WorldWideScience
 
 
1

Calculation using MVP and MVP-BURN in JRR-3  

International Nuclear Information System (INIS)

MVP is the particle-transport Monte Carlo code that has been developed in JAEA. MVP-BURN is an added function to do burn-up calculation. It is easy to built complex structure like core for MVP. And it is easy to do calculations of keff, any reaction rate, flux, burn-up and so on. In this report, it is introduced MVP and MVP-BURN. And some sample calculations of JRR-3 are shown. (author)

2007-09-01

2

Combined magnetic vector-scalar potential finite element computation of 3D magnetic field and performance of modified Lundell alternators in Space Station applications. Ph.D. Thesis  

Science.gov (United States)

A method of combined use of magnetic vector potential (MVP) based finite element (FE) formulations and magnetic scalar potential (MSP) based FE formulations for computation of three-dimensional (3D) magnetostatic fields is developed. This combined MVP-MSP 3D-FE method leads to considerable reduction by nearly a factor of 3 in the number of unknowns in comparison to the number of unknowns which must be computed in global MVP based FE solutions. This method allows one to incorporate portions of iron cores sandwiched in between coils (conductors) in current-carrying regions. Thus, it greatly simplifies the geometries of current carrying regions (in comparison with the exclusive MSP based methods) in electric machinery applications. A unique feature of this approach is that the global MSP solution is single valued in nature, that is, no branch cut is needed. This is again a superiority over the exclusive MSP based methods. A Newton-Raphson procedure with a concept of an adaptive relaxation factor was developed and successfully used in solving the 3D-FE problem with magnetic material anisotropy and nonlinearity. Accordingly, this combined MVP-MSP 3D-FE method is most suited for solution of large scale global type magnetic field computations in rotating electric machinery with very complex magnetic circuit geometries, as well as nonlinear and anisotropic material properties.

Wang, Ren H.

1991-01-01

3

Core calculation of 1MWatt PUSPATI TRIGA reactor (RTP) using continuous energy method of Monte Carlo MVP code system  

International Nuclear Information System (INIS)

The Monte Carlo MVP code system was adopted for the Reaktor TRIGA PUSAPTI (RTP) core calculation. MVP was developed by a group of researcher of Japan Atomic Energy Agency (JAEA) first in 1994. MVP is a general multi-purpose Monte Carlo code for neutron and photon transport calculation and able to estimate an accurate simulation problems. The MVP Monte Carlo code calculation is based on the continuous energy method. This code is capable of adopting an accurate physics model, geometry description and variance reduction technique faster than conventional method. With compared to the conventional scalar method, this code could achieve higher computational speed by several factor on the vector super-computer. In this calculation, RTP core was modeled as close as possible to the real core and results of keff, flux, fission densities and others obtained from MVP were outputted. (author)

2008-11-01

4

Vectorization, parallelization and implementation of nuclear codes =MVP/GMVP, QMDRELP, EQMD, HSABC, CURBAL, STREAM V3.1, TOSCA, EDDYCAL, RELAP5/MOD2/C36-05, RELAP5/MOD3= on the VPP500 computer system. Progress report 1995 fiscal year  

Energy Technology Data Exchange (ETDEWEB)

At Center for Promotion of Computational Science and Engineering, time consuming eight nuclear codes suggested by users have been vectorized, parallelized on the VPP500 computer system. In addition, two nuclear codes used on the VP2600 computer system were implemented on the VPP500 computer system. Neutron and photon transport calculation code MVP/GMVP and relativistic quantum molecular dynamics code QMDRELP have been parallelized. Extended quantum molecular dynamics code EQMD and adiabatic base calculation code HSABC have been parallelized and vectorized. Ballooning turbulence simulation code CURBAL, 3-D non-stationary compressible fluid dynamics code STREAM V3.1, operating plasma analysis code TOSCA and eddy current analysis code EDDYCAL have been vectorized. Reactor safety analysis code RELAP5/MOD2/C36-05 and RELAP5/MOD3 were implemented on the VPP500 computer system. (author)

Nemoto, Toshiyuki; Watanabe, Hideo; Fujita, Toyozo [Fujitsu Ltd., Tokyo (Japan); Kawai, Wataru; Harada, Hiroo; Gorai, Kazuo; Yamasaki, Kazuhiko; Shoji, Makoto; Fujii, Minoru

1996-06-01

5

Biochemical and structural analysis of the hyperpolarization-activated K(+) channel MVP.  

Science.gov (United States)

In contrast to the majority of voltage-gated ion channels, hyperpolarization-activated channels remain closed at depolarizing potentials and are activated at hyperpolarizing potentials. The basis for this reverse polarity is thought to be a result of differences in the way the voltage-sensing domain (VSD) couples to the pore domain. In the absence of structural data, the molecular mechanism of this reverse polarity coupling remains poorly characterized. Here we report the characterization of the structure and local dynamics of the closed activation gate (lower S6 region) of MVP, a hyperpolarization-activated potassium channel from Methanococcus jannaschii, by electron paramagnetic resonance (EPR) spectroscopy. We show that a codon-optimized version of MVP has high expression levels in Escherichia coli, is purified as a stable tetramer, and exhibits expected voltage-dependent activity when reconstituted in liposomes. EPR analysis of the mid to lower S6 region revealed positions exhibiting strong spin-spin coupling, indicating that the activation gate of MVP is closed at 0 mV. A comparison of local environmental parameters along the activation gate for MVP and KcsA indicates that MVP adopts a different closed conformation. These structural details set the stage for future evaluations of reverse electromechanical coupling in MVP. PMID:24490868

Randich, Amelia M; Cuello, Luis G; Wanderling, Sherry S; Perozo, Eduardo

2014-03-18

6

Reducing the Genotoxic Potential of Retroviral Vectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The recent development of leukemia in gene therapy patients with X-linked severe combined immunodeficiency disease due to retroviral vector insertional mutagenesis has prompted reassessment of the genotoxic potential of integrating vector systems. In this chapter, various strategies are described to reduce the associated risks of retroviral genomic integration. These include deletion of strong transcriptional enhancer-promoter elements in the retroviral long terminal repeats, flanking the ret...

2008-01-01

7

Fermions in scalar and vector potentials  

International Nuclear Information System (INIS)

This paper investigates the basic physical properties of spin-1/2 bound states, using numerical solutions of the Dirac equation to illustrate the distinctive differences between scalar and vector binding. The results are discussed in relation both to the quark structure of hadrons and to the further possibility that quarks and leptons might themselves be composite. The effect of scalar and vector potential strengths, separately and in combination, on energy levels and magnetic moments is discussed, together with the energy and potential dependence of the wave function parameters , 2>sup(1/2) and psi2(0), which provide the coefficients in perturbative mass formulae based on the Fermi-Breit Hamiltonian. The results are used to reassess a number of topics, including the ground-state meson and baryon mass spectrum, vector-meson leptonic-decay widths, effective quark mass and the shape of the confining potential. (author)

1981-08-21

8

On vector potential of the Coulomb gauge  

International Nuclear Information System (INIS)

The question of an instantaneous action (Stewart 2003 Eur. J. Phys. 24 519) can be approached in a systematic way applying the Helmholtz vector decomposition theorem to a two-parameter Lorenz-like gauge. We thus show that only the scalar potential may act instantaneously. (letters and comments)

2004-03-01

9

Faraday's law via the magnetic vector potential  

International Nuclear Information System (INIS)

Faraday's law for a filamentary circuit which is moving at relativistic velocities and also changing its shape as it moves is derived via the magnetic vector potential. The derivation is simpler than the usual one, based on the Hertz-Helmholtz identity. (note)

2007-03-01

10

Vector potential remap for 2d MHD  

Energy Technology Data Exchange (ETDEWEB)

This report describes an algorithm to remap (rezone) the magnetic vector potential in 2D MHD calculations. This extends a previously described Lagrangian scheme [1] for use with ALE grids, when combined with a suitable remap capability for the hydrodynamic variables. In this scheme, the magnetic field B is a zone quantity derived from the node based vector potential A (Bx, By, and Az in Cartesian geometry, (Bz, Br, and A(small phi) in cylindrical geometry). The scheme outlined here is closely related to a flux conserving remap of the magnetic field. Because B is derived from the updated vector potential, however, flux conservation and vanishing divergence are guaranteed; only accuracy is a concern. This is in contrast to schemes based directly on B, which require the additional constraint of preserving zero divergence [2, 3]. Beginning with Cartesian geometry, a straight forward development of the algorithm is first presented; an alternative view is then considered which makes clear the relationship to a flux conservative remapping of the zonal magnetic field. Examples comparing first and second order algorithms are shown, and the issue of energy conservation is discussed. Finally, the generalization to cylindrical geometry is given.

Rambo, P W

1998-10-13

11

Core Calculation of 1 MWatt PUSPATI TRIGA Reactor (RTP) using Monte Carlo MVP Code System  

International Nuclear Information System (INIS)

The Monte Carlo MVP code system was adopted for the Reaktor TRIGA PUSAPTI (RTP) core calculation. The code was developed by a group of researcher of Japan Atomic Energy Agency (JAEA) first in 1994. MVP is a general multi-purpose Monte Carlo code for neutron and photon transport calculation and able to estimate an accurate simulation problems. The code calculation is based on the continuous energy method. This code is capable of adopting an accurate physics model, geometry description and variance reduction technique faster than conventional method as compared to the conventional scalar method. This code could achieve higher computational speed by several factors on the vector super-computer. In this calculation, RTP core was modeled as close as possible to the real core and results of keff flux, fission densities and others were obtained

2008-05-20

12

Vector potential, electromagnetic induction and "physical meaning"  

CERN Document Server

A forgotten experiment by Andr\\'e Blondel (1914) proves, as held on the basis of theoretical arguments in a previous paper, that the time variation of the magnetic flux is not the cause of the induced $emf$: the physical agent is instead the vector potential through the term $-\\partial\\vec A/\\partial t$ (when the induced circuit is at rest). The "good electromagnetic potentials" are determined by the Lorenz condition and retarded formulas. Other pairs of potentials derived through appropriate gauge functions are only mathematical devices for calculating the fields: they are not physically related to the sources. The physical meaning of a theoretical term relies, primarily, on theoretical grounds: a theoretical term has physical meaning if it cannot be withdrawn without reducing the predictive power of a theory or, in a weaker sense, if it cannot be withdrawn without reducing the descriptive proficiency of a theory.

Giuliani, Giuseppe

2010-01-01

13

MVP and vaults: a role in the radiation response  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Vaults are evolutionary highly conserved ribonucleoproteins particles with a hollow barrel-like structure. The main component of vaults represents the 110 kDa major vault protein (MVP, whereas two minor vaults proteins comprise the 193 kDa vault poly(ADP-ribose polymerase (vPARP and the 240 kDa telomerase-associated protein-1 (TEP-1. Additionally, at least one small and untranslated RNA is found as a constitutive component. MVP seems to play an important role in the development of multidrug resistance. This particle has also been implicated in the regulation of several cellular processes including transport mechanisms, signal transmission and immune responses. Vaults are considered a prognostic marker for different cancer types. The level of MVP expression predicts the clinical outcome after chemotherapy in different tumour types. Recently, new roles have been assigned to MVP and vaults including the association with the insulin-like growth factor-1, hypoxia-inducible factor-1alpha, and the two major DNA double-strand break repair machineries: non-homologous endjoining and homologous recombination. Furthermore, MVP has been proposed as a useful prognostic factor associated with radiotherapy resistance. Here, we review these novel actions of vaults and discuss a putative role of MVP and vaults in the response to radiotherapy.

Zimmermann Martina

2011-10-01

14

Recent Developments of JAEA's Monte Carlo Code MVP for Reactor Physics Applications  

Science.gov (United States)

This paper describes the recent development status of a Monte Carlo code MVP developed at Japan Atomic Energy Agency. The basic features and capabilities of MVP are overviewed. In addition, new capabilities useful for reactor analysis are also described.

Nagaya, Yasunobu; Okumura, Keisuke; Mori, Takamasa

2014-06-01

15

Vector analyses of linearly and circularly polarized Bessel beams using Hertz vector potentials.  

Science.gov (United States)

Using the transverse Hertz vector potentials, vector analyses of linearly and circularly polarized Bessel beams of arbitrary orders are presented in this paper. Expressions for the electric and magnetic fields of vector Bessel beams in free space that are rigorous solutions to the vector Helmholtz equation are derived. Their respective time averaged energy density and Poynting vector are also obtained, in order to exhibit their non-diffracting properties. Polarization patterns and magnitude profiles with different parameters are displayed. Particular emphasis is placed on the cases where the ratio of wave number over its transverse component k/kt approximately equals to one and largely exceeds it, which corresponding to the nonparaxial and paraxial condition, respectively. These results allow us to recognize that the vector Bessel beams exhibit new and important features, compared with the scalar fields. PMID:24718158

Wang, Yanxun; Dou, Wenbin; Meng, Hongfu

2014-04-01

16

Algebraic solution for the vector potential in the Dirac equation  

CERN Document Server

The Dirac equation for an electron in an external electromagnetic field can be regarded as a singular set of linear equations for the vector potential. Radford's method of algebraically solving for the vector potential is reviewed, with attention to the additional constraints arising from non-maximality of the rank. The extension of the method to general spacetimes is illustrated by examples in diverse dimensions with both $c$- and $a$-number wavefunctions.

Booth, H S; Jarvis, P D

2001-01-01

17

Smoothed Particle Magnetohydrodynamics IV - Using the Vector Potential  

CERN Multimedia

In this paper we investigate the use of the vector potential as a means of maintaining the divergence constraint in the numerical solution of the equations of Magnetohydrodynamics (MHD) using the Smoothed Particle Hydrodynamics (SPH) method. We derive a self-consistent formulation of the equations of motion using a variational principle that is constrained by the numerical formulation of both the induction equation and the curl operator used to obtain the magnetic field, which guarantees exact and simultaneous conservation of momentum, energy and entropy in the numerical scheme. This leads to a novel formulation of the MHD force term, unique to the vector potential, which differs from previous formulations. We also demonstrate how dissipative terms can be correctly formulated for the vector potential such that the contribution to the entropy is positive definite and the total energy is conserved. On a standard suite of numerical tests in one, two and three dimensions we find firstly that the consistent formul...

Price, Daniel J

2009-01-01

18

Faraday's law via the magnetic vector potential  

Energy Technology Data Exchange (ETDEWEB)

Faraday's law for a filamentary circuit which is moving at relativistic velocities and also changing its shape as it moves is derived via the magnetic vector potential. The derivation is simpler than the usual one, based on the Hertz-Helmholtz identity. (note)

Redzic, Dragan V [Faculty of Physics, University of Belgrade, PO Box 368, 11001 Belgrade (Serbia)

2007-03-15

19

Renormalization Theory in the Electrostatic and Vector Potential Calculation  

CERN Document Server

In this work we attempt to show in a clear and simple manner the fundamental ideas of the Renormalization Theory. With that intention we use two well-known problems of the Physic and Engeneering undergraduate students, the calculation of the electrostatic and vector potential of a infinite line charge density and current, respectively. We still employ different regularization methods (cut-off, dimensional and zeta function) and the arising of the scale parameter is consider.

Spalenza, W; Spalenza, Wesley

2000-01-01

20

Localization for Schrodinger operators with random vector potentials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We prove Anderson localization at the internal band-edges for periodic magnetic Schr{\\"o}dinger operators perturbed by random vector potentials of Anderson-type. This is achieved by combining new results on the Lifshitz tails behavior of the integrated density of states for random magnetic Schr{\\"o}dinger operators, thereby providing the initial length-scale estimate, and a Wegner estimate, for such models.

Ghribi, F.; Hislop, P. D.; Klopp, F.

2007-01-01

 
 
 
 
21

Analogs of generalized hydrodynamic potentials in the theory of the vector Helmholtz equation and the vector wave equation  

International Nuclear Information System (INIS)

The authors introduce analogs of the generalized potential of a Gromeka field into the theory of the vector Helmholtz equation and the vector wave equation. These analogs are used to obtain rather large classes of solutions with the Hamilton description of the vector lines. These classes contain the known solutions of this type (those of Arnol'd-Beltrami-Childress and Zaslavskii-Sagdeev-Chernikov) as particular specializations. Particular analogs of the generations Gromeka potential field are introduced for a cylindrical coordinate system

1993-04-25

22

Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP, vault poly(ADP-ribose polymerase, and telomerase associated protein-1 and small untranslated RNA. Over-expression of MVP has been associated with chemotherapy resistance. Also, it has been related to poor outcome in patients treated with radiotherapy alone. The aim of the present study was to assess the relation of Major Vault Protein expression and tumor hypoxia in clinical cervical tumors. MVP, p53 and angiogenesis, together with tumor oxygenation, were determined in forty-three consecutive patients suffering from localized cervix carcinoma. High MVP expression was related to severe hypoxia compared to low MVP expressing tumors (p = 0.022. Tumors over-expressing MVP also showed increased angiogenesis (p = 0.003. Besides it, in this study we show for the first time that severe tumor hypoxia is associated with high MVP expression in clinical cervical tumors. Up-regulation of MVP by hypoxia is of critical relevance as chemotherapy is currently a standard treatment for those patients. From our results it could be suggested that hypoxia not only induces increased genetic instability, oncogenic properties and metastatization, but through the correlation observed with MVP expression, another pathway of chemo and radiation resistance could be developed.

Apolinario Rosa M

2009-08-01

23

Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression.  

Science.gov (United States)

Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP), vault poly(ADP-ribose) polymerase, and telomerase associated protein-1 and small untranslated RNA. Over-expression of MVP has been associated with chemotherapy resistance. Also, it has been related to poor outcome in patients treated with radiotherapy alone. The aim of the present study was to assess the relation of Major Vault Protein expression and tumor hypoxia in clinical cervical tumors. MVP, p53 and angiogenesis, together with tumor oxygenation, were determined in forty-three consecutive patients suffering from localized cervix carcinoma. High MVP expression was related to severe hypoxia compared to low MVP expressing tumors (p = 0.022). Tumors over-expressing MVP also showed increased angiogenesis (p = 0.003). Besides it, in this study we show for the first time that severe tumor hypoxia is associated with high MVP expression in clinical cervical tumors. Up-regulation of MVP by hypoxia is of critical relevance as chemotherapy is currently a standard treatment for those patients. From our results it could be suggested that hypoxia not only induces increased genetic instability, oncogenic properties and metastatization, but through the correlation observed with MVP expression, another pathway of chemo and radiation resistance could be developed. PMID:19660100

Lara, Pedro C; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa M; Henríquez-Hernández, Luis Alberto; Bordón, Elisa; Fontes, Fausto; Rey, Agustín

2009-01-01

24

Validation of the Monte Carlo method of MVP code on the first criticality of Indonesian multipurpose reactor  

International Nuclear Information System (INIS)

The validation research works in BATAN are focused using Monte Carlo method with recent nuclear data on the experimental results. In this paper, the validation results of Monte Carlo method of MVP code on the first criticality experimental of Indonesia Multipurpose Reactor (RSG GAS reactor) are presented. The MVP code is a vectorized and continuous energy Monte Carlo code developed by Japan Atomic Energy Agency (JAEA). The objective this paper is to show the accuracy of the code using recent nuclear data of JEF-3.0, JENDL- 3.3 and ENDF/B-VI.8. The final goal of this research is to use the code as a in-core fuel management code since the code has a module of burn-up calculation (MVP-BURN). SG GAS reactor is a beryllium (Be)-reflected, light-water-moderated and -cooled, 30 MWth (max.) multipurpose reactor. Presently, the reactor uses MTR-type LEU (19.75 w/o) silicide fuel (U3Si2-Al) elements (FEs). On the 10 x 10 core grid positions there are 40 standard FEs (each consisting of 21 fuel plates), eight control elements (CEs, each consisting f 15 fuel plates) initially loaded with 250 and 178.6 g 235U respectively, Beryllium reflector elements and other irradiation facilities. This fuel loading corresponds to a uranium meat density of 2.96 g/cm3. The equilibrium core is achieved through some transition cores with smaller core and lower power. In the first transition core, all FEs and CEs were fresh oxide fuel with same uranium meat density of 2.96 g/cm3. Some experiments were carried out in the core, including criticality experiments, as a part of commissioning activity. Since the first core using the fresh fuels, so the core can be used a bench mark core to validate the accuracy of a selected code. In the criticality experiments, there were some types of experiment have been performed as follows: - first criticality by adding FEs and CEs - criticality condition by adding the Beryllium reflector elements - criticality condition by adjustment various positions of six control rods - excess reactivity and total control rod worth In this paper, those criticality experimental results are compared to the calculated results by using the MVP code. The calculated results showed that using the selected nuclear data are very close to the experimental results. For example, the calculated core excess reactivity using JENDL-3.3 is in the range of 8.17 % ?k/k - 8.35 %?k/k. The calculated result is very close to the experimental result of 8.41 %?k/k. It can be concluded that the MVP code with JENDL-3.3 and ENDF/B-VI.8 nuclear data can be applied for the MTR type reactor with bulky Beryllium reflector. (author)

2007-11-05

25

On solution of Klein-Gordon equation in scalar and vector potentials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Based on the Coulomb gauge, the accurate Klein-Gordon equation in static scalar and vector potentials was derived from Klein-Gordon equation in electromagnetic environment. The correct equation developed in this comment demonstrates that so-called the Klein-Gordon equation with scalar and vector potentials is incorrect; therefore, some papers published to solve Klein-Gordon equation with equal scalar and vector potential are also wrong.

Changshi, Liu

2010-01-01

26

Flux Ropes as Singularities of the Vector Potential  

CERN Document Server

A flux rope is a domain of concentration of the magnetic field $\\textbf{B}$. Insofar as $\\textbf{B}$ outside such a domain is considered as vanishingly small, a flux rope can be described as the core of a singularity of the outer vector potential $\\textbf{A}$, whose topological invariant is the magnetic flux through the rope. By 'topological' it is meant that $\\oint_C\\textbf{A}\\cdot\\mathrm d\\textbf{s}$ measures along any loop $C$ surrounding the flux rope the same constant flux $\\Phi$. The electric current intensity is another invariant of the theory, but non-topological. We show that, in this theoretical framework, the linear force-free field (LFFF) Lundquist model and the non-linear (NLFFF) Gold-Hoyle model of a flux rope exhibit stable solutions distributed over quantized strata of increasing energies (an infinite number of strata in the first case, only one stratum in the second case); each stratum is made of a continuous set of stable states. The lowest LFFF stratum and the unique NLFFF stratum come nume...

Kleman, M

2014-01-01

27

Biology and dynamics of potential malaria vectors in Southern France  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Malaria is a former endemic problem in the Camargue, South East France, an area from where very few recent data concerning Anopheles are available. A study was undertaken in 2005 to establish potential malaria vector biology and dynamics and evaluate the risk of malaria re-emergence. Methods Mosquitoes were collected in two study areas, from March to October 2005, one week every two weeks, using light traps+CO2, horse bait traps, human bait catch, and by collecting females in resting sites. Results Anopheles hyrcanus was the most abundant Anopheles species. Anopheles melanoon was less abundant, and Anopheles atroparvus and Anopheles algeriensis were rare. Anopheles hyrcanus and An. melanoon were present in summer, whereas An. atroparvus was present in autumn and winter. A large number of An. hyrcanus females was collected on humans, whereas almost exclusively animals attracted An. melanoon. Based on an enzyme-linked immunosorbent assay, almost 90% of An. melanoon blood meals analysed had been taken on horse or bovine. Anopheles hyrcanus and An. melanoon parity rates showed huge variations according to the date and the trapping method. Conclusion Anopheles hyrcanus seems to be the only Culicidae likely to play a role in malaria transmission in the Camargue, as it is abundant and anthropophilic.

Schaffner Francis

2007-02-01

28

Core calculation of 1MW PUSPATI TRIGA Reactor (RTP) using continuous energy method of Monte Carlo MVP code system  

International Nuclear Information System (INIS)

The RTP is a light-water moderated and pool-type TRIGA MARK II reactor with power capacity of 1MWt. It was built in 1979 and attained the first criticality on 28 June 1982. The RTP was designed mainly for neutron activation analysis, small angle neutron scattering, neutron radiography, radioisotope production, education and training purposes. It uses standard TRIGA fuel developed by General Atomic in which the zirconium hydride moderator is homogeneously combined with enriched uranium. It has a cylindrical core with which possibility of locating 127 of fuel elements. Both of the coolant and moderator uses light water system and the reflector is made of high purity graphite. Because of its relatively small power, it uses natural convection for its cooling system. To ensure the integrity of the core, fuel shuffling have been carried out several times. Until now, there were 12 configurations of the core, the most recent change being in July 2006. This paper will describe the RTP core calculation using the Monte Carlo MVP code system. VP is a general multi-purpose Monte Carlo code for neutron and photon transport calculation in order to have an accurate and fast Monte Carlo simulation of neutron and photon transport problems. The MVP Monte Carlo code calculation is based on the continuous energy method. This code is capable of adopting an accurate physics model, geometry description and variance reduction technique. When compared to the conventional scalar method, this code could achieve higher computation speed by up to a factor of 10 on the vector super-computer. The RTP core has been modelled using cylinder geometry along the z-coordinate geometry with the MVP code system while its material cross section data is calculated beforehand. The JENDL3.3 data library was used in the whole calculation. The objectives of the calculation are to calculate the multiplication factor values (keff), fission density and flux distribution from the tally data. The calculation also gives control rod worth value and comparison with experimental data was made to evaluate the safety of the reactor. (author)

2007-11-05

29

Validation of the Monte Carlo code MVP on the first criticality of Indonesian multipurpose reactor  

International Nuclear Information System (INIS)

The validation research works in BATAN are focused using Monte Carlo codes with recent nuclear data on the experimental results. In this paper, the validation results of Monte Carlo code MVP on the first criticality experimental of Indonesia Multipurpose Reactor (RSG GAS reactor) are presented. The MVP code is a continuous energy Monte Carlo code developed by Japan Atomic Energy Research Institute (JAERI). The objective this paper is to show the accuracy of the code using recent nuclear data of JEF-3.0, JENDL-3.3 and ENDF/B-VI.8. The final goal of this research is to use the code as an in-core fuel management code since the code has a module of burn-up calculation (MVP-BURN). The MVP calculations with the three libraries produced keff values with excellent agreement to experiment data since the maximum differences are less than 0.5%. For the total control rod worth, the maximum difference is 3.6%. Systematically, ENDF/B-VI.8 library gave a maximum difference compared with other libraries. Therefore, the MVP code with recent libraries can be applied for the MTR type reactor with bulky Beryllium reflector. (author)

2008-11-01

30

Neutron cross section library production code system for continuous energy Monte Carlo code MVP. LICEM  

International Nuclear Information System (INIS)

A code system has been developed to produce neutron cross section libraries for the MVP continuous energy Monte Carlo code from an evaluated nuclear data library in the ENDF format. The code system consists of 9 computer codes, and can process nuclear data in the latest ENDF-6 format. By using the present system, MVP neutron cross section libraries for important nuclides in reactor core analyses, shielding and fusion neutronics calculations have been prepared from JENDL-3.1, JENDL-3.2, JENDL-FUSION file and ENDF/B-VI data bases. This report describes the format of MVP neutron cross section library, the details of each code in the code system and how to use them. (author)

1996-01-01

31

Josephson Effect in Graphene: Comparison of Real and Pseudo Vector Potential Barriers  

Science.gov (United States)

The Josephson currents through real vector potential (RVP) and pseudo vector potential (PVP) barriers in graphene are investigated. In graphene, the pseudo vector potential may be caused by a local strain. The comparison of supercurrents induced by the two type-barriers is focused. As a result, we find that not only will the RVP induce a transition Josephson current from the 0 ? ? state but also causes the difference in the phases of the order parameters of the two superconducting graphene layers to shift from varphi ? varphi. The critical current is PVP-independent around the neutrality point while it strongly depends on the RVP. The vector potential dependence of critical current is found to be perfectly linear for both PVP and RVP barriers.

Tatnatchai, Suwannasit; Rassmidara, Hoonsawat; I-Ming, Tang; Bumned, Soodchomshom

2014-03-01

32

An educational path for the magnetic vector potential and its physical implications  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present an educational path on the magnetic vector potential A addressed to undergraduate students and to pre-service physics teachers. Starting from the generalized Ampere-Laplace law, in the framework of a slowly varying time-dependent field approximation, the magnetic vector potential is written in terms of its empirical referent, i. e. the conduction current. Therefore, once the currents are known, our approach allows a clear and univocal physical determination of A o...

Barbieri, Sara; Cavinato, Michela; Giliberti, Marco

2013-01-01

33

Semiclassical methods to the Klein-Gordon equation with the unequal scalar and vector potentials  

International Nuclear Information System (INIS)

When the scalar potential is larger than the vector potential there are very few exactly solvable Klein-Gordon equations. Based on a general transformation between the unequal scalar and vector potential, in this paper, we employ two semiclassical methods to determine the bound state energy spectrum of the Klein-Gordon equation. To illustrate this procedure, the scalar potentials are chosen as the linear, exponential and linear plus Coulomb potentials and the corresponding energy spectra are analytically obtained. It is shown that the energy spectrum can be obtained by a simple algebraic method and our proposal methods can be extended to discuss the quasi-exactly solvable cases

2006-09-01

34

Potential of Scalable Vector Graphics (SVG) for Ocean Science Research  

Science.gov (United States)

Scalable Vector Graphics (SVG), a graphic format encoded in Extensible Markup Language (XML), is a recent W3C standard. SVG is text-based and platform-neutral, allowing interoperability and a rich array of features that offer significant promise for the presentation and publication of ocean and earth science research. This presentation (a) provides a brief introduction to SVG with real-world examples; (b) reviews browsers, editors, and other SVG tools; and (c) talks about some of the more powerful capabilities of SVG that might be important for ocean and earth science data presentation, such as searchability, animation and scripting, interactivity, accessibility, dynamic SVG, layers, scalability, SVG Text, SVG Audio, server-side SVG, and embedding metadata and data. A list of useful SVG resources is also given.

Sears, J. R.

2002-12-01

35

Assessing the potential for AAV vector genotoxicity in a murine model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Gene transfer using adeno-associated virus (AAV) vectors has great potential for treating human disease. Recently, questions have arisen about the safety of AAV vectors, specifically, whether integration of vector DNA in transduced cell genomes promotes tumor formation. This study addresses these questions with high-dose liver-directed AAV-mediated gene transfer in the adult mouse as a model (80 AAV-injected mice and 52 controls). After 18 months of follow-up, AAV-injected mice did not show a...

2011-01-01

36

Ecology of Anopheles mosquitoes in Belgrade area: Estimating vector potential for malaria retransmission  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Belgrade is situated in the area that is potentially at risk from malaria outbrakes. Until eradication, the main vector of malaria in this area was Anopheles maculipennis s. s. (previous name An. typicus) and secondary vectors were An. messeae and An. atroparvus. In this study we examined the distribution and ecology of Anopheles mosquitoes (Diptera, Culicidae) in Belgrade. Females of Anopheles mosquitoes were collected from animal shelters in Belgrade at eight locations during 2003. Egg morp...

Daki? Zorica; Kuliši? Z.; Stajkovi? N.; Pelemiš M.; ?obelji? M.; Stanimirovi? Zoran; In?i? N.; Poluga Jasmina; Pavlovi? M.

2008-01-01

37

Approximate analytical solutions of the Klein-Gordon equation with scalar and vector Eckart potentials  

International Nuclear Information System (INIS)

By using the functional analysis method, we solve approximately the Klein-Gordon equation with equal scalar and vector Eckart potentials for the arbitrary orbital angular momentum number l. The bound state energy eigenvalue equation and the unnormalized radial wavefunctions have been approximately obtained by considering a proper approximation to the centrifugal potential term

2008-07-01

38

Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP...

Lara Pedro C; Lloret Marta; Clavo Bernardino; Apolinario Rosa M; Henríquez-Hernández Luis; Bordón Elisa; Fontes Fausto; Rey Agustín

2009-01-01

39

Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP), vault poly(ADP-r...

Lara, Pedro C.; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa M.; Henri?quez-herna?ndez, Luis Alberto; Bordo?n, Elisa; Fontes, Fausto; Rey, Agusti?n

2009-01-01

40

Assessing the potential for AAV vector genotoxicity in a murine model.  

Science.gov (United States)

Gene transfer using adeno-associated virus (AAV) vectors has great potential for treating human disease. Recently, questions have arisen about the safety of AAV vectors, specifically, whether integration of vector DNA in transduced cell genomes promotes tumor formation. This study addresses these questions with high-dose liver-directed AAV-mediated gene transfer in the adult mouse as a model (80 AAV-injected mice and 52 controls). After 18 months of follow-up, AAV-injected mice did not show a significantly higher rate of hepatocellular carcinoma compared with controls. Tumors in mice treated with AAV vectors did not have significantly different amounts of vector DNA compared with adjacent normal tissue. A novel high-throughput method for identifying AAV vector integration sites was developed and used to clone 1029 integrants. Integration patterns in tumor tissue and adjacent normal tissue were similar to each other, showing preferences for active genes, cytosine-phosphate-guanosine islands, and guanosine/cytosine-rich regions. [corrected] Gene expression data showed that genes near integration sites did not show significant changes in expression patterns compared with genes more distal to integration sites. No integration events were identified as causing increased oncogene expression. Thus, we did not find evidence that AAV vectors cause insertional activation of oncogenes and subsequent tumor formation. PMID:21106988

Li, Hojun; Malani, Nirav; Hamilton, Shari R; Schlachterman, Alexander; Bussadori, Giulio; Edmonson, Shyrie E; Shah, Rachel; Arruda, Valder R; Mingozzi, Federico; Wright, J Fraser; Bushman, Frederic D; High, Katherine A

2011-03-24

 
 
 
 
41

Stationary states of fermions in a sign potential with a mixed vector–scalar coupling  

Energy Technology Data Exchange (ETDEWEB)

The scattering of a fermion in the background of a sign potential is considered with a general mixing of vector and scalar Lorentz structures with the scalar coupling stronger than or equal to the vector coupling under the Sturm–Liouville perspective. When the vector coupling and the scalar coupling have different magnitudes, an isolated solution shows that the fermion under a strong potential can be trapped in a highly localized region without manifestation of Klein’s paradox. It is also shown that the lonely bound-state solution disappears asymptotically as one approaches the conditions for the realization of spin and pseudospin symmetries. -- Highlights: •Scattering of fermions in a sign potential assessed under a Sturm–Liouville perspective. •An isolated bounded solution. •No pair production despite the high localization. •No bounded solution under exact spin and pseudospin symmetries.

Castilho, W.M., E-mail: castilho.w@gmail.com; Castro, A.S. de, E-mail: castro@pq.cnpq.br

2014-01-15

42

Calculation of the magnetic vector potential in the TJ-II  

International Nuclear Information System (INIS)

The properties of the vector magnetic potential and its usefulness to calculate magnetic fluxes in both stationary and time-dependent conditions are p revised in this report. We have adapted to the TJ-II Flexible Heliac efficient numerical expressions to calculate the vector potential, calculating in addition the magnetic flux with this formalism in circumstances whose complexity makes very convenient the use of the vector potential. The result on induced voltages offer theoretical support to the measurements of induced voltage due to the OH coils in the plasma, like the measurements provided by the loop voltage diagnostic installed in the TJ-II, as well as to the cylindrical approximation of the plasma often used to interpret experimental data. (Author) 11 refs

2005-01-01

43

An educational path for the magnetic vector potential and its physical implications  

Science.gov (United States)

We present an educational path for the magnetic vector potential A aimed at undergraduate students and pre-service physics teachers. Starting from the generalized Ampère-Laplace law, in the framework of a slowly varying time-dependent field approximation, the magnetic vector potential is written in terms of its empirical references, i.e. the conduction currents. Therefore, once the currents are known, our approach allows for a clear and univocal physical determination of A, overcoming the mathematical indeterminacy due to the gauge transformations. We have no need to fix a gauge, since for slowly varying time-dependent electric and magnetic fields, the ‘natural’ gauge for A is the Coulomb one. We stress the difference between our approach and those usually presented in the literature. Finally, a physical interpretation of the magnetic vector potential is discussed and some examples of the calculation of A are analysed.

Barbieri, S.; Cavinato, M.; Giliberti, M.

2013-09-01

44

An educational path for the magnetic vector potential and its physical implications  

CERN Document Server

We present an educational path on the magnetic vector potential A addressed to undergraduate students and to pre-service physics teachers. Starting from the generalized Ampere-Laplace law, in the framework of a slowly varying time-dependent field approximation, the magnetic vector potential is written in terms of its empirical referent, i. e. the conduction current. Therefore, once the currents are known, our approach allows a clear and univocal physical determination of A overcoming the mathematical indeterminacy due to the gauge transformations. We have no need to fix a gauge, since for slowly varying time-dependent electric and magnetic fields, the natural gauge for A is the Coulomb one. We stress the difference between our approach and those usually presented in the literature. Finally, a physical interpretation of the magnetic vector potential is discussed and some examples of calculation of A are analysed.

Barbieri, Sara; Giliberti, Marco

2013-01-01

45

Exact Solutions of Klein–Gordon Equation with Scalar and Vector Rosen–Morse-Type Potentials  

International Nuclear Information System (INIS)

We obtain an exact analytical solution of the Klein–Gordon equation for the equal vector and scalar Rosen– Morse and Eckart potentials as well as the parity-time (PT) symmetric version of the these potentials by using the asymptotic iteration method. Although these PT symmetric potentials are non-Hermitian, the corresponding eigenvalues are real as a result of the PT symmetry. (general)

2008-08-01

46

Spread of the West Nile virus vector Culex modestus and the potential malaria vector Anopheles hyrcanus in central Europe.  

Science.gov (United States)

Mosquito faunal studies were carried out in five separate wetland regions in the Czech Republic during 2004-2007, sampling with dry ice-baited and sentinel host-baited CDC traps. A total of 79,245 adults was identified, representing 23 mosquito species that belonged to the genera Anopheles, Culiseta, Coquillettidia, Aedes, and Culex. Our findings reveal that the mosquito fauna is enriched by new elements in the Mediterranean region. Historical and CDC trap data suggest that the newly-emerging potential malaria vector, Anopheles hyrcanus, has reached the northern limit of its distribution in the Czech Republic, and the important West Nile virus (WNV) vector, Culex modestus, has widened its distribution in the Czech Republic. No significant differences were observed in a total number of mosquitoes collected by traps baited with either the sentinel animals or with CO2, although species abundance differed. A relatively higher proportion of Cx. modestus was collected in the sentinel-baited traps, while the proportion of Cx. pipiens was higher in the CO2-baited traps. PMID:19263846

Votýpka, Jan; Seblová, Veronika; Rádrová, Jana

2008-12-01

47

Two-dimensional Dirac fermions with random axial-vector potential  

CERN Document Server

A Dirac fermion model with random axial-vector potential is proposed. At a special strength of randomness, the symmetry of the action is enhanced, which is due to the gauge symmetry \\`a la Nishimori. Some exact scaling exponents of single-particle Green functions are computed. The relationship with the XY gauge glass model is discussed.

Fukui, T; Yamada, H

2002-01-01

48

On the scattering of massive spinless bosons by a nonminimal vector smooth step potential  

Energy Technology Data Exchange (ETDEWEB)

The Duffin-Kemmer-Petiau (DKP) equation for massive spinless bosons in the presence of a nonminimal vector smooth step potential is revised. The problem is mapped into a Sturm-Liouville equation. The reflection and transmission coefficients are obtained and discussed in detail. Furthermore, we show that Klein's paradox does not show its face in this sort of interaction.

Castro, L.B., E-mail: benito@feg.unesp.b [UNESP Campus de Guaratingueta, Departamento de Fisica e Quimica, 12516-410, Guaratingueta, SP (Brazil); Cardoso, T.R., E-mail: cardoso@feg.unesp.b [UNESP Campus de Guaratingueta, Departamento de Fisica e Quimica, 12516-410, Guaratingueta, SP (Brazil); Castro, A.S. de, E-mail: castro@pq.cnpq.b [UNESP Campus de Guaratingueta, Departamento de Fisica e Quimica, 12516-410, Guaratingueta, SP (Brazil)

2010-02-15

49

On the scattering of massive spinless bosons by a nonminimal vector smooth step potential  

International Nuclear Information System (INIS)

The Duffin-Kemmer-Petiau (DKP) equation for massive spinless bosons in the presence of a nonminimal vector smooth step potential is revised. The problem is mapped into a Sturm-Liouville equation. The reflection and transmission coefficients are obtained and discussed in detail. Furthermore, we show that Klein's paradox does not show its face in this sort of interaction.

2010-02-01

50

Solutions of the Duffin–Kemmer–Petiau Equation Under a Vector Hellman Potential  

International Nuclear Information System (INIS)

We present the approximate analytical solutions of Duffin–Kemmer–Petiau equation with a vector Hellmann potential for spin-zero particles. The energy eigenvalues and the corresponding eigenfunctions are obtained in closed form and some numerical results are included. (author)

2014-03-01

51

Scattering and bound states of fermions in a mixed vector-scalar smooth step potential  

CERN Document Server

The scattering of a fermion in the background of a smooth step potential is considered with a general mixing of vector and scalar Lorentz structures with the scalar coupling stronger than or equal to the vector coupling. Charge-conjugation and chiral-conjugation transformations are discussed and it is shown that a finite set of intrinsically relativistic bound-state solutions appears as poles of the transmission amplitude. It is also shown that those bound solutions disappear asymptotically as one approaches the conditions for the realization of the so-called spin and pseudospin symmetries in a four-dimensional space-time.

Castilho, W M

2014-01-01

52

Dynamic polarization potential effects on vector analyzing powers of 6Li-28Si elastic scattering from non-monotonic potentials  

International Nuclear Information System (INIS)

Experimental cross section (CS) and vector analyzing power (VAP) data of the 6Li-28Si elastic scattering at 22.8 MeV are analyzed in the coupled-channels (CC) and coupled discretized continuum channels (CDCC) methods. Non-monotonic (NM) 6Li and ? potentials of microscopic origin are employed, respectively, in the CC calculations and to generate folding potentials for the CDCC calculations. The study demonstrates that the use of central NM potentials can generate an appropriate dynamic polarization potential (DPP) required to describe both the CS and VAP data without the necessity of renormalization. This also produces an effective spin-orbit (SO) potential to account for the iT11 data without the requirement of an additional static SO potential at the incident energy considered.

2010-08-16

53

Ecology of Anopheles mosquitoes in Belgrade area: Estimating vector potential for malaria retransmission  

Directory of Open Access Journals (Sweden)

Full Text Available Belgrade is situated in the area that is potentially at risk from malaria outbrakes. Until eradication, the main vector of malaria in this area was Anopheles maculipennis s. s. (previous name An. typicus and secondary vectors were An. messeae and An. atroparvus. In this study we examined the distribution and ecology of Anopheles mosquitoes (Diptera, Culicidae in Belgrade. Females of Anopheles mosquitoes were collected from animal shelters in Belgrade at eight locations during 2003. Egg morphology was used to identify the specimens. A total of 3704 females deposited eggs ready for identification. Three species of An. maculipennis complex were identified: An. messeae, An. atroparvus and An. maculipennis s. s.. The most abundant species were An. messeae (64%. The relative frequency of three species varied depending on the site of collection. Seasonal fluctuations of mosquitoes' species varied. Each develops in a distinct type of water, too. The three species of the An. maculipennis complex, particularly An. messeae and An. atroparvus, are considered as potential vectors of malaria in Belgrade. With the possible reintroduction of Plasmodium species due to climatic changes and increased travel to and from the countries where malaria is endemic, a more efficient vector control is necessary.

Daki? Zorica

2008-01-01

54

Predicting and mapping malaria under climate change scenarios: the potential redistribution of malaria vectors in Africa  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Malaria is rampant in Africa and causes untold mortality and morbidity. Vector-borne diseases are climate sensitive and this has raised considerable concern over the implications of climate change on future disease risk. The problem of malaria vectors (Anopheles mosquitoes shifting from their traditional locations to invade new zones is an important concern. The vision of this study was to exploit the sets of information previously generated by entomologists, e.g. on geographical range of vectors and malaria distribution, to build models that will enable prediction and mapping the potential redistribution of Anopheles mosquitoes in Africa. Methods The development of the modelling tool was carried out through calibration of CLIMEX parameters. The model helped estimate the potential geographical distribution and seasonal abundance of the species in relation to climatic factors. These included temperature, rainfall and relative humidity, which characterized the living environment for Anopheles mosquitoes. The same parameters were used in determining the ecoclimatic index (EI. The EI values were exported to a GIS package for special analysis and proper mapping of the potential future distribution of Anopheles gambiae and Anophles arabiensis within the African continent under three climate change scenarios. Results These results have shown that shifts in these species boundaries southward and eastward of Africa may occur rather than jumps into quite different climatic environments. In the absence of adequate control, these predictions are crucial in understanding the possible future geographical range of the vectors and the disease, which could facilitate planning for various adaptation options. Conclusion Thus, the outputs from this study will be helpful at various levels of decision making, for example, in setting up of an early warning and sustainable strategies for climate change and climate change adaptation for malaria vectors control programmes in Africa.

Kangalawe Richard YM

2010-04-01

55

MVP expression in the prediction of clinical outcome of locally advanced oral squamous cell carcinoma patients treated with radiotherapy  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Objective To explore the role of Major Vault Protein (MVP in oral cavity squamous cell carcinoma patients. Subjects and Methods 131 consecutive patients suffering from oral cavity squamous cell carcinoma were included in the study. In the whole series, the mean follow-up for survivors was 123.11?±?40.36?months. Patients in tumour stages I and II were referred to surgery; patients in stage III-IV to postoperative radiotherapy (mean dose?=?62.13?±?7.74?Gy in 1.8–2?Gy/fraction. MVP expression was studied by immunohistochemistry in paraffin-embedded tumour tissue. Results MVP expression was positive in 112 patients (85.5% and no relation was found with clinic pathological variables. MVP overexpression (those tumours with moderate or strong expression of the protein was related to insulin-like growth factor receptor-1 (IGF-1R expression (P?=?0.014. Tumour stage of the disease was the most important prognostic factor related to survival. Tumours overexpressing MVP and IGF-1R were strongly related to poor disease-free survival (P?=?0.008, Exp(B?=?2.730, CI95% (1.302-5.724 and cause-specific survival (P?=?0.014, Exp(B?=?2.570, CI95% (1.215-5.437 in patients achieving tumour stages III-IV, in multivariate analysis. Conclusions MVP and IGF-1R expression were related in oral squamous cell carcinoma and conferred reduced long-term survival in patients suffering from advanced stages of the disease.

Henríquez-Hernández Luis

2012-08-01

56

Vector Potential Electromagnetic Theory with Generalized Gauge for Inhomogeneous Anisotropic Media  

CERN Document Server

Vector and scalar potential formulation is valid from quantum theory to classical electromagnetics. The rapid development in quantum optics calls for electromagnetic solutions that straddle quantum physics as well as classical physics. The vector potential formulation is a good candidate to bridge these two regimes. Hence, there is a need to generalize this formulation to inhomogeneous media. A generalized gauge is suggested for solving electromagnetic problems in inhomogenous media which can be extended to the anistropic case. The advantages of the resulting equations are their absence of low-frequency catastrophe. Hence, usual di?erential equation solvers can be used to solve them over multi-scale and broad bandwidth. It is shown that the interface boundary conditions from the resulting equations reduce to those of classical Maxwell's equations. Also, classical Green's theorem can be extended to such a formulation, resulting in similar extinction theorem, and surface integral equation formulation for surfac...

Chew, Weng Cho

2014-01-01

57

Geometric phase for collinear conical intersections. I. Geometric phase angle and vector potentials  

International Nuclear Information System (INIS)

We present a method for properly treating collinear conical intersections in triatomic systems. The general vector potential (gauge theory) approach for including the geometric phase effects associated with collinear conical intersections in hyperspherical coordinates is presented. The current study develops an introductory method in the treatment of collinear conical intersections by using the phase angle method. The geometric phase angle, ?, in terms of purely internal coordinates is derived using the example of a spin-aligned quartet lithium triatomic system. A numerical fit and thus an analytical form for the associated vector potentials are explicitly derived for this triatomic A3 system. The application of this methodology to AB2 and ABC systems is also discussed.

2011-02-14

58

Dirac and Klein-Gordon equations with equal scalar and vector potentials  

International Nuclear Information System (INIS)

We study the three-dimensional Dirac and Klein-Gordon equations with scalar and vector potentials of equal magnitudes as an attempt to give a proper physical interpretation of this class of problems which has recently been accumulating interest. We consider a large class of these problems in which the potentials are noncentral (angular-dependent) such that the equations separate completely in spherical coordinates. The relativistic energy spectra are obtained and shown to differ from those of well-known problems that have the same nonrelativistic limit. Consequently, such problems should not be misinterpreted as the relativistic extension of the given potentials despite the fact that the nonrelativistic limit is the same. The Coulomb, oscillator and Hartmann potentials are considered. Additionally, we investigate the Klein-Gordon equation with uneven mix of potentials leading to the correct relativistic extension. We consider the case of spherically symmetric exponential-type potentials resulting in the S-wave Klein-Gordon-Morse problem

2006-01-09

59

Axial and vector constants of nucleons and valent quarks coupling in quasi-potential model  

International Nuclear Information System (INIS)

The procedure of calculating the ratio of the GA/GV coupling axial and vector constants for nucleons in the relativistic quasi-potential quark model is described. The nucleons magnetic moments in this depend on one nondimensional parameter, determined by the nucleons relativistic kinematics. It is shown, that the nucleons magnetic moments and GA/GV ratio depend on one model parameter and are coup by the ratio, independent of the type of the relative motion wave function

2004-11-01

60

Wolbachia transinfection in Aedes aegypti: A potential gene driver of dengue vectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The endosymbiotic bacteria in the genus Wolbachia are capable of inducing a wide range of reproductive abnormalities in their hosts, including cytoplasmic incompatibility (CI), which could lead to the replacement of uninfected host populations with infected ones. Because of this, Wolbachia have attracted considerable interest as a potential mechanism for spreading disease-blocking transgenes through vector populations. Here we report the establishment of double Wolbachia transinfection by dir...

Ruang-areerate, Toon; Kittayapong, Pattamaporn

2006-01-01

 
 
 
 
61

Transverse-longitudinal part of a vector potential in classical electrodynamics  

International Nuclear Information System (INIS)

Existence of a physical (gauge-invariant) degree of freedom of the vector potential generating no electromagnetic fields is proved in classical electrodynamics within the Dirac generalized Hamiltonian dynamics. The gauge-invariant form of electrodynamics of charged particles is given within which the question of observing the obtained degree of freedom is discussed. It is shown that it caused an electric current in a superconducting ring put on the solenoid. 20 refs

1989-01-01

62

Vector Potential Approach for Response of Infinite Periodic Systems to Electric Fields  

Science.gov (United States)

A detailed study of the vector potential approach (VPA) for the response of periodic systems to a finite electric field is carried out using a parameterized model self-consistent field (SCF) polymer Hamiltonian. Specific issues discussed include ``smoothing'' of crystal orbitals, convergence and accuracy of SCF solutions as a function of field and number of k points, Zener tunneling, field-dependent band structure, determination of (non)linear susceptibilities, and nuclear relaxation.

Kirtman, Bernard; Springborg, Michael

2007-12-01

63

Late generation lentiviral vectors: evaluation of inflammatory potential in human airway epithelial cells.  

Science.gov (United States)

Lentiviruses (LVs) are considered one of the most promising tools for gene transfer, however, their potential to induce pro-inflammatory cytokines on delivery into the respiratory tissue remains to be established. Here we tested a third-generation vesicular stomatitis virus (VSV)-G pseudotyped LV vector in the two respiratory epithelial cell lines A549 and CFT1-C2. We observed that the VSV-G LV vector does not induce (a) activation of the nuclear factor (NF)-kappaB, which intervenes in transcription of pro-inflammatory genes; (b) expression of ICAM-1; and (c) transcription of a panel of cytokines, with the exception of a mild and transient (24h) increase of IFN-gamma mRNA. In contrast, an adenovirus-derived vector strongly activated NF-kappaB and different transcripts such as those of ICAM-1, IL-8, RANTES, IP-10, TNF-alpha, IL-6, IL-1 beta. In conclusion, this third-generation VSV-G pseudotyped LV vector does not elicit major pro-inflammatory signals in human airway epithelial cells and appears to be better suited for gene delivery strategies. PMID:19447514

Copreni, Elena; Nicolis, Elena; Tamanini, Anna; Bezzerri, Valentino; Castellani, Stefano; Palmieri, Lucia; Giri, Maria Grazia; Vella, Antonio; Colombatti, Marco; Rizzotti, Paolo; Conese, Massimo; Cabrini, Giulio

2009-09-01

64

Calculation of the magnetic vector potential in the TJ-II; Calculo del Potencial Magnetico Vector en el TJ-II  

Energy Technology Data Exchange (ETDEWEB)

The properties of the vector magnetic potential and its usefulness to calculate magnetic fluxes in both stationary and time-dependent conditions are p revised in this report. We have adapted to the TJ-II Flexible Heliac efficient numerical expressions to calculate the vector potential, calculating in addition the magnetic flux with this formalism in circumstances whose complexity makes very convenient the use of the vector potential. The result on induced voltages offer theoretical support to the measurements of induced voltage due to the OH coils in the plasma, like the measurements provided by the loop voltage diagnostic installed in the TJ-II, as well as to the cylindrical approximation of the plasma often used to interpret experimental data. (Author) 11 refs.

Lopez Fraguas, A.; Lopez Bruna, D.; Romero, J. A.

2005-07-01

65

Gauge Transformation Properties of Vector and Tensor Potentials Revisited a Group Quantization Approach  

CERN Document Server

The standard rules of transformation for gauge connections, such as vector potentials and metric tensors, are reexamined according to a group-oriented approach to quantization. In this scheme, the gauge group coordinates acquire dynamics outside the null mass shell, and they transfer degrees of freedom to the gauge potentials, which then become massive. The quantization of massless and massive non-Abelian Yang-Mills, linear Gravity and Abelian two-form gauge field theories are fully developed from this new approach, where a cohomological origin of mass is pointed out.

Calixto, M

2000-01-01

66

Dirac equation with coupling to 1/r singular vector potentials for all angular momenta  

CERN Multimedia

We consider the Dirac equation in 3+1 dimensions with spherical symmetry and coupling to 1/r singular vector potential. An approximate analytic solution for all angular momenta is obtained. The approximation is made for the 1/r orbital term in the Dirac equation itself not for the traditional and more singular 1/r^2 term in the resulting second order differential equation. Consequently, the validity of the solution is for a wider energy spectrum. As examples, we consider the Hulthen and Eckart potentials.

Alhaidari, A D

2010-01-01

67

Diversity of Culex torrentium Martini, 1925 - a potential vector of arboviruses and filaria in Europe.  

Science.gov (United States)

Culex torrentium is one of the most common mosquito species in Germany. Due to its sympatric occurrence as well as its similar morphological and ecological characteristics, it has often been confused with another common species, Culex pipiens. Both species are known to be potential vectors for different arboviruses (not only in Germany) with C. torrentium being a possible vector for Sindbis or Ockelbo virus. In our study, we analyzed the genetic variability in a 658 bp fragment of the cytochrome c oxidase subunit I gene (coxI) of C. torrentium, from nine localities in the Frankfurt/Rhine-Main Metropolitan Region. The results of our genetic survey indicate a higher genetic diversity in this gene region for C. torrentium than for the morphologically similar C. pipiens. Our findings may explain the difficulties in the past to find morphological characteristics that apply to all populations of C. torrentium, when attempting to separate them clearly from C. pipiens, by any other criteria than male genitalia. Being ornithophilic, possible hybrids between C. torrentium and the humanophilic C. pipiens biotype molestus, could potentially serve as important vectors for zoonotic diseases. Therefore, we recommend that greater emphasis is placed on the ecological characteristics, population structure, and the taxonomy of this often neglected species, in the future. PMID:23604567

Werblow, Antje; Bolius, Sarah; Dorresteijn, Adriaan W C; Melaun, Christian; Klimpel, Sven

2013-07-01

68

ASPECTS REGARDING THE FACEBOOK USER IN ROMANIA AS A POTENTIAL DESTINATION IMAGE - VECTOR  

Directory of Open Access Journals (Sweden)

Full Text Available The Internet’s rapid development from the 1.0 version to the 2.0 one has triggered the appearance of social networks. Facebook is Illustrative of them due to the number of users it attracts and its international range of dispersion. Although a beginner in communication, Facebook Romania is prone to contribute highly to the “content generator” market in what concerns its users. In order to create or maintain a brand’s positive image it is necessary to know some elements regarding the demographic aspects of the target public, and its attitudes, predilections or behaviours in general. Thus, web pages created on Facebook can “transform” its users into fans and there is a possibility that afterwards these fans become image -vectors by way of the delivered experiences. This article tries to study the fundamental elements that could make up the profile of a user from the targeted group as a potential destination image- vector.

MIHAIL-CRISTIAN DI?OIU

2011-01-01

69

Implementation of a vector potential method in an ab initio Hartree-Fock code  

Science.gov (United States)

For extended systems exposed to an external, electrostatic field, the presence of the field leads to an extra term (Evec . Pvec ) to the Hamiltonian, where Evec is the field vector and Pvec is the polarization of the system of interest. In order to find out how a polymer chain responds to an external electric perturbation, a field with a charge and a current term for the polarization is added to an ab initio Hartree-Fock Hamiltonian. The polarization expression is taken from an efficient vector potential approach (VPA) [1] for calculating electronic and nuclear responses of infinite periodic systems to finite electric fields and is implemented in the ab initio LCAO-SCF algorithm [3], which computes band structure of regular or helical polymers, taking into account the one-dimensional translational symmetry. A smoothing procedure for numerical differentiation of the orbital coefficients is used in order to calculate self-consistently the charge flow contribution to the polarization.

Tevekeliyska, Violina; Springborg, Michael; Champagne, Benoît; Kirtman, Bernard

2012-12-01

70

Exact Klein-Gordon equation with spatially-dependent masses for unequal scalar-vector Coulomb-like potentials  

CERN Document Server

We study the effect of spatially dependent mass functions over the solution of the Klein-Gordon equation in the (3+1)-dimensions for spinless bosonic particles where the mixed scalar-vector Coulomb-like field potentials and masses are directly proportional and inversely proportional to the distance from force center. The exact bound state energy eigenvalues and the corresponding wave functions of the Klein-Gordon equation for mixed scalar-vector and pure scalar Coulomb-like field potentials are obtained by means of the Nikiforov-Uvarov (NU) method. The energy spectrum is discussed for different scalar-vector potential mixing cases and also for constant mass case.

Ikhdair, Sameer M

2009-01-01

71

Potential vectors of West Nile virus in a semiarid environment: Doña Ana County, New Mexico.  

Science.gov (United States)

The potential vectors of West Nile virus (family Flaviviridae, genus Flavivirus, WNV) in Doña Ana County, NM, were determined during 2004 and 2005. Trapping was conducted using Centers for Disease Control and Prevention miniature light-traps baited with dry ice, and gravid traps baited with a hay infusion. In addition, sentinel chickens were housed at four of the trapping locations to monitor WNV epizootic transmission. In total, 5,576 pools consisting of 115,797 female mosquitoes were tested for WNV by reverse transcription-polymerase chain reaction, of which 152 from 13 mosquito species representing six genera were positive. Culex tarsalis Coquillett, Culex quinquefasciatus Say, Culex erythrothorax Dyar, Aedes vexans (Meigan), and Psorophora columbiae (Dyar & Knab) accounted for 86% of all detections. Based on the frequency of WNV detection, our data indicate primary and secondary vector roles for Cx. tarsalis and Cx. quinquefasciatus, respectively, with Cx. erythrothorax, Ae. vexans, and Ps. columbiae as occasional vectors of WNV in Dofia Ana County. Other species testing positive for the virus included Aedes aegypti (L.), Anopheles franciscanus McCracken, Culex stigmatosoma Dyar, Culiseta inornata (Williston), Ochlerotatus dorsalis (Meigan), Ochlerotatus sollicitans (Walker), Ochlerotatus trivittatus (Coquillett), and Psorophora signipennis (Coquillett). Although they occurred after initial WNV detections in mosquitoes, in total, 21 seroconversions in sentinel chickens were detected during the study. PMID:19960700

Pitzer, Jimmy B; Byford, Ronnie L; Vuong, Holly B; Steiner, Robert L; Creamer, Rebecca J; Caccamise, Donald F

2009-11-01

72

Processors for wavelet analysis and synthesis: NIFS and TI-C80 MVP  

Science.gov (United States)

Two processors are considered for image quadrature mirror filtering (QMF). The neuromorphic infrared focal-plane sensor (NIFS) is an existing prototype analog processor offering high speed spatio-temporal Gaussian filtering, which could be used for the QMF low- pass function, and difference of Gaussian filtering, which could be used for the QMF high- pass function. Although not designed specifically for wavelet analysis, the biologically- inspired system accomplishes the most computationally intensive part of QMF processing. The Texas Instruments (TI) TMS320C80 Multimedia Video Processor (MVP) is a 32-bit RISC master processor with four advanced digital signal processors (DSPs) on a single chip. Algorithm partitioning, memory management and other issues are considered for optimal performance. This paper presents these considerations with simulated results leading to processor implementation of high-speed QMF analysis and synthesis.

Brooks, Geoffrey W.

1996-03-01

73

AN ANALYSIS OF TRANSMISSION LINE PARAMETERS ON VLSI MULTICONDUCTOR BY ELECTRIC VECTOR POTENTIAL.  

Directory of Open Access Journals (Sweden)

Full Text Available Solving lossy multiconductor transmission line (MTL equations is of fundamental importance for the design and signal integrity verification of interconnections in VLSI systems. It is well established that the critical issue is the efficient and accurate electrical characterization of the MTLs through the determination of their per-unit-length parameters. In this respect, the so-called complementarity has the potential to become a fast and accurate method for the extraction of these parameters. Besides the value of the parameters, in fact, complementarity provides rigorous error bounds for them. Despite this important feature, commercial software do not use complementarity yet, due to the fact that there are unsolved theoretical issues related to the nonstandard formulation based on the electric vector potential. Some attempts to fill this gap have been already reported. The aim of this paper is to fill this gap by introducing a general formulation based on the electric vector potential highlighting the advantages of complementarity with respect to the standard first- and second-order finite element formulations

R.S.Karthic

2014-02-01

74

Vector unpacking as a potential barrier for receptor-mediated polyplex gene delivery.  

Science.gov (United States)

Ligand-conjugated polymer (polyplex) gene delivery vectors have strong potential as targeted, in vivo gene transfer vehicles; however, they are currently limited by low delivery efficiency. A number of barriers to polyplex-mediated delivery have been previously identified, including receptor binding, internalization, endosomal escape, and nuclear localization. However, based on understanding of viral gene delivery systems, yet another potential barrier may exist; a limited ability to unpackage the plasmid DNA cargo following localization to the nucleus. We have developed a model system that employs a cationic polymer linked to epidermal growth factor (EGF) as a ligand to target delivery of plasmid DNA encoding the green fluorescent protein to mouse fibroblasts bearing the EGF receptor. Using fluorescence microscopy to simultaneously trace both the plasmid and polymer during gene delivery in combination with an in vitro transcription assay, we provide evidence that plasmid unpackaging can indeed be a limiting step for gene expression for sufficiently large polymer constructs. Short-term expression is significantly enhanced by using short polycations that dissociate from DNA more rapidly both in vitro and in vivo. Finally, we describe a thermodynamic model that supports these data by showing that shorter polycations can have a higher probability of dissociating from DNA. This work demonstrates that vector unpackaging should be added to the list of barriers to receptor-mediated polyplex gene delivery, thus providing an additional design principle for targeted synthetic delivery vehicles. PMID:10649234

Schaffer, D V; Fidelman, N A; Dan, N; Lauffenburger, D A

2000-03-01

75

Genetic variability in the compatibility between Schistosoma haematobium and its potential vectors in Niger. Epidemiological implications.  

Science.gov (United States)

A populational study of the compatibility between Schistosoma haematobium and its potential vectors has been carried out in the Niger, confronting samples of S. haematobium populations from three epidemiologic foci with Bulinus populations originating from the same focus (sympatric infection) and with Bulinus populations from other foci (allopatric infections). The three transmission foci selected were irrigation canals in ricefields along the Niger river where one finds: Bulinus truncatus rohlfsi, Bulinus globosus, Bulinus forskalii and Bulinus senegalensis; temporary pools in the Sahel area where one finds B. truncatus and B. senegalensis; permanent pools of the "guelta" type in Sahara area where only B. truncatus occurs. As a compatibility test, the snail infection test was selected, with particular emphasis on optimising its reliability. Snail-infection experiments showed that B. truncatus and B. senegalensis are very good potential vectors, with infection rates ranging between 71.5 and 85.9%. B. globosus and B. forskalii, on the other hand, are totally incompatible. The mean infection percentages in the sympatric and allopatric combinations carried out with the S. haematobium-B. truncatus couple were very similar. This character strongly suggests a lack of isolation in schistosome populations and a circulation of the parasite genome through the mobility of infected human populations (Peuls and Touaregs) in Sahel zone. This study, in relation with snail surveys carried out in parallel, shows that the main types of aquatic environments on the Niger act as high risk areas for schistosome transmission. PMID:2382092

Véra, C; Jourdane, J; Sellin, B; Combes, C

1990-06-01

76

Survey of the relative prevalence of potential yellow fever vectors in north-west Nigeria.  

Science.gov (United States)

The yellow fever epidemic in Nigeria in 1969-70 emphasized the lack of data concerning the possible importance of Aedes aegypti and other Stegomyia mosquitos as vectors. An entomological survey was therefore undertaken in September 1973 in 6 areas in the north-west of Nigeria to determine the prevalence of Stegomyia populations in the villages. An examination of over 6 700 water pots showed that 11-53% contained A. aegypti larvae, and in some areas larvae of A. vittatus were found in up to 18% of pots. In villages in the relatively dry Sudan savanna neither leaf axils nor tree-holes were important Stegomyia larval habitats, but in the more southern Kontagora area of the wetter northern Guinea savanna, these habitats were probably important breeding sites. In the early evening the most abundant man-biting mosquito in the villages was A. aegypti. A. vittatus was also caught at bait in some villages. It was concluded that the only potential yellow fever vectors in the area were A. aegypti and A. vittatus. There were large populations of A. aegypti, closely associated with man, in all the areas surveyed, but they should not present a risk of yellow fever transmission unless the disease were to be introduced into the area by man, or unless virus reservoirs, such as monkeys, were also present. Although monkeys were common in the Kontagora area they were rare in the Sudan savanna. PMID:4156499

Service, M W

1974-01-01

77

Larvicidal potential of silver nanoparticles synthesized from Leucas aspera leaf extracts against dengue vector Aedes aegypti.  

Science.gov (United States)

Vector-borne diseases caused by mosquitoes are one of the major economic and health problems in many countries. The Aedes aegypti mosquito is a vector of several diseases in humans like yellow fever and dengue. Vector control methods involving the use of chemical insecticides are becoming less effective due to development of insecticides resistance, biological magnification of toxic substances through the food chain, and adverse effects on environmental quality and non-target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are nontoxic, easily available at affordable prices, biodegradable, and show broad-spectrum target-specific activities against different species of vector mosquitoes. Today, nanotechnology is a promising research domain which has wide-ranging application vector control programs. The present study investigates the larvicidal potential of solvent leaf extracts of Leucas aspera and synthesized silver nanoparticles using aqueous leaf extract against fourth instar larvae of Aedes aegypti. Larvae were exposed to varying concentrations of plant extracts and synthesized AgNPs for 24 h. The results were recorded from UV-Vis spectra, x-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM), and were used to characterize and support the biosynthesis of silver nanoparticles. The formation of the AgNPs synthesized from the XRD spectrum compared with Bragg reflections can be indexed to the (111) orientations, respectively, confirmed the presence of AgNPs. The FT-IR spectra of AgNPs exhibited prominent peaks at 3,447.77; 2,923.30; and 1,618.66 cm(-1). The spectra showed sharp and strong absorption band at 1,618.66 cm(-1) assigned to the stretching vibration of (NH) C?O group. The band 1,383 developed for C?C and C?N stretching, respectively, and was commonly found in the proteins. SEM analysis of the synthesized AgNPs clearly showed the clustered and irregular shapes, mostly aggregated, and having the size of 25-80 nm. Energy-dispersive x-ray spectroscopy showed the complete chemical composition of the synthesized AgNPs. In larvicidal activity, the results showed that the maximum efficacy was observed in synthesized AgNPs leaf extracts against the fourth instar larvae of A. aegypti (LC50 values of 8.5632, 10.0361, 14.4689, 13.4579, 17.4108, and 27.4936 mg/l) and (LC90 values of 21.5685, 93.03928, 39.6485, 42.2029, 31.3009, and 53.2576 mg/l), respectively. These results suggest that the synthesized AgNPs leaf extracts have a higher larvicidal potential as compared to crude solvent extracts thus making them an effective combination for controlling A. aegypti. PMID:24553980

Suganya, Ganesan; Karthi, Sengodan; Shivakumar, Muthugounder S

2014-05-01

78

BCI Based Wheelchair Control Using Steady State Visual Evoked Potentials and Support Vector Machines  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a Steady State Visual Evoked Potential (SSVEP based Brain Computer Interface (BCI system to control a wheelchair in forward, backward, left, right and in stop positions. Four different flickering frequencies in low frequency region were used to elicit the SSVEPs and were displayed on a Liquid Crystal Display (LCD monitor using LabVIEW. The Electroencephalogram (EEG signals recorded from the occipital region were first segmented into 1 second window and features were extracted by using Fast Fourier Transform (FFT. Three different classifiers, two based on Artificial Neural Network (ANN and one based on Support Vector Machine (SVM were designed and compared to yield better accuracy. Ten subjects were participated in the experiment and the accuracy was calculated by considering the number of correct detections produced while performing a predefined movement sequence. One-Against-All (OAA based multiclass SVM classifier showed better accuracy than the ANN classifiers.

Rajesh Singla

2013-07-01

79

New gastropod vectors and tetrodotoxin potential expansion in temperate waters of the Atlantic Ocean.  

Science.gov (United States)

Tetrodotoxin is a potent low weight marine toxin found in warm waters, especially of the Indian and Pacific Oceans. Intoxications are usually linked to the consumption of the puffer fish, although TTX was already detected in several different edible taxa. Benthic organisms such as mollusks and echinoderms, with different feeding habits, were collected monthly along the Portuguese coast from the summer of 2009 until the end of 2010. The extraction and analysis techniques were optimized and TTX and some analogues were detected for the first time in two intertidal gastropod species-Gibbula umbilicalis and Monodonta lineata by LC-MS/MS and UPLC-MS/MS. Although the levels are low, these findings suggest that monitoring of TTX and analogues in North Atlantic species should be implemented so as to detect potentially new toxin vectors and seasonal and/or geographical patterns. PMID:22690139

Silva, Marisa; Azevedo, Joana; Rodriguez, Paula; Alfonso, Amparo; Botana, Luis M; Vasconcelos, Vítor

2012-04-01

80

New Gastropod Vectors and Tetrodotoxin Potential Expansion in Temperate Waters of the Atlantic Ocean  

Directory of Open Access Journals (Sweden)

Full Text Available Tetrodotoxin is a potent low weight marine toxin found in warm waters, especially of the Indian and Pacific Oceans. Intoxications are usually linked to the consumption of the puffer fish, although TTX was already detected in several different edible taxa. Benthic organisms such as mollusks and echinoderms, with different feeding habits, were collected monthly along the Portuguese coast from the summer of 2009 until the end of 2010. The extraction and analysis techniques were optimized and TTX and some analogues were detected for the first time in two intertidal gastropod species—Gibbula umbilicalis and Monodonta lineata by LC-MS/MS and UPLC-MS/MS. Although the levels are low, these findings suggest that monitoring of TTX and analogues in North Atlantic species should be implemented so as to detect potentially new toxin vectors and seasonal and/or geographical patterns.

Vítor Vasconcelos

2012-03-01

 
 
 
 
81

A Survey on Potential of the Support Vector Machines in Solving Classification and Regression Problems  

Directory of Open Access Journals (Sweden)

Full Text Available Kernel methods and support vector machines have become the most popular learning from examples paradigms. Several areas of application research make use of SVM approaches as for instance hand written character recognition, text categorization, face detection, pharmaceutical data analysis and drug design. Also, adapted SVM’s have been proposed for time series forecasting and in computational neuroscience as a tool for detection of symmetry when eye movement is connected with attention and visual perception. The aim of the paper is to investigate the potential of SVM’s in solving classification and regression tasks as well as to analyze the computational complexity corresponding to different methodologies aiming to solve a series of afferent arising sub-problems.

Luminita STATE

2010-01-01

82

Exact Klein-Gordon equation with spatially dependent masses for unequal scalar-vector Coulomb-like potentials  

International Nuclear Information System (INIS)

We study the effect of spatially dependent mass functions over the solution of the Klein-Gordon equation in the (3+1)-dimensions for spinless bosonic particles where the mixed scalar-vector Coulomb-like field potentials and masses are directly proportional and inversely proportional to the distance from the force center. The exact bound-state energy eigenvalues and the corresponding wave functions of the Klein-Gordon equation for mixed scalar-vector and pure scalar Coulomb-like field potentials are obtained by means of the Nikiforov-Uvarov (NU) method. The energy spectrum is discussed for different scalar-vector potential mixing cases and also for the constant-mass case. (orig.)

2009-05-01

83

Aedes albopictus (Diptera: Culicidae) as a potential vector of endemic and exotic arboviruses in Australia.  

Science.gov (United States)

In 2005, established populations of Aedes albopictus (Skuse) were discovered in the Torres Strait, the region that separates Papua New Guinea from northern Australia. This increased the potential for this species to be introduced to mainland Australia. Because it is an arbovirus vector elsewhere, we undertook laboratory-based infection and transmission experiments to determine the potential for Ae. albopictus from the Torres Strait to become infected with and transmit the four major Australian endemic arboviruses--Murray Valley encephalitis virus, West Nile virus Kunjin strain (WNV(KUN)), Ross River virus (RRV), and Barmah Forest virus--as well as the exotic Japanese encephalitis virus. Ae. albopictus is susceptible to infection with all viruses, with infection rates ranging between 8% for WNV(KUN) and 71% for RRV. Transmission rates of approximately 25% were observed for RRV and Barmah Forest virus, but these were chikungunya virus. Despite lower body titers, more mosquitoes reared and maintained at 28 degrees C became infected with and transmitted the virus than those reared and maintained at 22 degrees C. The minimum time between Ae. albopictus consuming an infected bloodmeal and transmitting chikungunya virus was 2 d at 28 degrees C and 4 d at 22 degrees C, and for RRV, it was 4 d, irrespective of the temperature. Given its opportunistic feeding habits and aggressive biting behavior, the establishment of Ae. albopictus on the Australian mainland could have a considerable impact on alphavirus transmission. PMID:24897860

Nicholson, J; Ritchie, S A; van den Hurk, A F

2014-05-01

84

Solution of the D-dimensional Klein-Gordon equation with equal scalar and vector ring-shaped pseudoharmonic potential  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present the exact solution of the Klein-Gordon equation in D-dimensions in the presence of the noncentral equal scalar and vector pseudoharmonic potential plus the new ring-shaped potential using the Nikiforov-Uvarov method. We obtain the exact bound-state energy levels and the corresponding eigen functions for a spin-zero particles. We also find that the solution for this noncentral ring-shaped pseudoharmonic potential can be reduced to the three-dimensional pseudoharmon...

Ikhdair, Sameer M.; Sever, Ramazan

2008-01-01

85

Bound states of the Klein-Gordon equation with vector and scalar Rosen-Morse-type potentials  

International Nuclear Information System (INIS)

Solving Klein-Gordon equation with equal scalar and vector Rosen-Morse-type potentials, we obtain the exact energy equation for the s-wave bound states. It has been shown that the energy equations and corresponding wavefunctions for the standard Rosen-Morse well, Eckart potential and their PT-symmetric versions are included in those for Rosen-Morse-type potential as special cases

2004-12-06

86

Bound states of the s-wave Klein-Gordon equation with equal scalar and vector Standard Eckart Potential  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A supersymmetric technique for the bound-state solutions of the s-wave Klein--Gordon equation with equal scalar and vector standard Eckart type potential is proposed. Its exact solutions are obtained. Possible generalization of our approach is outlined.

Olgar, Eser; Koc, Ramazan; Tutunculer, Hayriye

2006-01-01

87

Solutions to the Klein—Gordon Equation with Equal Scalar and Vector Modified Hylleraas Plus Exponential Rosen Morse Potentials  

International Nuclear Information System (INIS)

We present the bound-state solutions to the Klein—Gordon equation with equal scalar and vector modified Hylleraas plus exponential Rosen Morse potentials using the parametric Nikiforov—Uvarov method. We use the elegant approximation scheme to the centrifugal term. The bound state energy eigenvalues and the corresponding wave function are obtained. We also discuss the special cases. (general)

2012-06-01

88

An eddy current vector potential formulation for estimating hysteresis losses of superconductors with FEM  

International Nuclear Information System (INIS)

Many people these days employ only commercial finite element method (FEM) software when solving for the hysteresis losses of superconductors. Thus, the knowledge of a modeller is in the capability of using the black boxes of software efficiently. This has led to a relatively superficial examination of different formulations while the discussion stays mainly on the usage of the user interfaces of these programs. Also, if we stay only at the mercy of commercial software producers, we end up having less and less knowledge on the details of solvers. Then, it becomes more and more difficult to conceptually solve new kinds of problem. This may prevent us finding new kinds of method to solve old problems more efficiently, or finding a solution for a problem that was considered almost impossible earlier. In our earlier research, we presented the background of a co-tree gauged T-? FEM solver for computing the hysteresis losses of superconductors. In this paper, we examine the feasibility of FEM and eddy current vector potential formulation in the same problem.

2010-12-01

89

Exact analytical solution to the relativistic Klein-Gordon equation with noncentral equal scalar and vector potentials  

International Nuclear Information System (INIS)

We present an alternative and simple method for the exact solution of the Klein-Gordon equation in the presence of the noncentral equal scalar and vector potentials by using Nikiforov-Uvarov method. The exact bound state energy eigenvalues and corresponding eigenfunctions are obtained for a particle bound in a potential of V(r,?)=?/r+?/(r2 sin2 ?)+?cos ?/(r2 sin2 ?) type

2006-08-01

90

S-wave baryons in an equally mixed scalar-vector square root potential model of independent quarks  

International Nuclear Information System (INIS)

A relativistic model of independent quarks based on Dirac equation with an equally mixed scalar-vector square root confining potential is used to compute the quark core contributions to the static properties like magnetic moments, charge radii and axial vector coupling constant ratios of the baryon octet. The results obtained with appropriate corrections due to centre-of-mass motion agree fairly well with experimental values. The model is also extended to the study of magnetic moments of the quark core of baryons in the charmed and b-flavoured sectors and the overall predictions so obtained compare well with other model predictions. (author). 71 refs., 6 tabs

1995-04-01

91

Overcoming drug resistance of MCF-7/ADR cells by altering intracellular distribution of doxorubicin via MVP knockdown with a novel siRNA polyamidoamine-hyaluronic acid complex.  

Science.gov (United States)

Drug resistance is one of the critical reasons leading to failure in chemotherapy. Enormous studies have been focused on increasing intracellular drug accumulation through inhibiting P-glycoprotein (Pgp). Meanwhile, we found that major vault protein (MVP) may be also involved in drug resistance of human breast cancer MCF-7/ADR cells by transporting doxorubicin (DOX) from the action target (i.e. nucleus) to cytoplasma. Herein polyamidoamine (PAMAM) dendrimers was functionalized by a polysaccharide hyaluronic acid (HA) to effectively deliver DOX as well as MVP targeted small-interfering RNA (MVP-siRNA) to down regulate MVP expression and improve DOX chemotherapy in MCF-7/ADR cells. In comparison with DOX solution (IC50=48.5 ?M), an enhanced cytotoxicity could be observed for DOX PAMAM-HA (IC50=11.3 ?M) as well as enhanced tumor target, higher intracellular accumulation, increased blood circulating time and less in vivo toxicity. Furthermore, codelivery of siRNA and DOX by PAMAM-HA exhibited satisfactory gene silencing effect as well as enhanced stability and efficient intracellular delivery of siRNA, which allowed DOX access to nucleus and induced subsequent much more cytotoxicity than siRNA absent case as a result of MVP knockdown. This observation highlights a promising application of novel nanocarrier PAMAM-HA, which could co-deliver anticancer drug and siRNA, in reversing drug resistance by altering intracellular drug distribution. PMID:22940126

Han, Min; Lv, Qing; Tang, Xin-Jiang; Hu, Yu-Lan; Xu, Dong-Hang; Li, Fan-Zhu; Liang, Wen-Quan; Gao, Jian-Qing

2012-10-28

92

Nucleus-Nucleus (Non-monotonic Potentials and Vector Analyzing Powers of 6Li Scattering by 16O  

Directory of Open Access Journals (Sweden)

Full Text Available The data on the elastic scattering cross-section (CS and vector analyzing power (VAP of 6Li incident on 16O nuclei is analyzed in terms of an optical model (OM potential, the real part of which is generated from a realistic two-nucleon interaction using the energy-density functional (EDF formalism. The EDF-generated real part of the potential is non-monotonic (NM in nature. This NM real potential part, without any renormalization, along with an emperically determined imaginary part and spin-orbit potential, embodying theunderlying physics of projectile excitation, can successfully account for both CS and VAP data in all cases.

Pretam k. Das, samiron k. Saha

2013-11-01

93

Solution of the $D$-dimensional Klein-Gordon equation with equal scalar and vector ring-shaped pseudoharmonic potential  

CERN Document Server

We present the exact solution of the Klein-Gordon equation in $D$-dimensions in the presence of the noncentral equal scalar and vector pseudoharmonic potential plus the new ring-shaped potential using the Nikiforov-Uvarov method. We obtain the exact bound-state energy levels and the corresponding eigen functions for a spin-zero particles. We also find that the solution for this noncentral ring-shaped pseudoharmonic potential can be reduced to the three-dimensional pseudoharmonic solution once the coupling constant of the noncentral part of the potential becomes zero.

Sever, Sameer M Ikhdair a nd Ramazan

2008-01-01

94

On the nonminimal vector coupling in the Duffin-Kemmer-Petiau theory and the confinement of massive bosons by a linear potential  

International Nuclear Information System (INIS)

The vector couplings in the Duffin-Kemmer-Petiau (DKP) theory have been revised. It is shown that minimal and nonminimal vector potentials behave differently under charge-conjugation and time-reversal transformations. In particular, it is shown that nonminimal vector potentials have been erroneously applied to the description of elastic meson-nucleus scatterings and that the space component of the nonminimal vector potential plays a crucial role for the confinement of bosons. The DKP equation with nonminimal vector linear potentials is mapped into the nonrelativistic harmonic oscillator problem and the behavior of the solutions for this sort of DKP oscillator is discussed in detail. Furthermore, the absence of Klein's paradox and the localization of bosons in the presence of nonminimal vector interactions are discussed.

2010-02-05

95

A combined vector potential-scalar potential method for FE computation of 3D magnetic fields in electrical devices with iron cores  

Science.gov (United States)

A method of combined use of magnetic vector potential based finite-element (FE) formulations and magnetic scalar potential (MSP) based formulations for computation of three-dimensional magnetostatic fields is introduced. In this method, the curl-component of the magnetic field intensity is computed by a reduced magnetic vector potential. This field intensity forms the basic of a forcing function for a global magnetic scalar potential solution over the entire volume of the region. This method allows one to include iron portions sandwiched in between conductors within partitioned current-carrying subregions. The method is most suited for large-scale global-type 3-D magnetostatic field computations in electrical devices, and in particular rotating electric machinery.

Wang, R.; Demerdash, N. A.

1991-01-01

96

Vector constants of motion for time-dependent Kepler and isotropic harmonic oscillator potentials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A method of obtaining vector constants of motion for time-independent as well as time-dependent central fields is discussed. Some well-established results are rederived in this alternative way and new ones obtained.

Ritter, O. M.; Santos, F. C.; Tort, A. C.

2000-01-01

97

Evaluations of physical parameters of HEU and LEU fuel assemblies used in Dalat nuclear research reactor using MVP code  

International Nuclear Information System (INIS)

Lattice cell calculations for VVR-M2 fuel assemblies of DaLat Nuclear Research reactor were performed using Monte Carlo code MVP. The physical parameters like infinite multiplication factors, few group constants, neutron flux distributions and temperature effects were investigated for both HEU and LEU configurations. The infinite multiplication factor and thermal neutron flux for LEU fuel are lower than HEU one. In order to effectively use Monte Carlo codes the high performance computing with cluster technique is proposed for large problems. (author)

2007-11-01

98

Maximizing sparse matrix vector product performance in MIMD computers  

Energy Technology Data Exchange (ETDEWEB)

A considerable component of the computational effort involved in conjugate gradient solution of structured sparse matrix systems is expended during the Matrix-Vector Product (MVP), and hence it is the focus of most efforts at improving performance. Such efforts are hindered on MIMD machines due to constraints on memory, cache and speed of memory-cpu data transfer. This paper describes a strategy for maximizing the performance of the local computations associated with the MVP. The method focuses on single stride memory access, and the efficient use of cache by pre-loading it with data that is re-used while bypassing it for other data. The algorithm is designed to behave optimally for varying grid sizes and number of unknowns per gridpoint. Results from an assembly language implementation of the strategy on the iPSC/860 show a significant improvement over the performance using FORTRAN.

McLay, R.T.; Kohli, H.S.; Swift, S.L.; Carey, G.F.

1994-12-31

99

Potential vectors of West Nile virus following an equine disease outbreak in Italy.  

Science.gov (United States)

In the late summer of 1998, an outbreak of equine encephalomyelitis due to West Nile virus (WNV) occurred in the Tuscany region of central Italy. The disease was detected in 14 race horses from nine localities in four Provinces: Firenze, Lucca, Pisa and Pistoia. The outbreak area included Fucecchio wetlands (1800 ha), the largest inland marsh in Italy, and the adjacent hilly Cerbaie woodlands with farms breeding horses. To detect potential vectors of WNV, entomological surveys of Fucecchio and Cerbaie were undertaken during 1999-2002 by collecting mosquito larvae from breeding sites and adult mosquitoes by several methods of sampling. Among 6023 mosquitoes (Diptera: Culicidae) collected, 11 species were identified: Aedes albopictus (Skuse), Ae. vexans (Meigen), Anopheles atroparvus Van Thiel, An. maculipennis Meigen s.s., An. plumbeus Stephens, Culex impudicus Ficalbi, Cx. pipiens L., Culiseta longiareolata Macquart), Ochlerotatus caspius (Pallas), Oc. detritus (Haliday) and Oc. geniculatus (Olivier). In Fucecchio marshes, Cx. impudicus predominated with seasonal peak densities in spring and autumn: its greatest abundance during early spring coincides with arrival of migratory birds from Africa. In Cerbaie hills, Cx. pipiens predominated with peak population density in late summer. No viruses were isolated from 665 mosquitoes processed. These findings, plus other data on Italian mosquito bionomics, suggest a possible mode of WNV transmission involving the most abundant Culex in the Fucecchio-Cerbaie areas. Culex impudicus, being partly ornithophilic, might transmit WNV from migratory to non-migratory birds during springtime; Cx. pipiens, having a broader host range, would be more likely to transmit WNV from birds to horses and, perhaps, to humans by late summer. PMID:15009441

Romi, R; Pontuale, G; CIufolini, M G; Fiorentini, G; Marchi, A; Nicoletti, L; Cocchi, M; Tamburro, A

2004-03-01

100

Influence of pulsed electromagnetic and pulsed vector magnetic potential field on the growth of tumor cells.  

Science.gov (United States)

Abstract Aims and Background: Tumor diseases cause 20% of deaths in Europe and they are the second most common cause of death and morbidity after cardiovascular diseases. Thus, tumor cells are target of many therapeutic strategies and tumor research is focused on searching more efficient and specific drugs as well as new therapeutic approaches. One of the areas of tumor research is an issue of external fields. In our work, we tested influence of a pulsed electromagnetic field (PEMF) and a hypothetic field of the pulsed vector magnetic potential (PVMP) on the growth of tumor cells; and further the possible growth inhibition effect of the PVMP. Methods: Both unipolar and bipolar PEMF fields of 5?mT and PVMP fields of 0?mT at frequencies of 15?Hz, 125?Hz and 625?Hz were tested on cancer cell lines derived from various types of tumors: CEM/C2 (acute lymphoblastic leukemia), SU-DHL-4 (B-cell lymphoma), COLO-320DM (colorectal adenocarcinoma), MDA-BM-468 (breast adenocarcinoma), and ZR-75-1 (ductal carcinoma). Cell morphology was observed, proliferation activity using WST assay was measured and simultaneous proportion of live, early apoptotic and dead cells was detected using flow cytometry. Results: A PEMF of 125?Hz and 625?Hz for 24?h-48?h increased proliferation activity in the 2 types of cancer cell lines used, i.e. COLO-320DM and ZR-75-1. In contrast, any of employed methods did not confirm a significant inhibitory effect of hypothetic PVMP field on tumor cells. PMID:23781986

Loja, Tomas; Stehlikova, Olga; Palko, Lukas; Vrba, Kamil; Rampl, Ivan; Klabusay, Martin

2013-06-19

 
 
 
 
101

Zoom in at African country level: potential climate induced changes in areas of suitability for survival of malaria vectors  

Science.gov (United States)

Background Predicting anopheles vectors’ population densities and boundary shifts is crucial in preparing for malaria risks and unanticipated outbreaks. Although shifts in the distribution and boundaries of the major malaria vectors (Anopheles gambiae s.s. and An. arabiensis) across Africa have been predicted, quantified areas of absolute change in zone of suitability for their survival have not been defined. In this study, we have quantified areas of absolute change conducive for the establishment and survival of these vectors, per African country, under two climate change scenarios and based on our findings, highlight practical measures for effective malaria control in the face of changing climatic patterns. Methods We developed a model using CLIMEX simulation platform to estimate the potential geographical distribution and seasonal abundance of these malaria vectors in relation to climatic factors (temperature, rainfall and relative humidity). The model yielded an eco-climatic index (EI) describing the total favourable geographical locations for the species. The EI values were classified and exported to a GIS package. Using ArcGIS, the EI shape points were clipped to the extent of Africa and then converted to a raster layer using Inverse Distance Weighted (IDW) interpolation method. Generated maps were then transformed into polygon-based geo-referenced data set and their areas computed and expressed in square kilometers (km2). Results Five classes of EI were derived indicating the level of survivorship of these malaria vectors. The proportion of areas increasing or decreasing in level of survival of these malaria vectors will be more pronounced in eastern and southern African countries than those in western Africa. Angola, Ethiopia, Kenya, Mozambique, Tanzania, South Africa and Zambia appear most likely to be affected in terms of absolute change of malaria vectors suitability zones under the selected climate change scenarios. Conclusion The potential shifts of these malaria vectors have implications for human exposure to malaria, as recrudescence of the disease is likely to be recorded in several new areas and regions. Therefore, the need to develop, compile and share malaria preventive measures, which can be adapted to different climatic scenarios, remains crucial.

2014-01-01

102

Bovine herpesvirus 4 based vector as a potential oncolytic-virus for treatment of glioma  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The application of gene therapy for malignant gliomas is still under study and the use of specific vectors represents an important contribution. Here, we investigated bovine herpesvirus 4 (BoHV-4, which is non-pathogenic if injected into the rodent brain. We show that the vector can infect mouse, rat and human glioma cell lines and primary cultures obtained from human glioblastoma in vitro. BoHV-4 was injected into a tumour grown in rat brain. Although virus expression was scattered across the tumour mass, it was mainly located in the peripheral area of larger gliomas. These data support BoHV-4 as a candidate vector for glioma treatment.

D'Avella Domenico

2010-11-01

103

Phlebotomine sand flies (Diptera, Psychodidae) from Rio de Janeiro State, Brazil: species distribution and potential vectors of leishmaniases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Phlebotomine sand flies (Diptera, Psychodidae) from Rio de Janeiro State, Brazil: Species distribution and potential vectors of leishmaniases. Rio de Janeiro State, in Brazil, has endemic areas of both cutaneous and visceral leishmaniases. In these areas, entomologic surveillance actions are highly [...] recommended by Brazil's Ministry of Health. The present work describes the results of sand fly captures performed by the Health Department of Rio de Janeiro State between 2009 and 2011 in several municipalities. An updated species list and distribution of phlebotomine sand flies in the state are provided based on an extensive literature review. Currently, the sand fly fauna of Rio de Janeiro State has 65 species, belonging to the genera Brumptomyia (8 spp.) and Lutzomyia (57 spp.). Distribution maps of potential leishmaniases vector species Lutzomyia (Nyssomyia) intermedia, L. migonei, L. (N.) whitmani, L. (N.) flaviscutellata and L. (Lutzomyia) longipalpis are provided and their epidemiological importance is discussed.

Carvalho, Bruno Moreira; Dias, Cristina Maria Giordano; Rangel, Elizabeth Ferreira.

104

Host-Feeding Pattern of Culex theileri (Diptera: Culicidae), Potential Vector of Dirofilaria immitis in the Canary Islands, Spain  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To identify the host range of potential vectors of Diro?laria immitis Leidy, the causal agent of canine diroÞlariasis, we studied the bloodmeal origin of mosquitoes trapped on two of the Canary Islands, Gran Canaria and Tenerife, where this disease is considered hyperendemic. On Gran Canaria, mosquitoes were captured using Centers for Disease Control and Prevention (CDC) traps (outdoors) and resting in a bathroom (indoors). Only CDC traps were used to capture mosquitoes in Tenerife. The ...

2012-01-01

105

Rotational and vibrational diatomic molecule in the Klein-Gordon equation with hyperbolic scalar and vector potentials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present an approximate analytic solution of the Klein-Gordon equation in the presence of equal scalar and vector generalized deformed hyperbolic potential functions by means of parameteric generalization of the Nikiforov-Uvarov method. We obtain the approximate bound state rotational-vibrational (ro-vibrational) energy levels and the corresponding normalized wave functions expressed in terms of the Jacobi polynomial for a spin-zero particle in a closed form. Special cases...

Ikhdair, Sameer M.

2009-01-01

106

Virtual screening of potential bioactive substances using the support vector machine approach  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Die vorliegende Dissertation stellt eine kumulative Arbeit dar, die in insgesamt acht wissenschaftlichen Publikationen (fünf publiziert, zwei eingerichtet und eine in Vorbereitung) dargelegt ist. In diesem Forschungsprojekt wurden Anwendungen von maschinellem Lernen für das virtuelle Screening von Moleküldatenbanken durchgeführt. Das Ziel war primär die Einführung und Überprüfung des Support-Vector-Machine (SVM) Ansatzes für das virtuelle Screening nach potentiellen Wirkstoffkandidat...

Byvatov, Evgeny

2006-01-01

107

Dynamic polarization potential effects on vector analyzing powers of {sup 6}Li-{sup 28}Si elastic scattering from non-monotonic potentials  

Energy Technology Data Exchange (ETDEWEB)

Experimental cross section (CS) and vector analyzing power (VAP) data of the {sup 6}Li-{sup 28}Si elastic scattering at 22.8 MeV are analyzed in the coupled-channels (CC) and coupled discretized continuum channels (CDCC) methods. Non-monotonic (NM) {sup 6}Li and {alpha} potentials of microscopic origin are employed, respectively, in the CC calculations and to generate folding potentials for the CDCC calculations. The study demonstrates that the use of central NM potentials can generate an appropriate dynamic polarization potential (DPP) required to describe both the CS and VAP data without the necessity of renormalization. This also produces an effective spin-orbit (SO) potential to account for the iT{sub 11} data without the requirement of an additional static SO potential at the incident energy considered.

Basak, A.K., E-mail: akbasak@gmail.co [Department of Physics, University of Rajshahi, Rajshahi (Bangladesh); Roy, P.K. [Department of Physics, B.L. College, Daulatpur, Khulna (Bangladesh); Hossain, S. [Department of Physics, Shahjalal University of Science and Technology, Sylhet (Bangladesh); Abdullah, M.N.A. [Department of Physics, Rajshahi University of Engineering and Technology, Rajshahi (Bangladesh); Tariq, A.S.B.; Uddin, M.A. [Department of Physics, University of Rajshahi, Rajshahi (Bangladesh); Reichstein, I. [School of Computer Science, Carleton University, Ottawa, ON K1S 5B6 (Canada); Malik, F.B. [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Department of Physics, Washington University, St. Louis, MO 63130 (United States)

2010-08-16

108

Any J-state solution of the DKP equation for a vector deformed Woods-Saxon potential  

CERN Document Server

By using the Pekeris approximation, the Duffin-Kemmer-Petiau (DKP) equation is investigated for a vector deformed Woods-Saxon (dWS) potential. The parametric Nikiforov-Uvarov (NU) method is used in calculations. The approximate energy eigenvalue equation and the corresponding wave function spinor components are calculated for any total angular momentum J in closed form. The exact energy equation and wave function spinor components are also given for the J=0 case. We use a set of parameter values to obtain the numerical values for the energy states with various values of quantum levels (n,J) and potential's deformation constant q and width R.

Hamzavi, Majid

2012-01-01

109

West Nile Virus Transmission in Sentinel Chickens and Potential Mosquito Vectors, Senegal River Delta, 2008–2009  

Directory of Open Access Journals (Sweden)

Full Text Available West Nile virus (WNV is an arthropod-borne Flavivirus usually transmitted to wild birds by Culex mosquitoes. Humans and horses are susceptible to WNV but are dead-end hosts. WNV is endemic in Senegal, particularly in the Senegal River Delta. To assess transmission patterns and potential vectors, entomological and sentinel serological was done in Ross Bethio along the River Senegal. Three sentinel henhouses (also used as chicken-baited traps were set at 100 m, 800 m, and 1,300 m from the river, the latter close to a horse-baited trap. Blood samples were taken from sentinel chickens at 2-week intervals. Seroconversions were observed in sentinel chickens in November and December. Overall, the serological incidence rate was 4.6% with 95% confidence interval (0.9; 8.4 in the sentinel chickens monitored for this study. Based on abundance pattern, Culex neavei was the most likely mosquito vector involved in WNV transmission to sentinel chickens, and a potential bridge vector between birds and mammals.

Renaud Lancelot

2013-10-01

110

Species Distribution Models and Ecological Suitability Analysis for Potential Tick Vectors of Lyme Disease in Mexico  

Science.gov (United States)

Species distribution models were constructed for ten Ixodes species and Amblyomma cajennense for a region including Mexico and Texas. The model was based on a maximum entropy algorithm that used environmental layers to predict the relative probability of presence for each taxon. For Mexico, species geographic ranges were predicted by restricting the models to cells which have a higher probability than the lowest probability of the cells in which a presence record was located. There was spatial nonconcordance between the distributions of Amblyomma cajennense and the Ixodes group with the former restricted to lowlands and mainly the eastern coast of Mexico and the latter to montane regions with lower temperature. The risk of Lyme disease is, therefore, mainly present in the highlands where some Ixodes species are known vectors; if Amblyomma cajennense turns out to be a competent vector, the area of risk also extends to the lowlands and the east coast.

Illoldi-Rangel, Patricia; Rivaldi, Chissa-Louise; Sissel, Blake; Trout Fryxell, Rebecca; Gordillo-Perez, Guadalupe; Rodriguez-Moreno, Angel; Williamson, Phillip; Montiel-Parra, Griselda; Sanchez-Cordero, Victor; Sarkar, Sahotra

2012-01-01

111

Feeding Patterns of Potential West Nile Virus Vectors in South-West Spain  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Mosquito feeding behaviour determines the degree of vector-host contact and may have a serious impact on the risk of West Nile virus (WNV) epidemics. Feeding behaviour also interacts with other biotic and abiotic factors that affect virus amplification and transmission. Methodology/Principal Findings: We identified the origin of blood meals in five mosquito species from three different wetlands in SW Spain. All mosquito species analysed fed with different frequencies on birds, mam...

Mun?oz, Joaqui?n; Rui?z, Santiago; Soriguer, Ramo?n C.; Alcaide, Miguel; Viana, Duarte S.; Roiz, David; Va?zquez, Ana; Figuerola, Jordi

2012-01-01

112

DYNAMICS OF THE PLAGUE TRANSMISSION CYCLE IN CENTRAL JAVA (ECOLOGY OF POTENTIAL FLEA VECTORS  

Directory of Open Access Journals (Sweden)

Full Text Available Setelah begitu lama tidak ada laporan mengenai peristiwa penyakit pes di Indonesia, maka tiba-tiba pada tahun 1968 - 1969 dilaporkan adanya 102 penderita, 42 meninggal dan tahun 1969 - 1970 penderita, 2 meninggal. Oleh karena itu diadakan suatu penelitian untuk mendapatkan data-data ecology penyakit pes di Boyolali, Jawa Tengah. Walaupun tidak ada peningkatan jumlah penderita, pada waktu itu telah dapat diisolasi adanya bakteri pes dari binatang mengerat dan pinjal. Ini berarti transmisi masih berlangsung; terus dan selalu mengancam kesehatan penduduk. Daerah infeksi Boyolali terdapat dilereng gunung Merapi dan Merbabu diatas ketinggian 1.000 m. Tiga jenis pinjal Xenopsylla cheopis, Stivalius cognatus dan Neopsylla sondaica ada hubungannya dengan binatang menyusui didaerah tersebut. Diatas ketinggian 1.000 m S. cognatus dan N. sondaica merupakan pinjal yang paling banyak ditemukan didaerah ladang, dan X. cheopis diperumahan des Pada ketinggian kurang dari 1.000 m tidak ditemukan S. cognatus dan N. sondaica sedangkan X. cheopis ditemukan didaerah ladang dan perumahan desa. Walaupun X. cheopis merupakan vector yang effisien dan jarang ditemukan didaerah ladang maka diduga bahwa pinjal tersebut tidak utama memegang peranan dalam penularan ini. Namun demikian pada masa epizootik X. cheopis mempunyai peranan pada siklus penularan antara binatang menyusui, binatang mengerat dan manusia. Sedangkan S. cognatus diduga merupakan vector utama, dan N. sondaica vector kedua, pada penularan pes. Jarangnya vector pada daerah ketinggian kurang 1.000 m, memperlihatkan bahwa pes di Jawa bersifat pegunungan. Kepadatan binatang menyusui yang merupakan reservoir utama dari penyakit pes yaitu Rattus exulans dan tiomanicus lebih banyak pada daerah ketinggian diatas 1.000 m. Binatang mengerat dan pinjal jarang ditemukan didaerah ladang, sedangkan jenis hutan di pinggiran sering ditemukan didaerah tempat tinggal, sehingga mengakibatkan kemungkinan terjadinya penularan penyakit pes pada manusia. Pengamatan pendahuluan menunjukkan bahwa berbagai jenis pinjal hidup pada binatang menyusui yang paling sering ditemukan saja baik diladang maupun di perumahan.

Soeharto Arimbi Padmowiryono

2012-09-01

113

Vectorization, parallelization and porting of nuclear codes (vectorization and parallelization). Progress report fiscal 1998  

International Nuclear Information System (INIS)

Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 12 codes in fiscal 1998. These results are reported in 3 parts, i.e., the vectorization and parallelization on vector processors part, the parallelization on scalar processors part and the porting part. In this report, we describe the vectorization and parallelization on vector processors. In this vectorization and parallelization on vector processors part, the vectorization of General Tokamak Circuit Simulation Program code GTCSP, the vectorization and parallelization of Molecular Dynamics NTV (n-particle, Temperature and Velocity) Simulation code MSP2, Eddy Current Analysis code EDDYCAL, Thermal Analysis Code for Test of Passive Cooling System by HENDEL T2 code THANPACST2 and MHD Equilibrium code SELENEJ on the VPP500 are described. In the parallelization on scalar processors part, the parallelization of Monte Carlo N-Particle Transport code MCNP4B2, Plasma Hydrodynamics code using Cubic Interpolated Propagation Method PHCIP and Vectorized Monte Carlo code (continuous energy model / multi-group model) MVP/GMVP on the Paragon are described. In the porting part, the porting of Monte Carlo N-Particle Transport code MCNP4B2 and Reactor Safety Analysis code RELAP5 on the AP3000 are described. (author)

2000-01-01

114

Vectorization, parallelization and porting of nuclear codes (vectorization and parallelization). Progress report fiscal 1998  

Energy Technology Data Exchange (ETDEWEB)

Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 12 codes in fiscal 1998. These results are reported in 3 parts, i.e., the vectorization and parallelization on vector processors part, the parallelization on scalar processors part and the porting part. In this report, we describe the vectorization and parallelization on vector processors. In this vectorization and parallelization on vector processors part, the vectorization of General Tokamak Circuit Simulation Program code GTCSP, the vectorization and parallelization of Molecular Dynamics NTV (n-particle, Temperature and Velocity) Simulation code MSP2, Eddy Current Analysis code EDDYCAL, Thermal Analysis Code for Test of Passive Cooling System by HENDEL T2 code THANPACST2 and MHD Equilibrium code SELENEJ on the VPP500 are described. In the parallelization on scalar processors part, the parallelization of Monte Carlo N-Particle Transport code MCNP4B2, Plasma Hydrodynamics code using Cubic Interpolated Propagation Method PHCIP and Vectorized Monte Carlo code (continuous energy model / multi-group model) MVP/GMVP on the Paragon are described. In the porting part, the porting of Monte Carlo N-Particle Transport code MCNP4B2 and Reactor Safety Analysis code RELAP5 on the AP3000 are described. (author)

Ishizuki, Shigeru; Kawai, Wataru; Nemoto, Toshiyuki [Fujitsu Ltd., Tokyo (Japan); Ogasawara, Shinobu; Kume, Etsuo; Adachi, Masaaki; Kawasaki, Nobuo [Center for Promotion of Computational Science and Engineering (Tokai Site), Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Yatake, Yo-ichi [Hitachi Ltd., Tokyo (Japan)

2000-03-01

115

The potential of a new larviciding method for the control of malaria vectors  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Malaria pathogens are transmitted to humans by the bite of female Anopheles mosquitoes. The juvenile stages of these mosquitoes develop in a variety of water bodies and are key targets for vector control campaigns involving the application of larvicides. The effective operational implementation of these campaigns is difficult, time consuming, and expensive. New evidence however, suggests that adult mosquitoes can be co-opted into disseminating larvicides in a far more targeted and efficient manner than can be achieved using conventional methods.

Devine Gregor J

2010-05-01

116

Effects of medium composition on the production of plasmid DNA vector potentially for human gene therapy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Plasmid vector is increasingly applied to gene therapy or gene vaccine. The production of plasmid pCMV-AP3 for cancer gene therapy was conducted in a modified MBL medium using a recombinant E. coli BL21 system. The effects of different MMBL components on plasmid yield, cell mass and specific plasmid DNA productivity were evaluated on shake-flask scale. The results showed that glucose was the optimal carbon source. High plasmid yield (58.3 mg/L) was obtained when 5.0 g/L glucose was added to M...

2005-01-01

117

Potential Vectors of Dirofilaria immitis (Leidy, 1856) in Itacoatiara, Oceanic Region of Niterói Municipality, State of Rio de Janeiro, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Dirofilaria immitis is a widespread mosquito-borne parasite that causes dirofilariasis, a commonly diagnosed disease of dogs that is rarely reported in cats and humans. A mosquito survey was conducted in Itacoatiara in the State of Rio de Janeiro, from March 1995 to February 1996, using canine, feli [...] ne and human baits. A total of 3,667 mosquitoes were dissected for D. immitis larvae, representing 19 species and 10 genera. From those, Ae. scapularis, Ae taeniorhynchus, Cx. quinquefasciatus, Cx. declarator, Cx. saltanensis and Wy. bourrouli were found infected with D. immitis parasites, and among those, only the first three harbored infective larvae. The majority of larvae were found in the Malpighian tubules (889/936), and larval melanization was observed in the two Aedes species. In descending order, the best vectors were Ae. scapularis, Ae. taeniorhynchus, and Cx. quinquefasciatus which alternate seasonally in importance. Cx. quinquefasciatus is suggested to be a vector to cats. The potential transmission of D. immitis parasites by these three vectors to man is discussed.

Norma, Labarthe; Maria Lúcia, Serrão; Yuri Fontenele, Melo; Sebastião José de, Oliveira; Ricardo, Lourenço-de-Oliveira.

118

Potential Vectors of Dirofilaria immitis (Leidy, 1856 in Itacoatiara, Oceanic Region of Niterói Municipality, State of Rio de Janeiro, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Dirofilaria immitis is a widespread mosquito-borne parasite that causes dirofilariasis, a commonly diagnosed disease of dogs that is rarely reported in cats and humans. A mosquito survey was conducted in Itacoatiara in the State of Rio de Janeiro, from March 1995 to February 1996, using canine, feline and human baits. A total of 3,667 mosquitoes were dissected for D. immitis larvae, representing 19 species and 10 genera. From those, Ae. scapularis, Ae taeniorhynchus, Cx. quinquefasciatus, Cx. declarator, Cx. saltanensis and Wy. bourrouli were found infected with D. immitis parasites, and among those, only the first three harbored infective larvae. The majority of larvae were found in the Malpighian tubules (889/936, and larval melanization was observed in the two Aedes species. In descending order, the best vectors were Ae. scapularis, Ae. taeniorhynchus, and Cx. quinquefasciatus which alternate seasonally in importance. Cx. quinquefasciatus is suggested to be a vector to cats. The potential transmission of D. immitis parasites by these three vectors to man is discussed.

Norma Labarthe

1998-07-01

119

Developing a potentially immunologically inert tetracycline-regulatable viral vector for gene therapy in the peripheral nerve.  

Science.gov (United States)

Viral vector-mediated gene transfer of neurotrophic factors is an emerging and promising strategy to promote the regeneration of injured peripheral nerves. Unfortunately, the chronic exposure to neurotrophic factors results in local trapping of regenerating axons or other unwanted side effects. Therefore, tight control of therapeutic gene expression is required. The tetracycline/doxycycline-inducible system is considered to be one of the most promising systems for regulating heterologous gene expression. However, an immune response directed against the transactivator protein rtTA hampers further translational studies. Immunogenic proteins fused with the Gly-Ala repeat of the Epstein-Barr virus Nuclear Antigen-1 protein have been shown to successfully evade the immune system. In this article, we used this strategy to demonstrate that a chimeric transactivator, created by fusing the Gly-Ala repeat with rtTA and embedded in a lentiviral vector (i) retained its transactivator function in vitro, in muscle explants, and in vivo following injection into the rat peripheral nerve, (ii) exhibited a reduced leaky expression, and (iii) had an immune-evasive advantage over rtTA as shown in a novel bioassay for human antigen presentation. The current findings are an important step toward creating a clinically applicable potentially immune-evasive tetracycline-regulatable viral vector system. PMID:24694534

Hoyng, S A; Gnavi, S; de Winter, F; Eggers, R; Ozawa, T; Zaldumbide, A; Hoeben, R C; Malessy, M J A; Verhaagen, J

2014-06-01

120

Aphid (Hemiptera: Aphididae) species composition and potential aphid vectors of plum pox virus in Pennsylvania peach orchards.  

Science.gov (United States)

Plum pox, an invasive disease recently identified in Pennsylvania stone fruit orchards, is caused by the aphid-transmitted Plum pox virus (genus Potyvirus, family Potyviridae, PPV). To identify potential vectors, we described the aphid species communities and the seasonal dynamics of the dominant aphid species within Pennsylvania peach orchards. Aphids were trapped weekly in 2002 and 2003 from mid-April through mid-November within two central Pennsylvania orchards by using yellow and green water pan traps. In total, 42 aphid species were identified from both orchards over 2 yr. Within orchards, actual species richness ranged from 24 to 30 species. The Abundance Based Coverage Estimator predicted species richness to range from 30 to 36 species, indicating that trap catches were identifying most aphid species expected to occur in the orchard. Three species, Rhopalosiphum maidis (Fitch), Aphis spiraecola Patch, and Myzus persicae (Sulzer), were consistently dominant across locations and years. Orchard-trapped populations of these three species peaked in a similar chronological sequence each year. As expected, trap color influenced the total number and distribution of the predominate species collected. However, the same dominant species occurred in both yellow and green traps. Based on the seasonal population dynamics reported here and on published vector efficacy studies, the most probable significant PPV vector was identified as A. spiraecola. If the PPV pathogen escapes current quarantine or if subsequent reintroductions of PPV occur, these data will be useful for developing plum pox management strategies. PMID:16334309

Wallis, C M; Fleischer, S J; Luster, D; Gildow, F E

2005-10-01

 
 
 
 
121

Species Composition, Larval Habitats, Seasonal Occurrence and Distribution of Potential Malaria Vectors and Associated Species of Anopheles (Diptera: Culicidae) from the Republic of Korea.  

Science.gov (United States)

Larval mosquito habitats of potential malaria vectors and related species of Anopheles from three provinces (Gyeonggi, Gyeongsangbuk, Chungcheongbuk Provinces) of the Republic of Korea were surveyed in 2007. This study aimed to determine the species compo...

H. C. Kim L. M. Rueda S. Chong T. A. Klein T. L. Brown

2010-01-01

122

Preprocess the Photospheric Vector Magnetograms for NLFFF Extrapolation using a Potential Field Model and an Optimization Method  

CERN Multimedia

Numerical reconstruction/extrapolation of coronal nonlinear force-free magnetic field (NLFFF) usually takes the photospheric vector magnetogram as input at the bottom boundary. Magnetic field observed at the photosphere, however, contains force which is in conflict with the fundamental assumption of the force-free model and measurement noise which is unfavorable for practical computation. Preprocessing of the raw magnetogram has been proposed by Wiegelmann, Inhester, and Sakurai (2006) to remove the force and noise for providing better input for NLFFF modeling. In this paper we develop a new code of magnetogram preprocessing which is consistent with our extrapolation method CESE-MHD-NLFFF (Jiang, Feng, and Xiang, 2012; Jiang and Feng, 2012). Basing on a magnetic-splitting rule that a magnetic field can be split into a potential field part and a non-potential part, we split the magnetogram and deal with the two parts separately. Preprocessing of the magnetogram's potential part is based on a numerical potentia...

Jiang, Chaowei

2013-01-01

123

Scalar Charged Particle in Presence of Magnetic and Aharonov–Bohm Fields Plus Scalar–Vector Killingbeck Potentials  

International Nuclear Information System (INIS)

The generalized form of Killingbeck potential is an attractive Coulomb term plus a linear term and a harmonic oscillator term, i.e. ?a/r + br + ?r2, which has a useful application in quarkonium spectroscopy. The ground state energy with the corresponding wave function are obtained for any arbitrary m-state in two-dimensional Klein–Gordon equation with equal mixture of scalar–vector Killingbeck potentials in the presence of constant magnetic and singular Ahoronov–Bohm flux fields perpendicular to the plane where the interacting charged particle is confined. The analytical exact iteration method is used in our solution. We obtain the energy eigensolutions for particle and antiparticle corresponding to S(r) = V(r) and S(r) = ?V(r) cases, respectively. Some special cases like the Coulomb, harmonic oscillator potentials and the nonrelativistic limits are found in presence and absence of external fields. (author)

2013-11-01

124

Analysis of one month of CHAMP state vector and accelerometer data for the recovery of the gravity potential  

Directory of Open Access Journals (Sweden)

Full Text Available The energy conservation method is based on knowledge of the state vector and measurements of nonconservative forces. This is or will be provided by CHAMP, GRACE and GOCE. Here the analysis of one month of CHAMP state vector and accelerometer data is described. The energy conservation method is used to estimate the gravity potential at satellite altitude. When doing so we consider the tidal potential from the sun and the moon, the explicit time variation of the gravity potential in inertial space and loss of energy due to external forces. Fast Spherical Collocation have been used to estimate a gravity field model to degree and order 90, UCPH2002 04. This gravity field model is compared to EGM96 and EIGEN-2. The largest differences with respect to EGM96 are found at those places where the gravity data used to determine EGM96 had the largest uncertainty. EIGEN-2 and UCPH2002 04 are similar, though there are some differences in Antarctica and Central Asia.

E. Howe

2003-01-01

125

Survey of cyclopids (Crustacea, Copepoda in Brazil and preliminary screening of their potential as dengue vector predators  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCTION: Cyclopid copepods are known to be good mosquito controllers, specially as regards the larvae of the dengue vectors Aedes aegypti and Ae. albopictus. MATERIAL AND METHOD: The objective of the study was to survey the local copepod fauna and search for new strains of M. longisetus var. longisetus, comparing the potential of the samples found with the current strain ML-01 against Ae. albopictus larvae, under laboratory conditions. Eleven bodies of water in Campinas, SP, Brazil, were screened for copepods by collecting 1.5 l of water from each of then. The predatory potential of adults copepods was evaluated over 24 h, in the laboratory, for groups of 5 individuals preying upon 30 first instar Ae. albopictus larvae. RESULTS AND CONCLUSION: The following cyclopid species were found: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. The predatory potential of these copepods ranged from nil to 97.3%. A sample collected in the field containing only M. longisetus var. longisetus showed the best control efficiency with no significant difference from a three-year old laboratory culture (ML-01 of the same species evaluated for comparison. The sample with few M. albidus var. albidus was ranked in second place showing an average 25.9% efficiency. The use of copepods in trap tires as dengue vector controllers is discussed.

Santos Luciana Urbano dos

1997-01-01

126

Larval Bradysia impatiens (Diptera: Sciaridae) potential for vectoring Pythium root rot pathogens.  

Science.gov (United States)

A series of laboratory experiments were conducted to investigate the capacity of Bradysia impatiens (Johannsen) larvae to ingest propagules from two strains each of Pythium aphanidermatum (Edson) Fitzp. and P. ultimum Trow and transmit the pathogens to healthy geranium seedlings on a filter-paper substrate in petri dishes. The capacity of fungus gnat larvae to transmit P. aphanidermatum to seedlings rooted in a commercial peat-based potting mix and germination of Pythium oospores and hyphal swellings before and after passage through the guts of larval fungus gnats were also examined. Assays revealed that Pythium spp. transmission by larval fungus gnats varied greatly with the assay substrate and also with the number and nature of ingested propagules. Transmission was highest (65%) in the petri dish assays testing larvae fed P. aphanidermatum K-13, a strain that produced abundant oospores. Transmission of strain K-13 was much lower (potting mix. Larvae were less efficient at vectoring P. ultimum strain PSN-1, which produced few oospores, and no transmission was observed with two non-oospore-producing strains: P. aphanidermatum Pa58 and P. ultimum P4. Passage of P. aphanidermatum K-13 through larval guts significantly increased oospore germination. However, decreased germination of hyphal swellings was observed following larval gut passage for strains of P. ultimum. These results expand previous studies suggesting that larval fungus gnats may vector Pythium spp. PMID:22085299

Braun, S E; Sanderson, J P; Wraight, S P

2012-03-01

127

West Nile Virus Transmission in Sentinel Chickens and Potential Mosquito Vectors, Senegal River Delta, 2008–2009  

Digital Repository Infrastructure Vision for European Research (DRIVER)

West Nile virus (WNV) is an arthropod-borne Flavivirus usually transmitted to wild birds by Culex mosquitoes. Humans and horses are susceptible to WNV but are dead-end hosts. WNV is endemic in Senegal, particularly in the Senegal River Delta. To assess transmission patterns and potential vectors, entomological and sentinel serological was done in Ross Bethio along the River Senegal. Three sentinel henhouses (also used as chicken-baited traps) were set at 100 m, 800 m, and 1,300 m from the riv...

2013-01-01

128

ABCXYZ: vector potential (A) and magnetic field (B) code (C) for Cartesian (XYZ) geometry using general current elements  

International Nuclear Information System (INIS)

ABCXYZ is a computer code for obtaining the Cartesian components of the vector potential and the magnetic field on an observed grid from an arrangement of current-carrying wires. Arbitrary combinations of straight line segments, arcs, and loops are allowed in the specification of the currents. Arbitrary positions and orientations of the current-carrying elements are also allowed. Specification of the wire diameter permits the computation of well-defined fields, even in the interiors of the conductors. An optical feature generates magnetic field lines. Extensive graphical and printed output is available to the user including contour, grid-line, and field-line plots. 12 figures, 1 table

1976-01-01

129

Rotational and vibrational diatomic molecule in the Klein-Gordon equation with hyperbolic scalar and vector potentials  

CERN Document Server

We present an approximate analytic solution of the Klein-Gordon equation in the presence of equal scalar and vector generalized deformed hyperbolic potential functions by means of parameteric generalization of the Nikiforov-Uvarov method. We obtain the approximate bound state rotational-vibrational (ro-vibrational) energy levels and the corresponding normalized wave functions expressed in terms of the Jacobi polynomial for a spin-zero particle in a closed form. Special cases are studied including the non-relativistic solutions obtained by appropriate choice of parameters and also the s-wave solutions.

Ikhdair, Sameer M

2009-01-01

130

Approximate solution of the Duffin-Kemmer-Petiau equation for a vector Yukawa potential with arbitrary total angular momenta  

CERN Document Server

The usual approximation scheme is used to study the solution of the Duffin-Kemmer-Petiau (DKP) equation for a vector Yukawa potential in the framework of the parametric Nikiforov-Uvarov (NU) method. The approximate energy eigenvalue equation and the corresponding wave function spinor components are calculated for arbitrary total angular momentum in closed form. Further, the approximate energy equation and wave function spinor components are also given for case. A set of parameter values is used to obtain the numerical values for the energy states with various values of quantum levels

Hamzavi, Majid

2012-01-01

131

Approximate Solution of the Duffin–Kemmer–Petiau Equation for a Vector Yukawa Potential with Arbitrary Total Angular Momenta  

International Nuclear Information System (INIS)

The usual approximation scheme is used to study the solution of the Duffin–Kemmer–Petiau (DKP) equation for a vector Yukawa potential in the framework of the parametric Nikiforov-Uvarov (NU) method. The approximate energy eigenvalue equation and the corresponding wave function spinor components are calculated for any total angular momentum J in closed form. Further, the exact energy equation and wave function spinor components are also given for the J = 0 case. A set of parameter values is used to obtain the numerical values for the energy states with various values of quantum levels (n, J). (author)

2013-11-01

132

Construction of a novel zero background prokaryotic expression vector: potential advantages.  

Science.gov (United States)

A novel DNA sequence, derived from the antisense strand of the DNA gyrase inhibitor protein, CcdB, was toxic to E. coli. This protein (approximately 6 kDa) decreased the growth rate of E. coli K12 by three orders of magnitude upon induction. The expressed toxic protein in E. coli K12 was soluble while it was insoluble in induced E. coli BL21. A high efficiency prokaryotic cloning/expression vector was constructed using this toxic gene sequence and gave zero background with approximately 100% cloning efficiency requiring no dephosphorylation. The toxic gene product also affected the survival of a ccdB resistant cell line, thus indicating a different mechanism of toxicity, other than DNA gyrase inhibition, as compared to the ccdB toxicity. PMID:19690807

Mandi, Naganath; Kotwal, Prakash; Padmanabhan, Sriram

2009-12-01

133

Global climate change and its potential impact on disease transmission by salinity-tolerant mosquito vectors in coastal zones  

Directory of Open Access Journals (Sweden)

Full Text Available Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with <0.5 ppt or parts per thousand, 0.5–30 ppt and >30 ppt salt are termed fresh, brackish and saline respectively will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross-McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased coastal

RanjanRamasamy

2012-06-01

134

Curl-free vector potential observation on the macro-scale and a new dimension to the Lorentz trajectory  

International Nuclear Information System (INIS)

The recently reported curl-free vector potential observation on the macro-scale, which has been attributed to a macro-scale matter wave associated with the quantum modulation of the de Broglie wave along the magnetic field, is seen to be in apparent contravention with the Lorentz equation of classical electrodynamics, which as a descriptor on the macro-scale takes no cognizance of a curl-free vector potential. The two different formalisms—a deterministic one à la Lorentz and a probabilistic one by the quantum modulation—both existing on the macro-scale and, though in apparent contravention, complement each other and are essential for a complete description of all phenomena relating to charged particle dynamics. The quantum modulations which arise in consequence of transition across Landau levels appear as ‘hole’ auto-excitations in the Lorentz trajectory involving internal inelastic scattering. This lends a new dimension to the Lorentz trajectory which, though on the classical macro-scale, acts like a ‘quantum resonator’ and can now exist in a number of self-excited states labelled by the Landau level interval involved in the excitation, and which are of quantum origin and on the macro-scale, with the quantum modulations being the excitations. (paper)

2013-09-01

135

Predicting distribution of Aedes aegypti and Culex pipiens complex, potential vectors of Rift Valley fever virus in relation to disease epidemics in East Africa  

Science.gov (United States)

Background The East African region has experienced several Rift Valley fever (RVF) outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. Methods Diverse ecological niche modelling techniques have been developed for this purpose: we present a maximum entropy (Maxent) approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex) responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Results Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Conclusion Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods.

Mweya, Clement Nyamunura; Kimera, Sharadhuli Iddi; Kija, John Bukombe; Mboera, Leonard E. G.

2013-01-01

136

Predicting distribution of Aedes aegypti and Culex pipiens complex, potential vectors of Rift Valley fever virus in relation to disease epidemics in East Africa  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The East African region has experienced several Rift Valley fever (RVF outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. Methods: Diverse ecological niche modelling techniques have been developed for this purpose: we present a maximum entropy (Maxent approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Results: Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Conclusion: Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods.

Clement Nyamunura Mweya

2013-10-01

137

Anopheles plumbeus (Diptera: Culicidae in Europe: a mere nuisance mosquito or potential malaria vector?  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Anopheles plumbeus has been recognized as a minor vector for human malaria in Europe since the beginning of the 20th century. In recent years this tree hole breeding mosquito species appears to have exploited novel breeding sites, including large and organically rich man-made containers, with consequently larger mosquito populations in close vicinity to humans. This lead to investigate whether current populations of An. plumbeus would be able to efficiently transmit Plasmodium falciparum, the parasite responsible for the most deadly form of malaria. Methods Anopheles plumbeus immatures were collected from a liquid manure pit in Switzerland and transferred as adults to the CEPIA (Institut Pasteur, France where they were fed on P. falciparum gametocytes produced in vitro. Anopheles gambiae mosquitoes served as controls. Development of P. falciparum in both mosquito species was followed by microscopical detection of oocysts on mosquito midguts and by sporozoite detection in the head/thorax by PCR and microscopy. Results A total of 293 wild An. plumbeus females from four independent collections successfully fed through a membrane on blood containing P. falciparum gametocytes. Oocysts were observed in mosquito midguts and P. falciparum DNA was detected in head-thorax samples in all four experiments, demonstrating, on a large mosquito sample, that An. plumbeus is indeed receptive to P. falciparum NF54 and able to produce sporozoites. Importantly, the proportion of sporozoites-infected An. plumbeus was almost similar to that of An. gambiae (31 to 88% An. plumbeus versus 67 to 97% An. gambiae. However, the number of sporozoites produced was significantly lower in infected An. plumbeus. Conclusion The results show that a sample of field-caught An. plumbeus has a moderate to high receptivity towards P. falciparum. Considering the increased mobility of humans between Europe and malaria endemic countries and changes in environment and climate, these data strongly suggest that An. plumbeus could act as a vector for malaria and thus significantly contribute to increasing the malaria transmission risk in Central-Western Europe. In locations showing high vulnerability to the presence of gametocyte carriers, the risk of transmission of malaria by An. plumbeus should be considered.

Schaffner Francis

2012-11-01

138

Scalar–vector–pseudoscalar Cornell potential for a spin-1/2 particle under spin and pseudospin symmetries: 1+1 dimensions  

Energy Technology Data Exchange (ETDEWEB)

The Cornell potential consists of Coulomb and linear potentials, i.e. ?a/x+bx, that has received a great deal of attention in particle and nuclear physics. In this paper, we present exact solutions of the Dirac equation with the mixed scalar–vector–pseudoscalar Cornell potential under spin and pseudospin symmetry limits. The corresponding eigenfunctions are given in the form of the biconfluent Heun polynomials. -- Highlights: •We investigate the Dirac equation with the scalar–vector–pseudoscalar Cornell potential. •The solutions are discussed in view of spin and pseudospin symmetry limits. •The energy levels and the wave function are presented in Heun biconfluent equations.

Hamzavi, M., E-mail: majid.hamzavi@gmail.com; Rajabi, A.A.

2013-07-15

139

Range of retinal diseases potentially treatable by AAV-vectored gene therapy.  

Science.gov (United States)

Viable strategies for retinal gene therapy must be designed to cope with the genetic nature of the disease and/or the primary pathologic process responsible for retinal malfunction. For dominant gene defects the aim must be to destroy the presumably toxic gene product, for recessive gene defects the direct approach aims to provide a wild-type copy of the gene to the affected retinal cell type, and for diseases of either complex or unknown genetic origin, more general cell survival strategies that deal with preserving affected retinal cells are often the best and only option. Hence examples of each type of therapy will be briefly discussed in several animal models, including ribozyme therapy for autosomal dominant retinitis pigmentosa in the transgenic P23H opsin rat, beta-PDE gene augmentation therapy for autosomal recessive retinitis pigmentosa in the rd mouse, glial cell-derived neurotrophic factor (GDNF) gene therapy for autosomal dominant RP in the transgenic S334ter opsin rat and pigment epithelial cell-derived neurotrophic factor (PEDF) gene therapy for neovascular retinal disease in rodents. Each employs a recombinant AAV vectored passenger gene controlled by one of several promoters supporting either photoreceptor-specific expression or more general retinal cell expression depending on the therapeutic requirements. PMID:14750604

Hauswirth, William W; Li, Quihong; Raisler, Brian; Timmers, Adrian M; Berns, Kenneth I; Flannery, John G; LaVail, Matthew M; Lewin, Alfred S

2004-01-01

140

Preliminary assessment of avian stomach oils: a vector of contaminants to chicks and potential for diet analysis and biomonitoring.  

Science.gov (United States)

Bird species from the order Procellariiformes or petrels, including the northern fulmar (Fulmarus glacialis), produce high lipid and high energy content stomach oils from the prey they consume, which enables them to exploit distant marine food sources. Stomach oils are also used as a food source for chicks and for defensive purposes. Samples of stomach oils from two Arctic colonies, St. George Island Alaska, USA and Cape Vera, Devon Island Nunavut, Canada, were collected and analyzed for organochlorine contaminants. SigmaPCB concentrations ranged from 13 to 236 ng g(-1) wet weight (ww) and SigmaDDT concentrations from 5 to 158 ng g(-1) ww and were similar in both sites, though differences in chemical signatures were apparent. Stomach oils are a rich energy source; however, they may also provide a higher dose of contaminants per unit energy than the direct consumption of prey items, as illustrated using mass and energy balance calculations to estimate chick exposure to SigmaDDT for hypothetical stomach oil and whole prey diets. The results of this study suggest that stomach oils are an important vector of organochlorine contaminants to chicks and should be considered in future risk assessments of northern fulmars and other species of petrels. To our knowledge this is the first study of stomach oils as an overlooked vector of organochlorine contaminants to chicks and as a potentially valuable medium for dietary analysis and noninvasive biomonitoring both of petrel dietary exposure and of marine contaminant concentrations. PMID:20707316

Foster, Karen L; Wang, Shiway W; Mackay, Don; Mallory, Mark L; Blais, Jules M

2010-09-01

 
 
 
 
141

Unequal weighting of given doses in opposed fields in treatment of cancer of the tonsillar region using 60Co, 4-, 8-, 15-, 24-MVp photons  

International Nuclear Information System (INIS)

Weighting of given doses from parallel opposed fields is a widespread practice in radiation therapy of cancer in the tonsillar region. In order to determine when weighting is useful, dose distributions on the central axis were calculated for various energies (60Co, 4-, 8-, 15-, and 24-MVp photons), weighting factors, and field separations. Criteria for judging the usefulness of weighting were (i) that variation in the dose across the tumor volume not exceed 10%, and (ii) that the dose to critical tissues outside the target volume be at least 20% less than target volume dose. The clinical situation that met these criteria was a lateral lesion that extended to less than one-third of the transverse diameter of the head, treated with either 60Co, 8, or 4 MVp with 4:1 weighting. Under these conditions, weighting was considered to be justified

1976-01-01

142

Larvivorous Potential of Different Stages of Culex tigripes (Diptera, Culicidae in the Prospective of its Use in Biological Control of Malaria Vectors  

Directory of Open Access Journals (Sweden)

Full Text Available Carried out in the laboratory, the present study tends to assess the larvivorous potential of different stages of Culex tigripes against malaria vectors. The four stages of C. tigripes have effectively a larvivorous activity and may be used in the biological control of mosquito larvae, vector of malaria. Neither lower or higher larval density, large or small size of larvae nor any position pattern of prey larvae from the water surface do inhibit the larvivorous behaviour of C. tigripes.

Basabose, K.

1996-01-01

143

Mapping the potential distribution of #Bandicota indica$, vector of zoonoses in Thailand, by use of remote sensing and geographic information systems (a case of Nakhon Pathom Province)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Space technologies have been used increasingly for assessing the risk of infection by vector-borne diseases, providing tools for delimiting the distribution of vectors. As rodent-borne diseases are a growing concern in Thailand since the emergence of leptospirosis starting in 1998, this study was set up to determine the hazard, related to the potential presence of the main rodent with medical importance, Bandicota indica (Bechstein, 1800), the great bandicoot rat, widely distributed in the co...

Herbreteau, Vincent; Gonzalez, Jean-paul; Andrianasolo, Haja; Kittayapong, Pattamaporn; Hugot, Jean-pierre

2005-01-01

144

Transduction of human NOD/SCID-repopulating cells with both lymphoid and myeloid potential by foamy virus vectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The efficiency of gene transfer into human hematopoietic stem cells by oncoretroviral vectors is too low for effective gene therapy of most hematologic diseases. Retroviral vectors based on the nonpathogenic foamy viruses (FV) are an alternative gene-transfer system. In this study, human umbilical cord blood CD34+ cells were transduced with FV vectors by a single 10-h exposure to vector stocks and then injected into sublethally irradiated nonobese diabetic-severe combined immunodeficiency (NO...

2002-01-01

145

Transcriptome analysis of an mvp mutant reveals important changes in global gene expression and a role for methyl jasmonate in vernalization and flowering in wheat.  

Science.gov (United States)

The einkorn wheat mutant mvp-1 (maintained vegetative phase 1) has a non-flowering phenotype caused by deletions including, but not limited to, the genes CYS, PHYC, and VRN1. However, the impact of these deletions on global gene expression is still unknown. Transcriptome analysis showed that these deletions caused the upregulation of several pathogenesis-related (PR) and jasmonate-responsive genes. These results suggest that jasmonates may be involved in flowering and vernalization in wheat. To test this hypothesis, jasmonic acid (JA) and methyl jasmonate (MeJA) content in mvp and wild-type plants was measured. The content of JA was comparable in all plants, whereas the content of MeJA was higher by more than 6-fold in mvp plants. The accumulation of MeJA was also observed in vernalization-sensitive hexaploid winter wheat during cold exposure. This accumulation declined rapidly once plants were deacclimated under floral-inductive growth conditions. This suggests that MeJA may have a role in floral transition. To confirm this result, we treated vernalization-insensitive spring wheat with MeJA. The treatment delayed flowering with significant downregulation of both TaVRN1 and TaFT1 genes. These data suggest a role for MeJA in modulating vernalization and flowering time in wheat. PMID:24683181

Diallo, Amadou Oury; Agharbaoui, Zahra; Badawi, Mohamed A; Ali-Benali, Mohamed Ali; Moheb, Amira; Houde, Mario; Sarhan, Fathey

2014-06-01

146

Kronig-Penney model of scalar and vector potentials in graphene  

Science.gov (United States)

We consider a one-dimensional (1D) superlattice (SL) on graphene consisting of very high and very thin (?-function) magnetic and potential barriers with zero average potential and zero magnetic field. We calculate the energy spectrum analytically, study it in different limiting cases, and determine the condition under which an electron beam incident on an SL is highly collimated along its direction. In the absence of the magnetic SL the collimation is very sensitive to the value of W/Ws and is optimal for W/Ws = 1, where W is the distance between the positive and negative barriers and L = W + Ws is the size of the unit cell. In the presence of only the magnetic SL the collimation decreases and the symmetry of the spectrum around ky is broken for W/W_{s}\

Ramezani Masir, M.; Vasilopoulos, P.; Peeters, F. M.

2010-11-01

147

Real-time PCR investigation of potential vectors, reservoirs, and shedding patterns of feline hemotropic mycoplasmas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, "Candidatus Mycoplasma haemominutum," and "Candidatus Mycoplasma turicensis." The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods and from ...

Willi, B.; Boretti, F. S.; Meli, M. L.; Bernasconi, M. V.; Casati, S.; Hegglin, D.; Puorger, M.; Neimark, H.; Cattori, V.; Wengi, N.; Reusch, C. E.; Lutz, H.; Hofmann-lehmann, R.

2007-01-01

148

Real-Time PCR Investigation of Potential Vectors, Reservoirs, and Shedding Patterns of Feline Hemotropic Mycoplasmas?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, “Candidatus Mycoplasma haemominutum,” and “Candidatus Mycoplasma turicensis.” The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods a...

Willi, Barbara; Boretti, Felicitas S.; Meli, Marina L.; Bernasconi, Marco V.; Casati, Simona; Hegglin, Daniel; Puorger, Maria; Neimark, Harold; Cattori, Valentino; Wengi, Nicole; Reusch, Claudia E.; Lutz, Hans; Hofmann-lehmann, Regina

2007-01-01

149

Kronig-Penney model of scalar and vector potentials in graphene  

International Nuclear Information System (INIS)

We consider a one-dimensional (1D) superlattice (SL) on graphene consisting of very high and very thin (?-function) magnetic and potential barriers with zero average potential and zero magnetic field. We calculate the energy spectrum analytically, study it in different limiting cases, and determine the condition under which an electron beam incident on an SL is highly collimated along its direction. In the absence of the magnetic SL the collimation is very sensitive to the value of W/Ws and is optimal for W/Ws = 1, where W is the distance between the positive and negative barriers and L = W + Ws is the size of the unit cell. In the presence of only the magnetic SL the collimation decreases and the symmetry of the spectrum around ky is broken for W/Ws?1. In addition, a gap opens which depends on the strength of the magnetic field. We also investigate the effect of spatially separated potential and magnetic ?-function barriers and predict a better collimation in specific cases.

2010-11-24

150

A potential vector of Schistosoma mansoni in Uruguay Um vetor potencial do Schistosoma mansoni no Uruguai  

Directory of Open Access Journals (Sweden)

Full Text Available Susceptibily experiments were carried out with a Biomphalaria straminea-like planorbid snail (Biomphalaria aff. straminea, species inquirenda from Espinillar, near Salto (Uruguay, in the area of the Salto Grande reservoir, exposed individually to 5 miracidia of Schistosoma mansoni (SJ2 and BH2 strains. Of 130 snails exposed to the SJ2 strain, originally infective to Biomphalaria tenagophila, 30 became infected (23%. The prepatent (precercaria period ranged from 35 to 65 days. The cercarial output was irregular, following no definite pattern, varying from 138 to 76,075 per snail (daily average 4.3 to 447.5 and ending up with death. Three specimens that died, without having shed cercarie, on days 69 (2 and 80 after exposure to miracidia, had developing secondary sporocysts in their tissues, justifying the prospect of a longer precercarial period in these cases. In a control group of 120 B. teangophila, exposed to the SJ2 strain, 40 became infected, showing an infection rate (33.3% not significantly different from that of the Espinillar snail (X [raised to the power of] 2 = 3.26. No cercarie were produced by any of the Espinilar snails exposed to miracidia of the BH2 strain, originally infective to Biomphalaria glabrata. Four specimens showed each a primary sporocyst in one tentacle, which disappeared between 15 and 25 days post-exposure, and two others died with immature, very slender sporocysts in their tissues on days 36 and 54. In a control group of 100 B. glabrata exposed to BH2 miracidia, 94 shed cercariae (94% and 6 remained negative. Calculation of Frandsen's (1979a, b TCP/100 index shows that "Espinillar Biomphalaria-SJ2 S. mansoni" is a vector-parasite "compatible" combination. Seeing that tenagophila-borne schistosomiasis is prevalent in Rio de Janeiro and São Paulo states and has recently spread sothwards to Santa Catarina state, and the range of B. tenagophila overlaps taht of the Espinillar Biomphalaria, the possibility of schistosomiais establishing itself in Uruguay, although not imminent, is not to be disregarded.Foram feitas provas de suscetibilidade com um molusco planorbídeo semelhante à Biomphalaria straminea (species inquirenda de Espinillar, localidade próxima a Salto (Uruguay, na área da represa de Salto Grande, cada exemplar sendo exposto individualmente a 5 miracídios de Schistosom mansoni (cepas SJ2 e BH2. De 130 exemplares expostos à cepa SJ2, originalmente infectante para B. tenagophila, 30 se infectaram (23%. O período pré-patente (pré-cercariano variou de 35 a 65 dias. A emissão de cercárias foi irregular, não seguindo padrão definido, variando de 138 a 76.075 por exemplar (média diária de 4,3 a 447,5 e teminando com a morte. Três exemplares que morreram, sem ter eliminado cercárias, no 69º (2 e no 80º dia após exposição aos miracídios, tinham esporocistos secundários em desenvolvimento nos tecidos, justificando a expectativa de um período pré-patente mais longo nestes casos. Em um grupo-controle de 120 B. tenagophila, exposta à cepa SJ2, 40 se infectaram, não diferindo significativamente seu índice de infecção (33.3% daquele do planorbídeo de Espinillar (X [ao quadrado]=3.26. De 100 exemplares de Espinillar expostos a miracídios da cepa BH2, originalmente infectante para B. glabrata, nenhum produziu cercárias. Um esporocisto primário formou-se em um tentáculo em 4 exemplares, desaparecendo entre 15 e 25 dias após a exposição. Dois outros exemplares morreram com esporocistos imaturos e muito delgados nos tecidos (4 em um caso e 3 no outro, no 36º e 54º dias. Em um grupo-controle de 100 B. glabrata exposto à cepa BH2, 94 emitiram cercárias (94% e 6 permaneceram negativos. De acordo com o índice TCP/100 de Frandsen (1979a,b, a combinação Biomphalaria de Espinillar-S. mansoni SJ2 constitui uma relação vetor-parasito "compatível". Tendo em vista que a xistosomose transmitida pela B. tenagophila é prevalente nos estados do Rio de Janeiro e São Paulo e recentemente propagou-se para o sul até o estado de Santa Catarina, e a dist

W. Lobato Paraense

1989-09-01

151

A potential vector of Schistosoma mansoni in Uruguay / Um vetor potencial do Schistosoma mansoni no Uruguai  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Foram feitas provas de suscetibilidade com um molusco planorbídeo semelhante à Biomphalaria straminea (species inquirenda) de Espinillar, localidade próxima a Salto (Uruguay), na área da represa de Salto Grande, cada exemplar sendo exposto individualmente a 5 miracídios de Schistosom mansoni (cepas [...] SJ2 e BH2). De 130 exemplares expostos à cepa SJ2, originalmente infectante para B. tenagophila, 30 se infectaram (23%). O período pré-patente (pré-cercariano) variou de 35 a 65 dias. A emissão de cercárias foi irregular, não seguindo padrão definido, variando de 138 a 76.075 por exemplar (média diária de 4,3 a 447,5) e teminando com a morte. Três exemplares que morreram, sem ter eliminado cercárias, no 69º (2) e no 80º dia após exposição aos miracídios, tinham esporocistos secundários em desenvolvimento nos tecidos, justificando a expectativa de um período pré-patente mais longo nestes casos. Em um grupo-controle de 120 B. tenagophila, exposta à cepa SJ2, 40 se infectaram, não diferindo significativamente seu índice de infecção (33.3%) daquele do planorbídeo de Espinillar (X [ao quadrado]=3.26). De 100 exemplares de Espinillar expostos a miracídios da cepa BH2, originalmente infectante para B. glabrata, nenhum produziu cercárias. Um esporocisto primário formou-se em um tentáculo em 4 exemplares, desaparecendo entre 15 e 25 dias após a exposição. Dois outros exemplares morreram com esporocistos imaturos e muito delgados nos tecidos (4 em um caso e 3 no outro), no 36º e 54º dias. Em um grupo-controle de 100 B. glabrata exposto à cepa BH2, 94 emitiram cercárias (94%) e 6 permaneceram negativos. De acordo com o índice TCP/100 de Frandsen (1979a,b), a combinação Biomphalaria de Espinillar-S. mansoni SJ2 constitui uma relação vetor-parasito "compatível". Tendo em vista que a xistosomose transmitida pela B. tenagophila é prevalente nos estados do Rio de Janeiro e São Paulo e recentemente propagou-se para o sul até o estado de Santa Catarina, e a distribuição geográfica da B. tenagophila soprepõe-se à da Biomphalaria de Espinilar, a possibilidade do estabelecimento da xistosomose no Uruguai, ainda que não iminente, não deve ser desconsiderada. Abstract in english Susceptibily experiments were carried out with a Biomphalaria straminea-like planorbid snail (Biomphalaria aff. straminea, species inquirenda) from Espinillar, near Salto (Uruguay), in the area of the Salto Grande reservoir, exposed individually to 5 miracidia of Schistosoma mansoni (SJ2 and BH2 str [...] ains). Of 130 snails exposed to the SJ2 strain, originally infective to Biomphalaria tenagophila, 30 became infected (23%). The prepatent (precercaria) period ranged from 35 to 65 days. The cercarial output was irregular, following no definite pattern, varying from 138 to 76,075 per snail (daily average 4.3 to 447.5 and ending up with death. Three specimens that died, without having shed cercarie, on days 69 (2) and 80 after exposure to miracidia, had developing secondary sporocysts in their tissues, justifying the prospect of a longer precercarial period in these cases. In a control group of 120 B. teangophila, exposed to the SJ2 strain, 40 became infected, showing an infection rate (33.3%) not significantly different from that of the Espinillar snail (X [raised to the power of] 2 = 3.26). No cercarie were produced by any of the Espinilar snails exposed to miracidia of the BH2 strain, originally infective to Biomphalaria glabrata. Four specimens showed each a primary sporocyst in one tentacle, which disappeared between 15 and 25 days post-exposure, and two others died with immature, very slender sporocysts in their tissues on days 36 and 54. In a control group of 100 B. glabrata exposed to BH2 miracidia, 94 shed cercariae (94%) and 6 remained negative. Calculation of Frandsen's (1979a, b) TCP/100 index shows that "Espinillar Biomphalaria-SJ2 S. mansoni" is a vector-parasite "compatible" combination. Seeing that tenagophila-borne schi

Paraense, W. Lobato; Corrêa, Lygia R..

152

Ants in a hospital environment and their potential as mechanical bacterial vectors  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Introduction We studied the richness and abundance of ant species, their bacteria and the bacteria isolated from patient clinical samples. Methods Ants were collected with baited traps at 64 sites in a public hospital in São Luis, State of Maranhão, Brazil. Results In total, 1,659 ant [...] s from 14 species were captured. The most frequent species were Crematogaster victima, Solenopsis saevissima, Tapinoma melanocephalum, Camponotus vittatus and Paratrechina fulva. Forty-one species of bacteria were isolated from the ants and 18 from patients. Conclusions Ants are potential vehicles for pathogenic and opportunistic bacteria, and they can represent a risk factor in nosocomial infections.

Lima, Wanda Ramos dos Santos; Marques, Sirlei Garcia; Rodrigues, Fernanda Souto; Rebelo, Jose Manuel Macario.

153

REIC/Dkk-3-encoding adenoviral vector as a potentially effective therapeutic agent for bladder cancer.  

Science.gov (United States)

Bladder cancer is one of the most common urogenital malignancies. The intravesical instillation of anticancer agents is an attractive strategy to treat a superficial lesion or floating/disseminated cancer cells after transurethral operation. An adenovirus carrying REIC/Dkk-3, a tumor suppressor gene (Ad-REIC), exhibits cancer-specific apoptotic effects in various types of cancer cells. The aim of the present study was to examine the potential of Ad-REIC as a therapeutic agent for bladder cancer. KK47 and RT4 human bladder cancer cells were sensitive to the Ad-REIC treatment for apoptosis induction, but some human bladder cancer cell lines (T24, J82 and TccSup) were resistant. Significant cell growth inhibition was observed when these resistant cancer cell lines were treated with Ad-REIC in a condition of floating cells, which is clinically observed after transurethral operation and becomes a cause of intravesical cancer dissemination. The therapeutic potential of Ad-REIC for the treatment of multidrug-resistant bladder cancer was investigated. The adriamycin-resistant KK47 bladder cancer cells (KK47/ADM), which also present multidrug resistance, showed induction of significant apoptosis following Ad-REIC treatment. The Ad-REIC treatment induced downregulation of P-glycoprotein in KK47/ADM cells and restored the sensitivity to doxorubicin (adriamycin). Ad-REIC suppressed P-glycoprotein expression in a c-Jun-NH2-kinase (JNK)-dependent manner. Therefore, the current study indicated two therapeutic aspects of the Ad-REIC agent against human bladder cancer cells, as an apoptosis inducer/cell growth inhibitor and as a sensitizer of chemotherapeutic agents in multidrug-resistant cancer cells. The intravesical instillation of Ad-REIC could be an attractive therapeutic method in human bladder cancer where the treatment of superficial lesions and floating/disseminated or multidrug-resistant cancer cells is necessary. PMID:22665039

Hirata, Takeshi; Watanabe, Masami; Kaku, Haruki; Kobayashi, Yasuyuki; Yamada, Hiroshi; Sakaguchi, Masakiyo; Takei, Kohji; Huh, Nam-Ho; Nasu, Yasutomo; Kumon, Hiromi

2012-08-01

154

Wild deer as potential vectors of anthelmintic-resistant abomasal nematodes between cattle and sheep farms.  

Science.gov (United States)

Gastrointestinal (GI) nematodes are among the most important causes of production loss in farmed ruminants, and anthelmintic resistance is emerging globally. We hypothesized that wild deer could potentially act as reservoirs of anthelmintic-resistant GI nematodes between livestock farms. Adult abomasal nematodes and faecal samples were collected from fallow (n = 24), red (n = 14) and roe deer (n = 10) from venison farms and areas of extensive or intensive livestock farming. Principal components analysis of abomasal nematode species composition revealed differences between wild roe deer grazing in the areas of intensive livestock farming, and fallow and red deer in all environments. Alleles for benzimidazole (BZ) resistance were identified in ?-tubulin of Haemonchus contortus of roe deer and phenotypic resistance confirmed in vitro by an egg hatch test (EC50 = 0.149 µg ml(-1) ± 0.13 µg ml(-1)) on H. contortus eggs from experimentally infected sheep. This BZ-resistant H. contortus isolate also infected a calf experimentally. We present the first account of in vitro BZ resistance in wild roe deer, but further experiments should firmly establish the presence of phenotypic BZ resistance in vivo. Comprehensive in-field studies should assess whether nematode cross-transmission between deer and livestock occurs and contributes, in any way, to the development of resistance on livestock farms. PMID:24552838

Chintoan-Uta, C; Morgan, E R; Skuce, P J; Coles, G C

2014-04-01

155

Potential impacts of climate change on the ecology of dengue and its mosquito vector the Asian tiger mosquito (Aedes albopictus)  

Science.gov (United States)

Shifts in temperature and precipitation patterns caused by global climate change may have profound impacts on the ecology of certain infectious diseases. We examine the potential impacts of climate change on the transmission and maintenance dynamics of dengue, a resurging mosquito-vectored infectious disease. In particular, we project changes in dengue season length for three cities: Atlanta, GA; Chicago, IL and Lubbock, TX. These cities are located on the edges of the range of the Asian tiger mosquito within the United States of America and were chosen as test cases. We use a disease model that explicitly incorporates mosquito population dynamics and high-resolution climate projections. Based on projected changes under the Special Report on Emissions Scenarios (SRES) A1fi (higher) and B1 (lower) emission scenarios as simulated by four global climate models, we found that the projected warming shortened mosquito lifespan, which in turn decreased the potential dengue season. These results illustrate the difficulty in predicting how climate change may alter complex systems.

Erickson, R. A.; Hayhoe, K.; Presley, S. M.; Allen, L. J. S.; Long, K. R.; Cox, S. B.

2012-09-01

156

Virtual globes and geospatial health: the potential of new tools in the management and control of vector-borne diseases.  

Science.gov (United States)

The rapidly growing field of three-dimensional software modeling of the Earth holds promise for applications in the geospatial health sciences. Easy-to-use, intuitive virtual globe technologies such as Google Earth enable scientists around the world to share their data and research results in a visually attractive and readily understandable fashion without the need for highly sophisticated geographical information systems (GIS) or much technical assistance. This paper discusses the utility of the rapid and simultaneous visualization of how the agents of parasitic diseases are distributed, as well as that of their vectors and/or intermediate hosts together with other spatially-explicit information. The resulting better understanding of the epidemiology of infectious diseases, and the multidimensional environment in which they occur, are highlighted. In particular, the value of Google Earth, and its web-based pendant Google Maps, are reviewed from a public health view point, combining results from literature searches and experiences gained thus far from a multidisciplinary project aimed at optimizing schistosomiasis control and transmission surveillance in sub-Saharan Africa. Although the basic analytical capabilities of virtual globe applications are limited, we conclude that they have considerable potential in the support and promotion of the geospatial health sciences as a userfriendly, straightforward GIS tool for the improvement of data collation, visualization and exploration. The potential of these systems for data sharing and broad dissemination of scientific research and results is emphasized. PMID:19440958

Stensgaard, Anna-Sofie; Saarnak, Christopher F L; Utzinger, Jürg; Vounatsou, Penelope; Simoonga, Christopher; Mushinge, Gabriel; Rahbek, Carsten; Møhlenberg, Flemming; Kristensen, Thomas K

2009-05-01

157

Analysis of sodium void reactivity of control rod regions in Phenix sized core with Monte Carlo Code MVP  

International Nuclear Information System (INIS)

The cause of the abnormal power change phenomenon of Phenix core is studied under the assumption that a negative reactivity insertion is induced by a gas blow into the control rod assemblies. The size and layout of the core analyzed are set to simulate the Phenix core while material compositions of the assemblies are assumed to be a typical MOX fuel core and the control rod channel is assumed to be a simple sodium plenum zone at intact. The calculation has been conducted by using three-dimensional continuation energy Monte Carlo code MVP with JENDL-3.3 library so that the neutron moderation and leakage through the void channel can be evaluated exactly. The result of the analysis shows the negative void reactivity is about -80 cents when the sodium below the level of 1/3 of core height from the core bottom of the seven control assemblies including the center shutdown system is voided while it is about -1 cents when the sodium between the core bottom to the core top is voided in the same assemblies. The void reactivity for the region above the level of 2/3 of core height is again about -80 cents. The negative reactivity of -80 cents is consistent to the power decrease of about 40 % at the beginning of the event if zero-power reactor model can be applied to the transient of this phenomenon. The successive power swing observed can be explained by the reactivity change if the gas flows up through the control assemblies in which the cross sectional area of the gas is reduced by a half at the upper level of the assembly due to the absorber pins. (authors)

2011-05-02

158

Dos nuevos registros de vectores potenciales de Fiebre Amarilla selvática y Mayaro para el Ecuador / Two new records of potential Sylvan Yellow Fever and Mayaro species vectors from Ecuador  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Se registran por primera vez en el Ecuador dos especies de mosquitos (Diptera: Culicidae), vectores potenciales de los virus de la Fiebre Amarilla y Mayaro. Sabethes amazonicus Gordon and Evans y Haemagogus anastasionis Dyar fueron colectados en fase adulta en una localidad de la provincia de Zamora [...] -Chinchipe, en la cual se han presentado casos de Fiebre Amarilla selvática con anterioridad. Este hallazgo muestra la importancia de profundizar los estudios de linea base de vectores en el país, distribución geográfica y aspectos ecológicos y su posible relación epidemiológica con enfermedades emergentes y re-emergentes. Abstract in english Two new records of mosquitoes (Diptera: Culicidae) are presented from Ecuador, and both potential vectors of yellow fever virus and Mayaro. Sabethes amazonicus Gordon and Evans and Haemagogus anastasionis Dyar adults were collected in a locality in the province of Zamora-Chinchipe, in which there ha [...] ve been cases of yellow fever previously. This finding shows the importance of further studies of baseline vector in the country, geographical distribution and ecological aspects and possible epidemiological link with emerging and re-emerging diseases.

Juan Carlos, Navarro; Ponce, Patricio; Cevallos, Varsovia.

159

Exact solution of the one-dimensional Klein–Gordon equation with scalar and vector linear potentials in the presence of a minimal length  

International Nuclear Information System (INIS)

Using the momentum space representation, we solve the Klein–Gordon equation in one spatial dimension for the case of mixed scalar and vector linear potentials in the context of deformed quantum mechanics characterized by a finite minimal uncertainty in position. The expressions of bound state energies and the associated wave functions are exactly obtained. (general)

2010-02-01

160

Host-feeding pattern of Culex theileri (Diptera: Culicidae), potential vector of Dirofilaria immitis in the Canary Islands, Spain.  

Science.gov (United States)

To identify the host range of potential vectors of Dirofilaria immitis Leidy, the causal agent of canine dirofilariasis, we studied the bloodmeal origin of mosquitoes trapped on two of the Canary Islands, Gran Canaria and Tenerife, where this disease is considered hyperendemic. On Gran Canaria, mosquitoes were captured using Centers for Disease Control and Prevention (CDC) traps (outdoors) and resting in a bathroom (indoors). Only CDC traps were used to capture mosquitoes in Tenerife. The species captured in decreasing order of abundance were Culex theileri Theobald, Culex pipiens L., Culiseta longiareolata Macquart, Anopheles atroparvus van Thiel, and Anopheles cinereus Theobald. The origins of bloodmeals were identified for 121 Cx. theileri and 4 Cx. pipiens after amplification and sequencing of a fragment of the vertebrate cytochrome oxidase I (COI) gene. Cx. theileri fed on goats, sheep, dogs, cattle, cats, humans, and chickens, and Cx. pipiens fed on goats and chickens. A lower success of bloodmeal identification was obtained in mosquitoes captured resting indoors than outdoors in CDC traps, probably because of a longer time period between feeding and capture. Although most Cx. theileri fed on ruminants, this species also fed on different mammal species susceptible to dirofiliarasis, including humans, suggesting it could play a role on parasite transmission. PMID:23270171

Martínez-De La Puente, Josué; Moreno-Indias, Isabel; Hernández-Castellano, Lorenzo Enrique; Argüello, Anastasio; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

2012-11-01

 
 
 
 
161

Major and trace element geochemistry of Archean sulfidic black shale horizons as a potential vectoring tool for VMS exploration  

Science.gov (United States)

Metalliferous black shale horizons are a common but minor component of many subaqueous volcanic successions. These horizons are commonly drilled during volcanogenic massive sulfide (VMS) deposit exploration programs. Although ore metal enrichment can be identified by conventional assay methods, matrix dilution and post-burial hydrothermal and metamorphic activity may obscure information on the type and mechanism of metal addition to the shale. We used a combination of geochemical investigations at a variety of scales to discriminate between VMS-prospective and VMS-barren horizons. In addition, element signatures associated with hydrothermal plume fallout were identified and used and to determine relative direction to the palaeo-venting centre. Portable x-ray fluorescence (pXRF) analysers were used to identify and correlate prospective horizons within exploration drill cores. pXRF is a rapid and relatively inexpensive method of analysis that can deliver quantitative geochemical information at a cm-scale and help to identify intervals meriting further, more costly and time-consuming analyses. Subsequently, laser-ablation ICP-MS analysis of metal sulfides was used to constrain hydrothermal, hydrogenous and diagenetic end-member compositions, and to quantify element remobilization during post-burial alteration. These data were then used to refine the pXRF survey methodology and develop primary vectors toward potential concealed base metal deposits.

Chapman, J. B.; Peter, J. M.; Layton-Matthews, D.; Gemmell, J. B.

2009-05-01

162

Design, synthesis and experimental validation of novel potential chemopreventive agents using random forest and support vector machine binary classifiers.  

Science.gov (United States)

Compared to the current knowledge on cancer chemotherapeutic agents, only limited information is available on the ability of organic compounds, such as drugs and/or natural products, to prevent or delay the onset of cancer. In order to evaluate chemical chemopreventive potentials and design novel chemopreventive agents with low to no toxicity, we developed predictive computational models for chemopreventive agents in this study. First, we curated a database containing over 400 organic compounds with known chemoprevention activities. Based on this database, various random forest and support vector machine binary classifiers were developed. All of the resulting models were validated by cross validation procedures. Then, the validated models were applied to virtually screen a chemical library containing around 23,000 natural products and derivatives. We selected a list of 148 novel chemopreventive compounds based on the consensus prediction of all validated models. We further analyzed the predicted active compounds by their ease of organic synthesis. Finally, 18 compounds were synthesized and experimentally validated for their chemopreventive activity. The experimental validation results paralleled the cross validation results, demonstrating the utility of the developed models. The predictive models developed in this study can be applied to virtually screen other chemical libraries to identify novel lead compounds for the chemoprevention of cancers. PMID:24840854

Sprague, Brienne; Shi, Qian; Kim, Marlene T; Zhang, Liying; Sedykh, Alexander; Ichiishi, Eiichiro; Tokuda, Harukuni; Lee, Kuo-Hsiung; Zhu, Hao

2014-06-01

163

Analysis of auditory evoked potential parameters in the presence of radiofrequency fields using a support vector machines method.  

Science.gov (United States)

The paper presents a study of global system for mobile (GSM) phone radiofrequency effects on human cerebral activity. The work was based on the study of auditory evoked potentials (AEPs) recorded from healthy humans and epileptic patients. The protocol allowed the comparison of AEPs recorded with or without exposure to electrical fields. Ten variables measured from AEPs were employed in the design of a supervised support vector machines classifier. The classification performance measured the classifier's ability to discriminate features performed with or without radiofrequency exposure. Most significant features were chosen by a backward sequential selection that ranked the variables according to their pertinence for the discrimination. Finally, the most discriminating features were analysed statistically by a Wilcoxon signed rank test. For both populations, the N100 amplitudes were reduced under the influence of GSM radiofrequency (mean attenuation of -0.36 microV for healthy subjects and -0.60 microV for epileptic patients). Healthy subjects showed a N100 latency decrease (-5.23 ms in mean), which could be consistent with mild, localised heating. The auditory cortical activity in humans was modified by GSM phone radiofrequencies, but an effect on brain functionality has not been proven. PMID:15320468

Maby, E; Le Bouquin Jeannès, R; Liégeois-Chauvel, C; Gourevitch, B; Faucon, G

2004-07-01

164

Genetic diversity and potential vectors and reservoirs of Cucurbit aphid-borne yellows virus in southeastern Spain.  

Science.gov (United States)

The genetic variability of a Cucurbit aphid-borne yellows virus (CABYV) (genus Polerovirus, family Luteoviridae) population was evaluated by determining the nucleotide sequences of two genomic regions of CABYV isolates collected in open-field melon and squash crops during three consecutive years in Murcia (southeastern Spain). A phylogenetic analysis showed the existence of two major clades. The sequences did not cluster according to host, year, or locality of collection, and nucleotide similarities among isolates were 97 to 100 and 94 to 97% within and between clades, respectively. The ratio of nonsynonymous to synonymous nucleotide substitutions reflected that all open reading frames have been under purifying selection. Estimates of the population's genetic diversity were of the same magnitude as those previously reported for other plant virus populations sampled at larger spatial and temporal scales, suggesting either the presence of CABYV in the surveyed area long before it was first described, multiple introductions, or a particularly rapid diversification. We also determined the full-length sequences of three isolates, identifying the occurrence and location of recombination events along the CABYV genome. Furthermore, our field surveys indicated that Aphis gossypii was the major vector species of CABYV and the most abundant aphid species colonizing melon fields in the Murcia (Spain) region. Our surveys also suggested the importance of the weed species Ecballium elaterium as an alternative host and potential virus reservoir. PMID:23802870

Kassem, Mona A; Juarez, Miguel; Gómez, Pedro; Mengual, Carmen M; Sempere, Raquel N; Plaza, María; Elena, Santiago F; Moreno, Aranzazu; Fereres, Alberto; Aranda, Miguel A

2013-11-01

165

[Life cycle of Rhodnius brethesi Matta, 1919 (Hemiptera, Reduviidae, Triatominae), a potential vector of Chagas disease in the Amazon region].  

Science.gov (United States)

R. brethesi is a sylvatic species from the Amazon region; it has been incriminated as responsible for the transmission of Chagas disease in collectors of piacaba in this region. The aim of present study was to investigate the efficiency of these insects as potential vectors of Trypanosoma cruzi. Aspects related with feeding and defecation patterns, life time, and mortality had been observed in each instar of R. brethesi. We use 5th instar nymphs to get adults virgins, after the moulting 3 groups with 6 females and 2 males each were created to obtain eggs. After hatching, 1st instar nymphs had been weighed and kept in bottles until the next moult. Insects were fed once a week in mice. Results showed that the average period of incubation was 17 days, the number of blood meal was increasing from the 1st to the 5th instar nymph with 7 (average) to become adult, a significative numbers of the defecations occurring immediately after the bloodmeals. The total percentual of mortality was 16%. This results suggests that this species presents a good exploitation of blood meals and a brief nymphal development in laboratory conditions reflecting its behavior in sylvatic environments. PMID:15558169

Rocha, Dayse da Silva; dos Santos, Carolina Magalhães; Cunha, Vanda; Jurberg, José; Galvão, Cleber

2004-10-01

166

Exact Solutions of the Klein-Gordon Equation with Position-Dependent Mass for Mixed Vector and Scalar Kink-Like Potentials  

International Nuclear Information System (INIS)

The relativistic problem of spinless particles with position-dependent mass subject to kink-like potentials is investigated. By using the basic concepts of the supersymmetric quantum mechanics formalism and the functional analysis method, we solve exactly the position-dependent effective mass Klein-Gordon equation with the vector and scalar kink-like potential coupling, and obtain the bound state solutions in the closed form. It is found that in the presence of position-dependent mass there exists the symmetry that the discrete positive energy spectra and negative energy spectra are symmetric about zero energy for the case of a mixed vector and scalar kink-like potential coupling, and in the presence of constant mass this symmetry only appears for the cases of a pure scalar kink-like potential coupling or massless particles. (author)

2012-02-01

167

First report in italy of the exotic mosquito species Aedes (Finlaya koreicus, a potential vector of arboviruses and filariae  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In the Veneto region (north-eastern Italy an entomological surveillance system has been implemented since the introduction of the Asian tiger mosquito (Aedes albopictus in 1991. During the routine monitoring activity in a tiger mosquito-free area, an unexpected mosquito was noticed, which clearly did not belong to the recorded Italian fauna. Findings At the end of May 2011, twelve larvae and pupae were collected in a small village in Belluno province (Veneto region from a single manhole. Ten adults reared in the laboratory were morphologically and genetically identified as Aedes (Finlaya koreicus (Edwards, 1917, a species native to Southeast Asia. The subsequent investigations carried out in the following months in the same village provided evidence that this species had become established locally. Entomological and epidemiological investigations are currently ongoing in the surrounding area, to verify the eventual extension of the species outside the village and to trace back the route of entry into Italy. Conclusions This is the first report in Italy of the introduction of the exotic mosquito Ae. koreicus. This species has been shown experimentally to be competent in the transmission of the Japanese encephalitis virus and of the dog heartworm Dirofilaria immitis and is considered a potential vector of other arboviruses. Thus, the establishment of this species may increase the current risk or pose new potential threats, for human and animal health. This finding considerably complicates the entomological monitoring of the Asian tiger mosquito Ae. albopictus in Italy and stresses the importance of implementing the entomological surveillance for the early detection of and the rapid response against invasive mosquito species.

Capelli Gioia

2011-09-01

168

Beyond platinum: synthesis, characterization, and in vitro toxicity of Cu(II)-releasing polymer nanoparticles for potential use as a drug delivery vector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The field of drug delivery focuses primarily on delivering small organic molecules or DNA/RNA as therapeutics and has largely ignored the potential for delivering catalytically active transition metal ions and complexes. The delivery of a variety of transition metals has potential for inducing apoptosis in targeted cells. The chief aims of this work were the development of a suitable delivery vector for a prototypical transition metal, Cu2+, and demonstration of the ability to impact cancer c...

2011-01-01

169

Environmental risk assessment of replication competent viral vectors applied in clinical trials: potential effects of inserted sequences.  

Science.gov (United States)

Risk assessments of clinical applications involving genetically modified viral vectors are carried out according to general principles that are implemented in many national and regional legislations, e.g., in Directive 2001/18/EC of the European Union. Recent developments in vector design have a large impact on the concepts that underpin the risk assessments of viral vectors that are used in clinical trials. The use of (conditionally) replication competent viral vectors (RCVVs) may increase the likelihood of the exposure of the environment around the patient, compared to replication defective viral vectors. Based on this assumption we have developed a methodology for the environmental risk assessment of replication competent viral vectors, which is presented in this review. Furthermore, the increased likelihood of exposure leads to a reevaluation of what would constitute a hazardous gene product in viral vector therapies, and a keen interest in new developments in the inserts used. One of the trends is the use of inserts produced by synthetic biology. In this review the implications of these developments for the environmental risk assessment of RCVVs are highlighted, with examples from current clinical trials. The conclusion is drawn that RCVVs, notwithstanding their replication competency, can be applied in an environmentally safe way, in particular if adequate built-in safeties are incorporated, like conditional replication competency, as mitigating factors to reduce adverse environmental effects that could occur. PMID:24397527

van den Akker, Eric; van der Vlugt, Cecile J B; Bleijs, Diederik A; Bergmans, Hans E

2013-12-01

170

Oviposition-altering and ovicidal potentials of five essential oils against female adults of the dengue vector, Aedes aegypti L.  

Science.gov (United States)

The oviposition deterrence and ovicidal potential of five different essential oils, peppermint oil (Mentha piperita), basil oil (Ocimum basilicum), rosemary oil (Rosemarinus officinalis), citronella oil (Cymbopogon nardus), and celery seed oil (Apium graveolens), were assessed against female adults of the dengue vector, Aedes aegypti L. Multiple concentration tests were carried out where cups containing 1 mL of different concentrations (100%, 10%, 1%, 0.1%) of the oils and 199 mL of water were used for oviposition. The number of eggs laid and the larvae hatched in each cup were scored to evaluate the oviposition deterrent and ovicidal potentials of the oils. Our investigations revealed that the addition of 100% oil (pure oil) caused complete oviposition deterrence except in A. graveolens which resulted in 75% effective repellency. The use of 10% oil resulted in the maximum deterrence of 97.5% as shown by the M. piperita oil while other oils caused 36-97% oviposition deterrence as against the control. The oviposition medium with 1% oil showed decreased deterrent potential with 30-64% effective repellency, the M. piperita oil being exceptional. However, as the concentrations of the oil were reduced further to 0.1%, the least effective oil observed was A. graveolens (25% ER). Also, the M. piperita oil showed much reduced activity (40%) as compared to the control, while the other oils exhibited 51-58% repellency to oviposition. The studies on the ovicidal effects of these oils revealed that the eggs laid in the water with 100% essential oils did not hatch at all, whereas when 10% oils were used, only the R. officinalis oil resulted in 28% egg hatch. At lower concentrations (1%), the oils of M. piperita, O. basilicum, and C. nardus showed complete egg mortality while those of A. graveolens and R. officinalis resulted in 71% and 34% egg hatches, respectively. When used at 0.1%, the O. basilicum oil was found to be the only effective oil with 100% egg mortality, whereas other oils resulted in 16-76% egg mortality, the least mortality caused by the A. graveolens oil. These results suggest that these essential oils can be employed in a resistance-management program against A. aegypti. Further detailed research is needed to identify the active ingredient in the extracts and implement the effective mosquito management program. PMID:21445613

Warikoo, Radhika; Wahab, Naim; Kumar, Sarita

2011-10-01

171

Vector Field and Inflation  

CERN Multimedia

We have investigated if the vector field can give rise to an accelerating phase in the early universe. We consider a timelike vector field with a general quadratic kinetic term in order to preserve an isotropic background spacetime. The vector field potential is required to satisfy the three minimal conditions for successful inflation: i) $\\rho>0$, ii) $\\rho+3P < 0$ and iii) the slow-roll conditions. As an example, we consider the massive vector potential and small field type potential as like in scalar driven inflation.

Koh, Seoktae

2009-01-01

172

Imported Asian swamp eels (Synbranchidae: Monopterus) in North American live food markets: Potential vectors of non-native parasites  

Science.gov (United States)

Since the 1990s, possibly earlier, large numbers of Asian swamp eels (Synbranchidae: Monopterus spp.), some wild-caught, have been imported live from various countries in Asia and sold in ethnic food markets in cities throughout the USA and parts of Canada. Such markets are the likely introduction pathway of some, perhaps most, of the five known wild populations of Asian swamp eels present in the continental United States. This paper presents results of a pilot study intended to gather baseline data on the occurrence and abundance of internal macroparasites infecting swamp eels imported from Asia to North American retail food markets. These data are important in assessing the potential role that imported swamp eels may play as possible vectors of non-native parasites. Examination of the gastrointestinal tracts and associated tissues of 19 adult-sized swamp eels—identified as M. albus "Clade C"—imported from Vietnam and present in a U.S. retail food market revealed that 18 (95%) contained macroparasites. The 394 individual parasites recovered included a mix of nematodes, acanthocephalans, cestodes, digeneans, and pentastomes. The findings raise concern because of the likelihood that some parasites infecting market swamp eels imported from Asia are themselves Asian taxa, some possibly new to North America. The ecological risk is exacerbated because swamp eels sold in food markets are occasionally retained live by customers and a few reportedly released into the wild. For comparative purposes, M. albus "Clade C" swamp eels from a non-native population in Florida (USA) were also examined and most (84%) were found to be infected with internal macroparasites. The current level of analysis does not allow us to confirm whether these are non-native parasites.

Nico, Leo G.; Sharp, Paul; Collins, Timothy M.

2011-01-01

173

Investigating the Potential Range Expansion of the Vector Mosquito Aedes aegypti in Mexico with NASA Earth Science Remote Sensing Results  

Science.gov (United States)

In tropical and sub-tropical regions, the mosquito Aedes aegypti is the major vector for the virus causing dengue, a serious public health issue in these areas. Through ongoing NSF- and NASA-funded studies, field surveys of Aedes aegypti and an integrated modeling approach are being used to improve our understanding of the potential range of the mosquito to expand toward heavily populated high elevation areas such as Mexico City under various climate change and socio-economic scenarios. This work serves three primary objectives: (1) Employ NASA remotely-sensed data to supplement the environmental monitoring and modeling component of the project. These data -- for example, surface temperature, precipitation, vegetation indices, soil moisture and elevation -- are critical for understanding the habitat necessary for mosquito survival and abundance; (2) Implement training sessions to instruct scientists and students from Mexico and the U.S. on how to use remote sensing and implement the NASA SERVIR Regional Visualization and Monitoring System; (3) Employ the SERVIR framework to optimize the dissemination of key project results in order to increase their societal relevance and benefits in developing climate adaptation strategies. Field surveys of larval, pupal and adult Aedes aegypti, as well as detailed physical and social household characteristics, were conducted in the summers of 2011and 2012 at geographic scales from the household to the community along a transect from sea level to 2400 m ASL. These data are being used in models to estimate Aedes aegypti habitat suitability. In 2011, Aedes aegypti were identified at an elevation of over 2150 m in Puebla, the highest elevation at which this species has been observed.

Crosson, W. L.; Eisen, L.; Estes, M. G.; Estes, S. M.; Hayden, M.; Lozano-Fuentes, S.; Monaghan, A. J.; Moreno Madriñán, M. J.; Ochoa, C.; Quattrochi, D.; Tapia, B.; Welsh-Rodriguez, C. M.

2012-12-01

174

Potentiality of a New Minimum-Order Back-EMF State-Observer Taking Acceleration into Account for Sensorless Vector Control of Permanent-Magnet Synchronous Motors  

Science.gov (United States)

This paper proposes new sensorless vector control methods for permanent-magnet synchronous motors (PMSMs), which are based on a new minimum-order back-EMF state-observer taking acceleration into account, and examines potentiality of the improved back-EMF observer through experiments. Conventional sensorless vector control methods for PMSMs using an estimate of back-EMF are established under the assumption of constant speed or zero acceleration, consequently cannot operate properly at modes requiring rapid speed change especially in low speed region. On the other hand, the proposed back-EMF observer has the following features: 1) it is a new back-EMF state-observer taking acceleration into account and requiring no additional approximation to motor mathematical model; 2) it is a minimum order state-observer; 3) it utilizes motor parameters in the simplest manner; 4) it can be applied to both of salient-pole and non-salient-pole PMSMs; 5) it can be realized in both rotor and stator reference frames. Detailed designs and analyses for the improved state-observer and the sensorless vector control systems in both rotor and stator reference frames are given. In relation to the sensorless vector control systems, this paper newly proposes a double-integral type PLL method and an integral-feedback type acceleration/speed estimation method. Their potentialities are examined through experiments.

Shinnaka, Shinji; Saito, Yoji

175

Mapping the social network: tracking lice in a wild primate (Microcebus rufus population to infer social contacts and vector potential  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Studies of host-parasite interactions have the potential to provide insights into the ecology of both organisms involved. We monitored the movement of sucking lice (Lemurpediculus verruculosus, parasites that require direct host-host contact to be transferred, in their host population of wild mouse lemurs (Microcebus rufus. These lemurs live in the rainforests of Madagascar, are small (40 g, arboreal, nocturnal, solitary foraging primates for which data on population-wide interactions are difficult to obtain. We developed a simple, cost effective method exploiting the intimate relationship between louse and lemur, whereby individual lice were marked, without removal from their host, with an individualized code, and tracked throughout the lemur population. We then tested the hypotheses that 1 the frequency of louse transfers, and thus interactions, would decrease with increasing distance between paired individual lemurs; 2 due to host polygynandry, social interactions and hence louse transfers would increase during the onset of the breeding season; and 3 individual mouse lemurs would vary in their contributions to the spread of lice. Results We show that louse transfers involved 43.75% of the studied lemur population, exclusively males. Louse transfers peaked during the breeding season, perhaps due to increased social interactions between lemurs. Although trap-based individual lemur ranging patterns are restricted, louse transfer rate does not correlate with the distance between lemur trapping locales, indicating wider host ranging behavior and a greater risk of rapid population-wide pathogen transmission than predicted by standard trapping data alone. Furthermore, relatively few lemur individuals contributed disproportionately to the rapid spread of lice throughout the population. Conclusions Using a simple method, we were able to visualize exchanges of lice in a population of cryptic wild primates. This method not only provided insight into the previously unseen parasite movement between lemurs, but also allowed us to infer social interactions between them. As lice are known pathogen vectors, our method also allowed us to identify the lemurs most likely to facilitate louse-mediated epidemics. Our approach demonstrates the potential to uncover otherwise inaccessible parasite-host, and host social interaction data in any trappable species parasitized by sucking lice.

Zohdy Sarah

2012-03-01

176

Elativistic treatment in}$D$ - Dimensions to a spin-zero particle with noncentral equal scalar and vector ring-shaped Kratzer potential  

CERN Multimedia

The Klein-Gordon equation in D-dimensions for a recently proposed Kratzer potential plus ring-shaped potential is solved analytically by means of the conventional Nikiforov-Uvarov method. The exact energy bound-states and the corresponding wave functions of the Klein-Gordon are obtained in the presence of the noncentral equal scalar and vector potentials. The results obtained in this work are more general and can be reduced to the standard forms in three-dimensions given by other works.

Ikhdair, Sameer M

2007-01-01

177

Relativistic treatment in D-dimensions to a spin-zero particle with noncentral equal scalar and vector ring-shaped Kratzer potential  

CERN Document Server

The Klein-Gordon equation in D-dimensions for a recently proposed Kratzer potential plus ring-shaped potential is solved analytically by means of the conventional Nikiforov-Uvarov method. The exact energy bound-states and the corresponding wave functions of the Klein-Gordon are obtained in the presence of the noncentral equal scalar and vector potentials. The results obtained in this work are more general and can be reduced to the standard forms in three-dimensions given by other works.

Ikhdair, Sameer M

2007-01-01

178

Linking land cover and species distribution models to project potential ranges of malaria vectors: an example using Anopheles arabiensis in Sudan and Upper Egypt  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Anopheles arabiensis is a particularly opportunistic feeder and efficient vector of Plasmodium falciparum in Africa and may invade areas outside its normal range, including areas separated by expanses of barren desert. The purpose of this paper is to demonstrate how spatial models can project future irrigated cropland and potential, new suitable habitat for vectors such as An. arabiensis. Methods Two different but complementary spatial models were linked to demonstrate their synergy for assessing re-invasion potential of An. arabiensis into Upper Egypt as a function of irrigated cropland expansion by 2050. The first model (The Land Change Modeler was used to simulate changes in irrigated cropland using a Markov Chain approach, while the second model (MaxEnt uses species occurrence points, land cover and other environmental layers to project probability of species presence. Two basic change scenarios were analysed, one involving a more conservative business-as-usual (BAU assumption and second with a high probability of desert-to-cropland transition (Green Nile to assess a broad range of potential outcomes by 2050. Results The results reveal a difference of 82,000 sq km in potential An. arabiensis range between the BAU and Green Nile scenarios. The BAU scenario revealed a highly fragmented set of small, potential habitat patches separated by relatively large distances (maximum distance?=?64.02?km, mean?=?12.72?km, SD?=?9.92, while the Green Nile scenario produced a landscape characterized by large patches separated by relatively shorter gaps (maximum distance?=?49.38, km, mean?=?4.51?km, SD?=?7.89 that may be bridged by the vector. Conclusions This study provides a first demonstration of how land change and species distribution models may be linked to project potential changes in vector habitat distribution and invasion potential. While gaps between potential habitat patches remained large in the Green Nile scenario, the models reveal large areas of future habitat connectivity that may facilitate the re-invasion of An. arabiensis from Sudan into Upper Egypt. The methods used are broadly applicable to other land cover changes as they influence vector distribution, particularly those related to tropical deforestation and urbanization processes.

Fuller Douglas O

2012-08-01

179

Human-induced expanded distribution of Anopheles plumbeus, experimental vector of West Nile virus and a potential vector of human malaria in Belgium  

Digital Repository Infrastructure Vision for European Research (DRIVER)

For the majority of native species, human-created habitats provide a hostile environment that prevents their colonization. However, if the conditions encountered in this novel environment are part of the fundamental niche of a particular species, these low competitive environments may allow strong population expansion of even rare and stenotopic species. If these species are potentially harmful to humans, such anthropogenic habitat alterations may impose strong risks for human health. Here, w...

Dekoninck, W.; Hendrickx, F.; Bortel, W.; Versteirt, V.; Coosemans, M.; Damiens, D.; Hance, T.; Clercq, E. M.; Hendrickx, G.; Schaffner, F.; Grootaert, P.

2011-01-01

180

Culex quinquefasciatus (Diptera: Culicidae as a potential West Nile virus vector in Tucson, Arizona: Blood meal analysis indicates feeding on both humans and birds  

Directory of Open Access Journals (Sweden)

Full Text Available Most reports from the United States suggest Culex quinquefasciatus mosquitoes feed minimally on humans. Given the abundance of C. quinquefasciatus in residential Tucson and parts of metropolitan Phoenix, and the arrival of West Nile virus to this area, discovering the blood meal hosts of the local population is important. Using a sandwich ELISA technique, the local C. quinquefasciatus were found to feed on both humans and birds. This suggests they should be considered potential West Nile virus vectors.

Margaret Zinser

2004-06-01

 
 
 
 
181

Relativistic Coulomb excitation of the giant dipole resonance in nuclei: How to calculate transition probabilities without invoking the Lienard-Wiechert relativistic scalar and vector potentials  

International Nuclear Information System (INIS)

The conclusions extracted from a recent study of the excitation of giant dipole resonances in nuclei at relativistic bombarding energies open the way for a further simplification of the problem. It consists in the elimination of the relativistic scalar and vector electromagnetic potentials and the familiar numerical difficulties associated with their presence in the calculation scheme. The inherent advantage of a reformulation of the problem of relativistic Coulomb excitation of giant dipole resonances along these lines is discussed

2006-01-01

182

Theileriosis (Cytauxzoonosis in Roan antelope (Hippotragus equinus: Field exposure to infection and identification of potential vectors  

Directory of Open Access Journals (Sweden)

Full Text Available Four hand-reared, naïve roan antelope, 4 months of age, were exposed to naturally infected pasture on a game farm in Mpumalanga Province, South Africa, where roan are known to die from theileriosis. Various clinical parameters were recorded during this period. The predominant ticks parasitising these animals at the time (January to February, were Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi adults. After a period of 5?weeks the animals developed signs of clinical theileriosis and were treated with buparvaquone to prevent mortality. Primary hyperplasia of the local draining lymph nodes (Lnn. anorectales near the feeding site of adult R. evertsi evertsi indicated possible transmission of Theileria sp. (sable by this tick species. After recovery from theileriosis, these animals were confirmed carriers of Theileria sp. (sable by PCR (polymerase chain reaction and DNA probe analysis. Laboratory-bred larvae and nymphs of R. evertsi evertsi and R. appendiculatus respectively, were fed on the ears of these roan antelope. Salivary glands from moulted and prefed adult ticks of each species were dissected and stained for Theileria spp., and the PCR and DNA probe applied to a representative batch of dissected glands. R. appendiculatus adults collected from grass in infected camps were also dissected after prefeeding them on rabbits. Salivary glands of both tick species showed infected acini on staining and were also positive for Theileria sp. (sable only, on multiprotozoal PCR-screening analysis. There was no statistical significant difference between the infection rate and the intensity of infection between the two tick species. R. appendiculatus ticks collected from grass were also PCR-positive for Theileria sp. (sable.

How to cite this article: Steyl, J.C.A., Prozesky, L., Stoltsz, W.H. & Lawrence, J.A., 2012, ‘Theileriosis (Cytauxzoonosis in Roan antelope (Hippotragus equinus: Field exposure to infection and identification of potential vectors’, Onderstepoort Journal of Veterinary Research 79(1, Art. #367, 8 pages. http://dx.doi.org/10.4102/ojvr.v79i1.367

Johan C.A. Steyl

2012-02-01

183

Nucleon and isobar properties in a relativistic Hartree-Fock calculation with vector Richardson potential and various radial forms for scalar mass terms  

International Nuclear Information System (INIS)

Mean field models of the nucleon and the delta are established with the two-quark vector Richardson potential along with various prescriptions for a running quark mass (single particle) in the Dirac-Hartree-Fock formalism. The N-? splitting is obtained from colour magnetic interaction and the results for g_A and magnetic moment are discussed. An effective density dependent one body potential U(?) for quarks at a given density ? inside the nucleon, is derived. Asymptotic freedom and confinement properties are built-in in U (?) and the model dependence is restricted to the intermediate densities. (author). 18 refs, 1 fig., 2 tabs

1990-01-01

184

Nucleon and isobar properties in a relativistic Hartree-Fock calculation with vector Richardson potential and various radial forms for scalar mass terms  

International Nuclear Information System (INIS)

Mean-field models of the nucleon (N) and the delta (?) are established with the two-quark vector Richardson potential along with various prescriptions for a running quark mass (single particle) in the Dirac-Hartree-Fock formalism. The N-? splitting is obtained from colour magnetic interaction and the results for gA and the magnetic moment are discussed. An effective density dependent one-body potential U(?) for quarks at a given density ? inside the nucleon is derived. Asymptotic freedom and confinement properties are built in in U(?) and the model dependence is restricted to the intermediate densities. (Author) 18 refs., fig., 2 tabs

1991-06-01

185

Nucleon and isobar properties in a relativistic Hartree-Fock calculation with vector Richardson potential and various radial forms for scalar mass terms  

International Nuclear Information System (INIS)

Mean field models of the nucleon and the delta are established with the two-quark vector Richardson potential along with various prescriptions for a running quark mass. This is taken to be a one-particle operator in the Dirac-Hartree Fock formalism. An effective density dependent one body potential U(?) for quarks at a given density ? inside the nucleon is derived. It shows an interesting structure. Asymptotic freedom and confinement properties are built-in at high and low densities in U (?) and the model dependence is restricted to the intermediate desnsities. (author)

1989-01-01

186

Bound states of the Klein-Gordon equation for vector and scalar general Hulthen-type potentials in D-dimension  

CERN Document Server

We solve the Klein-Gordon equation in any $D$-dimension for the scalar and vector general Hulth\\'{e}n-type potentials with any $l$ by using an approximation scheme for the centrifugal potential. Nikiforov-Uvarov method is used in the calculations. We obtain the bound state energy eigenvalues and the corresponding eigenfunctions of spin-zero particles in terms of Jacobi polynomials. The eigenfunctions are physical and the energy eigenvalues are in good agreement with those results obtained by other methods for D=1 and 3 dimensions. Our results are valid for $q=1$ value when $l\

Ikhdair, Sameer M

2008-01-01

187

Vector Calculator  

Science.gov (United States)

A simple Java applet enabling users to add two two-dimensional vectors. The user can choose the two vectors by clicking on a grid. The components, magnitude, and direction are immediately shown. Once the two vectors are chosen, a press of a button shows the vector sum, its components, its magnitude and its direction.

Gea-Banacloche

2009-08-10

188

Vector Addition  

Science.gov (United States)

This 2D applet simulates vector addition geometrically. The user selects the angle and magnitude of two vectors, which are then added together by the applet. The resultant vector and the values of its magnitude and angle, as well as the values of the x and y components of all three vectors, are calculated and displayed.

Duffy, Andrew

2004-11-28

189

Preconditioning techniques for constrained vector potential integral equations, with application to 3-D magnetoquasistatic analysis of electronic packages  

Energy Technology Data Exchange (ETDEWEB)

In this paper techniques are presented for preconditioning equations generated by discretizing constrained vector integral equations associated with magnetoquasistatic analysis. Standard preconditioning approaches often fail on these problems. The authors present a specialized preconditioning technique and prove convergence bounds independent of the constraint equations and electromagnetic excitation frequency. Computational results from analyzing several electronic packaging examples are given to demonstrate that the new preconditioning approach can sometimes reduce the number of GMRES iterations by more than an order of magnitude.

Kamon, M.; Phillips, J.R. [Massachusetts Institute of Technology, Cambridge, MA (United States)

1994-12-31

190

Increasing transduction efficiency of recombinant murine retrovirus vectors by initiation of endogenous reverse transcription: potential utility for genetic therapies.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reverse transcription of retroviral genomic RNA in a target cell is influenced by cellular factors, including the concentration of deoxyribonucleoside triphosphates (dNTPs). In addition, recent data have demonstrated that reverse transcription can be driven within human immunodeficiency virus type 1 virions, prior to infection of a cell, by increasing extracellular concentrations of dNTPs. In attempts to increase the transduction efficiency of recombinant murine leukemia virus vectors, endoge...

1995-01-01

191

Bound states of the Klein-Gordon equation in D-dimensions with some physical scalar and vector exponential-type potentials including orbital centrifugal term  

CERN Multimedia

The approximate analytic bound state solutions of the Klein-Gordon equation with equal scalar and vector exponential-type potentials including the centrifugal potential term are obtained for any arbitrary orbital angular momentum number l and dimensional space D. The relativistic/non-relativistic energy spectrum equation and the corresponding unnormalized radial wave functions, in terms of the Jacobi polynomials P_{n}^{({\\alpha},{\\beta})}(z), where {\\alpha}>-1, {\\beta}>-1 and z\\in[-1,+1] or the generalized hypergeometric functions _{2}F_{1}(a,b;c;z), are found. The Nikiforov-Uvarov (NU) method is used in the solution. The solutions of the Eckart, Rosen-Morse, Hulth\\'en and Woods-Saxon potential models can be easily obtained from these solutions. Our results are identical with those ones appearing in the literature. Finally, under the PT-symmetry, we can easily obtain the bound state solutions of the trigonometric Rosen-Morse potential.

Ikhdair, Sameer M

2011-01-01

192

Mosquitos vetores potenciais de dirofilariose canina na Região Nordeste do Brasil / Mosquitoes potential vectors of canine heartworm in the Northeast Region from Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Portuguese Abstract in portuguese INTRODUÇÃO: Em alguns bairros costeiros de São Luís, Maranhão, a prevalência da dirofilariose chega a mais de 40% entre os cães domiciliados. Porém, desconhecem-se os vetores naturais, tanto lá quanto no resto do Nordeste do país. O objetivo do estudo foi identificar os prováveis vetores dessa paras [...] itose. MÉTODOS: Realizaram-se coletas mensais de mosquitos em um bairro costeiro de São Luís, MA, de março de 1996 a maio de 1997, no peridomicílio, tendo cão e homem como iscas. Os mosquitos foram dissecados para a pesquisa de larvas da Dirofilaria immitis. RESULTADOS: Coletaram-se 1.738 mosquitos de 11 espécies. Culex quinquefasciatus, capturada todos os meses, porém menos freqüente na estação chuvosa, correspondeu a 54,5% do total, seguido de Aedes albopictus (20,3%), Aedes taeniorhynchus e Aedes scapularis (ambos 11%). Larvas de D.immitis foram encontradas em 0,1% dos Cx. quinquefasciatus e 0,5% dos Ae. taeniorhynchus. CONCLUSÕES: Ae. taeniorhynchus e Cx. quinquefasciatus foram considerados vetores potenciais da dirofilariose em São Luís. A importância local de Cx. quinquefasciatus como transmissor primário da D. immitis necessita ser melhor avaliada. Abstract in english INTRODUCTION: In some coastal districts of São Luís, capital of the state of Maranhão, Brazil, the prevalence of Dirofilaria immitis is more than 40% in house dogs. Natural potential vectors, as found in other areas of Northeastern Brazil, are unknown. The aim of this study was to identify probable [...] vectors of the disease. METHODS: Mosquito catches were performed at a coastal, district Olho d'Água, in S. Luís, to look for local potential vectors. Captures were carried out monthly, from March 1996 to May 1997, outdoors, having a man and a dog as baits. Mosquitoes were dissected for D. immitis larvae. RESULTS: A total of 1,738 mosquitoes belonging to 11 species were collected. Culex quinquefasciatus, the only species collected every month, was more frequently in the dry season. It accounted for 54.5% of the total, followed by Aedes albopictus (20.3%), Ae. scapularis (11%) and Ae. taeniorhynchus (11%). D. immitis larvae were detected in 0.1% of the Cx. quinquefasciatus dissected (L3 in the Malpighian tubules) and 0.5% of the Ae. taeniorhynchus (L2 in the Malpighian tubules). CONCLUSION: Ae. taeniorhynchus and Cx. quinquefasciatus are considered natural potential vectors of the canine heartworm in São Luís. The role of Cx. quinquefasciatus as primary vector of D. immitis, however, needs further evaluation.

Silvia MM, Ahid; Ricardo, Lourenço-de-Oliveira.

193

Mosquitos vetores potenciais de dirofilariose canina na Região Nordeste do Brasil / Mosquitoes potential vectors of canine heartworm in the Northeast Region from Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese INTRODUÇÃO: Em alguns bairros costeiros de São Luís, Maranhão, a prevalência da dirofilariose chega a mais de 40% entre os cães domiciliados. Porém, desconhecem-se os vetores naturais, tanto lá quanto no resto do Nordeste do país. O objetivo do estudo foi identificar os prováveis vetores dessa paras [...] itose. MÉTODOS: Realizaram-se coletas mensais de mosquitos em um bairro costeiro de São Luís, MA, de março de 1996 a maio de 1997, no peridomicílio, tendo cão e homem como iscas. Os mosquitos foram dissecados para a pesquisa de larvas da Dirofilaria immitis. RESULTADOS: Coletaram-se 1.738 mosquitos de 11 espécies. Culex quinquefasciatus, capturada todos os meses, porém menos freqüente na estação chuvosa, correspondeu a 54,5% do total, seguido de Aedes albopictus (20,3%), Aedes taeniorhynchus e Aedes scapularis (ambos 11%). Larvas de D.immitis foram encontradas em 0,1% dos Cx. quinquefasciatus e 0,5% dos Ae. taeniorhynchus. CONCLUSÕES: Ae. taeniorhynchus e Cx. quinquefasciatus foram considerados vetores potenciais da dirofilariose em São Luís. A importância local de Cx. quinquefasciatus como transmissor primário da D. immitis necessita ser melhor avaliada. Abstract in english INTRODUCTION: In some coastal districts of São Luís, capital of the state of Maranhão, Brazil, the prevalence of Dirofilaria immitis is more than 40% in house dogs. Natural potential vectors, as found in other areas of Northeastern Brazil, are unknown. The aim of this study was to identify probable [...] vectors of the disease. METHODS: Mosquito catches were performed at a coastal, district Olho d'Água, in S. Luís, to look for local potential vectors. Captures were carried out monthly, from March 1996 to May 1997, outdoors, having a man and a dog as baits. Mosquitoes were dissected for D. immitis larvae. RESULTS: A total of 1,738 mosquitoes belonging to 11 species were collected. Culex quinquefasciatus, the only species collected every month, was more frequently in the dry season. It accounted for 54.5% of the total, followed by Aedes albopictus (20.3%), Ae. scapularis (11%) and Ae. taeniorhynchus (11%). D. immitis larvae were detected in 0.1% of the Cx. quinquefasciatus dissected (L3 in the Malpighian tubules) and 0.5% of the Ae. taeniorhynchus (L2 in the Malpighian tubules). CONCLUSION: Ae. taeniorhynchus and Cx. quinquefasciatus are considered natural potential vectors of the canine heartworm in São Luís. The role of Cx. quinquefasciatus as primary vector of D. immitis, however, needs further evaluation.

Silvia MM, Ahid; Ricardo, Lourenço-de-Oliveira.

194

Mosquitos vetores potenciais de dirofilariose canina na Região Nordeste do Brasil Mosquitoes potential vectors of canine heartworm in the Northeast Region from Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUÇÃO: Em alguns bairros costeiros de São Luís, Maranhão, a prevalência da dirofilariose chega a mais de 40% entre os cães domiciliados. Porém, desconhecem-se os vetores naturais, tanto lá quanto no resto do Nordeste do país. O objetivo do estudo foi identificar os prováveis vetores dessa parasitose. MÉTODOS: Realizaram-se coletas mensais de mosquitos em um bairro costeiro de São Luís, MA, de março de 1996 a maio de 1997, no peridomicílio, tendo cão e homem como iscas. Os mosquitos foram dissecados para a pesquisa de larvas da Dirofilaria immitis. RESULTADOS: Coletaram-se 1.738 mosquitos de 11 espécies. Culex quinquefasciatus, capturada todos os meses, porém menos freqüente na estação chuvosa, correspondeu a 54,5% do total, seguido de Aedes albopictus (20,3%, Aedes taeniorhynchus e Aedes scapularis (ambos 11%. Larvas de D.immitis foram encontradas em 0,1% dos Cx. quinquefasciatus e 0,5% dos Ae. taeniorhynchus. CONCLUSÕES: Ae. taeniorhynchus e Cx. quinquefasciatus foram considerados vetores potenciais da dirofilariose em São Luís. A importância local de Cx. quinquefasciatus como transmissor primário da D. immitis necessita ser melhor avaliada.INTRODUCTION: In some coastal districts of São Luís, capital of the state of Maranhão, Brazil, the prevalence of Dirofilaria immitis is more than 40% in house dogs. Natural potential vectors, as found in other areas of Northeastern Brazil, are unknown. The aim of this study was to identify probable vectors of the disease. METHODS: Mosquito catches were performed at a coastal, district Olho d'Água, in S. Luís, to look for local potential vectors. Captures were carried out monthly, from March 1996 to May 1997, outdoors, having a man and a dog as baits. Mosquitoes were dissected for D. immitis larvae. RESULTS: A total of 1,738 mosquitoes belonging to 11 species were collected. Culex quinquefasciatus, the only species collected every month, was more frequently in the dry season. It accounted for 54.5% of the total, followed by Aedes albopictus (20.3%, Ae. scapularis (11% and Ae. taeniorhynchus (11%. D. immitis larvae were detected in 0.1% of the Cx. quinquefasciatus dissected (L3 in the Malpighian tubules and 0.5% of the Ae. taeniorhynchus (L2 in the Malpighian tubules. CONCLUSION: Ae. taeniorhynchus and Cx. quinquefasciatus are considered natural potential vectors of the canine heartworm in São Luís. The role of Cx. quinquefasciatus as primary vector of D. immitis, however, needs further evaluation.

Silvia MM Ahid

1999-12-01

195

Index Sets and Vectorization  

Energy Technology Data Exchange (ETDEWEB)

Vectorization is data parallelism (SIMD, SIMT, etc.) - extension of ISA enabling the same instruction to be performed on multiple data items simultaeously. Many/most CPUs support vectorization in some form. Vectorization is difficult to enable, but can yield large efficiency gains. Extra programmer effort is required because: (1) not all algorithms can be vectorized (regular algorithm structure and fine-grain parallelism must be used); (2) most CPUs have data alignment restrictions for load/store operations (obey or risk incorrect code); (3) special directives are often needed to enable vectorization; and (4) vector instructions are architecture-specific. Vectorization is the best way to optimize for power and performance due to reduced clock cycles. When data is organized properly, a vector load instruction (i.e. movaps) can replace 'normal' load instructions (i.e. movsd). Vector operations can potentially have a smaller footprint in the instruction cache when fewer instructions need to be executed. Hybrid index sets insulate users from architecture specific details. We have applied hybrid index sets to achieve optimal vectorization. We can extend this concept to handle other programming models.

Keasler, J A

2012-03-27

196

Human Antibody Response to Aedes albopictus Salivary Proteins: A Potential Biomarker to Evaluate the Efficacy of Vector Control in an Area of Chikungunya and Dengue Virus Transmission  

Science.gov (United States)

Aedes borne viruses represent public health problems in southern countries and threat to emerge in the developed world. Their control is currently based on vector population control. Much effort is being devoted to develop new tools to control such arbovirus. Recent findings suggest that the evaluation of human antibody (Ab) response to arthropod salivary proteins is relevant to measuring the level of human exposure to mosquito bites. Using an immunoepidemiological approach, the present study aimed to assess the usefulness of the salivary biomarker for measuring the efficacy of Ae. albopictus control strategies in La Reunion urban area. The antisaliva Ab response of adult humans exposed to Ae. albopictus was evaluatedbefore and after vector control measures. Our results showed a significant correlation between antisaliva Ab response and the level of exposure to vectors bites. The decrease of Ae. albopictus density has been detected by this biomarker two weeks after the implementation of control measures, suggesting its potential usefulness for evaluating control strategies in a short time period. The identification of species specific salivary proteins/peptides should improve the use of this biomarker.

Doucoure, Souleymane; Mouchet, Francois; Cornelie, Sylvie; Drame, Papa Makhtar; D'Ortenzio, Eric; DeHecq, Jean Sebastien; Remoue, Franck

2014-01-01

197

Human Antibody Response to Aedes albopictus Salivary Proteins: A Potential Biomarker to Evaluate the Efficacy of Vector Control in an Area of Chikungunya and Dengue Virus Transmission.  

Science.gov (United States)

Aedes borne viruses represent public health problems in southern countries and threat to emerge in the developed world. Their control is currently based on vector population control. Much effort is being devoted to develop new tools to control such arbovirus. Recent findings suggest that the evaluation of human antibody (Ab) response to arthropod salivary proteins is relevant to measuring the level of human exposure to mosquito bites. Using an immunoepidemiological approach, the present study aimed to assess the usefulness of the salivary biomarker for measuring the efficacy of Ae. albopictus control strategies in La Reunion urban area. The antisaliva Ab response of adult humans exposed to Ae. albopictus was evaluatedbefore and after vector control measures. Our results showed a significant correlation between antisaliva Ab response and the level of exposure to vectors bites. The decrease of Ae. albopictus density has been detected by this biomarker two weeks after the implementation of control measures, suggesting its potential usefulness for evaluating control strategies in a short time period. The identification of species specific salivary proteins/peptides should improve the use of this biomarker. PMID:24822216

Doucoure, Souleymane; Mouchet, François; Cornelie, Sylvie; Drame, Papa Makhtar; D'Ortenzio, Eric; Dehecq, Jean Sébastien; Remoue, Franck

2014-01-01

198

$SU(1,1)$ coherent states for Dirac-Kepler-Coulomb problem in $D+1$ dimensions with scalar and vector potentials  

CERN Document Server

We decouple the Dirac's radial equations in $D+1$ dimensions with Coulomb-type scalar and vector potentials through appropriate transformations. We study each of these uncoupled second-order equations in an algebraic way by using an $su(1,1)$ algebra realization. Based on the theory of irreducible representations, we find the energy spectrum and the radial eigenfunctions. We construct the Perelomov coherent states for the Sturmian basis, which is the basis for the unitary irreducible representation of the $su(1,1)$ Lie algebra. The physical radial coherent states for our problem are obtained by applying the inverse original transformations to the Sturmian coherent states.

Ojeda-Guillen, D; Granados, V D

2013-01-01

199

Role of Culex and Anopheles mosquito species as potential vectors of rift valley fever virus in Sudan outbreak, 2007  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Rift Valley fever (RVF is an acute febrile arthropod-borne viral disease of man and animals caused by a member of the Phlebovirus genus, one of the five genera in the family Bunyaviridae. RVF virus (RVFV is transmitted between animals and human by mosquitoes, particularly those belonging to the Culex, Anopheles and Aedes genera. Methods Experiments were designed during RVF outbreak, 2007 in Sudan to provide an answer about many raised questions about the estimated role of vector in RVFV epidemiology. During this study, adult and immature mosquito species were collected from Khartoum and White Nile states, identified and species abundance was calculated. All samples were frozen individually for further virus detection. Total RNA was extracted from individual insects and RVF virus was detected from Culex, Anopheles and Aedes species using RT-PCR. In addition, data were collected about human cases up to November 24th, 2007 to asses the situation of the disease in affected states. Furthermore, a historical background of the RVF outbreaks was discussed in relation to global climatic anomalies and incriminated vector species. Results A total of 978 mosquitoes, belonging to 3 genera and 7 species, were collected during Sudan outbreak, 2007. Anopheles gambiae arabiensis was the most frequent species (80.7% in White Nile state. Meanwhile, Cx. pipiens complex was the most abundant species (91.2% in Khartoum state. RT-PCR was used and successfully amplified 551 bp within the M segment of the tripartite negative-sense single stranded RNA genome of RVFV. The virus was detected in female, male and larval stages of Culex and Anopheles species. The most affected human age interval was 15-29 years old followed by ? 45 years old, 30-44 years old, and then 5-14 years old. Regarding to the profession, housewives followed by farmers, students, shepherd, workers and the free were more vulnerable to the infection. Furthermore, connection between human and entomological studies results in important human case-vulnerability relatedness findings. Conclusion Model performance, integrated with epidemiologic and environmental surveillance systems should be assessed systematically for RVF and other mosquito-borne diseases using historical epidemiologic and satellite monitoring data. Case management related interventions; health education and vector control efforts are extremely effective in preparedness for viral hemorrhagic fever and other seasonal outbreaks.

Galal Fatma H

2010-03-01

200

A survey of mosquitoes breeding in used tires in Spain for the detection of imported potential vector species.  

Science.gov (United States)

The used tire trade has facilitated the introduction, spread, and establishment of the Asian tiger mosquito, Aedes albopictus, and other mosquito species in several countries of America, Africa, Oceania, and Europe. A strategy for detecting these imported mosquito vectors was developed in Spain during 2003-2004 by EVITAR (multidisciplinary network for the study of viruses transmitted by arthropods and rodents). A survey in 45 locations found no invasive species. Eight autochthonous species of mosquitoes were detected in used tires, including Culex pipiens, Cx. hortensis, Cx. modestus, Anopheles atroparvus, An. claviger, Culiseta longiareolata, Cs. annulata, and Aedes caspius. Dominant species were Cx. pipiens and Cs. longiareolata. Aedes caspius was found in only once, near its natural breeding habitat. Considering the recent discovery of an established population of Ae. albopictus in Catalonia, the increasing commerce of used tires in Spain for recycling, storage, and recapping might greatly contribute to the rapid spread of this species across the Iberian Peninsula. PMID:17633420

Roiz, D; Eritja, R; Escosa, R; Lucientes, J; Marquès, E; Melero-Alcíbar, R; Ruiz, S; Molina, R

2007-06-01

 
 
 
 
201

Host-feeding patterns of Culex pipiens and other potential mosquito vectors (Diptera: Culicidae) of West Nile virus (Flaviviridae) collected in Portugal.  

Science.gov (United States)

The host blood-feeding patterns of mosquito vectors affects the likelihood of human exposure to zoonotic pathogens, including West Nile Virus (family Flaviviridae, genus Flavivirus, WNV). In Portugal, data are unavailable regarding the blood-feeding habits of common mosquito species, including Culex pipiens L., considered the primary vector of WNV to humans. The sources of bloodmeals in 203 blood-fed mosquitoes of nine species collected from June 2007 to November 2010 in 34 Portuguese counties were analyzed by sequencing cytochrome-b partial fragments. Cx. pipiens was the most common species collected and successfully analyzed (n = 135/78). In addition, blood-fed females of the following species were analyzed: Ochlerotatus caspius Pallas (n = 20), Culex theileri Theobald (n = 16), Anopheles maculipennis s.l. Meigen (n = 10), Culiseta longiareolata Macquart (n = 7), Aedes aegypti L. (n = 6), Culex perexiguus Theobald (n = 3), Culiseta annulata Schrank (n = 3), and Ochlerotatus detritus Haliday (n = 3). The Cx. pipiens mosquitoes fed predominantly on birds (n = 55/78, 70.5%), with a high diversity of avian species used as hosts, although human blood was identified in 18 specimens (18/78, 23.1%). No significant differences were found between the host-feeding patterns of blood-fed Cx. pipiens collected in residential and nonresidential habitats. The occurrence of human derived blood meals and the presence of a mix avian-human bloodmeal accordingly suggest this species as a potential vector of WNV. Therefore, in Portugal, Cx. pipiens may play a role both in the avian-to-avian enzootic WNV cycle and in the avian-to-mammal transmission. In this context, the identity of Cx. pipiens (considering the forms molestus and pipiens) and the potential consequence on feeding behavior and WNV transmission are discussed. PMID:22679881

Osório, Hugo Costa; Zé-Zé, Líbia; Alves, Maria João

2012-05-01

202

Laboratory studies of a Brazilian strain of Aedes albopictus as a potential vector of Mayaro and Oropouche viruses.  

Science.gov (United States)

The vector efficiency of colonized Aedes albopictus from Brazil was assessed for Mayaro (MAY) and Oropouche (ORO) viruses. Female mosquitoes, 3-4 days old, were fed on a MAY-infected hamster with a viremia level of 5.3 log10 Vero cell plaque-forming units (PFU) of virus/ml or an ORO-infected hamster circulating 7.3 log10 PFU/ml. Mayaro infection rates among fed mosquitoes were 16.9 and 11% at 6, 13 and 20 days postfeeding, respectively, and 1/2 and 2/2 infected mosquitoes transmitted virus on days 13 and 20, respectively. Only 13, 5 and 3% of mosquitoes were infected with ORO virus at 6, 13 and 20 days, respectively, and no transmission occurred. Mosquitoes were also fed on 3 dilutions of MAY virus-blood suspensions in membrane feeders. The infection rate among mosquitoes fed the highest concentration (7.7 log10 PFU/ml) was 11/13 (85%), and 5/11 (46%) infected mosquitoes transmitted virus. PMID:1646286

Smith, G C; Francy, D B

1991-03-01

203

Geographical distribution and relative abundance of stock-associated Culicoides species (Diptera: Ceratopogonidae) in southern Africa in relation to their potential as viral vectors.  

Science.gov (United States)

To determine the geographical distribution and relative abundance of Culicoides species associated with livestock, 220-V down-draught light-traps equipped with 8-W blacklight tubes were operated at 34 sites in different climatic regions in South Africa and Lesotho. From January 1984 to September 1986, 3 041 631 Culicoides, belonging to at least 50 species, were collected in a total of 959 collections. Of these, 572 412 individuals were identified and sexed. Culicoides species were found to be widespread in South Africa and were collected in varying numbers at all the sites sampled. The average catch size, however, was larger in frost-free areas than in areas with extreme winters. The more abundant and widespread species, which have the potential to be vectors of stock-associated viruses such as bluetongue and African horsesickness, were C. imicola, C. leucostictus, C. schultzei s.l., C. pycnostictus, C. nivosus, C. similis, C. zuluensis, C. magnus, C. bedfordi, C. neavei, C. brucei, C. tropicalis, C. exspectator, C. gulbenkiani, C. bolitinos, C. ravus, C. coarctatus and C. onderstepoortensis. Of these, C. imicola was the most abundant species, being dominant at 17 of the 34 sites sampled and accounting for 71.4% of the specimens collected. As C. imicola is relatively uncommon in hot and dry as well as cool and wet areas, this species cannot be regarded as the only vector of stock-associated viruses in southern Africa. Further laboratory vector-competence studies, i.e. determination of viral-infection and -transmission rates, should first concentrate on the above-mentioned Culicoides species, especially those known to feed on livestock. PMID:8848300

Venter, G J; Nevill, E M; Van der Linde, T C

1996-03-01

204

Synthesis, and Characterization, and Evaluation of Cellular Effects of the FOL-PEG-g-PEI-GAL Nanoparticles as a Potential Non-Viral Vector for Gene Delivery  

Directory of Open Access Journals (Sweden)

Full Text Available In this manuscript, we synthesized the potential non viral vector for gene delivery with proper transfection efficiency and low cytotoxicity. Polyethylenimine (PEI is a well-known cationic polymer which has high positive surface charge for condensing plasmid DNA. However; it is highly cytotoxic in many cell lines because of the high surface charge, non-biodegradability and non-biocompatibility. To enhance PEI biodegradability, the graft copolymer “PEG-g-PEI” was synthesized. To target cancer liver cells, two targeting ligands folic acid and galactose (lactobionic acid which are over expressed on human hepatocyte carcinoma were attached to graft copolymer and “FOL-PEG-g-PEI-GAL” copolymer was synthesized. Composition of this grafted copolymer was characterized using 1H-NMR and FTIR spectra. The molecular weight and zeta potential of this copolymer was compared to PEI. The particle size and zeta potential of FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratio were measured using dynamic light scattering (DLS. Cytotoxicity of the copolymer was also studied in cultured HepG2 human hepatoblastoma cell line. The FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratios exhibited no cytotoxicity in HepG2 cell line compared to PEI 25K as a control. The novel copolymer showed enhanced biodegradability in physiological conditions in compared with PEI and targeted cultured HepG2 cells. More importantly, significant transfection efficiency was exhibited in cancer liver cells. Together, our results showed that “FOL-PEG-g-PEI-GAL” nanoparticals could be considered as a useful non-viral vector for targeted gene delivery.

S. Ghiamkazemi

2010-01-01

205

Synthesis, and Characterization, and Evaluation of Cellular Effects of the FOL-PEG-g-PEI-GAL Nanoparticles as a Potential Non-Viral Vector for Gene Delivery  

International Nuclear Information System (INIS)

In this manuscript, we synthesized the potential non viral vector for gene delivery with proper transfection efficiency and low cytotoxicity. Polyethylenimine (PEI) is a well-known cationic polymer which has high positive surface charge for condensing plasmid DNA. However; it is highly cytotoxic in many cell lines because of the high surface charge, non-biodegradability and non-biocompatibility. To enhance PEI biodegradability, the graft copolymer PEG-g-PEI was synthesized. To target cancer liver cells, two targeting ligands folic acid and galactose (lactobionic acid) which are over expressed on human hepatocyte carcinoma were attached to graft copolymer and FOL-PEG-g-PEI-GAL copolymer was synthesized. Composition of this grafted copolymer was characterized using 1H-NMR and FTIR spectra. The molecular weight and zeta potential of this copolymer was compared to PEI. The particle size and zeta potential of FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratio were measured using dynamic light scattering (DLS). Cytotoxicity of the copolymer was also studied in cultured HepG2 human hepatoblastoma cell line. The FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratios exhibited no cytotoxicity in HepG2 cell line compared to PEI 25K as a control. The novel copolymer showed enhanced biodegradability in physiological conditions in compared with PEI and targeted cultured HepG2 cells. More importantly, significant transfection efficiency was exhibited in cancer liver cells. Together, our results showed that FOL-PEG-g-PEI-GAL nanoparticles could be considered as a useful non-viral vector for targeted gene delivery.

2010-01-01

206

Influence of container design on predation rate of potential biocontrol agent, Toxorhynchites splendens (Diptera: Culicidae) against dengue vector.  

Science.gov (United States)

Toxorhynchites splendens larvae are a natural predator of dengue vector mosquito larvae, Aedes albopictus. This study was carried out to evaluate the predation rate of Tx. splendens third instar larvae on Ae. albopictus larvae in 24 h. Each predator was offered prey at a density between 10 to 50 individuals. Predation rate of Tx. splendens were also tested with two manipulated factors; various types of container and different water volumes. The experiment was evaluated in man-made containers (tin cans, plastic drinking glasses and rubber tires) and natural container (bamboo stumps) which were filled with different water volumes (full, half full, 1/4 full, and 1/8 full). The prey density and the characteristics of the container were found as significant factors which influence the predation rate of Tx. splendens. The predator consumed significantly more prey at higher prey densities (40 and 50 preys) compared to the lowest density (10 preys) (F=3.935, df=4, p=0.008). The results showed significantly higher consumption in horizontal shaped container of rubber tire than in vertical shape of bamboo stumps (F=3.100, df=3, p=0.029). However, the water volume had no significant effect on predation rate of Tx. splendens (F=1.736, df=3, p=0.162). We generally suggest that Tx. splendens is best to be released in discarded tires or any other containers with horizontal shape design with wide opening since Tx. splendens can become more effective in searching prey in this type of container design. This predator is also a suitable biocontrol candidates to be introduced either in wet and dry seasons in Malaysia. PMID:24862057

Mohamad, N; Zuharah, W F

2014-03-01

207

Vectorization, parallelization and porting of nuclear codes (porting). Progress report fiscal 1998  

International Nuclear Information System (INIS)

Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 12 codes in fiscal 1998. These results are reported in 3 parts, i.e., the vectorization and parallelization on vector processors part, the parallelization on scalar processors part and the porting part. In this report, we describe the porting. In this porting part, the porting of Monte Carlo N-Particle Transport code MCNP4B2 and Reactor Safety Analysis code RELAP5 on the AP3000 are described. In the vectorization and parallelization on vector processors part, the vectorization of General Tokamak Circuit Simulation Program code GTCSP, the vectorization and parallelization of Molecular Dynamics Ntv Simulation code MSP2, Eddy Current Analysis code EDDYCAL, Thermal Analysis Code for Test of Passive Cooling System by HENDEL T2 code THANPACST2 and MHD Equilibrium code SELENEJ on the VPP500 are described. In the parallelization on scalar processors part, the parallelization of Monte Carlo N-Particle Transport code MCNP4B2, Plasma Hydrodynamics code using Cubic Interpolated propagation Method PHCIP and Vectorized Monte Carlo code (continuous energy model/multi-group model) MVP/GMVP on the Paragon are described. (author)

208

Vectorization, parallelization and porting of nuclear codes (Parallelization on scalar processors). Progress report fiscal 1998  

Energy Technology Data Exchange (ETDEWEB)

Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 12 codes in fiscal 1998. These results are reported in 3 parts, i.e., the vectorization and parallelization on vector processors part, the parallelization on scalar processors part and the porting part. In this report, we describe the parallelization on scalar processors. In this parallelization on scalar processors part, the parallelization of Monte Carlo N-Particle Transport code MCNP4B2, Plasma Hydrodynamics code using Cubic Interpolated Propagation Method PHCIP and Vectorized Monte Carlo code (continuous energy model / multi-group model) MVP/GMVP on the Paragon are described. In the vectorization and parallelization on vector processors part, the vectorization of General Tokamak Circuit Simulation Program code GTCSP, the vectorization and parallelization of Molecular Dynamics Ntv Simulation code MSP2, Eddy Current Analysis code EDDYCAL, Thermal Analysis Code for Test of Passive Cooling System by HENDEL T2 code THANPACST2 and MHD Equilibrium code SELENEJ on the VPP500 are described. In the porting part, the porting of Monte Carlo N-Particle Transport code MCNP4B2 and Reactor Safety Analysis code RELAP5 on the AP3000 are described. (author)

Yatake, Yo-ichi [Hitachi Ltd., Tokyo (Japan); Adachi, Masaaki; Kume, Etsuo; Kawasaki, Nobuo; Ogasawara, Shinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kawai, Wataru; Nemoto, Toshiyuki; Ishizuki, Shigeru [Fujitsu Ltd., Tokyo (Japan)

2000-03-01

209

Vectorization, parallelization and porting of nuclear codes (porting). Progress report fiscal 1998  

Energy Technology Data Exchange (ETDEWEB)

Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 12 codes in fiscal 1998. These results are reported in 3 parts, i.e., the vectorization and parallelization on vector processors part, the parallelization on scalar processors part and the porting part. In this report, we describe the porting. In this porting part, the porting of Monte Carlo N-Particle Transport code MCNP4B2 and Reactor Safety Analysis code RELAP5 on the AP3000 are described. In the vectorization and parallelization on vector processors part, the vectorization of General Tokamak Circuit Simulation Program code GTCSP, the vectorization and parallelization of Molecular Dynamics Ntv Simulation code MSP2, Eddy Current Analysis code EDDYCAL, Thermal Analysis Code for Test of Passive Cooling System by HENDEL T2 code THANPACST2 and MHD Equilibrium code SELENEJ on the VPP500 are described. In the parallelization on scalar processors part, the parallelization of Monte Carlo N-Particle Transport code MCNP4B2, Plasma Hydrodynamics code using Cubic Interpolated propagation Method PHCIP and Vectorized Monte Carlo code (continuous energy model/multi-group model) MVP/GMVP on the Paragon are described. (author)

Nemoto, Toshiyuki; Kawai, Wataru; Ishizuki, Shigeru [Fujitsu Ltd., Tokyo (Japan); Kawasaki, Nobuo; Kume, Etsuo; Adachi, Masaaki; Ogasawara, Shinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yatake, Yo-ichi [Hitachi Ltd., Tokyo (Japan)

2000-03-01

210

Retention and tissue damage of PSP and NSP toxins in shrimp: Is cultured shrimp a potential vector of toxins to human population?  

Science.gov (United States)

Toxic microalgae outbreaks have caused significant economic losses in the Mexican aquaculture industry. Blooms that involve PSP and NSP phycotoxins are two of the most dangerous, causing harmful effects to the environment, economy and public health. The exact metabolic mechanism of these toxins in shrimp still remains unknown. Because shrimp consume microalgae their edible tissues are clearly possible vectors for human toxic syndrome. This study examined and verified the toxicological effects for white leg shrimp (Litopenaeus vannamei) exposed to different cell densities of Gymnodinium catenatum and Karenia brevis. Acute assays demonstrated good survival rates of shrimp at low densities of dinoflagellates (10(3) cell/L), while mortality and abnormal behavior were observed with higher densities (>10(4) cell/L). Chronic assays showed significant differences in survival rates, percentage of feed and weight gain of organisms exposed to the dinoflagellates with respect to controls. Furthermore, PSP and NSP toxins were detected in all the edible tissues. Gastric glands and muscle retained toxins for a longer period of time compared to other tissues, even after a depuration period. Histology damages were observed in the heart, gastric gland and brain. This study strongly supports that shrimp represent a potential risk for humans as unconventional vectors of phycotoxins. PMID:19028514

Pérez Linares, Jesús; Ochoa, José Luis; Gago Martínez, Ana

2009-02-01

211

The enzyme 3-hydroxykynurenine transaminase as potential target for 1,2,4-oxadiazoles with larvicide activity against the dengue vector Aedes aegypti.  

Science.gov (United States)

The mosquito Aedes aegypti is the vector agent responsible for the transmission of yellow fever and dengue fever viruses to over 80 million people in tropical and subtropical regions of the world. Exhaustive efforts have lead to a vaccine candidate with only 30% effectiveness against the dengue virus and failure to protect patients against the serotype 2. Hence, vector control remains the most viable route to dengue fever control programs. We have synthesized a class of 1,2,4-oxadiazole derivatives whose most biologically active compounds exhibit potent activity against Aedes aegypti larvae (ca. of 15 ppm) and low toxicity in mammals. Exposure to these larvicides results in larvae pigmentation in a manner correlated with the LC50 measurements. Structural comparisons of the 1,2,4-oxadiazole nucleus against known inhibitors of insect enzymes allowed the identification of 3-hydroxykynurenine transaminase as a potential target for these synthetic larvicides. Molecular docking calculations indicate that 1,2,4-oxadiazole compounds can bind to 3-hydroxykynurenine transaminase with similar conformation and binding energies as its crystallographic inhibitor 4-(2-aminophenyl)-4-oxobutanoic acid. PMID:24095017

Oliveira, Vanessa S; Pimenteira, Cecília; da Silva-Alves, Diana C B; Leal, Laylla L L; Neves-Filho, Ricardo A W; Navarro, Daniela M A F; Santos, Geanne K N; Dutra, Kamilla A; dos Anjos, Janaína V; Soares, Thereza A

2013-11-15

212

Which potential. A comparison of the various scalar and vector potentials for the numerical solution of the non-linear poisson problem  

International Nuclear Information System (INIS)

This paper summarises the formulation and results of a study aimed at deciding which potential definition to select for constructing a set of computer algorithms for the non-linear Poissonian field problem. The two dimensional Magnetostatic case is used in this investigation and solutions are presented for shielding and motor problems. Of the four potentials considered the choice of a double scalar potential appears to offer the most attractive formulation for extension to three dimensions. The report contains results for the first part of an on-going study which is ultimately to develop an efficient full three dimensional non-linear field computer program. (author)

1978-01-01

213

Production of neutron cross section library based on JENDL-4.0 to continuous-energy Monte Carlo code MVP and its application to criticality analysis of benchmark problems in the ICSBEP handbook  

International Nuclear Information System (INIS)

In May 2010, JENDL-4.0 was released from Japan Atomic Energy Agency as the updated Japanese Nuclear Data Library. It was processed by the nuclear data processing system LICEM and an arbitrary-temperature neutron cross section library MVPlib-nJ40 was produced for the neutron and photon transport calculation code MVP based on the continuous-energy Monte Carlo method. The library contains neutron cross sections for 406 nuclides on the free gas model, thermal scattering cross sections, and cross sections of pseudo fission products for burn-up calculations with MVP. Criticality benchmark calculations were carried out with MVP and MVPlib-nJ40 for about 1,000 cases of critical experiments stored in the hand book of International Criticality Safety Benchmark Evaluation Project (ICSBEP), which covers a wide variety of fuel materials, fuel forms, and neutron spectra. We report all comparison results (C/E values) of effective neutron multiplication factors between calculations and experiments to give a validation data for the prediction accuracy of JENDL-4.0 for criticalities. (author)

2011-01-01

214

Any l-state improved quasi-exact analytical solutions of the spatially dependent mass Klein-Gordon equation for the scalar and vector Hulthen potentials  

International Nuclear Information System (INIS)

We present a new approximation scheme for the centrifugal term to obtain a quasi-exact analytical bound state solution within the framework of the position-dependent effective mass radial Klein-Gordon equation with the scalar and vector Hulthen potentials in any arbitrary D dimension and orbital angular momentum quantum numbers l. The Nikiforov-Uvarov (NU) method is used in the calculations. The relativistic real energy levels and corresponding eigenfunctions for the bound states with different screening parameters have been given in a closed form. It is found that the solutions in the case of constant mass and in the case of s-wave (l=0) are identical with the ones obtained in the literature.

2009-03-01

215

Any l-state improved quasi-exact analytical solutions of the spatially dependent mass Klein-Gordon equation for the scalar and vector Hulthen potentials  

CERN Document Server

We present a new approximation scheme for the centrifugal term to obtain a quasi-exact analytical bound state solutions within the framework of the position-dependent effective mass radial Klein-Gordon equation with the scalar and vector Hulth\\'{e}n potentials in any arbitrary $D$ dimension and orbital angular momentum quantum numbers $l.$ The Nikiforov-Uvarov (NU) method is used in the calculations. The relativistic real energy levels and corresponding eigenfunctions for the bound states with different screening parameters have been given in a closed form. It is found that the solutions in the case of constant mass and in the case of s-wave ($l=0$) are identical with the ones obtained in literature.

Ikhdair, Sameer M

2009-01-01

216

Ecological aspects of mosquitoes (Diptera: Culicidae) in the gallery forest of Brasilia National Park, Brazil, with an emphasis on potential vectors of yellow fever  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Introduction We analyzed the vertical and monthly distributions of culicid species in the gallery forest of Brasília National Park, with an emphasis on the potential vectors of yellow fever (YF). Methods Between September 2010 and August 2011, mosquitoes were captured on the ground and in t [...] he canopy of the forest for five consecutive days per month, from nine to 15 hours. The mosquitoes were examined to verify natural infection with flaviviruses by isolation in Aedes albopictus Skuse, 1864 cells followed by indirect immunofluorescence. Results We identified 2,677 culicids distributed in 29 species. Most of the mosquitoes were captured at ground level (69%) during the rainy season (86%). The most abundant species were Sabethes (Sabethes) albiprivus Theobald, 1903; Limatus durhamii Theobald, 1901; Haemagogus (Conopostegus) leucocelaenus Dyar & Shannon, 1924; Haemagogus (Haemagogus) janthinomys Dyar, 1921; Aedes (Ochlerotatus) scapularis Rondani, 1848; Psorophora (Janthinosoma) ferox Von Humboldt, 1819; and Aedes (Ochlerotatus) serratus Theobald, 1901. Limatus durhamii, Limatus durhamii, Psorophora ferox, Aedes scapularis and Aedes serratus showed significant differences (p<0.05) in their habitat use. Limatus durhamii was found more often in the canopy, unlike the other species. During the rainy season, the most abundant species were Sa. albiprivus, Haemagogus leucocelaenus and Limatus durhamii. During the dry season, the potential YF vectors exhibited a very low frequency and abundance, except Aedes scapularis and Aedes serratus. No flavivirus was detected in the 2,677 examined mosquitoes. Conclusions We recommend continued and systematic entomological monitoring in areas vulnerable to the transmission of YF in the Federal District of Brazil.

Lira-Vieira, Ana Raquel; Gurgel-Goncalves, Rodrigo; Moreira, Israel Martins; Yoshizawa, Maria Amelia Cavalcanti; Coutinho, Milton Lopes; Prado, Paulo Sousa; Souza, Jorge Lopes de; Chaib, Antonio Jesus de Melo; Moreira, Joao Suender; Castro, Cleudson Nery de.

2013-15-10

217

Population dynamics of pest mosquitoes and potential malaria and West Nile virus vectors in relation to climatic factors and human activities in the Camargue, France.  

Science.gov (United States)

The Camargue is an extensive wetland in the southeast of France, which is highly influenced by human activities. Large ponds, marshes and irrigated fields provide abundant potential breeding sites for mosquitoes. mosquitoes, which are important in terms of the nuisance they cause to people and animals, the limitations they impose on tourism and their potential threat to human health. Several of the mosquito species present are potential vectors of malaria and West Nile virus. Therefore, the population dynamics of these species were monitored over an entire breeding season during March-October 2005. Mosquito populations were sampled in two study areas once every 2 weeks, using CDC light traps baited with CO(2). Sixteen species were collected. The majority (98.7%) of the catch were Aedes caspius (Pallas) (Diptera: Culicidae), Culex modestus (Ficalbi), Culex pipiens L. and Anopheles hyrcanus (Pallas). The population dynamics of these species varied considerably in relation to the species' biology, climatic conditions (rainfall, temperature and season), water management, implementation of mosquito control campaigns and landscape use. PMID:18092973

Ponçon, N; Toty, C; L'ambert, G; le Goff, G; Brengues, C; Schaffner, F; Fontenille, D

2007-12-01

218

Studies on the occurrence of Gram-negative bacteria in ticks: Ixodes ricinus as a potential vector of Pasteurella.  

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A total of 372 Ixodes ricinus ticks (101 females, 122 males, and 149 nymphs) collected by flagging in 6 mixed woodlands of eastern Poland were examined by culture for the presence of internal Gram-negative bacteria other than Borrelia burgdorferi. Adult ticks were examined in pools of 2 specimens each and nymphs were examined in pools of 3-5 specimens each. Ticks were disinfected in 70 % ethanol and homogenized in 0.85% NaCl. The diluted homogenate was inoculated onto 3 kinds of agar media: buffered charcoal yeast extract (BCYE-alpha) for isolation of fastidious Gram-negative bacteria, eosin methylene blue agar (EMB) for isolation of enterobacteria, and tryptic soya agar for isolation of all other non-fastidious Gram-negative bacteria. The Gram-negative isolates were identified with the API Systems 20E and NE microtests. A total of 9 species of Gram-negative bacteria were identified, of which the commonest were strains determined as Pasteurella pneumotropica/haemolytica, which were isolated on BCYE-alpha agar from ticks collected in all 6 examined woodlands. The total number of these strains (49) exceeded the total number of all other strains of Gram-negative bacteria recovered from ticks (30). Of the total number of examined ticks, the minimum infection rate with Pasteurella pneumotropica/haemolytica was highest in females (18.8%), and slightly lower in males (12.3%) and nymphs (10%). Besides Pasteurella pneumotropica/haemolytica, the following species of Gram-negative bacteria were isolated from examined ticks: Pantoea agglomerans, Serratia marcescens, Serratia plymuthica on EMB agar and Aeromonas hydrophila, Burkholderia cepacia, Chromobacterium violaceum, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia on tryptic soya agar. Minimal infection rates with these bacteria were low, ranging from 0.7-5.9%. Of the isolated bacteria, Chromobacterium violaceum, Pasteurella pneumotropica/haemolytica, Pseudomonas aeruginosa, and Serratia marcescens are potentially pathogenic for man and/or animals. In particular, the common occurrence of Pasteurella pneumotropica/haemolytica in Ixodes ricinus ticks poses a potential risk of pasteurellosis for humans and animals exposed to tick bites. PMID:15627343

Stojek, Nimfa Maria; Dutkiewicz, Jacek

2004-01-01

219

The status and potential of new radionuclide generators providing positron emitters to synthesise new targeting vectors for PET  

International Nuclear Information System (INIS)

Radionuclide generator systems continue to play a key role in providing both diagnostic and therapeutic radionuclides for various applications in nuclear medicine, oncology and interventional cardiology. Key advantages for the use of radionuclide generators include reasonable costs, the convenience of obtaining the desired daughter radionuclide on demand, and availability of the daughter radionuclide in high specific activity, no-carrier added form. Although many parent/daughter pairs have been evaluated as radionuclide generator systems, in particular for the application of labeled PET radiopharmaceuticals, there is a relatively small number of generators which are currently in routine clinical and research use. Those generators can be categorized according to the half-life of the daughter nuclide. The short-lived daughters cover half-lives of a few minutes. As the short half-lives do not allow radiochemical synthesis, these systems are relevant for perfusion imaging exclusively. The longer-lived daughter nuclides, on the other hand, provide a potential for the development of labeled radiopharmaceuticals

2005-11-14

220

Genetic characterization and molecular identification of the bloodmeal sources of the potential bluetongue vector Culicoides obsoletus in the Canary Islands, Spain  

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Background: Culicoides (Diptera: Ceratopogonidae) biting midges are vectors for a diversity of pathogens including bluetongue virus (BTV) that generate important economic losses. BTV has expanded its range in recent decades, probably due to the expansion of its main vector and the presence of other autochthonous competent vectors. Although the Canary Islands are still free of bluetongue disease (BTD), Spain and Europe have had to face up to a spread of bluetongue with disastrous consequ...

2012-01-01

 
 
 
 
221

Genetic characterization and molecular identification of the bloodmeal sources of the potential bluetongue vector Culicoides obsoletus in the Canary Islands, Spain  

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Abstract Background Culicoides (Diptera: Ceratopogonidae) biting midges are vectors for a diversity of pathogens including bluetongue virus (BTV) that generate important economic losses. BTV has expanded its range in recent decades, probably due to the expansion of its main vector and the presence of other autochthonous competent vectors. Although the Canary Islands are still free of bluetongue disease (BTD), Spain and Europe have had to face up to a spread of blueto...

2012-01-01

222

Genetic characterization and molecular identification of the bloodmeal sources of the potential bluetongue vector Culicoides obsoletus in the Canary Islands, Spain  

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[EN] Background: Culicoides (Diptera: Ceratopogonidae) biting midges are vectors for a diversity of pathogens including bluetongue virus (BTV) that generate important economic losses. BTV has expanded its range in recent decades, probably due to the expansion of its main vector and the presence of other autochthonous competent vectors. Although the Canary Islands are still free of bluetongue disease (BTD), Spain and Europe have had to face up to a spread of bluetongue with disastrous conseque...

2012-01-01

223

Larvicidal potentiality, longevity and fecundity inhibitory activities of Bacillus sphaericus (Bs G3-IV) on vector mosquitoes, Aedes aegypti and Culex quinquefasciatus  

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Intervention measures to control the transmission of vector-borne diseases include control of the vector population. In mosquito control, synthetic insecticides used against both the larvae (larvicides) and adults (adulticides) create numerous problems, such as environmental pollution, insecticide resistance and toxic hazards to humans. In the present study, a bacterial pesticide, Bacillus sphaericus (Bs G3-IV), was used to control the dengue and filarial vectors, Aedes aegypti

Arjunan Nareshkumar; Kadarkarai Murugan; Indra Baruah; Pari Madhiyazhagan; Thiyagarajan Nataraj

2012-01-01

224

Attraction of a free-living nematode, Caenorhabditis elegans, to foodborne pathogenic bacteria and its potential as a vector of Salmonella poona for preharvest contamination of cantaloupe.  

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Caenorhabditis elegans was studied to determine the potential role of free-living microbivorous nematodes as vectors for preharvest contamination of fruits and vegetables with foodborne pathogens. The propensity of C. elegans to be attracted to seven strains of Escherichia coli O157:H7, eight serotypes of Salmonella, six strains of Listeria monocytogenes, and cantaloupe juice was investigated. Twenty to 30 adult worms were placed on the surface of K agar midway between a 24-h bacterial colony and 10 microl of uninoculated tryptic soy broth (TSB) or cantaloupe juice positioned 1.5 cm apart. The numbers of nematodes that migrated to the colony, to the TSB, and to the cantaloupe juice within 5, 10, 15, and 20 min at 21 degrees C were determined, and then the plates were incubated at 37 degrees C for up to 7 days to determine the ability of C. elegans to survive and reproduce in bacterial colonies. The nematode was attracted to colonies of all test pathogens and survived and reproduced within colonies for up to 7 days. C. elegans was not attracted to cantaloupe juice. The potential of C. elegans to serve as a vector for the transport of Salmonella Poona to cantaloupe rinds was investigated. Adult worms that had been immersed in a suspension of Salmonella Poona were deposited 1 or 3 cm below the surface of soil on which a piece of cantaloupe rind was placed. The rind was analyzed for the presence of Salmonella Poona after 1, 3, 7, and 10 days at 21 degrees C. The presence of Salmonella Poona was evident more quickly on rinds positioned on soil beneath which C. elegans inoculated with Salmonella Poona was initially deposited than on rinds positioned on soil beneath which Salmonella Poona alone was deposited. The time required to detect Salmonella Poona on rinds was longer when the rind was placed 3 cm above the inoculum than when the rind was placed 1 cm above the inoculum. Free-living nematodes may play a role in the preharvest dispersal of incidental human pathogens in soil to the surfaces of raw fruits and vegetables in contact with soil during development and maturation, as evidenced by the behavior of C. elegans as a test model. PMID:14627270

Caldwell, Krishaun N; Anderson, Gary L; Williams, Phillip L; Beuchat, Larry R

2003-11-01

225

Insecticide-impregnated netting as a potential tool for long-lasting control of the leishmaniasis vector Lutzomyia longipalpis in animal shelters.  

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BACKGROUND: Leishmaniasis remains a serious neglected disease, with more than 350 million people potentially at risk worldwide. Control strategies often rely on spraying residual insecticides to target populations of the sand fly vectors that transmit Leishmania parasites when blood-feeding. These programmes are often difficult to sustain effectively, as sand fly resting sites must be resprayed on a regular basis. Here, we investigate whether application of insecticide-impregnated netting to a surface could act as an alternative to residual spraying for controlling the American visceral leishmaniasis vector Lutzomyia longipalpis. METHODS: Female L. longipalpis from our laboratory colony were exposed for 1 h to three treatments applied to plywood surfaces: 2% permethrin-impregnated netting (Olyset(R)), 20 mg a.i.m-2 micro-encapsulated lambda-cyhalothrin (Demand CS(R)) and a no-treatment control. We compared the speed at which these treatments acted, by measuring the percentage of sand flies killed both immediately after exposure to the treatment for 1 hour, as well as the number that had died 24 h after the 1 hour exposure. We repeated the experiment at 6 and 12 months following application to test the effectiveness of each treatment over time. RESULTS: When first applied, the lambda-cyhalothrin killed more sand flies in the first hour than the permethrin-impregnated netting. However, the effectiveness of the lambda-cyhalothrin diminished over time, so that there was no difference between the two treatments at 12 months. Both killed more sand flies than the control. When measured 24 h following exposure, both test treatments had killed close to 100% of sand flies when first applied, but while the lethal effect of the netting was maintained at close to 100% over 12 months, the effectiveness of the residual insecticide diminished to approximately 80% after 6 months. CONCLUSIONS: The results of these initial laboratory experiments indicate that covering surfaces with insecticide impregnated netting material may provide a longer-lasting solution for killing sand flies than residual spraying. Field trials are needed to identify the feasibility of treating surfaces with netting or similar impregnated materials as part of a control program. In targeting L. longipalpis, the greatest benefits may be seen in treating animal sheds with netting, where these sand flies aggregate in large numbers, and which can be difficult to treat repeatedly by conventional spraying. PMID:23642213

Bray, Daniel Peter; Hamilton, James G

2013-05-01

226

Energy dependence of EBT-1 radiochromic film response for photon (10 kVp-15 MVp) and electron beams (6-18 MeV) readout by a flatbed scanner  

International Nuclear Information System (INIS)

Purpose: The aim of this article is to investigate the energy dependence of the radiochromic film type, Gafchromic EBT-1, when scanned with a flatbed scanner for film readout. Methods: Dose response curves were determined for 12 different beam qualities ranging from a 10 kVp x-ray beam to a 15 MVp x-ray beam and include also two high energy electron beam qualities (6 and 18 MeV). The dose responses measured as net optical density (netOD) for the different beam qualities were normalized to the response of a reference beam quality (6 MVp). Results: A strong systematic energy dependence of the film response was found. The lower the effective beam energy, the less sensitive the EBT-1 films get. The maximum decrease in dose for the same film response between the 25 kVp and 6 MVp beam qualities was 44%. Additionally, a difference in energy dependence for different doses was discovered, meaning that higher doses show a smaller dependency on energy than lower doses. The maximum decrease in the normalized netOD was found to be 25% for a dose of 0.5 Gy relative to the normalized netOD for 10 Gy. Moreover, a scaling procedure is introduced, allowing the correction of the energy dependence for the investigated beam qualities and also for comparable x-ray beam qualities within the energy range studied. Conclusions: A strong energy dependence for EBT-1 radiochromic films was found. The films were readout with a flatbed scanner. If the effective beam energy is known, the energy dependence can be corrected with the introduced scaling procedure. Further investigation of the influence of the spectral band of the readout device on energy dependence is needed to understand the reason for the different energy dependences found in this and previous works.

2009-12-01

227

Comparatie study of the effect of adriamycin on the sensitivity of mice to whole-body irraidation with 6-MVp photons or fast neutrons (67 MeV p--Be)  

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The effect of Adriamycin on the response of mouse gut to irradiation with 6-MVp photons or fast neutrons (67 MeV p--Be), was assessed with the six-day death endpoint. The drug reduced the LD50/6 by the same factor for both types of radiation. Thus, the radiobiological effectiveness (RBE) (photons/neutrons) for gut damage is unaltered by the addition of Adriamycin. The data indicated no significant effect of drug scheduling if given within 16 hours before or after irradiation

1980-01-01

228

Comparative study of the effect of adriamycin on the sensitivity of mice to whole-body irradiation with 6-MVp photons or fast neutrons (67 MeV p ? Be)  

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The effect of Adriamycin (doxorubicin hydrochloride) (10 mg/kg intraperitoneally) on the response of mouse gut to irradiation with 6-MVp photons or fast neutrons (67 MeV p ? Be), was assessed with the six-day death endpoint. The drug reduced the LD/sub 50/6/ by the same factor (approx. 1.25) for both types of radiation. Thus, the radiobiological effectiveness (RBE) (photons/neutrons) for gut damage is unaltered by the addition of Adriamycin. The data indicate no significant effect of drug scheduling if given within 16 hours before or after irradiation

1980-01-01

229

Biosafety of lentiviral vectors.  

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The characteristics of lentiviral vectors (stable integration in non-dividing and dividing cells, long-term expression of the transgene, absence of immune response) make them ideal gene transfer vehicula for future gene therapy. However, the most potent lentiviral vectors are derived from highly pathogenic human viruses, such as HIV. We describe how the field has engineered lentivectors with increasing biosafety both for the lab worker and for the patient. The risk associated with state-of-the-art lentivectors is therefore minimal, although a psychological barrier to use these vectors in the clinic may still have to be overcome. Due to their increased performance, care should be taken to avoid accidental transduction of the lab worker with potential hazardous genes. The precautions which have to be taken are described in detail. PMID:14683448

Debyser, Zeger

2003-12-01

230

Biology of mosquitoes that are potential vectors of Rift Valley Fever virus in different biotopes of the central highlands of Madagascar.  

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There were epidemic-epizootics of Rift Valley Fever (RVF) affecting humans and cattle in Madagascar in the district of Anjozorobe in 2008. Little is known about the role of Malagasy mosquitoes in the circulation of RVF virus. Therefore, we investigated the species diversity, dynamics and biology of potential RVF virus vectors in the rainforest, rainforest edge (village of Anorana), and savanna biotope (village of Antanifotsy) of this district between November 2008 and July 2010. We captured 56,605 adults of 35 different species. Anopheles squamosus (Theobald), Anopheles coustani (Laveran), Culex antennatus (Becker), Culex pipiens (L.), and Culex univittatus (Theobald) were the most abundant during the rainy season with Cx. pipiens the most abundant species in the rainforest (47%), and An. squamosus the most abundant species in the rainforest edge and in the savanna biotope (56%, 60%, respectively). Only Cx. univittatus was abundant in the dry season. The parous rate was > 60% throughout the rainy season for An. squamosus and it was > 50% from the middle to the end of the rainy season for Cx. pipiens. Two additional species have been found only at larval stage. Cattle were the most attractive bait for all species, followed by sheep and poultry. Human was the least attractive for all species. Most of the 163 bloodmeals tested were taken from cattle. Three were from poultry, one was from dog and one was a mixed bloodmeal taken from sheep and cattle. These results on vectorial capacity parameters may allow considering the involvement of mosquito transmission of the virus in the district of Anjozorobe during the recent epidemic-epizootic. PMID:23802456

Tantely, Michaël Luciano; Rakotoniaina, Jean-Claude; Tata, Etienne; Andrianaivolambo, Lala; Razafindrasata, Fidimanana; Fontenille, Didier; Elissa, Nohal

2013-05-01

231

Species composition, larval habitats, seasonal occurrence and distribution of potential malaria vectors and associated species of Anopheles (Diptera: Culicidae from the Republic of Korea  

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Full Text Available Abstract Background Larval mosquito habitats of potential malaria vectors and related species of Anopheles from three provinces (Gyeonggi, Gyeongsangbuk, Chungcheongbuk Provinces of the Republic of Korea were surveyed in 2007. This study aimed to determine the species composition, seasonal occurrence and distributions of Anopheles mosquitoes. Satellite derived normalized difference vegetation index data (NDVI was also used to study the seasonal abundance patterns of Anopheles mosquitoes. Methods Mosquito larvae from various habitats were collected using a standard larval dipper or a white plastic larval tray, placed in plastic bags, and were preserved in 100% ethyl alcohol for species identification by PCR and DNA sequencing. The habitats in the monthly larval surveys included artificial containers, ground depressions, irrigation ditches, drainage ditches, ground pools, ponds, rice paddies, stream margins, inlets and pools, swamps, and uncultivated fields. All field-collected specimens were identified to species, and relationships among habitats and locations based on species composition were determined using cluster statistical analysis. Results In about 10,000 specimens collected, eight species of Anopheles belonging to three groups were identified: Hyrcanus Group - Anopheles sinensis, Anopheles kleini, Anopheles belenrae, Anopheles pullus, Anopheles lesteri, Anopheles sineroides; Barbirostris Group - Anopheles koreicus; and Lindesayi Group - Anopheles lindesayi japonicus. Only An. sinensis was collected from all habitats groups, while An. kleini, An. pullus and An. sineroides were sampled from all, except artificial containers. The highest number of Anopheles larvae was found in the rice paddies (34.8%, followed by irrigation ditches (23.4%, ponds (17.0%, and stream margins, inlets and pools (12.0%. Anopheles sinensis was the dominant species, followed by An. kleini, An. pullus and An. sineroides. The monthly abundance data of the Anopheles species from three locations (Munsan, Jinbo and Hayang were compared against NDVI and NDVI anomalies. Conclusion The species composition of Anopheles larvae varied in different habitats at various locations. Anopheles populations fluctuated with the seasonal dynamics of vegetation for 2007. Multi-year data of mosquito collections are required to provide a better characterization of the abundance of these insects from year to year, which can potentially provide predictive capability of their population density based on remotely sensed ecological measurements.

Foley Desmond H

2010-02-01

232

Present status of reactor physics in the United States and Japan-IV. 3. Analysis of High-Moderation MOX Core MISTRAL-3 with SRAC and MVP  

International Nuclear Information System (INIS)

To obtain reactor physics parameters for high-moderation mixed-oxide (MOX) cores, Nuclear Power Engineering Corporation (NPEC), the French Atomic Commission (CEA), and their industrial partners have conducted a MOX core physics experimental program called MISTRAL (Refs. 1, 2, and 3) with the EOLE critical facility of the Cadarache research center. This program consists of four high-moderation cores and was successfully completed in July 2000. This paper describes the analysis results of MISTRAL-3 that is a homogeneous full MOX cylindrical core (H/HM = 6.2) with an 80-cm height and a 59-cm diameter consisting of 1388 standard pressurized water reactor-type MOX fuel rods of 7.0 wt% plutonium-enrichment in a square pitch of 1.39 cm. NPEC has been analyzing the experimental results by using the SRAC and MVP code systems (Refs. 4 and 5, respectively). SRAC performs pin cell calculations by the collision probability method and core calculations by the diffusion method (SRAC-CITATION) or the discrete ordinates transport method (SRAC-TWOTRAN). MVP is a continuous-energy Monte Carlo code. The JENDL-3.2 nuclear data file has been employed for these analyses. The measured and analyzed items of MISTRAL-3 are criticality, radial fission rate distribution, fission spectrum indices, conversion factors, isothermal temperature coefficients, differential and integral boron efficiency, two-dimensional (2-D) void worth, and absorber worth. Table I shows comparisons of calculated and measured values of keff, radial fission rate distribution, fission spectrum indices, and conversion factors for MISTRAL-3 compared with those of MISTRAL-2 (homogeneous full MOX core, H/HM = 5.2) (Ref. 3). Regarding the criticality, the calculated values agree well with the measured. The differences of the calculated-to-experimental (C-E) values between MISTRAL-2 and MISTRAL-3 are within 0.1% ?k for all code systems. Regarding the radial fission rate distribution, the differences between the calculated and measured values are the same level as the experimental uncertainty for both the diffusion and Monte Carlo calculations. The fission spectrum indices are obtained by Pij calculations in SRAC with the 107-energy-group structure for a 5x5 multicell. A cell simulating a detector is placed at the corner of the array and is surrounded by 7.0 wt% MOX fuel rods. As shown in Table I, the calculated values agree well with the measured, being almost within the experimental uncertainty. The Pij calculations are performed to obtain the conversion factors in infinite lattice geometry, and the calculated value also agrees well with the measured. There are no apparent differences between MISTRAL-2 and MISTRAL-3 for the criticality, the fission rate distribution, the spectrum indices, and the conversion factors. The isothermal temperature coefficients were evaluated with measurement data among seven temperature points from 10 to 80 deg. C. The calculated values are obtained from the net reactivity change due to the temperature change with SRAC-CITATION, and they agree with the measured within approximately twice the experimental uncertainty. The differential boron efficiency was measured with changing boron concentration within ±3 ppm around the critical concentration of ?210 ppm. The calculated value of SRAC-CITATION shows good agreement with the measured within ?1 pcm/ppm. The integral boron efficiency measurements were performed for the boron concentrations of ?230, 330, 430, 630, and 820 ppm. The C-E values of the integral boron efficiency, which are calculated with SRAC-CITATION, vary from 0.98 to 1.03. The agreement between the calculated and measured values is within the experimental uncertainties (?5%). As for the isothermal temperature coefficients, the differential and integral boron efficiencies, there are also no apparent differences in the trend between MISTRAL-2 and MISTRAL-3. For the 2-D void worth measurements, the 7 x 7 cells at the center of the core were installed with thick over-claddings or Ag blocks in the whole length of the core so that the mod

2001-06-17

233

Survey of cyclopids (Crustacea, Copepoda) in Brazil and preliminary screening of their potential as dengue vector predators Levantamento de ciclopídeos (Crustacea, Copepoda) no Brasil e avaliação preliminar de seu potencial como predadores dos vetores da dengue  

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INTRODUCTION: Cyclopid copepods are known to be good mosquito controllers, specially as regards the larvae of the dengue vectors Aedes aegypti and Ae. albopictus. MATERIAL AND METHOD: The objective of the study was to survey the local copepod fauna and search for new strains of M. longisetus var. longisetus, comparing the potential of the samples found with the current strain ML-01 against Ae. albopictus larvae, under laboratory conditions. Eleven bodies of water in Campinas, SP, Brazil, were...

1997-01-01

234

Mosquitoes (Diptera: Culiciadae potential vectors of arbovirus in the Urabá region, Northwest of Colombia Mosquitos (Díptera: Culicidae vectores potenciales de arbovirus en la región de Urabá, noroccidente de Colombia  

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Full Text Available Introduction. Studies directed to investigate ecological parameters of sylvatic mosquitoes populations allows to establish the risk of arbovirus transmission and to bring recommendations for health authorities about prevention, surveillance and control.
Objective. To establish the diversity and abundance of arbovirus mosquitoes vectors of in rural areas of Apartado and Turbo, Antioquia.
Materials and methods. Quarterly sampling was done. For mosquito catching in forest fragments, CDC and Shannon traps was used, also human landing was used. Diversity and abundance indexes estimation was done.
Results. 583 mosquitoes belonging to ten genera and 27 species were collected. The most abundant species were: Cq. venezuelensis (14.6%, Ae. scapularis (14.08%, Ps. ferox (10.82% and Cx quinquefasciatus (10.3%. Specific richness and ecological indexes were highest in Turbo municipality; the fragment studied in Turbo is considered of most species richness and uniformity. The finding of Cx pedroi, Ae. scapularis, Ae. angustivittatus, Cq. venezuelensis, Cx. nigripalpus, Cx. quinquefasciatus, Cx. declarator, Ma. titillans, Ma. pseudotitillans, Ps. ferox y Tr. digitatum previously reported as arbovirus vectors warns about the possibility of transmission in the zone.
Conclusions. Mosquito diversity and abundance in the study zone is high. The ecological analysis plus previous reports about vectorial capacity of some of the registered species allows us to conclude that arbovirus outbreaks in the area could be presented.
Introducción. Estudios encaminados a conocer parámetros ecológicos de poblaciones de mosquitos selváticos, permiten establecer el riesgo de transmisión de arbovirus y aportar recomendaciones sobre prevención, vigilancia y control a las autoridades de salud.
Objetivo. Determinar la diversidad y abundancia de mosquitos nocturnos y crepusculares, potenciales vectores de arbovirus en zonas rurales de Apartadó y Turbo, Antioquia.
Materiales y métodos. Se realizaron muestreos trimestrales. Para la recolecta de mosquitos se usaron trampas CDC, Shannon y cebo humano protegido, en fragmentos de bosque entre las 18:00 y 06:00 horas. Se estimaron índices de diversidad y abundancia de especies.
Resultados. Se capturaron 583 mosquitos, de 10 géneros y 27 especies. Las especies más abundantes fueron Cq. venezuelensis (14,6%, Ae. scapularis (14,08%, Ps. ferox (10,82% y Cx quinquefasciatus (10,3%. La riqueza específica y los índices ecológicos calculados fueron mayores en Turbo; el fragmento de bosque estudiado en Turbo se considera de mayor riqueza y uniformidad de especies. El hallazgo de Cx pedroi, Ae. scapularis, Ae. angustivittatus, Cq. venezuelensis, Cx. nigripalpus, Cx. quinquefasciatus, Cx. declarator, Ma. titillans, Ma. pseudotitillans, Ps. ferox y Tr. digitatum reportados como vectores de arbovirus alerta sobre la posibilidad de transmisión en la zona.
Conclusión. La diversidad y abundancia de mosquitos en la zona de estudio es alta. Los análisis ecológicos, mas los reportes previos de capacidad vectorial de algunas de las especies registradas, permiten concluir que en la zona se pueden presentar brotes de arbovirosis.

Laura Suárez

2011-12-01

235

Larvicidal potentiality, longevity and fecundity inhibitory activities of Bacillus sphaericus (Bs G3-IV on vector mosquitoes, Aedes aegypti and Culex quinquefasciatus  

Directory of Open Access Journals (Sweden)

Full Text Available Intervention measures to control the transmission of vector-borne diseases include control of the vector population. In mosquito control, synthetic insecticides used against both the larvae (larvicides and adults (adulticides create numerous problems, such as environmental pollution, insecticide resistance and toxic hazards to humans. In the present study, a bacterial pesticide, Bacillus sphaericus (Bs G3-IV, was used to control the dengue and filarial vectors, Aedes aegypti and Culex quinquefasciatus. Bacillus sphaericus (Bs G3-IV was very effective against Aedes aegypti and Culex quinquefasciatus, showing significant larval mortality. Evaluated lethal concentrations (LC50 and LC90 were age-dependent, with early instars requiring a lower concentration compared with later stages of mosquitoes. Culex quinquefasciatus was more susceptible to Bacillus sphaericus (Bs G3-IV than was Aedes aegypti. Fecundity rate was highly reduced after treatment with different concentrations of Bacillus sphaericus (Bs G3-IV. Larval and pupal longevity both decreased after treatment with Bacillus sphaericus (Bs G3-IV, total number of days was lower in the B. sphaericus treatments compared with the control. Our results show the bacterial pesticide Bacillus sphaericus (Bs G3-IV to be an effective mosquito control agent that can be used for more integrated pest management programs.

Thiyagarajan Nataraj

2012-12-01

236

The Potential for Dispersal of Onchocerciasis in Ecuador in Relation to the Distribution of the Vector Simulium exiguum (Diptera:Simuliidae)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The future dispersal of onchocerciasis in Ecuador is dependent on the distribution of cytotypes of the vector species complex Simulium exiguum. Over the last 14 years, collections of larvae have been made from over 25 rivers, between 80-1600 m altitude, from various sites on both sides of the Andes. [...] Analysis of larval polytene chromosomes was used to determine the distributions of each cytotype. On the western side of the Andes, the Cayapa cytotype (the only cytotype directly incriminated as a vector) has a distribution from Santo Domingo de los Colorados northwards. The Quevedo and Bucay cytotypes occur from Santo Domingo de los Colorados southwards. On the eastern side of the Andes, the Aguarico cytotype occurs in the Rio Aguarico and a new cytotype is present in the tributaries of the Rio Napo. Whether the disease will spread south of Santo Domingo and on the eastern side of the Andes depends on vector capacity of the cytotypes and the dispersal patterns of individuals infected with onchocerciasis. At present the Aguarico, Bucay and Quevedo cytotypes are known to be efficient hosts, but their biting preferences and biting densities have not yet been evaluated

M, Charalambous; AJ, Shelley; M, Arzube.

237

Vector C: A vector processing language  

Energy Technology Data Exchange (ETDEWEB)

The language Vector C is a superset of the conventional (scalar) programming language C with extensions to facilitate vector processing. The design goals and a methodology for performing language extensions and the extended language features of Vector C are presented. The implementation of Vector C on the Cyber 205 is nearing completion. Some empirical data are presented which demonstrate that Vector C can generate a code which executes at speeds that meet or exceed those of equivalent statements from 205 Vector Fortran. Readers are assumed to have some knowledge of the C language.

Li, K.C.; Schwetman, H.

1985-05-01

238

Como o potencial vetor deve ser interpretado para revelar analogias entre grandezas magnéticas e elétricas / How the vector potential is to be interpreted in order to reveal analogies between magnetic and electric quantities  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Mostra-se a partir dos potenciais de Liénard-Wiechert que o potencial vetor pode, em geral, ser expresso como produto do potencial escalar e da velocidade da carga que o cria, constituindo-se como se fosse uma espécie de vento de potencial. Mostra-se daí como uma certa analogia existente entre grand [...] ezas magnéticas e elétricas pode ser entendida. Abstract in english Starting from the Liénard-Wiechert potentials, it is shown that the vector potential can always be expressed as a product of the scalar potential and the velocity of the charge creating it, looking like a kind of potential wind. From that, it is shown how a certain existing similarity between magnet [...] ic and electric quantities may be understood.

Ferreira, G.F. Leal.

239

Vector-associated diseases in the context of climate change: Analysis and evaluation of the differences in the potential spread of tertian malaria in the ecoregions of Lower Saxony  

Directory of Open Access Journals (Sweden)

Full Text Available

Background: The outbreak of vector-associated diseases is determined by different factors. One of them is the existence of appropriate climatic conditions which influence the development of vectors as well as pathogens. Nowadays, accurate data on the occurrence of both vectors and pathogens are often not available in Germany, espite the coastal zones of Lower Saxony (Germany being former malaria regions. Thus, the question arises, whether a new autochthonous transmission could take place due to the monthly mean temperatures of recent ears taking into consideration the predicted increase in air temperatures according to the IPCC scenarios.

Methods: To model areas at risk, the transmission potential for new tertian malaria spreads in respect to emperature was computed in a GIS environment using the Basic Reproduction Rate (R0 formula.

Results:We were able to corroborate that the risk of tertian malaria transmission is increasing as temperature s the determining variable of the mathematical model.

Conclusions: Lower Saxony is at risk of a new outbreak of tertian malaria assuming no other risk factors than emperature being of relevance.

Gunther Schmidt

2008-12-01

240

Exploiting the potential of vector control for disease prevention / Exploitation des possibilités de la lutte antivectorielle dans la prévention des maladies / Aprovechar el potencial de la lucha antivectorial como medio de prevención de enfermedades  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: English Abstract in spanish Aunque ha demostrado ser muy eficaz como medio de prevención de la transmisión de enfermedades, la lucha antivectorial no se explota al máximo, y eso priva a las poblaciones desfavorecidas de los beneficios de algunos métodos de probada eficacia. Tras el descubrimiento de los insecticidas sintéticos [...] de acción residual, en los años cuarenta, los programas a gran escala emprendidos consiguieron controlar muchas de las más importantes enfermedades de transmisión vectorial. A finales de los años sesenta, la mayoría de esas enfermedades -exceptuando la malaria en África- dejaron de ser un problema relevante de salud pública. El resultado fue que los programas de control cayeron en desuso, los recursos menguaron, y los especialistas en lucha antivectorial desaparecieron de las unidades de salud pública. En el término de dos décadas, muchas enfermedades importantes de transmisión vectorial reaparecieron o se propagaron a nuevas zonas. Ha llegado el momento de restituir a la lucha antivectorial su papel clave en la prevención de la transmisión de enfermedades, si bien es necesario hacer más hincapié en la adopción de múltiples medidas, basadas ya sea en el uso de plaguicidas o en la ordenación del medio, y en el refuerzo de la capacidad administrativa y operacional. El control integrado de los vectores brinda un marco conceptual sólido para desplegar métodos costoeficaces sostenibles de lucha antivectorial. Mediante este enfoque es posible abordar de forma exhaustiva los complejos determinantes de la transmisión de enfermedades, entre ellos su ecología local, el papel de la contribución humana a los riesgos de transmisión, y la situación socioeconómica de las comunidades afectadas. Abstract in english Although vector control has proven highly effective in preventing disease transmission, it is not being used to its full potential, thereby depriving disadvantaged populations of the benefits of well tried and tested methods. Following the discovery of synthetic residual insecticides in the 1940s, l [...] arge-scale programmes succeeded in bringing many of the important vector-borne diseases under control. By the late 1960s, most vector-borne diseases - with the exception of malaria in Africa - were no longer considered to be of primary public health importance. The result was that control programmes lapsed, resources dwindled, and specialists in vector control disappeared from public health units. Within two decades, many important vector-borne diseases had re-emerged or spread to new areas. The time has come to restore vector control to its key role in the prevention of disease transmission, albeit with an increased emphasis on multiple measures, whether pesticide-based or involving environmental modification, and with a strengthened managerial and operational capacity. Integrated vector management provides a sound conceptual framework for deployment of cost-effective and sustainable methods of vector control. This approach allows for full consideration of the complex determinants of disease transmission, including local disease ecology, the role of human activity in increasing risks of disease transmission, and the socioeconomic conditions of affected communities.

H, Townson; MB, Nathan; M, Zaim; P, Guillet; L, Manga; R, Bos; M, Kindhauser.

 
 
 
 
241

Foamy virus vectors.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human foamy virus (HFV) is a retrovirus of the spumavirus family. We have constructed vectors based on HFV that encode neomycin phosphotransferase and alkaline phosphatase. These vectors are able to transduce a wide variety of vertebrate cells by integration of the vector genome. Unlike vectors based on murine leukemia virus, HFV vectors are not inactivated by human serum, and they transduce stationary-phase cultures more efficiently than murine leukemia virus vectors. These properties, as we...

Russell, D. W.; Miller, A. D.

1996-01-01

242

Vectorization, parallelization and porting of nuclear codes (porting). Progress report fiscal 1999  

International Nuclear Information System (INIS)

Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system, the SX-4 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 18 codes in fiscal 1999. These results are reported in 3 parts, i.e., the vectorization and the parallelization part on vector processors, the parallelization port on scalar processors and the porting part. In this report, we describe the porting. In this porting part, the porting of Assisted Model Building with Energy Refinement code version 5 (AMBER5), general purpose Monte Carlo codes far neutron and photon transport calculations based on continuous energy and multigroup methods (MVP/GMVP), automatic editing system for MCNP library code (autonj), neutron damage calculations for materials irradiations and neutron damage calculations for compounds code (SPECTER/SPECOMP), severe accident analysis code (MELCOR) and COolant Boiling in Rod Arrays, Two-Fluid code (COBRA-TF) on the VPP500 system and/or the AP3000 system are described. (author)

243

Vectorization, parallelization and porting of nuclear codes (porting). Progress report fiscal 1999  

Energy Technology Data Exchange (ETDEWEB)

Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system, the SX-4 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 18 codes in fiscal 1999. These results are reported in 3 parts, i.e., the vectorization and the parallelization part on vector processors, the parallelization port on scalar processors and the porting part. In this report, we describe the porting. In this porting part, the porting of Assisted Model Building with Energy Refinement code version 5 (AMBER5), general purpose Monte Carlo codes far neutron and photon transport calculations based on continuous energy and multigroup methods (MVP/GMVP), automatic editing system for MCNP library code (autonj), neutron damage calculations for materials irradiations and neutron damage calculations for compounds code (SPECTER/SPECOMP), severe accident analysis code (MELCOR) and COolant Boiling in Rod Arrays, Two-Fluid code (COBRA-TF) on the VPP500 system and/or the AP3000 system are described. (author)

Kawasaki, Nobuo; Nemoto, Toshiyuki; Kawai, Wataru; Ishizuki, Shigeru [Fujitsu Ltd., Tokyo (Japan); Ogasawara, Shinobu; Kume, Etsuo; Adachi, Masaaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yatake, Yo-ichi [Hitachi Ltd., Tokyo (Japan)

2001-01-01

244

Rotations with Rodrigues' Vector  

Science.gov (United States)

The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears…

Pina, E.

2011-01-01

245

[Spatial vector electrocardiography: technique, perspectives of use].  

Science.gov (United States)

Potentials of the use of computer synthesis of integral electrical vector of the heart D0 are described. Calculation of spatial angular vector velocity and linear velocity of its movement along trajectory can be carried out in a framework of biophysical dipole model. Spatial presentation of vector is realized and its behavior in accordance with established pathologies discussed. Possible diagnostic value of obtained results and utility of their introduction into clinical practice are stressed. PMID:12891251

Bakutski?, V N; Volobuev, A N; Kriukov, N N; Romanchuk, P I

2003-01-01

246

Fractional Brownian Vector Fields  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work puts forward an extended definition of vector fractional Brownian motion (fBm) using a distribution theoretic formulation in the spirit of Gel?fand and Vilenkin's stochastic analysis. We introduce random vector fields that share the statistical invariances of standard vector fBm (self-similarity and rotation invariance) but which, in contrast, have dependent vector components in the general case. These random vector fields result from the transformation of white noise by a special...

Tafti, P. D.; Unser, M.

2010-01-01

247

Kochen-Specker vectors  

International Nuclear Information System (INIS)

We give a constructive and exhaustive definition of Kochen-Specker (KS) vectors in a Hilbert space of any dimension as well as of all the remaining vectors of the space. KS vectors are elements of any set of orthonormal states, i.e., vectors in an n-dimensional Hilbert space, Hn, n?3, to which it is impossible to assign 1s and 0s in such a way that no two mutually orthogonal vectors from the set are both assigned 1 and that not all mutually orthogonal vectors are assigned 0. Our constructive definition of such KS vectors is based on algorithms that generate MMP diagrams corresponding to blocks of orthogonal vectors in Rn, on algorithms that single out those diagrams on which algebraic (0)-(1) states cannot be defined, and on algorithms that solve nonlinear equations describing the orthogonalities of the vectors by means of statistically polynomially complex interval analysis and self-teaching programs. The algorithms are limited neither by the number of dimensions nor by the number of vectors. To demonstrate the power of the algorithms, all four-dimensional KS vector systems containing up to 24 vectors were generated and described, all three-dimensional vector systems containing up to 30 vectors were scanned, and several general properties of KS vectors were found

2005-02-18

248

Evaluation of Multi Potential Bioactive Endod, Phytolacca dodecandra (L’ Herit Berries Extracts Against Immature Filarial Vector Culex quinquefasciatus Say (Diptera: Culicidae  

Directory of Open Access Journals (Sweden)

Full Text Available Aim of the present study was to evaluate larvicidal and pupicidal properties of Phytolacca dodecandra plant extracts against immature filarial vector, Culex quinquefasciatus. The powdered berries were extracted with petroleum ether, acetone, benzene, methanol and water. The crude residue obtained from the extraction was used to prepare 62.5, 125, 250, 500 and 1000 ppm concentration, respectively. The experiment was conducted by using standard WHO protocol with modifications. The immature mosquitoes were exposed to selected concentration and the percentage mortality was observed continuously for 12, 24 and 48 h, respectively. Among the various solvent extracts tested, petroleum ether, acetone and benzene showed maximum mortality at 125 ppm concentration and above. At 1000 ppm concentration, all the solvent extracts tested showed 100% mortality. The III-instar larva was highly susceptible compared to IV-instar and pupa. The water and methanol extract was also proved to have larvicidal and pupicidal properties. This study showed P. dodecandra plant extract have bioactivity compound to kill the immature Cx. quinquefasciatus. These plants are growing naturally in Ethiopian highlands and proper utilization may prevent unwanted pollution to the environment.

Nagappan Raja

2012-07-01

249

Potential use of neem leaf slurry as a sustainable dry season management strategy to control the malaria vector Anopheles gambiae (DIPTERA: CULICIDAE) in west African villages.  

Science.gov (United States)

Larval management of the malaria vector, Anopheles gambiae Giles s.s., has been successful in reducing disease transmission. However, pesticides are not affordable to farmers in remote villages in Mali, and in other material resource poor countries. Insect resistance to insecticides and nontarget toxicity pose additional problems. Neem (Azadirachta indica A. Juss) is a tree with many beneficial, insect bioactive compounds, such as azadirachtin. We tested the hypothesis that neem leaf slurry is a sustainable, natural product, anopheline larvicide. A field study conducted in Sanambele (Mali) in 2010 demonstrated neem leaf slurry can work with only the available tools and resources in the village. Laboratory bioassays were conducted with third instar An. gambiae and village methods were used to prepare the leaf slurry. Experimental concentration ranges were 1,061-21,224 mg/L pulverized neem leaves in distilled water. The 50 and 90% lethal concentrations at 72 h were 8,825 mg/L and 15,212 mg/L, respectively. LC concentrations were higher than for other parts of the neem tree when compared with previous published studies because leaf slurry preparation was simplified by omitting removal of fibrous plant tissue. Using storytelling as a medium of knowledge transfer, villagers combined available resources to manage anopheline larvae. Preparation of neem leaf slurries is a sustainable approach which allows villagers to proactively reduce mosquito larval density within their community as part of an integrated management system. PMID:23270164

Luong, Kyphuong; Dunkel, Florence V; Coulibaly, Keriba; Beckage, Nancy E

2012-11-01

250

Viruses | Special Issue : Retroviral Vectors  

... Open Access Review Review: Retroviral Vectors: Post Entry Events and Genomic Alterations by Ali Nowrouzi, Hanno Glimm, Christof Von Kalle and Manfred Schmidt Viruses 2011, 3(5), 429-455; doi:10.3390/v3050429 Received: 9 February 2011; in revised form: 24 March 2011 / Accepted: 5 April 2011 / Published: 29 April 2011 Show/Hide Abstract | Download PDF Full-text (687 KB) Abstract: The curative potential of retroviral vectors for somatic gene therapy has been demonstrated impressively in several clinical trials ...

251

Caracteres moleculares para la determinación taxonómica de tres especies de Lutzomyia (Diptera: Psychodidae), vectores potenciales de Leishmania presentes en el valle de Aburrá, Colombia / Molecular characters for the taxonomic determination of three species of Lutzomyia (Diptera: Psychodidae), potential Leishmania vectors found in the Aburrá valley, Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish En Colombia están registradas 143 especies de Lutzomyia França, pero menos del 7% de éstas se encuentran incriminadas como vectores de Leishmania spp. Debido a la alta semejanza morfológica de algunas especies vectoras con otras no vectoras, se necesitan caracteres taxonómicos alternativos para iden [...] tificar correctamente los flebotomíneos de cada zona geográfica del país. Con este objetivo, en el presente trabajo se secuenció el extremo 3' del gen mitocondrial que codifica para la proteína citocromo b en tres vectores potenciales de Leishmania presentes en el valle de Aburrá, Colombia, Lutzomyia hartmanni (Fairchild y Hertig), L. columbiana (Ristorcelli y Van Ty) y L. tihuiliensis Le Pont, Torrez-Espejo y Dujardin. A partir del alineamiento múltiple de nucleótidos se determinaron los sitios polimórficos, las distancias genéticas pareadas netas (p) y la entropía. Las secuencias de nucleótidos fueron trasladadas a aminoácidos para estimar el número de sustituciones sinónimas y no sinónimas. En el alineamiento múltiple de 321 nucleótidos del gen citocromo b de L. columbiana, L. hartmanni y L. tihuiliensis se detectaron 83 sustituciones. En la secuencia parcial de la proteína se encontraron 18 reemplazos de aminoácidos. Las distancias genéticas interespecíficas fluctuaron en un rango mínimo de 0,137 entre L. tihuiliensis y L. columbiana, y un máximo de 0,215 entre L. columbiana y L. hartmanni. Los polimorfismos detectados en la secuencia de nucleótidos del gen y de aminoácidos de la proteína constituyen caracteres moleculares potencialmente útiles para la determinación taxonómica de estas especies de flebotomíneos. Abstract in english To date, 143 species of Lutzomyia França are recorded in Colombia, but less than 7% is incriminated in the transmission of Leishmania spp. Alternative taxonomic characters are necessary to correctly identify the particular sand fly fauna in each Colombian region, and the separation of morphologicall [...] y similar vector and non-vector species. In order to detect useful molecular characters for the taxonomic determination of three potential vectors of Leishmania present in the Valle de Aburrá, Colombia, the present work sequenced the 3' end of the mitochondrial cytochrome b gene in Lutzomyia hartmanni (Fairchild and Hertig), L. columbiana (Ristorcelli and Van Ty), and L. tihuiliensis Le Pont, Torrez-Espejo and Dujardin. Polymorphic sites, pairwise genetic distances (p), and entropy were determined from the multiple alignment of the nucleotide sequences. Numbers of silent and non silent substitutions were calculated from the amino acid sequences deduced from the nucleotide sequences of the gene. In the multiple alignment of the cytochrome b nucleotide sequences from Lutzomyia hartmanni, L. columbiana and L. tihuiliensis, 83 polymorphic sites were detected. A total of 18 amino acid replacements were found in the partial nucleotide sequences of the protein. Genetic distances varied from 0,137 between L. tihuiliensis and L. columbiana, to 0,215 among L. columbiana and L. hartmanni. Nucleotide and amino acid sequence polymorphisms within the cytochrome b gene and protein, respectively, constitute molecular characters potentially useful for the taxonomic determination of these sand fly species.

Pérez-Doria, Alveiro  ; Elías Bejarano, Eduar; Sierra, Diana; Vélez, Iván Darío.

252

Deterministic Vector Freak Waves  

CERN Document Server

We construct and discuss a semi-rational, multi-parametric vector solution of coupled nonlinear Schr\\"odinger equations (Manakov system). This family of solutions includes known vector Peregrine solutions, bright-dark-rogue solutions, and novel vector unusual freak waves. The vector freak (or rogue) waves could be of great interest in a variety of complex systems, from optics to Bose-Einstein condensates and finance.

Baronio, Fabio; Conforti, Matteo; Wabnitz, Stefan

2012-01-01

253

Potential Role of Diploscapter sp. Strain LKC25, a Bacterivorous Nematode from Soil, as a Vector of Food-Borne Pathogenic Bacteria to Preharvest Fruits and Vegetables  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Diploscapter, a thermotolerant, free-living soil bacterial-feeding nematode commonly found in compost, sewage, and agricultural soil in the United States, was studied to determine its potential role as a vehicle of Salmonella enterica serotype Poona, enterohemorrhagic Escherichia coli O157:H7, and Listeria monocytogenes in contaminating preharvest fruits and vegetables. The ability of Diploscapter sp. strain LKC25 to survive on agar media, in cow manure, and in composted turkey manure and to ...

Gibbs, Daunte S.; Anderson, Gary L.; Beuchat, Larry R.; Carta, Lynn K.; Williams, Phillip L.

2005-01-01

254

Lentiviral vector-mediated stable expression of sTNFR-Fc in human macrophage and neuronal cells as a potential therapy for neuroAIDS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Human immunodeficiency virus type 1 (HIV-1) infection frequently causes neurologic disease, which is the result of viral replication and activation of macrophages and microglia in the CNS, and subsequent secretion of high levels of neurotoxic products, including tumor necrosis factor-? (TNF-?). We therefore hypothesized that a soluble TNF-? antagonist might have potential utility as a neuroprotective effecter molecule, and conducted proof-of-concept stu...

2011-01-01

255

Rhotrix Vector Spaces  

Science.gov (United States)

By rhotrix we understand an object that lies in some way between (n x n)-dimensional matrices and (2n - 1) x (2n - 1)-dimensional matrices. Representation of vectors in rhotrices is different from the representation of vectors in matrices. A number of vector spaces in matrices and their properties are known. On the other hand, little seems to be…

Aminu, Abdulhadi

2010-01-01

256

An evaluation methodology for vector data updating  

Science.gov (United States)

The methods used to evaluate automation tools are a critical part of the development process. In general, the most meaningful measure of an automation method from an operational standpoint is its effect on productivity. Both timed comparison between manual and automation based-extraction, as well as measures of spatial accuracy are needed. In this paper, we introduce the notion of correspondence to evaluate spatial accuracy of an automated update method. Over time, existing vector data becomes outdated because 1) land cover changes occur, or 2) more accurate overhead images are acquired, and/or vector data resolution requirements by the user may increase. Therefore, an automated vector data updating process has the potential to significantly increase productivity, particularly as existing worldwide vector database holdings increase in size, and become outdated more quickly. In this paper we apply the proposed evaluation methodology specifically to the process of automated updating of existing road centerline vectors. The operational scenario assumes that the accuracy of the existing vector data is in effect outdated with respect to newly acquired imagery. Whether the particular approach used is referred to as 1) vector-to-image registration, or 2) vector data updating-based automated feature extraction (AFE), it is open to interpretation of the application and bias of the developer or user. The objective of this paper is to present a quantitative and meaningful evaluation methodology of spatial accuracy for automated vector data updating methods.

Doucette, Peter; Kovalerchuk, Boris; Kovalerchuk, Michael; Brigantic, Robert

2009-05-01

257

Rotations with Rodrigues' vector  

International Nuclear Information System (INIS)

The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears to be a fundamental matrix that is used to express the components of the angular velocity, the rotation matrix and the angular momentum vector. The Hamiltonian formalism of rotational dynamics in terms of this vector uses the same matrix. The quantization of the rotational dynamics is performed with simple rules if one uses Rodrigues' vector and similar formal expressions for the quantum operators that mimic the Hamiltonian classical dynamics.

2011-09-01

258

Survey of cyclopids (Crustacea, Copepoda) in Brazil and preliminary screening of their potential as dengue vector predators / Levantamento de ciclopídeos (Crustacea, Copepoda) no Brasil e avaliação preliminar de seu potencial como predadores dos vetores da dengue  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese INTRODUÇÃO: Copépodos ciclopídeos são conhecidos como bons controladores de mosquitos, especialmente quando considerado as larvas dos vetores da dengue Aedes aegypti e Ae. albopictus. MATERIAL E MÉTODO: Onze corpos d'água em Campinas, SP, Brasil, foram avaliados para copépodos coletando-se 1,5 l de [...] água de cada um deles. O potencial predador dos copépodos adultos foi avaliado por 24 h, em laboratório, em grupos de 5 indivíduos predadando sobre 30 larvas de 1° estádio de Ae. albopictus. RESULTADOS E CONCLUSÕES: No presente levantamento as seguintes espécies de ciclopídeos foram encontradas: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. O potencial predador desses copépodos variou de zero a 97,3%. A amostra coletada no campo contendo apenas com M. longisetus var. longisetus mostrou a melhor eficiência de controle, sem diferença significativa de uma cultura de laboratório (ML-01) criada por 3 anos, desta mesma espécie, que foi avaliada para comparação. A amostra com poucos M. albidus var. albidus foi cotada em segundo melhor lugar, apresentando em média 25,9% de eficiência. O uso de copépodos em pneus armadilha como controladores dos vetores da dengue é discutido. Abstract in english INTRODUCTION: Cyclopid copepods are known to be good mosquito controllers, specially as regards the larvae of the dengue vectors Aedes aegypti and Ae. albopictus. MATERIAL AND METHOD: The objective of the study was to survey the local copepod fauna and search for new strains of M. longisetus var. lo [...] ngisetus, comparing the potential of the samples found with the current strain ML-01 against Ae. albopictus larvae, under laboratory conditions. Eleven bodies of water in Campinas, SP, Brazil, were screened for copepods by collecting 1.5 l of water from each of then. The predatory potential of adults copepods was evaluated over 24 h, in the laboratory, for groups of 5 individuals preying upon 30 first instar Ae. albopictus larvae. RESULTS AND CONCLUSION: The following cyclopid species were found: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. The predatory potential of these copepods ranged from nil to 97.3%. A sample collected in the field containing only M. longisetus var. longisetus showed the best control efficiency with no significant difference from a three-year old laboratory culture (ML-01) of the same species evaluated for comparison. The sample with few M. albidus var. albidus was ranked in second place showing an average 25.9% efficiency. The use of copepods in trap tires as dengue vector controllers is discussed.

Santos, Luciana Urbano dos; Andrade, Carlos Fernando S. de.

259

Survey of cyclopids (Crustacea, Copepoda) in Brazil and preliminary screening of their potential as dengue vector predators / Levantamento de ciclopídeos (Crustacea, Copepoda) no Brasil e avaliação preliminar de seu potencial como predadores dos vetores da dengue  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: English Abstract in portuguese INTRODUÇÃO: Copépodos ciclopídeos são conhecidos como bons controladores de mosquitos, especialmente quando considerado as larvas dos vetores da dengue Aedes aegypti e Ae. albopictus. MATERIAL E MÉTODO: Onze corpos d'água em Campinas, SP, Brasil, foram avaliados para copépodos coletando-se 1,5 l de [...] água de cada um deles. O potencial predador dos copépodos adultos foi avaliado por 24 h, em laboratório, em grupos de 5 indivíduos predadando sobre 30 larvas de 1° estádio de Ae. albopictus. RESULTADOS E CONCLUSÕES: No presente levantamento as seguintes espécies de ciclopídeos foram encontradas: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. O potencial predador desses copépodos variou de zero a 97,3%. A amostra coletada no campo contendo apenas com M. longisetus var. longisetus mostrou a melhor eficiência de controle, sem diferença significativa de uma cultura de laboratório (ML-01) criada por 3 anos, desta mesma espécie, que foi avaliada para comparação. A amostra com poucos M. albidus var. albidus foi cotada em segundo melhor lugar, apresentando em média 25,9% de eficiência. O uso de copépodos em pneus armadilha como controladores dos vetores da dengue é discutido. Abstract in english INTRODUCTION: Cyclopid copepods are known to be good mosquito controllers, specially as regards the larvae of the dengue vectors Aedes aegypti and Ae. albopictus. MATERIAL AND METHOD: The objective of the study was to survey the local copepod fauna and search for new strains of M. longisetus var. lo [...] ngisetus, comparing the potential of the samples found with the current strain ML-01 against Ae. albopictus larvae, under laboratory conditions. Eleven bodies of water in Campinas, SP, Brazil, were screened for copepods by collecting 1.5 l of water from each of then. The predatory potential of adults copepods was evaluated over 24 h, in the laboratory, for groups of 5 individuals preying upon 30 first instar Ae. albopictus larvae. RESULTS AND CONCLUSION: The following cyclopid species were found: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. The predatory potential of these copepods ranged from nil to 97.3%. A sample collected in the field containing only M. longisetus var. longisetus showed the best control efficiency with no significant difference from a three-year old laboratory culture (ML-01) of the same species evaluated for comparison. The sample with few M. albidus var. albidus was ranked in second place showing an average 25.9% efficiency. The use of copepods in trap tires as dengue vector controllers is discussed.

Santos, Luciana Urbano dos; Andrade, Carlos Fernando S. de.

260

Survey of cyclopids (Crustacea, Copepoda in Brazil and preliminary screening of their potential as dengue vector predators Levantamento de ciclopídeos (Crustacea, Copepoda no Brasil e avaliação preliminar de seu potencial como predadores dos vetores da dengue  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCTION: Cyclopid copepods are known to be good mosquito controllers, specially as regards the larvae of the dengue vectors Aedes aegypti and Ae. albopictus. MATERIAL AND METHOD: The objective of the study was to survey the local copepod fauna and search for new strains of M. longisetus var. longisetus, comparing the potential of the samples found with the current strain ML-01 against Ae. albopictus larvae, under laboratory conditions. Eleven bodies of water in Campinas, SP, Brazil, were screened for copepods by collecting 1.5 l of water from each of then. The predatory potential of adults copepods was evaluated over 24 h, in the laboratory, for groups of 5 individuals preying upon 30 first instar Ae. albopictus larvae. RESULTS AND CONCLUSION: The following cyclopid species were found: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. The predatory potential of these copepods ranged from nil to 97.3%. A sample collected in the field containing only M. longisetus var. longisetus showed the best control efficiency with no significant difference from a three-year old laboratory culture (ML-01 of the same species evaluated for comparison. The sample with few M. albidus var. albidus was ranked in second place showing an average 25.9% efficiency. The use of copepods in trap tires as dengue vector controllers is discussed.INTRODUÇÃO: Copépodos ciclopídeos são conhecidos como bons controladores de mosquitos, especialmente quando considerado as larvas dos vetores da dengue Aedes aegypti e Ae. albopictus. MATERIAL E MÉTODO: Onze corpos d'água em Campinas, SP, Brasil, foram avaliados para copépodos coletando-se 1,5 l de água de cada um deles. O potencial predador dos copépodos adultos foi avaliado por 24 h, em laboratório, em grupos de 5 indivíduos predadando sobre 30 larvas de 1° estádio de Ae. albopictus. RESULTADOS E CONCLUSÕES: No presente levantamento as seguintes espécies de ciclopídeos foram encontradas: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. O potencial predador desses copépodos variou de zero a 97,3%. A amostra coletada no campo contendo apenas com M. longisetus var. longisetus mostrou a melhor eficiência de controle, sem diferença significativa de uma cultura de laboratório (ML-01 criada por 3 anos, desta mesma espécie, que foi avaliada para comparação. A amostra com poucos M. albidus var. albidus foi cotada em segundo melhor lugar, apresentando em média 25,9% de eficiência. O uso de copépodos em pneus armadilha como controladores dos vetores da dengue é discutido.

Luciana Urbano dos Santos

1997-06-01

 
 
 
 
261

Biosecurity and Vector Behaviour: Evaluating the Potential Threat Posed by Anglers and Canoeists as Pathways for the Spread of Invasive Non-Native Species and Pathogens  

Science.gov (United States)

Invasive non-native species (INNS) endanger native biodiversity and are a major economic problem. The management of pathways to prevent their introduction and establishment is a key target in the Convention on Biological Diversity's Aichi biodiversity targets for 2020. Freshwater environments are particularly susceptible to invasions as they are exposed to multiple introduction pathways, including non-native fish stocking and the release of boat ballast water. Since many freshwater INNS and aquatic pathogens can survive for several days in damp environments, there is potential for transport between water catchments on the equipment used by recreational anglers and canoeists. To quantify this biosecurity risk, we conducted an online questionnaire with 960 anglers and 599 canoeists to investigate their locations of activity, equipment used, and how frequently equipment was cleaned and/or dried after use. Anglers were also asked about their use and disposal of live bait. Our results indicate that 64% of anglers and 78.5% of canoeists use their equipment/boat in more than one catchment within a fortnight, the survival time of many of the INNS and pathogens considered in this study and that 12% of anglers and 50% of canoeists do so without either cleaning or drying their kit between uses. Furthermore, 8% of anglers and 28% of canoeists had used their equipment overseas without cleaning or drying it after each use which could facilitate both the introduction and secondary spread of INNS in the UK. Our results provide a baseline against which to evaluate the effectiveness of future biosecurity awareness campaigns, and identify groups to target with biosecurity awareness information. Our results also indicate that the biosecurity practices of these groups must improve to reduce the likelihood of inadvertently spreading INNS and pathogens through these activities.

Anderson, Lucy G.; White, Piran C. L.; Stebbing, Paul D.; Stentiford, Grant D.; Dunn, Alison M.

2014-01-01

262

Biofabrication of Ag nanoparticles using Sterculia foetida L. seed extract and their toxic potential against mosquito vectors and HeLa cancer cells.  

Science.gov (United States)

A one-step and eco-friendly process for the synthesis of silver-(protein-lipid) nanoparticles (Ag-PL NPs) (core-shell) has been developed using the seed extract from wild Indian Almond tree, Sterculia foetida (L.) (Sterculiaceae). The reaction temperature played a major role in controlling the size and shell formation of NPs. The amount of NPs synthesized and qualitative characterization was done by UV-vis spectroscopy and transmission electron microscopy (TEM), respectively. TEM studies exhibited controlled dispersity of spherical shaped NPs with an average size of 6.9±0.2nm. Selected area electron diffraction (SAED) and X-ray diffraction (XRD) revealed 'fcc' phase and crystallinity of the particles. X-ray photoelectron spectroscopy (XPS) was used to identify the protein-lipid (PL) bilayer that appears as a shell around the Ag core particles. The thermal stability of the Ag-PL NPs was examined using thermogravimetric analysis (TGA). Further analysis was carried out by using Fourier transform infrared spectroscopy (FTIR), where the spectra provided evidence for the presence of proteins and lipid moieties ((2n-octylcycloprop-1-enyl)-octanoic acid (I)), and their role in synthesis and stabilization of Ag NPs. This is the first report of plant seed assisted synthesis of PL conjugated Ag NPs. These formed Ag-PL NPs showed potential mosquito larvicidal activity against Aedes aegypti (L.), Anopheles stephensi Liston and Culex quinquefasciatus Say. These Ag-PL NPs can also act as promising agents in cancer therapy. They exhibited anti-proliferative activity against HeLa cancer cell lines and a promising toxicity was observed in a dose dependent manner. Toxicity studies were further supported by the cellular DNA fragmentation in the Ag-PL NPs treated HeLa cells. PMID:24863217

Rajasekharreddy, Pala; Rani, Pathipati Usha

2014-06-01

263

Cross-resistance, genetics, and realized heritability of resistance to fipronil in the house fly, Musca domestica (Diptera: Muscidae): a potential vector for disease transmission.  

Science.gov (United States)

Houseflies, Musca domestica (L.), are ubiquitous pests that have the potential to spread a variety of pathogens to humans, poultries, and dairies. Pesticides are commonly used for the management of this pest. Fipronil is a GABA-gated chloride channel-inhibiting insecticide that has been commonly used for the management of different pests including M. domestica throughout the world. Many pests have developed resistance to this insecticide. A field-collected strain of M. domestica was selected with fipronil for continuous 11 generations to assess the cross-resistance, genetics, and realized heritability for designing a resistance management strategy. Laboratory bioassays were performed using the feeding method of mixing insecticide concentrations with 20% sugar solutions and cotton soaks dipped in insecticide solutions were provided to tested adult flies. Bioassay results at G12 showed that the fipronil-selected strain developed a resistance ratio of 140-fold compared to the susceptible strain. Synergism bioassay with piperonyl butoxide (PBO) and S,S,S,-tributyl phosphorotrithioate (DEF) indicated that fipronil resistance was associated with microsomal oxidase and also esterase. Reciprocal crosses between resistant and susceptible strains showed an autosomal and incompletely dominant resistance to fipronil. The LC50 values of F1 and F'1 strains were not significantly different and dominance values were 0.74 and 0.64, respectively. The resistance to fipronil was completely recessive (D(ML) = 0.00) at the highest dose and incompletely dominant at the lowest dose (D(ML) = 0.87). The monogenic resistance based on chi-square goodness of fit test and calculation of the minimum number of segregating genes showed that resistance to fipronil is controlled by multiple genes. The fipronil resistance strain confirmed very low cross-resistance to emamectin benzoate and spinosad while no cross-resistance to chlorpyrifos and acetamiprid when compared to that of the field population. The heritability values were 0.112, 0.075, 0.084, 0.008, and 0.052 for fipronil, emamectin benzoate, spinosad, acetamiprid, and chlorpyrifos, respectively. It was concluded that fipronil resistance in M. domestica was autosomally inherited, incompletely dominant, and polygenic. These findings would be helpful for the better and successful management of M. domestica. PMID:24481906

Abbas, Naeem; Khan, Hafiz Azhar Ali; Shad, Sarfraz Ali

2014-04-01

264

Vector-associated diseases in the context of climate change: Analysis and evaluation of the differences in the potential spread of tertian malaria in the ecoregions of Lower Saxony  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: The outbreak of vector-associated diseases is determined by different factors. One of them is the existence of appropriate climatic conditions which influence the development of vectors as well as pathogens. Nowadays, accurate data on the occurrence of both vectors and pathogens are often not available in Germany, espite the coastal zones of Lower Saxony (Germany) being former malaria regions. Thus, the question arises, whether a new autochtho...

Gunther Schmidt; Marcel Holy; Winfried Schröder

2008-01-01

265

Vector Soliton Fiber Lasers  

CERN Document Server

Solitons, as stable localized wave packets that can propagate long distance in dispersive media without changing their shapes, are ubiquitous in nonlinear physical systems. Since the first experimental realization of optical bright solitons in the anomalous dispersion single mode fibers (SMF) by Mollenauer et al. in 1980 and optical dark solitons in the normal dispersion SMFs by P. Emplit et al. in 1987, optical solitons in SMFs had been extensively investigated. In reality a SMF always supports two orthogonal polarization modes. Taking fiber birefringence into account, it was later theoretically predicted that various types of vector solitons, including the bright-bright vector solitons, dark-dark vector solitons and dark-bright vector solitons, could be formed in SMFs. However, except the bright-bright type of vector solitons, other types of vector solitons are so far lack of clear experimental evidence. Optical solitons have been observed not only in the SMFs but also in mode locked fiber lasers. It has be...

Zhang, Han

2011-01-01

266

Complex vector functional equations  

CERN Document Server

The subject of complex vector functional equations is a new area in the theory of functional equations. This monograph provides a systematic overview of the authors' recently obtained results concerning both linear and nonlinear complex vector functional equations, in all aspects of their utilization. It is intended for mathematicians, physicists and engineers who use functional equations in their investigations. Contents: Linear Complex Vector Functional Equations: General Classes of Cyclic Functional Equations; Functional Equations with Operations Between Arguments; Functional Equations with

Risteski, Ice

2001-01-01

267

Clifford Fourier transform on vector fields.  

Science.gov (United States)

Image processing and computer vision have robust methods for feature extraction and the computation of derivatives of scalar fields. Furthermore, interpolation and the effects of applying a filter can be analyzed in detail and can be advantages when applying these methods to vector fields to obtain a solid theoretical basis for feature extraction. We recently introduced the Clifford convolution, which is an extension of the classical convolution on scalar fields and provides a unified notation for the convolution of scalar and vector fields. It has attractive geometric properties that allow pattern matching on vector fields. In image processing, the convolution and the Fourier transform operators are closely related by the convolution theorem and, in this paper, we extend the Fourier transform to include general elements of Clifford Algebra, called multivectors, including scalars and vectors. The resulting convolution and derivative theorems are extensions of those for convolution and the Fourier transform on scalar fields. The Clifford Fourier transform allows a frequency analysis of vector fields and the behavior of vector-valued filters. In frequency space, vectors are transformed into general multivectors of the Clifford Algebra. Many basic vector-valued patterns, such as source, sink, saddle points, and potential vortices, can be described by a few multivectors in frequency space. PMID:16138556

Ebling, Julia; Scheuermann, Gerik

2005-01-01

268

Flexi vector cloning.  

Science.gov (United States)

A protocol for ligation-dependent cloning using the Flexi Vector method in a 96-well format is described. The complete protocol includes PCR amplification of the desired gene to append Flexi Vector cloning sequences, restriction digestion of the PCR products, ligation of the digested PCR products into a similarly digested acceptor vector, transformation and growth of host cells, analysis of the transformed clones, and storage of a sequence-verified clone. The protocol also includes transfer of the sequence-verified clones into another Flexi Vector plasmid backbone. Smaller numbers of cloning reactions can be undertaken by appropriate scaling of the indicated reaction volumes. PMID:18988018

Blommel, Paul G; Martin, Peter A; Seder, Kory D; Wrobel, Russell L; Fox, Brian G

2009-01-01

269

Monopole vector spherical harmonics  

CERN Multimedia

Eigenfunctions of total angular momentum for a charged vector field interacting with a magnetic monopole are constructed and their properties studied. In general, these eigenfunctions can be obtained by applying vector operators to the monopole spherical harmonics in a manner similar to that often used for the construction of the ordinary vector spherical harmonics. This construction fails for the harmonics with the minimum allowed angular momentum. These latter form a set of vector fields with vanishing covariant curl and covariant divergence, whose number can be determined by an index theorem.

Weinberg, Erick J

1994-01-01

270

The Effects of Climate Change and Globalization on Mosquito Vectors: Evidence from Jeju Island, South Korea on the Potential for Asian Tiger Mosquito (Aedes albopictus) Influxes and Survival from Vietnam Rather Than Japan  

Science.gov (United States)

Background Climate change affects the survival and transmission of arthropod vectors as well as the development rates of vector-borne pathogens. Increased international travel is also an important factor in the spread of vector-borne diseases (VBDs) such as dengue, West Nile, yellow fever, chikungunya, and malaria. Dengue is the most important vector-borne viral disease. An estimated 2.5 billion people are at risk of infection in the world and there are approximately 50 million dengue infections and an estimated 500,000 individuals are hospitalized with dengue haemorrhagic fever annually. The Asian tiger mosquito (Aedes albopictus) is one of the vectors of dengue virus, and populations already exist on Jeju Island, South Korea. Currently, colder winter temperatures kill off Asian tiger mosquito populations and there is no evidence of the mosquitos being vectors for the dengue virus in this location. However, dengue virus-bearing mosquito vectors can inflow to Jeju Island from endemic area such as Vietnam by increased international travel, and this mosquito vector's survival during colder winter months will likely occur due to the effects of climate change. Methods and Results In this section, we show the geographical distribution of medically important mosquito vectors such as Ae. albopictus, a vector of both dengue and chikungunya viruses; Culex pipiens, a vector of West Nile virus; and Anopheles sinensis, a vector of Plasmodium vivax, within Jeju Island, South Korea. We found a significant association between the mean temperature, amount of precipitation, and density of mosquitoes. The phylogenetic analyses show that an Ae. albopictus, collected in southern area of Jeju Island, was identical to specimens found in Ho Chi Minh, Vietnam, and not Nagasaki, Japan. Conclusion Our results suggest that mosquito vectors or virus-bearing vectors can transmit from epidemic regions of Southeast Asia to Jeju Island and can survive during colder winter months. Therefore, Jeju Island is no longer safe from vector borne diseases (VBDs) due to the effects of globalization and climate change, and we should immediately monitor regional climate change to identify newly emerging VBDs.

Jeong, Ji Yeon; Yoo, Seung Jin; Koh, Young-Sang; Lee, Seogjae; Heo, Sang Taek; Seong, Seung-Yong; Lee, Keun Hwa

2013-01-01

271

Vectorized mixed radix discrete Fourier transform algorithms  

Energy Technology Data Exchange (ETDEWEB)

A number of previous attempts at the vectorization of the fast Fourier transform (FFT) algorithm have fallen somewhat short of achieving the full potential speed of vector processors. The algorithm formulation and implementation described here not only achieves full vector utilization but successfully copes with the problems of hierarchical storage. In the present paper, these techniques are described and extended to the general mixed radix algorithms, prime factor algorithm (PFA), the multidimensional discrete Fourier transform (DFT), the rectangular transform convolution algorithms, and the Winograd fast Fourier transform algorithm.

Agarwal, R.C.; Cooley, J.W.

1987-09-01

272

Bacteriophage lambda as a cloning vector.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Extensive research has been directed toward the development of multipurpose lambda vectors for cloning ever since the potential of using coliphage lambda as a cloning vector was recognized in the late 1970s. An understanding of the intrinsic molecular organization and of the genetic events which determine lysis or lysogeny in lambda has allowed investigators to modify it to suit the specific requirements of gene manipulations. Unwanted restriction sites have been altered and arranged together...

1992-01-01

273

Pulsed Vector Magnetic Potential Field Existence  

Directory of Open Access Journals (Sweden)

Full Text Available Experimental confirmation discussed the effect of the immediate surroundings of a pulse-powered toroidal coil on biological material which was placed in an environment without the influence of electromagnetic force.

Ivan Rampl

2012-11-01

274

Pulsed Vector Magnetic Potential Field Existence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Experimental confirmation discussed the effect of the immediate surroundings of a pulse-powered toroidal coil on biological material which was placed in an environment without the influence of electromagnetic force.

Ivan Rampl; LukᚠPalko; Pavel Hyršl; Libor Vojtek

2012-01-01

275

Vector generator scan converter  

Energy Technology Data Exchange (ETDEWEB)

High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold. 7 figs.

Moore, J.M.; Leighton, J.F.

1988-02-05

276

Vector generator scan converter  

Energy Technology Data Exchange (ETDEWEB)

This patent describes high printing speeds for graphics data that are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O (input/output) channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold.

Moore, J.M.; Leighton, J.F.

1990-04-17

277

Covariant and Contravariant Vectors  

CERN Multimedia

Vector is a physical quantity and it does not depend on any co-ordinate system. It need to be expanded in some basis for practical calculation and its components do depend on the chosen basis. The expansion in orthonormal basis is mathematically simple. But in many physical situations we have to choose an non-orthogonal basis (or oblique co-ordinate system). But the expansion of a vector in non-orthogonal basis is not convenient to work with. With the notion of contravariant and covariant components of a vector, we make non-orthogonal basis to behave like orthonormal basis. The same notion appears in quantum mechanics as Ket and Bra vectors and we compare the two equivalent situation via the completeness relation. This notion appears in the differential geometry of a metric manifold for tangent vectors at a point, where it takes into account the non-orthogonality of basis as well as non-Euclidean geometry.

Kumar, Alok

2010-01-01

278

Gene targeting with retroviral vectors  

Energy Technology Data Exchange (ETDEWEB)

The authors have designed and constructed integration-defective retroviral vectors to explore their potential for gene targeting in mammalian cells. Two nonoverlapping deletion mutants of the bacterial neomycin resistance (neo) gene were used to detect homologous recombination events between viral and chromosomal sequences. Stable neo gene correction events were selected at a frequency of approximately 1 G418/sup r/ cell per 3 x 10/sup 6/ infected cells. Analysis of the functional neo gene in independent targeted cell clones indicated that unintegrated retroviral linear DNA recombined with the target by gene conversion for variable distances into regions of nonhomology. In addition, transient neo gene correction events which were associated with the complete loss of the chromosomal target sequences were observed. These results demonstrated that retroviral vectors can recombine with homologous chromosomal sequences in rodent and human cells.

Ellis, J.; Bernstein, A. (Toronto Univ., ON (Canada))

1989-04-01

279

Null Killing vectors  

International Nuclear Information System (INIS)

Space-times admitting a null Killing vector are studied, using the Newman-Penrose spin coefficient formalism. The properties of the eigenrays (principal null curves of the Killing bivector) are shown to be related to the twist of the null Killing vector. Among the electrovacs, the ones containing a null Maxwell field turn out to belong to the twistfree class. An electrovac solution is obtained for which the null Killing vector is twisting and has geodesic and shearfree eigenrays. This solution is parameterless and appears to be the field of a zero-mass, spinning and charged source. (author)

1980-01-01

280

The Frame Potential, on Average  

CERN Document Server

A SIC consists of N^2 equiangular unit vectors in an N dimensional Hilbert space. The frame potential is a function of N^2 unit vectors. It has a unique global minimum if the vectors form a SIC, and this property has been made use of in numerical searches for SICs. When the vectors form an orbit of the Heisenberg group the frame potential becomes a function of a single fiducial vector. We analytically compute the average of this function over Hilbert space. We also compute averages when the fiducial vector is placed in certain special subspaces defined by the Clifford group.

Bengtsson, Ingemar

2008-01-01

 
 
 
 
281

The distribution of potential West Nile virus vectors, Culex pipiens pipiens and Culex pipiens quinquefasciatus (Diptera: Culicidae), in Mexico City  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Culex spp. mosquitoes are considered to be the most important vectors of West Nile virus (WNV) detected in at least 34 species of mosquitoes in the United States. In North America, Culex pipiens pipiens, Culex pipiens quinquefasciatus, and Culex tarsalis are all competent vectors of WNV, which is considered to be enzootic in the United States and has also been detected in equines and birds in many states of Mexico and in humans i...

Diaz-Badillo Alvaro; Bolling Bethany G; Perez-Ramirez Gerardo; Moore Chester G; Martinez-Munoz Jorge P; Padilla-Viveros America A; Camacho-Nuez Minerva; Diaz-Perez Alfonso; Beaty Barry J; de Lourdes Munoz Maria

2011-01-01

282

The midgut transcriptome of Phlebotomus (Larroussius perniciosus, a vector of Leishmania infantum: comparison of sugar fed and blood fed sand flies  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Parasite-vector interactions are fundamental in the transmission of vector-borne diseases such as leishmaniasis. Leishmania development in the vector sand fly is confined to the digestive tract, where sand fly midgut molecules interact with the parasites. In this work we sequenced and analyzed two midgut-specific cDNA libraries from sugar fed and blood fed female Phlebotomus perniciosus and compared the transcript expression profiles. Results A total of 4111 high quality sequences were obtained from the two libraries and assembled into 370 contigs and 1085 singletons. Molecules with putative roles in blood meal digestion, peritrophic matrix formation, immunity and response to oxidative stress were identified, including proteins that were not previously reported in sand flies. These molecules were evaluated relative to other published sand fly transcripts. Comparative analysis of the two libraries revealed transcripts differentially expressed in response to blood feeding. Molecules up regulated by blood feeding include a putative peritrophin (PperPer1, two chymotrypsin-like proteins (PperChym1 and PperChym2, a putative trypsin (PperTryp3 and four putative microvillar proteins (PperMVP1, 2, 4 and 5. Additionally, several transcripts were more abundant in the sugar fed midgut, such as two putative trypsins (PperTryp1 and PperTryp2, a chymotrypsin (PperChym3 and a microvillar protein (PperMVP3. We performed a detailed temporal expression profile analysis of the putative trypsin transcripts using qPCR and confirmed the expression of blood-induced and blood-repressed trypsins. Trypsin expression was measured in Leishmania infantum-infected and uninfected sand flies, which identified the L. infantum-induced down regulation of PperTryp3 at 24 hours post-blood meal. Conclusion This midgut tissue-specific transcriptome provides insight into the molecules expressed in the midgut of P. perniciosus, an important vector of visceral leishmaniasis in the Old World. Through the comparative analysis of the libraries we identified molecules differentially expressed during blood meal digestion. Additionally, this study provides a detailed comparison to transcripts of other sand flies. Moreover, our analysis of putative trypsins demonstrated that L. infantum infection can reduce the transcript abundance of trypsin PperTryp3 in the midgut of P. perniciosus.

Valenzuela Jesus G

2011-05-01

283

Optimally rotated vectors  

Directory of Open Access Journals (Sweden)

Full Text Available We study vectors which undergo maximum or minimum rotation by a matrix on the field of real numbers. The cosine of the angle between a maximally rotated vector and its image under the matrix is called the cosine or antieigenvalue of the matrix and has important applications in numerical methods. Using Lagrange multiplier technique, we obtain systems of nonlinear equations which represent these optimization problems. Furthermore, we solve these systems symbolically and numerically.

Morteza Seddighin

2003-11-01

284

Vector mesons in medium  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Based on an effective Lagrangian which combines chiral SU(3) dynamics with vector meson dominance, we have developed a model for the forward vector meson-nucleon scattering amplitudes. We use this as an input to calculate the low energy part of the current-current correlation function in nuclear matter. For the isovector channel we find a significant enhancement of the in-medium spectral density below the $\\rho$ resonance while the $\\rho$ meson mass itself changes only sligh...

Klingl, F.; Weise, W.

1998-01-01

285

Support vector machines applications  

CERN Document Server

Support vector machines (SVM) have both a solid mathematical background and good performance in practical applications. This book focuses on the recent advances and applications of the SVM in different areas, such as image processing, medical practice, computer vision, pattern recognition, machine learning, applied statistics, business intelligence, and artificial intelligence. The aim of this book is to create a comprehensive source on support vector machine applications, especially some recent advances.

Guo, Guodong

2014-01-01

286

On cosmic inflation in vector field theories  

CERN Multimedia

We investigate the longitudinal ghost issue in vector inflation. It turns out that, within the class of Lorentz-invariant vector field theories with three degres of freedom and without any extra (scalar) fields, the possibilities are essentially exhausted by the classical solution due to Larry Ford with an extremely flat potential which doesn't feel the fast roll of its argument. And, moreover, one needs to fulfill an extra condition on that potential in order to avoid severe gradient instability. At the same time, some Lorentz-violating modifications are worth to be explored.

Golovnev, Alexey

2011-01-01

287

The vector BPS Skyrme model  

CERN Document Server

We analyze the vector meson formulation of the BPS Skyrme model in (3+1) dimensions, where the term of sixth power in first derivatives characteristic for the original, integrable BPS Skyrme model (the topological or baryon current squared) is replaced by a coupling between the vector meson $\\omega_\\mu$ and the baryon current. We find that the model remains integrable in the sense of generalized integrability and almost solvable (reducible to a set of two first order ODEs) for any value of the baryon charge. Further, we analyze the appearance of topological solitons for two one-parameter families of one vacuum potentials: the old Skyrme potentials and the so-called BPS potentials. Depending on the value of the parameters we find several qualitatively different possibilities. In the massless case we have a parameter region with no skyrmions, a unique compact skyrmion with a discontinuous first derivative at the boundary (equivalently, with a source term located at the boundary, which screens the topological ch...

Adam, C; Sanchez-Guillen, J; Wereszczynski, A

2012-01-01

288

The Vector Curvaton  

CERN Document Server

We analyze a massive vector field with a non-canonical kinetic term in the action, minimally coupled to gravity, where the mass and kinetic function of the vector field vary as functions of time during inflation. The vector field is introduced following the same idea of a scalar curvaton, which must not affect the inflationary dynamics since its energy density during inflation is negligible compared to the total energy density in the Universe. Using this hypothesis, the vector curvaton will be solely responsible for generating the primordial curvature perturbation \\zeta. We have found that the spectra of the vector field perturbations are scale-invariant in superhorizon scales due to the suitable choice of the time dependence of the kinetic function and the effective mass during inflation. The preferred direction, generated by the vector field, makes the spectrum of \\zeta depend on the wavevector, i.e. there exists statistical anisotropy in \\zeta. This is discussed principally in the case where the mass of th...

Navarro, Andres A

2013-01-01

289

Equivalent local Dirac potentials  

International Nuclear Information System (INIS)

A transformation is used to obtain sets of equivalent Lorentz scalar, Lorentz four-vector, and tensor optical potentials. These potentials are used in the Dirac equation for describing elastic scattering observables

1985-01-01

290

Darboux Integrals for Schrödinger Planar Vector Fields via Darboux Transformations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we study the Darboux transformations of planar vector fields of Schrödinger type. Using the isogaloisian property of Darboux transformation we prove the ''invariance'' of the objects of the ''Darboux theory of integrability''. In particular, we also show how the shape invariance property of the potential is important in order to preserve the structure of the transformed vector field. Finally, as illustration of these results, some examples of planar vector fields coming from su...

2012-01-01

291

Darboux Integrals for Schrödinger Planar Vector Fields via Darboux Transformations  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we study the Darboux transformations of planar vector fields of Schrödinger type. Using the isogaloisian property of Darboux transformation we prove the ''invariance'' of the objects of the ''Darboux theory of integrability''. In particular, we also show how the shape invariance property of the potential is important in order to preserve the structure of the transformed vector field. Finally, as illustration of these results, some examples of planar vector fields coming from supersymmetric quantum mechanics are studied.

Primitivo B. Acosta-Humánez

2012-07-01

292

Vectorization in quantum chemistry  

International Nuclear Information System (INIS)

It is argued that the optimal vectorization algorithm for many steps (and sub-steps) in a typical ab initio calculation of molecular electronic structure is quite strongly dependent on the target vector machine. Details such as the availability (or lack) of a given vector construct in the hardware, vector startup times and asymptotic rates must all be considered when selecting the optimal algorithm. Illustrations are drawn from: gaussian integral evaluation, fock matrix construction, 4-index transformation of molecular integrals, direct-CI methods, the matrix multiply operation. A cross comparison of practical implementations on the CDC Cyber 205, the Cray-IS and Cray-XMP machines is presented. To achieve portability while remaining optimal on a wide range of machines it is necessary to code all available algorithms in a machine independent manner, and to select the appropriate algorithm using a procedure which is based on machine dependent parameters. Most such parameters concern the timing of certain vector loop kernals, which can usually be derived from a 'bench-marking' routine executed prior to the calculation proper

1987-01-01

293

Vector constants of the motion and orbits in the Coulomb/Kepler problem  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The equation for the conic sections describing the possible orbits in a potential $V \\sim r^{-1}$ is obtained by means of a vector constant of the motion differing from the traditional Laplace-Runge-Lenz vector.

Munoz, Gerardo

2003-01-01

294

Bluetongue vector species of Culicoides in Switzerland.  

Science.gov (United States)

Switzerland is historically recognized by the Office Internationale des Epizooties as free from bluetongue disease (BT) because of its latitude and climate. With bluetongue virus (BTV) moving north from the Mediterranean, an entomological survey was conducted in Switzerland in 2003 to assess the potential of the BTV vectors present. A total of 39 cattle farms located in three geographical regions, the Ticino region, the Western region and the region of the Grisons, were monitored during the vector season. Farms were located in areas at high risk of vector introduction and establishment based on the following characteristics: annual average temperature > 12.5 degrees C, average annual humidity >or= 60%, cattle farm. Onderstepoort black light traps were operated at the cattle farms generally for one night in July and one night in September. A total of 56 collections of Culicoides (Diptera: Ceratopogonidae) were identified morphologically. Only one single individual of Culicoides (Avaritia) imicola, the major Old World vector of BTV, was found in July 2003 in the Ticino region, one of the southernmost regions of Switzerland. In the absence of further specimens of C. imicola from Switzerland it is suggested that this individual may be a vagrant transported by wind from regions to the south of the country where populations of this species are known to occur. Alternative potential BTV vectors of the Culicoides (Culicoides) pulicaris and Culicoides (Avaritia) obsoletus complexes were abundant in all sampled regions with individual catches exceeding 70 000 midges per trap night. PMID:16874919

Cagienard, A; Griot, C; Mellor, P S; Denison, E; Stärk, K D C

2006-06-01

295

Interpolation of Vector Measures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

[EN] Let (Omega, Sigma) be a measurable space and m(0) : Sigma -> X-0 and m(1) : Sigma -> X-1 be positive vector measures with values in the Banach Kothe function spaces X-0 and X-1. If 0 < alpha < 1, we define a new vector measure [m(0), m(1)](alpha) with values in the Calderon lattice interpolation space (X01-alpha X1 alpha) and we analyze the space of integrable functions with respect to measure [m(0), m(1)](alpha) in order to prove suitable extensions of the classical Stein-Weiss formulas...

Sa?nchez Pe?rez, Enrique Alfonso; Del Campo Acosta, Ricardo; Ferna?ndez Carrio?n, Antonio; Mayoral, Fernando; Naranjo, Francisco

2011-01-01

296

Sums and Gaussian vectors  

CERN Document Server

Surveys the methods currently applied to study sums of infinite-dimensional independent random vectors in situations where their distributions resemble Gaussian laws. Covers probabilities of large deviations, Chebyshev-type inequalities for seminorms of sums, a method of constructing Edgeworth-type expansions, estimates of characteristic functions for random vectors obtained by smooth mappings of infinite-dimensional sums to Euclidean spaces. A self-contained exposition of the modern research apparatus around CLT, the book is accessible to new graduate students, and can be a useful reference for researchers and teachers of the subject.

Yurinsky, Vadim Vladimirovich

1995-01-01

297

Heavy vector mesons  

International Nuclear Information System (INIS)

The current status of heavy vector meson resonances in the prime rho, prime ? and prime phi families is discussed in the light of recent results, particularly from the CERN photoproduction experiment WA4. It is shown that the results from recent high statistics ?p and e+e- experiments have clarified the confused state of heavy vector meson spectroscopy somewhat but the tentative nature of the conclusions reached emphasises the fact that light quark radial excitations are still less well understood than upsilon radial excitations. (U.K.)

1980-04-01

298

Singularly perturbed vector fields  

Science.gov (United States)

A geometrically invariant concept of singularly perturbed systems of ordinary differential equations (singularly perturbed vector fields) is proposed in this paper. Singularly perturbed vector fields can be represented locally as singularly perturbed systems (for corresponding coordinate system choice. The paper focuses on possible ways of fast and slow directions/manifolds evaluations. A special algorithm for the evaluation is proposed. The algorithm is called as a global quasi-linearization procedure. A practical application of the proposed algorithm for numerical simulations is the main issue of the paper.

Bykov, V.; Goldfarb, I.; Gol'dshtein, V.

2006-12-01

299

The preloadable vector sensitive latch for orbital docking/berthing  

Science.gov (United States)

The workings and function of the Preloader Vector Sensitive Latch are described. A discussion of docking systems used in the U.S. manned space flight programs is included to show how docking systems have evolved, and to highlight the potential advantages of a preloadable vector sensitive latch in such systems.

Acres, William R.; Kennedy, John J.

1987-01-01

300

Random and vector measures  

CERN Document Server

The book is devoted to the structural analysis of vector and random (or both) valued countably additive measures, and used for integral representations of random fields. The spaces can be Banach or Frechet types. Several stationary aspects and related processes are analyzed whilst numerous new results are included and many research avenues are opened up.

Rao, M M

2011-01-01

 
 
 
 
301

Hamilton's Eccentricity Vector Generalised to Newton Wonders  

CERN Multimedia

The vectorial velocity is given as a function of the position of a particle in orbit when a Newtonian central force is supplemented by an inverse cubic force as in Newton's theorem on revolving orbits. Such expressions are useful in fitting orbits to radial velocities of orbital streams. The Hamilton-Laplace-Runge-Lenz eccentricity vector is generalised to give a constant of the motion for these systems and an approximate constant for orbits in general central potentials. A related vector is found for Hooke's centred ellipse.

Lynden-Bell, Donald

2006-01-01

302

A vector asymmetrical NNV equation  

Science.gov (United States)

A vector asymmetrical Nizhnik-Novikov-Veselov (NNV) equation is proposed based on its bilinear form. Soliton solutions expressed by Pfaffians are obtained. Bilinear Bäcklund transformation and the corresponding Lax pair for the vector ANNV equation are derived.

Yu, Guo-Fu; Tam, Hon-Wah

2008-08-01

303

Vertical vector face lift.  

Science.gov (United States)

Facial rejuvenation using local anesthesia has evolved in the past decade as a safer option for patients seeking fewer complications and minimal downtime. Mini- and short-scar face lifts using more conservative incision lengths and extent of undermining can be effective in the younger patient with lower face laxity and minimal loose, elastotic neck skin. By incorporating both an anterior and posterior approach and using an incision length between the mini and more traditional face lift, the Vertical Vector Face Lift can achieve longer-lasting and natural results with lesser cost and risk. Submentoplasty and liposuction of the neck and jawline, fundamental components of the vertical vector face lift, act synergistically with superficial musculoaponeurotic system plication to reestablish a more youthful, sculpted cervicomental angle, even in patients with prominent jowls. Dramatic results can be achieved in the right patient by combining with other procedures such as injectable fillers, chin implants, laser resurfacing, or upper and lower blepharoplasties. PMID:21276163

Somoano, Brian; Chan, Joanna; Morganroth, Greg

2011-01-01

304

Bloch vectors for qudits  

CERN Document Server

We present three different matrix bases that can be used to decompose density matrices of $d$--dimensional quantum systems, so-called qudits: the \\emph{generalized Gell-Mann matrix basis}, the \\emph{polarization operator basis}, and the \\emph{Weyl operator basis}. Such a decomposition can be identified with a vector --the Bloch vector, i.e. a generalization of the well known qubit case-- and is a convenient expression for comparison with measurable quantities and for explicit calculations avoiding the handling of large matrices. We present a new method to decompose density matrices via so--called standard matrices, consider the important case of an isotropic two--qudit state and decompose it according to each basis. In case of qutrits we show a representation of an entanglement witness in terms of expectation values of spin 1 measurements, which is appropriate for an experimental realization.

Bertlmann, Reinhold A

2008-01-01

305

Double vector bundles and duality  

CERN Multimedia

The most important examples of a double vector bundle are provided by iterated tangent and cotangent functors: TTM, TT^*M, T^*TM, and T^*T^*M. We introduce the notions of the dual double vector bundle and the dual double vector bundle morphism. Theorems on canonical isomorphisms are formulated and proved. Several examples are given.

Konieczna, K; Konieczna, Katarzyna; Urbanski, Pawel

1997-01-01

306

Helices and vector bundles  

CERN Document Server

This volume is devoted to the use of helices as a method for studying exceptional vector bundles, an important and natural concept in algebraic geometry. The work arises out of a series of seminars organised in Moscow by A. N. Rudakov. The first article sets up the general machinery, and later ones explore its use in various contexts. As to be expected, the approach is concrete; the theory is considered for quadrics, ruled surfaces, K3 surfaces and P3(C).

Rudakov, A N

1990-01-01

307

Benchmarking Support Vector Machines  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Support Vector Machines (SVMs) are rarely benchmarked against other classification or regression methods. We compare a popular SVM implementation (libsvm) to 16 classification methods and 9 regression methods-all accessible through the software R-by the means of standard performance measures (classification error and mean squared error) which are also analyzed by the means of bias-variance decompositions. SVMs showed mostly good performances both on classification and regression tasks, but ot...

Meyer, David; Leisch, Friedrich; Hornik, Kurt

2002-01-01

308

Eliminating malaria vectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Malaria vectors which predominantly feed indoors upon humans have been locally eliminated from several settings with insecticide treated nets (ITNs), indoor residual spraying or larval source management. Recent dramatic declines of An. gambiae in east Africa with imperfect ITN coverage suggest mosquito populations can rapidly collapse when forced below realistically achievable, non-zero thresholds of density and supporting resource availability. Here we explain why insecticide-based mosquito ...

Killeen, Gerry F.; Seyoum, Aklilu; Sikaala, Chadwick; Zomboko, Amri S.; Gimnig, John E.; Govella, Nicodem J.; White, Michael T.

2013-01-01

309

Supersymmetric vector particles  

International Nuclear Information System (INIS)

It is shown that a relativistic generalization of Witten's supersymmetric quantum mechanics yields the Proca field equations describing a spin one particle, and, in the massless case, the Maxwell equations and the Lorentz gauge condition. The generalization is based on a representation of the pseudoclassical complex Grassmann variables by rectangular rather than quadratic matrices at the quantum level and on a non-associative operator product. We study all possible supersymmetric couplings to external fields. These include scalar, vector and tensor fields. The couplings exhibit a quadrupole characteristics of the pseudoclassical particle. In particular the coupling to an external vector field may be formulated in a purely geometrical manner and interpreted as that of a pure electric quadrupole to the Maxwell field. The corresponding Schroedinger equation does therefore not obey the minimal coupling prescription. The tensor field may represent not only a Riemannian, but also a complex hermitian metric. In the Riemannian case the quantization prescription entails the well-known covariant generalization of the classical vector field equations. We also derive a classical limit of the quantum theory that involves only real numbers. Finally we speculate on the existance of na analogous non-standard quantization for extended supersymmetric field theories. (Author)

1984-01-01

310

Integrative vectors for heterologous gene expression in Streptomyces spp.  

Science.gov (United States)

Integrative expression vectors for heterologous expression of the genes in Streptomyces were developed. The vectors are comprised of a strong constitutive promoter, PE, a synthetic ribosome-binding site, ATG start codon, multiple cloning site, transcription terminator and hygromycin-resistance-encoding gene. The vectors also contain a ColE1 replicon for propagation in Escherichia coli and a wide-host-range Streptomyces integration element, the mini-circle, to direct the insertion of the vectors into the Streptomyces genome at the mini-circle attachment site. HyR transformants are stable in the absence of drug selection. Conjugative derivatives were also constructed by incorporating oriT, the origin of transfer of the IncP plasmid RK2, into these vectors, and conjugal transfer was demonstrated from an appropriate E. coli donor to Steptomyces lividans (Sl). Derivatives of these vectors potentially useful for gene disruption, as well as complementation, are also described. Replicative forms of the constructed mini-circle-based vectors in Sl, that co-exist with the integrated copy of the vector, were also present without any apparent instability problems. The utility of the vectors was demonstrated by expression of the gene encoding 31-O-methyltransferase, which is involved in methylation at position 31 of the immunosuppressive drug FK506, in Sl. PMID:7628712

Motamedi, H; Shafiee, A; Cai, S J

1995-07-01

311

Leishmaniasis vector behaviour in Kenya  

International Nuclear Information System (INIS)

Leishmaniasis in Kenya exists in two forms: cutaneous and visceral. The vectors of visceral leishmaniasis have been the subject of investigation by various researchers since World War II, when the outbreak of the disease was first noticed. The vectors of cutaneous leishmaniasis were first worked on only a decade ago after the discovery of the disease focus in Mt. Elgon. The vector behaviour of these diseases, namely Phlebotomus pedifer, the vector of cutaneous leishmaniasis, and Phlebotomus martini, the vector of visceral leishmaniasis, are discussed in detail. P. pedifer has been found to breed and bite inside caves, whereas P. martini mainly bites inside houses. (author)

1979-05-11

312

Vector representation of tourmaline compositions  

Science.gov (United States)

The vector method for representing mineral compositions of amphibole and mica groups is applied to the tourmaline group. Consideration is given to the methods for drawing the relevant vector diagrams, relating the exchange vectors to one another, and contouring the diagrams for constant values of Na, Ca, Li, Fe, Mg, Al, Si, and OH. The method is used to depict a wide range of possible tourmaline end-member compositions and solid solutions, starting from a single point. In addition to vector depictions of multicomponent natural tourmalines, vectors are presented for simpler systems such as (Na,Al)-tourmalines, alkali-free tourmalines, and elbaites.

Burt, Donald M.

1989-01-01

313

[Climate- and vector-borne diseases  

DEFF Research Database (Denmark)

The predicted changes in climate have raised concerns that vector-borne diseases may emerge or expand in tempered regions. Malaria, leishmaniasis and tick-borne illnesses are discussed in terms of climate change and their endemic potential, especially in Denmark. While climate may play an important role in disease patterns, it is evident that transmission potential is governed by a complex of factors, including socio-economy, health-care capacity and ecology. In Denmark, malaria and leishmaniasis are unlikely to become public health problems, whereas the potential for tick-borne illnesses may increase Udgivelsesdato: 2009/10/26

Bygbjerg, I.C.; Schioler, K.L.

2009-01-01

314

Alternative serotype adenovirus vaccine vectors elicit memory T cells with enhanced anamnestic capacity compared to Ad5 vectors.  

Science.gov (United States)

The failure of the adenovirus serotype 5 (Ad5) vector-based human immunodeficiency virus type 1 (HIV-1) vaccine in the STEP study has led to the development of adenovirus vectors derived from alternative serotypes, such as Ad26, Ad35, and Ad48. We have recently demonstrated that vaccines using alternative-serotype Ad vectors confer partial protection against stringent simian immunodeficiency virus (SIV) challenges in rhesus monkeys. However, phenotypic differences between the T cell responses elicited by Ad5 and those of alternative-serotype Ad vectors remain unexplored. Here, we report the magnitude, phenotype, functionality, and recall capacity of memory T cell responses elicited in mice by Ad5, Ad26, Ad35, and Ad48 vectors expressing lymphocytic choriomeningitis virus (LCMV) glycoprotein (GP). Our data demonstrate that memory T cells elicited by Ad5 vectors were high in magnitude but exhibited functional exhaustion and decreased anamnestic potential following secondary antigen challenge compared to Ad26, Ad35, and Ad48 vectors. These data suggest that vaccination with alternative-serotype Ad vectors offers substantial immunological advantages over Ad5 vectors, in addition to circumventing high baseline Ad5-specific neutralizing antibody titers. PMID:23152535

Penaloza-MacMaster, Pablo; Provine, Nicholas M; Ra, Joshua; Borducchi, Erica N; McNally, Anna; Simmons, Nathaniel L; Iampietro, Mark J; Barouch, Dan H

2013-02-01

315

Pseudotransduction of hepatocytes by using concentrated pseudotyped vesicular stomatitis virus G glycoprotein (VSV-G)-Moloney murine leukemia virus-derived retrovirus vectors: comparison of VSV-G and amphotropic vectors for hepatic gene transfer.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recombinant retrovirus vectors are widely used for gene transfer studies. The recent development of a pseudotyped Moloney murine leukemia virus vector that contains the G envelope protein from the vesicular stomatitis virus allows for efficient concentration of vector and offers hope for potential use of these vectors for gene expression in vivo. A standard amphotropic vector expressing a serum marker protein, human alpha 1-antitrypsin, was infused into regenerating mouse liver and was 10-fol...

1996-01-01

316

Current Knowledge of Leishmania Vectors in Mexico: How Geographic Distributions of Species Relate to Transmission Areas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Leishmaniases are a group of vector-borne diseases with different clinical manifestations caused by parasites transmitted by sand fly vectors. In Mexico, the sand fly Lutzomyia olmeca olmeca is the only vector proven to transmit the parasite Leishmania mexicana to humans, which causes leishmaniasis. Other vector species with potential medical importance have been obtained, but their geographic distributions and relation to transmission areas have never been assessed. We modeled the ecological...

Gonza?lez, Camila; Rebollar-te?llez, Eduardo A.; Iba?n?ez-bernal, Sergio; Becker-fauser, Ingeborg; Marti?nez-meyer, Enrique; Peterson, A. Townsend; Sa?nchez-cordero, Vi?ctor

2011-01-01

317

Vector-valued crustal magnetic field estimation using vector Slepian functions  

Science.gov (United States)

To solve for the terrestrial or a planetary magnetic field from vector-valued measurements made by a satellite, an inversion needs to be performed that correctly maps the noisily and incompletely observed data down to the source level. For the case of the scalar potential, powerful localization techniques have aided in regularizing the ill-posed inverse problem of making global inference from local data, or vice versa. One can use splines, wavelets, cap harmonics, and also Slepian functions, which are optimally concentrated spatio-spectrally with respect to a function-energy norm. The Slepian functions, in particular, have been very useful in gravity geodesy, but also for the study of planetary magnetic fields available as spherical-harmonic potential expansions. It is clear that the benefits of localization are not available to vector data by simply focusing on the vector components individually. Rather, for the most common problems where a potential-description remains adequate, a dedicated function basis needs to be sought that is harmonic, vectorial in nature, bandlimited, and localized to target regions on the surface of the sphere. We have recently developed such a "vectorial spherical Slepian basis", and are thus ready to tackle the study of the satellite geomagnetic inverse problems of the future. In this presentation we apply vector-Slepian functions to the estimation of the vector-valued crustal magnetic field from vector-valued data at satellite altitude. The downward continuation of vector functions that satisfy the source-free assumption can be performed similarly to the scalar downward continuation if the data are described in a suitably transformed vector-spherical harmonic basis. We test our approach with artificial data using different data and noise power spectra and for different target regions. The vector Slepian approach should be beneficial in cases where we either have only local data at satellite altitude but want to obtain as much crustal field information as possible or if we have global data at satellite altitude but want to perform a purely local analysis of the crustal field, as we show by example.

Plattner, A.; Simons, F. J.

2012-12-01

318

Mathematical tables vector entities  

CERN Document Server

Students and research workers in mathematics, physics, engineering and other sciences will find this compilation invaluable. All the information included is practical, rarely used results are excluded. Great care has been taken to present all results concisely and clearly. Excellent to keep as a handy reference! If you don't have a lot of time but want to excel in class, this book helps you: Brush up before tests Find answers fast Learn key formulas and tables Study quickly and more effectively Inside this guide, you will find: Most important Vector Identities Clear and concise explanations of

2010-01-01

319

Warm vector inflation  

Energy Technology Data Exchange (ETDEWEB)

In this Letter we introduce the “warm vector inflation” scenario. In warm inflation scenario radiation is produced during the inflation epoch and reheating is avoided. Slow-roll and perturbation parameters of this model are presented. We develop our model using intermediate inflation model. In this case, the model is compatible with observational data. We also study the model using another exact cosmological solution, named logamediate scenario. We present slow-roll and Hubble parameters, power spectrum and tensor–scalar ratio in terms of inflaton. The model is compatible with WMAP7 and Planck observational data.

Setare, M.R., E-mail: rezakord@ipm.ir; Kamali, V., E-mail: vkamali1362@gmail.com

2013-10-07

320

Canine vector-borne diseases in Brazil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Canine vector-borne diseases (CVBDs) are highly prevalent in Brazil and represent a challenge to veterinarians and public health workers, since some diseases are of great zoonotic potential. Dogs are affected by many protozoa (e.g., Babesia vogeli, Leishmania infantum, and Trypanosoma cruzi), bacteria (e.g., Anaplasma platys and Ehrlichia canis), and helminths (e.g., Dirofilaria immitis and Dipylidium caninum) t...

Dantas-Torres Filipe

2008-01-01

 
 
 
 
321

Matrix elements between vector hyperspherical states  

Science.gov (United States)

Three-body symmetrized vector hyperspherical harmonic functions, realizing irreducible representations of the permutation group of three particles, are constructed and expressed in terms of Wigner D functions. Matrix elements of arbitrary two-body potentials between these hyperspherical states, including their velocity-dependent parts, are calculated analytically and expressed through the sum of products of the Wigner 3-j symbols and explicitly written functions of the radial variable.

Barnea, Nir; Mandelzweig, Victor B.

1991-12-01

322

An integrable hierarchy from vector models  

International Nuclear Information System (INIS)

Completely analogous to the matrix model case, O(N) vector models of arbitrary potential can also be related to an integrable hierarchy of equations. We derive the finite-N lattice equations, and construct operators Ln and Vn fulfilling the zero curvature condition. In the continuum limit this hierarchy of lattice equations becomes identical to the Burgers hierarchy, which has been derived earlier for these models in the double scaling limit. (orig.)

1991-06-27

323

An integrable hierarchy from vector models  

Energy Technology Data Exchange (ETDEWEB)

Completely analogous to the matrix model case, O(N) vector models of arbitrary potential can also be related to an integrable hierarchy of equations. We derive the finite-N lattice equations, and construct operators L{sub n} and V{sub n} fulfilling the zero curvature condition. In the continuum limit this hierarchy of lattice equations becomes identical to the Burgers hierarchy, which has been derived earlier for these models in the double scaling limit. (orig.).

Damgaard, P.H. (Danmarks Tekniske Hoejskole, Lyngby (Denmark) European Organization for Nuclear Research, Geneva (Switzerland)); Shigemoto, K. (Tezukayama Univ., Nara (Japan). Dept. of Physics)

1991-06-27

324

Eliminating malaria vectors.  

Science.gov (United States)

Malaria vectors which predominantly feed indoors upon humans have been locally eliminated from several settings with insecticide treated nets (ITNs), indoor residual spraying or larval source management. Recent dramatic declines of An. gambiae in east Africa with imperfect ITN coverage suggest mosquito populations can rapidly collapse when forced below realistically achievable, non-zero thresholds of density and supporting resource availability. Here we explain why insecticide-based mosquito elimination strategies are feasible, desirable and can be extended to a wider variety of species by expanding the vector control arsenal to cover a broader spectrum of the resources they need to survive. The greatest advantage of eliminating mosquitoes, rather than merely controlling them, is that this precludes local selection for behavioural or physiological resistance traits. The greatest challenges are therefore to achieve high biological coverage of targeted resources rapidly enough to prevent local emergence of resistance and to then continually exclude, monitor for and respond to re-invasion from external populations. PMID:23758937

Killeen, Gerry F; Seyoum, Aklilu; Sikaala, Chadwick; Zomboko, Amri S; Gimnig, John E; Govella, Nicodem J; White, Michael T

2013-01-01

325

Computer vector multiprocessing control  

Energy Technology Data Exchange (ETDEWEB)

A multiprocessing system and method for multiprocessing is described. A pair of processors are included, and each are connected to a central memory through a memory reference ports. The processors are further each connected to shared registers which may be directly addressed by either processor at rates commensurate with intraprocessor operation. The shared registers include registers for holding scalar and address information and registers for holding information to be used in coordinating the transfer of information through the shared registers. A multiport memory is provided and includes a conflict resolution circuit which senses and prioritizes conflicting references to the central memory. Each CPU is interfaced with the central memory through three ports, with each of the ports handling different ones of several different types of memory references which may be made. At least one I/O port is provided to be shared by the processors in transferring information between the central memory and peripheral storage devices. A vector register design is also described for use in vector processing computers, and provides that each register consist of at least two independently addressable memories, to deliver data to or accept data from a functional unit. The method of multiprocessing permits, multiasking in the multiprocessor, in which the shared registers allow independent tasks of different jobs or related tasks of a single job to be run concurrently, and facilitate multi-threading of the operating system by permitting multiple critical code regions to be independently synchronized.

Chen, S.S.; Schiffleger, A.J.; Somdahl, E.R.; Higbie, L.

1987-01-13

326

Statistical properties of contact vectors.  

Science.gov (United States)

We study the statistical properties of contact vectors, a construct to characterize a protein's structure. The contact vector of an N-residue protein is a list of N integers n(i), representing the number of residues in contact with residue i. We study analytically (at mean-field level) and numerically the amount of structural information contained in a contact vector. Analytical calculations reveal that a large variance in the contact numbers reduces the degeneracy of the mapping between contact vectors and structures. Exact enumeration for lengths up to N=16 on the three-dimensional cubic lattice indicates that the growth rate of number of contact vectors as a function of N is only 3% less than that for contact maps. In particular, for compact structures we present numerical evidence that, practically, each contact vector corresponds to only a handful of structures. We discuss how this information can be used for better structure prediction. PMID:12005870

Kabakçioglu, A; Kanter, I; Vendruscolo, M; Domany, E

2002-04-01

327

Vanishing moments for scaling vectors  

Directory of Open Access Journals (Sweden)

Full Text Available One advantage of scaling vectors over a single scaling function is the compatibility of symmetry and orthogonality. This paper investigates the relationship between symmetry, vanishing moments, orthogonality, and support length for a scaling vector Φ. Some general results on scaling vectors and vanishing moments are developed, as well as some necessary conditions for the symbol entries of a scaling vector with both symmetry and orthogonality. If orthogonal scaling vector Φ has some kind of symmetry and a given number of vanishing moments, we can characterize the type of symmetry for Φ, give some information about the form of the symbol P(z, and place some bounds on the support of each ϕi. We then construct an L2(ℝ orthogonal, symmetric scaling vector with one vanishing moment having minimal support.

David K. Ruch

2004-08-01

328

Transfer Entropy on Rank Vectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Transfer entropy (TE) is a popular measure of information flow found to perform consistently well in different settings. Symbolic transfer entropy (STE) is defined similarly to TE but on the ranks of the components of the reconstructed vectors rather than the reconstructed vectors themselves. First, we correct STE by forming the ranks for the future samples of the response system with regard to the current reconstructed vector. We give the grounds for this modified version o...

Kugiumtzis, Dimitris

2010-01-01

329

Experimental infection of Hawai'i 'Amakihi (hemignathus virens) with West Nile virus and competence of a co-occurring vector, culex quinquefasciatus: potential impacts on endemic Hawaiian avifauna.  

Science.gov (United States)

Introduced mosquito-borne avian disease is a major limiting factor in the recovery and restoration of native Hawaiian forest birds. Annual epizootics of avian pox (Avipoxvirus) and avian malaria (Plasmodium relictum) likely led to the extinction of some species and continue to impact populations of susceptible Hawaiian honeycreepers (Drepanidinae). The introduction of a novel pathogen, such as West Nile virus (WNV), could result in further population declines and extinctions. During September and October 2004, we infected Hawai'i' Amakihi (Hemignathus virens) with a North American isolate of WNV by needle inoculation and mosquito bite to observe susceptibility, mortality, and illness in this endemic passerine, and to determine the vector competence of the co-occurring, introduced mosquito Culex quinquefasciatus. All experimentally infected Hawai'i ;Amakihi became viremic, with a mean titer >10(5) plaque-forming units (PFU)/ml, and they experienced clinical signs ranging from anorexia and lethargy to ataxia. The fatality rate among needle-inoculated Hawai'i' Amakihi (n=16) was 31.3%, but mortality in free-ranging birds is likely to increase due to predation, starvation, thermal stress, and concomitant infections of avian malaria and pox. Surviving Hawai'i' Amakihi seem to clear WNV from the peripheral blood by 7-10 days postinfection (DPI), and neutralizing antibodies were detected from 9 to 46 DPI. In transmission trials, Hawaiian Cx. quinquefasciatus proved to be a competent vector and Hawai'i Amakihi an adequate amplification host of WNV, suggesting that epizootic WNV could readily become an additional limiting factor of some native Hawaiian bird populations. PMID:19395735

Lapointe, Dennis A; Hofmeister, Erik K; Atkinson, Carter T; Porter, Robert E; Dusek, Robert J

2009-04-01

330

Maths Help: Working with Vectors  

Science.gov (United States)

Analysis of a wide range of physical properties such as force, velocity, and acceleration, requires a firm understanding of the mathematics of vectors. This comprehensive Web site covers many aspects of vector algebra and trigonometry. The often-used dot product and cross product are defined, as well as vector representations of lines and planes. Illustrations are used to demonstrate vector analysis and its real-world applications. A few extra sections delve into related topics, including transformation between Cartesian and spherical coordinates. The material is mostly suitable for high school or college students who have taken pre-calculus.

331

Simulation of a vector hysteresis measurement system taking hysteresis into account by the vector Preisach model  

Science.gov (United States)

The paper deals with the numerical analysis of a rotational single sheet tester with round-shaped specimen (RRSST) which is now under construction. The measurement setup consists of an induction motor the rotor of which has been removed, and its windings have been replaced to a special two phase one which can generate homogeneous magnetic field inside the motor. The two orthogonal components of the magnetic field intensity and of the magnetic flux density vectors can be measured by H-coils and B-coils, respectively. The Finite Element Method (FEM) with the T, ?-? potential formulation has been applied in the simulations. The vector hysteresis property of the specimen has been approximated by the vector Preisach model. Finally, the nonlinear problem has been solved by the fixed-point technique. The aim of the present work is to focus on the design aspects of this kind of measurement system.

Kuczmann, Miklós

2008-02-01

332

Simulation of a vector hysteresis measurement system taking hysteresis into account by the vector Preisach model  

International Nuclear Information System (INIS)

The paper deals with the numerical analysis of a rotational single sheet tester with round-shaped specimen (RRSST) which is now under construction. The measurement setup consists of an induction motor the rotor of which has been removed, and its windings have been replaced to a special two phase one which can generate homogeneous magnetic field inside the motor. The two orthogonal components of the magnetic field intensity and of the magnetic flux density vectors can be measured by H-coils and B-coils, respectively. The Finite Element Method (FEM) with the T, ?-? potential formulation has been applied in the simulations. The vector hysteresis property of the specimen has been approximated by the vector Preisach model. Finally, the nonlinear problem has been solved by the fixed-point technique. The aim of the present work is to focus on the design aspects of this kind of measurement system

2008-02-01

333

Distribution of Brugia malayi larvae and DNA in vector and non-vector mosquitoes: implications for molecular diagnostics  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The purpose of this study was to extend prior studies of molecular detection of Brugia malayi DNA in vector (Aedes aegypti- Liverpool and non-vector (Culex pipiens mosquitoes at different times after ingestion of infected blood. Results Parasite DNA was detected over a two week time course in 96% of pooled thoraces of vector mosquitoes. In contrast, parasite DNA was detected in only 24% of thorax pools from non-vectors; parasite DNA was detected in 56% of midgut pools and 47% of abdomen pools from non-vectors. Parasite DNA was detected in vectors in the head immediately after the blood meal and after 14 days. Parasite DNA was also detected in feces and excreta of the vector and non-vector mosquitoes which could potentially confound results obtained with field samples. However, co-housing experiments failed to demonstrate transfer of parasite DNA from infected to non-infected mosquitoes. Parasites were also visualized in mosquito tissues by immunohistololgy using an antibody to the recombinant filarial antigen Bm14. Parasite larvae were detected consistently after mf ingestion in Ae. aegypti- Liverpool. Infectious L3s were seen in the head, thorax and abdomen of vector mosquitoes 14 days after Mf ingestion. In contrast, parasites were only detected by histology shortly after the blood meal in Cx. pipiens, and these were not labeled by the antibody. Conclusion This study provides new information on the distribution of filarial parasites and parasite DNA in vector and non-vector mosquitoes. This information should be useful for those involved in designing and interpreting molecular xenomonitoring studies.

Christensen Bruce M

2009-11-01

334

Risk based surveillance for vector borne diseases  

DEFF Research Database (Denmark)

Increased temperatures and changes in rainfall pattern are likely to facilitate the spread and establishment of new vector borne diseases in the Baltic See Region. There are a large number of potential vector borne threats to the area. Existing endemic vector borne diseases are likely to increase and new exotic diseases like Usutu and West Nile Virus may lead to outbreaks in the region. In the worst case the combined effect of climate change and globalization may potentially lead to European outbreaks of important zoonotic mosquito borne infections like Rift Valley Fever in cattle and Japanese Encephalitis in swine. Being able to model the impact of climate and environmental change on the transmission intensity of vector borne diseases is potentially a powerful tool to both monitor and prevent outbreaks in a cost effective way. The recent unexpected outbreaks of bluetongue and Schmallenberg virus in ruminants have been attributed an increase in European temperatures. Mathematical models clearly demonstratethe potential for increased virus transmission at elevated temperatures. however there is little evidence to support the idea that the spread of these tropical viruses in northern Europe is the direct result of climate change. The potential for virus transmission by biting midges was here modeled monthly for the Baltic See Region and the rest of Europe. The results showed that Baltic See Region has a lower transmission potential than most other areas in Europe. And the model identified an increasing trend in transmission potential over the last 25 years. However the model suggested that the climate in the Baltic See Region has always permitted transmission of these diseases. The model therefore suggests that a presently unknown factor until recently prevented introduction and spread in Northern Europe. This model approach may be used as a basis for risk based surveillance. In risk based surveillance limited resources for surveillance are targeted at geographical areas most at risk and only when the risk is high. This makes risk based surveillance a cost effective alternative to the present surveillance strategies based on random samples. We still donâ??t understand the mechanisms underlying the recent outbreaks of bluetongue, Schmallenberg, Usutu virus, tick borne encephalitis or dirofilarial worms in the Baltic See Region. It is therefore not possible to use mathematical models to pinpoint the next outbreak of an exotic vector borne disease. A new outbreak will most likely be detected by a veterinarian deciding to submit a sample based on a subjective clinical suspicion. But the question is how far the epidemic will progress before a veterinarian decides to submit this crucial sample to a diagnostic laboratory. Risk based surveillance models may reduce this delay. An important feature of risk based surveillance models is their ability to continuously communicate the level of risk to veterinarians and hence increase awareness when risk is high. This is essential for submission of samples and hence early detection of outbreaks. Models for vector borne diseases in Denmark have demonstrated dramatic variation in outbreak risk during the season and between years. The Danish VetMap project aims to make these risk based surveillance estimates available on the veterinarians smart phones, thus allowing easy access to risk estimates when in the field. Knowing when and where the potential risk for transmission of a specific vector borne disease is high is likely to help veterinarians decide when and when not to submit a sample to a diagnostic laboratory. This may both increase sensitivity of national surveillance and reduce the cost.

Bødker, Rene

335

Noncausal Bayesian Vector Autoregression  

DEFF Research Database (Denmark)

We propose a Bayesian inferential procedure for the noncausal vector autoregressive (VAR) model that is capable of capturing nonlinearities and incorporating effects of missing variables. In particular, we devise a fast and reliable posterior simulator that yields the predictive distribution as a by-product. We apply the methods to postwar quarterly U.S. inflation and GDP growth series. The noncausal VAR model turns out to be superior in terms of both in-sample fit and out-of-sample forecasting performance over its conventional causal counterpart. In addition, we find GDP growth to have predictive power for the future distribution of inflation over and above the own history of inflation, but not vice versa. This may be interpreted as evidence against the new Keynesian model that implies Granger causality from inflation to GDP growth, provided GDP growth is a reasonable proxy of the marginal cost.

Lanne, Markku; Luoto, Jani

2014-01-01

336

Renormalization of Vector Fields  

CERN Document Server

These notes cover some of the recent developments in the renormalization of quasiperiodic flows. This includes skew flows over tori, Hamiltonian flows, and other flows on $\\torus^d\\times\\real^\\ell$. After stating some of the problems and describing alternative approaches, we focus on the definition and basic properties of a single renormalization step. A second part deals with the construction of conjugacies and invariant tori, including shearless tori, and non-differentiable tori for critical Hamiltonians. Then we discuss properties related to the spectrum of the linearized renormalization transformation, such as the accumulation rates for sequences of closed orbits. The last part describes extensions from "self-similar" to Diophantine rotation vectors. This involves sequences of renormalization transformations that are related to continued fractions expansions in one and more dimensions. Whenever appropriate, the discussion of details is restricted to special cases where inessential technical complications ...

Koch, H

2006-01-01

337

Vector-Tensor and Vector-Vector Decay Amplitude Analysis of B0->phi K*0  

CERN Document Server

We perform an amplitude analysis of the decays B0->phi K^*_2(1430)0, phi K^*(892)0, and phi(K pi)^0_S-wave with a sample of about 384 million BBbar pairs recorded with the BABAR detector. The fractions of longitudinal polarization f_L of the vector-tensor and vector-vector decay modes are measured to be 0.853 +0.061-0.069 +-0.036 and 0.506 +-0.040 +-0.015, respectively. Overall, twelve parameters are measured for the vector-vector decay and seven parameters for the vector-tensor decay, including the branching fractions and parameters sensitive to CP-violation.

Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, R; Allen, M T; Allison, J; Altenburg, D D; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Asgeirsson, D J; Aston, D; Azzolini, V; Baak, M A; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Bechtle, P; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Best, D S; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P C; Blount, N L; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Bowerman, D A; Boyd, J T; Bozzi, C; Brandenburg, G; Brandt, T; Brau, J E; Briand, H; Brown, C M; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Bugg, W; Bukin, A D; Bula, R; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, E; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Chen, X R; Cheng, B; Cheng, C H; Chia, Y M; Cibinetto, G; Clark, P J; Clarke, C K; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Corwin, L A; Cossutti, F; Cottingham, W N; Couderc, F; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cunha, A; Curry, S; Côté, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; De Nardo, Gallieno; De Sangro, R; Del Amo-Sánchez, P; Del Buono, L; Del Re, D; Della Ricca, G; Denig, A G; Di Lodovico, F; Di Marco, E; Dingfelder, J C; Dittongo, S; Dong, L; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Ebert, M; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Egede, U; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fang, F; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, K E; Ford, W T; Forster, I J; Forti, F; Fortin, D; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gao, Y; Gary, J W; Gaspero, M; Gatto, C; Gaz, A; George, K A; Gill, M S; Giorgi, M A; Gladney, L; Glanzman, T; Godang, R; Golubev, V B; Gowdy, S J; Gradl, W; Graham, M T; Graugès-Pous, E; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Z J; Hadavand, H K; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jain, V; Jasper, H; Jawahery, A; Jessop, C P; Judd, D; Kadyk, J A; Kagan, H; Karyotakis, Yu; Kass, R; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Klose, V; Knecht, N S; Koch, H; Kolb, J A; Kolomensky, Yu G; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lange, D J; Lankford, A J; Latham, T E; Latour, E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lee, C L; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, S; Li, X; Lista, L; Liu, H; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; Long, O; Lopes-Pegna, D; Lopez-March, N; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Mclachlin, S E; Meadows, B T; Mellado, B; Menges, W; Merkel, J; Messner, R; Meyer, N T; Meyer, W T; Mihályi, A; Mir, L M; Mishra, K; Mohanty, G B; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morganti, M; Morganti, S; Morii, M; Muheim, F; Müller, D R; Nagel, M; Naisbit, M T; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nesom, G; Nicholson, H; Nikolich, M B; Nogowski, R; Nugent, I M; O'Grady, C P; Ocariz, J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A

2007-01-01

338

Darboux integrals for Schrödinger planar vector fields via Darboux transformations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we study the Darboux transformations of planar vector fields of Schrödinger type. Using the isogaloisian property of Darboux transformation we prove the “invariance” of the elements of the “Darboux Theory of Integrability”. In particular, we also show how the shape invariance property of the potential is important in order to preserve the structure of the transformed vector field. Free particle, square well, harmonic oscillator, three dimensional harmonic oscillator and...

Acosta Huma?nez, Primitivo Bele?n; Pantazi, Chara

2011-01-01

339

Plasmids of endophytic bacteria as vectors for transformation in plants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The endophytic microorganisms in general have a rich potential as producers of novel bioactive compounds, as nitrogen fixers, IAA producers, plant toxicity reducers, etc. Endophytic bacteria can also be used as vectors for transferring genes of interest to plants. These plasmid bearers have the advantage of colonizing the plant and rhizosphere with ease. In the present work, plasmids of endophytic bacteria were used as vectors instead of whole organism, for genetic studies. The advantage bein...

2010-01-01

340

Phosphorylcholine-based copolymer as synthetic vector for gene delivery  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Gene therapy has a great potential for the treatment of a wide range of diseases. However, the development of a safe and efficient delivery vector is the major obstacle for gene therapy. Recently synthesized 2 - (dimethylamino) ethyl methacrylate 2-(methacryloxloxyethyl phosphorylcholine) (DMA-MPC) diblock copolymer was investigated in this work as a novel non-viral vector for gene delivery. It has been previously demonstrated that the cationic DMA block can condense DNA efficiently. The zwit...

Lam, Jenny Ka-wing

2006-01-01

 
 
 
 
341

Development of conditionally replicating integrase defective lentiviral vectors for Epstein-Barr virus gene therapy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Integrase defective lentiviral vectors show promise for achieving gene expression without integration, preserving some benefits of LVs, whereas reducing the potentially detrimental risk of insertional mutagenesis. Numerous reports supported the ability of these vectors to confer long-term gene expression in slowly dividing cell types for potentially corrective gene expression. These reports also highlighted additional applications of these vectors as delivery platforms for alternate integrati...

2012-01-01

342

Estimation of Motion Vector Fields  

DEFF Research Database (Denmark)

This paper presents an approach to the estimation of 2-D motion vector fields from time varying image sequences. We use a piecewise smooth model based on coupled vector/binary Markov random fields. We find the maximum a posteriori solution by simulated annealing. The algorithm generate sample fields by means of stochastic relaxation implemented via the Gibbs sampler.

Larsen, Rasmus

1993-01-01

343

Addendum H. Mass vector field  

International Nuclear Information System (INIS)

Appendix H summarizes the basic properties of a mass vector field. The relativistic Proca wave equation is given for a free particle with a spin of one and a nonzero mass, and the procedure for its solution is indicated. Relations are derived for polarization vectors of a mass particle with a spin of one. (Z.J.)

1993-01-01

344

Vector superconductivity in cosmic strings  

International Nuclear Information System (INIS)

We argue that in most realistic cases, the usual Witten-type bosonic superconductivity of the cosmic string is automatically (independent of the existence of superconducting currents) accompanied by the condensation of charged gauge vector bosons in the core giving rise to a new vector type superconductivity. The value of the charged vector condensate is related with the charged scalar expectation value, and vanishes only if the latter goes to zero. The mechanism for the proposed vector superconductivity, differing fundamentally from those in the literature, is delineated using the simplest realistic example of the two Higgs doublet standard model interacting with the extra cosmic string. It is shown that for a wide range of parameters, for which the string becomes scalarly superconducting, W boson condensates (the sources of vector superconductivity) are necessarily excited. (author). 14 refs

1992-01-01

345

Octonionic Reformulation of Vector Analysis  

CERN Multimedia

According to celebrated Hurwitz theorem, there exists four division algebras consisting of R (real numbers), C (complex numbers), H (quaternions) and O (octonions). Keeping in view the utility of octonion variable we have tried to extend the three dimensional vector analysis to seven dimensional one. Starting with the scalar and vector product in seven dimensions, we have redefined the gradient, divergence and curl in seven dimension. It is shown that the identity n(n-1)(n-3)(n-7)=0 is satisfied only for 0, 1, 3 and 7 dimensional vectors. We have tried to write all the vector inequalities and formulas in terms of seven dimensions and it is shown that same formulas loose their meaning in seven dimensions due to non-associativity of octonions. The vector formulas are retained only if we put certain restrictions on octonions and split octonions.

Chauhan, Bhupendra C S; Negi, O P S

2010-01-01

346

Canine vector-borne diseases in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Canine vector-borne diseases (CVBDs are highly prevalent in Brazil and represent a challenge to veterinarians and public health workers, since some diseases are of great zoonotic potential. Dogs are affected by many protozoa (e.g., Babesia vogeli, Leishmania infantum, and Trypanosoma cruzi, bacteria (e.g., Anaplasma platys and Ehrlichia canis, and helminths (e.g., Dirofilaria immitis and Dipylidium caninum that are transmitted by a diverse range of arthropod vectors, including ticks, fleas, lice, triatomines, mosquitoes, tabanids, and phlebotomine sand flies. This article focuses on several aspects (etiology, transmission, distribution, prevalence, risk factors, diagnosis, control, prevention, and public health significance of CVBDs in Brazil and discusses research gaps to be addressed in future studies.

Dantas-Torres Filipe

2008-08-01

347

Vector field equations in external electromagnetic fields  

Energy Technology Data Exchange (ETDEWEB)

An equation of vector field describing a charged massive vector particle particularly W-boson, in an external electromagnetic field complying with Maxwell equations in vacuum is considered. Vector representation of the Lorentz group Dsup((1/2, 1/2)) is used for describing vector particles. The vector field is described by 4-component wave function.

Obukhov, I.A.; Peres-Fernandes, V.K.; Khalilov, V.R. (Moskovskij Gosudarstvennyj Univ. (USSR))

1983-12-01

348

Relativistic Gamow Vectors, 2  

CERN Multimedia

Motivated by the debate of possible definitions of mass and width of resonances for Z-boson and hadrons, we suggest a third definition in addition to those given by a renormalization scheme of perturbation theory and a first order pole of S-matrix theory. It defines unstable particles by ``minimally complex'' semigroup representations of the Poincaré group characterized by $(j,s=(m-i\\Gamma/2)^{2})$ in which the Lorentz subgroup is unitary; Wigner's representations (j,m) are the limit case for $\\Gamma=0$. These representations have generalized vectors (Gamow kets) with all the properties that heuristically the unstable states need to possess : a Breit-Wigner invariant mass-squared distribution, a lifetime $\\tau=1/\\Gamma$ defined by the exactly exponential law for the decay probability ${\\cal P}(t)$ and rate $\\dot{\\cal P}(t)$ given by an exact Golden Rule which becomes Dirac's Golden Rule in the Born-approximation; and an S-matrix pole at $s = (m-i\\Gamma/2)^{2}$. In addition and unintended, they have an asymme...

Böhm, A; Wickramasekara, S; Kielanowski, Piotr

1999-01-01

349

The AAV vector toolkit: poised at the clinical crossroads.  

Science.gov (United States)

The discovery of naturally occurring adeno-associated virus (AAV) isolates in different animal species and the generation of engineered AAV strains using molecular genetics tools have yielded a versatile AAV vector toolkit. Promising results in preclinical animal models of human disease spurred the much awaited transition toward clinical application, and early successes in phase I/II clinical trials for a broad spectrum of genetic diseases have recently been reported. As the gene therapy community forges ahead with cautious optimism, both preclinical and clinical studies using first generation AAV vectors have highlighted potential challenges. These include cross-species variation in vector tissue tropism and gene transfer efficiency, pre-existing humoral immunity to AAV capsids and vector dose-dependent toxicity in patients. A battery of second generation AAV vectors, engineered through rational and combinatorial approaches to address the aforementioned concerns, are now available. This review will provide an overview of preclinical studies with the ever-expanding AAV vector portfolio in large animal models and an update on new lead AAV vector candidates poised for clinical translation. PMID:22273577

Asokan, Aravind; Schaffer, David V; Samulski, R Jude

2012-04-01

350

Hygromycin-resistance vectors for gene expression in Pichia pastoris.  

Science.gov (United States)

Pichia pastoris is a common host organism for heterologous protein expression and metabolic engineering. Zeocin-, G418-, nourseothricin- and blasticidin-resistance genes are the only dominant selectable markers currently available for selecting P. pastoris transformants. We describe here new P. pastoris expression vectors that confer a hygromycin resistance base on the Klebsiella pneumoniae hph gene. To demonstrate the application of the vectors for intracellular and secreted protein expression, green fluorescent protein (GFP) and human serum albumin (HSA) were cloned into the vectors and transformed into P. pastoris cells. The resulting strains expressed GFP and HSA constitutively or inducibly. The hygromycin resistance marker was also suitable for post-transformational vector amplication (PTVA) for obtaining strains with high plasmid copy numbers. A strain with multiple copies of the HSA expression cassette after PTVA had increased HSA expression compared with a strain with a single copy of the plasmid. To demonstrate compatibility of the new vectors with other vectors bearing antibiotic-resistance genes, P. pastoris was transformed with the Saccharomyces cerevisiae genes GSH1, GSH2 or SAM2 on plasmids containing genes for resistance to Zeocin, G418 or hygromycin. The resulting strain produced glutathione and S-adenosyl-L-methionine at levels approximately twice those of the parent strain. The new hygromycin-resistance vectors allow greater flexibility and potential applications in recombinant protein production and other research using P. pastoris. PMID:24822243

Yang, Junjie; Nie, Lei; Chen, Biao; Liu, Yingmiao; Kong, Yimeng; Wang, Haibin; Diao, Liuyang

2014-04-01

351

Stable piecewise polynomial vector fields  

Directory of Open Access Journals (Sweden)

Full Text Available Let $N={y>0}$ and $S={y<0}$ be the semi-planes of $mathbb{R}^2$ having as common boundary the line $D={y=0}$. Let $X$ and $Y$ be polynomial vector fields defined in $N$ and $S$, respectively, leading to a discontinuous piecewise polynomial vector field $Z=(X,Y$. This work pursues the stability and the transition analysis of solutions of $Z$ between $N$ and $S$, started by Filippov (1988 and Kozlova (1984 and reformulated by Sotomayor-Teixeira (1995 in terms of the regularization method. This method consists in analyzing a one parameter family of continuous vector fields $Z_{epsilon}$, defined by averaging $X$ and $Y$. This family approaches $Z$ when the parameter goes to zero. The results of Sotomayor-Teixeira and Sotomayor-Machado (2002 providing conditions on $(X,Y$ for the regularized vector fields to be structurally stable on planar compact connected regions are extended to discontinuous piecewise polynomial vector fields on $mathbb{R}^2$. Pertinent genericity results for vector fields satisfying the above stability conditions are also extended to the present case. A procedure for the study of discontinuous piecewise vector fields at infinity through a compactification is proposed here.

Claudio Pessoa

2012-09-01

352

Chiral structure of vector and axial-vector tetraquark currents  

Energy Technology Data Exchange (ETDEWEB)

We investigate the chiral structure of local vector and axial-vector tetraquark currents, and study their chiral transformation properties. We consider the charge-conjugation parity and classify all the isovector vector and axial-vector local tetraquark currents of quantum numbers I{sup G} J{sup PC} =1{sup -}1{sup -+}, I{sup G} J{sup PC} =1{sup +}1{sup --}, I{sup G} J{sup PC} = 1{sup -}1{sup ++} and I{sup G} J{sup PC} = 1{sup +}1{sup +-}. We find that there is a one to one correspondence among them. Using these currents, we perform QCD sum rule analyses. Our results suggest that there is a missing b{sub 1} state having I{sup G} J{sup PC} =1{sup +}1{sup +-} and a mass around 1.47-1.66 GeV. (orig.)

Chen, Hua-Xing [Beihang University, School of Physics and Nuclear Energy Engineering and International Research Center for Nuclei and Particles in the Cosmos, Beijing (China)

2013-11-15

353

Vector fields on nonorientable surfaces  

Directory of Open Access Journals (Sweden)

Full Text Available A one-to-one correspondence is established between the germs of functions and tangent vectors on a NOS X and the bi-germs of functions, respectively, elementary fields of tangent vectors (EFTV on the orientable double cover of X. Some representation theorems for the algebra of germs of functions, the tangent space at an arbitrary point of X, and the space of vector fields on X are proved by using a symmetrisation process. An example related to the normal derivative on the border of the Möbius strip supports the nontriviality of the concepts introduced in this paper.

Dorin Ghisa

2003-01-01

354

Initial conditions for vector inflation  

International Nuclear Information System (INIS)

Recently, a model of inflation using non-minimally coupled massive vector fields has been proposed. For a particular choice of non-minimal coupling parameter and for a flat Friedmann–Robertson–Walker model, the model is reduced to the model of chaotic inflation with massive scalar field. We study the effect of non-zero curvature of the universe on the onset of vector inflation. We find that in a curved universe the dynamics of vector inflation can be different from the dynamics of chaotic inflation, and the fraction of the initial conditions leading to inflationary solutions is reduced as compared with the chaotic inflation case

2008-08-01

355

Vector control of induction machines  

CERN Multimedia

After a brief introduction to the main law of physics and fundamental concepts inherent in electromechanical conversion, ""Vector Control of Induction Machines"" introduces the standard mathematical models for induction machines - whichever rotor technology is used - as well as several squirrel-cage induction machine vector-control strategies. The use of causal ordering graphs allows systematization of the design stage, as well as standardization of the structure of control devices. ""Vector Control of Induction Machines"" suggests a unique approach aimed at reducing parameter sensitivity for

Robyns, Benoit

2012-01-01

356

Relativistic Gamow vectors: State vectors for unstable particles  

Science.gov (United States)

The relativistic Gamow vectors are derived from the analytic continuation of the angular momentum velocity kets to the resonance pole of the S- matrix. This construction is justifiable within a Rigged Hilbert Space of Hardy class functions. The kets obtained | p j3[ sRjR ]-> are characterized by a spin jR and a complex mass square sR = (MR - i? R/2)2. Our use of the velocity kets renders the Gamow vectors | p j3[ sRjR ]-> ``minimally complex'', as the 4-velocities p?? = p ?/ rcd>srcd> are taken real and they remain real under Lorentz transformations. When the symmetry transformations of the Gamow vectors are considered, it is found that they obey a semigroup time evolution in the forward light cone for the subgroup of P with causal space- time translations, i.e., for space-time translations with 4-vectors x such that x2 >= 0. This semigroup evolution, which is a consequence of the characterization obtained for the Gamow vectors as functionals in a Rigged Hilbert Space, is in conformity with the time directedness associated with decay phenomena. The Gamow vectors, with a Breit-Wigner distribution and exponential decay law, provide a description of decaying particles with a wide range of ?/ M. Moreover, the Gamow vectors, being members of a complex basis vector expansion, allow the Wigner-Weisskopf's based effective theories, such as the Lee-Oehme-Yang theory for the neutral K-mesons, to be obtained as an approximation in an exact formalism.

Kaldas, Hany Kamel Halim

357

Evaluation of leading scalar and vector architectures for scientific computations  

Energy Technology Data Exchange (ETDEWEB)

The growing gap between sustained and peak performance for scientific applications is a well-known problem in high performance computing. The recent development of parallel vector systems offers the potential to reduce this gap for many computational science codes and deliver a substantial increase in computing capabilities. This project examines the performance of the cacheless vector Earth Simulator (ES) and compares it to superscalar cache-based IBM Power3 system. Results demonstrate that the ES is significantly faster than the Power3 architecture, highlighting the tremendous potential advantage of the ES for numerical simulation. However, vectorization of a particle-in-cell application (GTC) greatly increased the memory footprint preventing loop-level parallelism and limiting scalability potential.

Simon, Horst D.; Oliker, Leonid; Canning, Andrew; Carter, Jonathan; Ethier, Stephane; Shalf, John

2004-04-20

358

Biosafety challenges for use of lentiviral vectors in gene therapy.  

Science.gov (United States)

Lentiviral vectors are promising tools for the genetic modification of cells in biomedical research and gene therapy. Their use in recent clinical trials for the treatment of adrenoleukodystrophy, ?-thalassemia, Wiskott-Aldrich- Syndrome and metachromatic leukodystrophy underlined their efficacy for therapies especially in case of hereditary diseases. In comparison to gammaretroviral LTR-driven vectors, which were employed in the first clinical trials, lentiviral vectors present with some favorable features like the ability to transduce also non-dividing cells and a potentially safer insertion profile. However, genetic modification with viral vectors in general and stable integration of the therapeutic gene into the host cell genome bear concerns with respect to different levels of personal or environmental safety. Among them, insertional mutagenesis by enhancer mediated dysregulation of neighboring genes or aberrant splicing is still the biggest concern. However, also risks like immunogenicity of vector particles, the phenotoxicity of the transgene and potential vertical or horizontal transmission by replication competent retroviruses need to be taken into account. This review will give an overview on biosafety aspects that are relevant to the use of lentiviral vectors for genetic modification and gene therapy. Furthermore, assay systems aiming at evaluating biosafety in preclinical settings and recent promising clinical trials including efforts of monitoring of patients after gene therapy will be discussed. PMID:24195603

Rothe, Michael; Modlich, Ute; Schambach, Axel

2013-12-01

359

Understanding Polarization Correlation of Entangled Vector Meson Pairs  

CERN Document Server

Quantum mechanics (QM) disfavours local realism because it violates Bell's theorem, a theorem that must be valid for all local hidden variable theories (LHVT). Experimental tests of local realism in high energy particle physics have been proposed and carried out, but no decisive conclusion has been drawn. We find that the correlated distribution between polarization vectors of two entangled mesons predicted by QM can be reproduced in a natural way, by interpreting the two-body decay of vector mesons as a measurement to their polarization vector. The interpretation provides a method to simulate the correlated decay of entangled vector meson pairs, and a potential experimental approach for the discrimination between QM and LHVT in particle physics. Related data analysis can be carried out at currently running experiments and could give deeper insight for the understanding of local realism.

Chen, Xun; Mao, Yajun

2012-01-01

360

Vectorization at the KENO-IV code  

Energy Technology Data Exchange (ETDEWEB)

The multigroup criticality safety code KENO-IV has been vectorized and tested on the FACOM VP-100 vector processor. At first, the vectorized KENO-IV on a scalar processor was slower than the original one by a factor of 1.4 because of the overhead introduced by vectorization. Making modifications of algorithms and techniques for vectorization, the vectorized version has become faster than the original one by a factor of 1.4 on the vector processor. For further speedup of the code, some improvements on compiler and hardware, especially on addition of Monte Carlo pipelines to the vector processor, are discussed.

Asai, K.; Higuchi, K.; Katakura, J.

1986-02-01

 
 
 
 
361

Circadian rhythms in insect disease vectors  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Organisms from bacteria to humans have evolved under predictable daily environmental cycles owing to the Earth’s rotation. This strong selection pressure has generated endogenous circadian clocks that regulate many aspects of behaviour, physiology and metabolism, anticipating and synchronising [...] internal time-keeping to changes in the cyclical environment. In haematophagous insect vectors the circadian clock coordinates feeding activity, which is important for the dynamics of pathogen transmission. We have recently witnessed a substantial advance in molecular studies of circadian clocks in insect vector species that has consolidated behavioural data collected over many years, which provided insights into the regulation of the clock in the wild. Next generation sequencing technologies will facilitate the study of vector genomes/transcriptomes both among and within species and illuminate some of the species-specific patterns of adaptive circadian phenotypes that are observed in the field and in the laboratory. In this review we will explore these recent findings and attempt to identify potential areas for further investigation.

Meireles-Filho, Antonio Carlos Alves; Kyriacou, Charalambos Panayiotis.

362

Parallel Vector Tile Optimizing Library.  

Science.gov (United States)

PVTOL is a C++ library that allows cross-platform software portability without sacrificing high performance. Researchers at MIT Lincoln Laboratory developed the Parallel Vector Tile Optimizing Library (PVTOL) to address a primary challenge faced by develo...

E. M. Rutledge

2011-01-01

363

Vector superconductivity in cosmic strings.  

Science.gov (United States)

We argue that in most realistic cases, the usual Witten-type bosonic superconductivity of the cosmic string is automatically (independent of the existence of superconducting currents) accompanied by the condensation of charged gauge vector bosons in the c...

G. R. Dvali S. M. Mahajan

1992-01-01

364

Implementation of Poynting Vector Measurements.  

Science.gov (United States)

This report covers the design, construction, and field testing of an experimental device capable of measuring the magnitude of the Poynting vector associated with an electromagnetic field. With mechanical manipulation, it can determine the direction of th...

W. W. Cowles N. Farhat R. M. Showers

1966-01-01

365

Polynomial poly-vector fields  

CERN Document Server

In this text we give a decomposition result on polynomial poly-vector fields. This generalizes the decomposition of quadratic Poisson structures due to [Liu and Xu 1992]. We add an almost complete list of four dimensional quadratic Poisson structures.

Klinker, F

2004-01-01

366

Time-dependent vector stabilization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents necessary and sufficient conditions for a single input system defined by a time-dependent vector to be stabilized by a linear feedback. The paper employs a new technique based on averaging along a moving time interval.

Sergey Nikitin

2006-01-01

367

Expression Vector for Zymomonas mobilis†  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study describes the construction of several useful cloning vectors which can be conjugated from Escherichia coli into Zymomonas mobilis at high frequency, approaching 10?2 per donor or recipient. These vectors contain a broad-host-range replicon and mob site from RSF1010, a chloramphenicol acyltransferase gene under the control of an enteric consensus promoter, and a second mob site (originally derived from RP4). The addition of this second mob site appears to be responsible for a 2-or...

Conway, T.; Byun, M. O. -k; Ingram, L. O.

1987-01-01

368

Vector triplets at the LHC  

Science.gov (United States)

Several popular extensions of the Standard Model predict extra vector fields that transform as triplets under the gauge group SU(2)L. These multiplets contain Z' and W' bosons, with masses and couplings related by gauge invariance. We review some model-independent results about these new vector bosons, with emphasis on di-lepton and lepton-plus-missing-energy signals at the LHC.

Lizana, Javier M.; Pérez-Victoria, Manuel

2013-11-01

369

Vector triplets at the LHC  

CERN Document Server

Several popular extensions of the Standard Model predict extra vector fields that transform as triplets under the gauge group SU(2)_L. These multiplets contain Z' and W' bosons, with masses and couplings related by gauge invariance. We review some model-independent results about these new vector bosons, with emphasis on di-lepton and lepton-plus-missing-energy signals at the LHC.

Lizana, J M

2013-01-01

370

Theory of vector meson production  

International Nuclear Information System (INIS)

The theoretical status of the 'soft' pomeron and its place in describing generic diffractive processes is discussed. The role of perturbative QCD (pQCD) corrections is considered, in particular in the context of quasi-elastic vector meson production at high Q2. In those processes where short distances are dominant, the 'hard' (pQCD) pomeron is expected to reveal itself, such a process may well be that of diffractive vector meson production at high-t. (author)

1995-01-01

371

Vector triplets at the LHC  

Directory of Open Access Journals (Sweden)

Full Text Available Several popular extensions of the Standard Model predict extra vector fields that transform as triplets under the gauge group SU(2L. These multiplets contain Z’ and W’ bosons, with masses and couplings related by gauge invariance. We review some model-independent results about these new vector bosons, with emphasis on di-lepton and lepton-plus-missing-energy signals at the LHC.

Pérez-Victoria Manuel

2013-11-01

372

Writing Position Vectors in 3-d Space: A Student Difficulty With Spherical Unit Vectors in Intermediate E&M  

Science.gov (United States)

An intermediate E&M course (i.e. based on Griffiths [1]) involves the extensive integration of vector calculus concepts and notation with abstract physics concepts like field and potential. We hope that students take what they have learned in their math courses and apply it to help represent and make sense of the physics. To assess how well students are able to do this integration and application I have developed several simple concept tests on position and unit vectors in non-Cartesian coordinate systems as they are used in intermediate E&M. In this paper I describe one of these concept tests and present results that show both undergraduate physics majors and physics graduate students have difficulty using spherical unit vectors to write position vectors in 3-d space.

Hinrichs, Brant E.

2010-10-01

373

Adjuvants and vector systems for allergy vaccines.  

Science.gov (United States)

Allergen-specific immunotherapy represents a curative treatment of type I allergies. Subcutaneous immunotherapy is conducted with allergens adsorbed on aluminum hydroxide or calcium phosphate particles, whereas sublingual immunotherapy relies on high doses of soluble allergen without any immunopotentiator. There is a potential benefit of adjuvants enhancing regulatory and Th1 CD4+T cell responses during specific immunotherapy. Molecules affecting dendritic cells favor the induction of T regulatory cell and Th1 responses and represent valid candidate adjuvants for allergy vaccines. Furthermore, the interest in viruslike particles and mucoadhesive particulate vector systems, which may better address the allergen(s) to tolerogenic antigen-presenting cells, is documented. PMID:21530828

Moingeon, Philippe; Lombardi, Vincent; Saint-Lu, Nathalie; Tourdot, Sophie; Bodo, Véronique; Mascarell, Laurent

2011-05-01

374

Modeling Nuclear Properties with Support Vector Machines  

CERN Document Server

We have made initial studies of the potential of support vector machines (SVM) for providing statistical models of nuclear systematics with demonstrable predictive power. Using SVM regression and classification procedures, we have created global models of atomic masses, beta-decay halflives, and ground-state spins and parities. These models exhibit performance in both data-fitting and prediction that is comparable to that of the best global models from nuclear phenomenology and microscopic theory, as well as the best statistical models based on multilayer feedforward neural networks.

Li, H; Mavrommatis, E; Athanassopoulos, S; Gernoth, K A; Li, Haochen

2005-01-01

375

Intranasal Sendai viral vector vaccination is more immunogenic than intramuscular under pre-existing anti-vector antibodies.  

Science.gov (United States)

Viral vectors are promising vaccine tools for eliciting potent cellular immune responses. Pre-existing anti-vector antibodies, however, can be an obstacle to their clinical use in humans. We previously developed a Sendai virus (SeV) vector vaccine and showed the potential of this vector for efficient CD8(+) T-cell induction in macaques. Here, we investigated the immunogenicity of SeV vector vaccination in the presence of anti-SeV antibodies. We compared antigen-specific CD8(+) T-cell responses after intranasal or intramuscular immunization with a lower dose (one-tenth of that in our previous studies) of SeV vector expressing simian immunodeficiency virus Gag antigen (SeV-Gag) between naive and pre-SeV-infected cynomolgus macaques. Intranasal SeV-Gag immunization efficiently elicited Gag-specific CD8(+) T-cell responses not only in naive but also in pre-SeV-infected animals. In contrast, intramuscular SeV-Gag immunization induced Gag-specific CD8(+) T-cell responses efficiently in naive but not in pre-SeV-infected animals. These results indicate that both intranasal and intramuscular SeV administrations are equivalently immunogenic in the absence of anti-SeV antibodies, whereas intranasal SeV vaccination is more immunogenic than intramuscular in the presence of anti-SeV antibodies. It is inferred from a recent report investigating the prevalence of anti-SeV antibodies in humans that SeV-specific neutralizing titers in more than 70% of people are no more than those at the SeV-Gag vaccination in pre-SeV-infected macaques in the present study. Taken together, this study implies the potential of intranasal SeV vector vaccination to induce CD8(+) T-cell responses even in humans, suggesting a rationale for proceeding to a vaccine clinical trial using this vector. PMID:21939708

Moriya, Chikaya; Horiba, Satoshi; Kurihara, Kyoko; Kamada, Takeo; Takahara, Yusuke; Inoue, Makoto; Iida, Akihiro; Hara, Hiroto; Shu, Tsugumine; Hasegawa, Mamoru; Matano, Tetsuro

2011-11-01

376

Gammaretroviral Vector Integration Occurs Overwhelmingly Within and Near DNase Hypersensitive Sites  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Concerns surrounding the oncogenic potential of recombinant gammaretroviral vectors has spurred a great deal of interest in vector integration site (VIS) preferences. Although gammaretroviral vectors exhibit a modest preference for integration near transcription start sites (TSS) of active genes, such associations only account for about a third of all VIS. Previous studies suggested a correlation between gammaretroviral VIS and DNase hypersensitive sites (DHS), which mark chromatin regions as...

Liu, Mingdong; Li, Chang Long; Stamatoyannopoulos, George; Dorschner, Michael O.; Humbert, Richard; Stamatoyannopoulos, John A.; Emery, David W.

2012-01-01

377

A Multi-scale Vector Spline Method for Estimating the Fluids Motion on Satellite Images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Satellite image sequences visualize important patterns of the atmospheric and oceanographic circulation. Assessing motion from these data thus has a strong potential for improving the performances of the forecast models. Representing a vector field by a vector spline has been proven efficient for fluid motion assessment: the vector spline formulation makes it possible to initially select the locations where the conservation equation has to be taken into account; it efficiently implements the ...

Isambert, Till; Berroir, Jean-paul; Herlin, Isabelle

2008-01-01

378

On an identity for the volume integral of the square of a vector field  

CERN Multimedia

A proof is given of the vector identity proposed by Gubarev, Stodolsky and Zakarov that relates the volume integral of the square of a 3-vector field to non-local integrals of the curl and divergence of the field. The identity is applied to the case of the magnetic vector potential and magnetic field of a rotating charged shell. The latter provides a straightforward exercise in the use of the addition theorem of spherical harmonics.

Stewart, A M

2007-01-01

379

Vector interaction, charge neutrality and multiple chiral critical point structures  

CERN Document Server

We investigate the combined effect of the repulsive vector interaction and the positive electric chemical potential on the chiral phase transition by considering neutral color superconductivity (CSC). The chiral condensate, diquark condensate and quark number densities are solved in both two-flavor and two-plus-one-flavor Nambu-Jona-Lasinio(NJL) models with the so called Kobayashi-Maskawa-'t Hooft term under the charge neutrality constraint. We demonstrate that multiple chiral critical-point structures always exist in the NJL model within the self-consistent mean-field approximation and the number of chiral critical points can vary from zero to four, which is dependent on the magnitudes of vector interaction and the diquark coupling. The difference between the dynamical chemical potentials induced by vector interaction for u quark and d quark can effectively reduce the Fermi sphere disparity between the two components of diquark Cooper paring. This effect can significantly suppress the unstable region associa...

Zhang, Zhao

2009-01-01

380

Singular vectors, predictability and ensemble forecasting for weather and climate  

International Nuclear Information System (INIS)

The local instabilities of a nonlinear dynamical system can be characterized by the leading singular vectors of its linearized operator. The leading singular vectors are perturbations with the greatest linear growth and are therefore key in assessing the system’s predictability. In this paper, the analysis of singular vectors for the predictability of weather and climate and ensemble forecasting is discussed. An overview of the role of singular vectors in informing about the error growth rate in numerical models of the atmosphere is given. This is followed by their use in the initialization of ensemble weather forecasts. Singular vectors for the ocean and coupled ocean–atmosphere system in order to understand the predictability of climate phenomena such as ENSO and meridional overturning circulation are reviewed and their potential use to initialize seasonal and decadal forecasts is considered. As stochastic parameterizations are being implemented, some speculations are made about the future of singular vectors for the predictability of weather and climate for theoretical applications and at the operational level. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Lyapunov analysis: from dynamical systems theory to applications’. (review)

2013-06-28

 
 
 
 
381

Vector Algorithms for Solving 3 D Nonlinear Magnetostatic Problems  

International Nuclear Information System (INIS)

The differential formulation of the magnetostatic problem using two scalar potentials is considered. The discretization by finite element method reduces the problem to system of the nonlinear equations with sparse matrix. To solve the system some iteration process is used and on each iteration step the solving linearized system is required. For this purpose the vector algorithms are elaborated based on the incomplete Choleski factorization with conjugate gradient method. The use of combination of natural and suggested multicolor ordering of unknowns in the nodes of regular grid allowed one to keep the good qualities of the pre conditioner and essentially to increase the degree of vectorization of matrix-vector multiplication and of solving the system with pre conditioner. The advantages of the suggested approach are demonstrated on the example of three-dimensional spectrometric magnet field simulation on vector computer CONVEX C 120. The comparison of the computed results for grid consisting of 42120 nodes, when the suggested vector algorithms and the standard algorithms, compiled with the vector option are used, showed that the processor time of the solving nonlinear system in the first case is in 2,3 times less than in second case. (author). 18 refs., 4 figs., 3 tabs

1994-01-01

382

Shifting suitability for malaria vectors across Africa with warming climates  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Climates are changing rapidly, producing warm climate conditions globally not previously observed in modern history. Malaria is of great concern as a cause of human mortality and morbidity, particularly across Africa, thanks in large part to the presence there of a particularly competent suite of mosquito vector species. Methods I derive spatially explicit estimates of human populations living in regions newly suitable climatically for populations of two key Anopheles gambiae vector complex species in Africa over the coming 50 years, based on ecological niche model projections over two global climate models, two scenarios of climate change, and detailed spatial summaries of human population distributions. Results For both species, under all scenarios, given the changing spatial distribution of appropriate conditions and the current population distribution, the models predict a reduction of 11.3–30.2% in the percentage of the overall population living in areas climatically suitable for these vector species in coming decades, but reductions and increases are focused in different regions: malaria vector suitability is likely to decrease in West Africa, but increase in eastern and southern Africa. Conclusion Climate change effects on African malaria vectors shift their distributional potential from west to east and south, which has implications for overall numbers of people exposed to these vector species. Although the total is reduced, malaria is likely to pose novel public health problems in areas where it has not previously been common.

Peterson A Townsend

2009-05-01

383

Vector-valued automorphic forms and vector bundles  

CERN Document Server

For an arbitrary discrete group $\\Gamma$ and an $n$-dimensional complex representation $R$ of $\\Gamma$, we prove the existence of $n$ linearly independent vector-valued automorphic forms for $\\Gamma$ with multiplier $R$. To this end, we realize these automorphic forms as sections of a rank $n$ vector bundle attached to a 1-cocycle with coefficients in the sheaf $\\mbox{GL}(n,{\\mathcal O}_X)$, $X$ being the quotient of the Poincar\\'e half-plane by $\\Gamma$ completed with the cusps of $\\Gamma$.

Saber, Hicham

2013-01-01

384

Generalized Selection Weighted Vector Filters  

Directory of Open Access Journals (Sweden)

Full Text Available This paper introduces a class of nonlinear multichannel filters capable of removing impulsive noise in color images. The here-proposed generalized selection weighted vector filter class constitutes a powerful filtering framework for multichannel signal processing. Previously defined multichannel filters such as vector median filter, basic vector directional filter, directional-distance filter, weighted vector median filters, and weighted vector directional filters are treated from a global viewpoint using the proposed framework. Robust order-statistic concepts and increased degree of freedom in filter design make the proposed method attractive for a variety of applications. Introduced multichannel sigmoidal adaptation of the filter parameters and its modifications allow to accommodate the filter parameters to varying signal and noise statistics. Simulation studies reported in this paper indicate that the proposed filter class is computationally attractive, yields excellent performance, and is able to preserve fine details and color information while efficiently suppressing impulsive noise. This paper is an extended version of the paper by Lukac et al. presented at the 2003 IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing (NSIP '03 in Grado, Italy.

Smolka Bogdan

2004-01-01

385

Ensemble Dynamics and Bred Vectors  

CERN Multimedia

We introduce the new concept of an EBV to assess the sensitivity of model outputs to changes in initial conditions for weather forecasting. The new algorithm, which we call the "Ensemble Bred Vector" or EBV, is based on collective dynamics in essential ways. By construction, the EBV algorithm produces one or more dominant vectors. We investigate the performance of EBV, comparing it to the BV algorithm as well as the finite-time Lyapunov Vectors. We give a theoretical justification to the observed fact that the vectors produced by BV, EBV, and the finite-time Lyapunov vectors are similar for small amplitudes. Numerical comparisons of BV and EBV for the 3-equation Lorenz model and for a forced, dissipative partial differential equation of Cahn-Hilliard type that arises in modeling the thermohaline circulation, demonstrate that the EBV yields a size-ordered description of the perturbation field, and is more robust than the BV in the higher nonlinear regime. The EBV yields insight into the fractal structure of th...

Balci, Nusret; Restrepo, Juan M; Sell, George R

2011-01-01

386

Simian virus 40 vectors for pulmonary gene therapy  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Sepsis remains the leading cause of death in critically ill patients. One of the primary organs affected by sepsis is the lung, presenting as the Acute Respiratory Distress Syndrome (ARDS. Organ damage in sepsis involves an alteration in gene expression, making gene transfer a potential therapeutic modality. This work examines the feasibility of applying simian virus 40 (SV40 vectors for pulmonary gene therapy. Methods Sepsis-induced ARDS was established by cecal ligation double puncture (2CLP. SV40 vectors carrying the luciferase reporter gene (SV/luc were administered intratracheally immediately after sepsis induction. Sham operated (SO as well as 2CLP rats given intratracheal PBS or adenovirus expressing luciferase served as controls. Luc transduction was evaluated by in vivo light detection, immunoassay and luciferase mRNA detection by RT-PCR in tissue harvested from septic rats. Vector abundance and distribution into alveolar cells was evaluated using immunostaining for the SV40 VP1 capsid protein as well as by double staining for VP1 and for the surfactant protein C (proSP-C. Immunostaining for T-lymphocytes was used to evaluate the cellular immune response induced by the vector. Results Luc expression measured by in vivo light detection correlated with immunoassay from lung tissue harvested from the same rats. Moreover, our results showed vector presence in type II alveolar cells. The vector did not induce significant cellular immune response. Conclusion In the present study we have demonstrated efficient uptake and expression of an SV40 vector in the lungs of animals with sepsis-induced ARDS. These vectors appear to be capable of in vivo transduction of alveolar type II cells and may thus become a future therapeutic tool.

Oppenheim Ariella

2007-10-01

387

Skyrmions with vector mesons revisited  

CERN Multimedia

In order to develop a model that can describe both a single baryon and multi-baryon systems on the same footing, we re-investigate the Skyrme model in a chiral Lagrangian derived from the hidden local symmetry (HLS) up to $O(p^4)$ including the homogeneous Wess-Zumino terms. We use the master formulas that connect the parameters of the HLS Lagrangian and a class of holographic QCD models, which provides a controllable way to determine the low-energy constants of the Lagrangian once the pion decay constant and the vector meson mass are given. Therefore, this model allows us to study the role of vector mesons in the skyrmion structure. We find that the $\\rho$ and $\\omega$ vector mesons have different roles in the skyrmion structure and that the $\\omega$ meson has an important role in the properties of the nucleon.

Oh, Yongseok

2014-01-01

388

Quantum contextuality for rational vectors  

CERN Document Server

The Kochen-Specker theorem states that noncontextual hidden variable models are inconsistent with the quantum predictions for every yes-no question on a qutrit, corresponding to every projector in three dimensions. It has been suggested [D. A. Meyer, Phys. Rev. Lett. 83, 3751 (1999)] that the inconsistency would disappear when we are restricted to projectors on unit vectors with rational components; that noncontextual hidden variables could reproduce the quantum predictions for rational vectors. Here we show that a qutrit state with rational components violates an inequality valid for noncontextual hidden-variable models [A. A. Klyachko et al., Phys. Rev. Lett. 101, 020403 (2008)] using rational projectors. This shows that the inconsistency remains even when using only rational vectors.

Cabello, Adan

2010-01-01

389

Characteristics of the crops grown with the light vector altered relative to the gravity vector  

Science.gov (United States)

A series of laboratory experiments with soft wheat Triticum aestivum L., cult. Apogee had the purpose to look into the interference of such determinants of plant development as the gravity force and the light direction. Light vector relative to the gravity vector was set unidirectional, opposite directional or perpendicular. Plant orientation relative to the gravity vector was set natural, inverse or perpendicular. Seeds were put into a 2-mm layer of a fiber ion-exchange artificial soil overlaying horizontal hydrophilic plates of porous titanium or anchored to porous ceramic tubes using plastic rings. Plants grew at two levels of the photosynthetic photon flux (PPF): 55 ± 5 ? mol/(m2\\cdot s) and 550 ± 20 ? mol/(m2\\cdot s) during 24-hr lighting. Water potential at the membrane surface varied from 0 to - 10.0 kPa in different experiments. It was shown that PPF of 550 ? mol/(m2\\cdot s) and membrane surface WP no less than -1.0 kPa yielded normal plants with healthy germinating seeds no matter plant orientation. In the inverse orientation, dry mass on the full-ripe stage was 25% higher and the number of productive tillers was twice as large as in the control. At the same time, as compared with the control, dry mass of roots and shoot height were almost 50% and 35% less, respectively. With PPF reduced to 55 ? mol/(m2\\cdot s), dry mass of the inverted plants was by 22% higher than the control, but water potential reduction to -10.0 kPa decreased this parameter in the inverted plants by 63%. Dry mass of roots of the inverted plants was consistently less in comparison with the naturally oriented plants. The experiments evidenced that morphology and ontogenesis of plants are significantly dependent on the interposition of the light and gravity vectors.

Berkovich, Y. A.; Smolianina, S. O.; Krivobok, N. M.; Erokhin, A. N.; Ivanov, V. B.

390

Plant virus expression vector development: new perspectives.  

Science.gov (United States)

Plant made biologics have elicited much attention over recent years for their potential in assisting those in developing countries who have poor access to modern medicine. Additional applications such as the stockpiling of vaccines against pandemic infectious diseases or potential biological warfare agents are also under investigation. Plant virus expression vectors represent a technology that enables high levels of pharmaceutical proteins to be produced in a very short period of time. Recent advances in research and development have brought about the generation of superior virus expression systems which can be readily delivered to the host plant in a manner that is both efficient and cost effective. This review presents recent innovations in plant virus expression systems and their uses for producing biologics from plants. PMID:24745025

Hefferon, Kathleen

2014-01-01

391

Spontaneously broken technicolor and the dynamics of virtual vector technimesons  

International Nuclear Information System (INIS)

We propose spontaneously breaking technicolor, thus liberating techniquarks and suppressing large resonance contributions to the electroweak S parameter. The dynamics is modeled by a fermion bubble approximation to a single massive technigluon exchange potential. This contains a Nambu--Jona-Lasinio model with additional interactions. ''Virtual'' vector mesons occur and contribute to S, and their effects are studied. Models of broken technicolor are discussed

1993-04-01

392

Learning with Support Vector Machines  

CERN Multimedia

Support Vectors Machines have become a well established tool within machine learning. They work well in practice and have now been used across a wide range of applications from recognizing hand-written digits, to face identification, text categorisation, bioinformatics, and database marketing. In this book we give an introductory overview of this subject. We start with a simple Support Vector Machine for performing binary classification before considering multi-class classification and learning in the presence of noise. We show that this framework can be extended to many other scenarios such a

Campbell, Colin

2010-01-01

393

On Spinors and Null Vectors  

CERN Multimedia

We investigate the relations between spinors and null vectors in Clifford algebra with particular emphasis on the conditions that a spinor must satisfy to be simple (also: pure). In particular we prove: i) a new property for null vectors: each of them bisects spinor space into two parts of equal size; ii) that simple spinors form one-dimensional subspaces of spinor space; iii) a necessary and sufficient condition for a spinor to be simple that generalizes a theorem of Cartan and Chevalley that appears now as a corollary of this result. We also show how to write down easily the most general spinor with a given associated totally null plane.

Budinich, Marco

2014-01-01

394

Nuclear optical potential in first Born approximation  

Energy Technology Data Exchange (ETDEWEB)

We calculate nuclear scalar and vector optical potentials in the first Born approximation (FBA) using ..pi.., rho, ..omega.., sigma, eta, and delta meson exchanges. We obtain strong attractive scalar and repulsive vector optical potentials which are the characteristics of relativistic approaches based upon Dirac phenomenology.

Iqbal, M.J. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility; Maryland Univ., College Park (USA). Dept. of Physics)

1985-05-16

395

Imaginary part of the relativistic optical potential  

International Nuclear Information System (INIS)

The imaginary past of the relativistic optical potential is calculated in nuclear matter for the Walecka sigma + omega model. Large Lorentz scalar and vector contributions are found in addition to an important three-vector potential. 9 references, 1 figure, 1 table

1982-10-27

396

Reconstruction of Vector-like Top Partner from Fully Hadronic Final States  

CERN Multimedia

We investigate the potential to search for the vector-like top partner in fully hadronic final states at the LHC. An algorithm is developed which kinematically reconstructs the vector-like top. We show that for moderate masses and a large branching fraction into top quark and Higgs boson, the reconstruction works with good quality.

Endo, Motoi; Ishikawa, Kazuya; Stoll, Martin

2014-01-01

397

Impact of Vector-Current Interactions on the QCD Phase Diagram  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Using a nonlocal version of the Polyakov-loop-extended Nambu-Jona-Lasinio model, we investigate effects of a nonderivative vector-current interaction (relating to the quark-number density) at both real and imaginary chemical potentials. This repulsive vector interaction between quarks has the following impact on the chiral first-order phase transition: at ...

Thomas Hell; Kouji Kashiwa; Wolfram Weise

2013-01-01

398

On Peres approach to Fradkin-Bacry-Ruegg-Souriau's perihelion vector  

CERN Multimedia

We solve explicitely the differential system obtained by Peres for the construction of a conserved vector associated to any central potential. We then obtain a very direct access to the discontinuous behavior of this Fradkin-Bacry-Ruegg-Souriau perihelion vector.

Grandati, Yves; Mohrbach, Herve

2008-01-01

399

Testing Studentsâ Understanding of Vector Concepts  

Science.gov (United States)

After four years of research we designed a 20-item multiple choice vector concept test (Test of Understanding of Vectors, TUV). In this article we analyze: 1) the reliability and discriminatory power of the test, and 2) studentsâ understanding of the vector concepts evaluated in the test. The final version of the test was administered in English to 423 students who were finishing an Electricity and Magnetism course at a large private Mexican university. In the first part of the article, we show results indicating that the TUV is a reliable assessment tool. In the second part, we examine studentsâ overall performance on the test and analyze the results of the five most difficult items for students: geometric interpretation of dot product, calculation of dot product of two vectors written in unit-vector notation, graphic representation of a unit vector, calculation of the direction of a vector written in unit-vector notation, and graphical subtraction of vector in 2D.

Barniol, Pablo; Zavala, Genaro

2013-12-21

400

Experiences In Comprehensive Vector Control In Indonesia  

Directory of Open Access Journals (Sweden)

Full Text Available The vector control program has been implemented in Indonesia for many years, however, vector-borne diseases are presently still a problem in Indonesia. Past activities for vector control implemented indoor residual spraying and larviciding only. Vector control problems occur through many causes and this has complicated past control programs. Presently, these complicated causes are surveyed thoroughly and analyzed as a whole and a holistic approach implemented. Comprehensive vector control is determined to solve the vector control problem. In 1991, a study was conducted to introduce the Malaria Surveillance Program in Indonesia. This program uses the comprehensive and integrated approach for malaria control in general, and vector control in particular. This paper describes the vector control program in general and how comprehensive vector control is integrated into the system. It also describes the experiences obtained in Indonesia and its impact on malaria in various places in Indonesia.

Sustriayu Nalim

2012-09-01

 
 
 
 
401

Macroscopic representation of the magnetization vector field in a magnetic substance  

International Nuclear Information System (INIS)

Expressions for the parameters of the macroscopic magnetization vector field are obtained based on a model of point magnetic moments. It is shown that the magnetization vector