole interaction within inter-wires in the presence of the microwave field. The numerical calculations using Nicolson–Weiss–Ross algorithm are in agreement with the experimental results. The variation of the interwire distance proves to be a useful tool to obtain metastructures with controlled left-handed characteristics.

  3. A tuned mesh-generation strategy for image representation based on data-dependent triangulation.

    Science.gov (United States)

    Li, Ping; Adams, Michael D

    2013-05-01

    A mesh-generation framework for image representation based on data-dependent triangulation is proposed. The proposed framework is a modified version of the frameworks of Rippa and Garland and Heckbert that facilitates the development of more effective mesh-generation methods. As the proposed framework has several free parameters, the effects of different choices of these parameters on mesh quality are studied, leading to the recommendation of a particular set of choices for these parameters. A mesh-generation method is then introduced that employs the proposed framework with these best parameter choices. This method is demonstrated to produce meshes of higher quality (both in terms of squared error and subjectively) than those generated by several competing approaches, at a relatively modest computational and memory cost.

  4. Novel protein detection method based on proximity-dependent polymerase reaction and aptamers

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In recent years, specific detection of proteins is one of the hot issues about aptamers in proteomics.Here we reported a simple, sensitive and specific proximity-dependent protein assay with dual DNA aptamers. Thrombin was used as the model protein, and two aptamer probes with complementary sequence at 3'-end were designed for the two distinct epitopes of the protein. Association of the two aptamers with thrombin resulted in stable hybrids due to the proximity of 3'-end, then polymerase reaction was induced. The amount of obtained dsDNA was indicated using the fluorescence dye Sybr Green 1. The results showed that the initial velocity of polymerase reaction had a positive correlation with concentration of thrombin. The advantages of this dual-aptamer-based approach included simple and flexible design of aptamer probes, high selectivity and high sensitivity. The detection limit was 6.9pmol/L.

  5. Compositional dependence of microstructure and tribological properties of plasma sprayed Fe-based metallic glass coatings

    Institute of Scientific and Technical Information of China (English)

    YANG Qin; LI Ran; LIU ZengQian; SHI MinJie; LUO XueKun; ZHANG Tao

    2012-01-01

    Gas-atomized powders of three Fe-based glass-forming alloys were sprayed on mild steel substrates by atmospheric plasma spaying using the same spaying parameters.Microstructures,thermal stabilities and tribological properties of the sprayed coatings were analyzed.The coating performances showed a strong dependence on the intrinsic characters of the compositions,i,e.,glass-forming ability (GFA) and supercooled liquid region (ΔTx).The coatings tended to exhibit higher amorphous phase fraction for the composition with higher GFA and lower porosity for that with larger ΔTx.All the coatings exhibited superior wear resistance compared with the substrate.Higher wear resistance could be obtained in coatings with higher amorphous phase fraction,i.e.higher GFA of the composition.This study has important implications for composition selecting and optimizing in the fabrication of metallic glass coatings.

  6. Exercise-based transportation reduces oil dependence, carbon emissions and obesity

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, P.A.T.

    2005-09-15

    Societal dependence on oil leads to increasingly negative social consequences throughout the world, including climate change, air pollution, political and economic instability, and habitat degradation. Reliance on the automobile for transportation also contributes to a sedentary lifestyle, an obesity epidemic and poor health. These problems are particularly pronounced in the USA, which currently consumes c. 27% of global oil production and produces c. 25% of global carbon emissions, and where c. 65% of adults are overweight or obese. Other countries throughout the world that replicate or hope to replicate the automobile-based lifestyle of the USA face similar problems now or in the near future. This paper develops and applies calculations relating the distances that could be travelled through recommended daily walking or cycling with weight loss, oil consumption and carbon emissions. These straightforward calculations demonstrate that widespread substitution of driving with distances travelled during recommended daily exercise could reduce the USA's oil consumption by up to 38%. This saving far exceeds the amount of oil recoverable from the Arctic National Wildlife Refuge, suggesting that exercise can reduce foreign oil dependence and provide an alternative to oil extraction from environmentally sensitive habitat. At the same time, an average individual who substitutes this amount of exercise for transportation would burn respectively c. 12.2 and 26.0 kg of fat per year for walking and cycling. This is sufficient to eliminate obese and overweight conditions in a few years without dangerous or draconian diet plans. Furthermore, a reduction in carbon dioxide emissions of c. 35% is possible if the revenue saved through decreased health care spending on obesity is redirected toward carbon abatement. As a result, exercise-based transportation may constitute a favourable alternative to the energy and diet plans that are currently being implemented in the USA and may

  7. Towards adjoint-based inversion of time-dependent mantle convection with non-linear viscosity

    Science.gov (United States)

    Li, Dunzhu; Gurnis, Michael; Stadler, Georg

    2017-01-01

    We develop and study an adjoint-based inversion method for the simultaneous recovery of initial temperature conditions and viscosity parameters in time-dependent mantle convection from the current mantle temperature and historic plate motion. Based on a realistic rheological model with temperature- and strain rate-dependent viscosity, we formulate the inversion as a PDE-constrained optimization problem. The objective functional includes the misfit of surface velocity (plate motion) history, the misfit of the current mantle temperature, and a regularization for the uncertain initial condition. The gradient of this functional with respect to the initial temperature and the uncertain viscosity parameters is computed by solving the adjoint of the mantle convection equations. This gradient is used in a preconditioned quasi-Newton minimization algorithm. We study the prospects and limitations of the inversion, as well as the computational performance of the method using two synthetic problems, a sinking cylinder and a realistic subduction model. The subduction model is characterized by the migration of a ridge toward a trench whereby both plate motions and subduction evolve. The results demonstrate: (1) for known viscosity parameters, the initial temperature can be well recovered, as in previous initial condition-only inversions where the effective viscosity was given; (2) for known initial temperature, viscosity parameters can be recovered accurately, despite the existence of trade-offs due to ill-conditioning; (3) for the joint inversion of initial condition and viscosity parameters, initial condition and effective viscosity can be reasonably recovered, but the high dimension of the parameter space and the resulting ill-posedness may limit recovery of viscosity parameters.

  8. A Neutralizing Antibody Assay Based on a Reporter of Antibody-Dependent Cell-Mediated Cytotoxicity.

    Science.gov (United States)

    Wu, Yuling; Li, Jia J; Kim, Hyun Jun; Liu, Xu; Liu, Weiyi; Akhgar, Ahmad; Bowen, Michael A; Spitz, Susan; Jiang, Xu-Rong; Roskos, Lorin K; White, Wendy I

    2015-11-01

    Benralizumab is a humanized anti-IL5 receptor α (IL5Rα) monoclonal antibody (mAb) with enhanced (afucosylation) antibody-dependent cell-mediated cytotoxicity (ADCC) function. An ADCC reporter cell-based neutralizing antibody (NAb) assay was developed and characterized to detect NAb against benralizumab in human serum to support the clinical development of benralizumab. The optimal ratio of target cells to effector cells was 3:1. Neither parental benralizumab (fucosylated) nor benralizumab Fab resulted in ADCC activity, confirming the requirement for ADCC activity in the NAb assay. The serum tolerance of the cells was determined to be 2.5%. The cut point derived from normal and asthma serum samples was comparable. The effective range of benralizumab was determined, and 35 ng/mL [80% maximal effective concentration (EC80)] was chosen as the standard concentration to run in the assessment of NAb. An affinity purified goat anti-benralizumab polyclonal idiotype antibody preparation was shown to have NAb since it inhibited ADCC activity in a dose-dependent fashion. The low endogenous concentrations of IL5 and soluble IL5 receptor (sIL5R) did not demonstrate to interfere with the assay. The estimated assay sensitivities at the cut point were 1.02 and 1.10 μg/mL as determined by the surrogate neutralizing goat polyclonal and mouse monoclonal anti-drug antibody (ADA) controls, respectively. The assay can detect NAb (at 2.5 μg/mL) in the presence of 0.78 μg/mL benralizumab. The assay was not susceptible to non-specific matrix effects. This study provides an approach and feasibility of developing an ADCC cell-based NAb assay to support biopharmaceuticals with an ADCC function.

  9. Dependency Parsing

    CERN Document Server

    Kubler, Sandra; Nivre, Joakim

    2009-01-01

    Dependency-based methods for syntactic parsing have become increasingly popular in natural language processing in recent years. This book gives a thorough introduction to the methods that are most widely used today. After an introduction to dependency grammar and dependency parsing, followed by a formal characterization of the dependency parsing problem, the book surveys the three major classes of parsing models that are in current use: transition-based, graph-based, and grammar-based models. It continues with a chapter on evaluation and one on the comparison of different methods, and it close

  10. A Web of Drones: A 2040 Strategy to Reduce the United States Dependance on Space Based Capabilities

    Science.gov (United States)

    2015-02-17

    AIR WAR COLLEGE AIR UNIVERSITY A WEB OF DRONES : A 2040 STRATEGY TO REDUCE THE UNITED STATES DEPENDANCE ON SPACE BASED CAPABILITIES by...COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE A Web Of Drones : A 2040 Strategy To Reduce The United States Dependance On Space Based...these critical space services, this paper posits that in a denied space environment, a fleet of unmanned, autonomous drone aircraft whose primary

  11. Scatter-to-primary based scatter fractions for transmission-dependent convolution subtraction of SPECT images.

    Science.gov (United States)

    Larsson, Anne; Johansson, Lennart

    2003-11-21

    In single photon emission computed tomography (SPECT), transmission-dependent convolution subtraction has been shown to be useful when correcting for scattered events. The method is based on convolution subtraction, but includes a matrix of scatter fractions instead of a global scatter fraction. The method can be extended to iteratively improve the scatter estimate, but in this note we show that this requires a modification of the theory to use scatter-to-total scatter fractions for the first iteration only and scatter-to-primary fractions thereafter. To demonstrate this, scatter correction is performed on a Monte Carlo simulated image of a point source of activity in water. The modification of the theory is compared to corrections where the scatter fractions are based on the scatter-to-total ratio, using one and ten iterations. The resulting ratios of subtracted to original counts are compared to the true scatter-to-total ratio of the simulation and the most accurate result is found for our modification of the theory.

  12. A WAVELET-BASED MODEL FOR FOVEAL DETECTION OF SPATIAL CONTRAST WITH FREQUENCY DEPENDENT APERTURE EFFECT

    Directory of Open Access Journals (Sweden)

    Hamed Hooshangnejad

    2016-06-01

    Full Text Available The main purpose of this study is to build a Computational model based on ModelFest dataset which is able to predict contrast sensitivity while it benefits from simplicity, efficiency and accuracy, which makes it suitable for hardware implementation, practical uses, online tests, real-time processes, an improved Standard Observer and retina prostheses. It encompasses several components, and in particular, frequency dependent aperture effect (FDAE which is used for the first time on this dataset, which made the model more accurate and closer to reality. Shortcomings of previous models and the necessity of existence of FDAE for more accuracy led us to develop a new model based on Wavelet Transform that gives us the advantage of speed and the capability to process each frequency channels output. Considering our goal for building an efficient model, we introduce a new formula for modeling contrast sensitivity function, which generates lower RMS error and better timing performance. Eventually, this new model leads to having as yet lowest RMS error and solving the problem of long execution time of prior models and reduces them by almost a factor of twenty.

  13. The Influence of Web- Versus Paper-based Formats on the Assessment of Tobacco Dependence: Evaluating the Measurement Invariance of the Dimensions of Tobacco Dependence Scale

    Directory of Open Access Journals (Sweden)

    Chris G. Richardson

    2009-01-01

    Full Text Available The purpose of this study was to examine the influence of mode of administration (internet-based, web survey format versus pencil-and-paper format on responses to the Dimensions of Tobacco Dependence Scale (DTDS. Responses from 1,484 adolescents that reported using tobacco (mean age 16 years were examined; 354 (23.9% participants completed a web-based version and 1,130 (76.1% completed a paper-based version of the survey. Both surveys were completed in supervised classroom environments. Use of the web-based format was associated with significantly shorter completion times and a small but statistically significant increase in the number of missing responses. Tests of measurement invariance indicated that using a web-based mode of administration did not influence the psychometric functioning of the DTDS. There were no significant differences between the web- and paper-based groups’ ratings of the survey’s length, their question comprehension, and their response accuracy. Overall, the results of the study support the equivalence of scores obtained from web- and paper-based versions of the DTDS in secondary school settings.

  14. The Influence of Web- Versus Paper-based Formats on the Assessment of Tobacco Dependence: Evaluating the Measurement Invariance of the Dimensions of Tobacco Dependence Scale.

    Science.gov (United States)

    Richardson, Chris G; Johnson, Joy L; Ratner, Pamela A; Zumbo, Bruno D

    2009-01-01

    The purpose of this study was to examine the influence of mode of administration (internet-based, web survey format versus pencil-and-paper format) on responses to the Dimensions of Tobacco Dependence Scale (DTDS). Responses from 1,484 adolescents that reported using tobacco (mean age 16 years) were examined; 354 (23.9%) participants completed a web-based version and 1,130 (76.1%) completed a paper-based version of the survey. Both surveys were completed in supervised classroom environments. Use of the web-based format was associated with significantly shorter completion times and a small but statistically significant increase in the number of missing responses. Tests of measurement invariance indicated that using a web-based mode of administration did not influence the psychometric functioning of the DTDS. There were no significant differences between the web- and paper-based groups' ratings of the survey's length, their question comprehension, and their response accuracy. Overall, the results of the study support the equivalence of scores obtained from web- and paper-based versions of the DTDS in secondary school settings.

  15. An Emergy-Based Hybrid Method for Assessing Sustainability of the Resource-Dependent Region

    Directory of Open Access Journals (Sweden)

    Lulu Qu

    2017-01-01

    Full Text Available As the natural resources are getting exhausted, the concept of sustainable development of regions has received increasing attention, especially for resource-dependent cities. In this paper, an innovative method based on emergy analysis and the Human Impact Population Affluence Technology (IPAT model is developed to analyze the quantitative relationship of economic growth, energy consumption and its overall sustainability level. Taiyuan, a traditional, resource-dependent city in China, is selected as the case study region. The main results show that the total emergy of Taiyuan increased from 9.023 × 1023 sej in 2007 to 9.116 × 1023 sej in 2014, with a 38% decline in non-renewable emergy and an increase of imported emergy up to 125%. The regional emergy money ratio (EMB was reduced by 48% from 5.31 × 1013 sej/$ in 2007 to 2.74 × 1013 sej/$ in 2014, indicating that the increasing speed of consuming resources and energy was faster than the increase of GDP, and that Taiyuan’s money purchasing power declined. The lower emergy sustainability index (ESI indicates that Taiyuan was explored and produced large quantities of mineral resources, which puts more stress on the environment as a consequence, and that this is not sustainable in the long run. The IPAT analysis demonstrates that Taiyuan sticks to the efforts of energy conservation and environmental protection. In order to promote regional sustainable development, it is necessary to have an integrated effort. Policy insights suggest that resourceful regions should improve energy and resource efficiency, optimize energy and resourceful structure and carry out extensive public participation.

  16. Neural correlates of reward-based spatial learning in persons with cocaine dependence.

    Science.gov (United States)

    Tau, Gregory Z; Marsh, Rachel; Wang, Zhishun; Torres-Sanchez, Tania; Graniello, Barbara; Hao, Xuejun; Xu, Dongrong; Packard, Mark G; Duan, Yunsuo; Kangarlu, Alayar; Martinez, Diana; Peterson, Bradley S

    2014-02-01

    Dysfunctional learning systems are thought to be central to the pathogenesis of and impair recovery from addictions. The functioning of the brain circuits for episodic memory or learning that support goal-directed behavior has not been studied previously in persons with cocaine dependence (CD). Thirteen abstinent CD and 13 healthy participants underwent MRI scanning while performing a task that requires the use of spatial cues to navigate a virtual-reality environment and find monetary rewards, allowing the functional assessment of the brain systems for spatial learning, a form of episodic memory. Whereas both groups performed similarly on the reward-based spatial learning task, we identified disturbances in brain regions involved in learning and reward in CD participants. In particular, CD was associated with impaired functioning of medial temporal lobe (MTL), a brain region that is crucial for spatial learning (and episodic memory) with concomitant recruitment of striatum (which normally participates in stimulus-response, or habit, learning), and prefrontal cortex. CD was also associated with enhanced sensitivity of the ventral striatum to unexpected rewards but not to expected rewards earned during spatial learning. We provide evidence that spatial learning in CD is characterized by disturbances in functioning of an MTL-based system for episodic memory and a striatum-based system for stimulus-response learning and reward. We have found additional abnormalities in distributed cortical regions. Consistent with findings from animal studies, we provide the first evidence in humans describing the disruptive effects of cocaine on the coordinated functioning of multiple neural systems for learning and memory.

  17. Opinion mining feature-level using Naive Bayes and feature extraction based analysis dependencies

    Science.gov (United States)

    Sanda, Regi; Baizal, Z. K. Abdurahman; Nhita, Fhira

    2015-12-01

    Development of internet and technology, has major impact and providing new business called e-commerce. Many e-commerce sites that provide convenience in transaction, and consumers can also provide reviews or opinions on products that purchased. These opinions can be used by consumers and producers. Consumers to know the advantages and disadvantages of particular feature of the product. Procuders can analyse own strengths and weaknesses as well as it's competitors products. Many opinions need a method that the reader can know the point of whole opinion. The idea emerged from review summarization that summarizes the overall opinion based on sentiment and features contain. In this study, the domain that become the main focus is about the digital camera. This research consisted of four steps 1) giving the knowledge to the system to recognize the semantic orientation of an opinion 2) indentify the features of product 3) indentify whether the opinion gives a positive or negative 4) summarizing the result. In this research discussed the methods such as Naï;ve Bayes for sentiment classification, and feature extraction algorithm based on Dependencies Analysis, which is one of the tools in Natural Language Processing (NLP) and knowledge based dictionary which is useful for handling implicit features. The end result of research is a summary that contains a bunch of reviews from consumers on the features and sentiment. With proposed method, accuration for sentiment classification giving 81.2 % for positive test data, 80.2 % for negative test data, and accuration for feature extraction reach 90.3 %.

  18. Filling predictable and unpredictable gaps, with and without similarity-based interference: Evidence for LIFG effects of dependency processing

    Directory of Open Access Journals (Sweden)

    Kimberly eLeiken

    2015-11-01

    Full Text Available One of the most replicated findings in neurolinguistic literature on syntax is the increase of hemodynamic activity in the left inferior frontal gyrus (LIFG in response to object relative clauses (ORs compared to subject relative clauses (SRs. However, behavioral studies have shown that ORs are primarily only costly when similarity-based interference is involved and recently, Leiken & Pylkkänen (2014 showed with magnetoencephalography (MEG that an LIFG increase at an OR gap is also dependent on such interference. However, since ORs always involve a cue indicating an upcoming dependency formation, OR dependencies could be processed already prior to the gap-site and thus show no sheer dependency effects at the gap itself. To investigate the role of gap predictability in LIFG dependency effects, this MEG study compared ORs to Verb Phrase Ellipsis (VPE, which was used as an example of a non-predictable dependency. Additionally, we explored LIFG sensitivity to filler-gap order by including Right Node Raising (RNR structures, in which the order of filler and gap is reverse to that of ORs and VPE. Half of the stimuli invoked similarity-based interference and half did not. Our results demonstrate that LIFG effects of dependency can be elicited regardless of whether the dependency is predictable, the stimulus materials evoke similarity-based interference, or the filler precedes the gap. Thus, contrary to our own prior data, the current findings suggest a highly general role for the LIFG in dependency interpretation that is not limited to environments involving similarity-based interference. Additionally, the millisecond time-resolution of MEG allowed for a detailed characterization of the temporal profiles of LIFG dependency effects across our three constructions, revealing that the timing of these effects is somewhat construction-specific.

  19. Final Technical Report on Quantifying Dependability Attributes of Software Based Safety Critical Instrumentation and Control Systems in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Smidts, Carol [The Ohio State Univ., Columbus, OH (United States); Huang, Funqun [The Ohio State Univ., Columbus, OH (United States); Li, Boyuan [The Ohio State Univ., Columbus, OH (United States); Li, Xiang [The Ohio State Univ., Columbus, OH (United States)

    2016-03-25

    With the current transition from analog to digital instrumentation and control systems in nuclear power plants, the number and variety of software-based systems have significantly increased. The sophisticated nature and increasing complexity of software raises trust in these systems as a significant challenge. The trust placed in a software system is typically termed software dependability. Software dependability analysis faces uncommon challenges since software systems’ characteristics differ from those of hardware systems. The lack of systematic science-based methods for quantifying the dependability attributes in software-based instrumentation as well as control systems in safety critical applications has proved itself to be a significant inhibitor to the expanded use of modern digital technology in the nuclear industry. Dependability refers to the ability of a system to deliver a service that can be trusted. Dependability is commonly considered as a general concept that encompasses different attributes, e.g., reliability, safety, security, availability and maintainability. Dependability research has progressed significantly over the last few decades. For example, various assessment models and/or design approaches have been proposed for software reliability, software availability and software maintainability. Advances have also been made to integrate multiple dependability attributes, e.g., integrating security with other dependability attributes, measuring availability and maintainability, modeling reliability and availability, quantifying reliability and security, exploring the dependencies between security and safety and developing integrated analysis models. However, there is still a lack of understanding of the dependencies between various dependability attributes as a whole and of how such dependencies are formed. To address the need for quantification and give a more objective basis to the review process -- therefore reducing regulatory uncertainty

  20. Theory of valley-dependent transport in graphene-based lateral quantum structures

    Science.gov (United States)

    Chen, Feng-Wu; Chou, Mei-Yin; Chen, Yiing-Rei; Wu, Yu-Shu

    2016-08-01

    Modulation of electronic states in two-dimensional materials can be achieved by using in-plane variations of the band gap or the average potential in lateral quantum structures. In the atomic configurations with hexagonal symmetry, this approach makes it possible to tailor the valleytronic properties for potential device applications. In this work, we present a multiband theory to calculate the valley-dependent electron transport in graphene-based lateral quantum structures. As an example, we consider the structures with a single interface that exhibits an energy gap or potential discontinuity. The theoretical formalism proceeds within the tight-binding description, by first deriving the local bulk complex band structures in the regions of a constant gap or potential and, next, joining the local wave functions across the interface via a cell-averaged current operator to ensure the current continuity. The theory is applied to the study of electron reflection off and transmission through an interface. Both reflection and transmission are found to exhibit valley-contrast behavior that can be used to generate valley-polarized electron sources. The results vary with the type of interfaces, as well as between monolayer and bilayer graphene-based structures. In the monolayer case, the valley contrast originates from the band warping and only becomes sizable for incident carriers of high energy, whereas in AB-stacked bilayer graphene, the vertical interlayer coupling emerges as an additional important cause for valley contrast, and the favorable carrier energy is also found to be drastically lower. Our numerical results clearly demonstrate the propitious valleytronic properties of bilayer graphene structures.

  1. Cell cycle-dependent microtubule-based dynamic transport of cytoplasmic dynein in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Takuya Kobayashi

    Full Text Available BACKGROUND: Cytoplasmic dynein complex is a large multi-subunit microtubule (MT-associated molecular motor involved in various cellular functions including organelle positioning, vesicle transport and cell division. However, regulatory mechanism of the cell-cycle dependent distribution of dynein has not fully been understood. METHODOLOGY/PRINCIPAL FINDINGS: Here we report live-cell imaging of cytoplasmic dynein in HeLa cells, by expressing multifunctional green fluorescent protein (mfGFP-tagged 74-kDa intermediate chain (IC74. IC74-mfGFP was successfully incorporated into functional dynein complex. In interphase, dynein moved bi-directionally along with MTs, which might carry cargos such as transport vesicles. A substantial fraction of dynein moved toward cell periphery together with EB1, a member of MT plus end-tracking proteins (+TIPs, suggesting +TIPs-mediated transport of dynein. In late-interphase and prophase, dynein was localized at the centrosomes and the radial MT array. In prometaphase and metaphase, dynein was localized at spindle MTs where it frequently moved from spindle poles toward chromosomes or cell cortex. +TIPs may be involved in the transport of spindle dyneins. Possible kinetochore and cortical dyneins were also observed. CONCLUSIONS AND SIGNIFICANCE: These findings suggest that cytoplasmic dynein is transported to the site of action in preparation for the following cellular events, primarily by the MT-based transport. The MT-based transport may have greater advantage than simple diffusion of soluble dynein in rapid and efficient transport of the limited concentration of the protein.

  2. Density matrix based time-dependent configuration interaction approach to ultrafast spin-flip dynamics

    CERN Document Server

    Wang, H; Kühn, O

    2016-01-01

    Recent developments in attosecond spectroscopy yield access to the correlated motion of electrons on their intrinsic time scales. Spin-flip dynamics is usually considered in the context of valence electronic states, where spin-orbit coupling is weak and processes related to the electron spin are usually driven by nuclear motion. However, for core-excited states, where the core hole has a nonzero angular momentum, spin-orbit coupling is strong enough to drive spin-flips on a much shorter time scale. Using density matrix based time-dependent restricted active space configuration interaction including spin-orbit coupling, we address an unprecedentedly short spin-crossover for the example of L-edge (2p$\\rightarrow$3d) excited states of a prototypical Fe(II) complex. This process occurs on a time scale, which is faster than that of Auger decay ($\\sim$4\\,fs) treated here explicitly. Modest variations of carrier frequency and pulse duration can lead to substantial changes in the spin-state yield, suggesting its cont...

  3. PROSODIC FEATURE BASED TEXT DEPENDENT SPEAKER RECOGNITION USING MACHINE LEARNING ALGORITHMS

    Directory of Open Access Journals (Sweden)

    Sunil Agrawal

    2010-10-01

    Full Text Available Most of us are aware of the fact that voices of different individuals do not sound alike. The ability of recognizing a person solely from his voice is known as speaker recognition. Speaker recognition can not only assist in building better access control systems and security apparatus, it can be a useful tool in many other areas such as forensic speech analysis. The choice of features plays an important role in the performance of ML algorithm. Here we propose prosodic features based text dependent speaker recognition where the prosodic features can be extracted through linear predictive coding. Formants are efficient parameters to characterize a speaker’s voice. Formants are combined with their corresponding amplitudes, fundamental frequency, duration of speech utterance and energy ofthe windowed section. This feature vector is input to machine learning (ML algorithms for recognition. We investigate the performance of four ML algorithms namely MLP, RBFN, C4.5 decision tree, and BayesNet. Out of these ML algorithms, C4.5 decision tree performance is consistent. MLP performs better for gender recognition and experimental results show that RBFN gives better performance for increased population size.

  4. Shear time dependent viscosity of polystyrene-ethylacrylate based shear thickening fluid

    Science.gov (United States)

    Chen, Qian; Xuan, Shouhu; Jiang, Wanquan; Cao, Saisai; Gong, Xinglong

    2016-04-01

    In this study, the influence of the shear rate and shear time on the transient viscosity of polystyrene-ethylacrylate based shear thickening fluid (STF) is investigated. If the shear rate is stepwise changed, it is found that both the viscosity and critical shear rate are affected by the shear time. Above the critical shear rate, the viscosity of the STF with larger power law exponent (n) increases faster. However, the viscosity tends to decrease when the shear time is long enough. This phenomenon can be responsible for the reversible structure buildup and the break-down process. An effective volume fraction (EVF) mechanism is proposed to analyze the shear time dependent viscosity and it is found that viscosity changes in proportion to EVF. To further clarify the structure evolution, a structural kinetic model is studied because the structural kinetic parameter (λ) could describe the variation in the effective volume fraction. The theoretical results of the structural kinetic model agree well with the experimental results. With this model, the change in viscosity and EVF can be speculated from the variation of λ and then the structure evolution can be better illustrated.

  5. Microscopic predictions of fission yields based on the time dependent GCM formalism

    Science.gov (United States)

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-03-01

    Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r-process to fuel cycle optimization in nuclear energy. The need for a predictive theory applicable where no data is available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. One of the most promising theoretical frameworks is the time-dependent generator coordinate method (TDGCM) applied under the Gaussian overlap approximation (GOA). Previous studies reported promising results by numerically solving the TDGCM+GOA equation with a finite difference technique. However, the computational cost of this method makes it difficult to properly control numerical errors. In addition, it prevents one from performing calculations with more than two collective variables. To overcome these limitations, we developed the new code FELIX-1.0 that solves the TDGCM+GOA equation based on the Galerkin finite element method. In this article, we briefly illustrate the capabilities of the solver FELIX-1.0, in particular its validation for n+239Pu low energy induced fission. This work is the result of a collaboration between CEA,DAM,DIF and LLNL on nuclear fission theory.

  6. PET energy-based scatter estimation and image reconstruction with energy-dependent corrections

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, L M; Lewitt, Robert M; Matej, Samuel; Karp, Joel S [Department of Radiology, University of Pennsylvania, 423 Guardian Drive, 4th floor Blockley Hall, Philadelphia, PA 19104-6021 (United States)

    2006-06-07

    In this paper we propose a comprehensive energy-based scatter correction approach for positron emission tomography (PET). We take advantage of the marked difference between the energy spectra of the unscattered and scattered photons, and use the detailed energy information that comes with the list-mode data for the estimation of the scattered events distribution in the data space. Also, inside the maximum-likelihood expectation maximization (ML-EM) image reconstruction algorithm, we introduce energy-dependent factors that individualize the correction terms for each event, given its position and energy information. The central piece of our approach is the two-dimensional detector energy response model represented as a linear combination of four components, each one representing a particular state a PET event can be found in: both photons unscattered, the second scattered while the first not, the first photon scattered while the second not and both photons scattered. For a set of events collected in the vicinity of a point in the projection space, the coefficient of each component is determined by applying a statistical estimator. As a result we obtain the number of scattered events that are in the given set. The model also gives us the variation of scatter fraction with the photon pair energies for that particular position in the data space. A simulation study that demonstrates the proposed methods is presented.

  7. Microscopic predictions of fission yields based on the time dependent GCM formalism

    Directory of Open Access Journals (Sweden)

    Regnier D.

    2016-01-01

    Full Text Available Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r-process to fuel cycle optimization in nuclear energy. The need for a predictive theory applicable where no data is available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. One of the most promising theoretical frameworks is the time-dependent generator coordinate method (TDGCM applied under the Gaussian overlap approximation (GOA. Previous studies reported promising results by numerically solving the TDGCM+GOA equation with a finite difference technique. However, the computational cost of this method makes it difficult to properly control numerical errors. In addition, it prevents one from performing calculations with more than two collective variables. To overcome these limitations, we developed the new code FELIX-1.0 that solves the TDGCM+GOA equation based on the Galerkin finite element method. In this article, we briefly illustrate the capabilities of the solver FELIX-1.0, in particular its validation for n+239Pu low energy induced fission. This work is the result of a collaboration between CEA,DAM,DIF and LLNL on nuclear fission theory.

  8. A temperature dependent slip factor based thermal model for friction stir welding of stainless steel

    Indian Academy of Sciences (India)

    M Selvaraj

    2013-12-01

    This paper proposes a new slip factor based three-dimensional thermal model to predict the temperature distribution during friction stir welding of 304L stainless steel plates. The proposed model employs temperature and radius dependent heat source to study the thermal cycle, temperature distribution, power required, the effect of process parameters on heat generation per mm length of the weld and peak temperature during the friction stir welding process. Simulations of friction stir welding process were carried out on 304L stainless steel workpieces for various rotational and welding speeds. The predicted thermal cycle, power required and temperature distributions were found to be in good agreement with the experimental results. The heat generation per mm length of weld and peak temperature were found to be directly proportional to rotational speed and inversely proportional to welding speed. The rate of increase in heat generation per mm length of the weld and peak temperature are found to be higher at lower rotational speeds and lower at higher rotational speed. The heat generation during friction stir welding was found to be 80.8 % at shoulder, 16.1 % at pin side and 3.1 % at the bottom of the pin.

  9. Mechanism-based medication development for the treatment of nicotine dependence

    Institute of Scientific and Technical Information of China (English)

    Zheng-xiong XI; Krista SPILLER; Eliot L GARDNER

    2009-01-01

    Tobacco use is a global problem with serious health consequences. Though some treatment options exist, there remains a great need for new effective pharmacotherapies to aid smokers in maintaining long-term abstinence. In the present article, we first discuss the neural mechanisms underlying nicotine reward, and then review various mechanism-based pharmacological agents for the treatment of nicotine dependence. An oversimplified hypothesis of addiction to tobacco is that nicotine is the major addictive component of tobacco. Nicotine binds to a4β2 and a7 nicotinic acetylcholine receptors (nAChRs) located on dopaminergic, glutamatergic and GABAergic neurons in the mesolimbic dopamine (DA) system, which causes an increase in extracellular DA in the nucleus accumbens (NAc). That increase in DA reinforces tobacco use, particularly during the acquisition phase. Enhanced glutamate transmission to DA neurons in the ventral tegmental area appears to play an important role in this process. In addition, chronic nicotine treatment increases endocannabinoid levels in the mesolimbic DA system, which indirectly modulates NAc DA release and nicotine reward. Accordingly, pharmacological agents that target brain acetylcholine, DA, glutamate, GABA, or endocannabonoid signaling systems have been proposed to interrupt nicotine action. Furthermore, pharmacokinetic strategies that alter plasma nicotine availability, metabolism and clearance also significantly alter nicotine's action in the brain. Progress using these pharmacodynamic and pharmacokinetic agents is reviewed. For drugs in each category, we discuss the mechanistic rationale for their potential anti-nicotine efficacy, major findings in preclinical and clinical studies, and future research directions.

  10. Rough-Set-Based Attribute Dependencies: Foundations and Bio-Medical Data Applications

    Institute of Scientific and Technical Information of China (English)

    Dominik Slezak

    2006-01-01

    Theory of rough sets, proposed by Zdzislaw Pawlak in 1982, is a model of approximate reasoning. In applications, rough set methodology focuses on approximate representation of knowledge derivable from data. It leads to significant results in many areas including, for example, finance, industry, multimedia, medicine, and most recently bioinformatics. One of the key notions of rough sets is a reduct, an optimal subset of attributes providing enough information about pre-defined target concepts or whole data sources. Proposed originally within the framework of rough set approximations, it was extended regarding different application needs, using concepts of, for example, Boolean reasoning, Bayesian reasoning, and information theory. There have been developed efficient tools extracting reducts from data, based, for instance, on greedy heuristics and evolutionary algorithms. In this talk, we present foundations of rough sets, as well as current trends in rough-setbased attribute reduction, understood as the means for representation of multi-attribute approximate dependencies in real-world data. We pay a special attention to case studies of rough set applications to bio-medical problems, including MRI segmentation, geneexpression data analysis, as well as the cancer therapy survival analysis.

  11. Wavelet-Based Linear-Response Time-Dependent Density-Functional Theory

    CERN Document Server

    Natarajan, Bhaarathi; Casida, Mark E; Deutsch, Thierry; Burchak, Olga N; Philouze, Christian; Balakirev, Maxim Y

    2011-01-01

    Linear-response time-dependent (TD) density-functional theory (DFT) has been implemented in the pseudopotential wavelet-based electronic structure program BigDFT and results are compared against those obtained with the all-electron Gaussian-type orbital program deMon2k for the calculation of electronic absorption spectra of N2 using the TD local density approximation (LDA). The two programs give comparable excitation energies and absorption spectra once suitably extensive basis sets are used. Convergence of LDA density orbitals and orbital energies to the basis-set limit is significantly faster for BigDFT than for deMon2k. However the number of virtual orbitals used in TD-DFT calculations is a parameter in BigDFT, while all virtual orbitals are included in TD-DFT calculations in deMon2k. As a reality check, we report the x-ray crystal structure and the measured and calculated absorption spectrum (excitation energies and oscillator strengths) of the small organic molecule N-cyclohexyl-2-(4-methoxyphenyl)imidaz...

  12. Synthesis and characterization of a novel PNIPAAm-based copolymer with hydrolysis-dependent thermosensitivity.

    Science.gov (United States)

    Rosellini, Elisabetta; Cristallini, Caterina; Guerra, Giulio D; Barbani, Niccoletta; Giusti, Paolo

    2010-06-01

    The aim of this work was the synthesis and characterization of a novel poly(N-isopropylacrylamide)-based copolymer, with hydrolysis-dependent thermosensitivity, for bioengineering applications. For this purpose, N-isopropylacrylamide (NIPAAm) and 2-hydroxyethylmethacrylate-6-hydroxyhexanoate (HEMAHex) monomers were chosen. The poly(NIPAAm-co-HEMAHex) copolymer was synthesized by radical polymerization. The physicochemical, mechanical, functional and biological properties of the copolymer were investigated. The physicochemical characterization confirmed that the copolymerization was successfully carried out. In addition, the newly synthesized poly(NIPAAm-co-HEMAHex) copolymer showed temperature sensitivity, with a phase separation temperature under body temperature (at 23 °C). Fourier transform infrared spectroscopy and differential scanning calorimetry results after hydrolysis tests indicated that the incorporation of the HEMAHex ester groups provides the cleavage of the lateral chain, which leads to an increase in the hydrophilicity of the copolymer and, consequently, to an increase in the lower critical solution temperature (LCST) with time. Since the LCST increases above body temperature (up to 40.4 °C), the copolymer becomes soluble again and diffuses away. It was also demonstrated that the hydrolysis occurred on the peripheral ester bond of the lateral chain, with the release of 6-hydroxyhexanoic acid, whose bioresorbibility has been reported in the literature. Therefore, the properties of this copolymer are very interesting and make it particularly attractive for biomedical applications.

  13. Predictive model of nicotine dependence based on mental health indicators and self-concept

    Directory of Open Access Journals (Sweden)

    Hamid Kazemi Zahrani

    2014-12-01

    Full Text Available Background: The purpose of this research was to investigate the predictive power of anxiety, depression, stress and self-concept dimensions (Mental ability, job efficiency, physical attractiveness, social skills, and deficiencies and merits as predictors of nicotine dependency among university students in Isfahan. Methods: In this correlational study, 110 male nicotine-dependent students at Isfahan University were selected by convenience sampling. All samples were assessed by Depression Anxiety Stress Scale (DASS, self-concept test and Nicotine Dependence Syndrome Scale. Data were analyzed by Pearson correlation and stepwise regression. Results: The result showed that anxiety had the highest strength to predict nicotine dependence. In addition, the self-concept and its dimensions predicted only 12% of the variance in nicotine dependence, which was not significant. Conclusion: Emotional processing variables involved in mental health play an important role in presenting a model to predict students’ dependence on nicotine more than identity variables such as different dimensions of self-concept.

  14. Numerical modelling of softwood time-dependent behaviour based on microstructure

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2010-01-01

    by the basic physical mechanism behind the time-dependent behaviour. The mechanism causing time-dependency is thought to be sliding of the microfibrils past each other as a result breaking and re-bonding of hydrogen bonds. This can be incorporated in a numerical model by only allowing time-dependency in shear...... be predicted with the described method of modelling. This is seen by simulating experimental results for both single fibres and tissues in creep and relaxation experiments....

  15. Design of robust dependent networks against flow-based cascading failures

    NARCIS (Netherlands)

    Ouboter, T.M.; Worm, D.T.H.; Kooij, R.E.; Wang, H.

    2014-01-01

    In this paper we propose strategies to increase the robustness of a communication network which depends on the proper functioning of an electricity network. The strategies involve selecting nodes of the communication network and removing their dependency on the electricity network. Compared to exist

  16. Iso-spin Dependent Microscopic Optical Model Potential Based on Dirac Bruckner Haretree Fock Method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The microscopic optical model is investigated in the Dirac-Brueckner-Hartree-Fock (DBHF) framework with Bonn B meson exchange potential. Both real and imaginary parts of isospin-dependent self-energies are derived from a strict projection

  17. Motivation and exercise dependence: a study based on self-determination theory.

    Science.gov (United States)

    González-Cutre, David; Sicilia, Alvaro

    2012-06-01

    The objective of this study was to use self-determination theory to analyze the relationships of several motivational variables with exercise dependence. The study involved 531 exercisers, ranging in age from 16 to 60 years old, who responded to differentquestionnaires assessing perception of motivational climate, satisfaction of basic psychological needs, motivation types, and exercise dependence. The results of multiple mediation analysis revealed that ego-involving climate and perceived competence positively predicted exercise dependence in a directed and mediated manner through introjected and external regulation. Gender and age did not moderate the analyzed relationships. These results allow us to better understand the motivational process explaining exercise dependence, demonstrating the negative influence of the ego-involving climate in the context of exercise.

  18. Temperature dependency of the silicon heterojunction lifetime model based on the amphoteric nature of dangling bonds

    Science.gov (United States)

    Vasudevan, R.; Poli, I.; Deligiannis, D.; Zeman, M.; Smets, A. H. M.

    2016-11-01

    This work adapts a model to simulate the carrier injection dependent minority carrier lifetime of crystalline silicon passivated with hydrogenated amorphous silicon at elevated temperatures. Two existing models that respectively calculate the bulk lifetime and surface recombination velocity are used and the full temperature dependency of these models are explored. After a thorough description of these temperature dependencies, experimental results using this model show that the minority carrier lifetime changes upon annealing of silicon heterojunction structures are not universal. Furthermore, comparisons of the temperature dependent model to using the room temperature model at elevated temperatures is given and significant differences are observed when using temperatures above 100 °C. This shows the necessity of taking temperature effects into account during in-situ annealing experiments.

  19. Final Technical Report on Quantifying Dependability Attributes of Software Based Safety Critical Instrumentation and Control Systems in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Smidts, Carol [The Ohio State Univ., Columbus, OH (United States); Huang, Funqun [The Ohio State Univ., Columbus, OH (United States); Li, Boyuan [The Ohio State Univ., Columbus, OH (United States); Li, Xiang [The Ohio State Univ., Columbus, OH (United States)

    2016-03-25

    With the current transition from analog to digital instrumentation and control systems in nuclear power plants, the number and variety of software-based systems have significantly increased. The sophisticated nature and increasing complexity of software raises trust in these systems as a significant challenge. The trust placed in a software system is typically termed software dependability. Software dependability analysis faces uncommon challenges since software systems’ characteristics differ from those of hardware systems. The lack of systematic science-based methods for quantifying the dependability attributes in software-based instrumentation as well as control systems in safety critical applications has proved itself to be a significant inhibitor to the expanded use of modern digital technology in the nuclear industry. Dependability refers to the ability of a system to deliver a service that can be trusted. Dependability is commonly considered as a general concept that encompasses different attributes, e.g., reliability, safety, security, availability and maintainability. Dependability research has progressed significantly over the last few decades. For example, various assessment models and/or design approaches have been proposed for software reliability, software availability and software maintainability. Advances have also been made to integrate multiple dependability attributes, e.g., integrating security with other dependability attributes, measuring availability and maintainability, modeling reliability and availability, quantifying reliability and security, exploring the dependencies between security and safety and developing integrated analysis models. However, there is still a lack of understanding of the dependencies between various dependability attributes as a whole and of how such dependencies are formed. To address the need for quantification and give a more objective basis to the review process -- therefore reducing regulatory uncertainty

  20. GENERAL APROACH TO MODELING NONLINEAR AMPLITUDE AND FREQUENCY DEPENDENT HYSTERESIS EFFECTS BASED ON EXPERIMENTAL RESULTS

    Directory of Open Access Journals (Sweden)

    Christopher Heine

    2014-08-01

    Full Text Available A detailed description of the rubber parts’ properties is gaining in importance in the current simulation models of multi-body simulation. One application example is a multi-body simulation of the washing machine movement. Inside the washing machine, there are different force transmission elements, which consist completely or partly of rubber. Rubber parts or, generally, elastomers usually have amplitude-dependant and frequency-dependent force transmission properties. Rheological models are used to describe these properties. A method for characterization of the amplitude and frequency dependence of such a rheological model is presented within this paper. Within this method, the used rheological model can be reduced or expanded in order to illustrate various non-linear effects. An original result is given with the automated parameter identification. It is fully implemented in Matlab. Such identified rheological models are intended for subsequent implementation in a multi-body model. This allows a significant enhancement of the overall model quality.

  1. Angular dependence of coercivity with temperature in Co-based nanowires

    Science.gov (United States)

    Bran, C.; Espejo, A. P.; Palmero, E. M.; Escrig, J.; Vázquez, M.

    2015-12-01

    The magnetic behavior of arrays of Co and CoFe nanowire arrays has been measured in the temperature range between 100 and 300 K. We have paid particular attention to the angular dependence of magnetic properties on the applied magnetic field orientation. The experimental angular dependence of coercivity has been modeled according to micromagnetic analytical calculations, and we found that the propagation of a transversal domain wall mode gives the best fitting with experimental observations. That reversal mode holds in the whole measuring temperature range, for nanowires with different diameters and crystalline structure. Moreover, the quantitative strength of the magnetocrystalline anisotropy and its magnetization easy axis are determined to depend on the crystalline structure and nanowires diameter. The evolution of the magnetocrystalline anisotropy with temperature for nanowires with different composition gives rise to an opposite evolution of coercivity with increasing temperature: it decreases for CoFe while it increases for Co nanowire arrays.

  2. Angular dependence of coercivity with temperature in Co-based nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Bran, C., E-mail: cristina.bran@icmm.csic.es [Institute of Materials Science of Madrid, CSIC, 28049 Madrid (Spain); Espejo, A.P. [Departamento de Física, Universidad de Santiago de Chile (USACH) and Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avenida Ecuador 3493, 9170124 Santiago (Chile); Palmero, E.M. [Institute of Materials Science of Madrid, CSIC, 28049 Madrid (Spain); Escrig, J. [Departamento de Física, Universidad de Santiago de Chile (USACH) and Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avenida Ecuador 3493, 9170124 Santiago (Chile); Vázquez, M. [Institute of Materials Science of Madrid, CSIC, 28049 Madrid (Spain)

    2015-12-15

    The magnetic behavior of arrays of Co and CoFe nanowire arrays has been measured in the temperature range between 100 and 300 K. We have paid particular attention to the angular dependence of magnetic properties on the applied magnetic field orientation. The experimental angular dependence of coercivity has been modeled according to micromagnetic analytical calculations, and we found that the propagation of a transversal domain wall mode gives the best fitting with experimental observations. That reversal mode holds in the whole measuring temperature range, for nanowires with different diameters and crystalline structure. Moreover, the quantitative strength of the magnetocrystalline anisotropy and its magnetization easy axis are determined to depend on the crystalline structure and nanowires diameter. The evolution of the magnetocrystalline anisotropy with temperature for nanowires with different composition gives rise to an opposite evolution of coercivity with increasing temperature: it decreases for CoFe while it increases for Co nanowire arrays.

  3. Size dependent photoresponse characteristics of crystalline Ge quantum dots based photodetectors

    Science.gov (United States)

    Bar, Rajshekhar; Manna, Santanu; Ray, Samit K.

    2016-10-01

    We report on the size dependent photoresponse behaviour of crystalline Ge quantum dots (QDs) dispersed within the silica matrix. Our findings demonstrate an increasing nature of EQE with increase in QDs size, which could be attributed to the combined effect of Coulomb interaction of photogenerated carriers, QD/silica interface defects and electric field driven carrier separation and tunneling through the oxide barriers. In this regard, the bias dependent nonlinear response of the photocurrent has been explained on the basis of cold field emission (CFE) model. Besides, the EQE is extended (>100%) for larger sized QDs, suggesting the trapping of slower holes in Ge QDs creating a charge neutrality issue.

  4. A new differential equations-based model for nonlinear history-dependent magnetic behaviour

    CERN Document Server

    Aktaa, J

    2000-01-01

    The paper presents a new kind of numerical model describing nonlinear magnetic behaviour. The model is formulated as a set of differential equations taking into account history dependence phenomena like the magnetisation hysteresis as well as saturation effects. The capability of the model is demonstrated carrying out comparisons between measurements and calculations.

  5. Extraction and Visualization of Call Dependencies for Large C/C++ Code Bases : A Comparative Study

    NARCIS (Netherlands)

    Telea, Alexandru; Hoogendorp, Hessel; Ersoy, Ozan; Reniers, Dennie; Lanza, M; Storey, M; Muller, H

    2009-01-01

    Investigating program dependencies such as function calls is challenging for very large systems. We present here an integrated pipeline for extraction and visualization of call-and-hierarchy graphs for C/C++ programs. We present several adaptions and enhancements of a recent visualization method for

  6. Motivation and Exercise Dependence: A Study Based on Self-Determination Theory

    Science.gov (United States)

    Gonzalez-Cutre, David; Sicilia, Alvaro

    2012-01-01

    The objective of this study was to use self-determination theory to analyze the relationships of several motivational variables with exercise dependence. The study involved 531 exercisers, ranging in age from 16 to 60 years old, who responded to different questionnaires assessing perception of motivational climate, satisfaction of basic…

  7. Optimal Preventive Maintenance Schedule based on Lifecycle Cost and Time-Dependent Reliability

    Science.gov (United States)

    2011-11-10

    cost PC , the inspection cost IC and an expected variable cost EVC [2, 32]. These costs are a function of quality and reliability. The lifecycle...expected variable cost EVC is a function of the time- dependent reliability which is used to estimate the expected present value of repairing and/or

  8. Molecular-based mechanisms of Mendelian forms of salt-dependent hypertension: questioning the prevailing theory.

    Science.gov (United States)

    Kurtz, Theodore W; Dominiczak, Anna F; DiCarlo, Stephen E; Pravenec, Michal; Morris, R Curtis

    2015-05-01

    This critical review directly challenges the prevailing theory that a transient increase in cardiac output caused by genetically mediated increases in activity of the ENaC in the aldosterone sensitive distal nephron, or of the NCC in the distal convoluted tubule, accounts entirely for the hemodynamic initiation of all Mendelian forms of salt-dependent hypertension (Figure 1). The prevailing theory of how genetic mutations enable salt to hemodynamically initiate Mendelian forms of salt-dependent hypertension in humans (Figure 1) depends on the results of salt-loading studies of cardiac output and systemic vascular resistance in nongenetic models of hypertension that lack appropriate normal controls. The theory is inconsistent with the results of studies that include measurements of the initial hemodynamic changes induced by salt loading in normal, salt-resistant controls. The present analysis, which takes into account the results of salt-loading studies that include the requisite normal controls, indicates that mutation-induced increases in the renal tubular activity of ENaC or NCC that lead to transient increases in cardiac output will generally not be sufficient to enable increases in salt intake to initiate the increased BP that characterizes Mendelian forms of salt-dependent hypertension (Table). The present analysis also raises questions about whether mutation-dependent increases in renal tubular activity of ENaC or NCC are even necessary to account for increased risk for salt-dependent hypertension in most patients with such mutations. We propose that for the genetic alterations underlying Mendelian forms of salt-dependent hypertension to enable increases in salt intake to initiate the increased BP, they must often cause vasodysfunction, ie, an inability to normally vasodilate and decrease systemic vascular resistance in response to increases in salt intake within dietary ranges typically observed in most modern societies. A subnormal ability to vasodilate in

  9. Polynomial fuzzy model-based control systems stability analysis and control synthesis using membership function dependent techniques

    CERN Document Server

    Lam, Hak-Keung

    2016-01-01

    This book presents recent research on the stability analysis of polynomial-fuzzy-model-based control systems where the concept of partially/imperfectly matched premises and membership-function dependent analysis are considered. The membership-function-dependent analysis offers a new research direction for fuzzy-model-based control systems by taking into account the characteristic and information of the membership functions in the stability analysis. The book presents on a research level the most recent and advanced research results, promotes the research of polynomial-fuzzy-model-based control systems, and provides theoretical support and point a research direction to postgraduate students and fellow researchers. Each chapter provides numerical examples to verify the analysis results, demonstrate the effectiveness of the proposed polynomial fuzzy control schemes, and explain the design procedure. The book is comprehensively written enclosing detailed derivation steps and mathematical derivations also for read...

  10. Polygenic risk for alcohol dependence associates with alcohol consumption, cognitive function and social deprivation in a population-based cohort.

    Science.gov (United States)

    Clarke, Toni-Kim; Smith, Andrew H; Gelernter, Joel; Kranzler, Henry R; Farrer, Lindsay A; Hall, Lynsey S; Fernandez-Pujals, Ana M; MacIntyre, Donald J; Smith, Blair H; Hocking, Lynne J; Padmanabhan, Sandosh; Hayward, Caroline; Thomson, Pippa A; Porteous, David J; Deary, Ian J; McIntosh, Andrew M

    2016-03-01

    Alcohol dependence is frequently co-morbid with cognitive impairment. The relationship between these traits is complex as cognitive dysfunction may arise as a consequence of heavy drinking or exist prior to the onset of dependence. In the present study, we tested the genetic overlap between cognitive abilities and alcohol dependence using polygenic risk scores (PGRS). We created two independent PGRS derived from two recent genome-wide association studies (GWAS) of alcohol dependence (SAGE GWAS: n = 2750; Yale-Penn GWAS: n = 2377) in a population-based cohort, Generation Scotland: Scottish Family Health Study (GS:SFHS) (n = 9863). Data on alcohol consumption and four tests of cognitive function [Mill Hill Vocabulary (MHV), digit symbol coding, phonemic verbal fluency (VF) and logical memory] were available. PGRS for alcohol dependence were negatively associated with two measures of cognitive function: MHV (SAGE: P = 0.009, β = -0.027; Yale-Penn: P = 0.001, β = -0.034) and VF (SAGE: P = 0.0008, β = -0.036; Yale-Penn: P = 0.00005, β = -0.044). VF remained robustly associated after adjustment for education and social deprivation; however, the association with MHV was substantially attenuated. Shared genetic variants may account for some of the phenotypic association between cognitive ability and alcohol dependence. A significant negative association between PGRS and social deprivation was found (SAGE: P = 5.2 × 10(-7) , β = -0.054; Yale-Penn: P = 0.000012, β = -0.047). Individuals living in socially deprived regions were found to carry more alcohol dependence risk alleles which may contribute to the increased prevalence of problem drinking in regions of deprivation. Future work to identify genes which affect both cognitive impairment and alcohol dependence will help elucidate biological processes common to both disorders.

  11. An estimator of the survival function based on the semi-Markov model under dependent censorship.

    Science.gov (United States)

    Lee, Seung-Yeoun; Tsai, Wei-Yann

    2005-06-01

    Lee and Wolfe (Biometrics vol. 54 pp. 1176-1178, 1998) proposed the two-stage sampling design for testing the assumption of independent censoring, which involves further follow-up of a subset of lost-to-follow-up censored subjects. They also proposed an adjusted estimator for the survivor function for a proportional hazards model under the dependent censoring model. In this paper, a new estimator for the survivor function is proposed for the semi-Markov model under the dependent censorship on the basis of the two-stage sampling data. The consistency and the asymptotic distribution of the proposed estimator are derived. The estimation procedure is illustrated with an example of lung cancer clinical trial and simulation results are reported of the mean squared errors of estimators under a proportional hazards and two different nonproportional hazards models.

  12. Temperature dependence of Hall electron density of GaN-based heterostructures

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin-Feng; Zhang Jin-Cheng; Hao Yue

    2004-01-01

    The theoretic calculation and analysis of the temperature dependence of Hall electron density of a sample AlGaN/GaN heterostructure has been carried out in the temperature range from 77 to 300K. The densities of the twodimensional electron gas and the bulk electrons are solved by self-consistent calculation of one-dimensional Schrodinger and Poisson equations at different temperatures, which allow for the variation of energy gap and structure strain, and are used for evaluation of the temperature dependence of Hall electron density. The calculated Hall electron density agrees with the measured one quite well with the appropriate bulk mobility data. Analysis revealed that for the temper ature range considered, even in the heterostructures with a small bulk conductance the factors that determine the Hall mobility and electron density could be of different sources, and not just the two-dimensional electron gas as generally supposed.

  13. Plant Cell Imaging Based on Nanodiamonds with Excitation-Dependent Fluorescence.

    Science.gov (United States)

    Su, Li-Xia; Lou, Qing; Jiao, Zhen; Shan, Chong-Xin

    2016-12-01

    Despite extensive work on fluorescence behavior stemming from color centers of diamond, reports on the excitation-dependent fluorescence of nanodiamonds (NDs) with a large-scale redshift from 400 to 620 nm under different excitation wavelengths are so far much fewer, especially in biological applications. The fluorescence can be attributed to the combined effects of the fraction of sp(2)-hybridized carbon atoms among the surface of the fine diamond nanoparticles and the defect energy trapping states on the surface of the diamond. The excitation-dependent fluorescent NDs have been applied in plant cell imaging for the first time. The results reported in this paper may provide a promising route to multiple-color bioimaging using NDs.

  14. Plant Cell Imaging Based on Nanodiamonds with Excitation-Dependent Fluorescence

    Science.gov (United States)

    Su, Li-Xia; Lou, Qing; Jiao, Zhen; Shan, Chong-Xin

    2016-09-01

    Despite extensive work on fluorescence behavior stemming from color centers of diamond, reports on the excitation-dependent fluorescence of nanodiamonds (NDs) with a large-scale redshift from 400 to 620 nm under different excitation wavelengths are so far much fewer, especially in biological applications. The fluorescence can be attributed to the combined effects of the fraction of sp2-hybridized carbon atoms among the surface of the fine diamond nanoparticles and the defect energy trapping states on the surface of the diamond. The excitation-dependent fluorescent NDs have been applied in plant cell imaging for the first time. The results reported in this paper may provide a promising route to multiple-color bioimaging using NDs.

  15. Time-dependent prediction degredation assessment of neural-networks-based TEC forecasting models

    Directory of Open Access Journals (Sweden)

    Th. D. Xenos

    2003-01-01

    Full Text Available An estimation of the difference in TEC prediction accuracy achieved when the prediction varies from 1 h to 7 days in advance is described using classical neural networks. Hourly-daily Faraday-rotation derived TEC measurements from Florence are used. It is shown that the prediction accuracy for the examined dataset, though degrading when time span increases, is always high. In fact, when a relative prediction error margin of ± 10% is considered, the population percentage included therein is almost always well above the 55%. It is found that the results are highly dependent on season and the dataset wealth, whereas they highly depend on the foF2 - TEC variability difference and on hysteresis-like effect between these two ionospheric characteristics.

  16. Electrophilic warhead-based design of compounds preventing NLRP3 inflammasome-dependent pyroptosis.

    Science.gov (United States)

    Cocco, Mattia; Garella, Davide; Di Stilo, Antonella; Borretto, Emily; Stevanato, Livio; Giorgis, Marta; Marini, Elisabetta; Fantozzi, Roberto; Miglio, Gianluca; Bertinaria, Massimo

    2014-12-26

    Pyroptosis is a caspase-1-dependent pro-inflammatory form of programmed cell death implicated in the pathogenesis of autoinflammatory diseases as well as in disorders characterized by excessive cell death and inflammation. Activation of NLRP3 inflammasome is a key event in the pyroptotic cascade. In this study, we describe the synthesis and chemical tuning of α,β-unsaturated electrophilic warheads toward the development of antipyroptotic compounds. Their pharmacological evaluation and structure-activity relationships are also described. Compound 9 was selected as a model of this series, and it proved to be a reactive Michael acceptor, irreversibly trapping thiol nucleophiles, which prevented both ATP- and nigericin-triggered pyroptosis of human THP-1 cells in a time- and concentration-dependent manner. Moreover, 9 and other structurally related compounds, inhibited caspase-1 and NLRP3 ATPase activities. Our findings can contribute to the development of covalent, multitarget antipyroptotic compounds targeting molecular components of the NLRP3 inflammasome regulatory pathway.

  17. On a Class of Dual Risk Model with Dependence based on the FGM Copula

    Directory of Open Access Journals (Sweden)

    Hua Dong

    2010-12-01

    Full Text Available In this paper, we consider an extension to a dual model under a barrier strategy, in which the innovation sizes depend on the innovation time via the FGM copula. We first derive a renewal equation for the expected total discounted dividends until ruin. Some differential equations and closed-form expressions are given for exponential innovation sizes. Then the optimal dividend barrier and the Laplace transform of the time to ruin are considered. Finally, a numerical example is given.

  18. Device Concepts Based on Spin-dependent Transmission in Semiconductor Heterostructures

    Science.gov (United States)

    Ting, David Z. - Y.; Cartoixa, X.

    2004-01-01

    We examine zero-magnetic-field spin-dependent transmission in nonmagnetic semiconductor heterostructures with structural inversion asymmetry (SIA) and bulk inversion asymmetry (BIA), and report spin devices concepts that exploit their properties. Our modeling results show that several design strategies could be used to achieve high spin filtering efficiencies. The current spin polarization of these devices is electrically controllable, and potentially amenable to highspeed spin modulation, and could be integrated in optoelectronic devices for added functionality.

  19. Mechanisms and Modelling of Environment-Dependent Fatigue Crack Growth in a Nickel Based Superalloy

    Science.gov (United States)

    1991-12-12

    depends on the strain range, Pilling-Bedworth Ratio (PBR) and current crack length. If • oxygen penetration becomes more significant, Marshall [61...1978 [611 P. Marshall , "The Influence of Environment on Fatigue and Creep/Fatigue," in Fatigue at High Temperature, International Spring Meeting... Jhon arid W. Volker, Plenum Press, New York, NY, 1983, pp.377-390 (78] S. D. Antolovich and E. Rosa, "Low Cycle Fatigue of Rene 77 at Elevated

  20. STRESS DEPENDENT INTERNAL FRICTION AND MODULUS CHANGES IN IRON BASED METALLIC GLASSES

    OpenAIRE

    Posgay, G.; Kiss, S; Kedves, F.; Harangozó, I.; CseresnyÉs, Z.

    1987-01-01

    The measurements were made in a torsional pendulum at about 0.1 cps using longitudinal stress (5 - 150 MPa) in the temperature range 20 - 600°C. The internal friction (i.f.) decreases and the modulus increases monotonously with increasing longitudinal stress in the, amorphous state. This i.f. change is more pronounced in the temperature range of structural relaxation. Changing the stress at constant temperature the changes of the measured parameters were time and temperature dependent. These ...

  1. Directed Sample Interrogation Utilizing an Accurate Mass Exclusion-Based Data-Dependent Acquisition Strategy (AMEx)

    OpenAIRE

    Rudomin, Emily L.; Carr, Steven A.; Jaffe, Jacob D.

    2009-01-01

    The ability to perform thorough sampling is of critical importance when using mass spectrometry to characterize complex proteomic mixtures. A common approach is to re-interrogate a sample multiple times by LC-MS/MS. However, the conventional data-dependent acquisition methods that are typically used in proteomics studies will often redundantly sample high-intensity precursor ions while failing to sample low-intensity precursors entirely. We describe a method wherein the masses of successfully...

  2. Symmetry dependent spin injection from Fe/MgO in single crystal based magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hehn, Michel; Greullet, Fanny; Bernos, Julien; Tiusan, Coriolan; Bellouard, Christine; Montaigne, Francois; Lacour, Daniel; Alnot, Marc; Lu, Yuan; Lengaigne, Gwladys [LPM, Vandoeuvre les Nancy (France); Halley, David; Weber, Wolfgang [IPCMS, 67 - Strasbourg (France)

    2009-07-01

    The transport in crystalline magnetic tunnel junctions (MTJ) attracted the interest of the international community after the theoretical predictions of Butler et al of giant tunnel magnetoresistance (TMR) effects. In these model systems the electrons are classified with respect to the symmetry of their associated electronic Bloch wave function. The large predicted TMR ratio is related to a symmetry dependent attenuation rate within the MgO single crystal barrier combined with a half metallic property of a specific symmetry in the Fe electrode. After a brief introduction to the physics of the transport in Fe/MgO/Fe MTJ, I show how to exploit the symmetry dependence of the tunnel conductivity to engineer novel MTJs functionalities. We demonstrate that, a suitably chosen Cr(001) epitaxial metallic spacer layer quenches the transmission of particular electronic states, therefore acting as an additional symmetry dependent tunnel barrier for electrons at the Fermi level. Moreover, we show that this ultrathin Cr metallic barrier can promote quantum well states in an adjacent Fe layer. These results confirm the transport mechanism proposed by Butler et al. Extension to other materials are also discussed.

  3. Condition-based prediction of time-dependent reliability in composites

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper presents a reliability-based prediction methodology to obtain the remaining useful life of composite materials subjected to fatigue degradation....

  4. Area-dependent impedance-based voltage shifts during tribocorrosion of Ti-6Al-4V biomaterials: theory and experiment

    Science.gov (United States)

    Gilbert, Jeremy L.; Mali, Sachin A.; Liu, Yangping

    2016-09-01

    Tribocorrosion of medical devices causes the electrode potential across the device-solution interface to become more negative. This study provides a theoretical impedance-based understanding of voltage versus time changes that arise. It combines tribocorrosion with the voltage-dependent impedance characteristics of the surface, the relative anodic and cathodic areas and the mechanics and electrochemistry of oxide abrasion. An area-dependent Randle’s circuit is used with the tribocorrosion current equation to show the time-dependent voltage change with disruption and repassivation of the oxide. Heredity integrals are used to predict voltage over time for any arbitrary current-time path. Experiments using titanium pin-on-disk fretting corrosion are used to assess the theoretical model and to demonstrate its behavior.

  5. Prediction of Quality of Life of Non–Insulin-Dependent Diabetic Patients Based on Perceived Social Support

    Directory of Open Access Journals (Sweden)

    Hossein Shareh

    2012-04-01

    Full Text Available Background: The objective of this study was to predic quality of life based on perceived social support components in non–insulin-dependent diabetic patients.Materials and Method: Fifty patients with non–insulin-dependent diabetes mellitus from Al-Zahra diabetic center in Shiraz participated in a cross-sectional study via survey instrument. All subjects completed multidimensional scale of perceived social support (MSPSS and world health organization quality of life- brief (WHOQOL-BREF questionnaires. Results: On the basis of stepwise multiple regression analysis friends and family dimensions of perceived social support were the best predictors of the quality of life and its dimensions (p<0.01.Conclusion: Friends and family dimensions of perceived social support have significant contributions in predicting quality of life of patients with non–insulin-dependent diabetes mellitus.

  6. A Feasibility Study of Virtual Reality-Based Coping Skills Training for Nicotine Dependence

    Science.gov (United States)

    Bordnick, Patrick S.; Traylor, Amy C.; Carter, Brian L.; Graap, Ken M.

    2012-01-01

    Objective: Virtual reality (VR)-based cue reactivity has been successfully used for the assessment of drug craving. Going beyond assessment of cue reactivity, a novel VR-based treatment approach for smoking cessation was developed and tested for feasibility. Method: In a randomized experiment, 10-week treatment feasibility trial, 46…

  7. Quark matter at high density based on an extended confined isospin-density-dependent mass model

    Science.gov (United States)

    Qauli, A. I.; Sulaksono, A.

    2016-01-01

    We investigate the effect of the inclusion of relativistic Coulomb terms in a confined-isospin-density-dependent-mass (CIDDM) model of strange quark matter (SQM). We found that if we include the Coulomb term in scalar density form, the SQM equation of state (EOS) at high densities is stiffer but if we include the Coulomb term in vector density form it is softer than that of the standard CIDDM model. We also investigate systematically the role of each term of the extended CIDDM model. Compared with what was reported by Chu and Chen [Astrophys. J. 780, 135 (2014)], we found the stiffness of SQM EOS is controlled by the interplay among the oscillator harmonic, isospin asymmetry and Coulomb contributions depending on the parameter's range of these terms. We have found that the absolute stable condition of SQM and the mass of 2 M⊙ pulsars can constrain the parameter of oscillator harmonic κ1≈0.53 in the case the Coulomb term is excluded. If the Coulomb term is included, for the models with their parameters are consistent with SQM absolute stability condition, the 2.0 M⊙ constraint more prefers the maximum mass prediction of the model with the scalar Coulomb term than that of the model with the vector Coulomb term. On the contrary, the high densities EOS predicted by the model with the vector Coulomb is more compatible with the recent perturbative quantum chromodynamics result [1] than that predicted by the model with the scalar Coulomb. Furthermore, we also observed the quark composition in a very high density region depends quite sensitively on the kind of Coulomb term used.

  8. CONCENTRATION DEPENDENCE OF STERN LAYER CAPACITANCES AND SURFACE EQUILIBRIUM CONSTANTS IN SILICA-BASED NANOFLUIDIC CHANNELS

    DEFF Research Database (Denmark)

    Andersen, Mathias Bækbo; Frey, J.; Bruus, Henrik;

    2010-01-01

    Fundamental understanding of the unique physics at the solid-liquid interface in nanofluidic channels is essential for the advancement of basic scientific knowledge and the development of novel applications for pharmaceuticals, environmental health and safety, energy harvesting and biometrics [1......]. The current models used to describe surface phenomena in nanofluidics can differ by orders of magnitude from experimentally measured values [2]. To mitigate the discrepancies, we hypothesize that the Stern-layer capacitance Cs and the surface equilibrium constants pKa, vary with the composition of the solid......-liquid interface. We quantify these dependencies combining theoretical modeling and nanofluidic capillary filling experiments....

  9. On the Impact of Feature Dependencies when Maintaining Preprocessor-based Software Product Lines

    DEFF Research Database (Denmark)

    Ribeiro, Márcio; Queiroz, Felipe; Borba, Paulo

    2011-01-01

    During Software Product Line (SPL) maintenance tasks, Virtual Separation of Concerns (VSoC) allows the programmer to focus on one feature and hide the others. However, since features depend on each other through variables and control-flow, feature modularization is compromised since the maintenance...... the latter is important to better understand to what extent emergent interfaces complement VSoC during maintenance tasks. To answer them, we analyze 43 SPLs of different domains, size, and languages. The data we collect from them complement previous work on preprocessor usage....

  10. A substrate dependent biological containment systems for Pseudomonas putida based on the Escherichia coli gef gene

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Ramos, J. L.; Kaneva, Z.;

    1993-01-01

    A model substrate-dependent suicide system to biologically contain Pseudomonas putida KT2440 is reported. The system consists of two elements. One element carries a fusion between a synthetic lac promoter (PA1-04/03) and the gef gene, which encodes a killing function. This element is contained...... operon (Pm) and the lacI gene, encoding the Lac repressor, plus xylS2, coding for a positive regulator of Pm. In liquid culture under optimal growth conditions and in sterile and nonsterile soil microcosms, P. putida KT2440 (pWWO) bearing the containment system behaves as designed. In the presence...

  11. The Time-Dependent FX-SABR Model: Efficient Calibration based on Effective Parameters

    OpenAIRE

    Stoep, van der, H.; Grzelak, Lech Aleksander; OOSTERLEE, Cornelis

    2014-01-01

    We present a framework for efficient calibration of the time-dependent SABR model (Fern´andez et al. (2013) Mathematics and Computers in Simulation 94, 55–75; Hagan et al. (2002) Wilmott Magazine 84–108; Osajima (2007) Available at SSRN 965265.) in an foreign exchange (FX) context. In a similar fashion as in (Piterbarg (2005) Risk 18 (5), 71–75) we derive effective parameters, which yield an accurate and efficient calibration. On top of the calibrated FX-SABR model, we add a non-parametric lo...

  12. The Gravikinetic Response of Paramecium is Based on Orientation-Dependent Mechanotransduction

    Science.gov (United States)

    Gebauer, Manuel; Watzke, Daniela; Machemer, Hans

    Paramecium generates persistent shifts of the membrane potential of a few millivolts depending on its orientation with respect to the gravity vector. The resulting potential-induced modulation of the speed of propulsion is called gravikinesis because it acts to neutralize, fully or in part, sedimentation. Gravisensitivity is maximal at neutral orientation, i.e., in horizontally swimming cells, when the gravitational force per unit membrane area is at minimum. Stimulus-response relationships and energetic considerations show that sensing of the gravity vector by a nonspecialized, single-cell organism ranks among the most sensitive mechanoreceptors known in nature.

  13. Multi-configuration time-dependent density-functional theory based on range separation

    DEFF Research Database (Denmark)

    Fromager, E.; Knecht, S.; Jensen, Hans Jørgen Aagaard

    2013-01-01

    Multi-configuration range-separated density-functional theory is extended to the time-dependent regime. An exact variational formulation is derived. The approximation, which consists in combining a long-range Multi-Configuration- Self-Consistent Field (MCSCF) treatment with an adiabatic short...... (srGGA) approximations. As expected, when modeling long-range interactions with the MCSCF model instead of the adiabatic Buijse-Baerends density-matrix functional as recently proposed by Pernal [J. Chem. Phys. 136, 184105 (2012)10.1063/1.4712019], the description of both the 1D doubly-excited state...

  14. Quark Matter at High Density based on Extended Confined-isospin-density-dependent-mass Model

    CERN Document Server

    Qauli, A I

    2016-01-01

    We investigate the effect of the inclusion of relativistic Coulomb terms in a confined-isospin-density-dependent-mass (CIDDM) model of strange quark matter (SQM). We found that if we include Coulomb term in scalar density form, SQM equation of state (EOS) at high densities is stiffer but if we include Coulomb term in vector density form is softer than that of standard CIDDM model. We also investigate systematically the role of each term of the extended CIDDM model. Compared with what was reported in Ref.~\\cite {ref:isospin}, we found the stiffness of SQM EOS is controlled by the interplay among the the oscillator harmonic, isospin asymmetry and Coulomb contributions depending on the parameter's range of these terms. We have found that the absolute stable condition of SQM and the mass of 2 $M_\\odot$ pulsars can constrain the parameter of oscillator harmonic $\\kappa_1$ $\\approx 0.53$ in the case Coulomb term excluded. If the Coulomb term is included, for the models with their parameters are consistent with SQM ...

  15. Some Aspects of Modeling Dependence in Copula-based Markov chains

    CERN Document Server

    Longla, Martial

    2011-01-01

    Dependence coefficients have been widely studied for Markov processes defined by a set of transition probabilities and an initial distribution. This work clarifies some aspects of the theory of dependence structure of Markov chains generated by copulas that are useful in time series econometrics and other applied fields. The main aim of this paper is to clarify the relationship between the notions of geometric ergodicity and geometric {\\rho}-mixing; namely, to point out that for a large number of well known copulas, such as Clayton, Gumbel or Student, these notions are equivalent. Some of the results published in the last years appear to be redundant if one takes into account this fact. We apply this equivalence to show that any mixture of Clayton, Gumbel or Student copulas generate both geometrically ergodic and geometric {\\rho}-mixing stationary Markov chains, answering in this way an open question in the literature. We shall also point out that a sufficient condition for {\\rho}-mixing, used in the literatu...

  16. Wideband helicity dependent spoof surface plasmon polaritons coupling metasurface based on dispersion design

    Science.gov (United States)

    Dong, Guoxiang; Shi, Hongyu; He, Yuchen; Zhang, Anxue; Wei, Xiaoyong; Zhuang, Yongyong; Du, Bai; Xia, Song; Xu, Zhuo

    2016-12-01

    The surface plasmon polaritons (SPPs) have many potential application due to their local field enhancement and sub-wavelength characteristics. Recently, the gradient metasurface is introduced to couple the spoof SPPs in microwave frequency band. One of the most important issue which should be solved is the narrowband of spoof SPPs coupling on the gradient metasurface. Here, the metasurface is proposed to achieve the wideband helicity dependent directional spoof SPPs coupling for circular polarized light. Our research show that the coupling frequency of spoof SPPs on the gradient metasurface is determined by the dispersion of the metasurface, so the coupling frequency can be controlled by dispersion design. The careful design of each cell geometric parameters has provided many appropriate dispersion relations possessed by just one metasurface. The wave vector matching between the propagating wave and the spoof SPPs has been achieved at several frequencies for certain wave vector provided by the metasurface, which leads to wideband spoof SPPs coupling. This work has shown that wideband helicity dependent directional spoof SPPs coupling has been achieved with a high efficiency. Hence, the proposed wideband spoof SPPs coupling presents the improvement in practice applications.

  17. Time-Dependent Reliability Modeling and Analysis Method for Mechanics Based on Convex Process

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2015-01-01

    Full Text Available The objective of the present study is to evaluate the time-dependent reliability for dynamic mechanics with insufficient time-varying uncertainty information. In this paper, the nonprobabilistic convex process model, which contains autocorrelation and cross-correlation, is firstly employed for the quantitative assessment of the time-variant uncertainty in structural performance characteristics. By combination of the set-theory method and the regularization treatment, the time-varying properties of structural limit state are determined and a standard convex process with autocorrelation for describing the limit state is formulated. By virtue of the classical first-passage method in random process theory, a new nonprobabilistic measure index of time-dependent reliability is proposed and its solution strategy is mathematically conducted. Furthermore, the Monte-Carlo simulation method is also discussed to illustrate the feasibility and accuracy of the developed approach. Three engineering cases clearly demonstrate that the proposed method may provide a reasonable and more efficient way to estimate structural safety than Monte-Carlo simulations throughout a product life-cycle.

  18. Action-Dependent Adaptive Critic Design Based Neurocontroller for Cement Precalciner Kiln

    Directory of Open Access Journals (Sweden)

    Baosheng Yang

    2009-10-01

    Full Text Available There are many factors that can affect the calciner process of cement production, such as highly nonlinearity and time-lag, making it very difficult to establish an accurate model of the cement precalciner kiln (PCK system. In order to reduce transport energy consumption and to ensure the quality of cement clinker burning, one needs to explore different control methods from the traditional way. Adaptive Critic Design (ACD integrated neural network, reinforcement learning and dynamic programming techniques, is a new optimal method. As the PCK system parameters change frequently with high real-time property, ADACD (Action-Dependant ACD algorithm is used in PCK system to control the temperature of furnace export and oxygen content of exhaust. ADACD does not depend on the system model, it may use historical data to train a controller offline, and then adapt online. Also the BP network of artificial neural network is used to accomplish the network modeling, and action and critic modules of the algorithm. The results of simulation show that, after the fluctuations in the early control period, the controlled parameters tend to be stabilized guaranteeing the quality of cement clinker calcining.

  19. Matrix-dependent Strain Distributions of Au and Ag Nanoparticles in a Metal-oxide-semiconductor-based Nonvolatile Memory Device

    OpenAIRE

    Honghua Huang; Ying Zhang; Wenyan Wei; Ting Yu; Xingfang Luo; Cailei Yuan

    2015-01-01

    The matrix-dependent strain distributions of Au and Ag nanoparticles in a metal-oxide-semiconductor based nonvolatile memory device are investigated by finite element calculations. The simulation results clearly indicate that both Au and Ag nanoparticles incur compressive strain by high-k Al2O3 and conventional SiO2 dielectrics. The strain distribution of nanoparticles is closely related to the surrounding matrix. Nanoparticles embedded in different matrices experience different compressive s...

  20. Effectiveness of Mindfulness-Based Relapse Prevention in opioid Dependence Treatment &Mental Health

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Findings: therapy compliance, retention in treatment, decrease in somatic symptoms, anxiety, social dysfunction and increase in health was significantly in both combination of psychological intervention method than the Naltroxan group. Mindfulness-based on relapse prevention was more effective than CBT relapse prevention in decreasing of, social dysfunction, relapse prevention, increase of therapy compliance, and health. Results: Mindfulness based relapse prevention was superior to CBT and Naltroxan and considerably increased effectiveness of opioid relapse prevention therapy.

  1. Knowledge base interpolation of path-dependent data using irregularly spaced natural neighbors

    Energy Technology Data Exchange (ETDEWEB)

    Hipp, J.; Keyser, R.; Young, C.; Shepard-Dombroski, E.; Chael, E.

    1996-08-01

    This paper summarizes the requirements for the interpolation scheme needed for the CTBT Knowledge Base and discusses interpolation issues relative to the requirements. Based on these requirements, a methodology for providing an accurate and robust interpolation scheme for the CTBT Knowledge Base is proposed. The method utilizes a Delaunay triangle tessellation to mesh the Earth`s surface and employs the natural-neighbor interpolation technique to provide accurate evaluation of geophysical data that is important for CTBT verification. The natural-neighbor interpolation method is a local weighted average technique capable of modeling sparse irregular data sets as is commonly found in the geophysical sciences. This is particularly true of the data to be contained in the CTBT Knowledge Base. Furthermore, natural neighbor interpolation is first order continuous everywhere except at the data points. The non-linear form of the natural-neighbor interpolation method can provide continuous first and second order derivatives throughout the entire data domain. Since one of the primary support functions of the Knowledge Base is to provide event location capabilities, and the seismic event location algorithms typically require first and second order continuity, this is a prime requirement of any interpolation methodology chosen for use by the CTBT Knowledge Base.

  2. Investigation of negative bias temperature instability dependence on fin width of silicon-on-insulator-fin-based field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Young, Chadwin D., E-mail: chadwin.young@utdallas.edu; Wang, Zhe [Materials Science and Engineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080 (United States); Neugroschel, Arnost [Department of Electrical and Computer Enginering, University of Florida, Gainesville, Florida 32611 (United States); Majumdar, Kausik; Matthews, Ken; Hobbs, Chris [SEMATECH, Albany, New York 12203 (United States)

    2015-01-21

    The fin width dependence of negative bias temperature instability (NBTI) of double-gate, fin-based p-type Field Effect Transistors (FinFETs) fabricated on silicon-on-insulator (SOI) wafers was investigated. The NBTI degradation increased as the fin width narrowed. To investigate this phenomenon, simulations of pre-stress conditions were employed to determine any differences in gate oxide field, fin band bending, and electric field profile as a function of the fin width. The simulation results were similar at a given gate stress bias, regardless of the fin width, although the threshold voltage was found to increase with decreasing fin width. Thus, the NBTI fin width dependence could not be explained from the pre-stress conditions. Different physics-based degradation models were evaluated using specific fin-based device structures with different biasing schemes to ascertain an appropriate model that best explains the measured NBTI dependence. A plausible cause is an accumulation of electrons that tunnel from the gate during stress into the floating SOI fin body. As the fin narrows, the sidewall device channel moves in closer proximity to the stored electrons, thereby inducing more band bending at the fin/dielectric interface, resulting in a higher electric field and hole concentration in this region during stress, which leads to more degradation. The data obtained in this work provide direct experimental proof of the effect of electron accumulation on the threshold voltage stability in FinFETs.

  3. PRINCIPAL COMPONENT DECOMPOSITION BASED FINITE ELEMENT MODEL UPDATING FOR STRAIN-RATE-DEPENDENCE NONLINEAR DYNAMIC PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    GUO Qintao; ZHANG Lingmi; TAO Zheng

    2008-01-01

    Thin wall component is utilized to absorb impact energy of a structure. However, the dynamic behavior of such thin-walled structure is highly non-linear with material, geometry and boundary non-linearity. A model updating and validation procedure is proposed to build accurate finite element model of a frame structure with a non-linear thin-walled component for dynamic analysis. Design of experiments (DOE) and principal component decomposition (PCD) approach are applied to extract dynamic feature from nonlinear impact response for correlation of impact test result and FE model of the non-linear structure. A strain-rate-dependent non-linear model updating method is then developed to build accurate FE model of the structure. Computer simulation and a real frame structure with a highly non-linear thin-walled component are employed to demonstrate the feasibility and effectiveness of the proposed approach.

  4. Noise-Induced Transitions in a Population Growth Model Based on Size-Dependent Carrying Capacity

    Directory of Open Access Journals (Sweden)

    Neeme Lumi

    2014-01-01

    Full Text Available The stochastic dynamics of a population growth model with size-dependent carrying capacity is considered. The effect of a fluctuating environment on population growth is modeled as a multiplicative dichotomous noise. At intermediate values of population size the deterministic counterpart of the model behaves similarly to the Von Foerster model for human population, but at small and very large values of population size substantial differences occur. In the stochastic case, an exact analytical solution for the stationary probability distribution is found. It is established that variation of noise correlation time can cause noise-induced transitions between three different states of the system characterized by qualitatively different behaviors of the probability distributions of the population size. Also, it is shown that, in some regions of the system parameters, variation of the amplitude of environmental fluctuations can induce single unidirectional abrupt transitions of the mean population size.

  5. Adding voucher-based incentives to community reinforcement approach improves outcomes during treatment for cocaine dependence.

    Science.gov (United States)

    García-Fernández, Gloria; Secades-Villa, Roberto; García-Rodríguez, Olaya; Sánchez-Hervás, Emilio; Fernández-Hermida, José R; Higgins, Stephen T

    2011-01-01

    This study compares the efficacy of the Community Reinforcement Approach (CRA) with and without an incentive program for cocaine-dependent patients in Spain. A total of 58 patients were randomly assigned to the CRA or CRA plus vouchers condition. In the CRA plus vouchers group, mean percentage of cocaine-negative samples was 97.07%, versus 79.76% in the no-voucher group. Those treated in the CRA plus vouchers condition also achieved greater improvements in psychosocial functioning than those treated in the CRA condition. The present results show that treatment outcome is better if incentives are delivered contingent upon the submission of cocaine-free urine specimens. 

  6. TMR and spin-dependent transport of polyacetylene-based magnetic junctions

    Energy Technology Data Exchange (ETDEWEB)

    Ketabi, S A; Khozestani, H F [School of Physics, Damghan University, Damghan (Iran, Islamic Republic of); Vahedi, D, E-mail: saketabi@du.ac.ir [Department of Physics and Center for Nanotechnology Research, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

    2011-01-15

    A numerical study is presented that investigates the spin-dependent transport through a trans-polyacetylene (trans-PA) molecule sandwiched between ferromagnetic (FM) contacts. Using the tight-binding procedure and in the framework of a generalized Green's function technique, the room temperature current-voltage characteristics of the trans-PA molecule and the tunnel magnetoresistance (TMR) of the electrode/trans-PA/electrode structure, with iron (Fe) as the electrode, are studied. It is found that the parallel arrangement of magnetic moments in FM electrodes causes a much higher current through the polyacetylene molecule than does the anti-parallel arrangement. Also, our results indicate that TMR has its maximum value (more than 60%) at low bias voltages.

  7. Actin-based mechanisms for light-dependent intracellular positioning of nuclei and chloroplasts in Arabidopsis.

    Science.gov (United States)

    Iwabuchi, Kosei; Takagi, Shingo

    2010-08-01

    The plant organelles, chloroplast and nucleus, change their position in response to light. In Arabidopsis thaliana leaf cells, chloroplasts and nuclei are distributed along the inner periclinal wall in darkness. In strong blue light, they become positioned along the anticlinal wall, while in weak blue light, only chloroplasts are accumulated along the inner and outer periclinal walls. Blue-light dependent positioning of both organelles is mediated by the blue-light receptor phototropin and controlled by the actin cytoskeleton. Interestingly, however, it seems that chloroplast movement requires short, fine actin filaments organized at the chloroplast edge, whereas nuclear movement does cytoplasmic, thick actin bundles intimately associated with the nucleus. Although there are many similarities between photo-relocation movements of chloroplasts and nuclei, plant cells appear to have evolved distinct mechanisms to regulate actin organization required for driving the movements of these organelles.

  8. Temperature dependence of quantum efficiency of Schottky diodes based on 4H-SiC

    CERN Document Server

    Blank, T V; Kalinina, E V; Konstantinov, O V; Konstantinov, A O; Hallen, A

    2001-01-01

    The metal-semiconductor structures, which made it possible to create the photoreceivers of the Cr-4H-SiC ultraviolet radiation with the photosensitivity maximum by 4.9 eV and quantum efficiency up to 0.3 were manufactured on the basis of the n-4H-SiC pure epitaxial layer. The experimental study on the temperature dependence of the quantum efficiency of the photoelectric transformation showed, that by the photons energy of 3.4-4.7 eV and the temperatures above 300 K there takes place fast growth of the quantum efficiency with growth of temperatures, which is conditioned by participation of the phonons in the indirect interzonal transitions

  9. Global patterns in lake ecosystem responses to warming based on the temperature dependence of metabolism.

    Science.gov (United States)

    Kraemer, Benjamin M; Chandra, Sudeep; Dell, Anthony I; Dix, Margaret; Kuusisto, Esko; Livingstone, David M; Schladow, S Geoffrey; Silow, Eugene; Sitoki, Lewis M; Tamatamah, Rashid; McIntyre, Peter B

    2017-05-01

    Climate warming is expected to have large effects on ecosystems in part due to the temperature dependence of metabolism. The responses of metabolic rates to climate warming may be greatest in the tropics and at low elevations because mean temperatures are warmer there and metabolic rates respond exponentially to temperature (with exponents >1). However, if warming rates are sufficiently fast in higher latitude/elevation lakes, metabolic rate responses to warming may still be greater there even though metabolic rates respond exponentially to temperature. Thus, a wide range of global patterns in the magnitude of metabolic rate responses to warming could emerge depending on global patterns of temperature and warming rates. Here we use the Boltzmann-Arrhenius equation, published estimates of activation energy, and time series of temperature from 271 lakes to estimate long-term (1970-2010) changes in 64 metabolic processes in lakes. The estimated responses of metabolic processes to warming were usually greatest in tropical/low-elevation lakes even though surface temperatures in higher latitude/elevation lakes are warming faster. However, when the thermal sensitivity of a metabolic process is especially weak, higher latitude/elevation lakes had larger responses to warming in parallel with warming rates. Our results show that the sensitivity of a given response to temperature (as described by its activation energy) provides a simple heuristic for predicting whether tropical/low-elevation lakes will have larger or smaller metabolic responses to warming than higher latitude/elevation lakes. Overall, we conclude that the direct metabolic consequences of lake warming are likely to be felt most strongly at low latitudes and low elevations where metabolism-linked ecosystem services may be most affected.

  10. Transient Elastography-Based Liver Stiffness Age-Dependently Increases in Children

    Science.gov (United States)

    Tokuhara, Daisuke; Cho, Yuki; Shintaku, Haruo

    2016-01-01

    Background and Aims Pediatric use of liver transient elastography (TE) is attractive for its non-invasiveness, but reference values have not been established. We aimed to determine reference values for TE in children. Methods In pediatric patients (1 to 18 years), TE (FibroScan®) with an M probe was used for both liver stiffness measurement (LSM) and measurement of hepatic fat deposition by using a controlled attenuation parameter (CAP). The patients were divided into three relevant age groups: preschoolers (1 to 5 years), elementary school children (6 to 11 years), and adolescents (12 to 18 years). Overweight or obese patients or those with known liver disease, elevated serum liver enzymes, or hepatic echogenic abnormality were excluded from the study. Results Among 139 children, 123 (88.5%; 62 male; median age, 11.7 years; age range, 1.3 to 17.2 years) were successfully subjected to M-probe TE without anesthesia. Median LSM increased with age: it was 3.4 kPa (2.3 to 4.6 kPa, 5th to 95th percentiles) at ages 1 to 5 years; 3.8 (2.5 to 6.1) kPa at ages 6 to 11; and 4.1 (3.3 to 7.9) kPa at ages 12 to 18 (P = 0.001). Median CAP was not age dependent: it was 183 (112 to 242) for ages 1 to 18 years. Conclusions M-probe TE is suitable in a wide age range of children from age 1 year up. In children without evidence of liver disease, LSM has an age-dependent increase, whereas CAP does not differ between ages 1 and 18. PMID:27861607

  11. An interactive Tool for Writer Identification based on Offline Text Dependent Approach

    Directory of Open Access Journals (Sweden)

    Saranya K

    2013-01-01

    Full Text Available Writer identification is the process of identifying the writer of the document based on their handwriting. The growth of computational engineering, artificial intelligence and pattern recognition fields owes greatly to one of the highly challenged problem of handwriting identification. This paper proposes the computational intelligence technique to develop discriminative model for writer identification based on handwritten documents. Scanned images of handwritten documents are segmented into words and these words are further segmented into characters for word level and character level writer identification. A set of features are extracted from the segmented words and characters. Feature vectors are trained using support vector machine and obtained 94.27% accuracy for word level, 90.10% for character level. An interactive tool has been developed based on the word level writer identification model.

  12. Dependence and risk assessment for oil prices and exchange rate portfolios: A wavelet based approach

    Science.gov (United States)

    Aloui, Chaker; Jammazi, Rania

    2015-10-01

    In this article, we propose a wavelet-based approach to accommodate the stylized facts and complex structure of financial data, caused by frequent and abrupt changes of markets and noises. Specifically, we show how the combination of both continuous and discrete wavelet transforms with traditional financial models helps improve portfolio's market risk assessment. In the empirical stage, three wavelet-based models (wavelet-EGARCH with dynamic conditional correlations, wavelet-copula, and wavelet-extreme value) are considered and applied to crude oil price and US dollar exchange rate data. Our findings show that the wavelet-based approach provides an effective and powerful tool for detecting extreme moments and improving the accuracy of VaR and Expected Shortfall estimates of oil-exchange rate portfolios after noise is removed from the original data.

  13. Complex absorbing potential based Lorentzian fitting scheme and time dependent quantum transport

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Hang, E-mail: xiehanggm@gmail.com; Kwok, Yanho; Chen, GuanHua, E-mail: ghc@everest.hku.hk [Department of Chemistry, The University of Hong Kong, Pokfulam (Hong Kong); Jiang, Feng [Department of Physics, Shanghai University of Electric Power, Shanghai (China); Zheng, Xiao [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei (China)

    2014-10-28

    Based on the complex absorbing potential (CAP) method, a Lorentzian expansion scheme is developed to express the self-energy. The CAP-based Lorentzian expansion of self-energy is employed to solve efficiently the Liouville-von Neumann equation of one-electron density matrix. The resulting method is applicable for both tight-binding and first-principles models and is used to simulate the transient currents through graphene nanoribbons and a benzene molecule sandwiched between two carbon-atom chains.

  14. Complex absorbing potential based Lorentzian fitting scheme and time dependent quantum transport.

    Science.gov (United States)

    Xie, Hang; Kwok, Yanho; Jiang, Feng; Zheng, Xiao; Chen, GuanHua

    2014-10-28

    Based on the complex absorbing potential (CAP) method, a Lorentzian expansion scheme is developed to express the self-energy. The CAP-based Lorentzian expansion of self-energy is employed to solve efficiently the Liouville-von Neumann equation of one-electron density matrix. The resulting method is applicable for both tight-binding and first-principles models and is used to simulate the transient currents through graphene nanoribbons and a benzene molecule sandwiched between two carbon-atom chains.

  15. DECK: Distance and environment-dependent, coarse-grained, knowledge-based potentials for protein-protein docking

    Directory of Open Access Journals (Sweden)

    Vakser Ilya A

    2011-07-01

    Full Text Available Abstract Background Computational approaches to protein-protein docking typically include scoring aimed at improving the rank of the near-native structure relative to the false-positive matches. Knowledge-based potentials improve modeling of protein complexes by taking advantage of the rapidly increasing amount of experimentally derived information on protein-protein association. An essential element of knowledge-based potentials is defining the reference state for an optimal description of the residue-residue (or atom-atom pairs in the non-interaction state. Results The study presents a new Distance- and Environment-dependent, Coarse-grained, Knowledge-based (DECK potential for scoring of protein-protein docking predictions. Training sets of protein-protein matches were generated based on bound and unbound forms of proteins taken from the DOCKGROUND resource. Each residue was represented by a pseudo-atom in the geometric center of the side chain. To capture the long-range and the multi-body interactions, residues in different secondary structure elements at protein-protein interfaces were considered as different residue types. Five reference states for the potentials were defined and tested. The optimal reference state was selected and the cutoff effect on the distance-dependent potentials investigated. The potentials were validated on the docking decoys sets, showing better performance than the existing potentials used in scoring of protein-protein docking results. Conclusions A novel residue-based statistical potential for protein-protein docking was developed and validated on docking decoy sets. The results show that the scoring function DECK can successfully identify near-native protein-protein matches and thus is useful in protein docking. In addition to the practical application of the potentials, the study provides insights into the relative utility of the reference states, the scope of the distance dependence, and the coarse-graining of

  16. Dose-dependent dopaminergic modulation of reward-based learning in Parkinson's disease

    NARCIS (Netherlands)

    Wouwe, N.C. van; Ridderinkhof, K.R.; Band, G.P.H.; Wildenberg, W.P.M. van den; Wylie, S.A.

    2012-01-01

    Learning to select optimal behavior in new and uncertain situations is a crucial aspect of living and requires the ability to quickly associate stimuli with actions that lead to rewarding outcomes. Mathematical models of reinforcement-based learning to select rewarding actions distinguish between (1

  17. Sequence-dependent elasticity and electrostatics of single-stranded DNA: signatures of base-stacking.

    Science.gov (United States)

    McIntosh, Dustin B; Duggan, Gina; Gouil, Quentin; Saleh, Omar A

    2014-02-04

    Base-stacking is a key factor in the energetics that determines nucleic acid structure. We measure the tensile response of single-stranded DNA as a function of sequence and monovalent salt concentration to examine the effects of base-stacking on the mechanical and thermodynamic properties of single-stranded DNA. By comparing the elastic response of highly stacked poly(dA) and that of a polypyrimidine sequence with minimal stacking, we find that base-stacking in poly(dA) significantly enhances the polymer's rigidity. The unstacking transition of poly(dA) at high force reveals that the intrinsic electrostatic tension on the molecule varies significantly more weakly on salt concentration than mean-field predictions. Further, we provide a model-independent estimate of the free energy difference between stacked poly(dA) and unstacked polypyrimidine, finding it to be ∼-0.25 kBT/base and nearly constant over three orders of magnitude in salt concentration.

  18. Dose Dependent Dopaminergic Modulation of Reward-Based Learning in Parkinson's Disease

    Science.gov (United States)

    van Wouwe, N. C.; Ridderinkhof, K. R.; Band, G. P. H.; van den Wildenberg, W. P. M.; Wylie, S. A.

    2012-01-01

    Learning to select optimal behavior in new and uncertain situations is a crucial aspect of living and requires the ability to quickly associate stimuli with actions that lead to rewarding outcomes. Mathematical models of reinforcement-based learning to select rewarding actions distinguish between (1) the formation of stimulus-action-reward…

  19. Modeling Distance and Bandwidth Dependency of TOA-Based UWB Ranging Error for Positioning

    NARCIS (Netherlands)

    Bellusci, G.; Janssen, G.J.M.; Yan, J.; Tiberius, C.C.J.M.

    2009-01-01

    A statistical model for the range error provided by TOA estimation using UWB signals is given, based on UWB channel measurements between 3.1 and 10.6 GHz. The range error has been modeled as a Gaussian random variable for LOS and as a combination of a Gaussian and an exponential random variable for

  20. Indolinone based phosphoinositide-dependent kinase-1 (PDK1) inhibitors. Part 2: optimization of BX-517.

    Science.gov (United States)

    Islam, Imadul; Brown, Greg; Bryant, Judi; Hrvatin, Paul; Kochanny, Monica J; Phillips, Gary B; Yuan, Shendong; Adler, Marc; Whitlow, Marc; Lentz, Dao; Polokoff, Mark A; Wu, James; Shen, Jun; Walters, Janette; Ho, Elena; Subramanyam, Babu; Zhu, Daguang; Feldman, Richard I; Arnaiz, Damian O

    2007-07-15

    Based on the lead compound BX-517, a series of C-4' substituted indolinones have been synthesized and evaluated for PDK1 inhibition. Modification at C-4' of the pyrrole afforded potent compounds (7b and 7d) with improved solubility and ADME properties. In this letter, we describe the synthesis, selectivity profile, and pharmacokinetic data of selected compounds.

  1. Redox-State Dependent Ligand Exchange in Manganese-Based Oxidation Catalysis

    NARCIS (Netherlands)

    Abdolahzadeh, Shaghayegh; de Boer, Johannes W.; Browne, Wesley R.

    2015-01-01

    Manganese-based oxidation catalysis plays a central role both in nature, in the oxidation of water in photosystem II (PSII) and the control of reactive oxygen species, as well as in chemical processes, in the oxidation of organic substrates and bleaching applications. The focus of this review is on

  2. Context-Dependent Prognostics and Health Assessment: A Condition-Based Maintenance Approach That Supports Mission Compliance

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Kercel, S.W.

    1999-04-19

    In today's manufacturing environment, plants, systems, and equipment are being asked to perform at levels not thought possible a decade ago. The intent is to improve process operations and equipment reliability, availability, and maintainability without costly upgrades. Of course these gains must be achieved without impacting operational performance. Downsizing is also taking its toll on operations. Loss of personnel, particularly those who represent the corporate history, is depleting US industries of their valuable experiential base which has been relied on so heavily in the past. These realizations are causing companies to rethink their condition-based maintenance policies by moving away from reacting to equipment problems to taking a proactive approach by anticipating needs based on market and customer requirements. This paper describes a different approach to condition-based maintenance-context-dependent prognostics and health assessment. This diagnostic capability is developed around a context-dependent model that provides a capability to anticipate impending failures and determine machine performance over a protracted period of time. This prognostic capability links operational requirements to an economic performance model. In this context, a system may provide 100% operability with less than 100% functionality. This paradigm is used to facilitate optimal logistic supply and support.

  3. Application of thermodynamics-based rate-dependent constitutive models of concrete in the seismic analysis of concrete dams

    Directory of Open Access Journals (Sweden)

    Fei LENG

    2008-09-01

    Full Text Available This paper discusses the seismic analysis of concrete dams with consideration of material nonlinearity. Based on a consistent rate-dependent model and two thermodynamics-based models, two thermodynamics-based rate-dependent constitutive models were developed with consideration of the influence of the strain rate. They can describe the dynamic behavior of concrete and be applied to nonlinear seismic analysis of concrete dams taking into account the rate sensitivity of concrete. With the two models, a nonlinear analysis of the seismic response of the Koyna Gravity Dam and the Dagangshan Arch Dam was conducted. The results were compared with those of a linear elastic model and two rate-independent thermodynamics-based constitutive models, and the influences of constitutive models and strain rate on the seismic response of concrete dams were discussed. It can be concluded from the analysis that, during seismic response, the tensile stress is the control stress in the design and seismic safety evaluation of concrete dams. In different models, the plastic strain and plastic strain rate of concrete dams show a similar distribution. When the influence of the strain rate is considered, the maximum plastic strain and plastic strain rate decrease.

  4. Analysis of progressive failure of pillar and instability criterion based on gradient-dependent plasticity

    Institute of Scientific and Technical Information of China (English)

    王学滨

    2004-01-01

    A mechanical model for strain softening pillar is proposed considering the characteristics of progressive shear failure and strain localization. The pillar undergoes elastic, strain softening and slabbing stages. In the elastic stage, vertical compressive stress and deformation at upper end of pillar are uniform, while in the strain softening stage there appears nonuniform due to occurrence of shear bands, leading to the decrease of load-carrying capacity.In addition, the size of failure zone increases in the strain softening stage and reaches its maximum value when slabbing begins. In the latter two stages, the size of elastic core always decreases. In the slabbing stage, the size of failure zone remains a constant and the pillar becomes thinner. Total deformation of the pillar is derived by linearly elastic Hooke's law and gradient-dependent plasticity where thickness of localization band is determined according to the characteristic length. Post-peak stiffness is proposed according to analytical solution of averaged compressive stressaverage deformation curve. Instability criterion of the pillar and roof strata system is proposed analytically using instability condition given by Salamon. It is found that the constitutive parameters of material of pillar, the geometrical size of pillar and the number of shear bands influence the stability of the system; stress gradient controls the starting time of slabbing, however it has no influence on the post-peak stiffness of the pillar.

  5. REM Sleep-Dependent Bidirectional Regulation of Hippocampal-Based Emotional Memory and LTP.

    Science.gov (United States)

    Ravassard, Pascal; Hamieh, Al Mahdy; Joseph, Mickaël Antoine; Fraize, Nicolas; Libourel, Paul-Antoine; Lebarillier, Léa; Arthaud, Sébastien; Meissirel, Claire; Touret, Monique; Malleret, Gaël; Salin, Paul-Antoine

    2016-04-01

    Prolonged rapid-eye-movement (REM) sleep deprivation has long been used to study the role of REM sleep in learning and memory processes. However, this method potentially induces stress and fatigue that may directly affect cognitive functions. Here, by using a short-term and nonstressful REM sleep deprivation (RSD) method we assessed in rats the bidirectional influence of reduced and increased REM sleep amount on hippocampal-dependent emotional memory and plasticity. Our results indicate that 4 h RSD impaired consolidation of contextual fear conditioning (CFC) and induction of long-term potentiation (LTP), while decreasing density of Egr1/Zif268-expressing neurons in the CA1 region of the dorsal hippocampus. LTP and Egr1 expression were not affected in ventral CA1. Conversely, an increase in REM sleep restores and further facilitates CFC consolidation and LTP induction, and also increases Egr1 expression in dorsal CA1. Moreover, CFC consolidation, Egr1 neuron density, and LTP amplitude in dorsal CA1 show a positive correlation with REM sleep amount. Altogether, these results indicate that mild changes in REM sleep amount bidirectionally affect memory and synaptic plasticity mechanisms occurring in the CA1 area of the dorsal hippocampus.

  6. Angle-dependent quantum Otto heat engine based on coherent dipole-dipole coupling

    Science.gov (United States)

    Su, Shan-He; Luo, Xiao-Qing; Chen, Jin-Can; Sun, Chang-Pu

    2016-08-01

    Electromagnetic interactions between molecules or within a molecule have been widely observed in biological systems and exhibit broad application for molecular structural studies. Quantum delocalization of molecular dipole moments has inspired researchers to explore new avenues to utilize this physical effect for energy harvesting devices. Herein, we propose a simple model of the angle-dependent quantum Otto heat engine which seeks to facilitate the conversion of heat to work. Unlike previous studies, the adiabatic processes are accomplished by varying only the directions of the magnetic field. We show that the heat engine continues to generate power when the angle relative to the vector r joining the centres of coupled dipoles departs from the magic angle θm where the static coupling vanishes. A significant improvement in the device performance has to be attributed to the presence of the quantum delocalized levels associated with the coherent dipole-dipole coupling. These results obtained may provide a promising model for the biomimetic design and fabrication of quantum energy generators.

  7. Frequency dependent capacitance and conductance properties of Schottky diode based on rubrene organic semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Barış, Behzad, E-mail: behzadbaris@gmail.com

    2013-10-01

    Al/rubrene/p-Si Schottky diode has been fabricated by forming a rubrene layer on p type Si by using the spin coating method. The frequency dependent capacitance–voltage (C–V–f) and conductance–voltage (G–V–f) characteristics of Al/rubrene/p-Si Schottky diyotes has been investigated in the frequency range of 5 kHz–500 kHz at room temperature. The C–V plots show a peak for each frequency. The capacitance of the device decreased with increasing frequency. The decrease in capacitance results from the presence of interface states. The plots of series resistance–voltage (R{sub s}−V) gave a peak in the depletion region at all frequencies. The density of interface states (N{sub ss}) and relaxation time (τ) distribution profiles as a function of applied voltage bias have been determined from the C–V and G–V measurements. The values of the N{sub ss} and τ have been calculated in the ranges of 8.37×10{sup 11}–4.85×10{sup 11} eV{sup −1} cm{sup −2} and 5.17×10{sup −6}–1.02×10{sup −5} s, respectively.

  8. Thickness-dependent structural arrangement in nano-confined imidazolium-based ionic liquid films.

    Science.gov (United States)

    Rouha, Michael; Cummings, Peter T

    2015-02-14

    A fundamental understanding of interfacial processes in nano-confined ionic liquids is crucial to increase the performance of modern energy storage devices. It is well-known that interfaces between electrodes and ionic liquids exhibit structures distinct from that of the bulk liquid. Following the recent interest in these systems, we studied the structure of thin ionic liquid films confined in flexible uncharged carbon nano-pores by using fully-atomistic molecular dynamics simulations. We show that the interfacial ions self-assemble into a closely-packed chequerboard-like pattern, formed by both cations and anions in direct contact with the pore wall, and that within this structure we find changes dependent on the thickness of the confined films. At low coverages a dense layer is formed in which both the imidazolium-ring and its alkyl-tail lie parallel to the pore wall. With increasing coverage the alkyl-chains reorient perpendicular to the surface, making space for additional ions until a densified highly ordered layer is formed. This wall-induced self-patterning into interfacial layers with significantly higher than bulk density is consistent with recent experimental and theoretical studies of similar systems. This work reveals additional molecular-level details on the effect of the film-thickness on the structure and density of the ionic liquid.

  9. A wavelength-dependent visible and infrared spectrophotometric function for the Moon based on ROLO data

    Science.gov (United States)

    Buratti, B.J.; Hicks, M.D.; Nettles, J.; Staid, M.; Pieters, C.M.; Sunshine, J.; Boardman, J.; Stone, T.C.

    2011-01-01

    The USGS's Robotic Lunar Observatory (ROLO) dedicated ground-based lunar calibration project obtained photometric observations of the Moon over the spectral range attainable from Earth (0.347-2.39 ??m) and over solar phase angles of 1.55??-97??. From these observations, we derived empirical lunar surface solar phase functions for both the highlands and maria that can be used for a wide range of applications. The functions can be used to correct for the effects of viewing geometry to produce lunar mosaics, spectra, and quick-look products for future lunar missions and ground-based observations. Our methodology can be used for a wide range of objects for which multiply scattered radiation is not significant, including all but the very brightest asteroids and moons. Copyright 2011 by the American Geophysical Union.

  10. Distance-dependent proton transfer along water wires connecting acid-base pairs

    NARCIS (Netherlands)

    Cox, M.J.; Timmer, R.L.A.; Bakker, H.J.; Park, S.; Agmon, N.

    2009-01-01

    We report time-resolved mid-IR kinetics for the ultrafast acid−base reaction between photoexcited 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS), and acetate at three concentrations (0.5, 1.0, and 2.0 M) and three temperatures (5, 30, and 65 °C) in liquid D2O. The observed proton-trans

  11. Dependence of the modulation response of quantum dot based nanocavity devices on the number of emitters

    DEFF Research Database (Denmark)

    Lorke, Michael; Nielsen, Torben Roland; Mørk, Jesper

    2011-01-01

    A microscopic theory is used to study the dynamical properties of semiconductor quantum dot based nanocavity laser systems. The carrier kinetics and photon populations are determined using a fully quantum mechanical treatment of the light‐matter coupling. In this work, we investigate the dependen...... of the modulation response in such devices on the number of emitters coupled to the cavity mode. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)...

  12. Sensitivity Dependence of Surface Plasmon Resonance Based Sensors on Prism Refractive Index

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We theoretically and experimentally demonstrate that refractive index of the prism used toload metal film has significant influence on sensitivity of surface plasmon resonance based sensors. Theprism with lower refractive index gives the sensors a higher sensitivity in detecting refractive index varia-tions of a sample. We attribute this effect to the fact that a prism with low refractive index will increasecoupling distance between surface plasmons and the medium under investigation.

  13. Temperature-dependent efficiency droop behaviors of GaN-based green light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    Jiang Rong; Lu Hai; Chen Dun-Jun; Ren Fang-Fang; Yan Da-Wei; Zhang Rong; Zheng You-Dou

    2013-01-01

    The efficiency droop behaviors of GaN-based green light-emitting diodes (LEDs) are studied as a function of temperature from 300 K to 480 K.The overall quantum efficiency of the green LEDs is found to degrade as temperature increases,which is mainly caused by activation of new non-radiative recombination centers within the LED active layer.Meanwhile,the external quantum efficiency of the green LEDs starts to decrease at low injection current level (< 1 A/cm2) with a temperature-insensitive peak-efficiency-current.In contrast,the peak-efficiency-current of a control GaN-based blue LED shows continuous up-shift at higher temperatures.Around the onset point of efficiency droop,the electroluminescence spectra of the green LEDs also exhibit a monotonic blue-shift of peak energy and a reduction of full width at half maximum as injection current increases.Carrier delocalization is believed to play an important role in causing the efficiency droop in GaN-based green LEDs.

  14. Evaluation of Key Dependent S-Box Based Data Security Algorithm using Hamming Distance and Balanced Output

    Directory of Open Access Journals (Sweden)

    Balajee Maram K.

    2016-02-01

    Full Text Available Data security is a major issue because of rapid evolution of data communication over unsecured internetwork. Here the proposed system is concerned with the problem of randomly generated S-box. The generation of S-box depends on Pseudo-Random-Number-Generators and shared-secret-key. The process of Pseudo-Random-Number-Generator depends on large prime numbers. All Pseudo-Random-Numbers are scrambled according to shared-secret-key. After scrambling, the S-box is generated. In this research, large prime numbers are the inputs to the Pseudo-Random-Number-Generator. The proposed S-box will reduce the complexity of S-box generation. Based on S-box parameters, it experimentally investigates the quality and robustness of the proposed algorithm which was tested. It yields better results with the S-box parameters like Hamming Distance, Balanced Output and Avalanche Effect and can be embedded to popular cryptography algorithms

  15. NMR-Based Metabonomic Investigation of Heat Stress in Myotubes Reveals a Time-Dependent Change in the Metabolites

    DEFF Research Database (Denmark)

    Straadt, Ida K; Young, Jette F; Bross, Peter;

    2010-01-01

    NMR-based metabonomics was applied to elucidate the time-dependent stress responses in mouse myotubes after heat exposure of either 42 or 45 degrees C for 1 h. Principal component analysis (PCA) revealed that the gradual time-dependent changes in metabolites contributing to the clustering...... and separation of the control samples from the different time points after heat stress primarily are in the metabolites glucose, leucine, lysine, phenylalanine, creatine, glutamine, and acetate. In addition, PC scores revealed a maximum change in metabolite composition 4 h after the stress exposure; thereafter......, samples returned toward control samples, however, without reaching the control samples even 10 h after stress. The results also indicate that the myotubes efficiently regulate the pH level by release of lactate to the culture medium at a heat stress level of 42 degrees C, which is a temperature level...

  16. Expanding treatment capacity for opioid dependence with office-based treatment with buprenorphine: National surveys of physicians.

    Science.gov (United States)

    Arfken, Cynthia L; Johanson, Chris-Ellyn; di Menza, Salvatore; Schuster, Charles Roberts

    2010-09-01

    Office-based treatment of opioid dependence with buprenorphine has the potential to expand treatment capacity in the United States. However, nationally, little is known about the number, characteristics, and experiences of physicians certified to prescribe buprenorphine. Moreover, little is known about the impact of easing federal regulations on the number of patients a physician is allowed to treat concurrently. To address these questions, surveys of national samples of physicians certified to prescribe buprenorphine (2004-2008) were analyzed (N = 6,892). There has been a continual increase in the number of physicians certified to prescribe buprenorphine, increase in the mean number of patients treated by physicians, and decrease in patients turned away, coinciding temporally with easing of federal regulations. In addition, most physicians prescribed buprenorphine outside of traditional treatment settings. The U.S. experiment in expanding Schedule III-V medications for opioid dependence to physicians outside of formal substance abuse treatment facilities appears to have resulted in expanded capacity.

  17. Time-dependent Multi-group Multidimensional Relativistic Radiative Transfer Code Based On Spherical Harmonic Discrete Ordinate Method

    CERN Document Server

    Tominaga, Nozomu; Blinnikov, Sergei I

    2015-01-01

    We develop a time-dependent multi-group multidimensional relativistic radiative transfer code, which is required to numerically investigate radiation from relativistic fluids involved in, e.g., gamma-ray bursts and active galactic nuclei. The code is based on the spherical harmonic discrete ordinate method (SHDOM) that evaluates a source function including anisotropic scattering in spherical harmonics and implicitly solves the static radiative transfer equation with a ray tracing in discrete ordinates. We implement treatments of time dependence, multi-frequency bins, Lorentz transformation, and elastic Thomson and inelastic Compton scattering to the publicly available SHDOM code. Our code adopts a mixed frame approach; the source function is evaluated in the comoving frame whereas the radiative transfer equation is solved in the laboratory frame. This implementation is validated with various test problems and comparisons with results of a relativistic Monte Carlo code. These validations confirm that the code ...

  18. Structural characteristics of Ni3Al based alloys depending on the preparation conditions

    Directory of Open Access Journals (Sweden)

    J. Malcharcziková

    2015-10-01

    Full Text Available The paper presents an evaluation of the influence of the composition of alloys based on Ni3Al on their mechanical characteristics. The structure of the alloy was controlled through directional solidification. The achieved values of mechanical characteristics are in good agreement with the material structure. The alloys with sub-stoichiometric contents of aluminium have a multiphase structure. These alloys contain network with high values of tensile strain. The microstructure of the samples was investigated and behaviour of dislocations in the alloys was analysed by Transmission electron microscopy methods (TEM.

  19. Pulmonary Toxicity of Perfluorinated Silane-Based Nanofilm Spray Products: Solvent Dependency

    DEFF Research Database (Denmark)

    Nørgaard, Asger Wisti; Hansen, Jitka S.; Sørli, Jorid Birkelund;

    2014-01-01

    A number of cases of pulmonary injury by use of aerosolized surface coating products have been reported worldwide. The aerosol from a commercial alcohol-based nanofilm product (NFP) for coating of nonabsorbing surfaces was found to induce severe lung damage in a recent mouse bioassay. The NFP...... volume was observed after 13 and 9min, respectively; thus, the tidal volume was affected by increase of the chain length. This was confirmed in vitro by investigating lung surfactant function after addition of POTS in different solvents. The addition of vaporized methanol, 2-propanol, or acetone...

  20. Time-dependent measurement of base pressure in a blowdown tunnel with varying unit Reynolds number

    Science.gov (United States)

    Kangovi, S.; Rao, D. M.

    1978-01-01

    An operational characteristic of blowdown-type of wind tunnels is the drop in the stagnation temperature with time and the accompanying change in the test-section unit Reynolds number at constant stagnation pressure and Mach number. This apparent disadvantage can be turned to advantage in some cases where a Reynolds number scan is desired in order to study the effect of unit Reynolds number variation on a particular viscous flow phenomenon. This note presents such an instance arising from recent investigations on base pressure at transonic speeds conducted in the NAL 1-ft tunnel.

  1. Power dependence of terahertz carrier frequency in a plasma-based two-color generation process

    Science.gov (United States)

    Zhao, Ji; Zhang, Liang-Liang; Luo, Yi-Man; Wu, Tong; Zhang, Cun-Lin; Zhao, Yue-Jin

    2014-12-01

    We conduct a frequency spectrum experiment to investigate terahertz (THz) emissions from laser-induced air plasma under different laser incident powers. The frequency spectra are measured using both air-biased-coherent detection and a Michelson interferometer. The red-shift of the THz pulse carrier frequency is observed as a response to increased pump power. These phenomena are related to plasma collisions and can be explained by the plasma collision model. Based on these findings, it is apparent that the tuning of the THz carrier frequency can be achieved through regulation of the pump beam.

  2. Pump dependence of the dynamics of quantum dot based waveguide absorbers

    Science.gov (United States)

    Viktorov, Evgeny A.; Erneux, Thomas; Piwonski, Tomasz; Pulka, Jaroslaw; Huyet, Guillaume; Houlihan, John

    2012-06-01

    The nonlinear two stage recovery of quantum dot based reverse-biased waveguide absorbers is investigated experimentally and analytically as a function of the initial ground state occupation probability of the dot. The latter is controlled experimentally by the pump pulse power. The slow stage of the recovery is exponential and its basic timescale is independent of pump power. The fast stage of the recovery is a logistic function which we analyze in detail. The relative strength of slow to fast components is highlighted and the importance of higher order absorption processes at the highest pump level is demonstrated.

  3. Temperature-Dependent Charge Transport through Individually Contacted DNA Origami-Based Au Nanowires.

    Science.gov (United States)

    Teschome, Bezu; Facsko, Stefan; Schönherr, Tommy; Kerbusch, Jochen; Keller, Adrian; Erbe, Artur

    2016-10-11

    DNA origami nanostructures have been used extensively as scaffolds for numerous applications such as for organizing both organic and inorganic nanomaterials, studying single molecule reactions, and fabricating photonic devices. Yet, little has been done toward the integration of DNA origami nanostructures into nanoelectronic devices. Among other challenges, the technical difficulties in producing well-defined electrical contacts between macroscopic electrodes and individual DNA origami-based nanodevices represent a serious bottleneck that hinders the thorough characterization of such devices. Therefore, in this work, we have developed a method to electrically contact individual DNA origami-based metallic nanowires using electron beam lithography. We then characterize the charge transport of such nanowires in the temperature range from room temperature down to 4.2 K. The room temperature charge transport measurements exhibit ohmic behavior, whereas at lower temperatures, multiple charge transport mechanisms such as tunneling and thermally assisted transport start to dominate. Our results confirm that charge transport along metallized DNA origami nanostructures may deviate from pure metallic behavior due to several factors including partial metallization, seed inhomogeneities, impurities, and weak electronic coupling among AuNPs. Besides, this study further elucidates the importance of variable temperature measurements for determining the dominant charge transport mechanisms for conductive nanostructures made by self-assembly approaches.

  4. Responsivity Dependent Anodization Current Density of Nanoporous Silicon Based MSM Photodetector

    Directory of Open Access Journals (Sweden)

    Batool Eneaze B. Al-Jumaili

    2016-01-01

    Full Text Available Achieving a cheap and ultrafast metal-semiconductor-metal (MSM photodetector (PD for very high-speed communications is ever-demanding. We report the influence of anodization current density variation on the response of nanoporous silicon (NPSi based MSM PD with platinum (Pt contact electrodes. Such NPSi samples are grown from n-type Si (100 wafer using photoelectrochemical etching with three different anodization current densities. FESEM images of as-prepared samples revealed the existence of discrete pores with spherical and square-like shapes. XRD pattern displayed the growth of nanocrystals with (311 lattice orientation. The nanocrystallite sizes obtained using Scherrer formula are found to be between 20.8 nm and 28.6 nm. The observed rectifying behavior in the I-V characteristics is ascribed to the Pt/PSi/n-Si Schottky barrier formation, where the barrier height at the Pt/PSi interface is estimated to be 0.69 eV. Furthermore, this Pt/PSi/Pt MSM PD achieved maximum responsivity of 0.17 A/W and quantum efficiency as much as 39.3%. The photoresponse of this NPSi based MSM PD demonstrated excellent repeatability, fast response, and enhanced saturation current with increasing anodization current density.

  5. Thermal droop in InGaN-based LEDs: physical origin and dependence on material properties

    Science.gov (United States)

    De Santi, C.; Meneghini, M.; La Grassa, M.; Trivellin, N.; Galler, B.; Zeisel, R.; Hahn, B.; Goano, M.; Dominici, S.; Mandurrino, M.; Bertazzi, F.; Meneghesso, G.; Zanoni, E.

    2016-03-01

    The thermal droop (reduction of the optical power when the temperature is increased) is a phenomenon that strongly limits the efficiency of InGaN-based light-emitting diodes. In this paper we analyze the role of Shockley-Read-Hall (SRH) recombination and of the electron blocking layer (EBL) in the process by using numerical simulations and literature data. The benefic impact of EBL suggests that carrier escape from the quantum wells gives a significant contribution to the thermal droop, therefore we review some of the mechanisms described in the literature (thermionic emission, phonon-assisted tunneling, thermionic trap-assisted tunneling). Since no formulation is able to fit the behavior of the measured SQW devices, we develop a new model based on two phonon-assisted tunneling steps through a defective state, extended in order to take into account zero-field emission. By using experimental data, material constants from the literature and only two fitting parameters the model is able to reproduce the experimental behavior.

  6. Frequency-dependent performance analysis of a parallel DSP-based computer system

    Science.gov (United States)

    Christou, Ch. S.

    2014-11-01

    The performance of a shared-memory low-cost high-performance DSP-Based multiprocessor system [3] is investigated, by varying the frequency of the core processor from 200MHz to 1GHZ, in steps of 200 MHZ, and keeping constant parameters such as the shared-memory-access-time and the prefetching-workload-size. The innovation of this Parallel DSP-Based computer system is the introduction of two small programmable small fast memories (Twins) between the processor and the shared bus interconnect. While one memory (Twin) transfers data from/to the shared memory, the other Twin supplies the core DSP-processor with data. Results indicate an increase of the shared-bus bottleneck as the core DSP processors' clock-rate increases. Workload of the Twins is processed faster thus greater the demand of the shared-bus. Results show an effectively supported robust parallel shared-memory system where fewer but faster (clocked with higher frequency) processors produce the same execution times as a greater number of slower processors, with most system configurations achieving perfect speedups, mainly due to the twin-prefetching mechanism.

  7. MODSARE-V: Validation of Dependability and Safety Critical Software Components with Model Based Requirements

    Science.gov (United States)

    Silveira, Daniel T. de M. M.; Schoofs, Tobias; Alana Salazar, Elena; Rodriguez Rodriguez, Ana Isabel; Devic, Marie-Odile

    2010-08-01

    The wide use of RAMS methods and techniques [1] (e.g. SFMECA, SFTA, HAZOP, HA...) in critical software development resulted in the specification of new software requirements, design constraints and other issues such as mandatory coding rules. Given the large variety of RAMS Requirements and Techniques, different types of Verification and Validation (V&V) [14] are spread over the phases of the software engineering process. As a result, the V&V process becomes complex and the cost and time required for a complete and consistent V&V process is increased. By introducing the concept of a model based approach to facilitate the RAMS requirements definition process, the V&V may be reduce in time and effort. MODSARE-V is demonstrates the feasibility of this concept based on case studies applied to ground or on-board software space projects with critical functions/components. This paper describes the approach adopted at MODSARE-V to realize the concept into a prototype and summarizes the results and conclusions met after the prototype application on the case studies.

  8. Lithology- versus base level-dependent morphogenesis of the Hausruck - Kobernaußerwald range

    Science.gov (United States)

    Baumann, Sebastian; Robl, Jörg; Salcher, Bernhard; Prasicek, Günther; Keil, Melanie

    2016-04-01

    The Hausruck - Kobernaußerwald range has the highest relief in the Northern Molasse Basin in front of the Eastern Alps. The highest peaks of the range exceed an elevation of 800 m and are characterized by a local relief of about 400 m relative to the adjacent lowlands. The Hausruck - Kobernaußerwald range has never been glaciated and erosion is solely driven by fluvial incision and corresponding hillslope processes since the inversion of the Molasse Basin. Landslides are frequently observed at hillslopes in the Hausruck domain in the west but are completely missing in the Kobernaußerwald domain in the east. Recent tectonic activity like faulting has not been reported for that region and the stratigraphic record shows no evidence for tectonically induced discontinuities. The morphological expression of the western Kobernaußerwald and the eastern Hausruck apparently differ in their degree of erosional landscape decay with a gently incised western and deeply incised eastern domain. These domains correspond with two different lithological units of the Upper Freshwater Molasse: The simultaneously deposited western Kobernaußerwald Formation (Kobernaußerwald domain) and the eastern Ampfelwang Formation (Hausruck domain) are interpreted as sedimentary deposits of a fluvial fan in proximal and distal position, respectively, and show fining of the sedimentary record from west to east. The stratigraphic highest unit of the study region, the Hausruck Fm., consists of well consolidated fluvial gravels uniformly covering the hill tops of both domains. We used a high resolution LiDAR digital elevation model and performed a series of morphometric analyses to investigate the effects of different base levels and contrasting lithology on the topographic evolution of the Hausruck - Kobernaußerwald range. The analysis of longitudinal river profiles reveals that all channels independent from base level, bed rock and overall morphological expression are well graded with steep

  9. Robust demarcation of basal cell carcinoma by dependent component analysis-based segmentation of multi-spectral fluorescence images.

    Science.gov (United States)

    Kopriva, Ivica; Persin, Antun; Puizina-Ivić, Neira; Mirić, Lina

    2010-07-02

    This study was designed to demonstrate robust performance of the novel dependent component analysis (DCA)-based approach to demarcation of the basal cell carcinoma (BCC) through unsupervised decomposition of the red-green-blue (RGB) fluorescent image of the BCC. Robustness to intensity fluctuation is due to the scale invariance property of DCA algorithms, which exploit spectral and spatial diversities between the BCC and the surrounding tissue. Used filtering-based DCA approach represents an extension of the independent component analysis (ICA) and is necessary in order to account for statistical dependence that is induced by spectral similarity between the BCC and surrounding tissue. This generates weak edges what represents a challenge for other segmentation methods as well. By comparative performance analysis with state-of-the-art image segmentation methods such as active contours (level set), K-means clustering, non-negative matrix factorization, ICA and ratio imaging we experimentally demonstrate good performance of DCA-based BCC demarcation in two demanding scenarios where intensity of the fluorescent image has been varied almost two orders of magnitude.

  10. Development of a voltage-dependent current noise algorithm for conductance-based stochastic modelling of auditory nerve fibres.

    Science.gov (United States)

    Badenhorst, Werner; Hanekom, Tania; Hanekom, Johan J

    2016-12-01

    This study presents the development of an alternative noise current term and novel voltage-dependent current noise algorithm for conductance-based stochastic auditory nerve fibre (ANF) models. ANFs are known to have significant variance in threshold stimulus which affects temporal characteristics such as latency. This variance is primarily caused by the stochastic behaviour or microscopic fluctuations of the node of Ranvier's voltage-dependent sodium channels of which the intensity is a function of membrane voltage. Though easy to implement and low in computational cost, existing current noise models have two deficiencies: it is independent of membrane voltage, and it is unable to inherently determine the noise intensity required to produce in vivo measured discharge probability functions. The proposed algorithm overcomes these deficiencies while maintaining its low computational cost and ease of implementation compared to other conductance and Markovian-based stochastic models. The algorithm is applied to a Hodgkin-Huxley-based compartmental cat ANF model and validated via comparison of the threshold probability and latency distributions to measured cat ANF data. Simulation results show the algorithm's adherence to in vivo stochastic fibre characteristics such as an exponential relationship between the membrane noise and transmembrane voltage, a negative linear relationship between the log of the relative spread of the discharge probability and the log of the fibre diameter and a decrease in latency with an increase in stimulus intensity.

  11. Machine Learning Based Multi-Physical-Model Blending for Enhancing Renewable Energy Forecast -- Improvement via Situation Dependent Error Correction

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Siyuan; Hwang, Youngdeok; Khabibrakhmanov, Ildar; Marianno, Fernando J.; Shao, Xiaoyan; Zhang, Jie; Hodge, Bri-Mathias; Hamann, Hendrik F.

    2015-07-15

    With increasing penetration of solar and wind energy to the total energy supply mix, the pressing need for accurate energy forecasting has become well-recognized. Here we report the development of a machine-learning based model blending approach for statistically combining multiple meteorological models for improving the accuracy of solar/wind power forecast. Importantly, we demonstrate that in addition to parameters to be predicted (such as solar irradiance and power), including additional atmospheric state parameters which collectively define weather situations as machine learning input provides further enhanced accuracy for the blended result. Functional analysis of variance shows that the error of individual model has substantial dependence on the weather situation. The machine-learning approach effectively reduces such situation dependent error thus produces more accurate results compared to conventional multi-model ensemble approaches based on simplistic equally or unequally weighted model averaging. Validation over an extended period of time results show over 30% improvement in solar irradiance/power forecast accuracy compared to forecasts based on the best individual model.

  12. Spin-dependent Otto quantum heat engine based on a molecular substance

    Science.gov (United States)

    Hübner, Wolfgang; Lefkidis, Georgios; Dong, Chuanding; Chaudhuri, Debapriya; Chotorlishvili, Levan; Berakdar, Jamal

    2015-03-01

    We explore the potential of single molecules for thermodynamic cycles. To this end we propose two molecular heat engines based on the realistic Ni2 dimer: a quantum Otto engine and a modified quantum Otto engine for which laser-induced optical excitations substitute for one of the heat-exchange points. For reliable predictions and to inspect the role of spin and electronic correlations we perform fully correlated ab initio calculations of the electronic structure and the excited states. We analyze the efficiency and the word output of the derived engines and find an enhancement when the spin degree of freedom is included. We also use the von Neumann entropy to describe correlations and entanglement of the engines during the cycles. Furthermore, we link our results to previous results regarding an isobaric stroke and a magnetic quantum Diesel engine on the same substance.

  13. Thickness dependence on the optoelectronic properties of multilayered GaSe based photodetector

    Science.gov (United States)

    Ko, Pil Ju; Abderrahmane, Abdelkader; Takamura, Tsukasa; Kim, Nam-Hoon; Sandhu, Adarsh

    2016-08-01

    Two-dimensional (2D) layered materials exhibit unique optoelectronic properties at atomic thicknesses. In this paper, we fabricated metal-semiconductor-metal based photodetectors using layered gallium selenide (GaSe) with different thicknesses. The electrical and optoelectronic properties of the photodetectors were studied, and these devices showed good electrical characteristics down to GaSe flake thicknesses of 30 nm. A photograting effect was observed in the absence of a gate voltage, thereby implying a relatively high photoresponsivity. Higher values of the photoresponsivity occurred for thicker layers of GaSe with a maximum value 0.57 AW-1 and external quantum efficiency of of 132.8%, and decreased with decreasing GaSe flake thickness. The detectivity was 4.05 × 1010 cm Hz1/2 W-1 at 532 nm laser wavelength, underscoring that GaSe is a promising p-type 2D material for photodetection applications in the visible spectrum.

  14. Dependence of image quality on energy spread for a Bragg diffraction based radiography system

    Energy Technology Data Exchange (ETDEWEB)

    Baldelli, P. [Physics Department, University of Ferrara and INFN Section of Ferrara (Italy)], E-mail: baldelli@fe.infn.it; Bacci, A. [INFN Section of Milano (Italy); Bottigli, U. [Physics Department of University of Siena (Italy); INFN Section of Cagliari (Italy); Ferrario, M. [INFN National laboratory of Frascati (Italy); Gambaccini, M. [Physics Department, University of Ferrara and INFN Section of Ferrara (Italy); Giulietti, D. [IPCF-CNR and INFN Section of Pisa (Italy); Golosio, B. [INFN Section of Cagliari (Italy); Mathematics and Physics Department, University of Sassari (Italy); Maroli, C. [INFN Section of Milano (Italy); University of Milan (Italy); Oliva, P. [INFN Section of Cagliari (Italy); Mathematics and Physics Department, University of Sassari (Italy); Petrillo, V. [INFN Section of Milano (Italy); University of Milan (Italy); Serafini, L. [INFN Section of Milano (Italy); Stumbo, S. [INFN Section of Cagliari (Italy); Mathematics and Physics Department, University of Sassari (Italy); Taibi, A. [Physics Department, University of Ferrara and INFN Section of Ferrara (Italy); Tomassini, P. [IPCF-CNR and INFN Section of Pisa (Italy); Vaccarezza, C. [INFN National Laboratory of Frascati (Italy)

    2007-10-01

    The aim of this work is to investigate the relationship between contrast and energy resolution of a quasi-monochromatic X-ray system based on Bragg diffraction on a mosaic crystal. Three different energies have been considered: 18, 22 and 26 keV. A commercial phantom containing large and small area details and a digital detector have been used. Results show that for large area details and for a certain value of energy, the energy spread of the incident X-ray beams produces a small reduction of the contrast, while for small area details the high reduction of the contrast is principally due to the spatial resolution properties of the system.

  15. A faith-based intervention for cocaine-dependent Black women.

    Science.gov (United States)

    Stahler, Gerald J; Kirby, Kimberly C; Kerwin, MaryLouise E

    2007-06-01

    The purpose of the present study was to obtain preliminary data on the effectiveness of a faith-based treatment adjunct for cocaine-using homeless mothers in residential treatment. The Bridges intervention utilizes various Black church communities to provide culturally-relevant group activities and individual mentoring from volunteers. Eighteen women who were recent treatment admissions were randomly assigned to receive Standard Treatment plus Bridges or Standard Treatment with an Attention Control. Participants were assessed at intake and three and six months after intake. Bridges treatment resulted in significantly better treatment retention (75% vs. 20% at six months) than standard residential treatment alone. In addition, Bridges produced superior outcomes at the six month follow-up assessment on a secondary measure of cocaine abstinence. Creating a community of social support through Black churches appears feasible and promising, and may be a cost-effective means of providing longer-term post-treatment support for cocaine-addicted women.

  16. Assembly of IFT trains at the ciliary base depends on IFT74.

    Science.gov (United States)

    Brown, Jason M; Cochran, Deborah A; Craige, Branch; Kubo, Tomohiro; Witman, George B

    2015-06-15

    Intraflagellar transport (IFT) moves IFT trains carrying cargoes from the cell body into the flagellum and from the flagellum back to the cell body. IFT trains are composed of complexes IFT-A and IFT-B and cargo adaptors such as the BBSome. The IFT-B core proteins IFT74 and IFT81 interact directly through central and C-terminal coiled-coil domains, and recently it was shown that the N termini of these proteins form a tubulin-binding module important for ciliogenesis. To investigate the function of IFT74 and its domains in vivo, we have utilized Chlamydomonas reinhardtii ift74 mutants. In a null mutant, lack of IFT74 destabilized IFT-B, leading to flagella assembly failure. In this null background, expression of IFT74 lacking 130 amino acids (aa) of the charged N terminus stabilized IFT-B and promoted slow assembly of nearly full-length flagella. A further truncation (lacking aa 1-196, including part of coiled-coil 1) also stabilized IFT-B, but failure in IFT-A/IFT-B interaction within the pool at the base of the flagellum prevented entry of IFT-A into the flagellum and led to severely decreased IFT injection frequency and flagellar-assembly defects. Decreased IFT-A in these short flagella resulted in aggregates of stalled IFT-B in the flagella. We conclude that IFT74 is required to stabilize IFT-B; aa 197-641 are sufficient for this function in vivo. The N terminus of IFT74 may be involved in, but is not required for, tubulin entry into flagella. It is required for association of IFT-A and IFT-B at the base of the flagellum and flagellar import of IFT-A.

  17. Benchmarks for electronically excited states: Time-dependent density functional theory and density functional theory based multireference configuration interaction

    DEFF Research Database (Denmark)

    Silva-Junior, Mario R.; Schreiber, Marko; Sauer, Stephan P. A.;

    2008-01-01

    Time-dependent density functional theory (TD-DFT) and DFT-based multireference configuration interaction (DFT/MRCI) calculations are reported for a recently proposed benchmark set of 28 medium-sized organic molecules. Vertical excitation energies, oscillator strengths, and excited-state dipole...... moments are computed using the same geometries (MP2/6-31G*) and basis set (TZVP) as in our previous ab initio benchmark study on electronically excited states. The results from TD-DFT (with the functionals BP86, B3LYP, and BHLYP) and from DFT/MRCI are compared against the previous high-level ab initio...

  18. Effects of conventional sucrose-based, fructose-based and isomalt-based chocolates on postprandial metabolism in non-insulin-dependent diabetics.

    Science.gov (United States)

    Gee, J M; Cooke, D; Gorick, S; Wortley, G M; Greenwood, R H; Zumbe, A; Johnson, I T

    1991-11-01

    Milk chocolate is rich in both sucrose and fat, and is therefore considered unsuitable for diabetics. Nevertheless there is little information on the metabolic effects of conventional chocolate or specialized formulations with reduced sucrose content. In the present study six male non-insulin-dependent diabetes mellitus patients (age range 35-60 years; body-mass index less than 28) consumed test meals of chocolate (75 g) on three separate occasions. The control chocolate contained sucrose (45.5% w/w); the test chocolates contained either fructose (45.5% w/w) or isomalt (45.1% w/w). The latter is a sweet disaccharide alcohol which has no glycaemic effect when consumed as a pure compound. Venous blood samples were obtained at 30 min intervals for 5 h, and analysed for glucose, insulin, lactate and triglycerides. All three chocolates provoked a sustained rise in blood glucose, which reached a maximum at 90 min after ingestion and returned to baseline values by 5 h. The highest blood glucose levels occurred after conventional chocolate, and differences were statistically significant at 60 and 90 min (P less than 0.05). The area under the glycaemic curve for isomalt chocolate was 36% smaller than that for conventional chocolate (P less than 0.05), and there were differences in insulin and lactate levels, consistent with the lower glycaemic effect. The glycaemic response to the fructose-based chocolate was also lower than that to control chocolate but the difference was not significant. All three chocolates led to a similar sustained rise in serum triglyceride levels. Isomalt appears to be a palatable alternative sweetener capable of reducing the glycaemic effect of diabetic confectionary.

  19. Reconnaissance Estimates of Recharge Based on an Elevation-dependent Chloride Mass-balance Approach

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Russell; Tim Minor

    2002-08-31

    Significant uncertainty is associated with efforts to quantity recharge in arid regions such as southern Nevada. However, accurate estimates of groundwater recharge are necessary to understanding the long-term sustainability of groundwater resources and predictions of groundwater flow rates and directions. Currently, the most widely accepted method for estimating recharge in southern Nevada is the Maxey and Eakin method. This method has been applied to most basins within Nevada and has been independently verified as a reconnaissance-level estimate of recharge through several studies. Recharge estimates derived from the Maxey and Eakin and other recharge methodologies ultimately based upon measures or estimates of groundwater discharge (outflow methods) should be augmented by a tracer-based aquifer-response method. The objective of this study was to improve an existing aquifer-response method that was based on the chloride mass-balance approach. Improvements were designed to incorporate spatial variability within recharge areas (rather than recharge as a lumped parameter), develop a more defendable lower limit of recharge, and differentiate local recharge from recharge emanating as interbasin flux. Seventeen springs, located in the Sheep Range, Spring Mountains, and on the Nevada Test Site were sampled during the course of this study and their discharge was measured. The chloride and bromide concentrations of the springs were determined. Discharge and chloride concentrations from these springs were compared to estimates provided by previously published reports. A literature search yielded previously published estimates of chloride flux to the land surface. {sup 36}Cl/Cl ratios and discharge rates of the three largest springs in the Amargosa Springs discharge area were compiled from various sources. This information was utilized to determine an effective chloride concentration for recharging precipitation and its associated uncertainty via Monte Carlo simulations

  20. Local Cubic Law Simulation of Stress-dependent Aperture-based Permeability

    Science.gov (United States)

    Huo, D.; Benson, S. M.

    2014-12-01

    Research on calculating fracture permeability has been undergoing for decades (Witherspoon, 1980). Local Cubic Law (LCL) has been proposed to be one feasible way to simulate the fracture permeability with variable aperture changes (Brown, 1987). The purpose of this research is to present an evaluation of LCL based on a set of experimental results of permeability, aperture distribution and effective stress. We concurrently measure fracture permeability and fracture aperture distribution changes (using X-Ray CT) with cycling stress. Fractured Berea sandstone and Zenifim sandstone are measured, representing rough and smooth rock fracture surfaces. Using thin section data, we evaluate the grain size and apply Stokes fluid flow simulation in a synthetic field to estimate the stagnant fluid level between rock grains. By accounting for the stagnant fluid level, LCL simulation provides a reliable prediction for fracture permeability. Comparing with previous research (Konzuk and Kueper, 2004), we propose that LCL simulation requires detailed information about local grain arrangement. The experiment shows that permeability change is greater than expected from mean aperture change at different stress levels. LCL simulation demonstrates that this is mainly due to the change of fluid flow pattern with stress, which is caused by aperture distribution change. LCL simulation also exhibits that channeling behavior plays an important role in fluid flow in fractures, and sometimes a small number of channels dominate the flow. In the experiment, we apply different flow rates to assess the LCL simulation at different Reynolds number. The simulation results show that fluid flow rate (1.24 < Re < 15.28) does not have a large impact on LCL predictability in the highly tortuous and rough rock fractures, which agrees with the results of Konzuk and Kueper (2004). References: Brown, S. R., 1987, Fluid flow through rock joints: The effect of surface roughness, J. Geophys. Res., 92(B2), 1337

  1. Quantitative calculation for the dissipated energy of fault rock burst based on gradient-dependent plasticity

    Institute of Scientific and Technical Information of China (English)

    Xuebin Wang; Shuhong Dai; Long Hai

    2004-01-01

    The capacity of energy absorption by fault bands after rock burst was calculated quantitatively according to shear stressshear deformation curves considering the interactions and interplaying among microstructures due to the heterogeneity of strain softening rock materials. The post-peak stiffness of rock specimens subjected to direct shear was derived strictly based on gradientdependent plasticity, which can not be obtained from the classical elastoplastic theory. Analytical solutions for the dissipated energy of rock burst were proposed whether the slope of the post-peak shear stress-shear deformation curve is positive or not. The analytical solutions show that shear stress level, confining pressure, shear strength, brittleness, strain rate and heterogeneity of rock materials have important influence on the dissipated energy. The larger value of the dissipated energy means that the capacity of energy dissipation in the form of shear bands is superior and a lower magnitude of rock burst is expected under the condition of the same work done by external shear force. The possibility of rock burst is reduced for a lower softening modulus or a larger thickness of shear bands.

  2. Temperature Dependence of Sensors Based on Silver-Decorated Nitrogen-Doped Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Eduardo Gracia-Espino

    2016-01-01

    Full Text Available Vapor sensors are easily fabricated onto alumina substrates using foils of silver-decorated nitrogen-doped multiwalled carbon nanotubes (CNX-MWNTs-Ag as active sensing material. The vapor sensors are tested using carbon disulfide, acetone, ethanol, and chloroform vapors. The CNX-MWNTs are produced by chemical vapor deposition process and then decorated with 14 nm Ag nanoparticles (Ag-NPs. The samples are characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. Our results demonstrate that Ag-decorated CNX-MWNTs exhibit a better response and sensitivity when compared with pristine CNX-MWNTs based sensors, making them promising candidates for air-pollutants environmental monitoring. The temperature effect on the sensor performance is also studied; we found that the detection mechanism could be tuned from physisorption, at room temperature, to chemisorption at higher working temperature. Finally, first-principles density functional calculations are carried out to understand the interactions between the systems involved in the sensors, finding good agreement between experimental results and the theoretical approach.

  3. Analysis of localized shear deformation of ductile metal based on gradient-dependent plasticity

    Institute of Scientific and Technical Information of China (English)

    王学滨; 代树红; 海龙; 潘一山

    2003-01-01

    Shear localization in linear strain softening heterogeneous material under simple shear was investigated analytically.The closed-form solutions obtained based on gradient plasticity theory considering interactions and interplaying among microstructures due to heterogeneity of metal material show that in the normal direction of shear band,elastic shear displacement is linear; while plastic and total shear displacement are non-linear.Elastic shear strain in the band is uniform and the non-uniformity of total shear displacement stems from localized plastic shear displacement.In the center of the band,plastic and total shear displacement all reach their maximum values.In strain-softening process,elastic displacement decreases as flow shear stress decreases.Contrarily,plastic and total shear displacement increase and manifest shear localization occurs progressively.Under the same shear stress level,plastic and total shear displacement increase as strain softening modulus and elastic shear modulus decrease.The present analytical solutions were compared with many experimental results and the agreement is good.

  4. Damping Dependence of Reversal Magnetic Field on Co-based Nano-Ferromagnetic with Thermal Activation

    Directory of Open Access Journals (Sweden)

    Nadia Ananda Herianto

    2015-02-01

    Full Text Available Currently, hard disk development has used HAMR technology that applies heat to perpendicular media until near Curie temperature, then cools it down to room temperature. The use of HAMR technology is significantly influence by Gilbert damping constants. Damping affects the magnetization reversal and coercivity field. Simulation is used to evaluate magnetization reversal by completing Landau-Lifshitz-Gilbert explicit equation. A strong ferromagnetic cobalt based material with size 50×50×20 nm3 is used which parameters are anisotropy materials 3.51×106 erg/cm3, magnetic saturation 5697.5 G, exchange constant 1×10-7 erg/cm, and various Gilbert damping from 0.09 to 0.5. To observe the thermal effect, two schemes are used which are Reduced Barrier Writing and Curie Point Writing. As a result, materials with high damping is able to reverse the magnetizations faster and reduce the energy barrier. Moreover, it can lower the minimum field to start the magnetizations reversal, threshold field, and probability rate. The heating near Curie temperature has succeeded in reducing the reversal field to 1/10 compared to writing process in absence of thermal field.

  5. Angular Dependence of Spin Transfer Switching in Spin Valve Nanopillar Based Heusler Alloy

    Directory of Open Access Journals (Sweden)

    Pirat Khunkitti

    2016-01-01

    Full Text Available The spin transfer induced magnetization switching in current perpendicular-to-the-plane spin valve nanopillar based Co2FeAl0.5Si0.5 Heusler alloy with varying the initial angles of the magnetization of sensing layer, θ0, was investigated via macrospin simulations. The effects of an in-plane magnetic field, Hi, on the switching behavior were also evaluated. The magnetization switching was excited by spin polarized switching current, Is. The time varying magnetization was computed by the Landau-Lifshitz-Gilbert-Slonczewski equation, while the spin transfer induced noise was examined by using the power spectral density analysis. It was found that θ0 should be narrowly initialized since this configuration produces the small noise during the switching. Also, the negative Is produced more uniform switching than the positive Is due to existence of ferromagnetic exchange coupling. When Hi was presented, the noise generated at low frequencies could be suppressed, and then the switching behavior became more uniform. In addition, the results indicated that the noise configuration could be explained by the physical dynamic of magnetization behavior. Hence, the spin transfer induced noise needs to be minimized in order to improve the performance of spin transfer torque random access memory for high density recording.

  6. Ranking of Reactions Based on Sensitivity of Protein Noise Depends on the Choice of Noise Measure.

    Directory of Open Access Journals (Sweden)

    Sucheta Gokhale

    Full Text Available Gene expression is a stochastic process. Identification of the step maximally affecting noise in the protein level is an important aspect of investigation of gene product distribution. There are numerous experimental and theoretical studies that seek to identify this important step. However, these studies have used two different measures of noise, viz. coefficient of variation and Fano factor, and have compared different processes leading to contradictory observations regarding the important step. In this study, we performed systematic global and local sensitivity analysis on two models of gene expression to investigate relative contribution of reaction rate parameters to steady state noise in the protein level using both the measures of noise. We analytically and computationally showed that the ranking of parameters based on the sensitivity of the noise to variation in a given parameter is a strong function of the choice of the noise measure. If the Fano factor is used as the noise measure, translation is the important step whereas for coefficient of variation, transcription is the important step. We derived an analytical expression for local sensitivity and used it to explain the distinct contributions of each reaction parameter to the two measures of noise. We extended the analysis to a generic linear catalysis reaction system and observed that the reaction network topology was an important factor influencing the local sensitivity of the two measures of noise. Our study suggested that, for the analysis of contributions of reactions to the noise, consideration of both the measures of noise is important.

  7. Nickel-based catalysts: Dependence of properties on nickel loading and modification with palladium

    Directory of Open Access Journals (Sweden)

    Nikolić Vesna D.

    2016-01-01

    Full Text Available The aim of this study was comparative analysis of catalysts with 5 and 20 wt. % Ni loading, with and without Pd additive, and it included: determination of reduction degrees, investigation on microstructure by scanning electron microscopy and chemical analysis by energy-dispersive spectroscopy. Ni/Al2O3 and Ni-Pd/Al2O3 catalysts supported on α-Al2O3-based foams were synthesized by aerosol assisted impregnation. Impregnation of the foams by ultrasonically aerosolized chlorides was followed by drying at 473 K and hydrogen reduction at 533 and 633 K. Lower Ni loading resulted in higher reduction degrees. Ni loading of 20 wt. % enabled relatively uniform coverage of the foam with a metallic coating. With activity modifier (Pd, nearly complete reduction was achieved at both temperatures. Reduction degrees reached 99.4 and 98.2 wt. % at 533 K for 5 and 20 wt. % of Ni, respectively. [Projekat Ministarstva nauke Republike Srbije, br. 34033: Innovative synergy of by-products, waste minimization and clean technologies in metallurgy

  8. A second order residual based predictor-corrector approach for time dependent pollutant transport

    Science.gov (United States)

    Pavan, S.; Hervouet, J.-M.; Ricchiuto, M.; Ata, R.

    2016-08-01

    We present a second order residual distribution scheme for scalar transport problems in shallow water flows. The scheme, suitable for the unsteady cases, is obtained adapting to the shallow water context the explicit Runge-Kutta schemes for scalar equations [1]. The resulting scheme is decoupled from the hydrodynamics yet the continuity equation has to be considered in order to respect some important numerical properties at discrete level. Beyond the classical characteristics of the residual formulation presented in [1,2], we introduce the possibility to iterate the corrector step in order to improve the accuracy of the scheme. Another novelty is that the scheme is based on a precise monotonicity condition which guarantees the respect of the maximum principle. We thus end up with a scheme which is mass conservative, second order accurate and monotone. These properties are checked in the numerical tests, where the proposed approach is also compared to some finite volume schemes on unstructured grids. The results obtained show the interest in adopting the predictor-corrector scheme for pollutant transport applications, where conservation of the mass, monotonicity and accuracy are the most relevant concerns.

  9. Combined Prediction Model of Death Toll for Road Traffic Accidents Based on Independent and Dependent Variables

    Directory of Open Access Journals (Sweden)

    Feng Zhong-xiang

    2014-01-01

    Full Text Available In order to build a combined model which can meet the variation rule of death toll data for road traffic accidents and can reflect the influence of multiple factors on traffic accidents and improve prediction accuracy for accidents, the Verhulst model was built based on the number of death tolls for road traffic accidents in China from 2002 to 2011; and car ownership, population, GDP, highway freight volume, highway passenger transportation volume, and highway mileage were chosen as the factors to build the death toll multivariate linear regression model. Then the two models were combined to be a combined prediction model which has weight coefficient. Shapley value method was applied to calculate the weight coefficient by assessing contributions. Finally, the combined model was used to recalculate the number of death tolls from 2002 to 2011, and the combined model was compared with the Verhulst and multivariate linear regression models. The results showed that the new model could not only characterize the death toll data characteristics but also quantify the degree of influence to the death toll by each influencing factor and had high accuracy as well as strong practicability.

  10. Self-assembled monolayers based spintronics: from ferromagnetic surface functionalization to spin-dependent transport.

    Science.gov (United States)

    Tatay, Sergio; Galbiati, Marta; Delprat, Sophie; Barraud, Clément; Bouzehouane, Karim; Collin, Sophie; Deranlot, Cyrile; Jacquet, Eric; Seneor, Pierre; Mattana, Richard; Petroff, Frédéric

    2016-03-09

    Chemically functionalized surfaces are studied for a wide range of applications going from medicine to electronics. Whereas non-magnetic surfaces have been widely studied, functionalization of magnetic surfaces is much less common and has almost never been used for spintronics applications. In this article we present the functionalization of La2/3Sr1/3MnO3, a ferromagnetic oxide, with self-assembled monolayers for spintronics. La2/3Sr1/3MnO3 is the prototypical half-metallic manganite used in spintronics studies. First, we show that La2/3Sr1/3MnO3 can be functionalized by alkylphosphonic acid molecules. We then emphasize the use of these functionalized surfaces in spintronics devices such as magnetic tunnel junctions fabricated using a nano-indentation based lithography technique. The observed exponential increase of tunnel resistance as a function of alkyl chain length is a direct proof of the successful connection of molecules to ferromagnetic electrodes. For all alkyl chains studied we obtain stable and robust tunnel magnetoresistance, with effects ranging from a few tens to 10 000%. These results show that functionalized electrodes can be integrated in spintronics devices and open the door to a molecular engineering of spintronics.

  11. pH-dependent drug-drug interactions for weak base drugs: potential implications for new drug development.

    Science.gov (United States)

    Zhang, L; Wu, F; Lee, S C; Zhao, H; Zhang, L

    2014-08-01

    Absorption of an orally administered drug with pH-dependent solubility may be altered when it is coadministered with a gastric acid-reducing agent (ARA). Assessing a drug's potential for pH-dependent drug-drug interactions (DDIs), considering study design elements for such DDI studies, and interpreting and communicating study results in the drug labeling to guide drug dosing are important for drug development. We collected pertinent information related to new molecular entities approved from January 2003 to May 2013 by the US Food and Drug Administration for which clinical DDI studies with ARAs were performed. On the basis of assessments of data on pH solubility and in vivo DDIs with ARAs, we proposed a conceptual framework for assessing the need for clinical pH-dependent DDI studies for weak base drugs (WBDs). Important study design considerations include selection of ARAs and timing of dosing of an ARA relative to the WBD in a DDI study. Labeling implications for drugs having DDIs with ARAs are also illustrated.

  12. A FRET-based DNA biosensor tracks OmpR-dependent acidification of Salmonella during macrophage infection.

    Science.gov (United States)

    Chakraborty, Smarajit; Mizusaki, Hideaki; Kenney, Linda J

    2015-04-01

    In bacteria, one paradigm for signal transduction is the two-component regulatory system, consisting of a sensor kinase (usually a membrane protein) and a response regulator (usually a DNA binding protein). The EnvZ/OmpR two-component system responds to osmotic stress and regulates expression of outer membrane proteins. In Salmonella, EnvZ/OmpR also controls expression of another two-component system SsrA/B, which is located on Salmonella Pathogenicity Island (SPI) 2. SPI-2 encodes a type III secretion system, which functions as a nanomachine to inject bacterial effector proteins into eukaryotic cells. During the intracellular phase of infection, Salmonella switches from assembling type III secretion system structural components to secreting effectors into the macrophage cytoplasm, enabling Salmonella to replicate in the phagocytic vacuole. Major questions remain regarding how bacteria survive the acidified vacuole and how acidification affects bacterial secretion. We previously reported that EnvZ sensed cytoplasmic signals rather than extracellular ones, as intracellular osmolytes altered the dynamics of a 17-amino-acid region flanking the phosphorylated histidine. We reasoned that the Salmonella cytoplasm might acidify in the macrophage vacuole to activate OmpR-dependent transcription of SPI-2 genes. To address these questions, we employed a DNA-based FRET biosensor ("I-switch") to measure bacterial cytoplasmic pH and immunofluorescence to monitor effector secretion during infection. Surprisingly, we observed a rapid drop in bacterial cytoplasmic pH upon phagocytosis that was not predicted by current models. Cytoplasmic acidification was completely dependent on the OmpR response regulator, but did not require known OmpR-regulated genes such as ompC, ompF, or ssaC (SPI-2). Microarray analysis highlighted the cadC/BA operon, and additional experiments confirmed that it was repressed by OmpR. Acidification was blocked in the ompR null background in a Cad-dependent

  13. Requirement Pattern Based on Dependencies of Plan in i* for Detecting Proactivity in Information-Technology Systems

    Directory of Open Access Journals (Sweden)

    Alain Pérez Acosta

    2016-04-01

    Full Text Available This paper aims to present a requirement pattern based on i*’s models that allows detecting proactivityin information-technology systems from the Requirements’ phase. The pattern obtained as a result ofthis paper allows detecting proactivity when there is a plan’s dependence established between the actorsinvolved and in addition one of the actors has intentions that denote a future proactive behavior inthe software. In order to validate the pattern a case study was performed taking as logic of analysis thedevelopment of a proactive dashboard to support the decision making in a college faculty. Based on theresults of the case study, it can be concluded that the proposed pattern allowed modeling the intentionaldependencies between the actors, detecting a proactive behavior and delegating the proactivity in thesystem of software to be developed.

  14. Dramatic impact of the giant local magnetic fields on spin-dependent recombination processes in gadolinium based garnets

    Science.gov (United States)

    Romanov, N. G.; Tolmachev, D. O.; Gurin, A. S.; Uspenskaya, Yu. A.; Asatryan, H. R.; Badalyan, A. G.; Baranov, P. G.; Wieczorek, H.; Ronda, C.

    2015-06-01

    A giant magnetic field effect on spin-dependent recombination of the radiation-induced defects has been found in cerium doped gadolinium based garnet crystals and ceramics, promising materials for scintillator applications. A sharp and strong increase in the afterglow intensity stimulated by external magnetic field and an evidence of the magnetic field memory have been discovered. The effect was ascribed to huge Gd-induced internal magnetic fields, which suppress the recombination, and cross-relaxation with Gd3+ ions leading to reorientation of the spins of the electron and hole centers. Thus, the spin system of radiation-induced defects in gadolinium garnet based scintillator materials was shown to accumulate significant energy which can be released in external magnetic fields.

  15. Dramatic impact of the giant local magnetic fields on spin-dependent recombination processes in gadolinium based garnets

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, N. G., E-mail: nikolai.romanov@mail.ioffe.ru; Tolmachev, D. O.; Gurin, A. S.; Uspenskaya, Yu. A.; Asatryan, H. R.; Badalyan, A. G. [Ioffe Institute, St. Petersburg 194021 (Russian Federation); Baranov, P. G. [Ioffe Institute, St. Petersburg 194021 (Russian Federation); Peter the Great St. Petersburg Polytechnic University, St. Petersburg 195251 (Russian Federation); Wieczorek, H.; Ronda, C. [Philips Research, High Tech Campus 34, 5656 AE Eindhoven (Netherlands)

    2015-06-29

    A giant magnetic field effect on spin-dependent recombination of the radiation-induced defects has been found in cerium doped gadolinium based garnet crystals and ceramics, promising materials for scintillator applications. A sharp and strong increase in the afterglow intensity stimulated by external magnetic field and an evidence of the magnetic field memory have been discovered. The effect was ascribed to huge Gd-induced internal magnetic fields, which suppress the recombination, and cross-relaxation with Gd{sup 3+} ions leading to reorientation of the spins of the electron and hole centers. Thus, the spin system of radiation-induced defects in gadolinium garnet based scintillator materials was shown to accumulate significant energy which can be released in external magnetic fields.

  16. Dependence of ZnO-based dye-sensitized solar cell characteristics on the layer deposition method

    Indian Academy of Sciences (India)

    Anca Dumbrava; Gabriel Prodan; Adrian Georgescu; Florin Moscalu

    2015-02-01

    The selection of a proper method for the semiconductor layer deposition is an important requirement towards a high efficiency for dye-sensitized solar cells (DSSCs). We compared three techniques for deposition of the semiconductor thin layer in ZnO-based DSSCs, in order to determine the dependence between the deposition method, the ZnO film properties and finally the DSSCs characteristics. For this purpose, we varied the method used for deposition of the semiconductor film and we replaced ZnO with Al-doped ZnO. The nanostructured films morphology was analysed by transmission electron microscopy, high-resolution transmission electron microscopy and selected area electron diffraction. The optical properties were examined by UV–visible spectroscopy and the bandgap energies were calculated using the Tauc equation. The higher fill factor value was registered for DSSCs based on the ZnO film obtained by electrochemical method, but the higher efficiency was registered for doctorblading method.

  17. An Age-Dependent Physiologically-Based Pharmacokinetic/Pharmacodynamic Model for the Organophosphorus Insecticide Chlorpyrifos in the Preweanling Rat

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Chuck; Kousba, Ahmed A.; Poet, Torka S.

    2007-08-01

    Juvenile rats are more susceptible than adults to the acute toxicity of organophosphorus insecticides like chlorpyrifos (CPF). Age- and dose-dependent differences in metabolism may be responsible. Of importance is CYP450 activation and detoxification of CPF to chlorpyrifos-oxon (CPF-oxon) and trichloropyridinol (TCP), as well as B-esterase (cholinesterase; ChE) and A-esterase (PON-1) detoxification of CPF-oxon to TCP. In the current study, a modified physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model incorporating age-dependent changes in CYP450, PON-1, and tissue ChE levels for rats was developed. In this model, age was used as a dependent function to estimate body weight which was then used to allometrically scale both metabolism and tissue ChE levels. Model simulations suggest that preweanling rats are particularly sensitive to CPF toxicity, with levels of CPF-oxon in blood and brain disproportionately increasing, relative to the response in adult rats. This age-dependent non-linear increase in CPF-oxon concentration may potentially result from the depletion of non-target B-esterases, and a lower PON-1 metabolic capacity in younger animals. These results indicate that the PBPK/PD model behaves consistently with the general understanding of CPF toxicity, pharmacokinetics and tissue ChE inhibition in neonatal and adult rats. Hence, this model represents an important starting point for developing a computational model to assess the neurotoxic potential of environmentally relevant organophosphate exposures in infants and children.

  18. Framework based on Markov modulated Poisson processes for modeling traffic with long-range dependence

    Science.gov (United States)

    Ferreira Salvador, Paulo J.; Valadas, Rui J. M. T.

    2001-07-01

    This paper proposes a novel fitting procedure for Markov Modulated Poisson Processes (MMPPs), consisting of the superposition of N 2-MMPPs, that is capable of capturing the long-range characteristics of the traffic. The procedure matches both the autocovariance and marginal distribution functions of the rate process. We start by matching each 2-MMPP to a different component of the autocovariance function. We then map the parameters of the model with N individual 2-MMPPs (termed superposed MMPP) to the parameters of the equivalent MMPP with 2N states that results from the superposition of the N individual 2-MMPPs (termed generic MMPP). Finally, the parameters of the generic MMPP are fitted to the marginal distribution, subject to the constraints imposed by the autocovariance matching. Specifically, the matching of the distribution will be restricted by the fact that it may not be possible to decompose a generic MMPP back into individual 2-MMPPs. Overall, our procedure is motivated by the fact that direct relationships can be established between the autocovariance and the parameters of the superposed MMPP and between the marginal distribution and the parameters of the generic MMPP. We apply the fitting procedure to traffic traces exhibiting LRD including (i) IP traffic measured at our institution and (ii) IP traffic traces available in the Internet such as the well known, publicly available, Bellcore traces. The selected traces are representative of a wide range of services/protocols used in the Internet. We assess the fitting procedure by comparing the measured and fitted traces (traces generated from the fitted models) in terms of (i) Hurst parameter; (ii) degree of approximation between the autocovariance and marginal distribution curves; (iii) range of time scales where LRD is observed using a wavelet based estimator and (iv) packet loss ratio suffered in a single buffer for different values of the buffer capacity. Results are very clear in showing that MMPPs

  19. A Derivation of Source-based Kinetics Equation with Time Dependent Fission Kernel for Reactor Transient Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Song Hyun; Woo, Myeong Hyun; Shin, Chang Ho [Hanyang University, Seoul (Korea, Republic of); Pyeon, Cheol Ho [Kyoto University, Osaka (Japan)

    2015-10-15

    In this study, a new balance equation to overcome the problems generated by the previous methods is proposed using source-based balance equation. And then, a simple problem is analyzed with the proposed method. In this study, a source-based balance equation with the time dependent fission kernel was derived to simplify the kinetics equation. To analyze the partial variations of reactor characteristics, two representative methods were introduced in previous studies; (1) quasi-statics method and (2) multipoint technique. The main idea of quasistatics method is to use a low-order approximation for large integration times. To realize the quasi-statics method, first, time dependent flux is separated into the shape and amplitude functions, and shape function is calculated. It is noted that the method has a good accuracy; however, it can be expensive as a calculation cost aspect because the shape function should be fully recalculated to obtain accurate results. To improve the calculation efficiency, multipoint method was proposed. The multipoint method is based on the classic kinetics equation with using Green's function to analyze the flight probability from region r' to r. Those previous methods have been used to analyze the reactor kinetics analysis; however, the previous methods can have some limitations. First, three group variables (r{sub g}, E{sub g}, t{sub g}) should be considered to solve the time dependent balance equation. This leads a big limitation to apply large system problem with good accuracy. Second, the energy group neutrons should be used to analyze reactor kinetics problems. In time dependent problem, neutron energy distribution can be changed at different time. It can affect the change of the group cross section; therefore, it can lead the accuracy problem. Third, the neutrons in a space-time region continually affect the other space-time regions; however, it is not properly considered in the previous method. Using birth history of the

  20. Ligand-based pharmacophore modeling; atom-based 3D-QSAR analysis and molecular docking studies of phosphoinositide-dependent kinase-1 inhibitors

    Directory of Open Access Journals (Sweden)

    P Kirubakaran

    2012-01-01

    Full Text Available Phosphoinositide-dependent kinase-1 plays a vital role in the PI3-kinase signaling pathway that regulates gene expression, cell cycle growth and proliferation. The common human cancers include lung, breast, blood and prostate possess over stimulation of the phosphoinositide-dependent kinase-1 signaling and making phosphoinositide-dependent kinase-1 an interesting therapeutic target in oncology. A ligand-based pharmacophore and atom-based 3D-QSAR studies were carried out on a set of 82 inhibitors of PDK1. A six point pharmacophore with two hydrogen bond acceptors (A, three hydrogen bond donors (D and one hydrophobic group (H was obtained. The pharmacophore hypothesis yielded a 3D-QSAR model with good partial least square statistics results. The training set correlation is characterized by partial least square factors (R2 = 0.9557, SD = 0.2334, F = 215.5, P = 1.407e-32. The test set correlation is characterized by partial least square factors (Q2 ext = 0.7510, RMSE = 0.5225, Pearson-R =0.8676. The external validation indicated that our QSAR model possess high predictive power with good value of 0.99 and value of 0.88. The docking results show the binding orientations of these inhibitors at active site amino acid residues (Ala162, Thr222, Glu209 and Glu166 of phosphoinositide-dependent kinase-1 protein. The binding free energy interactions of protein-ligand complex have been calculated, which plays an important role in molecular recognition and drug design approach.

  1. Dependency Resolution Difficulty Increases with Distance in Persian Separable Complex Predicates: Evidence for Expectation and Memory-Based Accounts.

    Science.gov (United States)

    Safavi, Molood S; Husain, Samar; Vasishth, Shravan

    2016-01-01

    Delaying the appearance of a verb in a noun-verb dependency tends to increase processing difficulty at the verb; one explanation for this locality effect is decay and/or interference of the noun in working memory. Surprisal, an expectation-based account, predicts that delaying the appearance of a verb either renders it no more predictable or more predictable, leading respectively to a prediction of no effect of distance or a facilitation. Recently, Husain et al. (2014) suggested that when the exact identity of the upcoming verb is predictable (strong predictability), increasing argument-verb distance leads to facilitation effects, which is consistent with surprisal; but when the exact identity of the upcoming verb is not predictable (weak predictability), locality effects are seen. We investigated Husain et al.'s proposal using Persian complex predicates (CPs), which consist of a non-verbal element-a noun in the current study-and a verb. In CPs, once the noun has been read, the exact identity of the verb is highly predictable (strong predictability); this was confirmed using a sentence completion study. In two self-paced reading (SPR) and two eye-tracking (ET) experiments, we delayed the appearance of the verb by interposing a relative clause (Experiments 1 and 3) or a long PP (Experiments 2 and 4). We also included a simple Noun-Verb predicate configuration with the same distance manipulation; here, the exact identity of the verb was not predictable (weak predictability). Thus, the design crossed Predictability Strength and Distance. We found that, consistent with surprisal, the verb in the strong predictability conditions was read faster than in the weak predictability conditions. Furthermore, greater verb-argument distance led to slower reading times; strong predictability did not neutralize or attenuate the locality effects. As regards the effect of distance on dependency resolution difficulty, these four experiments present evidence in favor of working memory

  2. Design of Free Parameters of State-Dependent Coefficient Form Based on the Relation between State-Dependent Riccati Inequality and Hamilton Jacobi Inequality

    Science.gov (United States)

    Sakayanagi, Yoshihiro; Nakaura, Shigeki; Sampei, Mitsuji

    The solvable condition of nonlinear H∞ control problems is given by the Hamilton Jacobi inequality (HJI). The state-dependent Riccati inequality (SDRI) is one of the approaches used to solve the HJI. The SDRI contains the state-dependent coefficient (SDC) form of a nonlinear system. The SDC form is not unique. If a poor SDC form is chosen, then there is no solution for the SDRI. In other words, there exist free parameters of the SDC form that affect the solvability of the SDRI. This study focuses on the free parameters of the SDC form. First, a representation of the free parameters of the SDC form is introduced. The solvability of an SDRI is a sufficient condition for that of the related HJI, and the free parameters affect the conservativeness of the SDRI approach. In addition, a new method for designing the free parameters that reduces the conservativeness of the SDRI approach is introduced. Finally, numerical examples to verify the effect of this method are presented.

  3. IC50-based approaches as an alternative method for assessment of time-dependent inhibition of CYP3A4.

    Science.gov (United States)

    Burt, Howard J; Galetin, Aleksandra; Houston, J Brian

    2010-05-01

    The predictive utility of two in vitro methods (empirical IC(50)-based and mechanistic k(inact)/K(I)) for the assessment of time-dependent cytochrome P450 3A4 (CYP3A4) inhibition has been compared. IC(50) values were determined at multiple pre-incubation time points over 30 min for five CYP3A4 time-dependent inhibitors (verapamil, diltiazem, erythromycin, clarithromycin, and azithromycin). The ability of IC(50) data obtained following pre-incubation to predict k(inact)/K(I) parameters was investigated and its utility was assessed relative to the conventional k(inact)/K(I) model using 50 reported clinical drug-drug interactions (DDIs). Models with either hepatic or hepatic with intestinal components were explored. For low/medium potency time-dependent inhibitors, 81% of the predicted k(inact)/K(I(unbound)) from IC(50) data were within an order of magnitude of the actual values, in contrast to 50% of potent inhibitors. An underprediction trend and > 50% of false-negatives were observed when IC(50) data were used in the DDI hepatic prediction model; incorporation of the intestine improved the prediction accuracy. On the contrary, 86% of the DDI studies were predicted within twofold using k(inact)/K(I) mechanistic approach and the combined hepatic and intestinal model. Use of the empirical IC(50) approach as an alternative to the mechanistic k(inact)/K(I) model for in vivo DDI prediction is limited and is best restricted to preliminary investigations.

  4. Cation and anion sizes influence in the temperature dependence of the electrical conductivity in nine imidazolium based ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Vila, J.; Cabeza, O. [Dpto. de Fisica, Fac. de Ciencias, Universidade da Coruna, Campus da Zapateira s/n, 15072 A Coruna (Spain); Varela, L.M. [Dpto. de Fisica, Fac. de Ciencias, Universidade da Coruna, Campus da Zapateira s/n, 15072 A Coruna (Spain); Dpto. de Fisica de la Materia Condensada, Fac. de Fisica, Universidad de Santiago de Compostela, E-15782, Santiago de Compostela (Spain)

    2007-09-30

    In this paper we present experimental data on the temperature dependence of the electrical conductivity, {sigma}, in nine different imidazolium based ionic liquids. We have measured four 1-(alkyl chain)-3-methyl imidazolium tetrafluoroborate (C{sub n}MIM-BF{sub 4}) ionic liquids, with C{sub n} representing ethyl, butyl, hexyl and octyl chains, to study the dependence of {sigma} with the cation length. Moreover, to study the influence of the anion size in the electrical conductivity, we measured six different EMIM-X, with X being, from smaller to bigger sizes, Cl{sup -}, Br{sup -}, BF{sub 4}{sup -}, PF{sub 6}{sup -}, ethyl sulfate and tosylate. The measurements were performed at atmospheric pressure, and the studied temperature range covers the liquid phase of the analyzed compounds. We have fitted the electrical conductivity data of the nine ionic liquids using a Vogel-Tamman-Fulcher (VTF) equation with high precision. We observe from the measured data that the electrical conductivity decreases its value as the alkyl chain of the cation increases. In contrast, we do not observe that dependence with the anion size, where there seems to be an optimal size (that of BF{sub 4}{sup -}) for which {sigma} reaches its maximum value, being lower for smaller or bigger anion sizes. Finally, if we plot the natural logarithm of {sigma} versus the distance in temperature to the glass transition one for each IL, we observe that the resulting straight lines are ordered with the anion (or cation) sizes for all nine compounds measured, i.e., lower {sigma} values for bigger sizes. (author)

  5. Performance study of a PET scanner based on monolithic scintillators for different DoI-dependent methods

    Science.gov (United States)

    Preziosi, E.; Sánchez, S.; González, A. J.; Pani, R.; Borrazzo, C.; Bettiol, M.; Rodriguez-Alvarez, M. J.; González-Montoro, A.; Moliner, L.; Benlloch, J. M.

    2016-12-01

    One of the technical objectives of the MindView project is developing a brain-dedicated PET insert based on monolithic scintillation crystals. It will be inserted in MRI systems with the purpose to obtain simultaneous PET and MRI brain images. High sensitivity, high image quality performance and accurate detection of the Depth-of-Interaction (DoI) of the 511keV photons are required. We have developed a DoI estimation method, dedicated to monolithic scintillators, allowing continuous DoI estimation and a DoI-dependent algorithm for the estimation of the photon planar impact position, able to improve the single module imaging capabilities. In this work, through experimental measurements, the proposed methods have been used for the estimation of the impact positions within the monolithic crystal block. We have evaluated the PET system performance following the NEMA NU 4-2008 protocol by reconstructing the images using the STIR 3D platform. The results obtained with two different methods, providing discrete and continuous DoI information, are compared with those obtained from an algorithm without DoI capabilities and with the ideal response of the detector. The proposed DoI-dependent imaging methods show clear improvements in the spatial resolution (FWHM) of reconstructed images, allowing to obtain values from 2mm (at the center FoV) to 3mm (at the FoV edges).

  6. Polarity dependence of the electrical characteristics of Ag reflectors for high-power GaN-based light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae-Seong; Seong, Tae-Yeon, E-mail: tyseong@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Han, Jaecheon [Department of LED Business, Chip Development Group, LG Innotek, Paju 413-901 (Korea, Republic of); Ha, Jun-Seok [School of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of)

    2014-04-28

    We report on the polarity dependence of the electrical properties of Ag reflectors for high-power GaN-based light-emitting diodes. The (0001) c-plane samples become ohmic after annealing in air. However, the (11–22) semi-polar samples are non-ohmic after annealing, although the 300 °C-annealed sample shows the lowest contact resistivity. The X-ray photoemission spectroscopy (XPS) results show that the Ga 2p core level for the c-plane samples experiences larger shift toward the valence band than that for the semi-polar samples. The XPS depth profile results show that unlike the c-plane samples, the semi-polar samples contain some amounts of oxygen at the Ag/GaN interface regions. The outdiffusion of Ga atoms is far more significant in the c-plane samples than in the semi-polar samples, whereas the outdiffusion of N atoms is relatively less significant in the c-plane samples. On the basis of the electrical and XPS results, the polarity dependence of the electrical properties is described and discussed.

  7. A New User Dependent Iris Recognition System Based on an Area Preserving Pointwise Level Set Segmentation Approach

    Directory of Open Access Journals (Sweden)

    Nakissa Barzegar

    2009-01-01

    Full Text Available This paper presents a new user dependent approach in iris recognition systems. In the proposed method, consistent bits of iris code are calculated, based on the user specifications, using the user's mask. Another contribution of our work is in the iris segmentation phase, where a new pointwise level set approach with area preserving has been used for determining inner and outer iris boundaries, both exclusively performed in one step. Thanks to the special properties of this segmentation technique, there is no constraint about angles of head tilt. Furthermore, we showed that this algorithm is robust in noisy situations and can locate irises which are partly occluded by eyelid and eyelashes. Experimental results, on three renowned iris databases (CASIAIrisV3, Bath, and Ubiris, show that our method outperforms some of the existing methods, both in terms of accuracy and response time.

  8. Single-image-based solution for optics temperature-dependent nonuniformity correction in an uncooled long-wave infrared camera.

    Science.gov (United States)

    Cao, Yanpeng; Tisse, Christel-Loic

    2014-02-01

    In this Letter, we propose an efficient and accurate solution to remove temperature-dependent nonuniformity effects introduced by the imaging optics. This single-image-based approach computes optics-related fixed pattern noise (FPN) by fitting the derivatives of correction model to the gradient components, locally computed on an infrared image. A modified bilateral filtering algorithm is applied to local pixel output variations, so that the refined gradients are most likely caused by the nonuniformity associated with optics. The estimated bias field is subtracted from the raw infrared imagery to compensate the intensity variations caused by optics. The proposed method is fundamentally different from the existing nonuniformity correction (NUC) techniques developed for focal plane arrays (FPAs) and provides an essential image processing functionality to achieve completely shutterless NUC for uncooled long-wave infrared (LWIR) imaging systems.

  9. Structure-Based Design of Potent and Selective 3-Phosphoinositide-Dependent Kinase-1 (PDK1) Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Jesus R.; Becker, Christopher J.; Blackledge, Charles W.; Duquenne, Celine; Feng, Yanhong; Grant, Seth W.; Heerding, Dirk; Li, William H.; Miller, William H.; Romeril, Stuart P.; Scherzer, Daryl; Shu, Arthur; Bobko, Mark A.; Chadderton, Antony R.; Dumble, Melissa; Gardiner, Christine M.; Gilbert, Seth; Liu, Qi; Rabindran, Sridhar K.; Sudakin, Valery; Xiang, Hong; Brady, Pat G.; Campobasso, Nino; Ward, Paris; Axten, Jeffrey M. (GSKPA)

    2014-10-02

    Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.

  10. Analysis of frequency response of high power MUTC photodiodes based on photocurrent-dependent equivalent circuit model.

    Science.gov (United States)

    Li, Jin; Xiong, Bing; Sun, Changzheng; Miao, Di; Luo, Yi

    2015-08-24

    A back-illuminated mesa-structure InGaAs/InP modified uni-traveling-carrier photodiode (MUTC-PD) is fabricated and its frequency response is investigated. A bandwidth of 40 GHz and a saturation photocurrent up to 33 mA are demonstrated. A photocurrent-dependent equivalent circuit model is proposed to analyze the frequency response of the high power MUTC-PDs. The influences of the space-charge screening, self-induced electric field and over-shoot effects are discussed in detail based on the model. Fitted curves obtained from the simple equivalent circuit model are found to be in good agreement with the data measured under different bias voltages and photocurrents.

  11. Resveratrol rescues SIRT1-dependent adult stem cell decline and alleviates progeroid features in laminopathy-based progeria.

    Science.gov (United States)

    Liu, Baohua; Ghosh, Shrestha; Yang, Xi; Zheng, Huiling; Liu, Xinguang; Wang, Zimei; Jin, Guoxiang; Zheng, Bojian; Kennedy, Brian K; Suh, Yousin; Kaeberlein, Matt; Tryggvason, Karl; Zhou, Zhongjun

    2012-12-05

    Abnormal splicing of LMNA gene or aberrant processing of prelamin A results in progeroid syndrome. Here we show that lamin A interacts with and activates SIRT1. SIRT1 exhibits reduced association with nuclear matrix (NM) and decreased deacetylase activity in the presence of progerin or prelamin A, leading to rapid depletion of adult stem cells (ASCs) in Zmpste24(-/-) mice. Resveratrol enhances the binding between SIRT1 and A-type lamins to increases its deacetylase activity. Resveratrol treatment rescues ASC decline, slows down body weight loss, improves trabecular bone structure and mineral density, and significantly extends the life span in Zmpste24(-/-) mice. Our data demonstrate lamin A as an activator of SIRT1 and provide a mechanistic explanation for the activation of SIRT1 by resveratrol. The link between conserved SIRT1 longevity pathway and progeria suggests a stem cell-based and SIRT1 pathway-dependent therapeutic strategy for progeria.

  12. Physiological Signals based Day-Dependence Analysis with Metric Multidimensional Scaling for Sentiment Classification in Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2015-01-01

    Full Text Available The interaction of the affective has emerged in implicit human-computer interaction. Given the physiological signals in the recognition process of the affective, the different positions by which the physiological signal sensors are installed in the body, along with the daily habits and moods of human beings, influence the affective physiological signals. The scalar product matrix was calculated in this study based on metric multidimensional scaling with dissimilarity matrix. Subsequently, the matrix of individual attribute reconstructs was obtained using the principal component factor. The method proposed in this study eliminates day dependence, reduces the effect of time in the physiological signals of the affective, and improves the accuracy of affection classification.

  13. An atomic orbital based real-time time-dependent density functional theory for computing electronic circular dichroism band spectra.

    Science.gov (United States)

    Goings, Joshua J; Li, Xiaosong

    2016-06-21

    One of the challenges of interpreting electronic circular dichroism (ECD) band spectra is that different states may have different rotatory strength signs, determined by their absolute configuration. If the states are closely spaced and opposite in sign, observed transitions may be washed out by nearby states, unlike absorption spectra where transitions are always positive additive. To accurately compute ECD bands, it is necessary to compute a large number of excited states, which may be prohibitively costly if one uses the linear-response time-dependent density functional theory (TDDFT) framework. Here we implement a real-time, atomic-orbital based TDDFT method for computing the entire ECD spectrum simultaneously. The method is advantageous for large systems with a high density of states. In contrast to previous implementations based on real-space grids, the method is variational, independent of nuclear orientation, and does not rely on pseudopotential approximations, making it suitable for computation of chiroptical properties well into the X-ray regime.

  14. Dependence of deformation mechanisms on grain orientations and their changes calculated based on Sachs model in magnesium alloy AZ31

    Institute of Scientific and Technical Information of China (English)

    Qing-ge XIE; Ping YANG; Li MENG

    2008-01-01

    During deformation, the orientation of a grain influences not only the deformation mechanisms (slip or twinning) and the specific selection of activated slip or twinning systems for that grain, but also the kinetics of different types of transformation. Schmid factor analysis was applied to determine the orientation dependency of deformation mechanisms in magnesium alloys AZ31 in this work. The orientation changes after the operation of the specific deformation mechanisms were also calcu-lated based on Sachs model. It was found that different deformation mechanisms proceeded differently according to theoretical predictions. Basal slip occurred when basal planes of grains were tilted toward ND around TD. Prismatic slip dominated when basal planes were approxi-mately perpendicular to TD. Calculation results also indi-cated that the operating of pyramidal slip can not be neglected. {10 12} twinning was favorable when basal planes were approximately normal to RD and { 10 11 } twinning was analyzed to be related to the grains with basal orientations. The operating of slip could greatly suppress the activating of twinning by our Schmid factor analysis. Basal orientations with TD and RD scattering can favor basal slip and tension twinning, respectively, after the operation of compression twinning based on the Schmid factor calculations.

  15. Associations between parental deployment, relocation, and risky sexual behaviors among a clinic-based sample of military-dependent youth.

    Science.gov (United States)

    Hernandez, Belinda F; Peskin, Melissa F; Markham, Christine M; Burr, Jean; Roberts, Timothy; Tortolero, Susan

    2015-10-01

    Although sexual behaviors have been extensively studied among youth in general, they have been relatively understudied among military-dependent youth (MDY). Furthermore, the impact of unique military stressors, such as parental deployment and multiple relocations, on the sexual behaviors of MDY has not been assessed. In this pilot study, we estimated the prevalence of sexual behaviors among MDY, and examined the association between these behaviors and parental deployment and multiple relocations. Between June and September 2011, we recruited youth (N = 208; aged 15-19 years) who attended a military treatment facility in the southern United States, to complete a short, paper-based survey. We computed prevalence estimates and conducted Chi-square analyses, as well as logistic regression analyses, while adjusting for age, gender, and race/ethnicity. More than half (53.7 %) of the youth reported being sexually experienced, and many of these youth reported engaging in risky sexual behaviors. Parental deployment and multiple relocations were significantly associated only with having had sex in the past 3 months. Although with most sexual behaviors there was no significant association between parental deployment and multiple relocations, many MDY are sexually experienced and engage in risky sexual behaviors. MDY should thus be exposed to evidence-based strategies for sexually transmitted infection and pregnancy prevention, as well as provided with teen-friendly health care services and comprehensive sexual/reproductive health counseling.

  16. SVD-Based Technique for Interference Cancellation and Noise Reduction in NMR Measurement of Time-Dependent Magnetic Fields.

    Science.gov (United States)

    Chen, Wenjun; Ma, Hong; Yu, De; Zhang, Hua

    2016-03-04

    A nuclear magnetic resonance (NMR) experiment for measurement of time-dependent magnetic fields was introduced. To improve the signal-to-interference-plus-noise ratio (SINR) of NMR data, a new method for interference cancellation and noise reduction (ICNR) based on singular value decomposition (SVD) was proposed. The singular values corresponding to the radio frequency interference (RFI) signal were identified in terms of the correlation between the FID data and the reference data, and then the RFI and noise were suppressed by setting the corresponding singular values to zero. The validity of the algorithm was verified by processing the measured NMR data. The results indicated that, this method has a significantly suppression of RFI and random noise, and can well preserve the FID signal. At present, the major limitation of the proposed SVD-based ICNR technique is that the threshold value for interference cancellation needs to be manually selected. Finally, the inversion waveform of the applied alternating magnetic field was given by fitting the processed experimental data.

  17. NOTE: Scatter-to-primary based scatter fractions for transmission-dependent convolution subtraction of SPECT images

    Science.gov (United States)

    Larsson, Anne; Johansson, Lennart

    2003-11-01

    In single photon emission computed tomography (SPECT), transmission-dependent convolution subtraction has been shown to be useful when correcting for scattered events. The method is based on convolution subtraction, but includes a matrix of scatter fractions instead of a global scatter fraction. The method can be extended to iteratively improve the scatter estimate, but in this note we show that this requires a modification of the theory to use scatter-to-total scatter fractions for the first iteration only and scatter-to-primary fractions thereafter. To demonstrate this, scatter correction is performed on a Monte Carlo simulated image of a point source of activity in water. The modification of the theory is compared to corrections where the scatter fractions are based on the scatter-to-total ratio, using one and ten iterations. The resulting ratios of subtracted to original counts are compared to the true scatter-to-total ratio of the simulation and the most accurate result is found for our modification of the theory.

  18. Nicotine Dependence

    Science.gov (United States)

    Nicotine dependence Overview By Mayo Clinic Staff Nicotine dependence ― also called tobacco dependence ― is an addiction to tobacco products caused by the drug nicotine. Nicotine dependence means you can't stop using the substance, ...

  19. Relationships between Microstructural Parameters and Time-Dependent Mechanical Properties of a New Nickel-Based Superalloy AD730™

    Directory of Open Access Journals (Sweden)

    Louis Thébaud

    2015-11-01

    Full Text Available High temperature creep and dwell-fatigue properties of the new nickel-based superalloy AD730™ have been investigated. Three microstructures have been studied in creep (850 °C and 700 °C and dwell-fatigue (700 °C stress control with trapezoidal signals, and dwell times ranging from 1 s to 3600 s: a coarse grains microstructure, a fine grains one, and single crystalline samples. The aim of this study is to assess the influence of the grain size on creep and creep-fatigue properties. It is demonstrated that fine and coarse grains microstructures perform similarly in creep at 700 °C, showing that the creep properties at this temperature are controlled by the intragranular precipitation. Moreover, both the coarse grains and the fine grains microstructures show changes in creep deformation mechanisms depending on the applied stress in creep at 700 °C. At higher creep temperatures, the coarse grains microstructure performs better and almost no effect is observed by suppressing grain boundaries. During dwell-fatigue tests at 700 °C, a clear effect of the mechanical cycling has been evidenced on the time to failure on both the coarse and the fine grains microstructures. At high applied stresses, a beneficial effect of the cyclic unloading to the lifetime has been observed whereas at lower applied stresses, mechanical cycling is detrimental compared to the pure creep lifetime due to the development of a fatigue damage. Complex creep-fatigue interactions are hence clearly evidenced and they depend on the pure creep behavior reference.

  20. Employment-based abstinence reinforcement as a maintenance intervention for the treatment of cocaine dependence: post-intervention outcomes

    Science.gov (United States)

    DeFulio, Anthony; Silverman, Kenneth

    2011-01-01

    Aims Due to the chronicity of cocaine dependence, practical and effective maintenance interventions are needed to sustain long-term abstinence. We sought to assess the effects of long-term employment-based reinforcement of cocaine abstinence after discontinuation of the intervention. Design Participants who initiated sustained opiate and cocaine abstinence during a 6-month abstinence reinforcement and training program worked as data entry operators and were randomly assigned to a group that could work independent of drug use (Control, n = 24), or an abstinence-contingent employment (n = 27) group that was required to provide cocaine- and opiate-negative urine samples to work and maintain maximum rate of pay. Setting A nonprofit data entry business. Participants Unemployed welfare recipients who persistently used cocaine while in methadone treatment. Measurements Urine samples and self-reports were collected every six months for 30 months. Findings During the employment year, abstinence-contingent employment participants provided significantly more cocaine-negative samples than controls (82.7% and 54.2%; P = .01, OR = 4.61). During the follow-up year, the groups had similar rates of cocaine-negative samples (44.2% and 50.0%; P = .93), and HIV-risk behaviors. Participants’ social, employment, economic, and legal conditions were similar in the two groups across all phases of the study. Conclusions Employment-based reinforcement effectively maintains long-term cocaine abstinence, but many patients relapse to use when the abstinence contingency is discontinued, even after a year of abstinence-contingent employment. Relapse could be prevented in many patients by leaving employment-based abstinence reinforcement in place indefinitely, which could be facilitated by integrating it into typical workplaces. PMID:21226886

  1. H∞ Filtering for Discrete Markov Jump Singular Systems with Mode-Dependent Time Delay Based on T-S Fuzzy Model

    Directory of Open Access Journals (Sweden)

    Cheng Gong

    2014-01-01

    Full Text Available This paper investigates the H∞ filtering problem of discrete singular Markov jump systems (SMJSs with mode-dependent time delay based on T-S fuzzy model. First, by Lyapunov-Krasovskii functional approach, a delay-dependent sufficient condition on H∞-disturbance attenuation is presented, in which both stability and prescribed H∞ performance are required to be achieved for the filtering-error systems. Then, based on the condition, the delay-dependent H∞ filter design scheme for SMJSs with mode-dependent time delay based on T-S fuzzy model is developed in term of linear matrix inequality (LMI. Finally, an example is given to illustrate the effectiveness of the result.

  2. Inference of hierarchical regulatory network of estrogen-dependent breast cancer through ChIP-based data

    Directory of Open Access Journals (Sweden)

    Parvin Jeffrey

    2010-12-01

    Full Text Available Abstract Background Global profiling of in vivo protein-DNA interactions using ChIP-based technologies has evolved rapidly in recent years. Although many genome-wide studies have identified thousands of ERα binding sites and have revealed the associated transcription factor (TF partners, such as AP1, FOXA1 and CEBP, little is known about ERα associated hierarchical transcriptional regulatory networks. Results In this study, we applied computational approaches to analyze three public available ChIP-based datasets: ChIP-seq, ChIP-PET and ChIP-chip, and to investigate the hierarchical regulatory network for ERα and ERα partner TFs regulation in estrogen-dependent breast cancer MCF7 cells. 16 common TFs and two common new TF partners (RORA and PITX2 were found among ChIP-seq, ChIP-chip and ChIP-PET datasets. The regulatory networks were constructed by scanning the ChIP-peak region with TF specific position weight matrix (PWM. A permutation test was performed to test the reliability of each connection of the network. We then used DREM software to perform gene ontology function analysis on the common genes. We found that FOS, PITX2, RORA and FOXA1 were involved in the up-regulated genes. We also conducted the ERα and Pol-II ChIP-seq experiments in tamoxifen resistance MCF7 cells (denoted as MCF7-T in this study and compared the difference between MCF7 and MCF7-T cells. The result showed very little overlap between these two cells in terms of targeted genes (21.2% of common genes and targeted TFs (25% of common TFs. The significant dissimilarity may indicate totally different transcriptional regulatory mechanisms between these two cancer cells. Conclusions Our study uncovers new estrogen-mediated regulatory networks by mining three ChIP-based data in MCF7 cells and ChIP-seq data in MCF7-T cells. We compared the different ChIP-based technologies as well as different breast cancer cells. Our computational analytical approach may guide biologists to

  3. Employment-based abstinence reinforcement following inpatient detoxification in HIV-positive opioid and/or cocaine-dependent patients.

    Science.gov (United States)

    Dunn, Kelly E; Fingerhood, Michael; Wong, Conrad J; Svikis, Dace S; Nuzzo, Paul; Silverman, Kenneth

    2014-02-01

    Employment-based reinforcement interventions have been used to promote abstinence from drugs among chronically unemployed injection drug users. The current study used an employment-based reinforcement intervention to promote opioid and cocaine abstinence among opioid and/or cocaine-dependent, HIV-positive participants who had recently completed a brief inpatient detoxification. Participants (n = 46) were randomly assigned to an abstinence and work group that was required to provide negative urine samples in order to enter the workplace and to earn incentives for work (n = 16), a work-only group that was permitted to enter the workplace and to earn incentives independent of drug use (n = 15), and a no-voucher control group that did not receive any incentives for working (n = 15) over a 26-week period. The primary outcome was urinalysis-confirmed opioid, cocaine, and combined opioid/cocaine abstinence. Participants were 78% male and 89% African American. Results showed no significant between-groups differences in urinalysis-verified drug abstinence or HIV risk behaviors during the 6-month intervention. The work-only group had significantly greater workplace attendance, and worked more minutes per day when compared to the no-voucher group. Several features of the study design, including the lack of an induction period, setting the threshold for entering the workplace too high by requiring immediate abstinence from several drugs, and increasing the risk of relapse by providing a brief detoxification that was not supported by any continued pharmacological intervention, likely prevented the workplace from becoming established as a reinforcer that could be used to promote drug abstinence. However, increases in workplace attendance have important implications for adult training programs.

  4. Achieving complete nitrogen removal by coupling nitritation-anammox and methane-dependent denitrification: A model-based study.

    Science.gov (United States)

    Chen, Xueming; Guo, Jianhua; Xie, Guo-Jun; Yuan, Zhiguo; Ni, Bing-Jie

    2016-05-01

    The discovery of denitrifying anaerobic methane oxidation (DAMO) processes enables the complete nitrogen removal from wastewater by utilizing the methane produced on site from anaerobic digesters. This model-based study investigated the mechanisms and operational window for efficient nitrogen removal by coupling nitritation-anaerobic ammonium oxidation (Anammox) and methane-dependent denitrification in membrane biofilm reactors (MBfRs). A mathematical model was applied to describe the microbial interactions among Anammox bacteria, DAMO archaea, and DAMO bacteria. The model sufficiently described the batch experimental data from an MBfR containing an Anammox-DAMO biofilm with different feeding nitrogen compositions, which confirmed the validity of the model. The effects of process parameters on the system performance and microbial community structure could therefore be reliably evaluated. The impacts of nitritation produced NO2(-)/NH4(+) ratio, methane supply, biofilm thickness and total nitrogen (TN) surface loading were comprehensively investigated with the model. Results showed that the optimum NO2(-)/NH4(+) ratio produced from nitritation for the Anammox-DAMO biofilm system was around 1.0 in order to achieve the maximum TN removal (over 99.0%), independent on TN surface loading. The corresponding optimal methane supply increased while the associated methane utilization efficiency decreased with the increase of TN surface loading. The cooperation between DAMO organisms and Anammox bacteria played the key role in the TN removal. Based on these results, the proof-of-concept feasibility of a single-stage MBfR coupling nitritation-Anammox-DAMO for complete nitrogen removal was also tested through integrating the model with ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) processes whilst controlling the dissolved oxygen (DO) concentration in the simulated system. The maximum TN removal was found to be achieved at the bulk DO concentration of

  5. Linear-Scaling Time-Dependent Density Functional Theory Based on the Idea of "From Fragments to Molecule".

    Science.gov (United States)

    Wu, Fangqin; Liu, Wenjian; Zhang, Yong; Li, Zhendong

    2011-11-08

    To circumvent the cubic scaling and convergence difficulties encountered in the standard top-down localization of the global canonical molecular orbitals (CMOs), a bottom-up localization scheme is proposed based on the idea of "from fragments to molecule". That is, the global localized MOs (LMOs), both occupied and unoccupied, are to be synthesized from the primitive fragment LMOs (pFLMOs) obtained from subsystem calculations. They are orthonormal but are still well localized on the parent fragments of the pFLMOs and can hence be termed as "fragment LMOs" (FLMOs). This has been achieved by making use of two important factors. Physically, it is the transferability of the locality of the fragments that serves as the basis. Mathematically, it is the special block-diagonalization of the Kohn-Sham matrix that allows retention of the locality: The occupied-occupied and virtual-virtual diagonal blocks are only minimally modified when the occupied-virtual off-diagonal blocks are annihilated. Such a bottom-up localization scheme is applicable to systems composed of all kinds of chemical bonds. It is then shown that, by a simple prescreening of the particle-hole pairs, the FLMO-based time-dependent density functional theory (TDDFT) can achieve linear scaling with respect to the system size, with a very small prefactor. As a proof of principle, representative model systems are taken as examples to demonstrate the accuracy and efficiency of the algorithms. As both the orbital picture and integral number of electrons are retained, the FLMO-TDDFT offers a clear characterization of the nature of the excited states in line with chemical/physical intuition.

  6. Organogels based on 12-hydroxy stearic acid as a leitmotif: Dependence of gelation properties on chemical modifications.

    Science.gov (United States)

    Burkhardt, Markus; Noirez, Laurence; Gradzielski, Michael

    2016-03-15

    Various compounds based on the structural leitmotif of 12-hydroxy stearic acid (HSA) were studied with respect to their ability to form organogels. They were modified by ethoxylation in order to avoid the acid group of HSA, which is unwanted for many of the applications of organogels. In this paper, it is shown that the rheological performance of organogels depends strongly on the extent of ethoxylation, exhibiting an optimum at intermediate degrees of ethoxylation. Furthermore, we reveal that the ability for gelation as well as the mechanical properties are substantially reduced by the presence of stearic acid (SA) in the original reaction mixture, which is a typical contamination of HSA. This is quantified by the amount of gelator required for gelation and the elastic moduli observed for the gels. At the same time the mesoscopic structure, as probed by small-angle neutron scattering (SANS), is almost unchanged for different degrees of ethoxylation or the addition of SA--and similarly thick fibres are observed, while the viscoelastic parameters evolve. Accordingly the elastic efficiency of the individual structural units is responsible for the observed changes in the gelation properties. These findings are relevant for the application of such low molecular weight organogelators in practical formulations, as one can optimise the rheological properties of organogelators by appropriately choosing the degree of ethoxylation.

  7. Fabrication of novel microstructures based on orientation-dependent adsorption of surfactant molecules in a TMAH solution

    Science.gov (United States)

    Pal, Prem; Sato, K.; Gosalvez, M. A.; Tang, B.; Hida, H.; Shikida, M.

    2011-01-01

    In this work, the orientation-dependent adsorption of surfactant molecules on the silicon surface during etching in surfactant-added tetramethylammonium hydroxide (TMAH) is investigated. Triton X-100 (C14H22O(C2H4O)n, n = 9-10) and 25 wt% TMAH are used as surfactant and main etchant, respectively. The crystallographic planes affected by the surfactant molecules are determined by analyzing the etching behavior of different mask patterns on Si{1 0 0} wafers and silicon hemispheres in pure and surfactant-added TMAH. Taken together, the shapes of the etched profiles and the analysis of the hemispherical etch rates confirm that thick and dense adsorbed surfactant layers are typically formed on both the exact and vicinal Si{1 1 0} surfaces. In addition, the results indicate that the adsorbed surfactant layer behaves as a permeable mask, partially slowing down the etch rate of the affected surface orientation/s and thus enforcing their appearance on the etching front. The peculiar etching properties of surfactant-added and surfactant-free TMAH are then utilized for the fabrication of advanced micromechanical structures with new shapes on Si{1 0 0} wafers and polydimethylsiloxane based on complex Si{1 0 0} molds.

  8. A New Approach for Combining Time-of-Flight and RGB Cameras Based on Depth-Dependent Planar Projective Transformations

    Directory of Open Access Journals (Sweden)

    Carlota Salinas

    2015-09-01

    Full Text Available Image registration for sensor fusion is a valuable technique to acquire 3D and colour information for a scene. Nevertheless, this process normally relies on feature-matching techniques, which is a drawback for combining sensors that are not able to deliver common features. The combination of ToF and RGB cameras is an instance that problem. Typically, the fusion of these sensors is based on the extrinsic parameter computation of the coordinate transformation between the two cameras. This leads to a loss of colour information because of the low resolution of the ToF camera, and sophisticated algorithms are required to minimize this issue. This work proposes a method for sensor registration with non-common features and that avoids the loss of colour information. The depth information is used as a virtual feature for estimating a depth-dependent homography lookup table (Hlut. The homographies are computed within sets of ground control points of 104 images. Since the distance from the control points to the ToF camera are known, the working distance of each element on the Hlut is estimated. Finally, two series of experimental tests have been carried out in order to validate the capabilities of the proposed method.

  9. Low-temperature-dependent property in an avalanche photodiode based on GaN/AlN periodically-stacked structure

    Science.gov (United States)

    Zheng, Jiyuan; Wang, Lai; Yang, Di; Yu, Jiadong; Meng, Xiao; Hao, Zhibiao; Sun, Changzheng; Xiong, Bing; Luo, Yi; Han, Yanjun; Wang, Jian; Li, Hongtao; Li, Mo; Li, Qian

    2016-01-01

    In ultra-high sensitive APDs, a vibrate of temperature might bring a fatal decline of the multiplication performance. Conventional method to realize a temperature-stable APD focuses on the optimization of device structure, which has limited effects. While in this paper, a solution by reducing the carrier scattering rate based on an GaN/AlN periodically-stacked structure (PSS) APD is brought out to improve temperature stability essentially. Transport property is systematically investigated. Compared with conventional GaN homojunction (HJ) APDs, electron suffers much less phonon scatterings before it achieves ionization threshold energy and more electrons occupy high energy states in PSS APD. The temperature dependence of ionization coefficient and energy distribution is greatly reduced. As a result, temperature stability on gain is significantly improved when the ionization happens with high efficiency. The change of gain for GaN (10 nm)/AlN (10 nm) PSS APD from 300 K to 310 K is about 20% lower than that for HJ APD. Additionally, thicker period length is found favorable to ionization coefficient ratio but a bit harmful to temperature stability, while increasing the proportion of AlN at each period in a specific range is found favorable to both ionization coefficient ratio and temperature stability. PMID:27775088

  10. Theoretical and experimental studies of distance dependent response of micro-ring resonator-based ultrasonic detectors for photoacoustic microscopy.

    Science.gov (United States)

    Zhang, Zhen; Dong, Biqin; Li, Hao; Zhou, Fan; Zhang, Hao F; Sun, Cheng

    2014-10-14

    We present in this paper a systematic study of the distance dependent detection characteristics of the newly developed micro-ring resonator (MRR)-based ultrasonic detector for photoacoustic microscopy (PAM). A simple analytic model was first developed to study the steady-state response to the continuous ultrasonic waves. While placing the MRR detector at the acoustic far-field provides longer working distance and broader field of view, the detection at acoustic near-field offers the improved sensitivity and broader bandwidth but at the cost of reduction in the field of view. Furthermore, a numerical model was developed to analyze the transient response to the photoacoustic-induced impulsive waves. Notably, far-field detection exhibits a flat wavefront of its response pattern in the time domain while large distortions are clearly visible in the case of near-field detection. Finally, both analytic and numerical models are validated by experimental studies. This work establishes a theoretical framework for quantitatively analyzing the trade-offs between near-field and far-field detection using MRR detector, creating a guideline for optimizing the PAM for various applications in biomedical imaging and diagnostics.

  11. Dependence of the appearance-based perception of criminality, suggestibility, and trustworthiness on the level of pixelation of facial images.

    Science.gov (United States)

    Nurmoja, Merle; Eamets, Triin; Härma, Hanne-Loore; Bachmann, Talis

    2012-10-01

    While the dependence of face identification on the level of pixelation-transform of the images of faces has been well studied, similar research on face-based trait perception is underdeveloped. Because depiction formats used for hiding individual identity in visual media and evidential material recorded by surveillance cameras often consist of pixelized images, knowing the effects of pixelation on person perception has practical relevance. Here, the results of two experiments are presented showing the effect of facial image pixelation on the perception of criminality, trustworthiness, and suggestibility. It appears that individuals (N = 46, M age = 21.5 yr., SD = 3.1 for criminality ratings; N = 94, M age = 27.4 yr., SD = 10.1 for other ratings) have the ability to discriminate between facial cues ndicative of these perceived traits from the coarse level of image pixelation (10-12 pixels per face horizontally) and that the discriminability increases with a decrease in the coarseness of pixelation. Perceived criminality and trustworthiness appear to be better carried by the pixelized images than perceived suggestibility.

  12. Black carbon and wavelength-dependent aerosol absorption in the North China Plain based on two-year aethalometer measurements

    Science.gov (United States)

    Ran, L.; Deng, Z. Z.; Wang, P. C.; Xia, X. A.

    2016-10-01

    Light-absorbing components of atmospheric aerosols have gained particular attention in recent years due to their climatic and environmental effects. Based on two-year measurements of aerosol absorption at seven wavelengths, aerosol absorption properties and black carbon (BC) were investigated in the North China Plain (NCP), one of the most densely populated and polluted regions in the world. Aerosol absorption was stronger in fall and the heating season (from November to March) than in spring and summer at all seven wavelengths. Similar spectral dependence of aerosol absorption was observed in non-heating seasons despite substantially strong absorption in fall. With an average absorption Angström exponent (α) of 1.36 in non-heating seasons, freshly emitted BC from local fossil fuel burning was thought to be the major component of light-absorbing aerosols. In the heating season, strong ultraviolet absorption led to an average α of 1.81, clearly indicating the importance of non-BC light-absorbing components, which were possibly from coal burning for domestic heating and aging processes on a regional scale. Diurnally, the variation of BC mass concentrations experienced a double-peak pattern with a higher level at night throughout the year. However, the diurnal cycle of α in the heating season was distinctly different from that in non-heating seasons. α peaked in the late afternoon in non-heating seasons with concomitantly observed low valley in BC mass concentrations. In contrast, α peaked around the midnight in the heating season and lowered down during the daytime. The relationship of aerosol absorption and winds in non-heating seasons also differed from that in the heating season. BC mass concentrations declined while α increased with increasing wind speed in non-heating seasons, which suggested elevated non-BC light absorbers in transported aged aerosols. No apparent dependence of α on wind speed was found in the heating season, probably due to well mixed

  13. O⁶-carboxymethylguanine in DNA forms a sequence context-dependent wobble base-pair structure with thymine.

    Science.gov (United States)

    Zhang, Fang; Tsunoda, Masaru; Kikuchi, Yuji; Wilkinson, Oliver; Millington, Christopher L; Margison, Geoffrey P; Williams, David M; Takénaka, Akio

    2014-06-01

    N-Nitrosation of glycine and its derivatives generates potent alkylating agents that can lead to the formation of O(6)-carboxymethylguanine (O(6)-CMG) in DNA. O(6)-CMG has been identified in DNA derived from human colon tissue and its occurrence has been linked to diets high in red and processed meats, implying an association with the induction of colorectal cancer. By analogy to O(6)-methylguanine, O(6)-CMG is expected to be mutagenic, inducing G-to-A mutations that may be the molecular basis of increased cancer risk. Previously, the crystal structure of the DNA dodecamer d(CGCG[O(6)-CMG]ATTCGCG) has been reported, in which O(6)-CMG forms a Watson-Crick-type pair with thymine similar to the canonical A:T pair. In order to further investigate the versatility of O(6)-CMG in base-pair formation, the structure of the DNA dodecamer d(CGC[O(6)-CMG]AATTTGCG) containing O(6)-CMG at a different position has been determined by X-ray crystallography using four crystal forms obtained under conditions containing different solvent ions (Sr(2+), Ba(2+), Mg(2+), K(+) or Na(+)) with and without Hoechst 33258. The most striking finding is that the pairing modes of O(6)-CMG with T are quite different from those previously reported. In the present dodecamer, the T bases are displaced (wobbled) into the major groove to form a hydrogen bond between the thymine N(3) N-H and the carboxyl group of O(6)-CMG. In addition, a water molecule is bridged through two hydrogen bonds between the thymine O(2) atom and the 2-amino group of O(6)-CMG to stabilize the pairing. These interaction modes commonly occur in the four crystal forms, regardless of the differences in crystallization conditions. The previous and the present results show that O(6)-CMG can form a base pair with T in two alternative modes: the Watson-Crick type and a high-wobble type, the nature of which may depend on the DNA-sequence context.

  14. Size dependent electrochemical detection of trace heavy metal ions based on nano-patterned carbon sphere electrodes

    Science.gov (United States)

    Zhang, Lu-Hua; Li, Wen-Cui; Yan, Dong; Wang, Hua; Lu, An-Hui

    2016-07-01

    The challenge in efficient electrochemical detection of trace heavy metal ions (HMI) for early warning is to construct an electrode with a nano-patterned architecture. In this study, a range of carbon electrodes with ordered structures were fabricated using colloidal hollow carbon nanospheres (HCSs) as sensing materials for trace HMI (represented by Pb(ii)) detection by square wave anodic stripping voltammetry. The regular geometrical characteristics of the carbon electrode allow it to act as a model system for the estimation of electron transfer pathways by calculating contact points between HCSs and a glassy carbon electrode. A clear correlation between the contact points and the electron transfer resistance has been established, which fits well with the quadratic function model and is dependent on the size of HCSs. To our knowledge, this is the first clear function that expresses the structure-sensing activity relationship of carbon-based electrodes. The prepared carbon electrode is capable of sensing Pb(ii) with a sensitivity of 0.160 μA nM-1, which is much higher than those of other electrodes reported in the literature. Its detection limit of 0.6 nM is far below the guideline value (72 nM) given by the US Environmental Protection Agency. In addition, the carbon electrode could be a robust alternative to various heavy metal sensors.The challenge in efficient electrochemical detection of trace heavy metal ions (HMI) for early warning is to construct an electrode with a nano-patterned architecture. In this study, a range of carbon electrodes with ordered structures were fabricated using colloidal hollow carbon nanospheres (HCSs) as sensing materials for trace HMI (represented by Pb(ii)) detection by square wave anodic stripping voltammetry. The regular geometrical characteristics of the carbon electrode allow it to act as a model system for the estimation of electron transfer pathways by calculating contact points between HCSs and a glassy carbon electrode. A

  15. Development of a Subcell Based Modeling Approach for Modeling the Architecturally Dependent Impact Response of Triaxially Braided Polymer Matrix Composites

    Science.gov (United States)

    Sorini, Chris; Chattopadhyay, Aditi; Goldberg, Robert K.; Kohlman, Lee W.

    2016-01-01

    Understanding the high velocity impact response of polymer matrix composites with complex architectures is critical to many aerospace applications, including engine fan blade containment systems where the structure must be able to completely contain fan blades in the event of a blade-out. Despite the benefits offered by these materials, the complex nature of textile composites presents a significant challenge for the prediction of deformation and damage under both quasi-static and impact loading conditions. The relatively large mesoscale repeating unit cell (in comparison to the size of structural components) causes the material to behave like a structure rather than a homogeneous material. Impact experiments conducted at NASA Glenn Research Center have shown the damage patterns to be a function of the underlying material architecture. Traditional computational techniques that involve modeling these materials using smeared homogeneous, orthotropic material properties at the macroscale result in simulated damage patterns that are a function of the structural geometry, but not the material architecture. In order to preserve heterogeneity at the highest length scale in a robust yet computationally efficient manner, and capture the architecturally dependent damage patterns, a previously-developed subcell modeling approach where the braided composite unit cell is approximated as a series of four adjacent laminated composites is utilized. This work discusses the implementation of the subcell methodology into the commercial transient dynamic finite element code LS-DYNA (Livermore Software Technology Corp.). Verification and validation studies are also presented, including simulation of the tensile response of straight-sided and notched quasi-static coupons composed of a T700/PR520 triaxially braided [0deg/60deg/-60deg] composite. Based on the results of the verification and validation studies, advantages and limitations of the methodology as well as plans for future work

  16. Proposed mechanistic description of dose-dependent BDE-47 urinary elimination in mice using a physiologically based pharmacokinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Emond, Claude, E-mail: claude.emond@umontreal.ca [BioSimulation Consulting Inc., Newark, DE (United States); Departments of Environmental and Occupational Health, Medicine Faculty, University of Montreal, Montreal, Quebec (Canada); Sanders, J. Michael, E-mail: sander10@mail.nih.gov [National Cancer Institute, Research Triangle Park, NC (United States); Wikoff, Daniele, E-mail: dwikoff@toxstrategies.com [ToxStrategies, Austin, TX (United States); Birnbaum, Linda S., E-mail: birnbaumls@niehs.nih.gov [National Cancer Institute, Research Triangle Park, NC (United States)

    2013-12-01

    Polybrominated diphenyl ethers (PBDEs) have been used in a wide variety of consumer applications as additive flame retardants. In North America, scientists have noted continuing increases in the levels of PBDE congeners measured in human serum. Some recent studies have found that PBDEs are associated with adverse health effects in humans, in experimental animals, and wildlife. This laboratory previously demonstrated that urinary elimination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) is saturable at high doses in mice; however, this dose-dependent urinary elimination has not been observed in adult rats or immature mice. Thus, the primary objective of this study was to examine the mechanism of urinary elimination of BDE-47 in adult mice using a physiologically based pharmacokinetic (PBPK) model. To support this objective, additional laboratory data were collected to evaluate the predictions of the PBPK model using novel information from adult multi-drug resistance 1a/b knockout mice. Using the PBPK model, the roles of mouse major urinary protein (a blood protein carrier) and P-glycoprotein (an apical membrane transporter in proximal tubule cells in the kidneys, brain, intestines, and liver) were investigated in BDE-47 elimination. The resulting model and new data supported the major role of m-MUP in excretion of BDE-47 in the urine of adult mice, and a lesser role of P-gp as a transporter of BDE-47 in mice. This work expands the knowledge of BDE-47 kinetics between species and provides information for determining the relevancy of these data for human risk assessment purposes. - Highlights: • We report the first study on PBPK model on flame retardant in mice for BDE-47. • We examine mechanism of urinary elimination of BDE-47 in mice using a PBPK model. • We investigated roles of m-MUP and P-gp as transporters in urinary elimination.

  17. Fabrication and investigation on field-dependent properties of natural rubber based magneto-rheological elastomer isolator

    Science.gov (United States)

    Ain Abd Wahab, Nurul; Amri Mazlan, Saiful; Ubaidillah; Kamaruddin, Shamsul; Intan Nik Ismail, Nik; Choi, Seung-Bok; Haziq Rostam Sharif, Amirul

    2016-10-01

    This study presents a laminated magnetorheological elastomer (MRE) isolator which applies to vibration control in practice. The proposed isolator is fabricated with multilayer MRE sheets associated with the natural rubber (NR) as a matrix, and steel plates. The fabricated MRE isolator is then magnetically analysed to achieve high magnetic field intensity which can produce high damping force required for effective vibration control. Subsequently, the NR-based MRE specimen is tested to identify the field-dependent rheological properties such as storage modulus with 60 weight percentage of carbonyl iron particles. It is shown from this test that the MR effect of MRE specimen is quantified to reach up to 120% at 0.8 T. Following the design stage, the electromagnetic simulation using the finite element method magnetic (FEMM) software is carried out for analysing the magnetic flux distribution in the laminated MRE isolator. The laminated MRE isolator is then examined to a series of compression for static and dynamic test under various applied currents using the dynamic fatigue machine and biaxial dynamic testing machine. It is shown that the static compression force is increased by 14.5% under strong magnetic field compared to its off-state. Meanwhile, the dynamic compression test results show that the force increase of the laminated MRE isolator is up to 16% and 7% for low and high frequency respectively. From the results presented in this work, it is demonstrated that the full-scale concept of the MRE isolator can be one of the potential candidates for vibration control applications by tunability of the dynamic stiffness.

  18. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  19. Systems dependability assessment

    CERN Document Server

    Aubry, Jean-François

    2015-01-01

    Presents recent developments of probabilistic assessment of systems dependability based on stochastic models, including graph theory, finite state automaton and language theory, for both dynamic and hybrid contexts.

  20. Near-infrared spectroscopy (NIRS - electroencephalography (EEG based brain-state dependent electrotherapy (BSDE: A computational approach based on excitation-inhibition balance hypothesis

    Directory of Open Access Journals (Sweden)

    Snigdha Dagar

    2016-08-01

    Full Text Available Stroke is the leading cause of severe chronic disability and the second cause of death worldwide with 15 million new cases and 50 million stroke survivors. The post stroke chronic disability may be ameliorated with early neuro rehabilitation where non-invasive brain stimulation (NIBS techniques can be used as an adjuvant treatment to hasten the effects. However, the heterogeneity in the lesioned brain will require individualized NIBS intervention where innovative neuroimaging technologies of portable electroencephalography (EEG and functional-near-infrared spectroscopy (fNIRS can be leveraged for Brain State Dependent Electrotherapy (BSDE. In this hypothesis and theory article, we propose a computational approach based on excitation-inhibition (E-I balance hypothesis to objectively quantify the post stroke individual brain state using online fNIRS-EEG joint imaging. One of the key events that occurs following Stroke is the imbalance in local excitation-inhibition (that is the ratio of Glutamate/GABA which may be targeted with NIBS using a computational pipeline that includes individual forward models to predict current flow patterns through the lesioned brain or brain target region. The current flow will polarize the neurons which can be captured with excitation-inhibition based brain models. Furthermore, E-I balance hypothesis can be used to find the consequences of cellular polarization on neuronal information processing which can then be implicated in changes in function. We first review evidence that shows how this local imbalance between excitation-inhibition leading to functional dysfunction can be restored in targeted sites with NIBS (Motor Cortex, Somatosensory Cortex resulting in large scale plastic reorganization over the cortex, and probably facilitating recovery of functions. Secondly, we show evidence how BSDE based on inhibition–excitation balance hypothesis may target a specific brain site or network as an adjuvant treatment

  1. Wavelength-Dependent Transient Characteristics Caused by Gain Saturation in Highly Nonlinear Fiber-Based Raman Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Shinobu; Tamaoki; Tetsufumi; Tsuzaki; Motoki; Kakui; Masayuki; Shigematsu

    2003-01-01

    We have investigated the transient characteristics of discrete Raman Amplifiers and found that the response time caused by gain saturation is dependent upon the wavelength, which corresponds to the effective length of the pump light.

  2. 基于API依赖关系的代码相似度分析%Code Similarity Analysis Based on API Dependence Relation

    Institute of Scientific and Technical Information of China (English)

    姚新磊; 庞建民; 岳峰; 余勇

    2013-01-01

    Aiming at the problem of API feature obfuscation caused by API noise and API rearrangement which traditional System Call Dependence Graph(SCDG) can not eliminate, this paper presents a malicious code similarity analysis method based on API dependence. The method uses a program behavior description based on SCDG composed of control dependence and four types of data dependence between APIs. API noise and API rearrangement are eliminated through data dependence analysis and control dependence normalization. Experimental results show that, compared with API sequence similarity analysis method, this method significantly improves the accuracy of the similarity analysis of malicious code.%针对传统系统调用依赖图(SCDG)不能很好地消除API噪声、API重排等API特征混淆的问题,提出一种基于API依赖关系的恶意代码相似度分析方法.采用由API控制依赖关系和4类数据依赖关系组成的SCDG程序行为描述方式,通过数据依赖关系分析和控制依赖关系归一化,消除SCDG中的API噪声和API重排.实验结果表明,与API序列相似度分析方式相比,该方法能提高恶意代码相似度分析的准确性.

  3. Time-dependent multiconfiguration self-consistent-field method based on occupation restricted multiple active space model for multielectron dynamics in intense laser fields

    CERN Document Server

    Sato, Takeshi

    2014-01-01

    The time-dependent multiconfiguration self-consistent-field method based on the occupation-restricted multiple active space model is proposed (TD-ORMAS) for multielectron dynamics in intense laser fields. Extending the previously proposed time-dependent complete-active-space self-consistent-field method [TD-CASSCF; Phys. Rev. A, {\\bf 88}, 023402 (2013)], which divides the occupied orbitals into core and active orbitals, the TD-ORMAS method {\\it further} subdivides the active orbitals into an arbitrary number of subgroups, and poses the {\\it occupation restriction} by giving the minimum and maximum number of electrons distributed in each subgroup. This enables highly flexible construction of the configuration interaction (CI) space, allowing a large-active-space simulation of dynamics, e.g., the core excitation or ionization. The equations of motion both for CI coefficients and spatial orbitals are derived based on the time-dependent variational principle, and an efficient algorithm is proposed to solve for th...

  4. Diversity of endophytic bacteria of Dendrobium officinale based on culture-dependent and culture-independent methods

    Directory of Open Access Journals (Sweden)

    Cong Pei

    2017-01-01

    Full Text Available Culture-dependent and culture-independent methods were compared and evaluated in the study of the endophytic diversity of Dendrobium officinale. Culture-independent methods consisted of polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE and metagenome methods. According to the results, differences were found between the three methods. Three phyla, namely Firmicutes, Proteobacteria, and Actinobacteria, were detected using the culture-dependent method, and two phyla, Firmicutes and Proteobacteria, were detected by the DGGE method. Using the metagenome method, four major phyla were determined, including Proteobacteria (76.54%, Actinobacteria (18.56%, Firmicutes (2.27%, and Bacteroidetes (1.56%. A distinct trend was obtained at the genus level in terms of the method and the corresponding number of genera determined. There were 449 genera and 16 genera obtained from the metagenome and DGGE methods, respectively, and only 7 genera were obtained through the culture-dependent method. By comparison, all the genera from the culture-dependent and DGGE methods were contained in the members determined using the metagenome method. Overall, culture-dependent methods are limited to ‘finding’ endophytic bacteria in plants. DGGE is an alternative to investigating primary diversity patterns; however, the metagenome method is still the best choice for determining the endophytic profile in plants. It is essential to use multiphasic approaches to study cultured and uncultured microbes.

  5. Regarding the use and misuse of retinal protonated Schiff base photochemistry as a test case for time-dependent density-functional theory

    NARCIS (Netherlands)

    Valsson, O.; Filippi, C.; Casida, M.E.

    2015-01-01

    The excited-state relaxation of retinal protonated Schiff bases (PSBs) is an important test case for biological applications of time-dependent (TD) density-functional theory (DFT). While well-known shortcomings of approximate TD-DFT might seem discouraging for application to PSB relaxation, progress

  6. On-Chip Scan-Based Test Strategy for a Dependable Many-Core Processor Using a NoC as a Test Access Mechanism

    NARCIS (Netherlands)

    Zhang, Xiao; Kerkhoff, Hans G.; Vermeulen, Bart

    2010-01-01

    Periodic on-chip scan-based tests have to be applied to a many-core processor SoC to improve its dependability. An infrastructural IP module has been designed and incorporated into the SoC to function as an ATE. This paper introduces the reuse of a Network-on-Chip as a test access mechanism. Since t

  7. Explicit symplectic algorithms based on generating functions for relativistic charged particle dynamics in time-dependent electromagnetic field

    CERN Document Server

    Zhang, Ruili; He, Yang; Xiao, Jianyuan; Liu, Jian; Qin, Hong; Tang, Yifa

    2016-01-01

    Relativistic dynamics of a charged particle in time-dependent electromagnetic fields has theoretical significance and a wide range of applications. It is often multi-scale and requires accurate long-term numerical simulations using symplectic integrators. For modern large-scale particle simulations in complex, time-dependent electromagnetic field, explicit symplectic algorithms are much more preferable. In this paper, we treat the relativistic dynamics of a particle as a Hamiltonian system on the cotangent space of the space-time, and construct for the first time explicit symplectic algorithms for relativistic charged particles of order 2 and 3 using the sum-split technique and generating functions.

  8. A Randomized Trial of Extended Telephone-Based Continuing Care for Alcohol Dependence: Within-Treatment Substance Use Outcomes

    Science.gov (United States)

    McKay, James R.; Van Horn, Deborah H. A.; Oslin, David W.; Lynch, Kevin G.; Ivey, Megan; Ward, Kathleen; Drapkin, Michelle L.; Becher, Julie R.; Coviello, Donna M.

    2010-01-01

    Objective: The study tested whether adding up to 18 months of telephone continuing care, either as monitoring and feedback (TM) or longer contacts that included counseling (TMC), to intensive outpatient programs (IOPs) improved outcomes for alcohol-dependent patients. Method: Participants (N = 252) who completed 3 weeks of IOP were randomized to…

  9. Bias-voltage dependence of perpendicular spin-transfer torque in asymmetric MgO-based magnetic tunnel junctions

    KAUST Repository

    Oh, Se Chung

    2009-10-25

    Spin-transfer torque (STT) allows the electrical control of magnetic states in nanostructures. The STT in magnetic tunnel junctions (MTJs) is of particular importance owing to its potential for device applications. It has been demonstrated that the MTJ has a sizable perpendicular STT (, field-like torque), which substantially affects STT-driven magnetization dynamics. In contrast to symmetric MTJs where the bias dependence of is quadratic, it is theoretically predicted that the symmetry breaking of the system causes an extra linear bias dependence. Here, we report experimental results that are consistent with the predicted linear bias dependence in asymmetric MTJs. The linear contribution is quite significant and its sign changes from positive to negative as the asymmetry is modified. This result opens a way to design the bias dependence of the field-like term, which is useful for device applications by allowing, in particular, the suppression of the abnormal switching-back phenomena. © 2009 Macmillan Publishers Limited. All rights reserved.

  10. Structural and frequency dependencies of a.c. and dielectric characterizations of epitaxial InSb-based heterojunctions

    Indian Academy of Sciences (India)

    A ASHERY; A H ZAKI; M HUSSIEN MOURAD; A M AZAB; A A M FARAG

    2016-08-01

    In this work, heterojunction of InSb/InP was grown by liquid phase epitaxy (LPE). Surface morphology and crystalline structure of the heterojunction were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The frequency and temperature dependences of a.c. conductivity and dielectric properties of the heterojunctions were investigated in the ranges of 100 kHz–5 MHz and 298–628 K, respectively. The a.c. conductivity and its frequency exponents were interpreted in terms of correlated barrier hopping model (CBH), as the dominant conduction mechanism for charge carrier transport. The calculated activation energy, from the Arrhenius plot, was found to decrease with increasing frequency. Experimental results of both dielectric constant $\\epsilon_1$ and dielectric loss $\\epsilon_2$ showed a remarkable dependence of both frequency and temperature.

  11. Length dependence of the thermal conductance of alkane-based single-molecule junctions: An ab initio study

    Science.gov (United States)

    Klöckner, J. C.; Bürkle, M.; Cuevas, J. C.; Pauly, F.

    2016-11-01

    Motivated by recent experiments, we present here a systematic ab initio study of the length dependence of the thermal conductance of single-molecule junctions. We make use of a combination of density functional theory with nonequilibrium Green's function techniques to investigate the length dependence of the phonon transport in single-alkane chains, contacted with gold electrodes via both thiol and amine anchoring groups. Additionally, we study the effect of the substitution of the hydrogen atoms in the alkane chains by heavier fluorine atoms to form polytetrafluoroethylenes. Our results demonstrate that (i) the room-temperature thermal conductance is fairly length independent for chains with more than 5 methylene units and (ii) the efficiency of the thermal transport is strongly influenced by the strength of the phononic metal-molecule coupling. Our study sheds light on the phonon transport in molecular junctions, and it provides clear guidelines for the design of molecular junctions for thermal management.

  12. Age-specific, density-dependent and environment-based mortality of a short-lived perennial herb

    OpenAIRE

    Picó, F Xavier; Retana, Javier

    2008-01-01

    Density-independent and density-dependent processes affect plant mortality. Although less well understood, age-specific mortality can also play an important role in plant mortality. The goal of this study was to analyse sev- eral factors accounting for mortality in the Mediterranean short-lived peren- nial herb Lobularia maritima. We followed three cohorts of plants (from emergence to death) during 4 years in field conditions. We collected data on plant mortality ...

  13. Improving autocorrelation regression for the Hurst parameter estimation of long-range dependent time series based on golden section search

    Science.gov (United States)

    Li, Ming; Zhang, Peidong; Leng, Jianxing

    2016-03-01

    This article presents an improved autocorrelation correlation function (ACF) regression method of estimating the Hurst parameter of a time series with long-range dependence (LRD) by using golden section search (GSS). We shall show that the present method is substantially efficient than the conventional ACF regression method of H estimation. Our research uses fractional Gaussian noise as a data case but the method introduced is applicable to time series with LRD in general.

  14. Adiabatic shear localization evolution for steel based on the Johnson-Cook model and gradient-dependent plasticity

    Institute of Scientific and Technical Information of China (English)

    Xuebin Wang

    2006-01-01

    Gradient-dependent plasticity is introduced into the phenomenological Johnson-Cook model to study the effects of strainhardening, strain rate sensitivity, thermal-softening, and microstructure. The microstructural effect (interactions and interplay among microstructures) due to heterogeneity of texture plays an important role in the process of development or evolution of an adiabatic shear band with a certain thickness depending on the grain diameter. The distributed plastic shear strain and deformation in the shear band are derived and depend on the critical plastic shear strain corresponding to the peak flow shear stress, the coordinate or position, the internal length parameter, and the average plastic shear strain or the flow shear stress. The critical plastic shear strain, the distributed plastic shear strain, and deformation in the shear band are numerically predicted for a kind of steel deformed at a constant shear strain rate.Beyond the peak shear stress, the local plastic shear strain in the shear band is highly nonuniform and the local plastic shear deformation in the band is highly nonlinear. Shear localization is more apparent with the increase of the average plastic shear strain. The calculated distributions of the local plastic shear strain and deformation agree with the previous numerical and experimental results.

  15. Facilitating a transition from compulsory detention of people who use drugs towards voluntary community-based drug dependence treatment and support services in Asia.

    Science.gov (United States)

    Tanguay, Pascal; Kamarulzaman, Adeeba; Aramrattana, Apinun; Wodak, Alex; Thomson, Nicholas; Ali, Robert; Vumbaca, Gino; Lai, Gloria; Chabungbam, Anand

    2015-10-16

    Evidence indicates that detention of people who use drugs in compulsory centers in the name of treatment is common in Cambodia, China, Indonesia, Lao PDR, Malaysia, Myanmar, Philippines, Thailand, and Vietnam. The expansion of such practices has been costly, has not generated positive health outcomes, and has not reduced supply or demand for illicit drugs. United Nations agencies have convened several consultations with government and civil society stakeholders in order to facilitate a transition to voluntary evidence- and community-based drug dependence treatment and support services. In an effort to support such efforts, an informal group of experts proposes a three-step process to initiate and accelerate national-level transitions. Specifically, the working group recommends the establishment of a national multisectoral decision-making committee to oversee the development of national transition plans, drug policy reform to eliminate barriers to community-based drug dependence treatment and support services, and the integration of community-based drug dependence treatment in existing national health and social service systems.In parallel, the working group recommends that national-level transitions should be guided by overarching principles, including ethics, human rights, meaningful involvement of affected communities, and client safety, as well as good governance, transparency, and accountability. The transition also represents an opportunity to review the roles and responsibilities of various agencies across the public health and public security sectors in order to balance the workload and ensure positive results. The need to accelerate national-level transitions to voluntary community-based drug dependence treatment and support services is compelling--on economic, medical, sustainable community development, and ethical grounds--as extensively documented in the literature. In this context, the expert working group fully endorses initiation of a transition

  16. Comparative Analysis for the Urban Metabolic Differences of Two Types of Cities in the Resource-Dependent Region Based on Emergy Theory

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2016-07-01

    Full Text Available Urban metabolism analysis has become a useful and effective tool to explore urban socio-economic processes. In this research, in order to explore the similarities and differences of metabolic characteristics and variation rules of different types of resource-dependent cities, we selected two cities—Taiyuan and Jincheng, the capital and a traditional resource-dependent city of Shanxi province, respectively, as research subjects, we also established an urban metabolic evaluation framework by employing a set of eight emergy-based indicators from socio-economic data from 2007 to 2014, and compared the similarities and discrepancies from the perspectives of metabolic structure, intensity, pressure, and efficiency, and put forward some suggestions for pursuing sustainable development for both cities and pointed out that more types of resource-dependent cities should be incorporated in future research work.

  17. Quantum fluid dynamics based current-density functional study of a helium atom in a strong time-dependent magnetic field

    Science.gov (United States)

    Vikas, Hash(0x125f4490)

    2011-02-01

    Evolution of the helium atom in a strong time-dependent (TD) magnetic field ( B) of strength up to 1011 G is investigated through a quantum fluid dynamics (QFD) based current-density functional theory (CDFT). The TD-QFD-CDFT computations are performed through numerical solution of a single generalized nonlinear Schrödinger equation employing vector exchange-correlation potentials and scalar exchange-correlation density functionals that depend both on the electronic charge-density and the current-density. The results are compared with that obtained from a B-TD-QFD-DFT approach (based on conventional TD-DFT) under similar numerical constraints but employing only scalar exchange-correlation potential dependent on electronic charge-density only. The B-TD-QFD-DFT approach, at a particular TD magnetic field-strength, yields electronic charge- and current-densities as well as exchange-correlation potential resembling with that obtained from the time-independent studies involving static (time-independent) magnetic fields. However, TD-QFD-CDFT electronic charge- and current-densities along with the exchange-correlation potential and energy differ significantly from that obtained using B-TD-QFD-DFT approach, particularly at field-strengths >109 G, representing dynamical effects of a TD field. The work concludes that when a helium atom is subjected to a strong TD magnetic field of order >109 G, the conventional TD-DFT based approach differs "dynamically" from the CDFT based approach under similar computational constraints.

  18. Dependent Classes

    DEFF Research Database (Denmark)

    Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus

    2007-01-01

    Virtual classes allow nested classes to be refined in subclasses. In this way nested classes can be seen as dependent abstractions of the objects of the enclosing classes. Expressing dependency via nesting, however, has two limitations: Abstractions that depend on more than one object cannot...... be modeled and a class must know all classes that depend on its objects. This paper presents dependent classes, a generalization of virtual classes that expresses similar semantics by parameterization rather than by nesting. This increases expressivity of class variations as well as the flexibility...... of their modularization. Besides, dependent classes complement multi-methods in scenarios where multi-dispatched abstractions rather than multi-dispatched method are needed. They can also be used to express more precise signatures of multi-methods and even extend their dispatch semantics. We present a formal semantics...

  19. Distinct spatiotemporal patterns and PARP dependence of XRCC1 recruitment to single-strand break and base excision repair

    NARCIS (Netherlands)

    A. Campalans (Anna); R. Amouroux (Rachel); H. Menoni (Hervé); W. Vermeulen (Wim); J.P. Radicella (Pablo)

    2013-01-01

    textabstractSingle-strand break repair (SSBR) and base excision repair (BER) of modified bases and abasic sites share several players. Among them is XRCC1, an essential scaffold protein with no enzymatic activity, required for the coordination of both pathways. XRCC1 is recruited to SSBR by PARP-1,

  20. Phrase-Level Sentiment Polarity Classification Using Rule-Based Typed Dependencies and Additional Complex Phrases Consideration

    Institute of Scientific and Technical Information of China (English)

    Luke Kien-Weng Tan; Jin-Cheon Na; Yin-Leng Theng; Kuiyu Chang

    2012-01-01

    The advent of Web 2.0 has led to an increase in user-generated content on the Web. This has provided an extensive collection of free-style texts with opinion expressions that could influence the decisions and actions of their readters.Providers of such content exert a certain level of influence on the receivers and this is evident from blog sites having effect on their readers' purchase decisions,political view points,financial planning,and others.By detecting the opinion expressed,we can identify the sentiments on the topics discussed and the influence exerted on the readers.In this paper,we introduce an automatic approach in deriving polarity pattern rules to detect sentiment polarity at the phrase level,and in addition consider the effects of the more complex relationships found between words in sentiment polarity classification.Recent sentiment analysis research has focused on the functional relations of words using typed dependency parsing,providing a refined analysis on the grammar and semantics of textual data.Heuristics are typically used to determine the typed dependency polarity patterns,which may not comprehensively identify all possible rules.We study the use of class sequential rules (CSRs) to automatically learn the typed dependency patterns,and benchmark the performance of CSR against a heuristic method.Preliminary results show CSR leads to further improvements in classification performance achieving over 80% F1 scores in the test cases.In addition,we observe more complex relationships between words that could influence phrase sentiment polarity,and further discuss on possible approaches to handle the effects of these complex relationships.

  1. Inventory models with stock- and price-dependent demand for deteriorating items based on limited shelf space

    Directory of Open Access Journals (Sweden)

    Chang Chun-Tao

    2010-01-01

    Full Text Available This paper deals with the problem of determining the optimal selling price and order quantity simultaneously under EOQ model for deteriorating items. It is assumed that the demand rate depends not only on the on-display stock level but also the selling price per unit, as well as the amount of shelf/display space is limited. We formulate two types of mathematical models to manifest the extended EOQ models for maximizing profits and derive the algorithms to find the optimal solution. Numerical examples are presented to illustrate the models developed and sensitivity analysis is reported.

  2. Evaluation of AlGaN-based deep ultraviolet emitter active regions by temperature dependent time-resolved photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Sampath, A.V.; Shen, H.; Wraback, M. [Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, MD (United States); Sun, W.; Shatalov, M.; Hu, X.; Yang, J.; Bilenko, Y.; Lunev, A.; Shur, M.S.; Gaska, R. [Sensor Electronic Technology, Inc., Columbia, SC (United States); Grandusky, J.R.; Schowalter, L.J. [Crystal IS, Inc., Green Island, NY (United States); Garrett, G.A.

    2010-10-15

    Temperature dependent time-resolved photoluminescence is used to study the development of active regions for optoelectronic devices employing AlGaN nanostructures for deep-UV emission. The changing importance of dislocation versus point defects and their relationship to different forms of carrier localization are discussed. The results presented suggest that AlGaN nanostructure development for deep-UV emitters require both point defect/impurity suppression for improved efficiency and lower dislocation density for improved interface quality. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Temperature Dependence of a Period of the Modulated Structurein Atom-Vacancy Solid Solution Based on F.C.C. Nickel

    Directory of Open Access Journals (Sweden)

    V.A. Tatarenko

    2012-03-01

    Full Text Available The effective vacancy–vacancy interaction is considered. Based on the continuum approximation for the Fourier components of strain-induced vacancy–vacancy-interaction energies, approximating expressions for their expansion coefficients are obtained, depending on the elasticity moduli, longitudinal and transverse phonon frequencies, and vacancy-concentration-dependent lattice parameter. A non-analytical behaviour of the k-dependent Fourier components of the strain-induced vacancy–vacancy-interaction energies near the Brillouin zone centre, Avv(n + Bvv(n|k|2, is analysed. As shown, Avv(n  0 and Bvv(n  0 along all the high-symmetry [100], [110], [111] directions in reciprocal space for f.c.c. crystals with negative anisotropy factor. The criterion of modulated-structure formation for interacting vacancies in f.c.c. crystals is considered. Dependence of the f.c.c.-Ni–vacancies modulated-structure period on temperature is plotted. The effective vacancy–vacancy interaction is considered. Based on the continuum approximation for the Fourier components of strain-induced vacancy–vacancy-interaction energies, approximating expressions for their expansion coefficients are obtained, depending on the elasticity moduli, longitudinal and transverse phonon frequencies, and vacancy-concentration-dependent lattice parameter. A non-analytical behaviour of the k-dependent Fourier components of the strain-induced vacancy–vacancy-interaction energies near the Brillouin zone centre, Avv(n + Bvv(n|k|2, is analysed. As shown, Avv(n  0 and Bvv(n  0 along all the high-symmetry [100], [110], [111] directions in reciprocal space for f.c.c. crystals with negative anisotropy factor. The criterion of modulated-structure formation for interacting vacancies in f.c.c. crystals is considered. Dependence of the f.c.c.-Ni–vacancies modulated-structure period on temperature is plotted. The effective vacancy–vacancy interaction is considered

  4. Analysis on Current Situation and Countermeasure of Domestic Electronic Commerce Logistics in the Internet Age——Based on Resource Dependence Theory

    Directory of Open Access Journals (Sweden)

    Zhang Jiapeng

    2017-01-01

    Full Text Available This paper analyzes the status of electric business logistics in the current Internet era in China, and combines the SWOT analysis with AHP to do the empirical analysis, then puts forward the countermeasure that the electric business logistics resource should be shared based on the resource dependence theory. Through the empirical analysis, it is found that the disadvantages and opportunities of the logistics status are important in the Internet era.The resource sharing strategy based on the resource dependence theory is more scientific. The rational use of Internet technology in electric business logistics industry can achieve “sharing”. It is of great significance for its balanced development, intelligent development and optimization and development.

  5. Dependence of Magnetic Properties and Microstructure of Ni81Fe19 Film on Base Vacuum and Sputtering Pressure

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Ni81Fe19 / Ta films with different NiFe thickness were prepared at different base vacuums and sputtering pressures. The results of magnetic measurement and atomic force microscope (AFM) showed that the films prepared at higher base vacuum and lower sputtering pressure had larger R/R. The reason should be that higher base vacuum and lower sputtering pressure introduce larger grain-size and lower surface roughness, which will weaken the scattering of electrons, reduce the resistance R, and increase R/R.

  6. Effects of symmetry and spin configuration on spin-dependent transport properties of iron-phthalocyanine-based devices

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Li-Ling [Institute of Super Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083 (China); School of Science, Hunan University of Technology, Zhuzhou 412007 (China); Yang, Bing-Chu, E-mail: bingchuyang@csu.edu.cn; Li, Xin-Mei; Cao, Can [Institute of Super Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083 (China); Long, Meng-Qiu, E-mail: mqlong@csu.edu.cn [Institute of Super Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083 (China); Department of Physics and Materials Science, City University of Hong Kong, Hong Kong (China)

    2014-07-21

    Spin-dependent transport properties of nanodevices constructed by iron-phthalocyanine (FePc) molecule sandwiched between two zigzag graphene nanoribbon electrodes are studied using first-principles quantum transport calculations. The effects of the symmetry and spin configuration of electrodes have been taken into account. It is found that large magnetoresistance, large spin polarization, dual spin-filtering, and negative differential resistance (NDR) can coexist in these devices. Our results show that 5Z-FePc system presents well conductive ability in both parallel (P) and anti-parallel (AP) configurations. For 6Z-FePc-P system, spin filtering effect and large spin polarization can be found. A dual spin filtering and NDR can also be shown in 6Z-FePc-AP. Our studies indicate that the dual spin filtering effect depends on the orbitals symmetry of the energy bands and spin mismatching of the electrodes. And all the effects would open up possibilities for their applications in spin-valve, spin-filter as well as effective spin diode devices.

  7. Solar wind dependent models for the shapes of the Martian plasma boundaries based on Mars Express measurements

    Science.gov (United States)

    Ramstad, Robin; Barabash, Stas; Futaana, Yoshifumi; Holmstrom, Mats

    2016-10-01

    The long operational life (2003-) of Mars Express (MEX) has allowed the spacecraft to make plasma measurements in the Martian environment over a wide range of upstream conditions. We have analyzed ~5000 MEX orbits, covering three orders of magnitude in solar wind dynamic pressure, with data from the on-board Analyzer of Space Plasmas and Energetic Particles (ASPERA-3) package, mapping the locations where MEX crosses the main plasma boundaries; induced magnetosphere boundary (IMB), ionosphere boundary (IB) and bow shock (BS). A coincidence scheme was employed, where data from the Ion Mass Analyzer (IMA) and the Electron Spectrometer (ELS) had to agree for a positive boundary identification, which resulted in crossings from 882 orbit segments that were used to create dynamic 2-parameter (solar wind density, nsw, and velocity vsw dependent global dynamic models for the IMB, IB and BS. The modeled response is found to be individual to each boundary; the BS is stationary for all but extremely thin and slow solar wind, the IMB scales solely dependent on dynamic pressure and the IB changes morphology with different trends for nsw and vsw. We find no significant trend in IMB location with changing EUV intensities when the upstream solar wind is constrained to nominal conditions. Finally, the IMB model is used to extrapolate the solar wind stand-off distance in the ancient (0.7 Ga old) solar wind.

  8. Size-dependent geometrically nonlinear free vibration analysis of fractional viscoelastic nanobeams based on the nonlocal elasticity theory

    Science.gov (United States)

    Ansari, R.; Faraji Oskouie, M.; Gholami, R.

    2016-01-01

    In recent decades, mathematical modeling and engineering applications of fractional-order calculus have been extensively utilized to provide efficient simulation tools in the field of solid mechanics. In this paper, a nonlinear fractional nonlocal Euler-Bernoulli beam model is established using the concept of fractional derivative and nonlocal elasticity theory to investigate the size-dependent geometrically nonlinear free vibration of fractional viscoelastic nanobeams. The non-classical fractional integro-differential Euler-Bernoulli beam model contains the nonlocal parameter, viscoelasticity coefficient and order of the fractional derivative to interpret the size effect, viscoelastic material and fractional behavior in the nanoscale fractional viscoelastic structures, respectively. In the solution procedure, the Galerkin method is employed to reduce the fractional integro-partial differential governing equation to a fractional ordinary differential equation in the time domain. Afterwards, the predictor-corrector method is used to solve the nonlinear fractional time-dependent equation. Finally, the influences of nonlocal parameter, order of fractional derivative and viscoelasticity coefficient on the nonlinear time response of fractional viscoelastic nanobeams are discussed in detail. Moreover, comparisons are made between the time responses of linear and nonlinear models.

  9. A simple guiding principle for the temperature dependence of the solubility of light gases in imidazolium-based ionic liquids derived from molecular simulations.

    Science.gov (United States)

    Kerlé, Daniela; Namayandeh Jorabchi, Majid; Ludwig, Ralf; Wohlrab, Sebastian; Paschek, Dietmar

    2017-01-18

    We have determined the temperature dependence of the solvation behavior of a large collection of important light gases in imidazolium-based ionic liquids with the help of extensive molecular dynamics simulations. The motivation of our study is to unravel common features of the temperature dependent solvation under well controlled conditions, and to provide a guidance for cases, where experimental data from different sources disagree significantly. The solubility of molecular hydrogen, oxygen, nitrogen, methane, krypton, argon, neon and carbon dioxide in the imidazolium based ionic liquids of type 1-n-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cnmim][NTf2]) with varying alkyl side chain lengths n = 2, 4, 6, 8 is computed for a temperature range between 300 K and 500 K at 1 bar. By applying Widom's particle insertion technique and Bennet's overlapping distribution method, we are able to determine the temperature dependent solvation free energies of those selected light gases in simulated imidazolium based ionic liquids with high statistical accuracy. Our simulations demonstrate that the magnitude of the solvation free energy of a gas molecule at a chosen reference temperature and that of its temperature-derivatives are intimately related to one another. We conclude that this "universal" behavior is rooted in a solvation entropy-enthalpy compensation effect, which seems to be a defining feature of the solvation of small molecules in ionic liquids. The observations lead to simple analytical relations, determining the temperature dependence of the solubility data based on the absolute solubility at a certain reference temperature. By comparing our results with available experimental data from many sources, we can show that our approach is particularly helpful for providing reliable estimates for the solvation behavior of very light gases, such as hydrogen, where conflicting experimental data exist.

  10. Efficiently Paraphrasing Based on Semantic Dependency Grammar in NChiql%NChiql中基于语义依存树的语言转述

    Institute of Scientific and Technical Information of China (English)

    孟小峰; 王秋月; 王珊

    2001-01-01

    To enable natural language interfaces to databases more efficient and robust,two kinds of techniques,language paraphrasing and result analyzing,are widely used to help users to understand the system's intermediate language,and the query result meaning in some times. For the limitation of intermediate language adopted in some NLIDBs ,they could not give efficient and practical paraphrasing algorithms. Based on semantic dependency tree in NChiql,we present a completed paraphrasing algorithm which is suitable to Chinese languages.

  11. USING ECO-EVOLUTIONARY INDIVIDUAL-BASED MODELS TO INVESTIGATE SPATIALLY-DEPENDENT PROCESSES IN CONSERVATION GENETICS

    Science.gov (United States)

    Eco-evolutionary population simulation models are powerful new forecasting tools for exploring management strategies for climate change and other dynamic disturbance regimes. Additionally, eco-evo individual-based models (IBMs) are useful for investigating theoretical feedbacks ...

  12. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy.

  13. The genetics of alcohol dependence: Twin and SNP-based heritability, and genome-wide association study based on AUDIT scores

    NARCIS (Netherlands)

    Mbarek, H.; Milaneschi, Y.; Fedko, I.O; Hottenga, J.J.; Moor, M.H.M. de; Jansen, R.; Gelernter, J.; Sherva, R.; Willemsen, G.; Boomsma, D.I.; Penninx, B.W.J.H.; Vink, J.M.

    2015-01-01

    Alcohol dependence (AD) is among the most common and costly public health problems contributing to morbidity and mortality throughout the world. In this study, we investigate the genetic basis of AD in a Dutch population using data from the Netherlands Twin Register (NTR) and the Netherlands Study o

  14. A complexity measure based method for studying the dependence of 222Rn concentration time series on indoor air temperature and humidity

    CERN Document Server

    Mihailovic, Dragutin T; Krmar, Miodrag; Arsenić, Ilija

    2013-01-01

    We have suggested a complexity measure based method for studying the dependence of measured 222Rn concentration time series on indoor air temperature and humidity. This method is based on the Kolmogorov complexity (KL). We have introduced (i) the sequence of the KL, (ii) the Kolmogorov complexity highest value in the sequence (KLM) and (iii) the KL of the product of time series. The noticed loss of the KLM complexity of 222Rn concentration time series can be attributed to the indoor air humidity that keeps the radon daughters in air.

  15. A complexity measure based method for studying the dependance of 222Rn concentration time series on indoor air temperature and humidity.

    Science.gov (United States)

    Mihailovic, D T; Udovičić, V; Krmar, M; Arsenić, I

    2014-02-01

    We have suggested a complexity measure based method for studying the dependence of measured (222)Rn concentration time series on indoor air temperature and humidity. This method is based on the Kolmogorov complexity (KL). We have introduced (i) the sequence of the KL, (ii) the Kolmogorov complexity highest value in the sequence (KLM) and (iii) the KL of the product of time series. The noticed loss of the KLM complexity of (222)Rn concentration time series can be attributed to the indoor air humidity that keeps the radon daughters in air.

  16. A comparison of field-dependent rheological properties between spherical and plate-like carbonyl iron particles-based magneto-rheological fluids

    Science.gov (United States)

    Tan Shilan, Salihah; Amri Mazlan, Saiful; Ido, Yasushi; Hajalilou, Abdollah; Jeyadevan, Balachandran; Choi, Seung-Bok; Azhani Yunus, Nurul

    2016-09-01

    This work proposes different sizes of the plate-like particles from conventional spherical carbonyl iron (CI) particles by adjusting milling time in the ball mill process. The ball mill process to make the plate-like particles is called a solid-state powder processing technique which involves repeated welding, fracturing and re-welding of powder particles in a high-energy ball mill. The effect of ball milling process on the magnetic behavior of CI particles is firstly investigated by vibrating sample magnetometer. It is found form this investigation that the plate-like particles have higher saturation magnetization (about 8%) than that of the spherical particles. Subsequently, for the investigation on the sedimentation behavior the cylindrical measurement technique is used. It is observed from this measurement that the plate-like particles show slower sedimentation rate compared to the spherical particles indicating higher stability of the MR fluid. The field-dependent rheological properties of MR fluids based on the plate-like particles are then investigated with respect to the milling time which is directly connected to the size of the plate-like particles. In addition, the field-dependent rheological properties such as the yield stress are evaluated and compared between the plate-like particles based MR fluids and the spherical particles based MR fluid. It is found that the yield shear stress of the plate-like particles based MR fluid is increased up to 270% compared to the spherical particles based MR fluid.

  17. Community-Based Tourism - Option for Forest-Dependent Communities in 1A IUCN Protected Areas? Cameroon Case Study

    Directory of Open Access Journals (Sweden)

    Burgin Shelley

    2014-01-01

    Full Text Available In developing countries, ‘exponential’ growth in IUCN protected lands has occurred in the last 25 years. Approximately 6% of protected areas are ‘Strict Nature Reserve[s]’ (1A with emphasis on conservation and strict restrictions on human access. Before Bakossi Forest Reserve (Cameroon had 1A protection, 95% of local families used the Reserve for their livelihood. They farmed cash crops, collected fire wood, timber, and food with incomes equivalent to US$35,000/annually/family. Post-protection, the Reserve’s local communities lacked support to develop alternative livelihoods, and 75% reported being intercepted illegally trespassing by Reserve guards. Without illegal activity economic impacts would have been substantially greater. Protection has also meant foregone national income from timber and coffee exports. We used Bakossi Forest Reserve as a case study to identify issues facing local communities excluded from the Reserve that traditionally provided their livelihood. We also investigated potential alternative family livelihoods based on critical evaluation of the literature. We identified ‘exceptional’ community-based tourism potential. We also found that Cameroon was the first African country to develop community-based forestry with the dual roles of conservation and poverty alleviation. Using this model, community-based tourism could be a cost-effectively initiative to deliver the same dual roles as community-based forestry.

  18. Dependence of demagnetizing fields in Fe-based composite materials on magnetic particle size and the resin content

    Science.gov (United States)

    Kollár, Peter; Birčáková, Zuzana; Vojtek, Vladimír; Füzer, Ján; Bureš, Radovan; Fáberová, Mária

    2015-08-01

    Demagnetizing fields are in general produced by the volume and surface magnetic poles. The structure of soft magnetic composite materials, where the ferromagnetic particles are insulated from each other, causes the formation of demagnetizing fields produced by the particle surfaces. These fields depend on the amount of insulation and on the shapes, clustering and distribution of ferromagnetic particles. In this work the demagnetizing fields in iron-phenolphormaldehyde resin composite samples were investigated experimentally using the method for determining the demagnetization factor from the anhysteretic magnetization curve measurement. The initial magnetization curves were calculated for an ideal composite with 100% filler content using the values of the demagnetization factor. The results on the "ideal" permeability show differences between the samples with different resin content for each granulometric class, which tells about the internal stresses introduced into ferromagnetic material during the compaction process.

  19. High contrast all-optical diode based on direction-dependent optical bistability within asymmetric ring cavity

    Science.gov (United States)

    Xia, Xiu-Wen; Zhang, Xin-Qin; Xu, Jing-Ping; Yang, Ya-Ping

    2016-08-01

    We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bistability is obtained in a classical bistable system. Therefore, a giant optical non-reciprocity is generated, which guarantees an all-optical diode with a high contrast up to 22 dB. Furthermore, its application as an all-optical logic AND gate is also discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11274242, 11474221, and 11574229), the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics (Grant No. U1330203), and the National Key Basic Research Special Foundation of China (Grant Nos. 2011CB922203 and 2013CB632701).

  20. Unidirectional Spin-Dependent Molecule-Ferromagnet Hybridized States Anisotropy in Cobalt Phthalocyanine Based Magnetic Tunnel Junctions

    Science.gov (United States)

    Barraud, Clément; Bouzehouane, Karim; Deranlot, Cyrile; Fusil, Stéphane; Jabbar, Hashim; Arabski, Jacek; Rakshit, Rajib; Kim, Dong-Jik; Kieber, Christophe; Boukari, Samy; Bowen, Martin; Beaurepaire, Eric; Seneor, Pierre; Mattana, Richard; Petroff, Frédéric

    2015-05-01

    Organic or molecular spintronics is a rising field of research at the frontier between condensed matter physics and chemistry. It aims to mix spin physics and the richness of chemistry towards designing new properties for spin electronics devices through engineering at the molecular scale. Beyond the expectation of a long spin lifetime, molecules can be also used to tailor the spin polarization of the injected current through the spin-dependent hybridization between molecules and ferromagnetic electrodes. In this Letter, we provide direct evidence of a hybrid interface spin polarization reversal due to the differing hybridization between phthalocyanine molecules and each cobalt electrode in Co /CoPc /Co magnetic tunnel junctions. Tunnel magnetoresistance and anisotropic tunnel magnetoresistance experiments show that interfacial hybridized electronic states have a unidirectional anisotropy that can be controlled by an electric field and that spin hybridization at the bottom and top interfaces differ, leading to an inverse tunnel magnetoresistance.

  1. Temperature and bias voltage dependence of Co/Pd multilayer-based magnetic tunnel junctions with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, Zoe, E-mail: zkugler@physik.uni-bielefeld.d [Bielefeld University, Department of Physics, Universitaetsstr. 25, 33615 Bielefeld (Germany); Drewello, Volker; Schaefers, Markus; Schmalhorst, Jan; Reiss, Guenter; Thomas, Andy [Bielefeld University, Department of Physics, Universitaetsstr. 25, 33615 Bielefeld (Germany)

    2011-01-15

    Temperature- and bias voltage-dependent transport measurements of magnetic tunnel junctions (MTJs) with perpendicularly magnetized Co/Pd electrodes are presented. Magnetization measurements of the Co/Pd multilayers are performed to characterize the electrodes. The effects of the Co layer thickness in the Co/Pd bilayers, the annealing temperature, the Co thickness at the MgO barrier interface, and the number of bilayers on the tunneling magneto resistance (TMR) effect are investigated. TMR-ratios of about 11% at room temperature and 18.5% at 13 K are measured and two well-defined switching fields are observed. The results are compared to measurements of MTJs with Co-Fe-B electrodes and in-plane anisotropy.

  2. Doping Dependence of the $(\\pi,\\pi)$ Shadow Band in La-Based Cuprates Studied by Angle-Resolved Photoemission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Z. X.

    2011-08-15

    The ({pi},{pi}) shadow band (SB) in La-based cuprate family (La214) was studied by angle-resolved photoemission spectroscopy (ARPES) over a wide doping range from x = 0.01 to x = 0.25. Unlike the well-studied case of the Bi-based cuprate family, an overall strong, monotonic doping dependence of the SB intensity at the Fermi level (E{sub F}) was observed. In contrast to a previous report for the presence of the SB only close to x = 1/8, we found it exists in a wide doping range, associated with a doping-independent ({pi},{pi}) wave vector but strongly doping-dependent intensity: It is the strongest at x {approx} 0.03 and systematically diminishes as the doping increases until it becomes negligible in the overdoped regime. This SB with the observed doping dependence of intensity can in principle be caused by the antiferromagnetic fluctuations or a particular form of low-temperature orthorhombic lattice distortion known to persist up to x {approx} 0.21 in the system, with both being weakened with increasing doping. However, a detailed binding energy dependent analysis of the SB at x = 0.07 does not appear to support the former interpretation, leaving the latter as a more plausible candidate, despite a challenge in quantitatively linking the doping dependences of the SB intensity and the magnitude of the lattice distortion. Our finding highlights the necessity of a careful and global consideration of the inherent structural complications for correctly understanding the cuprate Fermiology and its microscopic implication.

  3. Modulation of epileptic activity by deep brain stimulation: a model-based study of frequency-dependent effects.

    Science.gov (United States)

    Mina, Faten; Benquet, Pascal; Pasnicu, Anca; Biraben, Arnaud; Wendling, Fabrice

    2013-01-01

    A number of studies showed that deep brain stimulation (DBS) can modulate the activity in the epileptic brain and that a decrease of seizures can be achieved in "responding" patients. In most of these studies, the choice of stimulation parameters is critical to obtain desired clinical effects. In particular, the stimulation frequency is a key parameter that is difficult to tune. A reason is that our knowledge about the frequency-dependant mechanisms according to which DBS indirectly impacts the dynamics of pathological neuronal systems located in the neocortex is still limited. We address this issue using both computational modeling and intracerebral EEG (iEEG) data. We developed a macroscopic (neural mass) model of the thalamocortical network. In line with already-existing models, it includes interconnected neocortical pyramidal cells and interneurons, thalamocortical cells and reticular neurons. The novelty was to introduce, in the thalamic compartment, the biophysical effects of direct stimulation. Regarding clinical data, we used a quite unique data set recorded in a patient (drug-resistant epilepsy) with a focal cortical dysplasia (FCD). In this patient, DBS strongly reduced the sustained epileptic activity of the FCD for low-frequency (LFS, 70 Hz) while intermediate-frequency stimulation (IFS, around 50 Hz) had no effect. Signal processing, clustering, and optimization techniques allowed us to identify the necessary conditions for reproducing, in the model, the observed frequency-dependent stimulation effects. Key elements which explain the suppression of epileptic activity in the FCD include: (a) feed-forward inhibition and synaptic short-term depression of thalamocortical connections at LFS, and (b) inhibition of the thalamic output at HFS. Conversely, modeling results indicate that IFS favors thalamic oscillations and entrains epileptic dynamics.

  4. Modulation of epileptic activity by deep brain stimulation: a model-based study of frequency-dependent effects

    Directory of Open Access Journals (Sweden)

    Faten eMina

    2013-07-01

    Full Text Available A number of studies showed that deep brain stimulation (DBS can modulate the activity in the epileptic brain and that a decrease of seizures can be achieved in responding patients. In most of these studies, the choice of stimulation parameters is critical to obtain desired clinical effects. In particular, the stimulation frequency is a key parameter that is difficult to tune. A reason is that our knowledge about the frequency-dependant mechanisms according to which DBS indirectly impacts the dynamics of pathological neuronal systems located in the neocortex is still limited. We address this issue using both computational modeling and intracerebral EEG (iEEG data.We developed a macroscopic (neural mass model of the thalamocortical network. In line with already-existing models, it includes interconnected neocortical pyramidal cells and interneurons, thalamocortical cells and reticular neurons. The novelty was to introduce, in the thalamic compartment, the biophysical effects of direct stimulation. Regarding clinical data, we used a quite unique data set recorded in a patient (drug-resistant epilepsy with a focal cortical dysplasia (FCD. In this patient, DBS strongly reduced the sustained epileptic activity of the FCD for low-frequency (LFS, < 2 Hz and high-frequency stimulation (HFS, > 70 Hz while intermediate-frequency stimulation (IFS, around 50 Hz had no effect.Signal processing, clustering and optimization techniques allowed us to identify the necessary conditions for reproducing, in the model, the observed frequency-dependent stimulation effects. Key elements which explain the suppression of epileptic activity in the FCD include a feed-forward inhibition and synaptic short-term depression of thalamocortical connections at LFS, and b inhibition of the thalamic output at HFS. Conversely, modeling results indicate that IFS favors thalamic oscillations and entrains epileptic dynamics.

  5. Statins dose-dependently exert a chemopreventive effect against lung cancer in COPD patients: a population-based cohort study

    Science.gov (United States)

    Hsu, Yi-Ping; Hao, Wen-Rui; Kao, Pai-Feng; Sung, Li-Chin; Chen, Chun-Chao; Wu, Szu-Yuan

    2016-01-01

    Purpose Chronic obstructive pulmonary disease (COPD) is associated with increased lung cancer risk. We evaluated the association of statin use with lung cancer risk in COPD patients and identified which statins possess the highest chemopreventive potential. Results After adjustment for age, sex, CCI, diabetes, hypertension, dyslipidemia, urbanization level, and monthly income according to propensity scores, lung cancer risk in the statin users was lower than that in the statin nonusers (adjusted hazard ratio [aHR] = 0.37). Of the individual statins, lovastatin and fluvastatin did not reduce lung cancer risk significantly. By contrast, lung cancer risk in patients using rosuvastatin, simvastatin, atorvastatin, and pravastatin was significantly lower than that in statin nonusers (aHRs = 0.41, 0.44, 0.52, and 0.58, respectively). Statins dose-dependently reduced lung cancer risk in all subgroups and the main model with additional covariates (nonstatin drug use). MATERIALS AND METHODS The study cohort comprised all patients diagnosed with COPD at health care facilities in Taiwan (n = 116,017) between January 1, 2001 and December 31, 2012. Our final study cohort comprised 43,802 COPD patients: 10,086 used statins, whereas 33,716 did not. Patients were followed up to assess lung cancer risk or protective factors. In addition, we also considered demographic characteristics, namely age, sex, comorbidities (diabetes, hypertension, dyslipidemia, and Charlson comorbidity index [CCI]), urbanization level, monthly income, and nonstatin drug use. The index date of statin use was the COPD confirmation date. To examine the dose–response relationship, we categorized statin use into four groups in each cohort: 365 cumulative defined daily doses (cDDDs). Patients receiving Statins dose-dependently exert a significant chemopreventive effect against lung cancer in COPD patients. Rosuvastatin, simvastatin, and atorvastatin exhibited the highest chemopreventive potential. PMID:27517752

  6. 基于自律计算的系统可信性自调节模型%System dependability self-tuning model based on autonomic computing

    Institute of Scientific and Technical Information of China (English)

    吴庆涛; 郑瑞娟; 张明川; 魏汪洋; 李冠峰

    2011-01-01

    Ensuring and strengthening the reliability, security and stability of computer systems are advanced requirement to system service.Based on autonomic computing, a self-tuning model on system dependability is proposed.By dynamically analyzing the change trend of object system dependability, and making reference to the grads fluctuation of accient dependability curve, it implements the on-line dependability evaluation, dependability dynamic prediction and self-tuning scheme selection in turn, which accomplishes the self-tuning function of system dependability.Confidence field grads calculation method is adopted to solve the optimization problem of self-tuning.%保障和增强系统的可靠性、安全性和稳定性等可信性质是对系统服务的高级要求.提出了一个基于自律计算理念的系统可信性自调节模型,该模型动态分析目标系统的可信度变化趋势,参考先验可信度变化曲线的梯度升降,依序实现可信度在线评估、可信度动态预测和自调节方案选择,完成系统可信度非降的自主调节过程,采用信赖域梯度计算策略解决自调节的最优化问题.

  7. A Randomized Trial Adapting Contingency Management Targets Based on Initial Abstinence Status of Cocaine-Dependent Patients

    Science.gov (United States)

    Petry, Nancy M.; Barry, Danielle; Alessi, Sheila M.; Rounsaville, Bruce J.; Carroll, Kathleen M.

    2012-01-01

    Objective: Contingency management (CM) reduces drug use, but questions remain regarding optimal targets and magnitudes of reinforcement. We evaluated the efficacy of CM reinforcing attendance in patients who initiated treatment with cocaine-negative samples, and of higher magnitude abstinence-based CM in patients who began treatment positive.…

  8. Osteoradionecrosis in cancer patients : the evidence base for treatment-dependent frequency, current management strategies, and future studies

    NARCIS (Netherlands)

    Peterson, Douglas E.; Doerr, Wolfgang; Hovan, Allan; Pinto, Andres; Saunders, Debbie; Elting, Linda S.; Spijkervet, Fred K. L.; Brennan, Michael T.

    2010-01-01

    The purpose of this study is to review the evidence base from 1990 to 2008 to (1) clarify the impact of cancer therapies on prevalence of osteoradionecrosis (ORN) in head and neck cancer patients, and to (2) evaluate management strategies and their consequences on quality of life and cost of care. A

  9. Pressure-Dependent Base-Wavefunction Admixture and Lifetime of R1 State of La3Lu2Ga3O12:Cr3+

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zheng-Jie; MA Dong-Ping

    2006-01-01

    As a key factor leading to the pressure-dependent R1-line-shift reversal and R1-state lifetime, at 10 K,the pressure-dependent variation of mixing-degree of |t22(3T1)e4T2> and |t322E> base-wavefunctions in the wavefunction of R1 state of LLGG:Cr3+ has been calculated and analyzed. From this, the physical origin of the pressure-dependent R1-line-shift reversal has been revealed. Furthermore, by using the pressure-dependent values of the sum of all square mixing-coefficients of|t22 (3T1)e4T2> in the wavefunction of R1 state, the lifetimes of Ri state of LLGG:Cr3+ at various pressures have been calculated, which are in good agreement with observed results. The quantum anticrossing effect between t322E and t22(3T1)e4T2 levels due to both spin-orbital interaction and electron-phonon interaction is remarkable,which is related to the admixture of |t22(3T1)e4T2> and |t32E> as well as the low-high crystal-field transition.

  10. Dependence of demagnetizing fields in Fe-based composite materials on magnetic particle size and the resin content

    Energy Technology Data Exchange (ETDEWEB)

    Kollár, Peter, E-mail: peter.kollar@upjs.sk [Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University, Park Angelinum 9, 04154 Košice (Slovakia); Birčáková, Zuzana; Vojtek, Vladimír; Füzer, Ján [Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University, Park Angelinum 9, 04154 Košice (Slovakia); Bureš, Radovan; Fáberová, Mária [Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 04001 Košice (Slovakia)

    2015-08-15

    Demagnetizing fields are in general produced by the volume and surface magnetic poles. The structure of soft magnetic composite materials, where the ferromagnetic particles are insulated from each other, causes the formation of demagnetizing fields produced by the particle surfaces. These fields depend on the amount of insulation and on the shapes, clustering and distribution of ferromagnetic particles. In this work the demagnetizing fields in iron–phenolphormaldehyde resin composite samples were investigated experimentally using the method for determining the demagnetization factor from the anhysteretic magnetization curve measurement. The initial magnetization curves were calculated for an ideal composite with 100% filler content using the values of the demagnetization factor. The results on the “ideal” permeability show differences between the samples with different resin content for each granulometric class, which tells about the internal stresses introduced into ferromagnetic material during the compaction process. - Highlights: • Demagnetization factor decreases as magnetic content and particle size increases. • Different “ideal” initial curves for each resin content due to stresses in particles. • “Ideal” permeability rises and H{sub C} decreases as resin content and particle size rises. • Demagnetizing fields in SMC studied by means of anhysteretic curve for the first time.

  11. Molten-salt synthesis and composition-dependent luminescent properties of barium tungsto-molybdate-based solid solution phosphors

    Science.gov (United States)

    Xiang-Hong, He; Zhao-Lian, Ye; Ming-Yun, Guan; Ning, Lian; Jian-Hua, Sun

    2016-02-01

    Pr3+-activated barium tungsto-molybdate solid solution phosphor Ba(Mo1-zWz)O4:Pr3+ is successfully fabricated via a facile molten-salt approach. The as-synthesized microcrystal is of truncated octahedron and exhibits deep-red-emitting upon blue light excitation. Powder x-ray diffraction and Raman spectroscopy techniques are utilized to investigate the formation of solid solution phosphor. The luminescence behaviors depend on the resulting composition of the microcrystals with fixed Pr3+-doping concentration, while the host lattices remain in a scheelite structure. The forming solid solution via the substitution of [WO4] for [MoO4] can significantly enhance its luminescence, which may be due to the fact that Ba(Mo1-zWz)O4:Pr3+ owns well-defined facets and uniform morphologies. Owing to its properties of high phase purity, well-defined facets, highly uniform morphologies, exceptional chemical and thermal stabilities, and stronger emission intensity, the resulting solid solution phosphor is expected to find potential applications in phosphor-converted white light-emitting diodes (LEDs). Project supported by the Construction Fund for Science and Technology Innovation Group from Jiangsu University of Technology, China, the Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, China (Grant No. KHK1409), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, and the National Natural Science Foundation of China (Grant No. 21373103).

  12. Investigation of field-dependent charge carrier generation and recombination in polymer based solar cells by transient extraction currents

    Energy Technology Data Exchange (ETDEWEB)

    Kniepert, Juliane; Blakesley, James; Neher, Dieter [University of Potsdam (Germany)

    2011-07-01

    There is an ongoing discussion as to whether photoinduced charge transfer in P3HT:PCBM solar cells leads to fully separated electrons and holes, independent of an electric field, or Coulombically bound interfacial charge pairs. While recent studies by R.A. Marsh et al. with transient absorption spectroscopy gave clear evidence for the formation and field-induced dissociation of bound polaron pairs, measurements by I.A. Howard et al. were in favour of hot exciton dissociation. Here, we present the results of bias-dependent Time Delayed Collection Field (TDCF) measurements to access directly the density of free charge carriers in P3HT:PCBM blends coated from dichlorobenzene. Solvent annealing was applied to yield a phase-separated morphology and the corresponding solar cells exhibit high values for the external quantum efficiency and fill factor. Our setup allowed us to follow the generation and recombination of photogenerated charges with a so far unattained time resolution of 40 ns. Our experiments show that the number of collected carriers is independent of the applied bias during pulsed illumination implying that extractable carriers in P3HT:PCBM blends are not generated by the field-assisted separation of bound polaron pairs. In addition, our experiments support the view that bimolecular recombination of free carriers is strongly suppressed in phase-separated P3HT:PBCM blends.

  13. Temperature-dependent gel-type ionic liquid compounds based on vanadium-substituted polyoxometalates with Keggin structure.

    Science.gov (United States)

    Huang, Tianpei; Xie, Zhirong; Wu, Qingyin; Yan, Wenfu

    2016-03-07

    A series of temperature-dependent gel-type ionic liquid compounds have been synthesized from 1-(3-sulfonic group) propyl-3-methyl imidazolium (abbreviated as MIMPS) and three vanadium-substituted heteropoly acids H5SiW11VO40, H5SiMo11VO40 and H7SiW9V3O40. The designed and synthesized gel-type polyoxometalate ionic liquids (POM-ILs) have demonstrated a tendency to exhibit a layered structure. Moreover, they can undergo a phase transformation from a viscous gel-state to a liquid-state below 100 °C, and ionic conductivity up to 10(-3) S cm(-1) was observed at 120 °C. Cyclic voltammetry was carried out to study their electrochemical properties in organic solutions, and it was found that the oxidizability of the three POM-ILs decreases in the order: [MIMPS]7SiW9V3O40 > [MIMPS]5SiMo11VO40 > [MIMPS]5SiW11VO40. This result indicates that the redox behavior can be tuned by changing the chemical composition of the heteropolyanions.

  14. Dynamic and rate-dependent yielding behavior of Co0.9Ni0.1 microcluster based magnetorheological fluids

    Science.gov (United States)

    Arief, Injamamul; Mukhopadhyay, P. K.

    2016-01-01

    In this paper we performed steady shear and oscillatory magnetorheological (MR) studies in magnetic fluids containing CoNi sub-micron sized clusters of 450 nm in diameter. Such Co-rich nanoclusters were synthesized by conventional homogeneous nucleation without any external surfactant or reducing agent in liquid polyol at elevated temperature. The x-ray diffraction, energy dispersive x-ray analysis, scanning and transmission electron microscopy studies were done for analyzing the sample composition and morphology. Two variants of fluid samples were prepared by dispersing 15 vol% and 20 vol% of CoNi powders in castor oil. Room temperature steady magnetoshear studies indicate viscoplastic behavior with stronger dependence of static yield stress on magnetization than a dipolar coupling that was operational in the dynamic yield stress. Magnetosweep measurements at constant shear rate showed interesting viscous relaxation at high magnetic fields. We also explored dynamical elastic behavior through oscillatory magnetorheological studies under both strain sweep and frequency sweep modes, and showed glass transition like phenomenon occurring in them above critical shear amplitudes.

  15. CS-dependent response probability in an auditory masked-detection task: considerations based on models of Pavlovian conditioning.

    Science.gov (United States)

    Mason, Christine R; Idrobo, Fabio; Early, Susan J; Abibi, Ayome; Zheng, Ling; Harrison, J Michael; Carney, Laurel H

    2003-05-01

    Experimental studies were performed using a Pavlovian-conditioned eyeblink response to measure detection of a variable-sound-level tone (T) in a fixed-sound-level masking noise (N) in rabbits. Results showed an increase in the asymptotic probability of conditioned responses (CRs) to the reinforced TN trials and a decrease in the asymptotic rate of eyeblink responses to the non-reinforced N presentations as a function of the sound level of the T. These observations are consistent with expected behaviour in an auditory masked detection task, but they are not consistent with predictions from a traditional application of the Rescorla-Wagner or Pearce models of associative learning. To implement these models, one typically considers only the actual stimuli and reinforcement on each trial. We found that by considering perceptual interactions and concepts from signal detection theory, these models could predict the CS dependence on the sound level of the T. In these alternative implementations, the animals response probabilities were used as a guide in making assumptions about the "effective stimuli".

  16. A low-cost biofuel cell with pH-dependent power output based on porous carbon as matrix.

    Science.gov (United States)

    Liu, Ying; Wang, Mingkui; Zhao, Feng; Liu, Baifeng; Dong, Shaojun

    2005-08-19

    A glucose/O2 biofuel cell (BFC) possessing a pH-dependent power output was fabricated by taking porous carbon (PC) as the matrix to load glucose oxidase or fungi laccase as the catalysts. The electrolytes in the anode and cathode compartments contain ferrocene monocarboxylic acid and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt as the mediators, respectively. The power of the BFC was enhanced significantly by using PC as the matrix, rather than glassy carbon electrode. Additionally, the power output of the BFC decreases as the pH of the solution increases from 4.0 to 7.0, which provides a simple and efficient method to achieve the required power output. More importantly, the BFC can operate at pH 6.0, and even at pH 7.0, which overcomes the requirement for cathode solutions of pHBFC at neutral pH may provide a means to power medical devices implanted in physiological systems. The facile and low-cost fabrication of this BFC may enable its development for other applications.

  17. The semantic representation of event information depends on the cue modality: an instance of meaning-based retrieval.

    Science.gov (United States)

    Karlsson, Kristina; Sikström, Sverker; Willander, Johan

    2013-01-01

    The semantic content, or the meaning, is the essence of autobiographical memories. In comparison to previous research, which has mainly focused on the phenomenological experience and the age distribution of retrieved events, the present study provides a novel view on the retrieval of event information by quantifying the information as semantic representations. We investigated the semantic representation of sensory cued autobiographical events and studied the modality hierarchy within the multimodal retrieval cues. The experiment comprised a cued recall task, where the participants were presented with visual, auditory, olfactory or multimodal retrieval cues and asked to recall autobiographical events. The results indicated that the three different unimodal retrieval cues generate significantly different semantic representations. Further, the auditory and the visual modalities contributed the most to the semantic representation of the multimodally retrieved events. Finally, the semantic representation of the multimodal condition could be described as a combination of the three unimodal conditions. In conclusion, these results suggest that the meaning of the retrieved event information depends on the modality of the retrieval cues.

  18. Cost-based Optimal Distributed Generation Planning with Considering Voltage Depended Loads and Power Factor of Distributed Generation

    Directory of Open Access Journals (Sweden)

    Babak Yousefi-Khangah

    2014-12-01

    Full Text Available If determination of location and size of Distributed Generation (DG are applied accurately, the DG’s ability will improve the network situation and reduce operation costs. In this paper, various market conditions are considered to maximize the benefit of DG’s presence and make a trade off among advantages of DG, network situation, and Distribution Company (DISCO owners. To determine the optimal location and size of DG, two methods of the cost minimization and the nodal pricing are combined. In addition to evaluating the impact of parameters such as variation of energy price and load on objective function, effect of these parameters on location and size of DG is considered. To confirm the results, impact of loads which are dependent on voltage and variation of the power factor of the DG units is applied and then effect of power factor on optimal location and size of DG is shown. A method is proposed for convergence of different results which is caused by different power factors. To observe long-term impact of the DG’s presence in the network, a load growth for five years is considered annually. Study is carried out on IEEE30 bus test circuit.

  19. Size-dependent dynamic stability analysis of microbeams actuated by piezoelectric voltage based on strain gradient elasticity theory

    Energy Technology Data Exchange (ETDEWEB)

    Sahmani, Saeid; Bahrami, Mohsen [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2015-01-15

    In the current paper, dynamic stability analysis of microbeams subjected to piezoelectric voltage is presented in which the microbeam is integrated with piezoelectric layers on the lower and upper surfaces. Both of the flutter and divergence instabilities of microbeams with clamped-clamped and clamped-free boundary conditions are predicted corresponding to various values of applied voltage. To take size effect into account, the classical Timoshenko beam theory in conjunction with strain gradient elasticity theory is utilized to develop nonclassical beam model containing three additional internal length scale parameters. By using Hamilton's principle, the higher-order governing differential equations and associated boundary conditions are derived. Afterward, generalized differential quadrature method is employed to discretize the size-dependent governing differential equations along with clamped-clamped and clamped-free end supports. The critical piezoelectric voltages corresponding to various values dimensionless length scale parameter are evaluated and compared with those predicted by the classical beam theory. It is revealed that in the case of clamped-free boundary conditions, the both of flutter and divergence instabilities occur. However, for the clamped-clamped microbeams, only divergence instability takes place.

  20. A Sequential, Implicit, Wavelet-Based Solver for Multi-Scale Time-Dependent Partial Differential Equations

    Directory of Open Access Journals (Sweden)

    Donald A. McLaren

    2013-04-01

    Full Text Available This paper describes and tests a wavelet-based implicit numerical method for solving partial differential equations. Intended for problems with localized small-scale interactions, the method exploits the form of the wavelet decomposition to divide the implicit system created by the time-discretization into multiple smaller systems that can be solved sequentially. Included is a test on a basic non-linear problem, with both the results of the test, and the time required to calculate them, compared with control results based on a single system with fine resolution. The method is then tested on a non-trivial problem, its computational time and accuracy checked against control results. In both tests, it was found that the method requires less computational expense than the control. Furthermore, the method showed convergence towards the fine resolution control results.

  1. Investigation of pump-wavelength dependence of terahertz-wave parametric oscillator based on LiNbO3

    Institute of Scientific and Technical Information of China (English)

    Sun Bo; Liu Jin-Song; Li En-Bang; Yao Jian-Quan

    2009-01-01

    This paper investigates the performances of terahertz-wave parametric oscillators (TPOs) based on the LiNbO3 crystal at different pump wavelengths. The calculated results show that TPO characteristics, including the frequency tuning range, the THz-wave gain and the stability of THz-wave output direction based on the Si-prism coupler, can be significantly improved by using a short-wavelength pump. It also demonstrates that a long-wavelength-pump allows the employment of a short TPO cavity due to an enlarged phase-matching angle, that is, an increased angular separation between the pump and oscillated Stokes beams under the THz-wave generation at a specific frequency. The study provides an useful guide and a theoretical basis for the further improvement of TPO systems.

  2. Assessing age-related grey matter decline with Voxel-Based Morphometry depends significantly on segmentation and normalisation procedures

    Directory of Open Access Journals (Sweden)

    Dorothée V Callaert

    2014-06-01

    Full Text Available Healthy ageing coincides with a progressive decline of brain grey matter (GM ultimately affecting the entire brain. For a long time, manual delineation-based volumetry within predefined regions of interest (ROI has been the gold standard for assessing such degeneration. Voxel-Based Morphometry (VBM offers an automated alternative approach that, however, relies critically on the segmentation and spatial normalization of a large collection of images from different subjects. This can be achieved via different algorithms, with SPM5/SPM8, DARTEL of SPM8 and FSL tools (FAST, FNIRT being three of the most frequently used. We complemented these voxel based measurements with a ROI based approach, whereby the ROIs are defined by transforms of an atlas (containing different tissue probability maps as well as predefined anatomic labels to the individual subject images in order to obtain volumetric information at the level of the whole brain or within separate ROIs. Comparing GM decline between 21 young subjects (mean age 23 and 18 elderly (mean age 66 revealed that volumetric measurements differed significantly between methods. The unified segmentation/normalisation of SPM5/SPM8 revealed the largest age-related differences and DARTEL the smallest, with FSL being more similar to the DARTEL approach. Method specific differences were substantial after segmentation and most pronounced for the cortical structures in close vicinity to major sulci and fissures. Our findings suggest that algorithms that provide only limited degrees of freedom for local deformations (such as the unified segmentation and normalisation of SPM5/SPM8 tend to overestimate between-group differences in VBM results when compared to methods providing more flexible warping. This difference seems to be most pronounced if the anatomy of one of the groups deviates from custom templates, a finding that is of particular importance when results are compared across studies using different VBM

  3. Quantum fluid dynamics based current-density functional study of a helium atom in a strong time-dependent magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Vikas [Quantum Chemistry Group, Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University, 160014 Chandigrah (India)

    2011-02-15

    Evolution of the helium atom in a strong time-dependent (TD) magnetic field (B) of strength up to 10{sup 11} G is investigated through a quantum fluid dynamics (QFD) based current-density functional theory (CDFT). The TD-QFD-CDFT computations are performed through numerical solution of a single generalized nonlinear Schroedinger equation employing vector exchange-correlation potentials and scalar exchange-correlation density functionals that depend both on the electronic charge-density and the current-density. The results are compared with that obtained from a B-TD-QFD-DFT approach (based on conventional TD-DFT) under similar numerical constraints but employing only scalar exchange-correlation potential dependent on electronic charge-density only. The B-TD-QFD-DFT approach, at a particular TD magnetic field-strength, yields electronic charge- and current-densities as well as exchange-correlation potential resembling with that obtained from the time-independent studies involving static (time-independent) magnetic fields. However, TD-QFD-CDFT electronic charge- and current-densities along with the exchange-correlation potential and energy differ significantly from that obtained using B-TD-QFD-DFT approach, particularly at field-strengths >10{sup 9} G, representing dynamical effects of a TD field. The work concludes that when a helium atom is subjected to a strong TD magnetic field of order >10{sup 9} G, the conventional TD-DFT based approach differs 'dynamically' from the CDFT based approach under similar computational constraints. (author)

  4. [Dependence disorders in psychopathology].

    Science.gov (United States)

    Fernandez, L; Sztulman, H

    1999-01-01

    Research concerning the psychopathological aspects of dependence implicates a wide range of behaviors reassembled under the term of "dependence behaviors": sexual, medical, alcoholic and tobacco dependencies. Speech samples of dependent subjects show that encountering the object of dependence (product, element, ...) introduces a particular form of organized psychological processes. According to several authors, psychopathological dependence can be attributed to: early personality development; failures in the separation-individuation processes; disorders in mother-infant interactions; and a deficit in the psychological functioning of the subjects. For psychopathology, the dependence cannot be reduced to physiological dependence on the product but is understood rather in terms of a complex process indicative of either specific or non-specific suffering which is addressed by abused substance that represents a solution--the effects of which constitute the addictive process. Understanding this process requires an analysis of the psychopathological dependence from a triple meta-psychological viewpoint (topographical, dynamic, economic). Such analysis allows for a psychoanalytical theoretical interpretation of dependence based on three models: pleasure, narcissism and stress reduction. At the same time, the analysis extends the examination of psychopathological dependence towards issues concerning the body. Such body issues are critically placed between the biological and the psychological processes.

  5. The dependence of the soft X ray spectral slope with radio property, luminosity, and redshift, for a large sample of AGN from the Einstein IPC data base

    Science.gov (United States)

    Brunner, H.; Worrall, D. M.; Wilkes, Belinda J.; Elvis, Martin

    1989-01-01

    The dependence of the soft X-ray spectral slope on radio, optical and X-ray properties, and on redshift are reported for a large sample of Active Galactic Nuclei (AGN). The sample includes 317 optically and radio-selected AGN from a preliminary version of the Einstein Imaging Proportional Counter (IPC) quasar and AGN data base. The main results are: the difference in X-ray slope between radio-loud and radio-quiet AGN were confirmed for an independent and much larger sample of sources; a difference in X-ray slope between flat and steep radio spectrum AGN is observed only in high luminosity sub-sample; in flat radio spectrum AGNs there is an indication for a dependence of the X-ray spectral index on X-ray luminosity redshift and alpha sub 0x.

  6. Physics-Based Compact Model for CIGS and CdTe Solar Cells: From Voltage-Dependent Carrier Collection to Light-Enhanced Reverse Breakdown: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xingshu; Alam, Muhammad Ashraful; Raguse, John; Garris, Rebekah; Deline, Chris; Silverman, Timothy

    2015-10-15

    In this paper, we develop a physics-based compact model for copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe) heterojunction solar cells that attributes the failure of superposition to voltage-dependent carrier collection in the absorber layer, and interprets light-enhanced reverse breakdown as a consequence of tunneling-assisted Poole-Frenkel conduction. The temperature dependence of the model is validated against both simulation and experimental data for the entire range of bias conditions. The model can be used to characterize device parameters, optimize new designs, and most importantly, predict performance and reliability of solar panels including the effects of self-heating and reverse breakdown due to partial-shading degradation.

  7. Add-Drop Filter Based on Wavelength-Dependent Light Interlink between Lithium-Niobate Microwaveguide Chip and Microfiber Knot Ring

    Directory of Open Access Journals (Sweden)

    Suxu Zhou

    2016-06-01

    Full Text Available In this paper, we experimentally demonstrate an add-drop filter based on wavelength-dependent light coupling between a lithium-niobate (LN microwaveguide chip and a microfiber knot ring (MKR. The MKR was fabricated from a standard single-mode fiber, and the LN microwaveguide chip works as a robust substrate to support the MKR. The guided light can be transmitted through add and drop functionality and the behaviors of the add-drop filter can be clearly observed. Furthermore, its performance dependence on the MKR diameter is also studied experimentally. The approach, using a LN microwaveguide chip as a platform to couple and integrate the MKR, may enable us to realize an optical interlink between the microstructured chip and the micro/nano fiber-optic device.

  8. Characterization of different FAD-dependent glucose dehydrogenases for possible use in glucose-based biosensors and biofuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zafar, Muhammad Nadeem; Beden, Najat; Gorton, Lo [Lund University, Department of Biochemistry and Structural Biology, Lund (Sweden); Leech, Donal [National University of Ireland Galway, School of Chemistry, Galway (Ireland); Sygmund, Christoph; Ludwig, Roland [BOKU-University of Natural Resources and Life Sciences Vienna, Food Biotechnology Laboratory, Department of Food Sciences and Technology, Wien (Austria)

    2012-02-15

    In this study, different flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenases (FADGDHs) were characterized electrochemically after ''wiring'' them with an osmium redox polymer [Os(4,4'-dimethyl-2,2'-bipyridine){sub 2}(PVI){sub 10}Cl]{sup +} on graphite electrodes. One tested FADGDH was that recently discovered in Glomerella cingulata (GcGDH), another was the recombinant form expressed in Pichia pastoris (rGcGDH), and the third was a commercially available glycosylated enzyme from Aspergillus sp. (AspGDH). The performance of the Os-polymer ''wired'' GDHs on graphite electrodes was tested with glucose as the substrate. Optimal operational conditions and analytical characteristics like sensitivity, linear ranges and current density of the different FADGDHs were determined. The performance of all three types of FADGDHs was studied at physiological conditions (pH 7.4). The current densities measured at a 20 mM glucose concentration were 494 {+-} 17, 370 {+-} 24, and 389 {+-} 19 {mu}A cm{sup -2} for GcGDH, rGcGDH, and AspGDH, respectively. The sensitivities towards glucose were 2.16, 1.90, and 1.42 {mu}A mM{sup -1} for GcGDH, rGcGDH, and AspGDH, respectively. Additionally, deglycosylated rGcGDH (dgrGcGDH) was investigated to see whether the reduced glycosylation would have an effect, e.g., a higher current density, which was indeed found. GcGDH/Os-polymer modified electrodes were also used and investigated for their selectivity for a number of different sugars. (orig.)

  9. Discovery of Potent Non-Nucleoside Inhibitors of Dengue Viral RNA-Dependent RNA Polymerase from a Fragment Hit Using Structure-Based Drug Design.

    Science.gov (United States)

    Yokokawa, Fumiaki; Nilar, Shahul; Noble, Christian G; Lim, Siew Pheng; Rao, Ranga; Tania, Stefani; Wang, Gang; Lee, Gladys; Hunziker, Jürg; Karuna, Ratna; Manjunatha, Ujjini; Shi, Pei-Yong; Smith, Paul W

    2016-04-28

    The discovery and optimization of non-nucleoside dengue viral RNA-dependent-RNA polymerase (RdRp) inhibitors are described. An X-ray-based fragment screen of Novartis' fragment collection resulted in the identification of a biphenyl acetic acid fragment 3, which bound in the palm subdomain of RdRp. Subsequent optimization of the fragment hit 3, relying on structure-based design, resulted in a >1000-fold improvement in potency in vitro and acquired antidengue activity against all four serotypes with low micromolar EC50 in cell-based assays. The lead candidate 27 interacts with a novel binding pocket in the palm subdomain of the RdRp and exerts a promising activity against all clinically relevant dengue serotypes.

  10. Mechanism-based pharmacokinetic-pharmacodynamic modeling of concentration-dependent hysteresis and biphasic electroencephalogram effects of alphaxalone in rats.

    Science.gov (United States)

    Visser, S A G; Smulders, C J G M; Reijers, B P R; Van der Graaf, P H; Peletier, L A; Danhof, M

    2002-09-01

    The neuroactive steroid alphaxalone reveals a complex biphasic concentration-effect relationship using the 11.5 to 30 Hz frequency band of the electroencephalogram (EEG) as biomarker. The purpose of the present investigation was to develop a mechanism-based pharmacokinetic-pharmacodynamic model to describe this observation. The proposed model is based on receptor theory and aims to separate the drug-receptor interaction from the transduction of the initial stimulus into the observed biphasic response. Individual concentration-time courses of alphaxalone were obtained in combination with continuous recording of the EEG parameter. Alphaxalone was administered intravenously in various dosages. The pharmacokinetics were described by a two-compartment model, and parameter estimates for clearance, intercompartmental clearance, volume of distribution 1 and 2 were 158 +/- 29 ml. min(-1). kg(-1), 143 +/- 31 ml. min(-1). kg(-1), 122 +/- 20 ml. kg(-1) and 606 +/- 48 ml. kg(-1), respectively. Concentration-effect relationships exhibited a biphasic pattern and delay in onset of effect. The hysteresis was described on the basis of an effect-compartment model with C(max) as covariate. The pharmacodynamic model consisted of a receptor model, featuring a monophasic saturable receptor activation model in combination with a biphasic stimulus-response model. The in vivo affinity (K(PD)) was estimated at 432 +/- 26 ng. ml(-1). Unique parameter estimates were obtained that were independent of the dose and the duration of the infusion. In conclusion, we have shown that this mechanism-based approach, which separates drug- and system-related properties in vivo, was successfully applied for the characterization of the biphasic effect versus time patterns of alphaxalone. The model should be of use in the characterization of other biphasic responses.

  11. Time-Dependent Fatigue Crack Propagation Behavior of Two Solid-Solution-Strengthened Ni-Based Superalloys—INCONEL 617 and HAYNES 230

    Science.gov (United States)

    Ma, Longzhou; Roy, Shawoon K.; Hasan, Muhammad H.; Pal, Joydeep; Chatterjee, Sudin

    2012-02-01

    The fatigue crack propagation (FCP) as well as the sustained loading crack growth (SLCG) behavior of two solid-solution-strengthened Ni-based superalloys, INCONEL 617 (Special Metals Corporation Family of Companies) and HAYNES 230 (Haynes International, Inc., Kokomo, IN), were studied at increased temperatures in laboratory air under a constant stress-intensity-factor ( K) condition. The crack propagation tests were conducted using a baseline cyclic triangular waveform with a frequency of 1/3 Hz. Various hold times were imposed at the maximum load of a fatigue cycle to study the hold time effect. The results show that a linear elastic fracture mechanics (LEFM) parameter, stress intensity factor ( K), is sufficient to describe the FCP and SLCG behavior at the testing temperatures ranging from 873 K to 1073 K (600 °C to 800 °C). As observed in the precipitation-strengthened superalloys, both INCONEL 617 and HAYNES 230 exhibited the time-dependent FCP, steady SLCG behavior, and existence of a damage zone ahead of crack tip. A thermodynamic equation was adapted to correlate the SLCG rates to determine thermal activation energy. The fracture modes associated with crack propagation behavior were discussed, and the mechanism of time-dependent FCP as well as SLCG was identified. Compared with INCONEL 617, the lower crack propagation rates of HAYNES 230 under the time-dependent condition were ascribed to the different fracture mode and the presence of numerous W-rich M6C-type and Cr-rich M23C6-type carbides. Toward the end, a phenomenological model was employed to correlate the FCP rates at cycle/time-dependent FCP domain. All the results suggest that an environmental factor, the stress assisted grain boundary oxygen embrittlement (SAGBOE) mechanism, is mainly responsible for the accelerated time-dependent FCP rates of INCONEL 617 and HAYNES 230.

  12. Geometry dependence of RMT-based methods to extract the low-energy constants Sigma and F

    CERN Document Server

    Lehner, Christoph; Hashimoto, Shoji; Wettig, Tilo

    2011-01-01

    The lowest-order low-energy constants $\\Sigma$ and $F$ of chiral pertubation theory can be extracted from lattice data using methods based on the equivalence of random matrix theory (RMT) and QCD in the epsilon regime. We discuss how the choice of the lattice geometry affects such methods. In particular, we show how to minimize systematic deviations from RMT by an optimal choice of the lattice geometry in the case of two light quark flavors. We illustrate our findings by determining $\\Sigma$ and $F$ from lattice configurations with two dynamical overlap fermions generated by JLQCD, using two different lattice geometries.

  13. Size-dependent characteristics of electrostatically actuated fluid-conveying carbon nanotubes based on modified couple stress theory.

    Science.gov (United States)

    Fakhrabadi, Mir Masoud Seyyed; Rastgoo, Abbas; Ahmadian, Mohammad Taghi

    2013-01-01

    The paper presents the effects of fluid flow on the static and dynamic properties of carbon nanotubes that convey a viscous fluid. The mathematical model is based on the modified couple stress theory. The effects of various fluid parameters and boundary conditions on the pull-in voltages are investigated in detail. The applicability of the proposed system as nanovalves or nanosensors in nanoscale fluidic systems is elaborated. The results confirm that the nanoscale system studied in this paper can be properly applied for these purposes.

  14. Cytotoxicity of cyclometalated platinum complexes based on tridentate NCN and CNN-coordinating ligands: remarkable coordination dependence.

    Science.gov (United States)

    Vezzu, Dileep A K; Lu, Qun; Chen, Yan-Hua; Huo, Shouquan

    2014-05-01

    A series of cyclometalated platinum complexes with diverse coordination patterns and geometries were screened for their anticancer activity. It was discovered that the N^C^N-coordinated platinum complex based on 1,3-di(pyridyl)benzene displayed much higher cytotoxicity against human lung cancer cells NCI-H522, HCC827, and NCI-H1299, and human prostate cancer cell RV1 than cisplatin. In a sharp contrast, the C^N^N-coordinated platinum complex based on 6-phenyl-2,2'-bipyridine was ineffective on these cancer cells. This remarkable difference in cytotoxicity displayed by N^C^N- and C^N^N-coordinated platinum complexes was related to the trans effect of the carbon donor in the cyclometalated platinum complexes, which played a crucial role in facilitating the dissociation of the chloride ligand to create an active binding site. The DNA binding was studied for the N^C^N-coordinated platinum complex using electrophoresis and emission titration. The cellular uptake observed by fluorescent microscope showed that the complex is largely concentrated in the cytoplasm. The possible pathways for the cell apoptosis were studied by western blot analysis and the activation of PARP via caspase 7 was observed.

  15. Explicating an evidence-based, theoretically informed, mobile technology-based system to improve outcomes for people in recovery for alcohol dependence.

    Science.gov (United States)

    Gustafson, David H; Shaw, Bret R; Isham, Andrew; Baker, Timothy; Boyle, Michael G; Levy, Michael

    2011-01-01

    Post-treatment relapse to uncontrolled alcohol use is common. Currently available communication technology can use existing models for relapse prevention to cost-effectively improve long-term relapse prevention. This paper describes: (1) research-based elements of alcohol consumption-related relapse prevention and how they can be encompassed in self-determination theory (SDT) and Marlatt's cognitive behavioral relapse prevention model, (2) how technology could help address the needs of people seeking recovery, (3) a technology-based prototype, organized around sexual transmitted disease and Marlatt's model, and (4) how we are testing a system based on the ideas in this article and related ethical and operational considerations.

  16. 基于流程案例簇的任务关系挖掘算法%Mining algorithm of task dependencies based on process case clusters

    Institute of Scientific and Technical Information of China (English)

    鲁法明; 曾庆田; 包云霞; 段华; 张昊

    2013-01-01

    To make process discovery,a case cluster-based derivation method of task dependencies was presented.The basic cases were classified into case clusters according to feature vectors.According to task traces of basic cases,task dependencies among case clusters were mined,and a modeling and discovery approach of loop structures based on loop-unit was proposed.All the task dependencies and loop structures in processes were generated from event logs.Compared to the existing methods,the proposed method could correctly handle such situations that task dependencies change with case attribute values.Based on the mined task dependencies and loop structure,a behavior-equivalent process model was obtained as long as the event log was complete.%为了进行流程发现,提出一种基于流程案例簇的任务关系挖掘方法.该方法首先将基本案例按照特征向量分为多个案例簇,根据基本案例的任务轨迹对案例簇中任务间的依赖关系进行挖掘;然后给出了基于循环基元的循环结构建模和挖掘方法,最终可以从事件日志导出流程中完整的任务依赖关系以及存在的循环结构.所提方法能正确处理任务依赖关系随案例属性取值不同而变化的情况.只要日志完备,基于挖掘到的任务关系和循环结构就能得到一个与原流程行为等价的流程模型.

  17. Na(+) dependent acid-base transporters in the choroid plexus; insights from slc4 and slc9 gene deletion studies.

    Science.gov (United States)

    Christensen, Henriette L; Nguyen, An T; Pedersen, Fredrik D; Damkier, Helle H

    2013-10-22

    The choroid plexus epithelium (CPE) is located in the ventricular system of the brain, where it secretes the majority of the cerebrospinal fluid (CSF) that fills the ventricular system and surrounds the central nervous system. The CPE is a highly vascularized single layer of cuboidal cells with an unsurpassed transepithelial water and solute transport rate. Several members of the slc4a family of bicarbonate transporters are expressed in the CPE. In the basolateral membrane the electroneutral Na(+) dependent Cl(-)/HCO3 (-) exchanger, NCBE (slc4a10) is expressed. In the luminal membrane, the electrogenic Na(+):HCO3 (-) cotransporter, NBCe2 (slc4a5) is expressed. The electroneutral Na(+):HCO3 (-) cotransporter, NBCn1 (slc4a7), has been located in both membranes. In addition to the bicarbonate transporters, the Na(+)/H(+) exchanger, NHE1 (slc9a1), is located in the luminal membrane of the CPE. Genetically modified mice targeting slc4a2, slc4a5, slc4a7, slc4a10, and slc9a1 have been generated. Deletion of slc4a5, 7 or 10, or slc9a1 has numerous impacts on CP function and structure in these mice. Removal of the transporters affects brain ventricle size (slc4a5 and slc4a10) and intracellular pH regulation (slc4a7 and slc4a10). In some instances, removal of the proteins from the CPE (slc4a5, 7, and 10) causes changes in abundance and localization of non-target transporters known to be involved in pH regulation and CSF secretion. The focus of this review is to combine the insights gathered from these knockout mice to highlight the impact of slc4 gene deletion on the CSF production and intracellular pH regulation resulting from the deletion of slc4a5, 7 and 10, and slc9a1. Furthermore, the review contains a comparison of the described human mutations of these genes to the findings in the knockout studies. Finally, the future perspective of utilizing these proteins as potential targets for the treatment of CSF disorders will be discussed.

  18. A Simple Guiding Principle for the Temperature Dependence of the Solubility of Light Gases in Imidazolium-based Ionic Liquids Derived from Molecular Simulations

    CERN Document Server

    Kerlé, Daniela; Ludwig, Ralf; Wohlrab, Sebastian; Paschek, Dietmar

    2015-01-01

    We have determined the temperature dependence of the solvation behavior of a large collection of light gases in imidazolium-based Ionic Liquids (ILs) with the help of extensive molecular dynamics simulations. The solubility of molecular hydrogen, oxygen, nitrogen, methane, krypton, argon, neon and carbon dioxide in the imidazolium based ILs of type 1-n-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C$_n$mim][NTf$_2$]) with varying chain lengths $n\\!=\\!2,4,6,8$ are computed for a temperature range between $300\\,\\mbox{K}$ and $500\\,\\mbox{K}$ at $1\\,\\mbox{bar}$. By applying Widom's particle insertion technique and Bennet's overlapping distribution method, we are able to determine the temperature dependent solvation free energies for those selected light gases in simulated imidazolium based ILs with high statistical accuracy. Our simulations show that the magnitude of the solvation free energy of a gas molecule at a chosen reference temperature and its temperature-derivatives are intimately related...

  19. Temperature dependent structures and properties of Bi0.5Na0.5TiO3-based lead free piezoelectric composite.

    Science.gov (United States)

    Zhang, Ji; Sun, Lei; Geng, Xiao-Yu; Zhang, Bin-Bin; Yuan, Guo-Liang; Zhang, Shan-Tao

    2016-07-05

    The thermal depolarization around 100 °C of the Bi0.5Na0.5TiO3-based piezoelectric solid solutions leads to the disappearance of macroscopic ferroelectric/piezoelectric properties and remains a long-standing obstacle for their actual applications. In this communication, we report lead-free piezoelectric composites of 0.94Bi0.5Na0.5TiO3-0.06BaTiO3:0.5ZnO (BNT-6BT:0.5ZnO, where 0.5 is the mole ratio of ZnO to BNT-6BT) with deferred thermal depolarization, which is experimentally confirmed by systematic temperature dependent dielectric, ferroelectric, piezoelectric measurements. Especially, based on temperature dependent X-ray diffraction measurements on unpoled and poled samples, thermal depolarization is confirmed to have no relationship with the structural phase transition, the possible mechanism for the deferred thermal depolarization is correlated with the ZnO-induced local electric field which can suppress the depolarization field. We believe our results may be helpful for understanding the origin of thermal depolarization in BNT-based piezoelectric materials, and thus provide an effective way to overcoming this obstacle.

  20. Bio-Psycho-Spiritual Modeling in Drug Dependents and Compiling of Intervention Program for Promotion of Resiliency Based on Cognitive Narratology and Positive Psychology

    Directory of Open Access Journals (Sweden)

    Ezat ollah Kordmirza Nikoozadeh

    2009-08-01

    Full Text Available Introduction: Since the past few decades, the concentration of researches on drug abuse and drugs dependency have shift from risk factor to protective factors. In the past two decades, the concept of resiliency was increasingly considered by developmental psychology. The concentration shifted from risk to resiliency originates from disadvantage in emphasizing on identification of risk factors. Method: Target population was all volunteer addicts who referred to clinics in Tehran city. The group selected based on random cluster sampling. In total 319 persons (male composed of two groups, dependent to drug (150 persons and independent to drug (169 persons were participated in research and in general, 108 questionnaires of non-addicts and 126 of addicts were analyzed. In order to determine the fit model based on assumed variables in the research, by utilizing LISREL softwar99e, initially the relation between primary fundamental variables and final endogenous variables were reviewed. In continuation, the - relations between intermediary and endogenous variables were determined. Results: The results showed the fitting of predicted model of resiliency. Conclusion: In this research the program based on bio-psycho-spiritual model for instructional intervention in order to enhance of resiliency of addict people provided.

  1. Neil3-dependent base excision repair regulates lipid metabolism and prevents atherosclerosis in Apoe-deficient mice

    DEFF Research Database (Denmark)

    Skarpengland, Tonje; Holm, Sverre; Scheffler, Katja

    2016-01-01

    Increasing evidence suggests that oxidative DNA damage accumulates in atherosclerosis. Recently, we showed that a genetic variant in the human DNA repair enzyme NEIL3 was associated with increased risk of myocardial infarction. Here, we explored the role of Neil3/NEIL3 in atherogenesis by both cl...... of oxidative DNA damage. These results suggest a novel role for the DNA glycosylase Neil3 in atherogenesis in balancing lipid metabolism and macrophage function, potentially independently of genome-wide canonical base excision repair of oxidative DNA damage....... an atherogenic lipid profile, increased hepatic triglyceride levels and attenuated macrophage cholesterol efflux capacity. Apoe-/- Neil3-/- mice showed marked alterations in several pathways affecting hepatic lipid metabolism, but no genotypic alterations in genome integrity or genome-wide accumulation...

  2. Size-dependent dynamic pull-in instability of vibrating electrically actuated microbeams based on the strain gradient elasticity theory

    Science.gov (United States)

    Sedighi, Hamid M.

    2014-02-01

    This paper presents the impact of vibrational amplitude on the dynamic pull-in instability and fundamental frequency of actuated microbeams by introducing the second order frequency-amplitude relationship. The nonlinear governing equation of microbeam predeformed by an electric force including the fringing field effect, based on the strain gradient elasticity theory is considered. The predicted results of the strain gradient elasticity theory are compared with the outcomes that arise from the classical and modified couple stress theory. The influences of basic nondimensional parameters on the pull-in instability as well as the natural frequency are investigated by a powerful asymptotic approach namely the Parameter Expansion Method (PEM). It is demonstrated that two terms in series expansions are sufficient to produce an acceptable solution of the microstructure. The phase portrait of the microstructure shows that by increasing the actuation voltage parameter, the stable center point loses its stability and coalesces with unstable saddle node.

  3. Dual-peptide-functionalized albumin-based nanoparticles with ph-dependent self-assembly behavior for drug delivery.

    Science.gov (United States)

    Chen, Bin; He, Xiao-Yan; Yi, Xiao-Qing; Zhuo, Ren-Xi; Cheng, Si-Xue

    2015-07-22

    Drug delivery has become an important strategy for improving the chemotherapy efficiency. Here we developed a multifunctionalized nanosized albumin-based drug-delivery system with tumor-targeting, cell-penetrating, and endolysosomal pH-responsive properties. cRGD-BSA/KALA/DOX nanoparticles were fabricated by self-assembly through electrostatic interaction between cell-penetrating peptide KALA and cRGD-BSA, with cRGD as a tumor-targeting ligand. Under endosomal/lysosomal acidic conditions, the changes in the electric charges of cRGD-BSA and KALA led to the disassembly of the nanoparticles to accelerate intracellular drug release. cRGD-BSA/KALA/DOX nanoparticles showed an enhanced inhibitory effect in the growth of αvβ3-integrin-overexpressed tumor cells, indicating promising application in cancer treatments.

  4. Shrinkage Behavior of Polystyrene-based Foam Molded Parts Depending on Volatile Matter Content and Other Factors

    Science.gov (United States)

    Ghafafian, Carineh

    Polymer foam materials play a large role in the modern world. Expanded polystyrene (EPS) bead foam is a lightweight, low density, and good thermal and acoustic insulating material whose properties make it attractive for a number of applications, especially as building insulation. However, EPS also experiences post-molding shrinkage; it shrinks dimensionally from its molded size after processing. This means parts must be stored in warehouses until they are considered stable by the industry standard, DIN EN 1603. This often takes 11--18 weeks and is thus very timely and expensive. This study aims to decrease the post-molding shrinkage time of EPS foam by understanding the mechanisms of shrinkage behavior. Samples were split into two groups based on their amount of initial volatile matter content and storage conditions, then compared to a control group. Based on thermogravimetric analysis and gas chromatography with mass spectrometry, the volatile matter content and composition was found to not be the sole contributor to EPS foam dimensional stability. Residual stress testing was done with the hole drilling method and Raman spectroscopy. As this type of testing has not been done with polymer foams before, the aim was to see if either method could reliably produce residual stress values. Both methods measured residual stress values with unknown accuracy. All samples stored at a higher temperature (60°C) reached dimensional stability by the end of this study. Thus, air diffusion into EPS foam, encouraged by the high temperature storage, was found to play a significant role in post-molding shrinkage.

  5. Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

  6. Design and analysis of a novel single-mode single-polarization photonic crystal fibre based on polarization-dependent coupling and absorption effect

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao-Yi; Zhang Fang-Di; Zhang Min; Ye Pei-Da

    2007-01-01

    A novel single-mode single-polarization (SMSP) photonic crystal fibre has been proposed and analysed based on the polarization-dependent coupling and absorption effect via a full-vector finite element method with perfectly matched layers. The numerical results predict that very efficient SMSP operation can be achieved with both high bandwidth and high extinction ratio at low loss penalty. Effects of the fibre structural parameters on the SMSP bandwidth and extinction ratio have been explored, which will provide useful guide for the design and fabrication of the fibre. The results obtained will be instructive for the realization of new SMSP fibres with high performance.

  7. Pressure dependence of the thermoelectric power of the iron-based high-T{sub c} superconductor SmFeAsO{sub 0.85}

    Energy Technology Data Exchange (ETDEWEB)

    Kang, N; Auban-Senzier, P; Pasquier, C R [Laboratoire de Physique des Solides, Universite Paris-Sud, 91405 Orsay (France); Ren, Z A; Yang, J; Che, G C; Zhao, Z X [National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China)], E-mail: kang@lps.u-psud.fr

    2009-02-15

    We have measured the thermoelectric power S of the iron-based superconductor SmFeAsO{sub 0.85} as a function of temperature at various pressures up to 1.1 GPa. The magnitude of thermoelectric power increases with decreasing temperature and exhibits a maximum at a characteristic temperature T* ({approx}110 K at ambient pressure), whereas the temperature dependence of the resistance shows metallic behavior. The superconducting transition temperature T{sub c} and T* decrease monotonically with pressure. We discuss our results in terms of the effects of Fermi-surface nesting and orbit degeneracy in the new iron-oxypnictides.

  8. Combined microscopies study of the C-contamination induced by extreme-ultraviolet radiation: A surface-dependent secondary-electron-based model

    Science.gov (United States)

    Prezioso, S.; Donarelli, M.; Bisti, F.; Palladino, L.; Santucci, S.; Spadoni, S.; Avaro, L.; Liscio, A.; Palermo, V.; Ottaviano, L.

    2012-05-01

    SiO2 and Al2O3 surfaces exposed to periodically modulated extreme ultraviolet (EUV) light (λ = 46.9 nm) have been investigated at the μm scale by optical microscopy, scanning electron microscopy, scanning Auger microscopy, atomic force microscopy, and Kelvin probe force microscopy. The formation of a carbon contamination layer preserving the same periodical modulation of the EUV dose has been observed. The mechanisms of hydrocarbon molecules deposition have been studied with the help of correlation plots between the modulated Auger signal and the corresponding EUV dose. A surface-dependent secondary-electron-based model has been proposed.

  9. Combined microscopies study of the C-contamination induced by extreme-ultraviolet radiation: A surface-dependent secondary-electron-based model

    Energy Technology Data Exchange (ETDEWEB)

    Prezioso, S.; Donarelli, M.; Bisti, F.; Palladino, L.; Santucci, S.; Ottaviano, L. [Dip. di Fisica, Universita dell' Aquila, Via Vetoio, 67100 L' Aquila (Italy); Spadoni, S.; Avaro, L. [Micron, Process R and D, Via C. Olivetti 2, 20864 Agrate Brianza (Italy); Liscio, A.; Palermo, V. [CNR-ISOF, Via Gobetti 101, 40129 Bologna (Italy)

    2012-05-14

    SiO{sub 2} and Al{sub 2}O{sub 3} surfaces exposed to periodically modulated extreme ultraviolet (EUV) light ({lambda} = 46.9 nm) have been investigated at the {mu}m scale by optical microscopy, scanning electron microscopy, scanning Auger microscopy, atomic force microscopy, and Kelvin probe force microscopy. The formation of a carbon contamination layer preserving the same periodical modulation of the EUV dose has been observed. The mechanisms of hydrocarbon molecules deposition have been studied with the help of correlation plots between the modulated Auger signal and the corresponding EUV dose. A surface-dependent secondary-electron-based model has been proposed.

  10. SIRT6 rescues the age related decline in base excision repair in a PARP1-dependent manner

    Science.gov (United States)

    Xu, Zhu; Zhang, Lei; Zhang, Wenjun; Meng, Du; Zhang, Hongxia; Jiang, Ying; Xu, Xiaojun; Van Meter, Michael; Seluanov, Andrei; Gorbunova, Vera; Mao, Zhiyong

    2015-01-01

    In principle, a decline in base excision repair (BER) efficiency with age should lead to genomic instability and ultimately contribute to the onset of the aging phenotype. Although multiple studies have indicated a negative link between aging and BER, the change of BER efficiency with age in humans has not been systematically analyzed. Here, with foreskin fibroblasts isolated from 19 donors between 20 and 64 y of age, we report a significant decline of BER efficiency with age using a newly developed GFP reactivation assay. We further observed a very strong negative correlation between age and the expression levels of SIRT6, a factor which is known to maintain genomic integrity by improving DNA double strand break (DSB) repair. Our mechanistic study suggests that, similar to the regulatory role that SIRT6 plays in DNA DSB repair, SIRT6 regulates BER in a PARP1-depdendent manner. Moreover, overexpression of SIRT6 rescues the decline of BER in aged fibroblasts. In summary, our results uncovered the regulatory mechanisms of BER by SIRT6, suggesting that SIRT6 reactivation in aging tissues may help delay the process of aging through improving BER. PMID:25607651

  11. Dependence of carrier doping on the impurity potential in transition-metal-substituted FeAs-based superconductors.

    Science.gov (United States)

    Ideta, S; Yoshida, T; Nishi, I; Fujimori, A; Kotani, Y; Ono, K; Nakashima, Y; Yamaichi, S; Sasagawa, T; Nakajima, M; Kihou, K; Tomioka, Y; Lee, C H; Iyo, A; Eisaki, H; Ito, T; Uchida, S; Arita, R

    2013-03-01

    In order to examine to what extent the rigid-band-like electron doping scenario is applicable to the transition metal-substituted Fe-based superconductors, we have performed angle-resolved photoemission spectroscopy studies of Ba(Fe(1-x)Ni(x))(2)As(2) (Ni-122) and Ba(Fe(1-x)Cu(x))(2)As(2) (Cu-122), and compared the results with Ba(Fe(1-x)Co(x))(2)As(2) (Co-122). We find that Ni 3d-derived features are formed below the Fe 3d band and that Cu 3d-derived ones further below it. The electron and hole Fermi surface (FS) volumes are found to increase and decrease with substitution, respectively, qualitatively consistent with the rigid-band model. However, the total extra electron number estimated from the FS volumes (the total electron FS volume minus the total hole FS volume) is found to decrease in going from Co-, Ni-, to Cu-122 for a fixed nominal extra electron number, that is, the number of electrons that participate in the formation of FS decreases with increasing impurity potential. We find that the Néel temperature T(N) and the critical temperature T(c) maximum are determined by the FS volumes rather than the nominal extra electron concentration or the substituted atom concentration.

  12. Instability criterion for the system composed of elastic beam and strain-softening pillar based on gradient-dependent plasticity

    Institute of Scientific and Technical Information of China (English)

    Xuebin Wang

    2005-01-01

    A mechanical model is proposed for the system of elastic beam and strain-softening pillar where strain localization is initiated at peak shear stress. To obtain the plastic deformation of the pillar due to the shear slips of multiple shear bands, the pillar is divided into several narrow slices where compressive deformation is treated as uniformity. In the light of the compatibility condition of deformation, the total compressive displacement of the pillar is equal to the displacement of the beam in the middle span. An insta bility criterion is derived analytically based on the energy principle using a known size of localization band according to gradientdependent plasticity. The main advantage of the present model is that the effects of the constitutive parameters of rock and the geometrical size of structure are reflected in the criterion. The condition that the derivative of distributed load with respect to the deflection of the beam in the middle span is less than zero is not only equivalent to, but also even more concise in form than the instability criterion. To study the influences of constitutive parameters and geometrical size on stability, some examples are presented.

  13. A Novel Approach to Testing for Average Bioequivalence Based on Modeling the Within-Period Dependence Structure.

    Science.gov (United States)

    Chandrasekhar, Rameela; Shi, Yi; Hutson, Alan D; Wilding, Gregory E

    2015-01-01

    Bioequivalence trials are commonly conducted to assess therapeutic equivalence between a generic and an innovator brand formulations. In such trials, drug concentrations are obtained repeatedly over time and are summarized using a metric such as the area under the concentration vs. time curve (AUC) for each subject. The usual practice is to then conduct two one-sided tests using these areas to evaluate for average bioequivalence. A major disadvantage of this approach is the loss of information encountered when ignoring the correlation structure between repeated measurements in the computation of areas. In this article, we propose a general linear model approach that incorporates the within-subject covariance structure for making inferences on mean areas. The model-based method can be seen to arise naturally from the reparameterization of the AUC as a linear combination of outcome means. We investigate and compare the inferential properties of our proposed method with the traditional two one-sided tests approach using Monte Carlo simulation studies. We also examine the properties of the method in the event of missing data. Simulations show that the proposed approach is a cost-effective, viable alternative to the traditional method with superior inferential properties. Inferential advantages are particularly apparent in the presence of missing data. To illustrate our approach, a real working example from an asthma study is utilized.

  14. Strain Amount Dependent Grain Size and Orientation Developments during Hot Compression of a Polycrystalline Nickel Based Superalloy

    Directory of Open Access Journals (Sweden)

    Guoai He

    2017-02-01

    Full Text Available Controlling grain size in polycrystalline nickel base superalloy is vital for obtaining required mechanical properties. Typically, a uniform and fine grain size is required throughout forging process to realize the superplastic deformation. Strain amount occupied a dominant position in manipulating the dynamic recrystallization (DRX process and regulating the grain size of the alloy during hot forging. In this article, the high-throughput double cone specimen was introduced to yield wide-range strain in a single sample. Continuous variations of effective strain ranging from 0.23 to 1.65 across the whole sample were achieved after reaching a height reduction of 70%. Grain size is measured to be decreased from the edge to the center of specimen with increase of effective strain. Small misorientation tended to generate near the grain boundaries, which was manifested as piled-up dislocation in micromechanics. After the dislocation density reached a critical value, DRX progress would be initiated at higher deformation region, leading to the refinement of grain size. During this process, the transformations from low angle grain boundaries (LAGBs to high angle grain boundaries (HAGBs and from subgrains to DRX grains are found to occur. After the accomplishment of DRX progress, the neonatal grains are presented as having similar orientation inside the grain boundary.

  15. A high-content image-based method for quantitatively studying context-dependent cell population dynamics.

    Science.gov (United States)

    Garvey, Colleen M; Spiller, Erin; Lindsay, Danika; Chiang, Chun-Te; Choi, Nathan C; Agus, David B; Mallick, Parag; Foo, Jasmine; Mumenthaler, Shannon M

    2016-01-01

    Tumor progression results from a complex interplay between cellular heterogeneity, treatment response, microenvironment and heterocellular interactions. Existing approaches to characterize this interplay suffer from an inability to distinguish between multiple cell types, often lack environmental context, and are unable to perform multiplex phenotypic profiling of cell populations. Here we present a high-throughput platform for characterizing, with single-cell resolution, the dynamic phenotypic responses (i.e. morphology changes, proliferation, apoptosis) of heterogeneous cell populations both during standard growth and in response to multiple, co-occurring selective pressures. The speed of this platform enables a thorough investigation of the impacts of diverse selective pressures including genetic alterations, therapeutic interventions, heterocellular components and microenvironmental factors. The platform has been applied to both 2D and 3D culture systems and readily distinguishes between (1) cytotoxic versus cytostatic cellular responses; and (2) changes in morphological features over time and in response to perturbation. These important features can directly influence tumor evolution and clinical outcome. Our image-based approach provides a deeper insight into the cellular dynamics and heterogeneity of tumors (or other complex systems), with reduced reagents and time, offering advantages over traditional biological assays.

  16. Implementation of a phase detection algorithm for dynamic cardiac computed tomography analysis based on time dependent contrast agent distribution.

    Directory of Open Access Journals (Sweden)

    Carsten Kendziorra

    Full Text Available This paper presents a phase detection algorithm for four-dimensional (4D cardiac computed tomography (CT analysis. The algorithm detects a phase, i.e. a specific three-dimensional (3D image out of several time-distributed 3D images, with high contrast in the left ventricle and low contrast in the right ventricle. The purpose is to use the automatically detected phase in an existing algorithm that automatically aligns the images along the heart axis. Decision making is based on the contrast agent distribution over time. It was implemented in KardioPerfusion--a software framework currently being developed for 4D CT myocardial perfusion analysis. Agreement of the phase detection algorithm with two reference readers was 97% (95% CI: 82-100%. Mean duration for detection was 0.020 s (95% CI: 0.018-0.022 s, which was 800 times less than the readers needed (16±7 s, p<03001. Thus, this algorithm is an accurate and fast tool that can improve work flow of clinical examinations.

  17. Explicating an Evidence-Based, Theoretically Informed, Mobile Technology-Based System to Improve Outcomes for People in Recovery for Alcohol Dependence

    Science.gov (United States)

    Gustafson, David H.; Isham, Andrew; Baker, Timothy; Boyle, Michael G.; Levy, Michael

    2011-01-01

    Post treatment relapse to uncontrolled alcohol use is common. More cost-effective approaches are needed. We believe currently available communication technology can use existing models for relapse prevention to cost-effectively improve long-term relapse prevention. This paper describes: 1) research-based elements of alcohol related relapse prevention and how they can be encompassed in Self Determination Theory (SDT) and Marlatt’s Cognitive Behavioral Relapse Prevention Model, 2) how technology could help address the needs of people seeking recovery, 3) a technology-based prototype, organized around Self Determination Theory and Marlatt’s model and 4) how we are testing a system based on the ideas in this article and related ethical and operational considerations. PMID:21190410

  18. Maize dependence or market integration? Caries prevalence among indigenous Maya communities with maize-based versus globalized economies.

    Science.gov (United States)

    Vega Lizama, Elma Maria; Cucina, Andrea

    2014-02-01

    The relationship between diet and oral health is widely known, yet data on dental caries prevalence is lacking for many indigenous groups with traditional or rapidly modernizing diets. This research documents caries prevalence in two Maya communities from northern Yucatán (Mexico) with significantly different levels of market integration, subsistence, and diet: Yalsihón, with a traditional, maize-based subsistence economy, and Dzilam, with access to globalized food markets. Each sample was subdivided by sex into 15-19, 20-24, and 25-30 years-of-age classes. Caries prevalence was considered separately both when the lesion affected the enamel superficially (grade 1+) and when it reached the dentin (grade 2+). In both villages, females of all age classes manifest more caries than males. Results show higher prevalence of caries at Dzilam than at Yalsihón, except for grade 1+ caries among 15-19-year-old males and grade 2+ caries among 15-19-year-old females. Though differences are not significant, earlier pregnancies among 15-19-year-old females at Yalsihón could be a causative factor. A survey indicated a more balanced diet at Yalsihón despite a heavier intake of maize than at Dzilam. Striking differences were documented in the ingestion of soda and globalized foods; sodas were virtually absent at Yalsihón, while at Dzilam they were ingested daily in great quantities. The decline in oral health at Dzilam is inferred to result from consumption of industrially processed foods and drinks, while a traditional diet leads to less caries despite daily heavy consumption of maize, which must be considered when interpreting caries rates in archaeological samples.

  19. Temperature-dependent rigidity and magnetism of polyamide 6 nanocomposites based on nanocrystalline Fe-Ni alloy of various geometries

    Directory of Open Access Journals (Sweden)

    M. A. A. Mohamed

    2016-10-01

    Full Text Available The focus of this study is to explore the potential use of Polyamide 6 nanocomposite reinforced with nanocrystalline (nc Fe20Ni80 alloy (Fe20Ni80/PA6 PNC in electromagnetic applications and provide understanding of how the alloy particle geometry is controlling the nanocomposite’s physical properties. Thermomechanical rigidity, room-temperature soft magnetic performance and thermal soft magnetic stability of Fe20Ni80/PA6 PNCs based on spherical-sea urchin alloy particles (UMB2-SU and necklace-like alloy chains (UMB2-NC have been investigated. Both PNCs have considerably superior bulk properties compared to neat PA6 and UMB2-SU exhibits the most remarkable overall performance. Morphological observations disclose two relevant phenomena: i improved dispersion and distribution of the SU alloy particles than the NC ones within PA6 matrix, leading to stronger filler-matrix interfacial interactions within the UMB2-SU as compared to the UMB2-NC and ii presence of constraint polymer regions in between alloy segments within the UMB2-SU that provide secondary reinforcing and soft magnetic mechanisms. Such phenomena along with the lower alloy crystallite size and PA6 γ-crystal type content within the UMB2-SU than in the UMB2-NC, are considered the main responsible factors for the distinctive performance of UMB2-SU. Overall, compared to various ferromagnetic nanocrystalline metallic materials, the research proposes the SU nc Fe20Ni80 alloy as a valuable nanofiller in polymers for electromagnetic applications.

  20. Observer-based robust finite time H∞ sliding mode control for Markovian switching systems with mode-dependent time-varying delay and incomplete transition rate.

    Science.gov (United States)

    Gao, Lijun; Jiang, Xiaoxiao; Wang, Dandan

    2016-03-01

    This paper investigates the problem of robust finite time H∞ sliding mode control for a class of Markovian switching systems. The system is subjected to the mode-dependent time-varying delay, partly unknown transition rate and unmeasurable state. The main difficulty is that, a sliding mode surface cannot be designed based on the unknown transition rate and unmeasurable state directly. To overcome this obstacle, the set of modes is firstly divided into two subsets standing for known transition rate subset and unknown one, based on which a state observer is established. A component robust finite-time sliding mode controller is also designed to cope with the effect of partially unknown transition rate. It is illustrated that the reachability, finite-time stability, finite-time boundedness, finite-time H∞ state feedback stabilization of sliding mode dynamics can be ensured despite the unknown transition rate. Finally, the simulation results verify the effectiveness of robust finite time control problem.

  1. A Hybrid Dependency-Based Query Expansion Method%一种基于依赖关系的综合查询扩展方法

    Institute of Scientific and Technical Information of China (English)

    曹均阔; 吴丽华

    2012-01-01

    To express the true intention is more difficult only by a few keywords due to ambiguity and diversity of natural language. Query expansion effectively enhances the understanding of the retrieval system by trying to dig the potential meaning of the original query. Assuming that the words in the returned sentence by the original query are more important as the sentence with high score, sentence weight is applied to calculate candidate expansion items for local context analysis. In the same time, the paper further assume that the candidate words will tied closer with the originally query if they have some position or dependency relationships. So two relation-based query expansion methods are putted forward, the first is Sentence Weight & Position-based Context Analysis, called SWPCA. And the second is Sentence Weight & Dependency-based Context Analysis,called SWDCA. Finally the two methods are used for the definitional question answering of TREC. The experiment data show that both methods are efficient, and SWDCA performs is a little better than SWPCA.%由于自然语言本身的歧义性和多样性,少数几个关键词难以表达真实的信息需求.查询扩展技术通过挖掘原始查询项的潜在信息,有效地增强了检索系统的理解能力.该文在上下文分析方法计算公式中加入了句子权重概念,即假设由原始查询项返回的句子越重要,则其中出现的词与查询项越相关.同时进一步假设,句中的词与查询项的位置关系与依赖关系也是选取扩展词的重要依据.为此,该文分别提出基于句子权重与位置上下文分析方法(Sentence Weight&Position-based Context Analysis,SWPCA),以及基于句子权重与依赖关系上下文分析方法(Sentence Weight&Dependency-based Context Analysis,SWDCA).并将这两种查询扩展技术应用于TREC的定义类问题回答,数据显示这两种方法均取得不错成绩,而SWDCA性能更好.

  2. Blog Sentiment Orientation Analysis Based on Dependency Parsing%基于依存句法的博文情感倾向分析研究

    Institute of Scientific and Technical Information of China (English)

    冯时; 付永陈; 阳锋; 王大玲; 张一飞

    2012-01-01

    Nowadays, blogs, which contain rich opinion and emotion information, have become an important platform for exchanging sentiments among netizens on the Web. Blog search provides a convenient way for these information exchanges. In many cases, users pay more attention to blogger's opinions and sentiments about an event when searching the blogosphere, but most existing blog search engines return results based only on topics without considering sentiment orientations. In this paper, an algorithm called SOAD (sentiment orientation analysis based on syntactic dependency) is proposed for analyzing blogs' sentiment orientation based on dependency parsing. A Chinese blog search engine prototype system is built based on the proposed algorithm, which reprocesses blog search results for sentiment analysis. Experiments show that, SOAD algorithm has more advantages, and the prototype system implements the purpose of this paper: the blog search results are returned according to blogger's sentiment orientation.%博客作为一种用户发表其观点和看法的载体己成为Web上一个重要的情感抒发与交流平台,博文搜索为这种交流提供了方便快捷的途径.很多时候,用户进行博文搜索时更关注作者对事件所持的观点或情感,但目前的博文搜索返回结果大多基于主题而非情感倾向.基于此提出一种基于句法依存分析技术的算法SOAD(sentiment orientation analysis based on syntactic dependency)对博文搜索结果进行情感倾向性分析.基于SOAD算法,构建了一个中文博文搜索原型系统,对博文搜索结果进行再处理.实验证明,一方面,SOAD算法在分析博文情感上具有更大的优势;另一方面,建立的原型系统实现了依据情感倾向返回搜索结果的目标.

  3. Analysis of chemical process safety based on data dependence%基于数据依赖关系的化工过程安全分析

    Institute of Scientific and Technical Information of China (English)

    史晟辉; 朱群雄; 耿志强

    2012-01-01

    针对化工过程间安全分析问题,结合计算机领域中数据依赖技术,提出一种新的应用于化工过程的安全分析解决方案.以双容水槽液位控制系统为实例,分析工艺流程和变量之间的关系,从中提取9个状态,10个迁移过程以及迁移的条件、事件及执行过程等信息,建立其扩展有限状态机模型.通过考察迁移T8中L2变量,分析其数据依赖关系路径,确定数据依赖正负影响关系,实现基于数据依赖的化工过程安全分析新方法,并通过对T4中L2变量的分析验证了所提方法的有效性,使得扩展有限状态机数据依赖技术成为计算机自动推理来实现化工过程的安全分析的一种新的有效方法.%For chemical process safety analysis, data dependencies method in the computer field is made Use of, and a new used in chemical process safety analysis solution is present. Token double water tank level control system as an example, the relationship between the process and the variables is analyzed, and nine states, ten transitions in which including the conditions, events and actions are extracted. Based on the above extended finite state machine model is established. Moreover, in order to get the factors affecting the result of variables L2 in 7g, related data dependency paths and positive and negative relations affecting L2 are analyzed. Then new method of chemical process safety analysis based on the data-dependent is achieved, and the validity of the proposed method is testified by analyzing of variables 12 in the Tt. Data dependency technology based on extended finite state machine becomes an effective method which applying computer automated reasoning to achieve safety analysis in chemical process.

  4. Low probability of intercept-based adaptive radar waveform optimization in signal-dependent clutter for joint radar and cellular communication systems

    Science.gov (United States)

    Shi, Chenguang; Salous, Sana; Wang, Fei; Zhou, Jianjiang

    2016-12-01

    In this paper, we investigate the problem of low probability of intercept (LPI)-based adaptive radar waveform optimization in signal-dependent clutter for joint radar and cellular communication systems, where the radar system optimizes the transmitted waveform such that the interference caused to the cellular communication systems is strictly controlled. Assuming that the precise knowledge of the target spectra, the power spectral densities (PSDs) of signal-dependent clutters, the propagation losses of corresponding channels and the communication signals is known by the radar, three different LPI based criteria for radar waveform optimization are proposed to minimize the total transmitted power of the radar system by optimizing the multicarrier radar waveform with a predefined signal-to-interference-plus-noise ratio (SINR) constraint and a minimum required capacity for the cellular communication systems. These criteria differ in the way the communication signals scattered off the target are considered in the radar waveform design: (1) as useful energy, (2) as interference or (3) ignored altogether. The resulting problems are solved analytically and their solutions represent the optimum power allocation for each subcarrier in the multicarrier radar waveform. We show with numerical results that the LPI performance of the radar system can be significantly improved by exploiting the scattered echoes off the target due to cellular communication signals received at the radar receiver.

  5. A chemo-mechanical free-energy-based approach to model durotaxis and extracellular stiffness-dependent contraction and polarization of cells.

    Science.gov (United States)

    Shenoy, Vivek B; Wang, Hailong; Wang, Xiao

    2016-02-06

    We propose a chemo-mechanical model based on stress-dependent recruitment of myosin motors to describe how the contractility, polarization and strain in cells vary with the stiffness of their surroundings and their shape. A contractility tensor, which depends on the distribution of myosin motors, is introduced to describe the chemical free energy of the cell due to myosin recruitment. We explicitly include the contributions to the free energy that arise from mechanosensitive signalling pathways (such as the SFX, Rho-Rock and MLCK pathways) through chemo-mechanical coupling parameters. Taking the variations of the total free energy, which consists of the chemical and mechanical components, in accordance with the second law of thermodynamics provides equations for the temporal evolution of the active stress and the contractility tensor. Following this approach, we are able to recover the well-known Hill relation for active stresses, based on the fundamental principles of irreversible thermodynamics rather than phenomenology. We have numerically implemented our free energy-based approach to model spatial distribution of strain and contractility in (i) cells supported by flexible microposts, (ii) cells on two-dimensional substrates, and (iii) cells in three-dimensional matrices. We demonstrate how the polarization of the cells and the orientation of stress fibres can be deduced from the eigenvalues and eigenvectors of the contractility tensor. Our calculations suggest that the chemical free energy of the cell decreases with the stiffness of the extracellular environment as the cytoskeleton polarizes in response to stress-dependent recruitment of molecular motors. The mechanical energy, which includes the strain energy and motor potential energy, however, increases with stiffness, but the overall energy is lower for cells in stiffer environments. This provides a thermodynamic basis for durotaxis, whereby cells preferentially migrate towards stiffer regions of the

  6. Apache Maven dependency management

    CERN Document Server

    Lalou, Jonathan

    2013-01-01

    An easy-to-follow, tutorial-based guide with chapters progressing from basic to advanced dependency management.If you are working with Java or Java EE projects and you want to take advantage of Maven dependency management, then this book is ideal for you. This book is also particularly useful if you are a developer or an architect. You should be well versed with Maven and its basic functionalities if you wish to get the most out of this book.

  7. Dependencies in Formal Mathematics

    CERN Document Server

    Alama, Jesse; Urban, Josef

    2011-01-01

    Dependencies in formal mathematical texts, large coherent formal libraries and proof assistants are introduced as an emerging research topic, analyzed from foundational, semantic, computational, and pragmatic perspectives, and put to practical use in computer-assisted mathematics. Two different approaches to dependency computation are implemented over two major proof assistants with different type disciplines, and a large-scale experimental comparison is provided based on large Coq and Mizar formal libraries. Apart from theoretical discussions, importance of dependency analysis for advanced automation of computer-assisted reasoning, and for efficient proof analysis and theory refactoring in substantial mathematical domains are experimentally demonstrated.

  8. 酒精依赖的基于基因和基于通路的全基因组关联研究%Gene-based and pathway-based genome-wide associaiton study of alcohol dependence

    Institute of Scientific and Technical Information of China (English)

    Zuo LJ; Zhang CK; Sayward FG; Cheung KH; Wang KS; Krystal JH; Zhao HY; Luo XG

    2015-01-01

      结果:我们发现了几个与酒精依赖显著相关的可重复的全基因组风险基因和风险通路。在多重比较Bonferroni校正后,“细胞-细胞外基质相互作用”通路(EA样本中p  结论:一些基因和生物信号传导过程可能与酒精依赖的风险相关,本研究的发现为此提供了新的证据。%Background:The organization of risk genes within signaling pathways may provide clues about the converging neurobiological effects of risk genes for alcohol dependence. Aims:Identify risk genes and risk gene pathways for alcohol dependence. Methods:We conducted a pathway-based genome-wide association study (GWAS) of alcohol dependence using a gene-set-rich analytic approach. Approximately one million genetic markers were tested in the discovery sample which included 1409 European-American (EA) alcohol dependent individuals and 1518 EA healthy comparison subjects. An additional 681 African-American (AA) cases and 508 AA healthy subjects served as the replication sample. Results:We identified several genome-wide replicable risk genes and risk pathways that were significantly associated with alcohol dependence. After applying the Bonferroni correction for multiple testing, the‘cell-extracellular matrix interactions’ pathway (p Conclusions:These findings provide new evidence highlighting several genes and biological signaling processes that may be related to the risk for alcohol dependence.

  9. Adam Smith and dependency.

    Science.gov (United States)

    Ozler, Sule

    2012-06-01

    The focus of this paper is the works and life of Adam Smith, who is widely recognized as the father and founder of contemporary economics. Latent content analysis is applied to his seminal text in economics, An Inquiry into the Nature and Causes of the Wealth of Nations (1776). The results reveal that Smith considers dependence on others a problem and sees the solution to this problem in impersonalized interdependence. In addition, his views on social dependency and personal dependency, reflected in his Lectures on Jurisprudence (1963) and The Theory of Moral Sentiments (1759), are analyzed. This analysis suggests a central tension between dependence and independence in Smith's writings. The personal dependency patterns he exhibited in his life, which also suggest a tension between dependence and independence, are identified through a reading of his biographies. Based on insights from psychoanalytic literature, this paper proposes that developing the ideas in the Wealth of Nations was part of Smith's creative solution to this tension. In particular, his solution to one individual's dependence on another was through a system of impersonalized interdependence. In other words, Smith defended against his personal dependence through his economic theorizing.

  10. Non-density dependent pollen dispersal of Shorea maxwelliana (Dipterocarpaceae revealed by a Bayesian mating model based on paternity analysis in two synchronized flowering seasons.

    Directory of Open Access Journals (Sweden)

    Shinsuke Masuda

    Full Text Available Pollinator syndrome is one of the most important determinants regulating pollen dispersal in tropical tree species. It has been widely accepted that the reproduction of tropical forest species, especially dipterocarps that rely on insects with weak flight for their pollination, is positively density-dependent. However differences in pollinator syndrome should affect pollen dispersal patterns and, consequently, influence genetic diversity via the mating process. We examined the pollen dispersal pattern and mating system of Shorea maxwelliana, the flowers of which are larger than those of Shorea species belonging to section Mutica which are thought to be pollinated by thrips (weak flyers. A Bayesian mating model based on the paternity of seeds collected from mother trees during sporadic and mass flowering events revealed that the estimated pollen dispersal kernel and average pollen dispersal distance were similar for both flowering events. This evidence suggests that the putative pollinators - small beetles and weevils - effectively contribute to pollen dispersal and help to maintain a high outcrossing rate even during sporadic flowering events. However, the reduction in pollen donors during a sporadic event results in a reduction in effective pollen donors, which should lead to lower genetic diversity in the next generation derived from seeds produced during such an event. Although sporadic flowering has been considered less effective for outcrossing in Shorea species that depend on thrips for their pollination, effective pollen dispersal by the small beetles and weevils ensures outcrossing during periods of low flowering tree density, as occurs in a sporadic flowering event.

  11. Prediction and evaluation of route dependent dosimetry of BPA in rats at different life stages using a physiologically based pharmacokinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoxia, E-mail: Xiaoxia.Yang@fda.hhs.gov; Doerge, Daniel R.; Fisher, Jeffrey W.

    2013-07-01

    Bisphenol A (BPA) has received considerable attention throughout the last decade due to its widespread use in consumer products. For the first time a physiologically based pharmacokinetic (PBPK) model was developed in neonatal and adult rats to quantitatively evaluate age-dependent pharmacokinetics of BPA and its phase II metabolites. The PBPK model was calibrated in adult rats using studies on BPA metabolism and excretion in the liver and gastrointestinal tract, and pharmacokinetic data with BPA in adult rats. For immature rats the hepatic and gastrointestinal metabolism of BPA was inferred from studies on the maturation of phase II enzymes coupled with serum time course data in pups. The calibrated model predicted the measured serum concentrations of BPA and BPA conjugates after administration of 100 μg/kg of d6-BPA in adult rats (oral gavage and intravenous administration) and postnatal days 3, 10, and 21 pups (oral gavage). The observed age-dependent BPA serum concentrations were partially attributed to the immature metabolic capacity of pups. A comparison of the dosimetry of BPA across immature rats and monkeys suggests that dose adjustments would be necessary to extrapolate toxicity studies from neonatal rats to infant humans. - Highlights: • A PBPK model predicts the kinetics of bisphenol A (BPA) in young and adult rats. • BPA metabolism within enterocytes is required for fitting of oral BPA kinetic data. • BPA dosimetry in young rats is different than adult rats and young monkeys.

  12. Chemical display of pyrimidine bases flipped out by modification-dependent restriction endonucleases of MspJI and PvuRts1I families.

    Directory of Open Access Journals (Sweden)

    Evelina Zagorskaitė

    Full Text Available The epigenetic DNA modifications 5-methylcytosine (5mC and 5-hydroxymethylcytosine (5hmC in eukaryotes are recognized either in the context of double-stranded DNA (e.g., by the methyl-CpG binding domain of MeCP2, or in the flipped-out state (e.g., by the SRA domain of UHRF1. The SRA-like domains and the base-flipping mechanism for 5(hmC recognition are also shared by the recently discovered prokaryotic modification-dependent endonucleases of the MspJI and PvuRts1I families. Since the mechanism of modified cytosine recognition by many potential eukaryotic and prokaryotic 5(hmC "readers" is still unknown, a fast solution based method for the detection of extrahelical 5(hmC would be very useful. In the present study we tested base-flipping by MspJI- and PvuRts1I-like restriction enzymes using several solution-based methods, including fluorescence measurements of the cytosine analog pyrrolocytosine and chemical modification of extrahelical pyrimidines with chloroacetaldehyde and KMnO4. We find that only KMnO4 proved an efficient probe for the positive display of flipped out pyrimidines, albeit the method required either non-physiological pH (4.3 or a substitution of the target cytosine with thymine. Our results imply that DNA recognition mechanism of 5(hmC binding proteins should be tested using a combination of all available methods, as the lack of a positive signal in some assays does not exclude the base flipping mechanism.

  13. A Pareto-Based Adaptive Variable Neighborhood Search for Biobjective Hybrid Flow Shop Scheduling Problem with Sequence-Dependent Setup Time

    Directory of Open Access Journals (Sweden)

    Huixin Tian

    2016-01-01

    Full Text Available Different from most researches focused on the single objective hybrid flowshop scheduling (HFS problem, this paper investigates a biobjective HFS problem with sequence dependent setup time. The two objectives are the minimization of total weighted tardiness and the total setup time. To efficiently solve this problem, a Pareto-based adaptive biobjective variable neighborhood search (PABOVNS is developed. In the proposed PABOVNS, a solution is denoted as a sequence of all jobs and a decoding procedure is presented to obtain the corresponding complete schedule. In addition, the proposed PABOVNS has three major features that can guarantee a good balance of exploration and exploitation. First, an adaptive selection strategy of neighborhoods is proposed to automatically select the most promising neighborhood instead of the sequential selection strategy of canonical VNS. Second, a two phase multiobjective local search based on neighborhood search and path relinking is designed for each selected neighborhood. Third, an external archive with diversity maintenance is adopted to store the nondominated solutions and at the same time provide initial solutions for the local search. Computational results based on randomly generated instances show that the PABOVNS is efficient and even superior to some other powerful multiobjective algorithms in the literature.

  14. Buckling and free vibration of shallow curved micro/nano-beam based on strain gradient theory under thermal loading with temperature-dependent properties

    Science.gov (United States)

    Rahmani, O.; Hosseini, S. A. H.; Ghoytasi, I.; Golmohammadi, H.

    2017-01-01

    In this study, influences of a uniform thermomechanical loading in buckling and free vibration of a curved FG microbeam have been investigated, based on strain gradient theory (SGT) theory and Timoshenko beam model. Distribution of structural materials varies continuously in thickness direction due to power-law exponent. Unlike classical models, this novel model employs three length scale parameters which can capture the size effect. This work is based on SGT theory and Timoshenko beam model. Governing equation of motion and associated boundary condition have been developed based on Hamilton's principle, which is the specified case of virtual work theorem. In continuance, final differential equations were solved by Navier's solution method and the results have been presented. Moreover, influences of dimensionless length-to-thickness ratio (aspect ratio), dimensionless length scale parameter, power-law exponent, temperature difference and arc angle for various values of mode numbers on natural frequency and critical temperature by considering temperature-dependent material properties have been investigated. In order to validate accomplished study, some of the results were compared with those of previous works. It has been concluded that applying a thermomechanical loading on a FG microbeam causes the natural frequency to become more sensitive about variations of geometrical, physical and mechanical properties and characteristics.

  15. A study of pH-dependent photodegradation of amiloride by a multivariate curve resolution approach to combined kinetic and acid-base titration UV data.

    Science.gov (United States)

    De Luca, Michele; Ioele, Giuseppina; Mas, Sílvia; Tauler, Romà; Ragno, Gaetano

    2012-11-21

    Amiloride photostability at different pH values was studied in depth by applying Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) to the UV spectrophotometric data from drug solutions exposed to stressing irradiation. Resolution of all degradation photoproducts was possible by simultaneous spectrophotometric analysis of kinetic photodegradation and acid-base titration experiments. Amiloride photodegradation showed to be strongly dependent on pH. Two hard modelling constraints were sequentially used in MCR-ALS for the unambiguous resolution of all the species involved in the photodegradation process. An amiloride acid-base system was defined by using the equilibrium constraint, and the photodegradation pathway was modelled taking into account the kinetic constraint. The simultaneous analysis of photodegradation and titration experiments revealed the presence of eight different species, which were differently distributed according to pH and time. Concentration profiles of all the species as well as their pure spectra were resolved and kinetic rate constants were estimated. The values of rate constants changed with pH and under alkaline conditions the degradation pathway and photoproducts also changed. These results were compared to those obtained by LC-MS analysis from drug photodegradation experiments. MS analysis allowed the identification of up to five species and showed the simultaneous presence of more than one acid-base equilibrium.

  16. Miniature Fourier transform spectrometer based on wavelength dependence of half-wave voltage of a LiNbO₃ waveguide interferometer.

    Science.gov (United States)

    Li, Jinyang; Lu, Dan-feng; Qi, Zhi-mei

    2014-07-01

    A simple and reliable spectrum-retrieval method was proposed for the development of miniature stationary Fourier transform (FT) spectrometers based on a LiNbO₃ (LN) waveguide Mach-Zehnder interferometer (MZI) modulator. The method takes into account the wavelength dependence of the optical pathlength difference (OPD) and allows us to use a nonlinear voltage ramp to modulate the OPD. The method is based on the dispersion of the half-wave voltage, which was measured to be a monotonous polynomial function of the wavelength for the LN waveguide MZI used. With the measured dispersion of the half-wave voltage, the OPD, as a linear function of the modulating voltage, can be accurately determined at each wavelength in the near-infrared region in which the MZI used is a single-mode device. A prototype FT spectrometer was prepared using a LN waveguide MZI modulator based on the above method. The experimental results demonstrated that the spectrometer can be used for accurate determination of the laser wavelength and for liquid absorptiometry.

  17. Solvent-dependent assembly of discrete and continuous CoCl₂ adamantane-based ligand complexes: observations by CSI-mass spectrometry and X-ray crystallography.

    Science.gov (United States)

    Ohara, Kazuaki; Tominaga, Masahide; Azumaya, Isao; Yamaguchi, Kentaro

    2013-01-01

    Discrete and continuous coordination structures were obtained in single crystals of CoCl₂ and an adamantane-based bidentate ligand bearing imidazolyl groups, depending on the methanol concentration in a methanol-chloroform mixture. Single-crystal X-ray structure analysis revealed that the metal centers exhibited a tetrahedral geometry in the discrete complex and an octahedral geometry in the continuous metal complex. Conventional analytical methods, including UV-vis and NMR spectroscopy, could not identify those two complexes in solution. In contrast, cold-spray ionization mass spectrometry could detect differences between the discrete complex and the continuous metal complex, and ion peaks due to continuous ligand adducts were found only in the spectrum of the continuous metal complex.

  18. Selective Detection of Mercury(Ⅱ) and Copper(Ⅱ) Based on the Opposite Size-dependent Fluorescence Quenching of CdTe Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    XIA Yun-Sheng; CAO Chun; ZHU Chang-Qing

    2007-01-01

    Three different size CdTe quantum dots (QDs) capped by 3-mercaptopropionic acid (MPA) have been prepared in aqueous solutions,and their interactions with Cu2+ and Hg2+ have been investigated.The opposite size-dependent fluorescence quenching of CdTe QDs by Hg2+ and Cu2+ was observed: Hg2+ quenched smaller particles more efficiently than larger ones while larger particles were more markedly quenched by Cu2+.Based on the different size responses,Hg2+ and Cu2+ were respectively detected with high sensitivity and selectivity,for the first time,using the QDs with different sizes but the same components and capping ligands.

  19. 一种高效的基于依赖树的Cube算法%AN EFFICIENT CUBE ALGORITHM BASED ON DEPENDENCY TREE

    Institute of Scientific and Technical Information of China (English)

    左劼; 唐常杰; 于中华; 李通; 殷华蓓; 刘欣

    2001-01-01

    多雏数据立方(Cube)的计算对联机事务分析有着极为重要的作用。本文针对传统的多雏数据Cube计算中的不足,提出了一种新的基于依赖树的多雏数据Cube计算模式,并对该计算模式提出了优化算法.实验表明,新的算法提高效率一个数量级以上。%Multiple dimension cubes play important role in On Line Analysis Processing, This Article analyses the shortage of traditional Cube computing. Based on dependency tree, the paper proposes a new model for Multiple Dimension Cubes computing and its optimization. The experiment results showed that the performance is boost up more than one magnitude.

  20. Dependency of Tunneling-Magnetoresistance Ratio on Nanoscale Spacer Thickness and Material for Double MgO Based Perpendicular-Magnetic-Tunneling-Junction.

    Science.gov (United States)

    Lee, Du-Yeong; Hong, Song-Hwa; Lee, Seung-Eun; Park, Jea-Gun

    2016-12-08

    It was found that in double MgO based perpendicular magnetic tunneling junction spin-valves ex-situ annealed at 400 °C, the tunneling magnetoresistance ratio was extremely sensitive to the material and thickness of the nanoscale spacer: it peaked at a specific thickness (0.40~0.53 nm), and the TMR ratio for W spacers (~134%) was higher than that for Ta spacers (~98%). This dependency on the spacer material and thickness was associated with the (100) body-centered-cubic crystallinity of the MgO layers: the strain enhanced diffusion length in the MgO layers of W atoms (~1.40 nm) was much shorter than that of Ta atoms (~2.85 nm) and the shorter diffusion length led to the MgO layers having better (100) body-centered-cubic crystallinity.

  1. Size-Dependent Non-FRET Photoluminescence Quenching in Nanocomposites Based on Semiconductor Quantum Dots CdSe/ZnS and Functionalized Porphyrin Ligands

    Directory of Open Access Journals (Sweden)

    Eduard I. Zenkevich

    2012-01-01

    Full Text Available We review recent experimental work to utilize the size dependence of the luminescence quenching of colloidal semiconductor quantum dots induced by functionalized porphyrin molecules attached to the surface to describe a photoluminescence (PL quenching process which is different from usual models of charge transfer (CT or Foerster resonant energy transfer (FRET. Steady-state and picosecond time-resolved measurements were carried out for nanocomposites based on colloidal CdSe/ZnS and CdSe quantum dots (QDs of various sizes and surfacely attached tetra-mesopyridyl-substituted porphyrin molecules (“Quantum Dot-Porphyrin” nanocomposites, in toluene at 295 K. It was found that the major part of the observed strong quenching of QD PL in “QD-Porphyrin” nanocomposites can neither be assigned to FRET nor to photoinduced charge transfer between the QD and the chromophore. This PL quenching depends on QD size and shell and is stronger for smaller quantum dots: QD PL quenching rate constants scale inversely with the QD diameter. Based on the comparison of experimental data and quantum mechanical calculations, it has been concluded that QD PL quenching in “QD-Porphyrin” nanocomposites can be understood in terms of a tunneling of the electron (of the excited electron-hole pair followed by a (self- localization of the electron or formation of trap states. The major contribution to PL quenching is found to be proportional to the calculated quantum-confined exciton wave function at the QD surface. Our findings highlight that single functionalized molecules can be considered as one of the probes for the complex interface physics and dynamics of colloidal semiconductor QD.

  2. Highly selective detection of microRNA based on distance-dependent electrochemiluminescence resonance energy transfer between CdTe nanocrystals and Au nanoclusters.

    Science.gov (United States)

    Cheng, Yan; Lei, Jianping; Chen, Yunlong; Ju, Huangxian

    2014-01-15

    A distance-dependent electrochemiluminescence resonance energy transfer (ERET) system based on CdTe nanocrystals and Au nanoclusters (Au NCs) was designed with the aid of ligase for highly selective detection of microRNA (miRNA). First, Au NCs functionalized hairpin DNA was synthesized via Au-S chemistry, and characterized with transmission electron microscopy and dynamic light scattering. The resulting hairpin DNA-Au NCs composite can be bound to the carboxylated CdTe nanocrystals via amide reaction on glass carbon electrode. The strong interaction between CdTe nanocrystals and AuNCs led to the electrochemiluminescence (ECL) quenching of CdTe nanocrystals. In the presence of assistant DNA and miRNA, the ligase can selectively ligate both of them on the strand of the hairpin DNA to form long DNA-RNA heteroduplexes. Thus the ECL signal was recovered due to the blocking of the ERET. As a comparison, when directly opening the hairpin DNA by the target, the ECL emission signal is weak owing to the presence of ERET effect at the short distance. Based on the distance-dependent ERET, a 'signal on' ECL system was utilized for the detection of miRNA with the advantages of 6 orders magnitude linear range and excellent sequence specificity. The total detection processing time of the biosensor was approximately 70 min. By substituting the hairpin DNA with different sequences, this strategy as a new signal transduction approach could be conveniently extended for detection of other short miRNA and DNA.

  3. Combinatorial DNA Damage Pairing Model Based on X-Ray-Induced Foci Predicts the Dose and LET Dependence of Cell Death in Human Breast Cells

    Energy Technology Data Exchange (ETDEWEB)

    Vadhavkar, Nikhil [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Pham, Christopher [University of Texas, Houston, TX (United States). MD Anderson Cancer Center; Georgescu, Walter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Deschamps, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Heuskin, Anne-Catherine [Univ. of Namur (Belgium). Namur Research inst. for Life Sciences (NARILIS), Research Center for the Physics of Matter and Radiation (PMR); Tang, Jonathan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Costes, Sylvain V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.

    2014-09-01

    In contrast to the classic view of static DNA double-strand breaks (DSBs) being repaired at the site of damage, we hypothesize that DSBs move and merge with each other over large distances (m). As X-ray dose increases, the probability of having DSB clusters increases as does the probability of misrepair and cell death. Experimental work characterizing the X-ray dose dependence of radiation-induced foci (RIF) in nonmalignant human mammary epithelial cells (MCF10A) is used here to validate a DSB clustering model. We then use the principles of the local effect model (LEM) to predict the yield of DSBs at the submicron level. Two mechanisms for DSB clustering, namely random coalescence of DSBs versus active movement of DSBs into repair domains are compared and tested. Simulations that best predicted both RIF dose dependence and cell survival after X-ray irradiation favored the repair domain hypothesis, suggesting the nucleus is divided into an array of regularly spaced repair domains of ~;;1.55 m sides. Applying the same approach to high-linear energy transfer (LET) ion tracks, we are able to predict experimental RIF/m along tracks with an overall relative error of 12percent, for LET ranging between 30 350 keV/m and for three different ions. Finally, cell death was predicted by assuming an exponential dependence on the total number of DSBs and of all possible combinations of paired DSBs within each simulated RIF. Relative biological effectiveness (RBE) predictions for cell survival of MCF10A exposed to high-LET showed an LET dependence that matches previous experimental results for similar cell types. Overall, this work suggests that microdosimetric properties of ion tracks at the submicron level are sufficient to explain both RIF data and survival curves for any LET, similarly to the LEM assumption. Conversely, high-LET death mechanism does not have to infer linear-quadratic dose formalism as done in the LEM. In addition, the size of repair domains derived in our model

  4. Characterization of temperature dependent operation of a GaInNAs-based RCEPD designed for 1.3 μm

    Science.gov (United States)

    Sarcan, F.; Nordin, M. S.; Kuruoğlu, F.; Erol, A.; Vickers, A. J.

    2017-02-01

    We report the characteristics of the temperature dependent operation of a GaInNAs-based resonant-cavity-enhanced photodetector (RCEPD), designed to be operated at the dispersion minimum optical communication window of 1.3 μm. A Transfer-Matrix Method (TMM) was used to design the structure of the device. The absorption layer of the photodetector is comprised of nine 7 nm-thick Ga0.733In0.267N0.025As0.975 (Sb)/GaN0.035As0.965 quantum wells, and 15 and 10 pairs of GaAs/AlAs distributed Bragg reflectors (DBRs) grown as the bottom and top mirrors, to form the cavity of the device. All electrical and optical measurements were carried out over a temperature range from 10 to 40 °C in order to investigate the characteristic of the device. The quantum efficiency is determined to be in the range of 16% (at 10 °C) and 31% (at 40 °C). An excellent wavelength selectivity is observed which changed from 3.7 nm (at 10 °C) to 5.4 nm (at 40 °C). The dark current of the device is measured as 11 nA at 10 °C and 19 nA at 40 °C without bias. The photocurrent at -0.5 V is measured to be 1.5 mA at 25 °C. The high dark current of the device is attributed to weak confinement of the electrons in GaInNAs QW surrounded by the strain-compensator GaNAs barrier layers. The temperature dependent cavity wavelength was analytically calculated and compared with that of experimental results. The temperature dependent linear shifts of the resonance wavelength (dλ / dT) is calculated as 0.077 nm/°C, which is in good agreement with the experimental result, 0.080 nm/°C. Our results reveal that the characteristics of a RCEPD, such as quantum efficiency, FWHM etc., are quite sensitive to temperature changes due to the temperature dependence of the refractive index of the DBRs.

  5. {sup 1}H NMR-based metabolomics of time-dependent responses of Eisenia fetida to sub-lethal phenanthrene exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lankadurai, Brian P.; Wolfe, David M.; Simpson, Andre J. [Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada (Canada); Simpson, Myrna J., E-mail: myrna.simpson@utoronto.ca [Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada (Canada)

    2011-10-15

    {sup 1}H NMR-based metabolomics was used to examine the response of the earthworm Eisenia fetida after exposure to sub-lethal concentrations of phenanthrene over time. Earthworms were exposed to 0.025 mg/cm{sup 2} of phenanthrene (1/64th of the LC{sub 50}) via contact tests over four days. Earthworm tissues were extracted using a mixture of chloroform, methanol and water, resulting in polar and non-polar fractions that were analyzed by {sup 1}H NMR after one, two, three and four days. NMR-based metabolomic analyses revealed heightened E. fetida responses with longer phenanthrene exposure times. Amino acids alanine and glutamate, the sugar maltose, the lipids cholesterol and phosphatidylcholine emerged as potential indicators of phenanthrene exposure. The conversion of succinate to fumarate in the Krebs cycle was also interrupted by phenanthrene. Therefore, this study shows that NMR-based metabolomics is a powerful tool for elucidating time-dependent relationships in addition to the mode of toxicity of phenanthrene in earthworm exposure studies. - Highlights: > NMR-based earthworm metabolomic analysis of the mode of action of phenanthrene is presented. > The earthworm species E. fetida were exposed to sub-lethal phenanthrene concentrations. > Both polar and non-polar metabolites of E. fetida tissue extracts were analyzed by {sup 1}H NMR. > Longer phenanthrene exposure times resulted in heightened earthworm responses. > An interruption of the Krebs cycle was also observed due to phenanthrene exposure. - {sup 1}H NMR metabolomics is used to determine the relationship between phenanthrene exposure and the metabolic response of the earthworm E. fetida over time and also to elucidate the phenanthrene mode of toxicity.

  6. Understanding the Size-Dependent Sodium Storage Properties of Na2C6O6-Based Organic Electrodes for Sodium-Ion Batteries.

    Science.gov (United States)

    Wang, Yaqun; Ding, Yu; Pan, Lijia; Shi, Ye; Yue, Zhuanghao; Shi, Yi; Yu, Guihua

    2016-05-11

    Organic electroactive materials represent a new generation of sustainable energy storage technology due to their unique features including environmental benignity, material sustainability, and highly tailorable properties. Here a carbonyl-based organic salt Na2C6O6, sodium rhodizonate (SR) dibasic, is systematically investigated for high-performance sodium-ion batteries. A combination of structural control, electrochemical analysis, and computational simulation show that rational morphological control can lead to significantly improved sodium storage performance. A facile antisolvent method was developed to synthesize microbulk, microrod, and nanorod structured SRs, which exhibit strong size-dependent sodium ion storage properties. The SR nanorod exhibited the best performance to deliver a reversible capacity of ∼190 mA h g(-1) at 0.1 C with over 90% retention after 100 cycles. At a high rate of 10 C, 50% of the capacity can be obtained due to enhanced reaction kinetics, and such high electrochemical activity maintains even at 80 °C. These results demonstrate a generic design route toward high-performance organic-based electrode materials for beyond Li-ion batteries. Using such a biomass-derived organic electrode material enables access to sustainable energy storage devices with low cost, high electrochemical performance and thermal stability.

  7. Substitutional group dependent colori/fluorimetric sensing of Mn2+, Fe3+ and Zn2+ ions by simple Schiff base chemosensor

    Science.gov (United States)

    Hariharan, P. S.; Anthony, Savarimuthu Philip

    2015-02-01

    Schiff base is one of the easiest synthesizable chemosensor and exhibit strong coordination with metal ions; the property that has been vastly exploited for metal ions sensing. Simple Schiff base chemosensors (1a-d and 2a-d) were synthesized and demonstrated substitutional group dependent colorimetric sensing of metal ions. Chemosensor without (1a, 2a) and OCH3 substitution (1b, 2b) did not show any significant colour change for metal ions. However, a highly selective colorimetric change (colourless to pink) for Mn2+ ions (10-6 M) was observed with diethylamine substituted 1c, 2c. Hydroxyl substitution (1d, 2d) leads to selective colorimetric sensing (colourless to orange) of Fe3+ ions (10-6 M). PVA thin films of 2c/2d were fabricated and demonstrated selective colorimetric sensing of Mn2+ and Fe3+ ions. The practical applicability of the synthesized chemosensors were also demonstrated by performing selective colorimetric sensing of Mn2+ and Fe3+ ions in real samples such as tap, ground, pond and river water. Effect of substitution on the fluorescence selectivity of Zn2+ has also been investigated.

  8. Conformational temperature-dependent behavior of a histone H2AX: a coarse-grained Monte Carlo approach via knowledge-based interaction potentials.

    Directory of Open Access Journals (Sweden)

    Miriam Fritsche

    Full Text Available Histone proteins are not only important due to their vital role in cellular processes such as DNA compaction, replication and repair but also show intriguing structural properties that might be exploited for bioengineering purposes such as the development of nano-materials. Based on their biological and technological implications, it is interesting to investigate the structural properties of proteins as a function of temperature. In this work, we study the spatial response dynamics of the histone H2AX, consisting of 143 residues, by a coarse-grained bond fluctuating model for a broad range of normalized temperatures. A knowledge-based interaction matrix is used as input for the residue-residue Lennard-Jones potential.We find a variety of equilibrium structures including global globular configurations at low normalized temperature (T* = 0.014, combination of segmental globules and elongated chains (T* = 0.016,0.017, predominantly elongated chains (T* = 0.019,0.020, as well as universal SAW conformations at high normalized temperature (T* ≥ 0.023. The radius of gyration of the protein exhibits a non-monotonic temperature dependence with a maximum at a characteristic temperature (T(c* = 0.019 where a crossover occurs from a positive (stretching at T* ≤ T(c* to negative (contraction at T* ≥ T(c* thermal response on increasing T*.

  9. Conformational temperature-dependent behavior of a histone H2AX: a coarse-grained Monte Carlo approach via knowledge-based interaction potentials.

    Science.gov (United States)

    Fritsche, Miriam; Pandey, Ras B; Farmer, Barry L; Heermann, Dieter W

    2012-01-01

    Histone proteins are not only important due to their vital role in cellular processes such as DNA compaction, replication and repair but also show intriguing structural properties that might be exploited for bioengineering purposes such as the development of nano-materials. Based on their biological and technological implications, it is interesting to investigate the structural properties of proteins as a function of temperature. In this work, we study the spatial response dynamics of the histone H2AX, consisting of 143 residues, by a coarse-grained bond fluctuating model for a broad range of normalized temperatures. A knowledge-based interaction matrix is used as input for the residue-residue Lennard-Jones potential.We find a variety of equilibrium structures including global globular configurations at low normalized temperature (T* = 0.014), combination of segmental globules and elongated chains (T* = 0.016,0.017), predominantly elongated chains (T* = 0.019,0.020), as well as universal SAW conformations at high normalized temperature (T* ≥ 0.023). The radius of gyration of the protein exhibits a non-monotonic temperature dependence with a maximum at a characteristic temperature (T(c)* = 0.019) where a crossover occurs from a positive (stretching at T* ≤ T(c)*) to negative (contraction at T* ≥ T(c)*) thermal response on increasing T*.

  10. Porous silicon-VO{sub 2} based hybrids as possible optical temperature sensor: Wavelength-dependent optical switching from visible to near-infrared range

    Energy Technology Data Exchange (ETDEWEB)

    Antunez, E. E.; Salazar-Kuri, U.; Estevez, J. O.; Basurto, M. A.; Agarwal, V., E-mail: vagarwal@uaem.mx [Centro de Investigación en Ingeniería y Ciencias Aplicadas, Instituto de Investigación en Ciencias Básicas y Aplicadas, UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Mor. 62209 (Mexico); Campos, J. [Instituto de Energías Renovables, UNAM, Priv. Xochicalco S/N, Temixco, Mor. 62580 (Mexico); Jiménez Sandoval, S. [Laboratorio de Investigación en Materiales, Centro de Investigación y estudios Avanzados del Instituto Politécnico Nacional, Unidad Querétaro, Qro. 76001 (Mexico)

    2015-10-07

    Morphological properties of thermochromic VO{sub 2}—porous silicon based hybrids reveal the growth of well-crystalized nanometer-scale features of VO{sub 2} as compared with typical submicron granular structure obtained in thin films deposited on flat substrates. Structural characterization performed as a function of temperature via grazing incidence X-ray diffraction and micro-Raman demonstrate reversible semiconductor-metal transition of the hybrid, changing from a low-temperature monoclinic VO{sub 2}(M) to a high-temperature tetragonal rutile VO{sub 2}(R) crystalline structure, coupled with a decrease in phase transition temperature. Effective optical response studied in terms of red/blue shift of the reflectance spectra results in a wavelength-dependent optical switching with temperature. As compared to VO{sub 2} film over crystalline silicon substrate, the hybrid structure is found to demonstrate up to 3-fold increase in the change of reflectivity with temperature, an enlarged hysteresis loop and a wider operational window for its potential application as an optical temperature sensor. Such silicon based hybrids represent an exciting class of functional materials to display thermally triggered optical switching culminated by the characteristics of each of the constituent blocks as well as device compatibility with standard integrated circuit technology.

  11. Comparison of frequency-distance relationship and Gaussian-diffusion-based methods of compensation for distance-dependent spatial resolution in SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kohli, Vandana [Department of Nuclear Medicine, The University of Massachusetts Medical Center, 55 Lake Ave North, Worcester, MA 01655 (United States); Department of Electrical Engineering, The University of Massachusetts Lowell, 1 University Ave, Lowell, MA 01854 (United States); King, Micgael A.; Glick, Stephen J. [Department of Nuclear Medicine, The University of Massachusetts Medical Center, 55 Lake Ave North, Worcester, MA 01655 (United States); Pan, Tin-Su [The Applied Science Laboratory, General Electric Company, Milwaukee, WI 53201 (United States)

    1998-04-01

    The goal of this investigation was to compare resolution recovery versus noise level of two methods for compensation of distance-dependent resolution (DDR) in SPECT imaging. The two methods of compensation were restoration filtering based on the frequency-distance relationship (FDR) prior to iterative reconstruction, and modelling DDR in the projector/backprojector pair employed in iterative reconstruction. FDR restoration filtering was computationally faster than modelling the detector response in iterative reconstruction. Using Gaussian diffusion to model the detector response in iterative reconstruction sped up the process by a factor of 2.5 over frequency domain filtering in the projector/backprojector pair. Gaussian diffusion modelling resulted in a better resolution versus noise tradeoff than either FDR restoration filtering or solely modelling attenuation in the projector/backprojector pair of iterative reconstruction. For the pixel size investigated herein (0.317 cm), accounting for DDR in the projector/backprojector pair by Gaussian diffusion, or by applying a blurring function based on the distance from the face of the collimator at each distance, resulted in very similar resolution recovery and slice noise level. (author)

  12. Weighting Collaborative Task Sequencing Based on Dependency Logic Breakdown%基于依赖关系的带权协同任务排序

    Institute of Scientific and Technical Information of China (English)

    梁学栋; 刘柱胜; 杨育; 包北方

    2011-01-01

    针对分布式协同设计环境下多任务复杂交叉协调困难的问题,基于协调理论(CT)中的依赖分析方法和项目管理中的工作分解结构(WBS)方法对协同设计业务规则以及任务-资源依赖关系进行逻辑分解,提出复杂协同设计环境下单主体的任务协调模型.鉴于分布式协同设计环境下任务重要程度不同、信息不完整的特点,同时考虑协同任务之间的耦合关系,采用灰关联分析法(GRA)对协同设计任务权重进行赋值,并对带权设计任务进行排序.最后,通过工程算例验证了该模型能够实现协同任务及其依赖资源的有效排序,有利于设计过程的冲突消解.%The difficulty of task coordination in complicate and crossing distributed collaborative design surroundings requires the effective sequencing of collaborative task. Therefore, the dependency logic of task-resource breakdown based on collaborative business rules is proposed with dependency analysis method in Coordination Theory (CT) and Work Breakdown StructUR (WBS) in Project Management (PM). In view of the incomplete information and different significance of collaborative design task, Grey Relational Analysis (GRA) is employed to value the weight of task.Furthermore, weighting collaborative tasks are ordered in an optimized sequence. Case study is demonstrated to illustrate the feasibility and applicability of this method.

  13. Pyrosequencing vs. culture-dependent approaches to analyze lactic acid bacteria associated to chicha, a traditional maize-based fermented beverage from Northwestern Argentina.

    Science.gov (United States)

    Elizaquível, Patricia; Pérez-Cataluña, Alba; Yépez, Alba; Aristimuño, Cecilia; Jiménez, Eugenia; Cocconcelli, Pier Sandro; Vignolo, Graciela; Aznar, Rosa

    2015-04-02

    The diversity of lactic acid bacteria (LAB) associated with chicha, a traditional maize-based fermented alcoholic beverage from Northwestern Argentina, was analyzed using culture-dependent and culture-independent approaches. Samples corresponding to 10 production steps were obtained from two local producers at Maimará (chicha M) and Tumbaya (chicha T). Whereas by culture-dependent approach a few number of species (Lactobacillus plantarum and Weissella viridescens in chicha M, and Enterococcus faecium and Leuconostoc mesenteroides in chicha T) were identified, a higher quantitative distribution of taxa was found in both beverages by pyrosequencing. The relative abundance of OTUs was higher in chicha M than in chicha T; six LAB genera were common for chicha M and T: Enterococcus, Lactococcus, Streptococcus, Weissella, Leuconostoc and Lactobacillus while Pediococcus only was detected in chicha M. Among the 46 identified LAB species, those of Lactobacillus were dominant in both chicha samples, exhibiting the highest diversity, whereas Enterococcus and Leuconostoc were recorded as the second dominant genera in chicha T and M, respectively. Identification at species level showed the predominance of Lb. plantarum, Lactobacillus rossiae, Leuconostoc lactis and W. viridescens in chicha M while Enterococcus hirae, E. faecium, Lc. mesenteroides and Weissella confusa predominated in chicha T samples. In parallel, when presumptive LAB isolates (chicha M: 146; chicha T: 246) recovered from the same samples were identified by ISR-PCR and RAPD-PCR profiles, species-specific PCR and 16S rRNA gene sequencing, most of them were assigned to the Leuconostoc genus (Lc. mesenteroides and Lc. lactis) in chicha M, Lactobacillus, Weissella and Enterococcus being also present. In contrast, chicha T exhibited the presence of Enterococcus and Leuconostoc, E. faecium being the most representative species. Massive sequencing approach was applied for the first time to study the diversity and

  14. 基于依存树的越南语新闻事件元素抽取%Extracting Vietnamese news event elements based on dependency tree

    Institute of Scientific and Technical Information of China (English)

    周晶晶; 周枫; 严馨

    2016-01-01

    为加强对越南政治、经济和文化等方面新闻事件的了解,提出一种基于依存树的越南语新闻事件元素抽取方法。分析越南语的语法特点,发现越南语最主要的特点是定语后置,其它和中文的语法结构类似,通过直接映射中文句法结构得到越南语依存树;在此基础上通过定义规则,在依存树中找到相应的句法结构,抽取句子的主语、宾语和状语。实验结果表明,该方法可以快速地定位到越南语句子的句法成分,有效地抽取出越南语新闻事件元素。%To enhance the understanding of the Vietnamese political,economic and cultural aspects of news events,a method ex-tracting Vietnamese news event element based on dependency tree was proposed.According to Vietnamese grammar characteris-tics,the facts that the main feature of Vietnamese is attributive post position and other grammatical structures are similar to Chi-nese were found,so Vietnamese dependency tree was got by directly mapping Chinese sentence structure.On this basis,by defi-ning rules,the syntactic structure in dependency tree was found,thereby extracting the subject,object and adverbial of a sen-tence.Experimental results show that this method can quickly locate the syntactic constituents of Vietnamese sentence and effec-tively extract the Vietnamese news event element.

  15. 基于网络挖掘的上下文相关词汇级复述研究%Context-Dependent Lexical Paraphrasing Based on Web Mining

    Institute of Scientific and Technical Information of China (English)

    赵世奇; 张宇; 赵琳; 刘挺; 李生

    2009-01-01

    Lexical paraphrasing is the task of extracting word-level paraphrases. Lexical paraphrases should be context dependent since a word may have different paraphrases in distinct contexts. This paper investigates a framework for acquiring context-dependent lexical paraphrases, in which a web mining method is developed for extracting candidate paraphrases and a classification method is introduced in paraphrase validation. Evaluations are carried out on the People's Daily corpus and the results show that: (1) the web mining method performs well in candidate paraphrase extraction, which extracts 2.3 correct paraphrases on average for each test word in each given context sentence; (2) the classifier for paraphrase validation is effective, which achieves an f-measure of 0.6023;(3) 75.11% and 98.31% of the paraphrases extracted by our method cannot be recognized by the two widely used context-independent methods, i.e., the thesaurus-based and clustering-based methods respectively. This indicates that the presented context-dependent method is a considerable supplement to the context-independent ones.%词汇级复述研究旨在为词汇获取复述.词汇级复述是上下文相关的,即对同一个词在不同上下文中应获取不同的复述词.提出了一种获取上下文相关词汇级复述的方法.该方法包括两部分:基于网络挖掘的候选复述词获取以及基于二元分类的复述词确认.在语料库上的实验结果表明:(1) 基于网络挖掘的候选复述词获取方法是切实可行的,平均为每个待复述词在每个给定的上下文句子中获取2.3个正确复述词;(2) 利用二元分类的方法进行复述确认是有效的,其F值达到0.6023;(3) 利用该方法抽取得到的复述中,有75.11%和98.31%无法通过两种常用的上下文无关方法,即基于辞典和基于聚类的方法来获得.这证明了所提出的上下文相关复述方法可以有效地补充传统的上下文无关方法.

  16. Early mortality in multiple myeloma: the time-dependent impact of comorbidity: A population-based study in 621 real-life patients.

    Science.gov (United States)

    Ríos-Tamayo, Rafael; Sáinz, Juan; Martínez-López, Joaquín; Puerta, José Manuel; Chang, Daysi-Yoe-Ling; Rodríguez, Teresa; Garrido, Pilar; de Veas, José Luís García; Romero, Antonio; Moratalla, Lucía; López-Fernández, Elisa; González, Pedro Antonio; Sánchez, María José; Jiménez-Moleón, José Juan; Jurado, Manuel; Lahuerta, Juan José

    2016-07-01

    Multiple myeloma is a heterogeneous disease with variable survival; this variability cannot be fully explained by the current systems of risk stratification. Early mortality remains a serious obstacle to further improve the trend toward increased survival demonstrated in recent years. However, the definition of early mortality is not standardized yet. Importantly, no study has focused on the impact of comorbidity on early mortality in multiple myeloma to date. Therefore, we analyzed the role of baseline comorbidity in a large population-based cohort of 621 real-life myeloma patients over a 31-year period. To evaluate early mortality, a sequential multivariate regression model at 2, 6, and 12 months from diagnosis was performed. It was demonstrated that comorbidity had an independent impact on early mortality, which is differential and time-dependent. Besides renal failure, respiratory disease at 2 months, liver disease at 6 months, and hepatitis virus C infection at 12 months, were, respectively, associated with early mortality, adjusting for other well-established prognostic factors. On the other hand, the long-term monitoring in our study points out a modest downward trend in early mortality over time. This is the first single institution population-based study aiming to assess the impact of comorbidity on early mortality in multiple myeloma. It is suggested that early mortality should be analyzed at three key time points (2, 6, and 12 months), in order to allow comparisons between studies. Comorbidity plays a critical role in the outcome of myeloma patients in terms of early mortality. Am. J. Hematol. 91:700-704, 2016. © 2016 Wiley Periodicals, Inc.

  17. Size-dependent dynamic pull-in analysis of geometric non-linear micro-plates based on the modified couple stress theory

    Science.gov (United States)

    Askari, Amir R.; Tahani, Masoud

    2017-02-01

    This paper focuses on the size-dependent dynamic pull-in instability in rectangular micro-plates actuated by step-input DC voltage. The present model accounts for the effects of in-plane displacements and their non-classical higher-order boundary conditions, von Kármán geometric non-linearity, non-classical couple stress components and the inherent non-linearity of distributed electrostatic pressure on the micro-plate motion. The governing equations of motion, which are clearly derived using Hamilton's principle, are solved through a novel computationally very efficient Galerkin-based reduced order model (ROM) in which all higher-order non-classical boundary conditions are completely satisfied. The present findings are compared and successfully validated by available results in the literature as well as those obtained by three-dimensional finite element simulations carried out using COMSOL Multyphysics. A detailed parametric study is also conducted to illustrate the effects of in-plane displacements, plate aspect ratio, couple stress components and geometric non-linearity on the dynamic instability threshold of the system.

  18. Natural History of Dependency in the Elderly: A 24-Year Population-Based Study Using a Longitudinal Item Response Theory Model.

    Science.gov (United States)

    Edjolo, Arlette; Proust-Lima, Cécile; Delva, Fleur; Dartigues, Jean-François; Pérès, Karine

    2016-02-15

    We aimed to describe the hierarchical structure of Instrumental Activities of Daily Living (IADL) and basic Activities of Daily Living (ADL) and trajectories of dependency before death in an elderly population using item response theory methodology. Data were obtained from a population-based French cohort study, the Personnes Agées QUID (PAQUID) Study, of persons aged ≥65 years at baseline in 1988 who were recruited from 75 randomly selected areas in Gironde and Dordogne. We evaluated IADL and ADL data collected at home every 2-3 years over a 24-year period (1988-2012) for 3,238 deceased participants (43.9% men). We used a longitudinal item response theory model to investigate the item sequence of 11 IADL and ADL combined into a single scale and functional trajectories adjusted for education, sex, and age at death. The findings confirmed the earliest losses in IADL (shopping, transporting, finances) at the partial limitation level, and then an overlapping of concomitant IADL and ADL, with bathing and dressing being the earliest ADL losses, and finally total losses for toileting, continence, eating, and transferring. Functional trajectories were sex-specific, with a benefit of high education that persisted until death in men but was only transient in women. An in-depth understanding of this sequence provides an early warning of functional decline for better adaptation of medical and social care in the elderly.

  19. Spectra and quantum efficiency of light-emitting diodes based on GaN heterostructures with quantum wells and their dependence on current and voltage

    CERN Document Server

    Kudryashov, V E; Turkin, A N; Yunovich, A E; Kovalev, A N; Manyakhin, F I

    2001-01-01

    Spectra and quantum efficiency of light-emitted diodes based on heterostructures InGaN/AlGaN/GaN with multiple quantum wells have been studied at currents J = 10 sup - sup 6 -10 sup - sup 1 A. Minor differences in quantum efficiency (of +- 10% at J approx = 10 mA) are caused by sufficiently different distribution of effective charges in the space charge region as well as by different role of the tunnel component of current at low voltages. The main peak in spectra near of 2.35-2.36 eV at small current (0.05-0.5 mA) does not depend on the voltage and is explained by radiative transitions in localized states. At J > 1 mA the spectral band 2.36-2.52 eV shifts with gamma current. The band form is described in the 4-parameter model of tail population of two-dimensional energy-level density

  20. Time-dependent quantum transport: an efficient method based on Liouville-von-Neumann equation for single-electron density matrix.

    Science.gov (United States)

    Xie, Hang; Jiang, Feng; Tian, Heng; Zheng, Xiao; Kwok, Yanho; Chen, Shuguang; Yam, ChiYung; Yan, YiJing; Chen, Guanhua

    2012-07-28

    Basing on our hierarchical equations of motion for time-dependent quantum transport [X. Zheng, G. H. Chen, Y. Mo, S. K. Koo, H. Tian, C. Y. Yam, and Y. J. Yan, J. Chem. Phys. 133, 114101 (2010)], we develop an efficient and accurate numerical algorithm to solve the Liouville-von-Neumann equation. We solve the real-time evolution of the reduced single-electron density matrix at the tight-binding level. Calculations are carried out to simulate the transient current through a linear chain of atoms, with each represented by a single orbital. The self-energy matrix is expanded in terms of multiple Lorentzian functions, and the Fermi distribution function is evaluated via the Padè spectrum decomposition. This Lorentzian-Padè decomposition scheme is employed to simulate the transient current. With sufficient Lorentzian functions used to fit the self-energy matrices, we show that the lead spectral function and the dynamics response can be treated accurately. Compared to the conventional master equation approaches, our method is much more efficient as the computational time scales cubically with the system size and linearly with the simulation time. As a result, the simulations of the transient currents through systems containing up to one hundred of atoms have been carried out. As density functional theory is also an effective one-particle theory, the Lorentzian-Padè decomposition scheme developed here can be generalized for first-principles simulation of realistic systems.

  1. Microtubule-dependent relocation of branchial V-H+-ATPase to the basolateral membrane in the Pacific spiny dogfish (Squalus acanthias): a role in base secretion.

    Science.gov (United States)

    Tresguerres, Martin; Parks, Scott K; Katoh, Fumi; Goss, Greg G

    2006-02-01

    We have previously shown that continuous intravenous infusion of NaHCO3 for 24 h ( approximately 1000 micromol kg(-1) h(-1)) results in the relocation of V-H+-ATPase from the cytoplasm to the basolateral membrane in the gills of the Pacific dogfish. To further investigate this putative base-secretive process we performed similar experiments with the addition of colchicine, an inhibitor of cytoskeleton-dependent cellular trafficking processes. Blood pH and plasma total CO2 were significantly higher in the colchicines-treated, HCO3- -infused fish compared with fish infused with HCO3- alone. The effect of colchicine was highest after 24 h of infusion (8.33+/-0.06 vs 8.02+/-0.03 pH units, 15.72+/-3.29 vs 6.74+/-1.34 mmol CO2 l(-1), N=5). Immunohistochemistry and western blotting confirmed that colchicine blocked the transit of V-H+-ATPase to the basolateral membrane. Furthermore, western blotting analyses from whole gill and cell membrane samples suggest that the short-term (6 h) response to alkaline stress consists of relocation of V-H+-ATPases already present in the cell to the basolateral membrane, while in the longer term (24 h) there is both relocation of preexistent enzyme and upregulation in the synthesis of new units. Our results strongly suggest that cellular relocation of V-H+-ATPase is necessary for enhanced HCO3- secretion across the gills of the Pacific dogfish.

  2. Combination therapy using fexofenadine, disodium cromoglycate, and a hypoallergenic amino acid-based formula induced remission in a patient with steroid-dependent, chronically active ulcerative colitis.

    Science.gov (United States)

    Raithel, M; Winterkamp, S; Weidenhiller, M; Müller, S; Hahn, E G

    2007-07-01

    Corticosteroids and 5-aminosalicylic acid are the primary standard therapy for inflammatory bowel disease. Recent immunologic data implicate an involvement of mast cell activation followed by increased histamine secretion and elevated tissue concentrations of histamine in the pathogenesis of ulcerative colitis. In the present case, the clinical course of a 35-year-old man with steroid-dependent chronic active ulcerative colitis, who did not respond to high-dose steroids, antibiotics, or azathioprine during 3 years, is reported. Clinical disease activity and established serological markers were recorded during 6 weeks of unsuccessful therapy and during the next 6 weeks, as a new nonsedative antihistaminergic drug, a mast cell stabilizer, and an hypoallergenic diet were implemented in addition to conventional therapy. Induction of remission was achieved within 2 weeks after treatment with fexofenadine, disodium cromoglycate, and an amino acid-based formula. Clinical disease activity, stool frequency, leukocytes, c-reactive protein, and orosomucoid levels in serum decreased rapidly. Daily steroid administration could be gradually reduced along with 6 weeks of this treatment. This report suggests that histamine and mast cell activity may be important pathophysiological factors responsible for persistent clinical and mucosal inflammatory activity in ulcerative colitis despite the use of steroids. In ulcerative colitis, patients unresponsive to conventional treatment, therapeutic considerations should also include an antiallergic approach when further signs of atopy or intestinal hypersensitivity are present.

  3. Impulsivity and voucher versus money preference in polydrug-dependent participants enrolled in a contingency-management-based substance abuse treatment program.

    Science.gov (United States)

    Reilly, M P; Roll, J M; Downey, K K

    2000-10-01

    Thirty-four polydrug-dependent participants enrolled in a voucher-based substance abuse treatment program were given choices between hypothetical amounts of money and hypothetical amounts of vouchers, which are traded for goods and services, to determine their preferences for the two payment modalities. It was hypothesized that the majority of participants would prefer money to voucher because under the circumstances of the treatment program, the delay associated with money exchange is shorter than the delay associated with voucher exchange. It was further hypothesized that those participants who selected money over voucher also would have greater levels of impulsivity as assessed by the Barratt Impulsiveness Rating Scale (BIS) (Barratt, 1965). The results show large individual differences in money/voucher preference with approximately half of the participants preferring money to voucher when the two amounts are equivalent. In addition, as the magnitude of the money/voucher comparisons increased from 0.50 dollars to 32.00 dollars, the percentage of participants that preferred money increased. No correlations were found between money/voucher preference and impulsivity scores.

  4. Fucose-based PAMPs prime dendritic cells for follicular T helper cell polarization via DC-SIGN-dependent IL-27 production.

    Science.gov (United States)

    Gringhuis, Sonja I; Kaptein, Tanja M; Wevers, Brigitte A; van der Vlist, Michiel; Klaver, Elsenoor J; van Die, Irma; Vriend, Lianne E M; de Jong, Marein A W P; Geijtenbeek, Teunis B H

    2014-10-03

    Dendritic cells (DCs) orchestrate antibody-mediated responses to combat extracellular pathogens including parasites by initiating T helper cell differentiation. Here we demonstrate that carbohydrate-specific signalling by DC-SIGN drives follicular T helper cell (TFH) differentiation via IL-27 expression. Fucose, but not mannose, engagement of DC-SIGN results in activation of IKKε, which collaborates with type I IFNR signalling to induce formation and activation of transcription factor ISGF3. Notably, ISGF3 induces expression of IL-27 subunit p28, and subsequent IL-27 secreted by DC-SIGN-primed DCs is pivotal for the induction of Bcl-6(+)CXCR5(+)PD-1(hi)Foxp1(lo) TFH cells, IL-21 secretion by TFH cells and T-cell-dependent IgG production by B cells. Thus, we have identified an essential role for DC-SIGN-induced ISGF3 by fucose-based PAMPs in driving IL-27 and subsequent TFH polarization, which might be harnessed for vaccination design.

  5. Polarization-dependent all-optical modulator with ultra-high modulation depth based on a stereo graphene-microfiber structure

    CERN Document Server

    Xu, Fei; Zheng, Bi-cai; Shao, Guang-hao; Ge, Shi-jun; Lu, Yan-qing

    2015-01-01

    We report an in-line polarization-dependent all-optical fiber modulator based on a stereo graphene-microfiber structure (GMF) by utilizing the lab-on-rod technique. Owing to the unique spring-like geometry, an ultra-long GMF interaction length can be achieved, and an ultra-high modulation depth (MD) of ~7.5 dB and a high modulation efficiency (ME) of ~0.2 dB/mW were demonstrated for one polarization state. The MD and ME are more than one order larger than those of other graphene-waveguide hybrid all-optical modulators. By further optimizing the transferring and cleaning process, the modulator can quickly switch between transparent and opaque states for both the two polarization states with a maximized MD of tens of decibels. This modulator is compatible with current fiber-optic communication systems and may be applied in the near future to meet the impending need for ultrafast optical signal processing.

  6. Association of the insulin-receptor variant Met-985 with hyperglycemia and non-insulin-dependent diabetes mellitus in the Netherlands: A population-based study

    Energy Technology Data Exchange (ETDEWEB)

    `t Hart, L.M.; Maassen, J.A. [Leiden Univ. (Netherlands); Does, F.E.E. van der [Free Univ., Amsterdam (Netherlands)] [and others

    1996-11-01

    One of the characteristics of non-insulin-dependent diabetes mellitus (NIDDM) is the presence of insulin. Most NIDDM patients have a normal sequence of the insulin receptor, indicating that, if insulin-receptor mutations contribute to the development of NIDDM, they will be present only in a minor fraction of the NIDDM population. The goal of the present study was to examine whether insulin-receptor mutations contribute to the development of NIDDM. We examined 161 individuals with NIDDM and 538 healthy controls from the population-based Rotterdam study for the presence of mutations in the insulin-receptor gene by SSCP. A heterozygous mutation changing valine-985 into methionine was detected in 5.6% of diabetic subjects and in 1.3% of individuals with normal oral glucose tolerance test. Adjusted for age, gender, and body-mass index, this revealed a relative risk for diabetes of 4.49 (95% confidence interval 1.59-12.25) for Met-985 carriers. When the total study group was analyzed, the prevalence of the mutation increased with increasing serum glucose levels (test for trend P < .005). We conclude that the Met-985 insulin-receptor variant associates with hyperglycemia and represents a risk factor for NIDDM. 30 refs., 3 figs., 1 tab.

  7. The roles of Tyr(91) and Lys(162) in general acid-base catalysis in the pigeon NADP+-dependent malic enzyme.

    Science.gov (United States)

    Kuo, Cheng-Chin; Lin, Kuan-Yu; Hsu, Yau-Jung; Lin, Shu-Yu; Lin, Yu-Tsen; Chang, Gu-Gang; Chou, Wei-Yuan

    2008-05-01

    The role of general acid-base catalysis in the enzymatic mechanism of NADP+-dependent malic enzyme was examined by detailed steady-state kinetic studies through site-directed mutagenesis of the Tyr(91) and Lys(162) residues in the putative catalytic site of the enzyme. Y91F and K162A mutants showed approx. 200- and 27000-fold decreases in k(cat) values respectively, which could be partially recovered with ammonium chloride. Neither mutant had an effect on the partial dehydrogenase activity of the enzyme. However, both Y91F and K162A mutants caused decreases in the k(cat) values of the partial decarboxylase activity of the enzyme by approx. 14- and 3250-fold respectively. The pH-log(k(cat)) profile of K162A was found to be different from the bell-shaped profile pattern of wild-type enzyme as it lacked a basic pK(a) value. Oxaloacetate, in the presence of NADPH, can be converted by malic enzyme into L-malate by reduction and into enolpyruvate by decarboxylation activities. Compared with wild-type, the K162A mutant preferred oxaloacetate reduction to decarboxylation. These results are consistent with the function of Lys(162) as a general acid that protonates the C-3 of enolpyruvate to form pyruvate. The Tyr(91) residue could form a hydrogen bond with Lys(162) to act as a catalytic dyad that contributes a proton to complete the enol-keto tautomerization.

  8. Understanding the anchoring behavior of titanium carbide-based MXenes depending on the functional group in Lisbnd S batteries: A density functional theory study

    Science.gov (United States)

    Sim, Eun Seob; Yi, Gyu Seong; Je, Minyeong; Lee, Youngbin; Chung, Yong-Chae

    2017-02-01

    In this study, the properties of F-functionalized Ti2C (Ti2CF2) and O-functionalized Ti2C (Ti2CO2) as conductive anchoring materials for lithium-sulfur (Lisbnd S) batteries were investigated using the density functional theory (DFT). It was confirmed that both of Ti2CF2 and Ti2CO2 will suppress the shuttle effect by different suppressing mechanisms depending on the Ti2CF2 and Ti2CO2. The F-functionalized surface of Ti2CF2 suppresses the shuttle effect by strong interaction with lithium polysulfides (LiPSs). On the other hand, the shuttle effect is suppressed on the O-functionalized surface by converting soluble high-order LiPSs (Li2S8, Li2S7, and Li2S6) to insoluble elemental sulfur. In addition, the redox reaction of anchored LiPSs takes place because Ti2CF2 and Ti2CO2 show metallic properties after anchoring the LiPSs. As a result, the Fsbnd and O-functionalized surfaces of the Ti2C-based MXenes will contribute to suppressing the shuttle effect as conductive anchoring materials for Lisbnd S batteries. This theoretical study will provide further insight into the application of MXenes as a conductive anchoring material for Lisbnd S batteries.

  9. Flow cytometric readout based on Mitotracker Red CMXRos staining of live asexual blood stage malarial parasites reliably assesses antibody dependent cellular inhibition

    Directory of Open Access Journals (Sweden)

    Jogdand Prajakta S

    2012-07-01

    Full Text Available Abstract Background Functional in vitro assays could provide insights into the efficacy of malaria vaccine candidates. For estimating the anti-parasite effect induced by a vaccine candidate, an accurate determination of live parasite count is an essential component of most in vitro bioassays. Although traditionally parasites are counted microscopically, a faster, more accurate and less subjective method for counting parasites is desirable. In this study mitochondrial dye (Mitotracker Red CMXRos was used for obtaining reliable live parasite counts through flow cytometry. Methods Both asynchronous and tightly synchronized asexual blood stage cultures of Plasmodium falciparum were stained with CMXRos and subjected to detection by flow cytometry and fluorescence microscopy. The parasite counts obtained by flow cytometry were compared to standard microscopic counts obtained through examination of Giemsa-stained thin smears. A comparison of the ability of CMXRos to stain live and compromised parasites (induced by either medium starvation or by anti-malarial drug treatment was carried out. Finally, parasite counts obtained by CMXRos staining through flow cytometry were used to determine specific growth inhibition index (SGI in an antibody-dependent cellular inhibition (ADCI assay. Results Mitotracker Red CMXRos can reliably detect live intra-erythrocytic stages of P. falciparum. Comparison between staining of live with compromised parasites shows that CMXRos predominantly stains live parasites with functional mitochondria. Parasite counts obtained by CMXRos staining and flow cytometry were highly reproducible and can reliably determine the ability of IgG from hyper-immune individuals to inhibit parasite growth in presence of monocytes in ADCI assay. Further, a dose-dependent parasite growth inhibitory effect could be detected for both total IgG purified from hyper-immune sera and affinity purified IgGs against the N-terminal non-repeat region of GLURP

  10. Comparison of prescriber evaluations and patient-directed self-reports in office-based practice for buprenorphine treatment of opiate-dependent individuals in France, 2002

    Directory of Open Access Journals (Sweden)

    Estelle Lavie

    2008-11-01

    Full Text Available Estelle Lavie1, Mélina Fatséas1, Jean-Pierre Daulouède1,2, Cécile Denis1, Jacques Dubernet1, Laurent Cattan3, Marc Auriacombe11Laboratoire de psychiatrie/EA4139, INSERM IFR-99 and Faculté de médecine Victor Pachon, University Victor Segalen Bordeaux 2, Bordeaux, France; 2Bizia, Centre de soins d’addictologie, Centre Hospitalier de la Côte Basque, Bayonne, France; 3Centre médical, Noisy-le-sec, FranceAbstract: The objective of this cross-sectional evaluation study was to compare data generated through prescriber assessments, and data generated from independent direct contact with opiate-dependent patients in office-based practice to evaluate buprenorphine treatment for modality of buprenorphine absorption, benzodiazepine use, and depressive symptoms. A group of buprenorphine office-based practice prescribers was selected to participate in this study. They were asked to screen for inclusion all their patients coming for a visit from February to August 2002. Once included by their prescribing physician, patients were given a series of self-administered questionnaires to be returned directly to the research staff, independently of their prescriber. Each prescriber was given a questionnaire to complete based on their knowledge and interview of the patient. Items assessed were history of current treatment, current substance use, buprenorphine treatment related behavior (daily frequency of intake, route of administration, benzodiazepine use and existence of a major depressive episode. Prescribers and patients’ questionnaires were compared. Concordance of both assessments was assessed by kappa statistics. The sensitivity and specificity as well as the positive and negative predictive values of prescriber collected information were compared to that of their patients’. There was an overall good correlation between both data sources on the procedures for buprenorphine use especially for intravenous use of buprenorphine. There were important

  11. Blood oxygenation level-dependent (BOLD)-based techniques for the quantification of brain hemodynamic and metabolic properties - theoretical models and experimental approaches.

    Science.gov (United States)

    Yablonskiy, Dmitriy A; Sukstanskii, Alexander L; He, Xiang

    2013-08-01

    The quantitative evaluation of brain hemodynamics and metabolism, particularly the relationship between brain function and oxygen utilization, is important for the understanding of normal human brain operation, as well as the pathophysiology of neurological disorders. It can also be of great importance for the evaluation of hypoxia within tumors of the brain and other organs. A fundamental discovery by Ogawa and coworkers of the blood oxygenation level-dependent (BOLD) contrast opened up the possibility to use this effect to study brain hemodynamic and metabolic properties by means of MRI measurements. Such measurements require the development of theoretical models connecting the MRI signal to brain structure and function, and the design of experimental techniques allowing MR measurements to be made of the salient features of theoretical models. In this review, we discuss several such theoretical models and experimental methods for the quantification of brain hemodynamic and metabolic properties. The review's main focus is on methods for the evaluation of the oxygen extraction fraction (OEF) based on the measurement of the blood oxygenation level. A combination of the measurement of OEF and the cerebral blood flow (CBF) allows an evaluation to be made of the cerebral metabolic rate of oxygen consumption (CMRO2 ). We first consider in detail the magnetic properties of blood - magnetic susceptibility, MR relaxation and theoretical models of the intravascular contribution to the MR signal under different experimental conditions. We then describe a 'through-space' effect - the influence of inhomogeneous magnetic fields, created in the extravascular space by intravascular deoxygenated blood, on the formation of the MR signal. Further, we describe several experimental techniques taking advantage of these theoretical models. Some of these techniques - MR susceptometry and T2 -based quantification of OEF - utilize the intravascular MR signal. Another technique

  12. The utility of a model-based cost-effectiveness analysis of degarelix versus leuprolide in the therapy of hormone-dependent advanced prostate cancer

    Directory of Open Access Journals (Sweden)

    Massimo Perachino

    2013-09-01

    Full Text Available INTRODUCTION: Prostate cancer (PC is a very common tumor among men: in Italy its prevalence in 2006 was 0.9%. Androgen deprivation therapy is a way to treat hormone-responsive PC by decreasing testosterone levels. GnRH-analogues, including GnRH-agonists and GnRH-antagonists, are effective for this purpose. AIM: This article presents a cost-effectiveness analysis based on a semi-Markov model comparing the GnRH-antagonist degarelix and GnRH-agonist leuprolide in the treatment of hormone-dependent advanced prostate cancer from the perspective of the Regional Health Service in Veneto Region (Italy.MATERIALS AND METHODS: Effectiveness data were retrieved by a 12-month phase III non-inferiority clinical trial, comparing degarelix and 7,5 mg leuprolide in 610 patients treated for hormone-dependent prostate cancer. Epidemiological data came from a national database and were referred to Veneto Region. The values of the healthcare resources were calculated using regional and national prices (€ 2012. The model considers 3 exhaustive and mutually exclusive health status: first-line treatment, further-lines treatment and death. It lasts 10 years, with 28 days per cycle. The entry in the model is hypothesized at the age of 70 (the age with most PCs in Veneto Region. Effectiveness endpoints were life years saved and quality-adjusted life years, using 3% social discount rate. The incremental cost per QALY was related to the range of acceptability proposed by the Associazione Italiana di Economia Sanitaria (€ 25,000-40,000. The budget impact was calculated on a 5-year time horizon. Univariate and probabilistic sensitivity analyses were performed on every hypothesis of the model.RESULTS: Degarelix resulted in minor costs if compared to 7.5 mg leuprolide (€ 20,511.64 vs 22,256.49. The cost-driver was chemotherapic care (32.45% degarelix vs 44.30% 7.5 mg leuprolide. Life years saved were the same for both the alternatives (5.58, while QALYs obtained were

  13. Regarding the use and misuse of retinal protonated Schiff base photochemistry as a test case for time-dependent density-functional theory

    Science.gov (United States)

    Valsson, Omar; Filippi, Claudia; Casida, Mark E.

    2015-04-01

    The excited-state relaxation of retinal protonated Schiff bases (PSBs) is an important test case for biological applications of time-dependent (TD) density-functional theory (DFT). While well-known shortcomings of approximate TD-DFT might seem discouraging for application to PSB relaxation, progress continues to be made in the development of new functionals and of criteria allowing problematic excitations to be identified within the framework of TD-DFT itself. Furthermore, experimental and theoretical ab initio advances have recently lead to a revised understanding of retinal PSB photochemistry, calling for a reappraisal of the performance of TD-DFT in describing this prototypical photoactive system. Here, we re-investigate the performance of functionals in (TD-)DFT calculations in light of these new benchmark results, which we extend to larger PSB models. We focus on the ability of the functionals to describe primarily the early skeletal relaxation of the chromophore and investigate how far along the out-of-plane pathways these functionals are able to describe the subsequent rotation around formal single and double bonds. Conventional global hybrid and range-separated hybrid functionals are investigated as the presence of Hartree-Fock exchange reduces problems with charge-transfer excitations as determined by the Peach-Benfield-Helgaker-Tozer Λ criterion and by comparison with multi-reference perturbation theory results. While we confirm that most functionals cannot render the complex photobehavior of the retinal PSB, do we also observe that LC-BLYP gives the best description of the initial part of the photoreaction.

  14. Intracellular localization of the M1 muscarinic acetylcholine receptor through clathrin-dependent constitutive internalization is mediated by a C-terminal tryptophan-based motif.

    Science.gov (United States)

    Uwada, Junsuke; Yoshiki, Hatsumi; Masuoka, Takayoshi; Nishio, Matomo; Muramatsu, Ikunobu

    2014-07-15

    The M1 muscarinic acetylcholine receptor (M1-mAChR, encoded by CHRM1) is a G-protein-coupled membrane receptor that is activated by extracellular cholinergic stimuli. Recent investigations have revealed the intracellular localization of M1-mAChR. In this study, we observed constitutive internalization of M1-mAChR in mouse neuroblastoma N1E-115 cells without agonist stimulation. Constitutive internalization depended on dynamin, clathrin and the adaptor protein-2 (AP-2) complex. A WxxI motif in the M1-mAChR C-terminus is essential for its constitutive internalization, given that replacement of W(442) or I(445) with alanine residues abolished constitutive internalization. This WxxI motif resembles YxxΦ, which is the canonical binding motif for the μ2 subunit of the AP-2 complex. The M1-mAChR C-terminal WxxI motif interacted with AP-2 μ2. W442A and I445A mutants of the M1-mAChR C-terminal sequence lost AP-2-μ2-binding activity, whereas the W442Y mutant bound more effectively than wild type. Consistent with these results, W442A and I445A M1-mAChR mutants selectively localized to the cell surface. By contrast, the W442Y receptor mutant was found only at intracellular sites. Our data indicate that the cellular distribution of M1-mAChR is governed by the C-terminal tryptophan-based motif, which mediates constitutive internalization.

  15. Regarding the use and misuse of retinal protonated Schiff base photochemistry as a test case for time-dependent density-functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Valsson, Omar [Department of Chemistry and Applied Biosciences, ETH Zurich and Facoltà di Informatica, Instituto di Scienze Computationali, Università della Svizzera italiana, Via Giuseppe Buffi 13, CH-6900 Lugano (Switzerland); Filippi, Claudia, E-mail: c.filippi@utwente.nl [MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Casida, Mark E., E-mail: mark.casida@ujf-grenoble.fr [Laboratoire de Chimie Théorique, Département de Chimie Moléculaire (DCM), Institut de Chimie Moléculaire de Grenoble (ICMG), Université Joseph Fourier, Grenoble I, F-3801 Grenoble (France)

    2015-04-14

    The excited-state relaxation of retinal protonated Schiff bases (PSBs) is an important test case for biological applications of time-dependent (TD) density-functional theory (DFT). While well-known shortcomings of approximate TD-DFT might seem discouraging for application to PSB relaxation, progress continues to be made in the development of new functionals and of criteria allowing problematic excitations to be identified within the framework of TD-DFT itself. Furthermore, experimental and theoretical ab initio advances have recently lead to a revised understanding of retinal PSB photochemistry, calling for a reappraisal of the performance of TD-DFT in describing this prototypical photoactive system. Here, we re-investigate the performance of functionals in (TD-)DFT calculations in light of these new benchmark results, which we extend to larger PSB models. We focus on the ability of the functionals to describe primarily the early skeletal relaxation of the chromophore and investigate how far along the out-of-plane pathways these functionals are able to describe the subsequent rotation around formal single and double bonds. Conventional global hybrid and range-separated hybrid functionals are investigated as the presence of Hartree-Fock exchange reduces problems with charge-transfer excitations as determined by the Peach-Benfield-Helgaker-Tozer Λ criterion and by comparison with multi-reference perturbation theory results. While we confirm that most functionals cannot render the complex photobehavior of the retinal PSB, do we also observe that LC-BLYP gives the best description of the initial part of the photoreaction.

  16. Web Application Presentation Layer Test Based Dependency Analysis%基于依赖分析的Web应用表示层测试方法研究

    Institute of Scientific and Technical Information of China (English)

    郑芳; 郑全

    2011-01-01

    随着Web技术的飞速发展,Web应用系统的应用越来越广泛,Web应用发生故障的频率也越来越高,Web应用发生的故障大多数情况下都会与Web页面发生直接或者间接的联系,如何对web应用的表示层即web页面做测试的研究,是一个非常值得研究的问题.为此,在利用依赖分析技术的基础上,通过对Web页面以及Web页面之间的依赖分析,提出了一种基于依赖分析的Web应用表示层测试方法;通过实验案例表明该测试方法更具有全面性和有效性.%With the rapid development of Web technology, Web application systems have been widely applied. In result, the frequency of Web application failures has been increasingly high. Mostly, the Web application failures are associated with the Web pages. So, how to test the presentation layer of Web application, which is Web page, has become a worth researching issue. Therefore, based on the analysis of the dependent relationship between Web pages, we proposed a testing method of the presentation layer of Web application, and proved its comprehensive and validity by an experimental example.

  17. Anti-anxiety, cognitive, and steroid biosynthetic effects of an isoflavone-based dietary supplement are gonad and sex-dependent in rats.

    Science.gov (United States)

    Friedman, Jonathan; Frye, Cheryl

    2011-03-16

    Isoflavone-rich diets are associated with reduced menopausal symptoms and lowered risk of cancers of reproductive tissues. Isoflavones may mimic some effects of estrogen by binding to estrogen receptors, and/or altering steroid availability. Despite their potential health benefits, neither the effects, nor mechanisms, of isoflavones are well understood. We hypothesized that isoflavones would alter behavior and physiology of rats in sex and/or gonad-dependent manner. An isoflavone-based, commercially-available, dietary supplement was administered via subcutaneous implantation to female and male, intact and gonadectomized Long-Evans rats. Affective (elevated plus-maze), cognitive (water-maze), and reproductive (sexual) behavior was examined. Weights of reproductive structures were measured, as an index of trophic effects. Steroid levels in circulation and brain regions associated with behavioral measures were evaluated by radioimmunoassay. The supplement increased anti-anxiety behavior of intact, but not gonadectomized, rats. The supplement enhanced visual-spatial performance of all rats, but this effect was most evident among proestrous female rats, which had the poorest spatial performance. There were neither effects of the supplement on sexual behavior, mass of reproductive tissues, nor plasma steroid levels. The supplement increased levels of 5α-androstane,17ß-diol-3α-diol (3α-diol) in the hippocampus (but not other brain regions) of gonadectomized females. Thus, the supplement altered anxiety and cognitive behavior and brain production of steroids; however, the anti-anxiety effects were limited to rats with an intact reproductive axis and effects on cognitive performance and neurosteriodogenesis were most evident among intact and gonadectomized, female rats respectively.

  18. Characterization of calibration curves and energy dependence GafChromic{sup TM} XR-QA2 model based radiochromic film dosimetry system

    Energy Technology Data Exchange (ETDEWEB)

    Tomic, Nada, E-mail: ntomic@roc.jgh.mcgill.ca; Quintero, Chrystian; Aldelaijan, Saad; Bekerat, Hamed; Liang, LiHeng; DeBlois, François; Devic, Slobodan [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4, Canada and Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montréal, Québec H3T 1E2 (Canada); Whiting, Bruce R. [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States); Seuntjens, Jan [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4 (Canada)

    2014-06-15

    Purpose: The authors investigated the energy response of XR-QA2 GafChromic{sup TM} film over a broad energy range used in diagnostic radiology examinations. The authors also made an assessment of the most suitable functions for both reference and relative dose measurements. Methods: Pieces of XR-QA2 film were irradiated to nine different values of air kerma in air, following reference calibration of a number of beam qualities ranging in HVLs from 0.16 to 8.25 mm Al, which corresponds to effective energy range from 12.7 keV to 56.3 keV. For each beam quality, the authors tested three functional forms (rational, linear exponential, and power) to assess the most suitable function by fitting the delivered air kerma in air as a function of film response in terms of reflectance change. The authors also introduced and tested a new parameterχ = netΔR·e{sup m} {sup netΔR} that linearizes the inherently nonlinear response of the film. Results: The authors have found that in the energy range investigated, the response of the XR-QA2 based radiochromic film dosimetry system ranges from 0.222 to 0.420 in terms of netΔR at K{sub air}{sup air} = 8 cGy. For beam qualities commonly used in CT scanners (4.03–8.25 mm Al), the variation in film response (netΔR at K{sub air}{sup air} = 8 cGy) amounts to ± 5%, while variation in K{sub air}{sup air} amounts to ± 14%. Conclusions: Results of our investigation revealed that the use of XR-QA2 GafChromic{sup TM} film is accompanied by a rather pronounced energy dependent response for beam qualities used for x-ray based diagnostic imaging purposes. The authors also found that the most appropriate function for the reference radiochromic film dosimetry would be the power function, while for the relative dosimetry one may use the exponential response function that can be easily linearized.

  19. Cyber Network Mission Dependencies

    Science.gov (United States)

    2015-09-18

    Technology applications 12 5 VMs allow one host to belong to multiple VLANs 14 6 Asset recommendation system mockup 15 7 Perturbative mapping may...extended list of critical assets based on communications patterns and software dependencies. Once vulnerabilities have been assessed, AMMO produces a...status of not just network machines, but also software tools, network connections, server room conditions, and many other mission parameters. From this

  20. 基于梯度塑性理论的断层活化机理%Faults activation mechanism based on gradient-dependent plasticity

    Institute of Scientific and Technical Information of China (English)

    林远东; 涂敏; 刘文震; 吴建强

    2012-01-01

    Analyzed the strain softening and consequent strain localization behavior for fault based on gradient-dependent plasticity.Regarded fault as continuous geological bodies with thickness.The gradient-dependent plasticity was introduced into the fault model.The theoretical expression of fault band displacement in direction of fault azimuth was presented,and ‘the equivalent shear stiffness of the fault band’ was defined.The displacement of fault hanging wall in direction of fault azimuth was presented and ‘the equivalent shear stiffness of the fault hanging-foot-wall’ was defined considering the stress conditions of element body in interface at the lower edge of fault hanging wall.The fault activation criterion was obtained according to comparing ‘the equivalent shear stiffness of the fault hanging-foot-wall’ with ‘the equivalent shear stiffness of the fault band’.The results show that fault activation is determined with the factors which not only include the material properties(such as brittleness,the internal structure size of geo-materials in fault),but also include fault hanging-foot-wall characteristic parameters(such as shear elastic modulus,Poisson’s ratio).Besides,fault activation is determined with the minimum width of the rock mass which include the integral fault.It is found that the lower internal parameter or ‘the shear equivalent stiffness of fault hanging-foot-wall’,and the higher brittleness of fault geo-materials or the minimum width of the rock mass which include the integral fault lead to increasing the possibility of fault activation.%基于梯度塑性理论,将断层视为内部连续、有厚度的地质体,分析断层带应变软化及其应变局部化问题。将梯度塑性理论引入断层带模型,得到了断层带沿倾向相对错动位移的理论表达式,定义了"断层带等效剪切刚度";通过对上盘岩体的下边缘界面处单元体应力分析,得到上盘岩体沿断层倾向的相对错动位

  1. Carbon nanotube-based substrates promote cardiogenesis in brown adipose-derived stem cells via β1-integrin-dependent TGF-β1 signaling pathway

    Directory of Open Access Journals (Sweden)

    Sun H

    2016-09-01

    Full Text Available Hongyu Sun,1,* Yongchao Mou,2,* Yi Li,3,* Xia Li,4,* Zi Chen,2 Kayla Duval,2 Zhu Huang,1 Ruiwu Dai,1 Lijun Tang,1 Fuzhou Tian1 1Department of General Surgery, Chengdu Military General Hospital, Chengdu, People’s Republic of China; 2Thayer School of Engineering, Dartmouth College, Hanover, NH, USA; 3Department of Cardiology, The General Hospital of Chinese People’s Armed Police Forces, Beijing, People’s Republic of China; 4Affiliated Hospital of Academy of Military Medical Sciences, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Stem cell-based therapy remains one of the promising approaches for cardiac repair and regeneration. However, its applications are restricted by the limited efficacy of cardiac differentiation. To address this issue, we examined whether carbon nanotubes (CNTs would provide an instructive extracellular microenvironment to facilitate cardiogenesis in brown adipose-derived stem cells (BASCs and to elucidate the underlying signaling pathways. In this study, we systematically investigated a series of cellular responses of BASCs due to the incorporation of CNTs into collagen (CNT-Col substrates that promoted cell adhesion, spreading, and growth. Moreover, we found that CNT-Col substrates remarkably improved the efficiency of BASCs cardiogenesis by using fluorescence staining and quantitative real-time reverse transcription-polymerase chain reaction. Critically, CNTs in the substrates accelerated the maturation of BASCs-derived cardiomyocytes. Furthermore, the underlying mechanism for promotion of BASCs cardiac differentiation by CNTs was determined by immunostaining, quantitative real-time reverse transcription-polymerase chain reaction, and Western blotting assay. It is notable that β1-integrin-dependent TGF-β1 signaling pathway modulates the facilitative effect of CNTs in cardiac differentiation of BASCs. Therefore, it is an efficient approach to regulate cardiac

  2. Age-dependent safety analysis of propofol-based deep sedation for ERCP and EUS procedures at an endoscopy training center in a developing country

    Directory of Open Access Journals (Sweden)

    Amornyotin S

    2012-07-01

    Full Text Available Somchai Amornyotin,1,2 Somchai Leelakusolvong,2,3 Wiyada Chalayonnawin,1,2 Siriporn Kongphlay1,21Department of Anesthesiology, 2Siriraj GI Endoscopy Center, 3Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, ThailandIntroduction: Endoscopic retrograde cholangiopancreatography (ERCP and endoscopic ultrasonography (EUS procedures in elderly patients are on the rise, and they play an important role in the diagnosis and management of various gastrointestinal diseases. The use of deep sedation in these patients has been established as a safe and effective technique in Western countries; however, it is uncertain if the situation holds true among Asians. The present study aimed to evaluate the age-dependent safety analysis and clinical efficacy of propofol-based deep sedation (PBDS for ERCP and EUS procedures in adult patients at a World Gastroenterology Organization (WGO Endoscopy Training Center in Thailand.Methods: We undertook a retrospective review of anesthesia or sedation service records of patients who underwent ERCP and EUS procedures. All procedures were performed by staff endoscopists, and all sedations were administered by anesthesia personnel in the endoscopy room.Results: PBDS was provided for 491 ERCP and EUS procedures. Of these, 252 patients (mean age, 45.1 ± 11.1 years, range 17–65 years were in the <65 age group, 209 patients (mean age, 71.7 ± 4.3 years, range 65–80 years were in the 65–80 year-old group, and 30 patients (mean age, 84.6 ± 4.2 years, range 81–97 years were in the >80 age group. Common indications for the procedures were pancreatic tumor, cholelithiasis, and gastric tumor. Fentanyl, propofol, and midazolam were the most common sedative drugs used in all three groups. The mean doses of propofol and midazolam in the very old patients were relatively lower than in the other groups. The combination of propofol, midazolam, and fentanyl, as well as propofol and fentanyl

  3. Accounting for the Effects of Surface BRDF on Satellite Cloud and Trace-Gas Retrievals: A New Approach Based on Geometry-Dependent Lambertian-Equivalent Reflectivity Applied to OMI Algorithms

    Science.gov (United States)

    Vasilkov, Alexander; Qin, Wenhan; Krotkov, Nickolay; Lamsal, Lok; Spurr, Robert; Haffner, David; Joiner, Joanna; Yang, Eun-Su; Marchenko, Sergey

    2017-01-01

    Most satellite nadir ultraviolet and visible cloud, aerosol, and trace-gas algorithms make use of climatological surface reflectivity databases. For example, cloud and NO2 retrievals for the Ozone Monitoring Instrument (OMI) use monthly gridded surface reflectivity climatologies that do not depend upon the observation geometry. In reality, reflection of incoming direct and diffuse solar light from land or ocean surfaces is sensitive to the sun-sensor geometry. This dependence is described by the bidirectional reflectance distribution function (BRDF). To account for the BRDF, we propose to use a new concept of geometry-dependent Lambertian equivalent reflectivity (LER). Implementation within the existing OMI cloud and NO2 retrieval infrastructure requires changes only to the input surface reflectivity database. The geometry-dependent LER is calculated using a vector radiative transfer model with high spatial resolution BRDF information from the Moderate Resolution Imaging Spectroradiometer (MODIS) over land and the Cox-Munk slope distribution over ocean with a contribution from water-leaving radiance. We compare the geometry-dependent and climatological LERs for two wavelengths, 354 and 466 nm, that are used in OMI cloud algorithms to derive cloud fractions. A detailed comparison of the cloud fractions and pressures derived with climatological and geometry-dependent LERs is carried out. Geometry-dependent LER and corresponding retrieved cloud products are then used as inputs to our OMI NO2 algorithm. We find that replacing the climatological OMI-based LERs with geometry-dependent LERs can increase NO2 vertical columns by up to 50% in highly polluted areas; the differences include both BRDF effects and biases between the MODIS and OMI-based surface reflectance data sets. Only minor changes to NO2 columns (within 5 %) are found over unpolluted and overcast areas.

  4. Accounting for the effects of surface BRDF on satellite cloud and trace-gas retrievals: a new approach based on geometry-dependent Lambertian equivalent reflectivity applied to OMI algorithms

    Science.gov (United States)

    Vasilkov, Alexander; Qin, Wenhan; Krotkov, Nickolay; Lamsal, Lok; Spurr, Robert; Haffner, David; Joiner, Joanna; Yang, Eun-Su; Marchenko, Sergey

    2017-01-01

    Most satellite nadir ultraviolet and visible cloud, aerosol, and trace-gas algorithms make use of climatological surface reflectivity databases. For example, cloud and NO2 retrievals for the Ozone Monitoring Instrument (OMI) use monthly gridded surface reflectivity climatologies that do not depend upon the observation geometry. In reality, reflection of incoming direct and diffuse solar light from land or ocean surfaces is sensitive to the sun-sensor geometry. This dependence is described by the bidirectional reflectance distribution function (BRDF). To account for the BRDF, we propose to use a new concept of geometry-dependent Lambertian equivalent reflectivity (LER). Implementation within the existing OMI cloud and NO2 retrieval infrastructure requires changes only to the input surface reflectivity database. The geometry-dependent LER is calculated using a vector radiative transfer model with high spatial resolution BRDF information from the Moderate Resolution Imaging Spectroradiometer (MODIS) over land and the Cox-Munk slope distribution over ocean with a contribution from water-leaving radiance. We compare the geometry-dependent and climatological LERs for two wavelengths, 354 and 466 nm, that are used in OMI cloud algorithms to derive cloud fractions. A detailed comparison of the cloud fractions and pressures derived with climatological and geometry-dependent LERs is carried out. Geometry-dependent LER and corresponding retrieved cloud products are then used as inputs to our OMI NO2 algorithm. We find that replacing the climatological OMI-based LERs with geometry-dependent LERs can increase NO2 vertical columns by up to 50 % in highly polluted areas; the differences include both BRDF effects and biases between the MODIS and OMI-based surface reflectance data sets. Only minor changes to NO2 columns (within 5 %) are found over unpolluted and overcast areas.

  5. Bases biológicas de la dependencia de las drogas: hacia un enfoque integral del proglema Biologic bases of drug dependence: toward an integral approach of the problem

    Directory of Open Access Journals (Sweden)

    Jorge Mario Tamayo

    1998-04-01

    Full Text Available El abuso y la dependencia de las drogas son problemas complejos y costosos que requieren una intervención terapéutica polimodal e integral. En los últimos años se han dado varios descubrimientos científicos relacionados con las bases biológicas de estos trastornos. Ello ha permitido desarrollar programas que incluyen el uso de diferentes psicofármacos y técnicas psicoterapéuticas que posibilitan una modulación de las vías neuronales disfuncionales. La investigación del sistema mesolímbico dopaminérgico y de los receptores opioides del tallo cerebral y del núcleo accumbens sumada al develamiento de los diferentes mecanismos intraneuronales, han permitido comprender me. jorlos cambios cerebrales ycomportamentales debidos al consumo agudo y crónico de drogas. Tales hallazgos biológicos son el propósito de esta revisión basada en una búsqueda de artículos a través de MEDLINE.. Drugs abuse and dependence are complex and expensive disorders that require a polymodal and integral therapeutic intervention. Several scientific discoveries related to the biological bases of these disorders have recently arisen. These discoveries guide the design of programs that include different psychotropic drugs and psychotherapeutic technics that allow a modulation of the neuronal dysfunction process. Research on the mesolimbic dopaminergic system and the opioid receptors in the brain stem and the nucleus accumbens added to new knowledge of different intraneuronal mechanisms, allow a better understanding of cerebral and behavioral changes due to acute and chronic consumption of drugs. Such biological findings are the purpose of this review based on a MEDLINE search of articles.

  6. Possibility of formation of functional dependences of homogeneous and heterogeneous systems burning rate on different factors on the base of precised theory of Mallard and Le Chatelier

    Energy Technology Data Exchange (ETDEWEB)

    Kashporov, L.Y.; Sheludyak, Y.E.; Obeziaev, N.V.; Raspopin, A.G. [Russian Corporation, Metalkhim, Moscow (Russian Federation)

    1996-12-31

    In this work it is shown that the hypothesis of Mallard and Le Chatelier about the existence of critical temperature T{sub c} in the stationary burning wave, which is analogous to the temperature of ignition, is well-grounded physically. The equation which comes out from this hypothesis allows to calculate the functional dependences of the burning rate on pressure P and initial temperature T{sub o} - for homogeneous systems and on the other factors influencing the burning rate (porosity M, mean particle sizes of oxidant d{sub o} and metal d{sub m} and so on) - for condensed systems. Functional dependences u(P, T{sub o}) for methane/air mixture, hexogen, nitroglycerin powder have been calculated, and for pyrotechnics composition Mg + NaNO{sub 3} the dependence u(T{sub o}, M, d{sub o}, d{sub m}) at the atmospheric pressure has been obtained. (authors) 15 refs.

  7. Myofilament length dependent activation

    Energy Technology Data Exchange (ETDEWEB)

    de Tombe, Pieter P.; Mateja, Ryan D.; Tachampa, Kittipong; Mou, Younss Ait; Farman, Gerrie P.; Irving, Thomas C. (IIT); (Loyola)

    2010-05-25

    The Frank-Starling law of the heart describes the interrelationship between end-diastolic volume and cardiac ejection volume, a regulatory system that operates on a beat-to-beat basis. The main cellular mechanism that underlies this phenomenon is an increase in the responsiveness of cardiac myofilaments to activating Ca{sup 2+} ions at a longer sarcomere length, commonly referred to as myofilament length-dependent activation. This review focuses on what molecular mechanisms may underlie myofilament length dependency. Specifically, the roles of inter-filament spacing, thick and thin filament based regulation, as well as sarcomeric regulatory proteins are discussed. Although the 'Frank-Starling law of the heart' constitutes a fundamental cardiac property that has been appreciated for well over a century, it is still not known in muscle how the contractile apparatus transduces the information concerning sarcomere length to modulate ventricular pressure development.

  8. The cause of anomaly of temperature dependence of electroresistance of the ordering nonstoichiometric FeCo compounds based on a b.c.c. lattice

    Energy Technology Data Exchange (ETDEWEB)

    Repetsky, S.P. [Taras Shevchenko Kyiv National University, 2 Acad. Glushkov Prosp., 03022 Kyiv (Ukraine); Melnyk, I.M. [Taras Shevchenko Kyiv National University, 2 Acad. Glushkov Prosp., 03022 Kyiv (Ukraine)], E-mail: iramel@ukr.net; Tatarenko, V.A. [Taras Shevchenko Kyiv National University, 2 Acad. Glushkov Prosp., 03022 Kyiv (Ukraine); G.V. Kurdyumov Institute for Metal Physics, N.A.S.U., 36 Acad. Vernadsky Blvd., 03142 Kyiv (Ukraine); Len, E.G. [G.V. Kurdyumov Institute for Metal Physics, N.A.S.U., 36 Acad. Vernadsky Blvd., 03142 Kyiv (Ukraine); Vyshivanaya, I.G. [Taras Shevchenko Kyiv National University, 2 Acad. Glushkov Prosp., 03022 Kyiv (Ukraine)

    2009-07-01

    A theory of energy spectrum and electrical conductivity, which takes into account the electron scattering by the potentials of ions and fluctuations of both the spin and charge densities of electrons in disordered substitutional alloys, is developed. Calculations of temperature-concentration dependence of electrical resistance were performed for b.c.c.-Fe{sub 1-c}Co{sub c} alloys. The causes of weak temperature dependence of electrical resistance of the Fe-Co alloys are governed by the presence of a quasi-gap in the electron-energy spectrum, which appears due to strong electron correlations as well as atomic and magnetic orders.

  9. A density matrix-based quasienergy formulation of the Kohn-Sham density functional response theory using perturbation- and time-dependent basis sets

    Science.gov (United States)

    Thorvaldsen, Andreas J.; Ruud, Kenneth; Kristensen, Kasper; Jørgensen, Poul; Coriani, Sonia

    2008-12-01

    A general method is presented for the calculation of molecular properties to arbitrary order at the Kohn-Sham density functional level of theory. The quasienergy and Lagrangian formalisms are combined to derive response functions and their residues by straightforward differentiation of the quasienergy derivative Lagrangian using the elements of the density matrix in the atomic orbital representation as variational parameters. Response functions and response equations are expressed in the atomic orbital basis, allowing recent advances in the field of linear-scaling methodology to be used. Time-dependent and static perturbations are treated on an equal footing, and atomic basis sets that depend on the applied frequency-dependent perturbations may be used, e.g., frequency-dependent London atomic orbitals. The 2n+1 rule may be applied if computationally favorable, but alternative formulations using higher-order perturbed density matrices are also derived. These may be advantageous in order to minimize the number of response equations that needs to be solved, for instance, when one of the perturbations has many components, as is the case for the first-order geometrical derivative of the hyperpolarizability.

  10. A density matrix-based quasienergy formulation of the Kohn-Sham density functional response theory using perturbation- and time-dependent basis sets.

    Science.gov (United States)

    Thorvaldsen, Andreas J; Ruud, Kenneth; Kristensen, Kasper; Jørgensen, Poul; Coriani, Sonia

    2008-12-07

    A general method is presented for the calculation of molecular properties to arbitrary order at the Kohn-Sham density functional level of theory. The quasienergy and Lagrangian formalisms are combined to derive response functions and their residues by straightforward differentiation of the quasienergy derivative Lagrangian using the elements of the density matrix in the atomic orbital representation as variational parameters. Response functions and response equations are expressed in the atomic orbital basis, allowing recent advances in the field of linear-scaling methodology to be used. Time-dependent and static perturbations are treated on an equal footing, and atomic basis sets that depend on the applied frequency-dependent perturbations may be used, e.g., frequency-dependent London atomic orbitals. The 2n+1 rule may be applied if computationally favorable, but alternative formulations using higher-order perturbed density matrices are also derived. These may be advantageous in order to minimize the number of response equations that needs to be solved, for instance, when one of the perturbations has many components, as is the case for the first-order geometrical derivative of the hyperpolarizability.

  11. Conditional dependence models and its applications of portfolios of assets based on Copula functions%基于Copula函数的组合资产条件相依性模型及其应用

    Institute of Scientific and Technical Information of China (English)

    易文德

    2011-01-01

    Conditional probability distributions have been often used in modcling the dependence structure between Markov chains. The dependence structures of portfolios of assets are affected by many factors.There exist two crucial classes of dependence relationships among portfolios of assets, temporal dependence and contemporaneous dependence. In this paper, a model based on Copula and conditional probability distributions is established to investigate the dependence structure between returns of Shanghai and Shenzhen stock markets, in which two types of dependence relationships in portfolios of assets are considered:the temporal dependence of a univariate time series and the contemporaneous dependence between two univariate time series. A three-stage pseudo maximum likelihood estimator (3SPMLE) is employed to estimate the parameters of model and the Chi-square goodness-of-fit test is used to evaluate the model. The results show that the model including the temporal dependence is better to fit the dependence structure between Shanghai and Shenzhen stock markets.%条件概率分布常用来研究马尔科夫序列相依模型的构建.组合资产的相依结构受多方面的影响,资产之间的同期相依与单个资产时间上的短期相依是组合资产两类主要的相依关系.结合条件概率的理论,考虑组合资产之间的同期相依与时间上的短期相依两类关系,建立基于Copula函数相依关系模型研究了沪深股市指数收益率的相依结构.应用三阶段极大似然估计方法对模型的参数进行估计,应用x2检验统计量对模型进行优度检验和模型的比较.研究结果表明:考虑了单个资产时间上短期相依关系的模型更适合描述沪深股市的相依结构.

  12. A novel manganese-dependent ATM-p53 signaling pathway is selectively impaired in patient-based neuroprogenitor and murine striatal models of Huntington's disease.

    Science.gov (United States)

    Tidball, Andrew M; Bryan, Miles R; Uhouse, Michael A; Kumar, Kevin K; Aboud, Asad A; Feist, Jack E; Ess, Kevin C; Neely, M Diana; Aschner, Michael; Bowman, Aaron B

    2015-04-01

    The essential micronutrient manganese is enriched in brain, especially in the basal ganglia. We sought to identify neuronal signaling pathways responsive to neurologically relevant manganese levels, as previous data suggested that alterations in striatal manganese handling occur in Huntington's disease (HD) models. We found that p53 phosphorylation at serine 15 is the most responsive cell signaling event to manganese exposure (of 18 tested) in human neuroprogenitors and a mouse striatal cell line. Manganese-dependent activation of p53 was severely diminished in HD cells. Inhibitors of ataxia telangiectasia mutated (ATM) kinase decreased manganese-dependent phosphorylation of p53. Likewise, analysis of ATM autophosphorylation and additional ATM kinase targets, H2AX and CHK2, support a role for ATM in the activation of p53 by manganese and that a defect in this process occurs in HD. Furthermore, the deficit in Mn-dependent activation of ATM kinase in HD neuroprogenitors was highly selective, as DNA damage and oxidative injury, canonical activators of ATM, did not show similar deficits. We assessed cellular manganese handling to test for correlations with the ATM-p53 pathway, and we observed reduced Mn accumulation in HD human neuroprogenitors and HD mouse striatal cells at manganese exposures associated with altered p53 activation. To determine if this phenotype contributes to the deficit in manganese-dependent ATM activation, we used pharmacological manipulation to equalize manganese levels between HD and control mouse striatal cells and rescued the ATM-p53 signaling deficit. Collectively, our data demonstrate selective alterations in manganese biology in cellular models of HD manifest in ATM-p53 signaling.

  13. Bio-Psycho-Spiritual Modeling in Drug Dependents and Compiling of Intervention Program for Promotion of Resiliency Based on Cognitive Narratology and Positive Psychology

    OpenAIRE

    2009-01-01

    Introduction: Since the past few decades, the concentration of researches on drug abuse and drugs dependency have shift from risk factor to protective factors. In the past two decades, the concept of resiliency was increasingly considered by developmental psychology. The concentration shifted from risk to resiliency originates from disadvantage in emphasizing on identification of risk factors. Method: Target population was all volunteer addicts who referred to clinics in Tehran city. The grou...

  14. Wavelength-Dependent Second Harmonic Generation Circular Dichroism for Differentiation of Col I and Col III Isoforms in Stromal Models of Ovarian Cancer Based on Intrinsic Chirality Differences.

    Science.gov (United States)

    Campbell, Kirby R; Campagnola, Paul J

    2017-03-02

    Extensive remodeling of the extracellular matrix (ECM) occurs in many epithelial cancers. For example, in ovarian cancer, upregulation of collagen isoform type III has been linked to invasive forms of the disease, and this change may be a potential biomarker. To examine this possibility, we implemented wavelength-dependent second harmonic generation circular dichroism (SHG-CD) imaging microscopy to quantitatively determine changes in chirality in ECM models comprised of different Col I/Col III composition. In these models, Col III was varied between 0 and 40%, and we found increasing Col III results in reduced net chirality, consistent with structural biology studies of Col I and III in tissues where the isoforms comingle in the same fibrils. We further examined the wavelength dependence of the SHG-CD to both optimize the response and gain insight into the underlying mechanism. We found using shorter SHG excitation wavelengths resulted in increased SHG-CD sensitivity, where this is consistent with the electric-dipole-coupled oscillator model suggested previously for the nonlinear chirality response from thin films. Moreover, the sensitivity is further consistent with the wavelength dependency of SHG intensity fit to a two-state model of the two-photon absorption in collagen. We also provide experimental calibration protocols to implement the SHG-CD modality on a laser scanning microscope. We last suggest that the technique has broad applicability in probing a wide range of diseased states with changes in collagen molecular structure.

  15. Time scales of bias voltage effects in FE/MgO-based magnetic tunnel junctions with voltage-dependent perpendicular anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Lytvynenko, Ia.M. [Sumy State University, 2, Rimskogo-Korsakova Str., 40007 Sumy (Ukraine); Hauet, T., E-mail: thomas.hauet@univ-lorraine.fr [Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre les Nancy (France); Montaigne, F. [Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre les Nancy (France); Bibyk, V.V. [Sumy State University, 2, Rimskogo-Korsakova Str., 40007 Sumy (Ukraine); Andrieu, S. [Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre les Nancy (France)

    2015-12-15

    Interplay between voltage-induced magnetic anisotropy transition and voltage-induced atomic diffusion is studied in epitaxial V/Fe (0.7 nm)/ MgO/ Fe(5 nm)/Co/Au magnetic tunnel junction where thin Fe soft electrode has in-plane or out-of-plane anisotropy depending on the sign of the bias voltage. We investigate the origin of the slow resistance variation occurring when switching bias voltage in opposite polarity. We demonstrate that the time to reach resistance stability after voltage switching is reduced when increasing the voltage amplitude or the temperature. A single energy barrier of about 0.2 eV height is deduced from temperature dependence. Finally, we demonstrate that the resistance change is not correlated to a change in soft electrode anisotropy. This conclusion contrasts with observations recently reported on analogous systems. - Highlights: • Voltage-induced time dependence of resistance is studied in epitaxial Fe/MgO/Fe. • Resistance change is not related to the bottom Fe/MgO interface. • The effect is thermally activated with an energy barrier of the order of 0.2 eV height.

  16. A randomized, controlled trial of the efficacy of an interoceptive exposure-based CBT for treatment-refractory outpatients with opioid dependence.

    Science.gov (United States)

    Otto, Michael W; Hearon, Bridget A; McHugh, R Kathryn; Calkins, Amanda W; Pratt, Elizabeth; Murray, Heather W; Safren, Steven A; Pollack, Mark H

    2014-01-01

    Many patients diagnosed with opioid dependence do not adequately respond to pharmacologic, psychosocial, or combination treatment, highlighting the importance of novel treatment strategies for this population. The current study examined the efficacy of a novel behavioral treatment focusing on internal cues for drug use (Cognitive Behavioral Therapy for Interoceptive Cues; CBT-IC) relative to an active comparison condition, Individual Drug Counseling (IDC), when added to methadone maintenance treatment (MMT) among those who had not responded to MMT. Participants (N=78) were randomly assigned to receive 15 sessions of CBT-IC or IDC as an adjunct to ongoing MMT and counseling. Oral toxicology screens were the primary outcome. Results indicated no treatment differences between CBT-IC and IDC and a small, significant reduction of self-reported drug use, but no change on toxicology screens. Tests of potential moderators, including sex, anxiety sensitivity, and coping motives for drug use, did not yield significant interactions. Among opioid-dependent outpatients who have not responded to MMT and counseling, the addition of IDC or CBT-IC did not result in additive outcome benefits. These results highlight the need for more potent treatment strategies for opioid dependence, particularly among those who do not fully respond to frontline treatment.

  17. 基于VAR-Copula模型的股价、交易量的相依结构%Dependence structure between the stock price and the trading volume based on the VAR-Copula model

    Institute of Scientific and Technical Information of China (English)

    易文德

    2011-01-01

    基于向量自回归(vector autoregression,VAR)误差修正模型,结合Copula理论建立VAR-Copula模型研究股市指数与交易量之间的Granger因果关系和相依结构.通过对三个股票市场的实证分析,发现各市场的指数与交易量之间存在长期的协整关系和由指数到交易量的单向因果关系;指数对数收益率与交易量对数差分的相依关系复杂,既有正的相依成分也包含负的相依结构,且都表现为上尾高的非对称的相依特征.%It is an important subject to study the dependence relationship between the stock price and the trading volume in financial field. It not only need to investigate Granger's causality relation and relational measure but also to study the dependence structure between them. Based on the VAR error correction model and associated with copula technique, a VAR-Copula model is structured to research the Granger's causality relation and the dependence structure between the stock price and the trading volume. The empirical study to three stock markets finds that there is a long-rang co-integration between stock price index and the trading volume and a unilateral Granger causality relationship from stock price to the trading volume, and also finds that the complex dependence relationship between the stock price index logarithmic returns and the trading volume logarithmic difference is positive dependence as well as negative dependence and the asymmetrical dependence structure with higher upper tail to all stock markets.

  18. Note: theoretical study on the gas pressure dependence of x-ray yield in TE(111) cavity based electron cyclotron resonance x-ray source.

    Science.gov (United States)

    Selvakumaran, T S; Sen, Soubhadra; Baskaran, R

    2014-11-01

    Adopting Langevin methodology, a pressure dependent frictional force term which represents the collisional effect is added to the Lorentz equation. The electrons are assumed to be starting from the uniformly distributed co-ordinates on the central plane. The trajectory of each electron is numerically simulated by solving the modified Lorentz equation for a given pressure. The Bremsstrahlung x-ray energy spectrum for each electron crossing the cavity wall boundary is obtained using the Duane-Hunt law. The total x-ray yield is estimated by adding the spectral contribution of each electron. The calculated yields are compared with the experimental results and a good agreement is found.

  19. Hermite-distributed approximating functional-based formulation of multiconfiguration time-dependent Hartree method: A case study of quantum tunnelling in a coupled double-well system

    Indian Academy of Sciences (India)

    KAUSHIK MAJI

    2016-08-01

    We propose a variant of the multiconfiguration time-dependent Hartree (MCTDH) method within the framework of Hermite-distributed approximating functional (HDAF) method. The discretized Hamiltonian is a highly banded Toeplitz matrix which significantly reduces computational cost in terms of both storage and number of operations. The method proposed is employed to carry out the study of tunnelling dynamics of two coupled double well oscillators. We have calculated the orthogonality time \\tau , which is a measure of the time interval for an initial state to evolve into its orthogonal state. It is observed that the coupling has a significant effect on \\tau .

  20. Computational Nanoelectronics: Applications to DNA, Carbon Nanotubes and Nanotransistors

    Science.gov (United States)

    Anantram, M. P.; Svizhenko, Alexei; Govindan, T. R.; Govindan, T. R.; Walch, S.; Mehrez, H.

    2003-01-01

    The topics covered by the panels of this viewgraph presentation include phonon scattering, layered structures, DNA as a device, the influence of twist and rise in the DNA molecule, counter-ions, conductance versus length, and intrinsic resonant tunneling.