A Novel Approach to Asynchronous MVP Data Interpretation Based on Elliptical-Vectors
Kruglyakov, M.; Trofimov, I.; Korotaev, S.; Shneyer, V.; Popova, I.; Orekhova, D.; Scshors, Y.; Zhdanov, M. S.
2014-12-01
We suggest a novel approach to asynchronous magnetic-variation profiling (MVP) data interpretation. Standard method in MVP is based on the interpretation of the coefficients of linear relation between vertical and horizontal components of the measured magnetic field.From mathematical point of view this pair of linear coefficients is not a vector which leads to significant difficulties in asynchronous data interpretation. Our approach allows us to actually treat such a pair of complex numbers as a special vector called an ellipse-vector (EV). By choosing the particular definitions of complex length and direction, the basic relation of MVP can be considered as the dot product. This considerably simplifies the interpretation of asynchronous data. The EV is described by four real numbers: the values of major and minor semiaxes, the angular direction of the major semiaxis and the phase. The notation choice is motivated by historical reasons. It is important that different EV's components have different sensitivity with respect to the field sources and the local heterogeneities. Namely, the value of major semiaxis and the angular direction are mostly determined by the field source and the normal cross-section. On the other hand, the value of minor semiaxis and the phase are responsive to local heterogeneities. Since the EV is the general form of complex vector, the traditional Schmucker vectors can be explicitly expressed through its components.The proposed approach was successfully applied to interpretation the results of asynchronous measurements that had been obtained in the Arctic Ocean at the drift stations "North Pole" in 1962-1976.
Vector potential photoelectron microscopy
Browning, R. [R. Browning Consultants, 14 John Street, Shoreham, New York 11786 (United States)
2011-10-15
A new class of electron microscope has been developed for the chemical microanalysis of a wide range of real world samples using photoelectron spectroscopy. Highly structured, three-dimensional samples, such as fiber mats and fracture surfaces can be imaged, as well as insulators and magnetic materials. The new microscope uses the vector potential field from a solenoid magnet as a spatial reference for imaging. A prototype instrument has demonstrated imaging of uncoated silk, magnetic steel wool, and micron-sized single strand tungsten wires.
Wang, Ren H.
1991-01-01
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.
Parallelization of Monte Carlo codes MVP/GMVP
Nagaya, Yasunobu; Mori, Takamasa; Nakagawa, Masayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sasaki, Makoto
1998-03-01
General-purpose Monte Carlo codes MVP/GMVP are well-vectorized and thus enable us to perform high-speed Monte Carlo calculations. In order to achieve more speedups, we parallelized the codes on the different types of the parallel processing platforms. The platforms reported are a distributed-memory vector-parallel computer Fujitsu VPP500, a distributed-memory massively parallel computer Intel Paragon and a distributed-memory scalar-parallel computer Hitachi SR2201. As mentioned generally, ideal speedup could be obtained for large-scale problems but parallelization efficiency got worse as the batch size per a processing element (PE) was smaller. (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
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)
Biochemical and structural analysis of the hyperpolarization-activated K(+) channel MVP.
Randich, Amelia M; Cuello, Luis G; Wanderling, Sherry S; Perozo, Eduardo
2014-03-18
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
Status of JAERI's Monte Carlo code MVP for neutron and photon transport problems
The special features of MVP are (1) vectorization and parallelization, (2) multiple lattice capability and statistical geometry model, (3) probability table method for unresolved resonance, (4) calculation at arbitrary temperatures, (5) depletion calculation, (6) perturbation calculation for eigenvalue (keff) problem, and so on. (orig.)
Spatial resolution in vector potential photoelectron microscopy
Browning, R. [R. Browning Consultants, 1 Barnhart Place, Shoreham, New York 11786 (United States)
2014-03-15
The experimental spatial resolution of vector potential photoelectron microscopy is found to be much higher than expected because of the cancellation of one of the expected contributions to the point spread function. We present a new calculation of the spatial resolution with support from finite element ray tracing, and experimental results.
Vector Potential, Electromagnetic Induction and "Physical Meaning"
Giuliani, G.
2010-01-01
A forgotten experiment by Andre 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 [equation omitted] (when the induced circuit is at rest). The "good…
Dirac operators coupled to vector potentials
Characteristic classes for the index of the Dirac family jA are computed in terms of differential forms on the orbit space of vector potentials under gauge transformations. The represent obstructions to the existence of a covariant Dirac propagator. The first obstruction is related to a chiral anomaly
Reception of longitudinal vector potential radiation with a plasma antenna
To help resolve the long-running debate between physicists and engineers regarding the existence of the magnetic vector potential, herewith we describe an experiment demonstrating reception of time-harmonic vector potential radiation at 1.3 GHz
Core Calculation of 1 MWatt PUSPATI TRIGA Reactor (RTP) using Monte Carlo MVP Code System
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
Parallel computing by Monte Carlo codes MVP/GMVP
General-purpose Monte Carlo codes MVP/GMVP are well-vectorized and thus enable us to perform high-speed Monte Carlo calculations. In order to achieve more speedups, we parallelized the codes on the different types of parallel computing platforms or by using a standard parallelization library MPI. The platforms used for benchmark calculations are a distributed-memory vector-parallel computer Fujitsu VPP500, a distributed-memory massively parallel computer Intel paragon and a distributed-memory scalar-parallel computer Hitachi SR2201, IBM SP2. As mentioned generally, linear speedup could be obtained for large-scale problems but parallelization efficiency decreased as the batch size per a processing element(PE) was smaller. It was also found that the statistical uncertainty for assembly powers was less than 0.1% by the PWR full-core calculation with more than 10 million histories and it took about 1.5 hours by massively parallel computing. (author)
Rigorous real-time Feynman path integral for vector potentials
In this paper, we will show the existence and uniqueness of a real-time, time-sliced Feynman path integral for quantum systems with vector potential. Our formulation of the path integral will be derived on the L2 transition probability amplitude via improper Riemann integrals. Our formulation will hold for a vector potential Hamiltonian for which its potential and vector potential each carry at most a finite number of singularities and discontinuities. (author)
On dynamics of velocity vector potential in incompressible fluids
An elegant quaternionic formulation is given for the Lagrangian advection equation for velocity vector potential in fluid dynamics. At first we study the topological significance of a restricted conserved quantity viz., stream-helicity and later more realistic configuration of open streamlines is figured out. Also, using Clebsch parameterisation of the velocity vector potential yet another physical significance for the stream-helicity is provided. Finally we give a Nambu-Poisson formalism of the Lagrangian advection equation for velocity vector potential.
The vector potential in a branched Riemann space
An attempt is made to extend the use of the vector potential to problems involving a branched space. As an example of a problem that is suitable to be solved entirely in terms of the vector potential the problem of a ring vortex element above a half-plane is worked out. The use of the scalar potential however remains slightly simpler. Another example that is treated is the simple looking problem of a straight vortex line perpendicularly crossing the edge of a half-plane. The problem is formulated in two ways, once using the scalar potential phi the other time using the vector potential A. It turns out that it is preferable to use the scalar potential and the Green's function formulation above using the method of images for the vector potential involving the more complicated integrals of distributions of ring vortices. (Auth.)
Exploiting the potential of vector control for disease prevention.
H Townson; MB Nathan; Zaim, M.; Guillet, P.; Manga, L.; Bos, R.; M Kindhauser
2005-01-01
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, large-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...
Design and Potential of Non-Integrating Lentiviral Vectors
Aaron Shaw
2014-01-01
Full Text Available Lentiviral vectors have demonstrated promising results in clinical trials that target cells of the hematopoietic system. For these applications, they are the vectors of choice since they provide stable integration into cells that will undergo extensive expansion in vivo. Unfortunately, integration can have unintended consequences including dysregulated cell growth. Therefore, lentiviral vectors that do not integrate are predicted to have a safer profile compared to integrating vectors and should be considered for applications where transient expression is required or for sustained episomal expression such as in quiescent cells. In this review, the system for generating lentiviral vectors will be described and used to illustrate how alterations in the viral integrase or vector Long Terminal Repeats have been used to generate vectors that lack the ability to integrate. In addition to their safety advantages, these non-integrating lentiviral vectors can be used when persistent expression would have adverse consequences. Vectors are currently in development for use in vaccinations, cancer therapy, site-directed gene insertions, gene disruption strategies, and cell reprogramming. Preclinical work will be described that illustrates the potential of this unique vector system in human gene therapy.
Recent developments of JAEA’s Monte Carlo code MVP for reactor physics applications
Highlights: • This paper describes the recent development status of the Monte Carlo code MVP. • The basic features and capabilities of MVP are briefly described. • New capabilities useful for reactor analysis are also described. - Abstract: 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
Telediagnostic Assessment of Intelligibility in Dysarthria: A Pilot Investigation of MVP-Online
Ziegler, Wolfram; Zierdt, Andreas
2008-01-01
Background: A most important index of functional impairment in dysarthria is "intelligibility". The "Munich Intelligibility Profile" (MVP) is a computer-based method for the assessment of the intelligibility of dysarthric patients. A multi-user online version of MVP is now available. Aims: To describe the structure of MVP-online and to evaluate…
TRR-1/M1 Core Analysis with MVP
Full text: Since early 1990s, the in-core fuel management of TRR-1/M1 has been performed by TRIGAP. This code was specifically developed for reactor physics calculations of the TRIGA-type reactor. However, because of its limitations in geometrical and cross sectional options, the attempt of using other techniques/codes are provoked. Nowadays, the choice of using the Monte Carlo method to perform core analysis becomes more satisfaction with acceptable computational time. The MVP is one of the codes that utilize the Monte Carlo method with continuous-energy library. It is able to explicitly model the problem in 3-D geometry. It also has a burn-up calculation feature called MVP-BURN. The aim of the current work is to apply the MVP code for TRR-1/M1 core analysis. In this paper, the MVP code was verified with the experiment results for the fresh core and some burn-up cores. The calculated-eigenvalue results agree well with the experimental data within an acceptable range of statistical error
Vector densities that potentiate dengue outbreaks in a Brazilian city.
Pontes, R J; Freeman, J; Oliveira-Lima, J W; Hodgson, J C; Spielman, A
2000-03-01
To identify the critical vector density that potentiates dengue outbreaks in an endemic site and to identify obstacles to anti-dengue activities, we correlated a series of dengue outbreaks in a Brazilian city with the intensity of its anti-vector source-reduction activities. The proportion of houses infested by vector mosquitoes correlated inversely with intensity of anti-mosquito interventions, and the vector population developed independently of rainfall. Local periods of drought promoted vector abundance in two ways: residents stored water in which vector mosquitoes could breed, and cholera outbreaks due to contaminated water diverted local health workers from routine anti-vector activities. One dengue outbreak became apparent to authorities more than two months after it commenced but would have been identified almost immediately had dengue-like disease in indicator hospitals been monitored. Active surveillance, therefore, offers a window of opportunity for promptly executed anti-dengue interventions. Source-reduction measures that suppress vector infestations to less than 1% of houses effectively avert outbreaks of dengue. PMID:11037781
Potential role of ticks as vectors of bluetongue virus
2010-01-01
When the first outbreak of bluetongue virus serotype 8 (BTV8) was recorded in North-West Europe in August 2006 and renewed outbreaks occurred in the summer of 2007 and again in 2008, the question was raised how the virus survived the winter. Since most adult Culicoides vector midges are assumed not to survive the northern European winter, and transovarial transmission in Culicoides is not recorded, we examined the potential vector role of ixodid and argasid ticks for bluetongue virus. Four sp...
MVP-Associated Filamin A Mutations Affect FlnA-PTPN12 (PTP-PEST) Interactions
Duval, Damien; Labbé, Pauline; Bureau, Léa; Le Tourneau, Thierry; Norris, Russell A.; Markwald, Roger R.; Levine, Robert; Schott, Jean-Jacques; Mérot, Jean
2015-01-01
Although the genetic basis of mitral valve prolapse (MVP) has now been clearly established, the molecular and cellular mechanisms involved in the pathological processes associated to a specific mutation often remain to be determined. The FLNA gene (encoding Filamin A; FlnA) was the first gene associated to non-syndromic X-linked myxomatous valvular dystrophy, but the impacts of the mutations on its function remain un-elucidated. Here, using the first repeats (1–8) of FlnA as a bait in a yeast two-hybrid screen, we identified the tyrosine phosphatase PTPN12 (PTP-PEST) as a specific binding partner of this region of FlnA protein. In addition, using yeast two-hybrid trap assay pull down and co-immunoprecipitation experiments, we showed that the MVP-associated FlnA mutations (G288R, P637Q, H743P) abolished FlnA/PTPN12 interactions. PTPN12 is a key regulator of signaling pathways involved in cell-extracellular matrix (ECM) crosstalk, cellular responses to mechanical stress that involve integrins, focal adhesion transduction pathways, and actin cytoskeleton dynamics. Interestingly, we showed that the FlnA mutations impair the activation status of two PTPN12 substrates, the focal adhesion associated kinase Src, and the RhoA specific activating protein p190RhoGAP. Together, these data point to PTPN12/FlnA interaction and its weakening by FlnA mutations as a mechanism potentially involved in the physiopathology of FlnA-associated MVP. PMID:26594644
MVP-Associated Filamin A Mutations Affect FlnA-PTPN12 (PTP-PEST Interactions
Damien Duval
2015-09-01
Full Text Available Although the genetic basis of mitral valve prolapse (MVP has now been clearly established, the molecular and cellular mechanisms involved in the pathological processes associated to a specific mutation often remain to be determined. The FLNA gene (encoding Filamin A; FlnA was the first gene associated to non-syndromic X-linked myxomatous valvular dystrophy, but the impacts of the mutations on its function remain un-elucidated. Here, using the first repeats (18 of FlnA as a bait in a yeast two-hybrid screen, we identified the tyrosine phosphatase PTPN12 (PTP-PEST as a specific binding partner of this region of FlnA protein. In addition, using yeast two-hybrid trap assay pull down and co-immunoprecipitation experiments, we showed that the MVP-associated FlnA mutations (G288R, P637Q, H743P abolished FlnA/PTPN12 interactions. PTPN12 is a key regulator of signaling pathways involved in cell-extracellular matrix (ECM crosstalk, cellular responses to mechanical stress that involve integrins, focal adhesion transduction pathways, and actin cytoskeleton dynamics. Interestingly, we showed that the FlnA mutations impair the activation status of two PTPN12 substrates, the focal adhesion associated kinase Src, and the RhoA specific activating protein p190RhoGAP. Together, these data point to PTPN12/FlnA interaction and its weakening by FlnA mutations as a mechanism potentially involved in the physiopathology of FlnA-associated MVP.
Boudoulas, Konstantinos Dean; Boudoulas, Harisios
2013-01-01
Mitral valve prolapse (MVP) results from the systolic movement of a portion or segments of the mitral valve leaflets into the left atrium during left ventricular systole. It is well appreciated today that floppy mitral valve (FMV) is the central issue in the MVP and mitral valve regurgitation (MVR) story. The term FMV refers to the expansion of the area of the mitral valve leaflets with elongated chordae tendineae, chordae rupture and mitral annular dilation. FMV/MVP occurs in a heterogeneous group of patients with a wide spectrum of mitral valve involvement from mild to severe. Two types of symptoms can be defined in FMV/MVP patients. In one group of patients, symptoms are directly related to progressive MVR. In the other group, symptoms cannot be explained by the degree of MVR alone; activation of the autonomic nervous system has been implicated for the explanation of symptoms in this group of patients which is referred to as the FMV/MVP syndrome. In this brief review, the natural history, pathophysiologic mechanisms and management of patients with FMV/MVP/MVR and FMV/MVP syndrome are discussed. PMID:23942374
Thermal vector potential theory of transport induced by temperature gradient
Tatara, Gen
2015-01-01
A microscopic formalism to calculate thermal transport coefficients is presented based on a thermal vector potential, whose time-derivative is related to a thermal force. The formalism is free from unphysical divergences reported to arise when Luttinger's formalism is applied naively, because the equilibrium (\\textquoteleft diamagnetic\\textquoteright) currents are treated consistently. The mathematical structure for thermal transport coefficients are shown to be identical with the electric on...
A symplectic integrator with arbitrary vector and scalar potentials
We study a new class of symplectic integrators for particles in arbitrary, time-dependent vector and scalar potentials. The methods were introduced in [Y.K. Wu, E. Forest, D.S. Robin, Phys. Rev. E 68 (2003) 046502] and are based on the ability to integrate Hamiltonians of the form (pi-ai(q))2 exactly for a finite time-step. We show that the integrators are symplectic in the non-relativistic case but not symplectic in the full six-dimensional phase space for relativistic Hamiltonians
Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression
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
Numerical simulation using vorticity-vector potential formulation
Tokunaga, Hiroshi
1993-01-01
An accurate and efficient computational method is needed for three-dimensional incompressible viscous flows in engineering applications. On solving the turbulent shear flows directly or using the subgrid scale model, it is indispensable to resolve the small scale fluid motions as well as the large scale motions. From this point of view, the pseudo-spectral method is used so far as the computational method. However, the finite difference or the finite element methods are widely applied for computing the flow with practical importance since these methods are easily applied to the flows with complex geometric configurations. However, there exist several problems in applying the finite difference method to direct and large eddy simulations. Accuracy is one of most important problems. This point was already addressed by the present author on the direct simulations on the instability of the plane Poiseuille flow and also on the transition to turbulence. In order to obtain high efficiency, the multi-grid Poisson solver is combined with the higher-order, accurate finite difference method. The formulation method is also one of the most important problems in applying the finite difference method to the incompressible turbulent flows. The three-dimensional Navier-Stokes equations have been solved so far in the primitive variables formulation. One of the major difficulties of this method is the rigorous satisfaction of the equation of continuity. In general, the staggered grid is used for the satisfaction of the solenoidal condition for the velocity field at the wall boundary. However, the velocity field satisfies the equation of continuity automatically in the vorticity-vector potential formulation. From this point of view, the vorticity-vector potential method was extended to the generalized coordinate system. In the present article, we adopt the vorticity-vector potential formulation, the generalized coordinate system, and the 4th-order accurate difference method as the computational method. We present the computational method and apply the present method to computations of flows in a square cavity at large Reynolds number in order to investigate its effectiveness.
Development of continuous energy Monte Carlo burn-up calculation code MVP-BURN
Burn-up calculations based on the continuous energy Monte Carlo method became possible by development of MVP-BURN. To confirm the reliably of MVP-BURN, it was applied to the two numerical benchmark problems; cell burn-up calculations for High Conversion LWR lattice and BWR lattice with burnable poison rods. Major burn-up parameters have shown good agreements with the results obtained by a deterministic code (SRAC95). Furthermore, spent fuel composition calculated by MVP-BURN was compared with measured one. Atomic number densities of major actinides at 34 GWd/t could be predicted within 10% accuracy. (author)
Potentiality of experimental analysis for characteristics of the Poynting vector components
Khrobatin R.; Mokhun I.; Viktorovskaya J.
2008-01-01
Potentiality of experimental analysis for the averaged Poynting vector components is considered. It is shown that joint application of traditional interferometry and Stocks polarimetry should allow for determining unambiguously characteristics of the Poynting vector components at each point of field.
Progress report -- February 1983 : Migration and survival of MVP Canada geese
US Fish and Wildlife Service, Department of the Interior The objectives of this study were 1 to document the variation in numbers, movements, harvest, and survival of MVP Canada geese and 2 to relate variation in these...
Circumventing Antivector Immunity: Potential Use of Nonhuman Adenoviral Vectors
Lopez-Gordo, Estrella; Podgorski, Iva I.; Downes, Nicholas; Alemany, Ramon
2014-01-01
Adenoviruses are efficient gene delivery vectors based on their ability to transduce a wide variety of cell types and drive high-level transient transgene expression. While there have been advances in modifying human adenoviral (HAdV) vectors to increase their safety profile, there are still pitfalls that need to be further addressed. Preexisting humoral and cellular immunity against common HAdV serotypes limits the efficacy of gene transfer and duration of transgene expression. As an alterna...
Stability estimate for the relativistic Schrödinger equation with time-dependent vector potentials
We consider the relativistic Schrödinger equation with a time dependent vector and scalar potential on a bounded cylindrical domain. Using a geometric optics ansatz we establish a logarithmic stability estimate for the recovery of vector and scalar potentials. (paper)
In order to realize fast and accurate Monte Carlo simulation of neutron and photon transport problems, two vectorized Monte Carlo codes MVP and GMVP have been developed at JAERI. MVP is based on the continuous energy model and GMVP is on the multigroup model. Compared with conventional scalar codes, these codes achieve higher computation speed by a factor of 10 or more on vector super-computers. Both codes have sufficient functions for production use by adopting accurate physics model, geometry description capability and variance reduction techniques. The first version of the codes was released in 1994. They have been extensively improved and new functions have been implemented. The major improvements and new functions are (1) capability to treat the scattering model expressed with File 6 of the ENDF-6 format, (2) time-dependent tallies, (3) reaction rate calculation with the pointwise response function, (4) flexible source specification, (5) continuous-energy calculation at arbitrary temperatures, (6) estimation of real variances in eigenvalue problems, (7) point detector and surface crossing estimators, (8) statistical geometry model, (9) function of reactor noise analysis (simulation of the Feynman-α experiment), (10) arbitrary shaped lattice boundary, (11) periodic boundary condition, (12) parallelization with standard libraries (MPI, PVM), (13) supporting many platforms, etc. This report describes the physical model, geometry description method used in the codes, new functions and how to use them. (author)
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)
Potential of Scalable Vector Graphics (SVG) for Ocean Science Research
Sears, J. R.
2002-12-01
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.
Semiclassical methods to the Klein-Gordon equation with the unequal scalar and vector potentials
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
Mosquito larvicidal potential of potash alum against malaria vector Anopheles stephensi (Liston)
Preet, Shabad; Seema, K. C.
2010-01-01
Mosquito larviciding may prove to be an effective tool for incorporating into integrated vector management strategies for reducing malaria transmission. Here, we report the potential of potash alum, a traditionally known salt in Indian Ayurveda and Chinese medicine system, in malaria vector control by evaluating its aqueous suspension as larvicide and growth disruptor of Anopheles stephensi, under laboratory conditions. Immature stages of the mosquito were tested using WHO guidelines. 50 and ...
Algebraic inversion of the Dirac equation for the vector potential in the non-Abelian case
We study the Dirac equation for spinor wavefunctions minimally coupled to an external field, from the perspective of an algebraic system of linear equations for the vector potential. By analogy with the method in electromagnetism, which has been well-studied, and leads to classical solutions of the Maxwell–Dirac equations, we set up the formalism for non-Abelian gauge symmetry, with the SU(2) group and the case of four-spinor doublets. An extended isospin-charge conjugation operator is defined, enabling the hermiticity constraint on the gauge potential to be imposed in a covariant fashion, and rendering the algebraic system tractable. The outcome is an invertible linear equation for the non-Abelian vector potential in terms of bispinor current densities. We show that, via application of suitable extended Fierz identities, the solution of this system for the non-Abelian vector potential is a rational expression involving only Pauli scalar and Pauli triplet, Lorentz scalar, vector and axial vector current densities, albeit in the non-closed form of a Neumann series. (paper)
Cosmological vector potential as a possible factor of cosmophysical and heliophysical connections.
Baurov, Yu. A.; Trukhanov, K. A.
1998-10-01
A hypothesis is developed considering the electromagnetic vector potential as one of the possible factors responsible for cosmophysical and heliophysical connections. At present this hypothesis can be based substantially on the theoretical and experimental works in which the cosmological vector potential is accepted as the fundamental concept of the physical vacuum structure theory. The total time variations in the vector potential, caused by changes in the mutual source arrangement and the processes occurring in them, are estimated on the basis of cosmophysical magnetic field source data. The possible influences of these variations on the processes in the nature and the possible explanations on this basis of the known effects of the correlation of the biological, physicochemical, and other processes with the cosmophysical and heliophysical factors are discussed.
An educational path for the magnetic vector potential and its physical implications
Barbieri, Sara; Giliberti, Marco
2013-01-01
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.
Stationary states of fermions in a sign potential with a mixed vectorscalar coupling
Castilho, W.M., E-mail: castilho.w@gmail.com; Castro, A.S. de, E-mail: castro@pq.cnpq.br
2014-01-15
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 SturmLiouville 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 Kleins 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 SturmLiouville perspective. An isolated bounded solution. No pair production despite the high localization. No bounded solution under exact spin and pseudospin symmetries.
Calculation of the magnetic vector potential in the TJ-II
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
Preliminary analyses for HTTR`s start-up physics tests by Monte Carlo code MVP
Nojiri, Naoki [Science and Technology Agency, Tokyo (Japan); Nakano, Masaaki; Ando, Hiroei; Fujimoto, Nozomu; Takeuchi, Mitsuo; Fujisaki, Shingo; Yamashita, Kiyonobu
1998-08-01
Analyses of start-up physics tests for High Temperature Engineering Test Reactor (HTTR) have been carried out by Monte Carlo code MVP based on continuous energy method. Heterogeneous core structures were modified precisely, such as the fuel compacts, fuel rods, coolant channels, burnable poisons, control rods, control rod insertion holes, reserved shutdown pellet insertion holes, gaps between graphite blocks, etc. Such precise modification of the core structures was difficult with diffusion calculation. From the analytical results, the followings were confirmed; The first criticality will be achieved around 16 fuel columns loaded. The reactivity at the first criticality can be controlled by only one control rod located at the center of the core with other fifteen control rods fully withdrawn. The excess reactivity, reactor shutdown margin and control rod criticality positions have been evaluated. These results were used for planning of the start-up physics tests. This report presents analyses of start-up physics tests for HTTR by MVP code. (author)
Preliminary analyses for HTTR's start-up physics tests by Monte Carlo code MVP
Analyses of start-up physics tests for High Temperature Engineering Test Reactor (HTTR) have been carried out by Monte Carlo code MVP based on continuous energy method. Heterogeneous core structures were modified precisely, such as the fuel compacts, fuel rods, coolant channels, burnable poisons, control rods, control rod insertion holes, reserved shutdown pellet insertion holes, gaps between graphite blocks, etc. Such precise modification of the core structures was difficult with diffusion calculation. From the analytical results, the followings were confirmed; The first criticality will be achieved around 16 fuel columns loaded. The reactivity at the first criticality can be controlled by only one control rod located at the center of the core with other fifteen control rods fully withdrawn. The excess reactivity, reactor shutdown margin and control rod criticality positions have been evaluated. These results were used for planning of the start-up physics tests. This report presents analyses of start-up physics tests for HTTR by MVP code. (author)
C595 antibody: A potential vector for targeted alpha therapy
Full text: Mucins are high molecular-weight heavily glycosylated glycoproteins with many oligosaccharide side-chains, linked to a protein backbone called apomucin. A total of 19 different mucin genes (MUC1-MUC4, MUC5B, MUC5AC, MUC6-MUC18) have been identified to date. Mucins are present on the surface of most epithelial cells and play a role in their protection and lubrication. In cancer cells the mucin molecule becomes altered, thus representing an important target for diagnosis and therapy. Urinary epithelial mucin1 (MUC1) is found to be frequently up-regulated and abnormally glycosylated in a number of common malignancies, including breast, bladder, colon, ovarian and gastric cancer. The monoclonal antibody C595 is an IgG3 murine MAb raised against the protein core of human MUC1. Epitope mapping has shown that C595 recognizes a tetrapeptide motif (RPAP) within the protein core of MUC1 mucin that contains a large domain of multiples of a highly conserved 20-amino-acid-repeat sequence (PDTRPAPGSTAPPAHGVTSA). This antibody has previously been radiolabelled with 99mTc and 111In and used for imaging a range of tumour types including ovary, breast and bladder. The antibody has also been radiolabelled with 67Cu and 188Re for the therapy of superficial bladder cancer. More recently we have investigated the pre-clinical use of the C595 antibody for targeted alpha therapy using 213Bi which emits alpha particles with high linear energy transfer (LET), short range (80 m) radiation and has a short physical half-life of 45.6 minutes. Alpha particles are some 7300 times heavier than beta particles and in theory, following binding of an alpha immunocongugates to the target, a large fraction of the alpha particle energy is delivered to cancer cells, with minimal concomitant radiation of normal tissues. 213Bi was produced from the 225Ac/213Bi generator. For antibody conjugation the chelator, cyclic diethylenetriaminepentacetic acid anhydride (DTPA) was used. Initial experimental studies have concentrated on the targeted therapy of carcinoma of the prostate, pancreas and ovary. On 120 paraffin embedded specimens from patients who underwent radical retro-pubic prostatectomy or trans-urethralresection of the prostate for primary untreated carcinoma of the pancreas MUC1 expression was detected in 58% primary Ca prostate tissues and 90% lymph node metastases but not in normal prostates or benign tissues. The 213Bi-C595 conjugate demonstrated cell killing in PC-3 and DU 145 cell lines isolated from human prostatic adenocarcinoma. Other results indicate that 213Bi-C595 targeting efficacy is in accordance with the expression of MUC1 in three pancreatic cancer cell clusters CFPAC-1, PANC-1 and CAPAN-1 and demonstrated effective toxicity of tumour spheroids of up to 100 m in diameter. When administered to tumour bearing mice at 333 MBq/kg the c595 alpha conjugate caused significant tumour growth delay, compared with the non-specific control at after 16 weeks. Similar results have been obtained in monolayers and cell clusters of the ovarian OVCAR-3 cell line. We believe this antibody conjugate offers great potential for targeted alpha therapy of prostatic, pancreatic and ovarian tumours. (author)
Ohkitani, Koji
2015-09-01
We consider incompressible Euler flows in terms of the stream function in two dimensions and the vector potential in three dimensions. We pay special attention to the case with singular distributions of the vorticity, e.g., point vortices in two dimensions. An explicit equation governing the velocity potentials is derived in two steps. (i) Starting from the equation for the stream function [Ohkitani, Nonlinearity 21, T255 (2009)NONLE50951-771510.1088/0951-7715/21/12/T02], which is valid for smooth flows as well, we derive an equation for the complex velocity potential. (ii) Taking a real part of this equation, we find a dynamical equation for the velocity potential, which may be regarded as a refinement of Bernoulli theorem. In three-dimensional incompressible flows, we first derive dynamical equations for the vector potentials which are valid for smooth fields and then recast them in hypercomplex form. The equation for the velocity potential is identified as its real part and is valid, for example, flows with vortex layers. As an application, the Kelvin-Helmholtz problem has been worked out on the basis the current formalism. A connection to the Navier-Stokes regularity problem is addressed as a physical application of the equations for the vector potentials for smooth fields. PMID:26465559
Species-specific fate of bacteria in house flies and impact on vector potential for pathogens
House flies ingest bacteria during filth-feeding and consequently can transport microbes from septic environments to human habitats and food. Vector potential is influenced both by flies encountering pathogens and by the fate of bacteria in the fly alimentary canal. In order for pathogens to be tran...
Comment on An educational path for the magnetic vector potential and its physical implications
In their recent paper, Barbieri etal (2013 Eur. J. Phys. 34 1209) proposed an educational path for the magnetic vector potential. In this comment I point out that this educational path involves several inconsistencies and is therefore unattractive from a pedagogical point of view. (letters and comments)
Yuan, Zixia; Niu, Pengcheng
2007-03-01
We study the existence and nonexistence of global solutions to the degenerate evolution inequalities with singular potential constructed from the generalized Greiner vector fields. For the proof of the existence results, we use the method of supersolution and the modified Bessel function. The nonexistence results are established by the test function method.
Comment on ‘An educational path for the magnetic vector potential and its physical implications’
Heras, José A.
2014-03-01
In their recent paper, Barbieri et al (2013 Eur. J. Phys. 34 1209) proposed an educational path for the magnetic vector potential. In this comment I point out that this educational path involves several inconsistencies and is therefore unattractive from a pedagogical point of view.
In order to realize fast and accurate Monte Carlo simulation of neutron and photon transport problems, new algorithms have been studied, and two fully vectorized Monte Carlo codes MVP and GMVP have been developed for FACOM VP series vector supercomputers. The former and latter codes use the continuous energy model and the multi-group model, respectively. Compared with conventional scalar codes, these codes achieve higher computation speed by a factor of 10 or more on FACOM VP-2600. Both codes have functions for production use including accurate physics model, geometry description capability and variance reduction technique. In addition to the execution on the vector supercomputers, these codes can be used on vector-parallel supercomputers with parallel calculation capability and on workstations with an OS of UNIX. For the continuous energy method, many nuclear data libraries have been prepared based on mainly JENDL 3. This report describes the physics model, geometry description method used in the codes and how to use them. (author)
We obtain general properties of N=2 gauged extended supergravity coupled to vector multiplets, which can gauge an arbitrary group. General formulas for masses and curvatures are derived. Particular attention is devoted to the scalar potential of the theory which determines the classical vacuum structure. Explicit examples are given in which the potential is identically zero, but supersymmetry is broken. It is found that these theories are symmetric under generalized duality transformations. (orig.)
Fermions embedded in a scalar-vector kink-like smooth potential
Castilho, W M
2015-01-01
The behaviour of massive fermions is analyzed with scalar and vector potentials. A continuous chiral-conjugation transformation decouples the equation for the upper component of the Dirac spinor provided the vector coupling does not exceed the scalar coupling. It is shown that a Sturm-Liouville perspective is convenient for studying scattering as well as bound states. One possible isolated solution (excluded from the Sturm-Liouville problem) corresponding to a bound state might also come into sight. For potentials with kink-like profiles, beyond the intrinsically relativistic isolated bound-state solution corresponding to the zero-mode solution of the massive Jackiw-Rebbi model in the case of no vector coupling, a finite set of bound-state solutions might appear as poles of the transmission amplitude in a strong coupling regime. It is also shown that the possible isolated bound solution disappears asymptotically as the magnitude of the scalar and vector coupling becomes the same. Furthermore, we show that due...
Stochastic and Deterministic Vector Chromatography of Suspended Particles in 1D-Periodic Potentials
Bernate, Jorge A
2011-01-01
We present a comprehensive description of vector chromatography that includes deterministic and stochastic transport in 1D-periodic free-energy landscapes, with both energetic and entropic contributions, and highlights the parameters governing the deflection angle, i.e. the Peclet number and the partition ratio. We also investigate the dependence of the deflection angle on the shape of the free-energy landscape by varying the width of the linear transitions in an otherwise dichotomous potential. Finally, we present experimental results obtained in a microfluidic system in which gravity drives the suspended particles and, in combination with a bottom surface patterned with shallow rectangular grooves, creates a periodic landscape of (potential) energy barriers. The experiments validate the model and demonstrate that a simple, passive microdevice can lead to vector separation of colloidal particles based on both size and density.
Comments on "What the Electromagnetic Vector Potential Describes" by E. J. Konopinski
Cote, Paul J
2010-01-01
The seminal paper on the meaning of the vector potential by E. J. Konopinski is revisited. The full significance of this work has not been generally recognized to date. We first briefly review Konopinski's findings and show that many of his key results can be obtained from a simpler and more familiar approach. We then discuss the additional implications of his analyses, which were overlooked by Konopinski himself.
Transmission routes and vector potential of the poultry red mite Dermanyssus gallinae
Brännström, Sara
2010-01-01
The poultry red mite, Dermanyssus gallinae is a blood-feeding ectoparasite causing irritation, stress, and in severe infection, anemia and death of its avian host. This parasite not only causes welfare problems in poultry but also financial losses in egg production worldwide. The aims of this thesis were to elucidate the transmission routes of D. gallinae to poultry facilities and to investigate the potential of the parasite to be a vector of Erysipelothrix rhusiopathiae, the agent causing po...
The WKB method for the Dirac equation with the vector and scalar potentials
The WKB approximation is developed for the Dirac equation with the spherically symmetrical vector and scalar potentials. The relativistic wavefunctions are constructed, new quantization rule containing the spin-orbital interaction is obtained. For spherically symmetrical model of the Stark effect the quasi-classical spectrum of relativistic hydrogen-like atom is calculated. Application of the WKB method to the mass spectrum of the hydrogen-like quark systems was done. (author)
A Proposal of Potentially Meaningful Material for Teaching of Vector Mechanics
Bruno Nunes Myrrha Ribeiro; Carlos Vitor de Alencar Carvalho2
2014-01-01
This paper presents didactic solutions to the Vector Mechanics subject, which aims to teach the calculation and the representation of the acting forces on a given particle in space. It is about developed and applied activities in GeoGebra software, called potentially meaningful materials. The whole proposal was based on MLT―Meaningful Learning Theory, proposed by David Ausubel, in order to contribute to a more efficient learning in general disciplines of engineering courses.
Chikungunya Viral Fitness Measures within the Vector and Subsequent Transmission Potential
Christofferson, Rebecca C.; Chisenhall, Daniel M; Wearing, Helen J.; Mores, Christopher N
2014-01-01
Given the recent emergence of chikungunya in the Americas, the accuracy of forecasting and prediction of chikungunya transmission potential in the U.S. requires urgent assessment. The La Reunion-associated sub-lineage of chikungunya (with a valine substitution in the envelope protein) was shown to increase viral fitness in the secondary vector, Ae. albopictus. Subsequently, a majority of experimental and modeling efforts focused on this combination of a sub-lineage of the East-Central-South A...
Vector potential of hospital houseflies with special reference to Klebsiella species.
Fotedar, R.; Banerjee, U.; Samantray, J. C.; Shriniwas
1992-01-01
The vector potential of houseflies (Musca domestica) for Klebsiella spp. was investigated. Klebsiella spp. (mostly Klebsiella pneumoniae) were isolated from 36.7% of hospital flies and 28.1% of infected wounds of patients. Antibiograms of Klebsiella spp. showed that 82.0% of isolates from hospital flies and 96.3% from infected wounds were resistant to four or more commonly used antimicrobials. In contrast, from the control group, only 8.7% klebsiella isolates showed similar antimicrobial resi...
Construction of metric and vector potential perturbations of a Reissner-Nordstroem black hole
When an appropriate decoupling of variables in a coupled linear system of partial differential equations is obtained, a recently described procedure enables solutions to the full coupled system of equations to be constructed. This procedure is used here to generate solutions of the linearized Einstein-Maxwell equations describing perturbations of a Reissner-Nordstrom black hole, using Chandrasekhar's recent decoupling of these equations. Explicit formulae are given for the metric and vector potential perturbations for each parity type. (author)
Enhancing the clinical potential of AAV vectors by capsid engineering to evade pre-existing immunity
DavidSchaffer
2011-10-01
Full Text Available Vectors based on adeno-associated viruses have shown considerable promise in both preclinical models and increasingly in clinical trials. However, one formidable challenge is pre-existing immunity due to widespread exposure to numerous AAV variants and serotypes within the human population, which affect efficacy of clinical trials due to the accompanying high levels of anti-capsid neutralizing antibodies. Transient immunosuppression has promise in mitigating cellular and humoral responses induced by vector application in naïve hosts, but cannot overcome the problem that pre-existing neutralizing antibodies pose towards the goal of safe and efficient gene delivery. Shielding of AAV from antibodies, however, may be possible by covalent attachment of polymers to the viral capsid or by encapsulation of vectors inside biomaterials. In addition, there has been considerable progress in using rational mutagenesis, combinatorial libraries, and directed evolution approaches to engineer capsid variants that are not recognized by anti-AAV antibodies generally present in the human population. While additional progress must be made, such strategies, alone or in combination with immunosuppression to avoid de novo induction of antibodies, have strong potential to significantly enhance the clinical efficacy of AAV vectors.
Lopez Fraguas, A.; Lopez Bruna, D.; Romero, J. A.
2005-07-01
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.
Synek, Petr; Popelková, Alena; Koubínová, Darina; Šťastný, Karel; Langrová, Iva; Votýpka, Jan; Munclinger, Pavel
2016-01-01
Sedentary bird species are suitable model hosts for identifying potential vectors of avian blood parasites. We studied haemosporidian infections in the Tengmalm's Owl (Aegolius funereus) in the Ore Mountains of the Czech Republic using molecular detection methods. Sex of owl nestlings was scored using molecular sexing based on fragment analysis of PCR-amplified CHD1 introns. Observed infection prevalences in nestlings and adult owls were 51 and 86 %, respectively. Five parasite lineages were detected. Most of the infections comprised the Leucocytozoon AEFUN02 and STOCC06 lineages that probably refer to distinct Leucocytozoon species. Other lineages were detected only sporadically. Mixed infections were found in 49 % of samples. The main factor affecting the probability of infection was host age. No effect of individual sex on infection probability was evidenced. The youngest infected nestling was 12 days old. High parasite prevalence in the Tengmalm's Owl nestlings suggests that insect vectors must enter nest boxes to transmit parasites before fledging. Hence, we placed sticky insect traps into modified nest boxes, collected potential insect vectors, and examined them for the presence of haemosporidian parasites using molecular detection. We trapped 201 insects which were determined as biting midges from the Culicoides genus and two black fly species, Simulium (Nevermannia) vernum and Simulium (Eusimulium) angustipes. Six haemosporidian lineages were detected in the potential insect vectors, among which the Leucocytozoon lineage BT2 was common to the Tengmalm's Owl and the trapped insects. However, we have not detected the most frequently encountered Tengmalm's Owl Leucocytozoon lineages AEFUN02 and STOCC06 in insects. PMID:26365667
To explore the role of Major Vault Protein (MVP) in oral cavity squamous cell carcinoma patients. 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. 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. 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
Cervical cancer is the most frequent cancer found in Indonesia. The primary treatment of cervical cancer at the locally advanced stage is usually performed by using radiotherapy and chemotherapy. The combination of the two techniques is often called chemoradiotherapy. The response to chemoradiotherapy is influenced by biological and physical factors. Major vault protein (MVP) is a ribonucleoprotein which contributes to drug resistance in some cancers. The purposes of this research were: (1) to determine the correlation between the expression of MVP and the index of p53, including AgNOR values and index of MIB-1; and (2) between MVP and chemoradiotherapy clinical response of cervical cancer. Twenty-one microscopic slides taken from biopsy tissues of cervical cancer patients before undergoing treatment were stained to identify MVP, p53, and MIB-1 by means of immunohistochemistry techniques and AgNORs staining. After undergoing chemoradiotherapy treatment, the patients’ clinical responses were observed by pelvic control method. Experimental results showed that there was a correlation between MVP and AgNOR value (P=0.05), but no correlation between MVP and index of p53 (P=0.729), including MIB-1 LI (P=0.63), in untreated cervical cancer. In addition, there was no association between MVP and chemoradiotherapy response. In conclusion, MVP expression correlates with the process of cell proliferation before the G2 phase of cell cycle in untreated cancer cells. Those have no association with clinical responses after the completion of treatment. (author)
Analysis of High-Moderation MOX Core MISTRAL-3 with SRAC and MVP
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 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. SRAC and MVP calculate the nuclear core characteristics correctly for the high-moderation MOX core MISTRAL-3. No apparent trend with the moderation ratio is observed in these calculation results
The poultry red mite (Dermanyssus gallinae): a potential vector of pathogenic agents.
Valiente Moro, Claire; De Luna, Carlos J; Tod, Alexander; Guy, Jonathan H; Sparagano, Olivier A E; Zenner, Lionel
2009-06-01
The poultry red mite, D. gallinae has been involved in the transmission of many pathogenic agents, responsible for serious diseases both in animals and humans. Nowadays, few effective methods are available to control the ectoparasite in poultry farms. Consequently, this is an emerging problem which must be taken into account to maintain good health in commercial egg production. This paper addresses the vector capacity of the ectoparasite with special emphasis on salmonellae, pathogenic agents responsible for many of the most important outbreaks of food-borne diseases worlwide. It has been experimentally shown that D. gallinae could act as a biological vector of S. enteritidis and natural carriage of these bacteria by the mite on poultry premises has also been reported. It was also found that D. gallinae carried other pathogens such as E. coli, Shigella sp., and Staphylococcus, thus increasing the list of pathogenic agents potentially transmitted by the mite. PMID:19205905
Aedes (Stegomyia) albopictus (Skuse): A Potential Vector of Zika Virus in Singapore
Wong, Pei-Sze Jeslyn; Li, Mei-zhi Irene; Chong, Chee-Seng; Ng, Lee-Ching; Tan, Cheong-Huat
2013-01-01
Background Zika virus (ZIKV) is a little known arbovirus until it caused a major outbreak in the Pacific Island of Yap in 2007. Although the virus has a wide geographic distribution, most of the known vectors are sylvatic Aedes mosquitoes from Africa where the virus was first isolated. Presently, Ae. aegypti is the only known vector to transmit the virus outside the African continent, though Ae. albopictus has long been a suspected vector. Currently, Ae. albopictus has been shown capable of transmitting more than 20 arboviruses and its notoriety as an important vector came to light during the recent chikungunya pandemic. The vulnerability of Singapore to emerging infectious arboviruses has stimulated our interest to determine the competence of local Ae. albopictus to transmit ZIKV. Methodology/Principal Findings To determine the competence of Ae. albopictus to ZIKV, we orally infected local mosquito strains to a Ugandan strain virus. Fully engorged mosquitoes were maintained in an environmental chamber set at 29C and 8085%RH. Twelve mosquitoes were then sampled daily from day one to seven and on day 10 and 14 post infection (pi). Zika virus titre in the midgut and salivary glands of each mosquito were determined using tissue culture infectious dose50 assay, while transmissibility of the virus was determined by detecting viral antigen in the mosquito saliva by qRT-PCR. High dissemination and transmission rate of ZIKV were observed. By day 7-pi, all mosquitoes have disseminated infection and 73% of these mosquitoes have ZIKV in their saliva. By day 10-pi, all mosquitoes were potentially infectious. Conclusions/Significance The study highlighted the potential of Ae. albopictus to transmit ZIKV and the possibility that the virus could be established locally. Nonetheless, the threat of ZIKV can be mitigated by existing dengue and chikungunya control program being implemented in Singapore. PMID:23936579
Howe, E.; Stenseng, L.; Tscherning, C. C.
2003-01-01
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 s...
On the fields of a torus and the role of the vector potential
Carron, N.J. [Mission Research Corporation, P.O. Drawer 719, Santa Barbara, California 93102 (United States)
1995-08-01
A toroidal current distribution has nonvanishing exterior vector potential {bold A}, but zero exterior field {bold B}={del}{times}{bold A}=0. This property, together with the absence of fringing fields as in a cylindrical solenoid, makes it convenient for studies involving the vector potential in a field-free region, such as the Aharonov--Bohm effect, or the effect of {bold A} in a Josephson junction. We present an immediate general result of magnetostatics, and use it to easily compute {bold A} for a torus, to visualize the static vector potential for any current distribution, and to show how one can construct a current distribution to produce any desired {bold A}. When the torus current {ital I} varies in time, nonzero quasistatic fields {bold E}({ital t}) and {bold B}({ital t}) are produced ({bold E}{similar_to}{omega}{ital I}/{ital r}{sup 3} and {bold B}{similar_to}{omega}{sup 2}{ital I}/{ital r}{sup 2}). Radiation is also produced, with the radiation pattern of an {ital electric} {ital dipole}. The torus provides a counterexample to the common erroneous notion that if all multipole moments of a current distribution vanish then quasistatic fields and radiation must also vanish. We then formulate Maxwell`s equations in a way that obviates the role of gauge transformations. This ``gauge irrelevant`` form clarifies the relation of potentials to current sources, isolating the role of the transverse part of {bold A}. The general result from magnetostatics is extended to time-varying sources, revealing a seldom recognized symmetry of Maxwell`s equations, and showing how one can visualize {bold A} for an arbitrary time-dependent current source. {copyright} {ital 1995} {ital American} {ital Association} {ital of} {ital Physics} {ital Teachers}.
Olano, Víctor Alberto; Matiz, María Inés; Lenhart, Audrey; Cabezas, Laura; Vargas, Sandra Lucía; Jaramillo, Juan Felipe; Sarmiento, Diana; Alexander, Neal; Stenström, Thor Axel; Overgaard, Hans J
2015-09-01
Dengue and other vector-borne diseases are of great public health importance in Colombia. Vector surveillance and control activities are often focused at the household level. Little is known about the importance of nonhousehold sites, including schools, in maintaining vector-borne disease transmission. The objectives of this paper were to determine the mosquito species composition in rural schools in 2 municipalities in Colombia and to assess the potential risk of vector-borne disease transmission in school settings. Entomological surveys were carried out in rural schools during the dry and rainy seasons of 2011. A total of 12 mosquito species were found: Aedes aegypti, Anopheles pseudopunctipennis, Culex coronator, Cx. quinquefasciatus, and Limatus durhamii in both immature and adult forms; Ae. fluviatilis, Cx. nigripalpus, Cx. corniger, and Psorophora ferox in immature forms only; and Ae. angustivittatus, Haemagogus equinus, and Trichoprosopon lampropus in adult forms only. The most common mosquito species was Cx. quinquefasciatus. Classrooms contained the greatest abundance of adult female Ae. aegypti and Cx. quinquefasciatus. The most common Ae. aegypti breeding sites were containers classified as "others" (e.g., cans), followed by containers used for water storage. A high level of Ae. aegypti infestation was found during the wet season. Our results suggest that rural schools are potentially important foci for the transmission of dengue and other mosquito-borne diseases. We propose that public health programs should be implemented in rural schools to prevent vector-borne diseases. PMID:26375902
Tick-borne pathogens and the vector potential of ticks in China.
Yu, Zhijun; Wang, Hui; Wang, Tianhong; Sun, Wenying; Yang, Xiaolong; Liu, Jingze
2015-01-01
Ticks, as obligate blood-sucking ectoparasites, attack a broad range of vertebrates and transmit a great diversity of pathogenic microorganisms. They are considered second only to mosquitoes as vectors of human disease, and the most important vector of pathogens of domestic and wild animals. Of the 117 described species in the Chinese tick fauna, 60 are known to transmit one or more diseases: 36 species isolated within China and 24 species isolated outside China. Moreover, 38 of these species carry multiple pathogens, indicating the potentially vast role of these vectors in transmitting pathogens. Spotted fever is the most common tick-borne disease, and is carried by at least 27 tick species, with Lyme disease and human granulocytic anaplasmosis ranked as the second and third most widespread tick-borne diseases, carried by 13 and 10 species, respectively. Such knowledge provides us with clues for the identification of tick-associated pathogens and suggests ideas for the control of tick-borne diseases in China. However, the numbers of tick-associated pathogens and tick-borne diseases in China are probably underestimated because of the complex distribution and great diversity of tick species in this country. PMID:25586007
A new type of the quark confinement potential that previously led to the prediction of the 1110 MeV vector particle is applied to calculate the masses of the radial excitations of the rho,ω,phi-mesons. The values of the masses obtained are close to those of the recently discovered vector resonances below 2 GeV. (Auth.)
The solution of Grad-Shafranov equation determines the stationary behavior of fusion plasma inside a tokamak. To solve the equation it is necessary to know the toroidal current density profile. Recent works show that it is possible to determine a magnetohydrodynamic (MHD) equilibrium with reversed current density (RCD) profiles that presents magnetic islands. In this work we show analytical MHD equilibrium with a RCD profile and analyze the structure of the vacuum vector potential associated with these equilibria using the virtual casing principle
A scalar/vector potential formulation of an airfoil in nonuniform stream
Wang, J. C. A.; Frost, Walter
1988-01-01
A recent innovation in aerodynamic calculation techniques is the formulation based upon scalar and vector potentials (Stokes-Helmholtz decomposition) for the velocity field. This technique is presented: an implementation involving classical panel method is studied. The application of interest is to two-dimensional airfoils moving into a nonuniform approach flow. Comparisons with theoretical and numerical results are included. Furthermore the variations of lift and moment coefficients of quasi-steady simulated flight of an airfoil through microburst wind shear data are studied.
An experimental proposal to test the physical effect of the vector potential
Wang, Rui-Feng
2016-01-01
There are two interpretations of the Aharonov-Bohm (A-B) effect. One interpretation asserts that the A-B effect demonstrates that the vector potential is a physical reality that can result in the phase shift of a moving charge in quantum mechanics. The other interpretation asserts that the phase shift of the moving charge results from the interaction energy between the electromagnetic field of the moving charge and external electromagnetic fields. This paper briefly reviews these two interpretations and analyzes their differences. In addition, a new experimental scheme is proposed to determine which interpretation is correct.
Calculations for a disk source and a general detector using a radiation vector potential
Conway, John T.
2008-04-01
A closed form expression for a radiation vector potential is derived for a generalized disk radiation source. By applying Stokes's theorem the surface integral for the radiation flux into a general detector is converted into a much simpler line integral of the vector potential around the edge of the detector. This line integral can be easily evaluated for general detector geometry and general location and angular orientation relative to the disk source. For a number of cases the line integral reduces to integrals of Bessel functions which give various generalizations of Ruby's formula. Explicit formulas and numerical results for the geometric efficiency are given for circular and elliptical detectors displaced and rotated relative to the disk source. Detectors with general polygonal boundaries are considered and formulas and sample numerical results are given. For uniform surface emissivity the corresponding formulas for a disk detector and a general planar source are easily obtained. Formulas are also obtained for a scalar radiation potential and some limitations for its applicability are identified.
SO(N) Higgs problem with adjoint + vector representations and non-linear potentials
Using the recently devised geometrical method, we analyze the quartic Higgs potential for SO(N) adjoint + vector representations. The minimum energy solutions are found to correspond to maxi-maximal little groups, but not all such groups are used. However, in the complete orbit space (including invariants not employed in the Higgs potential) we find that their strata have somewhat equal geometrical status of being low dimensional singular subspaces, i.e., cusps, edge curves, two-dimensional surfaces, etc. We also consider simple scalar potentials which are nonlinear with respect to orbit parameters and show that the directional extremum often, though not always, remains monotonic in orbit parameters within the orbit space and consequently the absolute extremum is likely to occur on the most protrudent portions of the orbit space boundary. Thus we clarify the range of validity of the Michel-Radicati conjecture and the Gell-Mann-Slansky conjecture. (orig.)
Analysis of the TRIGA Mark-II benchmark IEU-COMP-THERM-003 with Monte Carlo code MVP
The benchmark experiments of the TRIGA Mark-II reactor in the ICSBEP handbook have been analyzed with the Monte Carlo code MVP using the cross section libraries based on JENDL-3.3, JENDL-3.2 and ENDF/B-VI.8. The MCNP calculations have been also performed with the ENDF/B-VI.6 library for comparison between the MVP and MCNP results. For both cores labeled 132 and 133, which have different core configurations, the ratio of the calculated to the experimental results (C/E) for keff obtained by the MVP code is 0.999 for JENDL-3.3, 1.003 for JENDL-3.2, and 0.998 for ENDF/B-VI.8. For the MCNP code, the C/E values are 0.998 for both Core 132 and 133. All the calculated results agree with the reference values within the experimental uncertainties. The results obtained by MVP with ENDF/B-VI.8 and MCNP with ENDF/B-VI.6 differ only by 0.02% for Core 132, and by 0.01% for Core 133. (author)
Mills, James N.; Gage, Kenneth L; Ali S Khan
2010-01-01
Background Because of complex interactions of climate variables at the levels of the pathogen, vector, and host, the potential influence of climate change on vector-borne and zoonotic diseases (VBZDs) is poorly understood and difficult to predict. Climate effects on the nonvector-borne zoonotic diseases are especially obscure and have received scant treatment. Objective We described known and potential effects of climate change on VBZDs and proposed specific studies to increase our understand...
Alejandra Rumi
1990-09-01
Full Text Available Considering the possibility of introduction of schistosomiasis mansoni into Argentina as a consequence of dam construction on the Rio De La Plata basin, preliminary studies have been carried out on agrosystems such as ricefields in Corrientes province with the following purposes: 1 to survey and estimate the relative abundance of planorbids and identify potential vector species; 2 to identify environmental factors capable of influencing Biomphalaria population dynamics; and 3 to find out snail-parasite associations and estimate snail infection rates in order to detect possible competitive interactions between larval stages of native trematodes that could be used in biological control of Schistosoma mansoni. Three potential schistosome vectors were detected in ricefields, namely Biomphalaria straminea, B. tenagophila and B. peregrina, although B. orbignyi, a species refractory to infection with S. mansoni, proved the most frequent and abundant. Positive correlations (P0.05 was found in total iron, phosphates (SRP, pH and soil granulometry. Echinocercariae developed from rediae and belonging to Petasiger sp., Paryphostomum sp., and other undetermined species were found.
Fermions in a mixed vector-scalar double-step potential via continuous chiral transformation
Castilho, W M
2016-01-01
The behaviour of fermions in the background of a double-step potential is analyzed with a general mixing of scalar and vector couplings via continuous chiral-conjugation transformation. Provided the vector coupling does not exceed the scalar coupling, a Sturm-Liouville approaching for the double-step potential shows that the transmission coefficient exhibits oscillations and that a finite set of intrinsically relativistic bound-state solutions might appear as poles of the transmission amplitude in a strong coupling regime. An isolated bound-state solution resulting from coupled first-order equations might also come into sight. It is also shown that all those possible 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. Furthermore, we show that due to the additional mass acquired by the fermion from the scalar background the high localization of the fermion in an extreme relativistic regi...
Fermions in a mixed vector-scalar double-step potential via continuous chiral transformation
Castilho, W. M.; de Castro, A. S.
2016-04-01
The behaviour of fermions in the background of a double-step potential is analyzed with a general mixing of scalar and vector couplings via continuous chiral-conjugation transformation. Provided the vector coupling does not exceed the scalar coupling, a Sturm-Liouville approach for the double-step potential shows that the transmission coefficient exhibits oscillations and that a finite set of intrinsically relativistic bound-state solutions might appear as poles of the transmission amplitude in a strong coupling regime. An isolated bound-state solution resulting from coupled first-order equations might also come into sight. It is also shown that all those possible 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. Furthermore, we show that due to the additional mass acquired by the fermion from the scalar background the high localization of the fermion in an extreme relativistic regime does not violate the Heisenberg uncertainty principle.
Rumi, A; Hamann, M I
1990-01-01
Considering the possibility of introduction of schistosomiasis mansoni into Argentina as a consequence of dam construction on the Rio De La Plata basin, preliminary studies have been carried out on agrosystems such as ricefields in Corrientes province with the following purposes: 1) to survey and estimate the relative abundance of planorbids and identify potential vector species; 2) to identify environmental factors capable of influencing Biomphalaria population dynamics; and 3) to find out snail-parasite associations and estimate snail infection rates in order to detect possible competitive interactions between larval stages of native trematodes that could be used in biological control of Schistosoma mansoni. Three potential schistosome vectors were detected in ricefields, namely Biomphalaria straminea, B. tenagophila and B. peregrina, although B. orbignyi, a species refractory to infection with S. mansoni, proved the most frequent and abundant. Positive correlations (P less than 0.05) were found between Biomphalaria abundance and some environmental parameters: conductivity, hardness, calcium, nitrites plus nitrates, ammonium and bicarbonates. Water temperature correlation was negative (P less than 0.05). No correlation (P less than 0.05) was found in total iron, phosphates (SRP), pH and soil granulometry. PMID:2134706
Instrument for Measuring the Earth's Time-Retarded Transverse Gravitational Vector Potential
Hafele, J C
2010-01-01
Here within the basic design for a ground-based instrument for measuring the magnitude of the Earth's time-retarded transverse gravitational vector potential is described. The formula for the Earth's transverse vector potential is derived from the known formula for the neoclassical time-retarded transverse gravitational field (arXiv:0904.0383v2 [physics.gen-ph] 25May2010). The device senses the relativistic shift in the frequency of laser-diode oscillators set into circular motion at the tips of a two-arm rotor. The instrument employs fiber optics and a digital electronic interferometer/spectrometer to measure the effect of the relativistic time dilation on the frequency-modulated (FM) harmonic amplitudes in the beat signals between the tip-diodes and a stationary reference diode. The FM amplitudes depend on the orientation of the rotor. For the vertical-east-west orientation with a rotor frequency of 73.9 Hz, the predicted FM amplitudes for overtones at 148 Hz, 222 Hz, and 296 Hz are respectively 7x10^-10 Hz...
Spinless particles in the field of unequal Scalar-Vector Yukawa potentials
Hamzavi, Majid; Thylwe, Karl-Erik
2013-01-01
We present analytical bound state solutions of the spin-zero Klein-Gordon (KG) particles in the field of unequal mixture of scalar and vector Yukawa potentials within the framework of the approximation scheme to the centrifugal potential term for any arbitrary -state. The approximate energy eigenvalues and unnormalized wave functions are obtained in closed forms using a simple shortcut of the Nikiforov-Uvarov (NU) method. Further, we solve the KG-Yukawa problem for its exact numerical energy eigenvalues via amplitude phase (AP) method to test the accuracy of the present solutions found by using the NU method. Our numerical tests using energy calculations demonstrate the existence of inter-dimensional degeneracy amongst energy states of the KG-Yukawa problem. The dependence of the energy on the dimension is numerically discussed for spatial dimensions
Spinless particles in the field of unequal scalarvector Yukawa potentials
We present analytical bound state solutions of the spin-zero KleinGordon (KG) particles in the field of unequal mixture of scalar and vector Yukawa potentials within the framework of the approximation scheme to the centrifugal potential term for any arbitrary l-state. The approximate energy eigenvalues and unnormalized wave functions are obtained in closed forms using a simple shortcut of the NikiforovUvarov (NU) method. Further, we solve the KGYukawa problem for its exact numerical energy eigenvalues via the amplitude phase (AP) method to test the accuracy of the present solutions found by using the NU method. Our numerical tests using energy calculations demonstrate the existence of inter-dimensional degeneracy amongst the energy states of the KGYukawa problem. The dependence of the energy on the dimension D is numerically discussed for spatial dimensions D = 26. (general)
Potential-field estimation from satellite data using scalar and vector Slepian functions
Plattner, Alain
2013-01-01
In the last few decades a series of increasingly sophisticated satellite missions has brought us gravity and magnetometry data of ever improving quality. To make optimal use of this rich source of information on the structure of Earth and other celestial bodies, our computational algorithms should be well matched to the specific properties of the data. In particular, inversion methods require specialized adaptation if the data are only locally available, their quality varies spatially, or if we are interested in model recovery only for a specific spatial region. Here, we present two approaches to estimate potential fields on a spherical Earth, from gradient data collected at satellite altitude. Our context is that of the estimation of the gravitational or magnetic potential from vector-valued measurements. Both of our approaches utilize spherical Slepian functions to produce an approximation of local data at satellite altitude, which is subsequently transformed to the Earth's spherical reference surface. The ...
Feeding behaviour of potential vectors of West Nile virus in Senegal
Konaté Lassana
2011-06-01
Full Text Available Abstract Background West Nile virus (WNV is a widespread pathogen maintained in an enzootic cycle between mosquitoes and birds with occasional spill-over into dead-end hosts such as horses and humans. Migratory birds are believed to play an important role in its dissemination from and to the Palaearctic area, as well as its local dispersion between wintering sites. The Djoudj Park, located in Senegal, is a major wintering site for birds migrating from Europe during the study period (Sept. 2008- Jan. 2009. In this work, we studied the seasonal feeding behaviour dynamics of the potential WNV mosquito vectors at the border of the Djoudj Park, using a reference trapping method (CDC light CO2-baited traps and two host-specific methods (horse- and pigeon-baited traps. Blood meals of engorged females were analysed to determine their origin. Results Results indicated that Culex tritaeniorhynchus and Cx. neavei may play a key role in the WNV transmission dynamics, the latter being the best candidate bridging-vector species between mammals and birds. Moreover, the attractiveness of pigeon- and horse-baited traps for Cx. neavei and Cx. tritaeniorhynchus varied with time. Finally, Cx. tritaeniorhynchus was only active when the night temperature was above 20°C, whereas Cx. neavei was active throughout the observation period. Conclusions Cx. neavei and Cx. tritaeniorhynchus are the main candidate vectors for the transmission of WNV in the area. The changes in host attractiveness might be related to variable densities of the migratory birds during the trapping period. We discuss the importance of these results on the risk of WNV transmission in horses and humans.
ASPECTS REGARDING THE FACEBOOK USER IN ROMANIA AS A POTENTIAL DESTINATION IMAGE - VECTOR
MIHAIL-CRISTIAN DIȚOIU
2011-01-01
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.
Potential effects of warmer worms and vectors on onchocerciasis transmission in West Africa
Cheke, Robert A.; Basez, Maria-Gloria; Perry, Malorie; White, Michale T.; Garms, Rolf; Obuobie, E.; Lamberton, Poppy H.L.; Young, Stephen; Osei-Atweneboana, Mike Y.; Intsiful, Joseph; Shen, Mingwang; Boakye, Daniel A.; Michael D Wilson
2015-01-01
Development times of eggs, larvae and pupae of vectors of onchocerciasis (Simulium spp.) and of Onchocerca volvulus larvae within the adult females of the vectors decrease with increasing temperature. At and above 25C, the parasite could reach its infective stage in less than 7 days when vectors could transmit after only two gonotrophic cycles. After incorporating exponential functions for vector development into a novel blackfly population model, it was predicted that fly numbers in Liberia...
Li, Qiuhong; Miller, Rehae; Han, Ping-yang; Pang, Jijing; Dinculescu, Astra; Chiodo, Vince; Hauswirth, William W
2008-01-01
Purpose Safety and efficiency are critical for successful gene therapy. Adeno-associated viral (AAV) vectors are commonly used for gene transfer in both human and animal studies. However, administration of AAV vectors can lead to development of neutralizing antibodies against the vector capsid, thus decreasing the efficiency of therapeutic gene transfer and preventing effective vector readministration. We investigated immune responses to different routes of ocular administration and readminis...
Aedes hensilli as a Potential Vector of Chikungunya and Zika Viruses
Ledermann, Jeremy P.; Guillaumot, Laurent; Yug, Lawrence; Saweyog, Steven C.; Tided, Mary; Machieng, Paul; Pretrick, Moses; Marfel, Maria; Griggs, Anne; Bel, Martin; Duffy, Mark R.; Hancock, W Thane; Ho-Chen, Tai; Powers, Ann M.
2014-01-01
An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at...
Hornok, Sándor; Meli, Marina L; Perreten, Andrea; Farkas, Róbert; Willi, Barbara; Beugnet, Frederic; Lutz, Hans; Hofmann-Lehmann, Regina
2009-01-01
Abstract The aim of the present study was twofold. First, in general, to reveal new aspects of the potential vector role of ixodid ticks and fleas by screening large numbers of specimens with recently developed molecular biological methods. Second, to evaluate the occurrence of vector-borne infectious agents in a geographical context. Altogether 3,442 unfed hard ticks (Ixodes ricinus, Dermacentor marginatus, D. reticulatus, Haemaphysalis inermis, H. concinna, H. punctata) and 939 f...
Zero vector potential mechanism of attosecond absorption in strongly relativistic plasmas
Baeva, T; Robinson, A P L; Norreys, P A
2010-01-01
The understanding of the physics of lasermatter interactions in the strongly relativistic regime is of fundamental importance. In this article, a new mechanism of fast electron generation at the vacuum-solid boundary of intense laser pulse interaction with overdense plasma is described. It is one that has no analogue in classical, non-relativistic laser-plasma interactions. Here, conclusive proof is provided that the key contribution to the fast electron generation is given by the zero points of the vector potential. We demonstrate that the new mechanism leads to scalings for the fast electron energy, which explicitly depend on the plasma density, thus providing a new insight into relativistic laser-matter interaction. Furthermore, it is shown that this new mechanism provides the dominant contribution to the interaction by the injection of energy into the overdense plasma delivered by attosecondduration electron bunches. This new understanding will allow the future generation of a single ultra-bright attoseco...
BCI Based Wheelchair Control Using Steady State Visual Evoked Potentials and Support Vector Machines
Rajesh Singla
2013-07-01
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.
Mendoza-Cano, Fernando; Sánchez-Paz, Arturo; Terán-Díaz, Berenice; Galván-Alvarez, Diego; Encinas-García, Trinidad; Enríquez-Espinoza, Tania; Hernández-López, Jorge
2014-06-01
The susceptibility of the endemic copepod Calanus pacificus californicus to white spot syndrome virus (WSSV) was established by the temporal analysis of WSSV VP28 transcripts by quantitative real-time PCR (qRT-PCR). The copepods were collected from a shrimp pond located in Bahia de Kino Sonora, Mexico, and challenged per os with WSSV by a virus-phytoplankton adhesion route. Samples were collected at 0, 24, 48 and 84 h postinoculation (hpi). The VP28 transcripts were not detected at early stages (0 and 24 hpi); however, some transcript accumulation was observed at 48 hpi and gradually increased until 84 hpi. Thus, these results clearly show that the copepod C. pacificus californicus is susceptible to WSSV infection and that it may be a potential vector for the dispersal of WSSV. However, further studies are still needed to correlate the epidemiological outbreaks of WSSV with the presence of copepods in shrimp ponds. PMID:24895865
Control of tripod-scheme cold-atom wavepackets by manipulating a non-Abelian vector potential
Tripod-scheme cold atoms interacting with laser beams have attracted considerable interest for their role in synthesizing effective non-Abelian vector potentials. Such effective vector potentials can be exploited to realize an all-optical imprinting of geometric phases onto matter waves. By working on carefully designed extensions of our previous work, we show that coherent lattice structure of cold-atom sub-wavepackets can be formed and that the non-Abelian Aharonov-Bohm effect can be easily manifested via the translational motion of cold atoms. We also show that by changing the frame of reference, effects due to a non-Abelian vector potential may be connected with a simple dynamical phase effect, and that under certain conditions it can be understood as an Abelian geometric phase in a different frame of reference. Results should help design better schemes for the control of cold-atom matter waves.
A phenomenological model is developed in terms of bilocal meson fields in order to describe a vector meson and its leptonic decays. A new Salpeter equation for this particle and the Schwinger-Dyson equation allowing for the presence of an arbitrary potential and for a modification associated with the renormalization of the quark (antiquark ) wave function within the meson are given. An expression for the constant of the leptonic decay of the charged rho meson is obtained from an analysis of the decay process τ → ρν via parametrizing in it the hadronization of intermediate charged weak W bosons into a bilocal vector meson. The potential is chosen in the form of the sum of harmonic-oscillator and Coulomb potentials, and the respective boundary-value problem is formulated. It is shown that the solutions to this problem describe both the mass spectrum of vector mesons and their leptonic-decay constants
lvarez-Baz, G; Fernndez-Bravo, M; Pajares, J; Quesada-Moraga, E
2015-11-01
Three entomopathogenic fungal strains, Isaria farinosa (Holmsk.) Fr., Lecanicillium attenuatum (Zare & W. Games) and Beauveria pseudobassiana (Bals.) Vuill. were isolated in Spain from naturally infected Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae), the European vector of Pine Wilt Disease (PWD). This is the first time that these entomopathogenic fungi have been isolated from M. galloprovincialis beetles. Assays showed the B. pseudobassiana EABps 11/01-Mg strain to be highly virulent against the pine sawyer. Horizontal and vertical transmission were assessed for both aqueous (110(8)conidia/ml) and dry (4.2510(9)conidia/g) conidial formulations. Evidence of horizontal or vertical transmission was not found when insects were inoculated with the aqueous conidial suspension. However, when dry conidia were applied, 100% of the horizontally-infected insects died and their average survival times (AST) were significantly reduced (from 21.10 and 25.00days in controls to 10.40 and 10.00days in infected males and females, respectively). Compared to control females, numbers of egg-laying wounds, eggs laid, live larvae after 5days and larvae entering the xylem after 6months were significantly reduced in both inoculated females and clean females that had mated with inoculated males, pointing to horizontally-induced reduction of progeny. These results validate the potential of the isolated B. pseudobassiana strain as an important natural population regulator. Through auto-dissemination techniques, it could be used for the integrated control of Pine Wood Nematode vectors and constitute a new tool for Pine Wilt Disease management. PMID:26283466
Prabhu, K; Murugan, K; Nareshkumar, A; Ramasubramanian, N; Bragadeeswaran, S
2011-01-01
Objective To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera (M. oleifera) plant seeds against malarial vector Anopheles stephensi (A. stephensi) mosquitoes at different concentrations (20, 40, 60, 80 and 100 ppm). Methods M. oleifera was collected from the area of around Bharathiar University, Coimbatore. The dried plant materials were powdered by an electrical blender. From each sample, 100 g of the plant material were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus. The extracts were evaporated to dryness in rotary vacuum evaporator to yield 122 mg and 110 mg of dark greenish material (residue) from Arcang amara and Ocimum basilicum, respectively. One gram of the each plant residue was dissolved separately in 100 mL of acetone (stock solution) from which different concentrations, i.e., 20, 40, 60, 80 and 100 ppm were prepared. Results Larvicidal activity of M. oleifera exhibited in the first to fourth instar larvae of the A. stephensi, and the LC50 and LC90 values were 57.79 ppm and 125.93 ppm for the first instar, 63.90 ppm and 133.07 ppm for the second instar, 72.45 ppm and 139.82 ppm for the third instar, 78.93 ppm and 143.20 ppm for the fourth instar, respectively. During the pupal stage the methanolic extract of M. oleifera showed that the LC50 and LC90 values were 67.77 ppm and 141.00 ppm, respectively. Conclusions The present study indicates that the phytochemicals derived from M. oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs. PMID:23569741
Gabriela Teresani
2015-03-01
Full Text Available Candidatus Liberibacter solanacearum’ has recently been reported to be associated with vegetative disorders and economic losses in carrot and celery crops in Spain. The bacterium is a carrot seedborne pathogen and it is transmitted by psyllid vector species. From 2011 to 2014 seasonal and occasional surveys in carrot, celery and potato plots were performed. The sticky plant method was used to monitor the arthropods that visited the plants. The collected arthropods were classified into Aphididae and Cicadellidae, and the superfamily Psylloidea was identified to the species level. The superfamily Psylloidea represented 35.45% of the total arthropods captured on celery in Villena and 99.1% on carrot in Tenerife (Canary Islands. The maximum flight of psyllid species was in summer, both in mainland Spain and the Canary Islands, reaching a peak of 570 specimens in August in Villena and 6,063 in July in Tenerife. The main identified psyllid species were as follows: Bactericera trigonica Hodkinson, B. tremblayi Wagnerand B. nigricornis Förster. B. trigonica represented more than 99% of the psyllids captured in the Canary Islands and 75% and 38% in 2011 and 2012 in Villena, respectively. In addition, Trioza urticae Linnaeus, Bactericera sp.,Ctenarytaina sp., Cacopsylla sp., Trioza sp. and Psylla sp. were captured. ‘Ca. L. solanacearum’ targets were detected by squash real-time PCR in 19.5% of the psyllids belonging to the different Bactericera species. This paper reports at least three new psyllid species that carry the bacterium and can be considered as potential vectors.
Aedes (Stegomyia) albopictus (Skuse): A Potential Vector of Zika Virus in Singapore
Wong, Pei-Sze Jeslyn; Li, Mei-Zhi Irene; Chong, Chee-Seng; Ng, Lee-Ching; Tan, Cheong-Huat
2013-01-01
Background Zika virus (ZIKV) is a little known arbovirus until it caused a major outbreak in the Pacific Island of Yap in 2007. Although the virus has a wide geographic distribution, most of the known vectors are sylvatic Aedes mosquitoes from Africa where the virus was first isolated. Presently, Ae. aegypti is the only known vector to transmit the virus outside the African continent, though Ae. albopictus has long been a suspected vector. Currently, Ae. albopictus has been shown capable of t...
Non-invasively reconstructing the transmembrane potentials (TMPs) from body surface potentials (BSPs) constitutes one form of the inverse ECG problem that can be treated as a regression problem with multi-inputs and multi-outputs, and which can be solved using the support vector regression (SVR) method. In developing an effective SVR model, feature extraction is an important task for pre-processing the original input data. This paper proposes the application of principal component analysis (PCA) and kernel principal component analysis (KPCA) to the SVR method for feature extraction. Also, the genetic algorithm and simplex optimization method is invoked to determine the hyper-parameters of the SVR. Based on the realistic heart-torso model, the equivalent double-layer source method is applied to generate the data set for training and testing the SVR model. The experimental results show that the SVR method with feature extraction (PCA-SVR and KPCA-SVR) can perform better than that without the extract feature extraction (single SVR) in terms of the reconstruction of the TMPs on epi- and endocardial surfaces. Moreover, compared with the PCA-SVR, the KPCA-SVR features good approximation and generalization ability when reconstructing the TMPs.
Electrodynamics in terms of functions over the group SU(2). I. The equation of the vector potential
A method of harmonic analysis in terms of functions over the group SU(2) is applied to the description of interaction between matter and the electromagnetic field. Carmeli's SU(2) formulation of Maxwell's equations is extended to an SU(2) formulation of the equations for the electromagnetic vector potential. The four functions which describe the vector potential are expanded in a generalized Fourier series [SU(2) harmonic analysis] and the equations for the coefficients are derived. These equations are not independent of each other, but in a given order they can be solved consecutively one at a time
By a novel algebraic method we study the approximate solution to the Dirac equation with scalar and vector second Poeschl-Teller potential carrying spin symmetry. The transcendental energy equation and spinor wave functions with arbitrary spin-orbit coupling quantum number k are presented. It is found that there exist only positive-energy bound states in the case of spin symmetry. Also, the energy eigenvalue approaches a constant when the potential parameter ? goes to zero. The equally scalar and vector case is studied briefly. (orig.)
Wei, Gao-Feng [Xi' an University of Arts and Science, Department of Physics, Xi' an (China); Dong, Shi-Hai [Instituto Politecnico Nacional, Escuela Superior de Fisica y Matematicas, Mexico D.F. (Mexico)
2010-02-15
By a novel algebraic method we study the approximate solution to the Dirac equation with scalar and vector second Poeschl-Teller potential carrying spin symmetry. The transcendental energy equation and spinor wave functions with arbitrary spin-orbit coupling quantum number k are presented. It is found that there exist only positive-energy bound states in the case of spin symmetry. Also, the energy eigenvalue approaches a constant when the potential parameter {alpha} goes to zero. The equally scalar and vector case is studied briefly. (orig.)
Du, Jinsong; Chen, Chao; Lesur, Vincent; Lane, Richard; Wang, Huilin
2015-06-01
We examined the mathematical and computational aspects of the magnetic potential, vector and gradient tensor fields of a tesseroid in a geocentric spherical coordinate system (SCS). This work is relevant for 3-D modelling that is performed with lithospheric vertical scales and global, continent or large regional horizontal scales. The curvature of the Earth is significant at these scales and hence, a SCS is more appropriate than the usual Cartesian coordinate system (CCS). The 3-D arrays of spherical prisms (SP; `tesseroids') can be used to model the response of volumes with variable magnetic properties. Analytical solutions do not exist for these model elements and numerical or mixed numerical and analytical solutions must be employed. We compared various methods for calculating the response in terms of accuracy and computational efficiency. The methods were (1) the spherical coordinate magnetic dipole method (MD), (2) variants of the 3-D Gauss-Legendre quadrature integration method (3-D GLQI) with (i) different numbers of nodes in each of the three directions, and (ii) models where we subdivided each SP into a number of smaller tesseroid volume elements, (3) a procedure that we term revised Gauss-Legendre quadrature integration (3-D RGLQI) where the magnetization direction which is constant in a SCS is assumed to be constant in a CCS and equal to the direction at the geometric centre of each tesseroid, (4) the Taylor's series expansion method (TSE) and (5) the rectangular prism method (RP). In any realistic application, both the accuracy and the computational efficiency factors must be considered to determine the optimum approach to employ. In all instances, accuracy improves with increasing distance from the source. It is higher in the percentage terms for potential than the vector or tensor response. The tensor errors are the largest, but they decrease more quickly with distance from the source. In our comparisons of relative computational efficiency, we found that the magnetic potential takes less time to compute than the vector response, which in turn takes less time to compute than the tensor gradient response. The MD method takes less time to compute than either the TSE or RP methods. The efficiency of the (GLQI and) RGLQI methods depends on the polynomial order, but the response typically takes longer to compute than it does for the other methods. The optimum method is a complex function of the desired accuracy, the size of the volume elements, the element latitude and the distance between the source and the observation. For a model of global extent with typical model element size (e.g. 1 degree horizontally and 10 km radially) and observations at altitudes of 10s to 100s of km, a mixture of methods based on the horizontal separation of the source and observation separation would be the optimum approach. To demonstrate the RGLQI method described within this paper, we applied it to the computation of the response for a global magnetization model for observations at 300 and 30 km altitude.
Aedes (Stegomyia) albopictus (Skuse), a potential new Dengue vector in southern Cameroon.
Fontenille, D.; Toto, J.C.
2001-01-01
Aedes albopictus, a mosquito vector of Dengue virus, has been recorded for the first time in Cameroon. Entomologic surveys in 2000 demonstrated that it is widespread in southern Cameroon, colonizing a wide variety of breeding sites and biting humans in every district surveyed. The presence of this vector increases the risk for emergence of dengue in Cameroon.
CULICOIDES SONORENSIS AS A POTENTIAL BIOLOGICAL VECTOR FOR VESICULAR STOMATITIS VIRUS
Vesicular stomatitis virus (VSV) causes an economically important arboviral disease in cattle, horses and swine. No insect vector has been established for VSV transmission in the western U.S. The biting midge, Culicoides sonorensis, is a known vector of other arboviruses and is a prevalent livestock...
Dumitru, Spiridon
2014-01-01
It is suggested a testing puzzle able to reveal the self-asserting property of the homogeneous vector potential field. As pieces of the puzzle are taken three reliable entities : (i) influence of a potential vector on the de Broglie wavelength (ii) a G.P. Thomson-like experimental arrangement and (iii) a special coil designed to create a homogeneous vector potential. The alluded property is not connected with magnetic fluxes surrounded by the vector potential field lines, but it depends on the fluxes which are outside of the respective lines. Also the same property shows that in the tested case the vector potential field is uniquely defined physical quantity, free of any adjusting gauge. So the phenomenology of the suggested quantum test differs on that of macroscopic theory where the vector potential is not uniquely defined and allows a gauge adjustment. Of course that the proposed test has to be subjected to adequate experimental validation.
Li, S. X.; Zhang, Y. J.; Zeng, Q. Y.; Li, L. F.; Guo, Z. Y.; Liu, Z. M.; Xiong, H. L.; Liu, S. H.
2014-06-01
Cancer is the most common disease to threaten human health. The ability to screen individuals with malignant tumours with only a blood sample would be greatly advantageous to early diagnosis and intervention. This study explores the possibility of discriminating between cancer patients and normal subjects with serum surface-enhanced Raman spectroscopy (SERS) and a support vector machine (SVM) through a peripheral blood sample. A total of 130 blood samples were obtained from patients with liver cancer, colonic cancer, esophageal cancer, nasopharyngeal cancer, gastric cancer, as well as 113 blood samples from normal volunteers. Several diagnostic models were built with the serum SERS spectra using SVM and principal component analysis (PCA) techniques. The results show that a diagnostic accuracy of 85.5% is acquired with a PCA algorithm, while a diagnostic accuracy of 95.8% is obtained using radial basis function (RBF), PCA-SVM methods. The results prove that a RBF kernel PCA-SVM technique is superior to PCA and conventional SVM (C-SVM) algorithms in classification serum SERS spectra. The study demonstrates that serum SERS, in combination with SVM techniques, has great potential for screening cancerous patients with any solid malignant tumour through a peripheral blood sample.
Ordax, Mónica; Piquer-Salcedo, Jaime E; Santander, Ricardo D; Sabater-Muñoz, Beatriz; Biosca, Elena G; López, María M; Marco-Noales, Ester
2015-01-01
Monitoring the ability of bacterial plant pathogens to survive in insects is required for elucidating unknown aspects of their epidemiology and for designing appropriate control strategies. Erwinia amylovora is a plant pathogenic bacterium that causes fire blight, a devastating disease in apple and pear commercial orchards. Studies on fire blight spread by insects have mainly focused on pollinating agents, such as honeybees. However, the Mediterranean fruit fly (medfly) Ceratitis capitata (Diptera: Tephritidae), one of the most damaging fruit pests worldwide, is also common in pome fruit orchards. The main objective of the study was to investigate whether E. amylovora can survive and be transmitted by the medfly. Our experimental results show: i) E. amylovora can survive for at least 8 days inside the digestive tract of the medfly and until 28 days on its external surface, and ii) medflies are able to transmit the bacteria from inoculated apples to both detached shoots and pear plants, being the pathogen recovered from lesions in both cases. This is the first report on E. amylovora internalization and survival in/on C. capitata, as well as the experimental transmission of the fire blight pathogen by this insect. Our results suggest that medfly can act as a potential vector for E. amylovora, and expand our knowledge on the possible role of these and other insects in its life cycle. PMID:25978369
Cancer is the most common disease to threaten human health. The ability to screen individuals with malignant tumours with only a blood sample would be greatly advantageous to early diagnosis and intervention. This study explores the possibility of discriminating between cancer patients and normal subjects with serum surface-enhanced Raman spectroscopy (SERS) and a support vector machine (SVM) through a peripheral blood sample. A total of 130 blood samples were obtained from patients with liver cancer, colonic cancer, esophageal cancer, nasopharyngeal cancer, gastric cancer, as well as 113 blood samples from normal volunteers. Several diagnostic models were built with the serum SERS spectra using SVM and principal component analysis (PCA) techniques. The results show that a diagnostic accuracy of 85.5% is acquired with a PCA algorithm, while a diagnostic accuracy of 95.8% is obtained using radial basis function (RBF), PCA–SVM methods. The results prove that a RBF kernel PCA–SVM technique is superior to PCA and conventional SVM (C-SVM) algorithms in classification serum SERS spectra. The study demonstrates that serum SERS, in combination with SVM techniques, has great potential for screening cancerous patients with any solid malignant tumour through a peripheral blood sample. (letters)
Ordax, Mónica; Piquer-Salcedo, Jaime E.; Santander, Ricardo D.; Sabater-Muñoz, Beatriz; Biosca, Elena G.; López, María M.; Marco-Noales, Ester
2015-01-01
Monitoring the ability of bacterial plant pathogens to survive in insects is required for elucidating unknown aspects of their epidemiology and for designing appropriate control strategies. Erwinia amylovora is a plant pathogenic bacterium that causes fire blight, a devastating disease in apple and pear commercial orchards. Studies on fire blight spread by insects have mainly focused on pollinating agents, such as honeybees. However, the Mediterranean fruit fly (medfly) Ceratitis capitata (Diptera: Tephritidae), one of the most damaging fruit pests worldwide, is also common in pome fruit orchards. The main objective of the study was to investigate whether E. amylovora can survive and be transmitted by the medfly. Our experimental results show: i) E. amylovora can survive for at least 8 days inside the digestive tract of the medfly and until 28 days on its external surface, and ii) medflies are able to transmit the bacteria from inoculated apples to both detached shoots and pear plants, being the pathogen recovered from lesions in both cases. This is the first report on E. amylovora internalization and survival in/on C. capitata, as well as the experimental transmission of the fire blight pathogen by this insect. Our results suggest that medfly can act as a potential vector for E. amylovora, and expand our knowledge on the possible role of these and other insects in its life cycle. PMID:25978369
Govindarajan, Marimuthu; Rajeswary, Mohan; Veerakumar, Kaliyan; Muthukumaran, Udaiyan; Hoti, S L; Benelli, Giovanni
2016-02-01
Mosquitoes (Diptera: Culicidae) represent a key threat for millions of people worldwide, since they act as vectors for devastating parasites and pathogens. In this scenario, eco-friendly control tools against mosquito vectors are a priority. Green synthesis of silver nanoparticles (AgNP) using a cheap, aqueous leaf extract of Anisomeles indica by reduction of Ag(+) ions from silver nitrate solution has been investigated. Bio-reduced AgNP were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX) and X-ray diffraction analysis (XRD). The acute toxicity of A. indica leaf extract and biosynthesized AgNP was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Both the A. indica leaf extract and AgNP showed dose dependent larvicidal effect against all tested mosquito species. Compared to the leaf aqueous extract, biosynthesized AgNP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with LC50 values of 31.56, 35.21 and 38.08 μg/mL, respectively. Overall, this study firstly shed light on the mosquitocidal potential of A. indica, a potential bioresource for rapid, cheap and effective AgNP synthesis. PMID:26708933
Ita, B. I.; Obong, H. P.; Ehi-Eromosele, C. O.; Edobor-Osoh, A.; Ikeuba, A. I.
2014-11-01
The solutions of the Klein-Gordon equation with equal scalar and vector harmonic oscillator plus inverse quadratic potential for S-waves have been presented using the Nikiforov-Uvarov method. The bound state energy eigenvalues and the corresponding un-normalized eigenfunctions are obtained in terms of the Laguerre polynomials.
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)
Aedes hensilli as a potential vector of Chikungunya and Zika viruses.
Ledermann, Jeremy P; Guillaumot, Laurent; Yug, Lawrence; Saweyog, Steven C; Tided, Mary; Machieng, Paul; Pretrick, Moses; Marfel, Maria; Griggs, Anne; Bel, Martin; Duffy, Mark R; Hancock, W Thane; Ho-Chen, Tai; Powers, Ann M
2014-10-01
An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at select sites around the capital city. The predominant species found on the island was Aedes (Stegomyia) hensilli. No virus isolates were obtained from the adult field material collected, nor did any of the immature mosquitoes that were allowed to emerge to adulthood contain viable virus or nucleic acid. Therefore, laboratory studies of the probable vector, Ae. hensilli, were undertaken to determine the likelihood of this species serving as a vector for Zika virus and other arboviruses. Infection rates of up to 86%, 62%, and 20% and dissemination rates of 23%, 80%, and 17% for Zika, chikungunya, and dengue-2 viruses respectively, were found supporting the possibility that this species served as a vector during the Zika outbreak and that it could play a role in transmitting other medically important arboviruses. PMID:25299181
Aedes hensilli as a Potential Vector of Chikungunya and Zika Viruses
Ledermann, Jeremy P.; Guillaumot, Laurent; Yug, Lawrence; Saweyog, Steven C.; Tided, Mary; Machieng, Paul; Pretrick, Moses; Marfel, Maria; Griggs, Anne; Bel, Martin; Duffy, Mark R.; Hancock, W. Thane; Ho-Chen, Tai; Powers, Ann M.
2014-01-01
An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at select sites around the capital city. The predominant species found on the island was Aedes (Stegomyia) hensilli. No virus isolates were obtained from the adult field material collected, nor did any of the immature mosquitoes that were allowed to emerge to adulthood contain viable virus or nucleic acid. Therefore, laboratory studies of the probable vector, Ae. hensilli, were undertaken to determine the likelihood of this species serving as a vector for Zika virus and other arboviruses. Infection rates of up to 86%, 62%, and 20% and dissemination rates of 23%, 80%, and 17% for Zika, chikungunya, and dengue-2 viruses respectively, were found supporting the possibility that this species served as a vector during the Zika outbreak and that it could play a role in transmitting other medically important arboviruses. PMID:25299181
Maximizing sparse matrix vector product performance in MIMD computers
McLay, R.T.; Kohli, H.S.; Swift, S.L.; Carey, G.F.
1994-12-31
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.
Hornok, Sándor; Meli, Marina L; Perreten, Andrea; Farkas, Róbert; Willi, Barbara; Beugnet, Frederic; Lutz, Hans; Hofmann-Lehmann, Regina
2010-01-01
The aim of the present study was twofold. First, in general, to reveal new aspects of the potential vector role of ixodid ticks and fleas by screening large numbers of specimens with recently developed molecular biological methods. Second, to evaluate the occurrence of vector-borne infectious agents in a geographical context. Altogether 3442 unfed hard ticks (Ixodes ricinus, Dermacentor marginatus, D. reticulatus, Haemaphysalis inermis, H. concinna, H. punctata) and 939 fleas of cats and dogs (Ctenocephalides felis, C. canis, Pulex irritans) were collected in Hungary. DNA was extracted and analyzed in pools for representatives of the orders Rickettsiales and Mycoplasmatales. H. inermis was newly identified as the most important potential vector for Rickettsia helvetica in the study region. A novel Rickettsia genotype (designated 'Candidatus R. hungarica') was also detected in the same tick species, with a maximum of 95.8% gltA gene sequence identity to known rickettsiae. In addition, P. irritans tested positive for Rickettsia sp. RF2125, which has not been previously described in Europe. The human pathogen R. felis and the feline pathogen 'Candidatus Mycoplasma turicensis' were shown for the first time to occur in Central-Eastern Europe. Further novel findings include the presence of Spiroplasma spp. in D. marginatus and fleas. In conclusion, this molecular study extends the geographic range and vector spectrum of several arthropod-borne agents, some of which have zoonotic potential. PMID:19660880
Genetic specificity and potential for local adaptation between dengue viruses and mosquito vectors
Richardson Jason H
2009-07-01
Full Text Available Abstract Background Several observations support the hypothesis that vector-driven selection plays an important role in shaping dengue virus (DENV genetic diversity. Clustering of DENV genetic diversity at a particular location may reflect underlying genetic structure of vector populations, which combined with specific vector genotype × virus genotype (G × G interactions may promote adaptation of viral lineages to local mosquito vector genotypes. Although spatial structure of vector polymorphism at neutral genetic loci is well-documented, existence of G × G interactions between mosquito and virus genotypes has not been formally demonstrated in natural populations. Here we measure G × G interactions in a system representative of a natural situation in Thailand by challenging three isofemale families from field-derived Aedes aegypti with three contemporaneous low-passage isolates of DENV-1. Results Among indices of vector competence examined, the proportion of mosquitoes with a midgut infection, viral RNA concentration in the body, and quantity of virus disseminated to the head/legs (but not the proportion of infected mosquitoes with a disseminated infection strongly depended on the specific combinations of isofemale families and viral isolates, demonstrating significant G × G interactions. Conclusion Evidence for genetic specificity of interactions in our simple experimental design indicates that vector competence of Ae. aegypti for DENV is likely governed to a large extent by G × G interactions in genetically diverse, natural populations. This result challenges the general relevance of conclusions from laboratory systems that consist of a single combination of mosquito and DENV genotypes. Combined with earlier evidence for fine-scale genetic structure of natural Ae. aegypti populations, our finding indicates that the necessary conditions for local DENV adaptation to mosquito vectors are met.
Potential effects of warmer worms and vectors on onchocerciasis transmission in West Africa.
Cheke, Robert A; Basáñez, Maria-Gloria; Perry, Malorie; White, Michael T; Garms, Rolf; Obuobie, Emmanuel; Lamberton, Poppy H L; Young, Stephen; Osei-Atweneboana, Mike Y; Intsiful, Joseph; Shen, Mingwang; Boakye, Daniel A; Wilson, Michael D
2015-04-01
Development times of eggs, larvae and pupae of vectors of onchocerciasis (Simulium spp.) and of Onchocerca volvulus larvae within the adult females of the vectors decrease with increasing temperature. At and above 25°C, the parasite could reach its infective stage in less than 7 days when vectors could transmit after only two gonotrophic cycles. After incorporating exponential functions for vector development into a novel blackfly population model, it was predicted that fly numbers in Liberia and Ghana would peak at air temperatures of 29°C and 34°C, about 3°C and 7°C above current monthly averages, respectively; parous rates of forest flies (Liberia) would peak at 29°C and of savannah flies (Ghana) at 30°C. Small temperature increases (less than 2°C) might lead to changes in geographical distributions of different vector taxa. When the new model was linked to an existing framework for the population dynamics of onchocerciasis in humans and vectors, transmission rates and worm loads were projected to increase with temperature to at least 33°C. By contrast, analyses of field data on forest flies in Liberia and savannah flies in Ghana, in relation to regional climate change predictions, suggested, on the basis of simple regressions, that 13-41% decreases in fly numbers would be expected between the present and before 2040. Further research is needed to reconcile these conflicting conclusions. PMID:25688018
Wang, R.; Demerdash, N. A.
1991-01-01
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.
Brand, Louis
2006-01-01
The use of vectors not only simplifies treatments of differential geometry, mechanics, hydrodynamics, and electrodynamics, but also makes mathematical and physical concepts more tangible and easy to grasp. This text for undergraduates was designed as a short introductory course to give students the tools of vector algebra and calculus, as well as a brief glimpse into these subjects' manifold applications. The applications are developed to the extent that the uses of the potential function, both scalar and vector, are fully illustrated. Moreover, the basic postulates of vector analysis are brou
Castilho, W.M.; Castro, A.S. de [UNESP - Campus de Guaratingueta, SP (Brazil)
2013-07-01
Full text: Relativistic potentials involving mixtures of vector and scalar couplings has received attention in the literature. Heavy meson spectra can be explained by solutions of the Dirac equation with a convenient mixture of vector and scalar potentials. The same can be said about the treatment of the nuclear phenomena describing the influence of the nuclear medium on the nucleons. A few recent works has been devoted to the investigation of the solutions of the Dirac equation by assuming that the vector potential has the same magnitude as the scalar potential whereas other works take a more general mixing. Spin and pseudospin symmetries are SU(2) symmetries of a Dirac equation with vector and scalar potentials realized when the difference between the potentials, or their sum, is a constant. The one-dimensional step potential is of certain interest to model the transition between two structures. In the present work the scattering 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. The pole in the scattering amplitude shows that, when the vector potential and the scalar potential have different magnitudes, the fermion can be trapped in a highly localized region without manifestation of Klein's paradox. That bounded solution does not manifest in a nonrelativistic approach even though one can find E ? mc{sup 2} . Of course this problem neatly reveals that our nonrelativistic preconceptions are mistaken. (author)
Full text: Relativistic potentials involving mixtures of vector and scalar couplings has received attention in the literature. Heavy meson spectra can be explained by solutions of the Dirac equation with a convenient mixture of vector and scalar potentials. The same can be said about the treatment of the nuclear phenomena describing the influence of the nuclear medium on the nucleons. A few recent works has been devoted to the investigation of the solutions of the Dirac equation by assuming that the vector potential has the same magnitude as the scalar potential whereas other works take a more general mixing. Spin and pseudospin symmetries are SU(2) symmetries of a Dirac equation with vector and scalar potentials realized when the difference between the potentials, or their sum, is a constant. The one-dimensional step potential is of certain interest to model the transition between two structures. In the present work the scattering 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. The pole in the scattering amplitude shows that, when the vector potential and the scalar potential have different magnitudes, the fermion can be trapped in a highly localized region without manifestation of Klein's paradox. That bounded solution does not manifest in a nonrelativistic approach even though one can find E ≈ mc2 . Of course this problem neatly reveals that our nonrelativistic preconceptions are mistaken. (author)
Varroa destructor, a potential vector of Israeli Acute Paralysis Virus in honey bees, Apis mellifera
Although the role of the parasitic mite, Varroa destructor, as a vector in transmission of viruses between honey bees is well established, no study has shown that it can similarly transmit Israeli Acute Paralysis Virus (IAPV), a virus that was found to be associated with Colony Collapse Disorder (CC...
Potential for a Second Generation of Emerging Vector Borne Diseases in North America
North America has been dealing with the consequences of the introduction of West Nile virus since it was first discovered in New York City in 1999. Currently there are numerous other vector-borne pathogens that occur in various parts of the world that could be introduced into North America and becom...
RanjanRamasamy
2012-01-01
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...
f(R) gravity on non-linear scales: The post-Friedmann expansion and the vector potential
Thomas, Daniel B; Koyama, Kazuya; Li, Baojiu; Zhao, Gong-Bo
2015-01-01
Many modified gravity theories are under consideration in cosmology as the source of the accelerated expansion of the universe and linear perturbation theory, valid on the largest scales, has been examined in many of these models. However, smaller non-linear scales offer a richer phenomenology with which to constrain modified gravity theories. Here, we consider the Hu-Sawicki form of $f(R)$ gravity and apply the post-Friedmann approach to derive the leading order equations for non-linear scales, i.e. the equations valid in the Newtonian-like regime. We reproduce the standard equations for the scalar field, gravitational slip and the modified Poisson equation in a coherent framework. In addition, we derive the equation for the leading order correction to the Newtonian regime, the vector potential. We measure this vector potential from $f(R)$ N-body simulations at redshift zero and one, for two values of the $f_{R_0}$ parameter. We find that the vector potential at redshift zero in $f(R)$ gravity can be close t...
Analysis of void coefficient in fast spectrum BWR core with Monte Carlo code 'MVP'
An innovative large BWR core concept has been proposed for aiming at fuel breeding as well as negative void reactivity coefficient. The core consists of two types of MOX fuel assemblies. One is a triangular tight lattice bundle 1.6 m in active core height and the other is the same bundle 0.8 m. The ratio of flow area to fuel area of the bundle is set at about 0.5 in order to increase breeding ratio. A neutron-streaming channel that consists of a cavity-can containing helium gas and a flow gap between the cavity-can and the channel box is located above each short bundle. It will decrease void reactivity coefficient by enhancing neutron leakage from the core when the void fraction is increased in the flow gap. A core composed of tight lattice bundles provides a much harder neutron spectrum than that of conventional BWRs but a slightly softer one than that of typical FBRs. The cavity-can and the flow gap will cause a steep gradient of neutron flux. The neutronics for such a complicated core structure could not be properly analyzed by conventional analysis methods. In particular, the analysis of void reactivity coefficient requires a sophisticated method because it deals with a small change in core composition. In the analysis of the void reactivity coefficient, we adopted a three-dimensional Monte Carlo code 'MVP', which has been developed by JAERI and has many advantages such as an easy input form for lattice structures, a short run time and a continuous neutron energy method. The continuous neutron energy method is important for the analysis of this core because fission reactions occur mainly in the resonance energy region, where the evaluation of accurate cross sections is difficult with conventional methods. The library used is JENDL-3.2. The multi-layer structure of lattices is also essential for the analysis because its hard spectrum and relatively long neutron mean free path require a modeling for the full core with a lot of bundles. The analysis indicates that the void reactivity coefficient depends on flow gap width of the streaming channel and has a minimum value of about -2x10-4 Δk/k/%void, which is evaluated within an accuracy of about +-0.6x10-4 Δk/k/%void. The CPU time for one million histories calculating the full core model was about five hours with a PENTIUM-2 processor personal computer. (author)
Any J-state solution of the DKP equation for a vector deformed Woods-Saxon potential
Hamzavi, Majid
2012-01-01
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.
Enhancing the Clinical Potential of AAV Vectors by Capsid Engineering to Evade Pre-Existing Immunity
Bartel, Melissa; Schaffer, David; Büning, Hildegard
2011-01-01
Vectors based on adeno-associated viruses (AAV) have shown considerable promise in both preclinical models and increasingly in clinical trials. However, one formidable challenge is pre-existing immunity due to widespread exposure to numerous AAV variants and serotypes within the human population, which affect efficacy of clinical trials due to the accompanying high levels of anti-capsid neutralizing antibodies. Transient immunosuppression has promise in mitigating cellular and humoral respons...
Enhancing the clinical potential of AAV vectors by capsid engineering to evade pre-existing immunity
DavidSchaffer; HildegardBüning
2011-01-01
Vectors based on adeno-associated viruses have shown considerable promise in both preclinical models and increasingly in clinical trials. However, one formidable challenge is pre-existing immunity due to widespread exposure to numerous AAV variants and serotypes within the human population, which affect efficacy of clinical trials due to the accompanying high levels of anti-capsid neutralizing antibodies. Transient immunosuppression has promise in mitigating cellular and humoral responses ind...
State, Luminita; Catalina COCIANU; Doina FUSARU
2010-01-01
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 SVMâ€™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 vi...
Fall, Assane Gueye; Diaïté, Amadou; Seck, Momar Talla; Bouyer, Jérémy; Lefrançois, Thierry; Vachiéry, Nathalie; Aprelon, Rosalie; Faye, Ousmane; Konaté, Lassana; Lancelot, Renaud
2013-01-01
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. PMID:24084679
Vitek, Christopher J; Gutierrez, Joann A; Dirrigl, Frank J
2014-09-01
Dengue virus is an emerging disease of concern in the Americas. Recent outbreaks in Florida highlight the potential for the virus to return to the United States. The Lower Rio Grande Valley region of Texas directly borders Mexico, and has experienced dengue transmission in the past concurrent with outbreaks in Mexico along the border region. We examined the potential for dengue virus transmission by examining the vectors in the region, as well as assessing human behavior. We further hypothesized that dengue vector abundance would influence human behavior. Two dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), were found in the region in high abundance. More mosquitoes were collected in rural sites and sites with high vegetation. Of the two species, only Ae. albopictus showed any significant habitat preferences, being more common in rural site. While there was no correlation between human behavior and mosquito abundance, the results support a significant correlation between knowledge of mosquitoes and dengue virus and behavioral practices that might reduce risk of disease transmission. Dengue risk may be higher in certain regions of the Lower Rio Grande Valley based on socioeconomic conditions, specifically in economically poor regions such as the undeveloped colonias found in the region. Because of the proximity of this region to an area with endemic dengue, continued surveillance and risk assessment is suggested. PMID:25276932
Mara Guadalupe Vzquez-Martnez
2014-12-01
Full Text Available Introduction The use of entomopathogenic fungi to control disease vectors has become relevant because traditional chemical control methods have caused damage to the environment and led to the development of resistance among vectors. Thus, this study assessed the pathogenicity of entomopathogenic fungi in Triatoma dimidiata. Methods Preparations of 108 conidia/ml of Gliocladium virens, Talaromyces flavus, Beauveria bassiana and Metarhizium anisopliae were applied topically on T. dimidiata nymphs and adults. Controls were treated with the 0.0001% Tween-80 vehicle. Mortality was evaluated and recorded daily for 30 days. The concentration required to kill 50% of T. dimidiata (LC50 was then calculated for the most pathogenic isolate. Results Pathogenicity in adults was similar among B. bassiana, G. virens and T. flavus (p>0.05 and differed from that in triatomine nymphs (p=0.009. The most entomopathogenic strains in adult triatomines were B. bassiana and G. virens, which both caused 100% mortality. In nymphs, the most entomopathogenic strain was B. bassiana, followed by G. virens. The native strain with the highest pathogenicity was G. virens, for which the LC50 for T. dimidiata nymphs was 1.98 x108 conidia/ml at 13 days after inoculation. Conclusions Beauveria bassiana and G. virens showed entomopathogenic potential in T. dimidiata nymphs and adults. However, the native G. virens strain presents a higher probability of success in the field, and G. virens should thus be considered a potential candidate for the biological control of triatomine Chagas disease vectors.
Diaz-Perez Alfonso
2011-05-01
Full Text Available 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 in Nuevo Leon. There is potential for WNV to be introduced into Mexico City by various means including infected mosquitoes on airplanes, migrating birds, ground transportation and infected humans. Little is known of the geographic distribution of Culex pipiens complex mosquitoes and hybrids in Mexico City. Culex pipiens pipiens preferentially feed on avian hosts; Culex pipiens quinquefasciatus have historically been considered to prefer mammalian hosts; and hybrids of these two species could theoretically serve as bridge vectors to transmit WNV from avian hosts to humans and other mammalian hosts. In order to address the potential of WNV being introduced into Mexico City, we have determined the identity and spatial distribution of Culex pipiens complex mosquitoes and their hybrids. Results Mosquito larvae collected from 103 sites throughout Mexico City during 2004-2005 were identified as Culex, Culiseta or Ochlerotatus by morphological analysis. Within the genus Culex, specimens were further identified as Culex tarsalis or as belonging to the Culex pipiens complex. Members of the Culex pipiens complex were separated by measuring the ratio of the dorsal and ventral arms (DV/D ratio of the male genitalia and also by using diagnostic primers designed for the Ace.2 gene. Culex pipiens quinquefasciatus was the most abundant form collected. Conclusions Important WNV vectors species, Cx. p. pipiens, Cx. p. quinquefasciatus and Cx. tarsalis, are all present in Mexico City. Hybrids of Cx. p. pipiens and Cx. p. quinquefasciatus were also collected and identified. The presence and abundance of these WNV competent vectors is a cause for concern. Understanding the distribution of these vectors can help improve viral surveillance activities and mosquito control efforts in Mexico City.
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
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)
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)
Aggoun, L.; Benamira, F.; Guechi, L.; Sadoun, M. A.
2016-04-01
The Green's function associated with a Klein-Gordon particle moving in a D-dimensional space under the action of vector plus scalar q-deformed Hulthén potentials is constructed by path integration for {q ≥ 1} and {1/α ln q wave functions, for a state of orbital quantum number {l ≥ 0}, are obtained. Eventually, the vector q-deformed Hulthén potential and the Coulomb potentials in D dimensions are considered as special cases.
The masses of vector mesons in holographic QCD at finite chiral chemical potential
S.S. Afonin
2015-05-01
Full Text Available Central heavy-ion collisions may induce sizeable fluctuations of the topological charge. This effect is expected to distort the dispersion relation for the hadron masses. We construct a general setup for a compact description of this phenomenon in the framework of bottom-up holographic approach to QCD. A couple of soft wall holographic models are proposed for the vector mesons. The states having different circular polarizations are shown to have different effective mass. The requirement of stability imposes strong constraints on the possible choice of models.
Virtual screening of potential bioactive substances using the support vector machine approach
Byvatov, Evgeny
2006-01-01
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 Wirkstoffkandidaten. In de...
The masses of vector mesons in holographic QCD at finite chiral chemical potential
Afonin, S.S., E-mail: afonin24@mail.ru [V.A. Fock Department of Theoretical Physics, Saint-Petersburg State University, 1 ul. Ulyanovskaya, 198504 St. Petersburg (Russian Federation); Andrianov, A.A. [V.A. Fock Department of Theoretical Physics, Saint-Petersburg State University, 1 ul. Ulyanovskaya, 198504 St. Petersburg (Russian Federation); Espriu, D. [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Marti Franquès 1, 08028 Barcelona (Spain)
2015-05-18
Central heavy-ion collisions may induce sizeable fluctuations of the topological charge. This effect is expected to distort the dispersion relation for the hadron masses. We construct a general setup for a compact description of this phenomenon in the framework of bottom-up holographic approach to QCD. A couple of soft wall holographic models are proposed for the vector mesons. The states having different circular polarizations are shown to have different effective mass. The requirement of stability imposes strong constraints on the possible choice of models.
The masses of vector mesons in holographic QCD at finite chiral chemical potential
Afonin, S. S.; Andrianov, A. A.; Espriu, D.
2015-05-01
Central heavy-ion collisions may induce sizeable fluctuations of the topological charge. This effect is expected to distort the dispersion relation for the hadron masses. We construct a general setup for a compact description of this phenomenon in the framework of bottom-up holographic approach to QCD. A couple of soft wall holographic models are proposed for the vector mesons. The states having different circular polarizations are shown to have different effective mass. The requirement of stability imposes strong constraints on the possible choice of models.
The masses of vector mesons in holographic QCD at finite chiral chemical potential
Afonin, S S; Espriu, D
2015-01-01
Central heavy-ion collisions may induce sizeable fluctuations of the topological charge. This effect is expected to distort the dispersion relation for the hadron masses. We construct a general setup for a compact description of this phenomenon in the framework of bottom-up holographic approach to QCD. A couple of soft wall holographic models are proposed for the vector mesons. The states having different circular polarizations are shown to have different effective mass. The requirement of stability imposes strong constraints on the possible choice of models.
The masses of vector mesons in holographic QCD at finite chiral chemical potential
Central heavy-ion collisions may induce sizeable fluctuations of the topological charge. This effect is expected to distort the dispersion relation for the hadron masses. We construct a general setup for a compact description of this phenomenon in the framework of bottom-up holographic approach to QCD. A couple of soft wall holographic models are proposed for the vector mesons. The states having different circular polarizations are shown to have different effective mass. The requirement of stability imposes strong constraints on the possible choice of models
Labarthe Norma
1998-01-01
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.
Apperson, Charles S; Hassan, Hassan K; Harrison, Bruce A; Savage, Harry M; Aspen, Stephen E; Farajollahi, Ary; Crans, Wayne; Daniels, Thomas J; Falco, Richard C; Benedict, Mark; Anderson, Michael; McMillen, Larry; Unnasch, Thomas R
2004-01-01
An important variable in determining the vectorial capacity of mosquito species for arthropod-borne infections is the degree of contact of the vector and the vertebrate reservoir. This parameter can be estimated by examining the host-feeding habits of vectors. Serological and polymerase chain reaction based methods have been used to study the host-feedings patterns of 21 mosquito species from New York, New Jersey, and Tennessee, 19 of which previously have been found infected with West Nile virus. Mammalophilic mosquito species in New Jersey and New York fed primarily upon white-tailed deer, while those from Memphis, Tennessee, fed mainly upon domestic dogs. A total of 24 different avian host species were detected among the avian-derived blood meals. American Robin, Northern Cardinal, Northern Mockingbird, Tufted Titmouse, and Brown-headed Cowbird were common avian hosts, while blood meals derived from the American Crow were relatively rare. Although the majority of common host species were potentially among the most abundant birds at each location, the proportion of blood meals from the most commonly fed upon avian species was greater than was predicted based upon the likely abundance of these species alone. These findings suggest that vector species for West Nile virus may preferentially feed upon certain avian hosts. PMID:15018775
Mullen, G R; Hayes, M E; Nusbaum, K E
1985-01-01
Fourteen Culicoides spp. were collected on Holstein cattle in Alabama: C. arboricola, C. bickleyi, C. biguttatus, C. debilipalpis, C. guttipennis, C. haematopotus, C. obsoletus, C. paraensis, C. piliferus, C. sanguisuga, C. spinosus, C. stellifer, C. variipennis and C. venustus. Six Culicoides spp. were collected directly from white-tailed deer (Odocoileus virginianus): C. debilipalpis, C. niger, C. obsoletus, C. paraensis, C. sanguisuga and C. stellifer. Based on their host-feeding behavior, abundance and seasonal occurrence, the following 4 species warrant particular attention as potential vectors of bluetongue (BT) and epizootic hemorrhagic disease (EHD) viruses in the southeastern US: C. debilipalpis, C. obsoletus, C. paraensis and C. stellifer. PMID:2989854
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
Santos Luciana Urbano dos
1997-01-01
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.
E. Howe
2003-01-01
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.
Tanja Drobnjaković
2010-01-01
Full Text Available The first molecular analysis of samples collected in southern Bačka (Serbia confirmed the presence of aster yellows (16SrI and stolbur phytoplasmas (16SrXII in insects belonging to the family Cicadellidae, as well as in carrot plants where the insects were collected. A correct identification of the phytoplasmas and their vectors is essential to arrange effective control strategies to prevent diseases associated with phytoplasmas from spreading to carrots and other vegetable crops. In order to enhance knowledgeabout insect vectors of aster yellows and stolbur phytoplasmas in Serbia, Cicadellidae and Cixiidae (Homoptera Auchenorrhyncha, the most common vectors of these phytoplasmas,were monitored in southern Bačka during 2008. Adults leaf- and planthoppers were collected and identified at species level using standard entomological methods,and tested for phytoplasma presence by means of PCR/RFLP. A total of 13 insect species of Cicadellidae were identified, as follows: a three species of the subfamily Agallinae: Anaceratagallia ribauti (Ossiannilsson, Anaceratagallia venosa (Fourcroy,and Anaceratagallia laevis (Ribaut; b seven species of the subfamily Deltocephalinae: Psammotettix confinis (Dahlbom, Psammotettix striatus (Linnaues Psammottettix alienus (Dahlbom, Macrosteles sexnotatus (Fallén, Ophiola decumana (Kontkanen,Errastunus ocellaris Fallén, and Scaphoideus titanus Ball; c three species of the subfamily Typhlocibinae: Eupteryx atropunctata (Goeze, Eupteryx mellissae Curtis, Zyginidia pullula (Boheman. Female specimens of the genus Euscelis (Deltocephalinae were also collected, as well as one species of Reptalus quinquecostatus (Dufour of the family Cixiidae. Stolbur phytoplasmas were detected in A. laevis, A. ribauti, A. venosa, P. striatus, P. confinis and P. alienus. The species: A. laevis, O. decumana, and P. confinis were AY-infected (subgroup 16SrI-A, while subgroup 16SrI-C was found only in one specimen of P. confinis. Since some aster yellows- and stolbur-infected species of the genera Psammotettix and Anaceratagallia (especially P. confinis and A. laevis were regularly and commonly found in the infected carrot fields during the whole vegetative period, they could play a significant role in transmitting and spreading these pathogens in natural environment.
Jiang, Chaowei
2013-01-01
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...
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 + λr2, 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)
Global warming and the potential spread of vector-borne diseases
Patz, J. [Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (United States). Dept. of Microbiology and Immunology
1996-12-31
Climatic factors influence many vector-borne infectious diseases, in addition to demographic, biological, and ecological determinants. The United Nation`s Intergovernmental Panel on Climate Change (IPCC) estimates an unprecedented global rise of 2.0 C by the year 2100. Of major concern is that these changes can affect the spread of many serious infectious diseases, including malaria and dengue fever. Global warming would directly affect disease transmission by shifting the mosquito`s geographic range, increasing reproductive and biting rates, and shortening pathogen incubation period. Human migration and damage to health infrastructures from the projected increase in climate variability and sea level rise could indirectly contribute to disease transmission. A review of this literature, as well as preliminary data from ongoing studies will be presented.
Wankhar, Wankupar; Srinivasan, Sakthivel; Rathinasamy, Sheeladevi
2015-01-01
This study evaluates the larvicidal activity of Scoparia dulcis aqueous extract against dengue vector and determines its major chemical components. The extract was tested at various concentrations ranging from 0.1 to 2 mg/mL against Aedes aegypti larvae. The extracts displayed significant larvicidal efficacy against Ae. aegypt species after 24 h exposure revealing LC50 of 3.3835 (mg/mL) and LC90 of 5.7578 (mg/mL). Finger printing profile carried out by CAMAG automatic TLC sample applicator programmed through WIN CATS software revealed peaks with different Rf values for three different volumes injected: 16, 15 and 18 peaks were spotted for 3, 6 and 9 ?L, respectively. Ascending order of Rf values was also ascertained for each peak recorded. This study clearly signifies that S. dulcis extract contains numerous compounds that are known to have larvicidal properties which clearly substantiates its efficacy on Ae. aegypti larvae. PMID:25573588
Salazar-Ramírez, M; Mota, R D; Granados, V D
2011-01-01
We study the Dirac equation with Coulomb-type vector and scalar potentials in D + 1 dimensions from an su(1, 1) algebraic approach. The generators of this algebra are constructed by using the Schr\\"odinger factorization. The theory of unitary representations for the su(1, 1) Lie algebra allows us to obtain the energy spectrum and the supersymmetric ground state. For the cases where there exists either scalar or vector potential our results are reduced to those obtained by analytical techniques.
SWAT3.1 - the integrated burnup code system driving continuous energy Monte Carlo codes MVP and MCNP
Integrated burnup calculation code system SWAT is a system that combines neutronics calculation code SRAC,which is widely used in Japan, and point burnup calculation code ORIGEN2. It has been used to evaluate the composition of the uranium, plutonium, minor actinides and the fission products in the spent nuclear fuel. Based on this idea, the integrated burnup calculation code system SWAT3.1 was developed by combining the continuous energy Monte Carlo code MVP and MCNP, and ORIGEN2. This enables us to treat the arbitrary fuel geometry and to generate the effective cross section data to be used in the burnup calculation with few approximations. This report describes the outline, input data instruction and several examples of the calculation. (author)
RanjanRamasamy
2012-06-01
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, 0.530 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
Schaffner Francis
2012-11-01
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.
Doreswamy; Vastrad, Chanabasayya M.
2013-01-01
A new smoothing method for solving ? -support vector regression (?-SVR), tolerating a small error in fitting a given data sets nonlinearly is proposed in this study. Which is a smooth unconstrained optimization reformulation of the traditional linear programming associated with a ?-insensitive support vector regression. We term this redeveloped problem as ?-smooth support vector regression (?-SSVR). The performance and predictive ability of ?-SSVR are investigated and compared with other meth...
Dieng, Hamady; Hassan, Rahimah Binti; Hassan, Ahmad Abu; Ghani, Idris Abd; Abang, Fatimah Bt; Satho, Tomomitsu; Miake, Fumio; Ahmad, Hamdan; Fukumitsu, Yuki; Hashim, Nur Aida; Zuharah, Wan Fatma; Kassim, Nur Faeza Abu; Majid, Abdul Hafiz Ab; Selvarajoo, Rekha; Nolasco-Hipolito, Cirilo; Ajibola, Olaide Olawunmi; Tuen, Andrew Alek
2015-05-01
Even with continuous vector control, dengue is still a growing threat to public health in Southeast Asia. Main causes comprise difficulties in identifying productive breeding sites and inappropriate targeted chemical interventions. In this region, rural families keep live birds in backyards and dengue mosquitoes have been reported in containers in the cages. To focus on this particular breeding site, we examined the capacity of bird fecal matter (BFM) from the spotted dove, to support Aedes albopictus larval growth. The impact of BFM larval uptake on some adult fitness traits influencing vectorial capacity was also investigated. In serial bioassays involving a high and low larval density (HD and LD), BFM and larval standard food (LSF) affected differently larval development. At HD, development was longer in the BFM environment. There were no appreciable mortality differences between the two treatments, which resulted in similar pupation and adult emergence successes. BFM treatment produced a better gender balance. There were comparable levels of blood uptake and egg production in BFM and LSF females at LD; that was not the case for the HD one, which resulted in bigger adults. BFM and LSF females displayed equivalent lifespans; in males, this parameter was shorter in those derived from the BFM/LD treatment. Taken together these results suggest that bird defecations successfully support the development of Ae. albopictus. Due to their cryptic aspects, containers used to supply water to encaged birds may not have been targeted by chemical interventions. PMID:25617636
Breeding Sites of Aedes aegypti: Potential Dengue Vectors in Dire Dawa, East Ethiopia
Getachew, Dejene; Tekie, Habte; Gebre-Michael, Teshome; Balkew, Meshesha; Mesfin, Akalu
2015-01-01
Background and Objectives. Entomological survey was carried out from May-June to September-October 2014 to investigate the presence of dengue vectors in discarded tires and artificial water containers in houses and peridomestic areas. Methods. A cross-sectional immature stage survey was done indoors and outdoors in 301 houses. Mosquito larval sampling was conducted using pipette or dipper depending on container types. Larvae were identified morphologically and larval indices were also calculated. Results. A total of 750 containers were inspected, and of these 405 were positive for mosquito larvae. A total of 1,873 larvae were collected and morphologically identified as Aedes aegypti (n = 1580: 84.4%) and Culex (n = 293: 15.6%). The larval indices, house index, container index, and breteau index, varied from 33.3 to 86.2, from 23.2 to 73.9, and from 56.5 to 188.9, respectively. Conclusion. Aedes aegypti is breeding in a wide range of artificial containers. To control these mosquitoes, the integration of different methods should be taken into consideration. PMID:26435712
Cano-Garrido, Olivia; Seras-Franzoso, Joaquin; Garcia-Fruitós, Elena
2015-01-01
Lactic acid bacteria (LAB) have a long history of safe exploitation by humans, being used for centuries in food production and preservation and as probiotic agents to promote human health. Interestingly, some species of these Gram-positive bacteria, which are generally recognized as safe organisms by the US Food and Drug Administration (FDA), are able to survive through the gastrointestinal tract (GIT), being capable to reach and colonize the intestine, where they play an important role. Besides, during the last decades, an important effort has been done for the development of tools to use LAB as microbial cell factories for the production of proteins of interest. Given the need to develop effective strategies for the delivery of prophylactic and therapeutic molecules, LAB have appeared as an appealing option for the oral, intranasal and vaginal delivery of such molecules. So far, these genetically modified organisms have been successfully used as vehicles for delivering functional proteins to mucosal tissues in the treatment of many different pathologies including GIT related pathologies, diabetes, cancer and viral infections, among others. Interestingly, the administration of such microorganisms would suppose a significant decrease in the production cost of the treatments agents since being live organisms, such vectors would be able to autonomously amplify and produce and deliver the protein of interest. In this context, this review aims to provide an overview of the use of LAB engineered as a promising alternative as well as a safety delivery platform of recombinant proteins for the treatment of a wide range of diseases. PMID:26377321
We investigate the asymptotic behaviour of a family of multiple orthogonal polynomials that is naturally linked with the normal matrix model with a monomial potential of arbitrary degree d + 1. The polynomials that we investigate are multiple orthogonal with respect to a system of d analytic weights defined on a symmetric (d + 1)-star centred at the origin. In the first part we analyse in detail a vector equilibrium problem involving a system of d interacting measures (μ1, …, μd) supported on star-like sets in the plane. We show that in the subcritical regime, the first component μ1∗ of the solution to this problem is the asymptotic zero distribution of the multiple orthogonal polynomials. It also characterizes the domain where the eigenvalues in the normal matrix model accumulate, in the sense that the Schwarz function associated with the boundary of this domain can be expressed explicitly in terms of μ1∗. The second part of the paper is devoted to the asymptotic analysis of the multiple orthogonal polynomials. The asymptotic results are obtained again in the subcritical regime, and they follow from the Deift/Zhou steepest descent analysis of a Riemann–Hilbert problem of size (d + 1) × (d + 1). The vector equilibrium problem and the Riemann–Hilbert problem that we investigate are generalizations of those studied recently by Bleher–Kuijlaars in the case d = 2. (paper)
Hongwei Li, Jin Zhong Li, Debra D. Pittman, Andy Amalfitano, Gerald R. Hankins, Gregory A. Helm
2006-01-01
Full Text Available Osteogenic potentials of some recombinant human bone morphogenetic protein (BMP first-generation adenoviral vectors (ADhBMPs are significantly limited in immunocompetent animals. It is unclear what role expression of viral proteins and foreign proteins transduced by adenoviral vectors play in the host immune response and in ectopic bone formation. In this study two sets of experiments were designed and performed. First, rat BMP6 cDNA were amplified, sequenced, and recombined in first-generation adenoviral vector (ADrBMP6. A comparison of human and rat BMP6 adenoviral vectors demonstrated identical osteogenic activities in both immunodeficient and immunocompetent rats. Second, the activities of recombinant human BMP6 in E1- (ADhBMP6 and [E1-,E2b-] ( [E1-,E2b-]ADGFP&hBMP6, and [E1-,E2b-]ADhBMP6 adenoviral vectors were compared in both in vitro and in vivo models. Similar activities of these two generations of BMP adenoviral vectors were found in all models. These results indicate that the amount of viral gene expression and the source of the BMP cDNA are not major factors in the interruption of osteogenic potentials of recombinant BMP6 adenoviral vectors in immunocompetent animals.
Due to its geographical isolation and climatic constraints, Alaska is considered relatively free of diseases and insect pests; therefore, growers in the state are exploring the potential of producing seed potato for export. However, the biology of agricultural insect pests in the circumpolar region ...
Fuller Douglas O; Parenti Michael S; Hassan Ali N; Beier John C
2012-01-01
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 the...
Diarra, Maryam; Fall, Moussa; Fall, Assane G.; Diop, Aliou; Seck, Momar; Garros, Claire; Balenghien, Thomas; Allène, Xavier; Rakotoarivony, Ignace; Lancelot, Renaud; Mall, Iba; Bakhoum, Mame; Dosum, Ange; Ndao, Massouka; Bouyer, Jérémy
2014-01-01
Background: The African horse sickness epizootic in Senegal in 2007 caused considerable mortality in the equine population and hence major economic losses. The vectors involved in the transmission of this arbovirus have never been studied specifically in Senegal. This first study of the spatial and temporal dynamics of the Culicoides (Diptera: Ceratopogonidae) species, potential vectors of African horse sickness in Senegal, was conducted at five sites (Mbao, Parc Hann, Niague, Pout and Thies)...
Li, Hongwei; Li, Jin Zhong; D. Pittman, Debra; Amalfitano, Andy; Hankins, Gerald R; Helm, Gregory A.
2006-01-01
Osteogenic potentials of some recombinant human bone morphogenetic protein (BMP) first-generation adenoviral vectors (ADhBMPs) are significantly limited in immunocompetent animals. It is unclear what role expression of viral proteins and foreign proteins transduced by adenoviral vectors play in the host immune response and in ectopic bone formation. In this study two sets of experiments were designed and performed. First, rat BMP6 cDNA were amplified, sequenced, and recombined in first-genera...
Daeschlein, Georg; Reese, Kevin; Napp, Matthias; Spitzmueller, Romy; Hinz, Peter; Juenger, Michael; Kramer, Axel
2015-01-01
Background and aims: Debridement therapy with sterile bred larvae in non-healing wounds is a widely accepted safe and efficient treatment modality. However, during application in the contaminated wound bed microbial contamination with potential microbial pathogen spread after escape from the wound or after unreliable disposal procedure may happen, particularly in the case of not using bio-bags. The aims of this work were first to investigate the release of ingested bacteria into the environme...
Chintoan-Uta, C.; Morgan, E R; Skuce, P. J.; Coles, G.C.
2014-01-01
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 componen...
Drifting plastic debris as a potential vector for dispersing Harmful Algal Bloom (HAB) species
Masó, Mercedes; GARCÉS Esther; Pagès, Francesc; Camp, Jordi
2003-01-01
Macroscopic observations of floating plastic debris collected at several places along the Catalan coast (northwestern Mediterranean) showed conspicuous green-yellow patches adhered to them. The microscopic examination of these patches showed that they were constituted mainly of benthic diatoms and small flagellates (< 20 μm). Potential harmful dinoflagellates such as Ostreopsis sp. and Coalia sp., resting cysts of unidentified dinoflagellates and both temporary cysts and vegetative cells of A...
Hanafi-Bojd, Ahmad Ali; Yaghoobi-Ershadi, Mohammad Reza; Haghdoost, Ali Akbar; Akhavan, Amir Ahmad; Rassi, Yavar; Karimi, Ameneh; Charrahy, Zabihollah
2015-07-01
Cutaneous leishmaniasis (CL) is now the main vector-borne disease in Iran. Two forms of the disease exist in the country, transmitted by Phlebotomus papatasi and Phlebotomus sergenti s.l. Modeling distribution of the vector species is beneficial for preparedness and planning to interrupt the transmission cycle. Data on sand fly distribution during 1990-2013 were used to predict the niche suitability. MaxEnt algorithm model was used for prediction using bioclimatic and environmental variables (precipitation, temperature, altitude, slope, and aspect). Regularized training, area under the curve, and unregularized training gains were 0.916, 0.915, and 1.503, respectively, for Ph. papatasi. These values were calculated as 0.987, 0.923, and 1.588 for Ph. sergenti s.l. The jackknife test showed that the environmental variable with the highest gain when used in isolation has the mean temperature of the wettest quarter for both species, while slope decreases the gain the most when it is omitted from the model. Classification of probability of presence for two studied species was performed on five classes using equal intervals in ArcGIS. More than 60% probability of presence was considered as areas with high potential of CL transmission. These areas include arid and semiarid climates, mainly located in central part of the country. Mean of altitude, annual precipitation, and temperature in these areas were calculated 990 and 1,235?m, 273 and 226?mm, and 17.5 and 16.4C for Ph. papatasi and Ph. sergenti s.l., respectively. These findings can be used in the prediction of CL transmission potential, as well as for planning the disease control interventions. PMID:26335462
W. Lobato Paraense
1989-09-01
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 So 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 planorbdeo semelhante Biomphalaria straminea (species inquirenda de Espinillar, localidade prxima a Salto (Uruguay, na rea da represa de Salto Grande, cada exemplar sendo exposto individualmente a 5 miracdios de Schistosom mansoni (cepas SJ2 e BH2. De 130 exemplares expostos cepa SJ2, originalmente infectante para B. tenagophila, 30 se infectaram (23%. O perodo pr-patente (pr-cercariano variou de 35 a 65 dias. A emisso de cercrias foi irregular, no seguindo padro definido, variando de 138 a 76.075 por exemplar (mdia diria de 4,3 a 447,5 e teminando com a morte. Trs exemplares que morreram, sem ter eliminado cercrias, no 69 (2 e no 80 dia aps exposio aos miracdios, tinham esporocistos secundrios em desenvolvimento nos tecidos, justificando a expectativa de um perodo pr-patente mais longo nestes casos. Em um grupo-controle de 120 B. tenagophila, exposta cepa SJ2, 40 se infectaram, no diferindo significativamente seu ndice de infeco (33.3% daquele do planorbdeo de Espinillar (X [ao quadrado]=3.26. De 100 exemplares de Espinillar expostos a miracdios da cepa BH2, originalmente infectante para B. glabrata, nenhum produziu cercrias. Um esporocisto primrio formou-se em um tentculo em 4 exemplares, desaparecendo entre 15 e 25 dias aps a exposio. Dois outros exemplares morreram com esporocistos imaturos e muito delgados nos tecidos (4 em um caso e 3 no outro, no 36 e 54 dias. Em um grupo-controle de 100 B. glabrata exposto cepa BH2, 94 emitiram cercrias (94% e 6 permaneceram negativos. De acordo com o ndice TCP/100 de Frandsen (1979a,b, a combinao Biomphalaria de Espinillar-S. mansoni SJ2 constitui uma relao vetor-parasito "compatvel". Tendo em vista que a xistosomose transmitida pela B. tenagophila prevalente nos estados do Rio de Janeiro e So Paulo e recentemente propagou-se para o sul at o estado de Santa Catarina, e a dist
Daeschlein, Georg
2015-05-01
Full Text Available Background and aims: Debridement therapy with sterile bred larvae in non-healing wounds is a widely accepted safe and efficient treatment modality. However, during application in the contaminated wound bed microbial contamination with potential microbial pathogen spread after escape from the wound or after unreliable disposal procedure may happen, particularly in the case of not using bio-bags. The aims of this work were first to investigate the release of ingested bacteria into the environment by maggots and second to examine the common practice of freezing the maggots after use and/or disposal in trash-bags. Potential methods for hygienic safe disposal of used maggots should be deduced.Methods: First, Maggots were contaminated with by allowing them to crawl over an agar surface completely covered with bacterial growth over 24 h at 37°C. After external disinfection maggots were transferred onto sterile Columbia agar plates and shedding of was visualized. Second, maggots were frozen at –20°C for 1, 2, 5, 10, 30, and 60 min. After exposure, the larvae were transferred onto Columbia blood agar with consecutive incubation at 37°C over 48 h. The larvae were analyzed visually for mobility and eating activities. The frozen bodies of dead larvae were examined for viable bacteria.Results: We could demonstrate that maggots release formerly ingested pathogens (. Freezing at –20°C for at least 60 min was able to kill all maggots, however the contaminant bacteria inside could survive.Conclusion: Since freezing is apparently able to kill maggots but not to reliabely inactivate the ingested bacterial pathogens, we recommend the disposal of free-range larvae in screw cap vials after use to achieve full hygienic control.
Multiple Pathogens Including Potential New Species in Tick Vectors in Côte d’Ivoire
Ehounoud, Cyrille Bilé; Yao, Kouassi Patrick; Dahmani, Mustapha; Achi, Yaba Louise; Amanzougaghene, Nadia; Kacou N’Douba, Adèle; N’Guessan, Jean David; Raoult, Didier; Fenollar, Florence; Mediannikov, Oleg
2016-01-01
Background Our study aimed to assess the presence of different pathogens in ticks collected in two regions in Côte d’Ivoire. Methodology/Principal Findings Real-time PCR and standard PCR assays coupled to sequencing were used. Three hundred and seventy eight (378) ticks (170 Amblyomma variegatum, 161 Rhipicepalus microplus, 3 Rhipicephalus senegalensis, 27 Hyalomma truncatum, 16 Hyalomma marginatum rufipes, and 1 Hyalomma impressum) were identified and analyzed. We identified as pathogenic bacteria, Rickettsia africae in Am. variegatum (90%), Rh. microplus (10%) and Hyalomma spp. (9%), Rickettsia aeschlimannii in Hyalomma spp. (23%), Rickettsia massiliae in Rh. senegalensis (33%) as well as Coxiella burnetii in 0.2%, Borrelia sp. in 0.2%, Anaplasma centrale in 0.2%, Anaplasma marginale in 0.5%, and Ehrlichia ruminantium in 0.5% of all ticks. Potential new species of Borrelia, Anaplasma, and Wolbachia were detected. Candidatus Borrelia africana and Candidatus Borrelia ivorensis (detected in three ticks) are phylogenetically distant from both the relapsing fever group and Lyme disease group borreliae; both were detected in Am. variegatum. Four new genotypes of bacteria from the Anaplasmataceae family were identified, namely Candidatus Anaplasma ivorensis (detected in three ticks), Candidatus Ehrlichia urmitei (in nine ticks), Candidatus Ehrlichia rustica (in four ticks), and Candidatus Wolbachia ivorensis (in one tick). Conclusions/Significance For the first time, we demonstrate the presence of different pathogens such as R. aeschlimannii, C. burnetii, Borrelia sp., A. centrale, A. marginale, and E. ruminantium in ticks in Côte d’Ivoire as well as potential new species of unknown pathogenicity. PMID:26771308
Szaflarski, Witold; Sujka-Kordowska, Patrycja; Pula, Bartosz; Jaszczyńska-Nowinka, Karolina; Andrzejewska, Małgorzata; Zawierucha, Piotr; Dziegiel, Piotr; Nowicki, Michał; Ivanov, Pavel; Zabel, Maciej
2013-08-01
Vaults are cytoplasmic ribonucleoprotein particles composed of three proteins (MVP, TEP1, vPARP) and vault‑associated RNAs (vRNAs). Although the cellular functions of vaults remain unclear, vaults are strongly linked to the development of multidrug resistance (MDR), the major obstacle to the efficient treatment of cancers. Available published data suggest that vaults and their components are frequently upregulated in broad variety of multidrug-resistant cancer cell lines and tumors of different histological origin. Here, we provide detailed analysis of vault protein expression in post-surgery ovarian cancer samples from patients that were not exposed to chemotherapy. Our analysis suggests that vault proteins are expressed in the ovaries of healthy individuals but their expression in cancer patients is changed. Specifically, MVP, TEP1 and vPARP mRNA levels are significantly decreased in cancer samples with tendency of lower expression in higher-grade tumors. The pattern of vault protein mRNA expression is strongly correlated with the expression of other MDR-associated proteins such as MDR1, MRP1 and BCRP. Surprisingly, the protein levels of MVP, TEP1 and vPARP are actually increased in the higher‑grade tumors suggesting existence of post-transcriptional regulation of vault component production. PMID:23739867
Mara Fernanda Mattio
2008-06-01
Full Text Available Una enfermedad que afecta severamente el rendimiento del cultivo de maz es conocida como mal de Ro Cuarto. El vector ms importante es Delphacodes kuscheli. Este trabajo tuvo como objetivo determinar la capacidad vectora de una nueva especie, Tagosodes orizicolus, en campo y bajo condiciones experimentales. Los ensayos de transmisin se realizaron con ambas especies simultneamente. Para la adquisicin, latencia e infeccin se utilizaron los tiempos considerados ptimos para D. kuscheli. Las plantas fueron analizadas por DAS-ELISA. Se observaron glndulas salivales de T. orizicolus por microscopa electrnica. En las pruebas experimentales se obtuvieron porcentajes de transmisin del 10% para T. orizicolus y 42% para D. kuscheli. Los cortes ultrafinos de las glndulas salivales de T. orizicolus evidenciaron agregados de partculas virales de 70 nm de dimetro. No pudo comprobarse la capacidad vectora en condiciones naturales a partir de ensayos realizados con insectos capturados en campo. Asimismo, se mencionan por primera vez el trigo, la cebada y el triticale como cultivos adecuados para la cra de T. orizicolus. Estos resultados sealan a T. orizicolus como una especie de inters epidemiolgico en el Noreste de Argentina, por la capacidad demostrada de adquirir y trasmitir en condiciones experimentales dicho agente viral.An important disease affecting the yield of corn crops is known as mal de Ro Cuarto. Delphacodes kuscheli is the most important vector. The objective of this work was to determine the vector capacity of a new species, Tagosodes orizicolus, both in the field and under experimental conditions. Transmission trials were carried out on both species simultaneously. For acquisition, latency and infection the times considered optimum for D. kuscheli were used. The plants were analyzed by DAS-ELISA. Salivary glands of T. orizicolus were observed by electron microscopy. In experimental tests, values of percentages of transmission of 10% for T. orizicolus and 42% for D. kuscheli were obtained. The ultra-fine sections of the salivary glands of T. orizicolus showed the aggregation of viral particles 70 nm in diameter. Vectoral capacity could not be proven under natural conditions from a test conducted with insects captured in the field. Likewise, for the first time wheat, barley and triticale are mentioned as suitable crops for breeding T. orizicolus. These results show T. orizicolus to be a species of epidemiological interest in the northeast of Argentina due to the proven capacity of acquiring and transmitting this viral agent under experimental conditions.
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. (letter)
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
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
Zermoglio, Paula F; Martin-Herrou, Hadrien; Bignon, Yohan; Lazzari, Claudio R
2015-10-01
Insect repellents are known since many decades ago and constitute a major tool for personal protection against the biting of mosquitoes. Despite their wide use, the understanding of why and how repellents repel is relatively recent. In particular, the question about to what extent insects other than mosquitoes are repulsed by repellents remains open. We developed a series of bioassays aimed to test the performance of well established as well as potential repellent molecules on the Chagas disease vector Rhodnius prolixus. Besides testing their ability to prevent biting, we tested the way in which they act, i.e., by obstructing the detection of attractive odours or by themselves. By using three different experimental protocols (host-biting, open-loop orientation to odours and heat-triggered proboscis extension response) we show that DEET repels bugs both in the presence and in the absence of host-associated odours but only at the highest quantities tested. Piperidine was effective with or without a host and icaridine only repelled in the absence of a living host. Three other molecules recently proposed as potential repellents due to their affinity to the Ir40a(+) receptor (which is also activated by DEET) did not evoke significant repellency. Our work provides novel experimental tools and sheds light on the mechanism behind repellency in haematophagous bugs. PMID:26210345
Erickson, R. A.; Hayhoe, K.; Presley, S. M.; Allen, L. J. S.; Long, K. R.; Cox, S. B.
2012-09-01
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.
Anna-Sofie Stensgaard
2009-05-01
Full Text Available 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.
Edmunson, J.; Gaskin, J. A.; Jerman, G. A.; Harvey, R. P.; Doloboff, I. J.; Neidholdt, E. L.
2016-01-01
The Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Sciences (ROSES), will build upon previous miniaturized SEM designs and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. This project is a collaboration between NASA Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), electron gun and optics manufacturer Applied Physics Technologies, and small vacuum system manufacturer Creare. Dr. Ralph Harvery and environmental SEM (ESEM) inventor Dr. Gerry Danilatos serve as advisors to the team. Variable pressure SEMs allow for fine (nm-scale) resolution imaging and micron-scale chemical study of materials without sample preparation (e.g., carbon or gold coating). Charging of a sample is reduced or eliminated by the gas surrounding the sample. It is this property of ESEMs that make them ideal for locations where sample preparation is not yet feasible, such as the surface of Mars. In addition, the lack of sample preparation needed here will simplify the sample acquisition process and allow caching of the samples for future complementary payload use.
Chen, Yu; Xie, Xilin
2016-05-01
E and Liu [J. Comput. Phys. 138 (1997) 57-82] put forward a finite difference method for 3D viscous incompressible flows in the vorticity-vector potential formulation on non-staggered grids. In this paper, we will extend this method to the case of flows in the presence of a deformable surface. By use of two kinds of surface differential operators, the implementation of boundary conditions on a plane is generalized to a curved smooth surface with given velocity distribution, whether this be an inflow/outflow interface or a curved wall. To deal with the irregular and varying physical domain, time-dependent curvilinear coordinates are constructed and the corresponding tensor analysis is adopted in deriving the component form of the governing equations. Therefore, the equations can be discretized and solved in a regular and fixed parametric domain. Numerical results are presented for a 3D lid-driven cavity with a deforming surface and a 3D duct flow with a deforming boundary. A new way to validate numerical simulations is proposed based on an expression for the rate-of-strain tensor on a deformable surface.
Approximate analytical solutions of spin and pseudospin symmetry limits of Dirac equation are reported for the generalized Poeschl-Teller scalar and vector potentials and a Coulomb tensor interaction by Nikiforov-Uvarov method. On the contrary to the cumbersome numerical procedures, the analytical approach followed here can be followed even by the undergraduate students.
Capelli Gioia
2011-09-01
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.
Chu, Peng-Cheng; Chen, Lie-Wen; Huang, Mei
2014-01-01
We investigate properties of strange quark matter in the framework of SU(3) Nambu--Jona-Lasinio(NJL) model with vector interaction under strong magnetic fields. The effects of vector-isoscalar and vector-isovector interaction on the equation of state of strange quark matter are investigated, and it is found that the equation of state is not sensitive to the vector-isovector interaction, however, a repulsive interaction in the vector-isoscalar channel gives a stiffer equation of state for cold dense quark matter. In the presence of magnetic field, gluons will be magnetized via quark loops, and the contribution from magnetized gluons to the equation of state is also estimated. The sound velocity square is a quantity to measure the hardness or softness of dense quark matter, and in the NJL model without vector interaction at zero magnetic field the sound velocity square is always less than 1/3. It is found that a repulsive vector-isoscalar interaction and a positive pressure contribution from magnetized gluons c...
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)
Gabriel, Daz-Padilla; J. Isabel, Lpez-Arroyo; Ignacio, Snchez-Cohen; Rafael Alberto, Guajardo-Panes; Gustavo, Mora-Aguilera; Juan ngel, Quijano-Carranza.
2014-11-01
Full Text Available La presencia de Huanglongbing y su vector: Diaphorina citri Kuwayama (Hemiptera: Liviidae) en Mxico, aunado a la gran dispersin de la citricultura, dificultan su deteccin, control y manejo. Con el propsito de generar herramientas que faciliten la aplicacin de estrategias para confrontar la prob [...] lemtica asociada al Huanglongbing y su vector, el presente estudio se desarroll con el objetivo de implementar una metodologa prctica y de uso sencillo para clasificar la presencia y abundancia potencial del vector y generar un mapa con la delimitacin de las zonas potenciales de riesgo de desarrollo del insecto en el pas. Se modelaron tres ndices, dos basados en la temperatura (ndice de generaciones potenciales, y das con condiciones favorables), y uno en la disponibilidad del hospedero (superficie plantada con ctricos). En el mapa final, cada ndice fue ponderado respecto a su mximo, interpolado mediante el mtodo de inverso de la distancia optimizado, y promediado con los dems para obtener el ndice de riesgo promedio. Se encontr que los municipios con mayor ndice de das con condiciones favorables fueron: Tuzantn, Chiapas, y Atoyac de lvarez, Guerrero. Referente al ndice de generaciones potenciales, los municipios de Rosario, Sonora, y Pichucalco, Chiapas, resultaron con 34 y 28 generaciones potenciales anuales, respectivamente. El mximo riesgo, ndice de riesgo promedio, se encontr en los municipios de lamo Temapache, Martnez de la Torre, y Papantla, Veracruz, y Atoyac de lvarez, Guerrero. El mtodo propuesto es prctico, econmico y sin clculos complicados; para mejorarlo, sera necesario incorporar informacin de humedad relativa, precipitacin, fenologa y especie de ctricos. Su utilidad radica en que auxilia en la toma de decisiones relacionadas con acciones de deteccin, monitoreo, muestreo y control del vector. Abstract in english The presence of the citrus greening disease (HLB) and its vector: Diaphorina citri Kuwayama (Hemiptera: Liviidae) in Mexico, coupled with the large spread of the citrus industry, impede the detection, control and management. In order to generate tools that facilitate the implementation of strategies [...] to confront the problems associated with HLB and its vector, this study was developed with the goal of implementing a practical and easy way to use a methodology for classifying the presence and potential of vector abundance and generate a map, showing the delineation of potential risk areas within the country. Three indices were modeled, two temperature-based (index of potential generations, IGP, and days with favorable conditions, IDCF), and another one on the availability of the host (citrus plantings, ISPC). On the final map, each index was weighted with respect to its maximum, interpolated using the inverse distance optimized method and averaged with others for the Egalitarian Risk Index (IRPM). We found that, the municipalities with the highest IDCF were Tuzantn, Chiapas, and Atoyac de lvarez, Guerrero. Concerning IGP, the municipalities of Rosario, Sonora, and Pichucalco, Chiapas, presented 34 and 28 potential generations per year respectively. The maximum risk, IRPM, was found in the municipalities of Alamo Temapache, Martnez de la Torre, and Papantla, Veracruz, and Atoyac de lvarez, Guerrero. The proposed method is practical, cheap and without complicated calculations; for improving it, it would be necessary to incorporate information regarding relative humidity, rainfall, phenology and species of citrus. Its usefulness lies by helping for decision making about actions for detection, monitoring, sampling and vector control.
Charles S. Apperson; Hassan, Hassan K.; Bruce A. Harrison; SAVAGE, HARRY M.; ASPEN, STEPHEN E.; FARAJOLLAHI, ARY; CRANS, WAYNE; DANIELS, THOMAS J.; Falco, Richard C.; Benedict, Mark; Anderson, Michael; McMILLEN, LARRY; Unnasch, Thomas R.
2004-01-01
An important variable in determining the vectorial capacity of mosquito species for arthropod-borne infections is the degree of contact of the vector and the vertebrate reservoir. This parameter can be estimated by examining the host-feeding habits of vectors. Serological and polymerase chain reaction based methods have been used to study the host-feedings patterns of 21 mosquito species from New York, New Jersey, and Tennessee, 19 of which previously have been found infected with West Nile v...
We have constructed a lentiviral vector with expression limited to cells presenting active E2F-1 protein, a potential advantage for gene therapy of proliferative diseases. For the FE2FLW vector, the promoter region of the human E2F-1 gene was utilized to drive expression of luciferase cDNA, included as a reporter of viral expression. Primary, immortalized, and transformed cells were transduced with the FE2FLW vector and cell cycle alterations were induced with serum starvation/replacement, contact inhibition or drug treatment, revealing cell cycle-dependent changes in reporter activity. Forced E2F-1 expression, but not E2F-2 or E2F-3, increased reporter activity, indicating a major role for this factor in controlling expression from the FE2FLW virus. We show the utility of this vector as a reporter of E2F-1 and proliferation-dependent cellular alterations upon cytotoxic/cytostatic treatment, such as the introduction of tumor suppressor genes. We propose that the FE2FLW vector may be a starting point for the development of gene therapy strategies for proliferative diseases, such as cancer or restinosis
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
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.
Nico, Leo G.; Sharp, Paul; Collins, Timothy M.
2011-01-01
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.
Josaine Leila Almeida
2014-12-01
Full Text Available The aim of this study was to determine the isolation frequency and microbial sensitivity profiles of Escherichia coli, Salmonella spp., and Staphylococcus spp. isolated from synanthropic flies captured in entomological traps placed near the milking parlors of 30 dairy farms located in Northern Paraná, Brazil. In total, 192 flies were captured, and the isolation frequencies of muscids (21/30 = 70% and califorids (27/30 = 90% were significantly higher than that of sarcophagids (7/30 = 23.3%. Bacteriological tests on the internal contents and external surfaces of the flies showed that E. coli was present only in muscids (14.3% and caliphorids (33.3%. Salmonella spp. was isolated from 9.5% of the muscids, 7.4% of the caliphorids, and 14.29% of the sarcophagids. Staphylococcus spp. was isolated from 28.5% of the muscids and 29.6% of the caliphorids. E. coli isolation was more frequent in flies captured on farms at which domestic chickens were housed near the milking parlors (p = 0.031 and which did not use sugarcane for animal feed (p = 0.042. Two out of 27 (7.4% Staphylococcus spp. strains presented a phenotype of coagulase enzyme production. Ceftriaxone, ciprofloxacin, enrofloxacin, and gentamicin were the most effective antibiotics against E. coli and Salmonella spp. Tetracycline was the least effective antibiotic against the isolates. The Staphylococcus spp. strains isolated did not show the phenotype of oxacillin resistance. We conclude that regional flies are potential mechanical vectors of microbial agents able to cause enteritis in goats, mastitis in cows, and contamination of milk products for human consumption.
Zohdy Sarah
2012-03-01
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.
Reddy, S.T.; Stoker, A.W.; Bissell, M.J. (Lawrence Berkeley Lab., CA (United States))
1991-12-01
Retroviruses are valuable tools in studies of embryonic development, both as gene expression vectors and as cell lineage markers. In this study early chicken blastoderm cells are shown to be permissive for infection by Rous sarcoma virus and derivative replication-defective by Rous sarcoma virus and derivative replication-defective vectors, and, in contrast to previously published data, these cells will readily express viral genes. In cultured blastoderm cells, Rous sarcoma virus stably integrates and is transcribed efficiently, producing infectious virus particles. Using replication-defective vectors encoding the bacterial lacZ gene, the authors further show that blastoderms can be infected in culture and in ovo. In ovo, lacZ expression is seen within 24 hours of virus inoculation, and by 96 hours stably expressing clones of cells are observed in diverse tissues throughout the embryo, including epidermis, somites, and heart, as well as in extraembryonic membranes. Given the rapid onset of vector expression and the broad range of permissive cell types, it should be feasible to use Rous sarcoma virus-derived retroviruses as early lineage markers and expression vectors beginning at the blastoderm stage of avian embryogenesis.
Pablo Wenceslao Orellano
2008-08-01
Full Text Available OBJETIVOS: Evaluar el costo-beneficio de una intervencin de control de mosquitos adultos con fumigacin, junto con actividades de control de formas inmaduras de Aedes aegypti, para evitar la transmisin en una situacin de alto riesgo. MTODOS: Se realiz un anlisis de costo-beneficio desde una perspectiva social. Se compar una intervencin para el control de mosquitos adultos y formas inmaduras contra una hiptesis de no-intervencin, de enero a abril de 2007, en la ciudad de Clorinda, Argentina. Se consideraron los costos directos y los beneficios indirectos e intangibles, estandarizados a dlares internacionales (I$ utilizando la paridad de poder adquisitivo. Se asumi una incidencia de 50 casos de dengue por 1 000 habitantes en la hiptesis de no-intervencin. RESULTADOS: De enero a abril de 2007 se presentaron 176 casos de dengue en Clorinda, pero slo cinco fueron autctonos. El valor presente neto fue de I$ 196 879 en la estrategia de aplicacin de control, mientras que en la de no aplicacin se calcul en I$ -106 724, lo que significara un ahorro de I$ 303 602 (I$ 6,46 por habitante con la intervencin. El anlisis de sensibilidad evidenci que, con ms de 1 363 casos de dengue (incidencia total de 29 por 1 000 habitantes y un caso de dengue hemorrgico, la intervencin es costo-benfica. CONCLUSIONES: Los resultados sugieren que el control vectorial, incluyendo la fumigacin para mosquitos adultos, debe evaluarse en situaciones de alto riesgo de transmisin como una alternativa costo-benfica en pases no endmicos.OBJECTIVES: To evaluate the cost-benefit of an intervention utilizing fumigation against adult mosquitoes along with actions to control immature Aedes aegypti to prevent transmission in a high-risk area. METHODS: A cost-benefit analysis was performed from the social perspective. A program to control both adult mosquitoes and immature forms was compared to a non-intervention hypothesis, from January to April 2007, in the city of Clorinda, Argentina. Direct costs, as well as indirect and intangible benefits, were taken into account and standardized in international dollars (I$ using purchasing power parity. An incidence rate of 50 cases of dengue per 1 000 inhabitants was used in the non-intervention hypothesis. RESULTS: From January to April 2007 there were 176 cases of dengue in Clorinda, but only five were autochthonous. The net present value was I$ 196 879 with the control strategy, whereas the non-intervention was calculated to be I$ -106 724, indicating a savings of I$ 303 602 (I$ 6.46 per inhabitant for the intervention. The sensitivity analysis showed that, with more than 1 363 cases of dengue (total incidence rate of 29 per 1 000 inhabitants and one case of dengue hemorrhagic fever, there is a cost-benefit to intervention. CONCLUSIONS: The results suggest that vector control, including fumigation of adult mosquitoes, should be considered in high-risk areas as a cost-effective option for non-endemic countries.
Development of nonhuman adenoviruses as vaccine vectors
Bangari, Dinesh S.; Mittal, Suresh K.
2005-01-01
Human adenoviral (HAd) vectors have demonstrated great potential as vaccine vectors. Preclinical and clinical studies have demonstrated the feasibility of vector design, robust antigen expression and protective immunity using this system. However, clinical use of adenoviral vectors for vaccine purposes is anticipated to be limited by vector immunity that is either preexisting or develops rapidly following the first inoculation with adenoviral vectors. Vector immunity inactivates the vector pa...
Talavera, Sandra; Muñoz-Muñoz, Francesc; Durán, Mauricio; Verdún, Marta; Soler-Membrives, Anna; Oleaga, Álvaro; Arenas, Antonio; Ruiz-Fons, Francisco; Estrada, Rosa; Pagès, Nitu
2015-01-01
The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the hypothesis that wild ruminants could act as reservoirs for such pathogens, and subsequently be involved in the reintroduction of disease to livestock on neighbouring farms. PMID:26510136
Talavera, Sandra; Muñoz-Muñoz, Francesc; Durán, Mauricio; Verdún, Marta; Soler-Membrives, Anna; Oleaga, Álvaro; Arenas, Antonio; Ruiz-Fons, Francisco; Estrada, Rosa; Pagès, Nitu
2015-01-01
The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the hypothesis that wild ruminants could act as reservoirs for such pathogens, and subsequently be involved in the reintroduction of disease to livestock on neighbouring farms. PMID:26510136
Fuller Douglas O
2012-08-01
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.
Insulated Foamy Viral Vectors.
Browning, Diana L; Collins, Casey P; Hocum, Jonah D; Leap, David J; Rae, Dustin T; Trobridge, Grant D
2016-03-01
Retroviral vector-mediated gene therapy is promising, but genotoxicity has limited its use in the clinic. Genotoxicity is highly dependent on the retroviral vector used, and foamy viral (FV) vectors appear relatively safe. However, internal promoters may still potentially activate nearby genes. We developed insulated FV vectors, using four previously described insulators: a version of the well-studied chicken hypersensitivity site 4 insulator (650cHS4), two synthetic CCCTC-binding factor (CTCF)-based insulators, and an insulator based on the CCAAT box-binding transcription factor/nuclear factor I (7xCTF/NF1). We directly compared these insulators for enhancer-blocking activity, effect on FV vector titer, and fidelity of transfer to both proviral long terminal repeats. The synthetic CTCF-based insulators had the strongest insulating activity, but reduced titers significantly. The 7xCTF/NF1 insulator did not reduce titers but had weak insulating activity. The 650cHS4-insulated FV vector was identified as the overall most promising vector. Uninsulated and 650cHS4-insulated FV vectors were both significantly less genotoxic than gammaretroviral vectors. Integration sites were evaluated in cord blood CD34(+) cells and the 650cHS4-insulated FV vector had fewer hotspots compared with an uninsulated FV vector. These data suggest that insulated FV vectors are promising for hematopoietic stem cell gene therapy. PMID:26715244
Marini E
2012-12-01
Full Text Available Elisabetta Marini,1 Roberto Buffa,1 Bruno Saragat,1 Alessandra Coin,2 Elena Debora Toffanello,2 Linda Berton,2 Enzo Manzato,2 Giuseppe Sergi21Department of Environmental and Life Sciences, University of Cagliari, Italy; 2Department of Medicine-DIMED, Geriatrics Section, University of Padua, ItalyPurpose: The aim of this paper is to investigate whether bioelectrical impedance vector analysis (BIVA can be a suitable technique for the assessment of sarcopenia. We also investigate the potential use of specific BIVA as an indicator of sarcopenic obesity.Subjects and methods: The sample comprised 207 free-living elderly individuals of both sexes, aged 65 to 93 years. Anthropometric and bioelectrical measurements were taken according to standard criteria. The “classic” and “specific” BIVA procedures, which respectively correct bioelectrical values for body height and body geometry, were used. Dual energy X-ray absorptiometry (DXA was used as the reference method for identifying sarcopenic and obese sarcopenic individuals. Bioelectrical and DXA values were compared using Student’s t-test and Hotelling’s T2 test, as well as Pearson’s correlation coefficient.Results: According to classic BIVA, sarcopenic individuals of both sexes showed higher values of resistance/height (R/H; p < 0.01 and impedance/height (Z/H; p < 0.01, and a lower phase angle (p < 0.01. Similarly, specific BIVA showed significant differences between sarcopenic and nonsarcopenic individuals (men: T2 = 15.7, p < 0.01; women: T2 = 10.7, p < 0.01, with the sarcopenic groups showing a lower specific reactance and phase angle. Phase angle was positively correlated with the skeletal muscle mass index (men: r = 0.52, p < 0.01; women: r = 0.31, p < 0.01. Specific BIVA also recognized bioelectrical differences between sarcopenic and sarcopenic obese men (T2 = 13.4, p < 0.01, mainly due to the higher values of specific R in sarcopenic obese individuals.Conclusion: BIVA detected muscle-mass variations in sarcopenic individuals, and specific BIVA was able to discriminate sarcopenic individuals from sarcopenic obese individuals. These procedures are promising tools for screening for presarcopenia, sarcopenia, and sarcopenic obesity in routine practice.Keywords: aging, body composition, BIVA, DXA
Marie, Tiphanie; Yesou, Herve; Huber, Claire; De Fraipont, Paul; Uribe, Carlos; Lacaux, Jean-Pierre; Lafaye, Murielle; Lai, Xijun; Desnos, Yves-Louis
2013-01-01
Earth observation data and bibliography on environmental parameters were used for mapping Oncomelania hupensis distribution, the Schistosomiasis japonicum’s intermediate host snail, within Poyang Lake (Jiangxi Province, P.R. China). Areas suitable for the development of O. hupensis, the vector of schistosomiasis, were derived from submersion time parameters and vegetation community indicators. ENVISAT time series data acquired from 2000 to 2009 were used for submersion times mapping, and 5 Beijing-1 data acquired during the dry season between 2006 and 2008 were used to map suitable vegetation for vector development. Yearly maps obtained indicate four principally potential endemic areas: the Gan Delta, the bank of the Fu He River, the Dalianzi Hu sector and the Poyang Lake Nature Reserve. Monthly maps from December 2005 to December 2008 show the dynamic of potential O. hupensis presence areas.
Montarsi, Fabrizio; Martini, Simone; Dal Pont, Marco; Delai, Nicola; Ferro Milone, Nicola; Mazzucato, Matteo; Soppelsa, Fabio; Cazzola, Luigi; Cazzin, Stefania; Ravagnan, Silvia; Ciocchetta, Silvia; Russo, Francesca; Capelli, Gioia
2013-01-01
Background The container breeding species belonging to the genus Aedes (Meigen) are frequently recorded out of their place of origin. Invasive Aedes species are proven or potential vectors of important Arboviruses and their establishment in new areas pose a threat for human and animal health. A new species of exotic mosquito was recorded in 2011 in north-eastern Italy: Aedes (Finlaya) koreicus [Hulecoeteomyia koreica]. The aim of this study was to characterize the biology, the environment and...
Ram K Varma
2010-04-01
We discuss here the prediction, based on a formalism by the author, on the observable effects of a curl-free magnetic vector potential on the macroscale as against the microscale of the Aharonov–Bohm effect. A new quantum concept – the ‘transition amplitude wave’ – postulated in the formalism has already been shown to exhibit matter wave manifestations in the form of one-dimensional interference effects on the macroscale. It was predicted by the formalism that the same entity would lead to the detection of a curl-free magnetic vector potential on the macroscale. We describe here the manner of generation of this quantum entity in an inelastic scattering episode and work out an algorithm to observe this radically new phenomenon, the detection of a curl-free magnetic vector potential on the macroscale. We determine the various characteristic features of such an observation which can then be looked for experimentally so as to verify the predicted effect, establishing thereby the physical reality of the new quantum entity, and to fully validate the formalism predicting it. It is also shown that this ‘transition amplitude wave’ can be regarded as a novel kind of ‘quasiparticle’ excited in the charged particle trajectory as a consequence of the scattering episode.
Edmunson, J.; Gaskin, J. A.; Danilatos, G.; Doloboff, I. J.; Effinger, M. R.; Harvey, R. P.; Jerman, G. A.; Klein-Schoder, R.; Mackie, W.; Magera, B.; Neidholdt, E. L.
2016-01-01
The Miniaturized Variable Pressure Scanning Electron Microscope(MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Science (ROSES), will build upon previous miniaturized SEM designs for lunar and International Space Station (ISS) applications and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. By the end of the PICASSO work, a prototype of the primary proof-of-concept components (i.e., the electron gun, focusing optics and scanning system)will be assembled and preliminary testing in a Mars analog chamber at the Jet Propulsion Laboratory will be completed to partially fulfill Technology Readiness Level to 5 requirements for those components. The team plans to have Secondary Electron Imaging(SEI), Backscattered Electron (BSE) detection, and Energy Dispersive Spectroscopy (EDS) capabilities through the MVP-SEM.
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(ρ) for quarks at a given density ρ 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 (ρ) and the model dependence is restricted to the intermediate desnsities. (author)
Pakhomov, Anton; Sudin, Natalya
2013-01-01
This research is devoted to possible mechanisms of decision-making in frames of thermodynamic principles. It is also shown that the decision-making system in reply to emotion includes vector component which seems to be often a necessary condition to transfer system from one state to another. The phases of decision-making system can be described as supposed to be nonequilibrium and irreversible to which thermodynamics laws are applied. The mathematical model of a decision choice, proceeding fr...
GRTLER, RICARDO E.; Mara C. Cecere; Fernndez, Mara del Pilar; Vazquez-Prokopec, Gonzalo M.; CEBALLOS, LEONARDO A.; Gurevitz, Juan M.; Kitron, Uriel; COHEN, JOEL E.
2014-01-01
The major vectors of Chagas disease are species of triatomine bugs adapted to human sleeping quarters and peridomestic annexes where they feed on humans and domestic or synanthropic mammals or birds. Knowledge of the demography and nutritional status of Triatominae in real-life settings is still fragmentary, and this affects our ability to prevent or reduce house reinfestation after insecticide spraying. In addition to showing where the bugs are likely to live (occupancy and density informati...
Kamon, M.; Phillips, J.R. [Massachusetts Institute of Technology, Cambridge, MA (United States)
1994-12-31
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.
Harris Alesha
2011-01-01
Full Text Available Abstract 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 cell viability via exposure to such a Cu-loaded vector. Carboxylate-functionalized nanoparticles were synthesized by free radical polymerization and were subsequently loaded with Cu2+ via binding to particle-bound carboxylate functional groups. Cu loading and release were characterized via ICP MS, EDX, XPS, and elemental analysis. Results demonstrated that Cu could be loaded in high weight percent (up to 16 wt.% and that Cu was released from the particles in a pH-dependent manner. Metal release was a function of both pH and the presence of competing ligands. The toxicity of the particles was measured in HeLa cells where reductions in cell viability greater than 95% were observed at high Cu loading. The combined pH sensitivity and significant toxicity make this copper delivery vector an excellent candidate for the targeted killing of disease cells when combined with an effective cellular targeting strategy.
Hoffmann, Banesh
1975-01-01
From his unusual beginning in ""Defining a vector"" to his final comments on ""What then is a vector?"" author Banesh Hoffmann has written a book that is provocative and unconventional. In his emphasis on the unresolved issue of defining a vector, Hoffmann mixes pure and applied mathematics without using calculus. The result is a treatment that can serve as a supplement and corrective to textbooks, as well as collateral reading in all courses that deal with vectors. Major topics include vectors and the parallelogram law; algebraic notation and basic ideas; vector algebra; scalars and scalar p
Newell, Homer E
2006-01-01
When employed with skill and understanding, vector analysis can be a practical and powerful tool. This text develops the algebra and calculus of vectors in a manner useful to physicists and engineers. Numerous exercises (with answers) not only provide practice in manipulation but also help establish students' physical and geometric intuition in regard to vectors and vector concepts.Part I, the basic portion of the text, consists of a thorough treatment of vector algebra and the vector calculus. Part II presents the illustrative matter, demonstrating applications to kinematics, mechanics, and e
Ikhdair, Sameer M
2011-01-01
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.
Silvia MM Ahid
1999-12-01
Full Text Available INTRODUO: Em alguns bairros costeiros de So Lus, Maranho, a prevalncia da dirofilariose chega a mais de 40% entre os ces domiciliados. Porm, desconhecem-se os vetores naturais, tanto l quanto no resto do Nordeste do pas. O objetivo do estudo foi identificar os provveis vetores dessa parasitose. MTODOS: Realizaram-se coletas mensais de mosquitos em um bairro costeiro de So Lus, MA, de maro de 1996 a maio de 1997, no peridomiclio, tendo co e homem como iscas. Os mosquitos foram dissecados para a pesquisa de larvas da Dirofilaria immitis. RESULTADOS: Coletaram-se 1.738 mosquitos de 11 espcies. Culex quinquefasciatus, capturada todos os meses, porm menos freqente na estao 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. CONCLUSES: Ae. taeniorhynchus e Cx. quinquefasciatus foram considerados vetores potenciais da dirofilariose em So Lus. A importncia local de Cx. quinquefasciatus como transmissor primrio da D. immitis necessita ser melhor avaliada.INTRODUCTION: In some coastal districts of So Lus, capital of the state of Maranho, 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'gua, in S. Lus, 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 So Lus. The role of Cx. quinquefasciatus as primary vector of D. immitis, however, needs further evaluation.
Silvia MM, Ahid; Ricardo, Loureno-de-Oliveira.
1999-12-01
Full Text Available INTRODUO: Em alguns bairros costeiros de So Lus, Maranho, a prevalncia da dirofilariose chega a mais de 40% entre os ces domiciliados. Porm, desconhecem-se os vetores naturais, tanto l quanto no resto do Nordeste do pas. O objetivo do estudo foi identificar os provveis vetores dessa paras [...] itose. MTODOS: Realizaram-se coletas mensais de mosquitos em um bairro costeiro de So Lus, MA, de maro de 1996 a maio de 1997, no peridomiclio, tendo co e homem como iscas. Os mosquitos foram dissecados para a pesquisa de larvas da Dirofilaria immitis. RESULTADOS: Coletaram-se 1.738 mosquitos de 11 espcies. Culex quinquefasciatus, capturada todos os meses, porm menos freqente na estao 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. CONCLUSES: Ae. taeniorhynchus e Cx. quinquefasciatus foram considerados vetores potenciais da dirofilariose em So Lus. A importncia local de Cx. quinquefasciatus como transmissor primrio da D. immitis necessita ser melhor avaliada. Abstract in english INTRODUCTION: In some coastal districts of So Lus, capital of the state of Maranho, 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'gua, in S. Lus, 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 So Lus. The role of Cx. quinquefasciatus as primary vector of D. immitis, however, needs further evaluation.
Dhiman, Sunil; Yadav, Kavita; Rabha, Bipul; Goswami, Diganta; Hazarika, S.; Tyagi, Varun
2016-01-01
During the recent past, development of DDT resistance and reduction to pyrethroid susceptibility among the malaria vectors has posed a serious challenge in many Southeast Asian countries including India. Current study presents the insecticide susceptibility and knock-down data of field collected Anopheles annularis sensu lato and An. vagus mosquito species from endemic areas of Assam in northeast India. Anopheles annularis s.l. and An. vagus adult females were collected from four randomly selected sentinel sites in Orang primary health centre (OPHC) and Balipara primary health centre (BPHC) areas, and used for testing susceptibility to DDT, malathion, deltamethrin and lambda-cyhalothrin. After insecticide susceptibility tests, mosquitoes were subjected to VectorTest™ assay kits to detect the presence of malaria sporozoite in the mosquitoes. An. annularis s.l. was completely susceptible to deltamethrin, lambda-cyhalothrin and malathion in both the study areas. An. vagus was highly susceptible to deltamethrin in both the areas, but exhibited reduced susceptibility to lambda-cyhalothrin in BPHC. Both the species were resistant to DDT and showed very high KDT50 and KDT99 values for DDT. Probit model used to calculate the KDT50 and KDT99 values did not display normal distribution of percent knock-down with time for malathion in both the mosquito species in OPHC (p<0.05) and An. vagus in BPHC (χ2 = 25.3; p = 0.0), and also for deltamethrin to An. vagus in BPHC area (χ2 = 15.4; p = 0.004). Minimum infection rate (MIR) of Plasmodium sporozoite for An. vagus was 0.56 in OPHC and 0.13 in BPHC, while for An. annularis MIR was found to be 0.22 in OPHC. Resistance management strategies should be identified to delay the expansion of resistance. Testing of field caught Anopheles vectors from different endemic areas for the presence of malaria sporozoite may be useful to ensure their role in malaria transmission. PMID:27010649
Graversen, C; Frokjaer, J B; Brock, Christina; Drewes, A M; Farina, D
2012-01-01
patients were discriminated from the HV by a support vector machine (SVM) applied in regression mode. For the optimal DWT, the discriminative features were extracted and the SVM regression value representing the overall alteration of the EP was correlated to the clinical scores. A classification...... performance of 86.2% (P=0.01) was obtained by applying a majority voting scheme to the 5 best performing channels. The biomarker was identified as decreased theta band activity. The regression value was correlated to symptoms reported by the patients (P=0.04). The methodology is an improvement of the present...
Doucoure, Souleymane; Mouchet, François; Cornelie, Sylvie; Drame, Papa Makhtar; D'Ortenzio, Eric; DeHecq, Jean Sébastien; Remoue, Franck
2014-01-01
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
Roger François
2008-02-01
Full Text Available Abstract Background Although malaria disappeared from southern France more than 60 years ago, suspicions of recent autochthonous transmission in the French Mediterranean coast support the idea that the area could still be subject to malaria transmission. The main potential vector of malaria in the Camargue area, the largest river delta in southern France, is the mosquito Anopheles hyrcanus (Diptera: Culicidae. In the context of recent climatic and landscape changes, the evaluation of the risk of emergence or re-emergence of such a major disease is of great importance in Europe. When assessing the risk of emergence of vector-borne diseases, it is crucial to be able to characterize the arthropod vector's spatial distribution. Given that remote sensing techniques can describe some of the environmental parameters which drive this distribution, satellite imagery or aerial photographs could be used for vector mapping. Results In this study, we propose a method to map larval and adult populations of An. hyrcanus based on environmental indices derived from high spatial resolution imagery. The analysis of the link between entomological field data on An. hyrcanus larvae and environmental indices (biotopes, distance to the nearest main productive breeding sites of this species i.e., rice fields led to the definition of a larval index, defined as the probability of observing An. hyrcanus larvae in a given site at least once over a year. Independent accuracy assessments showed a good agreement between observed and predicted values (sensitivity and specificity of the logistic regression model being 0.76 and 0.78, respectively. An adult index was derived from the larval index by averaging the larval index within a buffer around the trap location. This index was highly correlated with observed adult abundance values (Pearson r = 0.97, p An. hyrcanus larval and adult populations from the landscape indices. Conclusion This work shows that it is possible to use high resolution satellite imagery to map malaria vector spatial distribution. It also confirms the potential of remote sensing to help target risk areas, and constitutes a first essential step in assessing the risk of re-emergence of malaria in southern France.
Ojeda-Guillén, D.; Mota, R. D.; Granados, V. D.
2014-08-01
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
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.
Galal Fatma H
2010-03-01
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.
Wolstenholme, E Œ
1978-01-01
Elementary Vectors, Third Edition serves as an introductory course in vector analysis and is intended to present the theoretical and application aspects of vectors. The book covers topics that rigorously explain and provide definitions, principles, equations, and methods in vector analysis. Applications of vector methods to simple kinematical and dynamical problems; central forces and orbits; and solutions to geometrical problems are discussed as well. This edition of the text also provides an appendix, intended for students, which the author hopes to bridge the gap between theory and appl
In the frame work of the working party on reactor and system (WPRS) of the OECD Nuclear Energy Agency (NEA), the benchmark on sodium cooled fast reactor (SFR) was conducted. Within the OECD/NEA/WPRS benchmark, study on medium size metallic fuel core was performed using code system for fast reactor core calculation with deterministic method MARBLE and with Monte Carlo method MVP. The latest nuclear library JENDL-4.0 is used for calculation of eigenvalues (keff) and reactivity (sodium void, Doppler and control rod worth). The differences of calculation results between the analysis methods are summarized in this paper. Sensitivity studies of eigenvalue and sodium void reactivity for the medium size metallic fuel benchmark core are conducted to determine the main reactions contributing to the difference between JENDL-4.0 and other libraries JEFF-3.1 and ENDF/B-VII.1. (author)
Boukraa, Slimane; de La Grandiere, Maria A; Bawin, Thomas; Raharimalala, Fara N; Zimmer, Jean-Yves; Haubruge, Eric; Thiry, Etienne; Francis, Frédéric
2016-02-01
Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne equine alphavirus from Americas. Prevention of these arboviruses requires a clear understanding of transmission cycles, especially their vectors. To characterize mosquito fauna, their ecology and identify potential vectors of equine arboviruses in Belgium, entomological surveys of six equestrian farms located in the Wolloon Region were conducted during 2011-2012. The harvest of mosquitoes was based on larval sampling (272 samples from 111 breeding sites) and monthly adults trapping (CO2-baited traps, Mosquito Magnet Liberty Plus). Among 51,493 larvae and 319 adult mosquitoes collected, morphological identification showed the presence of 11 species: Anopheles claviger (Meigen), An. maculipennis s.l. (Meigen), An. plumbeus (Stephens), Culex hortensis (Ficalbi), Cx. territans (Walker), Cx. pipiens s.l. L., Cx. torrentium (Martini), Coquillettidia richiardii (Ficalbi), Culiseta annulata (Schrank), Aedes cantans (Meigen), Ae. geniculatus (Olivier). Molecular identification of Cx. pipiens species complex allowed the detection of three molecular forms, Pipiens (92.3%), Molestus (4.6%) and Hybrid (3.1%). Larvae of Cx. pipiens sl and Cx. torrentium were omnipresent and the most abundant species. Water troughs, ponds and slurry (liquid manure) were the most favorable breeding sites of mosquito larvae. Based upon behavior and ecology of the identified mosquito species, Studied Belgian equestrian farms seem to provide a suitable environment and breeding sites for the proliferation of potential vectors of arboviruses and those being a real nuisance problem for horses and neighboring inhabitants. PMID:26775817
Martnez-de la Puente Josu
2012-07-01
Full Text Available 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 bluetongue with disastrous consequences. Therefore, it is essential to identify the distribution of biting midges and understand their feeding patterns in areas susceptible to BTD. To that end, we captured biting midges on two farms in the Canary Islands (i to identify the midge species in question and characterize their COI barcoding region and (ii to ascertain the source of their bloodmeals using molecular tools. Methods Biting midges were captured using CDC traps baited with a 4-W blacklight (UV bulb on Gran Canaria and on Tenerife. Biting midges were quantified and identified according to their wing patterns. A 688 bp segment of the mitochondrial COI gene of 20 biting midges (11 from Gran Canaria and 9 from Tenerife were PCR amplified using the primers LCO1490 and HCO2198. Moreover, after selected all available females showing any rest of blood in their abdomen, a nested-PCR approach was used to amplify a fragment of the COI gene from vertebrate DNA contained in bloodmeals. The origin of bloodmeals was identified by comparison with the nucleotide-nucleotide basic alignment search tool (BLAST. Results The morphological identification of 491 female biting midges revealed the presence of a single morphospecies belonging to the Obsoletus group. When sequencing the barcoding region of the 20 females used to check genetic variability, we identified two haplotypes differing in a single base. Comparison analysis using the nucleotide-nucleotide basic alignment search tool (BLAST showed that both haplotypes belong to Culicoides obsoletus, a potential BTV vector. As well, using molecular tools we identified the feeding sources of 136 biting midges and were able to confirm that C. obsoletus females feed on goats and sheep on both islands. Conclusions These results confirm that the feeding pattern of C. obsoletus is a potentially important factor in BTV transmission to susceptible hosts in case of introduction into the archipelago. Consequently, in the Canary Islands it is essential to maintain vigilance of Culicoides-transmitted viruses such as BTV and the novel Schmallenberg virus.
Yves M. Tourre
2008-11-01
Full Text Available A necessary condition for Rift Valley fever (RVF emergence is the presence of Aedes (Aedimorphus vexans and Culex (Culex poicilipes mosquitoes carrying the arbovirus and responsible for the infection. This paper presents a detailed mapping in the Sahelian region of Senegal of zones potentially occupied by these mosquitoes (ZPOMs whose population density is directly linked to ecozones in the vicinity of small ponds. The vectors habitats and breeding sites have been characterized through an integrated approach combining remote sensing technology, geographical information systems, geographical positioning systems and field observations for proper geo-referencing. From five SPOT-5 images (~10 m spatial resolution with appropriate channels, a meridional composite transect of 290 x 60 km was first constructed at the height of the summer monsoon. Subsequent ZPOMs covered major ecozones from north to south with different hydrological environments and different patterns pond distributions. It was found that an overall area of 12,817 ha ± 10% (about 0.8% of the transect is occupied by ponds with an average ZPOM 17 times larger than this (212,813 ha ± 10% or about 14% of the transect. By comparing the very humid year of 2003 with 2006 which had just below normal rainfall, the ZPOMs inter-annual variability was analyzed in a sandy-clayey ecozone with an important hydrofossil riverbed within the Ferlo region of Senegal. Very probably contributing to an increased abundance of vectors by the end of August 2003, it was shown that the aggregate pond area was already about 22 times larger than in August 2006, corresponding to an approximately five times larger total ZPOM. The results show the importance of pin-pointing small ponds (sizes down to 0.1 ha and their geographical distribution in order to assess animal exposure to the RVF vectors.
Tay, W T; Kerr, P J; Jermiin, L S
2016-01-01
Culicoides brevitarsis is a vector of the bluetongue virus (BTV), which infects sheep and cattle. It is an invasive species in Australia with an assumed Asian/South East Asian origin. Using one mitochondrial marker (i.e., part of the cytochrome oxidase subunit I gene) and six nuclear markers, we inferred population genetic structure and possible incursion pathways for Australian C. brevitarsis. Nine mitochondrial haplotypes, with low nucleotide sequence diversity (0.0-0.7%) among these, were identified in a sample of 70 individuals from seven sites. Both sets of markers revealed a homogeneous population structure, albeit with evidence of isolation by distance and two genetically distinct clusters distributed along a north-to-south cline. No evidence of a cryptic species complex was found. The geographical distribution of the mitochondrial haplotypes is consistent with at least two incursion pathways into Australia since the arrival of suitable livestock hosts. By contrast, 15 mitochondrial haplotypes, with up to four times greater nucleotide sequence diversity (0.0-2.9%) among these, were identified in a sample of 16 individuals of the endemic C. marksi (sampled from a site in South Australia and another in New South Wales). A phylogenetic tree inferred using the mitochondrial marker revealed that the Australian and Japanese samples of C. brevitarsis are as evolutionarily different from one another as some of the other Australian species (e.g., C. marksi, C. henryi, C. pallidothorax) are. The phylogenetic tree placed four of the species endemic to Australia (C. pallidothorax, C. bundyensis, C. marksi, C. henryi) in a clade, with a fifth such species (C. bunrooensis) sharing a common ancestor with that clade and a clade comprising two Japanese species (C. verbosus, C. kibunensis). PMID:26771743
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.
S. Ghiamkazemi
2010-01-01
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.
Salvador-Neto, Orlando; Gomes, Simone Azevedo; Soares, Angélica Ribeiro; Machado, Fernanda Lacerda da Silva; Samuels, Richard Ian; Nunes da Fonseca, Rodrigo; Souza-Menezes, Jackson; Moraes, Jorge Luiz da Cunha; Campos, Eldo; Mury, Flávia Borges; Silva, José Roberto
2016-01-01
Dengue is considered a serious public health problem in many tropical regions of the world including Brazil. At the moment, there is no viable alternative to reduce dengue infections other than controlling the insect vector, Aedes aegypti Linnaeus. In the continuing search for new sources of chemicals targeted at vector control, natural products are a promising alternative to synthetic pesticides. In our work, we investigated the toxicity of a bioactive compound extracted from the red alga Laurencia dendroidea J. Agardh. The initial results demonstrated that crude extracts, at a concentration of 5 ppm, caused pronounced mortality of second instar A. aegypti larvae. Two molecules, identified as (-)-elatol and (+)-obtusol were subsequently isolated from crude extract and further evaluated. Assays with (-)-elatol showed moderate larvicidal activity, whereas (+)-obtusol presented higher toxic activity than (-)-elatol, with a LC50 value of 3.5 ppm. Histological analysis of the larvae exposed to (+)-obtusol revealed damage to the intestinal epithelium. Moreover, (+)-obtusol-treated larvae incubated with 2 µM CM-H₂DCFDA showed the presence of reactive oxygen species, leading us to suggest that epithelial damage might be related to redox imbalance. These results demonstrate the potential of (+)-obtusol as a larvicide for use against A. aegypti and the possible mode of action of this compound. PMID:26821032
Salvador-Neto, Orlando; Gomes, Simone Azevedo; Soares, Angélica Ribeiro; Machado, Fernanda Lacerda da Silva; Samuels, Richard Ian; Nunes da Fonseca, Rodrigo; Souza-Menezes, Jackson; Moraes, Jorge Luiz da Cunha; Campos, Eldo; Mury, Flávia Borges; Silva, José Roberto
2016-01-01
Dengue is considered a serious public health problem in many tropical regions of the world including Brazil. At the moment, there is no viable alternative to reduce dengue infections other than controlling the insect vector, Aedes aegypti Linnaeus. In the continuing search for new sources of chemicals targeted at vector control, natural products are a promising alternative to synthetic pesticides. In our work, we investigated the toxicity of a bioactive compound extracted from the red alga Laurencia dendroidea J. Agardh. The initial results demonstrated that crude extracts, at a concentration of 5 ppm, caused pronounced mortality of second instar A. aegypti larvae. Two molecules, identified as (−)-elatol and (+)-obtusol were subsequently isolated from crude extract and further evaluated. Assays with (−)-elatol showed moderate larvicidal activity, whereas (+)-obtusol presented higher toxic activity than (−)-elatol, with a LC50 value of 3.5 ppm. Histological analysis of the larvae exposed to (+)-obtusol revealed damage to the intestinal epithelium. Moreover, (+)-obtusol-treated larvae incubated with 2 µM CM-H2DCFDA showed the presence of reactive oxygen species, leading us to suggest that epithelial damage might be related to redox imbalance. These results demonstrate the potential of (+)-obtusol as a larvicide for use against A. aegypti and the possible mode of action of this compound. PMID:26821032
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)
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. - Highlights: We solve the most general DiracKeplerCoulomb problem. The eigenfunctions and energy spectrum are obtained in a purely algebraic way. We construct the radial SU(1,1) coherent states for the KeplerCoulomb problem
Ojeda-Guillén, D., E-mail: dogphysics@gmail.com [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Ed. 9, Unidad Profesional Adolfo López Mateos, C.P. 07738, México D.F. (Mexico); Mota, R.D. [Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana No. 1000, Col. San Francisco Culhuacán, Delegación Coyoacán, C.P. 04430, México D.F. (Mexico); Granados, V.D. [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Ed. 9, Unidad Profesional Adolfo López Mateos, C.P. 07738, México D.F. (Mexico)
2014-08-14
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. - Highlights: • We solve the most general Dirac–Kepler–Coulomb problem. • The eigenfunctions and energy spectrum are obtained in a purely algebraic way. • We construct the radial SU(1,1) coherent states for the Kepler–Coulomb problem.
Ana Raquel Lira-Vieira
2013-10-01
Full Text Available 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 the 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.
Guilfoyle, Richard A.; Smith, Lloyd M.
1994-01-01
A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site.
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)
The coupled nonlinear volatility and option pricing model presented recently by Ivancevic is investigated, which generates a leverage effect, i.e., stock volatility is (negatively) correlated to stock returns, and can be regarded as a coupled nonlinear wave alternative of the Black–Scholes option pricing model. In this Letter, we analytically propose vector financial rogue waves of the coupled nonlinear volatility and option pricing model without an embedded w-learning. Moreover, we exhibit their dynamical behaviors for chosen different parameters. The vector financial rogue wave (rogon) solutions may be used to describe the possible physical mechanisms for the rogue wave phenomena and to further excite the possibility of relative researches and potential applications of vector rogue waves in the financial markets and other related fields. -- Highlights: ► We investigate the coupled nonlinear volatility and option pricing model. ► We analytically present vector financial rogue waves. ► The vector financial rogue waves may be used to describe the extreme events in financial markets. ► This results may excite the relative researches and potential applications of vector rogue waves.
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
Fujii, Yoichi; Murase, Yasunori; Otake, Kaori; Yokota, Yasuko; Omoto, Shinya; Hayashi, Hidetoshi; Okada, Hidetika; Okada, Noriko; Kawai, Masahiro; Okuyama, Harumi; Imakawa, Kazuhiko
2004-02-01
Interferon-tau (IFN-tau), produced by the embryonic trophectoderm, is a member of type I IFNs required for the establishment of pregnancy in the ruminant ungulates. Although this IFN possesses antiviral activity similar to other type I IFNs, the effectiveness of IFN-tau as an antiviral agent has not been well characterized. To investigate possible antiviral effects of ovine IFN-tau (oIFN-tau), oIFN-tau-GST fusion protein was expressed in E. coli BL21, from which the purified protein isolated possessed anti-viral activity. An apathogenic human foamy virus (hFV) was then used to establish a potential recombinant live vector consisting of oIFN-tau cDNA sense (+) or antisense (-) sequence, oIFN-tau(+)/hFV or oIFN-tau(-)/hFV, respectively. Human hematopoietic and other mammalian cell lines that had been transduced with hFV vector consisting of no oIFN-tau, oIFN-tau(+)/hFV or oIFN-tau(-)/hFV construct were cultured initially for 12 days, and three of cell lines were then maintained for up to 90 days. These cells with oIFN-tau expression directed by hFV exhibited the in vitro cytopathic effect minimally. Transduced cell lines that had been cultured for 90 days were subjected to studies on human immunodeficiency virus type-1 (HIV-1) infection, which was measured with infectivity of viral particles resulted from the GFP inserted T-cell tropic HIV SF2 or macrophage tropic HIV SF162: the number of HIV-1 positive cells was reduced by the hFV driven-intra-cellular oIFN-tau expression. Since oIFN-tau/hFV transduced cells exhibited the resistance to HIV-1 infection and/or replication, oIFN-tau could be considered as one of effective antiviral agents against HIV-1. These results suggest that the hFV genome could be an effective recombinant live vector for the expression of a targeted gene in various cell types. PMID:15031537
There have been two versions of SWAT depending on details of its development history: the revised SWAT that uses the deterministic calculation code SRAC as a neutron transportation solver, and the SWAT3.1 that uses the continuous energy Monte Carlo code MVP or MCNP5 for the same purpose. It takes several hours, however, to execute one calculation by the continuous energy Monte Carlo code even on the super computer of the Japan Atomic Energy Agency. Moreover, two-dimensional burnup calculation is not practical using the revised SWAT because it has problems on production of effective cross section data and applying them to arbitrary fuel geometry when a calculation model has multiple burnup zones. Therefore, SWAT4.0 has been developed by adding, to SWAT3.1, a function to utilize the deterministic code SARC2006, which has shorter calculation time, as an outer module of neutron transportation solver for burnup calculation. SWAT4.0 has been enabled to execute two-dimensional burnup calculation by providing an input data template of SRAC2006 to SWAT4.0 input data, and updating atomic number densities of burnup zones in each burnup step. This report describes outline, input data instruction, and examples of calculations of SWAT4.0. (author)
Godsey, Marvin S., Jr.; King, Raymond J.; Burkhalter, Kristen; Delorey, Mark; Colton, Leah; Charnetzky, Dawn; Sutherland, Genevieve; Ezenwa, Vanessa O.; Wilson, Lawrence A.; Coffey, Michelle; Milheim, Lesley E.; Taylor, Viki G.; Palmisano, Charles; Wesson, Dawn M.; Guptill, Stephen C.
2013-01-01
A study of West Nile virus (WNV) ecology was conducted in St. Tammany Parish, Louisiana, from 2002 to 2004. Mosquitoes were collected weekly throughout the year using Centers for Disease Control and Prevention (CDC) light traps placed at 1.5 and 6 m above the ground and gravid traps. A total of 379,466 mosquitoes was collected. WNV was identified in 32 pools of mosquitoes comprising four species; 23 positive pools were from Culex nigripalpus collected during 2003. Significantly more positive pools were obtained from Cx. nigripalpus collected in traps placed at 6 m than 1.5 m that year, but abundance did not differ by trap height. In contrast, Cx. nigripalpus abundance was significantly greater in traps placed at 6 m in 2002 and 2004. Annual temporal variation in Cx. nigripalpus peak seasonal abundance has important implications for WNV transmission in Louisiana. One WNV-positive pool, from Cx. erraticus, was collected during the winter of 2004, showing year-round transmission. The potential roles of additional mosquito species in WNV transmission in southeastern Louisiana are discussed. Disclaimer: The opinions expressed in this article are the opinions of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. This article has been peer reviewed and approved for publication consistent with U.S. Geological Survey Fundamental Science Practices (http//pubs.usgs.gov/circ/1367/). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Santhosh, S B; Yuvarajan, R; Natarajan, D
2015-08-01
Mosquitoes transmit several diseases which cause millions of deaths every year. The use of synthetic insecticides to control mosquitoes caused diverse effects to the environment, mammals, and high manufacturing cost. The present study was aimed to test the larvicidal activity of green synthesized silver nanoparticles using Annona muricata plant leaf extract against third instar larvae of three medically important mosquitoes, i.e., Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. The different concentrations of green synthesized Ag Nanoparticles (AgNPs; 6, 12, 18, 24, 30 μg mL(-1)) and aqueous crude leaf extract (30, 60, 90, 120, 150 μg mL(-1)) were tested against the larvae for 24 h. Significant larval mortality was observed after the treatment of A. muricata for all mosquitoes with lowest LC50 and LC90 values, viz., A. aegypti (LC50 and LC90 values of 12.58 and 26.46 μg mL(-1)), A. stephensi (LC50 and LC90 values of 15.28 and 31.91 μg mL(-1)) and C. quinquefasciatus (LC50 and LC90 values of 18.77 and 35.72 μg mL(-1)), respectively. The synthesized AgNPs from A. muricata were highly toxic than aqueous crude extract. The nanoparticle characterization was done using spectral and microscopic analysis, namely UV-visible spectroscopy which showed a sharp peak at 420 nm of aqueous medium containing AgNPs, X-ray diffraction (XRD) analysis revealed the average crystalline size of synthesized AgNPs (approximately 45 nm), and Fourier transform infrared spectroscopy (FTIR) study exhibited prominent peaks 3381.28, 2921.03, 1640.17, 1384.58, 1075.83, and 610.77 cm(-1). Particle size analysis (PSA) showed the size and distribution of AgNPs (103 nm); field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) analysis showed a spherical shape, size range from 20 to 53 nm; and energy-dispersive X-ray spectroscopy (EDX) reflects the chemical composition of synthesized AgNPs. Heat stability of the AgNPs was confirmed between the temperatures 20 to 70 °C. The result suggests that green synthesized AgNPs from A. muricata has the potential to be used as a low-cost and eco-friendly approach for the control of selected mosquitoes. PMID:26002825
Arjunan Nareshkumar; Kadarkarai Murugan; Indra Baruah; Pari Madhiyazhagan; Thiyagarajan Nataraj
2012-01-01
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 quin...
Vector ecology of equine piroplasmosis.
Scoles, Glen A; Ueti, Massaro W
2015-01-01
Equine piroplasmosis is a disease of Equidae, including horses, donkeys, mules, and zebras, caused by either of two protozoan parasites, Theileria equi or Babesia caballi. These parasites are biologically transmitted between hosts via tick vectors, and although they have inherent differences they are categorized together because they cause similar pathology and have similar morphologies, life cycles, and vector relationships. To complete their life cycle, these parasites must undergo a complex series of developmental events, including sexual-stage development in their tick vectors. Consequently, ticks are the definitive hosts as well as vectors for these parasites, and the vector relationship is restricted to a few competent tick species. Because the vector relationship is critical to the epidemiology of these parasites, we highlight current knowledge of the vector ecology of these tick-borne equine pathogens, emphasizing tick transmissibility and potential control strategies to prevent their spread. PMID:25564746
Robinson, Gilbert de B
2011-01-01
This brief undergraduate-level text by a prominent Cambridge-educated mathematician explores the relationship between algebra and geometry. An elementary course in plane geometry is the sole requirement for Gilbert de B. Robinson's text, which is the result of several years of teaching and learning the most effective methods from discussions with students. Topics include lines and planes, determinants and linear equations, matrices, groups and linear transformations, and vectors and vector spaces. Additional subjects range from conics and quadrics to homogeneous coordinates and projective geom
A series of critical experiments with PWR-type MOX fuel conducted at the TCA facility of Japan Atomic Energy Research Institute have been analyzed. The cores were composed of a central 4.91 wt% plutonium enriched mixed-oxide (PuO2-UO2) 10 x 10 test lattice with water-to-fuel volume ratio of 2.40 or 2.96, surrounded by 2.6 wt% enriched UO2 driver lattice with water-to-fuel volume ratio of 1.50. The fissile plutonium content was 91.4 wt%. The critical water level, the power distribution in MOX region, and the neutron activation distribution of Au-wire were measured for six different cores of which two contain soluble boron in 309.4 and 554.0 ppm, one contains four equidistant water holes in the central lattice and one contains a cross water gap at the core center. Calculation of corresponding effective multiplication factor, the fission reaction rate distribution, and the capture reaction rate distribution of Au have been performed using continuous-energy Monte Carlo code MVP with two nuclear data sets based on JENDL-3.2 and JENDL-3.3. The calculated results agreed to the measurement within a maximum difference of 0.27% for the effective multiplication factors, 3.0% for power distributions, 5.9% for the thermal activation distributions throughout the whole region, and 4.3% for the epithermal activation distributions in the core region. (author)
Laura Suárez; Gabriel Parra-Henao
2011-01-01
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 f...
Colette, W. Arden; Almas, Lal K.
2004-01-01
Production data provided by commercial producers of grain sorghum is used to estimate response functions for three alternative management decision models. The evaluation of yield to the total water availability, irrigation, and water application as a percent of potential evapotranspiration. The three methods provide similar results, but each provides unique information and adds valuable information to the decision process. The value product functions and the energy cost function are used to d...
2012-01-01
generation of a reference beam, a detector system comprising a first detector arrangement arranged in such a way that the signal beam and the reference beam are incident upon the first detector arrangement with the reference beam propagating at an angle relative to a signal beam, and wherein the first......The present invention relates to a compact, reliable and low-cost vector velocimeter for example for determining velocities of particles suspended in a gas or fluid flow, or for determining velocity, displacement, rotation, or vibration of a solid surface, the vector velocimeter comprising a laser...... assembly for emission of a measurement beam for illumination of an object in a measurement volume with coherent light whereby a signal beam emanating from the object in the measurement volume is formed in response to illumination of the object by the measurement beam, a reference beam generator for...
Fisher, Tonja W.; Meenal Vyas; Ruifeng He; William Nelson; Joseph M. Cicero; Mark Willer; Ryan Kim; Robin Kramer; May, Greg A.; John A. Crow; Soderlund, Carol A.; Gang, David R; Brown, Judith K.
2014-01-01
The potato psyllid (PoP) Bactericera cockerelli (Sulc) and Asian citrus psyllid (ACP) Diaphorina citri Kuwayama are the insect vectors of the fastidious plant pathogen, Candidatus Liberibacter solanacearum (CLso) and Ca. L. asiaticus (CLas), respectively. CLso causes Zebra chip disease of potato and vein-greening in solanaceous species, whereas, CLas causes citrus greening disease. The reliance on insecticides for vector management to reduce pathogen transmission has increased interest in alt...
The authors have previously described a defective herpes simplex virus (HSV-1) vector system that permits that introduction of virtually any gene into nonmitotic cells. pHSVlac, the prototype vector, stably expresses Escherichia coli β-galactosidase from a constitutive promoter in many human cell lines, in cultured rat neurons from throughout the nervous system, and in cells in the adult rat brain. HSV-1 vectors expressing other genes may prove useful for studying neuronal physiology or performing human gene therapy for neurological diseases, such as Parkinson disease or brain tumors. A HSV-1 temperature-sensitive (ts) mutant, ts K, has been used as helper virus; ts mutants revert to wild type. In contrast, HSV-1 deletion mutants essentially cannot revert to wild type; therefore, use of a deletion mutant as helper virus might permit human gene therapy with HSV-1 vectors. They now report an efficient packaging system for HSV-1 VECTORS USING A DELETION MUTANT, d30EBA, as helper virus; virus is grown on the complementing cell line M64A. pHSVlac virus prepared using the deletion mutant packaging system stably expresses β-galactosidase in cultured rat sympathetic neurons and glia. Both D30EBA and ts K contain a mutation in the IE3 gene of HSV-1 strain 17 and have the same phenotype; therefore, changing the helper virus from ts K to D30EBA does not alter the host range or other properties of the HSV-1 vector system
Effect of potential on bismuth telluride thin film growth by electrochemical atomic layer epitaxy
In the present study, bismuth telluride compound thin film was grown by means of electrochemical atomic layer epitaxy (ECALE) with an automated thin layer flow cell deposition system. The dependence of the Bi and Te deposition potentials on Pt electrode was studied. Because developing a contact potential between the substrate and the growing semiconductor, the deposition potential adjustment is necessary for the first 30 or more cycles of each component. The dependence of the deposit as a function of the deposition potential adjustment slope has been investigated. The results show that an excess elemental Bi existed at a slope of -2 mV/p (p indicates per cycle), indicating that this is a lack of deposition at the potential. Single-phase Bi2Te3 compound could be obtained between -4 and -6 mV/p. Bi2Te3 and Bi4Te3 coexistence is observed at a slope of -10 mV/p. The EDS data indicates that the stoichiometry of compound is consistent with XRD result. SEM studies show that the deposits are inhomogeneous and have an micron sized particles morphology
Govindarajan, Marimuthu; Rajeswary, Mohan; Arivoli, Subramanian; Tennyson, Samuel; Benelli, Giovanni
2016-05-01
Mosquitoes (Diptera: Culicidae) are important vectors of terms of public health relevance, especially in tropical and sub-tropical regions. The continuous and indiscriminate use of conventional pesticides for the control of mosquito vectors has resulted in the development of resistance and negative impacts on non-target organisms and the environment. Therefore, there is a need for development of effective mosquito control tools. In this study, the larvicidal and repellent activity of Zingiber nimmonii rhizome essential oil (EO) was evaluated against the malaria vector Anopheles stephensi, the dengue vector Aedes aegypti, and the lymphatic filariasis vector Culex quinquefasciatus. The chemical composition of the EO was analyzed by gas chromatography-mass spectroscopy (GC-MS). GC-MS revealed that the Z. nimmonii EO contained at least 33 compounds. Major constituents were myrcene, β-caryophyllene, α-humulene, and α-cadinol. In acute toxicity assays, the EO showed significant toxicity against early third-stage larvae of An. stephensi, Ae. aegypti, and Cx. quinquefasciatus, with LC50 values of 41.19, 44.46, and 48.26 μg/ml, respectively. Repellency bioassays at 1.0, 2.0, and 5.0 mg/cm(2) of Z. nimmonii EO gave 100 % protection up to 120, 150, and 180 min. against An. stephensi, followed by Ae. aegypti (90, 120, and 150 min) and Cx. quinquefasciatus (60, 90, and 120 min). Furthermore, the EO was safer towards two non-target aquatic organisms, Diplonychus indicus and Gambusia affinis, with LC50 values of 3241.53 and 9250.12 μg/ml, respectively. Overall, this research adds basic knowledge to develop newer and safer natural larvicides and repellent from Zingiberaceae plants against malaria, dengue, and filariasis mosquito vectors. PMID:26792432
Cassan, M; Berteaux, V; Angrand, P O; Rousset, J P
1990-01-01
Translational errors are necessary so as to allow gene expression in various organisms. In retroviruses, synthesis of pol gene products necessitates either readthrough of a stop codon or frameshifting. Here we present an experimental system that permits quantification of translational errors in vivo. It consists of a family of expression vectors carrying different mutated versions of the luc gene as reporter. Mutations include both an in-frame stop codon and 1-base-pair deletions that require readthrough or frameshift, respectively, to give rise to an active product. This system is sensitive enough to detect background errors in mammalian cells. In addition, one of the vectors contains two unique cloning sites that make it possible to insert any sequence of interest. This latter vector was used to analyse the effect of a DNA fragment, proposed to be the target of high level slippage at the gag-pol junction of HIV. The effect of paromomycin and kasugamycin, two antibiotics known to influence translational ambiguity, was also tested in cultured cells. The results indicate that paromomycin diversely affects readthrough and frameshifting, while kasugamycin had no effect. This family of vectors can be used to analyse the influence of structural and external factors on translational ambiguity in both mammalian cells and bacteria. PMID:2087598
Abd-Ella, Aly; Stankiewicz, Maria; Mikulska, Karolina; Nowak, Wieslaw; Pennetier, Cédric; Goulu, Mathilde; Fruchart-Gaillard, Carole; Licznar, Patricia; Apaire-Marchais, Véronique; List, Olivier; Corbel, Vincent; Servent, Denis; Lapied, Bruno
2015-01-01
Insect vector-borne diseases remain one of the principal causes of human mortality. In addition to conventional measures of insect control, repellents continue to be the mainstay for personal protection. Because of the increasing pyrethroid-resistant mosquito populations, alternative strategies to reconstitute pyrethroid repellency and knock-down effects have been proposed by mixing the repellent DEET (N,N-Diethyl-3-methylbenzamide) with non-pyrethroid insecticide to better control resistant ...
REISENMAN, CAROLINA E.; Gregory, Teresa; Guerenstein, Pablo G; HILDEBRAND, JOHN G.
2011-01-01
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host. We thus studied the feeding and defeca...
Tonja W. Fisher
2014-11-01
Full Text Available The potato psyllid (PoP Bactericera cockerelli (Sulc and Asian citrus psyllid (ACP Diaphorina citri Kuwayama are the insect vectors of the fastidious plant pathogen, Candidatus Liberibacter solanacearum (CLso and Ca. L. asiaticus (CLas, respectively. CLso causes Zebra chip disease of potato and vein-greening in solanaceous species, whereas, CLas causes citrus greening disease. The reliance on insecticides for vector management to reduce pathogen transmission has increased interest in alternative approaches, including RNA interference to abate expression of genes essential for psyllid-mediated Ca. Liberibacter transmission. To identify genes with significantly altered expression at different life stages and conditions of CLso/CLas infection, cDNA libraries were constructed for CLso-infected and -uninfected PoP adults and nymphal instars. Illumina sequencing produced 199,081,451 reads that were assembled into 82,224 unique transcripts. PoP and the analogous transcripts from ACP adult and nymphs reported elsewhere were annotated, organized into functional gene groups using the Gene Ontology classification system, and analyzed for differential in silico expression. Expression profiles revealed vector life stage differences and differential gene expression associated with Liberibacter infection of the psyllid host, including invasion, immune system modulation, nutrition, and development.
Sultana, Hameeda; Patel, Unnati; Toliver, Marce; Maggi, Ricardo G; Neelakanta, Girish
2016-02-01
Salp15, a 15-kDa salivary gland protein plays an important role in tick blood-feeding and transmission of Borrelia burgdorferi, the causative agent of Lyme borreliosis. The comparative studies reveal that Salp15 is a genetically conserved protein across various Ixodes species. In this study, we have identified a Salp15 homolog, designated as Iaff15, from Ixodes affinis ticks that are the principal enzootic vectors of B. burgdorferi sensu stricto in the southeastern part of the United States. Comparison of the annotated amino acid sequences showed that Iaff15 share 81% homology with I. sinensis Salp15 homolog and 64% homology with I. scapularis Salp15. Phylogenetic analysis revealed that Iaff15 come within the same clade with I. sinensis, I. scapularis, and I. pacificus Salp15 homologs. The bioinformatics analysis of the posttranslational modifications prediction revealed that all the Salp15 family members contain glycosylation sites. In addition, Iaff15 carried a higher number of Casein Kinase II phosphorylation sites in comparison to the other Salp15 family members. Collectively, high sequence conservation distributed over the entire amino acids sequence not only suggests an important role for Iaff15 in I. affinis blood feeding and vector-pathogen interactions but may also lead to the development of an anti-vector vaccine against this group of ticks. PMID:26296588
Charalambous M
1997-01-01
Full Text Available 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
Helper-Dependent Adenoviral Vectors
Rosewell, Amanda; Vetrini, Francesco; Ng, Philip
2011-01-01
Helper-dependent adenoviral vectors are devoid of all viral coding sequences, possess a large cloning capacity, and can efficiently transduce a wide variety of cell types from various species independent of the cell cycle to mediate long-term transgene expression without chronic toxicity. These non-integrating vectors hold tremendous potential for a variety of gene transfer and gene therapy applications. Here, we review the production technologies, applications, obstacles to clinical translat...
Allan Kardec Ribeiro Galardo
2015-06-01
Full Text Available INTRODUCTION: An entomological study was conducted as part of a vector-monitoring program in the area associated with the Santo Antônio hydroelectric system in State of Rondônia, Western Amazonian Brazil. METHODS: Fourteen sampling sites were surveyed to obtain data on the potential vectors of Leishmania spp. in the area. Sand flies were collected from 2011 to 2014 during the months of January/February (rainy season, May/June (dry season, and September/October (intermediary season using light traps arranged in three vertical strata (0.5, 1, and 20m. RESULTS : A total of 7,575 individuals belonging to 62 species/subspecies were collected. The five most frequently collected sand flies were Psychodopygus davisi (Root (36.67%, Trichophoromyia ubiquitalis (Mangabeira (8.51%, Nyssomyia umbratilis (Ward & Fraiha (6.14%, Bichromomyia flaviscutellata (Mangabeira (5.74%, and Psychodopygus complexus (Mangabeira (5.25%. These species have been implicated in the transmission of American cutaneous leishmaniasis agents in the Brazilian Amazon region and described as potential vectors of this disease in the study area. CONCLUSIONS: Additional surveillance is needed, especially in areas where these five species of sand fly are found.
Davydov, Evgeny
2011-01-01
Vector fields can arise in the cosmological context in different ways, and we discuss both abelian and nonabelian sector. In the abelian sector vector fields of the geometrical origin (from dimensional reduction and Einstein-Eddington modification of gravity) can provide a very non-trivial dynamics, which can be expressed in terms of the effective dilaton-scalar gravity with the specific potential. In the non-abelian sector we investigate the Yang-Mills SU(2) theory which admits isotropic and homogeneous configuration. Provided the non-linear dependence of the lagrangian on the invariant F*F(dual), one can obtain the inflationary regime with the exponential growth of the scale factor. The effective amplitudes of the 'electric' and 'magnetic' components behave like slowly varying scalars at this regime, what allows the consideration of some realistic models with non-linear terms in the Yang-Mills lagrangian.
Chikungunya Virus–Vector Interactions
Lark L. Coffey
2014-11-01
Full Text Available Chikungunya virus (CHIKV is a mosquito-borne alphavirus that causes chikungunya fever, a severe, debilitating disease that often produces chronic arthralgia. Since 2004, CHIKV has emerged in Africa, Indian Ocean islands, Asia, Europe, and the Americas, causing millions of human infections. Central to understanding CHIKV emergence is knowledge of the natural ecology of transmission and vector infection dynamics. This review presents current understanding of CHIKV infection dynamics in mosquito vectors and its relationship to human disease emergence. The following topics are reviewed: CHIKV infection and vector life history traits including transmission cycles, genetic origins, distribution, emergence and spread, dispersal, vector competence, vector immunity and microbial interactions, and co-infection by CHIKV and other arboviruses. The genetics of vector susceptibility and host range changes, population heterogeneity and selection for the fittest viral genomes, dual host cycling and its impact on CHIKV adaptation, viral bottlenecks and intrahost diversity, and adaptive constraints on CHIKV evolution are also discussed. The potential for CHIKV re-emergence and expansion into new areas and prospects for prevention via vector control are also briefly reviewed.
New Constitutive Vectors: Useful Genetic Engineering Tools for Biocatalysis
Xu, Youqiang; Tao, Fei; Ma, Cuiqing; Xu, Ping
2013-01-01
Constitutive vectors are useful tools for genetic engineering. Two constitutive vectors with high levels of expression and broad host ranges were developed and used in a range of Pseudomonas hosts. The vectors showed superior characteristics compared to the inducible vectors as well as the potential to be used as improved genetic tools for biocatalysis.
Vectorization, parallelization and porting of nuclear codes (porting). Progress report fiscal 1999
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)
Vectorization, parallelization and porting of nuclear codes (porting). Progress report fiscal 1999
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
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)
Rotations with Rodrigues' Vector
Pina, E.
2011-01-01
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
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
Viral vectors for vascular gene therapy
Fischer, Lukas; Preis, Meir; Weisz, Anat; Koren, Belly; Lewis, Basil S; Flugelman, Moshe Y.
2002-01-01
Vascular gene therapy is the focus of multiple experimental and clinical research efforts. While several genes with therapeutic potential have been identified, the best method of gene delivery is unknown. Viral vectors have the capacity to transfer genes at high efficiency rates. Several viral-based vectors have been used in experimental vascular gene therapy for in vivo and ex vivo gene transfer. Adenoviral-based vectors are being used for the induction of angiogenesis in phase 1 and 2 clini...
Nagappan Raja
2012-07-01
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.
Introduction to Vector Spaces, Vector Algebras, and Vector Geometries
Smith, Richard A
2011-01-01
An introductory overview of vector spaces, algebras, and linear geometries over an arbitrary commutative field is given. Quotient spaces are emphasized and used in constructing the exterior and the symmetric algebras of a vector space. Affine geometries are introduced and generalized by projective completion. General projective geometries are briefly introduced. Tensor products and multilinear functions are treated. The exterior algebra of a vector space and that of its dual are used in treating linear geometry and Grassmann's regressive product is treated. Scalar product spaces, orthogonality, and the Hodge star based on a general basis are covered.
Mok Tik
2014-06-01
Full Text Available This study formulates regression of vector data that will enable statistical analysis of various geodetic phenomena such as, polar motion, ocean currents, typhoon/hurricane tracking, crustal deformations, and precursory earthquake signals. The observed vector variable of an event (dependent vector variable is expressed as a function of a number of hypothesized phenomena realized also as vector variables (independent vector variables and/or scalar variables that are likely to impact the dependent vector variable. The proposed representation has the unique property of solving the coefficients of independent vector variables (explanatory variables also as vectors, hence it supersedes multivariate multiple regression models, in which the unknown coefficients are scalar quantities. For the solution, complex numbers are used to rep- resent vector information, and the method of least squares is deployed to estimate the vector model parameters after transforming the complex vector regression model into a real vector regression model through isomorphism. Various operational statistics for testing the predictive significance of the estimated vector parameter coefficients are also derived. A simple numerical example demonstrates the use of the proposed vector regression analysis in modeling typhoon paths.
Eliezer, C J; Maxwell, E A; Sneddon, I N
1963-01-01
Concise Vector Analysis is a five-chapter introductory account of the methods and techniques of vector analysis. These methods are indispensable tools in mathematics, physics, and engineering. The book is based on lectures given by the author in the University of Ceylon.The first two chapters deal with vector algebra. These chapters particularly present the addition, representation, and resolution of vectors. The next two chapters examine the various aspects and specificities of vector calculus. The last chapter looks into some standard applications of vector algebra and calculus.This book wil
Carlier, Guillaume; Chernozhukov, Victor; Galichon, Alfred
2015-01-01
We propose a notion of conditional vector quantile function and a vector quantile regression. A conditional vector quantile function (CVQF) of a random vector Y, taking values in ℝd given covariates Z=z, taking values in ℝk, is a map u↦QY∣Z(u,z), which is monotone, in the sense of being a gradient of a convex function, and such that given that vector U follows a reference non-atomic distribution FU, for instance uniform distribution on a unit cube in ℝd, the random vector QY∣Z(U,z) has the...
Adrias Araceli Q
2010-05-01
Full Text Available Abstract Background Mosquitoes that breed in temporary pools in remote areas that dry up seasonally are especially difficult to control through chemical or biological means. The annual killifish has been suggested as a means of eradicating the aquatic stages of mosquitoes in transient pools because they can maintain permanent populations in such habitats by undergoing suspended animation or diapause during the embryonic stages to survive periodic drought. However, very little is known about the predatory activity of annual killifish and their usefulness in mosquito control. Results The annual killifish, Nothobranchius guentheri, native to Tanzania, was used in this investigation. Food preference was tested under laboratory conditions by feeding juvenile killifish with 2nd instar mosquito larvae of Culex quinquefasciatus in the presence of alternative food sources, such as rotifers and chironomid larvae. Semi-field tests were conducted by introduction of hibernating killifish embryos and juvenile fish to artificial ponds in an outdoor open environment that allowed natural oviposition of Cx. quinquefasciatus. Food preference studies show that N. guentheri preferred to prey on mosquito larvae than either chironomid or rotifers. When hibernating killifish embryos were added to ponds simultaneously with the addition of freshwater, the embryos hatched and fed on mosquito larval population resulting in complete elimination of the immature stages. The introduction of juvenile fish to ponds with high density of mosquito larvae resulted in total eradication of the mosquito population due to predation by fish. Complete biocontrol of the mosquito larval population was achieved in the presence of 3 fish per m2 of pond surface area. Conclusions The annual killifish provides yet another tool that may be employed in the eradication diseases carried by mosquitoes through vector control, particularly in temporary bodies of freshwater. The fish can be conveniently transported in the absence of water in the form of hibernating embryos. Once introduced either as embryos or juveniles in ponds, the annual killifish can effectively reduce the larval population because of its aggressive predatory activity.
2010-01-01
Background Mosquitoes that breed in temporary pools in remote areas that dry up seasonally are especially difficult to control through chemical or biological means. The annual killifish has been suggested as a means of eradicating the aquatic stages of mosquitoes in transient pools because they can maintain permanent populations in such habitats by undergoing suspended animation or diapause during the embryonic stages to survive periodic drought. However, very little is known about the predatory activity of annual killifish and their usefulness in mosquito control. Results The annual killifish, Nothobranchius guentheri, native to Tanzania, was used in this investigation. Food preference was tested under laboratory conditions by feeding juvenile killifish with 2nd instar mosquito larvae of Culex quinquefasciatus in the presence of alternative food sources, such as rotifers and chironomid larvae. Semi-field tests were conducted by introduction of hibernating killifish embryos and juvenile fish to artificial ponds in an outdoor open environment that allowed natural oviposition of Cx. quinquefasciatus. Food preference studies show that N. guentheri preferred to prey on mosquito larvae than either chironomid or rotifers. When hibernating killifish embryos were added to ponds simultaneously with the addition of freshwater, the embryos hatched and fed on mosquito larval population resulting in complete elimination of the immature stages. The introduction of juvenile fish to ponds with high density of mosquito larvae resulted in total eradication of the mosquito population due to predation by fish. Complete biocontrol of the mosquito larval population was achieved in the presence of 3 fish per m2 of pond surface area. Conclusions The annual killifish provides yet another tool that may be employed in the eradication diseases carried by mosquitoes through vector control, particularly in temporary bodies of freshwater. The fish can be conveniently transported in the absence of water in the form of hibernating embryos. Once introduced either as embryos or juveniles in ponds, the annual killifish can effectively reduce the larval population because of its aggressive predatory activity. PMID:20492714
Axial Current, Killing Vector and Newtonian Gravity
Mahato, Prasanta
2010-01-01
Starting from the multiplicative torsion approach of gravity and assuming a Killing vector to be proportional to the axial-vector matter current, here we derive Newton's law of gravity where the logarithm of the proportionality factor has been found to be the potential function.
Vector perturbations of galaxy number counts
Durrer, Ruth
2016-01-01
We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, where the Bardeen potentials are replaced with line-of-sight projection of vector and tensor quantities. Since vector and tensor perturbations do not lead to density fluctuations the standard density term in the number counts is absent. We apply our results to vector perturbations which are induced from scalar perturbations at second order and give numerical estimates of their contributions to the power spectrum of relativistic galaxy number counts.
Production of high-capacity adenovirus vectors.
Kreppel, Florian
2014-01-01
High-capacity adenoviral vectors (HC-Ad), also known as "helper-dependent" (HD-Ad), "gutless", "gutted", or "third-generation" Ad vectors, are devoid of all viral coding sequences and have shown promising potential for a wide variety of different applications-from classic gene therapy to genetic vaccination and tumor treatment. However, compared to first-generation adenoviral vectors their production is more complex and requires specific in-depth knowledge. This chapter delivers a detailed protocol for the successful production of HC-Ad vectors to high titers. PMID:24132488
Complex Polynomial Vector Fields
vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields....
Ebrahimi, Javad; Fragouli, Christina
2010-01-01
We develop new algebraic algorithms for scalar and vector network coding. In vector network coding, the source multicasts information by transmitting vectors of length L, while intermediate nodes process and combine their incoming packets by multiplying them with L X L coding matrices that play a similar role as coding coefficients in scalar coding. Our algorithms for scalar network jointly optimize the employed field size while selecting the coding coefficients. Similarly, for vector co...
Vector Network Coding Algorithms
Ebrahimi, Javad; Fragouli, Christina
2010-01-01
We develop new algebraic algorithms for scalar and vector network coding. In vector network coding, the source multicasts information by transmitting vectors of length L, while intermediate nodes process and combine their incoming packets by multiplying them with L x L coding matrices that play a similar role as coding c in scalar coding. Our algorithms for scalar network jointly optimize the employed field size while selecting the coding coefficients. Similarly, for vector coding, our algori...
Aminu, Abdulhadi
2010-01-01
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
Becciolini, Diego; Franzosi, Diogo Buarque; Foadi, Roshan; Frandsen, Mads T.; Hapola, Tuomas; Sannino, Francesco
2015-01-01
We analyze the Large Hadron Collider (LHC) phenomenology of heavy vector resonances with a $SU(2)_L\\times SU(2)_R$ spectral global symmetry. This symmetry partially protects the electroweak S-parameter from large contributions of the vector resonances. The resulting custodial vector model spectrum...
Rosenberg, Ronald; Ben Beard, C.
2011-01-01
Infections with vector-borne pathogens are a major source of emerging diseases. The ability of vectors to bridge spatial and ecologic gaps between animals and humans increases opportunities for emergence. Small adaptations of a pathogen to a vector can have profound effects on the rate of transmission to humans.
A generalized nonlocal vector calculus
Alali, Bacim; Liu, Kuo; Gunzburger, Max
2015-10-01
A nonlocal vector calculus was introduced in Du et al. (Math Model Meth Appl Sci 23:493-540, 2013) that has proved useful for the analysis of the peridynamics model of nonlocal mechanics and nonlocal diffusion models. A formulation is developed that provides a more general setting for the nonlocal vector calculus that is independent of particular nonlocal models. It is shown that general nonlocal calculus operators are integral operators with specific integral kernels. General nonlocal calculus properties are developed, including nonlocal integration by parts formula and Green's identities. The nonlocal vector calculus introduced in Du et al. (Math Model Meth Appl Sci 23:493-540, 2013) is shown to be recoverable from the general formulation as a special example. This special nonlocal vector calculus is used to reformulate the peridynamics equation of motion in terms of the nonlocal gradient operator and its adjoint. A new example of nonlocal vector calculus operators is introduced, which shows the potential use of the general formulation for general nonlocal models.
Covariantised Vector Galileons
Hull, Matthew; Tasinato, Gianmassimo
2015-01-01
Vector galileons are ghost-free systems containing higher derivative interactions of vector fields. They break the vector gauge symmetry, and the dynamics of the longitudinal vector polarizations acquire a Galileon symmetry in an appropriate decoupling limit in Minkowski space. Using an ADM approach, we carefully reconsider the coupling with gravity of vector galileons, with the aim of studying the necessary conditions to avoid the propagation of ghosts. We develop arguments that put on a more solid footing the results previously obtained in the literature. Moreover, working in analogy with the scalar counterpart, we find indications for the existence of a `beyond Horndeski' theory involving vector degrees of freedom, that avoids the propagation of ghosts thanks to secondary constraints. In addition, we analyse a Higgs mechanism for generating vector galileons through spontaneous symmetry breaking, and we present its consistent covariantisation.
Rotations with Rodrigues' vector
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.
Oliveira, Francisco P. M.; Castelo-Branco, Miguel
2015-04-01
Objective. The aim of the present study was to develop a fully-automated computational solution for computer-aided diagnosis in Parkinson syndrome based on [123I]FP-CIT single photon emission computed tomography (SPECT) images. Approach. A dataset of 654 [123I]FP-CIT SPECT brain images from the Parkinson’s Progression Markers Initiative were used. Of these, 445 images were of patients with Parkinson’s disease at an early stage and the remainder formed a control group. The images were pre-processed using automated template-based registration followed by the computation of the binding potential at a voxel level. Then, the binding potential images were used for classification, based on the voxel-as-feature approach and using the support vector machines paradigm. Main results. The obtained estimated classification accuracy was 97.86%, the sensitivity was 97.75% and the specificity 98.09%. Significance. The achieved classification accuracy was very high and, in fact, higher than accuracies found in previous studies reported in the literature. In addition, results were obtained on a large dataset of early Parkinson’s disease subjects. In summation, the information provided by the developed computational solution potentially supports clinical decision-making in nuclear medicine, using important additional information beyond the commonly used uptake ratios and respective statistical comparisons. (ClinicalTrials.gov Identifier: NCT01141023)
Are Bred Vectors The Same As Lyapunov Vectors?
Kalnay, E.; Corazza, M.; Cai, M.
Regional loss of predictability is an indication of the instability of the underlying flow, where small errors in the initial conditions (or imperfections in the model) grow to large amplitudes in finite times. The stability properties of evolving flows have been studied using Lyapunov vectors (e.g., Alligood et al, 1996, Ott, 1993, Kalnay, 2002), singular vectors (e.g., Lorenz, 1965, Farrell, 1988, Molteni and Palmer, 1993), and, more recently, with bred vectors (e.g., Szunyogh et al, 1997, Cai et al, 2001). Bred vectors (BVs) are, by construction, closely related to Lyapunov vectors (LVs). In fact, after an infinitely long breeding time, and with the use of infinitesimal ampli- tudes, bred vectors are identical to leading Lyapunov vectors. In practical applications, however, bred vectors are different from Lyapunov vectors in two important ways: a) bred vectors are never globally orthogonalized and are intrinsically local in space and time, and b) they are finite-amplitude, finite-time vectors. These two differences are very significant in a dynamical system whose size is very large. For example, the at- mosphere is large enough to have "room" for several synoptic scale instabilities (e.g., storms) to develop independently in different regions (say, North America and Aus- tralia), and it is complex enough to have several different possible types of instabilities (such as barotropic, baroclinic, convective, and even Brownian motion). Bred vectors share some of their properties with leading LVs (Corazza et al, 2001a, 2001b, Toth and Kalnay, 1993, 1997, Cai et al, 2001). For example, 1) Bred vectors are independent of the norm used to define the size of the perturba- tion. Corazza et al. (2001) showed that bred vectors obtained using a potential enstro- phy norm were indistinguishable from bred vectors obtained using a streamfunction squared norm, in contrast with singular vectors. 2) Bred vectors are independent of the length of the rescaling period as long as the perturbations remain approximately linear (for example, for atmospheric models the interval for rescaling could be varied between a single time step and 1 day without affecting qualitatively the characteristics of the bred vectors. However, the finite-amplitude, finite-time, and lack of orthogonalization of the BVs introduces important differences with LVs: 1) In regions that undergo strong instabilities, the bred vectors tend to be locally domi- 1 nated by simple, low-dimensional structures. Patil et al (2001) showed that the BV-dim (appendix) gives a good estimate of the number of dominant directions (shapes) of the local k bred vectors. For example, if half of them are aligned in one direction, and half in a different direction, the BV-dim is about two. If the majority of the bred vectors are aligned predominantly in one direction and only a few are aligned in a second direction, then the BV-dim is between 1 and 2. Patil et al., (2001) showed that the regions with low dimensionality cover about 20% of the atmosphere. They also found that these low-dimensionality regions have a very well defined vertical structure, and a typical lifetime of 3-7 days. The low dimensionality identifies regions where the in- stability of the basic flow has manifested itself in a low number of preferred directions of perturbation growth. 2) Using a Quasi-Geostrophic simulation system of data assimilation developed by Morss (1999), Corazza et al (2001a, b) found that bred vectors have structures that closely resemble the background (short forecasts used as first guess) errors, which in turn dominate the local analysis errors. This is especially true in regions of low dimensionality, which is not surprising if these are unstable regions where errors grow in preferred shapes. 3) The number of bred vectors needed to represent the unstable subspace in the QG system is small (about 6-10). This was shown by computing the local BV-dim as a function of the number of independent bred vectors. Convergence in the local dimen- sion starts to occur at about 6 BVs, and is essentially complete when the number of vectors is about 10-15 (Corazza et al, 2001a). This should be contrasted with the re- sults of Snyder and Joly (1998) and Palmer et al (1998) who showed that hundreds of Lyapunov vectors with positive Lyapunov exponents are needed to represent the attractor of the system in quasi-geostrophic models. 4) Since only a few bred vectors are needed, and background errors project strongly in the subspace of bred vectors, Corazza et al (2001b) were able to develop cost-efficient methods to improve the 3D-Var data assimilation by adding to the background error covariance terms proportional to the outer product of the bred vectors, thus represent- ing the "errors of the day". This approach led to a reduction of analysis error variance of about 40% at very low cost. 5) The fact that BVs have finite amplitude provides a natural way to filter out instabil- ities present in the system that have fast growth, but saturate nonlinearly at such small amplitudes that they are irrelevant for ensemble perturbations. As shown by Lorenz (1996) Lyapunov vectors (and singular vectors) of models including these physical phenomena would be dominated by the fast but small amplitude instabilities, unless they are explicitly excluded from the linearized models. Bred vectors, on the other 2 hand, through the choice of an appropriate size for the perturbation, provide a natural filter based on nonlinear saturation of fast but irrelevant instabilities. 6) Every bred vector is qualitatively similar to the *leading* LV. LVs beyond the leading LV are obtained by orthogonalization after each time step with respect to the previous LVs subspace. The orthogonalization requires the introduction of a norm. With an enstrophy norm, the successive LVs have larger and larger horizontal scales, and a choice of a stream function norm would lead to successively smaller scales in the LVs. Beyond the first few LVs, there is little qualitative similarity between the background errors and the LVs. In summary, in a system like the atmosphere with enough physical space for several independent local instabilities, BVs and LVs share some properties but they also have significant differences. BV are finite-amplitude, finite-time, and because they are not globally orthogonalized, they have local properties in space. Bred vectors are akin to the leading LV, but bred vectors derived from different arbitrary initial perturba- tions remain distinct from each other, instead of collapsing into a single leading vec- tor, presumably because the nonlinear terms and physical parameterizations introduce sufficient stochastic forcing to avoid such convergence. As a result, there is no need for global orthogonalization, and the number of bred vectors required to describe the natural instabilities in an atmospheric system (from a local point of view) is much smaller than the number of Lyapunov vectors with positive Lyapunov exponents. The BVs are independent of the norm, whereas the LVs beyond the first one do depend on the choice of norm: for example, they become larger in scale with a vorticity norm, and smaller with a stream function norm. These properties of BVs result in significant advantages for data assimilation and en- semble forecasting for the atmosphere. Errors in the analysis have structures very similar to bred vectors, and it is found that they project very strongly on the subspace of a few bred vectors. This is not true for either Lyapunov vectors beyond the lead- ing LVs, or for singular vectors unless they are constructed with a norm based on the analysis error covariance matrix (or a bred vector covariance). The similarity between bred vectors and analysis errors leads to the ability to include "errors of the day" in the background error covariance and a significant improvement of the analysis beyond 3D-Var at a very low cost (Corazza, 2001b). References Alligood K. T., T. D. Sauer and J. A. Yorke, 1996: Chaos: an introduction to dynamical systems. Springer-Verlag, New York. Buizza R., J. Tribbia, F. Molteni and T. Palmer, 1993: Computation of optimal unstable 3 structures for numerical weather prediction models. Tellus, 45A, 388-407. Cai, M., E. Kalnay and Z. Toth, 2001: Potential impact of bred vectors on ensemble forecasting and data assimilation in the Zebiak-Cane model. Submitted to J of Climate. Corazza, M., E. Kalnay, D. J. Patil, R. Morss, M. Cai, I. Szunyogh, B. R. Hunt, E. Ott and J. Yorke, 2001: Use of the breeding technique to determine the structure of the "errors of the day". Submitted to Nonlinear Processes in Geophysics. Corazza, M., E. Kalnay, DJ Patil, E. Ott, J. Yorke, I Szunyogh and M. Cai, 2001: Use of the breeding technique in the estimation of the background error covariance matrix for a quasigeostrophic model. AMS Symposium on Observations, Data Assimilation and Predictability, Preprints volume, Orlando, FA, 14-17 January 2002. Farrell, B., 1988: Small error dynamics and the predictability of atmospheric flow, J. Atmos. Sciences, 45, 163-172. Kalnay, E 2002: Atmospheric modeling, data assimilation and predictability. Chapter 6. Cambridge University Press, UK. In press. Kalnay E and Z Toth 1994: Removing growing errors in the analysis. Preprints, Tenth Conference on Numerical Weather Prediction, pp 212-215. Amer. Meteor. Soc., July 18-22, 1994. Lorenz, E.N., 1965: A study of the predictability of a 28-variable atmospheric model. Tellus, 21, 289-307. Lorenz, E.N., 1996: Predictability- A problem partly solved. Proceedings of the ECMWF Seminar on Predictability, Reading, England, Vol. 1 1-18. Molteni F. and TN Palmer, 1993: Predictability and finite-time instability of the north- ern winter circulation. Q. J. Roy. Meteorol. Soc. 119, 269-298. Morss, R.E.: 1999: Adaptive observations: Idealized sampling strategies for improving numerical weather prediction. Ph.D. Thesis, Massachussetts Institute of Technology, 225pp. Ott, E., 1993: Chaos in Dynamical Systems. Cambridge University Press. New York. Palmer, TN, R. Gelaro, J. Barkmeijer and R. Buizza, 1998: Singular vectors, metrics and adaptive observations. J. Atmos Sciences, 55, 633-653. Patil, DJ, BR Hunt, E Kalnay, J. Yorke, and E. Ott, 2001: Local low dimensionality of atmospheric dynamics. Phys. Rev. Lett., 86, 5878. Patil, DJ, I. Szunyogh, BR Hunt, E Kalnay, E Ott, and J. Yorke, 2001: Using large 4 member ensembles to isolate local low dimensionality of atmospheric dynamics. AMS Symposium on Observations, Data Assimilation and Predictability, Preprints volume, Orlando, FA, 14-17 January 2002. Snyder, C. and A. Joly, 1998: Development of perturbations within growing baroclinic waves. Q. J. Roy. Meteor. Soc., 124, pp 1961. Szunyogh, I, E. Kalnay and Z. Toth, 1997: A comparison of Lyapunov and Singular vectors in a low resolution GCM. Tellus, 49A, 200-227. Toth, Z and E Kalnay 1993: Ensemble forecasting at NMC - the generation of pertur- bations. Bull. Amer. Meteorol. Soc., 74, 2317-2330. Toth, Z and E Kalnay 1997: Ensemble forecasting at NCEP and the breeding method. Mon Wea Rev, 125, 3297-3319. * Corresponding author address: Eugenia Kalnay, Meteorology Depart- ment, University of Maryland, College Park, MD 20742-2425, USA; email: ekalnay@atmos.umd.edu Appendix: BV-dimension Patil et al., (2001) defined local bred vectors around a point in the 3-dimensional grid of the model by taking the 24 closest horizontal neighbors. If there are k bred vectors available, and N model variables for each grid point, the k local bred vectors form the columns of a 25Nxk matrix B. The kxk covariance matrix is C=B^T B. Its eigen- values are positive, and its eigenvectors v(i) are the singular vectors of the local bred vector subspace. The Bred Vector dimension (BV-dim) measures the local effective dimension: BV-dim[s,s,...,s(k)]={SUM[s(i)]}^2/SUM[s(i)]^2 where s(i) are the square roots of the eigenvalues of the covariance matrix. 5
Subretinal gene delivery using helper-dependent adenoviral vectors
Wu Linda
2011-04-01
Full Text Available Abstract This study describes the successful delivery of helper-dependent adenoviral vectors to the mouse retina with long term and robust levels of reporter expression in the retina without apparent adverse effects. Since these vectors have a large cloning capacity, they have great potential to extend the success of gene therapy achieved using the adeno-associated viral vector.
Subretinal gene delivery using helper-dependent adenoviral vectors
Wu Linda; Lam Simon; Cao Huibi; Guan Rui; Duan Rongqi; van der Kooy Derek; Bremner Rod; Molday Robert S; Hu Jim
2011-01-01
Abstract This study describes the successful delivery of helper-dependent adenoviral vectors to the mouse retina with long term and robust levels of reporter expression in the retina without apparent adverse effects. Since these vectors have a large cloning capacity, they have great potential to extend the success of gene therapy achieved using the adeno-associated viral vector.
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 ± 0.2 nm. 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. - Highlights: • Green synthesis of protein-lipid conjugated Ag NPs using S. foetida L. seed extract. • S. foetida seed extract acted as good reducing and stabilizing agent for Ag NPs. • XPS and FTIR confirm the biomolecules associated with Ag NPs. • Synthesized Ag NPs showed potential biological activities
Rajasekharreddy, Pala; Rani, Pathipati Usha, E-mail: usharani65@yahoo.com
2014-06-01
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 ± 0.2 nm. 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. - Highlights: • Green synthesis of protein-lipid conjugated Ag NPs using S. foetida L. seed extract. • S. foetida seed extract acted as good reducing and stabilizing agent for Ag NPs. • XPS and FTIR confirm the biomolecules associated with Ag NPs. • Synthesized Ag NPs showed potential biological activities.
Risk based surveillance for vector borne diseases
Bødker, Rene
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......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...... 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...
Complex Polynomial Vector Fields
Dias, Kealey
The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions or m...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields.......The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions or...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...
An Update on Canine Adenovirus Type 2 and Its Vectors
Kremer, Eric J.; Sara Salinas; Thierry Bru
2010-01-01
Adenovirus vectors have significant potential for long- or short-term gene transfer. Preclinical and clinical studies using human derived adenoviruses (HAd) have demonstrated the feasibility of flexible hybrid vector designs, robust expression and induction of protective immunity. However, clinical use of HAd vectors can, under some conditions, be limited by pre-existing vector immunity. Pre-existing humoral and cellular anti-capsid immunity limits the efficacy and duration of transgene expre...
The Hertz vector revisited: a simple physical picture
The polarization potentials, also known as Hertz vectors, are useful auxiliary fields that permit the calculation of the fundamental electromagnetic fields in many cases of practical importance. In this article we show that in a vacuum a single Hertz vector written as the product of a scalar potential and a constant vector, naturally arises as consequence of the transversality of the electromagnetic fields. Thus, our treatment shines a new light on the physical meaning of a Hertz potential. (paper)
Tensor and vector analyzing powers of the 1H( vector d,pp)n reaction
Tensor analyzing powers Axx and Ayy and vector analyzing powers Ay of the 1H( vector d,pp)n breakup reaction at Ed=52.1 MeV were measured in the symmetric collinear and coplanar-star kinematic configurations. The experimental results are compared with rigorous three-nucleon continuum calculations using realistic nucleon-nucleon potentials. ((orig.))
Jean-Franois Degbomont
2010-10-01
Full Text Available This paper addresses the symbolic representation of non-convex real polyhedra, i.e., sets of real vectors satisfying arbitrary Boolean combinations of linear constraints. We develop an original data structure for representing such sets, based on an implicit and concise encoding of a known structure, the Real Vector Automaton. The resulting formalism provides a canonical representation of polyhedra, is closed under Boolean operators, and admits an efficient decision procedure for testing the membership of a vector.
A Pedestrian Introduction to Gamow Vectors
De la Madrid, R
2002-01-01
The Gamow vector description of resonances is compared with the S-matrix and the Green function descriptions using the example of the square barrier and similar potentials. By imposing different boundary conditions on the time independent Schrodinger equation, we get either eigenvectors corresponding to real eigenvalues (Dirac kets) and the real ``physical'' spectrum or we get eigenvectors corresponding to complex eigenvalues (Gamow vectors) and the resonance spectrum. We will show that the poles of the S-matrix are the same as the poles of the Green function and as the complex eigenvalues of the Schrodinger equation subject to a purely outgoing boundary condition. We also obtain the basis vector expansion generated by the Gamow vectors. The time asymmetry built into the purely outgoing boundary condition will be revealed. It will be also shown that the probability to detect the decay within a shell around the origin of the decaying state follows the exponential law if the Gamow vector (resonance) contributio...
Vectors and their applications
Pettofrezzo, Anthony J
2005-01-01
Geared toward undergraduate students, this text illustrates the use of vectors as a mathematical tool in plane synthetic geometry, plane and spherical trigonometry, and analytic geometry of two- and three-dimensional space. Its rigorous development includes a complete treatment of the algebra of vectors in the first two chapters.Among the text's outstanding features are numbered definitions and theorems in the development of vector algebra, which appear in italics for easy reference. Most of the theorems include proofs, and coordinate position vectors receive an in-depth treatment. Key concept
Ansciaux, Emilie; Burtea, Carmen; Laurent, Sophie; Crombez, Deborah; Nonclercq, Denis; Vander Elst, Luce; Muller, Robert N
2015-01-01
Alzheimer's disease (AD) is a neurodegenerative disorder most often diagnosed 10?years after its onset and development. It is characterized by the accumulation of amyloid-? peptide (ABP) into amyloid plaques between nerve cells, which produces a massive local neurodegeneration. Molecular magnetic resonance imaging allows diagnosis of AD by showing ABP accumulation in the brain. The ultrasmall particles of iron oxide (USPIO) derivatives proposed in the present work were functionalized with peptides that present an affinity for ABP, independently of its state of aggregation. Their nanomolar Kd * confirms the high affinity of our vectorized contrast agents (VCA) for ABP and therefore their high labeling potential, specificity and sensitivity. Their lack of toxicity has been demonstrated, both by in vitro studies using the MTT method on several cell types, and by in vivo investigations with assessment of renal and hepatic biomarkers and by histopathology evaluation. The results of biodistribution studies corroborated by MRI demonstrate that USPIO-PHO (USPIO coupled to peptide C-IPLPFYN-C) are able to cross the blood-brain barrier without any facilitating strategy, and accumulates in the brain 90?min after its injection in NMRI mice. None of the USPIO derivatives were found in any organs one week after administration. To conclude, USPIO-PHO seems to have a genuine potential for labeling amyloid plaques in the brain; it has a nanomolar binding affinity, no toxic effects, and its elimination half-life is about 3?h. Further tests will be made on transgenic mice, aimed at confirming the potential of early AD diagnosis using our VCA. PMID:25284012
Viral Vector Production: Adenovirus.
Kim, Julius W; Morshed, Ramin A; Kane, J Robert; Auffinger, Brenda; Qiao, Jian; Lesniak, Maciej S
2016-01-01
Adenoviral vectors have proven to be valuable resources in the development of novel therapies aimed at targeting pathological conditions of the central nervous system, including Alzheimer's disease and neoplastic brain lesions. Not only can some genetically engineered adenoviral vectors achieve remarkably efficient and specific gene delivery to target cells, but they also may act as anticancer agents by selectively replicating within cancer cells.Due to the great interest in using adenoviral vectors for various purposes, the need for a comprehensive protocol for viral vector production is especially apparent. Here, we describe the process of generating an adenoviral vector in its entirety, including the more complex process of adenoviral fiber modification to restrict viral tropism in order to achieve more efficient and specific gene delivery. PMID:26611583
Complex Polynomial Vector Fields
Dias, Kealey
The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions or...... meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...
Phytoplasmas and their insect vectors in Lithuania
Ivanauskas, Algirdas
2014-01-01
The aim of the research was to identify the phytoplasmas detected in insects that were found on various phytoplasma-infected plants, and to reveal phytoplasma insect-vectors as well as phytogenetical relationships of identified phytoplasmas. From previous research, we already know a few mostly widespread phytoplasma groups, subgroups, and many of their host plants in Lithuania. The data on potential vectors of these bacteria are very scarce in Lithuania. The identification and research o...
Canine vector-borne diseases in Brazil
Dantas-Torres Filipe
2008-01-01
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 ti...
Status of vectorized Monte Carlo for particle transport analysis
The conventional particle transport Monte Carlo algorithm is ill suited for modern vector supercomputers because the random nature of the particle transport process in the history based algorithm inhibits construction of vectors. An alternative, event-based algorithm is suitable for vectorization and has been used recently to achieve impressive gains in performance on vector supercomputers. This review describes the event-based algorithm and several variations of it. Implementations of this algorithm for applications in particle transport are described, and their relative merits are discussed. The implementation of Monte Carlo methods on multiple vector parallel processors is considered, as is the potential of massively parallel processors for Monte Carlo particle transport simulations
Kansas Data Access and Support Center — The Kansas Tagged Vector Contour (TVC) dataset consists of digitized contours from the 7.5 minute topographic quadrangle maps. Coverage for the state is incomplete....
Minnesota Department of Natural Resources — This vector dataset is a detailed (1-acre minimum), hierarchically organized vegetation cover map produced by computer classification of combined two-season pairs...
Douglas, Joanne T.
The practical implementation of gene therapy in the clinical setting mandates gene delivery vehicles, or vectors, capable of efficient gene delivery selectively to the target disease cells. The utility of adenoviral vectors for gene therapy is restricted by their dependence on the native adenoviral primary cellular receptor for cell entry. Therefore, a number of strategies have been developed to allow CAR-independent infection of specific cell types, including the use of bispecific conjugates and genetic modifications to the adenoviral capsid proteins, in particular the fibre protein. These targeted adenoviral vectors have demonstrated efficient gene transfer in vitro , correlating with a therapeutic benefit in preclinical animal models. Such vectors are predicted to possess enhanced efficacy in human clinical studies, although anatomical barriers to their use must be circumvented.
Šebesta, O.; Gelbič, Ivan
2015-01-01
Roč. 51, č. 3 (2015), s. 272-280. ISSN 0037-9271 Institutional support: RVO:60077344 Keywords : Anopheles hyrcanus * Culex modestus * vector Subject RIV: EH - Ecology, Behaviour Impact factor: 0.513, year: 2014
Support vector machines applications
Guo, Guodong
2014-01-01
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.
Navarro, Andres A
2013-01-01
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...
Prospects for Foamy Viral Vector Anti-HIV Gene Therapy
Arun K. Nalla
2016-03-01
Full Text Available Stem cell gene therapy approaches for Human Immunodeficiency Virus (HIV infection have been explored in clinical trials and several anti-HIV genes delivered by retroviral vectors were shown to block HIV replication. However, gammaretroviral and lentiviral based retroviral vectors have limitations for delivery of anti-HIV genes into hematopoietic stem cells (HSC. Foamy virus vectors have several advantages including efficient delivery of transgenes into HSC in large animal models, and a potentially safer integration profile. This review focuses on novel anti-HIV transgenes and the potential of foamy virus vectors for HSC gene therapy of HIV.
On cosmic inflation in vector field theories
Golovnev, Alexey
2011-01-01
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.
Vector Field Models of Inflation and Dark Energy
Koivisto, Tomi S
2008-01-01
Vector field models of inflation and dark energy are investigated. We consider nonminimal couplings of the vectors both in the matter and in the gravity sector. The cosmological equations, allowing anisotropic background expansion, are then studied as a dynamical system. We show the general conditions for the existence of scaling solutions for spatial fields. A vector with an inverse power-law potential, even if minimally coupled, scales with the matter component. For time-like fields in an isotropic background, we present a reconstruction method to deduce the form of the vector potential and couplings from a given expansion history. In particular, we reconstruct a vector-Gauss-Bonnet model which generates the concordance model acceleration at late times and supports an inflationary epoch at high curvatures. Thus, several classes of viable vector alternatives to the inflaton and quintessence scalar fields are found. These might help to make contact between the observed anomalies in the CMB and large scale str...
Current Advances and Future Challenges in Adenoviral Vector Biology and Targeting
Campos, Samuel K; Barry, Michael A.
2007-01-01
Gene delivery vectors based on Adenoviral (Ad) vectors have enormous potential for the treatment of both hereditary and acquired disease. Detailed structural analysis of the Ad virion, combined with functional studies has broadened our knowledge of the structure/function relationships between Ad vectors and host cells/tissues and substantial achievement has been made towards a thorough understanding of the biology of Ad vectors. The widespread use of Ad vectors for clinical gene therapy is co...
Duality in vector optimization
Bot, Radu Ioan
2009-01-01
This book presents fundamentals and comprehensive results regarding duality for scalar, vector and set-valued optimization problems in a general setting. After a preliminary chapter dedicated to convex analysis and minimality notions of sets with respect to partial orderings induced by convex cones a chapter on scalar conjugate duality follows. Then investigations on vector duality based on scalar conjugacy are made. Weak, strong and converse duality statements are delivered and connections to classical results from the literature are emphasized. One chapter is exclusively consecrated to the s
Yurinsky, Vadim Vladimirovich
1995-01-01
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.
Akcoglu, Mustafa A; Ha, Dzung Minh
2011-01-01
A rigorous introduction to calculus in vector spaces The concepts and theorems of advanced calculus combined with related computational methods are essential to understanding nearly all areas of quantitative science. Analysis in Vector Spaces presents the central results of this classic subject through rigorous arguments, discussions, and examples. The book aims to cultivate not only knowledge of the major theoretical results, but also the geometric intuition needed for both mathematical problem-solving and modeling in the formal sciences. The authors begin with an outline of key concepts, ter
Bunyavirus-Vector Interactions
Kate McElroy Horne
2014-11-01
Full Text Available The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are significant human or agricultural pathogens. The viruses within the Orthobunyavirus, Nairovirus, and Phlebovirus genera are transmitted by hematophagous arthropods, such as mosquitoes, midges, flies, and ticks, and their associated arthropods not only serve as vectors but also as virus reservoirs in many cases. This review presents an overview of several important emerging or re-emerging bunyaviruses and describes what is known about bunyavirus-vector interactions based on epidemiological, ultrastructural, and genetic studies of members of this virus family.
Rejon-Barrera, Fernando
2015-01-01
We work out all of the details required for implementation of the conformal bootstrap program applied to the four-point function of two scalars and two vectors in an abstract conformal field theory in arbitrary dimension. This includes a review of which tensor structures make appearances, a construction of the projectors onto the required mixed symmetry representations, and a computation of the conformal blocks for all possible operators which can be exchanged. These blocks are presented as differential operators acting upon the previously known scalar conformal blocks. Finally, we set up the bootstrap equations which implement crossing symmetry. Special attention is given to the case of conserved vectors, where several simplifications occur.
Eisenman, Richard L
2005-01-01
This outstanding text and reference applies matrix ideas to vector methods, using physical ideas to illustrate and motivate mathematical concepts but employing a mathematical continuity of development rather than a physical approach. The author, who taught at the U.S. Air Force Academy, dispenses with the artificial barrier between vectors and matrices--and more generally, between pure and applied mathematics.Motivated examples introduce each idea, with interpretations of physical, algebraic, and geometric contexts, in addition to generalizations to theorems that reflect the essential structur
Retargeting Adenoviral Vectors to Improve Gene Transfer into Tumors
Hogg, Richard T.; Thorpe, Philip; Gerard, Robert D.
2010-01-01
Gene targeting to tumors using adenoviral vectors holds great potential for cancer imaging and therapy, but the limited efficacy of current methods used to improve delivery to target tissues and reduce unwanted interactions remain substantial barriers to further development. Progress in characterizing the set of molecular interactions used by adenoviral vectors to infect particular tissues has aided the development of novel strategies for retargeting vectors to tumor cells. One method is chem...
Ontology for vector surveillance and management.
Lozano-Fuentes, Saul; Bandyopadhyay, Aritra; Cowell, Lindsay G; Goldfain, Albert; Eisen, Lars
2013-01-01
Ontologies, which are made up by standardized and defined controlled vocabulary terms and their interrelationships, are comprehensive and readily searchable repositories for knowledge in a given domain. The Open Biomedical Ontologies (OBO) Foundry was initiated in 2001 with the aims of becoming an "umbrella" for life-science ontologies and promoting the use of ontology development best practices. A software application (OBO-Edit; *.obo file format) was developed to facilitate ontology development and editing. The OBO Foundry now comprises over 100 ontologies and candidate ontologies, including the NCBI organismal classification ontology (NCBITaxon), the Mosquito Insecticide Resistance Ontology (MIRO), the Infectious Disease Ontology (IDO), the IDOMAL malaria ontology, and ontologies for mosquito gross anatomy and tick gross anatomy. We previously developed a disease data management system for dengue and malaria control programs, which incorporated a set of information trees built upon ontological principles, including a "term tree" to promote the use of standardized terms. In the course of doing so, we realized that there were substantial gaps in existing ontologies with regards to concepts, processes, and, especially, physical entities (e.g., vector species, pathogen species, and vector surveillance and management equipment) in the domain of surveillance and management of vectors and vector-borne pathogens. We therefore produced an ontology for vector surveillance and management, focusing on arthropod vectors and vector-borne pathogens with relevance to humans or domestic animals, and with special emphasis on content to support operational activities through inclusion in databases, data management systems, or decision support systems. The Vector Surveillance and Management Ontology (VSMO) includes >2,200 unique terms, of which the vast majority (>80%) were newly generated during the development of this ontology. One core feature of the VSMO is the linkage, through the has vector relation, of arthropod species to the pathogenic microorganisms for which they serve as biological vectors. We also recognized and addressed a potential roadblock for use of the VSMO by the vector-borne disease community: the difficulty in extracting information from OBO-Edit ontology files (*.obo files) and exporting the information to other file formats. A novel ontology explorer tool was developed to facilitate extraction and export of information from the VSMO*.obo file into lists of terms and their associated unique IDs in *.txt or *.csv file formats. These lists can then be imported into a database or data management system for use as select lists with predefined terms. This is an important step to ensure that the knowledge contained in our ontology can be put into practical use. PMID:23427646
Location - Managed Facility - St. Paul District (MVP)
Army Corps of Engineers, Department of the Army, Department of Defense — St. Paul District - US Army Corps of Engineers Managed Facility locations. District headquarters, Natural Resource, Recreation, Lock and Dam, and Regulatory offices...
M. Palaniyandi
2012-01-01
There have been several attemps made to the appreciation of remote sensing and GIS for the study of vectors,biodiversity, vector presence, vector abundance and the vector-borne diseases with respect to space and time.This study was made for reviewing and appraising the potential use of remote sensing and GIS applications forspatial prediction of vector-borne diseases transmission. The nature of the presence and the abundance of vectorsand vector-borne diseases, disease infection and the disea...
2011-04-18
This podcast discusses emerging vector-borne pathogens, their role as prominent contributors to emerging infectious diseases, how they're spread, and the ineffectiveness of mosquito control methods. Created: 4/18/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID). Date Released: 4/27/2011.
Treiman, Jay S
2014-01-01
Calculus with Vectors grew out of a strong need for a beginning calculus textbook for undergraduates who intend to pursue careers in STEM. fields. The approach introduces vector-valued functions from the start, emphasizing the connections between one-variable and multi-variable calculus. The text includes early vectors and early transcendentals and includes a rigorous but informal approach to vectors. Examples and focused applications are well presented along with an abundance of motivating exercises. All three-dimensional graphs have rotatable versions included as extra source materials and may be freely downloaded and manipulated with Maple Player; a free Maple Player App is available for the iPad on iTunes. The approaches taken to topics such as the derivation of the derivatives of sine and cosine, the approach to limits, and the use of "tables" of integration have been modified from the standards seen in other textbooks in order to maximize the ease with which students may comprehend the material. Additio...
Rao, M M
2011-01-01
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.
Killing vectors and anisotropy
Krisch, J P
2009-01-01
We consider an action that can generate fluids with three unequal stresses for metrics with a spacelike Killing vector. The parameters in the action are directly related to the stress anisotropies. The field equations following from the action are applied to an anisotropic cosmological expansion and an extension of the Gott-Hiscock cosmic string.
Emerging Vector-Borne Diseases – Incidence through Vectors
Savić, Sara; Vidić, Branka; Grgić, Zivoslav; Potkonjak, Aleksandar; Spasojevic, Ljubica
2014-01-01
Vector-borne diseases use to be a major public health concern only in tropical and subtropical areas, but today they are an emerging threat for the continental and developed countries also. Nowadays, in intercontinental countries, there is a struggle with emerging diseases, which have found their way to appear through vectors. Vector-borne zoonotic diseases occur when vectors, animal hosts, climate conditions, pathogens, and susceptible human population exist at the same time, at the same pla...
Hamilton's Eccentricity Vector Generalised to Newton Wonders
Lynden-Bell, Donald
2006-01-01
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.
Plant Virus Expression Vector Development: New Perspectives
Kathleen Hefferon
2014-01-01
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...
Okamoto, Kenichi W.; Gould, Fred; Lloyd, Alun L.
2016-01-01
Many vector-borne diseases lack effective vaccines and medications, and the limitations of traditional vector control have inspired novel approaches based on using genetic engineering to manipulate vector populations and thereby reduce transmission. Yet both the short- and long-term epidemiological effects of these transgenic strategies are highly uncertain. If neither vaccines, medications, nor transgenic strategies can by themselves suffice for managing vector-borne diseases, integrating these approaches becomes key. Here we develop a framework to evaluate how clinical interventions (i.e., vaccination and medication) can be integrated with transgenic vector manipulation strategies to prevent disease invasion and reduce disease incidence. We show that the ability of clinical interventions to accelerate disease suppression can depend on the nature of the transgenic manipulation deployed (e.g., whether vector population reduction or replacement is attempted). We find that making a specific, individual strategy highly effective may not be necessary for attaining public-health objectives, provided suitable combinations can be adopted. However, we show how combining only partially effective antimicrobial drugs or vaccination with transgenic vector manipulations that merely temporarily lower vector competence can amplify disease resurgence following transient suppression. Thus, transgenic vector manipulation that cannot be sustained can have adverse consequences—consequences which ineffective clinical interventions can at best only mitigate, and at worst temporarily exacerbate. This result, which arises from differences between the time scale on which the interventions affect disease dynamics and the time scale of host population dynamics, highlights the importance of accounting for the potential delay in the effects of deploying public health strategies on long-term disease incidence. We find that for systems at the disease-endemic equilibrium, even modest perturbations induced by weak interventions can exhibit strong, albeit transient, epidemiological effects. This, together with our finding that under some conditions combining strategies could have transient adverse epidemiological effects suggests that a relatively long time horizon may be necessary to discern the efficacy of alternative intervention strategies. PMID:26962871
Highlights: ► Joint growth for two or more living beings is addressed in a universality context. ► A vector extension of the growth universalities formalism is fully developed. ► Two useful theorems and the analysis of their implications are presented. ► Insights on the mutual influence between organisms/populations are obtained. - Abstract: A formalism to describe the interactive growth of two or more organisms in a given environment is presented. This is a vector generalization of the scheme developed by Castorina et al. to classify and interpret non-linear ontogenetic growth formulas, which can be applied to such complex self-organizing systems as solid tumors. A theorem that leads to the explicit solutions of the resulting equations is proven. These solutions can describe synergetic, antagonistic, and cooperative growth, and can be applied to both biological and ecological problems.
Gy Wolf
2006-04-01
One consequence of the chiral restoration is the mixing of parity partners. We look for a possible signature of the mixing of vector and axial vector mesons in heavy-ion collisions. We suggest an experimental method for its observation. The dynamical evolution of the heavy-ion collision is described by a transport equation of QMD-type evolving nucleons, * and resonances, ’s and $\\sum$ baryons, and furthermore, ’s, ’s ’s ’s ’s and kaons with their isospin degrees of freedom. The input cross-sections and resonance parameters of the model are fitted to the available nucleon–nucleon and pion–nucleon cross-sections.
Benchmarking Support Vector Machines
Meyer, David; Leisch, Friedrich; Hornik, Kurt
2002-01-01
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...
Rudakov, A N
1990-01-01
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).
Bunyavirus-Vector Interactions
Kate McElroy Horne; Vanlandingham, Dana L.
2014-01-01
The Bunyaviridae family is comprised of more than 350 viruses, of which many within the Hantavirus, Orthobunyavirus, Nairovirus, Tospovirus, and Phlebovirus genera are significant human or agricultural pathogens. The viruses within the Orthobunyavirus, Nairovirus, and Phlebovirus genera are transmitted by hematophagous arthropods, such as mosquitoes, midges, flies, and ticks, and their associated arthropods not only serve as vectors but also as virus reservoirs in many cases. This review pres...
VandenDriessche, Thierry; Thorrez, Lieven; Acosta-Sanchez, A; Petrus, Inge; L. Wang; Ma, L.; De Waele, Liesbeth; Iwasaki, Y.; Gillijns, Veerle; Wilson, J.M.; Collen, Desire; Chuah, M K L
2007-01-01
Background: Adeno-associated (AAV) and lentiviral vectors are promising vectors for gene therapy of hemophilia since they are devoid of viral genes and have the potential for long-term gene expression. Objectives: To compare the performance of different AAV serotypes (AAV8 and AAV9) versus lentiviral vectors expressing factor IX (FIX). Methods and Results: AAV-based and lentiviral vectors were generated that express FIX from the same hepatocyte-specific expression cassette. AAV9 transduced th...
Supersymmetric vector particles
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)
Leishmaniasis vector behaviour in Kenya
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)
Scalar - vector soliton fiber lasers
Wu, Zhichao; Li, Lei; Luo, Yiyang; Tang, Dingyuan; Shen, Deyuan; Tang, Ming; Fu, Songnian; Zhao, Luming
2016-01-01
Rapid progress in passively mode-locked fiber lasers is currently driven by the recent discovery of vector feature of mode-locking pulses, namely, the group velocity-locked vector solitons, the phase locked vector solitons, and the high-order vector solitons. Those vector solitons are fundamentally different from the previously known scalar solitons. Here, we report a fiber laser where the mode-locked pulse evolves as a vector soliton in the strong birefringent segment and is transformed into a regular scalar soliton after the polarizer within the laser cavity. The existence of solutions in a polarization-dependent cavity comprising a periodic combination of two distinct nonlinear waves is novel and likely to be applicable to various other nonlinear systems. For very large local birefringence, our laser approaches the working regime of vector soliton lasers, while it approaches scalar soliton fiber lasers under the conditions of very small birefringence.
Preclinical gene therapy studies for hemophilia using adenoviral vectors
Thorrez, Lieven; VandenDriessche, Thierry; Collen, Desire; Chuah, Marinee
2004-01-01
Hemophilia A and B are hereditary coagulation defects resulting from a deficiency of factor VIII (FVIII) and factor IX (FIX), respectively. Introducing a functional FVIII or FIX gene could potentially provide a cure for these bleeding disorders. Adenoviral vectors have been used as tools to introduce potentially therapeutic genes into mammalian cells and are by far the most efficient vectors for hepatic gene delivery. Long-term expression of both FVIII and FIX has been achieved in preclinical...
Integrative vectors for heterologous gene expression in Streptomyces spp.
Motamedi, H; Shafiee, A; Cai, S J
1995-07-01
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
Nelson, Ann E.; Walsh, Jonathan
2008-01-01
We show that for a force mediated by a vector particle coupled to a conserved U(1) charge, the apparent range and strength can depend on the size and density of the source, and the proximity to other sources. This "chameleon" effect is due to screening from a light charged scalar. Such screening can weaken astrophysical constraints on new gauge bosons. As an example we consider the constraints on chameleonic gauged B-L. We show that although Casimir measurements greatly constrain any B-L forc...
Acevedo Frías, Bernardo; Ospina Arteaga, Omar Evelio
1992-01-01
El texto Números, Vectores y Funciones que han elaborado los profesores Asociados Omar Evelio Ospina y Bernardo Acevedo, responden a esta necesidad con sobresalientes cualidades pedagógicas, entre las cuales se destacan el desarrollo detallado de los temas y la proliferación de ejercicios resueltos, lo cual genera un diálogo directo con el lector que puede así aprovechar totalmente su lectura. El material presentado es el fruto de un cuidadoso análisis de los autores, sobre las experiencias d...
Ramezani, Ali; Hawley, Teresa S; Hawley, Robert G
2008-01-01
Insertional mutagenesis by retroviral vectors has emerged as a serious impediment to the widespread application of hematopoietic stem cell gene transfer for the treatment of hematologic diseases. Here we report the development of a 77-bp element, FII/BEAD-A (FB), which contains the minimal enhancer blocking components of the chicken ?-globin 5?HS4 insulator and a homologous region from the human T-cell receptor ?/? BEAD-1 insulator. With a new flow cytometry-based assay, we show that the FB e...
Nielsen, Troels T; Jakobsson, Johan; Rosenqvist, Nina; Lundberg, Cecilia
2009-01-01
BACKGROUND: Lentiviral vectors hold great promise as gene transfer vectors in gene therapeutic settings. However, problems related to the risk of insertional mutagenesis, transgene silencing and positional effects have stalled the use of such vectors in the clinic. Chromatin insulators are boundary...... into lentiviral vectors in order to enhance their safety profile and improve transgene expression. Commonly such insulator vectors are produced at lower titers than control vectors thus limiting their potential use. RESULTS: In this study we cloned in tandem copies of the chicken beta-globin insulator...
Efficient intracellular assembly of papillomaviral vectors.
Buck, Christopher B; Pastrana, Diana V; Lowy, Douglas R; Schiller, John T
2004-01-01
Although the papillomavirus structural proteins, L1 and L2, can spontaneously coassemble to form virus-like particles, currently available methods for production of L1/L2 particles capable of transducing reporter plasmids into mammalian cells are technically demanding and relatively low-yield. In this report, we describe a simple 293 cell transfection method for efficient intracellular production of papillomaviral-based gene transfer vectors carrying reporter plasmids. Using bovine papillomavirus type 1 (BPV1) and human papillomavirus type 16 as model papillomaviruses, we have developed a system for producing papillomaviral vector stocks with titers of several billion transducing units per milliliter. Production of these vectors requires both L1 and L2, and transduction can be prevented by papillomavirus-neutralizing antibodies. The stocks can be purified by an iodixanol (OptiPrep) gradient centrifugation procedure that is substantially more effective than standard cesium chloride gradient purification. Although earlier data had suggested a potential role for the viral early protein E2, we found that E2 protein expression did not enhance the intracellular production of BPV1 vectors. It was also possible to encapsidate reporter plasmids devoid of BPV1 DNA sequences. BPV1 vector production efficiency was significantly influenced by the size of the target plasmid being packaged. Use of 6-kb target plasmids resulted in BPV1 vector yields that were higher than those with target plasmids closer to the native 7.9-kb size of papillomavirus genomes. The results suggest that the intracellular assembly of papillomavirus structural proteins around heterologous reporter plasmids is surprisingly promiscuous and may be driven primarily by a size discrimination mechanism. PMID:14694107
Hulot, Gauthier; Vigneron, Pierre; Leger, Jean-Michel; Fratter, Isabelle; Olsen, Nils; Jager, Thomas; Bertrand, François; Brocco, Laura; Sirol, Olivier
2015-01-01
, combining ASM scalar data with independent uxgate magnetometer vector data. The high level of agreement between these models demonstrates the potential of the ASM's vector mode for data quality control and as a stand alone magnetometer, and illustrates the way the evolution of key eld features can easily be...... monitored from space with such absolute vector magnetometers....
HIV-1-based lentiviral vectors.
Liu, Ying Poi; Berkhout, Ben
2014-01-01
Numerous viral vectors have been developed for the delivery of transgenes to specific target cells. For persistent transgene expression, vectors based on retroviruses are attractive delivery vehicles because of their ability to stably integrate their DNA into the host cell genome. Initially, vectors based on simple retroviruses were the vector of choice for such applications. However, these vectors can only transduce actively dividing cells. Therefore, much interest has turned to retroviral vectors based on the lentivirus genus because of their ability to transduce both dividing and non-dividing cells. The best characterized lentiviral vectors are derived from the human immunodeficiency virus type 1 (HIV-1). This chapter describes the basic features of the HIV-1 replication cycle and the many improvements reported for the lentiviral vector systems to increase the safety and efficiency. We also provide practical information on the production of HIV-1 derived lentiviral vectors, the cell transduction protocol and a method to determine the transduction titers of a lentiviral vector. PMID:24158830
Vector wave propagation method.
Fertig, M; Brenner, K-H
2010-04-01
In this paper, we extend the scalar wave propagation method (WPM) to vector fields. The WPM [Appl. Opt.32, 4984 (1993)] was introduced in order to overcome the major limitations of the beam propagation method (BPM). With the WPM, the range of application can be extended from the simulation of waveguides to simulation of other optical elements like lenses, prisms and gratings. In that reference it was demonstrated that the wave propagation scheme provides valid results for propagation angles up to 85 degrees and that it is not limited to small index variations in the axis of propagation. Here, we extend the WPM to three-dimensional vectorial fields (VWPMs) by considering the polarization dependent Fresnel coefficients for transmission in each propagation step. The continuity of the electric field is maintained in all three dimensions by an enhanced propagation vector and the transfer matrix. We verify the validity of the method by transmission through a prism and by comparison with the focal distribution from vectorial Debye theory. Furthermore, a two-dimensional grating is simulated and compared with the results from three-dimensional RCWA. Especially for 3D problems, the runtime of the VWPM exhibits special advantage over the RCWA. PMID:20360813
[Climate- and vector-borne diseases
Bygbjerg, I.C.; Schioler, K.L.; Konradsen, F.
2009-01-01
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...
Semitopological Vector Spaces and Hyperseminorms
Mark Burgin
2013-11-01
Full Text Available In this paper, we introduce and study semitopological vector spaces. The goal is to provide an efficient base for developing the theory of extrafunction spaces in an abstract setting of algebraic systems and topological spaces. Semitopological vector spaces are more general than conventional topological vector spaces, which proved to be very useful for solving many problems in functional analysis. To study semitopological vector spaces, hypermetrics and hyperpseudometrics are introduced and it is demonstrated that hyperseminorms, studied in previous works of the author, induce hyperpseudometrics, while hypernorms induce hypermetrics. Sufficient and necessary conditions for a hyperpseudometric (hypermetric to be induced by a hyperseminorm (hypernorm are found. We also show that semitopological vector spaces are closely related to systems of hyperseminorms. Then defining boundedness and continuity relative to associated systems of hyperseminorms, we study relations between relative boundedness and relative continuity for mappings of vector spaces with systems of hyperseminorms and systems of hypernorms.
Vector fields in multidimensional cosmology
Meierovich, Boris E.
2011-01-01
Vector fields in the expanding Universe are considered within the multidimensional theory of General Relativity. Vector fields in general relativity form a three-parametric variety. Our consideration includes the fields with a nonzero covariant divergence. Depending on the relations between the particular parameters and the symmetry of a problem, the vector fields can be longitudinal and/or transverse, ultrarelativistic (i.e. massless) or nonrelativistic (massive), and so on. The longitudinal...
Speculative Vectorization for Superscalar Processors
Pajuelo González, Manuel A. (Manuel Alejandro)
2005-01-01
Traditional vector architectures have been shown to be very effective in executing regular codes in which the compiler can detect data-level parallelism, i.e. repeating the same computation over different elements in the same code-level data structure.A skilled programmer can easily create efficient vector code from regular applications. Unfortunately, this vectorization can be difficult if applications are not regular or if the programmer does not have an exact knowledge of the underlying ar...
Integrating vector control across diseases
Golding, N.; Wilson, AL; Moyes, CL; Cano, J.; Pigott, DM; Velayudhan, R; Brooker, SJ; Smith, DL; Hay, SI; Lindsay, SW
2015-01-01
Background Vector-borne diseases cause a significant proportion of the overall burden of disease across the globe, accounting for over 10 % of the burden of infectious diseases. Despite the availability of effective interventions for many of these diseases, a lack of resources prevents their effective control. Many existing vector control interventions are known to be effective against multiple diseases, so combining vector control programmes to simultaneously tackle several diseases could of...
Cosmological implications of Bumblebee vector models
Capelo, Diogo
2015-01-01
The Bumblebee Model of spontaneous Lorentz symmetry breaking is explored in a cosmological context, considering a single non-zero time component for the vector field. The relevant dynamic equations for the evolution of the Universe are derived and its properties and physical significance studied. We conclude that a late-time de Sitter expansion of the Universe can be replicated, and attempt to constrain the parameter of the potential driving the spontaneous symmetry breaking.
Stabilized two-dimensional vector solitons
In this Letter, we introduce the concept of stabilized vector solitons as nonlinear waves constructed by the addition of mutually incoherent fractions of Townes solitons that are stabilized under the effect of a periodic modulation of the nonlinearity. We analyze the stability of these new kinds of structures and describe their behavior and formation in Manakov-like interactions. Potential applications of our results in Bose-Einstein condensation and nonlinear optics are also discussed
Vector correlations in rotationally inelastic molecular collisions
Lemeshko, Mikhail
2011-01-01
The thesis presents an analytic model that describes scalar and vector properties of molecular collisions, both field-free and in fields. The model is based on the sudden approximation and treats molecular scattering as the Fraunhofer diffraction of matter waves from the hard-core part of the interaction potential. The theory has no fitting parameters and is inherently quantum, rendering fully state- and energy-resolved scattering amplitudes and all the quantities that unfold from them in ana...
Observation of stable-vector vortex solitons.
Izdebskaya, Yana; Assanto, Gaetano; Krolikowski, Wieslaw
2015-09-01
We report on the first experimental observation of stable-vector vortex solitons in nonlocal nonlinear media with a reorientational response, such as nematic liquid crystals. These solitons consist of two co-polarized, mutually trapped beams of different colors, a bright fundamental spatial soliton, and a nonlinear optical vortex. The nonlinear vortex component, which is normally unstable in nonlinear media, is stabilized and confined here by the highly nonlocal refractive potential induced by the soliton. PMID:26368742
HSV Recombinant Vectors for Gene Therapy
Manservigi, Roberto; Argnani, Rafaela; Marconi, Peggy
2010-01-01
The very deep knowledge acquired on the genetics and molecular biology of herpes simplex virus (HSV), has allowed the development of potential replication-competent and replication-defective vectors for several applications in human healthcare. These include delivery and expression of human genes to cells of the nervous systems, selective destruction of cancer cells, prophylaxis against infection with HSV or other infectious diseases, and targeted infection to specific tissues or organs. Repl...
Localization and vector spherical harmonics
von Brecht, James H.
2016-01-01
This paper establishes the following localization property for vector spherical harmonics: a wide class of non-local, vector-valued operators reduce to local, multiplication-type operations when applied to a vector spherical harmonic. As localization occurs in a very precise, quantifiable and explicitly computable fashion, the localization property provides a set of useful formulae for analyzing vector-valued fractional diffusion and non-local differential equations defined on S d - 1. As such analyses require a detailed understanding of operators for which localization occurs, we provide several applications of the result in the context of non-local differential equations.
We show that for a force mediated by a vector particle coupled to a conserved U(1) charge, the apparent range and strength can depend on the size and density of the source, and the proximity to other sources. This chameleon effect is due to screening from a light charged scalar. Such screening can weaken astrophysical constraints on new gauge bosons. As an example we consider the constraints on chameleonic gauged B-L. We show that although Casimir measurements greatly constrain any B-L force much stronger than gravity with range longer than 0.1 ?m, there remains an experimental window for a long-range chameleonic B-L force. Such a force could be much stronger than gravity, and long or infinite range in vacuum, but have an effective range near the surface of the earth which is less than a micron.
Using a pulsed ultrasound field, the two-dimensional velocity vector can be determined with the invention. The method uses a transversally modulated ultrasound field for probing the moving medium under investigation. A modified autocorrelation approach is used in the velocity estimation. The new...... estimator automatically compensates for the axial velocity, when determining the transverse velocity by using fourth order moments rather than second order moments. The estimation is optimized by using a lag different from one in the estimation process, and noise artifacts are reduced by using averaging of...... RF samples. Further, compensation for the axial velocity can be introduced, and the velocity estimation is done at a fixed depth in tissue to reduce spatial velocity dispersion....
Nelson, A E
2008-01-01
We show that for a force mediated by a vector particle coupled to a conserved U(1) charge, the apparent range and strength can depend on the size and density of the source, and the proximity to other sources. This "chameleon" effect is due to screening from a light charged scalar. Such screening can weaken astrophysical constraints on new gauge bosons. As an example we consider the constraints on chameleonic gauged B-L. We show that although Casimir measurements greatly constrain any B-L force much stronger than gravity with range longer than 0.1 microns, there remains an experimental window for a long range chameleonic B-L force. Such a force could be much stronger than gravity, and long or infinite range in vacuum, but have an effective range near the surface of the earth which is less than a micron.
2000-01-01
Using a pulsed ultrasound field, the two-dimensional velocity vector can be determined with the invention. The method uses a transversally modulated ultrasound field for probing the moving medium under investigation. A modified autocorrelation approach is used in the velocity estimation. The new...... estimator automatically compensates for the axial velocity, when determining the transverse velocity by using fourth order moments rather than second order moments. The estimation is optimized by using a lag different from one in the estimation process, and noise artifacts are reduced by using averaging of...... RF samples. Further, compensation for the axial velocity can be introduced, and the velocity estimation is done at a fixed depth in tissue to reduce spatial velocity dispersion....
Lapointe, D.A.; Hofmeister, E.K.; Atkinson, C.T.; Porter, R.E.; Dusek, R.J.
2009-01-01
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.
Present status of vectorization for particle transport Monte Carlo
The conventional particle transport Monte Carlo algorithm is ill-suited for modern vector supercomputers. This history-based algorithm is not amenable to vectorization due to the random nature of the particle transport process, which inhibits the construction of vectors that are necessary for efficient utilization of a vector (pipelined) processor. An alternative algorithm, the event-based algorithm, is suitable for vectorization and has been used by several researchers in recent years to achieve impressive gains (5-20) in performance on modern vector supercomputers. This paper describes the event-based algorithm in some detail and discusses several implementations of this algorithm for specific applications in particle transport, including photon transport in a nuclear fusion plasma and neutron transport in a nuclear reactor. A discussion of the relative merits of these alternative approaches is included. A short discussion of the implementation of Monte Carlo methods on parallel processors, in particular multiple vector processors such as the Cray X-MP/48 and the IBM 3090/400, is included. The paper concludes with some thoughts regarding the potential of massively parallel processors (vector and scalar) for Monte Carlo simulation
Borhanian, Jafar, E-mail: borhanian@uma.ac.ir [Department of Physics, Faculty of Science, University of Mohaghegh Ardabili, P. O. Box 179, Ardabil (Iran, Islamic Republic of)
2014-06-15
The propagation of an elliptically polarized intense laser pulse in an unmagnetized collisionless uniform plasma is considered. A multiple scale perturbation theory is employed to show that in a weakly relativistic regime, evolution of the components of vector potential is governed by two coherently coupled nonlinear Schrödinger (NLS) equations. A set of equations describing the evolution of Stokes parameters is derived within the continuous wave approximation and the dynamics of components of field amplitude is studied. The polarization dynamics of a pulse is investigated by means of numerical solution of the coupled NLS equations. A detailed analysis of vector modulational instability is presented and the possibility for occurrence of various kinds of vector solitary waves is addressed.
An Update on Canine Adenovirus Type 2 and Its Vectors
Eric J. Kremer
2010-09-01
Full Text Available Adenovirus vectors have significant potential for long- or short-term gene transfer. Preclinical and clinical studies using human derived adenoviruses (HAd have demonstrated the feasibility of flexible hybrid vector designs, robust expression and induction of protective immunity. However, clinical use of HAd vectors can, under some conditions, be limited by pre-existing vector immunity. Pre-existing humoral and cellular anti-capsid immunity limits the efficacy and duration of transgene expression and is poorly circumvented by injections of larger doses and immuno-suppressing drugs. This review updates canine adenovirus serotype 2 (CAV-2, also known as CAdV-2 biology and gives an overview of the generation of early region 1 (E1-deleted to helper-dependent (HD CAV-2 vectors. We also summarize the essential characteristics concerning their interaction with the anti-HAd memory immune responses in humans, the preferential transduction of neurons, and its high level of retrograde axonal transport in the central and peripheral nervous system. CAV-2 vectors are particularly interesting tools to study the pathophysiology and potential treatment of neurodegenerative diseases, as anti-tumoral and anti-viral vaccines, tracer of synaptic junctions, oncolytic virus and as a platform to generate chimeric vectors.
Vectors on the Basketball Court
Bergman, Daniel
2010-01-01
An Idea Bank published in the April/May 2009 issue of "The Science Teacher" describes an experiential physics lesson on vectors and vector addition (Brown 2009). Like its football predecessor, the basketball-based investigation presented in this Idea Bank addresses National Science Education Standards Content B, Physical Science, 9-12 (NRC 1996)
The vector resultant phase shifter
A new type of voltage controlled phase shifter developed by HIRFL laboratory is better than mechanical phase shifter in all respects of performance, price, and reliability. It's principle is based on vector composition, so this new phase shifter is called vector resultant voltage controlled phase shifter. This new phase shifter has been applied in HIRFL phase stabilization system and satisfactory result has been obtained
Vector Measurement with Scalar Analyser
K. Hoffmann
1996-12-01
Full Text Available A novel method for vector scattering parameter measurement is presented. The method is based on scalar (SWR measurement only. Vector data is obtained using a controlled perturbation two-port (CPTP. The method promises broadband operation and cost-effectiveness for both reflection and transmission measurements. Design considerations for CPTP synthesis are presented.
Fine, Jonathan
1997-01-01
This note defines a flag vector for $i$-graphs. The construction applies to any finite combinatorial object that can be shelled. Two possible connections to quantum topology are mentioned. Further details appear in the author's "On quantum topology, hypergraphs and flag vectors", (preprint q-alg/9708001).
Estimation of Motion Vector Fields
Larsen, Rasmus
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...
Vector Measurement with Scalar Analyser
Hoffmann, K.; Z. Skvor; V. Klusacek
1996-01-01
A novel method for vector scattering parameter measurement is presented. The method is based on scalar (SWR) measurement only. Vector data is obtained using a controlled perturbation two-port (CPTP). The method promises broadband operation and cost-effectiveness for both reflection and transmission measurements. Design considerations for CPTP synthesis are presented.
In-vivo examples of synthetic aperture vector flow imaging
Oddershede, Niels; Hansen, Kristoffer Lindskov; Nielsen, Michael Bachmann; Jensen, Jørgen Arendt
2007-01-01
would be needed. Synthetic aperture vector flow imaging could potentially provide this. The purpose of this paper is to test the synthetic aperture vector flow imaging method on challenging in-vivo data. Two synthetic aperture in-vivo data sets are acquired using a commercial linear array transducer and......The majority of the commercial ultrasound scanners feature blood flow velocity estimation based on the autocorrelation method, yielding estimates of the axial velocity component only. For studying complex flow patterns like arterial bifurcations or venous confluences, 2-D vector velocity estimates...
Development of an AIDS vaccine using Sendai virus vectors.
Ishii, Hiroshi; Matano, Tetsuro
2015-11-01
Development of an effective AIDS vaccine is crucial for the control of global human immunodeficiency virus type 1 (HIV-1) prevalence. We have developed a novel AIDS vaccine using a Sendai virus (SeV) vector and investigated its efficacy in a macaque AIDS model of simian immunodeficiency virus (SIV) infection. Its immunogenicity and protective efficacy have been shown, indicating that the SeV vector is a promising delivery tool for AIDS vaccines. Here, we describe the potential of SeV vector as a vaccine antigen delivery tool to induce effective immune responses against HIV-1 infection. PMID:26232346
Analysis of Vector-Inflation Models Using Dynamical Systems
Rodriguez, Jose F
2015-01-01
We analyze two possible vector-field models using the techniques of dynamical systems. The first model involves a U(1)-vector field and the second a triad of SU(2)-vector fields. Both models include a gauge-fixing term and a power-law potential. A dynamical system is formulated and it is found that one of the critical points, for each model, corresponds to inflation, the origin of these critical points being the respective gauge-fixing terms. The conditions for the existence of an inflationary era which lasts for at least 60 efolds are studied.
State Vectors and Physical States
Watson, W N
2000-01-01
Causality and the relativity of simultaneity seem at odds with the apparently sudden, acausal state-vector changes ("collapses") characteristic of quantum phenomena. The problem of how physical phenomena can be causally determined, have the probabilities predicted by quantum theory, and be consistent with special relativity appears to be solved by the assumption, essentially the same as one first used by Aharonov, Bergmann, and Lebowitz to address a different problem, that the "initial" and "final" state vectors of a phenomenon or observation, along with certain other state vectors, all represent the system's state at all times. Each member of such an aggregate of state vectors is postulated to represent a different aspect of a physical state rather than a state, so that most of the state vectors in effect constitute a set of nonlocal hidden variables. Various implications of this assumption are illustrated through several physical situations. Among the results is a somewhat surprising resolution of a paradox...
Vector superconductivity in cosmic strings
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
Nielsen, Troels T; Jakobsson, Johan; Rosenqvist, Nina; Lundberg, Cecilia
2009-01-01
BACKGROUND: Lentiviral vectors hold great promise as gene transfer vectors in gene therapeutic settings. However, problems related to the risk of insertional mutagenesis, transgene silencing and positional effects have stalled the use of such vectors in the clinic. Chromatin insulators are boundary...... into lentiviral vectors in order to enhance their safety profile and improve transgene expression. Commonly such insulator vectors are produced at lower titers than control vectors thus limiting their potential use. RESULTS: In this study we cloned in tandem copies of the chicken beta-globin insulator...... (cHS4) on both sides of the transgene cassette in order to enhance the insulating effect. Our insulator vectors were produced at significantly lower titers compared to control vectors, and we show that this reduction in titer is due to a block during the transduction process that appears after...
Vector Field Models of Inflation and Dark Energy
Koivisto, Tomi S.; Mota, David F.
2008-01-01
We consider several new classes of viable vector field alternatives to the inflaton and quintessence scalar fields. Spatial vector fields are shown to be compatible with the cosmological anisotropy bounds if only slightly displaced from the potential minimum while dominant, or if driving an anisotropic expansion with nearly vanishing quadropole today. The Bianchi I model with a spatial field and an isotropic fluid is studied as a dynamical system, and several types of scaling solutions are fo...
Effective Vector Data Transmission and Visualization Using HTML5
Corcoran, Padraig; Mooney, Peter; Winstanley, Adam; Bertolotto, Michela
2011-01-01
In this paper we evaluate the potential of the next major revision of HTML (Hypertext Markup Language), that is HTML5, to provide an effective platform for the transmission and visualization of vector based geographical data. Relative to the current version of HTML, HTML 4.01, HTML5 offers an improved platform to perform these tasks through greater interoperability with existing technologies and the introduction of many new APIs. Visualization of vector data can be achieved us...
Paras, K L; O'Brien, V A; Reiskind, M H
2014-08-01
Dirofilaria immitis Leidy (Spirurida: Onchocercidae), or heartworm, is a mosquito-borne nematode that causes a fatal disease in carnivores. Although infection is preventable through prophylactic drugs, compliance and the spectre of resistance suggest vector control is a viable alternative. There were two main objectives in this study: (a) to evaluate the relationships between landscape and social factors and the number and species of heartworm-positive mosquitoes, with a specific focus on the importance of the invasive Asian tiger mosquito, Aedes albopictus (Skuse) (Stegomyia albopicta) (Diptera: Culicidae), and (b) to test the hypothesis that dog heartworm is more prevalent in suburban than in rural areas. To achieve these objectives, mosquitoes were collected from May to November 2010 at 16 rural and 16 urban locations in Payne County, Oklahoma, U.S.A. using three trapping methods that utilized, respectively, resting boxes, carbon dioxide traps and BG Sentinel traps. Urban areas showed greater numbers of Ae.?albopictus and a higher overall likelihood of infection with D.?immitis. Because many species of mosquito are responsible for heartworm transmission, current prophylactic treatment remains the best method of controlling this parasite. PMID:24898348
Thrust vector control using electric actuation
Bechtel, Robert T.; Hall, David K.
1995-01-01
Presently, gimbaling of launch vehicle engines for thrust vector control is generally accomplished using a hydraulic system. In the case of the space shuttle solid rocket boosters and main engines, these systems are powered by hydrazine auxiliary power units. Use of electromechanical actuators would provide significant advantages in cost and maintenance. However, present energy source technologies such as batteries are heavy to the point of causing significant weight penalties. Utilizing capacitor technology developed by the Auburn University Space Power Institute in collaboration with the Auburn CCDS, Marshall Space Flight Center (MSFC) and Auburn are developing EMA system components with emphasis on high discharge rate energy sources compatible with space shuttle type thrust vector control requirements. Testing has been done at MSFC as part of EMA system tests with loads up to 66000 newtons for pulse times of several seconds. Results show such an approach to be feasible providing a potential for reduced weight and operations costs for new launch vehicles.
SIT for African malaria vectors: Epilogue
Townson Harold
2009-11-01
Full Text Available Abstract As a result of increased support and the diligent application of new and conventional anti-malaria tools, significant reductions in malaria transmission are being accomplished. Historical and current evolutionary responses of vectors and parasites to malaria interventions demonstrate that it is unwise to assume that a limited suite of tools will remain effective indefinitely, thus efforts to develop new interventions should continue. This collection of manuscripts surveys the prospects and technical challenges for applying a novel tool, the sterile insect technique (SIT, against mosquitoes that transmit malaria. The method has been very successful against many agricultural pest insects in area-wide programs, but demonstrations against malaria vectors have not been sufficient to determine its potential relative to current alternatives, much of which will hinge ultimately upon cost. These manuscripts provide an overview of current efforts to develop SIT and identify key research issues that remain.
Canine vector-borne diseases in Brazil
Dantas-Torres Filipe
2008-08-01
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.
Canine vector-borne diseases in Brazil.
Dantas-Torres, Filipe
2008-01-01
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. PMID:18691408
Genetically engineering adenoviral vectors for gene therapy.
Coughlan, Lynda
2014-01-01
Adenoviral (Ad) vectors are commonly used for various gene therapy applications. Significant advances in the genetic engineering of Ad vectors in recent years has highlighted their potential for the treatment of metastatic disease. There are several methods to genetically modify the Ad genome to incorporate retargeting peptides which will redirect the natural tropism of the viruses, including homologous recombination in bacteria or yeast. However, homologous recombination in yeast is highly efficient and can be achieved without the need for extensive cloning strategies. In addition, the method does not rely on the presence of unique restriction sites within the Ad genome and the reagents required for this method are widely available and inexpensive. Large plasmids containing the entire adenoviral genome (~36 kbp) can be modified within Saccharomyces cerevisiae yeast and genomes easily rescued in Escherichia coli hosts for analysis or amplification. A method for two-step homologous recombination in yeast is described in this chapter. PMID:24243238
Stable piecewise polynomial vector fields
Claudio Pessoa
2012-09-01
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.
Samrat, Subodh Kumar; Vedi, Satish; Singh, Shakti; Li, Wen; Kumar, Rakesh; Agrawal, Babita
2015-01-01
Multispecific, broad, and potent T cell responses have been correlated with viral clearance in hepatitis C virus (HCV) infection. However, the majority of infected patients develop chronic infection, suggesting that natural infection mostly leads to development of inefficient T cell immunity. Multiple mechanisms of immune modulation and evasion have been shown in HCV infection through various investigations. This study examined the generation and modulation of T cell responses against core and frameshift (F) proteins of HCV. A single immunization of mice with replication incompetent recombinant adenovirus vectors encoding for F or core antigens induces poor T cell responses and leads to generation of CD4+ and CD8+ T cells with low granzyme B (GrB) expression. These T cells have impaired GrB enzyme activity and are unable to kill peptide loaded target cells. The low intracellular expression of GrB is not due to degranulation of cytotoxic granules containing cytotoxic T cells. Addition of exogenous IL-2 in in vitro cultures leads to partial recovery of GrB production, whereas immunization with the Toll-like receptor (TLR) agonist poly I:C leads to complete restoration of GrB expression in both CD4+ and CD8+ T cells. Thus, a possible new strategy of T cell modulation is recognized wherein effector T cells are caused to be dysfunctional by HCV-derived antigens F or core, and strategies are also delineated to overcome this dysfunction. These studies are important in the investigation of prophylactic vaccine and immunotherapy strategies for HCV infection. PMID:26133045
Vector meson and axial-vector diquark decay constants
A natural generalization to the case of unequal constituent masses of the formula which gives the correct decay constants for vector mesons of the quarkonium type is proposed. Within the philosophy where diquarks are used as baryonic constituents, this allows us to evaluate the decay widths for all vector particles both mesons and diquarks to be used later on the calculate the baryon lifetimes. (Author)
Vector control of induction machines
Robyns, Benoit
2012-01-01
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
Moduli of toric vector bundles
Payne, Sam
2007-01-01
We give a presentation of the moduli stack of toric vector bundles with fixed equivariant total Chern class as a quotient of a fine moduli scheme of framed bundles by a linear group action. This fine moduli scheme is described explicitly as a locally closed subscheme of a product of partial flag varieties cut out by combinatorially specified rank conditions. We use this description to show that the moduli of rank three toric vector bundles satisfy Murphy's Law, in the sense of Vakil. The preliminary sections of the paper give a self-contained introduction to Klyachko's classification of toric vector bundles.
Davis, Christopher James; Kedlaya, Kiran
2014-01-01
We study the kernel and cokernel of the Frobenius map on the p-typical Witt vectors of a commutative ring, not necessarily of characteristic p. We give many equivalent conditions to surjectivity of the Frobenius map on both finite and infinite length Witt vectors. In particular, surjectivity on...... finite Witt vectors turns out to be stable under certain integral extensions; this provides a clean formulation of a strong generalization of Faltings’s almost purity theorem from p-adic Hodge theory, incorporating recent improvements by Kedlaya–Liu and by Scholze....
Transcriptional Silencing of Retroviral Vectors
Lund, Anders Henrik; Duch, M.; Pedersen, F.S.
1996-01-01
Although retroviral vector systems have been found to efficiently transduce a variety of cell types in vitro, the use of vectors based on murine leukemia virus in preclinical models of somatic gene therapy has led to the identification of transcriptional silencing in vivo as an important problem...... transcription is known from a number of cellular and animal models, major insight has been gained from studies in the germ line and embryonal cells of the mouse. Key elements for the transfer and expression of retroviral vectors, such as the viral transcriptional enhancer and the binding site for the t...
Ovine Adenovirus Vectors Overcome Preexisting Humoral Immunity against Human Adenoviruses In Vivo
Hofmann, Christian; Löser, Peter; Cichon, Günter; Arnold, Wolfgang; Both, Gerald W.; Strauss, Michael
1999-01-01
Recombinant human adenoviruses (hAd) have become widely used as tools to achieve efficient gene transfer. However, successful application of hAd-derived vectors in clinical trials is limited due to immunological and potential safety problems inherent in their human origin. In this study, we describe a recombinant ovine adenovirus (OAV) as an alternative vector for gene transfer in vivo. In contrast to an hAd vector, the OAV vector was not neutralized by human sera. An OAV vector which contain...
Solid rocket thrust vector control
1974-01-01
Thrust vector control systems that superimpose a side force on the motor thrust, steering being achieved by the side force causing a moment about the vehicle center of gravity are described. A brief review of thrust vector control systems is presented, and two systems, flexible joint and liquid injection, are treated in detail. Treatment of the flexible-joint thrust vector control system is limited to the design of the flexible joint and its insulation against hot motor gases. Treatment of the liquid injection thrust vector control system is limited to discussion of the injectant, valves, piping, storage tanks, and pressurization system; no evaluation is presented of the nozzle except for (1) the effect of the injectant and erosion at the injection port and (2) the effect of injection on pressure distribution within the nozzle.
Scalable production of adenovirus vectors.
Silva, Ana Carina; Fernandes, Paulo; Sousa, Marcos F Q; Alves, Paula M
2014-01-01
Recombinant adenoviruses (AdV) are highly efficient at gene transfer for a broad spectrum of cell types and species. They became one of the vectors of choice for gene delivery and expression of foreign proteins in gene therapy and vaccination purposes. To meet the need of significant amounts of adenoviral vectors for preclinical and possibly clinical uses, scalable and reproducible production processes are required.In this chapter, we review processes used for scalable production of two types of first generation (E1-deleted) adenoviral vectors (Human and Canine) using stirred tank bioreactors. The production of adenovirus vectors using either suspension (HEK 293) or anchorage-dependent cells (MDCK-E1) are described to exemplify scalable production processes with different cell-culture types. The downstream processes will be covered in the next chapter. PMID:24132486
All optical vector magnetometer Project
National Aeronautics and Space Administration — This Phase I research project will investigate a novel method of operating an atomic magnetometer to simultaneously measure total magnetic fields and vector...
Molaei, Goudarz; Andreadis, Theodore G; Armstrong, Philip M; Diuk-Wasser, Maria
2008-11-01
We evaluated the blood-feeding patterns in several mosquito species that may serve as vectors of disease agents in the northeastern United States. Blood-fed mosquitoes were collected from 91 different sites throughout Connecticut over a 6-yr period (June-October 2002-2007), and the host-feeding patterns of 23 mosquito species representing six genera were examined by using a polymerase chain reaction-based assay and sequencing portions of the cytochrome b gene of mitochondrial DNA. This study was part of a statewide surveillance program and for some of the mosquito species a limited number of specimens were examined [e.g., Aedes communis (De Geer) (1), Anopheles barberi Coquillett (1), Uranotaenia sapphirina (Osten Sacken) (5)]. With the exception of Culex territans Walker that acquired bloodmeals from all four classes of vertebrates--birds, reptiles, amphibians, and mammals--all species of Aedes, Anopheles, Coquillettidia, Psorophora, and to a lesser degree, Uranotaenia, were found to feed predominately upon mammalian hosts. Fourteen mammalian species were identified as sources of blood, but the majority of feedings were taken from the white-tailed deer, Odocoileus virginianus. Human-derived bloodmeals were identified from 13 of the 23 mosquito species. Limited avian-derived bloodmeals were detected in Aedes canadensis (Theobald), Aedes cantator (Coquillett), Aedes cinereus Meigen, Aedes triseriatus (Coquillett), Aedes trivittatus (Coquillett), Coquillettidia perturbans (Walker) Cx. territans, Psorophoraferox (von Humboldt), and Ur. sapphirina. American robin, Turdus migratorius, was the most common source of avian blood, followed by a few other mostly Passeriformes birds. We conclude that the white-tailed deer serve as the main vertebrate host for these mammalophilic mosquitoes in this region of the United States. This feeding pattern supports enzootic amplification of arboviruses, including Jamestown Canyon, Cache Valley, and Potosi viruses that perpetuate in cervid hosts. Occasional feeding on avian hosts suggests that some of these mosquito species, such as Cq. perturbans, also could facilitate transmission of West Nile and eastern equine encephalitis viruses from viremic birds to mammalian hosts. PMID:19058640
Vector field visualization with streamlines
Sparavigna, A.; Montrucchio, B.
2006-01-01
We have recently developed an algorithm for vector field visualization with oriented streamlines, able to depict the flow directions everywhere in a dense vector field and the sense of the local orientations. The algorithm has useful applications in the visualization of the director field in nematic liquid crystals. Here we propose an improvement of the algorithm able to enhance the visualization of the local magnitude of the field. This new approach of the algorithm is compared with the same...
Lizana, J M
2013-01-01
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.
An exotic composite vector boson
An exotic composite vector boson, V, is introduced in two dynamical models of composite quarks, leptons, W and Z. One is based on four Fermi interactions, in which composite vector bosons are regarded as fermion-antifermion bound states and the other is based on the confining SU(2)L gauge model, in which they are given by scalar-antiscalar bound states. Both approaches describe the same effective interactions for the sector of composite quarks, leptons, W, Z, ? and V. (author)
Nonlinear vector perturbations in a contracting universe
A number of scalar field models proposed as alternatives to the standard inflationary scenario involve contracting phases which precede the universe's present phase of expansion. An important question concerning such models is whether there are effects which could potentially distinguish them from purely expanding cosmologies. Vector perturbations have recently been considered in this context. At first order such perturbations are not supported by a scalar field. In this paper, therefore, we consider second-order vector perturbations. We show that such perturbations are generated by first-order scalar mode-mode couplings, and give an explicit expression for them. We compare the magnitude of vector perturbations produced in collapsing models with the corresponding amplitudes produced during inflation, using a number of suitable power-law solutions to model the inflationary and collapsing scenarios. We conclude that the ratios of the magnitudes of these perturbations depend on the details of the collapsing scenario as well as on how the hot big bang is recovered, but for certain cases could be large, growing with the duration of the collapse
Nordic climate change: data for modeling vector borne diseases
Kristensen, Birgit; Bødker, Rene
The distribution of vector species is generally restricted by a range of different climatic and geographical factors, while the development and spread of the vector-borne diseases (veterinary and zoonotic) is often primarily temperature driven. Thus temperature and its derivatives are key factors...... in the modelling of vector-borne diseases. This puts a high demand on the quality and accuracy of the temperature data to be used as input in such models. In order to best capture the local temporal and spatial variation in the temperature surfaces, accurate daily temperature data were used in the...... Scandinavia. Various temperature derivatives were calculated in order to assess the geographical and seasonal variation in the area. In order to evaluate the response of vector borne diseases to possible future climate changes and the subsequent potential spread into new areas, daily temperature predictions...
Overcoming Gene-Delivery Hurdles: Physiological Considerations for Nonviral Vectors.
Hill, Andrew B; Chen, Mingfu; Chen, Chih-Kuang; Pfeifer, Blaine A; Jones, Charles H
2016-02-01
With the use of contemporary tools and techniques, it has become possible to more precisely tune the biochemical mechanisms associated with using nonviral vectors for gene delivery. Consequently, nonviral vectors can incorporate numerous vector compositions and types of genetic cargo to develop diverse genetic therapies. Despite these advantages, gene-delivery strategies using nonviral vectors have poorly translated into clinical success due to preclinical experimental design considerations that inadequately predict therapeutic efficacy. Furthermore, the manufacturing and distribution processes are critical considerations for clinical application that should be considered when developing therapeutic platforms. In this review, we evaluate potential avenues towards improving the transition of gene-delivery technologies from in vitro assessment to human clinical therapy. PMID:26727153
Hinrichs, Brant E.
2010-10-01
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.
Linear matrix inequalities for analysis and control of linear vector second-order systems
Adegas, Fabiano D. [Aalborg Univ. (Denmark); Stoustrup, Jakob [Aalborg Univ. (Denmark)
2014-10-06
Many dynamical systems are modeled as vector second-order differential equations. This paper presents analysis and synthesis conditions in terms of LMI with explicit dependence in the coefficient matrices of vector second-order systems. These conditions benefit from the separation between the Lyapunov matrix and the system matrices by introducing matrix multipliers, which potentially reduce conservativeness in hard control problems. Multipliers facilitate the usage of parameter-dependent Lyapunov functions as certificates of stability of uncertain and time-varying vector second-order systems. The conditions introduced in this work have the potential to increase the practice of analyzing and controlling systems directly in vector second-order form.
Vector dark energy models with quadratic terms in the Maxwell tensor derivatives
Haghani, Zahra; Harko, Tiberiu(Department of Mathematics, University College London, Gower Street, WC1E 6BT, London, UK); Sepangi, Hamid Reza; Shahidi, Shahab
2016-01-01
We consider a vector-tensor gravitational model in which the action for the minimally coupled vector field also contains additional terms quadratic in the Maxwell tensor derivatives, and corresponds to the covariant form of the so-called Bopp-Podolsky electrodynamics. A term describing the non-minimal coupling between the cosmological mass current and the four-potential of the vector field as well as the self-interaction potential of the vector field is also included in the action. From a cos...
Based on the light-cone effective Hamiltonian with confining potential and SU(3) flavor mixing interactions, the flavor mixing mesons on the u, d, and s quark sectors are investigated. The mass eigen equations of the flavor mixing vector and pseudo vector mesons are solved. The calculated masses are in good agreement with the experimental data. (the physics of elementary particles and fields)
Vector-valued automorphic forms and vector bundles
Saber, Hicham
2013-01-01
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 $\\Gamma$.
Progress and challenges in viral vector manufacturing.
van der Loo, Johannes C M; Wright, J Fraser
2016-04-15
Promising results in several clinical studies have emphasized the potential of gene therapy to address important medical needs and initiated a surge of investments in drug development and commercialization. This enthusiasm is driven by positive data in clinical trials including gene replacement for Hemophilia B, X-linked Severe Combined Immunodeficiency, Leber's Congenital Amaurosis Type 2 and in cancer immunotherapy trials for hematological malignancies using chimeric antigen receptor T cells. These results build on the recent licensure of the European gene therapy product Glybera for the treatment of lipoprotein lipase deficiency. The progress from clinical development towards product licensure of several programs presents challenges to gene therapy product manufacturing. These include challenges in viral vector-manufacturing capacity, where an estimated 1-2 orders of magnitude increase will likely be needed to support eventual commercial supply requirements for many of the promising disease indications. In addition, the expanding potential commercial product pipeline and the continuously advancing development of recombinant viral vectors for gene therapy require that products are well characterized and consistently manufactured to rigorous tolerances of purity, potency and safety. Finally, there is an increase in regulatory scrutiny that affects manufacturers of investigational drugs for early-phase clinical trials engaged in industry partnerships. Along with the recent increase in biopharmaceutical funding in gene therapy, industry partners are requiring their academic counterparts to meet higher levels of GMP compliance at earlier stages of clinical development. This chapter provides a brief overview of current progress in the field and discusses challenges in vector manufacturing. PMID:26519140
Pre-existing immunity against vaccine vectors--friend or foe?
Saxena, Manvendra; Van, Thi Thu Hao; Baird, Fiona J; Coloe, Peter J; Smooker, Peter M
2013-01-01
Over the last century, the successful attenuation of multiple bacterial and viral pathogens has led to an effective, robust and safe form of vaccination. Recently, these vaccines have been evaluated as delivery vectors for heterologous antigens, as a means of simultaneous vaccination against two pathogens. The general consensus from published studies is that these vaccine vectors have the potential to be both safe and efficacious. However, some of the commonly employed vectors, for example Salmonella and adenovirus, often have pre-existing immune responses in the host and this has the potential to modify the subsequent immune response to a vectored antigen. This review examines the literature on this topic, and concludes that for bacterial vectors there can in fact, in some cases, be an enhancement in immunogenicity, typically humoral, while for viral vectors pre-existing immunity is a hindrance for subsequent induction of cell-mediated responses. PMID:23175507
Comparison of lentiviral vector titration methods
Debyser Zeger; Baekelandt Veerle; Willems Sofie; Geraerts Martine; Gijsbers Rik
2006-01-01
Abstract Background Lentiviral vectors are efficient vehicles for stable gene transfer in dividing and non-dividing cells. Several improvements in vector design to increase biosafety and transgene expression, have led to the approval of these vectors for use in clinical studies. Methods are required to analyze the quality of lentiviral vector production, the efficiency of gene transfer and the extent of therapeutic gene expression. Results We compared lentiviral vector titration methods that ...
Pihl, Michael Johannes
The main purpose of this PhD project is to develop an ultrasonic method for 3D vector flow imaging. The motivation is to advance the field of velocity estimation in ultrasound, which plays an important role in the clinic. The velocity of blood has components in all three spatial dimensions, yet...... conventional methods can estimate only the axial component. Several approaches for 3D vector velocity estimation have been suggested, but none of these methods have so far produced convincing in vivo results nor have they been adopted by commercial manufacturers. The basis for this project is the Transverse...... the TO fields are suggested. They can be used to optimize the TO method. In the third part, a TO method for 3D vector velocity estimation is proposed. It employs a 2D phased array transducer and decouples the velocity estimation into three velocity components, which are estimated simultaneously based...
Fiber propagation of vector modes
Ndagano, Bienvenu; McLaren, Melanie; Duparre, Michael; Forbes, Andrew
2015-01-01
Here we employ both dynamic and geometric phase control of light to produce radially modulated vector-vortex modes, the natural modes of optical fibers. We then measure these modes using a vector modal decomposition set-up as well as a tomography measurement, the latter providing a degree of the non-separability of the vector states, akin to an entanglement measure for quantum states. We demonstrate the versatility of the approach by creating the natural modes of a step-index fiber, which are known to exhibit strong mode coupling, and measure the modal cross-talk and non-separability decay during propagation. Our approach will be useful in mode division multiplexing schemes for transport of classical and quantum states.
Toward lattice fractional vector calculus
Tarasov, Vasily E.
2014-09-01
An analog of fractional vector calculus for physical lattice models is suggested. We use an approach based on the models of three-dimensional lattices with long-range inter-particle interactions. The lattice analogs of fractional partial derivatives are represented by kernels of lattice long-range interactions, where the Fourier series transformations of these kernels have a power-law form with respect to wave vector components. In the continuum limit, these lattice partial derivatives give derivatives of non-integer order with respect to coordinates. In the three-dimensional description of the non-local continuum, the fractional differential operators have the form of fractional partial derivatives of the Riesz type. As examples of the applications of the suggested lattice fractional vector calculus, we give lattice models with long-range interactions for the fractional Maxwell equations of non-local continuous media and for the fractional generalization of the Mindlin and Aifantis continuum models of gradient elasticity.
Search for intermediate vector bosons
Klajn, D.B.; Rubbia, K.; Meer, S.
1983-01-01
Problem of registration and search for intermediate vector bosons is discussed. According to weak-current theory there are three intermediate vector bosons with +1(W/sup +/)-1(W/sup -/) and zero (Z/sup 0/) electric charges. It was suggested to conduct the investigation into particles in 1976 by cline, Rubbia and Makintair using proton-antiproton beams. Major difficulties of the experiment are related to the necessity of formation of sufficient amount of antiparticles and the method of antiproton beam ''cooling'' for the purpose of reduction of its random movements. The stochastic method was suggested by van der Meer in 1968 as one of possible cooling methods. Several large detectors were designed for searching intermediate vector bosons.
Search for intermediate vector bosons
Problem of registration and search for intermediate vector bosons is discussed. According to weak-current theory there are three intermediate vector bosons with +1(W+)-1(W-) and zero (Z0) electric charges. It was suggested to conduct the investigation into particles in 1976 by cline, Rubbia and Makintair using proton-antiproton beams. Major difficulties of the experiment are related to the necessity of formation of sufficient amount of antiparticles and the method of antiproton beam ''cooling'' for the purpose of reduction of its random movements. The stochastic method was suggested by van der Meer in 1968 as one of possible cooling methods. Several large detectors were designed for searching intermediate vector bosons
Gauge Theories of Vector Particles
Glashow, S. L.; Gell-Mann, M.
1961-04-24
The possibility of generalizing the Yang-Mills trick is examined. Thus we seek theories of vector bosons invariant under continuous groups of coordinate-dependent linear transformations. All such theories may be expressed as superpositions of certain "simple" theories; we show that each "simple theory is associated with a simple Lie algebra. We may introduce mass terms for the vector bosons at the price of destroying the gauge-invariance for coordinate-dependent gauge functions. The theories corresponding to three particular simple Lie algebras - those which admit precisely two commuting quantum numbers - are examined in some detail as examples. One of them might play a role in the physics of the strong interactions if there is an underlying super-symmetry, transcending charge independence, that is badly broken. The intermediate vector boson theory of weak interactions is discussed also. The so-called "schizon" model cannot be made to conform to the requirements of partial gauge-invariance.
Shifting suitability for malaria vectors across Africa with warming climates
Peterson A Townsend
2009-05-01
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.
Vector Algorithms for Solving 3 D Nonlinear Magnetostatic Problems
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
Singular vectors, predictability and ensemble forecasting for weather and climate
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)
Steffensen, Maria Abildgaard; Jensen, Benjamin Anderschou Holbech; Holst, Peter Johannes; Bassi, Maria Rosaria; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup
2012-01-01
Adenoviral vectors have shown a great potential for vaccine development due to their inherent ability to induce potent and protective CD8 T-cell responses. However, a critical issue regarding the use of these vectors is the existence of inhibitory immunity against the most commonly used Ad5 vector in a large part of the human population. We have recently developed an improved adenoviral vaccine vector system in which the vector expresses the transgene tethered to the MHC class II associated i...
Moduli of toric vector bundles
Payne, Sam
2007-01-01
We give a presentation of the moduli stack of toric vector bundles with fixed equivariant total Chern class as a quotient of a fine moduli scheme of framed bundles by a linear group action. This fine moduli scheme is described explicitly as a locally closed subscheme of a product of partial flag varieties cut out by combinatorially specified rank conditions. We use this description to show that the moduli of rank three toric vector bundles satisfy Murphy's Law, in the sense of Vakil. The prel...
Evaluation of integrated vector management.
van den Berg, Henk; Takken, Willem
2009-02-01
Initiatives on integrated vector management (IVM) approaches are increasingly undertaken as alternatives to existing vector control. An impact model of IVM is presented with performance and impact indicators at six causal steps from coverage of the intervention to impact on disease. Impacts in fields other than health are also discussed because of the emphasis in IVM on capacity building, partnerships and sustainability. A conceptual framework for evaluation of IVM is designed, based on considerations of the selection of indicators, level of inference, cluster size and method of evaluation. The framework, which is tested in three case studies, is intended as guidance for public health workers and policy-makers. PMID:19110470
Learning with Support Vector Machines
Campbell, Colin
2010-01-01
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
Visual and olfactory associative learning in the malaria vector Anopheles gambiae sensu stricto
Chilaka Nora; Perkins Elisabeth; Tripet Frédéric
2012-01-01
Abstract Background Memory and learning are critical aspects of the ecology of insect vectors of human pathogens because of their potential effects on contacts between vectors and their hosts. Despite this epidemiological importance, there have been only a limited number of studies investigating associative learning in insect vector species and none on Anopheline mosquitoes. Methods A simple behavioural assays was developed to study visual and olfactory associative learning in Anopheles gambi...
Pre-existing immunity against vaccine vectors – friend or foe?
Saxena, Manvendra; Van, Thi Thu Hao; Baird, Fiona J.; Coloe, Peter J; Smooker, Peter M.
2013-01-01
Over the last century, the successful attenuation of multiple bacterial and viral pathogens has led to an effective, robust and safe form of vaccination. Recently, these vaccines have been evaluated as delivery vectors for heterologous antigens, as a means of simultaneous vaccination against two pathogens. The general consensus from published studies is that these vaccine vectors have the potential to be both safe and efficacious. However, some of the commonly employed vectors, for example Sa...
Alpharetroviral Vectors: From a Cancer-Causing Agent to a Useful Tool for Human Gene Therapy
Suerth, Julia D; Verena Labenski; Axel Schambach
2014-01-01
Gene therapy using integrating retroviral vectors has proven its effectiveness in several clinical trials for the treatment of inherited diseases and cancer. However, vector-mediated adverse events related to insertional mutagenesis were also observed, emphasizing the need for safer therapeutic vectors. Paradoxically, alpharetroviruses, originally discovered as cancer-causing agents, have a more random and potentially safer integration pattern compared to gammaretro- and lentiviruses. In thi...
Bartosik, Aneta A.; GLABSKI, Krzysztof; Kulinska, Anna; Lewicka, Ewa; Godziszewska, Jolanta; Markowska, Aleksandra; Jagura-Burdzy, Grazyna
2016-01-01
Background Low-copy-number vectors of potential wide application in biotechnology need to encode stabilization modules ensuring their stable inheritance. The efficiency of stabilization may vary depending on the plasmid host so a thorough analysis of stabilization functions is required before use. Results To facilitate such analysis highly unstable, mobilizable, broad-host-range (BHR) vectors based on RK2 replicon were constructed. The vectors are suitable for testing of various stabilization...
Simian virus 40 vectors for pulmonary gene therapy
Oppenheim Ariella
2007-10-01
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.
Emerging adenoviral vectors for stable correction of genetic disorders.
Jager, Lorenz; Ehrhardt, Anja
2007-08-01
Recent drawbacks in treating patients with severe combined immunodeficiency disorders with retroviral vectors underline the importance of generating novel tools for stable transduction of mammalian cells. Substantial progress has been made over the recent years which may offer important steps towards stable and more importantly safer correction of genetic diseases. This article discusses recent advances for stable transduction of target cells based on adenoviral gene transfer. There is accumulating evidence that recombinant adenoviral vectors (AdVs) based on various human serotypes with a broad cellular tropism and adenoviruses (Ads) from different species will play an important role in future gene therapy applications. In combination with recombinant AdVs for somatic integration these gene transfer vectors offer high transduction efficiencies with potentially safer integration patterns. Other approaches for persistent transgene expression include excision of stable episomes from the adenoviral vector genome, but also long-term persistence of the complete adenoviral vector genome as an episomal DNA molecule was demonstrated and exemplified by the treatment of various genetic diseases in small and large animal models. This review displays advantages but also limitations of these Ad based vector systems. This is the perfect time to pursue such approaches because alternative strategies for stable transduction of mammalian cells undergoing many cell divisions are urgently needed. Looking into the future, we believe that a combination of different components from different viral vectors in concert with non-viral vector systems will be successful in designing significantly optimized transfer vehicles for a broad range of different genetic diseases. PMID:17969560
Characteristics of the crops grown with the light vector altered relative to the gravity vector
Berkovich, Y. A.; Smolianina, S. O.; Krivobok, N. M.; Erokhin, A. N.; Ivanov, V. B.
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.
IP Sunish
2007-02-01
Full Text Available OBJECTIVE: To determine the role of vector control in further decreasing the transmission of bancroftian filariasis achieved by mass drug administration and the long-term impact on filariometric indices. METHODS: Three rounds of annual mass drug administration, with diethylcarbamazine and ivermectin, were complemented by vector control (mainly using polystyrene beads in villages of Tirukoilur, south India, during 1995-99. Subsequently, drug administration is being carried out with diethylcarbamazine and albendazole or diethylcarbamazine alone. We evaluated the impact of mass drug administration used alone or in conjunction with vector control (from 1995 to 2005 on vector transmission indices (such as transmission intensity index, monthly biting rate, monthly transmission potential and annual transmission potential. We analysed data on filarial infection in the community to estimate the prevalence of microfilaraemia and antigenaemia using chi2 analysis and Fisher's exact test. FINDINGS: Vector density greatly decreased in villages where vector control was used as an adjunct to mass drug administration and almost no infective mosquitoes were found in the small numbers still remaining. Filarial antigenaemia was low and continued to decrease significantly in the age group 15-25 years in villages receiving mass drug administration with vector control in contrast to villages receiving only mass drug administration. CONCLUSION: The gains of mass drug administration were sustained only with the integration of vector control measures. We advocate the incorporation of vector control in the Global Programme to Eliminate Lymphatic Filariasis as it can potentially decrease the time required for eliminating lymphatic filariasis.
Vector ecology of equine piroplasmosis
Equine piroplasmosis (EP) is a disease of equidae including horses, donkeys, mules and zebras caused by either of two protozoan parasites, Theileria equi or Babesia caballi. These parasites are biologically transmitted between hosts via tick-vectors and although they have inherent differences, they ...
Portfolio Analysis for Vector Calculus
Kaplan, Samuel R.
2015-01-01
Classic stock portfolio analysis provides an applied context for Lagrange multipliers that undergraduate students appreciate. Although modern methods of portfolio analysis are beyond the scope of vector calculus, classic methods reinforce the utility of this material. This paper discusses how to introduce classic stock portfolio analysis in a…
Vector-meson dominance revisited
Terschlüsen Carla
2012-12-01
Full Text Available The interaction of mesons with electromagnetism is often well described by the concept of vector-meson dominance (VMD. However, there are also examples where VMD fails. A simple chiral Lagrangian for pions, rho and omega mesons is presented which can account for the respective agreement and disagreement between VMD and phenomenology in the sector of light mesons.
Some properties of vector gluinonium
Strong radiation transitions between the levels of the gluonic bound states are considered. The decay probability for vector gluinonium into Z-bozon and has calculated, and the possibility to observe this state in the Z-bozon and gluon jet
On Weighted Support Vector Regression
Han, Xixuan; Clemmensen, Line Katrine Harder
2014-01-01
We propose a new type of weighted support vector regression (SVR), motivated by modeling local dependencies in time and space in prediction of house prices. The classic weights of the weighted SVR are added to the slack variables in the objective function (OF‐weights). This procedure directly...
Portfolio Analysis for Vector Calculus
Kaplan, Samuel R.
2015-01-01
Classic stock portfolio analysis provides an applied context for Lagrange multipliers that undergraduate students appreciate. Although modern methods of portfolio analysis are beyond the scope of vector calculus, classic methods reinforce the utility of this material. This paper discusses how to introduce classic stock portfolio analysis in a
Parallel Sparse Matrix - Vector Product
Alexandersen, Joe; Lazarov, Boyan Stefanov; Dammann, Bernd
This technical report contains a case study of a sparse matrix-vector product routine, implemented for parallel execution on a compute cluster with both pure MPI and hybrid MPI-OpenMP solutions. C++ classes for sparse data types were developed and the report shows how these class can be used, as...
Finite elements in vector lattices
Weber, Martin R
2014-01-01
The book is the first systematical treatment of the theory of finite elements in Archimedean vector lattices and contains the results known on this topic up to the year 2013.It joins all importantcontributions achieved by a series of mathematicians that can only be found in scattered in literature.
Gene therapy of HIV-1 infection using lentiviral vectors expressing anti-HIV-1 genes.
Mautino, Mario R; Morgan, Richard A
2002-01-01
The use of vectors based on primate lentiviruses for gene therapy of human immunodeficiency virus type 1 (HIV-1) infection has many potential advantages over the previous murine retroviral vectors used for delivery of genes that inhibit replication of HIV-1. First, lentiviral vectors have the ability to transduce dividing and nondividing cells that constitute the targets of HIV-1 infection such as resting T cells, dendritic cells, and macrophages. Lentiviral vectors can also transfer genes to hematopoietic stem cells with a superior gene transfer efficiency and without affecting the repopulating capacity of these cells. Second, these vectors could be potentially mobilized in vivo by the wild-type virus to secondary target cells, thus expanding the protection to previously untransduced cells. And finally, lentiviral vector backbones have the ability to block HIV-1 replication by several mechanisms that include sequestration of the regulatory proteins Tat and Rev, competition for packaging into virions, and by inhibition of reverse transcription in heterodimeric virions with possible generation of nonfunctional recombinants between the vector and viral genomes. The inhibitory ability of lentiviral vectors can be further increased by expression of anti-HIV-1 genes. In this case, the lentiviral vector packaging system has to be modified to become resistant to the anti-HIV-1 genes expressed by the vector in order to avoid self-inhibition of the vector packaging system during vector production. This review focuses on the use of lentiviral vectors as the main agents to mediate inhibition of HIV-1 replication and discusses the different genetic intervention strategies for gene therapy of HIV-1 infection. PMID:11839215
Amblyomma imitator Ticks as Vectors of Rickettsia rickettsii, Mexico
Oliveira, Karla A.; Pinter, Adriano; Medina-Sanchez, Aaron; Boppana, Venkata D.; Wikel, Stephen K; Saito, Tais B; Shelite, Thomas; Blanton, Lucas; POPOV, Vsevolod; Teel, Pete D; David H Walker; Galvao, Marcio A.M.; Mafra, Claudio; BOUYER, DONALD H.
2010-01-01
Real-time PCR of Amblyomma imitator tick egg masses obtained in Nuevo Leon State, Mexico, identified a Rickettsia species. Sequence analyses of 17-kD common antigen and outer membrane protein A and B gene fragments showed to it to be R. rickettsii, which suggested a potential new vector for this bacterium.
Designing gene therapy vectors targeting tumor cell endothelium
Pınar ÖZKAL BAYDIN; AKBULUT, Hakan
2013-01-01
Angiogenesis is essential for tumor growth and metastasis. Targeting angiogenesis is one of the recent progresses in the therapeutic area of cancer. Gene therapy is one of the promis- ing strategies in the treatment of cancer. The gene therapy vectors targeting tumor endothelium carry the great therapeu- tic potential in cancer.
Designing gene therapy vectors targeting tumor cell endothelium
P?nar O?ZKAL BAYDIN
2013-12-01
Full Text Available Angiogenesis is essential for tumor growth and metastasis. Targeting angiogenesis is one of the recent progresses in the therapeutic area of cancer. Gene therapy is one of the promis- ing strategies in the treatment of cancer. The gene therapy vectors targeting tumor endothelium carry the great therapeu- tic potential in cancer.
Plant viral vectors based on tobamoviruses.
Yusibov, V; Shivprasad, S; Turpen, T H; Dawson, W; Koprowski, H
1999-01-01
The potential of plant virus-based transient expression vectors is substantial. One objective is the production of large quantities of foreign peptides or proteins. At least one commercial group (Biosource Technologies) is producing large quantities of product in the field, has built factories to process truck-loads of material and soon expects to market virus-generated products. In the laboratory, large amounts of protein have been produced for structural or biochemical analyses. An important aspect of producing large amounts of a protein or peptide is to make the product easily purifiable. This has been done by attaching peptides or proteins to easily purified units such as virion particles or by exporting proteins to the apoplast so that purification begins with a highly enriched product. For plant molecular biology, virus-based vectors have been useful in identifying previously unknown genes by overexpression or silencing or by expression in different genotypes. Also, foreign peptides fused to virions are being used as immunogens for development of antisera for experimental use or as injected or edible vaccines for medical use. As with liposomes and microcapsules, plant cells and plant viruses are also expected to provide natural protection for the passage of antigen through the gastrointestinal tract. Perhaps the greatest advantage of plant virus-based transient expression vectors is their host, plants. For the production of large amounts of commercial products, plants are one of the most economical and productive sources of biomass. They also present the advantages of lack of contamination with animal pathogens, relative ease of genetic manipulation and the presence eukaryotic protein modification machinery. PMID:10394716
Vector variational inequalities and their relations with vector optimization
Surjeet Kaur Suneja
2014-01-01
Full Text Available In this paper, K- quasiconvex, K- pseudoconvex and other related functions have been introduced in terms of their Clarke subdifferentials, where is an arbitrary closed convex, pointed cone with nonempty interior. The (strict, weakly -pseudomonotonicity, (strict K- naturally quasimonotonicity and K- quasimonotonicity of Clarke subdifferential maps have also been defined. Further, we introduce Minty weak (MVVIP and Stampacchia weak (SVVIP vector variational inequalities over arbitrary cones. Under regularity assumption, we have proved that a weak minimum solution of vector optimization problem (VOP is a solution of (SVVIP and under the condition of K- pseudoconvexity we have obtained the converse for MVVIP (SVVIP. In the end we study the interrelations between these with the help of strict K-naturally quasimonotonicity of Clarke subdifferential map.
Reorientation effects for 52 MeV vector polarized deuterons
The differential cross sections and the vector analysing powers were measured for the elastic and inelastic scattering of 52 MeV vector polarized deuterons from 20Ne, 22Ne, 26Mg, 28Si, 32S, 34S, 36Ar and 40Ar nuclei. Coupled channels analysis was carried out using an axially symmetric rotational model with either prolate or oblate quadrupole deformations for each isotope. Calculations assuming harmonic vibrator model were also carried out. In general, reorientation effects were found to be weak. A global optical model potential containing an imaginary spin-orbit component was found to be the most suitable in describing the experimental data at this energy
Parallel and vector implementation of APROS simulator code
In this paper the vector and parallel processing implementation of a general purpose simulator code is discussed. In this code the utilization of vector processing is straightforward. In addition to the loop level parallel processing, the functional decomposition and the domain decomposition have been considered. Results represented for a PWR-plant simulation illustrate the potential speed-up factors of the alternatives. It turns out that the loop level parallelism and the domain decomposition are the most promising alternative to employ the parallel processing. (author)
Dynamical system approach to scalar-vector-tensor cosmology
Ghaffarnejad, H
2016-01-01
We use scalar-vector-tensor gravity [1] which is obtained by generalizing Brans Dicke (BD) gravity model [2] via dynamical vector field. We study flat Friedmann Robertson Walker (FRW) cosmology by using dynamical system approach in the presence of self interaction BD potential and perfect fluid matter stress tensor. We obtained 3 critical points for $\\Lambda CDM$ vacuum de Sitter era which one of them is spiral attractor absolutely independent of particular values of the BD parameter $\\omega$ but not two other critical points. The latter take real values only for $-0.54-0.54.$ Even if the eigne values become complex imaginary where $\\omega\
Vector correlations in rotationally inelastic molecular collisions
The thesis presents an analytic model that describes scalar and vector properties of molecular collisions, both field-free and in fields. The model is based on the sudden approximation and treats molecular scattering as the Fraunhofer diffraction of matter waves from the hard-core part of the interaction potential. The theory has no fitting parameters and is inherently quantum, rendering fully state- and energy-resolved scattering amplitudes and all the quantities that unfold from them in analytic form. This allows to obtain complex polarization moments inherent to quantum stereodynamics, and to account for interference and other non-classical effects. The simplicity and analyticity of the model paves a way to understanding the origin of the features observed in experiment and exact computations, such as the angular oscillations in the state-to-state differential cross sections and the polarization moments, the rotational-state dependent variation of the integral cross sections, and change of these quantities as a function of the applied field. The theory was applied to study the k - k' vector correlation (differential cross section) for the following collision systems: Ar-NO(X2Π) and Ne-OCS(X1Σ) in an electrostatic field, Na+-N2(X1Σ) in a laser field, and He-CaH(2Σ), He-O2(X3Σ), and He-OH(X2Π) in a magnetic field. The model was able to reproduce the behavior of the differential cross sections and their variation with field strength. Combining the Fraunhofer model with the quantum theory of vector correlations made it possible to study three- and four-vector properties. The model results for the k-k'-j' vector correlation in Ar-NO(X2Π) and He-NO(X2Π) scattering were found to be in good agreement with experiment and exact computations. This allowed to demonstrate that the stereodynamics of such collisions is contained solely in the diffractive part of the scattering amplitude which is governed by a single Legendre moment characterizing the anisotropy of the hard-core part of the system's potential energy surface. The alignment moments obtained for He-OH(X2Π), He-O2(X3Σ), and He-CaH(X2Σ) allowed to identify the fingerprints of diffraction, which can be used to discern diffraction-driven stereodynamics in future experiments and exact computations. Analytic results for the Ne-NO(A2Σ) system were found to be in good agreement with experiment and exact computations for low rotational energy transfer; the discrepancy found for higher excitation channels could be traced back to the breakdown of the sudden approximation. The model was also applied to the k-j-k' and k-j-k'-j' correlations in rotationally inelastic Ar-NO(X2Π) scattering. It was shown that preparing the reagents with polarized angular momentum j makes it possible to significantly alter the collision dynamics and stereodynamics. In the final part of the thesis the analytic theory was extended to the study of multiple scattering of matter waves propagating through atomic and molecular gases. The combination of the Fraunhofer model with the semiclassical approximation to account, respectively, for the repulsive and attractive part of the potential energy surface resulted in a simple analytic formula, which agree well with experiment for the refraction of a Li beam passing through Xe gas. (orig.)
Vector correlations in rotationally inelastic molecular collisions
Lemeshko, Mikhail
2011-04-13
The thesis presents an analytic model that describes scalar and vector properties of molecular collisions, both field-free and in fields. The model is based on the sudden approximation and treats molecular scattering as the Fraunhofer diffraction of matter waves from the hard-core part of the interaction potential. The theory has no fitting parameters and is inherently quantum, rendering fully state- and energy-resolved scattering amplitudes and all the quantities that unfold from them in analytic form. This allows to obtain complex polarization moments inherent to quantum stereodynamics, and to account for interference and other non-classical effects. The simplicity and analyticity of the model paves a way to understanding the origin of the features observed in experiment and exact computations, such as the angular oscillations in the state-to-state differential cross sections and the polarization moments, the rotational-state dependent variation of the integral cross sections, and change of these quantities as a function of the applied field. The theory was applied to study the k - k{sup '} vector correlation (differential cross section) for the following collision systems: Ar-NO(X{sup 2}{pi}) and Ne-OCS(X{sup 1}{sigma}) in an electrostatic field, Na{sup +}-N{sub 2}(X{sup 1}{sigma}) in a laser field, and He-CaH({sup 2}{sigma}), He-O{sub 2}(X{sup 3}{sigma}), and He-OH(X{sup 2}{pi}) in a magnetic field. The model was able to reproduce the behavior of the differential cross sections and their variation with field strength. Combining the Fraunhofer model with the quantum theory of vector correlations made it possible to study three- and four-vector properties. The model results for the k-k{sup '}-j{sup '} vector correlation in Ar-NO(X{sup 2}{pi}) and He-NO(X{sup 2}{pi}) scattering were found to be in good agreement with experiment and exact computations. This allowed to demonstrate that the stereodynamics of such collisions is contained solely in the diffractive part of the scattering amplitude which is governed by a single Legendre moment characterizing the anisotropy of the hard-core part of the system's potential energy surface. The alignment moments obtained for He-OH(X{sup 2}{pi}), He-O{sub 2}(X{sup 3}{sigma}), and He-CaH(X{sup 2}{sigma}) allowed to identify the fingerprints of diffraction, which can be used to discern diffraction-driven stereodynamics in future experiments and exact computations. Analytic results for the Ne-NO(A{sup 2}{sigma}) system were found to be in good agreement with experiment and exact computations for low rotational energy transfer; the discrepancy found for higher excitation channels could be traced back to the breakdown of the sudden approximation. The model was also applied to the k-j-k{sup '} and k-j-k{sup '}-j{sup '} correlations in rotationally inelastic Ar-NO(X{sup 2}{pi}) scattering. It was shown that preparing the reagents with polarized angular momentum j makes it possible to significantly alter the collision dynamics and stereodynamics. In the final part of the thesis the analytic theory was extended to the study of multiple scattering of matter waves propagating through atomic and molecular gases. The combination of the Fraunhofer model with the semiclassical approximation to account, respectively, for the repulsive and attractive part of the potential energy surface resulted in a simple analytic formula, which agree well with experiment for the refraction of a Li beam passing through Xe gas. (orig.)
Dobson, Andrew D M; Auld, Stuart K J R
2016-04-01
Models used to investigate the relationship between biodiversity change and vector-borne disease risk often do not explicitly include the vector; they instead rely on a frequency-dependent transmission function to represent vector dynamics. However, differences between classes of vector (e.g., ticks and insects) can cause discrepancies in epidemiological responses to environmental change. Using a pair of disease models (mosquito- and tick-borne), we simulated substitutive and additive biodiversity change (where noncompetent hosts replaced or were added to competent hosts, respectively), while considering different relationships between vector and host densities. We found important differences between classes of vector, including an increased likelihood of amplified disease risk under additive biodiversity change in mosquito models, driven by higher vector biting rates. We also draw attention to more general phenomena, such as a negative relationship between initial infection prevalence in vectors and likelihood of dilution, and the potential for a rise in density of infected vectors to occur simultaneously with a decline in proportion of infected hosts. This has important implications; the density of infected vectors is the most valid metric for primarily zoonotic infections, while the proportion of infected hosts is more relevant for infections where humans are a primary host. PMID:27028070
Attenuation of Replication-Competent Adenovirus Serotype 26 Vaccines by Vectorization.
Maxfield, Lori F; Abbink, Peter; Stephenson, Kathryn E; Borducchi, Erica N; Ng'ang'a, David; Kirilova, Marinela M; Paulino, Noelix; Boyd, Michael; Shabram, Paul; Ruan, Qian; Patel, Mayank; Barouch, Dan H
2015-11-01
Replication-competent adenovirus (rcAd)-based vaccine vectors may theoretically provide immunological advantages over replication-incompetent Ad vectors, but they also raise additional potential clinical and regulatory issues. We produced replication-competent Ad serotype 26 (rcAd26) vectors by adding the E1 region back into a replication-incompetent Ad26 vector backbone with the E3 or E3/E4 regions deleted. We assessed the effect of vectorization on the replicative capacity of the rcAd26 vaccines. Attenuation occurred in a stepwise fashion, with E3 deletion, E4 deletion, and human immunodeficiency virus type 1 (HIV-1) envelope (Env) gene insertion all contributing to reduced replicative capacity compared to that with the wild-type Ad26 vector. The rcAd26 vector with E3 and E4 deleted and containing the Env transgene exhibited 2.7- to 4.4-log-lower replicative capacity than that of the wild-type Ad26 in vitro. This rcAd26 vector is currently being evaluated in a phase 1 clinical trial. Attenuation as a result of vectorization and transgene insertion has implications for the clinical development of replication-competent vaccine vectors. PMID:26376928
Challenges and future perspective for dengue vector control in the Western Pacific Region
Rashid Md Abdur
2011-06-01
Full Text Available Dengue remains a significant public health issue in the Western Pacific Region. In the absence of a vaccine, vector control is the mainstay for dengue prevention and control. In this paper we describe vector surveillance and vector control in the Western Pacific countries and areas.Vector surveillance and control strategies used by countries and areas of the Western Pacific Region vary. Vector control strategies include chemical, biological and environmental management that mainly target larval breeding sites. The use of insecticides targeting larvae and adult mosquitoes remains the mainstay of vector control programmes. Existing vector control tools have several limitations in terms of cost, delivery and long-term sustainability. However, there are several new innovative tools in the pipeline. These include Release of Insects Carrying a Dominant Lethal system and Wolbachia, an endosymbiotic bacterium, to inhibit dengue virus in the vector. In addition, the use of biological control such as larvivorous fish in combination with community participation has potential to be scaled up. Any vector control strategy should be selected based on evidence and appropriateness for the entomological and epidemiological setting and carried out in both inter-epidemic and epidemic periods. Community participation and interagency collaboration are required for effective and sustainable dengue prevention and control. Countries and areas are now moving towards integrated vector management.
Homogenization of maximal monotone vector fields via selfdual variational calculus
Ghoussoub, Nassif; Saiz, Ramon Zarate
2010-01-01
We use the theory of selfdual Lagrangians to give a variational approach to the homogenization of equations in divergence form, that are driven by a periodic family of maximal monotone vector fields. The approach has the advantage of using $\\Gamma$-convergence methods for corresponding functionals just as in the classical case of convex potentials, as opposed to the graph convergence methods used in the absence of potentials. A new variational formulation for the homogenized equation is also given.
Fusion rule estimation using vector space methods
In a system of N sensors, the sensor Sj, j = 1, 2 .... N, outputs Y(j) element-of Re, according to an unknown probability distribution P(Y(j)/X), corresponding to input X element-of [0, 1]. A training n-sample (X1, Y1), (X2, Y2), ..., (Xn, Yn) is given where Yi = (Yi(1), Yi(2), . . . , YiN) such that Yi(j) is the output of Sj in response to input Xi. The problem is to estimate a fusion rule f : Re N → [0, 1], based on the sample, such that the expected square error is minimized over a family of functions Y that constitute a vector space. The function f* that minimizes the expected error cannot be computed since the underlying densities are unknown, and only an approximation f to f* is feasible. We estimate the sample size sufficient to ensure that f provides a close approximation to f* with a high probability. The advantages of vector space methods are two-fold: (a) the sample size estimate is a simple function of the dimensionality of F, and (b) the estimate f can be easily computed by well-known least square methods in polynomial time. The results are applicable to the classical potential function methods and also (to a recently proposed) special class of sigmoidal feedforward neural networks
Towards an open architecture for vector GIS
Dunfey, Robert I.; Gittings, Bruce M.; Batcheller, James K.
2006-12-01
A range of open source software tools are now available to the Geographical Information Systems (GIS) analyst. However these tools are not necessarily interoperable and rarely significantly interoperable with proprietary systems. The open architectures, which have been developed for web-oriented systems, together with those proposed by the Open Geospatial Consortium (OGC), suggest that an open GIS architecture could be developed as an alternative to proprietary systems. The architecture would use open source components to store, translate, analyse, render and visualise GI data and would escape many of the problems of monolithic systems. Particularly what is proposed permits the loose coupling of any number of components and data stores in a manner that is both open and flexible. This paper proposes such an architecture and focuses on determining the suitability of Scalable Vector Graphics (SVG), an open vector-oriented eXtensible Markup Language (XML) grammar, as a significant component of such architecture. SVG is shown as an effective means of rendering GI data, not least because of its compatibility with the WC3 Document Object Model (DOM), permitting GIS-specific client tools to be written and transmitted to the web browser along with the SVG pages. While realising that the technology is in its infancy, the conclusion reached is that SVG currently provides a powerful solution and has enormous future potential.
Chikungunya virus and its mosquito vectors.
Higgs, Stephen; Vanlandingham, Dana
2015-04-01
Chikungunya virus (CHIKV), a mosquito-borne alphavirus of increasing public health significance, has caused large epidemics in Africa and the Indian Ocean basin; now it is spreading throughout the Americas. The primary vectors of CHIKV are Aedes (Ae.) aegypti and, after the introduction of a mutation in the E1 envelope protein gene, the highly anthropophilic and geographically widespread Ae. albopictus mosquito. We review here research efforts to characterize the viral genetic basis of mosquito-vector interactions, the use of RNA interference and other strategies for the control of CHIKV in mosquitoes, and the potentiation of CHIKV infection by mosquito saliva. Over the past decade, CHIKV has emerged on a truly global scale. Since 2013, CHIKV transmission has been reported throughout the Caribbean region, in North America, and in Central and South American countries, including Brazil, Columbia, Costa Rica, El Salvador, French Guiana, Guatemala, Guyana, Nicaragua, Panama, Suriname, and Venezuela. Closing the gaps in our knowledge of driving factors behind the rapid geographic expansion of CHIKV should be considered a research priority. The abundance of multiple primate species in many of these countries, together with species of mosquito that have never been exposed to CHIKV, may provide opportunities for this highly adaptable virus to establish sylvatic cycles that to date have not been seen outside of Africa. The short-term and long-term ecological consequences of such transmission cycles, including the impact on wildlife and people living in these areas, are completely unknown. PMID:25674945
Poplawski, A M; He, C; Irwin, J A; Manners, J M
1997-07-01
Previous research has indicated that biotypes A and B of Collectotrichum gloeosporioides that infect Stylosanthes spp. in Australia are asexual and vegetatively incompatible. Selectable marker genes conferring resistance either to hygromycin or phleomycin were introduced into isolates of these biotypes. Vectors conferring resistance to hygromycin and carrying telomeric sequences from Fusarium oxysporum replicated autonomously in C. gloesoporioides and gave frequencies of transformation 100-times higher than vectors that integrated into the genome. Monoconidial colonies resistant to both antibiotics were recovered when hygromycin-resistant biotype-A transformants carrying an autonomously replicating vector were paired in culture with a phleomycin-resistant biotype-B transformant carrying integrative vector sequences. Molecular analysis of double antibiotic-resistant progeny indicated that they contained the autonomous vector in a biotype-B genetic background. Results indicate that transfer of the autonomous vector had occurred from biotype A to biotype B, demonstrating the potential for transfer of genetic information between these biotypes. PMID:9309172
Classification of integrable polynomial vector evolution equations
Several classes of systems of evolution equations with one or two vector unknowns are considered. We also investigate systems with one vector and one scalar unknown. For these classes all equations having the simplest higher symmetry are listed. (author)
Symbolic Vector Analysis in Plasma Physics
Qin, H.; Rewoldt, G.; Tang, W.M.
1997-10-01
Many problems in plasma physics involve substantial amounts of analytical vector calculation. The complexity usually originates from both the vector operations themselves and the choice of underlying coordinate system. A computer algebra package for symbolic vector analysis in general coordinate systems, GeneralVectorAnalysis (GVA), is developed using Mathematica. The modern viewpoint for 3D vector calculus, differential forms on 3-manifolds, is adopted to unify and systematize the vector calculus operations in general coordinate systems. This package will benefit physicists and applied mathematicians in their research where complicated vector analysis is required. It will not only save a huge amount of human brain-power and dramatically improve accuracy, but this package will also be an intelligent tool to assist researchers in finding the right approaches to their problems. Several applications of this symbolic vector analysis package to plasma physics are also given.
Symbolic Vector Analysis in Plasma Physics
Qin, H.; Tang, W.M.; Rewoldt, G.
1997-10-09
Many problems in plasma physics involve substantial amounts of analytical vector calculation. The complexity usually originates from both the vector operations themselves and the choice of underlying coordinate system. A computer algebra package for symbolic vector analysis in general coordinate systems, General Vector Analysis (GVA), is developed using Mathematica. The modern viewpoint for 3D vector calculus, differential forms on 3-manifolds, is adopted to unify and systematize the vector calculus operations in general coordinate systems. This package will benefit physicists and applied mathematicians in their research where complicated vector analysis is required. It will not only save a huge amount of human brain-power and dramatically improve accuracy, but this package will also be an intelligent tool to assist researchers in finding the right approaches to their problems. Several applications of this symbolic vector analysis package to plasma physics are also given.
Transversals of Complex Polynomial Vector Fields
Dias, Kealey
Vector fields in the complex plane are defined by assigning the vector determined by the value P(z) to each point z in the complex plane, where P is a polynomial of one complex variable. We consider special families of so-called rotated vector fields that are determined by a polynomial multiplied...... by rotational constants. Transversals are a certain class of curves for such a family of vector fields that represent the bifurcation states for this family of vector fields. More specifically, transversals are curves that coincide with a homoclinic separatrix for some rotation of the vector field....... Given a concrete polynomial, it seems to take quite a bit of work to prove that it is generic, i.e. structurally stable. This has been done for a special class of degree d polynomial vector fields having simple equilibrium points at the d roots of unity, d odd. In proving that such vector fields are...
Vector analysis for direction prediction on image strings
Tickle, Andrew J.; Grindley, Josef E.
2012-10-01
Vector analysis is a well-developed field that deals with details about line, surface and volume integrals which can be solved analytically to provide solutions to many problems. Using vector analysis, a curve can be divided up into many small arcs, each of which is a position vector. The summation of these position vectors can be used to represent the curve in detail; this is known as the total vector field. In this paper, there is shown a vector analysis methodology when applied to the wake immediately after a moving or stationary object, caused by the movement of the object through free space or the surrounding medium moving around the object respectively. The aim was to create a system that can determine the vectors between successive images in a video with the end result being able to establish an overall trajectory of the object. This could be implemented on a Field Programmable Gate Array (FPGA) or other device to be deployed in the field to track any type of object. If the device's orientation with magnetic north-south is known, the direction of the object is travelling in can be calculated and then relayed on. This could be useful as an easily deployable warning system for the armed forces or rescue services to inform personnel of potential incoming threats. This work builds upon the Morphological Scene Change Detection (MSCD) mechanism implemented in the DSP Builder environment and describes how the changes allow the system to track the wake and plot its trajectory. System simulations of real world data are shown and the resultant imagery is then discussed. Furthermore, tests are conducted on single objects and then multiple objects to investigate how the system responds as real world situations are likely to have more than a single object.
Peculiarities of massive vector mesons and their zero mass limits
Schroer, Bert
2015-08-01
Massive QED, in contrast with its massless counterpart, possesses two conserved charges; one is a screened (vanishing) Maxwell charge which is directly associated with the massive vector mesons through the identically conserved Maxwell current, while the presence of a particle-antiparticle counting charge depends on the matter. A somewhat peculiar situation arises for couplings of Hermitian matter fields to massive vector potentials; in that case the only current is the screened Maxwell current and the coupling disappears in the massless limit. In the case of self-interacting massive vector mesons the situation becomes even more peculiar in that the usually renormalizability guaranteeing validity of the first order power-counting criterion breaks down in second order and requires the compensatory presence of additional Hermitian H-fields. Some aspect of these observation have already been noticed in the BRST gauge theoretic formulation, but here we use a new setting based on string-local vector mesons which is required by Hilbert space positivity ("off-shell unitarity"). This new formulation explains why spontaneous symmetry breaking cannot occur in the presence of higher spin fields. The coupling to H-fields induces Mexican hat-like self-interactions; they are not imposed and bear no relation with spontaneous symmetry breaking; they are rather consequences of the foundational causal localization properties realized in a Hilbert space setting. In the case of self-interacting massive vector mesons their presence is required in order to maintain the first order power-counting restriction of renormalizability also in second order. The presentation of the new Hilbert space setting for vector mesons which replaces gauge theory and extends on-shell unitarity to its off-shell counterpart is the main motivation for this work. The new Hilbert space setting also shows that the second order Lie-algebra structure of self-interacting vector mesons is a consequence of the principles of QFT and promises a deeper understanding of the origin of confinement.
Weak gravitational field and Coriolis potential
Z Y Turakulov
2009-03-01
In mechanics of the mass point passage from one frame of reference to another moving with velocity $\\vec{u}$ consists in subtracting this vector from the velocity of the particle. In general case the vector $\\vec{u}$ is not constant, as, for example, when passing through a rotating frame, this operation creates inertial forces. Analysis of this phenomenon from the point of view of Lagrangian and Hamiltonian mechanics is interesting from the general relativistic point of view due to Einstein's principle of equivalence. We show that the vector $\\vec{u}$ plays the role of vector potential which, however, essentially differs from vector potential known in classical electrodynamics. Comparative analysis of the two kinds of vector potentials is completed.
Introduction to vector velocity imaging
Jensen, Jørgen Arendt; Udesen, Jesper; Hansen, Kristoffer Lindskov; Nielsen, Michael Bachmann
Current ultrasound scanners can only estimate the velocity along the ultrasound beam and this gives rise to the cos() factor on all velocity estimates. This is a major limitation as most vessels are close to perpendicular to the beam. Also the angle varies as a function of space and time making it...... virtually impossible to compensate for the factor and obtain correct velocity estimates for either CFM or spectral velocity estimation. This talk will describe methods for finding the correct velocity by estimating both the axial and lateral component of the velocity vector. The transverse oscillation...... method introduces an ultrasound field that oscillation not only along the ultrasound beam both also transverse to it to estimate both the lateral and axial velocity for the full velocity vector. The correct velocity magnitude can be found from this as well as the instantaneous angle. This can be obtained...
General Scaled Support Vector Machines
Liu, Xin; Bao, Forrest Sheng
2010-01-01
Support Vector Machines (SVMs) are popular tools for data mining tasks such as classification, regression, and density estimation. However, original SVM (C-SVM) only considers local information of data points on or over the margin. Therefore, C-SVM loses robustness. To solve this problem, one approach is to translate (i.e., to move without rotation or change of shape) the hyperplane according to the distribution of the entire data. But existing work can only be applied for 1-D case. In this paper, we propose a simple and efficient method called General Scaled SVM (GS-SVM) to extend the existing approach to multi-dimensional case. Our method translates the hyperplane according to the distribution of data projected on the normal vector of the hyperplane. Compared with C-SVM, GS-SVM has better performance on several data sets.
The jerk vector in projectile motion
A. Tan and M. E. Edwards
2011-06-01
Full Text Available The existence of the jerk vector is investigated in projectile motion under gravity. The jerk vector is zero in the absence of air resistance, but comes into life when velocity-dependent air drag is present. The jerk vector is calculated when the air resistance is proportional to the velocity. It is found that the jerk vector maintains a constant sense in the upward andforward direction, with its magnitude attenuated exponentially as a function of time
The jerk vector in projectile motion
A. Tan and M. E. Edwards
2011-01-01
The existence of the jerk vector is investigated in projectile motion under gravity. The jerk vector is zero in the absence of air resistance, but comes into life when velocity-dependent air drag is present. The jerk vector is calculated when the air resistance is proportional to the velocity. It is found that the jerk vector maintains a constant sense in the upward andforward direction, with its magnitude attenuated exponentially as a function of time
Cascade Support Vector Machines with Dimensionality Reduction
Oliver Kramer
2015-01-01
Cascade support vector machines have been introduced as extension of classic support vector machines that allow a fast training on large data sets. In this work, we combine cascade support vector machines with dimensionality reduction based preprocessing. The cascade principle allows fast learning based on the division of the training set into subsets and the union of cascade learning results based on support vectors in each cascade level. The combination with dimensionality reduction as prep...
On the benefits of vector network coding
Ebrahimi Boroojeni, Javad; Fragouli, Christina
2010-01-01
In vector network coding, the source multi- casts information by transmitting vectors of length L, while intermediate nodes process and combine their incoming packets by multiplying them with L × L coding matrices that play a similar role as coding coefficients in scalar coding. Vector network coding generalizes scalar coding, and thus offers a wider range of solutions over which to optimize. This paper starts exploring the new possibilities vector network coding can offer along two direction...
Support Vector Selection for Regression Machines
Lee, Wan-Jui; Yang, Chih-Cheng; Lee, Shie-Jue
2009-01-01
In this paper, we propose a method to select support vectors to improve the performance of support vector regression machines. First, the orthogonal leastsquares method is adopted to evaluate the support vectors based on their error reduction ratios. By selecting the representative support vectors, we can obtain a simpler model which helps avoid the over-fitting problem. Second, the simplified model is further refined by applying the gradient descent method to tune the parameters of the kerne...
Vector optical fields broken in the spatial frequency domain
Gao, Xu-Zhen; Pan, Yue; Li, Si-Min; Wang, Dan; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian
2016-03-01
We theoretically and experimentally explore the redistribution of polarization states and orbital angular momentum (OAM) in the output plane, induced by the symmetry breaking in the spatial frequency domain. When the vector fields are obstructed by sector-shaped filters in the spatial frequency domain, the local polarization states in the output plane undergo an abrupt transition from linear to circular polarization. The results reveal the polarization-dependent splitting and the appearance of a series of opposite OAMs in the output plane. We also find the self-healing effect of the vector fields broken in the spatial frequency domain and further explore its potential application. If the vector optical fields are used for information transferring or for imaging, even if the optical field carrying the information or image is partially blocked, the complete information or image can still be obtained, implying that which may increase the robustness of the information transferring and the imaging.
The immunopathology of canine vector-borne diseases
Day Michael J
2011-04-01
Full Text Available Abstract The canine vector-borne infectious diseases (CVBDs are an emerging problem in veterinary medicine and the zoonotic potential of many of these agents is a significant consideration for human health. The successful diagnosis, treatment and prevention of these infections is dependent upon firm understanding of the underlying immunopathology of the diseases in which there are unique tripartite interactions between the microorganism, the vector and the host immune system. Although significant advances have been made in the areas of molecular speciation and the epidemiology of these infections and their vectors, basic knowledge of the pathology and immunology of the diseases has lagged behind. This review summarizes recent studies of the pathology and host immune response in the major CVBDs (leishmaniosis, babesiosis, ehrlichiosis, hepatozoonosis, anaplasmosis, bartonellosis and borreliosis. The ultimate application of such immunological investigation is the development of effective vaccines. The current commercially available vaccines for canine leishmaniosis, babesiosis and borreliosis are reviewed.
Retrovirus-based vectors for transient and permanent cell modification.
Schott, Juliane W; Hoffmann, Dirk; Schambach, Axel
2015-10-01
Retroviral vectors are commonly employed for long-term transgene expression via integrating vector technology. However, three alternative retrovirus-based platforms are currently available that allow transient cell modification. Gene expression can be mediated from either episomal DNA or RNA templates, or selected proteins can be directly transferred through retroviral nanoparticles. The different technologies are functionally graded with respect to safety, expression magnitude and expression duration. Improvement of the initial technologies, including modification of vector designs, targeted increase in expression strength and duration as well as improved safety characteristics, has allowed maturation of retroviral systems into efficient and promising tools that meet the technological demands of a wide variety of potential application areas. PMID:26433198