Intramolecular Diels-Alder Reactions in Organic Synthesis

OpenAIRE

Sizemore, Nicholas Blandford Luke

2014-01-01

Intramolecular Diels-Alder (IMDA) reactions are an important class of reactions in synthetic organic chemistry for the rapid construction of polycyclic frameworks. Three classes of IMDA reactions were investigated synthetically and computationally: 1) all-carbon type 1 IMDA reactions, 2) N-acylnitroso type 2 IMDA reactions, and 3) cyano-azadiene IMDA reactions. The first class was implemented in research toward the total synthesis of maoecrystal Z and isopalhinine A. The second class was stud...

Two-component multistep direct reactions: A microscopic approach

International Nuclear Information System (INIS)

Koning, A.J.; Chadwick, M.B.

1998-03-01

The authors present two principal advances in multistep direct theory: (1) A two-component formulation of multistep direct reactions, where neutron and proton excitations are explicitly accounted for in the evolution of the reaction, for all orders of scattering. While this may at first seem to be a formidable task, especially for multistep processes where the many possible reaction pathways becomes large in a two-component formalism, the authors show that this is not so -- a rather simple generalization of the FKK convolution expression 1 automatically generates these pathways. Such considerations are particularly relevant when simultaneously analyzing both neutron and proton emission spectra, which is always important since these processes represent competing decay channels. (2) A new, and fully microscopic, method for calculating MSD cross sections which does not make use of particle-hole state densities but instead directly calculates cross sections for all possible particle-hole excitations (again including an exact book-keeping of the neutron/proton type of the particle and hole at all stages of the reaction) determined from a simple non-interacting shell model. This is in contrast to all previous numerical approaches which sample only a small number of such states to estimate the DWBA strength, and utilize simple analytical formulae for the partial state density, based on the equidistant spacing model. The new approach has been applied, along with theories for multistep compound, compound, and collective reactions, to analyze experimental emission spectra for a range of targets and energies. The authors show that the theory correctly accounts for double-differential nucleon spectra

Quantum Chemical Approach to Estimating the Thermodynamics of Metabolic Reactions

OpenAIRE

Adrian Jinich; Dmitrij Rappoport; Ian Dunn; Benjamin Sanchez-Lengeling; Roberto Olivares-Amaya; Elad Noor; Arren Bar Even; Alán Aspuru-Guzik

2014-01-01

Thermodynamics plays an increasingly important role in modeling and engineering metabolism. We present the first nonempirical computational method for estimating standard Gibbs reaction energies of metabolic reactions based on quantum chemistry, which can help fill in the gaps in the existing thermodynamic data. When applied to a test set of reactions from core metabolism, the quantum chemical approach is comparable in accuracy to group contribution methods for isomerization and group transfe...

Tandem Wittig-ene reaction approach to kainic acid

Digital Repository Service at National Institute of Oceanography (India)

Majik, M.S.; Parameswaran, P.S.; Tilve, S.G.

The first example of a tandem Wittig-intramolecular ene reaction approach and its application toward the synthesis of kainic acid is reported. The synthetic pathway involves conversion of prenyl bromide into phosphorane 3, followed by one-pot Wittig...

Giant resonances: reaction theory approach

International Nuclear Information System (INIS)

Toledo Piza, A.F.R. de; Foglia, G.A.

1989-09-01

The study of giant resonances through the use of reaction theory approach is presented and discussed. Measurements of cross-sections to the many available decay channels following excitation of giant multipole resonances (GMR) led one to view these phenomena as complicated dynamical syndromes so that theoretical requirements for their study must be extended beyond the traditional bounds of nuclear structure models. The spectra of decay products following GMR excitation in heavy nuclei are well described by statistical model (Hauser-Feshback, HF) predictions indicated that spreading of the collective modes plays a major role in shaping exclusive cross-sections. (A.C.A.S.) [pt

Approach to defining de minimis, intermediate, and other classes of radioactive waste

International Nuclear Information System (INIS)

Cohen, J.J.; Smith, C.F.

1986-01-01

This study has developed a framework within which the complete spectrum of radioactive wastes can be defined. An approach has been developed that reflects both concerns in the framework of a radioactive waste classification system. In this approach, the class of any radioactive waste stream is dependent on its degree of radioactivity and its persistence. To be consistent with conventional systems, four waste classes are defined. In increasing order of concern due to radioactivity and/or duration, these are: 1. De Minimis Wastes: This waste has such a low content of radioactive material that it can be considered essentially nonradioactive and managed according to its nonradiological characteristics. 2. Low-Level Waste (LLW): Maximum concentrations for wastes considered to be in this class are prescribed in 10CFR61 as wastes that can be disposed of by shallow land burial methods. 3. Intermediate Level Waste (ILW): This category defines a class of waste whose content exceeds class C (10CFR61) levels, yet does not pose a sufficient hazard to justify management as a high-level waste (i.e., permanent isolation by deep geologic disposal). 4. High-Level Waste: HLW poses the most serious management problem and requires the most restrictive disposal methods. It is defined in NWPA as waste derived from the reprocessing of nuclear fuel and/or as highly radioactive wastes that require permanent isolation

Effect of Conceptual Change Approach on Students' Understanding of Reaction Rate Concepts

Science.gov (United States)

Kingir, Sevgi; Geban, Omer

2012-01-01

The purpose of the present study was to investigate the effect of conceptual change text oriented instruction compared to traditional instruction on 10th grade students' understanding of reaction rate concepts. 45 students from two classes of the same teacher in a public high school participated in this study. Students in the experimental group…

Inverse-Electron-Demand Diels-Alder Reactions: Principles and Applications.

Science.gov (United States)

Png, Zhuang Mao; Zeng, Huining; Ye, Qun; Xu, Jianwei

2017-09-05

Inverse-electron-demand Diels-Alder (iEDDA) reactions are an intriguing class of cycloaddition reactions that have attracted increasing attention for their application in bioorthogonal chemistry, the total synthesis of natural products, and materials science. In many cases, the application of the iEDDA reaction has been demonstrated as an innovative approach to achieve target structures. The theoretical aspects of this class of reactions are of particular interest for scientists as a means to understand the various factors, such as steric strain and electron density of the attached groups, that govern the reaction and thus to elucidate the reaction mechanism. This review aims to summarize both theoretical investigations and application-driven research work on the iEDDA reaction. First, the historical aspects and the theoretical basis of the reaction, especially recent advances in time-dependent density functional theory (TD-DFT) calculations, as well as catalysis strategies will be highlighted and discussed. Second, the applications of this novel reaction in the context of materials science, bioorthogonal chemistry, and total synthesis of natural products will be elaborated with selected recent examples. The challenges and opportunities of the iEDDA reaction will be highlighted to give more insight into its potential applications in many other research areas. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dual unitarisation - a new approach to hadron reactions

International Nuclear Information System (INIS)

Chan, H.-M.; Tsou, S.T.

1976-09-01

The new approach of dual unitarisation (or topological expansion) to hadron reactions is reviewed with particular emphasis on its aspect as a practical calculational method and the consistent manner in which it has been applied to a wide range of hadronic phenomena. (author)

Splitting Schemes & Segregation In Reaction-(Cross-)Diffusion Systems

OpenAIRE

Carrillo, José A.; Fagioli, Simone; Santambrogio, Filippo; Schmidtchen, Markus

2017-01-01

One of the most fascinating phenomena observed in reaction-diffusion systems is the emergence of segregated solutions, i.e. population densities with disjoint supports. We analyse such a reaction cross-diffusion system. In order to prove existence of weak solutions for a wide class of initial data without restriction about their supports or their positivity, we propose a variational splitting scheme combining ODEs with methods from optimal transport. In addition, this approach allows us to pr...

Practice expenses in the MFS (Medicare fee schedule): the service-class approach.

Science.gov (United States)

Latimer, E A; Kane, N M

1995-01-01

The practice expense component of the Medicare fee schedule (MFS), which is currently based on historical charges and rewards physician procedures at the expense of cognitive services, is due to be changed by January 1, 1998. The Physician Payment Review Commission (PPRC) and others have proposed microcosting direct costs and allocating all indirect costs on a common basis, such as physician time or work plus direct costs. Without altering the treatment of direct costs, the service-class approach disaggregates indirect costs into six practice function costs. The practice function costs are then allocated to classes of services using cost-accounting and statistical methods. This approach would make the practice expense component more resource-based than other proposed alternatives.

Laboratory approaches of nuclear reactions involved in primordial and stellar nucleosynthesis

International Nuclear Information System (INIS)

Rolfs, C.; California Inst. of Tech., Pasadena

1986-01-01

Laboratory-based studies of primordial and stellar nucleosynthesis are reviewed, with emphasis on the nuclear reactions induced by charged particles. The analytical approach used to investigate nuclear reactions associated with stellar reactions is described, as well as the experimental details and procedures used to investigate nuclear reactions induced by charged particles. The present knowledge of some of the key reactions involved in primordial nucleosynthesis is discussed, along with the progress and problems of nuclear reactions involved in the hydrogen and helium burning phases of a star. Finally, a description is given of new experimental techniques which might be useful for future experiments in the field of nuclear astrophysics. (U.K.)

"SCAFFOLDING" STUDENTS' WRITING IN EFL CLASS: IMPLEMENTING PROCESS APPROACH

Directory of Open Access Journals (Sweden)

Ekaning Dewanti Laksmi

2006-01-01

Full Text Available The writing process approach views a writing learner as a creator of text, and hence, he needs to experience what writers actually do as they write, and so do students in EFL writing classes. The approach offers an answer to the need of helping the students develop their writing skill without their having to master the basic fundamental elements of writing, i.e. grammar, prior to attending the writing courses. This article highlights the potential of the process approach-with which students go through a write-rewrite process-in giving students a scaffold to work in a real, live process of how a real writer engages in the process of writing. However, the most important harvest is the fact that students have become more confident in expressing their ideas in writings.

Kinetics of subdiffusion-assisted reactions: non-Markovian stochastic Liouville equation approach

International Nuclear Information System (INIS)

Shushin, A I

2005-01-01

Anomalous specific features of the kinetics of subdiffusion-assisted bimolecular reactions (time-dependence, dependence on parameters of systems, etc) are analysed in detail with the use of the non-Markovian stochastic Liouville equation (SLE), which has been recently derived within the continuous-time random-walk (CTRW) approach. In the CTRW approach, subdiffusive motion of particles is modelled by jumps whose onset probability distribution function is of a long-tailed form. The non-Markovian SLE allows for rigorous describing of some peculiarities of these reactions; for example, very slow long-time behaviour of the kinetics, non-analytical dependence of the reaction rate on the reactivity of particles, strong manifestation of fluctuation kinetics showing itself in very slowly decreasing behaviour of the kinetics at very long times, etc

The Cascade-Exciton Approach to Nuclear Reactions. (Foundation and Achievements)

International Nuclear Information System (INIS)

Mashnik, S.G.

1994-01-01

The relativistic kinetic equations describing nuclear reactions at intermediate energies are obtained on the dynamical basis. These equations are analyzed and realized in several versions of the Cascade Exciton Model (CEM). The CEM assumes that reactions occur in three stages: the intranuclear cascade, pre-equilibrium and the evaporative ones. A large variety of experimental data on hadron- and photonuclear reactions in the bombarding energy range up to several GeV are analyzed in this approach. The contributions of different pion and photon absorption mechanisms and the relative role of different particle and photon production mechanisms in these reactions are estimated. The CEM describes adequately nuclear reactions at intermediate energies and has one of the best predictive powers as compared to other available modern models. 55 refs., 10 figs., 1 tab

Bilateral sagittal split osteotomy: Surgery first approach for correction of skeletal Class II

Directory of Open Access Journals (Sweden)

Revathi Peddu

2018-01-01

Full Text Available Most of the skeletal malocclusions which require orthognathic surgeries are treated by traditional approach which requires time-consuming and unesthetic presurgical orthodontic phase. Surgery first approach (SFA avoids these disadvantages of the traditional approach. A 24-year-old female patient with skeletal and dental class II malocclusion due to retrognathic mandible was treated with SFA. Bilateral sagittal split osteotomy with mandibular advancement was done immediately after initial alignment and closure of the existing spaces in the maxillary arch. Angle's class I molar and canine relation was achieved after surgery. Bonding of the mandibular arch was done after 1 month of orthognathic surgery and treatment was completed within 13 months. A wrap-around retainer was placed in upper arch, and bonded lingual retainer was given in the lower arch.

Non-equilibrium statistical mechanical approach for describing heavy ion reactions

International Nuclear Information System (INIS)

Sventek, J.S.

1979-01-01

With the availability of heavy-ion projectiles (A > 4) at low to intermediate energies (4 < E/A < 10), products showing various stages of relaxation for certain macroscopic variables (center-of-mass energy, orbital angular momentum, etc.) were produced in various reactions. The distributions for these macroscopic variables showed a correlation between the stage of relaxation reached and the net amount of mass transfer which had occurred in the reaction. There was also evidence that there was an asymmetry in the number of net transfers necessary for complete relaxation between stripping ad pickup reactions. A model for describing the time-evolution of these reactions has been formulated, the keystone of which is a master-equation approach for describing the time-dependence of the mass-asymmetry. This, coupled with deterministic equations of motion for the other macroscopic coordinates in the reaction lead to calculated distributions which provide an excellent qualitative description of these reactions, and, in some cases, quantitatively reproduce the experimental data quite well

Unified path integral approach to theories of diffusion-influenced reactions

Science.gov (United States)

Prüstel, Thorsten; Meier-Schellersheim, Martin

2017-08-01

Building on mathematical similarities between quantum mechanics and theories of diffusion-influenced reactions, we develop a general approach for computational modeling of diffusion-influenced reactions that is capable of capturing not only the classical Smoluchowski picture but also alternative theories, as is here exemplified by a volume reactivity model. In particular, we prove the path decomposition expansion of various Green's functions describing the irreversible and reversible reaction of an isolated pair of molecules. To this end, we exploit a connection between boundary value and interaction potential problems with δ - and δ'-function perturbation. We employ a known path-integral-based summation of a perturbation series to derive a number of exact identities relating propagators and survival probabilities satisfying different boundary conditions in a unified and systematic manner. Furthermore, we show how the path decomposition expansion represents the propagator as a product of three factors in the Laplace domain that correspond to quantities figuring prominently in stochastic spatially resolved simulation algorithms. This analysis will thus be useful for the interpretation of current and the design of future algorithms. Finally, we discuss the relation between the general approach and the theory of Brownian functionals and calculate the mean residence time for the case of irreversible and reversible reactions.

A Data-Driven Sparse-Learning Approach to Model Reduction in Chemical Reaction Networks

OpenAIRE

Harirchi, Farshad; Khalil, Omar A.; Liu, Sijia; Elvati, Paolo; Violi, Angela; Hero, Alfred O.

2017-01-01

In this paper, we propose an optimization-based sparse learning approach to identify the set of most influential reactions in a chemical reaction network. This reduced set of reactions is then employed to construct a reduced chemical reaction mechanism, which is relevant to chemical interaction network modeling. The problem of identifying influential reactions is first formulated as a mixed-integer quadratic program, and then a relaxation method is leveraged to reduce the computational comple...

Report of seminar on relativistic approach to nuclear reaction and nuclear structure

International Nuclear Information System (INIS)

1986-05-01

A seminar on 'Relativistic Approach to Nuclear Reaction and Nuclear Structure' was held in 1985 at Osaka University. This booklet includes twenty-four reports given at the seminar, which deal with: Conventional Nonrelativistic Description of Nuclear Matter and Nuclear Spin-Orbit Interactions; Relativistic Approach to Nuclear Structure; Atomic and Molecular Structure Calculations; Electromagnetic Interaction in Nucleus and Relativistic Effect; Nuclear Magnetic Moment in the Relativistic Mean Field Theory, Effective Mass and Particle-Vibration Coupling in the Relativistic σ-ω Model; Gauge Invariance in Relativistic Many-Body Theory; Relativistic Description of Nucleon-Nucleon Interaction in Review; σ-Particle in NN Interaction; Nuclear Optical Potentials Based on the Brueckner-Hartree-Fock Approach; Elastic Backscattering and Optical Potential; Description of Intermediate-Energy Nuclear Reactions; Dirac Phenomenology at E(p) = 65 MeV; Relativistic Impulse Approximation; Reaction Studies with Intermediate Energy Deuterons at SATURNE; Folding Model for Intermediate-Energy Deutron Scattering; Folding Model for Polarized Deutron Scattering at 700 MeV; Dirac Approach Problems and a Different Viewpoint; Relativistic Approach and EMC Effect; Quasielastic Electron Scattering; Response Function of Quasielastic Electron Scattering; Relativistic Hartree Response Function for Quasielastic Electron Scattering on 12 C and 40 Ca; Backflow-, Retardation- and Relativistic Effects on the Longitudinal Response Function of Nuclear Matter; Pion-Photoproduction in the σ-ω Model. (Nogami, K.)

An Approach for a Synthetic CTL Vaccine Design against Zika Flavivirus Using Class I and Class II Epitopes Identified by Computer Modeling

Directory of Open Access Journals (Sweden)

Edecio Cunha-Neto

2017-06-01

Full Text Available The threat posed by severe congenital abnormalities related to Zika virus (ZKV infection during pregnancy has turned development of a ZKV vaccine into an emergency. Recent work suggests that the cytotoxic T lymphocyte (CTL response to infection is an important defense mechanism in response to ZKV. Here, we develop the rationale and strategy for a new approach to developing cytotoxic T lymphocyte (CTL vaccines for ZKV flavivirus infection. The proposed approach is based on recent studies using a protein structure computer model for HIV epitope selection designed to select epitopes for CTL attack optimized for viruses that exhibit antigenic drift. Because naturally processed and presented human ZKV T cell epitopes have not yet been described, we identified predicted class I peptide sequences on ZKV matching previously identified DNV (Dengue class I epitopes and by using a Major Histocompatibility Complex (MHC binding prediction tool. A subset of those met the criteria for optimal CD8+ attack based on physical chemistry parameters determined by analysis of the ZKV protein structure encoded in open source Protein Data File (PDB format files. We also identified candidate ZKV epitopes predicted to bind promiscuously to multiple HLA class II molecules that could provide help to the CTL responses. This work suggests that a CTL vaccine for ZKV may be possible even if ZKV exhibits significant antigenic drift. We have previously described a microsphere-based CTL vaccine platform capable of eliciting an immune response for class I epitopes in mice and are currently working toward in vivo testing of class I and class II epitope delivery directed against ZKV epitopes using the same microsphere-based vaccine.

Targeting implicit approach reactions to snack food in children; Effects on intake

NARCIS (Netherlands)

Folkvord, Frans; Veling, Harm; Hoeken, J.A.L.

Objective: Implicit approach reactions to energy-dense snack food can facilitate unhealthy eating in children. Therefore, an experiment was conducted to test whether modifying implicit reactions to snack food by means of a go/no-go task can reduce consumption of this food. The effectiveness of this

Convergence Analysis of a Class of Computational Intelligence Approaches

Directory of Open Access Journals (Sweden)

Junfeng Chen

2013-01-01

Full Text Available Computational intelligence approaches is a relatively new interdisciplinary field of research with many promising application areas. Although the computational intelligence approaches have gained huge popularity, it is difficult to analyze the convergence. In this paper, a computational model is built up for a class of computational intelligence approaches represented by the canonical forms of generic algorithms, ant colony optimization, and particle swarm optimization in order to describe the common features of these algorithms. And then, two quantification indices, that is, the variation rate and the progress rate, are defined, respectively, to indicate the variety and the optimality of the solution sets generated in the search process of the model. Moreover, we give four types of probabilistic convergence for the solution set updating sequences, and their relations are discussed. Finally, the sufficient conditions are derived for the almost sure weak convergence and the almost sure strong convergence of the model by introducing the martingale theory into the Markov chain analysis.

Fat versus Thin Threading Approach on GPUs: Application to Stochastic Simulation of Chemical Reactions

KAUST Repository

Klingbeil, Guido; Erban, Radek; Giles, Mike; Maini, Philip K.

2012-01-01

We explore two different threading approaches on a graphics processing unit (GPU) exploiting two different characteristics of the current GPU architecture. The fat thread approach tries to minimize data access time by relying on shared memory and registers potentially sacrificing parallelism. The thin thread approach maximizes parallelism and tries to hide access latencies. We apply these two approaches to the parallel stochastic simulation of chemical reaction systems using the stochastic simulation algorithm (SSA) by Gillespie [14]. In these cases, the proposed thin thread approach shows comparable performance while eliminating the limitation of the reaction system's size. © 2006 IEEE.

Fat versus Thin Threading Approach on GPUs: Application to Stochastic Simulation of Chemical Reactions

KAUST Repository

Klingbeil, Guido

2012-02-01

We explore two different threading approaches on a graphics processing unit (GPU) exploiting two different characteristics of the current GPU architecture. The fat thread approach tries to minimize data access time by relying on shared memory and registers potentially sacrificing parallelism. The thin thread approach maximizes parallelism and tries to hide access latencies. We apply these two approaches to the parallel stochastic simulation of chemical reaction systems using the stochastic simulation algorithm (SSA) by Gillespie [14]. In these cases, the proposed thin thread approach shows comparable performance while eliminating the limitation of the reaction system\\'s size. © 2006 IEEE.

Novel error propagation approach for reducing H2S/O2 reaction mechanism

International Nuclear Information System (INIS)

Selim, H.; Gupta, A.K.; Sassi, M.

2012-01-01

A reduction strategy of hydrogen sulfide/oxygen reaction mechanism is conducted to simplify the detailed mechanism. Direct relation graph and error propagation methodology (DRGEP) has been used. A novel approach of direct elementary reaction error (DERE) has been developed in this study. The developed approach allowed for further reduction of the reaction mechanism. The reduced mechanism has been compared with the detailed mechanism under different conditions to emphasize its validity. The results obtained from the resulting reduced mechanism showed good agreement with that from the detailed mechanism. However, some discrepancies have been found for some species. Hydrogen and oxygen mole fractions showed the largest discrepancy of all combustion products. The reduced mechanism was also found to be capable of tracking the changes that occur in chemical kinetics through the change in reaction conditions. A comparison on the ignition delay time obtained from the reduced mechanism and previous experimental data showed good agreement. The reduced mechanism was used to track changes in mechanistic pathways of Claus reactions with the reaction progress.

Current and evolving approaches for improving the oral permeability of BCS Class III or analogous molecules.

Science.gov (United States)

Dave, Vivek S; Gupta, Deepak; Yu, Monica; Nguyen, Phuong; Varghese Gupta, Sheeba

2017-02-01

The Biopharmaceutics Classification System (BCS) classifies pharmaceutical compounds based on their aqueous solubility and intestinal permeability. The BCS Class III compounds are hydrophilic molecules (high aqueous solubility) with low permeability across the biological membranes. While these compounds are pharmacologically effective, poor absorption due to low permeability becomes the rate-limiting step in achieving adequate bioavailability. Several approaches have been explored and utilized for improving the permeability profiles of these compounds. The approaches include traditional methods such as prodrugs, permeation enhancers, ion-pairing, etc., as well as relatively modern approaches such as nanoencapsulation and nanosizing. The most recent approaches include a combination/hybridization of one or more traditional approaches to improve drug permeability. While some of these approaches have been extremely successful, i.e. drug products utilizing the approach have progressed through the USFDA approval for marketing; others require further investigation to be applicable. This article discusses the commonly studied approaches for improving the permeability of BCS Class III compounds.

Linear decomposition approach for a class of nonconvex programming problems.

Science.gov (United States)

Shen, Peiping; Wang, Chunfeng

2017-01-01

This paper presents a linear decomposition approach for a class of nonconvex programming problems by dividing the input space into polynomially many grids. It shows that under certain assumptions the original problem can be transformed and decomposed into a polynomial number of equivalent linear programming subproblems. Based on solving a series of liner programming subproblems corresponding to those grid points we can obtain the near-optimal solution of the original problem. Compared to existing results in the literature, the proposed algorithm does not require the assumptions of quasi-concavity and differentiability of the objective function, and it differs significantly giving an interesting approach to solving the problem with a reduced running time.

Alexithymia and psychosocial problems among Italian preadolescents. A latent class analysis approach.

Science.gov (United States)

Mannarini, Stefania; Balottin, Laura; Toldo, Irene; Gatta, Michela

2016-10-01

The study, conducted on Italian preadolscents aged 11 to 13 belonging to the general population, aims to investigate the relationship between the emotional functioning, namely, alexithymia, and the risk of developing behavioral and emotional problems measured using the Strength and Difficulty Questionnaire. The latent class analysis approach allowed to identify two latent variables, accounting for the internalizing (emotional symptoms and difficulties in emotional awareness) and for the externalizing problems (conduct problems and hyperactivity, problematic relationships with peers, poor prosocial behaviors and externally oriented thinking). The two latent variables featured two latent classes: the difficulty in dealing with problems and the strength to face problems that was representative of most of the healthy participants with specific gender differences. Along with the analysis of psychopathological behaviors, the study of resilience and strengths can prove to be a key step in order to develop valuable preventive approaches to tackle psychiatric disorders. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Polymer reaction engineering, an integrated approach

NARCIS (Netherlands)

Meyer, T.; Keurentjes, J.T.F.; Meyer, T.; Keurentjes, J.T.F.

2005-01-01

Summary This chapter contains sections titled: Polymer Materials A Short History of Polymer Reaction Engineering The Position of Polymer Reaction Engineering Toward Integrated Polymer Reaction Engineering The Disciplines in Polymer Reaction Engineering The Future: Product-inspired Polymer Reaction

Sartorial symbols of social class elicit class-consistent behavioral and physiological responses: a dyadic approach.

Science.gov (United States)

Kraus, Michael W; Mendes, Wendy Berry

2014-12-01

Social rank in human and nonhuman animals is signaled by a variety of behaviors and phenotypes. In this research, we examined whether a sartorial manipulation of social class would engender class-consistent behavior and physiology during dyadic interactions. Male participants donned clothing that signaled either upper-class (business-suit) or lower-class (sweatpants) rank prior to engaging in a modified negotiation task with another participant unaware of the clothing manipulation. Wearing upper-class, compared to lower-class, clothing induced dominance--measured in terms of negotiation profits and concessions, and testosterone levels--in participants. Upper-class clothing also elicited increased vigilance in perceivers of these symbols: Relative to perceiving lower-class symbols, perceiving upper-class symbols increased vagal withdrawal, reduced perceptions of social power, and catalyzed physiological contagion such that perceivers' sympathetic nervous system activation followed that of the upper-class target. Discussion focuses on the dyadic process of social class signaling within social interactions. PsycINFO Database Record (c) 2014 APA, all rights reserved.

A Synthesis of Behavioral and Communication Approaches to Child Rearing for Parenting Skills Classes. Practicum II.

Science.gov (United States)

Silverman, Marvin

This report describes the design, implementation and evaluation of a class on effective parenting skills that combined behavioral and communication based (client-centered and Adlerian) approaches to child rearing. Seventeen parents of elementary school age children attended the class; twelve parents attended five or more sessions. The class…

Open quantum system approach to the modeling of spin recombination reactions.

Science.gov (United States)

Tiersch, M; Steiner, U E; Popescu, S; Briegel, H J

2012-04-26

In theories of spin-dependent radical pair reactions, the time evolution of the radical pair, including the effect of the chemical kinetics, is described by a master equation in the Liouville formalism. For the description of the chemical kinetics, a number of possible reaction operators have been formulated in the literature. In this work, we present a framework that allows for a unified description of the various proposed mechanisms and the forms of reaction operators for the spin-selective recombination processes. On the basis of the concept that master equations can be derived from a microscopic description of the spin system interacting with external degrees of freedom, it is possible to gain insight into the underlying microscopic processes and develop a systematic approach toward determining the specific form of the reaction operator in concrete scenarios.

High Class-Imbalance in pre-miRNA Prediction: A Novel Approach Based on deepSOM.

Science.gov (United States)

Stegmayer, Georgina; Yones, Cristian; Kamenetzky, Laura; Milone, Diego H

2017-01-01

The computational prediction of novel microRNA within a full genome involves identifying sequences having the highest chance of being a miRNA precursor (pre-miRNA). These sequences are usually named candidates to miRNA. The well-known pre-miRNAs are usually only a few in comparison to the hundreds of thousands of potential candidates to miRNA that have to be analyzed, which makes this task a high class-imbalance classification problem. The classical way of approaching it has been training a binary classifier in a supervised manner, using well-known pre-miRNAs as positive class and artificially defining the negative class. However, although the selection of positive labeled examples is straightforward, it is very difficult to build a set of negative examples in order to obtain a good set of training samples for a supervised method. In this work, we propose a novel and effective way of approaching this problem using machine learning, without the definition of negative examples. The proposal is based on clustering unlabeled sequences of a genome together with well-known miRNA precursors for the organism under study, which allows for the quick identification of the best candidates to miRNA as those sequences clustered with known precursors. Furthermore, we propose a deep model to overcome the problem of having very few positive class labels. They are always maintained in the deep levels as positive class while less likely pre-miRNA sequences are filtered level after level. Our approach has been compared with other methods for pre-miRNAs prediction in several species, showing effective predictivity of novel miRNAs. Additionally, we will show that our approach has a lower training time and allows for a better graphical navegability and interpretation of the results. A web-demo interface to try deepSOM is available at http://fich.unl.edu.ar/sinc/web-demo/deepsom/.

Reciprocity theory of homogeneous reactions

Science.gov (United States)

Agbormbai, Adolf A.

1990-03-01

The reciprocity formalism is applied to the homogeneous gaseous reactions in which the structure of the participating molecules changes upon collision with one another, resulting in a change in the composition of the gas. The approach is applied to various classes of dissociation, recombination, rearrangement, ionizing, and photochemical reactions. It is shown that for the principle of reciprocity to be satisfied it is necessary that all chemical reactions exist in complementary pairs which consist of the forward and backward reactions. The backward reaction may be described by either the reverse or inverse process. The forward and backward processes must satisfy the same reciprocity equation. Because the number of dynamical variables is usually unbalanced on both sides of a chemical equation, it is necessary that this balance be established by including as many of the dynamical variables as needed before the reciprocity equation can be formulated. Statistical transformation models of the reactions are formulated. The models are classified under the titles free exchange, restricted exchange and simplified restricted exchange. The special equations for the forward and backward processes are obtained. The models are consistent with the H theorem and Le Chatelier's principle. The models are also formulated in the context of the direct simulation Monte Carlo method.

Classification of cancerous cells based on the one-class problem approach

Science.gov (United States)

Murshed, Nabeel A.; Bortolozzi, Flavio; Sabourin, Robert

1996-03-01

One of the most important factors in reducing the effect of cancerous diseases is the early diagnosis, which requires a good and a robust method. With the advancement of computer technologies and digital image processing, the development of a computer-based system has become feasible. In this paper, we introduce a new approach for the detection of cancerous cells. This approach is based on the one-class problem approach, through which the classification system need only be trained with patterns of cancerous cells. This reduces the burden of the training task by about 50%. Based on this approach, a computer-based classification system is developed, based on the Fuzzy ARTMAP neural networks. Experimental results were performed using a set of 542 patterns taken from a sample of breast cancer. Results of the experiment show 98% correct identification of cancerous cells and 95% correct identification of non-cancerous cells.

α-Bromodiazoacetamides – a new class of diazo compounds for catalyst-free, ambient temperature intramolecular C–H insertion reactions

Directory of Open Access Journals (Sweden)

Åsmund Kaupang

2013-07-01

Full Text Available In this work, we introduce a new class of halodiazocarbonyl compounds, α-halodiazoacetamides, which through a metal-free, ambient-temperature thermolysis perform intramolecular C–H insertions to produce α-halo-β-lactams. When carried out with α-bromodiazoacetamides bearing cyclic side chains, the thermolysis reaction affords bicyclic α-halo-β-lactams, in some cases in excellent yields, depending on the ring size and substitution pattern of the cyclic amide side chains.

alpha,beta-unsaturated 2-acyl imidazoles as a practical class of dienophiles for the DNA-Based catalytic asymmetric diels-alder reaction in water

NARCIS (Netherlands)

Boersma, A.J.; Feringa, B.L.; Roelfes, G.

2007-01-01

alpha,beta-Unsaturated 2-acyl imidazoles are a novel and practical class of dienophiles for the DNA-based catalytic asymmetric Diels-Alder reaction in water. The Diels-Alder products are obtained with very high diastereoselectivities and enantioselectivities in the range of 83-98%. The catalytic

Practice and effectiveness of web-based problem-based learning approach in a large class-size system: A comparative study.

Science.gov (United States)

Ding, Yongxia; Zhang, Peili

2018-06-12

Problem-based learning (PBL) is an effective and highly efficient teaching approach that is extensively applied in education systems across a variety of countries. This study aimed to investigate the effectiveness of web-based PBL teaching pedagogies in large classes. The cluster sampling method was used to separate two college-level nursing student classes (graduating class of 2013) into two groups. The experimental group (n = 162) was taught using a web-based PBL teaching approach, while the control group (n = 166) was taught using conventional teaching methods. We subsequently assessed the satisfaction of the experimental group in relation to the web-based PBL teaching mode. This assessment was performed following comparison of teaching activity outcomes pertaining to exams and self-learning capacity between the two groups. When compared with the control group, the examination scores and self-learning capabilities were significantly higher in the experimental group (P web-based PBL teaching approach. In a large class-size teaching environment, the web-based PBL teaching approach appears to be more optimal than traditional teaching methods. These results demonstrate the effectiveness of web-based teaching technologies in problem-based learning. Copyright © 2018. Published by Elsevier Ltd.

Autonomous optical navigation using nanosatellite-class instruments: a Mars approach case study

Science.gov (United States)

Enright, John; Jovanovic, Ilija; Kazemi, Laila; Zhang, Harry; Dzamba, Tom

2018-02-01

This paper examines the effectiveness of small star trackers for orbital estimation. Autonomous optical navigation has been used for some time to provide local estimates of orbital parameters during close approach to celestial bodies. These techniques have been used extensively on spacecraft dating back to the Voyager missions, but often rely on long exposures and large instrument apertures. Using a hyperbolic Mars approach as a reference mission, we present an EKF-based navigation filter suitable for nanosatellite missions. Observations of Mars and its moons allow the estimator to correct initial errors in both position and velocity. Our results show that nanosatellite-class star trackers can produce good quality navigation solutions with low position (<300 {m}) and velocity (<0.15 {m/s}) errors as the spacecraft approaches periapse.

Recent developments of the quantum chemical cluster approach for modeling enzyme reactions.

Science.gov (United States)

Siegbahn, Per E M; Himo, Fahmi

2009-06-01

The quantum chemical cluster approach for modeling enzyme reactions is reviewed. Recent applications have used cluster models much larger than before which have given new modeling insights. One important and rather surprising feature is the fast convergence with cluster size of the energetics of the reactions. Even for reactions with significant charge separation it has in some cases been possible to obtain full convergence in the sense that dielectric cavity effects from outside the cluster do not contribute to any significant extent. Direct comparisons between quantum mechanics (QM)-only and QM/molecular mechanics (MM) calculations for quite large clusters in a case where the results differ significantly have shown that care has to be taken when using the QM/MM approach where there is strong charge polarization. Insights from the methods used, generally hybrid density functional methods, have also led to possibilities to give reasonable error limits for the results. Examples are finally given from the most extensive study using the cluster model, the one of oxygen formation at the oxygen-evolving complex in photosystem II.

"Cleaning" the Surface of Hydroxyapatite Nanorods by a Reaction-Dissolution Approach.

Science.gov (United States)

Cao, Binrui; Yang, Mingying; Wang, Lin; Xu, Hong; Zhu, Ye; Mao, Chuanbin

2015-10-21

Synthetic nanoparticles are always terminated with coating molecules, which are often cytotoxic and not desired in biomedicine. Here we propose a novel reaction-dissolution approach to remove the cytotoxic coating molecules. A two-component solution is added to the nanoparticle solution; one component reacts with the coating molecules to form a salt whereas another is a solvent for dissolving and thus removing the salt. As a proof of concept, this work uses a NaOH-ethanol solution to remove the cytotoxic linoleic acid molecules coated on the hydroxyapatite nanorods (HAP-NRs). The removal of the coating molecules not only significantly improves the biocompatibility of HAP-NRs but also enables their oriented attachment into tightly-bound superstructures, which mimic the organized HAP crystals in bone and enamel and can promote the osteogenic differentiation of mesenchymal stem cells. Our reaction-dissolution approach can be extended to the surface "cleaning" of other nanomaterials.

Neutron-induced reactions on U and Th - A new approach via AMS

International Nuclear Information System (INIS)

Wallner, A.; Capote, R.; Christl, M.; Fifield, L.K.; Srncik, M.; Tims, S.; Hotchkis, M.; Krasa, A.; Lachner, J.; Lippold, J.; Plompen, A.; Semkova, V.; Steier, P.; Winkler, S.

2014-01-01

Recent studies exhibit discrepancies at keV and MeV energies between major nuclear data libraries for 238 U(n,γ), 232 Th(n,γ) and also for (n,xn) reactions. We have extended our initial (n,γ) measurements on 235,238 U to higher neutron energies and to additional reaction channels. Neutron-induced reactions on 232 Th and 238 U were measured by a combination of the activation technique and atom counting of the reaction products using accelerator mass spectrometry (AMS). Natural thorium and uranium samples were activated with quasi-monoenergetic neutrons at IRMM. Neutron capture data were produced for neutron energies between 0.5 and 5 MeV. Fast neutron-induced reactions were studied in the energy range from 17 to 22 MeV. Preliminary data indicate a fair agreement with data libraries; however at the lower band of existing data. This approach represents a complementary method to on-line particle detection techniques and also to conventional decay counting. (authors)

A blended learning approach for teaching computer programming: design for large classes in Sub-Saharan Africa

Science.gov (United States)

Bayu Bati, Tesfaye; Gelderblom, Helene; van Biljon, Judy

2014-01-01

The challenge of teaching programming in higher education is complicated by problems associated with large class teaching, a prevalent situation in many developing countries. This paper reports on an investigation into the use of a blended learning approach to teaching and learning of programming in a class of more than 200 students. A course and learning environment was designed by integrating constructivist learning models of Constructive Alignment, Conversational Framework and the Three-Stage Learning Model. Design science research is used for the course redesign and development of the learning environment, and action research is integrated to undertake participatory evaluation of the intervention. The action research involved the Students' Approach to Learning survey, a comparative analysis of students' performance, and qualitative data analysis of data gathered from various sources. The paper makes a theoretical contribution in presenting a design of a blended learning solution for large class teaching of programming grounded in constructivist learning theory and use of free and open source technologies.

Multilevel latent class casemix modelling: a novel approach to accommodate patient casemix.

Science.gov (United States)

Gilthorpe, Mark S; Harrison, Wendy J; Downing, Amy; Forman, David; West, Robert M

2011-03-01

Using routinely collected patient data we explore the utility of multilevel latent class (MLLC) models to adjust for patient casemix and rank Trust performance. We contrast this with ranks derived from Trust standardised mortality ratios (SMRs). Patients with colorectal cancer diagnosed between 1998 and 2004 and resident in Northern and Yorkshire regions were identified from the cancer registry database (n = 24,640). Patient age, sex, stage-at-diagnosis (Dukes), and Trust of diagnosis/treatment were extracted. Socioeconomic background was derived using the Townsend Index. Outcome was survival at 3 years after diagnosis. MLLC-modelled and SMR-generated Trust ranks were compared. Patients were assigned to two classes of similar size: one with reasonable prognosis (63.0% died within 3 years), and one with better prognosis (39.3% died within 3 years). In patient class one, all patients diagnosed at stage B or C died within 3 years; in patient class two, all patients diagnosed at stage A, B or C survived. Trusts were assigned two classes with 51.3% and 53.2% of patients respectively dying within 3 years. Differences in the ranked Trust performance between the MLLC model and SMRs were all within estimated 95% CIs. A novel approach to casemix adjustment is illustrated, ranking Trust performance whilst facilitating the evaluation of factors associated with the patient journey (e.g. treatments) and factors associated with the processes of healthcare delivery (e.g. delays). Further research can demonstrate the value of modelling patient pathways and evaluating healthcare processes across provider institutions.

Multilevel latent class casemix modelling: a novel approach to accommodate patient casemix

Directory of Open Access Journals (Sweden)

Forman David

2011-03-01

Full Text Available Abstract Background Using routinely collected patient data we explore the utility of multilevel latent class (MLLC models to adjust for patient casemix and rank Trust performance. We contrast this with ranks derived from Trust standardised mortality ratios (SMRs. Methods Patients with colorectal cancer diagnosed between 1998 and 2004 and resident in Northern and Yorkshire regions were identified from the cancer registry database (n = 24,640. Patient age, sex, stage-at-diagnosis (Dukes, and Trust of diagnosis/treatment were extracted. Socioeconomic background was derived using the Townsend Index. Outcome was survival at 3 years after diagnosis. MLLC-modelled and SMR-generated Trust ranks were compared. Results Patients were assigned to two classes of similar size: one with reasonable prognosis (63.0% died within 3 years, and one with better prognosis (39.3% died within 3 years. In patient class one, all patients diagnosed at stage B or C died within 3 years; in patient class two, all patients diagnosed at stage A, B or C survived. Trusts were assigned two classes with 51.3% and 53.2% of patients respectively dying within 3 years. Differences in the ranked Trust performance between the MLLC model and SMRs were all within estimated 95% CIs. Conclusions A novel approach to casemix adjustment is illustrated, ranking Trust performance whilst facilitating the evaluation of factors associated with the patient journey (e.g. treatments and factors associated with the processes of healthcare delivery (e.g. delays. Further research can demonstrate the value of modelling patient pathways and evaluating healthcare processes across provider institutions.

Case Studies of Interactive Whole-Class Teaching in Primary Science: Communicative approach and pedagogic purposes

Science.gov (United States)

McMahon, Kendra

2012-07-01

By developing two case studies of expert teaching in action, this study aimed to develop knowledge of talk in whole-class teaching in UK primary science lessons and understand this in relation to both the teachers' interpretations and sociocultural theoretical frameworks. Lessons were observed and video-recorded and the teachers engaged in video-stimulated-reflective dialogue to capture participants' reflections upon their own pedagogic purposes and interactions in the classroom. The analytic framework was developed at three levels: sequence of lessons, lesson, and episode. For each episode, the 'communicative approach' and teaching purposes were recorded. Transcripts were developed for fine grain analysis of selected episodes and a quantitative analysis was undertaken of the use of communicative approaches. Findings exemplify how different communicative approaches were used by the case-study teachers for different pedagogical purposes at different points in the sequence of lessons, contributing to primary teachers' repertoire for planning and practice. The initial elicitation of children's ideas can be understood as pooling them to enhance multivoicedness and develop a shared resource for future dialogues. Whole-class talk can support univocality by rehearsing procedural knowledge and exploring the meanings of scientific terminology. Identifying salient features of phenomena in the context of the whole-class marks them as significant as shared knowledge but valuing other observations extends the multivoicedness of the discourse.

Is there a nonadherent subtype of hypertensive patient? A latent class analysis approach

Directory of Open Access Journals (Sweden)

Ranak B Trivedi

2010-07-01

Full Text Available Ranak B Trivedi1, Brian J Ayotte2, Carolyn T Thorpe3, David Edelman4, Hayden B Bosworth51Northwest Health Services Research and Development Service Center of Excellence, VA Puget Sound Health Care System, Seattle, Washington; 2Boston VA Health Care System, Boston, Massachusetts; 3Department of Population Health Sciences, University of Wisconsin, Madison, Wisconsin; 4Department of Medicine, Duke University Medical Center, Durham, North Carolina; 5Research Professor, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USAAbstract: To determine subtypes of adherence, 636 hypertensive patients (48% White, 34% male reported adherence to medications, diet, exercise, smoking, and home blood pressure monitoring. A latent class analysis approach was used to identify subgroups that adhere to these five self-management behaviors. Fit statistics suggested two latent classes. The first class (labeled “more adherent” included patients with greater probability of adhering to ­recommendations compared with the second class (labeled “less adherent” with regard to nonsmoking (97.7% versus 76.3%, medications (75.5% versus 49.5%, diet (70.7% versus 46.9%, exercise (63.4% versus 27.2%, and blood pressure monitoring (32% versus 3.4%. Logistic regression analyses used to characterize the two classes showed that “more adherent” participants were more likely to report full-time employment, adequate income, and better emotional and physical well-being. Results suggest the presence of a less adherent subtype of hypertensive patients. Behavioral interventions designed to improve adherence might best target these at-risk patients for greater treatment efficiency.Keywords: adherence, hypertension, latent class analysis, self-management

Strategies for method development for an inductively coupled plasma mass spectrometer with bandpass reaction cell. Approaches with different reaction gases for the determination of selenium

International Nuclear Information System (INIS)

Hattendorf, Bodo; Guenther, Detlef

2003-01-01

An inductively coupled plasma mass spectrometer with dynamic reaction cell (DRC) was used to investigate different approaches for chemical resolution of Ar 2 + ions and to improve the determination of Se. Hydrogen, methane, oxygen and nitrous oxide were used as reaction gases. The method development for each approach consists of the acquisition of spectra for blank and spiked samples at different operating parameters, including reaction gas flow and transmission settings, of the DRC. Isotope ratio studies and the analytes signal to background ratio (SBR), were used as criteria to determine the operating conditions of the DRC where spectral interferences from the ion source or from polyatomic ions formed inside the DRC are minimized. Methane was found to provide the highest reaction efficiency for determination of Se. Nitrous oxide and oxygen also very efficiently suppress the Ar 2 + interference but reaction or scattering losses of Se + and SeO + are significant. Hydrogen is the least efficient gas for Ar 2 + reduction but little scattering or reactive loss lead to a good SBR. The determination of Se as SeO + was investigated with oxygen and nitrous oxide as reaction gases. The efficiency when using the oxygenation reaction was found to be similar to the efficiency for the charge transfer reactions but the slow oxygenation of the potentially interfering Mo + renders this approach less useful for analytical purposes. Using a natural water sample it could be shown that very good agreement is obtained using methane or hydrogen for analysis of 80 Se + at the μg/l level. Limits of detection are lowest (2 ng/l) when methane is used to suppress the Ar 2 + ion and when 80 Se + is used for analysis

A dynamical theory of incomplete fusion reactions: The breakup-fusion reaction approach

International Nuclear Information System (INIS)

Udagawa, T.

1984-01-01

A dynamical theory of partial fusion reactions is presented, which may fill the gap between direct and compound nuclear reaction theories. With the new theory one can calculate partial fusion taking place in three-body (and many more) channels reached via direct reactions, e.g., breakup and knockout reactions. The authors present first the results for the cross section for such reactions, taking as an example breakup followed by fusion. They then discuss a physical picture which emerges from their theory, namely that the partial fusion reactions, particularly of the massive-transfer type, take place in a so-called deep peripheral region. It is also shown that the deep peripheral character of such processes diminishes as the mass of the fused system decreases, so that the reactions essentially evolve to the usual peripheral character. Finally, comparisons are made of results of numerical calculations with experimental data, taking as an example the /sup 159/Tb(/sup 14/N,α) reaction with E/sub lab/ = 95 MeV

An Ensemble Based Evolutionary Approach to the Class Imbalance Problem with Applications in CBIR

Directory of Open Access Journals (Sweden)

Aun Irtaza

2018-03-01

Full Text Available In order to lower the dependence on textual annotations for image searches, the content based image retrieval (CBIR has become a popular topic in computer vision. A wide range of CBIR applications consider classification techniques, such as artificial neural networks (ANN, support vector machines (SVM, etc. to understand the query image content to retrieve relevant output. However, in multi-class search environments, the retrieval results are far from optimal due to overlapping semantics amongst subjects of various classes. The classification through multiple classifiers generate better results, but as the number of negative examples increases due to highly correlated semantic classes, classification bias occurs towards the negative class, hence, the combination of the classifiers become even more unstable particularly in one-against-all classification scenarios. In order to resolve this issue, a genetic algorithm (GA based classifier comity learning (GCCL method is presented in this paper to generate stable classifiers by combining ANN with SVMs through asymmetric and symmetric bagging. The proposed approach resolves the classification disagreement amongst different classifiers and also resolves the class imbalance problem in CBIR. Once the stable classifiers are generated, the query image is presented to the trained model to understand the underlying semantic content of the query image for association with the precise semantic class. Afterwards, the feature similarity is computed within the obtained class to generate the semantic response of the system. The experiments reveal that the proposed method outperforms various state-of-the-art methods and significantly improves the image retrieval performance.

Chemical kinetics of gas reactions

CERN Document Server

Kondrat'Ev, V N

2013-01-01

Chemical Kinetics of Gas Reactions explores the advances in gas kinetics and thermal, photochemical, electrical discharge, and radiation chemical reactions. This book is composed of 10 chapters, and begins with the presentation of general kinetic rules for simple and complex chemical reactions. The next chapters deal with the experimental methods for evaluating chemical reaction mechanisms and some theories of elementary chemical processes. These topics are followed by discussions on certain class of chemical reactions, including unimolecular, bimolecular, and termolecular reactions. The rema

Chemical reaction rates and non-equilibrium pressure of reacting gas mixtures in the state-to-state approach

International Nuclear Information System (INIS)

Kustova, Elena V.; Kremer, Gilberto M.

2014-01-01

Highlights: • State-to-state approach for coupled vibrational relaxation and chemical reactions. • Self-consistent model for rates of non-equilibrium reactions and energy transitions. • In viscous flows mass action law is violated. • Cross coupling between reaction rates and non-equilibrium pressure in viscous flow. • Results allow implementing the state-to-state approach for viscous flow simulations. - Abstract: Viscous gas flows with vibrational relaxation and chemical reactions in the state-to-state approach are analyzed. A modified Chapman–Enskog method is used for the determination of chemical reaction and vibrational transition rates and non-equilibrium pressure. Constitutive equations depend on the thermodynamic forces: velocity divergence and chemical reaction/transition affinity. As an application, N 2 flow with vibrational relaxation across a shock wave is investigated. Two distinct processes occur behind the shock: for small values of the distance the affinity is large and vibrational relaxation is in its initial stage; for large distances the affinity is small and the chemical reaction is in its final stage. The affinity contributes more to the transition rate than the velocity divergence and the effect of these two contributions are more important for small distances from the shock front. For the non-equilibrium pressure, the term associated with the bulk viscosity increases by a small amount the hydrostatic pressure

Chemical reaction rates and non-equilibrium pressure of reacting gas mixtures in the state-to-state approach

Energy Technology Data Exchange (ETDEWEB)

Kustova, Elena V., E-mail: e.kustova@spbu.ru [Department of Mathematics and Mechanics, Saint Petersburg State University, 198504 Universitetskiy pr. 28, Saint Petersburg (Russian Federation); Kremer, Gilberto M., E-mail: kremer@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba (Brazil)

2014-12-05

Highlights: • State-to-state approach for coupled vibrational relaxation and chemical reactions. • Self-consistent model for rates of non-equilibrium reactions and energy transitions. • In viscous flows mass action law is violated. • Cross coupling between reaction rates and non-equilibrium pressure in viscous flow. • Results allow implementing the state-to-state approach for viscous flow simulations. - Abstract: Viscous gas flows with vibrational relaxation and chemical reactions in the state-to-state approach are analyzed. A modified Chapman–Enskog method is used for the determination of chemical reaction and vibrational transition rates and non-equilibrium pressure. Constitutive equations depend on the thermodynamic forces: velocity divergence and chemical reaction/transition affinity. As an application, N{sub 2} flow with vibrational relaxation across a shock wave is investigated. Two distinct processes occur behind the shock: for small values of the distance the affinity is large and vibrational relaxation is in its initial stage; for large distances the affinity is small and the chemical reaction is in its final stage. The affinity contributes more to the transition rate than the velocity divergence and the effect of these two contributions are more important for small distances from the shock front. For the non-equilibrium pressure, the term associated with the bulk viscosity increases by a small amount the hydrostatic pressure.

A Networks Approach to Modeling Enzymatic Reactions.

Science.gov (United States)

Imhof, P

2016-01-01

Modeling enzymatic reactions is a demanding task due to the complexity of the system, the many degrees of freedom involved and the complex, chemical, and conformational transitions associated with the reaction. Consequently, enzymatic reactions are not determined by precisely one reaction pathway. Hence, it is beneficial to obtain a comprehensive picture of possible reaction paths and competing mechanisms. By combining individually generated intermediate states and chemical transition steps a network of such pathways can be constructed. Transition networks are a discretized representation of a potential energy landscape consisting of a multitude of reaction pathways connecting the end states of the reaction. The graph structure of the network allows an easy identification of the energetically most favorable pathways as well as a number of alternative routes. © 2016 Elsevier Inc. All rights reserved.

Development of a multiplex polymerase chain reaction protocol for the simultaneous detection of Salmonella enterica serovar Typhi and Class 1 integron

Directory of Open Access Journals (Sweden)

Juthika Mandal

2014-09-01

Full Text Available Objective: To develop a multiplex polymerase chain reaction (PCR protocol for the simultaneous detection of Salmonella enterica serovar Typhi (S. Typhi and Class 1 integron, so as to aid rapid diagnosis of S. Typhi cases and help in the selection of treatment options based on the presence of the Class 1 integron that can carry resistance cassettes to a range of antibiotics. Methods: PCR for amplification of specific regions was done using fliC-d and intl primers and agarose gel electrophoresis was used for resolution of PCR products. Results: The fliC-d primer (S. Typhi specific amplified a 587 bp region and the intl primer (Class 1 integron specific amplified two bands approximately 500 and 550 bps. The developed method was specific for S. Typhi and did not amplify any products with Salmonella enterica serovar Typhimurium ATCC 14028, Salmonella enterica serovar Paratyphi and Escherichia coli O157:H7. Conclusions: The developed multiplex PCR protocol can be used for rapid diagnosis and aid in proper treatment strategies for patients infected with S. Typhi.

The In Situ Enzymatic Screening (ISES) Approach to Reaction Discovery and Catalyst Identification.

Science.gov (United States)

Swyka, Robert A; Berkowitz, David B

2017-12-14

The importance of discovering new chemical transformations and/or optimizing catalytic combinations has led to a flurry of activity in reaction screening. The in situ enzymatic screening (ISES) approach described here utilizes biological tools (enzymes/cofactors) to advance chemistry. The protocol interfaces an organic reaction layer with an adjacent aqueous layer containing reporting enzymes that act upon the organic reaction product, giving rise to a spectroscopic signal. ISES allows the experimentalist to rapidly glean information on the relative rates of a set of parallel organic/organometallic reactions under investigation, without the need to quench the reactions or draw aliquots. In certain cases, the real-time enzymatic readout also provides information on sense and magnitude of enantioselectivity and substrate specificity. This article contains protocols for single-well (relative rate) and double-well (relative rate/enantiomeric excess) ISES, in addition to a colorimetric ISES protocol and a miniaturized double-well procedure. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Quantum Chemical Modeling of Enzymatic Reactions: The Case of Decarboxylation.

Science.gov (United States)

Liao, Rong-Zhen; Yu, Jian-Guo; Himo, Fahmi

2011-05-10

We present a systematic study of the decarboxylation step of the enzyme aspartate decarboxylase with the purpose of assessing the quantum chemical cluster approach for modeling this important class of decarboxylase enzymes. Active site models ranging in size from 27 to 220 atoms are designed, and the barrier and reaction energy of this step are evaluated. To model the enzyme surrounding, homogeneous polarizable medium techniques are used with several dielectric constants. The main conclusion is that when the active site model reaches a certain size, the solvation effects from the surroundings saturate. Similar results have previously been obtained from systematic studies of other classes of enzymes, suggesting that they are of a quite general nature.

A flexible latent class approach to estimating test-score reliability

NARCIS (Netherlands)

van der Palm, D.W.; van der Ark, L.A.; Sijtsma, K.

2014-01-01

The latent class reliability coefficient (LCRC) is improved by using the divisive latent class model instead of the unrestricted latent class model. This results in the divisive latent class reliability coefficient (DLCRC), which unlike LCRC avoids making subjective decisions about the best solution

Peer-led, transformative learning approaches increase classroom engagement in care self-management classes during inpatient rehabilitation of individuals with spinal cord injury.

Science.gov (United States)

Gassaway, Julie; Jones, Michael L; Sweatman, W Mark; Young, Tamara

2017-10-16

Evaluate effects of revised education classes on classroom engagement during inpatient rehabilitation for individuals with spinal cord injury/disease (SCI/D). Multiple-baseline, quasi-experimental design with video recorded engagement observations during conventional and revised education classes; visual and statistical analysis of difference in positive engagement responses observed in classes using each approach. 81 patients (72% male, 73% white, mean age 36 SD 15.6) admitted for SCI/D inpatient rehabilitation in a non-profit rehabilitation hospital, who attended one or more of 33 care self-management education classes that were video recorded. All study activities were approved by the host facility institutional review board. Conventional nurse-led self-management classes were replaced with revised peer-led classes incorporating approaches to promote transformative learning. Revised classes were introduced across three subject areas in a step-wise fashion over 15 weeks. Positive engagement responses (asking questions, participating in discussion, gesturing, raising hand, or otherwise noting approval) were documented from video recordings of 14 conventional and 19 revised education classes. Significantly higher average (per patient per class) positive engagement responses were observed in the revised compared to conventional classes (p=0.008). Redesigning SCI inpatient rehabilitation care self-management classes to promote transformative learning increased patient engagement. Additional research is needed to examine longer term outcomes and replicability in other settings.

Preliminary study of oaklins, a new class of brick-red catechinpyrylium pigments resulting from the reaction between catechin and wood aldehydes.

Science.gov (United States)

Sousa, Carlos; Mateus, Nuno; Perez-Alonso, Joaquín; Santos-Buelga, Celestino; Freitas, Victor de

2005-11-16

Several structurally related pigments were found to result from the reaction between catechin and coniferaldehyde/sinapaldehyde extracted from oak wood. Their structures were tentatively identified by mass spectrometry, and their formation was studied in different pH and temperature conditions for several days. They were all found to have a characteristic catechinpyrylium core, thereby constituting a new class of compounds named as oaklins. One of the main oaklins was also detected in a commercial table red wine aged in oak barrels.

Imagining class : A study into material social class position, subjective identification, and voting behavior across Europe

NARCIS (Netherlands)

D'Hooge, L.; Achterberg, P.H.J.; Reeskens, T.

2018-01-01

The traditional approach to class voting has largely ignored the question whether material class positions coincide with subjective class identification. Following Sosnaud et al. (2013), this study evaluates party preferences when Europeans’ material and subjective social class do not coincide.

Using a CBL Unit, a Temperature Sensor, and a Graphing Calculator to Model the Kinetics of Consecutive First-Order Reactions as Safe In-Class Demonstrations

Science.gov (United States)

Moore-Russo, Deborah A.; Cortes-Figueroa, Jose E.; Schuman, Michael J.

2006-01-01

The use of Calculator-Based Laboratory (CBL) technology, the graphing calculator, and the cooling and heating of water to model the behavior of consecutive first-order reactions is presented, where B is the reactant, I is the intermediate, and P is the product for an in-class demonstration. The activity demonstrates the spontaneous and consecutive…

A cellular automata approach to chemical reactions : 1 reaction controlled systems

NARCIS (Netherlands)

Korte, de A.C.J.; Brouwers, H.J.H.

2013-01-01

A direct link between the chemical reaction controlled (shrinking core) model and cellular automata, to study the dissolution of particles, is derived in this paper. Previous research on first and second order reactions is based on the concentration of the reactant. The present paper describes the

Effect of Solvents on the Product Distribution and Reaction Rate of a Buchwald-Hartwig Amination Reaction

DEFF Research Database (Denmark)

Christensen, H.; Kiil, Søren; Dam-Johansen, Kim

2006-01-01

The Buchwald-Hartwig amination reaction between p-bromotoluene and piperazine in the presence of the homogeneous catalytic system Pd(dba)(2)/(+/-)-BINAP and the base NaO-t-Bu was investigated in two different classes of solvents: aprotic, nonpolar and aprotic, polar. The reaction was carried out...... solvent for the Buchwald-Hartwig amination reaction under the conditions applied was m-xylene....

Using the latent class approach to cluster firms in benchmarking: An application to the US electricity transmission industry

Directory of Open Access Journals (Sweden)

Manuel Llorca

2014-03-01

Full Text Available In this paper we advocate using the latent class model (LCM approach to control for technological differences in traditional efficiency analysis of regulated electricity networks. Our proposal relies on the fact that latent class models are designed to cluster firms by uncovering differences in technology parameters. Moreover, it can be viewed as a supervised method for clustering data that takes into account the same (production or cost relationship that is analysed later, often using nonparametric frontier techniques. The simulation exercises show that the proposed approach outperforms other sample selection procedures. The proposed methodology is illustrated with an application to a sample of US electricity transmission firms for the period 2001–2009.

A Hierarchy of Homodesmotic Reactions for Thermochemistry

Science.gov (United States)

Schleyer, Paul v. R.

2009-01-01

Chemical equations that balance bond types and atom hybridization to different degrees are often used in computational thermochemistry, for example, to increase accuracy when lower levels of theory are employed. We expose the widespread confusion over such classes of equations and demonstrate that the two most widely used definitions of “homodesmotic” reactions are not equivalent. New definitions are introduced and a consistent hierarchy of reaction classes (RC1 – RC5) for hydrocarbons is constructed: isogyric (RC1) ⊇ isodesmic (RC2) ⊇ hypohomodesmotic (RC3) ⊇ homodesmotic (RC4) ⊇ hyperhomodesmotic (RC5). Each of these successively conserves larger molecular fragments. The concept of isodesmic bond separation reactions is generalized to all classes in this hierarchy, providing a unique sectioning of a given molecule for each reaction type. Several ab initio and density functional methods are applied to the bond separation reactions of 38 hydrocarbons containing five or six carbon atoms. RC4 and RC5 reactions provide bond separation enthalpies with errors consistently less than 0.4 kcal mol−1 across a wide range of theoretical levels, performing significantly better than the other reaction types and far superior to atomization routes. Our recommended bond separation reactions were demonstrated by determining the enthalpies of formation (at 298 K) of 1,3,5-hexatriyne (163.7 ± 0.4 kcal mol−1), 1,3,5,7-octatetrayne (217.6 ± 0.6 kcal mol−1), the larger polyynes C10H2 through C26H2, and an infinite acetylenic carbon chain. PMID:19182999

Two Experiments to Approach the Boltzmann Factor: Chemical Reaction and Viscous Flow

Science.gov (United States)

Fazio, Claudio; Battaglia, Onofrio R.; Guastella, Ivan

2012-01-01

In this paper we discuss a pedagogical approach aimed at pointing out the role played by the Boltzmann factor in describing phenomena usually perceived as regulated by different mechanisms of functioning. Experimental results regarding some aspects of a chemical reaction and of the viscous flow of some liquids are analysed and described in terms…

Ion-Molecule Reaction Dynamics.

Science.gov (United States)

Meyer, Jennifer; Wester, Roland

2017-05-05

We review the recent advances in the investigation of the dynamics of ion-molecule reactions. During the past decade, the combination of single-collision experiments in crossed ion and neutral beams with the velocity map ion imaging detection technique has enabled a wealth of studies on ion-molecule reactions. These methods, in combination with chemical dynamics simulations, have uncovered new and unexpected reaction mechanisms, such as the roundabout mechanism and the subtle influence of the leaving group in anion-molecule nucleophilic substitution reactions. For this important class of reactions, as well as for many fundamental cation-molecule reactions, the information obtained with crossed-beam imaging is discussed. The first steps toward understanding micro-solvation of ion-molecule reaction dynamics are presented. We conclude with the presentation of several interesting directions for future research.

Exploring Communication and Course Format: Conversation Frequency and Duration, Student Motives, and Perceived Teacher Approachability for Out-of-Class Contact

Science.gov (United States)

Brooks, Catherine F.; Young, Stacy L.

2016-01-01

This study explored how course instructional format (i.e., online, face-to-face, or hybrid) is related to the frequency and duration of out-of-class communication (OCC) between college instructors and students, to student motives for communicating with teachers, and to perceived teacher approachability for conversation outside of class. Though…

Differences between Drug-Induced and Contrast Media-Induced Adverse Reactions Based on Spontaneously Reported Adverse Drug Reactions.

Science.gov (United States)

Ryu, JiHyeon; Lee, HeeYoung; Suh, JinUk; Yang, MyungSuk; Kang, WonKu; Kim, EunYoung

2015-01-01

We analyzed differences between spontaneously reported drug-induced (not including contrast media) and contrast media-induced adverse reactions. Adverse drug reactions reported by an in-hospital pharmacovigilance center (St. Mary's teaching hospital, Daejeon, Korea) from 2010-2012 were classified as drug-induced or contrast media-induced. Clinical patterns, frequency, causality, severity, Schumock and Thornton's preventability, and type A/B reactions were recorded. The trends among causality tools measuring drug and contrast-induced adverse reactions were analyzed. Of 1,335 reports, 636 drug-induced and contrast media-induced adverse reactions were identified. The prevalence of spontaneously reported adverse drug reaction-related admissions revealed a suspected adverse drug reaction-reporting rate of 20.9/100,000 (inpatient, 0.021%) and 3.9/100,000 (outpatients, 0.004%). The most common adverse drug reaction-associated drug classes included nervous system agents and anti-infectives. Dermatological and gastrointestinal adverse drug reactions were most frequently and similarly reported between drug and contrast media-induced adverse reactions. Compared to contrast media-induced adverse reactions, drug-induced adverse reactions were milder, more likely to be preventable (9.8% vs. 1.1%, p contrast media-induced adverse reactions (56.6%, p = 0.066). Causality patterns differed between the two adverse reaction classes. The World Health Organization-Uppsala Monitoring Centre causality evaluation and Naranjo algorithm results significantly differed from those of the Korean algorithm version II (p contrast media-induced adverse reactions. The World Health Organization-Uppsala Monitoring Centre and Naranjo algorithm causality evaluation afforded similar results.

Class D management implementation approach of the first orbital mission of the Earth Venture series

Science.gov (United States)

Wells, James E.; Scherrer, John; Law, Richard; Bonniksen, Chris

2013-09-01

A key element of the National Research Council's Earth Science and Applications Decadal Survey called for the creation of the Venture Class line of low-cost research and application missions within NASA (National Aeronautics and Space Administration). One key component of the architecture chosen by NASA within the Earth Venture line is a series of self-contained stand-alone spaceflight science missions called "EV-Mission". The first mission chosen for this competitively selected, cost and schedule capped, Principal Investigator-led opportunity is the CYclone Global Navigation Satellite System (CYGNSS). As specified in the defining Announcement of Opportunity, the Principal Investigator is held responsible for successfully achieving the science objectives of the selected mission and the management approach that he/she chooses to obtain those results has a significant amount of freedom as long as it meets the intent of key NASA guidance like NPR 7120.5 and 7123. CYGNSS is classified under NPR 7120.5E guidance as a Category 3 (low priority, low cost) mission and carries a Class D risk classification (low priority, high risk) per NPR 8705.4. As defined in the NPR guidance, Class D risk classification allows for a relatively broad range of implementation strategies. The management approach that will be utilized on CYGNSS is a streamlined implementation that starts with a higher risk tolerance posture at NASA and that philosophy flows all the way down to the individual part level.

Class D Management Implementation Approach of the First Orbital Mission of the Earth Venture Series

Science.gov (United States)

Wells, James E.; Scherrer, John; Law, Richard; Bonniksen, Chris

2013-01-01

A key element of the National Research Council's Earth Science and Applications Decadal Survey called for the creation of the Venture Class line of low-cost research and application missions within NASA (National Aeronautics and Space Administration). One key component of the architecture chosen by NASA within the Earth Venture line is a series of self-contained stand-alone spaceflight science missions called "EV-Mission". The first mission chosen for this competitively selected, cost and schedule capped, Principal Investigator-led opportunity is the CYclone Global Navigation Satellite System (CYGNSS). As specified in the defining Announcement of Opportunity, the Principal Investigator is held responsible for successfully achieving the science objectives of the selected mission and the management approach that he/she chooses to obtain those results has a significant amount of freedom as long as it meets the intent of key NASA guidance like NPR 7120.5 and 7123. CYGNSS is classified under NPR 7120.5E guidance as a Category 3 (low priority, low cost) mission and carries a Class D risk classification (low priority, high risk) per NPR 8705.4. As defined in the NPR guidance, Class D risk classification allows for a relatively broad range of implementation strategies. The management approach that will be utilized on CYGNSS is a streamlined implementation that starts with a higher risk tolerance posture at NASA and that philosophy flows all the way down to the individual part level.

Effects of Brain-Based Learning Approach on Students' Motivation and Attitudes Levels in Science Class

Science.gov (United States)

Akyurek, Erkan; Afacan, Ozlem

2013-01-01

The purpose of the study was to examine the effect of brain-based learning approach on attitudes and motivation levels in 8th grade students' science classes. The main reason for examining attitudes and motivation levels, the effect of the short-term motivation, attitude shows the long-term effect. The pre/post-test control group research model…

A novel KFCM based fault diagnosis method for unknown faults in satellite reaction wheels.

Science.gov (United States)

Hu, Di; Sarosh, Ali; Dong, Yun-Feng

2012-03-01

Reaction wheels are one of the most critical components of the satellite attitude control system, therefore correct diagnosis of their faults is quintessential for efficient operation of these spacecraft. The known faults in any of the subsystems are often diagnosed by supervised learning algorithms, however, this method fails to work correctly when a new or unknown fault occurs. In such cases an unsupervised learning algorithm becomes essential for obtaining the correct diagnosis. Kernel Fuzzy C-Means (KFCM) is one of the unsupervised algorithms, although it has its own limitations; however in this paper a novel method has been proposed for conditioning of KFCM method (C-KFCM) so that it can be effectively used for fault diagnosis of both known and unknown faults as in satellite reaction wheels. The C-KFCM approach involves determination of exact class centers from the data of known faults, in this way discrete number of fault classes are determined at the start. Similarity parameters are derived and determined for each of the fault data point. Thereafter depending on the similarity threshold each data point is issued with a class label. The high similarity points fall into one of the 'known-fault' classes while the low similarity points are labeled as 'unknown-faults'. Simulation results show that as compared to the supervised algorithm such as neural network, the C-KFCM method can effectively cluster historical fault data (as in reaction wheels) and diagnose the faults to an accuracy of more than 91%. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

WOWW: A Solution Orientated Approach to Enhance Classroom Relationships and Behaviour within a Primary Three Class

Science.gov (United States)

Fernie, Lynne; Cubeddu, Daniela

2016-01-01

A Working on What Works (WOWW) approach was utilised over six sessions in a mainstream Scottish primary class to enhance classroom relationships and behaviours. The aim of the intervention was to manage everyday classroom problems within a natural classroom environment. WOWW incorporates positive psychology and implements a solution-focused…

Mechanisms before Reactions: A Mechanistic Approach to the Organic Chemistry Curriculum Based on Patterns of Electron Flow

Science.gov (United States)

Flynn, Alison B.; Ogilvie, William W.

2015-01-01

A significant redesign of the introductory organic chemistry curriculum at the authors' institution is described. There are two aspects that differ greatly from a typical functional group approach. First, organic reaction mechanisms and the electron-pushing formalism are taught before students have learned a single reaction. The conservation of…

A class Hierarchical, object-oriented approach to virtual memory management

Science.gov (United States)

Russo, Vincent F.; Campbell, Roy H.; Johnston, Gary M.

1989-01-01

The Choices family of operating systems exploits class hierarchies and object-oriented programming to facilitate the construction of customized operating systems for shared memory and networked multiprocessors. The software is being used in the Tapestry laboratory to study the performance of algorithms, mechanisms, and policies for parallel systems. Described here are the architectural design and class hierarchy of the Choices virtual memory management system. The software and hardware mechanisms and policies of a virtual memory system implement a memory hierarchy that exploits the trade-off between response times and storage capacities. In Choices, the notion of a memory hierarchy is captured by abstract classes. Concrete subclasses of those abstractions implement a virtual address space, segmentation, paging, physical memory management, secondary storage, and remote (that is, networked) storage. Captured in the notion of a memory hierarchy are classes that represent memory objects. These classes provide a storage mechanism that contains encapsulated data and have methods to read or write the memory object. Each of these classes provides specializations to represent the memory hierarchy.

First-Principles Approach to Model Electrochemical Reactions: Understanding the Fundamental Mechanisms behind Mg Corrosion

Science.gov (United States)

Surendralal, Sudarsan; Todorova, Mira; Finnis, Michael W.; Neugebauer, Jörg

2018-06-01

Combining concepts of semiconductor physics and corrosion science, we develop a novel approach that allows us to perform ab initio calculations under controlled potentiostat conditions for electrochemical systems. The proposed approach can be straightforwardly applied in standard density functional theory codes. To demonstrate the performance and the opportunities opened by this approach, we study the chemical reactions that take place during initial corrosion at the water-Mg interface under anodic polarization. Based on this insight, we derive an atomistic model that explains the origin of the anodic hydrogen evolution.

Explorations into Chemical Reactions and Biochemical Pathways.

Science.gov (United States)

Gasteiger, Johann

2016-12-01

A brief overview of the work in the research group of the present author on extracting knowledge from chemical reaction data is presented. Methods have been developed to calculate physicochemical effects at the reaction site. It is shown that these physicochemical effects can quite favourably be used to derive equations for the calculation of data on gas phase reactions and on reactions in solution such as aqueous acidity of alcohols or carboxylic acids or the hydrolysis of amides. Furthermore, it is shown that these physicochemical effects are quite effective for assigning reactions into reaction classes that correspond to chemical knowledge. Biochemical reactions constitute a particularly interesting and challenging task for increasing our understanding of living species. The BioPath.Database is a rich source of information on biochemical reactions and has been used for a variety of applications of chemical, biological, or medicinal interests. Thus, it was shown that biochemical reactions can be assigned by the physicochemical effects into classes that correspond to the classification of enzymes by the EC numbers. Furthermore, 3D models of reaction intermediates can be used for searching for novel enzyme inhibitors. It was shown in a combined application of chemoinformatics and bioinformatics that essential pathways of diseases can be uncovered. Furthermore, a study showed that bacterial flavor-forming pathways can be discovered. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prediction of Protein Structural Class Based on Gapped-Dipeptides and a Recursive Feature Selection Approach

Directory of Open Access Journals (Sweden)

Taigang Liu

2015-12-01

Full Text Available The prior knowledge of protein structural class may offer useful clues on understanding its functionality as well as its tertiary structure. Though various significant efforts have been made to find a fast and effective computational approach to address this problem, it is still a challenging topic in the field of bioinformatics. The position-specific score matrix (PSSM profile has been shown to provide a useful source of information for improving the prediction performance of protein structural class. However, this information has not been adequately explored. To this end, in this study, we present a feature extraction technique which is based on gapped-dipeptides composition computed directly from PSSM. Then, a careful feature selection technique is performed based on support vector machine-recursive feature elimination (SVM-RFE. These optimal features are selected to construct a final predictor. The results of jackknife tests on four working datasets show that our method obtains satisfactory prediction accuracies by extracting features solely based on PSSM and could serve as a very promising tool to predict protein structural class.

Alternative approach for fire suppression of class A, B and C fires in gloveboxes

Energy Technology Data Exchange (ETDEWEB)

Rosenberger, Mark S [Los Alamos National Laboratory; Tsiagkouris, James A [Los Alamos National Laboratory

2011-02-10

Department of Energy (DOE) Orders and National Fire Protection Association (NFPA) Codes and Standards require fire suppression in gloveboxes. Several potential solutions have been and are currently being considered at Los Alamos National Laboratory (LANL). The objective is to provide reliable, minimally invasive, and seismically robust fire suppression capable of extinguishing Class A, B, and C fires; achieve compliance with DOE and NFPA requirements; and provide value-added improvements to fire safety in gloveboxes. This report provides a brief summary of current approaches and also documents the successful fire tests conducted to prove that one approach, specifically Fire Foe{trademark} tubes, is capable of achieving the requirement to provide reliable fire protection in gloveboxes in a cost-effective manner.

Transformation of Teacher Practice Using Mobile Technology with One-to-One Classes: M-Learning Pedagogical Approaches

Science.gov (United States)

Lindsay, Lucie

2016-01-01

The rapid global uptake of mobile technology is reflected in pioneering New Zealand schools. Teachers of classes where each student uses a mobile device were surveyed on how frequently they use various mobile learning activities and asked to describe the new pedagogical opportunities it offers. The teachers' m-learning pedagogical approaches and…

Molecule-Level g-C3N4 Coordinated Transition Metals as a New Class of Electrocatalysts for Oxygen Electrode Reactions

KAUST Repository

Zheng, Yao

2017-02-21

Organometallic complexes with metal-nitrogen/carbon (M-N/C) coordination are the most important alternatives to precious metal catalysts for oxygen reduction and evolution reactions (ORR and OER) in energy conversion devices. Here, we designed and developed a range of molecule-level graphitic carbon nitride (g-C3N4) coordinated transition metals (M-C3N4) as a new generation of M-N/C catalysts for these oxygen electrode reactions. As a proof-of-concept example, we conducted theoretical evaluation and experimental validation on a cobalt-C3N4 catalyst with a desired molecular configuration, which possesses comparable electrocatalytic activity to that of precious metal benchmarks for the ORR and OER in alkaline media. The correlation of experimental and computational results confirms that this high activity originates from the precise M-N2 coordination in the g-C3N4 matrix. Moreover, the reversible ORR/OER activity trend for a wide variety of M-C3N4 complexes has been constructed to provide guidance for the molecular design of this promising class of catalysts.

Development of a novel fingerprint for chemical reactions and its application to large-scale reaction classification and similarity.

Science.gov (United States)

Schneider, Nadine; Lowe, Daniel M; Sayle, Roger A; Landrum, Gregory A

2015-01-26

Fingerprint methods applied to molecules have proven to be useful for similarity determination and as inputs to machine-learning models. Here, we present the development of a new fingerprint for chemical reactions and validate its usefulness in building machine-learning models and in similarity assessment. Our final fingerprint is constructed as the difference of the atom-pair fingerprints of products and reactants and includes agents via calculated physicochemical properties. We validated the fingerprints on a large data set of reactions text-mined from granted United States patents from the last 40 years that have been classified using a substructure-based expert system. We applied machine learning to build a 50-class predictive model for reaction-type classification that correctly predicts 97% of the reactions in an external test set. Impressive accuracies were also observed when applying the classifier to reactions from an in-house electronic laboratory notebook. The performance of the novel fingerprint for assessing reaction similarity was evaluated by a cluster analysis that recovered 48 out of 50 of the reaction classes with a median F-score of 0.63 for the clusters. The data sets used for training and primary validation as well as all python scripts required to reproduce the analysis are provided in the Supporting Information.

Social Class and Work-Related Decisions: Measurement, Theory, and Social Mobility

Science.gov (United States)

Fouad, Nadya A.; Fitzpatrick, Mary E.

2009-01-01

In this reaction to Diemer and Ali's article, "Integrating Social Class Into Vocational Psychology: Theory and Practice Implications," the authors point out concerns with binary schema of social class, highlight the contribution of social class to the social cognitive career theory, argue for a more nuanced look at ways that work…

A Systematic Approach for the Design and Analysis of Reaction-Separation Systems with Recycle

DEFF Research Database (Denmark)

Gani, Rafiqul; Jimenez, Edgar Ramirez

2004-01-01

This paper presents a methodology for a systematic model-based analysis and the results obtained from it for an integrated design and analysis of reaction-separation systems with recycle. The methodology (systematic approach) consists of three stages where stage 1 identifies the limiting values...

Use of nanostructure initiator mass spectrometry (NIMS to deduce selectivity of reaction in glycoside hydrolases

Directory of Open Access Journals (Sweden)

Kai eDeng

2015-10-01

Full Text Available Chemically synthesized nanostructure-initiator mass spectrometry (NIMS probes derivatized with tetrasaccharides were used to study the reactivity of representative Clostridium thermocellum β-glucosidase, endoglucanases and cellobiohydrolase. Diagnostic patterns for reactions of these different classes of enzymes were observed. Results show sequential removal of glucose by the β-glucosidase and a progressive increase in specificity of reaction from endoglucanases to cellobiohydrolase. Time-dependent reactions of these polysaccharide-selective enzymes were modeled by numerical integration, which provides a quantitative basis to make functional distinctions among a continuum of naturally evolved catalytic properties. Consequently, our method, which combines automated protein translation with high-sensitivity and time-dependent detection of multiple products, provides a new approach to annotate glycoside hydrolase phylogenetic trees with functional measurements.

Catalytic Organometallic Reactions of Ammonia

Science.gov (United States)

Klinkenberg, Jessica L.

2012-01-01

Until recently, ammonia had rarely succumbed to catalytic transformations with homogeneous catalysts, and the development of such reactions that are selective for the formation of single products under mild conditions has encountered numerous challenges. However, recently developed catalysts have allowed several classes of reactions to create products with nitrogen-containing functional groups from ammonia. These reactions include hydroaminomethylation, reductive amination, alkylation, allylic substitution, hydroamination, and cross-coupling. This Minireview describes examples of these processes and the factors that control catalyst activity and selectivity. PMID:20857466

On the implicit programming approach in a class of mathematical programs with equilibrium constraints

Czech Academy of Sciences Publication Activity Database

Outrata, Jiří; Červinka, Michal

2009-01-01

Roč. 38, 4B (2009), s. 1557-1574 ISSN 0324-8569 R&D Projects: GA ČR GA201/09/1957 Institutional research plan: CEZ:AV0Z10750506 Keywords : mathematical problem with equilibrium constraint * state constraints * implicit programming * calmness * exact penalization Subject RIV: BA - General Mathematics Impact factor: 0.378, year: 2009 http://library.utia.cas.cz/separaty/2010/MTR/outrata-on the implicit programming approach in a class of mathematical programs with equilibrium constraints.pdf

Novel Reagents for Multi-Component Reactions

Science.gov (United States)

Wang, Yanguang; Basso, Andrea; Nenajdenko, Valentine G.; Gulevich, Anton V.; Krasavin, Mikhail; Bushkova, Ekaterina; Parchinsky, Vladislav; Banfi, Luca; Basso, Andrea; Cerulli, Valentina; Guanti, Giuseppe; Riva, Renata; Rozentsveig, Igor B.; Rozentsveig, Gulnur N.; Popov, Aleksandr V.; Serykh, Valeriy J.; Levkovskaya, Galina G.; Cao, Song; Shen, Li; Liu, Nianjin; Wu, Jingjing; Li, Lina; Qian, Xuhong; Chen, Xiaopeng; Wang, Hongbo; Feng, Jinwu; Wang, Yanguang; Lu, Ping; Heravi, Majid M.; Sadjadi, Samaheh; Kazemizadeh, Ali Reza; Ramazani, Ali; Kudyakova, Yulia S.; Goryaeva, Marina V.; Burgart, Yanina V.; Saloutin, Victor I.; Mossetti, Riccardo; Pirali, Tracey; Tron, Gian Cesare; Rozhkova, Yulia S.; Mayorova, Olga A.; Shklyaev, Yuriy V.; Zhdanko, Alexander G.; Nenajdenko, Valentine G.; Stryapunina, Olga G.; Plekhanova, Irina V.; Glushkov, Vladimir A.; Shklyaev, Yurii V.

Ketenimines are a class of versatile and highly reactive intermediates that can participate in a variety of organic reactions, such as nucleophilic additions, radical additions, [2 + 2] and [2 + 4] cycloadditions, and sigmatropic rearrangements. In this presentation, we report on a series of multi-component reactions that involve a ketenimine intermediate. These reactions could furnish diverse heterocyclic compounds, including functionalized iminocoumarin, iminodihydroqunolines, iminothiochromens, pyrrolines, isoquinolines, pyridines, β-lactams, imino-1,2-dihydrocoumarins, and benzimidazoles.

Class teacher’s gender culture

OpenAIRE

GOGOL-SAVRIY M.V.

2012-01-01

The article considers the gender approach in the professional culture of a class teacher. The nature, levels and sublevels of class teacher’s gender culture development are defined. Taking into consideration the concepts of leading researchers, the essence of components of class teacher’s gender culture is discovered according to the levels of its development as professional and educational activity. Proceeding from the results of the diagnostics of class teachers’ gender culture at comprehen...

A Remote Sensing Approach to Estimate Vertical Profile Classes of Phytoplankton in a Eutrophic Lake

Directory of Open Access Journals (Sweden)

Kun Xue

2015-10-01

Full Text Available The extension and frequency of algal blooms in surface waters can be monitored using remote sensing techniques, yet knowledge of their vertical distribution is fundamental to determine total phytoplankton biomass and understanding temporal variability of surface conditions and the underwater light field. However, different vertical distribution classes of phytoplankton may occur in complex inland lakes. Identification of the vertical profile classes of phytoplankton becomes the key and first step to estimate its vertical profile. The vertical distribution profile of phytoplankton is based on a weighted integral of reflected light from all depths and is difficult to determine by reflectance data alone. In this study, four Chla vertical profile classes (vertically uniform, Gaussian, exponential and hyperbolic were found to occur in three in situ vertical surveys (28 May, 19–24 July and 10–12 October in a shallow eutrophic lake, Lake Chaohu. We developed and validated a classification and regression tree (CART to determine vertical phytoplankton biomass profile classes. This was based on an algal bloom index (Normalized Difference algal Bloom Index, NDBI applied to both in situ remote sensing reflectance (Rrs and MODIS Rayleigh-corrected reflectance (Rrc data in combination with data of local wind speed. The results show the potential of retrieving Chla vertical profiles information from integrated information sources following a decision tree approach.

Randomness in multi-step direct reactions

International Nuclear Information System (INIS)

Koning, A.J.; Akkermans, J.M.

1991-01-01

The authors propose a quantum-statistical framework that provides an integrated perspective on the differences and similarities between the many current models for multi-step direct reactions in the continuum. It is argued that to obtain a statistical theory two physically different approaches are conceivable to postulate randomness, respectively called leading-particle statistics and residual-system statistics. They present a new leading-particle statistics theory for multi-step direct reactions. It is shown that the model of Feshbach et al. can be derived as a simplification of this theory and thus can be founded solely upon leading-particle statistics. The models developed by Tamura et al. and Nishioka et al. are based upon residual-system statistics and hence fall into a physically different class of multi-step direct theories, although the resulting cross-section formulae for the important first step are shown to be the same. The widely used semi-classical models such as the generalized exciton model can be interpreted as further phenomenological simplification of the leading-particle statistics theory

Serpentinization reaction pathways: implications for modeling approach

Energy Technology Data Exchange (ETDEWEB)

Janecky, D.R.

1986-01-01

Experimental seawater-peridotite reaction pathways to form serpentinites at 300/sup 0/C, 500 bars, can be accurately modeled using the EQ3/6 codes in conjunction with thermodynamic and kinetic data from the literature and unpublished compilations. These models provide both confirmation of experimental interpretations and more detailed insight into hydrothermal reaction processes within the oceanic crust. The accuracy of these models depends on careful evaluation of the aqueous speciation model, use of mineral compositions that closely reproduce compositions in the experiments, and definition of realistic reactive components in terms of composition, thermodynamic data, and reaction rates.

Combining choice experiments with psychometric scales to assess the social acceptability of wind energy projects: A latent class approach

International Nuclear Information System (INIS)

Strazzera, Elisabetta; Mura, Marina; Contu, Davide

2012-01-01

A choice experiment exercise is combined with psychometric scales in order: (1) to identify factors that explain support/opposition toward a wind energy development project; and (2) to assess (monetary) trade-offs between attributes of the project. A Latent Class estimator is fitted to the data, and different utility parameters are estimated, conditional on class allocation. It is found that the probability of class membership depends on specific psychometric variables. Visual impacts on valued sites are an important factor of opposition toward a project, and this effect is magnified when identity values are attached to the specific site, so much that no trade-off would be acceptable for a class of individuals characterized by strong place attachment. Conversely, other classes of individuals are willing to accept compensations, in form of private and/or public benefits. The distribution of benefits in the territory, and preservation of the option value related to the possible development of an archeological site, are important for a class of individuals concerned with the sustainability of the local economy. - Highlights: ► A Choice Experiment approach is used to assess acceptability of a wind farm project. ► Psychometric variables are used to model heterogeneity in a Latent Class model. ► No trade-off would be acceptable for a class of individuals. ► Another class of individuals is interested in private benefits. ► Other classes are interested in public benefits and sustainability of the development.

Contribution to an effective design method for stationary reaction-diffusion patterns

International Nuclear Information System (INIS)

Szalai, István; Horváth, Judit; De Kepper, Patrick

2015-01-01

The British mathematician Alan Turing predicted, in his seminal 1952 publication, that stationary reaction-diffusion patterns could spontaneously develop in reacting chemical or biochemical solutions. The first two clear experimental demonstrations of such a phenomenon were not made before the early 1990s when the design of new chemical oscillatory reactions and appropriate open spatial chemical reactors had been invented. Yet, the number of pattern producing reactions had not grown until 2009 when we developed an operational design method, which takes into account the feeding conditions and other specificities of real open spatial reactors. Since then, on the basis of this method, five additional reactions were shown to produce stationary reaction-diffusion patterns. To gain a clearer view on where our methodical approach on the patterning capacity of a reaction stands, numerical studies in conditions that mimic true open spatial reactors were made. In these numerical experiments, we explored the patterning capacity of Rabai's model for pH driven Landolt type reactions as a function of experimentally attainable parameters that control the main time and length scales. Because of the straightforward reversible binding of protons to carboxylate carrying polymer chains, this class of reaction is at the base of the chemistry leading to most of the stationary reaction-diffusion patterns presently observed. We compare our model predictions with experimental observations and comment on agreements and differences

Contribution to an effective design method for stationary reaction-diffusion patterns

Energy Technology Data Exchange (ETDEWEB)

Szalai, István; Horváth, Judit [Laboratory of Nonlinear Chemical Dynamics, Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, H-1518 Budapest 112 (Hungary); De Kepper, Patrick [Centre de Recherche Paul Pascal, CNRS, University of Bordeaux, 115, Avenue Schweitzer, F-33600 Pessac (France)

2015-06-15

The British mathematician Alan Turing predicted, in his seminal 1952 publication, that stationary reaction-diffusion patterns could spontaneously develop in reacting chemical or biochemical solutions. The first two clear experimental demonstrations of such a phenomenon were not made before the early 1990s when the design of new chemical oscillatory reactions and appropriate open spatial chemical reactors had been invented. Yet, the number of pattern producing reactions had not grown until 2009 when we developed an operational design method, which takes into account the feeding conditions and other specificities of real open spatial reactors. Since then, on the basis of this method, five additional reactions were shown to produce stationary reaction-diffusion patterns. To gain a clearer view on where our methodical approach on the patterning capacity of a reaction stands, numerical studies in conditions that mimic true open spatial reactors were made. In these numerical experiments, we explored the patterning capacity of Rabai's model for pH driven Landolt type reactions as a function of experimentally attainable parameters that control the main time and length scales. Because of the straightforward reversible binding of protons to carboxylate carrying polymer chains, this class of reaction is at the base of the chemistry leading to most of the stationary reaction-diffusion patterns presently observed. We compare our model predictions with experimental observations and comment on agreements and differences.

Extension of a Kinetic-Theory Approach for Computing Chemical-Reaction Rates to Reactions with Charged Particles

Science.gov (United States)

Liechty, Derek S.; Lewis, Mark J.

2010-01-01

Recently introduced molecular-level chemistry models that predict equilibrium and nonequilibrium reaction rates using only kinetic theory and fundamental molecular properties (i.e., no macroscopic reaction rate information) are extended to include reactions involving charged particles and electronic energy levels. The proposed extensions include ionization reactions, exothermic associative ionization reactions, endothermic and exothermic charge exchange reactions, and other exchange reactions involving ionized species. The extensions are shown to agree favorably with the measured Arrhenius rates for near-equilibrium conditions.

Oxidation reaction of polyether-based material and its suppression in lithium rechargeable battery using 4 V class cathode, LiNi1/3Mn1/3Co1/3O2.

Science.gov (United States)

Kobayashi, Takeshi; Kobayashi, Yo; Tabuchi, Masato; Shono, Kumi; Ohno, Yasutaka; Mita, Yuichi; Miyashiro, Hajime

2013-12-11

The all solid-state lithium battery with polyether-based solid polymer electrolyte (SPE) is regarded as one of next-generation lithium batteries, and has potential for sufficient safety because of the flammable-electrolyte-free system. It has been believed that polyether-based SPE is oxidized at the polymer/electrode interface with 4 V class cathodes. Therefore, it has been used for electric devices such as organic transistor, and lithium battery under 3 V. We estimated decomposition reaction of polyether used as SPE of all solid-state lithium battery. We first identified the decomposed parts of polyether-based SPE and the conservation of most main chain framework, considering the results of SPE analysis after long cycle operations. The oxidation reaction was found to occur slightly at the ether bond in the main chain with the branched side chain. Moreover, we resolved the issue by introducing a self-sacrificing buffer layer at the interface. The introduction of sodium carboxymethyl cellulose (CMC) to the 4 V class cathode surface led to the suppression of SPE decomposition at the interface as a result of the preformation of a buffer layer from CMC, which was confirmed by the irreversible exothermic reaction during the first charge, using electrochemical calorimetry. The attained 1500 cycle operation is 1 order of magnitude longer than those of previously reported polymer systems, and compatible with those of reported commercial liquid systems. The above results indicate to proceed to an intensive research toward the realization of 4 V class "safe" lithium polymer batteries without flammable liquid electrolyte.

ReactionMap: an efficient atom-mapping algorithm for chemical reactions.

Science.gov (United States)

Fooshee, David; Andronico, Alessio; Baldi, Pierre

2013-11-25

Large databases of chemical reactions provide new data-mining opportunities and challenges. Key challenges result from the imperfect quality of the data and the fact that many of these reactions are not properly balanced or atom-mapped. Here, we describe ReactionMap, an efficient atom-mapping algorithm. Our approach uses a combination of maximum common chemical subgraph search and minimization of an assignment cost function derived empirically from training data. We use a set of over 259,000 balanced atom-mapped reactions from the SPRESI commercial database to train the system, and we validate it on random sets of 1000 and 17,996 reactions sampled from this pool. These large test sets represent a broad range of chemical reaction types, and ReactionMap correctly maps about 99% of the atoms and about 96% of the reactions, with a mean time per mapping of 2 s. Most correctly mapped reactions are mapped with high confidence. Mapping accuracy compares favorably with ChemAxon's AutoMapper, versions 5 and 6.1, and the DREAM Web tool. These approaches correctly map 60.7%, 86.5%, and 90.3% of the reactions, respectively, on the same data set. A ReactionMap server is available on the ChemDB Web portal at http://cdb.ics.uci.edu .

Culture and social class.

Science.gov (United States)

Miyamoto, Yuri

2017-12-01

A large body of research in Western cultures has demonstrated the psychological and health effects of social class. This review outlines a cultural psychological approach to social stratification by comparing psychological and health manifestations of social class across Western and East Asian cultures. These comparisons suggest that cultural meaning systems shape how people make meaning and respond to material/structural conditions associated with social class, thereby leading to culturally divergent manifestations of social class. Specifically, unlike their counterparts in Western cultures, individuals of high social class in East Asian cultures tend to show high conformity and other-orientated psychological attributes. In addition, cultures differ in how social class impacts health (i.e. on which bases, through which pathways, and to what extent). Copyright © 2017 Elsevier Ltd. All rights reserved.

Analytically solvable models of reaction-diffusion systems

Energy Technology Data Exchange (ETDEWEB)

Zemskov, E P; Kassner, K [Institut fuer Theoretische Physik, Otto-von-Guericke-Universitaet, Universitaetsplatz 2, 39106 Magdeburg (Germany)

2004-05-01

We consider a class of analytically solvable models of reaction-diffusion systems. An analytical treatment is possible because the nonlinear reaction term is approximated by a piecewise linear function. As particular examples we choose front and pulse solutions to illustrate the matching procedure in the one-dimensional case.

Assessing Adolescents' Understanding of and Reactions to Stress in Different Cultures: Results of a Mixed-Methods Approach

Science.gov (United States)

Nastasi, Bonnie K.; Hitchcock, John H.; Burkholder, Gary; Varjas, Kristen; Sarkar, Sreeroopa; Jayasena, Asoka

2007-01-01

This article expands on an emerging mixed-method approach for validating culturally-specific constructs (see Hitchcock et al., 2005). Previous work established an approach for dealing with cultural impacts when assessing psychological constructs and the current article extends these efforts into studying stress reactions among adolescents in Sri…

A multi-component reaction towards the development of highly modular hydrogelators.

Science.gov (United States)

Sundén, Henrik; Sauvée, Claire; Haukka, Matti; Stöm, Anna

2018-04-16

Herein we report a multi-component reaction approach for the development of a new class of hydrogelators based on the OxoTriphenylHexanOate (OTHO) backbone. A focused library of OTHOs has been synthesized and their hydrogelation features evaluated. The two most potent hydrogelators were studied by rheology revealing different gel strengths, appearances and thixotropic behaviours. The new gelators showcase the versatility of the OTHO backbone as a platform for the design of functionalized hydrogels with tunable gel properties. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adaptive exponential synchronization of delayed neural networks with reaction-diffusion terms

International Nuclear Information System (INIS)

Sheng Li; Yang Huizhong; Lou Xuyang

2009-01-01

This paper presents an exponential synchronization scheme for a class of neural networks with time-varying and distributed delays and reaction-diffusion terms. An adaptive synchronization controller is derived to achieve the exponential synchronization of the drive-response structure of neural networks by using the Lyapunov stability theory. At the same time, the update laws of parameters are proposed to guarantee the synchronization of delayed neural networks with all parameters unknown. It is shown that the approaches developed here extend and improve the ideas presented in recent literatures.

A convergent approach to the total synthesis of telmisartan via a Suzuki cross-coupling reaction between two functionalized benzimidazoles.

Science.gov (United States)

Martin, Alex D; Siamaki, Ali R; Belecki, Katherine; Gupton, B Frank

2015-02-06

A direct and efficient total synthesis has been developed for telmisartan, a widely prescribed treatment for hypertension. This approach brings together two functionalized benzimidazoles using a high-yielding Suzuki reaction that can be catalyzed by either a homogeneous palladium source or graphene-supported palladium nanoparticles. The ability to perform the cross-coupling reaction was facilitated by the regio-controlled preparation of the 2-bromo-1-methylbenzimidazole precursor. This convergent approach provides telmisartan in an overall yield of 72% while circumventing many issues associated with previously reported processes.

Perceived risk associated with ecstasy use: a latent class analysis approach

Science.gov (United States)

Martins, SS; Carlson, RG; Alexandre, PK; Falck, RS

2011-01-01

This study aims to define categories of perceived health problems among ecstasy users based on observed clustering of their perceptions of ecstasy-related health problems. Data from a community sample of ecstasy users (n=402) aged 18 to 30, in Ohio, was used in this study. Data was analyzed via Latent Class Analysis (LCA) and Regression. This study identified five different subgroups of ecstasy users based on their perceptions of health problems they associated with their ecstasy use. Almost one third of the sample (28.9%) belonged to a class with “low level of perceived problems” (Class 4). About one fourth (25.6%) of the sample (Class 2), had high probabilities of “perceiving problems on sexual-related items”, but generally low or moderate probabilities of perceiving problems in other areas. Roughly one-fifth of the sample (21.1%, Class 1) had moderate probabilities of perceiving ecstasy health-related problems in all areas. A small proportion of respondents (11.9%, Class 5) had high probabilities of reporting “perceived memory and cognitive problems, and of perceiving “ecstasy related-problems in all areas” (12.4%, Class 3). A large proportion of ecstasy users perceive either low or moderate risk associated with their ecstasy use. It is important to further investigate whether lower levels of risk perception are associated with persistence of ecstasy use. PMID:21296504

Applications of Palladium-Catalyzed C-N Cross-Coupling Reactions.

Science.gov (United States)

Ruiz-Castillo, Paula; Buchwald, Stephen L

2016-10-12

Pd-catalyzed cross-coupling reactions that form C-N bonds have become useful methods to synthesize anilines and aniline derivatives, an important class of compounds throughout chemical research. A key factor in the widespread adoption of these methods has been the continued development of reliable and versatile catalysts that function under operationally simple, user-friendly conditions. This review provides an overview of Pd-catalyzed N-arylation reactions found in both basic and applied chemical research from 2008 to the present. Selected examples of C-N cross-coupling reactions between nine classes of nitrogen-based coupling partners and (pseudo)aryl halides are described for the synthesis of heterocycles, medicinally relevant compounds, natural products, organic materials, and catalysts.

Computational Approach to Electron Charge Transfer Reactions

DEFF Research Database (Denmark)

Jónsson, Elvar Örn

-molecular mechanics scheme, and tools to analyse statistical data and generate relative free energies and free energy surfaces. The methodology is applied to several charge transfer species and reactions in chemical environments - chemical in the sense that solvent, counter ions and substrate surfaces are taken...... in to account - which directly influence the reactants and resulting reaction through both physical and chemical interactions. All methods are though general and can be applied to different types of chemistry. First, the basis of the various theoretical tools is presented and applied to several test systems...... and asymmetric charge transfer reactions between several first-row transition metals in water. The results are compared to experiments and rationalised with classical analytic expressions. Shortcomings of the methods are accounted for with clear steps towards improved accuracy. Later the analysis is extended...

The statistics of multi-step direct reactions

International Nuclear Information System (INIS)

Koning, A.J.; Akkermans, J.M.

1991-01-01

We propose a quantum-statistical framework that provides an integrated perspective on the differences and similarities between the many current models for multi-step direct reactions in the continuum. It is argued that to obtain a statistical theory two physically different approaches are conceivable to postulate randomness, respectively called leading-particle statistics and residual-system statistics. We present a new leading-particle statistics theory for multi-step direct reactions. It is shown that the model of Feshbach et al. can be derived as a simplification of this theory and thus can be founded solely upon leading-particle statistics. The models developed by Tamura et al. and Nishioka et al. are based upon residual-system statistics and hence fall into a physically different class of multi-step direct theories, although the resulting cross-section formulae for the important first step are shown to be the same. The widely used semi-classical models such as the generalized exciton model can be interpreted as further phenomenological simplifications of the leading-particle statistics theory. A more comprehensive exposition will appear before long. (author). 32 refs, 4 figs

Progress in microscopic direct reaction modeling of nucleon induced reactions

Energy Technology Data Exchange (ETDEWEB)

Dupuis, M.; Bauge, E.; Hilaire, S.; Lechaftois, F.; Peru, S.; Pillet, N.; Robin, C. [CEA, DAM, DIF, Arpajon (France)

2015-12-15

A microscopic nuclear reaction model is applied to neutron elastic and direct inelastic scatterings, and pre-equilibrium reaction. The JLM folding model is used with nuclear structure information calculated within the quasi-particle random phase approximation implemented with the Gogny D1S interaction. The folding model for direct inelastic scattering is extended to include rearrangement corrections stemming from both isoscalar and isovector density variations occurring during a transition. The quality of the predicted (n,n), (n,n{sup '}), (n,xn) and (n,n{sup '}γ) cross sections, as well as the generality of the present microscopic approach, shows that it is a powerful tool that can help improving nuclear reactions data quality. Short- and long-term perspectives are drawn to extend the present approach to more systems, to include missing reactions mechanisms, and to consistently treat both structure and reaction problems. (orig.)

Chemical potential and reaction electronic flux in symmetry controlled reactions.

Science.gov (United States)

Vogt-Geisse, Stefan; Toro-Labbé, Alejandro

2016-07-15

In symmetry controlled reactions, orbital degeneracies among orbitals of different symmetries can occur along a reaction coordinate. In such case Koopmans' theorem and the finite difference approximation provide a chemical potential profile with nondifferentiable points. This results in an ill-defined reaction electronic flux (REF) profile, since it is defined as the derivative of the chemical potential with respect to the reaction coordinate. To overcome this deficiency, we propose a new way for the calculation of the chemical potential based on a many orbital approach, suitable for reactions in which symmetry is preserved. This new approach gives rise to a new descriptor: symmetry adapted chemical potential (SA-CP), which is the chemical potential corresponding to a given irreducible representation of a symmetry group. A corresponding symmetry adapted reaction electronic flux (SA-REF) is also obtained. Using this approach smooth chemical potential profiles and well defined REFs are achieved. An application of SA-CP and SA-REF is presented by studying the Cs enol-keto tautomerization of thioformic acid. Two SA-REFs are obtained, JA'(ξ) and JA'' (ξ). It is found that the tautomerization proceeds via an in-plane delocalized 3-center 4-electron O-H-S hypervalent bond which is predicted to exist only in the transition state (TS) region. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Reaction time for trimolecular reactions in compartment-based reaction-diffusion models

Science.gov (United States)

Li, Fei; Chen, Minghan; Erban, Radek; Cao, Yang

2018-05-01

Trimolecular reaction models are investigated in the compartment-based (lattice-based) framework for stochastic reaction-diffusion modeling. The formulae for the first collision time and the mean reaction time are derived for the case where three molecules are present in the solution under periodic boundary conditions. For the case of reflecting boundary conditions, similar formulae are obtained using a computer-assisted approach. The accuracy of these formulae is further verified through comparison with numerical results. The presented derivation is based on the first passage time analysis of Montroll [J. Math. Phys. 10, 753 (1969)]. Montroll's results for two-dimensional lattice-based random walks are adapted and applied to compartment-based models of trimolecular reactions, which are studied in one-dimensional or pseudo one-dimensional domains.

General approach to standardization of the solid-phase radioimmunoassay for quantitation of class-specific antibodies

Energy Technology Data Exchange (ETDEWEB)

Zollinger, W D; Boslego, J W [Walter Reed Army Inst. of Research, Washington, DC (USA)

1981-10-30

The feasibility of using an anti-human immunoglobulin/human immunoglobulin/(/sup 125/I)anti-human immunoglobulin 'sandwich' in a solid-phase radioimmunoassay to produce a standard curve which could be used to quantitate antigen-specific antibody of a particular immunoglobulin class was investigated. The amount of secondary antibody (SAb) bound was determined as a function of whether the primary antibody (PAb) was bound to its specific solid-phase antigen or by a solid-phase anti-human immunoglobulin. No significant difference between the two values was observed. Quantitation of anti-tetanus toxoid antibody by this method was in a good agreement with quantitative precipitin tests. Comparison of SAb binding as a function of the way the PAb is bound was extended to class-specific PAb by use of murine monoclonal antibodies to meningococcal antigens. In most cases somewhat greater binding of SAb occurred when PAb was bound to antigen, but in several cases where low avidity antibody and/or poor quality antigens were used, greater SAb binding occurred when PAb was bound by anti-mouse immunoglobulin. The results indicate that this approach may be useful as a general method for standardizing the SPRIA and other solid-phase immunoassays such as the ELISA to measure class-specific antibody.

Formation of flavour compounds in the Maillard reaction

NARCIS (Netherlands)

Boekel, van M.A.J.S.

2006-01-01

This paper discusses the importance of the Maillard reaction for food quality and focuses on flavour compound formation. The most important classes of Maillard flavour compounds are indicated and it is shown where they are formed in the Maillard reaction. Some emphasis is given on the kinetics of

Wang-Landau Reaction Ensemble Method: Simulation of Weak Polyelectrolytes and General Acid-Base Reactions.

Science.gov (United States)

Landsgesell, Jonas; Holm, Christian; Smiatek, Jens

2017-02-14

We present a novel method for the study of weak polyelectrolytes and general acid-base reactions in molecular dynamics and Monte Carlo simulations. The approach combines the advantages of the reaction ensemble and the Wang-Landau sampling method. Deprotonation and protonation reactions are simulated explicitly with the help of the reaction ensemble method, while the accurate sampling of the corresponding phase space is achieved by the Wang-Landau approach. The combination of both techniques provides a sufficient statistical accuracy such that meaningful estimates for the density of states and the partition sum can be obtained. With regard to these estimates, several thermodynamic observables like the heat capacity or reaction free energies can be calculated. We demonstrate that the computation times for the calculation of titration curves with a high statistical accuracy can be significantly decreased when compared to the original reaction ensemble method. The applicability of our approach is validated by the study of weak polyelectrolytes and their thermodynamic properties.

Second-order splitting schemes for a class of reactive systems

International Nuclear Information System (INIS)

Ren Zhuyin; Pope, Stephen B.

2008-01-01

We consider the numerical time integration of a class of reaction-transport systems that are described by a set of ordinary differential equations for primary variables. In the governing equations, the terms involved may require the knowledge of secondary variables, which are functions of the primary variables. Specifically, we consider the case where, given the primary variables, the evaluation of the secondary variables is computationally expensive. To solve this class of reaction-transport equations, we develop and demonstrate several computationally efficient splitting schemes, wherein the portions of the governing equations containing chemical reaction terms are separated from those parts containing the transport terms. A computationally efficient solution to the transport sub-step is achieved through the use of linearization or predictor-corrector methods. The splitting schemes are applied to the reactive flow in a continuously stirred tank reactor (CSTR) with the Davis-Skodjie reaction model, to the CO+H 2 oxidation in a CSTR with detailed chemical kinetics, and to a reaction-diffusion system with an extension of the Oregonator model of the Belousov-Zhabotinsky reaction. As demonstrated in the test problems, the proposed splitting schemes, which yield efficient solutions to the transport sub-step, achieve second-order accuracy in time

Beyond mean-field approach to heavy-ion reactions around the Coulomb barrier

Directory of Open Access Journals (Sweden)

Ayik Sakir

2011-10-01

Full Text Available Dissipation and fluctuations of one-body observables in heavy-ion reactions around the Coulomb barrier are investigated with a microscopic stochastic mean-field approach. By projecting the stochastic meanfield dynamics on a suitable collective path, transport coefficients associated with the relative distance between colliding nuclei and a fragment mass are extracted. Although microscopic mean-field approach is know to underestimate the variance of fragment mass distribution, the description of the variance is much improved by the stochastic mean-field method. While fluctuations are consistent with the empirical (semiclassical analysis of the experimental data, concerning mean values of macroscopic variables the semiclassical description breaks down below the Coulomb barrier.

Maximal Predictability Approach for Identifying the Right Descriptors for Electrocatalytic Reactions.

Science.gov (United States)

Krishnamurthy, Dilip; Sumaria, Vaidish; Viswanathan, Venkatasubramanian

2018-02-01

Density functional theory (DFT) calculations are being routinely used to identify new material candidates that approach activity near fundamental limits imposed by thermodynamics or scaling relations. DFT calculations are associated with inherent uncertainty, which limits the ability to delineate materials (distinguishability) that possess high activity. Development of error-estimation capabilities in DFT has enabled uncertainty propagation through activity-prediction models. In this work, we demonstrate an approach to propagating uncertainty through thermodynamic activity models leading to a probability distribution of the computed activity and thereby its expectation value. A new metric, prediction efficiency, is defined, which provides a quantitative measure of the ability to distinguish activity of materials and can be used to identify the optimal descriptor(s) ΔG opt . We demonstrate the framework for four important electrochemical reactions: hydrogen evolution, chlorine evolution, oxygen reduction and oxygen evolution. Future studies could utilize expected activity and prediction efficiency to significantly improve the prediction accuracy of highly active material candidates.

Improved prediction of MHC class I and class II epitopes using a novel Gibbs sampling approach

DEFF Research Database (Denmark)

Nielsen, Morten; Lundegaard, Claus; Worning, Peder

2004-01-01

Prediction of which peptides will bind a specific major histocompatibility complex (MHC) constitutes an important step in identifying potential T-cell epitopes suitable as vaccine candidates. MHC class II binding peptides have a broad length distribution complicating such predictions. Thus......, identifying the correct alignment is a crucial part of identifying the core of an MHC class II binding motif. In this context, we wish to describe a novel Gibbs motif sampler method ideally suited for recognizing such weak sequence motifs. The method is based on the Gibbs sampling method, and it incorporates...

The Latent Class Model as a Measurement Model for Situational Judgment Tests

Directory of Open Access Journals (Sweden)

Frank Rijmen

2011-11-01

Full Text Available In a situational judgment test, it is often debatable what constitutes a correct answer to a situation. There is currently a multitude of scoring procedures. Establishing a measurement model can guide the selection of a scoring rule. It is argued that the latent class model is a good candidate for a measurement model. Two latent class models are applied to the Managing Emotions subtest of the Mayer, Salovey, Caruso Emotional Intelligence Test: a plain-vanilla latent class model, and a second-order latent class model that takes into account the clustering of several possible reactions within each hypothetical scenario of the situational judgment test. The results for both models indicated that there were three subgroups characterised by the degree to which differentiation occurred between possible reactions in terms of perceived effectiveness. Furthermore, the results for the second-order model indicated a moderate cluster effect.

Zero-Shot Learning via Attribute Regression and Class Prototype Rectification.

Science.gov (United States)

Luo, Changzhi; Li, Zhetao; Huang, Kaizhu; Feng, Jiashi; Wang, Meng

2018-02-01

Zero-shot learning (ZSL) aims at classifying examples for unseen classes (with no training examples) given some other seen classes (with training examples). Most existing approaches exploit intermedia-level information (e.g., attributes) to transfer knowledge from seen classes to unseen classes. A common practice is to first learn projections from samples to attributes on seen classes via a regression method, and then apply such projections to unseen classes directly. However, it turns out that such a manner of learning strategy easily causes projection domain shift problem and hubness problem, which hinder the performance of ZSL task. In this paper, we also formulate ZSL as an attribute regression problem. However, different from general regression-based solutions, the proposed approach is novel in three aspects. First, a class prototype rectification method is proposed to connect the unseen classes to the seen classes. Here, a class prototype refers to a vector representation of a class, and it is also known as a class center, class signature, or class exemplar. Second, an alternating learning scheme is proposed for jointly performing attribute regression and rectifying the class prototypes. Finally, a new objective function which takes into consideration both the attribute regression accuracy and the class prototype discrimination is proposed. By introducing such a solution, domain shift problem and hubness problem can be mitigated. Experimental results on three public datasets (i.e., CUB200-2011, SUN Attribute, and aPaY) well demonstrate the effectiveness of our approach.

Measuring energy efficiency under heterogeneous technologies using a latent class stochastic frontier approach: An application to Chinese energy economy

International Nuclear Information System (INIS)

Lin, Boqiang; Du, Kerui

2014-01-01

The importance of technology heterogeneity in estimating economy-wide energy efficiency has been emphasized by recent literature. Some studies use the metafrontier analysis approach to estimate energy efficiency. However, for such studies, some reliable priori information is needed to divide the sample observations properly, which causes a difficulty in unbiased estimation of energy efficiency. Moreover, separately estimating group-specific frontiers might lose some common information across different groups. In order to overcome these weaknesses, this paper introduces a latent class stochastic frontier approach to measure energy efficiency under heterogeneous technologies. An application of the proposed model to Chinese energy economy is presented. Results show that the overall energy efficiency of China's provinces is not high, with an average score of 0.632 during the period from 1997 to 2010. - Highlights: • We introduce a latent class stochastic frontier approach to measure energy efficiency. • Ignoring technological heterogeneity would cause biased estimates of energy efficiency. • An application of the proposed model to Chinese energy economy is presented. • There is still a long way for China to develop an energy efficient regime

Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping

Directory of Open Access Journals (Sweden)

Skrollan Stockinger

2013-09-01

Full Text Available A new approach for the investigation of a higher-order reaction by on-column reaction gas chromatography is presented. The reaction and the analytical separation are combined in a single experiment to investigate the Diels–Alder reaction of benzenediazonium-2-carboxylate as a benzyne precursor with various anthracene derivatives, i.e. anthracene, 9-bromoanthracene, 9-anthracenecarboxaldehyde and 9-anthracenemethanol. To overcome limitations of short reaction contact times at elevated temperatures a novel experimental setup was developed involving a cooling trap to achieve focusing and mixing of the reactants at a defined spot in a fused-silica capillary. This trap functions as a reactor within the separation column in the oven of a gas chromatograph. The reactants are sequentially injected to avoid undefined mixing in the injection port. An experimental protocol was developed with optimized injection intervals and cooling times to achieve sufficient conversions at short reaction times. Reaction products were rapidly identified by mass spectrometric detection. This new approach represents a practical procedure to investigate higher-order reactions at an analytical level and it simultaneously provides valuable information for the optimization of the reaction conditions.

A network dynamics approach to chemical reaction networks

NARCIS (Netherlands)

van der Schaft, Abraham; Rao, S.; Jayawardhana, B.

2016-01-01

A treatment of chemical reaction network theory is given from the perspective of nonlinear network dynamics, in particular of consensus dynamics. By starting from the complex-balanced assumption the reaction dynamics governed by mass action kinetics can be rewritten into a form which allows for a

Exact analytical solutions for nonlinear reaction-diffusion equations

International Nuclear Information System (INIS)

Liu Chunping

2003-01-01

By using a direct method via the computer algebraic system of Mathematica, some exact analytical solutions to a class of nonlinear reaction-diffusion equations are presented in closed form. Subsequently, the hyperbolic function solutions and the triangular function solutions of the coupled nonlinear reaction-diffusion equations are obtained in a unified way

Phase transition universality classes of classical, nonequilibrium systems

CERN Document Server

Ódor, G

2004-01-01

In the first chapter I summarize the most important critical exponents and relations used in this work. In the second chapter I briefly address the question of scaling behavior at first order phase transitions.In chapter three I review dynamical extensions of basic static classes, show the effect of mixing dynamics and percolation behavior. The main body of this work is given in chapter four where genuine, dynamical universality classes specific to nonequilibrium systems are introduced. In chapter five I continue overviewing such nonequilibrium classes but in coupled, multi-component systems. Most of known transitions in low dimensional systems are between active and absorbing states of reaction-diffusion type systems, but I briefly introduce related classes that appear in interface growth models in chapter six. Some of them are related to critical behavior of coupled, multi-component systems. Finally in chapter seven I summarize families of absorbing state system classes, mean-field classes and the most freq...

Machine Learning-Assisted Network Inference Approach to Identify a New Class of Genes that Coordinate the Functionality of Cancer Networks.

Science.gov (United States)

Ghanat Bari, Mehrab; Ung, Choong Yong; Zhang, Cheng; Zhu, Shizhen; Li, Hu

2017-08-01

Emerging evidence indicates the existence of a new class of cancer genes that act as "signal linkers" coordinating oncogenic signals between mutated and differentially expressed genes. While frequently mutated oncogenes and differentially expressed genes, which we term Class I cancer genes, are readily detected by most analytical tools, the new class of cancer-related genes, i.e., Class II, escape detection because they are neither mutated nor differentially expressed. Given this hypothesis, we developed a Machine Learning-Assisted Network Inference (MALANI) algorithm, which assesses all genes regardless of expression or mutational status in the context of cancer etiology. We used 8807 expression arrays, corresponding to 9 cancer types, to build more than 2 × 10 8 Support Vector Machine (SVM) models for reconstructing a cancer network. We found that ~3% of ~19,000 not differentially expressed genes are Class II cancer gene candidates. Some Class II genes that we found, such as SLC19A1 and ATAD3B, have been recently reported to associate with cancer outcomes. To our knowledge, this is the first study that utilizes both machine learning and network biology approaches to uncover Class II cancer genes in coordinating functionality in cancer networks and will illuminate our understanding of how genes are modulated in a tissue-specific network contribute to tumorigenesis and therapy development.

Not all experiences of (inauthenticity are created equal: A latent class analysis approach(retitled Identifying Differences in the Experience of (InAuthenticity: A Latent Class Analysis Approach

Directory of Open Access Journals (Sweden)

Alison P. Lenton

2014-07-01

Full Text Available Generally, psychologists consider state authenticity– that is, the subjective sense of being one’s true self – to be a unitary and unidimensional construct, such that (a the phenomenological experience of authenticity is thought to be similar no matter its trigger, and (b inauthenticity is thought to be simply the opposing pole (on the same underlying construct of authenticity. Using latent class analysis, we put this conceptualization to a test. In order to avoid over-reliance on a Western conceptualization of authenticity, we used a cross-cultural sample (N = 543, comprising participants from Western, South-Asian, East-Asian, and South-East Asian cultures. Participants provided either a narrative in which the described when they felt most like being themselves or one in which they described when they felt least like being themselves. The analysis identified six distinct classes of experiences: two authenticity classes ('everyday' and 'extraordinary', three inauthenticity classes ('self-conscious,' 'deflated,' and 'extraordinary', and a class representing convergence between authenticity and inauthenticity. The classes were phenomenologically distinct, especially with respect to negative affect, private and public self-consciousness, and self-esteem. Furthermore, relatively more interdependent cultures were less likely to report experiences of extraordinary (inauthenticity than relatively more independent cultures. Understanding the many facets of (inauthenticity may enable researchers to connect different findings and explain why the attainment of authenticity can be difficult.

Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases

Science.gov (United States)

Haupt, V. Joachim; Schroeder, Michael; Labudde, Dirk

2018-01-01

The origin of the machinery that realizes protein biosynthesis in all organisms is still unclear. One key component of this machinery are aminoacyl tRNA synthetases (aaRS), which ligate tRNAs to amino acids while consuming ATP. Sequence analyses revealed that these enzymes can be divided into two complementary classes. Both classes differ significantly on a sequence and structural level, feature different reaction mechanisms, and occur in diverse oligomerization states. The one unifying aspect of both classes is their function of binding ATP. We identified Backbone Brackets and Arginine Tweezers as most compact ATP binding motifs characteristic for each Class. Geometric analysis shows a structural rearrangement of the Backbone Brackets upon ATP binding, indicating a general mechanism of all Class I structures. Regarding the origin of aaRS, the Rodin-Ohno hypothesis states that the peculiar nature of the two aaRS classes is the result of their primordial forms, called Protozymes, being encoded on opposite strands of the same gene. Backbone Brackets and Arginine Tweezers were traced back to the proposed Protozymes and their more efficient successors, the Urzymes. Both structural motifs can be observed as pairs of residues in contemporary structures and it seems that the time of their addition, indicated by their placement in the ancient aaRS, coincides with the evolutionary trace of Proto- and Urzymes. PMID:29659563

Context-sensitive intra-class clustering

KAUST Repository

Yu, Yingwei

2014-02-01

This paper describes a new semi-supervised learning algorithm for intra-class clustering (ICC). ICC partitions each class into sub-classes in order to minimize overlap across clusters from different classes. This is achieved by allowing partitioning of a certain class to be assisted by data points from other classes in a context-dependent fashion. The result is that overlap across sub-classes (both within- and across class) is greatly reduced. ICC is particularly useful when combined with algorithms that assume that each class has a unimodal Gaussian distribution (e.g., Linear Discriminant Analysis (LDA), quadratic classifiers), an assumption that is not always true in many real-world situations. ICC can help partition non-Gaussian, multimodal distributions to overcome such a problem. In this sense, ICC works as a preprocessor. Experiments with our ICC algorithm on synthetic data sets and real-world data sets indicated that it can significantly improve the performance of LDA and quadratic classifiers. We expect our approach to be applicable to a broader class of pattern recognition problems where class-conditional densities are significantly non-Gaussian or multi-modal. © 2013 Elsevier Ltd. All rights reserved.

A modern approach for epitope prediction: identification of foot-and-mouth disease virus peptides binding bovine leukocyte antigen (BoLA) class I molecules

DEFF Research Database (Denmark)

Pandya, Mital; Rasmussen, Michael; Hansen, Andreas

2015-01-01

Major histocompatibility complex (MHC) class I molecules regulate adaptive immune responses through the presentation of antigenic peptides to CD8+ T cells. Polymorphisms in the peptide binding region of class I molecules determine peptide binding affinity and stability during antigen presentation......, and different antigen peptide motifs are associated with specific genetic sequences of class I molecules. Understanding bovine leukocyte antigen (BoLA), peptide-MHC class I binding specificities may facilitate development of vaccines or reagents for quantifying the adaptive immune response to intracellular...... pathogens, such as foot-and-mouth disease virus (FMDV). Six synthetic BoLA class I (BoLA-I) molecules were produced, and the peptide binding motif was generated for five of the six molecules using a combined approach of positional scanning combinatorial peptide libraries (PSCPLs) and neural network...

Effective dynamics along given reaction coordinates, and reaction rate theory.

Science.gov (United States)

Zhang, Wei; Hartmann, Carsten; Schütte, Christof

2016-12-22

In molecular dynamics and related fields one considers dynamical descriptions of complex systems in full (atomic) detail. In order to reduce the overwhelming complexity of realistic systems (high dimension, large timescale spread, limited computational resources) the projection of the full dynamics onto some reaction coordinates is examined in order to extract statistical information like free energies or reaction rates. In this context, the effective dynamics that is induced by the full dynamics on the reaction coordinate space has attracted considerable attention in the literature. In this article, we contribute to this discussion: we first show that if we start with an ergodic diffusion process whose invariant measure is unique then these properties are inherited by the effective dynamics. Then, we give equations for the effective dynamics, discuss whether the dominant timescales and reaction rates inferred from the effective dynamics are accurate approximations of such quantities for the full dynamics, and compare our findings to results from approaches like Mori-Zwanzig, averaging, or homogenization. Finally, by discussing the algorithmic realization of the effective dynamics, we demonstrate that recent algorithmic techniques like the "equation-free" approach and the "heterogeneous multiscale method" can be seen as special cases of our approach.

A generalized volumetric dispersion model for a class of two-phase separation/reaction: finite difference solutions

Science.gov (United States)

Siripatana, Chairat; Thongpan, Hathaikarn; Promraksa, Arwut

2017-03-01

This article explores a volumetric approach in formulating differential equations for a class of engineering flow problems involving component transfer within or between two phases. In contrast to conventional formulation which is based on linear velocities, this work proposed a slightly different approach based on volumetric flow-rate which is essentially constant in many industrial processes. In effect, many multi-dimensional flow problems found industrially can be simplified into multi-component or multi-phase but one-dimensional flow problems. The formulation is largely generic, covering counter-current, concurrent or batch, fixed and fluidized bed arrangement. It was also intended to use for start-up, shut-down, control and steady state simulation. Since many realistic and industrial operation are dynamic with variable velocity and porosity in relation to position, analytical solutions are rare and limited to only very simple cases. Thus we also provide a numerical solution using Crank-Nicolson finite difference scheme. This solution is inherently stable as tested against a few cases published in the literature. However, it is anticipated that, for unconfined flow or non-constant flow-rate, traditional formulation should be applied.

Development and validation of a reduced combined biodiesel–diesel reaction mechanism

DEFF Research Database (Denmark)

Ng, Hoon Kiat; Gan, Suyin; Ng, Jo-Han

2013-01-01

In this study, a compact combined biodiesel–diesel (CBD) reaction mechanism for diesel engine simulations is proposed through the combination of three component mechanisms using a chemical class-based approach. The proposed mechanism comprises the reaction mechanisms of methyl crotonate (MC...... to characterise the combustion of fossil diesel. Here, the MC and MB mechanisms are reduced before integrating with a compact n-heptane mechanism. CHEMKIN-PRO is used as the solver for the zero-dimensional, closed homogenous reactor with a constant volume in this study. In the first phase, the mechanisms of MC...... ranging from initial temperatures of 750–1350 K, pressures of 40–60 bar and equivalence ratios of 0.4–1.5. The mechanism is generally found to accurately predict the timing and duration of ID for the combustion of each surrogate fuel. This model is also shown to be feasible for use with multidimensional...

Reaction Hamiltonian and state-to-state description of chemical reactions

International Nuclear Information System (INIS)

Ruf, B.A.; Kresin, V.Z.; Lester, W.A. Jr.

1985-08-01

A chemical reaction is treated as a quantum transition from reactants to products. A specific reaction Hamiltonian (in second quantization formalism) is introduced. The approach leads to Franck-Condon-like factor, and adiabatic method in the framework of the nuclear motion problems. The influence of reagent vibrational state on the product energy distribution has been studied following the reaction Hamiltonian method. Two different cases (fixed available energy and fixed translational energy) are distinguished. Results for several biomolecular reactions are presented. 40 refs., 5 figs

Global exponential stability and periodicity of reaction-diffusion delayed recurrent neural networks with Dirichlet boundary conditions

International Nuclear Information System (INIS)

Lu Junguo

2008-01-01

In this paper, the global exponential stability and periodicity for a class of reaction-diffusion delayed recurrent neural networks with Dirichlet boundary conditions are addressed by constructing suitable Lyapunov functionals and utilizing some inequality techniques. We first prove global exponential converge to 0 of the difference between any two solutions of the original reaction-diffusion delayed recurrent neural networks with Dirichlet boundary conditions, the existence and uniqueness of equilibrium is the direct results of this procedure. This approach is different from the usually used one where the existence, uniqueness of equilibrium and stability are proved in two separate steps. Furthermore, we prove periodicity of the reaction-diffusion delayed recurrent neural networks with Dirichlet boundary conditions. Sufficient conditions ensuring the global exponential stability and the existence of periodic oscillatory solutions for the reaction-diffusion delayed recurrent neural networks with Dirichlet boundary conditions are given. These conditions are easy to check and have important leading significance in the design and application of reaction-diffusion recurrent neural networks with delays. Finally, two numerical examples are given to show the effectiveness of the obtained results

New approach to analyzing and evaluating cross sections for partial photoneutron reactions

International Nuclear Information System (INIS)

Varlamov, V. V.; Ishkhanov, B. S.; Orlin, V. N.

2012-01-01

The presence of substantial systematic discrepancies between the results of different experiments devoted to determining cross sections for partial photoneutron reactions—first of all, (γ, n), (γ, 2n), and (γ, 3n) reactions—is a strong motivation for studying the reliability and authenticity of these data and for developing methods for taking into account and removing the discrepancies in question. In order to solve the first problem, we introduce objective absolute criteria involving transitional photoneutron-multiplicity functions F 1 , F 2 , F 3 , …; by definition, their values cannot exceed 1.0, 0.5, 0.33, …, respectively. With the aim of solving the second problem, we propose a new experimental-theoretical approach. In this approach, reaction cross sections are evaluated by simultaneously employing experimental data on the cross section for the total photoneutron yield, σ expt (γ, xn) = σ expt (γ, n) + 2σ expt (γ, 2n) + 3σ expt (γ, 3n) + …, which are free from drawbacks plaguing experimental methods for sorting neutrons in multiplicity, and the results obtained by calculating the functions F theor 1 , F theor 2 , F theor 3 , … on the basis of the modern model of photonuclear reactions. The reliability and authenticity of data on the cross sections for (γ, n), (γ, 2n), and (γ, 3n) partial reactions—σ eval (γ, in) = F i theor σ expt (γ, xn)—were evaluated for the 90 Zr, 115 In, 112,114,116,117,118,119,120,122,124 Sn, 159 Tb, and 197 Au nuclei.

Imagining class: A study into material social class position, subjective identification, and voting behavior across Europe.

Science.gov (United States)

D'Hooge, Lorenzo; Achterberg, Peter; Reeskens, Tim

2018-02-01

The traditional approach to class voting has largely ignored the question whether material class positions coincide with subjective class identification. Following Sosnaud et al. (2013), this study evaluates party preferences when Europeans' material and subjective social class do not coincide. Seminal studies on voting behavior have suggested that members of lower classes are more likely to vote for the economic left and cultural right and that higher classes demonstrate the opposite pattern. Yet, these studies have on the one hand overlooked the possibility that there is a mismatch between the material class people can be classified in and the class they think they are part of, and on the other hand the consequences of this discordant class identification on voting behavior. Analyzing the 2009 wave of the European Elections Study, we find that the majority of the Europeans discordantly identify with the middle class, whereas only a minority of the lower and higher classes concordantly identify with their material social class. Further, material class only seems to predict economic voting behavior when it coincides with subjective class; for instance, individuals who have an inflated class identification are more likely to vote for the economic left, even when they materially can be classified as middle or high class. We conclude this paper with a discussion on scholarly debates concerning class and politics. Copyright © 2017 Elsevier Inc. All rights reserved.

Enantioselective Decarboxylative Alkylation Reactions: Catalyst Development, Substrate Scope, and Mechanistic Studies

Science.gov (United States)

Behenna, Douglas C.; Mohr, Justin T.; Sherden, Nathaniel H.; Marinescu, Smaranda C.; Harned, Andrew M.; Tani, Kousuke; Seto, Masaki; Ma, Sandy; Novák, Zoltán; Krout, Michael R.; McFadden, Ryan M.; Roizen, Jennifer L.; Enquist, John A.; White, David E.; Levine, Samantha R.; Petrova, Krastina V.; Iwashita, Akihiko; Virgil, Scott C.; Stoltz, Brian M.

2012-01-01

α-Quaternary ketones are accessed through novel enantioselective alkylations of allyl and propargyl electrophiles by unstabilized prochiral enolate nucleophiles in the presence of palladium complexes with various phosphinooxazoline (PHOX) ligands. Excellent yields and high enantiomeric excesses are obtained from three classes of enolate precursors: enol carbonates, enol silanes, and racemic β-ketoesters. Each of these substrate classes functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reaction scope, and applications in target-directed synthesis are reported. Experimental observations suggest that these alkylation reactions occur through an unusual inner-sphere mechanism involving binding of the prochiral enolate nucleophile directly to the palladium center. PMID:22083969

Enantioselective Decarboxylative Alkylation Reactions: Catalyst Development, Substrate Scope, and Mechanistic Studies

KAUST Repository

Behenna, Douglas C.; Mohr, Justin T.; Sherden, Nathaniel H.; Marinescu, Smaranda C.; Harned, Andrew M.; Tani, Kousuke; Seto, Masaki; Ma, Sandy; Nová k, Zoltá n; Krout, Michael R.; McFadden, Ryan M.; Roizen, Jennifer L.; Enquist, John A.; White, David E.; Levine, Samantha R.; Petrova, Krastina V.; Iwashita, Akihiko; Virgil, Scott C.; Stoltz, Brian M.

2011-01-01

α-Quaternary ketones are accessed through novel enantioselective alkylations of allyl and propargyl electrophiles by unstabilized prochiral enolate nucleophiles in the presence of palladium complexes with various phosphinooxazoline (PHOX) ligands. Excellent yields and high enantiomeric excesses are obtained from three classes of enolate precursor: enol carbonates, enol silanes, and racemic β-ketoesters. Each of these substrate classes functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reaction scope, and applications in target-directed synthesis are reported. Experimental observations suggest that these alkylation reactions occur through an unusual inner-sphere mechanism involving binding of the prochiral enolate nucleophile directly to the palladium center.

Enantioselective Decarboxylative Alkylation Reactions: Catalyst Development, Substrate Scope, and Mechanistic Studies

KAUST Repository

Behenna, Douglas C.

2011-11-14

α-Quaternary ketones are accessed through novel enantioselective alkylations of allyl and propargyl electrophiles by unstabilized prochiral enolate nucleophiles in the presence of palladium complexes with various phosphinooxazoline (PHOX) ligands. Excellent yields and high enantiomeric excesses are obtained from three classes of enolate precursor: enol carbonates, enol silanes, and racemic β-ketoesters. Each of these substrate classes functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reaction scope, and applications in target-directed synthesis are reported. Experimental observations suggest that these alkylation reactions occur through an unusual inner-sphere mechanism involving binding of the prochiral enolate nucleophile directly to the palladium center.

Composition of amino acid using carbon monoxide. Amide carbonylation reaction

Energy Technology Data Exchange (ETDEWEB)

Izawa, Kunisuke (Ajinomoto Co., Inc., Tokyo (Japan))

1989-02-01

Amide carbonylation reaction is a method to compose N-acyl-{alpha}-amino acid from aldehyde, carboxylic acid amide, and carbon monoxide in a phase and with high yield. Unlike the conventional Strecker reaction, this method does not use HCN which is in question on public pollution and does not require hydrolysis. This amide carbonylation reaction was discovered by Wakamatsu and others of Ajinomoto Co.,Ltd. Present application examples of this method are the composition of N-acetyl amino acid from the aldehyde class, the composition of N-Acyl amino acid from olefin, the composition of N-acyl or acetyl amino acid from the raw material of alcohol and the halide class, the composition of N-acyl or acetyl amino acid via the isomerization of epoxide and allyl alcohol, the composition of amino dicarboxylic acid, applying deoxidation of ring acid anhydride, the composition of N-acyl amino acid from the raw material of the amine class, the stereoselective composition of -substitution ring-{alpha}-amino acid, and the composition of amino aldehyde. 24 refs., 2 figs., 2 tabs.

A classical approach in simple nuclear fusion reaction 1H2+1H3 using two-dimension granular molecular dynamics model

International Nuclear Information System (INIS)

Viridi, S.; Kurniadi, R.; Waris, A.; Perkasa, Y. S.

2012-01-01

Molecular dynamics in 2-D accompanied by granular model provides an opportunity to investigate binding between nuclei particles and its properties that arises during collision in a fusion reaction. A fully classical approach is used to observe the influence of initial angle of nucleus orientation to the product yielded by the reaction. As an example, a simplest fusion reaction between 1 H 2 and 1 H 3 is observed. Several products of the fusion reaction have been obtained, even the unreported ones, including temporary 2 He 4 nucleus.

Analysis of Brownian Dynamics Simulations of Reversible Bimolecular Reactions

KAUST Repository

Lipková, Jana

2011-01-01

A class of Brownian dynamics algorithms for stochastic reaction-diffusion models which include reversible bimolecular reactions is presented and analyzed. The method is a generalization of the λ-bcȳ model for irreversible bimolecular reactions which was introduced in [R. Erban and S. J. Chapman, Phys. Biol., 6(2009), 046001]. The formulae relating the experimentally measurable quantities (reaction rate constants and diffusion constants) with the algorithm parameters are derived. The probability of geminate recombination is also investigated. © 2011 Society for Industrial and Applied Mathematics.

Social class and body weight among Chinese urban adults: the role of the middle classes in the nutrition transition.

Science.gov (United States)

Bonnefond, Céline; Clément, Matthieu

2014-07-01

While a plethoric empirical literature addresses the relationship between socio-economic status and body weight, little is known about the influence of social class on nutritional outcomes, particularly in developing countries. The purpose of this article is to contribute to the analysis of the social determinants of adult body weight in urban China by taking into account the influence of social class. More specifically, we propose to analyse the position of the Chinese urban middle class in terms of being overweight or obese. The empirical investigations conducted as part of this research are based on a sample of 1320 households and 2841 adults from the China Health and Nutrition Survey for 2009. For the first step, we combine an economic approach and a sociological approach to identify social classes at household level. First, households with an annual per capita income between 10,000 Yuan and the 95th income percentile are considered as members of the middle class. Second, we strengthen the characterization of the middle class using information on education and employment. By applying clustering methods, we identify four groups: the elderly and inactive middle class, the old middle class, the lower middle class and the new middle class. For the second step, we implement an econometric analysis to assess the influence of social class on adult body mass index and on the probability of being overweight or obese. We use multinomial treatment regressions to deal with the endogeneity of the social class variable. Our results show that among the four subgroups of the urban middle class, the new middle class is the only one to be relatively well-protected against obesity. We suggest that this group plays a special role in adopting healthier food consumption habits and seems to be at a more advanced stage of the nutrition transition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Friction force experimental approach in High School Physics classes

Directory of Open Access Journals (Sweden)

Marco Aurélio Alvarenga Monteiro

2012-12-01

Full Text Available http://dx.doi.org/10.5007/2175-7941.2012v29n3p1121 In this paper we propose and describe the performance of an experimental activity to address the concept of friction in High School Physics practical classes. We use a low-cost and simple construction device that enables the determination of the coefficient of static friction between two materials through three different procedures. The results were coherent, with small percentage deviation, which gives reliability to the activity and can stimulate discussions in class. The activity also allows greater contextualization of concepts that are usually discussed only theoretically, requiring a higher abstraction level of the students. This can stimulate discussions and greater interaction between teacher and students.

A NEW APPROACH TO CLASS SCHEDULING. FINAL REPORT.

Science.gov (United States)

CANTER, JOHN; AND OTHERS

AN INVESTIGATION OF THE USE OF A PROTOTYPE DEVICE FOR CLASS SCHEDULING WAS MADE. THE BEEKLEY INSITE DEVICE THAT WAS STUDIED USES THE "PEEK-A-BOO" PRINCIPLE OF MATCHING COMPUTER TAPES. A TEST GROUP OF 149 GRADUATE STUDENTS WAS USED. THEIR DESIRED SCHEDULES WERE MATCHED AUTOMATICALLY AGAINST A PROPOSED MASTER SCHEDULE TO EVALUATE THE…

A Multinomial Logit Approach to Estimating Regional Inventories by Product Class

Science.gov (United States)

Lawrence Teeter; Xiaoping Zhou

1998-01-01

Current timber inventory projections generally lack information on inventory by product classes. Most models available for inventory projection and linked to supply analyses are limited to projecting aggregate softwood and hardwood. The objective of this research is to develop a methodology to distribute the volume on each FIA survey plot to product classes and...

A Neurocomputational Approach to Trained and Transitive Relations in Equivalence Classes

Directory of Open Access Journals (Sweden)

Ángel E. Tovar

2017-10-01

Full Text Available A stimulus class can be composed of perceptually different but functionally equivalent stimuli. The relations between the stimuli that are grouped in a class can be learned or derived from other stimulus relations. If stimulus A is equivalent to B, and B is equivalent to C, then the equivalence between A and C can be derived without explicit training. In this work we propose, with a neurocomputational model, a basic learning mechanism for the formation of equivalence. We also describe how the relatedness between the members of an equivalence class is developed for both trained and derived stimulus relations. Three classic studies on stimulus equivalence are simulated covering typical and atypical populations as well as nodal distance effects. This model shows a mechanism by which certain stimulus associations are selectively strengthened even when they are not co-presented in the environment. This model links the field of equivalence classes to accounts of Hebbian learning and categorization, and points to the pertinence of modeling stimulus equivalence to explore the effect of variations in training protocols.

Evolutionary change in continuous reaction norms

DEFF Research Database (Denmark)

Murren, Courtney J; Maclean, Heidi J; Diamond, Sarah E

2014-01-01

Understanding the evolution of reaction norms remains a major challenge in ecology and evolution. Investigating evolutionary divergence in reaction norm shapes between populations and closely related species is one approach to providing insights. Here we use a meta-analytic approach to compare...... divergence in reaction norms of closely related species or populations of animals and plants across types of traits and environments. We quantified mean-standardized differences in overall trait means (Offset) and reaction norm shape (including both Slope and Curvature). These analyses revealed...... contributed to the best-fitting models, especially for Offset, Curvature, and the total differences (Total) between reaction norms. Congeneric species had greater differences in reaction norms than populations, and novel environmental conditions increased the differences in reaction norms between populations...

Extent of reaction in open systems with multiple heterogeneous reactions

Science.gov (United States)

Friedly, John C.

1991-01-01

The familiar batch concept of extent of reaction is reexamined for systems of reactions occurring in open systems. Because species concentrations change as a result of transport processes as well as reactions in open systems, the extent of reaction has been less useful in practice in these applications. It is shown that by defining the extent of the equivalent batch reaction and a second contribution to the extent of reaction due to the transport processes, it is possible to treat the description of the dynamics of flow through porous media accompanied by many chemical reactions in a uniform, concise manner. This approach tends to isolate the reaction terms among themselves and away from the model partial differential equations, thereby enabling treatment of large problems involving both equilibrium and kinetically controlled reactions. Implications on the number of coupled partial differential equations necessary to be solved and on numerical algorithms for solving such problems are discussed. Examples provided illustrate the theory applied to solute transport in groundwater flow.

Application of Enzyme Coupling Reactions to Shift Thermodynamically Limited Biocatalytic Reactions

DEFF Research Database (Denmark)

Abu, Rohana; Woodley, John M.

2015-01-01

, it can be challenging to combine several engineered enzymes in vitro for the conversion of non-natural substrates. In this mini-review we focus on enzyme coupling reactions as a tool to alleviate thermodynamic constraints in synthetically useful biocatalytic reactions. The implications of thermodynamic...... shift the equilibrium of otherwise thermodynamically unfavourable reactions to give a higher conversion of the target product. By coupling an energetically unfavourable reaction with a more favourable one, the multi-enzyme cascade mimics the approach taken in nature in metabolic pathways. Nevertheless...

Modified two-body potential approach to the peripheral direct capture astrophysical a+A->B+γ reaction and asymptotic normalization coefficients

International Nuclear Information System (INIS)

Igamov, S.B.; Yarmukhamedov, R.

2007-01-01

A modified two-body potential approach is proposed for determination of both the asymptotic normalization coefficient (ANC) (or the respective nuclear vertex constant (NVC)) for the A+a->B (for the virtual decay B->A+a) from an analysis of the experimental S-factor for the peripheral direct capture a+A->B+γ reaction and the astrophysical S-factor, S(E), at low experimentally inaccessible energy regions. The approach proposed involves two additional conditions which verify the peripheral character of the considered reaction and expresses S(E) in terms of the ANC. The connection between NVC (ANC) and the effective range parameters for Aa-scattering is derived. To test this approach we reanalyse the precise experimental astrophysical S-factors for t+α->Li7+γ reaction at energies E= Li7(g.s.), α+t->Li7(0.478 MeV) and of S(E) at E=<50 keV. These ANC values have been used for getting information about the ''indirect'' measured values of the effective range parameters and the p-wave phase shift for αt-scattering in the energy range of 100-bar E-bar 180 keV

Solvent-Free Wittig Reaction: A Green Organic Chemistry Laboratory Experiment

Science.gov (United States)

Leung, Sam H.; Angel, Stephen A.

2004-01-01

Some Wittig reactions can be carried out by grinding the reactants in a mortar with a pestle for about 20 minutes, as per investigation. A laboratory experiment involving a solvent-free Wittig reaction that can be completed in a three-hour sophomore organic chemistry laboratory class period, are developed.

Chaos control for a class of chaotic systems using PI-type state observer approach

International Nuclear Information System (INIS)

Jiang Guoping; Zheng Weixing

2004-01-01

In this paper, by using the PI-type state observer design approach and the characteristic of ergodicity of chaos, a new method is presented for controlling chaos, including the stabilization of unstable equilibrium points and set-point tracking, for a class of chaotic systems. Based on the theory of nonlinear ordinary differential equations, a simple criterion is derived for designing the controller gains for stabilization and tracking, in which control parameters can be selected via the pole placement technique of linear control theory. More importantly, this control method has a simple controller structure, high robustness against system parametric variations, and strong rejection of external constant disturbances. The method is applied to the chaotic Lorenz system for demonstration

The effectiveness of TBL with real patients in neurology education in terms of knowledge retention, in-class engagement, and learner reactions.

Science.gov (United States)

Alimoglu, Mustafa Kemal; Yardım, Selda; Uysal, Hilmi

2017-03-01

In our medical school, we changed from a lecture-based method to a team-based learning (TBL) method to teach "polyneuropathies" in the neurology clerkship starting from the 2014 to 2015 academic year. Real patients were used instead of written scenarios in TBL sessions. This study aimed to compare former lecture-based and the current TBL methods in terms of knowledge retention, in-class learner engagement, and learner reactions. First, we determined in-class engagement and satisfaction of the students for the lectures given in the 2013-2014 academic year. The following year, besides the same criteria, we also determined individual (IRAT) and group readiness test (GRAT) scores in the TBL group. End-of-clerkship exam scores for both groups were recorded. Additionally, opinions of patients about their experiences throughout the TBL process were determined. One year later (2015 for lecture and 2016 for TBL), both groups sat for an MCQ test to determine their knowledge retention levels. We found no difference between groups regarding end-of-clerkship exam scores. The mean knowledge retention test score of the TBL group was significantly higher than that of the lecture group (5.85 ± 1.74 vs. 3.28 ± 1.70). The differences between IRAT, GRAT, and retention test scores in the TBL group were significant. The mean student satisfaction score on a five-point scale was 3.01 ± 0.9 (median = 3) in the lecture group and 4.11 ± 1.1 (median = 4) in the TBL group. Our results seem encouraging for use of TBL performed with real patients in neurology education to achieve better long-term knowledge retention and higher in-class engagement and student satisfaction. Copyright © 2017 the American Physiological Society.

Stepwise radical cation Diels-Alder reaction via multiple pathways.

Science.gov (United States)

Shimizu, Ryo; Okada, Yohei; Chiba, Kazuhiro

2018-01-01

Herein we disclose the radical cation Diels-Alder reaction of aryl vinyl ethers by electrocatalysis, which is triggered by an oxidative SET process. The reaction clearly proceeds in a stepwise fashion, which is a rare mechanism in this class. We also found that two distinctive pathways, including "direct" and "indirect", are possible to construct the Diels-Alder adduct.

The γp → na2+ (1320) → nρ0π+ reactions within an effective Lagrangian approach

International Nuclear Information System (INIS)

Huang, Yin; Xie, Jujun; He, Jun; Chen, Xurong; Zhang, Hongfei

2014-01-01

We investigate the tensor meson a 2 (1320) photon-production off proton in the γp → na 2 + (1320) and γp → nρ 0 π + reactions within the effective Lagrangian approach and isobar model. For γp → na 2 + (1320) reaction, by considering the contributions from only the t-channel π + exchange, we get a fairly good description of the current experimental data for the total cross-section. Based on the theoretical results of the γp → na 2 + (1320) reaction, we studied the role of a 2 (1320) meson in the γp → nρ 0 π + reaction, which mainly contributes to the γp → nπ + π + π - reaction. The latter reaction has been measured by the CLAS Collaboration at the photon energy E γ around 5.1 GeV. For the γp → nρ 0 π + reaction, we pay attention to the low photon energy region where the contribution from a 2 (1320) meson is dominant, while the contribution from the π 2 (1670) meson could be very small and hence can be neglected. The total cross-sections, invariant mass distribution and the Dalitz plot of γp → nρ 0 π + reaction are shown, which can be tested by future experiments. (author)

Gas-phase ion/ion reactions of peptides and proteins: acid/base, redox, and covalent chemistries.

Science.gov (United States)

Prentice, Boone M; McLuckey, Scott A

2013-02-01

Gas-phase ion/ion reactions are emerging as useful and flexible means for the manipulation and characterization of peptide and protein biopolymers. Acid/base-like chemical reactions (i.e., proton transfer reactions) and reduction/oxidation (redox) reactions (i.e., electron transfer reactions) represent relatively mature classes of gas-phase chemical reactions. Even so, especially in regards to redox chemistry, the widespread utility of these two types of chemistries is undergoing rapid growth and development. Additionally, a relatively new class of gas-phase ion/ion transformations is emerging which involves the selective formation of functional-group-specific covalent bonds. This feature details our current work and perspective on the developments and current capabilities of these three areas of ion/ion chemistry with an eye towards possible future directions of the field.

Approximations for Markovian multi-class queues with preemptive priorities

NARCIS (Netherlands)

van der Heijden, Matthijs C.; van Harten, Aart; Sleptchenko, Andrei

2004-01-01

We discuss the approximation of performance measures in multi-class M/M/k queues with preemptive priorities for large problem instances (many classes and servers) using class aggregation and server reduction. We compared our approximations to exact and simulation results and found that our approach

Translation in ESL Classes

Directory of Open Access Journals (Sweden)

Nagy Imola Katalin

2015-12-01

Full Text Available The problem of translation in foreign language classes cannot be dealt with unless we attempt to make an overview of what translation meant for language teaching in different periods of language pedagogy. From the translation-oriented grammar-translation method through the complete ban on translation and mother tongue during the times of the audio-lingual approaches, we have come today to reconsider the role and status of translation in ESL classes. This article attempts to advocate for translation as a useful ESL class activity, which can completely fulfil the requirements of communicativeness. We also attempt to identify some activities and games, which rely on translation in some books published in the 1990s and the 2000s.

Is the relativistic approach really useful to nuclear reactions?

CERN Document Server

Miyazaki, K

2003-01-01

We have reconsidered the non-relativistic distorted-wave t-matrix approximation (NR-DWTA) for proton knockout (p,2p) reaction using modern high-quality phenomenological optical potentials and NN t-matrix. We have calculated 40Ca(p,2p) reactions at T_LAB=200MeV and compared the results with the relativistic distorted-wave impulse approximation (RDWIA) calculations. It is found that the NR-DWTA is superior to the RDWIA in consistent description of the cross section and the analyzing power. An immediate relativistic extension of the DWIA to the nuclear reaction has a problem.

Reaction to and Coping With Domestic Violence by Iranian Women Victims: A Qualitative Approach.

Science.gov (United States)

Bahrami, Masoud; Shokrollahi, Paymaneh; Kohan, Shahnaz; Momeni, Ghodratollah; Rivaz, Mozhgan

2015-11-18

Domestic violence is a continual stressor that motivates its victim to react. The way a woman deals with her husband's violence determine the consequence of the violent relationship. In the present study, a qualitative approach was employed to investigate women's reactions to and ways of coping with domestic violence. Semi-structured interviews were conducted in 2014 with 18 women who experienced domestic violence in an attempt to explain how women deal with domestic violence. After the interviews were transcribed word by word, they were explored in the form of meaningful units and encoded as subcategories and categories through inductive content analysis. The reliability and validity of the interviews were measured by an external supervisor. Two categories of reaction and coping were identified through content analysis: passive and non-normative measures and active measures. Passive and non-normative measures included the subcategories of harmful behaviors, retaliation, tolerance, and silence. Active measures included seeking help and advice, legal measures, leaving the spouse, positive and health promoting measures. In the present study, ways of coping with a husband's violence among women experiencing domestic violence were divided into two categories: passive and non-normative measures and active measures. These categories confirmed the models of coping with stress in previous studies. Adopting an appropriate approach to dealing with domestic violence is affected by a woman's capacity and beliefs, the dominant culture, intensity of the violence, available social and legal supports, and effectiveness of evaluation measures. To generalize service provision to victimized women, the type of coping and the reason for adopting the chosen approach need to be taken into account.

Dyslipidemias as generating issue in Biochemistry classes

Directory of Open Access Journals (Sweden)

R. M. Lima

2015-08-01

Full Text Available The traditional didactic model is based on the transmission of the teacher's encyclopedic knowledge. In this model, the teaching of Science aims at the transmission of dominant values, regarded as absolute truths. The teacher is seen is an expert on scientific contents who transmits them to students without motivating them, and without taking into consideration their previous ideas and life experience. This model contributes to the formation of professionals who accept those values uncritically. An effective approach to break up this traditional teaching model in Biochemistry is the use of a generating issue. A Generating Issue is the starting point to the knowledge construction process which, in turn, replaces traditional models. Thus, this study aimed at developing a lesson for a 12th grade class at IF Fluminense on the following content: alcohol, carboxylic acid, ester, and esterification reaction, using dyslipidemias as the Generating Issue. To verify the value of such methodology in Biochemistry classroom, data was collected by applying a questionnaire and images with texts produced by students. In addition, they had a class based on the methodology known as Three Pedagogical Moments, proposed by Delizoicov et al. (2007. Several didactic resources designed by the authors were used, such as slide presentation, tridimensional molecular models, and a roulette game named “Bioquimicados”, based on the Facebook game “Perguntados” ("Trivia Crack". After this, students developed more grounded scientific concepts, making use of terms common in scientific language. This suggests that the use of the Generating Issue in a lesson based on problematization, and supported by a ludic activity, provided a meaningful contribution to improve the students' understanding of the scientific content. This type of non-traditional class promotes greater student motivation, resulting in meaningful learning.

Reversible logic gates based on enzyme-biocatalyzed reactions and realized in flow cells: a modular approach.

Science.gov (United States)

Fratto, Brian E; Katz, Evgeny

2015-05-18

Reversible logic gates, such as the double Feynman gate, Toffoli gate and Peres gate, with 3-input/3-output channels are realized using reactions biocatalyzed with enzymes and performed in flow systems. The flow devices are constructed using a modular approach, where each flow cell is modified with one enzyme that biocatalyzes one chemical reaction. The multi-step processes mimicking the reversible logic gates are organized by combining the biocatalytic cells in different networks. This work emphasizes logical but not physical reversibility of the constructed systems. Their advantages and disadvantages are discussed and potential use in biosensing systems, rather than in computing devices, is suggested. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Thermodynamically-consistent FBA-based Approach to Biogeochemical Reaction Modeling

Science.gov (United States)

Shapiro, B.; Jin, Q.

2015-12-01

Microbial rates are critical to understanding biogeochemical processes in natural environments. Recently, flux balance analysis (FBA) has been applied to predict microbial rates in aquifers and other settings. FBA is a genome-scale constraint-based modeling approach that computes metabolic rates and other phenotypes of microorganisms. This approach requires a prior knowledge of substrate uptake rates, which is not available for most natural microbes. Here we propose to constrain substrate uptake rates on the basis of microbial kinetics. Specifically, we calculate rates of respiration (and fermentation) using a revised Monod equation; this equation accounts for both the kinetics and thermodynamics of microbial catabolism. Substrate uptake rates are then computed from the rates of respiration, and applied to FBA to predict rates of microbial growth. We implemented this method by linking two software tools, PHREEQC and COBRA Toolbox. We applied this method to acetotrophic methanogenesis by Methanosarcina barkeri, and compared the simulation results to previous laboratory observations. The new method constrains acetate uptake by accounting for the kinetics and thermodynamics of methanogenesis, and predicted well the observations of previous experiments. In comparison, traditional methods of dynamic-FBA constrain acetate uptake on the basis of enzyme kinetics, and failed to reproduce the experimental results. These results show that microbial rate laws may provide a better constraint than enzyme kinetics for applying FBA to biogeochemical reaction modeling.

Pain management for children with cerebral palsy in school settings in two cultures: action and reaction approaches.

Science.gov (United States)

Adolfsson, Margareta; Johnson, Ensa; Nilsson, Stefan

2017-05-18

Children with cerebral palsy (CP) face particular challenges, e.g. daily pain that threaten their participation in school activities. This study focuses on how teachers, personal assistants, and clinicians in two countries with different cultural prerequisites, Sweden and South Africa, manage the pain of children in school settings. Participants' statements collected in focus groups were analysed using a directed qualitative content analysis framed by a Frequency of attendance-Intensity of involvement model, which was modified into a Knowing-Doing model. Findings indicated that pain management focused more on children's attendance in the classroom than on their involvement, and a difference between countries in terms of action-versus-reaction approaches. Swedish participants reported action strategies to prevent pain whereas South African participants primarily discussed interventions when observing a child in pain. Differences might be due to school- and healthcare systems. To provide effective support when children with CP are in pain in school settings, an action-and-reaction approach would be optimal and the use of alternative and augmentative communication strategies would help to communicate children's pain. As prevention of pain is desired, structured surveillance and treatment programs are recommended along with trustful collaboration with parents and access to "hands-on" pain management when needed. Implications for rehabilitation • When providing support, hands-on interventions should be supplemented by structured preventive programs and routines for parent collaboration (action-and-reaction approach). • When regulating support, Sweden and South Africa can learn from each other; ○ In Sweden, the implementation of a prevention program has been successful. ○ In South Africa, the possibilities giving support directly when pain in children is observed have been beneficial.

Identifying classes of persons with mild intellectual disability or borderline intellectual functioning: a latent class analysis.

Science.gov (United States)

Nouwens, Peter J G; Lucas, Rosanne; Smulders, Nienke B M; Embregts, Petri J C M; van Nieuwenhuizen, Chijs

2017-07-17

Persons with mild intellectual disability or borderline intellectual functioning are often studied as a single group with similar characteristics. However, there are indications that differences exist within this population. Therefore, the aim of this study was to identify classes of persons with mild intellectual disability or borderline intellectual functioning and to examine whether these classes are related to individual and/or environmental characteristics. Latent class analysis was performed using file data of 250 eligible participants with a mean age of 26.1 (SD 13.8, range 3-70) years. Five distinct classes of persons with mild intellectual disability or borderline intellectual functioning were found. These classes significantly differed in individual and environmental characteristics. For example, persons with a mild intellectual disability experienced fewer problems than those with borderline intellectual disability. The identification of five classes implies that a differentiated approach is required towards persons with mild intellectual disability or borderline intellectual functioning.

A novel approach to sports concussion assessment: Computerized multilimb reaction times and balance control testing.

Science.gov (United States)

Vartiainen, Matti V; Holm, Anu; Lukander, Jani; Lukander, Kristian; Koskinen, Sanna; Bornstein, Robert; Hokkanen, Laura

2016-01-01

Mild traumatic brain injuries (MTBI) or concussions often result in problems with attention, executive functions, and motor control. For better identification of these diverse problems, novel approaches integrating tests of cognitive and motor functioning are needed. The aim was to characterize minor changes in motor and cognitive performance after sports-related concussions with a novel test battery, including balance tests and a computerized multilimb reaction time test. The cognitive demands of the battery gradually increase from a simple stimulus response to a complex task requiring executive attention. A total of 113 male ice hockey players (mean age = 24.6 years, SD = 5.7) were assessed before a season. During the season, nine concussed players were retested within 36 hours, four to six days after the concussion, and after the season. A control group of seven nonconcussed players from the same pool of players with comparable demographics were retested after the season. Performance was measured using a balance test and the Motor Cognitive Test battery (MotCoTe) with multilimb responses in simple reaction, choice reaction, inhibition, and conflict resolution conditions. The performance of the concussed group declined at the postconcussion assessment compared to both the baseline measurement and the nonconcussed controls. Significant changes were observed in the concussed group for the multilimb choice reaction and inhibition tests. Tapping and balance showed a similar trend, but no statistically significant difference in performance. In sports-related concussions, complex motor tests can be valuable additions in assessing the outcome and recovery. In the current study, using subtasks with varying cognitive demands, it was shown that while simple motor performance was largely unaffected, the more complex tasks induced impaired reaction times for the concussed subjects. The increased reaction times may reflect the disruption of complex and integrative cognitive

Modeling Studies of Inhomogeneity Effects during Laser Flash Photolysis Experiments: A Reaction-Diffusion Approach.

Science.gov (United States)

Dóka, Éva; Lente, Gábor

2017-04-13

This work presents a rigorous mathematical study of the effect of unavoidable inhomogeneities in laser flash photolysis experiments. There are two different kinds of inhomegenities: the first arises from diffusion, whereas the second one has geometric origins (the shapes of the excitation and detection light beams). Both of these are taken into account in our reported model, which gives rise to a set of reaction-diffusion type partial differential equations. These equations are solved by a specially developed finite volume method. As an example, the aqueous reaction between the sulfate ion radical and iodide ion is used, for which sufficiently detailed experimental data are available from an earlier publication. The results showed that diffusion itself is in general too slow to influence the kinetic curves on the usual time scales of laser flash photolysis experiments. However, the use of the absorbances measured (e.g., to calculate the molar absorption coefficients of transient species) requires very detailed mathematical consideration and full knowledge of the geometrical shapes of the excitation laser beam and the separate detection light beam. It is also noted that the usual pseudo-first-order approach to evaluating the kinetic traces can be used successfully even if the usual large excess condition is not rigorously met in the reaction cell locally.

The structural dynamics of social class.

Science.gov (United States)

Kraus, Michael W; Park, Jun Won

2017-12-01

Individual agency accounts of social class persist in society and even in psychological science despite clear evidence for the role of social structures. This article argues that social class is defined by the structural dynamics of society. Specifically, access to powerful networks, groups, and institutions, and inequalities in wealth and other economic resources shape proximal social environments that influence how individuals express their internal states and motivations. An account of social class that highlights the means by which structures shape and are shaped by individuals guides our understanding of how people move up or down in the social class hierarchy, and provides a framework for interpreting neuroscience studies, experimental paradigms, and approaches that attempt to intervene on social class disparities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Healthy cooking classes at a children’s cancer hospital and patient/survivor summer camp: initial reactions and feasibility

Science.gov (United States)

Raber, Margaret; Crawford, Karla; Chandra, Joya

2018-01-01

Objective Childhood cancer survivors (CCS) have been shown to practice sub-optimal dietary intake and may benefit from nutrition interventions during and after treatment. Cooking classes have become popular for encouraging healthy eating behaviors in community-based programming and academic research, however, literature on teaching cooking classes in CCS is limited. The purpose of this study is to address the development and implementation of classes for CCS based on a recently developed framework of healthy cooking behavior. Design A conceptual framework was developed from a systematic literature review and used to guide healthy cooking classes for CCS in different settings. Setting One pediatric cancer hospital inpatient unit, one pediatric cancer in-hospital camp program and two off-site pediatric cancer summer camp programs. Subjects One hundred and eighty nine CCS of varying ages and thirteen parents of CCS. Results Seventeen classes were taught at camps and seven classes in the hospital inpatient unit. Healthy cooking classes based on the conceptual framework are feasible and were well received by CCS. Conclusions Cooking classes for CCS, both at the hospital and at camp, reinforced the principles of the conceptual framework. Future trials should assess the dietary and anthropometric impact of evidence-based healthy cooking classes in CCS. PMID:28463101

On the treatment of exchange effects in direct reactions

International Nuclear Information System (INIS)

Bencze, G.; Chandler, C.; Argonne National Lab., IL; New Mexico Univ., Albuquerque

1985-01-01

Exchange effects in direct reactions are investigated in the framework of the general algebraic theory of identical particle scattering. It is shown that effects due to the permutation symmetry of the system can be separated from the treatment of reaction dynamics. Dynamical aspects of the problem are investigated within the framework of the channel coupling class of N-body theories. (orig.)

Rates of Thermonuclear Reactions in Dense Plasmas

International Nuclear Information System (INIS)

Tsytovich, V.N.; Bornatici, M.

2000-01-01

The problem of plasma screening of thermonuclear reactions has attracted considerable scientific interest ever since Salpeter's seminal paper, but it is still faced with controversial statements and without any definite conclusion. It is of relevant importance to thermonuclear reactions in dense astrophysical plasmas, for which charge screening can substantially affect the reaction rates. Whereas Salpeter and a number of subsequent investigations have dealt with static screening, Carraro, Schafer, and Koonin have drawn attention to the fact that plasma screening of thermonuclear reactions is an essentially dynamic effect. In addressing the issue of collective plasma effects on the thermonuclear reaction rates, the first critical overview of most of the work carried out so far is presented and the validity of the test particle approach is assessed. In contrast to previous investigations, we base our description on the kinetic equation for nonequilibrium plasmas, which accounts for the effects on the rates of thermonuclear reactions of both plasma fluctuations and screening and allows one to analyze explicitly the effects of the fluctuations on the reaction rates. Such a kinetic formulation is more general than both Salpeter's approach and the recently developed statistical approaches and makes it possible to obtain a more comprehensive understanding of the problem. A noticeable result of the fluctuation approach is that the static screening, which affects both the interaction and the self-energy of the reacting nuclei, does not affect the reaction rates, in contrast with the results obtained so far. Instead, a reduction of the thermonuclear reaction rates is obtained as a result of the effect of plasma fluctuations related to the free self-energy of the reacting nuclei. A simple physical explanation of the slowing down of the reaction rates is given, and the relation to the dynamically screened test particle approach is discussed. Corrections to the reaction rates

Organometallic copper I, II or III species in an intramolecular dechlorination reaction

KAUST Repository

Poater, Albert; Cavallo, Luigi

2013-01-01

these species are less stable than other isomers. Thus this study constitutes an additional piece towards the full understanding of a class of reaction of biological relevance. Further, the lack of high energy barriers and deep energy wells along the reaction

General theory of the multistage geminate reactions of the isolated pairs of reactants. II. Detailed balance and universal asymptotes of kinetics.

Science.gov (United States)

Kipriyanov, Alexey A; Doktorov, Alexander B

2014-10-14

The analysis of general (matrix) kinetic equations for the mean survival probabilities of any of the species in a sample (or mean concentrations) has been made for a wide class of the multistage geminate reactions of the isolated pairs. These kinetic equations (obtained in the frame of the kinetic approach based on the concept of "effective" particles in Paper I) take into account various possible elementary reactions (stages of a multistage reaction) excluding monomolecular, but including physical and chemical processes of the change in internal quantum states carried out with the isolated pairs of reactants (or isolated reactants). The general basic principles of total and detailed balance have been established. The behavior of the reacting system has been considered on macroscopic time scales, and the universal long-term kinetics has been determined.

Dynamic phase transition in diffusion-limited reactions

International Nuclear Information System (INIS)

Tauber, U.C.

2002-01-01

Many non-equilibrium systems display dynamic phase transitions from active to absorbing states, where fluctuations cease entirely. Based on a field theory representation of the master equation, the critical behavior can be analyzed by means of the renormalization group. The resulting universality classes for single-species systems are reviewed here. Generically, the critical exponents are those of directed percolation (Reggeon field theory), with critical dimension d c = 4. Yet local particle number parity conservation in even-offspring branching and annihilating random walks implies an inactive phase (emerging below d c = 4/3) that is characterized by the power laws of the pair annihilation reaction, and leads to different critical exponents at the transition. For local processes without memory, the pair contact process with diffusion represents the only other non-trivial universality class. The consistent treatment of restricted site occupations and quenched random reaction rates are important open issues (Author)

75 FR 12165 - Class E Airspace; Batesville, AR

Science.gov (United States)

2010-03-15

...-1177; Airspace Docket No. 09-ASW-34] Class E Airspace; Batesville, AR AGENCY: Federal Aviation... Class E airspace at Batesville, AR. Decommissioning of the Independence County non-directional beacon... for standard instrument approach procedures at Batesville Regional Airport, Batesville, AR. Airspace...

Bacterial discrimination by means of a universal array approach mediated by LDR (ligase detection reaction

Directory of Open Access Journals (Sweden)

Consolandi Clarissa

2002-09-01

Full Text Available Abstract Background PCR amplification of bacterial 16S rRNA genes provides the most comprehensive and flexible means of sampling bacterial communities. Sequence analysis of these cloned fragments can provide a qualitative and quantitative insight of the microbial population under scrutiny although this approach is not suited to large-scale screenings. Other methods, such as denaturing gradient gel electrophoresis, heteroduplex or terminal restriction fragment analysis are rapid and therefore amenable to field-scale experiments. A very recent addition to these analytical tools is represented by microarray technology. Results Here we present our results using a Universal DNA Microarray approach as an analytical tool for bacterial discrimination. The proposed procedure is based on the properties of the DNA ligation reaction and requires the design of two probes specific for each target sequence. One oligo carries a fluorescent label and the other a unique sequence (cZipCode or complementary ZipCode which identifies a ligation product. Ligated fragments, obtained in presence of a proper template (a PCR amplified fragment of the 16s rRNA gene contain either the fluorescent label or the unique sequence and therefore are addressed to the location on the microarray where the ZipCode sequence has been spotted. Such an array is therefore "Universal" being unrelated to a specific molecular analysis. Here we present the design of probes specific for some groups of bacteria and their application to bacterial diagnostics. Conclusions The combined use of selective probes, ligation reaction and the Universal Array approach yielded an analytical procedure with a good power of discrimination among bacteria.

Type classes for mathematics in type theory

OpenAIRE

Spitters, Bas; Van der Weegen, Eelis

2011-01-01

The introduction of first-class type classes in the Coq system calls for re-examination of the basic interfaces used for mathematical formalization in type theory. We present a new set of type classes for mathematics and take full advantage of their unique features to make practical a particularly flexible approach formerly thought infeasible. Thus, we address both traditional proof engineering challenges as well as new ones resulting from our ambition to build upon this development a library...

Class and Politics in Denmark: Are Both Old and New Politics Structured by Class?

DEFF Research Database (Denmark)

Harrits, Gitte Sommer; Prieur, Annick; Rosenlund, Lennart

2010-01-01

The trend within studies of voting and political attitudes has been to give less attention to class as a structuring dimension and more to post-material values. The basic argument of this article is that this is a false opposition: The adherence to different sets of values is related to social...... background, although in complex ways, which can only be discovered with a multidimensional conception of what class is. This conception may be found in Pierre Bourdieu's analytical approach, which we here apply in an analysis of survey data from a Danish city, Aalborg. Data from a survey of political...... the constructed space of attitudes to a set of indicators based on a two-dimensional conception of social class. On the basis of this analysis the article concludes that the political landscape appears as highly structured by the two principles of social differentiation from Bourdieu’s class model: volume...

Molecular Interactions and Reaction Dynamics in Supercritical Water Oxidation

National Research Council Canada - National Science Library

Johnston, K

1998-01-01

.... From UV-vis spectroscopic measurements and molecular dynamics simulation of chemical equilibria, we have shown that density effects on broad classes of reactions may be explained in terms of changes...

Structure-reactivity modeling using mixture-based representation of chemical reactions.

Science.gov (United States)

Polishchuk, Pavel; Madzhidov, Timur; Gimadiev, Timur; Bodrov, Andrey; Nugmanov, Ramil; Varnek, Alexandre

2017-09-01

We describe a novel approach of reaction representation as a combination of two mixtures: a mixture of reactants and a mixture of products. In turn, each mixture can be encoded using an earlier reported approach involving simplex descriptors (SiRMS). The feature vector representing these two mixtures results from either concatenated product and reactant descriptors or the difference between descriptors of products and reactants. This reaction representation doesn't need an explicit labeling of a reaction center. The rigorous "product-out" cross-validation (CV) strategy has been suggested. Unlike the naïve "reaction-out" CV approach based on a random selection of items, the proposed one provides with more realistic estimation of prediction accuracy for reactions resulting in novel products. The new methodology has been applied to model rate constants of E2 reactions. It has been demonstrated that the use of the fragment control domain applicability approach significantly increases prediction accuracy of the models. The models obtained with new "mixture" approach performed better than those required either explicit (Condensed Graph of Reaction) or implicit (reaction fingerprints) reaction center labeling.

Precompound Reactions: Basic Concepts

International Nuclear Information System (INIS)

Weidenmueller, H. A.

2008-01-01

Because of the non-zero nuclear equilibration time, the compound-nucleus scattering model fails when the incident energy exceeds 10 or 20 MeV, and precompound reactions become important. Basic ideas used in the quantum-statistical approaches to these reactions are described

SISGR - In situ characterization and modeling of formation reactions under extreme heating rates in nanostructured multilayer foils

Energy Technology Data Exchange (ETDEWEB)

Hufnagel, Todd C.

2014-06-09

Materials subjected to extreme conditions, such as very rapid heating, behave differently than materials under more ordinary conditions. In this program we examined the effect of rapid heating on solid-state chemical reactions in metallic materials. One primary goal was to develop experimental techniques capable of observing these reactions, which can occur at heating rates in excess of one million degrees Celsius per second. One approach that we used is x-ray diffraction performed using microfocused x-ray beams and very fast x-ray detectors. A second approach is the use of a pulsed electron source for dynamic transmission electron microscopy. With these techniques we were able to observe how the heating rate affects the chemical reaction, from which we were able to discern general principles about how these reactions proceed. A second thrust of this program was to develop computational tools to help us understand and predict the reactions. From atomic-scale simulations were learned about the interdiffusion between different metals at high heating rates, and about how new crystalline phases form. A second class of computational models allow us to predict the shape of the reaction front that occurs in these materials, and to connect our understanding of interdiffusion from the atomistic simulations to measurements made in the laboratory. Both the experimental and computational techniques developed in this program are expected to be broadly applicable to a wider range of scientific problems than the intermetallic solid-state reactions studied here. For example, we have already begun using the x-ray techniques to study how materials respond to mechanical deformation at very high rates.

Interdisciplinary orthognathic treatment of high angle class III ...

African Journals Online (AJOL)

For Class III adult patients, combined treatment strategy must be followed which includes either further dentoalveolar compensation or orthognathic surgery following decompensation of the teeth. This case report presents the interdisciplinary approach of a skeletal Class III malocclusion with increased vertical facial ...

Safety class methodology

International Nuclear Information System (INIS)

Donner, E.B.; Low, J.M.; Lux, C.R.

1992-01-01

DOE Order 6430.1A, General Design Criteria (GDC), requires that DOE facilities be evaluated with respect to ''safety class items.'' Although the GDC defines safety class items, it does not provide a methodology for selecting safety class items. The methodology described in this paper was developed to assure that Safety Class Items at the Savannah River Site (SRS) are selected in a consistent and technically defensible manner. Safety class items are those in the highest of four categories determined to be of special importance to nuclear safety and, merit appropriately higher-quality design, fabrication, and industrial test standards and codes. The identification of safety class items is approached using a cascading strategy that begins at the 'safety function' level (i.e., a cooling function, ventilation function, etc.) and proceeds down to the system, component, or structure level. Thus, the items that are required to support a safety function are SCls. The basic steps in this procedure apply to the determination of SCls for both new project activities, and for operating facilities. The GDC lists six characteristics of SCls to be considered as a starting point for safety item classification. They are as follows: 1. Those items whose failure would produce exposure consequences that would exceed the guidelines in Section 1300-1.4, ''Guidance on Limiting Exposure of the Public,'' at the site boundary or nearest point of public access 2. Those items required to maintain operating parameters within the safety limits specified in the Operational Safety Requirements during normal operations and anticipated operational occurrences. 3. Those items required for nuclear criticality safety. 4. Those items required to monitor the release of radioactive material to the environment during and after a Design Basis Accident. Those items required to achieve, and maintain the facility in a safe shutdown condition 6. Those items that control Safety Class Item listed above

Ring-Expansion/Contraction Radical Crossover Reactions of Cyclic Alkoxyamines: A Mechanism for Ring Expansion-Controlled Radical Polymerization

Directory of Open Access Journals (Sweden)

Atsushi Narumi

2018-06-01

Full Text Available Macrocyclic polymers present an important class of macromolecules, displaying the reduced radius of gyration or impossibility to entangle. A rare approach for their synthesis is the ring expansion-controlled radical “vinyl” polymerization, starting from a cyclic alkoxyamine. We here describe ring-expansion radical crossover reactions of cyclic alkoxyamines which run in parallel to chain-propagation reactions in the polymerization system. The radical crossover reactions extensively occurred at 105–125 °C, eventually producing high molecular weight polymers with multiple inherent dynamic covalent bonds (NOC bonds. A subsequent ring-contraction radical crossover reaction and the second ring-expansion radical crossover reaction are also described. The major products for the respective three stages were shown to possess cyclic morphologies by the molecular weight profiles and the residual ratios for the NOC bonds (φ in %. In particular, the high φ values ranging from ca. 80% to 98% were achieved for this cyclic alkoxyamine system. This result verifies the high availability of this system as a tool demonstrating the ring-expansion “vinyl” polymerization that allows them to produce macrocyclic polymers via a one-step vinyl polymerization.

Interfacial reactions in intermetallic matrix composites

International Nuclear Information System (INIS)

Cantrell, L.B.; Clevenger, E.M.; Perepezko, J.H.

1993-01-01

The thermal stability of advanced composites is dominated by the behavior of internal interfaces. Analysis of these internal interfaces often involves consideration of at least ternary order phase equilibria. Limited thermodynamic data exists for ternary and higher order systems. However, a combined approach based upon the use of binary data to estimate ternary phase equilibria and experimentally determined reaction pathways is effective in the analysis of interface reactions in composite systems. In blended powder samples, thermal analysis was used to find possible reaction temperatures, while X-ray analysis, EDS, and EPMA of diffusion couples were used to assess interdiffusion reaction pathways. The approach is illustrated by compatibility studies between TiAl and TiSi 2 at 1,100 C, and in-situ reactions between B 4 C and TiAl at 1300 C where multiple reaction sequences have been analyzed to provide guidance for the design of in-situ reaction processing of composites

Sparse Solutions for Single Class SVMs: A Bi-Criterion Approach

Data.gov (United States)

National Aeronautics and Space Administration — In this paper we propose an innovative learning algorithm - a variation of One-class Support Vector Machines (SVMs) learning algorithm to produce sparser solutions...

75 FR 12162 - Class E Airspace; Manila, AR

Science.gov (United States)

2010-03-15

...-1184; Airspace Docket No. 09-ASW-39] Class E Airspace; Manila, AR AGENCY: Federal Aviation... Class E airspace at Manila, AR. Decommissioning of the Manila non-directional beacon (NDB) at Manila... instrument approach procedures at Manila Municipal Airport, Manila, AR. Airspace reconfiguration is necessary...

Runtime Support for Type-Safe Dynamic Java Classes

National Research Council Canada - National Science Library

Malabarba, Scott; Pandey, Raju; Gragg, Jeff; Barr, Earl; Barnes, J. F

2000-01-01

.... In this paper we present an approach for supporting dynamic evolution of Java programs. In this approach, Java programs can evolve by changing their components, namely classes, during their execution...

Learning to predict chemical reactions.

Science.gov (United States)

Kayala, Matthew A; Azencott, Chloé-Agathe; Chen, Jonathan H; Baldi, Pierre

2011-09-26

Being able to predict the course of arbitrary chemical reactions is essential to the theory and applications of organic chemistry. Approaches to the reaction prediction problems can be organized around three poles corresponding to: (1) physical laws; (2) rule-based expert systems; and (3) inductive machine learning. Previous approaches at these poles, respectively, are not high throughput, are not generalizable or scalable, and lack sufficient data and structure to be implemented. We propose a new approach to reaction prediction utilizing elements from each pole. Using a physically inspired conceptualization, we describe single mechanistic reactions as interactions between coarse approximations of molecular orbitals (MOs) and use topological and physicochemical attributes as descriptors. Using an existing rule-based system (Reaction Explorer), we derive a restricted chemistry data set consisting of 1630 full multistep reactions with 2358 distinct starting materials and intermediates, associated with 2989 productive mechanistic steps and 6.14 million unproductive mechanistic steps. And from machine learning, we pose identifying productive mechanistic steps as a statistical ranking, information retrieval problem: given a set of reactants and a description of conditions, learn a ranking model over potential filled-to-unfilled MO interactions such that the top-ranked mechanistic steps yield the major products. The machine learning implementation follows a two-stage approach, in which we first train atom level reactivity filters to prune 94.00% of nonproductive reactions with a 0.01% error rate. Then, we train an ensemble of ranking models on pairs of interacting MOs to learn a relative productivity function over mechanistic steps in a given system. Without the use of explicit transformation patterns, the ensemble perfectly ranks the productive mechanism at the top 89.05% of the time, rising to 99.86% of the time when the top four are considered. Furthermore, the system

Learning to Predict Chemical Reactions

Science.gov (United States)

Kayala, Matthew A.; Azencott, Chloé-Agathe; Chen, Jonathan H.

2011-01-01

Being able to predict the course of arbitrary chemical reactions is essential to the theory and applications of organic chemistry. Approaches to the reaction prediction problems can be organized around three poles corresponding to: (1) physical laws; (2) rule-based expert systems; and (3) inductive machine learning. Previous approaches at these poles respectively are not high-throughput, are not generalizable or scalable, or lack sufficient data and structure to be implemented. We propose a new approach to reaction prediction utilizing elements from each pole. Using a physically inspired conceptualization, we describe single mechanistic reactions as interactions between coarse approximations of molecular orbitals (MOs) and use topological and physicochemical attributes as descriptors. Using an existing rule-based system (Reaction Explorer), we derive a restricted chemistry dataset consisting of 1630 full multi-step reactions with 2358 distinct starting materials and intermediates, associated with 2989 productive mechanistic steps and 6.14 million unproductive mechanistic steps. And from machine learning, we pose identifying productive mechanistic steps as a statistical ranking, information retrieval, problem: given a set of reactants and a description of conditions, learn a ranking model over potential filled-to-unfilled MO interactions such that the top ranked mechanistic steps yield the major products. The machine learning implementation follows a two-stage approach, in which we first train atom level reactivity filters to prune 94.00% of non-productive reactions with a 0.01% error rate. Then, we train an ensemble of ranking models on pairs of interacting MOs to learn a relative productivity function over mechanistic steps in a given system. Without the use of explicit transformation patterns, the ensemble perfectly ranks the productive mechanism at the top 89.05% of the time, rising to 99.86% of the time when the top four are considered. Furthermore, the system

ReactionPredictor: prediction of complex chemical reactions at the mechanistic level using machine learning.

Science.gov (United States)

Kayala, Matthew A; Baldi, Pierre

2012-10-22

Proposing reasonable mechanisms and predicting the course of chemical reactions is important to the practice of organic chemistry. Approaches to reaction prediction have historically used obfuscating representations and manually encoded patterns or rules. Here we present ReactionPredictor, a machine learning approach to reaction prediction that models elementary, mechanistic reactions as interactions between approximate molecular orbitals (MOs). A training data set of productive reactions known to occur at reasonable rates and yields and verified by inclusion in the literature or textbooks is derived from an existing rule-based system and expanded upon with manual curation from graduate level textbooks. Using this training data set of complex polar, hypervalent, radical, and pericyclic reactions, a two-stage machine learning prediction framework is trained and validated. In the first stage, filtering models trained at the level of individual MOs are used to reduce the space of possible reactions to consider. In the second stage, ranking models over the filtered space of possible reactions are used to order the reactions such that the productive reactions are the top ranked. The resulting model, ReactionPredictor, perfectly ranks polar reactions 78.1% of the time and recovers all productive reactions 95.7% of the time when allowing for small numbers of errors. Pericyclic and radical reactions are perfectly ranked 85.8% and 77.0% of the time, respectively, rising to >93% recovery for both reaction types with a small number of allowed errors. Decisions about which of the polar, pericyclic, or radical reaction type ranking models to use can be made with >99% accuracy. Finally, for multistep reaction pathways, we implement the first mechanistic pathway predictor using constrained tree-search to discover a set of reasonable mechanistic steps from given reactants to given products. Webserver implementations of both the single step and pathway versions of Reaction

Class Energy Image Analysis for Video Sensor-Based Gait Recognition: A Review

Directory of Open Access Journals (Sweden)

Zhuowen Lv

2015-01-01

Full Text Available Gait is a unique perceptible biometric feature at larger distances, and the gait representation approach plays a key role in a video sensor-based gait recognition system. Class Energy Image is one of the most important gait representation methods based on appearance, which has received lots of attentions. In this paper, we reviewed the expressions and meanings of various Class Energy Image approaches, and analyzed the information in the Class Energy Images. Furthermore, the effectiveness and robustness of these approaches were compared on the benchmark gait databases. We outlined the research challenges and provided promising future directions for the field. To the best of our knowledge, this is the first review that focuses on Class Energy Image. It can provide a useful reference in the literature of video sensor-based gait representation approach.

A variational approach to moment-closure approximations for the kinetics of biomolecular reaction networks

Science.gov (United States)

Bronstein, Leo; Koeppl, Heinz

2018-01-01

Approximate solutions of the chemical master equation and the chemical Fokker-Planck equation are an important tool in the analysis of biomolecular reaction networks. Previous studies have highlighted a number of problems with the moment-closure approach used to obtain such approximations, calling it an ad hoc method. In this article, we give a new variational derivation of moment-closure equations which provides us with an intuitive understanding of their properties and failure modes and allows us to correct some of these problems. We use mixtures of product-Poisson distributions to obtain a flexible parametric family which solves the commonly observed problem of divergences at low system sizes. We also extend the recently introduced entropic matching approach to arbitrary ansatz distributions and Markov processes, demonstrating that it is a special case of variational moment closure. This provides us with a particularly principled approximation method. Finally, we extend the above approaches to cover the approximation of multi-time joint distributions, resulting in a viable alternative to process-level approximations which are often intractable.

Project Based Learning in Multi-Grade Class

Science.gov (United States)

Ciftci, Sabahattin; Baykan, Ayse Aysun

2013-01-01

The purpose of this study is to evaluate project based learning in multi-grade classes. This study, based on a student-centered learning approach, aims to analyze students' and parents' interpretations. The study was done in a primary village school belonging to the Centre of Batman, already adapting multi-grade classes in their education system,…

Metal-free bioconjugation reactions.

Science.gov (United States)

van Berkel, Sander S; van Delft, Floris L

2013-01-01

The recent strategy to apply chemical reactions to address fundamental biological questions has led to the emergence of entirely new conjugation reactions that are fast and irreversible, yet so mild and selective that they can be performed even in living cells or organisms. These so-called bioorthogonal reactions open novel avenues, not only in chemical biology research, but also in many other life sciences applications, including the modulation of biopharmaceuticals by site-specific modification approaches.

An Innovative Approach to Balancing Chemical-Reaction Equations: A Simplified Matrix-Inversion Technique for Determining The Matrix Null Space

OpenAIRE

Thorne, Lawrence R.

2011-01-01

I propose a novel approach to balancing equations that is applicable to all chemical-reaction equations; it is readily accessible to students via scientific calculators and basic computer spreadsheets that have a matrix-inversion application. The new approach utilizes the familiar matrix-inversion operation in an unfamiliar and innovative way; its purpose is not to identify undetermined coefficients as usual, but, instead, to compute a matrix null space (or matrix kernel). The null space then...

Behavioral and Mental Health Correlates of Youth Stalking Victimization: A Latent Class Approach.

Science.gov (United States)

Reidy, Dennis E; Smith-Darden, Joanne P; Kernsmith, Poco D

2016-12-01

Although recognized as a public health problem, little attention has been paid to the problem of stalking among youth. Latent profile analysis was used to identify latent groups of adolescent stalking victims and their behavioral and mental health correlates. A cross-sectional sample of 1,236 youths were randomly selected from 13 schools stratified by community risk level (i.e., low, moderate, and high risk) and gender. Students completed surveys assessing behavioral indicators of stalking victimization, as well as substance use, sexual behavior, dating violence, and psychiatric symptoms. Data were collected in 2013 and data analyses were performed in 2015. Analysis indicated the presence of a non-victim class, a minimal exposure class, and a victim class for boys and girls alike. Approximately 14% of girls and 13% of boys were in the stalking victim class. Adolescents in the victim class reported more symptoms of post-traumatic stress, mood disorder, and hopelessness, as well as more instances of alcohol use, binge drinking, and physical dating violence victimization. Girls in the victim class also reported engaging in sexting behaviors and oral sex with significantly more partners than their non-victim peers. These findings provide valuable knowledge of the prevalence and pertinent health correlates of stalking victimization in adolescence. The data suggest a substantial proportion of adolescents are victims of stalking and are likewise at risk for a number of deleterious health outcomes. As such, this population merits further attention by prevention researchers and practitioners. Published by Elsevier Inc.

IgE-mediated hypersensitivity reactions to cannabis in laboratory personnel.

Science.gov (United States)

Herzinger, T; Schöpf, P; Przybilla, B; Ruëff, F

2011-01-01

There have been sporadic reports of hypersensitivity reactions to plants of the Cannabinaceae family (hemp and hops), but it has remained unclear whether these reactions are immunologic or nonimmunologic in nature. We examined the IgE-binding and histamine-releasing properties of hashish and marijuana extracts by CAP-FEIA and a basophil histamine release test. Two workers at a forensic laboratory suffered from nasal congestion, rhinitis, sneezing and asthmatic symptoms upon occupational contact with hashish or marijuana, which they had handled frequently for 25 and 16 years, respectively. Neither patient had a history of atopic disease. Serum was analyzed for specific IgE antibodies to hashish or marijuana extract by research prototype ImmunoCAP, and histamine release from basophils upon exposure to hashish or marijuana extracts was assessed. Results were matched to those of 4 nonatopic and 10 atopic control subjects with no known history of recreational or occupational exposure to marijuana or hashish. Patient 1 had specific IgE to both hashish and marijuana (CAP class 2), and patient 2 to marijuana only (CAP class 2). Controls proved negative for specific IgE except for 2 atopic individuals with CAP class 1 to marijuana and 1 other atopic individual with CAP class 1 to hashish. Stimulation of basophils with hashish or marijuana extracts elicited histamine release from basophils of both patients and 4 atopic control subjects. Our results suggest an IgE-related pathomechanism for hypersensitivity reactions to marijuana or hashish. Copyright © 2011 S. Karger AG, Basel.

76 FR 70051 - Establishment of Class D and Amendment of Class E Airspace; Los Angeles, CA

Science.gov (United States)

2011-11-10

... approach instructions currently require this communication. Also of concern was that the FAA pursues a full... Los Angeles Class B airspace area may provide a unified airspace utilization solution in the Los...

A new approach to the Danish guidelines for fire protection of combustible insulation

Directory of Open Access Journals (Sweden)

Dragsted Anders

2013-11-01

Full Text Available The tendency to use thicker layers of insulation and a wider use of combustible insulation materials is identified to pose a potential risk to fire safety of buildings. A new approach to the current Danish prescriptive code on fire protection of combustible insulation is proposed as a way to meet the concern. The new approach uses the fire properties of the insulation material itself to point out the necessary protective measures. This is contrary to the most European countries were only a reaction to fire class of the façade construction as a whole is required. The basic principle is presented but more research is needed to complete the new approach.

Exploring Class-Based Intersectionality

Science.gov (United States)

Block, David; Corona, Victor

2014-01-01

This paper argues that language, culture and identity researchers need to take the intersectionality of identity inscriptions seriously and, further to this, that an intersectional approach which emanates from an interest in social class provides a productive way to examine the lives and experience of individuals living in multicultural societies.…

Study of hyperon-nucleon interactions with d(e,e'K) reactions

International Nuclear Information System (INIS)

Lee, T.-S. H.

1998-01-01

The dependence of the d(e,eprimeK + ) reaction cross sections on the hyperon-nucleon interactions is investigated. It is shown that the data obtained with Longitudinal-Transverse separation or polarized photons can distinguish a class of Nijmegen models of hyperon-nucleon interactions which are χ 2 -equivalent in fitting the existing 35 data points of hyperon-nucleon reactions

The Character Strengths of Class Clowns

Directory of Open Access Journals (Sweden)

Willibald F. Ruch

2014-09-01

Full Text Available Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of identified as a class clown, comic talent, disruptive rule-breaker, and subversive joker. Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park & Peterson, 2006 showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, generally class clown behaviors were shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors identified as the class clown and comic talent were correlated with leadership strengths and the two negative factors (disruptive rule-breaker, subversive joker were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by teachers.

The character strengths of class clowns.

Science.gov (United States)

Ruch, Willibald; Platt, Tracey; Hofmann, Jennifer

2014-01-01

Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of "identified as a class clown," "comic talent," "disruptive rule-breaker," and "subversive joker." Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park and Peterson, 2006) showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, class clown behaviors were generally shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors "identified as the class clown" and "comic talent" were correlated with leadership strengths and the two negative factors ("disruptive rule-breaker," "subversive joker") were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by teachers.

Hierarchical object class representation using holes and notches

Energy Technology Data Exchange (ETDEWEB)

Osbourn, G.C.

1989-01-01

A general representation approach is described which employs a hierarchy of holes and notches. A matching procedure is also described which allows non-ideal image hierarchies to be matched to class representations. The representation and matching methods are demonstrated on a set of handgun photographs. Examples of handguns which are different in detail are shown to exhibit the same class characteristics, while other similarly shaped objects are correctly distinguished from the handgun class. 6 refs., 8 figs.

High-throughput multiplex HLA-typing by ligase detection reaction (LDR) and universal array (UA) approach.

Science.gov (United States)

Consolandi, Clarissa

2009-01-01

One major goal of genetic research is to understand the role of genetic variation in living systems. In humans, by far the most common type of such variation involves differences in single DNA nucleotides, and is thus termed single nucleotide polymorphism (SNP). The need for improvement in throughput and reliability of traditional techniques makes it necessary to develop new technologies. Thus the past few years have witnessed an extraordinary surge of interest in DNA microarray technology. This new technology offers the first great hope for providing a systematic way to explore the genome. It permits a very rapid analysis of thousands genes for the purpose of gene discovery, sequencing, mapping, expression, and polymorphism detection. We generated a series of analytical tools to address the manufacturing, detection and data analysis components of a microarray experiment. In particular, we set up a universal array approach in combination with a PCR-LDR (polymerase chain reaction-ligation detection reaction) strategy for allele identification in the HLA gene.

Instruction sequence based non-uniform complexity classes

NARCIS (Netherlands)

Bergstra, J.A.; Middelburg, C.A.

2013-01-01

We present an approach to non-uniform complexity in which single-pass instruction sequences play a key part, and answer various questions that arise from this approach. We introduce several kinds of non-uniform complexity classes. One kind includes a counterpart of the well-known non-uniform

Nuclear Astrophysics and Neutron Induced Reactions: Quasi-Free Reactions and RIBs

International Nuclear Information System (INIS)

Cherubini, S.; Spitaleri, C.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Coc, A.; Kubono, S.; Binh, D. N.; Hayakawa, S.; Wakabayashi, Y.; Yamaguchi, H.; Burjan, V.; Kroha, V.; De Sereville, N.

2010-01-01

The use of quasi-free reactions in studying nuclear reactions between charged particles of astrophysical interest has received much attention over the last two decades. The Trojan Horse Method is based on this approach and it has been used to study a number of reactions relevant for Nuclear Astrophysics. Recently we applied this method to the study of nuclear reactions that involve radioactive species, namely to the study of the 18 F+p→ 15 O+α process at temperatures corresponding to the energies available in the classical novae scenario. Quasi-free reactions can also be exploited to study processes induced by neutrons. This technique is particularly interesting when applied to reaction induced by neutrons on unstable short-lived nuclei. Such processes are very important in the nucleosynthesis of elements in the sand r-processes scenarios and this technique can give hints for solving key questions in nuclear astrophysics where direct measurements are practically impossible.

Flexible Word Classes

DEFF Research Database (Denmark)

• First major publication on the phenomenon • Offers cross-linguistic, descriptive, and diverse theoretical approaches • Includes analysis of data from different language families and from lesser studied languages This book is the first major cross-linguistic study of 'flexible words', i.e. words...... that cannot be classified in terms of the traditional lexical categories Verb, Noun, Adjective or Adverb. Flexible words can - without special morphosyntactic marking - serve in functions for which other languages must employ members of two or more of the four traditional, 'specialised' word classes. Thus......, flexible words are underspecified for communicative functions like 'predicating' (verbal function), 'referring' (nominal function) or 'modifying' (a function typically associated with adjectives and e.g. manner adverbs). Even though linguists have been aware of flexible world classes for more than...

Large-time behavior of solutions to a reaction-diffusion system with distributed microstructure

NARCIS (Netherlands)

Muntean, A.

2009-01-01

Abstract We study the large-time behavior of a class of reaction-diffusion systems with constant distributed microstructure arising when modeling diffusion and reaction in structured porous media. The main result of this Note is the following: As t ¿ 8 the macroscopic concentration vanishes, while

Nuclear Reactions for Astrophysics and Other Applications

Energy Technology Data Exchange (ETDEWEB)

Escher, J E; Burke, J T; Dietrich, F S; Scielzo, N D; Ressler, J J

2011-03-01

Cross sections for compound-nuclear reactions are required for many applications. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

Wave Packet Based Statistical Approach to Complex-Forming Reactions

Energy Technology Data Exchange (ETDEWEB)

Guo, Hua [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemistry and Chemical Biology

2017-12-06

Combustion represents a key chemical process in energy consumption in modern societies and a clear and comprehensive understanding of the elemental reactions in combustion is of great importance to a number of challenging areas such as engine efficiency and environmental protection. In this award, we proposed to develop new theoretical tools to understand elemental chemical processes in combustion environments. With the support of this DOE grant, we have made significant advances in developing new and more efficient and accurate algorithms to characterize reaction dynamics.

A Comparison of Deterministic and Stochastic Modeling Approaches for Biochemical Reaction Systems: On Fixed Points, Means, and Modes.

Science.gov (United States)

Hahl, Sayuri K; Kremling, Andreas

2016-01-01

In the mathematical modeling of biochemical reactions, a convenient standard approach is to use ordinary differential equations (ODEs) that follow the law of mass action. However, this deterministic ansatz is based on simplifications; in particular, it neglects noise, which is inherent to biological processes. In contrast, the stochasticity of reactions is captured in detail by the discrete chemical master equation (CME). Therefore, the CME is frequently applied to mesoscopic systems, where copy numbers of involved components are small and random fluctuations are thus significant. Here, we compare those two common modeling approaches, aiming at identifying parallels and discrepancies between deterministic variables and possible stochastic counterparts like the mean or modes of the state space probability distribution. To that end, a mathematically flexible reaction scheme of autoregulatory gene expression is translated into the corresponding ODE and CME formulations. We show that in the thermodynamic limit, deterministic stable fixed points usually correspond well to the modes in the stationary probability distribution. However, this connection might be disrupted in small systems. The discrepancies are characterized and systematically traced back to the magnitude of the stoichiometric coefficients and to the presence of nonlinear reactions. These factors are found to synergistically promote large and highly asymmetric fluctuations. As a consequence, bistable but unimodal, and monostable but bimodal systems can emerge. This clearly challenges the role of ODE modeling in the description of cellular signaling and regulation, where some of the involved components usually occur in low copy numbers. Nevertheless, systems whose bimodality originates from deterministic bistability are found to sustain a more robust separation of the two states compared to bimodal, but monostable systems. In regulatory circuits that require precise coordination, ODE modeling is thus still

Rule-Based Event Processing and Reaction Rules

Science.gov (United States)

Paschke, Adrian; Kozlenkov, Alexander

Reaction rules and event processing technologies play a key role in making business and IT / Internet infrastructures more agile and active. While event processing is concerned with detecting events from large event clouds or streams in almost real-time, reaction rules are concerned with the invocation of actions in response to events and actionable situations. They state the conditions under which actions must be taken. In the last decades various reaction rule and event processing approaches have been developed, which for the most part have been advanced separately. In this paper we survey reaction rule approaches and rule-based event processing systems and languages.

Examining Patterns of Exposure to Family Violence in Preschool Children: A Latent Class Approach.

Science.gov (United States)

Grasso, Damion J; Petitclerc, Amélie; Henry, David B; McCarthy, Kimberly J; Wakschlag, Lauren S; Briggs-Gowan, Margaret J

2016-12-01

Young children can experience violence directly or indirectly in the home, with some children exposed to multiple forms of violence. These polyvictims often experience violence that is severe, chronic, and multifaceted. The current study used latent class analysis to identify and examine the pattern of profiles of exposure to family violence (i.e., violence directed towards the child and between caregivers) among a sample of 474 children ages 3-6 year who were drawn from the Multidimensional Assessment of Preschoolers Study (Wakschlag et al., 2014). The data yielded 3 classes: a polyvictimized class (n = 72; 15.2%) with high probability of exposure to all forms of violence, a harsh parenting class (n = 235; 49.5%), distinguished mainly by child-directed physical discipline in the absence of more severe forms of violence, and a low-exposure class (n = 167; 35.2%). Classes were differentiated by contextual factors, maternal characteristics, and mother-reported and observational indicators of parenting and child functioning with most effect sizes between medium and large. These findings add to emerging evidence linking polyvictimization to impaired caregiving and adverse psychological outcomes for children and offer important insight for prevention and intervention for this vulnerable population. Copyright © 2016 International Society for Traumatic Stress Studies.

Quantum chemical modeling of enzymatic reactions: the case of histone lysine methyltransferase.

Science.gov (United States)

Georgieva, Polina; Himo, Fahmi

2010-06-01

Quantum chemical cluster models of enzyme active sites are today an important and powerful tool in the study of various aspects of enzymatic reactivity. This methodology has been applied to a wide spectrum of reactions and many important mechanistic problems have been solved. Herein, we report a systematic study of the reaction mechanism of the histone lysine methyltransferase (HKMT) SET7/9 enzyme, which catalyzes the methylation of the N-terminal histone tail of the chromatin structure. In this study, HKMT SET7/9 serves as a representative case to examine the modeling approach for the important class of methyl transfer enzymes. Active site models of different sizes are used to evaluate the methodology. In particular, the dependence of the calculated energies on the model size, the influence of the dielectric medium, and the particular choice of the dielectric constant are discussed. In addition, we examine the validity of some technical aspects, such as geometry optimization in solvent or with a large basis set, and the use of different density functional methods. Copyright 2010 Wiley Periodicals, Inc.

Sex-related and non-sex-related comorbidity subtypes of tic disorders: a latent class approach.

Science.gov (United States)

Rodgers, S; Müller, M; Kawohl, W; Knöpfli, D; Rössler, W; Castelao, E; Preisig, M; Ajdacic-Gross, V

2014-05-01

Recent evidence suggests that there may be more than one Gilles de la Tourette syndrome (GTS)/tic disorder phenotype. However, little is known about the common patterns of these GTS/tic disorder-related comorbidities. In addition, sex-specific phenomenological data of GTS/tic disorder-affected adults are rare. Therefore, this community-based study used latent class analyses (LCA) to investigate sex-related and non-sex-related subtypes of GTS/tic disorders and their most common comorbidities. The data were drawn from the PsyCoLaus study (n = 3691), a population-based survey conducted in Lausanne, Switzerland. LCA were performed on the data of 80 subjects manifesting motor/vocal tics during their childhood/adolescence. Comorbid attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder, depressive, phobia and panic symptoms/syndromes comprised the selected indicators. The resultant classes were characterized by psychosocial correlates. In LCA, four latent classes provided the best fit to the data. We identified two male-related classes. The first class exhibited both ADHD and depression. The second class comprised males with only depression. Class three was a female-related class depicting obsessive thoughts/compulsive acts, phobias and panic attacks. This class manifested high psychosocial impairment. Class four had a balanced sex proportion and comorbid symptoms/syndromes such as phobias and panic attacks. The complementary occurrence of comorbid obsessive thoughts/compulsive acts and ADHD impulsivity was remarkable. To the best of our knowledge, this is the first study applying LCA to community data of GTS symptoms/tic disorder-affected persons. Our findings support the utility of differentiating GTS/tic disorder subphenotypes on the basis of comorbid syndromes. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Software Sensors Design for a Class of Aerobic Fermentation Processes

Directory of Open Access Journals (Sweden)

Trayana Patarinska

2010-08-01

Full Text Available The problem of on-line state and parameter estimation (software sensors design of a class of aerobic fermentation processes for metabolite product formation is considered. The class is characterized by: two limiting substrates one of which, growth factor, is practically depleted during the biomass growth where the product formation is negligible; corresponding general reaction scheme – a qualitative description of the main metabolic reactions between the main components in the liquid phase (biomass, substrates, product and dissolved oxygen concentrations. Two separate sensors – state and parameter estimators – are designed. The state estimator is developed based on knowledge of only one on-line measurable variable, the dissolved oxygen, and the yield factors assumed as constant coefficients. Parameter estimator of the specific reaction rates is developed under the assumption that all the process variables are known on-line by measurements or estimates. The yield factors are estimated also as non-stationary parameters, thus creating a basis for comparison with the specified constant values used for the state estimator design. As a case study industrial Lysine fermentation in fed-batch mode of operation is considered. Simulation investigations under different operating conditions are done in order to highlight the performances of the proposed sensors.

Reaction paths based on mean first-passage times

International Nuclear Information System (INIS)

Park, Sanghyun; Sener, Melih K.; Lu Deyu; Schulten, Klaus

2003-01-01

Finding representative reaction pathways is important for understanding the mechanism of molecular processes. We propose a new approach for constructing reaction paths based on mean first-passage times. This approach incorporates information about all possible reaction events as well as the effect of temperature. As an application of this method, we study representative pathways of excitation migration in a photosynthetic light-harvesting complex, photosystem I. The paths thus computed provide a complete, yet distilled, representation of the kinetic flow of excitation toward the reaction center, thereby succinctly characterizing the function of the system

Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

Directory of Open Access Journals (Sweden)

Sang-Mi Yun

2012-02-01

Full Text Available Objectives The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10. Each experimental group was restored with Caviton (GC, Spacer (Vericom, IRM (Dentsply-Caulk, or Fuji II(GC. Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiple-comparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM. Results There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

Figure-ground segmentation based on class-independent shape priors

Science.gov (United States)

Li, Yang; Liu, Yang; Liu, Guojun; Guo, Maozu

2018-01-01

We propose a method to generate figure-ground segmentation by incorporating shape priors into the graph-cuts algorithm. Given an image, we first obtain a linear representation of an image and then apply directional chamfer matching to generate class-independent, nonparametric shape priors, which provide shape clues for the graph-cuts algorithm. We then enforce shape priors in a graph-cuts energy function to produce object segmentation. In contrast to previous segmentation methods, the proposed method shares shape knowledge for different semantic classes and does not require class-specific model training. Therefore, the approach obtains high-quality segmentation for objects. We experimentally validate that the proposed method outperforms previous approaches using the challenging PASCAL VOC 2010/2012 and Berkeley (BSD300) segmentation datasets.

Minimizers of a Class of Constrained Vectorial Variational Problems: Part I

KAUST Repository

Hajaiej, Hichem

2014-04-18

In this paper, we prove the existence of minimizers of a class of multiconstrained variational problems. We consider systems involving a nonlinearity that does not satisfy compactness, monotonicity, neither symmetry properties. Our approach hinges on the concentration-compactness approach. In the second part, we will treat orthogonal constrained problems for another class of integrands using density matrices method. © 2014 Springer Basel.

A hybrid approach for predicting promiscuous MHC class I restricted ...

Indian Academy of Sciences (India)

Prakash

2006-09-15

Sep 15, 2006 ... with existing MHC binder prediction methods for alleles studied by both ... in locating the promiscuous MHC binding regions from antigen sequence. ... Artificial neural network; MHC class I alleles; promiscuous binders; ... this problem by developing methods for prediction for ... In case equal number of.

Semantic Analysis of Virtual Classes and Nested Classes

DEFF Research Database (Denmark)

Madsen, Ole Lehrmann

1999-01-01

Virtual classes and nested classes are distinguishing features of BETA. Nested classes originated from Simula, but until recently they have not been part of main stream object- oriented languages. C++ has a restricted form of nested classes and they were included in Java 1.1. Virtual classes...... classes and parameterized classes have been made. Although virtual classes and nested classes have been used in BETA for more than a decade, their implementation has not been published. The purpose of this paper is to contribute to the understanding of virtual classes and nested classes by presenting...

Unimolecular reaction dynamics of free radicals

International Nuclear Information System (INIS)

Terry A. Miller

2006-01-01

Free radical reactions are of crucial importance in combustion and in atmospheric chemistry. Reliable theoretical models for predicting the rates and products of these reactions are required for modeling combustion and atmospheric chemistry systems. Unimolecular reactions frequently play a crucial role in determining final products. The dissociations of vinyl, CH2= CH, and methoxy, CH3O, have low barriers, about 13,000 cm-1 and 8,000 cm-1, respectively. Since barriers of this magnitude are typical of free radicals these molecules should serve as benchmarks for this important class of reactions. To achieve this goal, a detailed understanding of the vinyl and methoxy radicals is required. Results for dissociation dynamics of vinyl and selectively deuterated vinyl radical are reported. Significantly, H-atom scrambling is shown not to occur in this reaction. A large number of spectroscopic experiments for CH3O and CHD2O have been performed. Spectra recorded include laser induced fluorescence (LIF), laser excited dispersed fluorescence (LEDF), fluorescence dip infrared (FDIR) and stimulated emission pumping (SEP). Such results are critical for implementing dynamics experiments involving the dissociation of methoxy

Prediction of reacting atoms for the major biotransformation reactions of organic xenobiotics.

Science.gov (United States)

Rudik, Anastasia V; Dmitriev, Alexander V; Lagunin, Alexey A; Filimonov, Dmitry A; Poroikov, Vladimir V

2016-01-01

The knowledge of drug metabolite structures is essential at the early stage of drug discovery to understand the potential liabilities and risks connected with biotransformation. The determination of the site of a molecule at which a particular metabolic reaction occurs could be used as a starting point for metabolite identification. The prediction of the site of metabolism does not always correspond to the particular atom that is modified by the enzyme but rather is often associated with a group of atoms. To overcome this problem, we propose to operate with the term "reacting atom", corresponding to a single atom in the substrate that is modified during the biotransformation reaction. The prediction of the reacting atom(s) in a molecule for the major classes of biotransformation reactions is necessary to generate drug metabolites. Substrates of the major human cytochromes P450 and UDP-glucuronosyltransferases from the Biovia Metabolite database were divided into nine groups according to their reaction classes, which are aliphatic and aromatic hydroxylation, N- and O-glucuronidation, N-, S- and C-oxidation, and N- and O-dealkylation. Each training set consists of positive and negative examples of structures with one labelled atom. In the positive examples, the labelled atom is the reacting atom of a particular reaction that changed adjacency. Negative examples represent non-reacting atoms of a particular reaction. We used Labelled Multilevel Neighbourhoods of Atoms descriptors for the designation of reacting atoms. A Bayesian-like algorithm was applied to estimate the structure-activity relationships. The average invariant accuracy of prediction obtained in leave-one-out and 20-fold cross-validation procedures for five human isoforms of cytochrome P450 and all isoforms of UDP-glucuronosyltransferase varies from 0.86 to 0.99 (0.96 on average). We report that reacting atoms may be predicted with reasonable accuracy for the major classes of metabolic reactions

Nonequilibrium thermodynamics and a fluctuation theorem for individual reaction steps in a chemical reaction network

International Nuclear Information System (INIS)

Pal, Krishnendu; Das, Biswajit; Banerjee, Kinshuk; Gangopadhyay, Gautam

2015-01-01

We have introduced an approach to nonequilibrium thermodynamics of an open chemical reaction network in terms of the propensities of the individual elementary reactions and the corresponding reverse reactions. The method is a microscopic formulation of the dissipation function in terms of the relative entropy or Kullback-Leibler distance which is based on the analogy of phase space trajectory with the path of elementary reactions in a network of chemical process. We have introduced here a fluctuation theorem valid for each opposite pair of elementary reactions which is useful in determining the contribution of each sub-reaction on the nonequilibrium thermodynamics of overall reaction. The methodology is applied to an oligomeric enzyme kinetics at a chemiostatic condition that leads the reaction to a nonequilibrium steady state for which we have estimated how each step of the reaction is energy driven or entropy driven to contribute to the overall reaction. (paper)

Safety learning from drugs of the same class

DEFF Research Database (Denmark)

Stefansdottir, G; Knol, M J; Arnardottir, A H

2012-01-01

This study was aimed at assessing the extent of safety learning from data pertaining to other drugs of the same class. We studied drug classes for which the first and second drugs were centrally registered in the European Union from 1995 to 2008. We assessed whether adverse drug reactions (ADRs......) associated with one of the drugs also appeared in the Summary of Product Characteristics (SPC) of the other drug, either initially or during the postmarketing phase. We identified 977 ADRs from 19 drug pairs, of which 393 ADRs (40.2%) were listed in the SPCs of both drugs of a pair. Of these 393 that were...... present in both SPCs of a drug pair, 241 (61.3%) were present when the drug entered the market and 152 (30.7%) appeared in the postmarketing phase. The mention of ADRs in the SPCs of both same-class drugs in the postmarketing phase was associated with type A ADRs, marketing in the same regulator country...

Photosynthetic antennas and reaction centers: Current understanding and prospects for improvement

Energy Technology Data Exchange (ETDEWEB)

Blankenship, R.E. [Arizona State Univ., Tempe, AZ (United States)

1996-09-01

A brief introduction to the principles, structures and kinetic processes that take place in natural photosynthetic reaction center complexes is presented. Energy is first collected by an antenna system, and is transferred to a reaction center complex where primary electron transfer takes place. Secondary reactions lead to oxidation of water and reduction of CO{sub 2} in some classes of organisms. Antenna systems are highly regulated to maximize energy collection efficiency while avoiding photodamage. Some areas that are presently not well understood are listed.

Social Class and Workplace Harassment during the Transition to Adulthood

Science.gov (United States)

McLaughlin, Heather; Uggen, Christopher; Blackstone, Amy

2008-01-01

Young disadvantaged workers are especially vulnerable to harassment due to their age and social class position. As young people enter the workforce, their experiences of, and reactions to, harassment may vary dramatically from those of older adult workers. Three case studies introduce theory and research on the relationship between social class…

Spallation reactions: calculations

International Nuclear Information System (INIS)

Bertini, H.W.

1975-01-01

Current methods for calculating spallation reactions over various energy ranges are described and evaluated. Recent semiempirical fits to existing data will probably yield the most accurate predictions for these reactions in general. However, if the products in question have binding energies appreciably different from their isotropic neighbors and if the cross section is approximately 30 mb or larger, then the intranuclear-cascade-evaporation approach is probably better suited. (6 tables, 12 figures, 34 references) (U.S.)

Immunoglobulin class-switch recombination deficiencies.

Science.gov (United States)

Durandy, Anne; Kracker, Sven

2012-07-30

Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants in humans. This approach has revealed that T cell-B cell interaction (resulting in CD40-mediated signaling), intrinsic B-cell mechanisms (activation-induced cytidine deaminase-induced DNA damage), and complex DNA repair machineries (including uracil-N-glycosylase and mismatch repair pathways) are all involved in class-switch recombination and SHM. However, several of the mechanisms required for full antibody maturation have yet to be defined. Elucidation of the molecular defects underlying the diverse set of Ig-CSR-Ds is essential for understanding Ig diversification and has prompted better definition of the clinical spectrum of diseases and the development of increasingly accurate diagnostic and therapeutic approaches.

Lagrangian descriptors of driven chemical reaction manifolds.

Science.gov (United States)

Craven, Galen T; Junginger, Andrej; Hernandez, Rigoberto

2017-08-01

The persistence of a transition state structure in systems driven by time-dependent environments allows the application of modern reaction rate theories to solution-phase and nonequilibrium chemical reactions. However, identifying this structure is problematic in driven systems and has been limited by theories built on series expansion about a saddle point. Recently, it has been shown that to obtain formally exact rates for reactions in thermal environments, a transition state trajectory must be constructed. Here, using optimized Lagrangian descriptors [G. T. Craven and R. Hernandez, Phys. Rev. Lett. 115, 148301 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.148301], we obtain this so-called distinguished trajectory and the associated moving reaction manifolds on model energy surfaces subject to various driving and dissipative conditions. In particular, we demonstrate that this is exact for harmonic barriers in one dimension and this verification gives impetus to the application of Lagrangian descriptor-based methods in diverse classes of chemical reactions. The development of these objects is paramount in the theory of reaction dynamics as the transition state structure and its underlying network of manifolds directly dictate reactivity and selectivity.

Optimized reaction mechanism rate rules for ignition of normal alkanes

KAUST Repository

Cai, Liming; Pitsch, Heinz; Mohamed, Samah; Raman, Venkat; Bugler, John; Curran, Henry; Sarathy, Mani

2016-01-01

fidelity reacting flow simulations capable of improving combustor design and operation. The development of such models for many new fuel components and/or surrogate molecules is greatly facilitated by the application of reaction classes and rate rules

Study of Cold Fusion Reactions Using Collective Clusterization Approach

Science.gov (United States)

Kaur, Gurjit; Sandhu, Kirandeep; Sharma, Manoj K.

2017-10-01

Within the framework of the dynamical cluster decay model (DCM), the 1n evaporation cross-sections ({σ }1n) of cold fusion reactions (Pb and Bi targets) are calculated for {Z}{CN}=104-113 superheavy nuclei. The calculations are carried out in the fixed range of excitation energy {E}{CN}* =15+/- 1 {MeV}, so that the comparative analysis of reaction dynamics can be worked out. First of all, the fission barriers (B f ) and neutron separation energies ({S}1n) are estimated to account the decreasing cross-sections of cold fusion reactions. In addition to this, the importance of hot optimum orientations of β 2i-deformed nuclei over cold one is explored at fixed angular momentum and neck-length parameters. The hot optimum orientations support all the target-projectile (t,p) combinations, which are explored experimentally in the cold fusion reactions. Some new target-projectile combinations are also predicted for future exploration. Further, the 1n cross-sections are addressed for {Z}{CN}=104-113 superheavy nuclei at comparable excitation energies which show the decent agrement with experimental data upto {Z}{CN}=109 nuclei. Finally, to understand the dynamics of higher-Z superheavy nuclei, the cross-sections are also calculated at maximum available energies around the Coulomb barrier and the effect of non-sticking moment of inertia ({I}{NS}) is also investigated at these energies. Supported by the Council of Scientific and Industrial Research (CSIR), in the Form of Research Project Grant No. 03(1341)/15/EMR-II, and to DST, New Delhi, for INSPIRE-Fellowship Grant No. DST/INSPIRE/03/2015/000199

Social class, dementia and the fourth age.

Science.gov (United States)

Jones, Ian Rees

2017-02-01

Research addressing social class and dementia has largely focused on measures of socioeconomic status as causal risk factors for dementia and in observed differences in diagnosis, treatment and care. This large body of work has produced important insights but also contains numerous problems and weaknesses. Research needs to take account of the ways in which ageing and social class have been transformed in tandem with the economic, social and cultural coordinates of late modernity. These changes have particular consequences for individual identities and social relations. With this in mind this article adopts a critical gaze on research that considers interactions between dementia and social class in three key areas: (i) epidemiological approaches to inequalities in risk (ii) the role of social class in diagnosis and treatment and (iii) class in the framing of care and access to care. Following this, the article considers studies of dementia and social class that focus on lay understandings and biographical accounts. Sociological insights in this field come from the view that dementia and social class are embedded in social relations. Thus, forms of distinction based on class relations may still play an important role in the lived experience of dementia. © 2017 Foundation for the Sociology of Health & Illness.

Oversampling the Minority Class in the Feature Space.

Science.gov (United States)

Perez-Ortiz, Maria; Gutierrez, Pedro Antonio; Tino, Peter; Hervas-Martinez, Cesar

2016-09-01

The imbalanced nature of some real-world data is one of the current challenges for machine learning researchers. One common approach oversamples the minority class through convex combination of its patterns. We explore the general idea of synthetic oversampling in the feature space induced by a kernel function (as opposed to input space). If the kernel function matches the underlying problem, the classes will be linearly separable and synthetically generated patterns will lie on the minority class region. Since the feature space is not directly accessible, we use the empirical feature space (EFS) (a Euclidean space isomorphic to the feature space) for oversampling purposes. The proposed method is framed in the context of support vector machines, where the imbalanced data sets can pose a serious hindrance. The idea is investigated in three scenarios: 1) oversampling in the full and reduced-rank EFSs; 2) a kernel learning technique maximizing the data class separation to study the influence of the feature space structure (implicitly defined by the kernel function); and 3) a unified framework for preferential oversampling that spans some of the previous approaches in the literature. We support our investigation with extensive experiments over 50 imbalanced data sets.

Lie and Q-Conditional Symmetries of Reaction-Diffusion-Convection Equations with Exponential Nonlinearities and Their Application for Finding Exact Solutions

Directory of Open Access Journals (Sweden)

Roman Cherniha

2018-04-01

Full Text Available This review is devoted to search for Lie and Q-conditional (nonclassical symmetries and exact solutions of a class of reaction-diffusion-convection equations with exponential nonlinearities. A complete Lie symmetry classification of the class is derived via two different algorithms in order to show that the result depends essentially on the type of equivalence transformations used for the classification. Moreover, a complete description of Q-conditional symmetries for PDEs from the class in question is also presented. It is shown that all the well-known results for reaction-diffusion equations with exponential nonlinearities follow as particular cases from the results derived for this class of reaction-diffusion-convection equations. The symmetries obtained for constructing exact solutions of the relevant equations are successfully applied. The exact solutions are compared with those found by means of different techniques. Finally, an application of the exact solutions for solving boundary-value problems arising in population dynamics is presented.

The validity of world class business criteria across developed and developing countries

Directory of Open Access Journals (Sweden)

Andre J. Parker

2010-11-01

Research purpose: To assess the validity of the general assumption in the literature that world class criteria are equally applicable worldwide. Motivation for research: The possibility exists that developing countries require an adjusted mix of world class criteria and practices to become globally competitive. Research design, approach and method: A quantitative field survey research approach was adopted. A web-enabled questionnaire was designed, covering 35 world class practices grouped under 7 world class criteria. A cross-section of the senior management from 14 developing and 20 developed country’s organisations partook in the study. Main findings: It was empirically confirmed that the majority of world class practices posited in the literature are used by participating organisations; that world class criteria do not apply equally across developed and developing countries; and that more important than country location, is the deliberate choice by an organisation’s leadership to become world class. An empirically based model of ascending to world class was proposed. Practical/managerial implications: Regardless of country location, the leadership of an organisation can make their organisation world class by applying the proposed world class model. Contribution/value add: A reliable web enabled instrument was designed that can be used to assess an organisation’s world class standing; the assumption that world class criteria are equally valid across developing and developed countries was proven partially incorrect; since becoming or being world class is also a leadership choice regardless of location.

Constrained dynamical systems: separation of constraints into first and second classes

International Nuclear Information System (INIS)

Chitaya, N.P.; Gogilidze, S.A.; Surovtsev, Yu.S.

1996-01-01

In the Dirac approach to the generalized Hamiltonian formalism, dynamical systems with first- and second-class constraints are investigated. The classification and separation of constraints into the first- and second-class ones are presented with the help of passing to an equivalent canonical set of constraints. The general structure of second-class constraints is clarified. 14 refs

An American instructor in an upper-level Italian physics class

International Nuclear Information System (INIS)

Feldman, Gerald

2015-01-01

In this paper, I report on my experience in teaching a 3rd-year undergraduate physics class at the University of Trento during the Spring 2014 semester. I address questions relating to the application of active-learning techniques, usage of English language in the classroom, and student reactions to an innovative style of pedagogy.

Reaction theories for N* excitations in πN and γN reactions

International Nuclear Information System (INIS)

Lee, T.S.H.

1996-01-01

The importance of developing reaction theories for investigating N* physics is illustrated in an analysis of pion photoproduction on the nucleon. It is shown that the γN ↔ Δ transition amplitudes predicted by the constituent quark model are in agreement with the values extracted from the γN → πN data only when the contributions from the reaction mechanisms calculated using a dynamical approach are taken into account in the analysis

Neural network approach to time-dependent dividing surfaces in classical reaction dynamics

Science.gov (United States)

Schraft, Philippe; Junginger, Andrej; Feldmaier, Matthias; Bardakcioglu, Robin; Main, Jörg; Wunner, Günter; Hernandez, Rigoberto

2018-04-01

In a dynamical system, the transition between reactants and products is typically mediated by an energy barrier whose properties determine the corresponding pathways and rates. The latter is the flux through a dividing surface (DS) between the two corresponding regions, and it is exact only if it is free of recrossings. For time-independent barriers, the DS can be attached to the top of the corresponding saddle point of the potential energy surface, and in time-dependent systems, the DS is a moving object. The precise determination of these direct reaction rates, e.g., using transition state theory, requires the actual construction of a DS for a given saddle geometry, which is in general a demanding methodical and computational task, especially in high-dimensional systems. In this paper, we demonstrate how such time-dependent, global, and recrossing-free DSs can be constructed using neural networks. In our approach, the neural network uses the bath coordinates and time as input, and it is trained in a way that its output provides the position of the DS along the reaction coordinate. An advantage of this procedure is that, once the neural network is trained, the complete information about the dynamical phase space separation is stored in the network's parameters, and a precise distinction between reactants and products can be made for all possible system configurations, all times, and with little computational effort. We demonstrate this general method for two- and three-dimensional systems and explain its straightforward extension to even more degrees of freedom.

76 FR 75449 - Establishment of Class E Airspace; Stuart, IA

Science.gov (United States)

2011-12-02

...-0831; Airspace Docket No. 11-ACE-17] Establishment of Class E Airspace; Stuart, IA AGENCY: Federal... for Stuart, IA, to accommodate new COPTER area navigation (RNAV) Standard Instrument Approach... Federal Register a notice of proposed rulemaking to establish Class E airspace for Stuart, IA, creating...

76 FR 73505 - Establishment of Class E Airspace; Nashville, AR

Science.gov (United States)

2011-11-29

...-0497; Airspace Docket No. 11-ASW-4] Establishment of Class E Airspace; Nashville, AR AGENCY: Federal... for Nashville, AR, to accommodate new Area Navigation (RNAV) Standard Instrument Approach Procedures... a notice of proposed rulemaking to amend Class E airspace for Nashville, AR, creating additional...

Sodium-Water Reaction approach and mastering for ASTRID Steam Generator design

International Nuclear Information System (INIS)

Saez, Manuel; Allou, Alexandre; Beauchamp, François; Bertrand, Carole; Rodriguez, Gilles; Menou, Sylvain; Prele, Gérard

2013-01-01

Conclusions: • Modular Steam Generator concept selected for ASTRID: → Brings flexibility for the expertise of failed modules after their removal; → Intrinsically limit the mechanical consequences of a postulated large Sodium-Water Reaction. • Sodium-Water-Air Reaction studies include both prevention and mitigation aspects, with dedicated tools to be developed through R&D. • Regarding Safety analysis, the possibility to move from the scenario of instantaneous failure of the whole Steam Generator tube bundle toward a scenario with sequenced failure needs to be investigated. • The Steam Generator is one of the key components in the Sodium-cooled Fast Reactor system for it provides an interface between sodium and water. The design objective for the Steam Generator is related to the improvement of mastering of Sodium-Water Reaction. • Potential Sodium-Water Reactions can be eliminated by adopting a Gas based Power Conversion System

Prediction of protein structural classes by Chou's pseudo amino acid composition: approached using continuous wavelet transform and principal component analysis.

Science.gov (United States)

Li, Zhan-Chao; Zhou, Xi-Bin; Dai, Zong; Zou, Xiao-Yong

2009-07-01

A prior knowledge of protein structural classes can provide useful information about its overall structure, so it is very important for quick and accurate determination of protein structural class with computation method in protein science. One of the key for computation method is accurate protein sample representation. Here, based on the concept of Chou's pseudo-amino acid composition (AAC, Chou, Proteins: structure, function, and genetics, 43:246-255, 2001), a novel method of feature extraction that combined continuous wavelet transform (CWT) with principal component analysis (PCA) was introduced for the prediction of protein structural classes. Firstly, the digital signal was obtained by mapping each amino acid according to various physicochemical properties. Secondly, CWT was utilized to extract new feature vector based on wavelet power spectrum (WPS), which contains more abundant information of sequence order in frequency domain and time domain, and PCA was then used to reorganize the feature vector to decrease information redundancy and computational complexity. Finally, a pseudo-amino acid composition feature vector was further formed to represent primary sequence by coupling AAC vector with a set of new feature vector of WPS in an orthogonal space by PCA. As a showcase, the rigorous jackknife cross-validation test was performed on the working datasets. The results indicated that prediction quality has been improved, and the current approach of protein representation may serve as a useful complementary vehicle in classifying other attributes of proteins, such as enzyme family class, subcellular localization, membrane protein types and protein secondary structure, etc.

Probabilistic sensitivity analysis of biochemical reaction systems.

Science.gov (United States)

Zhang, Hong-Xuan; Dempsey, William P; Goutsias, John

2009-09-07

Sensitivity analysis is an indispensable tool for studying the robustness and fragility properties of biochemical reaction systems as well as for designing optimal approaches for selective perturbation and intervention. Deterministic sensitivity analysis techniques, using derivatives of the system response, have been extensively used in the literature. However, these techniques suffer from several drawbacks, which must be carefully considered before using them in problems of systems biology. We develop here a probabilistic approach to sensitivity analysis of biochemical reaction systems. The proposed technique employs a biophysically derived model for parameter fluctuations and, by using a recently suggested variance-based approach to sensitivity analysis [Saltelli et al., Chem. Rev. (Washington, D.C.) 105, 2811 (2005)], it leads to a powerful sensitivity analysis methodology for biochemical reaction systems. The approach presented in this paper addresses many problems associated with derivative-based sensitivity analysis techniques. Most importantly, it produces thermodynamically consistent sensitivity analysis results, can easily accommodate appreciable parameter variations, and allows for systematic investigation of high-order interaction effects. By employing a computational model of the mitogen-activated protein kinase signaling cascade, we demonstrate that our approach is well suited for sensitivity analysis of biochemical reaction systems and can produce a wealth of information about the sensitivity properties of such systems. The price to be paid, however, is a substantial increase in computational complexity over derivative-based techniques, which must be effectively addressed in order to make the proposed approach to sensitivity analysis more practical.

Field classes: key to involve and attract students to soils

Science.gov (United States)

Muggler, Cristine Carole; Cardoso, Irene Maria; da Silva Lopes, Angelica

2015-04-01

Soil genesis is a subject taught to students of Agrarian Sciences and Geography at the Federal University of Viçosa in Minas Gerais, Brazil. Each semester 200 to 250 students inscribe for it. It is organized as the first 60 hours course on soils for 1st and 2nd year's students. The course has a distinct pedagogical approach, which is based on Paulo Freire's education principles, known as socio constructivism. In such approach, learning environments and materials are prepared to stimulate dialogues and exchange of knowledge between students themselves, strengthening that their role is crucial to their own learning. During the course, students have different types of practical classes: indoors, in a class room or at the Earth Sciences museum and outdoors, in the field. In the class room they have the opportunity to handle materials -minerals, rocks, soils and maps-, follow demonstrations and perform small experiments. The classes given in the museum intend a broadening of the subjects approached in theoretical and practical classes. In the field classes the students are organized in small groups with the task to investigate soil formation by observation and description of geology, landscape, land use, soil expositions and some of the soil properties. Attracting students to soils involves looking at meanings and perceptions related to soils they bring with themselves and follow this up to sensitize and create awareness about their importance. With this aim, it is also included, as part of the evaluation, a final voluntary presentation that many of the students do. The presentation can be a song, a poem, a sketch or whatever they propose and create. Many of the presentations bring topics related to the new perception about soils they get during the semester and to ideas or questions raised in the field classes. A survey with the students showed that field classes are by far the preferred classes and they are considered more dynamic. Since students have less and less

A class-chest for deriving transport protocols

Energy Technology Data Exchange (ETDEWEB)

Strayer, W.T.

1996-10-01

Development of new transport protocols or protocol algorithms suffers from the complexity of the environment in which they are intended to run. Modeling techniques attempt to avoid this by simulating the environment. Another approach to promoting rapid prototyping of protocols and protocol algorithms is to provide a pre-built infrastructure that is common to transport protocols, so that the focus is placed on the protocol-specific aspects. The Meta-Transport Library is a library of C++ base classes that implement or abstract out the mundane functions of a protocol, new protocol implementations are derived from base classes. The result is a fully viable user- level transport protocol implementation, with emphasis on modularity. The collection of base classes form a ``class-chest`` of tools .from which protocols can be developed and studied with as little change to a normal UNIX environment as possible.

Class prediction for high-dimensional class-imbalanced data

Directory of Open Access Journals (Sweden)

Lusa Lara

2010-10-01

Full Text Available Abstract Background The goal of class prediction studies is to develop rules to accurately predict the class membership of new samples. The rules are derived using the values of the variables available for each subject: the main characteristic of high-dimensional data is that the number of variables greatly exceeds the number of samples. Frequently the classifiers are developed using class-imbalanced data, i.e., data sets where the number of samples in each class is not equal. Standard classification methods used on class-imbalanced data often produce classifiers that do not accurately predict the minority class; the prediction is biased towards the majority class. In this paper we investigate if the high-dimensionality poses additional challenges when dealing with class-imbalanced prediction. We evaluate the performance of six types of classifiers on class-imbalanced data, using simulated data and a publicly available data set from a breast cancer gene-expression microarray study. We also investigate the effectiveness of some strategies that are available to overcome the effect of class imbalance. Results Our results show that the evaluated classifiers are highly sensitive to class imbalance and that variable selection introduces an additional bias towards classification into the majority class. Most new samples are assigned to the majority class from the training set, unless the difference between the classes is very large. As a consequence, the class-specific predictive accuracies differ considerably. When the class imbalance is not too severe, down-sizing and asymmetric bagging embedding variable selection work well, while over-sampling does not. Variable normalization can further worsen the performance of the classifiers. Conclusions Our results show that matching the prevalence of the classes in training and test set does not guarantee good performance of classifiers and that the problems related to classification with class

Estimation of parameter sensitivities for stochastic reaction networks

KAUST Repository

Gupta, Ankit

2016-01-07

Quantification of the effects of parameter uncertainty is an important and challenging problem in Systems Biology. We consider this problem in the context of stochastic models of biochemical reaction networks where the dynamics is described as a continuous-time Markov chain whose states represent the molecular counts of various species. For such models, effects of parameter uncertainty are often quantified by estimating the infinitesimal sensitivities of some observables with respect to model parameters. The aim of this talk is to present a holistic approach towards this problem of estimating parameter sensitivities for stochastic reaction networks. Our approach is based on a generic formula which allows us to construct efficient estimators for parameter sensitivity using simulations of the underlying model. We will discuss how novel simulation techniques, such as tau-leaping approximations, multi-level methods etc. can be easily integrated with our approach and how one can deal with stiff reaction networks where reactions span multiple time-scales. We will demonstrate the efficiency and applicability of our approach using many examples from the biological literature.

76 FR 59503 - Establishment of Class E Airspace; Lebanon, PA

Science.gov (United States)

2011-09-27

...-0558; Airspace Docket No. 11-AEA-13] Establishment of Class E Airspace; Lebanon, PA AGENCY: Federal... at Lebanon, PA, to accommodate new Standard Instrument Approach Procedures that have been developed... amend Class E airspace 700 feet above the surface, at Lebanon, PA (76 FR 39038). Subsequent to...

Mass Transfer and Chemical Reaction Approach of the Kinetics of the Acetylation of Gadung Flour using Glacial Acetic Acid

Directory of Open Access Journals (Sweden)

Andri Cahyo Kumoro

2015-03-01

Full Text Available Acetylation is one of the common methods of modifying starch properties by introducing acetil (CH3CO groups to starch molecules at low temperatures. While most acetylation is conducted using starch as anhidroglucose source and acetic anhydride or vinyl acetate as nucleophilic agents, this work employ reactants, namely flour and glacial acetic acid. The purpose of this work are to study the effect of pH reaction and GAA/GF mass ratio on the rate of acetylation reaction and to determine its rate constants. The acetylation of gadung flour with glacial acetic acid in the presence of sodium hydroxide as a homogenous catalyst was studied at ambient temperature with pH ranging from 8-10 and different mass ratio of acetic acid : gadung flour (1:3; 1:4; and 1:5. It was found that increasing pH, lead to increase the degree of substitution, while increasing GAA/GF mass ratio caused such decreases in the degree of substitution, due to the hydrolysis of the acetylated starch. The desired starch acetylation reaction is accompanied by undesirable hydrolysis reaction of the acetylated starch after 40-50 minutes reaction time. Investigation of kinetics of the reaction observed that the value of mass transfer rate constant (Kcs is smaller than the surface reaction rate constant (k. Thus, it can be concluded that rate controlling step is mass transfer.  © 2015 BCREC UNDIP. All rights reservedReceived: 7th August 2014; Revised: 8th September 2014; Accepted: 14th September 2014How to Cite: Kumoro, A.C., Amelia, R. (2015. Mass Transfer and Chemical Reaction Approach of the Kinetics of the Acetylation of Gadung Flour using Glacial Acetic Acid. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (1: 30-37. (doi:10.9767/bcrec.10.1.7181.30-37Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.1.7181.30-37

Method for Selection of Solvents for Promotion of Organic Reactions

DEFF Research Database (Denmark)

Gani, Rafiqul; Jiménez-González, Concepción; Constable, David J.C.

2005-01-01

is to produce, for a given reaction, a short list of chemicals that could be considered as potential solvents, to evaluate their performance in the reacting system, and, based on this, to rank them according to a scoring system. Several examples of application are given to illustrate the main features and steps......A method to select appropriate green solvents for the promotion of a class of organic reactions has been developed. The method combines knowledge from industrial practice and physical insights with computer-aided property estimation tools for selection/design of solvents. In particular, it employs...... estimates of thermodynamic properties to generate a knowledge base of reaction, solvent and environment related properties that directly or indirectly influence the rate and/or conversion of a given reaction. Solvents are selected using a rules-based procedure where the estimated reaction-solvent properties...

First observation of excision and integration in Class 1 integron in ...

African Journals Online (AJOL)

So in this study, we tested in S. aureus, the class 1 integron mediated excision and integration. We first asked 8 plasmids from previous studies, then established some transformants and perform the excision and integration reaction. As the results revealed, we observed positive excision assay, which had been confirmed by ...

Variation in reaction norms: Statistical considerations and biological interpretation.

Science.gov (United States)

Morrissey, Michael B; Liefting, Maartje

2016-09-01

Analysis of reaction norms, the functions by which the phenotype produced by a given genotype depends on the environment, is critical to studying many aspects of phenotypic evolution. Different techniques are available for quantifying different aspects of reaction norm variation. We examine what biological inferences can be drawn from some of the more readily applicable analyses for studying reaction norms. We adopt a strongly biologically motivated view, but draw on statistical theory to highlight strengths and drawbacks of different techniques. In particular, consideration of some formal statistical theory leads to revision of some recently, and forcefully, advocated opinions on reaction norm analysis. We clarify what simple analysis of the slope between mean phenotype in two environments can tell us about reaction norms, explore the conditions under which polynomial regression can provide robust inferences about reaction norm shape, and explore how different existing approaches may be used to draw inferences about variation in reaction norm shape. We show how mixed model-based approaches can provide more robust inferences than more commonly used multistep statistical approaches, and derive new metrics of the relative importance of variation in reaction norm intercepts, slopes, and curvatures. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Structure-based prediction and identification of 4-epimerization activity of phosphate sugars in class II aldolases.

Science.gov (United States)

Lee, Seon-Hwa; Hong, Seung-Hye; An, Jung-Ung; Kim, Kyoung-Rok; Kim, Dong-Eun; Kang, Lin-Woo; Oh, Deok-Kun

2017-05-16

Sugar 4-epimerization reactions are important for the production of rare sugars and their derivatives, which have various potential industrial applications. For example, the production of tagatose, a functional sweetener, from fructose by sugar 4-epimerization is currently constrained because a fructose 4-epimerase does not exist in nature. We found that class II D-fructose-1,6-bisphosphate aldolase (FbaA) catalyzed the 4-epimerization of D-fructose-6-phosphate (F6P) to D-tagatose-6-phosphate (T6P) based on the prediction via structural comparisons with epimerase and molecular docking and the identification of the condensed products of C3 sugars. In vivo, the 4-epimerization activity of FbaA is normally repressed. This can be explained by our results showing the catalytic efficiency of D-fructose-6-phosphate kinase for F6P phosphorylation was significantly higher than that of FbaA for F6P epimerization. Here, we identified the epimerization reactions and the responsible catalytic residues through observation of the reactions of FbaA and L-rhamnulose-1-phosphate aldolases (RhaD) variants with substituted catalytic residues using different substrates. Moreover, we obtained detailed potential epimerization reaction mechanism of FbaA and a general epimerization mechanism of the class II aldolases L-fuculose-1-phosphate aldolase, RhaD, and FbaA. Thus, class II aldolases can be used as 4-epimerases for the stereo-selective synthesis of valuable carbohydrates.

Reaction of [3H]-taurine maleimide with platelet surface thiols

International Nuclear Information System (INIS)

Karl, D.W.; Mills, D.C.B.

1986-01-01

Taurine Maleimide (2-maleimidoethanesulfonate, TM) was synthesized from [2- 3 H]-taurine and methoxycarbonylmaleimide (MCM). The yield of a 1 μmol synthesis approached 100% (based on taurine) when MCM was used in 4-fold excess. The product (TM*) was purified by ion exchange chromatography. TM* reacted irreversibly with thiol groups on the surface of washed human platelets, leading to incorporation of radioactivity into platelet pellets. Incorporation was blocked by cysteine, mercuribenzenesulfonate (MBS), dithiobisnitrobenzoate, and N-ethylmaleimide, but not by taurine or by inhibitors of anion transport. Reaction of TM* with platelets showed the dependence on time and concentration characteristics of a bimolecular reaction. The number of reactive sites ranged from 1 to 5 x 10 5 /platelet, and the apparent rate constant from 1 to 3 x 10 3 /(M x min). TM was less effective than MBS as an inhibitor of platelet aggregation induced by several agents. TM had no effect on the uptake of serotonin, taurine, or phosphate by the platelets, processes which are sensitive to MBS. These differences, considered with the similarity in size and charge of TM and MBS, suggest that classes of thiols defined as exofacial by their accessibility to MBS can differ substantially in their reactivity with other impermeant reagents

Cascaded discrimination of normal, abnormal, and confounder classes in histopathology: Gleason grading of prostate cancer

Directory of Open Access Journals (Sweden)

Doyle Scott

2012-10-01

Full Text Available Abstract Background Automated classification of histopathology involves identification of multiple classes, including benign, cancerous, and confounder categories. The confounder tissue classes can often mimic and share attributes with both the diseased and normal tissue classes, and can be particularly difficult to identify, both manually and by automated classifiers. In the case of prostate cancer, they may be several confounding tissue types present in a biopsy sample, posing as major sources of diagnostic error for pathologists. Two common multi-class approaches are one-shot classification (OSC, where all classes are identified simultaneously, and one-versus-all (OVA, where a “target” class is distinguished from all “non-target” classes. OSC is typically unable to handle discrimination of classes of varying similarity (e.g. with images of prostate atrophy and high grade cancer, while OVA forces several heterogeneous classes into a single “non-target” class. In this work, we present a cascaded (CAS approach to classifying prostate biopsy tissue samples, where images from different classes are grouped to maximize intra-group homogeneity while maximizing inter-group heterogeneity. Results We apply the CAS approach to categorize 2000 tissue samples taken from 214 patient studies into seven classes: epithelium, stroma, atrophy, prostatic intraepithelial neoplasia (PIN, and prostate cancer Gleason grades 3, 4, and 5. A series of increasingly granular binary classifiers are used to split the different tissue classes until the images have been categorized into a single unique class. Our automatically-extracted image feature set includes architectural features based on location of the nuclei within the tissue sample as well as texture features extracted on a per-pixel level. The CAS strategy yields a positive predictive value (PPV of 0.86 in classifying the 2000 tissue images into one of 7 classes, compared with the OVA (0.77 PPV and OSC

78 FR 48294 - Amendment of Class E Airspace; Mason, TX

Science.gov (United States)

2013-08-08

...-1141; Airspace Docket No. 12-ASW-12] Amendment of Class E Airspace; Mason, TX AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action amends Class E airspace at Mason, TX... Approach Procedures at Mason County Airport. This action enhances the safety and management of Instrument...

Guided Classification System for Conceptual Overlapping Classes in OpenStreetMap

Directory of Open Access Journals (Sweden)

Ahmed Loai Ali

2016-06-01

Full Text Available The increased development of Volunteered Geographic Information (VGI and its potential role in GIScience studies raises questions about the resulting data quality. Several studies address VGI quality from various perspectives like completeness, positional accuracy, consistency, etc. They mostly have consensus on the heterogeneity of data quality. The problem may be due to the lack of standard procedures for data collection and absence of quality control feedback for voluntary participants. In our research, we are concerned with data quality from the classification perspective. Particularly in VGI-mapping projects, the limited expertise of participants and the non-strict definition of geographic features lead to conceptual overlapping classes, where an entity could plausibly belong to multiple classes, e.g., lake or pond, park or garden, marsh or swamp, etc. Usually, quantitative and/or qualitative characteristics exist that distinguish between classes. Nevertheless, these characteristics might not be recognizable for non-expert participants. In previous work, we developed the rule-guided classification approach that guides participants to the most appropriate classes. As exemplification, we tackle the conceptual overlapping of some grass-related classes. For a given data set, our approach presents the most highly recommended classes for each entity. In this paper, we present the validation of our approach. We implement a web-based application called Grass&Green that presents recommendations for crowdsourcing validation. The findings show the applicability of the proposed approach. In four months, the application attracted 212 participants from more than 35 countries who checked 2,865 entities. The results indicate that 89% of the contributions fully/partially agree with our recommendations. We then carried out a detailed analysis that demonstrates the potential of this enhanced data classification. This research encourages the development of

The effects of whole-class interactive instruction with single display groupware for triangles

NARCIS (Netherlands)

Caballero, D.; van Riesen, Siswa; Alvarez, S.; Nussbaum, M.; de Jong, Anthonius J.M.; Alario-Hoyos, C.

2013-01-01

Whole-class interactive instruction is an instructional approach in which all of the students in a class create knowledge together in an interactive way, mediated by the teacher. The current mixed-method study compared the effects of a specific implementation of whole-class interactive instruction,

Revisiting Parametric Types and Virtual Classes

DEFF Research Database (Denmark)

Madsen, Anders Bach; Ernst, Erik

2010-01-01

manner, because virtual classes are closely tied to nominal typing. This paper adds new insight about the dichotomy between these two approaches; it illustrates how virtual constraints and type refinements, as recently introduced in gbeta and Scala, enable structural treatment of virtual types; finally...

International Consensus (ICON): allergic reactions to vaccines.

Science.gov (United States)

Dreskin, Stephen C; Halsey, Neal A; Kelso, John M; Wood, Robert A; Hummell, Donna S; Edwards, Kathryn M; Caubet, Jean-Christoph; Engler, Renata J M; Gold, Michael S; Ponvert, Claude; Demoly, Pascal; Sanchez-Borges, Mario; Muraro, Antonella; Li, James T; Rottem, Menachem; Rosenwasser, Lanny J

2016-01-01

Routine immunization, one of the most effective public health interventions, has effectively reduced death and morbidity due to a variety of infectious diseases. However, allergic reactions to vaccines occur very rarely and can be life threatening. Given the large numbers of vaccines administered worldwide, there is a need for an international consensus regarding the evaluation and management of allergic reactions to vaccines. Following a review of the literature, and with the active participation of representatives from the World Allergy Organization (WAO), the European Academy of Allergy and Clinical Immunology (EAACI), the American Academy of Allergy, Asthma, and Immunology (AAAAI), and the American College of Allergy, Asthma, and Immunology (ACAAI), the final committee was formed with the purpose of having members who represented a wide-range of countries, had previously worked on vaccine safety, and included both allergist/immunologists as well as vaccinologists. Consensus was reached on a variety of topics, including: definition of immediate allergic reactions, including anaphylaxis, approaches to distinguish association from causality, approaches to patients with a history of an allergic reaction to a previous vaccine, and approaches to patients with a history of an allergic reaction to components of vaccines. This document provides comprehensive and internationally accepted guidelines and access to on-line documents to help practitioners around the world identify allergic reactions following immunization. It also provides a framework for the evaluation and further management of patients who present either following an allergic reaction to a vaccine or with a history of allergy to a component of vaccines.

Pre-recombination quenching of the radiation induced fluorescence as the approach to study kinetics of ion-molecular reactions

International Nuclear Information System (INIS)

Borovkov, V.I.; Ivanishko, I.S.

2011-01-01

This study deals with the geminate ion recombination in the presence of bulk scavengers, that is the so-called scavenger problem, as well as with the effect of the scavenging reaction on the radiation-induced recombination fluorescence. have proposed a method to determine the rate constant of the bulk reaction between neutral scavengers and one of the geminate ions if the ion-molecular reaction prevented the formation of electronically excited states upon recombination involving a newly formed ion. If such pre-recombination quenching of the radiation-induced fluorescence took place, it manifested itself as a progressive decrease in the decay of the fluorescence intensity. The relative change in the fluorescence decay as caused by the scavengers was believed to be closely related to the kinetics of the scavenging reaction. The goal of the present study is to support this method, both computationally and experimentally because there are two factors, which cast doubt on the intuitively obvious approach to the scavenger problem: spatial correlations between the particles involved and the drift of the charged reagent in the electric field of its geminate partner. Computer simulation of geminate ions recombination with an explicit modeling of the motion trajectories of scavengers has been performed for media of low dielectric permittivity, i.e. for the maximal Coulomb interaction between the ions. The simulation has shown that upon continuous diffusion of the particles involved, the joint effect of the two above factors can be considered as insignificant with a high accuracy. Besides, it is concluded then that the method of pre-recombination quenching could be applied to study parallel and consecutive reactions where the yields of excited states in the reaction pathways are different with the use of very simple analytical relations of the formal chemical kinetics. The conclusion has been confirmed experimentally by the example of the reactions of electron transfer from

Two decades of Neo-Marxist class analysis and health inequalities: A critical reconstruction

Science.gov (United States)

Muntaner, Carles; Ng, Edwin; Chung, Haejoo; Prins, Seth J

2015-01-01

Most population health researchers conceptualize social class as a set of attributes and material conditions of life of individuals. The empiricist tradition of ‘class as an individual attribute' equates class to an ‘observation', precluding the investigation of unobservable social mechanisms. Another consequence of this view of social class is that it cannot be conceptualized, measured, or intervened upon at the meso- or macro levels, being reduced to a personal attribute. Thus, population health disciplines marginalize rich traditions in Marxist theory whereby ‘class' is understood as a ‘hidden' social mechanism such as exploitation. Yet Neo-Marxist social class has been used over the last two decades in population health research as a way of understanding how health inequalities are produced. The Neo-Marxist approach views social class in terms of class relations that give persons control over productive assets and the labour power of others (property and managerial relations). We critically appraise the contribution of the Neo-Marxist approach during the last two decades and suggest realist amendments to understand class effects on the social determinants of health and health outcomes. We argue that when social class is viewed as a social causal mechanism it can inform social change to reduce health inequalities. PMID:26345311

Nitrogen-doped graphene prepared by a transfer doping approach for the oxygen reduction reaction application

Science.gov (United States)

Mo, Zaiyong; Zheng, Ruiping; Peng, Hongliang; Liang, Huagen; Liao, Shijun

2014-01-01

Well defined nitrogen-doped graphene (NG) is prepared by a transfer doping approach, in which the graphene oxide (GO) is deoxidized and nitrogen doped by the vaporized polyaniline, and the GO is prepared by a thermal expansion method from graphite oxide. The content of doped nitrogen in the doped graphene is high up to 6.25 at% by the results of elements analysis, and oxygen content is lowered to 5.17 at%. As a non-precious metal cathode electrocatalyst, the NG catalyst exhibits excellent activity toward the oxygen reduction reaction, as well as excellent tolerance toward methanol. In 0.1 M KOH solution, its onset potential, half-wave potential and limiting current density for the oxygen reduction reaction reach 0.98 V (vs. RHE), 0.87 V (vs. RHE) and 5.38 mA cm-2, respectively, which are comparable to those of commercial 20 wt% Pt/C catalyst. The well defined graphene structure of the catalyst is revealed clearly by HRTEM and Raman spectra. It is suggested that the nitrogen-doping and large surface area of the NG sheets give the main contribution to the high ORR catalytic activity.

Dependent Classes

DEFF Research Database (Denmark)

Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus

2007-01-01

of dependent classes and a machine-checked type soundness proof in Isabelle/HOL [29], the first of this kind for a language with virtual classes and path-dependent types. [29] T.Nipkow, L.C. Poulson, and M. Wenzel. Isabelle/HOL -- A Proof Assistant for Higher-Order Logic, volume 2283 of LNCS, Springer, 2002......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...

Cu-catalyzed esterification reaction via aerobic oxygenation and C-C bond cleavage: an approach to α-ketoesters.

Science.gov (United States)

Zhang, Chun; Feng, Peng; Jiao, Ning

2013-10-09

The Cu-catalyzed novel aerobic oxidative esterification reaction of 1,3-diones for the synthesis of α-ketoesters has been developed. This method combines C-C σ-bond cleavage, dioxygen activation and oxidative C-H bond functionalization, as well as provides a practical, neutral, and mild synthetic approach to α-ketoesters which are important units in many biologically active compounds and useful precursors in a variety of functional group transformations. A plausible radical process is proposed on the basis of mechanistic studies.

78 FR 47237 - Proposed Amendment of Class E Airspace; Chariton, IA

Science.gov (United States)

2013-08-05

...-0255; Airspace Docket No. 13-ACE-4] Proposed Amendment of Class E Airspace; Chariton, IA AGENCY... action proposes to amend Class E airspace at Chariton, IA. Decommissioning of the Chariton non... for standard instrument approach procedures at Chariton Municipal Airport, Chariton, IA. Airspace...

Cyclist–motorist crash patterns in Denmark: A latent class clustering approach

DEFF Research Database (Denmark)

Kaplan, Sigal; Prato, Carlo Giacomo

2013-01-01

to prioritize safety issues and to devise efficient preventive measures. Method: The current study focused on cyclist–motorist crashes that occurred in Denmark during the period between 2007 and 2011. To uncover crash patterns, the current analysis applied latent class clustering, an unsupervised probabilistic...

Markovian dynamics on complex reaction networks

Energy Technology Data Exchange (ETDEWEB)

Goutsias, J., E-mail: goutsias@jhu.edu; Jenkinson, G., E-mail: jenkinson@jhu.edu

2013-08-10

Complex networks, comprised of individual elements that interact with each other through reaction channels, are ubiquitous across many scientific and engineering disciplines. Examples include biochemical, pharmacokinetic, epidemiological, ecological, social, neural, and multi-agent networks. A common approach to modeling such networks is by a master equation that governs the dynamic evolution of the joint probability mass function of the underlying population process and naturally leads to Markovian dynamics for such process. Due however to the nonlinear nature of most reactions and the large size of the underlying state-spaces, computation and analysis of the resulting stochastic population dynamics is a difficult task. This review article provides a coherent and comprehensive coverage of recently developed approaches and methods to tackle this problem. After reviewing a general framework for modeling Markovian reaction networks and giving specific examples, the authors present numerical and computational techniques capable of evaluating or approximating the solution of the master equation, discuss a recently developed approach for studying the stationary behavior of Markovian reaction networks using a potential energy landscape perspective, and provide an introduction to the emerging theory of thermodynamic analysis of such networks. Three representative problems of opinion formation, transcription regulation, and neural network dynamics are used as illustrative examples.

Markovian dynamics on complex reaction networks

International Nuclear Information System (INIS)

Goutsias, J.; Jenkinson, G.

2013-01-01

Complex networks, comprised of individual elements that interact with each other through reaction channels, are ubiquitous across many scientific and engineering disciplines. Examples include biochemical, pharmacokinetic, epidemiological, ecological, social, neural, and multi-agent networks. A common approach to modeling such networks is by a master equation that governs the dynamic evolution of the joint probability mass function of the underlying population process and naturally leads to Markovian dynamics for such process. Due however to the nonlinear nature of most reactions and the large size of the underlying state-spaces, computation and analysis of the resulting stochastic population dynamics is a difficult task. This review article provides a coherent and comprehensive coverage of recently developed approaches and methods to tackle this problem. After reviewing a general framework for modeling Markovian reaction networks and giving specific examples, the authors present numerical and computational techniques capable of evaluating or approximating the solution of the master equation, discuss a recently developed approach for studying the stationary behavior of Markovian reaction networks using a potential energy landscape perspective, and provide an introduction to the emerging theory of thermodynamic analysis of such networks. Three representative problems of opinion formation, transcription regulation, and neural network dynamics are used as illustrative examples

Class-first analysis in a continuum: an approach to the complexities of schools, society, and insurgent science

Science.gov (United States)

Valdiviezo, Laura Alicia

2010-06-01

This essay addresses Katherine Richardson Bruna's paper: Mexican Immigrant Transnational Social Capital and Class Transformation: Examining the Role of Peer Mediation in Insurgent Science, through five main points . First, I offer a comparison between the traditional analysis of classism in Latin America and Richardson Bruna's call for a class-first analysis in the North American social sciences where there has been a tendency to obviate the specific examination of class relations and class issues. Secondly, I discuss that a class-first analysis solely cannot suffice to depict the complex dimensions in the relations of schools and society. Thus, I suggest a continuum in the class-first analysis. Third, I argue that social constructions surrounding issues of language, ethnicity, and gender necessarily intersect with issues of class and that, in fact, those other constructions offer compatible epistemologies that aid in representing the complexity of social and institutional practices in the capitalist society. Richardson Bruna's analysis of Augusto's interactions with his teacher and peers in the science class provides a fourth point of discussion in this essay. As a final point in my response I discuss Richardson Bruna's idea of making accessible class-first analysis knowledge to educators and especially to science teachers.

Social closure, micro-class immobility and the intergenerational reproduction of the upper class: a comparative study.

Science.gov (United States)

Ruggera, Lucia; Barone, Carlo

2017-06-01

This article assesses how processes of social closure enhance intergenerational immobility in the regulated professions and thus promote persistence at the top of the occupational hierarchy. We compare four European countries (GB, Germany, Denmark and Sweden) that differ considerably in their degree of professional regulation and in their broader institutional arrangements. We run log-linear and logistic regression models on a cumulative dataset based on three large-scale surveys with detailed and highly comparable information at the level of unit occupations. Our analyses indicate that children of licensed professionals are far more likely to inherit the occupation of their parents and that this stronger micro-class immobility translates into higher chances of persistence in the upper class. These results support social closure theory and confirm the relevance of a micro-class approach for the explanation of social fluidity and of its cross-national variations. Moreover, we find that, when children of professionals do not reproduce the micro-class of their parents, they still display disproportionate chances of persistence in professional employment. Hence, on the one hand, processes of social closure erect barriers between professions and fuel micro-class immobility at the top. On the other hand, the cultural proximity of different professional groups drives intense intergenerational exchanges between them. Our analyses indicate that these micro- and meso-class rigidities work as complementary routes to immobility at the top. © London School of Economics and Political Science 2017.

Organized for Genocide: Student Reactions and Learning from Use of Emotive Documentaries on the Holocaust

Science.gov (United States)

Kearney, Kerri S.; Krumm, Bernita; Hughes, Robin L.; Satterfield, James W.

2013-01-01

This article reports the qualitative analysis of the use of highly emotive documentaries of the Holocaust in a graduate-level organizational theory class. Specifically, the article looks at student reactions and impacts on learning. Student-produced work captured a broad range of reactions that led to increased insights about organizations (the…

Adverse drug reactions of angiotensin converting enzyme inhibitors : towards precision medicine

NARCIS (Netherlands)

Mahmoud Pour, S.H.

2016-01-01

Worldwide, millions of patients with cardiovascular diseases are treated with angiotensin converting enzyme inhibitors (ACEIs) according to the international treatment guidelines. Although this class of medications is generally well tolerated, adverse drug reactions (ADRs) may prevent their use in

Double Displacement: an Improved Bioorthogonal Reaction Strategy for Templated Nucleic Acid Detection

OpenAIRE

Kleinbaum, Daniel J.; Miller, Gregory P.; Kool, Eric T.

2010-01-01

Quenched autoligation probes have been employed previously in a target-templated nonenzymatic ligation strategy for detecting nucleic acids in cells by fluorescence. A common source of background signal in such probes is undesired reaction with water and other cellular nucleophiles. Here we describe a new class of self-ligating probes, double displacement (DD) probes, that rely on two displacement reactions to fully unquench a nearby fluorophore. Three potential double displacement architectu...

Spallation reactions; Reactions de spallation

Energy Technology Data Exchange (ETDEWEB)

Cugon, J.

1996-12-31

Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from {approx} 0.1 to {approx} 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author). 84 refs.

Correlations between reaction product yields as a tool for probing heavy-ion reaction scenarios

International Nuclear Information System (INIS)

Gawlikowicz, W.; Agnihotri, D. K.; Baldwin, S. A.; Schroeder, W. U.; Toke, J.; Charity, R. J.; Sarantites, D. G.; Sobotka, L. G.; Souza, R. T. de; Barczyk, T.; Grotowski, K.; Micek, S.; Planeta, R.; Sosin, Z.

2010-01-01

Experimental multidimensional joint distributions of neutrons and charged reaction products were analyzed for 136 Xe + 209 Bi reactions at E/A=28, 40, and 62 MeV and were found to exhibit several different types of prominent correlation patterns. Some of these correlations have a simple explanation in terms of the system excitation energy and pose little challenge to most statistical decay theories. However, several other types of correlation patterns are difficult to reconcile with some, but not other, possible reaction scenarios. In this respect, correlations between the average atomic numbers of intermediate-mass fragments, on the one hand, and light particle multiplicities, on the other, are notable. This kind of multiparticle correlation provides a useful tool for probing reaction scenarios, which is different from the traditional approach of interpreting inclusive yields of individual reaction products.

Nuclear reactions as structure probes

International Nuclear Information System (INIS)

Fernandez, Bernard; Cugnon, Joseph; Roussel-Chomaz, Patricia; Sparenberg, Jean-Marc; Oliveira Santos, Francois de; Bauge, Eric; Poves, Alfredo; Keeley, Nicholas; Simenel, Cedric; Avez, Benoit; Lacroix, Denis; Baye, Daniel; Cortina-Gil, Dolores; Pons, Alexandre

2007-09-01

This publication gathers courses which aim at giving a view on new experiments which are performed by using radioactive beams, notably low intensity beams, in different accelerators, and allow the structure of very exotic nuclei to be characterized. Experimental as well as theoretical aspects are thus addressed. The contributions propose: a brief history of nuclear reactions and of instruments used to study them from the discovery of nucleus to the DWBA (Distorted Wave Born Approximation); an overview of nuclear reactions; experimental techniques; the theory of collisions at low energy; resonant elastic scattering, inelastic scattering and astrophysical reactions; to probe nuclear structure with nucleons; shell model and spectroscopic factors; analysis of transfer reactions and determination of spectroscopic factors; microscopic approaches of nuclear dynamics; theoretical aspects of dissociation reactions; experimental aspects of knockout reactions; research in oenology with the chemical characterisation of defective ageing of dry white wines

75 FR 17637 - Proposed Amendment of Class E Airspace; Cherokee, IA

Science.gov (United States)

2010-04-07

...-0085; Airspace Docket No. 10-ACE-1] Proposed Amendment of Class E Airspace; Cherokee, IA AGENCY... action proposes to amend Class E airspace at Cherokee, IA. Decommissioning of the Pilot Rock non... for standard instrument approach procedures at Cherokee County Regional Airport, Cherokee, IA...

77 FR 71362 - Proposed Amendment of Class E Airspace; Decorah, IA

Science.gov (United States)

2012-11-30

...-1433; Airspace Docket No. 11-ACE-26] Proposed Amendment of Class E Airspace; Decorah, IA AGENCY... action proposes to amend Class E airspace at Decorah, IA. Decommissioning of the Decorah non-directional... instrument approach procedures at Decorah Municipal Airport, Decorah, IA. Airspace reconfiguration is...

78 FR 25231 - Proposed Establishment of Class E Airspace; Colt, AR

Science.gov (United States)

2013-04-30

...-1281; Airspace Docket No. 12-ASW-13] Proposed Establishment of Class E Airspace; Colt, AR AGENCY... action proposes to establish Class E airspace at Colt, AR. Controlled airspace is necessary to...-mile radius of Delta Regional Airport, Colt, AR, to accommodate new standard instrument approach...

Bromine incorporation into five DBP classes upon chlorination of water with extremely low SUVA values.

Science.gov (United States)

Hong, Huachang; Yan, Xiaoqing; Song, Xuhui; Qin, Yanyan; Sun, Hongjie; Lin, Hongjun; Chen, Jianrong; Liang, Yan

2017-07-15

The main objective of this study was to assess the effects of disinfection conditions on bromine incorporation into disinfection by-products (DBPs) during chlorination of water with low specific UV absorbance (SUVA). Five classes of DBPs were included: trihalomethanes (THMs), dihaloacetic acids (di-HAAs), trihaloacetic acids (tri-HAAs), dihaloacetonitriles (DHANs) and trihalonitromethanes (THNMs). Results showed that the bromine utilization in DBPs formation was positive related with reaction time, pH and temperature. On the other hand, the bromine substitution factors (BSFs) of DBPs were generally increased with pH (except tri-HAAs) and bromide concentration, but decreased with the reaction time, temperature and chlorine dose. Moreover, the BSFs values varied with DBP classes with the ranking being as following: THNMs≫DHANs≫tri-HAAs>THM≈di-HAAs. These results were mostly similar with the references, yet the pH effect on BSFs as well as the rank of BSFs for different DBP classes may differ with the specific UV absorbance of organic matter. Copyright © 2017 Elsevier B.V. All rights reserved.

A Hamiltonian viewpoint in the modeling of switching power converters : A systematic modeling procedure of a large class of switching power converters using the Hamiltonian approach

NARCIS (Netherlands)

Escobar, Gerardo; Schaft, Arjan J. van der; Ortega, Romeo

1999-01-01

In this paper we show how, using the Hamiltonian formalism, we can systematically derive mathematical models that describe the behaviour of a large class of switching power converters, including the "Boost", "Buck", "Buck-Boost", "Čuk" and "Flyback" converters. We follow the approach earlier

HISTORICAL-CRITICAL PEDAGOGY, CLASS STRUGGLE AND SCHOOL EDUCATION

Directory of Open Access Journals (Sweden)

Dermeval Saviani

2013-12-01

Full Text Available After introducing the approach of the relationship between education and class struggle in today's society, this article deals with the meaning of the concept of violence pointing out the current condition of a world ruled by violence that finds justification in the fascism, defined as the metaphysics of the violence. Next it approaches the problem of the eradication of the violence in the social praxis in the perspectives of the Christian Personalism (metaphysics of the non-violence, Existentialism (subjective conception of the violence and of the Marxism (objective conception of the violence and of the nonviolence. Based on those analyses it makes evident, in the conclusion, the relationship between class struggle and school education in the historical—critical perspective.

A combinatorial chemistry approach to the investigation of cerium oxide and plutonium oxide reactions with small molecules

Science.gov (United States)

Brady, John T.; Warner, Benjamin P.; Bridgewater, Jon S.; Havrilla, George J.; Morris, David E.; Buscher, C. Thomas

2000-07-01

We are currently investigating the potential chemistry of the 3013 Standard waste storage containers. These containers are filled with waste that is a mixture of inorganic salts and plutonium oxide that has been calcined to remove water and other volatiles. There has been concern about possible pressure buildup due to the formation of hydrogen or other gases. We are utilizing a combinatorial chemistry approach to investigate a range of possible reactions that may occur in the containers with various concentrations of metal oxides and inorganic salts.

Assessing Disease Class-Specific Diagnostic Ability: A Practical Adaptive Test Approach.

Science.gov (United States)

Papa, Frank J.; Schumacker, Randall E.

Measures of the robustness of disease class-specific diagnostic concepts could play a central role in training programs designed to assure the development of diagnostic competence. In the pilot study, the authors used disease/sign-symptom conditional probability estimates, Monte Carlo procedures, and artificial intelligence (AI) tools to create…

Common adverse drug reactions with psychiatric medications and ...

African Journals Online (AJOL)

Common adverse drug reactions with psychiatric medications and an approach to their management: Adverse drug reactions are as important in psychiatric practice as they are in any other branch of medicine.

Calculation of the energetics of chemical reactions

Energy Technology Data Exchange (ETDEWEB)

Dunning, T.H. Jr.; Harding, L.B.; Shepard, R.L.; Harrison, R.J.

1988-01-01

To calculate the energetics of chemical reactions we must solve the electronic Schroedinger equation for the molecular conformations of importance for the reactive encounter. Substantial changes occur in the electronic structure of a molecular system as the reaction progresses from reactants through the transition state to products. To describe these changes, our approach includes the following three elements: the use of multiconfiguration self-consistent field wave functions to provide a consistent zero-order description of the electronic structure of the reactants, transition state, and products; the use of configuration interaction techniques to describe electron correlation effects needed to provide quantitative predictions of the reaction energetics; and the use of large, optimized basis sets to provide the flexibility needed to describe the variations in the electronic distributions. With this approach we are able to study reactions involving as many as 5--6 atoms with errors of just a few kcal/mol in the predicted reaction energetics. Predictions to chemical accuracy, i.e., to 1 kcal/mol or less, are not yet feasible, although continuing improvements in both the theoretical methodology and computer technology suggest that this will soon be possible, at least for reactions involving small polyatomic species. 4 figs.

Social class, social capital, social practice and language in British sociolinguistics

DEFF Research Database (Denmark)

Fabricius, Anne H.

2017-01-01

Social class has recently re-emerged strongly within academic sociology in the UK, and I argue in this paper that sociolinguists benefit from an awareness of these currents in our work with speakers and communities in the UK setting. The discussion will elaborate on the approaches to social class...... ideological construct within British society all have ramifications for the resonance of social class in sociolinguistics and real-time corpus work. I will look at several research traditions of social class analysis and examine their potential contributions to sociolinguistic research. The importance of fine...

Entropy Generation in a Chemical Reaction

Science.gov (United States)

Miranda, E. N.

2010-01-01

Entropy generation in a chemical reaction is analysed without using the general formalism of non-equilibrium thermodynamics at a level adequate for advanced undergraduates. In a first approach to the problem, the phenomenological kinetic equation of an elementary first-order reaction is used to show that entropy production is always positive. A…

DisoMCS: Accurately Predicting Protein Intrinsically Disordered Regions Using a Multi-Class Conservative Score Approach.

Directory of Open Access Journals (Sweden)

Zhiheng Wang

Full Text Available The precise prediction of protein intrinsically disordered regions, which play a crucial role in biological procedures, is a necessary prerequisite to further the understanding of the principles and mechanisms of protein function. Here, we propose a novel predictor, DisoMCS, which is a more accurate predictor of protein intrinsically disordered regions. The DisoMCS bases on an original multi-class conservative score (MCS obtained by sequence-order/disorder alignment. Initially, near-disorder regions are defined on fragments located at both the terminus of an ordered region connecting a disordered region. Then the multi-class conservative score is generated by sequence alignment against a known structure database and represented as order, near-disorder and disorder conservative scores. The MCS of each amino acid has three elements: order, near-disorder and disorder profiles. Finally, the MCS is exploited as features to identify disordered regions in sequences. DisoMCS utilizes a non-redundant data set as the training set, MCS and predicted secondary structure as features, and a conditional random field as the classification algorithm. In predicted near-disorder regions a residue is determined as an order or a disorder according to the optimized decision threshold. DisoMCS was evaluated by cross-validation, large-scale prediction, independent tests and CASP (Critical Assessment of Techniques for Protein Structure Prediction tests. All results confirmed that DisoMCS was very competitive in terms of accuracy of prediction when compared with well-established publicly available disordered region predictors. It also indicated our approach was more accurate when a query has higher homologous with the knowledge database.The DisoMCS is available at http://cal.tongji.edu.cn/disorder/.

76 FR 53360 - Proposed Establishment of Class E Airspace; Stuart, IA

Science.gov (United States)

2011-08-26

...-0831; Airspace Docket No. 11-ACE-17] Proposed Establishment of Class E Airspace; Stuart, IA AGENCY... action proposes to establish Class E airspace at Stuart, IA. Controlled airspace is necessary to... surface for new standard instrument approach procedures at the City of Stuart Helistop, Stuart, IA...

77 FR 50650 - Proposed Amendment of Class E Airspace; Boone, IA

Science.gov (United States)

2012-08-22

...-1432; Airspace Docket No. 11-ACE-25] Proposed Amendment of Class E Airspace; Boone, IA AGENCY: Federal... proposes to amend Class E airspace at Boone, IA. Decommissioning of the Boone non-directional beacon (NDB... instrument approach procedures at Boone Municipal Airport, Boone, IA. Airspace reconfiguration is necessary...

78 FR 48840 - Proposed Amendment of Class E Airspace; Hampton, IA

Science.gov (United States)

2013-08-12

...-0585; Airspace Docket No. 13-ACE-7] Proposed Amendment of Class E Airspace; Hampton, IA AGENCY: Federal... proposes to amend Class E airspace at Hampton, IA. Decommissioning of the Hampton non-directional beacon... for standard instrument approach procedures at Hampton Municipal Airport, Hampton, IA. A segment would...

78 FR 25234 - Proposed Establishment of Class E Airspace; Walker, MN

Science.gov (United States)

2013-04-30

...-0266; Airspace Docket No. 13-AGL-11] Proposed Establishment of Class E Airspace; Walker, MN AGENCY... action proposes to establish Class E airspace at Walker, MN. Controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAP) at Walker Municipal Airport. The FAA is taking...

76 FR 44288 - Establishment of Class E Airspace; New Market, VA

Science.gov (United States)

2011-07-25

...-380; Airspace Docket No. 11-AEA-12] Establishment of Class E Airspace; New Market, VA AGENCY: Federal... proposes to establish Class E Airspace at New Market, VA, to accommodate the additional airspace needed for the Standard Instrument Approach Procedures developed for New Market Airport. This action would...

77 FR 4711 - Proposed Establishment of Class E Airspace; Houston, MO

Science.gov (United States)

2012-01-31

...-0903; Airspace Docket No. 11-ACE-20] Proposed Establishment of Class E Airspace; Houston, MO AGENCY... action proposes to establish Class E airspace at Houston, MO. Controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAP) at Houston Memorial Airport. The FAA is taking...

76 FR 30299 - Proposed Establishment of Class E Airspace; Kayenta, AZ

Science.gov (United States)

2011-05-25

...-0393; Airspace Docket No. 11-AWP-2] Proposed Establishment of Class E Airspace; Kayenta, AZ AGENCY... action proposes to establish Class E Airspace at Kayenta Airport, Kayenta, AZ. Controlled airspace is...) standard instrument approach procedures at Kayenta Airport. The FAA is proposing this action to enhance the...

78 FR 33019 - Proposed Amendment of Class E Airspace; Commerce, TX

Science.gov (United States)

2013-06-03

...-0269; Airspace Docket No. 13-ASW-3] Proposed Amendment of Class E Airspace; Commerce, TX AGENCY... action proposes to amend Class E airspace at Commerce, TX. Additional controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAPs) at Commerce Municipal Airport (AAF). The FAA...

76 FR 53359 - Proposed Establishment of Class E Airspace; Nashville, AR

Science.gov (United States)

2011-08-26

...-0497; Airspace Docket No. 11-ASW-4] Proposed Establishment of Class E Airspace; Nashville, AR AGENCY... action proposes to establish Class E airspace at Nashville, AR. Controlled airspace is necessary to... approach procedures at Howard County Airport, Nashville, AR. Controlled airspace is needed for the safety...

77 FR 16783 - Proposed Amendment of Class E Airspace; Orlando, FL

Science.gov (United States)

2012-03-22

...-0503; Airspace Docket No. 11-ASO-19] Proposed Amendment of Class E Airspace; Orlando, FL AGENCY... action proposes to amend Class E Airspace at Orlando, FL, as new Standard Instrument Approach Procedures have been developed at Orlando Executive Airport. This action would enhance the safety and airspace...

Nuclear structure in deep-inelastic reactions

International Nuclear Information System (INIS)

Rehm, K.E.

1986-01-01

The paper concentrates on recent deep inelastic experiments conducted at Argonne National Laboratory and the nuclear structure effects evident in reactions between super heavy nuclei. Experiments indicate that these reactions evolve gradually from simple transfer processes which have been studied extensively for lighter nuclei such as 16 O, suggesting a theoretical approach connecting the one-step DWBA theory to the multistep statistical models of nuclear reactions. This transition between quasi-elastic and deep inelastic reactions is achieved by a simple random walk model. Some typical examples of nuclear structure effects are shown. 24 refs., 9 figs

Recent developments in heavy ion deep inelastic reactions

International Nuclear Information System (INIS)

Lefort, M.; Ngo, C.

1979-01-01

In the first attempts to understand deep inelastic reactions (DIR), the attention was focussed on the dissipation mechanism and simple classical models have been elaborated to describe the dynamical evolution of the mean values of the macroscopic variables. Very early, it has also been realized that the distributions around the mean values were rather broad and that this might reveal the importance of fluctuations which are mainly expected to be statistical fluctuations. In section II, we shall only say a few words about the two classes of models: dynamical evolution and diffusion model, which have been described many time. Each of them accounts for a particular aspect of the DI phenomena. It appeared worthwhile to unify these approaches and to treat on the same footing both dissipation and statistical fluctuations. Microscopic attempts have succeeded in understanding the evolution of the macroscopic degrees which are slow as compared to the intrinsic degrees. In section III we shall briefly discuss them and in section IV we will more extensively see how they can be applied to the computation of multidifferential cross section for DIR. (autho.)

Teaching Chinese Film in an Advanced Language Class

OpenAIRE

Chen, Luying

2011-01-01

Instructors often face a dilemma when using film in language classes. While film is appealing for the rich cultural and linguistic information it offers, finding the balance between teaching content and building language skills can present significant challenges for an instructor. Common approaches to using film in courses taught in English, such as screening one film a week, reading critical essays about the films, and class discussions and lectures, seldom offer the same benefits in a forei...

An integrative approach to CTL epitope prediction: A combined algorithm integrating MHC class I binding, TAP transport efficiency, and proteasomal cleavage predictions

DEFF Research Database (Denmark)

Larsen, Mette Voldby; Lundegaard, Claus; Lamberth, K

2005-01-01

Reverse immunogenetic approaches attempt to optimize the selection of candidate epitopes, and thus minimize the experimental effort needed to identify new epitopes. When predicting cytotoxic T cell epitopes, the main focus has been on the highly specific MHC class I binding event. Methods have al.......The method is available at http://www.cbs.dtu.dk/services/NetCTL. Supplementary material is available at http://www.cbs.dtu.dk/suppl/immunology/CTL.php....

An improved approach to measuring drug innovation finds steady rates of first-in-class pharmaceuticals, 1987-2011.

Science.gov (United States)

Lanthier, Michael; Miller, Kathleen L; Nardinelli, Clark; Woodcock, Janet

2013-08-01

For more than a decade, industry analysts and policy makers have raised concerns about declining pharmaceutical innovation, citing declining numbers of new molecular entities (NMEs) approved in the United States each year. Yet there is little consensus on whether this is the best measure of "innovation." We examined NME approvals during 1987-2011 and propose the three distinct subcategories of NMEs--first-in-class, advance-in-class, and addition-to-class--to provide more nuanced and informative insights into underlying trends. We found that trends in NME approvals were largely driven by addition-to-class, or "me too," drug approvals, while first-in-class approvals remained fairly steady over the study period. Moreover, the higher proportion of first-in-class drug approvals over the most recent decade is an encouraging sign of the health of the industry as a whole.

Arabic web pages clustering and annotation using semantic class features

Directory of Open Access Journals (Sweden)

Hanan M. Alghamdi

2014-12-01

Full Text Available To effectively manage the great amount of data on Arabic web pages and to enable the classification of relevant information are very important research problems. Studies on sentiment text mining have been very limited in the Arabic language because they need to involve deep semantic processing. Therefore, in this paper, we aim to retrieve machine-understandable data with the help of a Web content mining technique to detect covert knowledge within these data. We propose an approach to achieve clustering with semantic similarities. This approach comprises integrating k-means document clustering with semantic feature extraction and document vectorization to group Arabic web pages according to semantic similarities and then show the semantic annotation. The document vectorization helps to transform text documents into a semantic class probability distribution or semantic class density. To reach semantic similarities, the approach extracts the semantic class features and integrates them into the similarity weighting schema. The quality of the clustering result has evaluated the use of the purity and the mean intra-cluster distance (MICD evaluation measures. We have evaluated the proposed approach on a set of common Arabic news web pages. We have acquired favorable clustering results that are effective in minimizing the MICD, expanding the purity and lowering the runtime.

Diastereoselective synthesis of tetrahydropyrans via Prins-Ritter and Prins-arylthiolation cyclization reactions.

Science.gov (United States)

Hazarika, Nabajyoti; Sarmah, Barnali; Bordoloi, Manobjyoti; Phukan, Prodeep; Baishya, Gakul

2017-03-01

An efficient method has been developed for the synthesis of two new classes of tetrahydropyran derivatives comprising amide, tetrazole or benzothiazole moieties via a three-component reaction of 6-methylhept-5-en-2-ol, arylaldehydes and nitriles/thiols in the presence of a tetrafluoroboric acid diethyl ether complex. The reaction proceeds via the formation of an oxocarbenium ion. This protocol is highly diastereoselective and only single diastereomer has been isolated in each case.

Class size versus class composition

DEFF Research Database (Denmark)

Jones, Sam

Raising schooling quality in low-income countries is a pressing challenge. Substantial research has considered the impact of cutting class sizes on skills acquisition. Considerably less attention has been given to the extent to which peer effects, which refer to class composition, also may affect...... bias from omitted variables, the preferred IV results indicate considerable negative effects due to larger class sizes and larger numbers of overage-for-grade peers. The latter, driven by the highly prevalent practices of grade repetition and academic redshirting, should be considered an important...

Global Elite as Transnational Capitalist Class

Directory of Open Access Journals (Sweden)

Lukáš Kantor

2017-01-01

Full Text Available As a contribution to the burgeoning field of multidisciplinary globalization studies, this article evaluates how IR grand theories can conceptualize the phenomenon of global elite. It compares and synthesizes (neoliberalism, constructivism, feminism and neo-Marxism. Liberal approaches use the analytical tool of transnational actors or transnational networks. In constructivist’s perspective, part of global elite falls into the category of epistemic community. Feminists offer the term Davos Men. Neo-Marxist conceptualization revolves around the notion of transnational capitalist class. The paper concludes that neo-Marxist IR theory best accounts for the global elite and therefore, the debates on the transnational capitalist class are thoroughly and critically reviewed.

Construction of UML class diagram with Model-Driven Development

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Tomasz Górski

2016-03-01

Full Text Available Model transformations play a key role in software development projects based on Model--Driven Development (MDD principles. Transformations allow for automation of repetitive and well-defined steps, thus shortening design time and reducing a number of errors. In the object-oriented approach, the key elements are use cases. They are described, modelled and later designed until executable application code is obtained. The aim of the paper is to present transformation of a model-to-model type, Communication-2-Class, which automates construction of Unified Modelling Language (UML class diagram in the context of the analysis/design model. An UML class diagram is created based on UML communication diagram within use case realization. As a result, a class diagram shows all of the classes involved in the use case realization and the relationships among them. The plug-in which implements Communication-2-Class transformation was implemented in the IBM Rational Software Architect. The article presents the tests results of developed plug-in, which realizes Communication-2-Class transformation, showing capabilities of shortening use case realization’s design time.[b]Keywords[/b]: Model-Driven Development, transformations, Unified Modelling Language, analysis/design model, UML class diagram, UML communication diagram

THE DEVELOPMENT OF ELECTRONIC TEACHING MATERIALS BY FLIPBOOK ASSISTANCE BASED PROBLEM SOLVING SKILL WITH CTL APPROACH ON LEARNING MATHEMATICS CLASS V

Directory of Open Access Journals (Sweden)

RUSNILAWATI Eva Gustiana RUSNILAWATI

2018-01-01

Full Text Available The purpose of this research is to produce Flipbook-based Electronic Teaching Materials (BAE based on problem solving skills with CTL Approach on Vocational School Class V learning valid, practical, and effective. This type of research is development research (Development Research. This research developed Flipbook-assisted Electronic Teaching Materials (BAE on the mathematics learning of Class V Primary School by using the 4-D development model developed by Thiagarajan, Semmel, and Semmel. The validation results show that the developed Teaching Materials are worthy of use with a good minimum category. The results of the experiments show that Electronic Materials developed are practical and effective. Completed learning in the classical has reached the minimum criteria of 75% that is for problem-solving test reached 86%. Based on a questionnaire of attitudes toward mathematics, 88% of students showed an increase in attitude scores on mathematics, and 85% of students showed attitudes toward mathematics with a good minimum category.

A multi target approach to control chemical reactions in their inhomogeneous solvent environment

International Nuclear Information System (INIS)

Keefer, Daniel; Thallmair, Sebastian; Zauleck, Julius P P; Vivie-Riedle, Regina de

2015-01-01

Shaped laser pulses offer a powerful tool to manipulate molecular quantum systems. Their application to chemical reactions in solution is a promising concept to redesign chemical synthesis. Along this road, theoretical developments to include the solvent surrounding are necessary. An appropriate theoretical treatment is helpful to understand the underlying mechanisms. In our approach we simulate the solvent by randomly selected snapshots from molecular dynamics trajectories. We use multi target optimal control theory to optimize pulses for the various arrangements of explicit solvent molecules simultaneously. This constitutes a major challenge for the control algorithm, as the solvent configurations introduce a large inhomogeneity to the potential surfaces. We investigate how the algorithm handles the new challenges and how well the controllability of the system is preserved with increasing complexity. Additionally, we introduce a way to statistically estimate the efficiency of the optimized laser pulses in the complete thermodynamical ensemble. (paper)

Social Class Dialogues and the Fostering of Class Consciousness

Science.gov (United States)

Madden, Meredith

2015-01-01

How do critical pedagogies promote undergraduate students' awareness of social class, social class identity, and social class inequalities in education? How do undergraduate students experience class consciousness-raising in the intergroup dialogue classroom? This qualitative study explores undergraduate students' class consciousness-raising in an…

Immediate reaction to lidocaine with periorbital edema during upper blepharoplasty

Directory of Open Access Journals (Sweden)

Benjamin Presman

2016-01-01

Conclusion: In clinical practice, we recommend that patient should be informed about the possibility of recurrence of an adverse reaction in case of re-exposure to lidocaine, even in the vast majority of cases where true allergy could not be proven. In case of further need for local anesthesia with history of an adverse event, a different agent may be chosen even from the same class (another amide as cross-reactions in the amide group are rare. Otherwise, an anesthetic from the ester group can also be safely used.

76 FR 30298 - Proposed Amendment of Class E Airspace; Cocoa, FL

Science.gov (United States)

2011-05-25

...-0070; Airspace Docket No. 10-ASO-43] Proposed Amendment of Class E Airspace; Cocoa, FL AGENCY: Federal... proposes to amend Class E Airspace at Cocoa, FL, as the Merritt Island Non-Directional Beacon (NDB) has... surface to support new standard instrument approach procedures developed at Merritt Island Airport, Cocoa...

75 FR 15360 - Proposed Amendment of Class E Airspace; Austin, TX

Science.gov (United States)

2010-03-29

...-1152; Airspace Docket No. 09-ASW-31] Proposed Amendment of Class E Airspace; Austin, TX AGENCY: Federal... proposes to amend Class E airspace in the Austin, TX area. Additional controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAPs) at Austin Executive Airport, Austin, TX. The...

78 FR 31429 - Proposed Amendment of Class E Airspace; Mason, TX

Science.gov (United States)

2013-05-24

...-1141; Airspace Docket No. 12-ASW-12] Proposed Amendment of Class E Airspace; Mason, TX AGENCY: Federal... proposes to amend Class E airspace at Mason, TX. Additional controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAP) at Mason County Airport. The FAA is taking this...

Teaching chemical reactions in the laboratory: linking theory and practice in teacher’s education and didactic action

Directory of Open Access Journals (Sweden)

Cleonice Puggian

2013-03-01

Full Text Available This paper presents the results of an investigation about chemistry teaching laboratory, describing the potential of a methodology that combines theoretical and hands on activities about chemical reactions. This proposal explores the curriculum content of high school chemistry, highlighting the teaching of chemical reactions, seeking the establishment of inter-relationships between the theoretical and practical knowledge inherent in the processes of school knowledge in Chemistry, challenging teachers to think about experimental activities not as an isolated moment in their class, but as an integral part of it. The methodology was qualitative in nature, adopting semi-structured interviews as instruments for data collection. The research was conducted with eight teachers of chemistry and seventy students from the second grade of high school from a technical school in Rio de Janeiro state. The results of this study indicate that this approach appears as an alternative to conducting laboratory experimental activities, contributing to a more formative and informative, less technical and fragmented teaching of chemistry in Basic Education. The research also shows that this approach supports teachers on their reflection of teaching practices, as well as on the planning and execution of experimental activities. We conclude that pedagogical proposals that articulate theory and practice are more effective in promoting the learning of high school students.

Genotyping of major histocompatibility complex Class II DRB gene in Rohilkhandi goats by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing

Directory of Open Access Journals (Sweden)

Kush Shrivastava

2015-10-01

Full Text Available Aim: To study the major histocompatibility complex (MHC Class II DRB1 gene polymorphism in Rohilkhandi goat using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP and nucleotide sequencing techniques. Materials and Methods: DNA was isolated from 127 Rohilkhandi goats maintained at sheep and goat farm, Indian Veterinary Research Institute, Izatnagar, Bareilly. A 284 bp fragment of exon 2 of DRB1 gene was amplified and digested using BsaI and TaqI restriction enzymes. Population genetic parameters were calculated using Popgene v 1.32 and SAS 9.0. The genotypes were then sequenced using Sanger dideoxy chain termination method and were compared with related breeds/species using MEGA 6.0 and Megalign (DNASTAR software. Results: TaqI locus showed three and BsaI locus showed two genotypes. Both the loci were found to be in Hardy–Weinberg equilibrium (HWE, however, population genetic parameters suggest that heterozygosity is still maintained in the population at both loci. Percent diversity and divergence matrix, as well as phylogenetic analysis revealed that the MHC Class II DRB1 gene of Rohilkhandi goats was found to be in close cluster with Garole and Scottish blackface sheep breeds as compared to other goat breeds included in the sequence comparison. Conclusion: The PCR-RFLP patterns showed population to be in HWE and absence of one genotype at one locus (BsaI, both the loci showed excess of one or the other homozygote genotype, however, effective number of alleles showed that allelic diversity is present in the population. Sequence comparison of DRB1 gene of Rohilkhandi goat with other sheep and goat breed assigned Rohilkhandi goat in divergence with Jamanupari and Angora goats.

Describing three-class task performance: three-class linear discriminant analysis and three-class ROC analysis

Science.gov (United States)

He, Xin; Frey, Eric C.

2007-03-01

Binary ROC analysis has solid decision-theoretic foundations and a close relationship to linear discriminant analysis (LDA). In particular, for the case of Gaussian equal covariance input data, the area under the ROC curve (AUC) value has a direct relationship to the Hotelling trace. Many attempts have been made to extend binary classification methods to multi-class. For example, Fukunaga extended binary LDA to obtain multi-class LDA, which uses the multi-class Hotelling trace as a figure-of-merit, and we have previously developed a three-class ROC analysis method. This work explores the relationship between conventional multi-class LDA and three-class ROC analysis. First, we developed a linear observer, the three-class Hotelling observer (3-HO). For Gaussian equal covariance data, the 3- HO provides equivalent performance to the three-class ideal observer and, under less strict conditions, maximizes the signal to noise ratio for classification of all pairs of the three classes simultaneously. The 3-HO templates are not the eigenvectors obtained from multi-class LDA. Second, we show that the three-class Hotelling trace, which is the figureof- merit in the conventional three-class extension of LDA, has significant limitations. Third, we demonstrate that, under certain conditions, there is a linear relationship between the eigenvectors obtained from multi-class LDA and 3-HO templates. We conclude that the 3-HO based on decision theory has advantages both in its decision theoretic background and in the usefulness of its figure-of-merit. Additionally, there exists the possibility of interpreting the two linear features extracted by the conventional extension of LDA from a decision theoretic point of view.

Deteksi Penyakit Dengue Hemorrhagic Fever dengan Pendekatan One Class Classification

Directory of Open Access Journals (Sweden)

Zida Ziyan Azkiya

2017-10-01

Full Text Available Two class classification problem maps input into two target classes. In certain cases, training data is available only in the form of a single class, as in the case of Dengue Hemorrhagic Fever (DHF patients, where only data of positive patients is available. In this paper, we report our experiment in building a classification model for detecting DHF infection using One Class Classification (OCC approach. Data from this study is sourced from laboratory tests of patients with dengue fever. The OCC methods compared are One-Class Support Vector Machine and One-Class K-Means. The result shows SVM method obtained precision value = 1.0, recall = 0.993, f-1 score = 0.997, and accuracy of 99.7% while the K-Means method obtained precision value = 0.901, recall = 0.973, f- 1 score = 0.936, and accuracy of 93.3%. This indicates that the SVM method is slightly superior to K-Means for One-Class Classification of DHF patients.

Dynamical barrier and isotope effects in the simplest substitution reaction via Walden inversion mechanism

Science.gov (United States)

Zhao, Zhiqiang; Zhang, Zhaojun; Liu, Shu; Zhang, Dong H.

2017-02-01

Reactions occurring at a carbon atom through the Walden inversion mechanism are one of the most important and useful classes of reactions in chemistry. Here we report an accurate theoretical study of the simplest reaction of that type: the H+CH4 substitution reaction and its isotope analogues. It is found that the reaction threshold versus collision energy is considerably higher than the barrier height. The reaction exhibits a strong normal secondary isotope effect on the cross-sections measured above the reaction threshold, and a small but reverse secondary kinetic isotope effect at room temperature. Detailed analysis reveals that the reaction proceeds along a path with a higher barrier height instead of the minimum-energy path because the umbrella angle of the non-reacting methyl group cannot change synchronously with the other reaction coordinates during the reaction due to insufficient energy transfer from the translational motion to the umbrella mode.

'Sum rules' for preequilibrium reactions

International Nuclear Information System (INIS)

Hussein, M.S.

1981-03-01

Evidence that suggests a correct relationship between the optical transmission matrix, P, and the several correlation widths, gamma sub(n), found in nsmission matrix, P, and the several correlation widths, n, found in multistep compound (preequilibrium) nuclear reactions, is presented. A second sum rule is also derived within the shell model approach to nuclear reactions. Indications of the potential usefulness of the sum rules in preequilibrium studies are given. (Author) [pt

Student Responses to a Flipped Introductory Physics Class with built-in Post-Video Feedback Quizzes

Science.gov (United States)

Ramos, Roberto

We present and analyze student responses to multiple Introductory physics classes in a university setting, taught in a ''flipped'' class format. The classes included algebra- and calculus-based introductory physics. Outside class, students viewed over 100 online video lectures on Classical Mechanics, Electricity and Magnetism, and Modern Physics prepared by this author and in some cases, by a third-party lecture package available over YouTube. Inside the class, students solved and discussed problems and conceptual issues in greater detail. A pre-class online quiz was deployed as an important source of feedback. I will report on the student reactions to the feedback mechanism, student responses using data based on anonymous surveys, as well as on learning gains from pre-/post- physics diagnostic tests. The results indicate a broad mixture of responses to different lecture video packages that depend on learning styles and perceptions. Students preferred the online quizzes as a mechanism to validate their understanding. The learning gains based on FCI and CSEM surveys were significant.

Facile approach to prepare pH and redox-responsive nanogels via Diels-Alder click reaction

Directory of Open Access Journals (Sweden)

C. M. Q. Le

2018-08-01

Full Text Available A novel pH and redox responsive system of sub-100 nm nanogels was prepared by arm-first approach via Diels-Alder click reaction. First, well-defined poly(ethylene glycol-block-poly(styrene-alt-maleic anhydride (PEG-b-PSM was synthesized and subsequently functionalized with furfuryl amine, leading to the formation of the dual-functional block copolymer of PEG-b-PSMf. The furfuryl groups in the PSMf block were employed to incorporate a redox-responsive linkage and the carboxylic acid moieties generated through functionalization acted as a pH-responsive part. The Diels-Alder click reaction between a bismaleimide crosslinker and PEG-b-PSMf was conducted at 60 °C, affording star-like nanogel structures. Doxorubicin, a model anticancer drug, was loaded into to the core of the nanogels primarily by the ionic interaction with carboxylates of core blocks and a highest drug loading capacity of 38.1% was obtained. Furthermore, the in vitro profile showed a low release percentage (11.2% of DOX at PBS pH 7.4, whereas a burst release (62% at pH 5.0 in the presence of 10 mM glutathione, indicating the effective pH and redox responsive characteristic of the PEG-b-PSMf nanogels.

Thermal theory of autowave processes in low-temperature solid-phase radiochemical reactions

International Nuclear Information System (INIS)

Barelko, V.V.; Barkalov, I.M.; Vaganov, D.A.; Zanin, A.M.; Kiryukhin, D.P.

1982-01-01

A new phenomenon in radiation cryochemistry concerning the class of autowave processes was previously discovered. It was observed in halogenation and hydrohalogenation of hydrocarbons and consisted of spontaneous, laminar propagation of a chemical transformation wave based on a frozen mixture of reagents previously irradiated with 60 Co γ-rays. The effect of the positive inverse correlation between the chemical conversion and brittle fracture of a solid sample of reagents is the phenomenological basis of the phenomenon; formation of fractures triggers a reactive process which takes place on their active surface (or in the layer adjacent to it), and the chemical reaction, in turn, stimulates the subsequent development of the process of decomposition. As a result, a single brittle fracture and chemical conversion wave which moves along the solid sample arises. Different mechanisms of generation of fracture surfaces under the effect of the reaction are possible. A difference in the densities of the initial reagents and the products of the reaction could be one of the causes of brittle fracture, and the thermal stresses induced by the exothermicity of the chemical processes could be another cause. The present work concerns the analysis of the features of the wave process which occurs based on the second, thermal mechanism. The analysis was conducted within the framework of a phenomenological approach which does not require specific definition of the nature of the chemical activation of the system during its brittle fracture

Social affiliation in same-class and cross-class interactions.

Science.gov (United States)

Côté, Stéphane; Kraus, Michael W; Carpenter, Nichelle C; Piff, Paul K; Beermann, Ursula; Keltner, Dacher

2017-02-01

Historically high levels of economic inequality likely have important consequences for relationships between people of the same and different social class backgrounds. Here, we test the prediction that social affiliation among same-class partners is stronger at the extremes of the class spectrum, given that these groups are highly distinctive and most separated from others by institutional and economic forces. An internal meta-analysis of 4 studies (N = 723) provided support for this hypothesis. Participant and partner social class were interactively, rather than additively, associated with social affiliation, indexed by affiliative behaviors and emotions during structured laboratory interactions and in daily life. Further, response surface analyses revealed that paired upper or lower class partners generally affiliated more than average-class pairs. Analyses with separate class indices suggested that these patterns are driven more by parental income and subjective social class than by parental education. The findings illuminate the dynamics of same- and cross-class interactions, revealing that not all same-class interactions feature the same degree of affiliation. They also reveal the importance of studying social class from an intergroup perspective. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Efficient Discovery of Novel Multicomponent Mixtures for Hydrogen Storage: A Combined Computational/Experimental Approach

Energy Technology Data Exchange (ETDEWEB)

Wolverton, Christopher [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Ozolins, Vidvuds [Univ. of California, Los Angeles, CA (United States). Dept. of Materials Science and Engineering; Kung, Harold H. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemical and Biological Engineering; Yang, Jun [Ford Scientific Research Lab., Dearborn, MI (United States); Hwang, Sonjong [California Inst. of Technology (CalTech), Pasadena, CA (United States). Dept. of Chemistry and Chemical Engineering; Shore, Sheldon [The Ohio State Univ., Columbus, OH (United States). Dept. of Chemistry and Biochemistry

2016-11-28

The objective of the proposed program is to discover novel mixed hydrides for hydrogen storage, which enable the DOE 2010 system-level goals. Our goal is to find a material that desorbs 8.5 wt.% H₂ or more at temperatures below 85°C. The research program will combine first-principles calculations of reaction thermodynamics and kinetics with material and catalyst synthesis, testing, and characterization. We will combine materials from distinct categories (e.g., chemical and complex hydrides) to form novel multicomponent reactions. Systems to be studied include mixtures of complex hydrides and chemical hydrides [e.g. LiNH²⁺NH₃BH₃] and nitrogen-hydrogen based borohydrides [e.g. Al(BH₄)₃(NH₃)₃]. The 2010 and 2015 FreedomCAR/DOE targets for hydrogen storage systems are very challenging, and cannot be met with existing materials. The vast majority of the work to date has delineated materials into various classes, e.g., complex and metal hydrides, chemical hydrides, and sorbents. However, very recent studies indicate that mixtures of storage materials, particularly mixtures between various classes, hold promise to achieve technological attributes that materials within an individual class cannot reach. Our project involves a systematic, rational approach to designing novel multicomponent mixtures of materials with fast hydrogenation/dehydrogenation kinetics and favorable thermodynamics using a combination of state-of-the-art scientific computing and experimentation. We will use the accurate predictive power of first-principles modeling to understand the thermodynamic and microscopic kinetic processes involved in hydrogen release and uptake and to design new material/catalyst systems with improved properties. Detailed characterization and atomic-scale catalysis experiments will elucidate the effect of dopants and nanoscale catalysts in achieving fast kinetics and reversibility. And

Maximum Principles for Discrete and Semidiscrete Reaction-Diffusion Equation

Directory of Open Access Journals (Sweden)

Petr Stehlík

2015-01-01

Full Text Available We study reaction-diffusion equations with a general reaction function f on one-dimensional lattices with continuous or discrete time ux′  (or  Δtux=k(ux-1-2ux+ux+1+f(ux, x∈Z. We prove weak and strong maximum and minimum principles for corresponding initial-boundary value problems. Whereas the maximum principles in the semidiscrete case (continuous time exhibit similar features to those of fully continuous reaction-diffusion model, in the discrete case the weak maximum principle holds for a smaller class of functions and the strong maximum principle is valid in a weaker sense. We describe in detail how the validity of maximum principles depends on the nonlinearity and the time step. We illustrate our results on the Nagumo equation with the bistable nonlinearity.

Global exponential stability of reaction-diffusion recurrent neural networks with time-varying delays

International Nuclear Information System (INIS)

Liang Jinling; Cao Jinde

2003-01-01

Employing general Halanay inequality, we analyze the global exponential stability of a class of reaction-diffusion recurrent neural networks with time-varying delays. Several new sufficient conditions are obtained to ensure existence, uniqueness and global exponential stability of the equilibrium point of delayed reaction-diffusion recurrent neural networks. The results extend and improve the earlier publications. In addition, an example is given to show the effectiveness of the obtained result

"CLASS APPROACH" AND "PROLETARIAN CHARACTER" OF RUSSIAN REVOLUTION OF 1917

Directory of Open Access Journals (Sweden)

Эдуард Эдуардович Шульц

2014-12-01

Full Text Available Study of the problem of “class character” of 1917’ revolution and competency of the term “proletarian revolution”. The author considers questions of participation of various social groups in the Russian revolution, draws analogies of social composition of previous revolutions, considers the principle of “proletarian revolution”, as an ideology element for positioning of Bolsheviks and power capture. It is necessary to consider that an age, gender and national factor played much bigger role un Russian revolution than class factor. Revolution in Russia in many respects leaned on young generations which made more than a third of the population of the Russian Empire by 1917. In fight against tsarism separate calculation was based on the non-russian population and national suburbs of the empire. The special role in the Russian revolution was played by the peasantry. Revolution happened in the capital (in two capitals in Russia, the peasantry remained indifferent to revolution while Bolsheviks didn't begin to take away from them the food violently. This period:(summer - fall of 1919 became the time of peak of the Civil war. However return of landowners and their claim for property of the land forced peasants to turn bayonets for revolution and the earth and, eventually, to provide to Bolsheviks a victory in the Civil war.

The application of individual approach in how to conduct aerobics classes with students of different levels of preparedness.

Directory of Open Access Journals (Sweden)

Barybina L.N.

2012-09-01

Full Text Available The aim of this work was to develop a system of classes in aerobics in high school with an individual approach. On this subject has been analyzed about 15 references. 105 students took part in an experiment. The technique, which combines fitness aerobics and step aerobics. The technique allows to take into account the physical capacity, functional differences, the level of preparedness and dealing with their needs, as well as to use an individual approach in the selection of means and methods of physical education. We propose the organization of activities in which the hall can simultaneously engage up to 5-6 subgroups: students with low fitness and low levels of coordination abilities, students with an average level of physical fitness and low levels of coordination abilities, students with high levels of physical fitness and low levels of coordination abilities, students with an average level of physical fitness and a high level of coordination abilities, students with high levels of physical fitness and coordination abilities.

Revisiting the Reaction Between Diaminomaleonitrile and Aromatic Aldehydes: a Green Chemistry Approach

Directory of Open Access Journals (Sweden)

Francisco León

2006-11-01

Full Text Available The reaction between diaminomaleonitrile (DAMN and aldehydes and the resulting monoimines are well known. Since the standard reaction conditions involve the use of toxic solvents (typically methanol, we have sought to apply green chemistry principles to this reaction by either using water as the solvent without any catalysts or employing “solvent-free” conditions. The monoimines derived from DAMN are of interest as precursors for obtaining different heterocyclic systems and linear polymers. The methodologies used have significant advantages with regards to cost and environmental considerations.

The nuclear structure and low-energy reactions (NSLER) collaboration

International Nuclear Information System (INIS)

Dean, D J

2006-01-01

The long-term vision of the Nuclear Structure and Low-Energy Reactions (NSLER) collaboration is to arrive at a comprehensive and unified description of nuclei and their reactions that is grounded in the interactions between the constituent nucleons. For this purpose, we will develop a universal energy density functional for nuclei and replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that will deliver maximum predictive power with minimal uncertainties that are well quantified. Nuclear structure and reactions play an essential role in the science to be investigated at rare isotope facilities, and in nuclear physics applications to the Science-Based Stockpile Stewardship Program, next-generation reactors, and threat reduction. We anticipate an expansion of the computational techniques and methods we currently employ, and developments of new treatments, to take advantage of petascale architectures and demonstrate the capability of the leadership class machines to deliver new science heretofore impossible

Market reactions to the ECB's Comprehensive Assessment

NARCIS (Netherlands)

Sahin, Cenkhan; de Haan, Jakob

Using an event study approach, we examine financial markets' reactions to the publication of the ECB's Comprehensive Assessment of banks in the euro area. Our results suggest that banks' stock market prices and CDS spreads generally showed no reaction. (C) 2015 Elsevier B.V. All rights reserved.

WCOM (World Class Operations Management) why you need more than lean

CERN Document Server

Ballerio, Noela

2016-01-01

This book deals with World Class Operations Management (WCOM), detailing its principles, methods and organisation, and the results that this approach can bring about. Utilising real-world case studies illustrated by companies that have adopted this model (interviews with Saint-Gobain, L’Oréal, Tetra Pak, Bemis, and Bel Executives), it describes common patterns drawn from decades of hands-on experience, so as to present a theoretical approach together with the concrete application of its principles. WCOM, adopted by several multinational companies, is one of the more innovative management practises, as it integrates the best Continuous Improvement approaches (Lean, Total Productive Management, World Class Manufacturing) as well as the most innovative approaches in human dynamics like Change Leadership, Performance Behavior, Shingo Model, to name a few. Maximising reader insights into the successful implementation of such an approach, and explaining not only its potentialities, but also its implementation dy...

The Color Red Supports Avoidance Reactions to Unhealthy Food.

Science.gov (United States)

Rohr, Michaela; Kamm, Friederike; Koenigstorfer, Joerg; Groeppel-Klein, Andrea; Wentura, Dirk

2015-01-01

Empirical evidence suggests that the color red acts like an implicit avoidance cue in food contexts. Thus specific colors seem to guide the implicit evaluation of food items. We built upon this research by investigating the implicit meaning of color (red vs. green) in an approach-avoidance task with healthy and unhealthy food items. Thus, we examined the joint evaluative effects of color and food: Participants had to categorize food items by approach-avoidance reactions, according to their healthfulness. Items were surrounded by task-irrelevant red or green circles. We found that the implicit meaning of the traffic light colors influenced participants' reactions to the food items. The color red (compared to green) facilitated automatic avoidance reactions to unhealthy foods. By contrast, approach behavior toward healthy food items was not moderated by color. Our findings suggest that traffic light colors can act as implicit cues that guide automatic behavioral reactions to food.

Construction of a Hierarchical Architecture of Covalent Organic Frameworks via a Postsynthetic Approach.

Science.gov (United States)

Zhang, Gen; Tsujimoto, Masahiko; Packwood, Daniel; Duong, Nghia Tuan; Nishiyama, Yusuke; Kadota, Kentaro; Kitagawa, Susumu; Horike, Satoshi

2018-02-21

Covalent organic frameworks (COFs) represent an emerging class of crystalline porous materials that are constructed by the assembly of organic building blocks linked via covalent bonds. Several strategies have been developed for the construction of new COF structures; however, a facile approach to fabricate hierarchical COF architectures with controlled domain structures remains a significant challenge, and has not yet been achieved. In this study, a dynamic covalent chemistry (DCC)-based postsynthetic approach was employed at the solid-liquid interface to construct such structures. Two-dimensional imine-bonded COFs having different aromatic groups were prepared, and a homogeneously mixed-linker structure and a heterogeneously core-shell hollow structure were fabricated by controlling the reactivity of the postsynthetic reactions. Solid-state nuclear magnetic resonance (NMR) spectroscopy and transmission electron microscopy (TEM) confirmed the structures. COFs prepared by a postsynthetic approach exhibit several functional advantages compared with their parent phases. Their Brunauer-Emmett-Teller (BET) surface areas are 2-fold greater than those of their parent phases because of the higher crystallinity. In addition, the hydrophilicity of the material and the stepwise adsorption isotherms of H 2 O vapor in the hierarchical frameworks were precisely controlled, which was feasible because of the distribution of various domains of the two COFs by controlling the postsynthetic reaction. The approach opens new routes for constructing COF architectures with functionalities that are not possible in a single phase.

Global Inequalities: Gender, Class, and Race/Ethnicity.

Science.gov (United States)

Shope, Janet Hinson; Singer, Eric

1996-01-01

Discusses a case study approach to internationalizing an undergraduate interdisciplinary sociology course that explores the sources and consequences of inequality. Presents three case studies from Baltimore (Maryland), Japan, and Zimbabwe, each one detailing social and economic causes of inequality. Briefly covers class assignments and a…

Pi-activated alcohols: an emerging class of alkylating agents for catalytic Friedel-Crafts reactions.

Science.gov (United States)

Bandini, Marco; Tragni, Michele

2009-04-21

The direct functionalization of aromatic compounds, via Friedel-Crafts alkylation reactions with alcohols, is one of the cornerstones in organic chemistry. The present emerging area deals with the recent advances in the use of pi-activated alcohols in the catalytic and stereoselective construction of benzylic stereocenters.

7Li(d,p)8Li transfer reaction in the NCSM/RGM approach

Science.gov (United States)

Raimondi, F.; Hupin, G.; Navrátil, P.; Quaglioni, S.

2018-03-01

Recently, we applied an ab initio method, the no-core shell model combined with the resonating group method, to the transfer reactions with light p-shell nuclei as targets and deuteron as the projectile. In particular, we studied the elastic scattering of deuterium on 7Li and the 7Li(d,p)8Li transfer reaction starting from a realistic two-nucleon interaction. In this contribution, we review of our main results on the 7Li(d,p)8Li transfer reaction, and we extend the study of the relevant reaction channels, by showing the dominant resonant phase shifts of the scattering matrix. We assess also the impact of the polarization effects of the deuteron below the breakup on the positive-parity resonant states in the reaction. For this purpose, we perform an analysis of the convergence trend of the phase and eigenphase shifts, with respect to the number of deuteron pseudostates included in the model space.

DIAGNOSTIC GUIDANCE AND EARLY INTERVENTION IN CLASS III MALOCCLUSION

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Rinandri Charea Runizar

2015-06-01

Full Text Available Timing of orthodontic treatment for Class III malocclusion has always been somewhat controversial. Many orthodontic pioneers like Angle, Tweed, and Graber have advocated early interception of class II malocclusion because this kind of skeletal discrepancy once established, would usually progress rapidly. What kind of early treatment would be appropriate for this malocclusion? Would this approach be effective and promises a stable result? Early orthodontic treatment is defined as a treatment that is initiated during the primary or mixed dentition stage to enhance skeletal and dental development. It is usually done in two phases. The first phase is intended to correct skeletal discrepancy by taking advantage of growth and development period. The second phase followed to improve occlusal relationship. Early treatment of Class III malocclusion is a possible alternative to improve skeletal discrepancy or at the very east may serve to prevent a worsening malocclusion. Principles of Class III early treatment depend on whether it is dental Class III, functional Class III, or skeletal Class III. Practitioners should consider positive and negative factors of a patient before initiating treatment. Likewise, they should understand factors that affect prognosis and stability of the results.

Adverse drug reactions induced by cardiovascular drugs in outpatients.

Science.gov (United States)

Gholami, Kheirollah; Ziaie, Shadi; Shalviri, Gloria

2008-01-01

Considering increased use of cardiovascular drugs and limitations in pre-marketing trials for drug safety evaluation, post marketing evaluation of adverse drug reactions (ADRs) induced by this class of medicinal products seems necessary. To determine the rate and seriousness of adverse reactions induced by cardiovascular drugs in outpatients. To compare sex and different age groups in developing ADRs with cardiovascular agents. To assess the relationship between frequencies of ADRs and the number of drugs used. This cross-sectional study was done in cardiovascular clinic at a teaching hospital. All patients during an eight months period were evaluated for cardiovascular drugs induced ADRs. Patient and reaction factors were analyzed in detected ADRs. Patients with or without ADRs were compared in sex and age by using chi-square test. Assessing the relationship between frequencies of ADRs and the number of drugs used was done by using Pearson analysis. The total number of 518 patients was visited at the clinic. ADRs were detected in 105 (20.3%) patients. The most frequent ADRs were occurred in the age group of 51-60. The highest rate of ADRs was recorded to be induced by Diltiazem (23.5%) and the lowest rate with Atenolol (3%). Headache was the most frequent detected ADR (23%). Assessing the severity and preventability of ADRs revealed that 1.1% of ADRs were detected as severe and 1.9% as preventable reactions. Women significantly developed more ADRs in this study (chi square = 3.978, PPearson=0.259, P<0.05). Monitoring ADRs in patients using cardiovascular drugs is a matter of importance since this class of medicines is usually used by elderly patients with critical conditions and underlying diseases.

ADOPTING THE PROBLEM BASED LEARNING APPROACH IN A GIS PROJECT MANAGEMENT CLASS

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Problem Based Learning (PBL) is a process that emphasizes the need for developing problem solving skills through hands-on project formulation and management. A class adopting the PBL method provides students with an environment to acquire necessary knowledge to encounter, unders...

Mannich reaction: A versatile and convenient approach to bioactive ...

Indian Academy of Sciences (India)

tions of multifaceted Mannich reaction in the synthesis of antimalarial, antitumour ..... R1, R2 = methyl, ethyl, n-propyl, n-butyl, (CH2)4, (CH2)2O(CH2)2, (CH2)5. R1 =H, R2 = Et or .... Kumbhare et al. reported zinc chloride cat- alyzed Mannich ...

Exploring social class: voices of inter-class couples.

Science.gov (United States)

McDowell, Teresa; Melendez-Rhodes, Tatiana; Althusius, Erin; Hergic, Sara; Sleeman, Gillian; Ton, Nicky Kieu My; Zimpfer-Bak, A J

2013-01-01

Social class is not often discussed or examined in-depth in couple and family therapy research and literature even though social class shapes familial relationships and is considered an important variable in marital satisfaction. In this qualitative study, we explored the perceptions of eight couples who made lasting commitments across class lines by asking them about the impact of their social class backgrounds on their relationships. Three categories of themes emerged including: (a) differences and similarities in values and attitudes toward education, work, money, and class awareness/classism, (b) relationship issues involving families of origin, friends, and class-based couple conflict, and (c) differences in economic resources, social capital and privileges/opportunities. Implications for assessment and treatment of couples are included. © 2012 American Association for Marriage and Family Therapy.

Co-solvent effects on reaction rate and reaction equilibrium of an enzymatic peptide hydrolysis.

Science.gov (United States)

Wangler, A; Canales, R; Held, C; Luong, T Q; Winter, R; Zaitsau, D H; Verevkin, S P; Sadowski, G

2018-04-25

This work presents an approach that expresses the Michaelis constant KaM and the equilibrium constant Kth of an enzymatic peptide hydrolysis based on thermodynamic activities instead of concentrations. This provides KaM and Kth values that are independent of any co-solvent. To this end, the hydrolysis reaction of N-succinyl-l-phenylalanine-p-nitroanilide catalysed by the enzyme α-chymotrypsin was studied in pure buffer and in the presence of the co-solvents dimethyl sulfoxide, trimethylamine-N-oxide, urea, and two salts. A strong influence of the co-solvents on the measured Michaelis constant (KM) and equilibrium constant (Kx) was observed, which was found to be caused by molecular interactions expressed as activity coefficients. Substrate and product activity coefficients were used to calculate the activity-based values KaM and Kth for the co-solvent free reaction. Based on these constants, the co-solvent effect on KM and Kx was predicted in almost quantitative agreement with the experimental data. The approach presented here does not only reveal the importance of understanding the thermodynamic non-ideality of reactions taking place in biological solutions and in many technological applications, it also provides a framework for interpreting and quantifying the multifaceted co-solvent effects on enzyme-catalysed reactions that are known and have been observed experimentally for a long time.

Solvent engineering and other reaction design methods for favouring enzyme-catalysed synthesis

DEFF Research Database (Denmark)

Zeuner, Birgitte

. However, both FAEs catalysed the feruloylation and/or sinapoylation of solvent cation C2OHMIm+, thus underlining the broad acceptor specificity of FAEs and their potential for future solvent reactions. An engineered sialidase from Trypanosoma rangeli, Tr6, catalyses trans-sialylation but the yield......This thesis investigates different methods for improving reaction yields of enzyme-catalysed synthesis reactions. These methods include the use of non-conventional media such as ionic liquids (ILs) and organic solvents as main solvents or as co-solvents as well as the use of more classical reaction...... design methods, i.e. enzyme immobilization and the use of an enzymatic membrane reactor. Two different enzyme classes, namely feruloyl esterases (FAEs) and sialidases are employed. Using sinapoylation of glycerol as a model reaction it was shown that both the IL anion nature and the FAE structure were...

Effect of Substrate Character on Heterogeneous Ozone Reaction Rate with Individual PAHs and Their Reaction Mixtures

Science.gov (United States)

Holmen, B. A.; Stevens, T.

2009-12-01

Vehicle exhaust contains many unregulated chemical compounds that are harmful to human health and the natural environment, including polycyclic aromatic hydrocarbons (PAH), a class of organic compounds derived from fuel combustion that can be carcinogenic and mutagenic. PAHs have been quantified in vehicle-derived ultrafine particles (Dpsolid, reacting the samples with gas-phase ozone, and determining both PAH loss over time and products formed, using thermal-desorption gas chromatography / mass spectrometry (TD-GC/MS). The individual PAHs anthracene, phenanthrene, and fluorene, adsorbed to a QFF were also separately reacted with 0.4 ppm ozone. A volatilization control and the collection of volatilized PAHs using a Tenax-packed thermal desorption vial completed the mass balance and aided determination parent-product relationships. Heterogeneous reaction products analyzed directly without derivatization indicate the formation of 9,10-anthracenedione, 9H-fluoren-9-one, and (1,1’-biphenyl)-2,2’-dicarboxaldehyde from the reaction of ozone with the PAH mix on a QFF, but only 9,10-anthracenedione was detected for the diesel PM reaction. The implications of these results for aging of diesel particulate in urban environments will be discussed.

A kinetic-theory approach for computing chemical-reaction rates in upper-atmosphere hypersonic flows.

Science.gov (United States)

Gallis, Michael A; Bond, Ryan B; Torczynski, John R

2009-09-28

Recently proposed molecular-level chemistry models that predict equilibrium and nonequilibrium reaction rates using only kinetic theory and fundamental molecular properties (i.e., no macroscopic reaction-rate information) are investigated for chemical reactions occurring in upper-atmosphere hypersonic flows. The new models are in good agreement with the measured Arrhenius rates for near-equilibrium conditions and with both measured rates and other theoretical models for far-from-equilibrium conditions. Additionally, the new models are applied to representative combustion and ionization reactions and are in good agreement with available measurements and theoretical models. Thus, molecular-level chemistry modeling provides an accurate method for predicting equilibrium and nonequilibrium chemical-reaction rates in gases.

Latent class factor and cluster models, bi-plots and tri-plots and related graphical displays

NARCIS (Netherlands)

Magidson, J.; Vermunt, J.K.

2001-01-01

We propose an alternative method of conducting exploratory latent class analysis that utilizes latent class factor models, and compare it to the more traditional approach based on latent class cluster models. We show that when formulated in terms of R mutually independent, dichotomous latent

76 FR 54148 - Proposed Amendment of Class E Airspace; Emmonak, AK

Science.gov (United States)

2011-08-31

... AK E5 Emmonak, AK [Revised] Emmonak Airport, AK (Lat. 62[deg]47'10'' N., long. 164[deg]29'27'' W...-0880 Airspace Docket No. 11-AAL-17] Proposed Amendment of Class E Airspace; Emmonak, AK AGENCY: Federal... proposes to revise Class E airspace at Emmonak, AK. The amendment of two standard instrument approach...

Popular Culture in the Classroom: Using Audio and Video Clips to Enhance Survey Classes

Science.gov (United States)

Hoover, D. Sandy

2006-01-01

Students often approach history survey classes with a significant degree of dread. Nevertheless, at least one history class is required for graduation from most, if not all, universities, and most students elect to take survey courses to fulfill that requirement. Students rarely enroll in an American history class eagerly, because they anticipate…

Approaching the Speed of Light with Class.

Science.gov (United States)

Dance, Rosalie A.; Sandefur, James T.

1997-01-01

Describes an experimental approach to determining the speed of light in water using some simple observations and Fermat's principle. Enables students to integrate mathematical techniques and encourages mathematical exploration in which the students have control over what mathematics and technology to use and when to use them. Presents extensions…

Contemporary solutions for managing Class III malocclusion

Directory of Open Access Journals (Sweden)

Nathamuni Rengarajan Krishnaswamy

2015-01-01

Full Text Available Although patients with Class III malocclusions constitute a small percentage of the average orthodontic practice, providing them with optimal treatment is a daunting task. The treatment approach is dependent upon the growth status of the individual and the severity of the skeletal dysplasia. For growing individuals, facemask therapy to protract the maxilla is ineffective because of its dependence on dental anchorage to bring forth skeletal correction. Orthodontic camouflage in nongrowing mild skeletal Class III individuals is met with limited success because of the anatomical boundaries and the conventional biomechanics. Orthognathic surgery to correct the maxillomandibular relations is time-consuming, and the facial esthetics is compromised during the orthodontic decompensation period. Contemporary solutions to overcome these limitations are now viable with the use of temporary anchorage devices and by performing surgery prior to orthodontic decompensation. The rationale for employing these contemporary approaches will be discussed in this study with illustrative cases.

Invariant class operators in the decoherent histories analysis of timeless quantum theories

International Nuclear Information System (INIS)

Halliwell, J. J.; Wallden, P.

2006-01-01

The decoherent histories approach to quantum theory is applied to a class of reparametrization-invariant models whose state is an energy eigenstate. A key step in this approach is the construction of class operators characterizing the questions of physical interest, such as the probability of the system entering a given region of configuration space without regard to time. In nonrelativistic quantum mechanics these class operators are given by time-ordered products of projection operators. But in reparametrization-invariant models, where there is no time, the construction of the class operators is more complicated, the main difficulty being to find operators which commute with the Hamiltonian constraint (and so respect the invariance of the theory). Here, inspired by classical considerations, we put forward a proposal for the construction of such class operators for a class of reparametrization-invariant systems. They consist of continuous infinite temporal products of Heisenberg picture projection operators. We investigate the consequences of this proposal in a number of simple models and also compare with the evolving constants method. The formalism developed here is ultimately aimed at cosmological models described by a Wheeler-DeWitt equation, but the specific features of such models are left to future papers

Engaging unactivated alkyl, alkenyl and aryl iodides in visible-light-mediated free radical reactions

Science.gov (United States)

Nguyen, John D.; D'Amato, Erica M.; Narayanam, Jagan M. R.; Stephenson, Corey R. J.

2012-10-01

Radical reactions are a powerful class of chemical transformations. However, the formation of radical species to initiate these reactions has often required the use of stoichiometric amounts of toxic reagents, such as tributyltin hydride. Recently, the use of visible-light-mediated photoredox catalysis to generate radical species has become popular, but the scope of these radical precursors has been limited. Here, we describe the identification of reaction conditions under which photocatalysts such as fac-Ir(ppy)3 can be utilized to form radicals from unactivated alkyl, alkenyl and aryl iodides. The generated radicals undergo reduction via hydrogen atom abstraction or reductive cyclization. The reaction protocol utilizes only inexpensive reagents, occurs under mild reaction conditions, and shows exceptional functional group tolerance. Reaction efficiency is maintained upon scale-up and decreased catalyst loading, and the reaction time can be significantly shortened when the reaction is performed in a flow reactor.

Creative class as the leading group of modern society

Directory of Open Access Journals (Sweden)

O. Y. Sakalo

2015-06-01

Full Text Available In the article one of the modern approaches to the social structure of the society is considered. The creative class is determined as the main driving force and as a leading social class of modern society. The author studies the history of the concept of creative class, and R. Florida’s concept in particular, and determines its characteristics and peculiarities. The influence of the creative class on the society, on its transformation processes, and the system of social values is analyzed. The role of creative class in developing creative and innovative economy of the post­industrial society era is found out. The author considers the relationship between the creative class and the other social classes of modern society. The essence of the concept of creativity is defined, and one of the most important problems of the modern era that is a constant conflict between creativity and organization is examined. The comparative historical analysis of the so­called «institutional»/ «industrial» and «creative»/ «post­industrial» era is made. The role of the creative class in developing and social changing the modern American society is studied. The questions of forming and developing creative class in modern Ukrainian society are analyzed, and the peculiarities and problems of this process are figured out. The need of state support for forming national creative class, for its strengthening and growth is emphasized.

Nonparametric variational optimization of reaction coordinates

Energy Technology Data Exchange (ETDEWEB)

Banushkina, Polina V.; Krivov, Sergei V., E-mail: s.krivov@leeds.ac.uk [Astbury Center for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT (United Kingdom)

2015-11-14

State of the art realistic simulations of complex atomic processes commonly produce trajectories of large size, making the development of automated analysis tools very important. A popular approach aimed at extracting dynamical information consists of projecting these trajectories into optimally selected reaction coordinates or collective variables. For equilibrium dynamics between any two boundary states, the committor function also known as the folding probability in protein folding studies is often considered as the optimal coordinate. To determine it, one selects a functional form with many parameters and trains it on the trajectories using various criteria. A major problem with such an approach is that a poor initial choice of the functional form may lead to sub-optimal results. Here, we describe an approach which allows one to optimize the reaction coordinate without selecting its functional form and thus avoiding this source of error.

New Class of Wide Energy Gap Benzotriimidazole Optical Materials

Directory of Open Access Journals (Sweden)

Jianmin Shi

2017-10-01

Full Text Available A new class of wide energy gap benzotriimidazole materials have been synthesized by a two-step condensation reaction. All of the benzotriimidazole compounds have π-π* absorption bands in the range of 250–400 nm. The photoluminescence (PL quantum efficiency of each benzotriimidazole depends strongly on the presence of electron withdrawing groups. PL quantum efficiencies of benzotriimidazoles without electron withdrawing groups were less than desirable (40–43%, while molecules with electron withdrawing groups displayed much stronger PL with efficiencies in the range of 73–75%. The electron withdrawing groups shift the emission to a longer wavelength, towards a more “true blue” color. This new class of benzotriimidazole optical materials could be used as electron-injecting and electron-transporting blue luminescence materials for potential organic light-emitting diode (OLED applications.

Active Site Loop Dynamics of a Class IIa Fructose 1,6-Bisphosphate Aldolase from Mycobacterium tuberculosis

Energy Technology Data Exchange (ETDEWEB)

Pegan, Scott D. [Univ. of Denver, CO (United States); Rukseree, Kamolchanok [National Center for Genetic Engineering and Biotechnology (BIOTEC), Tha Khlong (Thailand); Capodagli, Glenn C. [Univ. of Denver, CO (United States); Baker, Erica A. [Univ. of Denver, CO (United States); Krasnykh, Olga [Univ. of Illinois, Chicago, IL (United States); Franzblau, Scott G. [Univ. of Illinois, Chicago, IL (United States); Mesecar, Andrew D. [Purdue Univ., West Lafayette, IN (United States)

2013-01-08

The class II fructose 1,6-bisphosphate aldolases (FBAs, EC 4.1.2.13) comprises one of two families of aldolases. Instead of forming a Schiff base intermediate using an ε-amino group of a lysine side chain, class II FBAs utilize Zn(II) to stabilize a proposed hydroxyenolate intermediate (HEI) in the reversible cleavage of fructose 1,6-bisphosphate, forming glyceraldehyde 3-phosphate and dihydroxyacetone phosphate (DHAP). As class II FBAs have been shown to be essential in pathogenic bacteria, focus has been placed on these enzymes as potential antibacterial targets. Although structural studies of class II FBAs from Mycobacterium tuberculosis (MtFBA), other bacteria, and protozoa have been reported, the structure of the active site loop responsible for catalyzing the protonation–deprotonation steps of the reaction for class II FBAs has not yet been observed. We therefore utilized the potent class II FBA inhibitor phosphoglycolohydroxamate (PGH) as a mimic of the HEI- and DHAP-bound form of the enzyme and determined the X-ray structure of the MtFBA–PGH complex to 1.58 Å. Remarkably, we are able to observe well-defined electron density for the previously elusive active site loop of MtFBA trapped in a catalytically competent orientation. Utilization of this structural information and site-directed mutagenesis and kinetic studies conducted on a series of residues within the active site loop revealed that E169 facilitates a water-mediated deprotonation–protonation step of the MtFBA reaction mechanism. Furthermore, solvent isotope effects on MtFBA and catalytically relevant mutants were used to probe the effect of loop flexibility on catalytic efficiency. Additionally, we also reveal the structure of MtFBA in its holoenzyme form.

Novel Chiral Bis-Phosphoramides as Organocatalysts for Tetrachlorosilane-Mediated Reactions

Directory of Open Access Journals (Sweden)

Sergio Rossi

2017-12-01

Full Text Available The formation of novel chiral bidentate phosphoroamides structures able to promote Lewis base-catalyzed Lewis acid-mediated reactions was investigated. Two different classes of phosphoroamides were synthetized: the first class presents a phthalic acid/primary diamine moiety, designed with the aim to perform a self-assembly recognition process through hydrogen bonds; the second one is characterized by the presence of two phosphoroamides as side arms connected to a central pyridine unit, able to chelate SiCl4 in a 2:1 adduct. These species were tested as organocatalysts in the stereoselective allylation of benzaldehyde and a few other aromatic aldehydes with allyl tributyltin in the presence of SiCl4 with good results. NMR studies confirm that only pyridine-based phosphoroamides effectively coordinate tetrachlorosilane and may lead to the generation of a self-assembled entity that would act as a promoter of the reaction. Although further work is necessary to clarify and confirm the formation of the hypothesized adduct, the study lays the foundation for the design and the synthesis of chiral supramolecular organocatalysts.

Reaction between (Z)-arylchlorooximes and α-isocyanoacetamides: a procedure for the synthesis of aryl-α-ketoamide amides.

Science.gov (United States)

Giustiniano, Mariateresa; Mercalli, Valentina; Cassese, Hilde; Di Maro, Salvatore; Galli, Ubaldina; Novellino, Ettore; Tron, Gian Cesare

2014-07-03

(Z)-Arylchlorooximes and α-isocyanoacetamides undergo a smooth reaction to produce 1,3-oxazol-2-oxime derivatives in good yields. Opening of the oxazole ring and deoximation reaction give a facile access to aryl-α-ketoamide amides, a class of privileged scaffolds in medicinal chemistry and important synthetic intermediates in organic chemistry.

77 FR 4713 - Proposed Establishment of Class E Airspace; Red Cloud, NE

Science.gov (United States)

2012-01-31

...-0426; Airspace Docket No. 11-ACE-7] Proposed Establishment of Class E Airspace; Red Cloud, NE AGENCY... action proposes to establish Class E airspace at Red Cloud, NE. Controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAP) at Red Cloud Municipal Airport. The FAA is...

77 FR 49399 - Proposed Amendment of Class E Airspace; Forest City, IA

Science.gov (United States)

2012-08-16

...-0654; Airspace Docket No. 12-ACE-3] Proposed Amendment of Class E Airspace; Forest City, IA AGENCY... action proposes to amend Class E airspace at Forest City, IA. Additional controlled airspace is necessary... accommodate new standard instrument approach procedures at Forest City Municipal Airport, Forest City, IA. The...

77 FR 71361 - Proposed Amendment of Class E Airspace; West Union, IA

Science.gov (United States)

2012-11-30

...-1434; Airspace Docket No. 11-ACE-27] Proposed Amendment of Class E Airspace; West Union, IA AGENCY... action proposes to amend Class E airspace at West Union, IA. Decommissioning of the West Union non... instrument approach procedures at George L. Scott Municipal Airport, West Union, IA. Airspace reconfiguration...

77 FR 41939 - Proposed Establishment of Class E Airspace; Deer Lodge, MT

Science.gov (United States)

2012-07-17

...-0379; Airspace Docket No. 12-ANM-7 Proposed Establishment of Class E Airspace; Deer Lodge, MT AGENCY... action proposes to establish Class E airspace at Deer Lodge-City-County Airport, Deer Lodge, MT... System (GPS) standard instrument approach procedures at Deer Lodge-City-County Airport, Deer Lodge, MT...

Class impressions : Higher social class elicits lower prosociality

NARCIS (Netherlands)

Van Doesum, Niels J.; Tybur, Joshua M.; Van Lange, Paul A.M.

2017-01-01

Social class predicts numerous important life outcomes and social orientations. To date, literature has mainly examined how an individual's own class shapes interactions with others. But how prosocially do people treat others they perceive as coming from lower, middle, or higher social classes?

Isocyanide based multi component reactions in combinatorial chemistry.

NARCIS (Netherlands)

Dömling, A.

1998-01-01

Although usually regarded as a recent development, the combinatorial approach to the synthesis of libraries of new drug candidates was first described as early as 1961 using the isocyanide-based one-pot multicomponent Ugi reaction. Isocyanide-based multi component reactions (MCR's) markedly differ

Accelerating rejection-based simulation of biochemical reactions with bounded acceptance probability

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); Zunino, Roberto, E-mail: roberto.zunino@unitn.it [Department of Mathematics, University of Trento, Trento (Italy)

2016-06-14

Stochastic simulation of large biochemical reaction networks is often computationally expensive due to the disparate reaction rates and high variability of population of chemical species. An approach to accelerate the simulation is to allow multiple reaction firings before performing update by assuming that reaction propensities are changing of a negligible amount during a time interval. Species with small population in the firings of fast reactions significantly affect both performance and accuracy of this simulation approach. It is even worse when these small population species are involved in a large number of reactions. We present in this paper a new approximate algorithm to cope with this problem. It is based on bounding the acceptance probability of a reaction selected by the exact rejection-based simulation algorithm, which employs propensity bounds of reactions and the rejection-based mechanism to select next reaction firings. The reaction is ensured to be selected to fire with an acceptance rate greater than a predefined probability in which the selection becomes exact if the probability is set to one. Our new algorithm improves the computational cost for selecting the next reaction firing and reduces the updating the propensities of reactions.

Integrating social class and privilege in the community medicine curriculum.

Science.gov (United States)

Haymaker, Christopher; Cadick, Amber; Seavey, Allison

2017-05-01

Social class and privilege are hidden variables that impact the physician-patient relationship and health outcomes. This article presents a sample of activities from three programs utilized in the community health curriculum to teach resident physicians about patients within context, including how social class and privilege impact physician-patient relationships and patient health. These activities address resident physicians' resistance to discussion of privilege, social class, and race by emphasizing direct experience and active learning rather than traditional didactic sessions. The group format of these activities fosters flexible discussion and personal engagement that provide opportunities for reflection. Each activity affords opportunities to develop a vocabulary for discussing social class and privilege with compassion and to adopt therapeutic approaches that are more likely to meet patients where they are.

Promoting children's health through physically active math classes: a pilot study.

Science.gov (United States)

Erwin, Heather E; Abel, Mark G; Beighle, Aaron; Beets, Michael W

2011-03-01

School-based interventions are encouraged to support youth physical activity (PA). Classroom-based PA has been incorporated as one component of school wellness policies. The purpose of this pilot study is to examine the effects of integrating PA with mathematics content on math class and school day PA levels of elementary students. Participants include four teachers and 75 students. Five math classes are taught without PA integration (i.e., baseline) followed by 13 math classes that integrate PA. Students wear pedometers and accelerometers to track PA during math class and throughout the school day. Students perform significantly more PA on school days and in math classes during the intervention. In addition, students perform higher intensity (step min(-1)) PA during PA integration math classes compared with baseline math classes. Integrating PA into the classroom is an effective alternative approach to improving PA levels among youth and is an important component of school-based wellness policies.

Robust Sensor Faults Reconstruction for a Class of Uncertain Linear Systems Using a Sliding Mode Observer: An LMI Approach

International Nuclear Information System (INIS)

Iskander, Boulaabi; Faycal, Ben Hmida; Moncef, Gossa; Anis, Sellami

2009-01-01

This paper presents a design method of a Sliding Mode Observer (SMO) for robust sensor faults reconstruction of systems with matched uncertainty. This class of uncertainty requires a known upper bound. The basic idea is to use the H ∞ concept to design the observer, which minimizes the effect of the uncertainty on the reconstruction of the sensor faults. Specifically, we applied the equivalent output error injection concept from previous work in Fault Detection and Isolation (FDI) scheme. Then, these two problems of design and reconstruction can be expressed and numerically formulate via Linear Matrix Inequalities (LMIs) optimization. Finally, a numerical example is given to illustrate the validity and the applicability of the proposed approach.

Fusion reaction cross-sections using the Wong model within Skyrme energy density based semiclassical extended Thomas Fermi approach

Energy Technology Data Exchange (ETDEWEB)

Kumar, Raj, E-mail: rajkumarfzr@gmail.com [Department of Physics, Panjab University, Chandigarh-160014 (India); School of Physics and Material Science, Thapar University, Patiala-147004 (India); Sharma, Manoj K. [School of Physics and Material Science, Thapar University, Patiala-147004 (India); Gupta, Raj K. [Department of Physics, Panjab University, Chandigarh-160014 (India)

2011-11-15

First, the nuclear proximity potential, obtained by using the semiclassical extended Thomas Fermi (ETF) approach in Skyrme energy density formalism (SEDF), is shown to give more realistic barriers in frozen density approximation, as compared to the sudden approximation. Then, taking advantage of the fact that, in ETF method, different Skyrme forces give different barriers (height, position and curvature), we use the l-summed extended-Wong model of Gupta and collaborators (2009) under frozen densities approximation for calculating the cross-sections, where the Skyrme force is chosen with proper barrier characteristics, not-requiring additional 'barrier modification' effects (lowering or narrowing, etc.), for a best fit to data at sub-barrier energies. The method is applied to capture cross-section data from {sup 48}Ca + {sup 238}U, {sup 244}Pu, and {sup 248}Cm reactions and to fusion-evaporation cross-sections from {sup 58}Ni + {sup 58}Ni, {sup 64}Ni + {sup 64}Ni, and {sup 64}Ni + {sup 100}Mo reactions, with effects of deformations and orientations of nuclei included, wherever required. Interestingly, whereas the capture cross-sections in Ca-induced reactions could be fitted to any force, such as SIII, SV and GSkI, by allowing a small change of couple of units in deduced l{sub max}-values at below-barrier energies, the near-barrier data point of {sup 48}Ca + {sup 248}Cm reaction could not be fitted to l{sub max}-values deduced for below-barrier energies, calling for a check of data. On the other hand, the fusion-evaporation cross-sections in Ni-induced reactions at sub-barrier energies required different Skyrme forces, representing 'modifications of the barrier', for the best fit to data at all incident center-of-mass energies E{sub c.m.}'s, displaying a kind of fusion hindrance at sub-barrier energies. This barrier modification effect is taken into care here by using different Skyrme forces for reactions belonging to different regions of

Neutral theory of chemical reaction networks

International Nuclear Information System (INIS)

Lee, Sang Hoon; Holme, Petter; Minnhagen, Petter; Bernhardsson, Sebastian; Kim, Beom Jun

2012-01-01

To what extent do the characteristic features of a chemical reaction network reflect its purpose and function? In general, one argues that correlations between specific features and specific functions are key to understanding a complex structure. However, specific features may sometimes be neutral and uncorrelated with any system-specific purpose, function or causal chain. Such neutral features are caused by chance and randomness. Here we compare two classes of chemical networks: one that has been subjected to biological evolution (the chemical reaction network of metabolism in living cells) and one that has not (the atmospheric planetary chemical reaction networks). Their degree distributions are shown to share the very same neutral system-independent features. The shape of the broad distributions is to a large extent controlled by a single parameter, the network size. From this perspective, there is little difference between atmospheric and metabolic networks; they are just different sizes of the same random assembling network. In other words, the shape of the degree distribution is a neutral characteristic feature and has no functional or evolutionary implications in itself; it is not a matter of life and death. (paper)

Condensed Matter Cluster Reactions in LENR Power Cells for a Radical New Type of Space Power Source

Science.gov (United States)

Yang, Xiaoling; Miley, George H.; Hora, Heinz

2009-03-01

This paper reviews previous theoretical and experimental study on the possibility of nuclear events in multilayer thin film electrodes (Lipson et al., 2004 and 2005; Miley et al., 2007), including the correlation between excess heat and transmutations (Miley and Shrestha, 2003) and the cluster theory that predicts it. As a result of this added understanding of cluster reactions, a new class of electrodes is under development at the University of Illinois. These electrodes are designed to enhance cluster formation and subsequent reactions. Two approaches are under development. The first employs improved loading-unloading techniques, intending to obtain a higher volumetric density of sites favoring cluster formation. The second is designed to create nanostructures on the electrode where the cluster state is formed by electroless deposition of palladium on nickel micro structures. Power units employing these electrodes should offer unique advantages for space applications. This is a fundamental new nuclear energy source that is environmentally compatible with a minimum of radiation involvement, high specific power, very long lifetime, and scalable from micro power to kilowatts.

Condensed Matter Cluster Reactions in LENR Power Cells for a Radical New Type of Space Power Source

International Nuclear Information System (INIS)

Yang Xiaoling; Miley, George H.; Hora, Heinz

2009-01-01

This paper reviews previous theoretical and experimental study on the possibility of nuclear events in multilayer thin film electrodes (Lipson et al., 2004 and 2005; Miley et al., 2007), including the correlation between excess heat and transmutations (Miley and Shrestha, 2003) and the cluster theory that predicts it. As a result of this added understanding of cluster reactions, a new class of electrodes is under development at the University of Illinois. These electrodes are designed to enhance cluster formation and subsequent reactions. Two approaches are under development. The first employs improved loading-unloading techniques, intending to obtain a higher volumetric density of sites favoring cluster formation. The second is designed to create nanostructures on the electrode where the cluster state is formed by electroless deposition of palladium on nickel micro structures. Power units employing these electrodes should offer unique advantages for space applications. This is a fundamental new nuclear energy source that is environmentally compatible with a minimum of radiation involvement, high specific power, very long lifetime, and scalable from micro power to kilowatts.

Magnetic resonance imaging in the evaluation of periosteal reactions

Energy Technology Data Exchange (ETDEWEB)

Nogueira-Barbosa, Marcello Henrique; Trad, Clovis Simao; Muglia, Valdair Francisco; Elias Junior, Jorge; Simao, Marcelo Novelino, E-mail: marcello@fmrp.usp.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Sa, Jose Luiz de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas; Oliveira, Rodrigo Cecilio Vieira de [Clinica de Diagnostico por Imagem Tomoson, Aracatuba, SP (Brazil); Engel, Edgard Eduard [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Biomecanica, Medicina e Reabilitacao do Aparelho Locomotor

2010-07-15

The objective of the present essay was to encourage a careful evaluation of periosteal reactions on magnetic resonance images. The initial approach to bone lesions is made by conventional radiography and, based on the imaging findings, periosteal reactions are classified into classical subtypes. Although magnetic resonance imaging is considered as the gold standard for local staging of bone tumors, the utilization of such method in the study of periosteal reactions related to focal bone lesions has been poorly emphasized, with relatively few studies approaching this subject. The literature review revealed a study describing an experimental animal model of osteomyelitis suggesting that magnetic resonance imaging is superior to other imaging methods in the early identification of periosteal reactions. Another study has suggested a good correlation between conventional radiography and magnetic resonance imaging in the identification and classification of periosteal reactions in cases of osteosarcoma. The present essay illustrates cases of periosteal reactions observed at magnetic resonance imaging in correlation with findings of conventional radiography or other imaging methods. (author)

Magnetic resonance imaging in the evaluation of periosteal reactions

International Nuclear Information System (INIS)

Nogueira-Barbosa, Marcello Henrique; Trad, Clovis Simao; Muglia, Valdair Francisco; Elias Junior, Jorge; Simao, Marcelo Novelino; Engel, Edgard Eduard

2010-01-01

The objective of the present essay was to encourage a careful evaluation of periosteal reactions on magnetic resonance images. The initial approach to bone lesions is made by conventional radiography and, based on the imaging findings, periosteal reactions are classified into classical subtypes. Although magnetic resonance imaging is considered as the gold standard for local staging of bone tumors, the utilization of such method in the study of periosteal reactions related to focal bone lesions has been poorly emphasized, with relatively few studies approaching this subject. The literature review revealed a study describing an experimental animal model of osteomyelitis suggesting that magnetic resonance imaging is superior to other imaging methods in the early identification of periosteal reactions. Another study has suggested a good correlation between conventional radiography and magnetic resonance imaging in the identification and classification of periosteal reactions in cases of osteosarcoma. The present essay illustrates cases of periosteal reactions observed at magnetic resonance imaging in correlation with findings of conventional radiography or other imaging methods. (author)

Hierarchical zeolites from class F coal fly ash

Science.gov (United States)

Chitta, Pallavi

Fly ash, a coal combustion byproduct is classified as types class C and class F. Class C fly ash is traditionally recycled for concrete applications and Class F fly ash often disposed in landfills. Class F poses an environmental hazard due to disposal and leaching of heavy metals into ground water and is important to be recycled in order to mitigate the environmental challenges. A major recycling option is to reuse the fly ash as a low-cost raw material for the production of crystalline zeolites, which serve as catalysts, detergents and adsorbents in the chemical industry. Most of the prior literature of fly ash conversion to zeolites does not focus on creating high zeolite surface area zeolites specifically with hierarchical pore structure, which are very important properties in developing a heterogeneous catalyst for catalysis applications. This research work aids in the development of an economical process for the synthesis of high surface area hierarchical zeolites from class F coal fly ash. In this work, synthesis of zeolites from fly ash using classic hydrothermal treatment approach and fusion pretreatment approach were examined. The fusion pretreatment method led to higher extent of dissolution of silica from quartz and mullite phases, which in turn led to higher surface area and pore size of the zeolite. A qualitative kinetic model developed here attributes the difference in silica content to Si/Al ratio of the beginning fraction of fly ash. At near ambient crystallization temperatures and longer crystallization times, the zeolite formed is a hierarchical faujasite with high surface area of at least 360 m2/g. This work enables the large scale recycling of class F coal fly ash to produce zeolites and mitigate environmental concerns. Design of experiments was used to predict surface area and pore sizes of zeolites - thus obviating the need for intense experimentation. The hierarchical zeolite catalyst supports tested for CO2 conversion, yielded hydrocarbons

Transfer and breakup reactions at intermediate energies

International Nuclear Information System (INIS)

Stokstad, R.G.

1986-04-01

The origin of the quasi-elastic peak in peripheral heavy-ion reactions is discussed in terms of inelastic scattering and transfer reactions to unbound states of the primary projectile-like fragment. The situation is analogous to the use of reverse kinematics in fusion reactions, a technique in which the object of study is moving with nearly the beam velocity. It appears that several important features of the quasi-elastic peak may be explained by this approach. Projectile-breakup reactions have attractive features for the study of nuclear structure. They may also be used to determine the partition of excitation energy in peripheral reactions. At intermediate energies, neutron-pickup reactions leading to four-body final states become important. Examples of experiments are presented that illustrate these points. 15 refs., 14 figs

Interaction of benzoate pyrimidine analogues with class 1A dihydroorotate dehydrogenase from Lactococcus lactis

DEFF Research Database (Denmark)

Wolfe, Abigail E; Thymark, Majbritt; Gattis, Samuel G

2007-01-01

Dihydroorotate dehydrogenases (DHODs) catalyze the oxidation of dihydroorotate to orotate in the only redox reaction in pyrimidine biosynthesis. The pyrimidine binding sites are very similar in all structurally characterized DHODs, suggesting that the prospects for identifying a class-specific in......-system of the flavin, resulting in a green color....

Calculation of total free energy yield as an alternative approach for predicting the importance of potential chemolithotrophic reactions in geothermal springs.

Science.gov (United States)

Dodsworth, Jeremy A; McDonald, Austin I; Hedlund, Brian P

2012-08-01

To inform hypotheses regarding the relative importance of chemolithotrophic metabolisms in geothermal environments, we calculated free energy yields of 26 chemical reactions potentially supporting chemolithotrophy in two US Great Basin hot springs, taking into account the effects of changing reactant and product activities on the Gibbs free energy as each reaction progressed. Results ranged from 1.2 × 10(-5) to 3.6 J kg(-1) spring water, or 3.7 × 10(-5) to 11.5 J s(-1) based on measured flow rates, with aerobic oxidation of CH(4) or NH4 + giving the highest average yields. Energy yields calculated without constraining pH were similar to those at constant pH except for reactions where H(+) was consumed, which often had significantly lower yields when pH was unconstrained. In contrast to the commonly used normalization of reaction chemical affinities per mole of electrons transferred, reaction energy yields for a given oxidant varied by several orders of magnitude and were more sensitive to differences in the activities of products and reactants. The high energy yield of aerobic ammonia oxidation is consistent with previous observations of significant ammonia oxidation rates and abundant ammonia-oxidizing archaea in sediments of these springs. This approach offers an additional lens through which to view the thermodynamic landscape of geothermal springs. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Proton-transfer reactions in ionized gases

International Nuclear Information System (INIS)

Stiller, W.; Schmidt, R.; Schuster, R.

1985-01-01

Ion-molecule reactions play an important role in various radiolytic processes, e.g. gas-pulse radiolysis, environmental research. For a discussion of mechanisms rate coefficients have to be assessed. Here gas-phase rate coefficients of ion-(polar) molecule reactions are calculated using the ideas of interaction potentials, reactive cross-sections and distribution functions of the translational energies of both the reactants (ions I, molecules M). The starting point of our approach, directed especially to gas-phase proton-transfer reactions, is the idea that the rate coefficient k can be calculated as an ion-molecule capture-rate coefficient multiplied by a 'steric factor' representing the probability for proton transfer. Mutual capture of the reaction partners within a possible reaction zone is caused by the physical interaction between an ion and a polar molecule. A model is discussed. Results are presented. (author)

Benchmarking road safety performance: Identifying a meaningful reference (best-in-class).

Science.gov (United States)

Chen, Faan; Wu, Jiaorong; Chen, Xiaohong; Wang, Jianjun; Wang, Di

2016-01-01

For road safety improvement, comparing and benchmarking performance are widely advocated as the emerging and preferred approaches. However, there is currently no universally agreed upon approach for the process of road safety benchmarking, and performing the practice successfully is by no means easy. This is especially true for the two core activities of which: (1) developing a set of road safety performance indicators (SPIs) and combining them into a composite index; and (2) identifying a meaningful reference (best-in-class), one which has already obtained outstanding road safety practices. To this end, a scientific technique that can combine the multi-dimensional safety performance indicators (SPIs) into an overall index, and subsequently can identify the 'best-in-class' is urgently required. In this paper, the Entropy-embedded RSR (Rank-sum ratio), an innovative, scientific and systematic methodology is investigated with the aim of conducting the above two core tasks in an integrative and concise procedure, more specifically in a 'one-stop' way. Using a combination of results from other methods (e.g. the SUNflower approach) and other measures (e.g. Human Development Index) as a relevant reference, a given set of European countries are robustly ranked and grouped into several classes based on the composite Road Safety Index. Within each class the 'best-in-class' is then identified. By benchmarking road safety performance, the results serve to promote best practice, encourage the adoption of successful road safety strategies and measures and, more importantly, inspire the kind of political leadership needed to create a road transport system that maximizes safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

RxClass

Data.gov (United States)

U.S. Department of Health & Human Services — The RxClass Browser is a web application for exploring and navigating through the class hierarchies to find the RxNorm drug members associated with each class....

Improving package structure of object-oriented software using multi-objective optimization and weighted class connections

Directory of Open Access Journals (Sweden)

Amarjeet

2017-07-01

Full Text Available The software maintenance activities performed without following the original design decisions about the package structure usually deteriorate the quality of software modularization, leading to decay of the quality of the system. One of the main reasons for such structural deterioration is inappropriate grouping of source code classes in software packages. To improve such grouping/modular-structure, previous researchers formulated the software remodularization problem as an optimization problem and solved it using search-based meta-heuristic techniques. These optimization approaches aimed at improving the quality metrics values of the structure without considering the original package design decisions, often resulting into a totally new software modularization. The entirely changed software modularization becomes costly to realize as well as difficult to understand for the developers/maintainers. To alleviate this issue, we propose a multi-objective optimization approach to improve the modularization quality of an object-oriented system with minimum possible movement of classes between existing packages of original software modularization. The optimization is performed using NSGA-II, a widely-accepted multi-objective evolutionary algorithm. In order to ensure minimum modification of original package structure, a new approach of computing class relations using weighted strengths has been proposed here. The weights of relations among different classes are computed on the basis of the original package structure. A new objective function has been formulated using these weighted class relations. This objective function drives the optimization process toward better modularization quality simultaneously ensuring preservation of original structure. To evaluate the results of the proposed approach, a series of experiments are conducted over four real-worlds and two random software applications. The experimental results clearly indicate the effectiveness

Bridge between bound state and reaction effective nucleon–nucleon ...

Indian Academy of Sciences (India)

Y R WAGHMARE. Department of Physics, University of Pune, Pune 411 007, India ... Effective nucleon–nucleon interactions; heavy-ion reactions; microscopic approach; fu- sion reactions. .... [2] M K Pal, private communication. [3] S Godre and ...

The Service Learning Projects: Stakeholder Benefits and Potential Class Topics

Science.gov (United States)

Rutti, Raina M.; LaBonte, Joanne; Helms, Marilyn Michelle; Hervani, Aref Agahei; Sarkarat, Sy

2016-01-01

Purpose: The purpose of this paper is to summarize the benefits of including a service learning project in college classes and focusses on benefits to all stakeholders, including students, community, and faculty. Design/methodology/approach: Using a snowball approach in academic databases as well as a nominal group technique to poll faculty, key…

Towards an unified microscopic approach of the description of the nuclear structure and reaction

International Nuclear Information System (INIS)

Hoang, Sy Than

2009-09-01

This thesis contains 3 main parts. The first one: nuclear matter. The motivation of the study is to establish a link between the bare nucleon-nucleon interaction and nuclear matter properties. The properties of nuclear matter are examined using finite range effective interactions either derived from the Brueckner theory or determined in a purely phenomenological way. Skyrme-type interactions are also used for comparison. We have focused our discussion on several main aspects: the pressure ins symmetric nuclear matter and in neutron matter, the density dependence of the symmetric energy S and the nuclear matter incompressibility. The second part: the structure of finite nuclei and of the inner crust of neutrons stars. We present the non-relativistic HF and HF-BCS approaches in coordinate representation using finite-range density-dependent interactions in both the mean field and pairing channels. An iterative scheme is used for solving the integral-differential HF equations. We have studied the doubly magic nuclei, the Sn isotopes and the possible occurrence of bubble structures in the nuclei O 22 , Si 34 , Ar 46 and Ar 68 . We have also examined the different zones of the inner crust of neutron stars. The third part: nuclear reactions. Using the same effective interactions derived from the Brueckner theory we have performed a coupled channel analysis of (p,n) charge exchange reactions at 35 and 45 MeV incident energies on Ca 48 , Zr 90 , Sn 120 and Pb 208 targets leading to isobaric analog states. (A.C.)

Efficient rejection-based simulation of biochemical reactions with stochastic noise and delays

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 (Italy); Zunino, Roberto, E-mail: roberto.zunino@unitn.it [Department of Mathematics, University of Trento (Italy)

2014-10-07

We propose a new exact stochastic rejection-based simulation algorithm for biochemical reactions and extend it to systems with delays. Our algorithm accelerates the simulation by pre-computing reaction propensity bounds to select the next reaction to perform. Exploiting such bounds, we are able to avoid recomputing propensities every time a (delayed) reaction is initiated or finished, as is typically necessary in standard approaches. Propensity updates in our approach are still performed, but only infrequently and limited for a small number of reactions, saving computation time and without sacrificing exactness. We evaluate the performance improvement of our algorithm by experimenting with concrete biological models.

Designing Class Activities to Meet Specific Core Training Competencies: A Developmental Approach

Science.gov (United States)

Guth, Lorraine J.; McDonnell, Kelly A.

2004-01-01

This article presents a developmental model for designing and utilizing class activities to meet specific Association for Specialists in Group Work (ASGW) core training competencies for group workers. A review of the relevant literature about teaching group work and meeting core training standards is provided. The authors suggest a process by…

Automatic NMR-based identification of chemical reaction types in mixtures of co-occurring reactions.

Science.gov (United States)

Latino, Diogo A R S; Aires-de-Sousa, João

2014-01-01

The combination of chemoinformatics approaches with NMR techniques and the increasing availability of data allow the resolution of problems far beyond the original application of NMR in structure elucidation/verification. The diversity of applications can range from process monitoring, metabolic profiling, authentication of products, to quality control. An application related to the automatic analysis of complex mixtures concerns mixtures of chemical reactions. We encoded mixtures of chemical reactions with the difference between the (1)H NMR spectra of the products and the reactants. All the signals arising from all the reactants of the co-occurring reactions were taken together (a simulated spectrum of the mixture of reactants) and the same was done for products. The difference spectrum is taken as the representation of the mixture of chemical reactions. A data set of 181 chemical reactions was used, each reaction manually assigned to one of 6 types. From this dataset, we simulated mixtures where two reactions of different types would occur simultaneously. Automatic learning methods were trained to classify the reactions occurring in a mixture from the (1)H NMR-based descriptor of the mixture. Unsupervised learning methods (self-organizing maps) produced a reasonable clustering of the mixtures by reaction type, and allowed the correct classification of 80% and 63% of the mixtures in two independent test sets of different similarity to the training set. With random forests (RF), the percentage of correct classifications was increased to 99% and 80% for the same test sets. The RF probability associated to the predictions yielded a robust indication of their reliability. This study demonstrates the possibility of applying machine learning methods to automatically identify types of co-occurring chemical reactions from NMR data. Using no explicit structural information about the reactions participants, reaction elucidation is performed without structure elucidation of

Automatic NMR-based identification of chemical reaction types in mixtures of co-occurring reactions.

Directory of Open Access Journals (Sweden)

Diogo A R S Latino

Full Text Available The combination of chemoinformatics approaches with NMR techniques and the increasing availability of data allow the resolution of problems far beyond the original application of NMR in structure elucidation/verification. The diversity of applications can range from process monitoring, metabolic profiling, authentication of products, to quality control. An application related to the automatic analysis of complex mixtures concerns mixtures of chemical reactions. We encoded mixtures of chemical reactions with the difference between the (1H NMR spectra of the products and the reactants. All the signals arising from all the reactants of the co-occurring reactions were taken together (a simulated spectrum of the mixture of reactants and the same was done for products. The difference spectrum is taken as the representation of the mixture of chemical reactions. A data set of 181 chemical reactions was used, each reaction manually assigned to one of 6 types. From this dataset, we simulated mixtures where two reactions of different types would occur simultaneously. Automatic learning methods were trained to classify the reactions occurring in a mixture from the (1H NMR-based descriptor of the mixture. Unsupervised learning methods (self-organizing maps produced a reasonable clustering of the mixtures by reaction type, and allowed the correct classification of 80% and 63% of the mixtures in two independent test sets of different similarity to the training set. With random forests (RF, the percentage of correct classifications was increased to 99% and 80% for the same test sets. The RF probability associated to the predictions yielded a robust indication of their reliability. This study demonstrates the possibility of applying machine learning methods to automatically identify types of co-occurring chemical reactions from NMR data. Using no explicit structural information about the reactions participants, reaction elucidation is performed without structure

The Use of Persuassive Approach in Classroom Interaction

Directory of Open Access Journals (Sweden)

Fibri Indira Lisanty

2016-02-01

Full Text Available In interaction between teachers and students, there are some approaches that the teachers usually apply in teaching process in the classroom but the case here is what kinds of approaches that the students can appropriate. The approach which is not appropriate in the teaching and learning process will have an impact on development of cognitive, affective, and psychomotor students themselves. One of the existing approaches in teaching is persuasive approach, in which this approach can convince the students to adopt the material. This research is qualitative research which uses discourse analysis to analyze the data that the researcher has found. The samples of this research are three classes of sixth grade of Elementary school. The quantities of this class is 25 people for every class and it has been taken in one of course in Makassar, namely JILC. Having done the research, the researcher found that the negative persuasive appeals that to be used in classes and it makes the negative impacts of the students’ motivation in teaching and learning process.

Reactions of carbon acids and 1,3-dipoles in the presence of ionic liquids

International Nuclear Information System (INIS)

Zlotin, Sergei G; Makhova, Nina N

2010-01-01

The review is devoted to the use of ionic liquids as solvents, immobilized organocatalysts and reagents in reactions involving carbon acids and 1,3-dipoles, which are widely used to prepare practically valuable organic compounds of various classes. The characteristic features of processes in the presence of ionic liquids, the effects of the structure of cations and anions on the regio-, stereo- and enantioselectivities of reactions and methods of recovery of ionic liquids are considered.

On the use temperature parameterized rate coefficients in the estimation of non-equilibrium reaction rates

Science.gov (United States)

Shizgal, Bernie D.; Chikhaoui, Aziz

2006-06-01

The present paper considers a detailed analysis of the nonequilibrium effects for a model reactive system with the Chapman-Eskog (CE) solution of the Boltzmann equation as well as an explicit time dependent solution. The elastic cross sections employed are a hard sphere cross section and the Maxwell molecule cross section. Reactive cross sections which model reactions with and without activation energy are used. A detailed comparison is carried out with these solutions of the Boltzmann equation and the approximation introduced by Cukrowski and coworkers [J. Chem. Phys. 97 (1992) 9086; Chem. Phys. 89 (1992) 159; Physica A 188 (1992) 344; Chem. Phys. Lett. A 297 (1998) 402; Physica A 275 (2000) 134; Chem. Phys. Lett. 341 (2001) 585; Acta Phys. Polonica B 334 (2003) 3607.] based on the temperature of the reactive particles. We show that the Cukrowski approximation has limited applicability for the large class of reactive systems studied in this paper. The explicit time dependent solutions of the Boltzmann equation demonstrate that the CE approach is valid only for very slow reactions for which the corrections to the equilibrium rate coefficient are very small.

Type Families with Class, Type Classes with Family

DEFF Research Database (Denmark)

Serrano, Alejandro; Hage, Jurriaan; Bahr, Patrick

2015-01-01

Type classes and type families are key ingredients in Haskell programming. Type classes were introduced to deal with ad-hoc polymorphism, although with the introduction of functional dependencies, their use expanded to type-level programming. Type families also allow encoding type-level functions......, now as rewrite rules. This paper looks at the interplay of type classes and type families, and how to deal with shortcomings in both of them. Furthermore, we show how to use families to simulate classes at the type level. However, type families alone are not enough for simulating a central feature...... of type classes: elaboration, that is, generating code from the derivation of a rewriting. We look at ways to solve this problem in current Haskell, and propose an extension to allow elaboration during the rewriting phase....

Few-body semiclassical approach to nucleon transfer and emission reactions

Directory of Open Access Journals (Sweden)

Sultanov Renat A.

2014-04-01

Full Text Available A three-body semiclassical model is proposed to describe the nucleon transfer and emission reactions in a heavy-ion collision. In this model the two heavy particles, i.e. nuclear cores A1(ZA1, MA1 and A2(ZA2, MA2, move along classical trajectories R→1(t${{\\vec R}_1}\\left( t \\right$ and R→2(t${{\\vec R}_2}\\left( t \\right$ respectively, while the dynamics of the lighter neutron (n is considered from a quantum mechanical point of view. Here, Mi are the nucleon masses and Zi are the Coulomb charges of the heavy nuclei (i = 1, 2. A Faddeev-type semiclassical formulation using realistic paired nuclear-nuclear potentials is applied so that all three channels (elastic, rearrangement and break-up are described in a unified manner. In order to solve the time-dependent equations the Faddeev components of the total three-body wave-function are expanded in terms of the input and output channel target eigenfunctions. In the special case, when the nuclear cores are identical (A1 ≡ A2 and also the two-level approximation in the expansion over the target (subsystem functions is used, the time-dependent semiclassical Faddeev equations are resolved in an explicit way. To determine the realistic R→1(t${{\\vec R}_1}\\left( t \\right$ and R→2(t${{\\vec R}_2}\\left( t \\right$ trajectories of the nuclear cores, a self-consistent approach based on the Feynman path integral theory is applied.

Unified definition of a class of Monte Carlo estimators

International Nuclear Information System (INIS)

Lux, I.

1978-01-01

A unified definition of a wide class of Monte Carlo reaction rate estimators is presented, since most commonly used estimators belong to that class. The definition is given through an integral transformation of an arbitrary estimator of the class. Since the transformation contains an arbitrary function, in principle an infinite number of new estimators can be defined on the basis of one known estimator. It is shown that the most common estimators belonging to the class, such as the track-length and expectation estimators, are special cases of transformation, corresponding to the simplest transformation kernels when transforming the usual collision estimator. A pair of new estimators is defined and their variances are compared to the variance of the expectation estimator. One of the new estimators, called the trexpectation estimator, seems to be appropriate for flux-integral estimation in moderator regions. The other one, which uses an intermediate estimation of the final result and is therefore called the self-improving estimator, always yields a lower variance than the expectation estimator. As is shown, this estimator approximates well to possibly the best estimator of the class. Numerical results are presented for the simplest geometries, and these results indicate that for absorbers that are not too strong, in practical cases the standard deviation of the self-improving estimator is less than that of the expectation estimator by more than 10%. The experiments also suggest that the self-improving estimator is always superior to the track-length estimator as well, i.e., that it is the best of all known estimators belonging to the class. In the Appendices, for simplified cases, approximate conditions are given for which the trexpectation and track-length estimators show a higher efficiency than the expectation estimator

Autoimmunity and inflammation are independent of class II transactivator type PIV-dependent class II major histocompatibility complex expression in peripheral tissues during collagen-induced arthritis.

Science.gov (United States)

Waldburger, Jean-Marc; Palmer, Gaby; Seemayer, Christian; Lamacchia, Celine; Finckh, Axel; Christofilopoulos, Panayiotis; Baeten, Dominique; Reith, Walter; Gabay, Cem

2011-11-01

To determine the regulation of class II major histocompatibility complex (MHC) expression in fibroblast-like synoviocytes (FLS) in order to investigate their role as nonprofessional antigen-presenting cells in collagen-induced arthritis (CIA). Expression of class II MHC, class II MHC transactivator (CIITA), and Ciita isoforms PI, PIII, and PIV was examined by real-time quantitative polymerase chain reaction, immunohistochemistry, and flow cytometry in human synovial tissues, arthritic mouse joints, and human and murine FLS. CIA was induced in mice in which isoform PIV of Ciita was knocked out (PIV(-/-) ), in PIV(-/-) mice transgenic for CIITA in the thymus (K14 CIITA), and in their control littermates. HLA-DRA, total CIITA, and CIITA PIII messenger RNA levels were significantly increased in synovial tissue samples from patients with rheumatoid arthritis compared with the levels in tissue from patients with osteoarthritis. Human FLS expressed surface class II MHC via CIITA PIII and PIV, while class II MHC expression in murine FLS was entirely mediated by PIV. Mice with a targeted deletion of CIITA PIV lack CD4+ T cells and were protected against CIA. The expression of CIITA was restored in the thymus of PIV(-/-) K14 CIITA-transgenic mice, which had a normal CD4+ T cell repertoire and normal surface levels of class II MHC on professional antigen-presenting cells, but did not induce class II MHC on FLS. Synovial inflammation and immune responses against type II collagen were similar in PIV(-/-) K14 CIITA-transgenic mice and control mice with CIA, but bone erosion was significantly reduced in the absence of PIV. Overexpression of class II MHC is tightly correlated with CIITA expression in arthritic synovium and in FLS. Selective targeting of Ciita PIV in peripheral tissues abrogates class II MHC expression by murine FLS but does not protect against inflammation and autoimmune responses in CIA. Copyright © 2011 by the American College of Rheumatology.

Synchronization of Reaction-Diffusion Neural Networks With Dirichlet Boundary Conditions and Infinite Delays.

Science.gov (United States)

Sheng, Yin; Zhang, Hao; Zeng, Zhigang

2017-10-01

This paper is concerned with synchronization for a class of reaction-diffusion neural networks with Dirichlet boundary conditions and infinite discrete time-varying delays. By utilizing theories of partial differential equations, Green's formula, inequality techniques, and the concept of comparison, algebraic criteria are presented to guarantee master-slave synchronization of the underlying reaction-diffusion neural networks via a designed controller. Additionally, sufficient conditions on exponential synchronization of reaction-diffusion neural networks with finite time-varying delays are established. The proposed criteria herein enhance and generalize some published ones. Three numerical examples are presented to substantiate the validity and merits of the obtained theoretical results.

Class imbalance in unsupervised change detection - A diagnostic analysis from urban remote sensing

Science.gov (United States)

Leichtle, Tobias; Geiß, Christian; Lakes, Tobia; Taubenböck, Hannes

2017-08-01

Automatic monitoring of changes on the Earth's surface is an intrinsic capability and simultaneously a persistent methodological challenge in remote sensing, especially regarding imagery with very-high spatial resolution (VHR) and complex urban environments. In order to enable a high level of automatization, the change detection problem is solved in an unsupervised way to alleviate efforts associated with collection of properly encoded prior knowledge. In this context, this paper systematically investigates the nature and effects of class distribution and class imbalance in an unsupervised binary change detection application based on VHR imagery over urban areas. For this purpose, a diagnostic framework for sensitivity analysis of a large range of possible degrees of class imbalance is presented, which is of particular importance with respect to unsupervised approaches where the content of images and thus the occurrence and the distribution of classes are generally unknown a priori. Furthermore, this framework can serve as a general technique to evaluate model transferability in any two-class classification problem. The applied change detection approach is based on object-based difference features calculated from VHR imagery and subsequent unsupervised two-class clustering using k-means, genetic k-means and self-organizing map (SOM) clustering. The results from two test sites with different structural characteristics of the built environment demonstrated that classification performance is generally worse in imbalanced class distribution settings while best results were reached in balanced or close to balanced situations. Regarding suitable accuracy measures for evaluating model performance in imbalanced settings, this study revealed that the Kappa statistics show significant response to class distribution while the true skill statistic was widely insensitive to imbalanced classes. In general, the genetic k-means clustering algorithm achieved the most robust results

Low energy nuclear reaction polyplasmon postulate

Energy Technology Data Exchange (ETDEWEB)

Russell, John L. [201 Heritage Drive, Apt. 208, Canton, GA 30093 (United States)], E-mail: RUSSELLJL@aol.com

2008-11-15

An explanation is proposed for the nuclear reactions that occur in the electrolysis class of LENR processes. The proposed explanation postulates that a proton, or deuteron, dissolved in the hydrogen bearing metal cathode, absorbs its associated atomic electron to become a short lived state of the neutron with the resulting neutrino in a singular wave function centered on the neutron. The energy required to initiate this endothermic reaction is supplied either by the ion current during electrolysis type experiments, or by ion bombardment in plasma type experiments. It is the energy of this bombardment of the cathode with heavy ions that creates a coherent polyplasmon field within crystalline metallic grains that are present in the metal cathode of typical active electrolysis cells. The LENR process consists of a second order reaction mediated by a coherent plasmon field excited in the conduction electrons in a hydrogen bearing metal that is in the form of crystalline grains of the order of a few microns in dimension. The coherent plasmon field in each grain is called a polyplasmon. The metallic grains typically form during solidification of a metal, the impurities being forced to the grain surfaces. The resulting grain thus forms a resonant structure that can be filled with a number of coherent plasmons, i.e., a polyplasmon. Energy from the polyplasmon is coupled to the nucleus via electron capture by hydrogen. Because the neutrino has mass, its wave function has a second class of solutions. This description can take the form of a short lived pairing with the neutron that results from electron capture by the hydrogen nucleus. This short-lived compound particle is named the 'dion' and in the case of deuterium results in a 'dineutron'. Because the dion and dineutron are formed with essentially thermal kinetic energy, they can capture in nearby nuclei, either in hydrogen or in the host metal. Most of the resulting exothermic nuclear energy is

Low energy nuclear reaction polyplasmon postulate

International Nuclear Information System (INIS)

Russell, John L.

2008-01-01

An explanation is proposed for the nuclear reactions that occur in the electrolysis class of LENR processes. The proposed explanation postulates that a proton, or deuteron, dissolved in the hydrogen bearing metal cathode, absorbs its associated atomic electron to become a short lived state of the neutron with the resulting neutrino in a singular wave function centered on the neutron. The energy required to initiate this endothermic reaction is supplied either by the ion current during electrolysis type experiments, or by ion bombardment in plasma type experiments. It is the energy of this bombardment of the cathode with heavy ions that creates a coherent polyplasmon field within crystalline metallic grains that are present in the metal cathode of typical active electrolysis cells. The LENR process consists of a second order reaction mediated by a coherent plasmon field excited in the conduction electrons in a hydrogen bearing metal that is in the form of crystalline grains of the order of a few microns in dimension. The coherent plasmon field in each grain is called a polyplasmon. The metallic grains typically form during solidification of a metal, the impurities being forced to the grain surfaces. The resulting grain thus forms a resonant structure that can be filled with a number of coherent plasmons, i.e., a polyplasmon. Energy from the polyplasmon is coupled to the nucleus via electron capture by hydrogen. Because the neutrino has mass, its wave function has a second class of solutions. This description can take the form of a short lived pairing with the neutron that results from electron capture by the hydrogen nucleus. This short-lived compound particle is named the 'dion' and in the case of deuterium results in a 'dineutron'. Because the dion and dineutron are formed with essentially thermal kinetic energy, they can capture in nearby nuclei, either in hydrogen or in the host metal. Most of the resulting exothermic nuclear energy is absorbed in the plasmon

Investigating the Cellular and Metabolic Responses of World-Class Canoeists Training: A Sportomics Approach

Directory of Open Access Journals (Sweden)

Wagner Santos Coelho

2016-11-01

Full Text Available (1 Background: We have been using the Sportomics approach to evaluate biochemical and hematological changes in response to exercise. The aim of this study was to evaluate the metabolic and hematologic responses of world-class canoeists during a training session; (2 Methods: Blood samples were taken at different points and analyzed for their hematological properties, activities of selected enzymes, hormones, and metabolites; (3 Results: Muscle stress biomarkers were elevated in response to exercise which correlated with modifications in the profile of white blood cells, where a leukocyte rise was observed after the canoe session. These results were accompanied by an increase in other exercise intensity parameters such as lactatemia and ammonemia. Adrenocorticotropic hormone and cortisol increased during the exercise sessions. The acute rise in both erythrocytes and white blood profile were probably due to muscle cell damage, rather than hepatocyte integrity impairment; (4 Conclusion: The cellular and metabolic responses found here, together with effective nutrition support, are crucial to understanding the effects of exercise in order to assist in the creation of new training and recovery planning. Also we show that Sportomics is a primal tool for training management and performance improvement, as well as to the understanding of metabolic response to exercise.

The hexadehydro-Diels-Alder reaction.

Science.gov (United States)

Hoye, Thomas R; Baire, Beeraiah; Niu, Dawen; Willoughby, Patrick H; Woods, Brian P

2012-10-11

Arynes (aromatic systems containing, formally, a carbon-carbon triple bond) are among the most versatile of all reactive intermediates in organic chemistry. They can be 'trapped' to give products that are used as pharmaceuticals, agrochemicals, dyes, polymers and other fine chemicals. Here we explore a strategy that unites the de novo generation of benzynes-through a hexadehydro-Diels-Alder reaction-with their in situ elaboration into structurally complex benzenoid products. In the hexadehydro-Diels-Alder reaction, a 1,3-diyne is engaged in a [4+2] cycloisomerization with a 'diynophile' to produce the highly reactive benzyne intermediate. The reaction conditions for this simple, thermal transformation are notable for being free of metals and reagents. The subsequent and highly efficient trapping reactions increase the power of the overall process. Finally, we provide examples of how this de novo benzyne generation approach allows new modes of intrinsic reactivity to be revealed.

Statistical formulation of gravitational radiation reaction

International Nuclear Information System (INIS)

Schutz, B.F.

1980-01-01

A new formulation of the radiation-reaction problem is proposed, which is simpler than alternatives which have been used before. The new approach is based on the initial-value problem, uses approximations which need be uniformly valid only in compact regions of space-time, and makes no time-asymmetric assumptions (no a priori introduction of retarded potentials or outgoing-wave asymptotic conditions). It defines radiation reaction to be the expected evolution of a source obtained by averaging over a statistical ensemble of initial conditions. The ensemble is chosen to reflect one's complete lack of information (in real systems) about the initial data for the radiation field. The approach is applied to the simple case of a weak-field, slow-motion source in general relativity, where it yields the usual expressions for radiation reaction when the gauge is chosen properly. There is a discussion of gauge freedom, and another of the necessity of taking into account reaction corrections to the particle-conservation equation. The analogy with the second law of thermodynamics is very close, and suggests that the electromagnetic and thermodynamic arrows of time are the same. Because the formulation is based on the usual initial-value problem, it has no spurious ''runaway'' solutions

Catalytic asymmetric diels-alder reaction of quinone imine ketals: a site-divergent approach.

Science.gov (United States)

Hashimoto, Takuya; Nakatsu, Hiroki; Maruoka, Keiji

2015-04-07

The catalytic asymmetric Diels-Alder reaction of quinone imine ketals with diene carbamates catalyzed by axially chiral dicarboxylic acids is reported herein. A variety of primary and secondary alkyl-substituted quinone derivatives which have not been applied in previous asymmetric quinone Diels-Alder reactions could be employed using this method. More importantly, we succeeded in developing a strategy to divert the reaction site in unsymmetrical 3-alkyl quinone imine ketals from the inherently favored unsubstituted C=C bond to the disfavored alkyl-substituted C=C bond. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Consistent post-reaction vibrational energy redistribution in DSMC simulations using TCE model

Science.gov (United States)

Borges Sebastião, Israel; Alexeenko, Alina

2016-10-01

The direct simulation Monte Carlo (DSMC) method has been widely applied to study shockwaves, hypersonic reentry flows, and other nonequilibrium flow phenomena. Although there is currently active research on high-fidelity models based on ab initio data, the total collision energy (TCE) and Larsen-Borgnakke (LB) models remain the most often used chemistry and relaxation models in DSMC simulations, respectively. The conventional implementation of the discrete LB model, however, may not satisfy detailed balance when recombination and exchange reactions play an important role in the flow energy balance. This issue can become even more critical in reacting mixtures involving polyatomic molecules, such as in combustion. In this work, this important shortcoming is addressed and an empirical approach to consistently specify the post-reaction vibrational states close to thermochemical equilibrium conditions is proposed within the TCE framework. Following Bird's quantum-kinetic (QK) methodology for populating post-reaction states, the new TCE-based approach involves two main steps. The state-specific TCE reaction probabilities for a forward reaction are first pre-computed from equilibrium 0-D simulations. These probabilities are then employed to populate the post-reaction vibrational states of the corresponding reverse reaction. The new approach is illustrated by application to exchange and recombination reactions relevant to H2-O2 combustion processes.

Combustion kinetics and reaction pathways

Energy Technology Data Exchange (ETDEWEB)

Klemm, R.B.; Sutherland, J.W. [Brookhaven National Laboratory, Upton, NY (United States)

1993-12-01

This project is focused on the fundamental chemistry of combustion. The overall objectives are to determine rate constants for elementary reactions and to elucidate the pathways of multichannel reactions. A multitechnique approach that features three independent experiments provides unique capabilities in performing reliable kinetic measurements over an exceptionally wide range in temperature, 300 to 2500 K. Recent kinetic work has focused on experimental studies and theoretical calculations of the methane dissociation system (CH{sub 4} + Ar {yields} CH{sub 3} + H + Ar and H + CH{sub 4} {yields} CH{sub 3} + H{sub 2}). Additionally, a discharge flow-photoionization mass spectrometer (DF-PIMS) experiment is used to determine branching fractions for multichannel reactions and to measure ionization thresholds of free radicals. Thus, these photoionization experiments generate data that are relevant to both reaction pathways studies (reaction dynamics) and fundamental thermochemical research. Two distinct advantages of performing PIMS with high intensity, tunable vacuum ultraviolet light at the National Synchrotron Light Source are high detection sensitivity and exceptional selectivity in monitoring radical species.