WorldWideScience

Sample records for vector potential mvp

  1. Vector potential photoelectron microscopy.

    Browning, R

    2011-10-01

    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.

  2. 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)

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

    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)

  4. APPLICATION OF MVP IN REAL-TIME IMAGE PROCESSING

    2000-01-01

    MVP is a digital signal processor, which is of MIMD structure and fit for multimedia application. MVP has several processors in it, and its operation is characteristic of parallelism and pipeline; therefore, real-time signal processing can be done on it. This paper presents the image processing system based on MVP, explains the principles of parallel task assignment and hardware pipeline design, and gives out the example of target tracking and edge detection.

  5. Vector Potential Generation for Numerical Relativity Simulations

    Silberman, Zachary; Faber, Joshua; Adams, Thomas; Etienne, Zachariah; Ruchlin, Ian

    2017-01-01

    Many different numerical codes are employed in studies of highly relativistic magnetized accretion flows around black holes. Based on the formalisms each uses, some codes evolve the magnetic field vector B, while others evolve the magnetic vector potential A, the two being related by the curl: B=curl(A). Here, we discuss how to generate vector potentials corresponding to specified magnetic fields on staggered grids, a surprisingly difficult task on finite cubic domains. The code we have developed solves this problem in two ways: a brute-force method, whose scaling is nearly linear in the number of grid cells, and a direct linear algebra approach. We discuss the success both algorithms have in generating smooth vector potential configurations and how both may be extended to more complicated cases involving multiple mesh-refinement levels. NSF ACI-1550436

  6. Weyl node with random vector potential

    Sbierski, Björn; Decker, Kevin S. C.; Brouwer, Piet W.

    2016-12-01

    We study Weyl semimetals in the presence of generic disorder, consisting of a random vector potential as well as a random scalar potential. We derive renormalization group flow equations to second order in the disorder strength. These flow equations predict a disorder-induced phase transition between a pseudoballistic weak-disorder phase and a diffusive strong-disorder phase for a sufficiently strong random scalar potential or for a pure three-component random vector potential. We verify these predictions using a numerical study of the density of states near the Weyl point and of quantum transport properties at the Weyl point. In contrast, for a pure single-component random vector potential, the diffusive strong-disorder phase is absent.

  7. 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…

  8. Vector Potential Quantization and the Quantum Vacuum

    Constantin Meis

    2014-01-01

    Full Text Available We investigate the quantization of the vector potential amplitude of the electromagnetic field to a single photon state starting from the fundamental link equations between the classical electromagnetic theory and the quantum mechanical expressions. The resulting wave-particle formalism ensures a coherent transition between the classical electromagnetic wave theory and the quantum representation. A quantization constant of the photon vector potential is defined. A new quantum vacuum description results directly in having very low energy density. The calculated spontaneous emission rate and Lambs shift for the nS states of the hydrogen atom are in agreement with quantum electrodynamics. This low energy quantum vacuum state might be compatible with recent astrophysical observations.

  9. 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 (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.

  10. Correspondence between constrained transport and vector potential methods for magnetohydrodynamics

    Mocz, Philip

    2017-01-01

    We show that one can formulate second-order field- and flux-interpolated constrained transport/central difference (CT/CD) type methods as cell-centered magnetic vector potential schemes. We introduce four vector potential CTA/CDA schemes - three of which correspond to CT/CD methods of Tóth (2000) [1] and one of which is a new simple flux-CT-like scheme - where the centroidal vector potential is the primal update variable. These algorithms conserve a discretization of the ∇ ṡ B = 0 condition to machine precision and may be combined with shock-capturing Godunov type base schemes for magnetohydrodynamics. Recasting CT in terms of a centroidal vector potential allows for some simple generalizations of divergence-preserving methods to unstructured meshes, and potentially new directions to generalize CT schemes to higher-order.

  11. Data-driven identification of potential Zika virus vectors

    Evans, Michelle V; Dallas, Tad A; Han, Barbara A; Murdock, Courtney C; Drake, John M

    2017-01-01

    Zika is an emerging virus whose rapid spread is of great public health concern. Knowledge about transmission remains incomplete, especially concerning potential transmission in geographic areas in which it has not yet been introduced. To identify unknown vectors of Zika, we developed a data-driven model linking vector species and the Zika virus via vector-virus trait combinations that confer a propensity toward associations in an ecological network connecting flaviviruses and their mosquito vectors. Our model predicts that thirty-five species may be able to transmit the virus, seven of which are found in the continental United States, including Culex quinquefasciatus and Cx. pipiens. We suggest that empirical studies prioritize these species to confirm predictions of vector competence, enabling the correct identification of populations at risk for transmission within the United States. DOI: http://dx.doi.org/10.7554/eLife.22053.001 PMID:28244371

  12. 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…

  13. Smoothed Particle Magnetohydrodynamics IV - Using the Vector Potential

    Price, Daniel J

    2009-01-01

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

  14. Matrix Ernst potentials for EMDA with multiple vector fields

    Galtsov, D V

    1997-01-01

    We show that the Einstein-Maxwell-Dilaton-Axion system with multiple vector fields (bosonic sector of the D=4, N=4 supergravity) restricted to spacetimes possessing a non-null Killing vector field admits a concise representation in terms of the Ernst-type matrix valued potentials. A constructive derivation of the SWIP solutions is given and a colliding waves counterpart of the DARN-NUT solution is obtained. SU(m,m) chiral representation of the two-dimensionally reduced system is derived and the corresponding Kramer-Neugebauer-type map is presented.

  15. Deriving Potential Coronal Magnetic Fields from Vector Magnetograms

    Welsch, Brian T.; Fisher, George H.

    2016-08-01

    The minimum-energy configuration for the magnetic field above the solar photosphere is curl-free (hence, by Ampère's law, also current-free), so can be represented as the gradient of a scalar potential. Since magnetic fields are divergence free, this scalar potential obeys Laplace's equation, given an appropriate boundary condition (BC). With measurements of the full magnetic vector at the photosphere, it is possible to employ either Neumann or Dirichlet BCs there. Historically, the Neumann BC was used with available line-of-sight magnetic field measurements, which approximate the radial field needed for the Neumann BC. Since each BC fully determines the 3D vector magnetic field, either choice will, in general, be inconsistent with some aspect of the observed field on the boundary, due to the presence of both currents and noise in the observed field. We present a method to combine solutions from both Dirichlet and Neumann BCs to determine a hybrid, "least-squares" potential field, which minimizes the integrated square of the residual between the potential and actual fields. We also explore weighting the residuals in the fit by spatially uniform measurement uncertainties. This has advantages both in not overfitting the radial field used for the Neumann BC, and in maximizing consistency with the observations. We demonstrate our methods with SDO/HMI vector magnetic field observations of active region 11158, and find that residual discrepancies between the observed and potential fields are significant, and they are consistent with nonzero horizontal photospheric currents. We also analyze potential fields for two other active regions observed with two different vector magnetographs, and find that hybrid-potential fields have significantly less energy than the Neumann fields in every case - by more than 10^{32} erg in some cases. This has major implications for estimates of free magnetic energy in coronal field models, e.g., non-linear force-free field extrapolations.

  16. 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...

  17. A Vector Potential implementation for Smoothed Particle Magnetohydrodynamics

    Stasyszyn, Federico

    2014-01-01

    The development of smooth particle magnetohydrodynamic (SPMHD) has significantly improved the simulation of complex astrophysical processes. However, the preservation the solenoidality of the magnetic field is still a severe problem for the MHD. A formulation of the induction equation with a vector potential would solve the problem. Unfortunately all previous attempts suffered from instabilities. In the present work, we evolve the vector potential in the Coulomb gauge and smooth the derived magnetic field for usage in the momentum equation. With this implementation we could reproduce classical test cases in a stable way. A simple test case demonstrates the possible failure of widely used direct integration of the magnetic field, even with the usage of a divergence cleaning method.

  18. Vector potentials in gauge theories in flat spacetime

    Wong, C W

    2015-01-01

    A recent suggestion that vector potentials in electrodynamics (ED) are nontensorial objects under 4D frame rotations is found to be both unnecessary and confusing. As traditionally used in ED, a vector potential $A$ always transforms homogeneously under 4D rotations in spacetime, but if the gauge is changed by the rotation, one can restore the gauge back to the original gauge by adding an inhomogeneous term. It is then "not a 4-vector", but two: one for rotation and one for translation. For such a gauge, it is much more important to preserve {\\it explicit} homogeneous Lorentz covariance by simply skipping the troublesome gauge-restoration step. A gauge-independent separation of $A$ into a dynamical term and a non-dynamical term in Abelian gauge theories is re-defined more generally as the terms caused by the presence and absence respectively of the 4-current term in the inhomogeneous Maxwell equations for $A$. Such a separation {\\it cannot} in general be extended to non-Abelian theories where $A$ satisfies no...

  19. Culex pipiens quinquefasciatus: a potential vector to transmit Zika virus.

    Guo, Xiao-Xia; Li, Chun-Xiao; Deng, Yong-Qiang; Xing, Dan; Liu, Qin-Mei; Wu, Qun; Sun, Ai-Juan; Dong, Yan-de; Cao, Wu-Chun; Qin, Cheng-Feng; Zhao, Tong-Yan

    2016-09-07

    Zika virus (ZIKV) has become a threat to global health since the outbreak in Brazil in 2015. Although ZIKV is generally considered an Aedes-transmitted pathogen, new evidence has shown that parts of the virus closely resemble Culex-transmitted viruses. Therefore, it is important to evaluate the competence of Culex species for ZIKV to understand their potential as vectors. In this study, female Culex pipiens quinquefasciatus were orally exposed to ZIKV. Mosquito midguts, salivary glands and ovaries were tested for ZIKV to measure infection and dissemination at 2, 4, 6, 8, 12, 16 and 18 days post exposure (pe). In addition, saliva was collected from mosquitoes after infection and infant mice were bitten by infected mosquitoes to measure the transmission ability of Cx. p. quinquefasciatus. The results showed that the peak time of virus appearance in the salivary glands was day 8 pe, with 90% infection rate and an estimated virus titer of 3.92±0.49 lg RNA copies/mL. Eight of the nine infant mice had positive brains after being bitten by infected mosquitoes, which meant that Cx. p. quinquefasciatus could be infected with and transmit ZIKV following oral infection. These laboratory results clearly demonstrate the potential role of Cx. p. quinquefasciatus as a vector of ZIKV in China. Because there are quite different vector management strategies required to control Aedes (Stegomyia) species and Cx. p. quinquefasciatus, an integrated approach may be required should a Zika epidemic occur.

  20. Potential North American vectors of West Nile virus.

    Turell, M J; Sardelis, M R; Dohm, D J; O'Guinn, M L

    2001-12-01

    The outbreak of disease in the New York area in 1999 due to West Nile (WN) virus was the first evidence of the occurrence of this virus in the Americas. To determine potential vectors, more than 15 mosquito species (including Culex pipiens, Cx. nigripalpus, Cx. quinquefasciatus, Cx. salinarius, Aedes albopictus, Ae. vexans, Ochlerotatus japonicus, Oc. sollicitans, Oc. taeniorhynchus, and Oc. triseriatus) from the eastern United States were evaluated for their ability to serve as vectors for the virus isolated from birds collected during the 1999 outbreak in New York. Mosquitoes were allowed to feed on one- to four-day old chickens that had been inoculated with WN virus 1-3 days previously. The mosquitoes were incubated for 12-15 days at 26 degrees C and then allowed to refeed on susceptible chickens and assayed to determine transmission and infection rates. Several container-breeding species (e.g., Ae. albopictus, Oc. atropalpus, and Oc. japonicus) were highly efficient laboratory vectors of WN virus. The Culex species were intermediate in their susceptibility. However, if a disseminated infection developed, all species were able to transmit WN virus by bite. Factors such as population density, feeding preference, longevity, and season of activity also need to be considered in determining the role these species could play in the transmission of WN virus.

  1. Vectores

    2016-01-01

    Documento que contiene la explicación sobre las temáticas de Sistemas coordenados, Cantidades vectoriales y escalares, Algunas propiedades de los vectores, Componentes de un vector y vectores unitarios

  2. Seismic liquefaction potential assessment by using relevance vector machine

    Pijush Samui

    2007-01-01

    Determining the liquefaction potential of soil is important in earthquake engineering.This study proposes the use of the Relevance Vector Machine (RVM) to determine the liquefaction potential of soil by using actual cone penetration test(CPT) data.RVM is based on a Bayesian formulation of a linear model with an appropriate prior that results in a sparse representation.The results are compared with a widely used artificial neural network(ANN) model.Overall,the RVM shows good performance and is proven to be more accurate than the ANN model.It also provides probabilistic output.The model provides a viable tool for earthquake engineers to assess seismic conditions for sites that are susceptible to liquefaction.

  3. Unusual developing sites of dengue vectors and potential epidemiological implications

    Hamady Dieng; Ronald Enrique Morales; Rahman GM Saifur; Abu Hassan Ahmad; MR Che Salmah; Al Thbiani Aziz; Tomomitsu Satho; Fumio Miake; Zairi Jaal; Sazaly Abubakar

    2012-01-01

    Objective: To identify the unusual breeding sites of two dengue vectors, i.e. Aedes albopictus (Ae. albopictus) and Aedes aegypti (Ae. aegypti). Methods: During the second half of 2010, we performed an occasional survey in rural (Teluk Tempoyak) and urban (Gelugor) areas of Penang Island, Malaysia, to identify cryptic breeding sites. Results: In the rural area, we found heterogeneous immature stages of Ae. albopictus in the water bowl of an encaged bird. We also observed Ae. aegypti eggs deposited in the flush tank of a toilet in the urban area. Conclusions:It can be concluded that both breeding patterns can increase contact with hosts (humans and birds) and presumably population densities of Ae. albopictus and Ae. aegypti, thereby potentially boosting the risks for spread and transmission of arboviral diseases.

  4. Many-body delocalization with random vector potentials

    Cheng, Chen; Mondaini, Rubem

    2016-11-01

    We study the ergodic properties of excited states in a model of interacting fermions in quasi-one-dimensional chains subjected to a random vector potential. In the noninteracting limit, we show that arbitrarily small values of this complex off-diagonal disorder trigger localization for the whole spectrum; the divergence of the localization length in the single-particle basis is characterized by a critical exponent ν which depends on the energy density being investigated. When short-range interactions are included, the localization is lost, and the system is ergodic regardless of the magnitude of disorder in finite chains. Our numerical results suggest a delocalization scheme for arbitrary small values of interactions. This finding indicates that the standard scenario of the many-body localization cannot be obtained in a model with random gauge fields.

  5. Vectors

    Boeriis, Morten; van Leeuwen, Theo

    2017-01-01

    This article revisits the concept of vectors, which, in Kress and van Leeuwen’s Reading Images (2006), plays a crucial role in distinguishing between ‘narrative’, action-oriented processes and ‘conceptual’, state-oriented processes. The use of this concept in image analysis has usually focused...... on the most salient vectors, and this works well, but many images contain a plethora of vectors, which makes their structure quite different from the linguistic transitivity structures with which Kress and van Leeuwen have compared ‘narrative’ images. It can also be asked whether facial expression vectors...... should be taken into account in discussing ‘reactions’, which Kress and van Leeuwen link only to eyeline vectors. Finally, the question can be raised as to whether actions are always realized by vectors. Drawing on a re-reading of Rudolf Arnheim’s account of vectors, these issues are outlined...

  6. VERIFIKASI PAKET PROGRAM MVP-II DAN SRAC2006 PADA KASUS TERAS REAKTOR VERA BENCHMARK.

    Jati Susilo

    2015-03-01

    Full Text Available Dalam penelitian ini dilakukan verifikasi perhitungan benchmark VERA pada kasus Zero Power Physical Test (ZPPT teras reaktor Watts Bar 1. Reaktor tersebut merupakan jenis PWR kelas 1000 MWe yang didesain oleh Westinghouse, tersusun dari 193 perangkat bahan bakar 17×17 dengan 3 jenis pengkayaan UO2 yaitu 2,1wt%, 2,619wt% dan 3,1wt%. Perhitungan nilai k-eff dan distribusi faktor daya dilakukan pada siklus operasi pertama teras dengan kondisi beginning of cycle (BOC dan hot zero power (HZP. Posisi batang kendali dibedakan menjadi uncontrolled (semua batang kendali berada di luar teras, dan controlled (batang kendali Bank D didalam teras. Paket program komputer yang digunakan dalam perhitungan adalah MVP-II dan SRAC2006 modul CITATION dengan data pustaka tampang lintang ENDF/B-VII.0. Hasil perhitungan menunjukkan bahwa perbedaan nilai k-eff teras pada kondisi controlled dan uncontrolled antara referensi dengan MVP-II (-0,07% dan -0,014% dan SRAC2006 (0,92% dan 0,99% sangat kecil atau masih dibawah 1%. Perbedaan faktor daya maksimum teras pada kondisi controlled dan uncontrolled dengan referensi dengan MVP-II adalah 0,38% dan 1,53%, sedangkan dengan SRAC2006 adalah 1,13% dan -2,45%. Dapat dikatakan bahwa kedua paket program komputer menunjukkan hasil perhitungan yang sesuai dengan nilai referensi. Dalam hal penentuan kekritisan teras, maka hasil perhitungan MVP-II lebih konservatif dibandingkan dengan SRAC2006. Kata kunci : MVP-II, SRAC2006, PWR, VERA   In this research, verification calculation for VERA core physics benchmark on the Zero Power Physical Test (ZPPT of the nuclear reactor Watts Bar 1. The reactor is a 1000 MWe class of PWR designed by Westinghouse, arranged from 193 unit of 17×17 fuel assembly consisting 3 type enrichment of UO2 that are 2.1wt%, 2.619wt% and 3.1wt%. Core power factor distribution and k-eff calculation has been done for the first cycle operation of the core at beginning of cycle (BOC and hot zero power (HZP. In this

  7. Preventing and exploiting the oncogenic potential of integrating gene vectors.

    Modlich, Ute; Baum, Christopher

    2009-04-01

    Gene therapy requires efficient gene delivery to cure or prevent disease by modifying the genome of somatic cells. However, gene vectors, which insert themselves into the host genome in order to achieve persistent protein expression, can trigger oncogenesis by upregulating cellular protooncogenes. This adverse event, known as insertional mutagenesis, has become a major hurdle in the field. Vectors developed on the basis of lentiviruses are considered to be less genotoxic than the hitherto used gamma-retroviral vectors. For their report in this issue of the JCI, Montini et al. utilized a tumor-prone mouse model to identify the genetic determinants of insertional mutagenesis (see the related article beginning on page 964). They report that the lentiviral integration pattern and additional improvements in vector design reduce the genotoxic risk. These findings will inform future vector design with the goal of limiting genotoxicity for gene therapy or increasing genotoxicity for protooncogene discovery.

  8. Increasing the potential for malaria elimination by targeting zoophilic vectors

    Waite, Jessica L.; Swain, Sunita; Lynch, Penelope A.; Sharma, S. K.; Haque, Mohammed Asrarul; Montgomery, Jacqui; Thomas, Matthew B.

    2017-01-01

    Countries in the Asia Pacific region aim to eliminate malaria by 2030. A cornerstone of malaria elimination is the effective management of Anopheles mosquito vectors. Current control tools such as insecticide treated nets or indoor residual sprays target mosquitoes in human dwellings. We find in a high transmission region in India, malaria vector populations show a high propensity to feed on livestock (cattle) and rest in outdoor structures such as cattle shelters. We also find evidence for a shift in vector species complex towards increased zoophilic behavior in recent years. Using a malaria transmission model we demonstrate that in such regions dominated by zoophilic vectors, existing vector control tactics will be insufficient to achieve elimination, even if maximized. However, by increasing mortality in the zoophilic cycle, the elimination threshold can be reached. Current national vector control policy in India restricts use of residual insecticide sprays to domestic dwellings. Our study suggests substantial benefits of extending the approach to treatment of cattle sheds, or deploying other tactics that target zoophilic behavior. Optimizing use of existing tools will be essential to achieving the ambitious 2030 elimination target. PMID:28091570

  9. Electronic Energy Band and Transport Properties in Monolayer Graphene with Periodically Modulated Magnetic Vector Potential and Electrostatic Potential

    刘正方; 伍清萍; 刘念华

    2012-01-01

    We investigated the electronic energy band and transport features of graphene superlattice with periodically modulated magnetic vector potential and electrostatic potential. It is found that both parallel magnetic vector potential and electrostatic potential can decisively shift Dirac point in a different way, which may be an efficient way to achieve electron or hole filter. We a/so find that applying modulated parallel and anti-parallel magnetic vector potential to the electrons can efficiently change electronic states between pass and stop states, which can be useful in designing electron or hole switches and lead to large magneto-resistance.

  10. Exactly Solvable Combinations of Scalar and Vector Potentials for the Dirac Equation Interrelated by Riccati Equations

    Axel Schulze-Halberg

    2006-01-01

    New classes of solvable scalar and vector potentials for the Dirac equation are obtained, together with the associated exact Dirac spinors. The method of derivation is based on an a priori constraint between the solutions, leading to an interrelation between the scalar and vector potential in the form of a Riccati equation. The present note generalizes a series of former articles.

  11. Potential role of ticks as vectors of bluetongue virus

    Bouwknegt, C.; Rijn, van P.A.; Schipper, J.M.J.; Holzel, D.R.; Boonstra, J.; Nijhof, A.; Rooij, van E.M.A.; Jongejan, F.

    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

  12. 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)

  13. A Comparison of Android Native App Architecture – MVC, MVP and MVVM

    Lou, Tian

    2016-01-01

    Fast iteration in Android application is a big challenge for development efficiency and quality that are influenced by architecture. It is claimed that Model-View-Presenter (MVP) and Model-View-ViewModel (MVVM) are better than the default Android native app architecture Model-View-Controller (MVC). But there is no empirical data to support this point of view. In addition, refactoring the project to adopt the new architecture requires a lot of efforts from development to test. Thus, some app ...

  14. Pengaruh Strategi Pengembangan Mutu Dan Kompensasi Terhadap Kinerja Guru Di SMK MVP ARS Internasional Bandung

    Suryana Suryana

    2016-11-01

      The Influence of Quality Development Strategy and Compensation on Teachers’ Performance at SMK MVP ARS International Bandung, is  a research to get to know the result of teacher’ quality development strategy, the compensastion for the teachers, the performance of teachers and the influence of the tachers’ development strategy and compensastion on teachers’ performance at SMK MVP ARS Internasional Bandung. The methods used in this research is qualitative methods where the analysis unit is population of teaching staff without sampling because all the teachers filled out the questionaires.Based on the result of research indicates that teachers’ quality development strategy at SMK MVP ARS International Bandung is correlated to the compensation received by the teachers. So it has positive effect on the teacher’s performance, techer’s quality development strategy and compensastion simultinuously influence on the teacher’s development. And partially compensation has larger influence on teahers’ performance than quality development.By using SPSS software, it is resulted; partially, the influence of teacher’s developement program on performance is 0,010 or 1% and compensation on teachers’ performance is 0,572 atau 57,20%, the value of influence in simultant between techers’ development and, compensation on teacher’s performance is0,329 or 32,90%, but the correlation between quality development strategy and compensation is  0,148%.   Key Words : Quality Development, Compensation and Performance

  15. The ecological foundations of transmission potential and vector-borne disease in urban landscapes.

    LaDeau, Shannon L; Allan, Brian F; Leisnham, Paul T; Levy, Michael Z

    2015-07-01

    Urban transmission of arthropod-vectored disease has increased in recent decades. Understanding and managing transmission potential in urban landscapes requires integration of sociological and ecological processes that regulate vector population dynamics, feeding behavior, and vector-pathogen interactions in these unique ecosystems. Vectorial capacity is a key metric for generating predictive understanding about transmission potential in systems with obligate vector transmission. This review evaluates how urban conditions, specifically habitat suitability and local temperature regimes, and the heterogeneity of urban landscapes can influence the biologically-relevant parameters that define vectorial capacity: vector density, survivorship, biting rate, extrinsic incubation period, and vector competence.Urban landscapes represent unique mosaics of habitat. Incidence of vector-borne disease in urban host populations is rarely, if ever, evenly distributed across an urban area. The persistence and quality of vector habitat can vary significantly across socio-economic boundaries to influence vector species composition and abundance, often generating socio-economically distinct gradients of transmission potential across neighborhoods.Urban regions often experience unique temperature regimes, broadly termed urban heat islands (UHI). Arthropod vectors are ectothermic organisms and their growth, survival, and behavior are highly sensitive to environmental temperatures. Vector response to UHI conditions is dependent on regional temperature profiles relative to the vector's thermal performance range. In temperate climates UHI can facilitate increased vector development rates while having countervailing influence on survival and feeding behavior. Understanding how urban heat island (UHI) conditions alter thermal and moisture constraints across the vector life cycle to influence transmission processes is an important direction for both empirical and modeling research.There remain

  16. Silica nanoparticle: a potential new insecticide for mosquito vector control.

    Barik, Tapan K; Kamaraju, Raghavendra; Gowswami, Arunava

    2012-09-01

    Presently, there is a need for increased efforts to develop newer and effective methods to control mosquito vectors as the existing chemical and biological methods are not as effective as in earlier period owing to different technical and operational reasons. The use of nanomaterial products in various sectors of science including health increased during the last decade. We tested three types of nanosilica, namely lipophilic, hydrophilic and hydrophobic, to assess their larvicidal, pupicidal and growth inhibitor properties and also their influence on oviposition behaviour (attraction/deterrence) of mosquito species that transmit human diseases, namely malaria (Anopheles), yellow fever, chickungunya and dengue (Aedes), lymphatic filariasis and encephalitis (Culex and Aedes). Application of hydrophobic nanosilica at 112.5 ppm was found effective against mosquito species tested. The larvicidal effect of hydrophobic nanosilica on mosquito species tested was in the order of Anopheles stephensi > Aedes aegypti > Culex quinquefasciatus, and the pupicidal effect was in the order of A. stephensi > C. quinquefasciatus > Ae. aegypti. Results of combined treatment of hydrophobic nanosilica with temephos in larvicidal test indicated independent toxic action without any additive effect. This is probably the first report that demonstrated that nanoparticles particularly nanosilica could be used in mosquito vector control.

  17. Amblyomma americanum: a potential vector of human ehrlichiosis.

    Anderson, B E; Sims, K G; Olson, J G; Childs, J E; Piesman, J F; Happ, C M; Maupin, G O; Johnson, B J

    1993-08-01

    Polymerase chain reaction primers specific for Ehrlichia chaffeensis were used to amplify DNA from extracts of pooled ticks. Amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. The characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult Amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. No specific product was observed after amplification of 20 pools (105 ticks) of Dermacentor variabilis and three pools of Ixodes scapularis (12 ticks). Ehrlichia chaffeensis was present in A. americanum at a minimum frequency of > or = 0.48%, suggesting that A. americanum may be a vector of human ehrlichiosis.

  18. Supersymmetry and the Dirac Equation with Vector and Scalar Coupling Potentials

    2000-01-01

    This paper shows that one type of first-order Dirac equation with vector coupling and scalar coupling potentials can be brought into the framework of non-relativistic supersymmetric quantum mechanics. The conclusion is independent of the concrete forms of the vector and scalar coupling potentials because of the nilpotent matrix realization of supersymmetric quantum mechanical algebra. The supersymmetry of this kind of Dirac equation requires that a spin-orbit coupling term be introduced into the associated supersymmetric Hamiltonian.

  19. Ecological Niche Modeling of Potential West Nile Virus Vector Mosquito Species in Iowa

    2010-01-01

    Ecological niche modeling (ENM) algorithms, Maximum Entropy Species Distribution Modeling (Maxent) and Genetic Algorithm for Rule-set Prediction (GARP), were used to develop models in Iowa for three species of mosquito — two significant, extant West Nile virus (WNV) vectors (Culex pipiens L and Culex tarsalis Coquillett (Diptera: Culicidae)), and the nuisance mosquito, Aedes vexans Meigen (Diptera: Culicidae), a potential WNV bridge vector. Occurrence data for the three mosquito species from ...

  20. Symmetries and Supersymmetries of the Dirac Hamiltonian with Axially-Deformed Scalar and Vector Potentials

    Leviatan, A

    2009-01-01

    We consider several classes of symmetries of the Dirac Hamiltonian in 3+1 dimensions, with axially-deformed scalar and vector potentials. The symmetries include the known pseudospin and spin limits and additional symmetries which occur when the potentials depend on different variables. Supersymmetries are observed within each class and the corresponding charges are identified.

  1. Symmetries and supersymmetries of the dirac hamiltonian with axially deformed scalar and vector potentials.

    Leviatan, A

    2009-07-24

    We consider several classes of symmetries of the Dirac Hamiltonian in 3 + 1 dimensions, with axially deformed scalar and vector potentials. The symmetries include the known pseudospin and spin limits and additional symmetries which occur when the potentials depend on different variables. Supersymmetries are observed within each class and the corresponding charges are identified.

  2. Supersymmetry and Solution of Dirac Equation with Vector and Scalar Potentials

    ZHANG Xiao-Long; JU Guo-Xing; FENG Mang; REN Zhong-Zhou; GAO Ke-Lin

    2008-01-01

    The Dirac equations with vector and scalar potentials of the Coulomb types in two and three dimensions are solved using the supersymmetric quantum mechanics method. For the system of such potentials, the analytical expressions of the matrix dements for both position and momentum operators are obtained.

  3. Paper money and coins as potential vectors of transmissible disease.

    Angelakis, Emmanouil; Azhar, Esam I; Bibi, Fehmida; Yasir, Muhammad; Al-Ghamdi, Ahmed K; Ashshi, Ahmad M; Elshemi, Adel G; Raoult, Didier

    2014-01-01

    Paper currency and coins may be a public health risk when associated with the simultaneous handling of food and could lead to the spread of nosocomial infections. Banknotes recovered from hospitals may be highly contaminated by Staphylococcus aureus. Salmonella species, Escherichia coli and S. aureus are commonly isolated from banknotes from food outlets. Laboratory simulations revealed that methicillin-resistant S. aureus can easily survive on coins, whereas E. coli, Salmonella species and viruses, including human influenza virus, Norovirus, Rhinovirus, hepatitis A virus, and Rotavirus, can be transmitted through hand contact. Large-scale, 16S rRNA, metagenomic studies and culturomics have the capacity to dramatically expand the known diversity of bacteria and viruses on money and fomites. This review summarizes the latest research on the potential of paper currency and coins to serve as sources of pathogenic agents.

  4. Dynamical equations for the vector potential and the velocity potential in incompressible irrotational Euler flows: a refined Bernoulli theorem.

    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.

  5. Ctenocephalides felis an in vitro potential vector for five Bartonella species.

    Bouhsira, Emilie; Ferrandez, Yann; Liu, MaFeng; Franc, Michel; Boulouis, Henri-Jean; Biville, Francis

    2013-03-01

    The blood-sucking arthropod Ctenocephalides felis has been confirmed as a vector for Bartonella henselae and is a suspected vector for Bartonella clarridgeiae, Bartonella quintana and Bartonella koehlerae in Bartonella transmission to mammals. To understand the absence of other Bartonella species in the cat flea, we have developed an artificial flea-feeding method with blood infected successively with five different Bartonella species. The results demonstrated the ability of these five Bartonella species to persist in C. felis suggesting an ability of fleas to be a potential vector for several Bartonella species. In addition, we demonstrated a regurgitation of Bartonella DNA in uninfected blood used to feed C. felis thus suggesting a potential horizontal transmission of Bartonella through C. felis saliva. On the contrary, no vertical transmission was detected in these artificial conditions.

  6. Bound States of the S-Wave Equation with Equal Scalar and Vector Standard Eckart Potential

    Eser Ol(g)ar; Ramazan Ko(c); Hayriye Tütüncüler

    2006-01-01

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

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

    Kangalawe Richard YM

    2010-04-01

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

  8. Heterologous viral expression systems in fosmid vectors increase the functional analysis potential of metagenomic libraries

    2013-01-01

    The extraordinary potential of metagenomic functional analyses to identify activities of interest present in uncultured microorganisms has been limited by reduced gene expression in surrogate hosts. We have developed vectors and specialized E. coli strains as improved metagenomic DNA heterologous expression systems, taking advantage of viral components that prevent transcription termination at metagenomic terminators. One of the systems uses the phage T7 RNA-polymerase to drive metagenomic ge...

  9. Enhancing the clinical potential of AAV vectors by capsid engineering to evade pre-existing immunity

    Melissa eBartel

    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.

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

    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.

  11. Haemosporidian infections in the Tengmalm's Owl (Aegolius funereus) and potential insect vectors of their transmission.

    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.

  12. Biosynthesized silver nanoparticles using floral extract of Chrysanthemum indicum L.--potential for malaria vector control.

    Arokiyaraj, Selvaraj; Dinesh Kumar, Vannam; Elakya, Vijay; Kamala, Tamilselvan; Park, Sung Kwon; Ragam, Muthiah; Saravanan, Muthupandian; Bououdina, Mohomad; Arasu, Mariadhas Valan; Kovendan, Kalimuthu; Vincent, Savariar

    2015-07-01

    Mosquitoes transmit serious human diseases, causing millions of deaths every year. The use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides synthesized of natural products for vector control have been a priority in this area. In the present study, silver nanoparticles (Ag NPs) were green-synthesized using a floral extract of Chrysanthemum indicum screened for larvicidal and pupicidal activity against the first to fourth instar larvae and pupae of the malaria vector Anopheles stephensi mosquitoes. The synthesized Ag NPs were characterized by using UV-vis absorption, X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy techniques. The textures of the yielded Ag NPs were found to be spherical and polydispersed with a mean size in the range of 25-59 nm. Larvae and pupae were exposed to various concentrations of aqueous extract of C. indicum and synthesized Ag NPs for 24 h, and the maximum mortality was observed from the synthesized Ag NPs against the vector A. stephensi (LC50 = 5.07, 10.35, 14.19, 22.81, and 35.05 ppm; LC90 = 29.18, 47.15, 65.53, 87.96, and 115.05 ppm). These results suggest that the synthesized Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of A. stephensi. Additionally, this study provides the larvicidal and pupicidal properties of green-synthesized Ag NPs with the floral extract of C. indicum against vector mosquito species from the geographical location of India.

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

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

    2013-07-01

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

  14. Bartonella species in small mammals and their potential vectors in Asia

    Tawisa; Jiyipong; Sathaporn; Jittapalapong; Serge; Morand; Jean-Marc; Rolain

    2014-01-01

    In this article,authors review the current knowledge of Bartonella infection in small mammals including rodents,insectivores,bats and exotic small mammal pets and their vectors in Asia.Species of Bartonella are Gram-negative intracellular bacteria that infect erythrocytes of various mammalian and non-mammalian animals and mainly transmitted by blood sucking arthropod vectors.The genus Bartonella includes several species of important human diseases with severe clinical signs.Several new Bartonella species were isolated from rodents and other small mammals,and from human patients in Asia.Bartonella species are identified using standard polymerase chain reaction amplification and a sequencing targeting two housekeeping genes(glt.A and rpoB) and the internal transcribed spacer fragment.Authors also discuss the implications in term of potential emerging zoonotic diseases.

  15. Bartonella species in small mammals and their potential vectors in Asia

    Tawisa Jiyipong; Sathaporn Jittapalapong; Serge Morand; Jean-Marc Rolain

    2014-01-01

    In this article, authors review the current knowledge of Bartonella infection in small mammals including rodents, insectivores, bats and exotic small mammal pets and their vectors in Asia. Species of Bartonella are Gram-negative intracellular bacteria that infect erythrocytes of various mammalian and non-mammalian animals and mainly transmitted by blood sucking arthropod vectors. The genus Bartonella includes several species of important human diseases with severe clinical signs. Several new Bartonella species were isolated from rodents and other small mammals, and from human patients in Asia. Bartonella species are identified using standard polymerase chain reaction amplification and a sequencing targeting two housekeeping genes (gltA and rpoB) and the internal transcribed spacer fragment. Authors also discuss the implications in term of potential emerging zoonotic diseases.

  16. Potential Distribution of Chagas Disease Vectors (Hemiptera, Reduviidae, Triatominae) in Colombia, Based on Ecological Niche Modeling

    Suárez-Escudero, Laura C.; González-Caro, Sebastián

    2016-01-01

    Ecological niche modeling of Triatominae bugs allow us to establish the local risk of transmission of the parasite Trypanosoma cruzi, which causes Chagas disease. This information could help to guide health authority recommendations on infection monitoring, prevention, and control. In this study, we estimated the geographic distribution of triatomine species in Colombia and identified the relationship between landscape structure and climatic factors influencing their occurrence. A total of 2451 records of 4 triatomine species (Panstrongylus geniculatus, Rhodnius pallescens, R. prolixus, and Triatoma maculata) were analyzed. The variables that provided more information to explain the ecologic niche of these vectors were related to precipitation, altitude, and temperature. We found that the species with the broadest potential geographic distribution were P. geniculatus, R. pallescens, and R. prolixus. In general, the models predicted the highest occurrence probability of these vectors in the eastern slope of the Eastern Cordillera, the southern region of the Magdalena valley, and the Sierra Nevada of Santa Marta. PMID:28115946

  17. 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.

  18. Bartonella species in small mammals and their potential vectors in Asia

    Tawisa Jiyipong

    2014-10-01

    Full Text Available In this article, authors review the current knowledge of Bartonella infection in small mammals including rodents, insectivores, bats and exotic small mammal pets and their vectors in Asia. Species of Bartonella are Gram-negative intracellular bacteria that infect erythrocytes of various mammalian and non-mammalian animals and mainly transmitted by blood sucking arthropod vectors. The genus Bartonella includes several species of important human diseases with severe clinical signs. Several new Bartonella species were isolated from rodents and other small mammals, and from human patients in Asia. Bartonella species are identified using standard polymerase chain reaction amplification and a sequencing targeting two housekeeping genes (gltA and rpoB and the internal transcribed spacer fragment. Authors also discuss the implications in term of potential emerging zoonotic diseases.

  19. Aedes (Stegomyia albopictus (Skuse: a potential vector of Zika virus in Singapore.

    Pei-Sze Jeslyn Wong

    Full Text Available 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.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 29°C and 80-85%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.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.

  20. The response of the polarized Fermi mixture to an artificial vector potential: The interaction strength and imbalance chemical potential effects

    Ebrahimian, N.; Safiee, Z.

    2017-03-01

    We consider a polarized Fermi mixture (with normal-superfluid phase separation), subjected to artificial vector potential. We concentrate on the BCS regime with various interaction strengths and numerically obtain the polarisability of the system. We obtain the functional dependence of the polarisability of the system on frequency and the relevant physical parameters, namely the interaction strength, the mass ratio, the average and imbalance chemical potentials. Also, we find the special frequency (ωs), for which the rate of the response of system to the potential is changed and the cut-off frequency (ωcutoff), for which the response starts to become infinity. We investigate the behavior of the curves of polarisability versus proper physical parameters for ω physical parameters. Finally, the system's response can be controlled by relevant physical parameters, such as interaction strength.

  1. Spatial and temporal variation in biting rates and parasite transmission potentials of onchocerciasis vectors in Ecuador.

    Vieira, J C; Brackenboro, L; Porter, C H; Basáñez, M-G; Collins, R C

    2005-03-01

    The influence of spatial and temporal factors on onchocerciasis transmission by Simulium exiguum s.l. and S. quadrivittatum in Ecuador was investigated to help develop sampling protocols for entomological surveillance of ivermectin programmes. Flies were collected in alternate months (November 1995-November 1996) at four sites each in the hyperendemic communities of San Miguel and El Tigre. A fixed-effects analysis of variance was used to explore the influence on vector abundance of locality, site, month and hour. Infectivity rates detected by dissection and PCR assays were compared. Simulium exiguum s.l. predominated at El Tigre (75%) whereas S. quadrivittatum prevailed at San Miguel (62%). Vector abundance was highest on river banks and outside houses. Biting and infection rates peaked from March to July. Hourly activity patterns were bimodal in S. exiguum but unimodal in S. quadrivittatum. Annual transmission potentials (ATP) for both species combined were 385 and 733 third stage larvae/person in San Miguel and El Tigre respectively, with S. exiguum accounting for 80% of the combined ATP at both localities. We recommend protocols that may maximize detection of parasite transmission. Infection rates thus obtained must be linked with vector density estimates to assess meaningfully host exposure as treatment progresses.

  2. Chikungunya viral fitness measures within the vector and subsequent transmission potential.

    Rebecca C Christofferson

    Full Text Available 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 African genotype (ECSA-V-Ae. albopictus, despite the Asian genotype being the etiologic agent of recent chikungunya outbreaks world-wide. We explore a collection of data to investigate relative transmission efficiencies of the three major genotypes/sub-lineages of chikungunya and found difference in the extrinsic incubation periods to be largely overstated. However, there is strong evidence supporting the role of Ae. albopictus in the expansion of chikungunya that our R0 calculations cannot attribute to fitness increases in one vector over another. This suggests other ecological factors associated with the Ae. albopictus-ECSA-V cycle may drive transmission intensity differences. With the apparent bias in literature, however, we are less prepared to evaluate transmission where Ae. aegypti plays a significant role. Holistic investigations of CHIKV transmission cycle(s will allow for more complete assessment of transmission risk in areas affected by either or both competent vectors.

  3. Oviposition deterring and oviciding potentials of Ipomoea cairica L. leaf extract against dengue vectors.

    Ahbirami, Rattanam; Zuharah, Wan Fatma; Yahaya, Zary Shariman; Dieng, Hamady; Thiagaletchumi, Maniam; Fadzly, Nik; Ahmad, Abu Hassan; Abu Bakar, Sazaly

    2014-09-01

    Bioprospecting of plant-based insecticides for vector control has become an area of interest within the last two decades. Due to drawbacks of chemical insecticides, phytochemicals of plant origin with mosquito control potential are being utilized as alternative sources in integrated vector control. In this regard, the present study aimed to investigate oviposition deterring and oviciding potentials of Ipomoea cairica (L.) (Family: Convolvulaceae) crude leaf extract against dengue vectors, Aedes aegypti and Aedes albopictus. Ipomoea cairica is an indigenous plant that has demonstrated marked toxicity towards larvae of Ae. aegypti and Ae. albopictus. Leaves of I. cairica were extracted using Soxhlet apparatus with acetone as solvent. Oviposition deterrent activity and ovicidal assay was carried out in oviposition site choice tests with three different concentrations (50, 100, 450 ppm). Acetone extract of I. cairica leaf strongly inhibited oviposition with 100% repellence to Ae. aegypti at lower concentration of 100 ppm, while for Ae. albopictus was at 450 ppm. The oviposition activity index (OAI) values which ranged from -0.69 to -1.00 revealed that I. cairica demonstrated deterrent effect. In ovicidal assay, similar trend was observed whereby zero hatchability was recorded for Ae. aegypti and Ae. albopictus eggs at 100 and 450 ppm, respectively. It is noteworthy that I. cairica leaf extract had significantly elicited dual properties as oviposition deterrent and oviciding agent in both Aedes species. Reduction in egg number through oviposition deterring activity, reduction in hatching percentage and survival rates, suggested an additional hallmark of this plant to be integrated in Aedes mosquito control. Ipomoea cairica deserved to be considered as one of the potential alternative sources for the new development of novel plant based insecticides in future.

  4. Potential of Helper-Dependent Adenoviral Vectors in Modulating Airway Innate Immunity

    Rahul Kushwah; Huibi Cao; Jim Hu

    2007-01-01

    Innate immune responses form the first line of defense against foreign insults and recently significant advances have been made in our understanding of the initiation of innate immune response along with its ability to modulate inflammation. In airway diseases such as asthma, COPD and cystic fibrosis, over reacting of the airway innate immune responses leads to cytokine imbalance and airway remodeling or damage. Helper-dependent adenoviral vectors have the potential to deliver genes to modulate airway innate immune responses and have many advantages over its predecessors. However, there still are a few limitations that need to be addressed prior to their use in clinical applications.

  5. Barcoding Turkish Culex mosquitoes to facilitate arbovirus vector incrimination studies reveals hidden diversity and new potential vectors.

    Gunay, Filiz; Alten, Bulent; Simsek, Fatih; Aldemir, Adnan; Linton, Yvonne-Marie

    2015-03-01

    As a precursor to planned arboviral vector incrimination studies, an integrated systematics approach was adopted using morphology and DNA barcoding to examine the Culex fauna present in Turkey. The mitochondrial COI gene (658bp) were sequenced from 185 specimens collected across 11 Turkish provinces, as well as from colony material. Although by morphology only 9 species were recognised, DNA barcoding recovered 13 distinct species including: Cx. (Barraudius) modestus, Cx. (Culex) laticinctus, Cx. (Cux.) mimeticus, Cx. (Cux.) perexiguus, Cx. (Cux.) pipiens, Cx. (Cux.) pipiens form molestus, Cx. (Cux.) quinquefasciatus, Cx. (Cux.) theileri, Cx. (Cux.) torrentium, Cx. (Cux.) tritaeniorhynchus and Cx. (Maillotia) hortensis. The taxon formerly identified as Cx. (Neoculex) territans was shown to comprise two distinct species, neither of which correspond to Cx. territans s.s. These include Cx. (Neo.) impudicus and another uncertain species, which may be Cx. (Neo.) europaeus or Cx. (Neo.) martinii (herein=Cx. (Neo.) sp. 1). Detailed examination of the Pipiens Group revealed Cx. pipiens, Cx. pipiens f. molestus and the widespread presence of the highly efficient West Nile virus vector Cx. quinquefasciatus for the first time. Four new country records are reported, increasing the Culex of Turkey to 15 recognised species and Cx. pipiens f. molestus. A new taxonomic checklist is provided, annotated with respective vector competencies for transmission of arboviruses.

  6. Categorization of potential breeding sites of dengue vectors in Johor, Malaysia.

    Nyamah, M A; Sulaiman, S; Omar, B

    2010-04-01

    This cross-sectional study was to compare and categorize potential breeding sites of dengue vectors, Aedes aegypti and Aedes albopictus at three different places, namely, an urban (Taman Permas Jaya, Johor Bahru, Johor), a suburban (Kg. Melayu Gelang Patah, Johor Bahru, Johor) and a rural (Felda Simpang Waha, Kota Tinggi, Johor) habitats in Malaysia. Larval surveys were conducted once in every two months at each habitat over a period of 11 months from August 2000 until June 2001. There was a significant difference between the three study sites in terms of potential breeding sites inspected (psuburban (29.35)>urban habitat (16.97). Both breeding sites and potential breeding sites were the nominator and the total number of containers inspected as the denominator in the formula of PCI, thus the latter could be a potential indicator to initiate anti-dengue campaign at the community level to rid off potential Aedes breeding sites. The three most common potential breeding sites of Aedes species were similar for urban and suburban habitats (flower pots, pails and bowls respectively). However, flower pots, vases and tyres were the three most common potential breeding sites for the rural habitat. Another finding in this study was that various types of larval habitats were found indoors and outdoors for both species.

  7. Gene therapy vectors: the prospects and potentials of the cut-and-paste transposons.

    Claeys Bouuaert, Corentin; Chalmers, Ronald M

    2010-05-01

    Gene therapy applications require efficient tools for the stable delivery of genetic information into eukaryotic genomes. Most current gene delivery strategies are based on viral vectors. However, a number of drawbacks, such as the limited cargo capacity, host immune response and mutational risks, highlight the need for alternative gene delivery tools. A comprehensive gene therapy tool kit should contain a range of vectors and techniques that can be adapted to different targets and purposes. Transposons provide a potentially powerful approach. However, transposons encompass a large number of different molecular mechanisms, some of which are better suited to gene delivery applications than others. Here, we consider the range and potentials of the various mechanisms, focusing on the cut-and-paste transposons as one of the more promising avenues towards gene therapy applications. Several cut-and-paste transposition systems are currently under development. We will first consider the mechanisms of piggyBac and the hAT family elements Tol1 and Tol2, before focusing on the mariner family elements including Mos1, Himar1 and Hsmar1.

  8. Broader prevalence of Wolbachia in insects including potential human disease vectors.

    de Oliveira, C D; Gonçalves, D S; Baton, L A; Shimabukuro, P H F; Carvalho, F D; Moreira, L A

    2015-06-01

    Wolbachia are intracellular, maternally transmitted bacteria considered the most abundant endosymbionts found in arthropods. They reproductively manipulate their host in order to increase their chances of being transmitted to the offspring, and currently are being used as a tool to control vector-borne diseases. Studies on distribution of Wolbachia among its arthropod hosts are important both for better understanding why this bacterium is so common, as well as for its potential use as a biological control agent. Here, we studied the incidence of Wolbachia in a broad range of insect species, collected from different regions of Brazil, using three genetic markers (16S rRNA, wsp and ftsZ), which varied in terms of their sensitivity to detect this bacterium. The overall incidence of Wolbachia among species belonging to 58 families and 14 orders was 61.9%. The most common positive insect orders were Coleoptera, Diptera, Hemiptera and Hymenoptera, with Diptera and Hemiptera having the highest numbers of Wolbachia-positive families. They included potential human disease vectors whose infection status has never been reported before. Our study further shows the importance of using quantitative polymerase chain reaction for high-throughput and sensitive Wolbachia screening.

  9. Potential schistosome-vector snails and associated trematodes in ricefields of Corrients province, Argentina: preliminary results

    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.

  10. Groundwater Seepage Vectors and the Potential for Hillslope Failure and Debris Flow Mobilization

    Iverson, Richard M.; Major, Jon J.

    1986-10-01

    Insight for understanding the effect of groundwater flow on the potential for hillslope failure and liquefaction is provided by a novel limit-equilibrium analysis of infinite slopes with steady, uniform Darcian seepage of arbitrary magnitude and direction. Normalization of the limit-equilibrium solution shows that three dimensionless parameters govern completely the Coulomb failure potential of saturated, cohesionless, infinite homogeneous hillslopes: (1) the ratio of seepage force magnitude to gravitational body force magnitude; (2) the angle θ - Φ, where θ is the surface slope angle and Φ is the angle of internal friction of the soil; and (3) the angle λ + Φ, where λ is the angle of the seepage vector measured with respect to an outward-directed surface-normal vector. An additional dimensionless parameter affects the solution if soil cohesion is included in the analysis. Representation of the normalized solution as a single family of curves shows that minimum slope stability universally occurs when the seepage direction is given by λ = 90° - Φ. It also shows that for some upward seepage conditions, slope stability is limited by static liquefaction rather than by Coulomb failure. Close association between these liquefaction conditions and certain Coulomb failure conditions indicates that slope failure in such instances could be responsible for nearly spontaneous mobilization of destructive flowing soil masses on hillslopes.

  11. Application of support vector machines for copper potential mapping in Kerman region, Iran

    Shabankareh, Mahdi; Hezarkhani, Ardeshir

    2017-04-01

    The first step in systematic exploration studies is mineral potential mapping, which involves classification of the study area to favorable and unfavorable parts. Support vector machines (SVM) are designed for supervised classification based on statistical learning theory. This method named support vector classification (SVC). This paper describes SVC model, which combine exploration data in the regional-scale for copper potential mapping in Kerman copper bearing belt in south of Iran. Data layers or evidential maps were in six datasets namely lithology, tectonic, airborne geophysics, ferric alteration, hydroxide alteration and geochemistry. The SVC modeling result selected 2220 pixels as favorable zones, approximately 25 percent of the study area. Besides, 66 out of 86 copper indices, approximately 78.6% of all, were located in favorable zones. Other main goal of this study was to determine how each input affects favorable output. For this purpose, the histogram of each normalized input data to its favorable output was drawn. The histograms of each input dataset for favorable output showed that each information layer had a certain pattern. These patterns of SVC results could be considered as regional copper exploration characteristics.

  12. 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

  13. Spinless particles in the field of unequal scalar-vector Yukawa potentials

    M.Hamzavi; S.M.Ikhdair; K.E.Thylwe

    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 arbitraryl-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 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 KG-Yukawa problem.The dependence of the energy on the dimension D is numerically discussed for spatial dimensions D =2-6.

  14. 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 ...

  15. Connection between Proliferation Rate and Temozolomide Sensitivity of Primary Glioblastoma Cell Culture and Expression of YB-1 and LRP/MVP.

    Moiseeva, N I; Susova, O Yu; Mitrofanov, A A; Panteleev, D Yu; Pavlova, G V; Pustogarov, N A; Stavrovskaya, A A; Rybalkina, E Yu

    2016-06-01

    Glioblastomas (GBL) are the most common and aggressive brain tumors. They are distinguished by high resistance to radiation and chemotherapy. To find novel approaches for GBL classification, we obtained 16 primary GBL cell cultures and tested them with real-time PCR for mRNA expression of several genes (YB-1, MGMT, MELK, MVP, MDR1, BCRP) involved in controlling cell proliferation and drug resistance. The primary GBL cultures differed in terms of proliferation rate, wherein a group of GBL cell cultures with low proliferation rate demonstrated higher resistance to temozolomide. We found that GBL primary cell cultures characterized by high proliferation rate and lower resistance to temozolomide expressed higher mRNA level of the YB-1 and MDR1 genes, whereas upregulated expression of MVP/LRP mRNA was a marker in the group of GBL with low proliferation rate and high resistance. A moderate correlation between expression of YB-1 and MELK as well as YB-1 and MDR1 was found. In the case of YB-1 and MGMT expression, no correlation was found. A significant negative correlation was revealed between mRNA expression of MVP/LRP and MELK, MDR1, and BCRP. No correlation in expression of YB-1 and MVP/LRP genes was observed. It seems that mRNA expression of YB-1 and MVP/LRP may serve as a marker for GBL cell cultures belonging to distinct groups, each of which is characterized by a unique pattern of gene activity.

  16. Reptiles as potential vectors and hosts of the amphibian pathogen Batrachochytrium dendrobatidis in Panama.

    Kilburn, Vanessa L; Ibáñez, Roberto; Green, David M

    2011-12-06

    Chytridiomycosis, the disease caused by Batrachochytrium dendrobatidis, is considered to be a disease exclusively of amphibians. However, B. dendrobatidis may also be capable of persisting in the environment, and non-amphibian vectors or hosts may contribute to disease transmission. Reptiles living in close proximity to amphibians and sharing similar ecological traits could serve as vectors or reservoir hosts for B. dendrobatidis, harbouring the organism on their skin without succumbing to disease. We surveyed for the presence of B. dendrobatidis DNA among 211 lizards and 8 snakes at 8 sites at varying elevations in Panama where the syntopic amphibians were at pre-epizootic, epizootic or post-epizootic stages of chytridiomycosis. Detection of B. dendrobatidis DNA was done using qPCR analysis. Evidence of the amphibian pathogen was present at varying intensities in 29 of 79 examined Anolis humilis lizards (32%) and 9 of 101 A. lionotus lizards (9%), and in one individual each of the snakes Pliocercus euryzonus, Imantodes cenchoa, and Nothopsis rugosus. In general, B. dendrobatidis DNA prevalence among reptiles was positively correlated with the infection prevalence among co-occurring anuran amphibians at any particular site (r = 0.88, p = 0.004). These reptiles, therefore, may likely be vectors or reservoir hosts for B. dendrobatidis and could serve as disease transmission agents. Although there is no evidence of B. dendrobatidis disease-induced declines in reptiles, cases of coincidence of reptile and amphibian declines suggest this potentiality. Our study is the first to provide evidence of non-amphibian carriers for B. dendrobatidis in a natural Neotropical environment.

  17. Potentiation of anthrax vaccines using protective antigen-expressing viral replicon vectors.

    Wang, Hai-Chao; An, Huai-Jie; Yu, Yun-Zhou; Xu, Qing

    2015-02-01

    DNA vaccines require improvement for human use because they are generally weak stimulators of the immune system in humans. The efficacy of DNA vaccines can be improved using a viral replicon as vector to administer antigen of pathogen. In this study, we comprehensively evaluated the conventional non-viral DNA, viral replicon DNA or viral replicon particles (VRP) vaccines encoding different forms of anthrax protective antigen (PA) for specific immunity and protective potency against anthrax. Our current results clearly suggested that these viral replicon DNA or VRP vaccines derived from Semliki Forest virus (SFV) induced stronger PA-specific immune responses than the conventional non-viral DNA vaccines when encoding the same antigen forms, which resulted in potent protection against challenge with the Bacillus anthracis strain A16R. Additionally, the naked PA-expressing SFV replicon DNA or VRP vaccines without the need for high doses or demanding particular delivery regimens elicited robust immune responses and afforded completely protective potencies, which indicated the potential of the SFV replicon as vector of anthrax vaccines for use in clinical application. Therefore, our results suggest that these PA-expressing SFV replicon DNA or VRP vaccines may be suitable as candidate vaccines against anthrax.

  18. A high excision potential of TALENs for integrated DNA of HIV-based lentiviral vector.

    Ebina, Hirotaka; Kanemura, Yuka; Misawa, Naoko; Sakuma, Tetsushi; Kobayashi, Tomoko; Yamamoto, Takashi; Koyanagi, Yoshio

    2015-01-01

    DNA-editing technology has made it possible to rewrite genetic information in living cells. Human immunodeficiency virus (HIV) provirus, an integrated form of viral complementary DNA in host chromosomes, could be a potential target for this technology. We recently reported that HIV proviral DNA could be excised from the chromosomal DNA of HIV-based lentiviral DNA-transduced T cells after multiple introductions of a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 endonuclease system targeting HIV long terminal repeats (LTR). Here, we generated a more efficient strategy that enables the excision of HIV proviral DNA using customized transcription activator-like effector nucleases (TALENs) targeting the same HIV LTR site. A single transfection of TALEN-encoding mRNA, prepared from in vitro transcription, resulted in more than 80% of lentiviral vector DNA being successfully removed from the T cell lines. Furthermore, we developed a lentiviral vector system that takes advantage of the efficient proviral excision with TALENs and permits the simple selection of gene-transduced and excised cells in T cell lines.

  19. A high excision potential of TALENs for integrated DNA of HIV-based lentiviral vector.

    Hirotaka Ebina

    Full Text Available DNA-editing technology has made it possible to rewrite genetic information in living cells. Human immunodeficiency virus (HIV provirus, an integrated form of viral complementary DNA in host chromosomes, could be a potential target for this technology. We recently reported that HIV proviral DNA could be excised from the chromosomal DNA of HIV-based lentiviral DNA-transduced T cells after multiple introductions of a clustered regularly interspaced short palindromic repeat (CRISPR/Cas9 endonuclease system targeting HIV long terminal repeats (LTR. Here, we generated a more efficient strategy that enables the excision of HIV proviral DNA using customized transcription activator-like effector nucleases (TALENs targeting the same HIV LTR site. A single transfection of TALEN-encoding mRNA, prepared from in vitro transcription, resulted in more than 80% of lentiviral vector DNA being successfully removed from the T cell lines. Furthermore, we developed a lentiviral vector system that takes advantage of the efficient proviral excision with TALENs and permits the simple selection of gene-transduced and excised cells in T cell lines.

  20. Aedes hensilli as a Potential Vector of Chikungunya and Zika Viruses

    Ledermann, Jeremy P.; Laurent Guillaumot; Lawrence Yug; Saweyog, Steven C.; Mary Tided; Paul Machieng; Moses Pretrick; Maria Marfel; Anne Griggs; Martin Bel; Duffy, Mark R.; W Thane Hancock; Tai Ho-Chen; 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...

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

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

    2014-05-01

    Vector-borne diseases caused by mosquitoes are one of the major economic and health problems in many countries. The Aedes aegypti mosquito is a vector of several diseases in humans like yellow fever and dengue. Vector control methods involving the use of chemical insecticides are becoming less effective due to development of insecticides resistance, biological magnification of toxic substances through the food chain, and adverse effects on environmental quality and non-target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are nontoxic, easily available at affordable prices, biodegradable, and show broad-spectrum target-specific activities against different species of vector mosquitoes. Today, nanotechnology is a promising research domain which has wide-ranging application vector control programs. The present study investigates the larvicidal potential of solvent leaf extracts of Leucas aspera and synthesized silver nanoparticles using aqueous leaf extract against fourth instar larvae of Aedes aegypti. Larvae were exposed to varying concentrations of plant extracts and synthesized AgNPs for 24 h. The results were recorded from UV-Vis spectra, x-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM), and were used to characterize and support the biosynthesis of silver nanoparticles. The formation of the AgNPs synthesized from the XRD spectrum compared with Bragg reflections can be indexed to the (111) orientations, respectively, confirmed the presence of AgNPs. The FT-IR spectra of AgNPs exhibited prominent peaks at 3,447.77; 2,923.30; and 1,618.66 cm(-1). The spectra showed sharp and strong absorption band at 1,618.66 cm(-1) assigned to the stretching vibration of (NH) C═O group. The band 1,383 developed for C═C and C═N stretching, respectively, and was commonly found in the proteins. SEM

  2. Heterologous viral expression systems in fosmid vectors increase the functional analysis potential of metagenomic libraries.

    Terrón-González, L; Medina, C; Limón-Mortés, M C; Santero, E

    2013-01-01

    The extraordinary potential of metagenomic functional analyses to identify activities of interest present in uncultured microorganisms has been limited by reduced gene expression in surrogate hosts. We have developed vectors and specialized E. coli strains as improved metagenomic DNA heterologous expression systems, taking advantage of viral components that prevent transcription termination at metagenomic terminators. One of the systems uses the phage T7 RNA-polymerase to drive metagenomic gene expression, while the other approach uses the lambda phage transcription anti-termination protein N to limit transcription termination. A metagenomic library was constructed and functionally screened to identify genes conferring carbenicillin resistance to E. coli. The use of these enhanced expression systems resulted in a 6-fold increase in the frequency of carbenicillin resistant clones. Subcloning and sequence analysis showed that, besides β-lactamases, efflux pumps are not only able contribute to carbenicillin resistance but may in fact be sufficient by themselves to convey carbenicillin resistance.

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

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

    2014-05-01

    In 2005, established populations of Aedes albopictus (Skuse) were discovered in the Torres Strait, the region that separates Papua New Guinea from northern Australia. This increased the potential for this species to be introduced to mainland Australia. Because it is an arbovirus vector elsewhere, we undertook laboratory-based infection and transmission experiments to determine the potential for Ae. albopictus from the Torres Strait to become infected with and transmit the four major Australian endemic arboviruses--Murray Valley encephalitis virus, West Nile virus Kunjin strain (WNV(KUN)), Ross River virus (RRV), and Barmah Forest virus--as well as the exotic Japanese encephalitis virus. Ae. albopictus is susceptible to infection with all viruses, with infection rates ranging between 8% for WNV(KUN) and 71% for RRV. Transmission rates of approximately 25% were observed for RRV and Barmah Forest virus, but these were < 17% for Murray Valley encephalitis virus, WNV(KUN), and Japanese encephalitis virus. Given its relative vector competence for alphaviruses, we also examined the replication kinetics and extrinsic incubation periods required for transmission of RRV and chikungunya virus. Despite lower body titers, more mosquitoes reared and maintained at 28 degrees C became infected with and transmitted the virus than those reared and maintained at 22 degrees C. The minimum time between Ae. albopictus consuming an infected bloodmeal and transmitting chikungunya virus was 2 d at 28 degrees C and 4 d at 22 degrees C, and for RRV, it was 4 d, irrespective of the temperature. Given its opportunistic feeding habits and aggressive biting behavior, the establishment of Ae. albopictus on the Australian mainland could have a considerable impact on alphavirus transmission.

  4. Bacteria isolated from parasitic nematodes--a potential novel vector of pathogens?

    Lacharme-Lora, Lizeth; Salisbury, Vyv; Humphrey, Tom J; Stafford, Kathryn; Perkins, Sarah E

    2009-12-21

    Bacterial pathogens are ubiquitous in soil and water - concurrently so are free-living helminths that feed on bacteria. These helminths fall into two categories; the non-parasitic and the parasitic. The former have been the focus of previous work, finding that bacterial pathogens inside helminths are conferred survival advantages over and above bacteria alone in the environment, and that accidental ingestion of non-parasitic helminths can cause systemic infection in vertebrate hosts. Here, we determine the potential for bacteria to be associated with parasitic helminths. After culturing helminths from fecal samples obtained from livestock the external bacteria were removed. Two-hundred parasitic helminths from three different species were homogenised and the bacteria that were internal to the helminths were isolated and cultured. Eleven different bacterial isolates were found; of which eight were indentified. The bacteria identified included known human and cattle pathogens. We concluded that bacteria of livestock can be isolated in parasitic helminths and that this suggests a mechanism by which bacteria, pathogenic or otherwise, can be transmitted between individuals. The potential for helminths to play a role as pathogen vectors poses a potential livestock and human health risk. Further work is required to assess the epidemiological impact of this finding.

  5. Search for potential vectors of ‘Candidatus Liberibacter solanacearum’: population dynamics in host crops

    Teresani, G.; Hernández, E.; Bertolini, E.; Siverio, F.; Marroquín, C.; Molina, J.; Hermoso de Mendoza, A.; Cambra, M.

    2015-07-01

    ‘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 Wagner and 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. (Author)

  6. Search for potential vectors of ‘Candidatus Liberibacter solanacearum’: population dynamics in host crops

    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.

  7. 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.

  8. Polyethylenimine functionalized magnetic nanoparticles as a potential non-viral vector for gene delivery.

    Zhou, Yangbo; Tang, Zhaomin; Shi, Chunli; Shi, Shuai; Qian, Zhiyong; Zhou, Shaobing

    2012-11-01

    Polyethylenimine (PEI) functionalized magnetic nanoparticles were synthesized as a potential non-viral vector for gene delivery. The nanoparticles could provide the magnetic-targeting, and the cationic polymer PEI could condense DNA and avoid in vitro barriers. The magnetic nanoparticles were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, dynamic light scattering measurements, transmission electron microscopy, vibrating sample magnetometer and atomic force microscopy. Agarose gel electrophoresis was used to asses DNA binding and perform a DNase I protection assay. The Alamar blue assay was used to evaluate negative effects on the metabolic activity of cells incubated with PEI modified magnetic nanoparticles and their complexes with DNA both in the presence or absence of an external magnetic field. Flow cytometry and fluorescent microscopy were also performed to investigate the transfection efficiency of the DNA-loaded magnetic nanoparticles in A549 and B16-F10 tumor cells with (+M) or without (-M) the magnetic field. The in vitro transfection efficiency of magnetic nanoparticles was improved obviously in a permanent magnetic field. Therefore, the magnetic nanoparticles show considerable potential as nanocarriers for gene delivery.

  9. Exact Solutions of Klein-Gordon Equation with Scalar and Vector Rosen-Morse-Type Poten-tials

    A. Soylu; O. Bayrak; I. Boztosun

    2008-01-01

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

  10. Medfly Ceratitis capitata as Potential Vector for Fire Blight Pathogen Erwinia amylovora: Survival and Transmission.

    Mónica Ordax

    Full Text Available 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.

  11. Medfly Ceratitis capitata as Potential Vector for Fire Blight Pathogen Erwinia amylovora: Survival and Transmission.

    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.

  12. Green synthesis and characterization of silver nanoparticles fabricated using Anisomeles indica: Mosquitocidal potential against malaria, dengue and Japanese encephalitis vectors.

    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.

  13. Solutions of the Klein-Gordon equation with equal scalar and vector harmonic oscillator plus inverse quadratic potential

    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.

  14. Bound states of the Klein-Gordon and Dirac equation for scalar and vector pseudoharmonic oscillator potentials

    Chen Gang; Chen Zi-Dong; Lou Zhi-Mei

    2004-01-01

    The exact bound state solutions of the Klein-Gordon equation and Dirac equation with scalar and vector pseudoharmonic oscillator potentials are obtained in this paper. Furthermore, we have used the supersymmetric quantum mechanics, shape invariance and alternative method to obtain the required results.

  15. Supersymmetric Patterns in the Pseudospin Spin and Coulomb Limits of the Dirac Equation with Scalar and Vector Potentials

    Leviatan, A

    2004-01-01

    We show that the Dirac equation in 3+1 dimensions gives rise to supersymmetric patterns when the scalar and vector potentials are (i) Coulombic with arbitrary strengths or (ii) when their sum or difference is a constant, leading to relativistic pseudospin and spin symmetries. The conserved quantities and the common intertwining relation responsible for such patterns are discussed.

  16. Supersymmetric patterns in the pseudospin, spin, and coulomb limits of the dirac equation with scalar and vector potentials.

    Leviatan, A

    2004-05-21

    We show that the Dirac equation in (3+1) dimensions gives rise to supersymmetric patterns when the scalar and vector potentials are (i). Coulombic with arbitrary strengths or (ii). when their sum or difference is a constant, leading to relativistic pseudospin and spin symmetries. The conserved quantities and the common intertwining relation responsible for such patterns are discussed.

  17. Aedes hensilli as a potential vector of Chikungunya and Zika viruses.

    Jeremy P Ledermann

    2014-10-01

    Full Text Available 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.

  18. 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.

  19. 应用MVP模式改进软件架构%Improving software architecture with MVP mode

    王念桥

    2012-01-01

    模型-视图-控制器(MVC)模式是一个框架级的设计模式,该模式将软件设计中的关注点分离开来,从而使程序更有弹性.随着软硬件的发展,基于MVC模式演化出了一些相关模式.模型-视图-表示器(MVP)模式就是由MVC 演变而来.文章将首先介绍了可能的MVP模式的实现方法,然后讨论了该模式的应用,以及所带来的益处.

  20. Bound states of Klein-Gordon equation for double ring-shaped oscillator scalar and vector potentials

    Lu Fa-Lin; Chen Chang-Yuan; Sun Dong-Sheng

    2005-01-01

    In Spherical polar coordinates, double ring-shaped oscillator potentials have supersymmetry and shape invariance for θ and τ coordinates. Exact bound state solutions of Klein-gordon equation with equal double ring-shaped oscillator scalar and vector potentials are obtained. The normalized angular wavefunction expressed in terms of Jacobi polynomials and the normalized radial wavefunction expressed in terms of the Laguerre polynomials are presented. Energy spectrum equations are obtained.

  1. Larvicidal and repellent potential of Moringa oleifera against malarial vector, Anopheles stephensi Liston (Insecta: Diptera: Culicidae

    K Prabhu

    2011-04-01

    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.

  2. Molecular identification of Lutzomyia migonei (Diptera: Psychodidae) as a potential vector for Leishmania infantum (Kinetoplastida: Trypanosomatidae).

    Rodrigues, Ana Caroline Moura; Melo, Luciana Magalhães; Magalhães, Rafaela Damasceno; de Moraes, Nélio Batista; de Souza Júnior, Antônio Domingos; Bevilaqua, Claudia Maria Leal

    2016-04-15

    Visceral leishmaniasis (VL) in Brazil is caused by the protozoan Leishmania infantum. This parasite is transmitted by the bite of a female sand fly. The most important sand fly species in VL transmission is Lutzomyia longipalpis. In Fortaleza, the capital of Ceará State, Brazil, the simultaneous occurrence of Lutzomyia migonei and L. longipalpis was detected in localities where VL transmission is observed. The purpose of this study was to determine conclusively if L. migonei can be found naturally infected with L. infantum in key focus in Fortaleza. Using a CDC traps we performed phlebotomine capture during one year. External morphological features and qPCR targeting species-specific gene sequences of Lutzomyia species were used to identify the female phlebotomine sand flies. The molecular identification of the Leishmania species was performed using qPCR targeting species-specific gene sequences of L. infantum and Leishmania braziliensis. The males L. migonei abundance was higher in the rainy season. Humidity and rainfall positively correlated with males L. migonei abundance, while temperature showed a negative correlation. The correlation between the density of L. migonei female with rainfall, relative air humidity, and temperature were not statistically significant. According to the molecular data produced by qPCR amplifications, three positive sand flies were identified as L. longipalpis, and one was identified as L. migonei. The infection rate was 0.35% and 0.18%, respectively. The parasite load was 32,492±2572 L. infantum in L. migonei while the L. longipalpis had parasite loads between 2,444,964.6±116,000 and 6,287,130±124,277. Our findings confirm L. migonei as a potential vector of VL in Fortaleza at a molecular level.

  3. Vector analysis

    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

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

    Bruno Moreira Carvalho

    2014-03-01

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

  5. Scattering and bound states of spin-1/2 particles in a sign potential with a mixing of scalar and vector couplings

    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)

  6. Potential for cellular stress response to hepatic factor VIII expression from AAV vector

    Zolotukhin, Irene; Markusic, David M; Palaschak, Brett; Hoffman, Brad E; Srikanthan, Meera A; Herzog, Roland W

    2016-01-01

    Hemophilia A and B are coagulation disorders resulting from the loss of functional coagulation factor VIII (FVIII) or factor IX proteins, respectively. Gene therapy for hemophilia with adeno-associated virus vectors has shown efficacy in hemophilia B patients. Although hemophilia A patients are more prevalent, the development of therapeutic adeno-associated virus vectors has been impeded by the size of the F8 cDNA and impaired secretion of FVIII protein. Further, it has been reported that over-expression of the FVIII protein induces endoplasmic reticulum stress and activates the unfolded protein response pathway both in vitro and in hepatocytes in vivo, presumably due to retention of misfolded FVIII protein within the endoplasmic reticulum. Engineering of the F8 transgene, including removal of the B domain (BDD-FVIII) and codon optimization, now allows for the generation of adeno-associated virus vectors capable of expressing therapeutic levels of FVIII. Here we sought to determine if the risks of inducing the unfolded protein response in murine hepatocytes extend to adeno-associated virus gene transfer. Although our data show a mild activation of unfolded protein response markers following F8 gene delivery at a certain vector dose in C57BL/6 mice, it was not augmented upon further elevated dosing, did not induce liver pathology or apoptosis, and did not impact FVIII immunogenicity. PMID:27738644

  7. Plant Virus–Insect Vector Interactions: Current and Potential Future Research Directions

    Ralf G. Dietzgen

    2016-11-01

    Full Text Available Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus with its insect host/vector requires specific molecular interactions between virus and host, commonly via proteins. Understanding the interactions between plant viruses and their insect host can underpin approaches to protect plants from infection by interfering with virus uptake and transmission. Here, we provide a perspective focused on identifying novel approaches and research directions to facilitate control of plant viruses by better understanding and targeting virus–insect molecular interactions. We also draw parallels with molecular interactions in insect vectors of animal viruses, and consider technical advances for their control that may be more broadly applicable to plant virus vectors.

  8. Plant Virus-Insect Vector Interactions: Current and Potential Future Research Directions.

    Dietzgen, Ralf G; Mann, Krin S; Johnson, Karyn N

    2016-11-09

    Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus with its insect host/vector requires specific molecular interactions between virus and host, commonly via proteins. Understanding the interactions between plant viruses and their insect host can underpin approaches to protect plants from infection by interfering with virus uptake and transmission. Here, we provide a perspective focused on identifying novel approaches and research directions to facilitate control of plant viruses by better understanding and targeting virus-insect molecular interactions. We also draw parallels with molecular interactions in insect vectors of animal viruses, and consider technical advances for their control that may be more broadly applicable to plant virus vectors.

  9. Support vector machine applied to predict the zoonotic potential of E. coli O157 cattle isolates

    Methods based on sequence data analysis facilitate the tracking of disease outbreaks, allow relationships between strains to be reconstructed and virulence factors to be identified. However, these methods are used postfactum after an outbreak has happened. Here, we show that support vector machine a...

  10. 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...

  11. Prognostic significance of miR-23b in combination with P-gp, MRP and LRP/MVP expression in non-small cell lung cancer.

    Janikova, M; Zizkova, V; Skarda, J; Kharaishvili, G; Radova, L; Kolar, Z

    2016-01-01

    Recently, miR-23b has emerged as a promising new cancer biomarker but its role in lung cancer has not been established yet. Patients still do not respond well to available treatments, probably due to expression of multidrug resistance (MDR) proteins, such as P-gp, MRP and LRP/MVP. The aim of this study was to determine the role of miR-23b in non-small cell lung cancer (NSCLC) and its relationship to the patient outcome together with MDR transporter proteins. We immunohistochemically evaluated expression of P-gp, MRP and LRP/MVP and quantified the relative levels of miR-23b in 62 NSCLC patients´ samples. The prognostic significance of miR-23b and MDR proteins was tested by Kaplan-Meier and Cox-regression analysis. Our results showed that miR-23b is mostly downregulated in NSCLC samples (57/62) and that its upregulation in tumors is connected with longer progression-free survival (PFS; P = 0.065) and overall survival (OS; P = 0.048). The Cox proportional hazard model revealed that the risk of death or relapse in NSCLC patients with miR-23b downregulation increases together with LRP/MVP expression and both risks decrease with miR-23b upregulation (HRPFS = 4.342, PPFS = 0.022; HROS = 4.408, POS = 0.015). Our findings indicate that miR-23b, especially in combination with LRP/MVP expression, might serve as a suitable prognostic biomarker for NSCLC patients.

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

    Patricia Illoldi-Rangel

    2012-01-01

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

  13. [BLOODSUCKING MOSQUITOES (DIPTERA: CULICIDAE) IN, THE TULA REGION ARE POTENTIAL VECTORS OF DIROFILARIAS].

    Bogacheva, A S; Ganushkina, L A; Lopatina, Yu V

    2015-01-01

    Bloodsucking mosquitoes were collected in Tula and its Region in May to August 2013-2014. The fauna included 17 species from 5 genera in the subfamily Culicinae and Anopheles maculipennis complex in the subsystem Anophelinae. Ochlerotatus cantans was a dominant species in the collections. The dominant species also included Aedes einereus, Ae. vexans, Ae. geniculatus, Och. diantaeus, Och. intrudens, Och. Cataphylla, and Culex pipiens. The possible value of different mosquito species Dirofilaria repens and D. immitis as vectors of dirofilarasis was discussed.

  14. Plant Virus–Insect Vector Interactions: Current and Potential Future Research Directions

    Dietzgen, Ralf G.; Krin S. Mann; Karyn N. Johnson

    2016-01-01

    Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus...

  15. West Nile virus transmission in sentinel chickens and potential mosquito vectors, Senegal River Delta, 2008-2009.

    Fall, Assane Gueye; Diaïté, Amadou; Seck, Momar Talla; Bouyer, Jérémy; Lefrançois, Thierry; Vachiéry, Nathalie; Aprelon, Rosalie; Faye, Ousmane; Konaté, Lassana; Lancelot, Renaud

    2013-10-01

    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.

  16. Potential for entomopathogenic fungi to control Triatoma dimidiata (Hemiptera: Reduviidae, a vector of Chagas disease in Mexico

    María Guadalupe Vázquez-Martínez

    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.

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

    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

  18. Insect-specific viruses detected in laboratory mosquito colonies and their potential implications for experiments evaluating arbovirus vector competence.

    Bolling, Bethany G; Vasilakis, Nikos; Guzman, Hilda; Widen, Steven G; Wood, Thomas G; Popov, Vsevolod L; Thangamani, Saravanan; Tesh, Robert B

    2015-02-01

    Recently, there has been a dramatic increase in the detection and characterization of insect-specific viruses in field-collected mosquitoes. Evidence suggests that these viruses are ubiquitous in nature and that many are maintained by vertical transmission in mosquito populations. Some studies suggest that the presence of insect-specific viruses may inhibit replication of a super-infecting arbovirus, thus altering vector competence of the mosquito host. Accordingly, we screened our laboratory mosquito colonies for insect-specific viruses. Pools of colony mosquitoes were homogenized and inoculated into cultures of Aedes albopictus (C6/36) cells. The infected cells were examined by electron microscopy and deep sequencing was performed on RNA extracts. Electron micrograph images indicated the presence of three different viruses in three of our laboratory mosquito colonies. Potential implications of these findings for vector competence studies are discussed.

  19. Screening mosquito house entry points as a potential method for integrated control of endophagic filariasis, arbovirus and malaria vectors.

    Sheila B Ogoma

    Full Text Available BACKGROUND: Partial mosquito-proofing of houses with screens and ceilings has the potential to reduce indoor densities of malaria mosquitoes. We wish to measure whether it will also reduce indoor densities of vectors of neglected tropical diseases. METHODOLOGY: The main house entry points preferred by anopheline and culicine vectors were determined through controlled experiments using specially designed experimental huts and village houses in Lupiro village, southern Tanzania. The benefit of screening different entry points (eaves, windows and doors using PVC-coated fibre glass netting material in terms of reduced indoor densities of mosquitoes was evaluated compared to the control. FINDINGS: 23,027 mosquitoes were caught with CDC light traps; 77.9% (17,929 were Anopheles gambiae sensu lato, of which 66.2% were An. arabiensis and 33.8% An. gambiae sensu stricto. The remainder comprised 0.2% (50 An. funestus, 10.2% (2359 Culex spp. and 11.6% (2664 Mansonia spp. Screening eaves reduced densities of Anopheles gambiae s. l. (Relative ratio (RR = 0.91; 95% CI = 0.84, 0.98; P = 0.01; Mansonia africana (RR = 0.43; 95% CI = 0.26, 0.76; P<0.001 and Mansonia uniformis (RR = 0.37; 95% CI = 0.25, 0.56; P<0.001 but not Culex quinquefasciatus, Cx. univittatus or Cx. theileri. Numbers of these species were reduced by screening windows and doors but this was not significant. SIGNIFICANCE: This study confirms that across Africa, screening eaves protects households against important mosquito vectors of filariasis, Rift Valley Fever and O'Nyong nyong as well as malaria. While full house screening is required to exclude Culex species mosquitoes, screening of eaves alone or fitting ceilings has considerable potential for integrated control of other vectors of filariasis, arbovirus and malaria.

  20. A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for In-Situ Mars Surface Sample Analysis

    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.

  1. 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.

  2. 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.

  3. Host feeding patterns of established and potential mosquito vectors of West Nile virus in the eastern United States.

    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.

  4. Canine visceral leishmaniasis in the metropolitan area of São Paulo: Pintomyia fischeri as potential vector of Leishmania infantum.

    Galvis-Ovallos, Fredy; da Silva, Mariana Dantas; Bispo, Giulia Baldaconi da Silva; de Oliveira, Alessandra Gutierrez; Neto, José Rodriguez Gonçalves; Malafronte, Rosely Dos Santos; Galati, Eunice Aparecida Bianchi

    2017-01-01

    American visceral leishmaniasis is a zoonosis caused by Leishmania infantum and transmitted mainly by Lutzomyia longipalpis. However, canine cases have been reported in the absence of this species in the Greater São Paulo region, where Pintomyia fischeri and Migonemyia migonei are the predominant species. This raises the suspicion that they could be acting as vectors. Therefore, this study sought to investigate specific vector capacity parameters of these species and to compare them with those of Lu. longipalpis s.l. Among these parameters the blood feeding rate, the survival, and the susceptibility to the development of Le. infantum were evaluated for the three species, and the attractiveness of dogs to Pi. fischeri and Mg. migonei was evaluated. The estimated interval between blood meals was shorter for Lu. longipalpis s.l, followed by Pi. fischeri and Mg. migonei. The infection rate with Le. infantum flagellates in Lu. longipalpis was 9.8%, in Pi. fischeri 4.8%, and in Mg. migonei nil. The respective infective life expectancies (days) of Lu. longipalpis, Mg. migonei, and Pi. fischeri were 2.4, 1.94, and 1.68. Both Pi. fischeri and Mg. migonei were captured in the kennel with a predominance (95%) of Pi. fischeri. Considering the great attractiveness of dogs to Pi. fischeri, its susceptibility to infection by Le. infantum, infective life expectancies, and predominance in Greater São Paulo, this study presents evidence of Pi. fischeri as a potential vector of this parasite in the region.

  5. Integrable nonlocal vector nonlinear Schrödinger equation with self-induced parity-time-symmetric potential

    Sinha, Debdeep; Ghosh, Pijush K.

    2017-01-01

    A two component nonlocal vector nonlinear Schrödinger equation (VNLSE) is considered with a self-induced parity-time-symmetric potential. It is shown that the system possess a Lax pair and an infinite number of conserved quantities and hence integrable. Some of the conserved quantities like number operator, Hamiltonian etc. are found to be real-valued, in spite of the corresponding charge densities being complex. The soliton solution for the same equation is obtained through the method of inverse scattering transformation and the condition of reduction from nonlocal to local case is mentioned.

  6. Comments on ’’What the Vector Potential Measures’’ by E. J. Konopinski

    2010-12-07

    J. Konopinski, Am.J. Phys. 46(5) 499(1978). 2. R.P. Feynman , R.B. Leighton, and M. Sands, The Feynman Lectures , (Addison-Wesley, Palo Alto, CA, 1965). 3. P.J. Cote and M.A. Johnson, arXiv:0912.2977 v2. ...generally held view that the vector potential has no physical meaning in classical electromagnetism. His paper follows up on Feynman’s complaint that a...it is generally recognized from the Bohm-Arhonov effect that has physical meaning as a real “field” in quantum mechanics [2]. The Coulomb

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

    Luciana Urbano dos Santos

    1997-06-01

    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.

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

    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.

  9. 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.

  10. Ecological niche modelling of potential West Nile virus vector mosquito species and their geographical association with equine epizootics in Italy.

    Mughini-Gras, Lapo; Mulatti, Paolo; Severini, Francesco; Boccolini, Daniela; Romi, Roberto; Bongiorno, Gioia; Khoury, Cristina; Bianchi, Riccardo; Montarsi, Fabrizio; Patregnani, Tommaso; Bonfanti, Lebana; Rezza, Giovanni; Capelli, Gioia; Busani, Luca

    2014-01-01

    In Italy, West Nile virus (WNV) equine outbreaks have occurred annually since 2008. Characterizing WNV vector habitat requirements allows for the identification of areas at risk of viral amplification and transmission. Maxent-based ecological niche models were developed using literature records of 13 potential WNV Italian vector mosquito species to predict their habitat suitability range and to investigate possible geographical associations with WNV equine outbreak occurrence in Italy from 2008 to 2010. The contribution of different environmental variables to the niche models was also assessed. Suitable habitats for Culex pipiens, Aedes albopictus, and Anopheles maculipennis were widely distributed; Culex modestus, Ochlerotatus geniculatus, Ochlerotatus caspius, Coquillettidia richiardii, Aedes vexans, and Anopheles plumbeus were concentrated in north-central Italy; Aedes cinereus, Culex theileri, Ochlerotatus dorsalis, and Culiseta longiareolata were restricted to coastal/southern areas. Elevation, temperature, and precipitation variables showed the highest predictive power. Host population and landscape variables provided minor contributions. WNV equine outbreaks had a significantly higher probability to occur in habitats suitable for Cx. modestus and Cx. pipiens, providing circumstantial evidence that the potential distribution of these two species coincides geographically with the observed distribution of the disease in equines.

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

    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

  12. Lactic acid bacteria: reviewing the potential of a promising delivery live vector for biomedical purposes.

    Cano-Garrido, Olivia; Seras-Franzoso, Joaquin; Garcia-Fruitós, Elena

    2015-09-16

    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.

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

    XU Zhi-nan; SHEN Wen-he; CHEN Hao; CEN Pei-lin

    2005-01-01

    Plasmid vector is increasingly applied to gene therapy or gene vaccine. The production of plasmid pCMV-AP3 for cancer gene therapy was conducted in a modified MBL medium using a recombinant E. coli BL21 system. The effects of different MMBL components on plasmid yield, cell mass and specific plasmid DNA productivity were evaluated on shake-flask scale. The results showed that glucose was the optimal carbon source. High plasmid yield (58.3 mg/L) was obtained when 5.0 g/L glucose was added to MMBL. Glycerol could be chosen as a complementary carbon source because of the highest specific plasmid productivity (37.9 mg DNA/g DCW). After tests of different levels of nitrogen source and inorganic phosphate, a modified MMBL medium was formulated for optimal plasmid production. Further study showed that the initial acetate addition (less than 4.0 g/L) in MMBL improved plasmid production significantly, although it inhibited cell growth. The results will be useful for large-scale plasmid production using recombinant E. coli system.

  14. The poultry red mite Dermanyssus gallinae as a potential carrier of vector-borne diseases.

    De Luna, Carlos J; Arkle, Samuel; Harrington, David; George, David R; Guy, Jonathan H; Sparagano, Olivier A E

    2008-12-01

    The poultry red mite Dermanyssus gallinae is an obligatory blood-sucking parasite that is considered to be one of the most important ectoparasites in the poultry industry, mainly because it is responsible for important economic losses, leads to a reduction of welfare of laying hens, and may pose a disease risk to humans. As a result of these problems, much of the current research on this parasite targets new methods of control. Less attention has been paid to the importance of D. gallinae as a carrier of vector-borne diseases. Some authors have mentioned the possible involvement of D. gallinae in the transmission (both in vitro and directly isolated from the mites) of viral and bacterial agents. Our research group has demonstrated the presence of Mycobacterium spp. within D. gallinae. DNA coding for Mycobacterium spp. was successfully amplified from unfed adult D. gallinae, larvae, and eggs by using reverse transcription-polymerase chain reaction targeting the 16S rRNA gene. The results have suggested the possible transovarial and transstadial transmission of pathogens by D. gallinae.

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

    Ramasamy, Ranjan; Surendran, Sinnathamby Noble

    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 with 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 the 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 transmission of mosquito-borne diseases

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

    Clement Nyamunura Mweya

    2013-10-01

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

  17. A novel vector potential formulation of 3D Navier-Stokes equations with through-flow boundaries by a local meshless method

    Young, D. L.; Tsai, C. H.; Wu, C. S.

    2015-11-01

    An alternative vector potential formulation is used to solve the Navier-Stokes (N-S) equations in 3D incompressible viscous flow problems with and without through-flow boundaries. Difficulties of the vector potential formulation include the implementation of boundary conditions for through-flow boundaries and the numerical treatment of fourth-order partial differential equations. The advantages on the other hand are the automatic satisfaction of the continuity equation; and pressure is decoupled from the velocity. The objective of this paper is to introduce the appropriate gauge and boundary conditions on the vector potential formulation by a localized meshless method. To handle the divergence-free property, a Coulomb gauge condition is enforced on the vector potential to ensure its existence and uniqueness mathematically. We further improve the algorithm to through-flow problems for the boundary conditions of vector potential by introducing the concept of Stokes' theorem. Based on this innovation, there is no need to include an additional variable to tackle the through-flow fields. This process will greatly simplify the imposition of boundary conditions by the vector potential approach. Under certain conditions, the coupled fourth-order partial differential equations can be easily solved by using this meshless local differential quadrature (LDQ) method. Due to the LDQ capability to deal with the high order differential equations, this algorithm is very attractive to solve this fourth-order vector potential formulation for the N-S equations as comparing to the conventional numerical schemes such as finite element or finite difference methods. The proposed vector potential formulation is simpler and has improved accuracy and efficiency compared to other pressure-free or pressure-coupled algorithms. This investigation can be regarded as the first complete study to obtain the N-S solutions by vector potential formulation through a LDQ method. Two classic 3D benchmark

  18. Assessment of Local Mosquito Species Incriminates Aedes aegypti as the Potential Vector of Zika Virus in Australia

    Hall-Mendelin, Sonja; Pyke, Alyssa T.; Moore, Peter R.; Mackay, Ian M.; McMahon, Jamie L.; Ritchie, Scott A.; Taylor, Carmel T.; Moore, Frederick A.J.; van den Hurk, Andrew F.

    2016-01-01

    Background Within the last 10 years Zika virus (ZIKV) has caused unprecedented epidemics of human disease in the nations and territories of the western Pacific and South America, and continues to escalate in both endemic and non-endemic regions. We evaluated the vector competence of Australian mosquitoes for ZIKV to assess their potential role in virus transmission. Methodology/Principal Findings Mosquitoes were exposed to infectious blood meals containing the prototype African ZIKV strain. After 14 days incubation at 28°C and high relative humidity, infection, dissemination and transmission rates were assessed. Infection in Culex annulirostris and Cx. sitiens could not be detected. 8% of Cx. quinquefasciatus were infected, but the virus did not disseminate in this species. Despite having infection rates > 50%, Aedes notoscriptus and Ae. vigilax did not transmit ZIKV. In contrast, Ae. aegypti had infection and transmission rates of 57% and 27%, respectively. In susceptibility trials, the virus dose required to infect 50% (ID50) of Ae. aegypti was106.4 tissue culture infectious dose50 (TCID50)/mL. Additionally, a threshold viral load within the mosquito of at least 105.1 TCID50 equivalents/mL had to be reached before virus transmission occurred. Conclusions/Significance We confirmed Ae. aegypti to be the most likely mosquito vector of ZIKV in Australia, although the restricted distribution of this species will limit the receptive zone to northern Queensland where this species occurs. Importantly, the role in ZIKV transmission of Culex and other Aedes spp. tested will be negligible. Despite being the implicated vector, the relatively high ID50 and need for a high titer disseminated infection in Ae. aegypti suggest that high mosquito population densities will be required to facilitate epidemic ZIKV transmission among the currently immunologically naïve human population in Australia. PMID:27643685

  19. A scheme to interpolate potential energy surfaces and derivative coupling vectors without performing a global diabatization.

    Evenhuis, Christian; Martínez, Todd J

    2011-12-14

    Simulation of non-adiabatic molecular dynamics requires the description of multiple electronic state potential energy surfaces and their couplings. Ab initio molecular dynamics approaches provide an attractive avenue to accomplish this, but at great computational expense. Interpolation approaches provide a possible route to achieve flexible descriptions of the potential energy surfaces and their couplings at reduced expense. A previously developed approach based on modified Shepard interpolation required global diabatization, which can be problematic. Here, we extensively revise this previous approach, avoiding the need for global diabatization. The resulting interpolated potentials provide only adiabatic energies, gradients, and derivative couplings. This new interpolation approach has been integrated with the ab initio multiple spawning method and it has been rigorously validated against direct dynamics. It is shown that, at least for small molecules, constructing an interpolated PES can be more efficient than performing direct dynamics as measured by the total number of ab initio calculations that are required for a given accuracy.

  20. Potential mosquito (Diptera:Culicidae) vector of Dirofilaria repens and Dirofilaria immitis in urban areas of Eastern Slovakia.

    Bocková, Eva; Iglódyová, Adriana; Kočišová, Alica

    2015-12-01

    This paper follows the study from 2013 focused on the molecular screening of mosquitoes as vectors of Dirofilaria spp. which provided the information on Aedes vexans as a potential vector of Dirofilaria repens in Slovakia. Current entomological and molecular research indicates that Ae. vexans can participate also in the transmission of Dirofilaria immitis within the region. Using the standard PCR method, we examined 10,500 mosquitoes (Ae. vexans, Ae. rossicus, Anopheles maculipennis s.l., Ochlerotatus sticticus, Ochlerotatus cantans, Ochlerotatus caspius, Culex pipiens/Culex torrentium, Coquillettidia richiardii), collected using CO2-baited traps at six locations in the Eastern Slovakia. Out of 105 pools, 6 pools of mosquitoes Ae. vexans were positive for D. repens DNA (minimum infective rate in Ae. vexas was 6:6.900, i.e. 0.8 per 1.000 mosquitoes), within which 4 were concurrently positive for D. immitis (minimum infective rate in Ae. vexans was 4:6.900 i.e. 0.5 per 1.000 mosquitoes).

  1. Green synthesis of selenium nanoparticles conjugated Clausena dentata plant leaf extract and their insecticidal potential against mosquito vectors.

    Sowndarya, P; Ramkumar, G; Shivakumar, M S

    2016-11-10

    Mosquitoes are major vectors for the transmission of many diseases like chikungunya, malaria, dengue, zika, etc. worldwide. In the present study, selenium nanoparticles (SeNPs) were synthesized from Clausena dentata and were tested for their larvicidal efficacy against the fourth-instar larvae of Anopheles stephensi, Aedes Aegypti, and Culex quinquefasciatus. The synthesized nanoparticles were characterized using UV-Vis spectroscopy, Fourier Transform Infrared Radiation (FTIR) spectroscopy, EDaX, and SEM. The results recorded from UV-Vis spectroscopy show the peak absorption spectrum at 420 nm. In FTIR, the maximum peak value is 2922.25 cm(-1) assigned to N-H group (amide group). In EDaX analysis shows peak around 72.64 which confirm the binding intensity of selenium. In SEM analysis, the synthesized SeNPs sizes were ranging from 46.32 nm to 78.88 nm. The synthesized SeNPs produced high mortality with very low concentration (LC50) were 240.714 mg/L; 104.13 mg/L, and 99.602 mg/L for A. stephensi, A. Aegypti, and C. quinquefasciatus, respectively. These results suggest that the C. dentata leaf extract-mediated biosynthesis of SeNPs has the potential to be used as an ideal ecofriendly approach toward the control of mosquito vectors at early stages.

  2. VBORNET gap analysis: Mosquito vector distribution models utilised to identify areas of potential species distribution in areas lacking records.

    Francis Schaffner

    2016-12-01

    Full Text Available This is the second of a number of planned data papers presenting modelled vector distributions produced originally during the ECDC funded VBORNET project. This work continues under the VectorNet project now jointly funded by ECDC and EFSA. Further data papers will be published after sampling seasons when more field data will become available allowing further species to be modelled or validation and updates to existing models.  The data package described here includes those mosquito species first modelled in 2013 & 2014 as part of the VBORNET gap analysis work which aimed to identify areas of potential species distribution in areas lacking records. It comprises three species models together with suitability masks based on land class and environmental limits. The species included as part of this phase are the mosquitoes 'Aedes vexans', 'Anopheles plumbeus' and 'Culex modestus'. The known distributions of these species within the area covered by the project (Europe, the ­Mediterranean Basin, North Africa, and Eurasia are currently incomplete to a greater or lesser degree. The models are designed to fill the gaps with predicted distributions, to provide a assistance in ­targeting surveys to collect distribution data for those areas with no field validated information, and b a first indication of the species distributions within the project areas.

  3. Comparison of osteogenic potentials of human rat BMP4 and BMP6 gene therapy using [E1-] and [E1-,E2b-] adenoviral vectors

    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.

  4. The house fly (Musca domestica) as a potential vector of metazoan parasites caught in a pig-pen in Germany.

    Förster, Maike; Klimpel, Sven; Sievert, Kai

    2009-03-09

    In the present study a total of 224 specimens of the synanthropic house fly (Musca domestica) were caught in a pig-pen of an organic farmer in Dormagen (Germany). The flies were examined for their potential as a carrier of metazoan parasites. On the exoskeletons and in the intestines of the flies the eggs and/or larvae of four endoparasite nematode species of domestic pigs (Ascaris suum, Strongyloides ransomi, Metastrongylus sp., undetermined Strongylida) were isolated. Also one ectoparasite species, the hog louse (Haematopinus suis), was detected on the exoskeleton of one fly. The analysis of the pig faeces as potential source revealed many eggs and larvae of nematodes. A high number of A. suum eggs (62.0% of all found nematode eggs), many eggs of strongylid nematodes (21.0%), some eggs of S. ransomi and few eggs of Trichuris suis were detected. However Metastrongylus sp. could not be identified in the faeces. Further laboratory experiments verified the potential of the house fly as a transmitter of the pig parasites A. suum and T. suis. In the intestines of 59 flies (49.2%) from 120 experimentally used house flies, nematode eggs of both nematode species were detected. The present study clearly demonstrates the potential of the house fly as a vector of metazoan pig parasites.

  5. Comparison of osteogenic potentials of human rat BMP4 and BMP6 gene therapy using [E1-] and [E1-,E2b-] adenoviral vectors

    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...

  6. Zika virus, vectors, reservoirs, amplifying hosts, and their potential to spread worldwide: what we know and what we should investigate urgently

    Rengina Vorou

    2016-01-01

    Objectives: The widespread epidemic of Zika virus infection in South and Central America and the Caribbean in 2015, along with the increased incidence of microcephaly in fetuses born to mothers infected with Zika virus and the potential for worldwide spread, indicate the need to review the current literature regarding vectors, reservoirs, and amplification hosts. Vectors: The virus has been isolated in Africa in mosquitoes of the genera Aedes, Anopheles, and Mansonia, and in Southeast Asia...

  7. A High Excision Potential of TALENs for Integrated DNA of HIV-Based Lentiviral Vector

    Hirotaka Ebina; Yuka Kanemura; Naoko Misawa; Tetsushi Sakuma; Tomoko Kobayashi; Takashi Yamamoto; Yoshio Koyanagi

    2015-01-01

    DNA-editing technology has made it possible to rewrite genetic information in living cells. Human immunodeficiency virus (HIV) provirus, an integrated form of viral complementary DNA in host chromosomes, could be a potential target for this technology. We recently reported that HIV proviral DNA could be excised from the chromosomal DNA of HIV-based lentiviral DNA-transduced T cells after multiple introductions of a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 endonuc...

  8. Kronig-Penney model of scalar and vector potentials in graphene.

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

    2010-11-24

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

  9. Modeling the Distribution of Cutaneous Leishmaniasis Vectors (Psychodidae: Phlebotominae) in Iran: A Potential Transmission in Disease Prone Areas.

    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 16.4°C 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.

  10. Infections with immunogenic trypanosomes reduce tsetse reproductive fitness: potential impact of different parasite strains on vector population structure.

    Changyun Hu

    Full Text Available The parasite Trypanosoma brucei rhodesiense and its insect vector Glossina morsitans morsitans were used to evaluate the effect of parasite clearance (resistance as well as the cost of midgut infections on tsetse host fitness. Tsetse flies are viviparous and have a low reproductive capacity, giving birth to only 6-8 progeny during their lifetime. Thus, small perturbations to their reproductive fitness can have a major impact on population densities. We measured the fecundity (number of larval progeny deposited and mortality in parasite-resistant tsetse females and untreated controls and found no differences. There was, however, a typanosome-specific impact on midgut infections. Infections with an immunogenic parasite line that resulted in prolonged activation of the tsetse immune system delayed intrauterine larval development resulting in the production of fewer progeny over the fly's lifetime. In contrast, parasitism with a second line that failed to activate the immune system did not impose a fecundity cost. Coinfections favored the establishment of the immunogenic parasites in the midgut. We show that a decrease in the synthesis of Glossina Milk gland protein (GmmMgp, a major female accessory gland protein associated with larvagenesis, likely contributed to the reproductive lag observed in infected flies. Mathematical analysis of our empirical results indicated that infection with the immunogenic trypanosomes reduced tsetse fecundity by 30% relative to infections with the non-immunogenic strain. We estimate that a moderate infection prevalence of about 26% with immunogenic parasites has the potential to reduce tsetse populations. Potential repercussions for vector population growth, parasite-host coevolution, and disease prevalence are discussed.

  11. Smoke repellency and mosquito larvicidal potentiality of Mesua ferra L. leaf extract against filarial vector Culex quinquefasciatus Say

    Someshwar Singha; Utpal Adhikari; Goutam Chandra

    2011-01-01

    Objective: Present study was made to evaluate the smoke repellent potentiality and mosquito larvicidal activity of Mesua ferra (M. ferra) leaves against filarial vector Culex quinquefasciatus (Cx.quinquefasciatus ). Methods: Crude, petroleum-ether, chloroform: methanol (1:1 v/v) and ethyl acetate extracts of mature plant leaves were investigated to establish its biocontrol potentiality under laboratory condition against larvae of Cx. quinquefasciatus at different concentrations i.e. 25 ppm, 50 ppm and 75 ppm. Mosquito coil prepared from M. ferra leaves powder were tested for smoke toxicity effect against Cx. quinquefasciatus adult mosquitoes. Results: The mortality rates of crude extract at 0.5% concentration were higher than all other concentrations tested against the first, second, third and fourth instars larvae at 24 h, 48 h and 72 h of exposure. Larval mortality rate in chloroform: methanol (1:1 v/v) extract was significantly higher (P<0.05) than other extracts. LC50 value of petroleum ether, chloroform: methanol (1:1 v/v) and ethyl acetate extracts were 195.33 ppm, 27.28 ppm and 74.19 ppm respectively, after 48 h of exposure. Smoke exposed gravid females oviposited fewer eggs when compared to non exposed female mosquitoes. Conclusions:In conclusion M. ferra crude and chloroform: methanol (1:1) extract can be used effectively against mosquito control programmes. Smoke from M. ferra can play an important role in the interruption of transmission of those diseases where mosquitoes act as vector at the individual level.

  12. A combined vector and scalar potential method for 3D magnetic fields and transient Eddy current effects in recording head coils

    Hrkac, G. [Department of Engineering Materials, University of Sheffield, Western Bank, Sheffield (United Kingdom)]. E-mail: g.hrkac@sheffield.ac.uk; Schrefl, T. [Department of Engineering Materials, University of Sheffield, Western Bank, Sheffield (United Kingdom); Schabes, M. [Hitachi San Jose Research Center, Hitachi Global Storage Technologies, San Jose, CA 95193 (United States)

    2006-10-01

    A mixed 3D finite element vector and scalar potential method was developed to treat inhomogeneities in coils of recording heads. It is assumed that in the yoke of the recording head the change of magnetization, generates a magnetic field that leads to Eddy current effects in the coil. The problem is separated into two regions, a conducting (the coil) and in a non-conducting one. For the conducting region we solve a vector potential diffusion equation with all contributing currents as a source term, including the Eddy currents produced by the yoke and for the non-conducting region a scalar potential partial differential equation is solved. To combine the vector and the scalar potential method special boundary conditions are implemented. The combined system of partial differential equations are solved simultaneously with a finite element/boundary element method.

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

    Wanda Ramos dos Santos Lima

    2013-09-01

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

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

    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 São Paulo states and has recently spread sothwards to Santa Catarina state, and the range of B. tenagophila overlaps taht of the Espinillar Biomphalaria, the possibility of

  15. Strange Stars with Realistic Quark Vector Interaction and Phenomenological Density-dependent Scalar Potential

    Dey, M; Dey, J; Ray, S; Samanta, B C; Dey, Mira; Bombaci, Ignazio; Dey, Jishnu; Ray, Subharthi

    1998-01-01

    We derive an equation of state (EOS) for strange matter, starting from an interquark potential which (i) has asymptotic freedom built into it, (ii) shows confinement at zero density ($\\rho_B = 0$) and deconfinement at high $\\rho_B$, and (iii) gives a stable configuration for chargeless, $\\beta$-stable quark matter. This EOS is then used to calculate the structure of Strange Stars, and in particular their mass-radius relation. Our present results confirm and reinforce the recent claim\\cite{li,b} that the compact objects associated with the x-ray pulsar Her X-1, and with the x-ray burster 4U 1820-30 are strange stars.

  16. Larvicidal and adulticidal potential of medicinal plant extracts from south India against vectors

    Chinnaperumal Kamaraj; Abdul Abdul Rahuman

    2010-01-01

    Objective: To determine the larvicidal and adulticidal activities of hexane, ethyl acetate and methanol extracts of Momordica charantia (M.charantia), Moringa oleifera(M. oleifera), Ocimumgratissimum (O. gratissimum), Ocimum tenuiflorum (O. tenuiflorum), Punica granatum(P. granatum) and Tribulus terrestris (T. terrestris) against Culex gelidus (Cx. gelidus) and Culex quinquefasciatus (Cx. quinquefasciatus). Methods: Bioassay test was carried out by WHO method for determination of larvicidal and adulticidal activity against mosquitoes. Results: All plant extracts showed moderate larvicidal and adulticidal activities, however the effective larval mortality was found in the leaf ethyl acetate and methanol extract of O. gratissimum and bark methanol extract of M. oleifera against Cx.gelidus with LC50 values of 39.31, 66.28, and 21.83 μg/mL respectively, and methanol extract of O. gratissimum, O. tenuiflorum and P. granatum againstCx. quinquefasciatus exposed for 1 h and mortality was recorded at 24 h recovery period. Above 90% mortality was found in the ethyl acetate and methanol extract of all experimental plants at the concentrations of 500 μg/mL. Conclusions: The present results suggest that the medicinal plant extracts provided an excellent potential for controlling Cx. gelidus and Cx. quinquefasciatus. with LC50 values of 38.47, 24.90 and 67.20 μg/mL, respectively. The adult feoxupnods eidn tfhore 1e thhy al nadc emtaotert aalnidty m weatsh arneoclo redxetrda catt o2f4 a lhl erxepcoevriemrye nptearl ipodla.n Atsb aotv teh e9 0c%on mceonrttraaltiitoyn ws aosf 500 μg/mL. Conclusions: The present results suggest that the medicinal plant extracts provided an excellent potential for controlling Cx. gelidus and Cx. quinquefasciatus.

  17. Reliability of lower leg proximal end and forefoot kinematics during different paces of barefoot racewalking on a treadmill using a motion recorder (MVP-RF8-BC).

    Wang, Hongzhao; Huo, Ming; An, Xiangde; Li, Yong; Onoda, Ko; Li, Desheng; Huang, Qiuchen; Maruyama, Hitoshi

    2016-04-01

    [Purpose] This study was performed to investigate the changes in lower leg proximal end and forefoot kinematics, and reliability of measurement during different paces of barefoot racewalking on treadmill. [Subjects] Eleven junior racewalking men participated in this study. [Methods] To identify changes in lower leg proximal end and forefoot kinematics, during different paces of barefoot racewalking on a treadmill, a wireless motion recorder (MVP-RF8-BC) was used. Interclass correlation coefficients (ICC 1, 2) were used to estimate reliability. [Results] There were significant differences in the lower leg proximal end and forefoot maximum medial/lateral rotations at a pace of 9 km/h compared with those at a pace of 5 km/h pace. The intra-examiner reliability estimates ranged from 0.82 and 0.89 to 0.87 and 0.93 for lower leg proximal end inversion/eversion rotation and medial/lateral rotation, and from 0.92 and 0.84 to 0.93 and 0.91 for forefoot inversion/eversion rotation and medial/lateral rotation. [Conclusion] We conclude that the lower leg proximal end and forefoot kinematics of barefoot racewalking on a treadmill are influenced by different paces and that assessment of lower leg proximal end and forefoot kinematics by means of the wireless motion recorder (MVP-RF8-BC) is adequately reliable. This information may be useful for determining exercise prescriptions.

  18. A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for the Surface of Mars: An Instrument for the Planetary Science Community

    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.

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

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

    2014-04-07

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

  20. Acanthamoeba polyphaga, a potential environmental vector for the transmission of food-borne and opportunistic pathogens.

    Anacarso, Immacolata; de Niederhäusern, Simona; Messi, Patrizia; Guerrieri, Elisa; Iseppi, Ramona; Sabia, Carla; Bondi, Moreno

    2012-06-01

    The endosymbiotic relationship could represent for many bacteria an important condition favouring their spread in the environment and in foods. For this purpose we studied the behaviour of some food-borne and opportunistic pathogens (Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Salmonella enterica serovar Enteritidis, Aeromonas hydrophila, Yersinia enterocolitica) when internalized in Acanthamoeba polyphaga. Our results confirm the capability of the bacteria tested to grow within amoebal hosts. We can observe two types of interactions of the bacteria internalized in A. polyphaga. The first type, showed by Y. enterocolitica and A. hydrophila, was characterized by an early replication, probably followed by the killing and digestion of the bacteria. The second type, showed by E. faecalis and S. aureus was characterized by the persistence and grow inside the host without lysis. Lastly, when amoebae were co-cultured with L. monocytogenes and S. Enteritidis, an eclipse phase followed by an active intracellular growth was observed, suggesting a third type of predator-prey trend. The extracellular count in presence of A. polyphaga, as a result of an intracellular multiplication and subsequent release, was characterized by an increase of E. faecalis, S. aureus, L. monocytogenes and S. Enteritidis, and by a low or absent cell count for Y. enterocolitica and A. hydrophila. Our study suggests that the investigated food-borne and opportunistic pathogens are, in most cases, able to interact with A. polyphaga, to intracellularly replicate and, lastly, to be potentially spread in the environment, underlining the possible role of this protozoan in food contamination.

  1. Current and potential impacts of mosquitoes and the pathogens they vector in the Pacific region

    LaPointe, Dennis

    2007-01-01

    Mosquitoes and the pathogens they transmit are ubiquitous throughout most of the temperate and tropical regions of the world. The natural and pre-European distribution and diversity of mosquitoes and mosquito-borne diseases throughout much of the Pacific region, however, depicts a depauperate and relatively benign fauna reinforcing the dream of “paradise regained”. In the central and South Pacific few mosquito species were able to colonize the remotest islands and atolls. Native mosquitoes are limited to a few far-ranging species and island endemics are typically restricted to the genera of Aedes and Culex. Only lymphatic filariasis appears to have been present as an endemic mosquito-borne disease before European contact. In nearby Australia, however, some 242 species of mosquitoes are known to occur and more than 70 arboviruses have been identified (Mackenzie 1999). In this regard Australia is more similar to the rest of the tropic and subtropical world than the smaller islands of Oceania. In our ever-shrinking world of global commerce, military activity and travel, the nature of mosquito-borne disease in the Pacific was bound to change. This paper is a brief summary of introduced mosquitoes in the Pacific and their potential impacts on human and wildlife health.

  2. Larvicidal and repellent potential ofMoringa oleiferaagainst malarial vector,Anopheles stephensi Liston (Insecta:Diptera:Culicidae)

    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 vectorAnopheles stephensi(A. stephensi) mosquitoes at different concentrations (20,40,60,80 and100 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 with300 mL of methanol for8 h in a Soxhlet apparatus. The extracts were evaporated to dryness in rotary vacuum evaporator to yield122 mg and110 mg of dark greenish material (residue) fromArcang amara andOcimum basilicum, respectively. One gram of the each plant residue was dissolved separately in100 mL of acetone (stock solution) from which different concentrations, i.e.,20,40,60,80 and100 ppm were prepared.Results: Larvicidal activity ofM.oleifera exhibited in the first to fourth instar larvae of theA. stephensi, and the LC50 and LC90 values were57.79 ppm and125.93 ppm for the first instar,63.90 ppm and133.07 ppm for the second instar,72.45 ppm and139.82 ppm for the third instar,78.93 ppm and143.20 ppm for the fourth instar, respectively. During the pupal stage the methanolic extract ofM.oleifera showed that the LC50 and LC90 values were67.77 ppm and141.00 ppm, respectively.Conclusions:The present study indicates that the phytochemicals derived fromM. oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs.

  3. Monitoring of Plasmodium infection in humans and potential vectors of malaria in a newly emerged focus in southern Iran.

    Kalantari, Mohsen; Soltani, Zahra; Ebrahimi, Mostafa; Yousefi, Masoud; Amin, Masoumeh; Shafiei, Ayda; Azizi, Kourosh

    2017-02-01

    Despite control programs, which aim to eliminate malaria from Iran by 2025, transmission of malaria has not been removed from the country. This study aimed to monitor malaria from asymptomatic parasitaemia and clinical cases from about one year of active case surveillance and potential vectors of malaria in the newly emerged focus of Mamasani and Rostam, southern Iran during 2014-2015. Samples were collected and their DNAs were extracted for Polymerase Chain Reaction (PCR) assay using specific primers for detection of Plasmodium species. The Annual Parasite Incidence rate (API) was three cases per 1,000 population from 2,000 individuals in three villages. Parasites species were detected in 9 out of the 4,000 blood smear samples among which, 6 cases were indigenous and had no history of travels to endemic areas of malaria. Also, the prevalence rate of asymptomatic parasites was about 0.3%. Overall, 1073 Anopheles spp. were caught from 9 villages. Totally, 512 female samples were checked by PCR, which indicated that none of them was infected with Plasmodium. Despite new malaria local transmission in humans in Mamasani and Rostam districts, no infection with Plasmodium was observed in Anopheles species. Because of neighboring of the studied area to the re-emerged focus in Fars province (Kazerun) and important endemic foci of malaria in other southern provinces, such as Hormozgan and Kerman, monitoring of the vectors and reservoir hosts of Plasmodium species would be unavoidable. Application of molecular methods, such as PCR, can simplify access to the highest level of accuracy in malaria researches.

  4. Metabonomic analysis of hepatitis B virus-induced liver failure: identification of potential diagnostic biomarkers by fuzzy support vector machine

    Yong MAO; Xin HUANG; Ke YU; Hai-bin QU; Chang-xiao LIU; Yi-yu CHENG

    2008-01-01

    Hepatitis B virus (HBV)-induced liver failure is an emergent liver disease leading to high mortality. The severity of liver failure may be reflected by the profile of some metabolites. This study assessed the potential of using metabolites as biomarkers for liver failure by identifying metabolites with good discriminative performance for its phenotype. The serum samples from 24 HBV-induced liver failure patients and 23 healthy volunteers were collected and analyzed by gas chromatography-mass spectrometry (GC-MS) to generate metabolite profiles. The 24 patients were further grouped into two classes according to the severity of liver failure. Twenty-five commensal peaks in all metabolite profiles were extracted, and the relative area values of these peaks were used as features for each sample. Three algorithms, F-test, k-nearest neighbor (KNN) and fuzzy support vector machine (FSVM) combined with exhaustive search (ES), were employed to identify a subset of metabolites (biomarkers) that best predict liver failure. Based on the achieved experimental dataset, 93.62% predictive accuracy by 6 features was selected with FSVM-ES and three key metabolites, glyceric acid, cis-aconitic acid and citric acid, are identified as potential diagnostic biomarkers.

  5. Analysis of plant soil seed banks and seed dispersal vectors: Its potential and limits for forensic investigations.

    Šumberová, Kateřina; Ducháček, Michal

    2017-01-01

    Plant seeds exhibit many species-specific traits, thus potentially being especially helpful for forensic investigations. Seeds of a broad range of plant species occur in soil seed banks of various habitats and may become attached in large quantities to moving objects. Although plant seeds are now routinely used as trace evidence in forensic practice, only scant information has been published on this topic in the scientific literature. Thus, the standard methods remain unknown to specialists in such botanical subjects as plant ecology and plant geography. These specialists, if made aware of the forensic uses of seeds, could help in development of new, more sophisticated approaches. We aim to bridge the gap between forensic analysts and botanists. Therefore, we explore the available literature and compare it with our own experiences to reveal both the potential and limits of soil seed bank and seed dispersal analysis in forensic investigations. We demonstrate that habitat-specific and thus relatively rare species are of the greatest forensic value. Overall species composition, in terms of species presence/absence and relative abundance can also provide important information. In particular, the ecological profiles of seeds found on any moving object can help us identify the types of environments through which the object had travelled. We discuss the applicability of this approach to various European environments, with the ability to compare seed samples with georeferenced vegetation databases being particularly promising for forensic investigations. We also explore the forensic limitations of soil seed bank and seed dispersal vector analyses.

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

    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.

  7. Bound States for a Klein-Gordon Particle in Vector Plus Scalar Generalized Hulthén Potentials in D Dimensions

    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 potential term and the technique of space-time transformation are used to reduce the path integral for the generalized Hulthén potentials into a path integral for q-deformed Rosen-Morse potential. Explicit path integration leads to the radial Green's function for any l state in closed form. The energy spectrum and the correctly normalized 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.

  8. Mosquito repellent potential ofPithecellobium dulce leaf and seed against malaria vectorAnopheles stephensi (Diptera:Culicidae)

    Mohan Rajeswary; Marimuthu Govindarajan

    2016-01-01

    Objective:To determine the repellent properties of hexane, benzene, ethyl acetate, chloroform and methanol extract ofPithecellobium dulce (P. dulce) leaf and seed against Anopheles stephensi(An. stephensi). Methods:Repellent activity assay was carried out in a net cage (45 cmí30 cmí25 cm) containing 100 blood starved female mosquitoes ofAn. stephensi. This assay was carried out in the laboratory conditions according to theWHO 2009 protocol. Plant crude extracts ofP. dulce were applied at 1.0, 2.5, and 5.0 mg/cm2 separately in the exposed fore arm of study subjects. Ethanol was used as the sole control. Results: In this study, the applied plant crude extracts were observed to protect against mosquito bites. There were no allergic reactions experienced by the study subjects. The repellent activity of the extract was dependent on the concentration of the extract. Among the tested solvents, the leaf and seed methanol extract showed the maximum efficacy. The highest concentration of 5.0 mg/cm2 leaf and seed methanol extract ofP. dulceprovided over 180 min and 150 min protection, respectively. Conclusions: Crude extracts ofP. dulceexhibit the potential for controlling malaria vector mosquitoAn. stephensi.

  9. Introducing Vectors.

    Roche, John

    1997-01-01

    Suggests an approach to teaching vectors that promotes active learning through challenging questions addressed to the class, as opposed to subtle explanations. Promotes introducing vector graphics with concrete examples, beginning with an explanation of the displacement vector. Also discusses artificial vectors, vector algebra, and unit vectors.…

  10. Bound states of Klein-Gordon equation and Dirac equation for ring-shaped non-spherical oscillator scalar and vector potentials

    张学骜; 陈柯; 段正路

    2005-01-01

    Solving the Klein-Gordon equation and Dirac equation with ring-shaped non-spherical oscillator gives the exact bound state wavefunction and energy equation, and the relations between non-relativistic Schrodinger equation, KleinGordon equation and Dirac equation with equal scalar and vector potentials.

  11. Approximate solution of the spin-one Duffin-Kemmer-Petiau (DKP) equation under a non-minimal vector Yukawa potential in (1+1)-dimensions

    H.Hassanabadi; Z.Molaee

    2012-01-01

    We solve the Duffin Kemmer-Petiau (DKP) equation with a non-minimal vector Yukawa potential in (1+1)-dimensional space-time for spin-1 particles.The Nikiforov-Uvarov method is used in the calculations,and the eigen-functions as well as the energy eigenvalues are obtained in a proper Pekeris-type approximation.

  12. Climate Change Influences on the Global Potential Distribution of the Mosquito Culex quinquefasciatus, Vector of West Nile Virus and Lymphatic Filariasis.

    Samy, Abdallah M; Elaagip, Arwa H; Kenawy, Mohamed A; Ayres, Constância F J; Peterson, A Townsend; Soliman, Doaa E

    2016-01-01

    Rapid emergence of most vector-borne diseases (VBDs) may be associated with range expansion of vector populations. Culex quinquefasciatus Say 1823 is a potential vector of West Nile virus, Saint Louis encephalitis virus, and lymphatic filariasis. We estimated the potential distribution of Cx. quinquefasciatus under both current and future climate conditions. The present potential distribution of Cx. quinquefasciatus showed high suitability across low-latitude parts of the world, reflecting the current distribution of the species. Suitable conditions were identified also in narrow zones of North Africa and Western Europe. Model transfers to future conditions showed a potential distribution similar to that under present-day conditions, although with higher suitability in southern Australia. Highest stability with changing climate was between 30°S and 30°N. The areas present high agreement among diverse climate models as regards distributional potential in the future, but differed in anticipating potential for distribution in North and Central Africa, southern Asia, central USA, and southeastern Europe. Highest disparity in model predictions across representative concentration pathways (RCPs) was in Saudi Arabia and Europe. The model predictions allow anticipation of changing distributional potential of the species in coming decades.

  13. Climate Change Influences on the Global Potential Distribution of the Mosquito Culex quinquefasciatus, Vector of West Nile Virus and Lymphatic Filariasis

    Elaagip, Arwa H.; Kenawy, Mohamed A.; Ayres, Constância F. J.; Peterson, A. Townsend; Soliman, Doaa E.

    2016-01-01

    Rapid emergence of most vector-borne diseases (VBDs) may be associated with range expansion of vector populations. Culex quinquefasciatus Say 1823 is a potential vector of West Nile virus, Saint Louis encephalitis virus, and lymphatic filariasis. We estimated the potential distribution of Cx. quinquefasciatus under both current and future climate conditions. The present potential distribution of Cx. quinquefasciatus showed high suitability across low-latitude parts of the world, reflecting the current distribution of the species. Suitable conditions were identified also in narrow zones of North Africa and Western Europe. Model transfers to future conditions showed a potential distribution similar to that under present-day conditions, although with higher suitability in southern Australia. Highest stability with changing climate was between 30°S and 30°N. The areas present high agreement among diverse climate models as regards distributional potential in the future, but differed in anticipating potential for distribution in North and Central Africa, southern Asia, central USA, and southeastern Europe. Highest disparity in model predictions across representative concentration pathways (RCPs) was in Saudi Arabia and Europe. The model predictions allow anticipation of changing distributional potential of the species in coming decades. PMID:27695107

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

    Warikoo, Radhika; Wahab, Naim; Kumar, Sarita

    2011-10-01

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

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

    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.

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

    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.

  17. Muscoid Diptera as potential vectors of bacterial agents on dairy farms in the northern region of Paraná, Brazil

    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.

  18. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

    Clement N. Mweya

    2015-01-01

    Full Text Available Background: Rift Valley fever (RVF is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results: A total of 1,823 mosquitoes were collected, of which 87% (N=1,588 were Culex pipiens complex, 12% (N=226 Aedes aegypti, and 0.5% (N=9 Anopheles species. About two-thirds (67%; N=1,095 of C. pipiens complex and nearly 100% (N=225 of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78% of C. pipiens complex and most (85% of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions: These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

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

    Zohdy Sarah

    2012-03-01

    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.

  20. Culicoides Species Communities Associated with Wild Ruminant Ecosystems in Spain: Tracking the Way to Determine Potential Bridge Vectors for Arboviruses.

    Sandra Talavera

    Full Text Available 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

  1. Culicoides Species Communities Associated with Wild Ruminant Ecosystems in Spain: Tracking the Way to Determine Potential Bridge Vectors for Arboviruses.

    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

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

    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

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

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

    2014-01-01

    Viral vector-mediated gene transfer of neurotrophic factors is an emerging and promising strategy to promote the regeneration of injured peripheral nerves. Unfortunately, the chronic exposure to neurotrophic factors results in local trapping of regenerating axons or other unwanted side effects. Ther

  4. Observability of the effects of curl-free magnetic vector potential on the macroscale and the nature of the ‘transition amplitude wave’

    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.

  5. Survey of potential sharpshooter and spittlebug vectors of Xylella fastidiosa to grapevines at the São Francisco River Valley, Brazil

    Rudiney Ringenberg

    2014-06-01

    Full Text Available Survey of potential sharpshooter and spittlebug vectors of Xylella fastidiosa to grapevines at the São Francisco River Valley, Brazil. Pierce's disease of grapevines, caused by Xylella fastidiosa, is a serious problem in some regions of North America, not yet reported in Brazil. In this study, a survey of potential sharpshooter (Hemiptera, Cicadellidae, Cicadellinae and spittlebug (Hemiptera, Cercopidae vectors of X. fastidiosa was conducted in vineyards at the São Francisco River Valley, a major grape growing region in Brazil. Four vineyards of Vitis vinifera L. were sampled fortnightly from June/2005 to June/2007, using yellow sticky cards, each placed at two different heights (45 cm aboveground and 45 cm above the crop canopy in 10 sampling localities. A total of 4,095 specimens of sharpshooters were collected, nearly all from 3 Proconiini species, Homalodisca spottii Takiya, Cavichioli & McKamey, 2006 (96.8% of the specimens, Tapajosa fulvopunctata (Signoret, 1854 (3.1%, and Tretogonia cribrata Melichar, 1926 (1 specimen. Hortensia similis (Walker, 1851 (2 specimens was the only Cicadellini species. Only 1 cercopid specimen, belonging to Aeneolamia colon (Germar, 1821, was trapped. Even though they are not considered potential Xylella vectors, 2 Gyponini leafhoppers were collected: Curtara samera DeLong & Freytag, 1972 (11 specimens and Curtara inflata DeLong & Freytag, 1976 (1 specimen. Homalodisca spottii was observed feeding and mating on green branches of grapevines, in addition to egg masses. Because of its prevalence on the crop canopy, occurrence throughout the year (with peaks from February to August, and ability to colonize grapevines, H. spottii could be an important vector if a X. fastidiosa strain pathogenic to grapevines becomes introduced at the São Francisco River Valley.

  6. Cytosine deaminase adenoviral vector and 5-fluorocytosine selectively reduce breast cancer cells 1 million-fold when they contaminate hematopoietic cells: a potential purging method for autologous transplantation.

    Garcia-Sanchez, F; Pizzorno, G; Fu, S Q; Nanakorn, T; Krause, D S; Liang, J; Adams, E; Leffert, J J; Yin, L H; Cooperberg, M R; Hanania, E; Wang, W L; Won, J H; Peng, X Y; Cote, R; Brown, R; Burtness, B; Giles, R; Crystal, R; Deisseroth, A B

    1998-07-15

    48 hours. All of the BCC lines tested were shown to be sensitive to infection by adenoviral vectors when exposed to a recombinant adenoviral vector containing the reporter gene betagalactosidase (Ad.CMV-betagal). In contrast, less than 1% of the CD34-selected cells and their more immature subsets, such as the CD34+CD38- or CD34(+)CD33- subpopulations, were positive for infection by the Ad.CMV-betagal vector, as judged by fluorescence-activated cell sorting (FACS) analysis, when exposed to the adenoviral vector under conditions that did not commit the early hematopoietic precursor cells to maturation. When artificial mixtures of hematopoietic cells and BCCs were exposed for 90 minutes to the Ad.CMV-CD vector and to 5-FC for 10 days or more, a greater than 1 million fold reduction in the number of BCCs, as measured by colony-limiting dilution assays, was observed. To test if the conditions were damaging for the hematopoietic reconstituting cells, marrow cells collected from 5-FU-treated male donor mice were incubated with the cytosine deaminase adenoviral vector and then exposed to 5-FC either for 4 days in vitro before transplantation or for 14 days immediately after transplantation in vivo. There was no significant decrease in the reconstituting capability of the male marrow cells, as measured by their persistence in female irradiated recipients for up to 6 months after transplantation. These observations suggest that adenovirus-mediated gene transfer of the Escherichia coli cytosine deaminase gene followed by exposure to the nontoxic pro-drug 5-FC may be a potential strategy to selectively reduce the level of contaminating BCCs in collections of hematopoietic cells used for autografts in breast cancer patients.

  7. Solution of Effective-Mass Dirac Equation with Scalar-Vector and Pseudoscalar Terms for Generalized Hulthén Potential

    Altuğ Arda

    2017-01-01

    Full Text Available We find the exact bound state solutions and normalization constant for the Dirac equation with scalar-vector-pseudoscalar interaction terms for the generalized Hulthén potential in the case where we have a particular mass function m(x. We also search the solutions for the constant mass where the obtained results correspond to the ones when the Dirac equation has spin and pseudospin symmetry, respectively. After giving the obtained results for the nonrelativistic case, we search then the energy spectra and corresponding upper and lower components of Dirac spinor for the case of PT-symmetric forms of the present potential.

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

    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.

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

    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.

  10. Vector Potential of Blattella germanica (L.) (Dictyoptera: Blattidae) for Medically Important Bacteria at Food Handling Establishments in Jimma Town, Southwest Ethiopia

    Belayneh, Fanuel; Kibru, Gebre

    2016-01-01

    Cockroaches have been regarded as possible vectors of human enteropathogens. Their presence and crawl particularly in food handling establishments could be risky for human health. Therefore, this study was done to determine the vector potential of cockroach for medically important bacterial pathogens in restaurants and cafeterias. A cross-sectional study was conducted on cockroaches from restaurants and cafeterias in Jimma town from May to September 2014. Standard taxonomic keys and microbiological techniques were applied for species identification and isolation. Data was analyzed in SPSS version 16.0. All cockroaches trapped were the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattidae). Escherichia coli was the most frequently isolated followed by Salmonella species (serogroups B, D, E, C1, and NG), Bacillus cereus, and Shigella flexneri. Wide varieties of bacteria of medical relevance were also identified. Of which, Klebsiella spp. 49(40.8%), Bacillus spp., and Staphylococcus saprophyticus were predominant. Blattella germanica (L.) (Dictyoptera: Blattidae) could serve as a potential vector for the dissemination of foodborne pathogens such as Salmonella spp., Shigella flexneri, E. coli, S. aureus, and B. cereus and these bacteria could be a major threat to public health. Therefore, environmental sanitation and standard hygiene need to be applied in the food handling establishments in that locality. PMID:27294115

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

    Harris, Alesha N.; Hinojosa, Barbara R.; Chavious, Montaleé D.; Petros, Robby A.

    2011-07-01

    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.

  12. Vector Potential of Blattella germanica (L. (Dictyoptera: Blattidae for Medically Important Bacteria at Food Handling Establishments in Jimma Town, Southwest Ethiopia

    Fithamlak Solomon

    2016-01-01

    Full Text Available Cockroaches have been regarded as possible vectors of human enteropathogens. Their presence and crawl particularly in food handling establishments could be risky for human health. Therefore, this study was done to determine the vector potential of cockroach for medically important bacterial pathogens in restaurants and cafeterias. A cross-sectional study was conducted on cockroaches from restaurants and cafeterias in Jimma town from May to September 2014. Standard taxonomic keys and microbiological techniques were applied for species identification and isolation. Data was analyzed in SPSS version 16.0. All cockroaches trapped were the German cockroach, Blattella germanica (L. (Dictyoptera: Blattidae. Escherichia coli was the most frequently isolated followed by Salmonella species (serogroups B, D, E, C1, and NG, Bacillus cereus, and Shigella flexneri. Wide varieties of bacteria of medical relevance were also identified. Of which, Klebsiella spp. 49(40.8%, Bacillus spp., and Staphylococcus saprophyticus were predominant. Blattella germanica (L. (Dictyoptera: Blattidae could serve as a potential vector for the dissemination of foodborne pathogens such as Salmonella spp., Shigella flexneri, E. coli, S. aureus, and B. cereus and these bacteria could be a major threat to public health. Therefore, environmental sanitation and standard hygiene need to be applied in the food handling establishments in that locality.

  13. Application of MVVM design pattern and MVP design pattern based on ZK%基于ZK的MVVM与MVP设计模式应用研究

    林亚明

    2012-01-01

    The ZK-based RIA architecture was briefly described.The technical features and applications about MVVM design pattern and MVP design pattern used in ZK were discussed.The best practices about the complex business systems interface development were proposed with the advantages of the integrated two design patterns,which is given to demonstrate by examples.The examples show that the best practices in maximizing the use of the MVVM design pattern are able to cope with the complexity of the interface development needs,thereby improving the maintainability of the system.%简要介绍基于ZK框架的RIA系统架构,讨论MVVM设计模式和MVP设计模式在ZK框架中实现的技术特点和应用场合,综合两种设计模式的优点提出了复杂业务系统界面开发的最佳实践,并通过实例给予论证.实例表明,该最佳实践能够应付复杂的界面开发需求,同时保持代码的结构简洁,从而提高系统的维护性.

  14. Trafficking of the myrosinase-associated protein GLL23 requires NUC/MVP1/GOLD36/ERMO3 and the p24 protein CYB.

    Jancowski, Sylwia; Catching, Amanda; Pighin, Jamie; Kudo, Takamasa; Foissner, Ilse; Wasteneys, Geoffrey O

    2014-02-01

    Proteins detrimental to endoplasmic reticulum (ER) morphology need to be efficiently exported. Here, we identify two mechanisms that control trafficking of Arabidopsis thalianaGLL23, a 43 kDa GDSL-like lipase implicated in glucosinolate metabolism through its association with the β-glucosidase myrosinase. Using immunofluorescence, we identified two mutants that showed aberrant accumulation of GLL23: large perinuclear ER aggregates in the nuclear cage (nuc) mutant; and small compartments contiguous with the peripheral ER in the cytoplasmic bodies (cyb) mutant. Live imaging of fluorescently tagged GLL23 confirmed its presence in the nuc and cyb compartments, but lack of fluorescent signals in the wild-type plants suggested that GLL23 is normally post-translationally modified for ER export. NUC encodes the MVP1/GOLD36/ERMO3 myrosinase-associated protein, previously shown to have vacuolar distribution. CYB is an ER and Golgi-localized p24 type I membrane protein component of coat protein complex (COP) vesicles, animal and yeast homologues of which are known to be involved in selective cargo sorting for ER-Golgi export. Without NUC, GLL23 accumulates in the ER this situation suggests that NUC is in fact active in the ER. Without CYB, both GLL23 and NUC were found to accumulate in cyb compartments, consistent with a role for NUC in GLL23 processing and indicated that GLL23 is the likely sorting target of the CYB p24 protein.

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

    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.

  16. About vectors

    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

  17. Vector analysis

    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

  18. Thermodynamic view on decision-making process: emotions as a potential power vector of realization of the choice.

    Pakhomov, Anton; Sudin, Natalya

    2013-12-01

    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 from principles of the nonlinear dynamics considering instability of movement and bifurcation is offered. The thermodynamic component of decision-making process on the basis of vector transfer of energy induced by emotion at the given time is surveyed. It is proposed a three-modular model of decision making based on principles of thermodynamics. Here it is suggested that at entropy impact due to effect of emotion, on the closed system-the human brain,-initially arises chaos, then after fluctuations of possible alternatives which were going on-reactions of brain zones in reply to external influence, an order is forming and there is choice of alternatives, according to primary entrance conditions and a state of the closed system. Entropy calculation of a choice expectation of negative and positive emotion shows judgment possibility of existence of "the law of emotion conservation" in accordance with several experimental data.

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

    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.

  20. Prevalence of neutralizing antibodies against liver-tropic adeno-associated virus serotype vectors in 100 healthy Chinese and its potential relation to body constitutions

    Chen Ling; Irene Zolotukhin; Arun Srivastava; Chang-quan Ling; Yuan Wang; Ying-lu Feng; Ya-ni Zhang; Jun Li; Xin-rui Hu; Li-na Wang; Mao-feng Zhong; Xiao-feng Zhai

    2015-01-01

    Recombinant adeno-associated virus (rAAV) serotype 2, 3 and 8 vectors are the most promising liver-tropic AAV serotype vectors. Liver diseases are signiifcant problems in China. However, to date, few studies on AAV neutralizing antibodies (Nabs) were working with the Chinese population or with the rAAV3 vectors. The present study aimed to determine the prevalence of Nabs in Chinese population against wild-type AAV2, AAV3 and AAV8 capsids as wel as additional two AAV3 variants. In addition, we performed a preliminary analysis to investigate the potential inlfuence of traditional Chinese medicine body constitutions on AAV Nabs. Our work demonstrated that the majority of healthy Chinese subjects were positive for AAV Nabs, with the order of AAV2 > AAV3 = AAVLK03 > AAV8. There was no difference between: 1) AAV3 and its variants; 2) male and female subjects; and 3) different age cohorts (≤ 35, 36–50, and ≥ 51 years old). People in the Qi-deifciency constitution had signiifcantly increased AAV8 Nabs than people in the Gentleness constitution. Our studies may have impact on the future clinical design of AAV-based gene therapy in the Chinese population.

  1. Using remote sensing to map larval and adult populations of Anopheles hyrcanus (Diptera: Culicidae a potential malaria vector in Southern France

    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

  2. Vector and Spinor Decomposition of SU(2) Gauge Potential, Their Equivalence, and Knot Structure in SU(2) Chern-Simons Theory

    DUAN Yi-Shi; REN Ji-Rong; LI Ran

    2007-01-01

    In this paper, spinor and vector decompositions of SU(2) gauge potential are presented and their equivalence is constructed using a simply proposal. We also obtain the action of Faddeev nonlinear O(3) sigma model from the SU(2)massive gauge field theory, which is proposed according to the gauge invariant principle. At last, the knot structure in SU(2) Chern-Simons filed theory is discussed in terms of the φ-mapping topological current theory. The topological charge of the knot is characterized by the Hopf indices and the Brouwer degrees of φ-mapping.

  3. Two new cytoforms of the Simulium damnosum complex (Diptera: Simuliidae) from Malawi and Tanzania and potential onchocerciasis vectors.

    Krüger, A; Kalinga, A K; Post, R J; Maegga, B T A

    2004-07-01

    During a distribution survey of Simulium damnosum s.l. around the Tukuyu onchocerciasis focus at the northern tip of Lake Malawi/Nyasa (Tanzania), we discovered two new cytoforms of the S. damnosum complex in onchocerciasis-free areas. The Nyika form is related to Simulium thyolense, a vector of onchocerciasis, and can be identified by the new inversion 3L-L on the long arm of chromosome 3. It was found breeding in five rivers in northern Malawi and neighbouring Tanzania and is assumed to be zoophilic. The Njombe form represents a member of the Sanje group of the complex and is characterized by the new diagnostic inversion 2L-35 on chromosome 2. So far, it is only known from around Njombe town in southern Tanzania, where it breeds at remarkably high altitudes. Anthropophily for the Njombe form is well known. The medical importance and systematic position of the new forms within the S. damnosum complex are discussed.

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

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

    2007-06-01

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

  5. Identification of potential insect vectors of the Cape Saint Paul Wilt Disease of coconut in Ghana by PCR

    Pilet Fabian

    2009-03-01

    Full Text Available The vector of the phytoplasma responsible for the coconut lethal yellowing disease in West Africa is unknown to date. However, it is known that phytoplasmas are transmitted by leafhoppers and planthoppers, which are supposed to be the only ones able to inject the phytoplasma in the phloem. Whereas the presence of phytoplasma in the insect does not prove its capacity to transmit the disease. We have tested a large number of insects for the presence of phytoplamas by PCR (direct PCR and Nested PCR using both primer pairs specific for all phytoplasmas and those specific for the coconut lethal yellowing disease phytoplasma. In effect the evidence of one or several species carrying the phytoplasma would direct us on the insects to focus on in our transmission cages trials.

  6. Cloning vectors based on cryptic plasmids isolated from lactic acid bacteria: their characteristics and potential applications in biotechnology.

    Shareck, Julie; Choi, Young; Lee, Byong; Miguez, Carlos B

    2004-01-01

    Lactic acid bacteria (LAB) are Gram positive bacteria, widely distributed in nature, and industrially important as they are used in a variety of industrial food fermentations. The use of genetic engineering techniques is an effective means of enhancing the industrial applicability of LAB. However, when using genetic engineering technology, safety becomes an essential factor for the application of improved LAB to the food industry. Cloning and expression systems should be derived preferably from LAB cryptic plasmids that generally encode genes for which functions can be proposed, but no phenotypes can be observed. However, some plasmid-encoded functions have been discovered in cryptic plasmids originating from Lactobacillus, Streptococcus thermophilus, and Pediococcus spp. and can be used as selective marker systems in vector construction. This article presents information concerning LAB cryptic plasmids, and their structures, functions, and applications. A total of 134 cryptic plasmids collated are discussed.

  7. Diversity and ecology survey of mosquitoes potential vectors in Belgian equestrian farms: A threat prevention of mosquito-borne equine arboviruses.

    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.

  8. Elementary vectors

    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

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

    Smith, G C; Francy, D B

    1991-03-01

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

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

    Martínez-de la Puente Josué

    2012-07-01

    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.

  11. Decay Constants of Vector Mesons

    LI Heng-Mei; WAN Shao-Long

    2008-01-01

    @@ The light vector mesons are studied within the framework of the Bethe-Salpeter equation with the vector-vectortype flat-bottom potential The Bethe-Salpeter wavefunctions and the decay constants of the vector mesons are obtained. All the obtained results, fρ, fφ, and fΚ* , are in agreement with the experimental values, respectively.

  12. Mapping of zones potentially occupied by Aedes vexans and Culex poicilipes mosquitoes, the main vectors of Rift Valley fever in Senegal

    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.

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

    Mohamad, N; Zuharah, W F

    2014-03-01

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

  14. Novel genotypes of Trypanosoma binneyi from wild platypuses (Ornithorhynchus anatinus) and identification of a leech as a potential vector.

    Paparini, Andrea; Macgregor, James; Irwin, Peter J; Warren, Kristin; Ryan, Una M

    2014-10-01

    Little is known about the prevalence and pathogenesis of trypanosomes in Australian monotremes, and few genetic characterisation studies have been conducted with these haemoparasites. During the present investigation, molecular and microscopic methods were used to screen peripheral blood (n=28) and ectoparasites (n=10 adult ticks; n=5 tick nymphs; n=1 leech; and n>500 tick eggs) collected from wild Tasmanian platypuses (Ornithorhynchus anatinus), for the presence of trypanosomatid-specific DNA and/or trypomastigotes. The genes for the small ribosomal subunit RNA (18S rDNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) were amplified and sequenced, prior to conducting phylogenetic analyses. The detection rate of the parasite-specific 18S rDNA in platypus blood was 85.7% (n=24/28), and the leech was also positive at both loci. Microscopically, high parasitaemia and the presence of abundant trypomastigotes, morphologically consistent with Trypanosoma binneyi Mackerras (1959), were observed in the blood films. Phylogenetic analyses at the 18S locus revealed the existence of four trypanosomatid-like genotypes, with variable similarity to two previously-described genotypes of T. binneyi (range of genetic p-distance: 0.0-0.5%). For the gGAPDH locus, for which only one T. binneyi sequence is available in GenBank, three genotypes closely related T. binneyi were identified (range of genetic p-distance: 0.1-0.4%). The leech-derived trypanosome isolate was virtually identical (at the two loci studied) to the other parasites sequenced from infected platypuses; however, the molecular or morphological identification of the leech species was not possible. Although further studies are required, the molecular detection of trypanosomes in an aquatic leech removed from a platypus, suggests the possibility that these haematophagous hirudineans may be a vector for T. binneyi (and closely related genotypes).

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

    Silvia MM Ahid

    1999-12-01

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

  16. Predicting the potential distribution of main malaria vectors Anopheles stephensi, An. culicifacies s.l. and An. fluviatilis s.l. in Iran based on maximum entropy model.

    Pakdad, Kamran; Hanafi-Bojd, Ahmad Ali; Vatandoost, Hassan; Sedaghat, Mohammad Mehdi; Raeisi, Ahmad; Moghaddam, Abdolreza Salahi; Foroushani, Abbas Rahimi

    2017-05-01

    Malaria is considered as a major public health problem in southern areas of Iran. The goal of this study was to predict best ecological niches of three main malaria vectors of Iran: Anopheles stephensi, Anopheles culicifacies s.l. and Anopheles fluviatilis s.l. A databank was created which included all published data about Anopheles species of Iran from 1961 to 2015. The suitable environmental niches for the three above mentioned Anopheles species were predicted using maximum entropy model (MaxEnt). AUC (area under Roc curve) values were 0.943, 0.974 and 0.956 for An. stephensi, An. culicifacies s.l. and An. fluviatilis s.l respectively, which are considered as high potential power of model in the prediction of species niches. The biggest bioclimatic contributor for An. stephensi and An. fluviatilis s.l. was bio 15 (precipitation seasonality), 25.5% and 36.1% respectively, followed by bio 1 (annual mean temperature), 20.8% for An. stephensi and bio 4 (temperature seasonality) with 49.4% contribution for An. culicifacies s.l. This is the first step in the mapping of the country's malaria vectors. Hence, future weather situation can change the dispersal maps of Anopheles. Iran is under elimination phase of malaria, so that such spatio-temporal studies are essential and could provide guideline for decision makers for IVM strategies in problematic areas.

  17. Larvicidal Potential of the Halogenated Sesquiterpene (+)-Obtusol, Isolated from the Alga Laurencia dendroidea J. Agardh (Ceramiales: Rhodomelaceae), against the Dengue Vector Mosquito Aedes aegypti (Linnaeus) (Diptera: Culicidae).

    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

    2016-02-01

    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.

  18. Larvicidal Potential of the Halogenated Sesquiterpene (+-Obtusol, Isolated from the Alga Laurencia dendroidea J. Agardh (Ceramiales: Rhodomelaceae, against the Dengue Vector Mosquito Aedes aegypti (Linnaeus (Diptera: Culicidae

    Orlando Salvador-Neto

    2016-01-01

    Full Text Available 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.

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

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

    2013-11-15

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

  20. Larvicidal Potential of the Halogenated Sesquiterpene (+)-Obtusol, Isolated from the Alga Laurencia dendroidea J. Agardh (Ceramiales: Rhodomelaceae), against the Dengue Vector Mosquito Aedes aegypti (Linnaeus) (Diptera: Culicidae)

    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

  1. The Repellent DEET Potentiates Carbamate Effects via Insect Muscarinic Receptor Interactions: An Alternative Strategy to Control Insect Vector-Borne Diseases.

    Aly Abd-Ella

    Full Text Available 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 insect vector-borne diseases. By using electrophysiological, biochemichal, in vivo toxicological techniques together with calcium imaging, binding studies and in silico docking, we have shown that DEET, at low concentrations, interacts with high affinity with insect M1/M3 mAChR allosteric site potentiating agonist effects on mAChRs coupled to phospholipase C second messenger pathway. This increases the anticholinesterase activity of the carbamate propoxur through calcium-dependent regulation of acetylcholinesterase. At high concentrations, DEET interacts with low affinity on distinct M1/M3 mAChR site, counteracting the potentiation. Similar dose-dependent dual effects of DEET have also been observed at synaptic mAChR level. Additionally, binding and in silico docking studies performed on human M1 and M3 mAChR subtypes indicate that DEET only displays a low affinity antagonist profile on these M1/M3 mAChRs. These results reveal a selective high affinity positive allosteric site for DEET in insect mAChRs. Finally, bioassays conducted on Aedes aegypti confirm the synergistic interaction between DEET and propoxur observed in vitro, resulting in a higher mortality of mosquitoes. Our findings reveal an unusual allosterically potentiating action of the repellent DEET, which involves a selective site in insect. These results open exciting research areas in public health particularly in the control of the pyrethroid-resistant insect-vector borne diseases. Mixing low

  2. The Repellent DEET Potentiates Carbamate Effects via Insect Muscarinic Receptor Interactions: An Alternative Strategy to Control Insect Vector-Borne Diseases.

    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 insect vector-borne diseases. By using electrophysiological, biochemichal, in vivo toxicological techniques together with calcium imaging, binding studies and in silico docking, we have shown that DEET, at low concentrations, interacts with high affinity with insect M1/M3 mAChR allosteric site potentiating agonist effects on mAChRs coupled to phospholipase C second messenger pathway. This increases the anticholinesterase activity of the carbamate propoxur through calcium-dependent regulation of acetylcholinesterase. At high concentrations, DEET interacts with low affinity on distinct M1/M3 mAChR site, counteracting the potentiation. Similar dose-dependent dual effects of DEET have also been observed at synaptic mAChR level. Additionally, binding and in silico docking studies performed on human M1 and M3 mAChR subtypes indicate that DEET only displays a low affinity antagonist profile on these M1/M3 mAChRs. These results reveal a selective high affinity positive allosteric site for DEET in insect mAChRs. Finally, bioassays conducted on Aedes aegypti confirm the synergistic interaction between DEET and propoxur observed in vitro, resulting in a higher mortality of mosquitoes. Our findings reveal an unusual allosterically potentiating action of the repellent DEET, which involves a selective site in insect. These results open exciting research areas in public health particularly in the control of the pyrethroid-resistant insect-vector borne diseases. Mixing low doses of DEET and a

  3. BOUND STATES OF KLEIN-GORDON EQUATION FOR HARTMANN SCALAR AND VECTOR POTENTIALS%Hartmann势Klein-Gordon方程的束缚态

    陆法林

    2005-01-01

    By using the usual method of variable separation, bound states of Klein-Gordon equation with equal Hartmann scalar and vector potentials are solved. Properties of the system relate to three quantum numbers and parameters of Hartmann potential. The normalized angle wave function expressed in terms of the universal associated-Legendre polynomial and the normalized radial wave function expressed in terms of the confluent hypergeometric function are presented. The exacl energy spectrum equations are obtained. Bound states of Klein-Gordon equation for Hydrogen potential are special cases for the Hartmann potential in the Letter.%用分离变量方法讨论了在Hartmann标量势和矢量势相等条件下Klein-Gordon方程的束缚态解.体系的性质与三个量子数及Hartmann势的势参数有关.给出了用广义连带勒让得多项式表示的归一化角向波函数和用合流超几何函数表示的归一化径向波函数,获得了精确的束缚态能谱方程.氢原子势是本文Hartmann势的特例.

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

    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.

  5. Exploration of larvicidal and adult emergence inhibition activities of Ricinus communis seed extract against three potential mosquito vectors in Kolkata, India

    Shyamapada Mandal

    2010-01-01

    Objective:To determine the larvicidal and adult emergence inhibition activities of castor (Ricinus communis) seed extract against three potential mosquito vectorsAnopheles stephensi (An. stephensi), Culex quinquefasciatus (Cx. quinquefasciatus) andAedes albopictus (Ae. albopictus) in India.Methods: TheR. communis seed extract was tested, employingWHO procedure, against fourth larval instars of the three mosquito species for 24 h and larval mortalities were recorded at various concentrations (2-64 μg/mL); the 24 hLC50 values of theR. communis seed extract were determined following Probit analysis. The larval killing, antipupation and adult emergence inhibition rates of the test extract, using a single concentration of2μLC50, were studied at different time periods (24-72 h); the extract toxicity was tested against a fish,Oreochromis niloticus (O. niloticus).Results: TheR. communis seed extract exhibited larvicidal effects with 100 % killing activities at concentrations32-64 μg/mL, and withLC50values 7.10, 11.64 and 16.84μg/mL forCx. quinquefasciatus, An. stephensiand Ae. albopictuslarvae, respectively. When the larvae were treated with the extract at a single concentration of2×LC50, significant differences were observed, compared to control groups, in rate of pupation (P<0.001) as well as in adult formation (P<0.001).Conclusions: The present findings suggest that theR. communis seed extract provided an excellent potential for controllingAn. stephensi, Cx. quinquefasciatus andAe. albopictus mosquito vectors.

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

    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.

  7. Cloning vector

    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.

  8. Cross-linked Polyethylenimine as Potential DNA Vector for Gene Delivery with High Efficiency and Low Cytotoxicity

    Wei DONG; Guang-Hui JIN; Shu-Feng LI; Qi-Ming SUN; Ding-Yuan MA; Zi-Chun HUA

    2006-01-01

    Polyethylenimine (PEI) has been known as an efficient gene carrier with the highest cationic charge potential. High transfection efficiency of PEI, along with its cytotoxicity, strongly depends on its molecular weight. To enhance its gene delivery efficiency and minimize cytotoxicity, we have synthesized small cross-linked PEI with biodegradable linkages and evaluated their transfection efficiencies in vitro. In this study, branched PEI with a molecular weight of 800 Da was cross-linked by small diacrylate [ 1,4-butanediol diacrylate or ethyleneglycol dimethacrylate (EGDMA)] for 2-6 h. The efficiencies of the cross-linked PEI in in vitro transfection of plasmid DNA containing enhanced green fluorescent protein (EGFP) reporter gene were assessed in melanoma B 16F10 cell line and other cell lines. Flow cytometry was used to quantify the cellular entry efficiency of plasmid and the transgene expression level. The cytotoxicities of the cross-linked PEI in these cells were evaluated by MTT assay. EGDMA-PEI 800-4h, a typical cross-linked PEI reported here, mediated a more efficient expression of reporter gene than the commercially available 25-kDa branched PEI control, and resulted in a 9-fold increase in gene delivery in B16F10 cells and a 16-fold increase in 293T cells, while no cytotoxicity was found at the optimized condition for gene delivery. Furthermore, the transfection activity of polyplexes was preserved in the presence of serum proteins.

  9. Ecology of potential West Nile virus vectors in southeastern Louisiana: enzootic transmission in the relative absence of Culex quinquefasciatus

    Godsey, Marvin S.; 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.

  10. Annona muricata leaf extract-mediated silver nanoparticles synthesis and its larvicidal potential against dengue, malaria and filariasis vector.

    Santhosh, S B; Yuvarajan, R; Natarajan, D

    2015-08-01

    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.

  11. A design of novel type superconducting magnet for super-high field functional magnetic resonance imaging by using the harmonic analysis method of magnetic vector potentials

    俎栋林; 郭华; 宋枭禹; 包尚联

    2002-01-01

    The approach of expanding the magnetic scalar potential in a series of Legendre polynomials is suitable for designing a conventional superconducting magnetic resonance imaging magnet of distributed solenoidal configuration. Whereas the approach of expanding the magnetic vector potential in associated Legendre harmonics is suitable for designing a single-solenoid magnet that has multiple tiers, in which each tier may have multiple layers with different winding lengths. A set of three equations to suppress some of the lowest higher-order harmonics is found. As an example, a 4T single-solenoid magnetic resonance imaging magnet with 4 × 6 layers of superconducting wires is de signed The degree of homogeneity in the 0.5m diameter sphere volume is better than 5.8 ppm. The same degree of homogeneity is retained after optimal integralization of turns in each correction layer. The ratio Bm/Bo in the single-solenoid magnet is 30%lower than that in the conventional six-solenoid magnet. This tolerates higher rated superconducting current in the coil. The Lorentz force of the coil in the single-solenoid system is also much lower than in the six-solenoid system. This novel type of magnet possesses significant advantage over conventional magnets, especially when used as a super-high field functional magnetic resonance imaging magnet.

  12. Abnormal regional homogeneity as potential imaging biomarker for psychosis risk syndrome: a resting-state fMRI study and support vector machine analysis.

    Wang, Shuai; Wang, Guodong; Lv, Hailong; Wu, Renrong; Zhao, Jingping; Guo, Wenbin

    2016-06-08

    Subjects with psychosis risk syndrome (PRS) have structural and functional abnormalities in several brain regions. However, regional functional synchronization of PRS has not been clarified. We recruited 34 PRS subjects and 37 healthy controls. Regional homogeneity (ReHo) of resting-state functional magnetic resonance scans was employed to analyze regional functional synchronization in these participants. Receiver operating characteristic curves and support vector machines were used to detect whether abnormal regional functional synchronization could be utilized to separate PRS subjects from healthy controls. We observed that PRS subjects showed significant ReHo decreases in the left inferior temporal gyrus and increases in the right inferior frontal gyrus and right putamen compared with the controls. No correlations between abnormal regional functional synchronization in these brain regions and clinical characteristics existed. A combination of the ReHo values in the three brain regions showed sensitivity, specificity, and accuracy of 88.24%, 91.89%, and 90.14%, respectively, for discriminating PRS subjects from healthy controls. We inferred that abnormal regional functional synchronization exists in the cerebrum of PRS subjects, and a combination of ReHo values in these abnormal regions could be applied as potential image biomarker to identify PRS subjects from healthy controls.

  13. Vector geometry

    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

  14. Vector velocimeter

    2012-01-01

    for 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...

  15. Larvicidal, Repellent and Irritant Potential of the Seed-derived Essential oil of Apium graveolens against Dengue Vector, Aedes aegypti L. (Diptera: Culicidae

    Sarita eKumar

    2014-09-01

    Full Text Available Aedes aegypti L., the primary carrier for viruses causing dengue, chikungunya and yellow fever is widespread over large areas of the tropics and subtropics. Keeping in view the adverse effects of chemical insecticides-based intervention measures; the eco-friendly, bio-degradable essential oil extracted from the seeds of celery, Apium graveolens; was investigated for anti-mosquito potential against Ae. aegypti. Evaluation of larvicidal potential of celery seed oil against early fourth instars of Ae. aegypti resulted in LC50 and LC90 values of 16.10 ppm and 29.08 ppm, respectively, after an exposure to 24 h; the toxic effect of the oil increasing by 1.2 fold with an LC50 value of 13.22 ppm after an exposure to 48h. Interestingly, the seed oil did not cause rapid mortality, suggesting a delayed type of larval killing effect. The remarkable finding of the present study was effective repellency of the essential oil leading to 100% protection till 165 min as compared to control that did not show any repellency against mosquitoes. Only 1 bite was recorded in the 165th minute after which only 2 bites were scored until 180 min of exposure of the oil to the adult mosquitoes. An exciting observation was the knocked-down of mosquitoes caused by the exposure to 10% oil-impregnated papers. The exposure to 1% oil resulted in first flight only after 4 sec and a total of 63.66 average flights during 15 min exposure revealing the relative irritability of 26.97.The qualitative phytochemical study of the oil showed the presence of terpenoids, lactones and flavonoids as the major constituents suggesting their possible role in the toxicity. Present investigations proved celery seed essential oil to be an efficient larvicide and repellent against dengue vector. Further studies are needed to identify the active principles involved, their mode of action, formulated preparations for enhancing potency and stability, toxicity and effects on non-target organisms and the

  16. Multipurpose effectiveness of Couroupita guianensis-synthesized gold nanoparticles: high antiplasmodial potential, field efficacy against malaria vectors and synergy with Aplocheilus lineatus predators.

    Subramaniam, Jayapal; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Kovendan, Kalimuthu; Madhiyazhagan, Pari; Dinesh, Devakumar; Kumar, Palanisamy Mahesh; Chandramohan, Balamurugan; Suresh, Udaiyan; Rajaganesh, Rajapandian; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Canale, Angelo; Benelli, Giovanni

    2016-04-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. According to recent estimates, about 3.2 billion people, almost half of the world's population, are at risk of malaria. Malaria control is particularly challenging due to a growing number of chloroquine-resistant Plasmodium and pesticide-resistant Anopheles vectors. Newer and safer control tools are required. In this research, gold nanoparticles (AuNPs) were biosynthesized using a cheap flower extract of Couroupita guianensis as reducing and stabilizing agent. The biofabrication of AuNP was confirmed by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), zeta potential, and particle size analysis. AuNP showed different shapes including spheres, ovals, and triangles. AuNPs were crystalline in nature with face-centered cubic geometry; mean size was 29.2-43.8 nm. In laboratory conditions, AuNPs were toxic against Anopheles stephensi larvae, pupae, and adults. LC50 was 17.36 ppm (larva I), 19.79 ppm (larva II), 21.69 ppm (larva III), 24.57 ppm (larva IV), 28.78 ppm (pupa), and 11.23 ppm (adult). In the field, a single treatment with C. guianensis flower extract and AuNP (10 × LC50) led to complete larval mortality after 72 h. In standard laboratory conditions, the predation efficiency of golden wonder killifish, Aplocheilus lineatus, against A. stephensi IV instar larvae was 56.38 %, while in an aquatic environment treated with sub-lethal doses of the flower extract or AuNP, predation efficiency was boosted to 83.98 and 98.04 %, respectively. Lastly, the antiplasmodial activity of C. guianensis flower extract and AuNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. IC50 of C. guianensis flower extract was 43.21 μg/ml (CQ-s) and 51.16 μg/ml (CQ-r). AuNP IC50 was 69.47 μg/ml (CQ-s) and 76

  17. Bunyavirus-vector interactions.

    Beaty, B J; Bishop, D H

    1988-06-01

    Recent advances in the genetics and molecular biology of bunyaviruses have been applied to understanding bunyavirus-vector interactions. Such approaches have revealed which virus gene and gene products are important in establishing infections in vectors and in transmission of viruses. However, much more information is required to understand the molecular mechanisms of persistent infections of vectors which are lifelong but apparently exert no untoward effect. In fact, it seems remarkable that LAC viral antigen can be detected in almost every cell in an ovarian follicle, yet no untoward effect on fecundity and no teratology is seen. Similarly the lifelong infection of the vector would seem to provide ample opportunity for bunyavirus evolution by genetic drift and, under the appropriate circumstances, by segment reassortment. The potential for bunyavirus evolution by segment reassortment in vectors certainly exists. For example the Group C viruses in a small forest in Brazil seem to constitute a gene pool, with the 6 viruses related alternately by HI/NT and CF reactions, which assay respectively M RNA and S RNA gene products (Casals and Whitman, 1960; Shope and Causey, 1962). Direct evidence for naturally occurring reassortant bunyaviruses has also been obtained. Oligonucleotide fingerprint analyses of field isolates of LAC virus and members of the Patois serogroup of bunyaviruses have demonstrated that reassortment does occur in nature (El Said et al., 1979; Klimas et al., 1981; Ushijima et al., 1981). Determination of the genotypic frequencies of viruses selected by the biological interactions of viruses and vectors after dual infection and segment reassortment is an important issue. Should a virus result that efficiently interacts with alternate vector species, the virus could be expressed in different circumstances with serious epidemiologic consequences. Dual infection of vectors with different viruses is not unlikely, because many bunyaviruses are sympatric in

  18. Mosquito-Disseminated Insecticide for Citywide Vector Control and Its Potential to Block Arbovirus Epidemics: Entomological Observations and Modeling Results from Amazonian Brazil

    Abad-Franch, Fernando; Luz, Sérgio L. B.

    2017-01-01

    Background Mosquito-borne viruses threaten public health worldwide. When the ratio of competent vectors to susceptible humans is low enough, the virus’s basic reproductive number (R0) falls below 1.0 (each case generating, on average, <1.0 additional case) and the infection fades out from the population. Conventional mosquito control tactics, however, seldom yield R0 < 1.0. A promising alternative uses mosquitoes to disseminate a potent growth-regulator larvicide, pyriproxyfen (PPF), to aquatic larval habitats; this kills most mosquito juveniles and substantially reduces adult mosquito emergence. We tested mosquito-disseminated PPF in Manacapuru, a 60,000-inhabitant city (~650 ha) in Amazonian Brazil. Methods and Findings We sampled juvenile mosquitoes monthly in 100 dwellings over four periods in February 2014–January 2016: 12 baseline months, 5 mo of citywide PPF dissemination, 3 mo of focal PPF dissemination around Aedes-infested dwellings, and 3 mo after dissemination ended. We caught 19,434 juvenile mosquitoes (66% Aedes albopictus, 28% Ae. aegypti) in 8,271 trap-months. Using generalized linear mixed models, we estimated intervention effects on juvenile catch and adult emergence while adjusting for dwelling-level clustering, unequal sampling effort, and weather-related confounders. Following PPF dissemination, Aedes juvenile catch decreased by 79%–92% and juvenile mortality increased from 2%–7% to 80%–90%. Mean adult Aedes emergence fell from 1,077 per month (range 653–1,635) at baseline to 50.4 per month during PPF dissemination (range 2–117). Female Aedes emergence dropped by 96%–98%, such that the number of females emerging per person decreased to 0.06 females per person-month (range 0.002–0.129). Deterministic models predict, under plausible biological-epidemiological scenarios, that the R0 of typical Aedes-borne viruses would fall from 3–45 at baseline to 0.004–0.06 during PPF dissemination. The main limitations of our study were

  19. Zika virus, vectors, reservoirs, amplifying hosts, and their potential to spread worldwide: what we know and what we should investigate urgently

    Rengina Vorou

    2016-07-01

    Conclusions: It is a public health imperative to define the domestic and wild animal reservoirs, amplification hosts, and vector capacity of the genera Aedes, Anopheles, and Mansonia. These variables will define the geographic distribution of Zika virus along with the indicated timing and scale of the environmental public health interventions worldwide.

  20. Safety considerations in vector development.

    Kappes, J C; Wu, X

    2001-11-01

    The inadvertent production of replication competent retrovirus (RCR) constitutes the principal safety concern for the use of lentiviral vectors in human clinical protocols. Because of limitations in animal models to evaluate lentiviral vectors for their potential to recombine and induce disease, the vector design itself should ensure against the emergence of RCR in vivo. Issues related to RCR generation and one approach to dealing with this problem are discussed in this chapter. To assess the risk of generating RCR, a highly sensitive biological assay was developed to specifically detect vector recombination in transduced cells. Analysis of lentiviral vector stocks has shown that recombination occurs during reverse transcription in primary target cells. Rejoining of viral protein-coding sequences of the packaging construct and cis-acting sequences of the vector was demonstrated to generate env-minus recombinants (LTR-gag-pol-LTR). Mobilization of recombinant lentiviral genomes was also demonstrated but was dependent on pseudotyping of the vector core with an exogenous envelope protein. 5' sequence analysis has demonstrated that recombinants consist of U3, R, U5, and the psi packaging signal joined with an open gag coding region. Analysis of the 3' end has mapped the point of vector recombination to the poly(A) tract of the packaging construct's mRNA. The state-of-the-art third generation packaging construct and SIN vector also have been shown to generate env-minus proviral recombinants capable of mobilizing retroviral DNA when pseudotyped with an exogenous envelope protein. A new class of HIV-based vector (trans-vector) was recently developed that splits the gag-pol component of the packaging construct into two parts: one that expresses Gag/Gag-Pro and another that expresses Pol (RT and IN) fused with Vpr. Unlike other lentiviral vectors, the trans-vector has not been shown to form recombinants capable of DNA mobilization. These results indicate the trans-vector

  1. Vector nematicons

    Horikis, Theodoros P

    2016-01-01

    Families of soliton pairs, namely vector solitons, are found within the context of a coupled nonlocal nonlinear Schrodinger system of equations, as appropriate for modeling beam propagation in nematic liquid crystals. In the focusing case, bright soliton pairs have been found to exist provided their amplitudes satisfy a specific condition. In our analytical approach, focused on the defocusing regime, we rely on a multiscale expansion methods, which reveals the existence of dark-dark and antidark-antidark solitons, obeying an effective Korteweg-de Vries equation, as well as dark-bright solitons, obeying an effective Mel'nikov system. These pairs are discriminated by the sign of a constant that links all physical parameters of the system to the amplitude of the stable continuous wave solutions, and, much like the focusing case, the solitons' amplitudes are linked leading to mutual guiding.

  2. Comparison of Potato and Asian Citrus Psyllid Adult and Nymph Transcriptomes Identified Vector Transcripts with Potential Involvement in Circulative, Propagative Liberibacter Transmission

    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.

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

    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

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

    Arjunan Nareshkumar

    2012-12-01

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

  5. 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)

  6. Phlebotominae sand flies (Diptera: Psychodidae: potential vectors of American cutaneous leishmaniasis agents in the area associated with the Santo Antônio Hydroelectric System in Western Amazonian Brazil

    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.

  7. Vector fields in cosmology

    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.

  8. Expression of VP7, a Bluetongue virus group specific antigen by viral vectors: analysis of the induced immune responses and evaluation of protective potential in sheep.

    Coraline Bouet-Cararo

    Full Text Available Bluetongue virus (BTV is an economically important Orbivirus transmitted by biting midges to domestic and wild ruminants. The need for new vaccines has been highlighted by the occurrence of repeated outbreaks caused by different BTV serotypes since 1998. The major group-reactive antigen of BTV, VP7, is conserved in the 26 serotypes described so far, and its role in the induction of protective immunity has been proposed. Viral-based vectors as antigen delivery systems display considerable promise as veterinary vaccine candidates. In this paper we have evaluated the capacity of the BTV-2 serotype VP7 core protein expressed by either a non-replicative canine adenovirus type 2 (Cav-VP7 R0 or a leporipoxvirus (SG33-VP7, to induce immune responses in sheep. Humoral responses were elicited against VP7 in almost all animals that received the recombinant vectors. Both Cav-VP7 R0 and SG33-VP7 stimulated an antigen-specific CD4+ response and Cav-VP7 R0 stimulated substantial proliferation of antigen-specific CD8+ lymphocytes. Encouraged by the results obtained with the Cav-VP7 R0 vaccine vector, immunized animals were challenged with either the homologous BTV-2 or the heterologous BTV-8 serotype and viral burden in plasma was followed by real-time RT-PCR. The immune responses triggered by Cav-VP7 R0 were insufficient to afford protective immunity against BTV infection, despite partial protection obtained against homologous challenge. This work underscores the need to further characterize the role of BTV proteins in cross-protective immunity.

  9. Expression of VP7, a Bluetongue Virus Group Specific Antigen by Viral Vectors: Analysis of the Induced Immune Responses and Evaluation of Protective Potential in Sheep

    Bouet-Cararo, Coraline; Contreras, Vanessa; Caruso, Agathe; Top, Sokunthea; Szelechowski, Marion; Bergeron, Corinne; Viarouge, Cyril; Desprat, Alexandra; Relmy, Anthony; Guibert, Jean-Michel; Dubois, Eric; Thiery, Richard; Bréard, Emmanuel; Bertagnoli, Stephane; Richardson, Jennifer; Foucras, Gilles; Meyer, Gilles; Schwartz-Cornil, Isabelle; Zientara, Stephan; Klonjkowski, Bernard

    2014-01-01

    Bluetongue virus (BTV) is an economically important Orbivirus transmitted by biting midges to domestic and wild ruminants. The need for new vaccines has been highlighted by the occurrence of repeated outbreaks caused by different BTV serotypes since 1998. The major group-reactive antigen of BTV, VP7, is conserved in the 26 serotypes described so far, and its role in the induction of protective immunity has been proposed. Viral-based vectors as antigen delivery systems display considerable promise as veterinary vaccine candidates. In this paper we have evaluated the capacity of the BTV-2 serotype VP7 core protein expressed by either a non-replicative canine adenovirus type 2 (Cav-VP7 R0) or a leporipoxvirus (SG33-VP7), to induce immune responses in sheep. Humoral responses were elicited against VP7 in almost all animals that received the recombinant vectors. Both Cav-VP7 R0 and SG33-VP7 stimulated an antigen-specific CD4+ response and Cav-VP7 R0 stimulated substantial proliferation of antigen-specific CD8+ lymphocytes. Encouraged by the results obtained with the Cav-VP7 R0 vaccine vector, immunized animals were challenged with either the homologous BTV-2 or the heterologous BTV-8 serotype and viral burden in plasma was followed by real-time RT-PCR. The immune responses triggered by Cav-VP7 R0 were insufficient to afford protective immunity against BTV infection, despite partial protection obtained against homologous challenge. This work underscores the need to further characterize the role of BTV proteins in cross-protective immunity. PMID:25364822

  10. 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.

  11. Emerging vector borne diseases – incidence through vectors

    Sara eSavic

    2014-12-01

    Full Text Available 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. Nowdays, in intercontinetal 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 place. Global climate change is predicted to lead to an increase in vector borne infectious diseases and disease outbreaks. It could affect the range and popultion of pathogens, host and vectors, transmission season, etc. Reliable surveilance for diseases that are most likely to emerge is required. Canine vector borne diseases represent a complex group of diseases including anaplasmosis, babesiosis, bartonellosis, borreliosis, dirofilariosis, erlichiosis, leishmaniosis. Some of these diseases cause serious clinical symptoms in dogs and some of them have a zoonotic potential with an effect to public health. It is expected from veterinarians in coordination with medical doctors to play a fudamental role at primeraly prevention and then treatment of vector borne diseases in dogs. The One Health concept has to be integrated into the struggle against emerging diseases.During a four year period, from 2009-2013, a total number of 551 dog samples were analysed for vector borne diseases (borreliosis, babesiosis, erlichiosis, anaplasmosis, dirofilariosis and leishmaniasis in routine laboratory work. The analysis were done by serological tests – ELISA for borreliosis, dirofilariosis and leishmaniasis, modified Knott test for dirofilariosis and blood smear for babesiosis, erlichiosis and anaplasmosis. This number of samples represented 75% of total number of samples that were sent for analysis for different diseases in dogs. Annually, on avarege more then half of the samples

  12. Acoustic vector sensor signal processing

    SUN Guiqing; LI Qihu; ZHANG Bin

    2006-01-01

    Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on.

  13. Multiple Insecticide Resistance in the Malaria Vector Anopheles funestus from Northern Cameroon Is Mediated by Metabolic Resistance Alongside Potential Target Site Insensitivity Mutations

    Menze, Benjamin D.; Riveron, Jacob M.; Ibrahim, Sulaiman S.; Irving, Helen; Antonio-Nkondjio, Christophe; Awono-Ambene, Parfait H.; Wondji, Charles S.

    2016-01-01

    Background Despite the recent progress in establishing the patterns of insecticide resistance in the major malaria vector Anopheles funestus, Central African populations of this species remain largely uncharacterised. To bridge this important gap and facilitate the implementation of suitable control strategies against this vector, we characterised the resistance patterns of An. funestus population from northern Cameroon. Methods and Findings Collection of indoor-resting female mosquitoes in Gounougou (northern Cameroon) in 2012 and 2015 revealed a predominance of An. funestus during dry season. WHO bioassays performed using F1 An. funestus revealed that the population was multiple resistant to several insecticide classes including pyrethroids (permethrin, deltamethrin, lambda-cyhalothrin and etofenprox), carbamates (bendiocarb) and organochlorines (DDT and dieldrin). However, a full susceptibility was observed against the organophosphate malathion. Bioassays performed with 2015 collection revealed that resistance against pyrethroids and DDT is increasing. PBO synergist assays revealed a significant recovery of susceptibility for all pyrethroids but less for DDT. Analysis of the polymorphism of a portion of the voltage-gated sodium channel gene (VGSC) revealed the absence of the L1014F/S kdr mutation but identified 3 novel amino acid changes I877L, V881L and A1007S. However, no association was established between VGSC polymorphism and pyrethroid/DDT resistance. The DDT resistant 119F-GSTe2 allele (52%) and the dieldrin resistant 296S-RDL allele (45%) were detected in Gounougou. Temporal analysis between 2006, 2012 and 2015 collections revealed that the 119F-GSTe2 allele was relatively stable whereas a significant decrease is observed for 296S-RDL allele. Conclusion This multiple resistance coupled with the temporal increased in resistance intensity highlights the need to take urgent measures to prolong the efficacy of current insecticide-based interventions against

  14. Unsupervised learning of binary vectors

    Copelli Lopes da Silva, Mauro

    In this thesis, unsupervised learning of binary vectors from data is studied using methods from Statistical Mechanics of disordered systems. In the model, data vectors are distributed according to a single symmetry-breaking direction. The aim of unsupervised learning is to provide a good approximation to this direction. The difference with respect to previous studies is the knowledge that this preferential direction has binary components. It is shown that sampling from the posterior distribution (Gibbs learning) leads, for general smooth distributions, to an exponentially fast approach to perfect learning in the asymptotic limit of large number of examples. If the distribution is non-smooth, then first order phase transitions to perfect learning are expected. In the limit of poor performance, a second order phase transition ("retarded learning") is predicted to occur if the data distribution is not biased. Using concepts from Bayesian inference, the center of mass of the Gibbs ensemble is shown to have maximal average (Bayes-optimal) performance. This upper bound for continuous vectors is extended to a discrete space, resulting in the clipped center of mass of the Gibbs ensemble having maximal average performance among the binary vectors. To calculate the performance of this best binary vector, the geometric properties of the center of mass of binary vectors are studied. The surprising result is found that the center of mass of infinite binary vectors which obey some simple constraints, is again a binary vector. When disorder is taken into account in the calculation, however, a vector with continuous components is obtained. The performance of the best binary vector is calculated and shown to always lie above that of Gibbs learning and below the Bayes-optimal performance. Making use of a variational approach under the replica symmetric ansatz, an optimal potential is constructed in the limits of zero temperature and mutual overlap 1. Minimization of this potential

  15. 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…

  16. The use of annual killifish in the biocontrol of the aquatic stages of mosquitoes in temporary bodies of fresh water; a potential new tool in vector control

    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

  17. Concise vector analysis

    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

  18. Light axial vector mesons

    Chen, Kan; Liu, Xiang; Matsuki, Takayuki

    2015-01-01

    Inspired by the abundant experimental observation of axial vector states, we study whether the observed axial vector states can be categorized into the conventional axial vector meson family. In this paper we carry out analysis based on the mass spectra and two-body Okubo-Zweig-Iizuka-allowed decays. Besides testing the possible axial vector meson assignments, we also predict abundant information for their decays and the properties of some missing axial vector mesons, which are valuable to further experimental exploration of the observed and predicted axial vector mesons.

  19. microRNA as a potential vector for the propagation of robustness in protein expression and oscillatory dynamics within a ceRNA network.

    Claude Gérard

    Full Text Available microRNAs (miRNAs are small noncoding RNAs that are important post-transcriptional regulators of gene expression. miRNAs can induce thresholds in protein synthesis. Such thresholds in protein output can be also achieved by oligomerization of transcription factors (TF for the control of gene expression. First, we propose a minimal model for protein expression regulated by miRNA and by oligomerization of TF. We show that miRNA and oligomerization of TF generate a buffer, which increases the robustness of protein output towards molecular noise as well as towards random variation of kinetics parameters. Next, we extend the model by considering that the same miRNA can bind to multiple messenger RNAs, which accounts for the dynamics of a minimal competing endogenous RNAs (ceRNAs network. The model shows that, through common miRNA regulation, TF can control the expression of all proteins formed by the ceRNA network, even if it drives the expression of only one gene in the network. The model further suggests that the threshold in protein synthesis mediated by the oligomerization of TF can be propagated to the other genes, which can increase the robustness of the expression of all genes in such ceRNA network. Furthermore, we show that a miRNA could increase the time delay of a "Goodwin-like" oscillator model, which may favor the occurrence of oscillations of large amplitude. This result predicts important roles of miRNAs in the control of the molecular mechanisms leading to the emergence of biological rhythms. Moreover, a model for the latter oscillator embedded in a ceRNA network indicates that the oscillatory behavior can be propagated, via the shared miRNA, to all proteins formed by such ceRNA network. Thus, by means of computational models, we show that miRNAs could act as vectors allowing the propagation of robustness in protein synthesis as well as oscillatory behaviors within ceRNA networks.

  20. Larvicidal potential of wild mustard (Cleome viscosa) and gokhru (Tribulus terrestris) against mosquito vectors in the semi-arid region of Western Rajasthan.

    Bansal, S K; Singh, Karam V; Sharma, Sapna

    2014-03-01

    effective as compared to the fruit extracts of T. terrestris indicating that active larvicidal principle may be present in the fruits of this plant species. The studywould be of great importance while formulating the control strategy, for vectors of malaria, dengue and lymphatic filariasis, based on alternative plant based insecticides in this semi-arid region.

  1. Yersinia pestis insecticidal-like toxin complex (Tc family proteins: characterization of expression, subcellular localization, and potential role in infection of the flea vector

    Spinner Justin L

    2012-12-01

    Full Text Available Abstract Background Toxin complex (Tc family proteins were first identified as insecticidal toxins in Photorhabdus luminescens and have since been found in a wide range of bacteria. The genome of Yersinia pestis, the causative agent of bubonic plague, contains a locus that encodes the Tc protein homologues YitA, YitB, YitC, and YipA and YipB. Previous microarray data indicate that the Tc genes are highly upregulated by Y. pestis while in the flea vector; however, their role in the infection of fleas and pathogenesis in the mammalian host is unclear. Results We show that the Tc proteins YitA and YipA are highly produced by Y. pestis while in the flea but not during growth in brain heart infusion (BHI broth at the same temperature. Over-production of the LysR-type regulator YitR from an exogenous plasmid increased YitA and YipA synthesis in broth culture. The increase in production of YitA and YipA correlated with the yitR copy number and was temperature-dependent. Although highly synthesized in fleas, deletion of the Tc proteins did not alter survival of Y. pestis in the flea or prevent blockage of the proventriculus. Furthermore, YipA was found to undergo post-translational processing and YipA and YitA are localized to the outer membrane of Y. pestis. YitA was also detected by immunofluorescence microscopy on the surface of Y. pestis. Both YitA and YipA are produced maximally at low temperature but persist for several hours after transfer to 37°C. Conclusions Y. pestis Tc proteins are highly expressed in the flea but are not essential for Y. pestis to stably infect or produce a transmissible infection in the flea. However, YitA and YipA localize to the outer membrane and YitA is exposed on the surface, indicating that at least YitA is present on the surface when Y. pestis is transmitted into the mammalian host from the flea.

  2. Vector perturbations of galaxy number counts

    Durrer, Ruth; Tansella, Vittorio

    2016-07-01

    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.

  3. 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.

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

    Alveiro Pérez-Doria

    2008-12-01

    similar vector and non-vector species. In order to detect useful molecular characters for the taxonomic determination of three potential vectors of Leishmania present in the Valle de Aburrá, Colombia, the present work sequenced the 3' end of the mitochondrial cytochrome b gene in Lutzomyia hartmanni (Fairchild and Hertig, L. columbiana (Ristorcelli and Van Ty, and L. tihuiliensis Le Pont, Torrez-Espejo and Dujardin. Polymorphic sites, pairwise genetic distances (p, and entropy were determined from the multiple alignment of the nucleotide sequences. Numbers of silent and non silent substitutions were calculated from the amino acid sequences deduced from the nucleotide sequences of the gene. In the multiple alignment of the cytochrome b nucleotide sequences from Lutzomyia hartmanni, L. columbiana and L. tihuiliensis, 83 polymorphic sites were detected. A total of 18 amino acid replacements were found in the partial nucleotide sequences of the protein. Genetic distances varied from 0,137 between L. tihuiliensis and L. columbiana, to 0,215 among L. columbiana and L. hartmanni. Nucleotide and amino acid sequence polymorphisms within the cytochrome b gene and protein, respectively, constitute molecular characters potentially useful for the taxonomic determination of these sand fly species.

  5. Exact Solutions of the Mass-Dependent Klein-Gordon Equation with the Vector Quark-Antiquark Interaction and Harmonic Oscillator Potential

    M. K. Bahar

    2013-01-01

    Full Text Available Using the asymptotic iteration and wave function ansatz method, we present exact solutions of the Klein-Gordon equation for the quark-antiquark interaction and harmonic oscillator potential in the case of the position-dependent mass.

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

    Su Hyun Lee; Kwang Woo Nam; Ji Yeon Jeong; Seung Jin Yoo; Young-Sang Koh; Seogjae Lee; Sang Taek Heo; Seung-Yong Seong; Keun Hwa Lee

    2013-01-01

    BACKGROUND: Climate change affects the survival and transmission of arthropod vectors as well as the development rates of vector-borne pathogens. Increased international travel is also an important factor in the spread of vector-borne diseases (VBDs) such as dengue, West Nile, yellow fever, chikungunya, and malaria. Dengue is the most important vector-borne viral disease. An estimated 2.5 billion people are at risk of infection in the world and there are approximately 50 million dengue infect...

  7. Black holes with vector hair

    Fan, Zhong-Ying

    2016-09-01

    In this paper, we consider Einstein gravity coupled to a vector field, either minimally or non-minimally, together with a vector potential of the type V = 2{Λ}_0+1/2{m}^2{A}^2 + {γ}_4{A}^4 . For a simpler non-minimally coupled theory with Λ0 = m = γ4 = 0, we obtain both extremal and non-extremal black hole solutions that are asymptotic to Minkowski space-times. We study the global properties of the solutions and derive the first law of thermodynamics using Wald formalism. We find that the thermodynamical first law of the extremal black holes is modified by a one form associated with the vector field. In particular, due to the existence of the non-minimal coupling, the vector forms thermodynamic conjugates with the graviton mode and partly contributes to the one form modifying the first law. For a minimally coupled theory with Λ0 ≠ 0, we also obtain one class of asymptotically flat extremal black hole solutions in general dimensions. This is possible because the parameters ( m 2 , γ4) take certain values such that V = 0. In particular, we find that the vector also forms thermodynamic conjugates with the graviton mode and contributes to the corresponding first law, although the non-minimal coupling has been turned off. Thus all the extremal black hole solutions that we obtain provide highly non-trivial examples how the first law of thermodynamics can be modified by a either minimally or non-minimally coupled vector field. We also study Gauss-Bonnet gravity non-minimally coupled to a vector and obtain asymptotically flat black holes and Lifshitz black holes.

  8. VectorBase

    U.S. Department of Health & Human Services — VectorBase is a Bioinformatics Resource Center for invertebrate vectors. It is one of four Bioinformatics Resource Centers funded by NIAID to provide web-based...

  9. Vector bundles on toric varieties

    Gharib, Saman

    2011-01-01

    Following Sam Payne's work, we study the existence problem of nontrivial vector bundles on toric varieties. The first result we prove is that every complete fan admits a nontrivial conewise linear multivalued function. Such functions could potentially be the Chern classes of toric vector bundles. Then we use the results of Corti\\~nas, Haesemeyer, Walker and Weibel to show that the (non-equivariant) Grothendieck group of the toric 3-fold studied by Payne is large, so the variety has a nontrivial vector bundle. Using the same computation, we show that every toric 3-fold X either has a nontrivial line bundle, or there is a finite surjective toric morphism from Y to X, such that Y has a large Grothendieck group.

  10. On Double Vector Bundles

    Zhuo CHEN; Zhang Ju LIU; Yun He SHENG

    2014-01-01

    In this paper, we construct a category of short exact sequences of vector bundles and prove that it is equivalent to the category of double vector bundles. Moreover, operations on double vector bundles can be transferred to operations on the corresponding short exact sequences. In particular, we study the duality theory of double vector bundles in term of the corresponding short exact sequences. Examples including the jet bundle and the Atiyah algebroid are discussed.

  11. On Double Vector Bundles

    Chen, Zhuo; Liu, Zhangju; Sheng, Yunhe

    2011-01-01

    In this paper, we construct a category of short exact sequences of vector bundles and prove that it is equivalent to the category of double vector bundles. Moreover, operations on double vector bundles can be transferred to operations on the corresponding short exact sequences. In particular, we study the duality theory of double vector bundles in term of the corresponding short exact sequences. Examples including the jet bundle and the Atiyah algebroid are discussed.

  12. Custodial vector model

    Becciolini, Diego; Franzosi, Diogo Buarque; Foadi, Roshan;

    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...

  13. Computer-aided diagnosis of Parkinson’s disease based on [123I]FP-CIT SPECT binding potential images, using the voxels-as-features approach and support vector machines

    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)

  14. 核子-核子散射过程的研究和矢量介子交换势%Studies of NN Scattering Process and Vector Meson Exchange Potential

    戴连荣; 张宗烨; 余友文; 袁淑立

    2004-01-01

    In this work, the vector meson exchange effect in NN interaction is studied on quark level in the extended chiral SU(3) quark model. The r, ρ and ω-meson exchange GCM potentials of central force and NN scattering phase shifts for all scattering partial waves are given. It shows that the vetor meson exchange potential can substitute one-gluon exchange (OGE) potential to explain repulsive core of the NN interaction.%在推广的手征SU(3)夸克模型下讨论了核子-核子散射过程和矢量介子交换势.给出了赝标π介子和矢量ρ和ω介子的GCM中心力的交换势和NN散射14个分波的相移.研究表明,矢量介子交换势可以替代单胶子交换势以解释核力的短程排斥.

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

    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

  16. 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...

  17. Biosecurity and vector behaviour: evaluating the potential threat posed by anglers and canoeists as pathways for the spread of invasive non-native species and pathogens.

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

    2014-01-01

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

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

    Rajasekharreddy, Pala; Rani, Pathipati Usha

    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±0.2nm. Selected area electron diffraction (SAED) and X-ray diffraction (XRD) revealed 'fcc' phase and crystallinity of the particles. X-ray photoelectron spectroscopy (XPS) was used to identify the protein-lipid (PL) bilayer that appears as a shell around the Ag core particles. The thermal stability of the Ag-PL NPs was examined using thermogravimetric analysis (TGA). Further analysis was carried out by using Fourier transform infrared spectroscopy (FTIR), where the spectra provided evidence for the presence of proteins and lipid moieties ((2n-octylcycloprop-1-enyl)-octanoic acid (I)), and their role in synthesis and stabilization of Ag NPs. This is the first report of plant seed assisted synthesis of PL conjugated Ag NPs. These formed Ag-PL NPs showed potential mosquito larvicidal activity against Aedes aegypti (L.), Anopheles stephensi Liston and Culex quinquefasciatus Say. These Ag-PL NPs can also act as promising agents in cancer therapy. They exhibited anti-proliferative activity against HeLa cancer cell lines and a promising toxicity was observed in a dose dependent manner. Toxicity studies were further supported by the cellular DNA fragmentation in the Ag-PL NPs treated HeLa cells.

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

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

    2014-04-01

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

  20. Lentiviral vectors in cancer immunotherapy.

    Oldham, Robyn Aa; Berinstein, Elliot M; Medin, Jeffrey A

    2015-01-01

    Basic science advances in cancer immunotherapy have resulted in various treatments that have recently shown success in the clinic. Many of these therapies require the insertion of genes into cells to directly kill them or to redirect the host's cells to induce potent immune responses. Other analogous therapies work by modifying effector cells for improved targeting and enhanced killing of tumor cells. Initial studies done using γ-retroviruses were promising, but safety concerns centered on the potential for insertional mutagenesis have highlighted the desire to develop other options for gene delivery. Lentiviral vectors (LVs) have been identified as potentially more effective and safer alternative delivery vehicles. LVs are now in use in clinical trials for many different types of inherited and acquired disorders, including cancer. This review will discuss current knowledge of LVs and the applications of this viral vector-based delivery vehicle to cancer immunotherapy.

  1. Vehicle Based Vector Sensor

    2015-09-28

    300001 1 of 16 VEHICLE-BASED VECTOR SENSOR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...unmanned underwater vehicle that can function as an acoustic vector sensor . (2) Description of the Prior Art [0004] It is known that a propagating...mechanics. An acoustic vector sensor measures the particle motion via an accelerometer and combines Attorney Docket No. 300001 2 of 16 the

  2. Implicit Real Vector Automata

    Jean-François 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.

  3. The effects of climate change and globalization on mosquito vectors: evidence from Jeju Island, South Korea on the potential for Asian tiger mosquito (Aedes albopictus influxes and survival from Vietnam rather than Japan.

    Su Hyun Lee

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

  4. Complex Polynomial Vector Fields

    Dias, Kealey

    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...... 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...

  5. 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

  6. Clifford Fourier transform on vector fields.

    Ebling, Julia; Scheuermann, Gerik

    2005-01-01

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

  7. Advancing vector biology research

    Kohl, Alain; Pondeville, Emilie; Schnettler, Esther; Crisanti, Andrea; Supparo, Clelia; Christophides, George K.; Kersey, Paul J.; Maslen, Gareth L.; Takken, Willem; Koenraadt, Constantianus J.M.; Oliva, Clelia F.; Busquets, Núria; Abad, F.X.; Failloux, Anna Bella; Levashina, Elena A.; Wilson, Anthony J.; Veronesi, Eva; Pichard, Maëlle; Arnaud Marsh, Sarah; Simard, Frédéric; Vernick, Kenneth D.

    2016-01-01

    Vector-borne pathogens impact public health, animal production, and animal welfare. Research on arthropod vectors such as mosquitoes, ticks, sandflies, and midges which transmit pathogens to humans and economically important animals is crucial for development of new control measures that target t

  8. 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...... 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....

  9. 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...

  10. Gene targeting with retroviral vectors

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

    1989-04-01

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

  11. A Note on Polarization Vectors in Quantum Electrodynamics

    Lieb, Elliott H.; Loss, Michael

    2004-12-01

    A photon of momentum k can have only two polarization states, not three. Equivalently, one can say that the magnetic vector potential A must be divergence-free in the Coulomb gauge. These facts are normally taken into account in QED by introducing two polarization vectors ɛλ(k) with λ ∈ {1,2}, which are orthogonal to the wave-vector k. These vectors must be very discontinuous functions of k and, consequently, their Fourier transforms have bad decay properties. Since these vectors have no physical significance there must be a way to eliminate them and their bad decay properties from the theory. We propose such a way here.

  12. ON VECTOR NETWORK EQUILIBRIUM PROBLEMS

    Guangya CHEN

    2005-01-01

    In this paper we define a concept of weak equilibrium for vector network equilibrium problems.We obtain sufficient conditions of weak equilibrium points and establish relation with vector network equilibrium problems and vector variational inequalities.

  13. Tagged Vector Contour (TVC)

    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....

  14. GAP Land Cover - Vector

    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 of...

  15. Noncausal Bayesian Vector Autoregression

    Lanne, Markku; Luoto, Jani

    We propose a Bayesian inferential procedure for the noncausal vector autoregressive (VAR) model that is capable of capturing nonlinearities and incorporating effects of missing variables. In particular, we devise a fast and reliable posterior simulator that yields the predictive distribution...

  16. Image Coding Based on Address Vector Quantization.

    Feng, Yushu

    Image coding is finding increased application in teleconferencing, archiving, and remote sensing. This thesis investigates the potential of Vector Quantization (VQ), a relatively new source coding technique, for compression of monochromatic and color images. Extensions of the Vector Quantization technique to the Address Vector Quantization method have been investigated. In Vector Quantization, the image data to be encoded are first processed to yield a set of vectors. A codeword from the codebook which best matches the input image vector is then selected. Compression is achieved by replacing the image vector with the index of the code-word which produced the best match, the index is sent to the channel. Reconstruction of the image is done by using a table lookup technique, where the label is simply used as an address for a table containing the representative vectors. A code-book of representative vectors (codewords) is generated using an iterative clustering algorithm such as K-means, or the generalized Lloyd algorithm. A review of different Vector Quantization techniques are given in chapter 1. Chapter 2 gives an overview of codebook design methods including the Kohonen neural network to design codebook. During the encoding process, the correlation of the address is considered and Address Vector Quantization is developed for color image and monochrome image coding. Address VQ which includes static and dynamic processes is introduced in chapter 3. In order to overcome the problems in Hierarchical VQ, Multi-layer Address Vector Quantization is proposed in chapter 4. This approach gives the same performance as that of the normal VQ scheme but the bit rate is about 1/2 to 1/3 as that of the normal VQ method. In chapter 5, a Dynamic Finite State VQ based on a probability transition matrix to select the best subcodebook to encode the image is developed. In chapter 6, a new adaptive vector quantization scheme, suitable for color video coding, called "A Self -Organizing

  17. Vector Lattice Vortex Solitons

    WANG Jian-Dong; YE Fang-Wei; DONG Liang-Wei; LI Yong-Ping

    2005-01-01

    @@ Two-dimensional vector vortex solitons in harmonic optical lattices are investigated. The stability properties of such solitons are closely connected to the lattice depth Vo. For small Vo, vector vortex solitons with the total zero-angular momentum are more stable than those with the total nonzero-angular momentum, while for large Vo, this case is inversed. If Vo is large enough, both the types of such solitons are stable.

  18. 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.

  19. Declining Prevalence of Disease Vectors Under Climate Change

    Escobar, Luis E.; Romero-Alvarez, Daniel; Leon, Renato; Lepe-Lopez, Manuel A.; Craft, Meggan E.; Borbor-Cordova, Mercy J.; Svenning, Jens-Christian

    2016-12-01

    More than half of the world population is at risk of vector-borne diseases including dengue fever, chikungunya, zika, yellow fever, leishmaniasis, chagas disease, and malaria, with highest incidences in tropical regions. In Ecuador, vector-borne diseases are present from coastal and Amazonian regions to the Andes Mountains; however, a detailed characterization of the distribution of their vectors has never been carried out. We estimate the distribution of 14 vectors of the above vector-borne diseases under present-day and future climates. Our results consistently suggest that climate warming is likely threatening some vector species with extinction, locally or completely. These results suggest that climate change could reduce the burden of specific vector species. Other vector species are likely to shift and constrain their geographic range to the highlands in Ecuador potentially affecting novel areas and populations. These forecasts show the need for development of early prevention strategies for vector species currently absent in areas projected as suitable under future climate conditions. Informed interventions could reduce the risk of human exposure to vector species with distributional shifts, in response to current and future climate changes. Based on the mixed effects of future climate on human exposure to disease vectors, we argue that research on vector-borne diseases should be cross-scale and include climatic, demographic, and landscape factors, as well as forces facilitating disease transmission at fine scales.

  20. Weaving knotted vector fields with tunable helicity

    Kedia, Hridesh; Dennis, Mark R; Irvine, William T M

    2016-01-01

    We present a general construction of divergence-free knotted vector fields from complex scalar fields, whose closed field lines encode many kinds of knots and links, including torus knots, their cables, the figure-8 knot and its generalizations. As finite-energy physical fields they represent initial states for fields such as the magnetic field in a plasma, or the vorticity field in a fluid. We give a systematic procedure for calculating the vector potential, starting from complex scalar functions with knotted zero filaments, thus enabling an explicit computation of the helicity of these knotted fields. The construction can be used to generate isolated knotted flux tubes, filled by knots encoded in the lines of the vector field. Lastly we give examples of manifestly knotted vector fields with vanishing helicity. Our results provide building blocks for analytical models and simulations alike.

  1. The Vector Curvaton

    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...

  2. The vector BPS Skyrme model

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

    2012-01-01

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

  3. Vector cross product in n-dimensional vector space

    Tian, Xiu-Lao; Yang, Chao; Hu, Yang; Tian, Chao

    2013-01-01

    The definition of vector cross product (VCP) introduced by Eckmann only exists in thethree- and the seven- dimensional vector space. In this paper, according to the orthogonal completeness, magnitude of basis vector cross product and all kinds of combinations of basis vector $\\hat{e}_i$, the generalized definition of VCP in the odd n-dimensional vector space is given by introducing a cross term $X_{AB}$. In addition, the definition is validated by reducing the generalization definition to the...

  4. Extended Mixed Vector Equilibrium Problems

    Mijanur Rahaman

    2014-01-01

    Full Text Available We study extended mixed vector equilibrium problems, namely, extended weak mixed vector equilibrium problem and extended strong mixed vector equilibrium problem in Hausdorff topological vector spaces. Using generalized KKM-Fan theorem (Ben-El-Mechaiekh et al.; 2005, some existence results for both problems are proved in noncompact domain.

  5. Vector Fields on Product Manifolds

    Kurz, Stefan

    2011-01-01

    This short report establishes some basic properties of smooth vector fields on product manifolds. The main results are: (i) On a product manifold there always exists a direct sum decomposition into horizontal and vertical vector fields. (ii) Horizontal and vertical vector fields are naturally isomorphic to smooth families of vector fields defined on the factors. Vector fields are regarded as derivations of the algebra of smooth functions.

  6. Boosting Support Vector Machines

    Elkin Eduardo García Díaz

    2006-11-01

    Full Text Available En este artículo, se presenta un algoritmo de clasificación binaria basado en Support Vector Machines (Máquinas de Vectores de Soporte que combinado apropiadamente con técnicas de Boosting consigue un mejor desempeño en cuanto a tiempo de entrenamiento y conserva características similares de generalización con un modelo de igual complejidad pero de representación más compacta./ In this paper we present an algorithm of binary classification based on Support Vector Machines. It is combined with a modified Boosting algorithm. It run faster than the original SVM algorithm with a similar generalization error and equal complexity model but it has more compact representation.

  7. Robustifying Vector Median Filter

    Valentín Gregori

    2011-08-01

    Full Text Available This paper describes two methods for impulse noise reduction in colour images that outperform the vector median filter from the noise reduction capability point of view. Both methods work by determining first the vector median in a given filtering window. Then, the use of complimentary information from componentwise analysis allows to build robust outputs from more reliable components. The correlation among the colour channels is taken into account in the processing and, as a result, a more robust filter able to process colour images without introducing colour artifacts is obtained. Experimental results show that the images filtered with the proposed method contain less noisy pixels than those obtained through the vector median filter. Objective measures demonstrate the goodness of the achieved improvement.

  8. Matrix vector analysis

    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

  9. Free topological vector spaces

    Gabriyelyan, Saak S.; Morris, Sidney A.

    2016-01-01

    We define and study the free topological vector space $\\mathbb{V}(X)$ over a Tychonoff space $X$. We prove that $\\mathbb{V}(X)$ is a $k_\\omega$-space if and only if $X$ is a $k_\\omega$-space. If $X$ is infinite, then $\\mathbb{V}(X)$ contains a closed vector subspace which is topologically isomorphic to $\\mathbb{V}(\\mathbb{N})$. It is proved that if $X$ is a $k$-space, then $\\mathbb{V}(X)$ is locally convex if and only if $X$ is discrete and countable. If $X$ is a metrizable space it is shown ...

  10. 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

  11. Scalar-Vector Bootstrap

    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.

  12. Topological vector spaces

    Narici, Lawrence

    2011-01-01

    BackgroundTopology Valuation Theory Algebra Linear Functionals Hyperplanes Measure Theory Normed SpacesCommutative Topological GroupsElementary ConsiderationsSeparation and Compactness Bases at 0 for Group Topologies Subgroups and Products Quotients S-Topologies Metrizability CompletenessCompleteness Function Groups Total BoundednessCompactness and Total Boundedness Uniform Continuity Extension of Uniformly Continuous Maps CompletionTopological Vector SpacesAbsorbent and Balanced Sets Convexity-AlgebraicBasic PropertiesConvexity-Topological Generating Vector Topologies A Non-Locally Convex Spa

  13. Ontology for vector surveillance and management.

    Lozano-Fuentes, Saul; Bandyopadhyay, Aritra; Cowell, Lindsay G; Goldfain, Albert; Eisen, Lars

    2013-01-01

    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.

  14. Calculus with vectors

    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...

  15. Synthetic Space Vector Modulation

    2013-06-01

    Modulation RF Radio Frequency SVM Space Vector Modulation VCO Voltage Controlled Oscillator VSI Voltage Source Inverter xvi THIS PAGE...examining the literature, an NE566 voltage controlled oscillator ( VCO ) chip as seen in Figure 10 was used to design a circuit that produced the

  16. Vectors Point Toward Pisa

    Dean, Richard A.

    1971-01-01

    The author shows that the set of all sequences in which each term is the sum of the two previous terms forms a vector space of dimension two. He uses this result to obtain the formula for the Fibonacci sequence and applies the same technique to other linear recursive relations. (MM)

  17. Vector-borne Infections

    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.

  18. Estimation of vector velocity

    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...

  19. A mariner transposon vector adapted for mutagenesis in oral streptococci

    Nilsson, Martin; Christiansen, Natalia; Høiby, Niels

    2014-01-01

    This article describes the construction and characterization of a mariner-based transposon vector designed for use in oral streptococci, but with a potential use in other Gram-positive bacteria. The new transposon vector, termed pMN100, contains the temperature-sensitive origin of replication rep...

  20. VECTOR BUNDLE, KILLING VECTOR FIELD AND PONTRYAGIN NUMBERS

    周建伟

    1991-01-01

    Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E.

  1. Antigenic structures stably expressed by recombinant TGEV-derived vectors.

    Becares, Martina; Sanchez, Carlos M; Sola, Isabel; Enjuanes, Luis; Zuñiga, Sonia

    2014-09-01

    Coronaviruses (CoVs) are positive-stranded RNA viruses with potential as immunization vectors, expressing high levels of heterologous genes and eliciting both secretory and systemic immune responses. Nevertheless, its high recombination rate may result in the loss of the full-length foreign gene, limiting their use as vectors. Transmissible gastroenteritis virus (TGEV) was engineered to express porcine reproductive and respiratory syndrome virus (PRRSV) small protein domains, as a strategy to improve heterologous gene stability. After serial passage in tissue cultures, stable expression of small PRRSV protein antigenic domains was achieved. Therefore, size reduction of the heterologous genes inserted in CoV-derived vectors led to the stable expression of antigenic domains. Immunization of piglets with these TGEV vectors led to partial protection against a challenge with a virulent PRRSV strain, as immunized animals showed reduced clinical signs and lung damage. Further improvement of TGEV-derived vectors will require the engineering of vectors with decreased recombination rate.

  2. Integrating Transgenic Vector Manipulation with Clinical Interventions to Manage Vector-Borne Diseases.

    Kenichi W Okamoto

    2016-03-01

    Full Text Available 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

  3. Efficacy of sunlight-activatable porphyrin formulates on larvae of Anopheles gambiae M and S molecular forms and An. arabiensis: a potential novel biolarvicide for integrated malaria vector control.

    Fabris, Clara; Ouédraogo, Robert Kossivi; Coppellotti, Olimpia; Dabiré, Roch K; Diabaté, Abdoulaye; Di Martino, Piera; Guidolin, Laura; Jori, Giulio; Lucantoni, Leonardo; Lupidi, Giulio; Martena, Valentina; Sawadogo, Simon P; Soncin, Marina; Habluetzel, Annette

    2012-09-01

    Biolarvicides, such as microbial formulations based on Bacillus thuringiensis and B. sphaericus, have been found to be highly effective against mosquito larvae and are currently employed as eco-friendly alternatives to synthetic chemical insecticides for vector control. Recently, a porphyrin of natural origin has been suggested as a sunlight-activatable larvicide against the dengue vector Aedes aegypti. In order to validate the approach for the control of the malaria vector, we tested the photo-larvicidal activity of a novel porphyrin, namely meso-tri(N-methyl-pyridyl), mono(N-dodecyl-pyridyl)porphine, C12, associated with two specifically selected carriers, against Anopheles gambiae s.s. and An. arabiensis larvae, both laboratory reared and collected from malaria endemic sites in Burkina Faso. Both C12-porphyrin formulates, when administered to larvae at a 50μM porphyrin dose, were accumulated in the alimentary canal. Subsequent exposure of the porphyrin-loaded larvae to sunlight for short times (0.5-3h) led to a complete mortality. The high efficacy exhibited by a "foodstuff" porphyrin formulate also in the presence of typical larval food particles opens promising perspectives for the development of an effective photocidal larvicide.

  4. Vector grammars and PN machines

    蒋昌俊

    1996-01-01

    The concept of vector grammars under the string semantic is introduced.The dass of vector grammars is given,which is similar to the dass of Chomsky grammars.The regular vector grammar is divided further.The strong and weak relation between the vector grammar and scalar grammar is discussed,so the spectrum system graph of scalar and vector grammars is made.The equivalent relation between the regular vector grammar and Petri nets (also called PN machine) is pointed.The hybrid PN machine is introduced,and its language is proved equivalent to the language of the context-free vector grammar.So the perfect relation structure between vector grammars and PN machines is formed.

  5. On Generalized Vector Equilibrium Problems

    An-hua Wan; Jun-yi Fu; Wei-hua Mao

    2006-01-01

    A new generalized vector equilibrium problem involving set-valued mappings and the proper quasi-concavity of set-valued mappings in topological vector spaces are introduced; its existence theorems and the convexity of the solution sets are established.

  6. Isotropy theorem for cosmological vector fields

    Cembranos, J A R; Maroto, A L; Jareño, S J Núñez

    2012-01-01

    We consider homogeneous abelian vector fields in an expanding universe. We find a mechanical analogy in which the system behaves as a particle moving in three dimensions under the action of a central potential. In the case of bounded and rapid evolution compared to the rate of expansion, we show by making use of the virial theorem that for arbitrary potential and polarization pattern, the average energy-momentum tensor is always diagonal and isotropic despite the intrinsic anisotropic evolution of the vector field. For simple power-law potentials of the form V=\\lambda (A^\\mu A_\\mu)^n, the average equation of state is found to be w=(n-1)/(n+1). This implies that vector coherent oscillations could act as natural dark matter or dark energy candidates. Finally, we show that under very general conditions, the average energy-momentum tensor of a rapidly evolving bounded vector field in any background geometry is always isotropic and has the perfect fluid form for any locally inertial observer.

  7. Improving DNA vaccine performance through vector design.

    Williams, James A

    2014-01-01

    DNA vaccines are a rapidly deployed next generation vaccination platform for treatment of human and animal disease. DNA delivery devices, such as electroporation and needle free jet injectors, are used to increase gene transfer. This results in higher antigen expression which correlates with improved humoral and cellular immunity in humans and animals. This review highlights recent vector and transgene design innovations that improve DNA vaccine performance. These new vectors improve antigen expression, increase plasmid manufacturing yield and quality in bioreactors, and eliminate antibiotic selection and other potential safety issues. A flowchart for designing synthetic antigen transgenes, combining antigen targeting, codon-optimization and bioinformatics, is presented. Application of improved vectors, of antibiotic free plasmid production, and cost effective manufacturing technologies will be critical to ensure safety, efficacy, and economically viable manufacturing of DNA vaccines currently under development for infectious disease, cancer, autoimmunity, immunotolerance and allergy indications.

  8. Vector mesons in matter

    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.

  9. Helices and vector bundles

    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).

  10. Perceptual vector quantization for video coding

    Valin, Jean-Marc; Terriberry, Timothy B.

    2015-03-01

    This paper applies energy conservation principles to the Daala video codec using gain-shape vector quantization to encode a vector of AC coefficients as a length (gain) and direction (shape). The technique originates from the CELT mode of the Opus audio codec, where it is used to conserve the spectral envelope of an audio signal. Conserving energy in video has the potential to preserve textures rather than low-passing them. Explicitly quantizing a gain allows a simple contrast masking model with no signaling cost. Vector quantizing the shape keeps the number of degrees of freedom the same as scalar quantization, avoiding redundancy in the representation. We demonstrate how to predict the vector by transforming the space it is encoded in, rather than subtracting off the predictor, which would make energy conservation impossible. We also derive an encoding of the vector-quantized codewords that takes advantage of their non-uniform distribution. We show that the resulting technique outperforms scalar quantization by an average of 0.90 dB on still images, equivalent to a 24.8% reduction in bitrate at equal quality, while for videos, the improvement averages 0.83 dB, equivalent to a 13.7% reduction in bitrate.

  11. Student Preconceptions about Vector Kinematics.

    Aguirre, Jose M.

    1988-01-01

    Examines preconceptions regarding several implicit vector characteristics that 15- to 17-year-old students possess just before taking their first physics course. Shows seven vector characteristics and three tasks for interviewing students. Presents the most common student preconceptions regarding each of the implicit vector characteristics. (YP)

  12. Interpolation of Vector Measures

    Ricardo del CAMPO; Antonio FERN(A)NDEZ; Fernando MAYORAL; Francisco NARANJO; Enrique A. S(A)NCHEZ-P(E)REZ

    2011-01-01

    Let (Ω, ∑) be a measurable space and m0: ∑→ X0 and m1: ∑ -→ X1 be positive vector measures with values in the Banach K(o)the function spaces X0 and X1. If 0 < α < 1, we define a X10-αXα1 and we analyze the space of integrable functions with respect to measure [m0, m1]α in order to prove suitable extensions of the classical Stein-Weiss formulas that hold for the complex interpolation of Lp-spaces.Since each p-convex order continuous K(o)the function space with weak order unit can be represented as a space of p-integrable functions with respect to a vector measure, we provide in this way a technique to obtain representations of the corresponding complex interpolation spaces. As applications, we provide a Riesz-Thorin theorem for spaces of p-integrable functions with respect to vector measures and a formula for representing the interpolation of the injective tensor product of such spaces.

  13. Vector-mediated cancer gene therapy: an overview.

    Seth, Prem

    2005-05-01

    In recent years there has been a dramatic increase in developing gene therapy approaches for the treatment of cancer. The two events that have permitted the formulation of concept of cancer gene therapy are the new understanding of the molecular mechanisms underlying oncogenesis, and the development of the DNA-delivery vehicles or vectors. Many approaches to cancer gene therapy have been proposed, and several viral and non-viral vectors have been utilized. The purpose of this review article is to describe the various strategies of cancer gene therapy (transfer of tumor suppressor genes, suicide genes-enzyme/pro-drug approach, inhibition of dominant oncogenes, immunomodulation approaches, expression of molecules that affect angiogenesis, tumor invasion and metastasis, chemosensitization and radiosensitization approaches, and chemoprotection of stem cells). The chapter also reviews the commonly used vectors (retroviral vectors, adenoviral vectors, adeno-associated viral vectors, pox viruses, herpes simplex viruses, HIV- vectors, non-viral vectors and targetable vectors) for cancer gene therapy. Some of the important issues in cancer gene therapy, and the potential future directions are also being discussed.

  14. A Space Vector Modulation Scheme for Three-level ANPC Inverters With Neutral-point Potential Balancing and Switching Loss Reduction%三电平ANPC逆变器中点电压平衡和开关损耗减小的SVM控制策略

    胡存刚; 芮涛; 马大俊; 王群京; 罗方林

    2016-01-01

    The active neutral point clamped (ANPC) topology enable additional switch states and commutations compared to the neutral point clamped (NPC) topology. ANPC topology can overcome disadvantages of unequal semiconductor loss distribution in NPC topology. This paper investigated the control strategy of the neutral-point potential (NP) balancing and the switching loss (SL) reduction for three-level ANPC inverters. An novel three-level space vector pulse width modulation (SVM) was proposed to control the NP imbalance and to reduce the SL simultaneously. The novel virtual medium vectors were redefined, which were synthesized by the original medium vector and the adjacent two pairs of small vectors. Therefore, using the proposed VSVM, there are two pairs of small vectors in any region of the space vector diagram, which one pair of small vectors can be used to control the NP, and another pair of small vectors can be used for reducing the SL. The coordinately selected small vectors consider both the NP charge and the pulse sequence, so that the minimized NP ripple and switching events are guaranteed in one switching cycle. The simulation and experimental results are provided to verify the effectiveness of the proposed control strategy.%有源中点钳位型拓扑通过选择冗余开关状态和不同的电流通路能够有效控制器件的损耗平衡。论文对三电平有源中点钳位型逆变器中点电压平衡和开关损耗减少的控制策略进行研究,提出一种中点电压平衡和减小损耗的三电平空间矢量调制方法。将虚拟中矢量重新定义,新的虚拟中矢量由原中矢量和邻近的两对小矢量合成,因此参考矢量在空间矢量图的任何区域都有两个成对的正负小矢量参与合成,其中一个优先用于控制中点电压的平衡,另外一个可以用于其他控制目标。在每个开关周期内根据中点电压波动和开关序列选择合适的小矢量,在控

  15. Relativistic Rotating Vector Model

    Lyutikov, Maxim

    2016-01-01

    The direction of polarization produced by a moving source rotates with the respect to the rest frame. We show that this effect, induced by pulsar rotation, leads to an important correction to polarization swings within the framework of rotating vector model (RVM); this effect has been missed by previous works. We construct relativistic RVM taking into account finite heights of the emission region that lead to aberration, time-of-travel effects and relativistic rotation of polarization. Polarizations swings at different frequencies can be used, within the assumption of the radius-to-frequency mapping, to infer emission radii and geometry of pulsars.

  16. Números, vectores y funciones

    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...

  17. [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...

  18. Extended vector-tensor theories

    Kimura, Rampei; Naruko, Atsushi; Yoshida, Daisuke

    2017-01-01

    Recently, several extensions of massive vector theory in curved space-time have been proposed in many literatures. In this paper, we consider the most general vector-tensor theories that contain up to two derivatives with respect to metric and vector field. By imposing a degeneracy condition of the Lagrangian in the context of ADM decomposition of space-time to eliminate an unwanted mode, we construct a new class of massive vector theories where five degrees of freedom can propagate, corresponding to three for massive vector modes and two for massless tensor modes. We find that the generalized Proca and the beyond generalized Proca theories up to the quartic Lagrangian, which should be included in this formulation, are degenerate theories even in curved space-time. Finally, introducing new metric and vector field transformations, we investigate the properties of thus obtained theories under such transformations.

  19. 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.

  20. VLSI Processor For Vector Quantization

    Tawel, Raoul

    1995-01-01

    Pixel intensities in each kernel compared simultaneously with all code vectors. Prototype high-performance, low-power, very-large-scale integrated (VLSI) circuit designed to perform compression of image data by vector-quantization method. Contains relatively simple analog computational cells operating on direct or buffered outputs of photodetectors grouped into blocks in imaging array, yielding vector-quantization code word for each such block in sequence. Scheme exploits parallel-processing nature of vector-quantization architecture, with consequent increase in speed.

  1. Entangled vector vortex beams

    D'Ambrosio, Vincenzo; Carvacho, Gonzalo; Graffitti, Francesco; Vitelli, Chiara; Piccirillo, Bruno; Marrucci, Lorenzo; Sciarrino, Fabio

    2016-09-01

    Light beams having a vectorial field structure, or polarization, that varies over the transverse profile and a central optical singularity are called vector vortex (VV) beams and may exhibit specific properties such as focusing into "light needles" or rotation invariance. VV beams have already found applications in areas ranging from microscopy to metrology, optical trapping, nano-optics, and quantum communication. Individual photons in such beams exhibit a form of single-particle quantum entanglement between different degrees of freedom. On the other hand, the quantum states of two photons can be also entangled with each other. Here, we combine these two concepts and demonstrate the generation of quantum entanglement between two photons that are both in VV states: a form of entanglement between two complex vectorial fields. This result may lead to quantum-enhanced applications of VV beams as well as to quantum information protocols fully exploiting the vectorial features of light.

  2. Vectors in a Box

    Buchin, Kevin; Moser, Robin A; Pálvölgyi, Dömötör

    2009-01-01

    For an integer d>=1, let tau(d) be the smallest integer with the following property: If v1,v2,...,vt is a sequence of t>=2 vectors in [-1,1]^d with v1+v2+...+vt in [-1,1]^d, then there is a subset S of {1,2,...,t} of indices, 2= d^{d/2-o(d)}. These results contribute to understanding the master equality polyhedron with multiple rows defined by Dash et al., which is a "universal" polyhedron encoding valid cutting planes for integer programs (this line of research was started by Gomory in the late 1960s). In particular, the upper bound on tau(d) implies a pseudo-polynomial running time for an algorithm of Dash et al. for integer programming with a fixed number of constraints. The algorithm consists in solving a linear program, and it provides an alternative to a 1981 dynamic programming algorithm of Papadimitriou.

  3. Resonance vector mode locking

    Kolpakov, Stanislav A; Loika, Yuri; Tarasov, Nikita; Kalashnikov, Vladimir; Agrawal, Govind P

    2015-01-01

    A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow linewidth. However, further progress in linewidth narrowing seems to be limited by the complexity of the carrier-envelope phase control. Here for the first time we demonstrate experimentally and theoretically a new mechanism of resonance vector self-mode locking where tuning in-cavity birefringence leads to excitation of the longitudinal modes sidebands accompanied by the resonance phase locking of sidebands with the adjacent longitudinal modes. An additional resonance with acoustic phonons provides the repetition rate tunability and linewidth narrowing down to Hz range that drastically reduces the complexity of the carrier-envelope phase control and so will open the way to advance lasers in the context of applications in metrology, spectroscopy, microwave photonics, astronomy...

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

    Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, R; Allen, M T; Allison, J; Altenburg, D D; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Asgeirsson, D J; Aston, D; Azzolini, V; Baak, M A; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Bechtle, P; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Best, D S; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P C; Blount, N L; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Bowerman, D A; Boyd, J T; Bozzi, C; Brandenburg, G; Brandt, T; Brau, J E; Briand, H; Brown, C M; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Bugg, W; Bukin, A D; Bula, R; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, E; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Chen, X R; Cheng, B; Cheng, C H; Chia, Y M; Cibinetto, G; Clark, P J; Clarke, C K; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Corwin, L A; Cossutti, F; Cottingham, W N; Couderc, F; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cunha, A; Curry, S; Côté, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; De Nardo, Gallieno; De Sangro, R; Del Amo-Sánchez, P; Del Buono, L; Del Re, D; Della Ricca, G; Denig, A G; Di Lodovico, F; Di Marco, E; Dingfelder, J C; Dittongo, S; Dong, L; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Ebert, M; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Egede, U; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fang, F; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, K E; Ford, W T; Forster, I J; Forti, F; Fortin, D; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gao, Y; Gary, J W; Gaspero, M; Gatto, C; Gaz, A; George, K A; Gill, M S; Giorgi, M A; Gladney, L; Glanzman, T; Godang, R; Golubev, V B; Gowdy, S J; Gradl, W; Graham, M T; Graugès-Pous, E; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Z J; Hadavand, H K; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jain, V; Jasper, H; Jawahery, A; Jessop, C P; Judd, D; Kadyk, J A; Kagan, H; Karyotakis, Yu; Kass, R; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Klose, V; Knecht, N S; Koch, H; Kolb, J A; Kolomensky, Yu G; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lange, D J; Lankford, A J; Latham, T E; Latour, E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lee, C L; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, S; Li, X; Lista, L; Liu, H; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; Long, O; Lopes-Pegna, D; Lopez-March, N; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Mclachlin, S E; Meadows, B T; Mellado, B; Menges, W; Merkel, J; Messner, R; Meyer, N T; Meyer, W T; Mihályi, A; Mir, L M; Mishra, K; Mohanty, G B; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morganti, M; Morganti, S; Morii, M; Muheim, F; Müller, D R; Nagel, M; Naisbit, M T; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nesom, G; Nicholson, H; Nikolich, M B; Nogowski, R; Nugent, I M; O'Grady, C P; Ocariz, J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A; Palombo, F; Pan, B; Pan, Y; Panduro, W; Paoloni, E; Paolucci, P; Pappagallo, M; Park, W; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Perazzo, A; Perl, M; Peruzzi, I M; Peters, K; Petersen, B A; Petrella, A; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Piredda, G; Playfer, S; Poireau, V; Polci, F; Pompili, A; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prencipe, E; Prepost, R; Pripstein, M; Pruvot, S; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rahmat, R; Rama, M; Ratcliff, B N; Raven, G; Regensburger, J J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roberts, D A; Robertson, A I; Robertson, S H; Robutti, E; Rodier, S; Roe, N A; Ronan, M T; Roney, J M; Rong, G; Roodman, A; Roos, L; Rosenberg, E I; Rotondo, M; Roudeau, P; Rubin, A E; Ruddick, W O; Röthel, W; Sacco, R; Saeed, M A; Safai-Tehrani, F; Saleem, M; Salnikov, A A; Salvatore, F; Sanders, D A; Santroni, A; Saremi, S; Satpathy, A; Schalk, T; Schenk, S; Schilling, C J; Schindler, R H; Schofield, K C; Schott, G; Schröder, T; Schröder, H; Schubert, J; Schubert, K R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Serrano, J; Sharma, V; Shen, B C; Sherwood, D J; Simard, M; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spitznagel, M; Spradlin, P; Steinke, M; Stelzer, J; Stocchi, A; Stoker, D P; Stroili, R; Strom, D; Strube, J; Stugu, B; Stängle, H; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; Suzuki, K; Swain, S K; Taras, P; Taylor, F; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Therin, G; Thiebaux, C; Thompson, J M; Tisserand, V; Todyshev, Y K; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Ulmer, K A; Uwer, U; Van Bakel, N; Vasseur, G; Vavra, J; Vazquez, A; Verderi, M; Viaud, F B; Vitale, L; Voci, C; Voena, C; Volk, A; Wagner, A P; Wagner, S R; Wagoner, D E; Waldi, R; Walker, D; Walsh, J J; Wang, K; Wang, P; Wang, W F; Wappler, F R; Watson, A T; Weaver, M; Weinstein, A J R; Wenzel, W A; Wilden, L; Williams, D C; Williams, J C; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Winklmeier, F; Wisniewski, W J; Wittgen, M; Wong, Q K; Wormser, G; Wren, A C; Wright, D H; Wright, D M; Wu, J; Wu, S L; Wulsin, H W; Xie, Y; Yamamoto, R K; Yarritu, A K; Ye, S; Yi, J I; Yi, K; Young, C C; Yu, Z; Yéche, C; Zain, S B; Zallo, A; Zeng, Q; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Ziegler, V; Zito, M; Çuhadar-Dönszelmann, T; al, et

    2007-01-01

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

  5. Alphavirus vectors: applications for DNA vaccine production and gene expression.

    Lundstrom, K

    2000-01-01

    Replication-deficient alphavirus vectors have been developed for efficient high-level transgene expression. The broad host range of alphaviruses has allowed infection of a wide variety of mammalian cell lines and primary cultures. Particularly, G protein-coupled receptors have been expressed at high levels and subjected to binding and functional studies. Expression in suspension cultures has greatly facilitated production of large quantities of recombinant proteins for structural studies. Injection of recombinant alphavirus vectors into rodent brain resulted in local reporter gene expression. Highly neuron-specific expression was obtained in hippocampal slice cultures in vivo. Additionally, preliminary studies in animal models suggest that alphavirus vectors can be attractive candidates for gene therapy applications. Traditionally alphavirus vectors, either attenuated strains or replication-deficient particles, have been used to elicit efficient immune responses in animals. Recently, the application of alphaviruses has been extended to naked nucleic acids. Injection of DNA as well as RNA vectors has demonstrated efficient antigen production. In many cases, protection against lethal challenges has been obtained after immunization with alphavirus particles or nucleic acid vectors. Alphavirus vectors can therefore be considered as potentially promising vectors for vaccine production.

  6. 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.

  7. 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.

  8. Testing identifiablility of cointegrating vectors

    H.P. Boswijk

    1996-01-01

    This article analyzes the identification and normalization of cointegrating vectors. Normalizing a cointegrating relation with respect to one of the relevant variables is with loss of generality; and restrictions that are supposed to identify a vector may fail to do so for particular parameter value

  9. The Neural Support Vector Machine

    Wiering, Marco; van der Ree, Michiel; Embrechts, Mark; Stollenga, Marijn; Meijster, Arnold; Nolte, A; Schomaker, Lambertus

    2013-01-01

    This paper describes a new machine learning algorithm for regression and dimensionality reduction tasks. The Neural Support Vector Machine (NSVM) is a hybrid learning algorithm consisting of neural networks and support vector machines (SVMs). The output of the NSVM is given by SVMs that take a centr

  10. GPU Accelerated Vector Median Filter

    Aras, Rifat; Shen, Yuzhong

    2011-01-01

    Noise reduction is an important step for most image processing tasks. For three channel color images, a widely used technique is vector median filter in which color values of pixels are treated as 3-component vectors. Vector median filters are computationally expensive; for a window size of n x n, each of the n(sup 2) vectors has to be compared with other n(sup 2) - 1 vectors in distances. General purpose computation on graphics processing units (GPUs) is the paradigm of utilizing high-performance many-core GPU architectures for computation tasks that are normally handled by CPUs. In this work. NVIDIA's Compute Unified Device Architecture (CUDA) paradigm is used to accelerate vector median filtering. which has to the best of our knowledge never been done before. The performance of GPU accelerated vector median filter is compared to that of the CPU and MPI-based versions for different image and window sizes, Initial findings of the study showed 100x improvement of performance of vector median filter implementation on GPUs over CPU implementations and further speed-up is expected after more extensive optimizations of the GPU algorithm .

  11. 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)…

  12. Simplified Representation of Vector Fields

    Telea, Alexandru; Wijk, Jarke J. van

    1999-01-01

    Vector field visualization remains a difficult task. Although many local and global visualization methods for vector fields such as flow data exist, they usually require extensive user experience on setting the visualization parameters in order to produce images communicating the desired insight. We

  13. Estimation of Motion Vector Fields

    Larsen, Rasmus

    1993-01-01

    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...

  14. 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.

  15. Vector Meson Production in Collisions of Nucleons

    Brinkmann, K.-Th.; Abdel-Bary, M.; Abdel-Samad, S.; Clement, H.; Doroshkevich, E.; Dshemuchadse, S.; Dutz, H.; Ehrhardt, K.; Erhardt, A.; Eyrich, W.; Filippi, A.; Freiesleben, H.; Fritsch, M.; Georgi, J.; Gillitzer, A.; Gonser, P.; Jäkel, R.; Karsch, L.; Kilian, K.; Koch, H.; Kreß, J.; Kuhlmann, E.; Marcello, S.; Meyer, W.; Michel, P.; Morsch, H. P.; Möller, K.; Mörtel, H.; Naumann, L.; Pinna, L.; Pizzolotto, L.; Roderburg, E.; Schamlott, A.; Schönmeier, P.; Schroeder, W.; Schulte-Wissermann, M.; Sefzick, T.; Steinke, M.; Stinzing, F.; Sun, G. Y.; Ucar, A.; Ullrich, W.; Wagner, G. J.; Wagner, M.; Wilms, A.; Wintz, P.; Wirth, S.; Wüstner, P.; Zupranski, P.

    The production of vector mesons in collisions between nucleons is studied in order to address a variety of issues concerning nucleon-nucleon interaction, reaction mechanism and properties of baryons. These studies are summarized with emphasis on the most recent experiments at the Time-of-Flight spectrometer TOF and results obtained at the COoler SYnchrotron COSY in Jülich. While currently the open questions regarding the so-called OZI violation, its relation to the meson exchange picture and the relative importance of contributions to the production mechanism from various channels within this formalism are still unresolved, the present-day experiments hold the potential to clarify the situation greatly. Possible extensions of the experimental program on vector mesons using 4π detection techniques for charged as well as neutral particles, in particular π0, are discussed.

  16. 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.

  17. 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.

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

    Blasi, Maria

    2012-01-01

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

  19. 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.

  20. Vector fields on nonorientable surfaces

    Dorin Ghisa

    2003-01-01

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

  1. Vector boson scattering at CLIC

    Kilian, Wolfgang; Fleper, Christian [Department Physik, Universitaet Siegen, 57068 Siegen (Germany); Reuter, Juergen [DESY Theory Group, 22603 Hamburg (Germany); Sekulla, Marco [Institut fuer Theoretische Physik, Karlsruher Institut fuer Technologie, 76131 Karlsruhe (Germany)

    2016-07-01

    Linear colliders operating in a range of multiple TeV are able to investigate the details of vector boson scattering and electroweak symmetry breaking. We calculate cross sections with the Monte Carlo generator WHIZARD for vector boson scattering processes at the future linear e{sup +} e{sup -} collider CLIC. By finding suitable cuts, the vector boson scattering signal processes are isolated from the background. Finally, we are able to determine exclusion sensitivities on the non-Standard Model parameters of the relevant dimension eight operators.

  2. 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

  3. On the Witt vector Frobenius

    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....

  4. 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 magnetic...

  5. Introduction to matrices and vectors

    Schwartz, Jacob T

    2001-01-01

    In this concise undergraduate text, the first three chapters present the basics of matrices - in later chapters the author shows how to use vectors and matrices to solve systems of linear equations. 1961 edition.

  6. GRE Enzymes for Vector Analysis

    U.S. Environmental Protection Agency — Microbial enzyme data that were collected during the 2004-2006 EMAP-GRE program. These data were then used by Moorhead et al (2016) in their ecoenzyme vector...

  7. Transcriptional Silencing of Retroviral Vectors

    Lund, Anders Henrik; Duch, M.; Pedersen, F.S.

    1996-01-01

    . Extinction of long-term vector expression has been observed after implantation of transduced hematopoietic cells as well as fibroblasts, myoblasts and hepatocytes. Here we review the influence of vector structure, integration site and cell type on transcriptional silencing. While down-regulation of proviral...... 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......RNA primer for reverse transcription may have a major influence on transcriptional silencing. Alterations of these elements of the vector backbone as well as the use of internal promoter elements from housekeeping genes may contribute to reduce transcriptional silencing. The use of cell culture and animal...

  8. Disease Vector Ecology Profile: Colombia

    1998-12-01

    Cordillera Oriental. Studies in Norte de Santander Department in 1985 indicate 15.6% of the houses were infested with the vector, 30% of the...population studied had positive serologies, and 9% displayed abnormal heart function. Trypanosoma cruzi is found in animals and extradomiciliary vectors...drainage toward Lopez, the river slows and Simulium exiguum are less abundant than they are near San Antonio. From 1990-1995, Ivermectin (antihelminthic

  9. Identifying Cancer Driver Genes Using Replication-Incompetent Retroviral Vectors

    Victor M. Bii

    2016-10-01

    Full Text Available Identifying novel genes that drive tumor metastasis and drug resistance has significant potential to improve patient outcomes. High-throughput sequencing approaches have identified cancer genes, but distinguishing driver genes from passengers remains challenging. Insertional mutagenesis screens using replication-incompetent retroviral vectors have emerged as a powerful tool to identify cancer genes. Unlike replicating retroviruses and transposons, replication-incompetent retroviral vectors lack additional mutagenesis events that can complicate the identification of driver mutations from passenger mutations. They can also be used for almost any human cancer due to the broad tropism of the vectors. Replication-incompetent retroviral vectors have the ability to dysregulate nearby cancer genes via several mechanisms including enhancer-mediated activation of gene promoters. The integrated provirus acts as a unique molecular tag for nearby candidate driver genes which can be rapidly identified using well established methods that utilize next generation sequencing and bioinformatics programs. Recently, retroviral vector screens have been used to efficiently identify candidate driver genes in prostate, breast, liver and pancreatic cancers. Validated driver genes can be potential therapeutic targets and biomarkers. In this review, we describe the emergence of retroviral insertional mutagenesis screens using replication-incompetent retroviral vectors as a novel tool to identify cancer driver genes in different cancer types.

  10. Biosafety challenges for use of lentiviral vectors in gene therapy.

    Rothe, Michael; Modlich, Ute; Schambach, Axel

    2013-12-01

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

  11. Pattern vectors from algebraic graph theory.

    Wilson, Richard C; Hancock, Edwin R; Luo, Bin

    2005-07-01

    Graph structures have proven computationally cumbersome for pattern analysis. The reason for this is that, before graphs can be converted to pattern vectors, correspondences must be established between the nodes of structures which are potentially of different size. To overcome this problem, in this paper, we turn to the spectral decomposition of the Laplacian matrix. We show how the elements of the spectral matrix for the Laplacian can be used to construct symmetric polynomials that are permutation invariants. The coefficients of these polynomials can be used as graph features which can be encoded in a vectorial manner. We extend this representation to graphs in which there are unary attributes on the nodes and binary attributes on the edges by using the spectral decomposition of a Hermitian property matrix that can be viewed as a complex analogue of the Laplacian. To embed the graphs in a pattern space, we explore whether the vectors of invariants can be embedded in a low-dimensional space using a number of alternative strategies, including principal components analysis (PCA), multidimensional scaling (MDS), and locality preserving projection (LPP). Experimentally, we demonstrate that the embeddings result in well-defined graph clusters. Our experiments with the spectral representation involve both synthetic and real-world data. The experiments with synthetic data demonstrate that the distances between spectral feature vectors can be used to discriminate between graphs on the basis of their structure. The real-world experiments show that the method can be used to locate clusters of graphs.

  12. Live bacterial vaccine vectors: An overview

    Adilson José da Silva

    2014-12-01

    Full Text Available Genetically attenuated microorganisms, pathogens, and some commensal bacteria can be engineered to deliver recombinant heterologous antigens to stimulate the host immune system, while still offering good levels of safety. A key feature of these live vectors is their capacity to stimulate mucosal as well as humoral and/or cellular systemic immunity. This enables the use of different forms of vaccination to prevent pathogen colonization of mucosal tissues, the front door for many infectious agents. Furthermore, delivery of DNA vaccines and immune system stimulatory molecules, such as cytokines, can be achieved using these special carriers, whose adjuvant properties and, sometimes, invasive capacities enhance the immune response. More recently, the unique features and versatility of these vectors have also been exploited to develop anti-cancer vaccines, where tumor-associated antigens, cytokines, and DNA or RNA molecules are delivered. Different strategies and genetic tools are constantly being developed, increasing the antigenic potential of agents delivered by these systems, opening fresh perspectives for the deployment of vehicles for new purposes. Here we summarize the main characteristics of the different types of live bacterial vectors and discuss new applications of these delivery systems in the field of vaccinology.

  13. Handling S/MAR vectors.

    Hagedorn, Claudia; Baiker, Armin; Postberg, Jan; Ehrhardt, Anja; Lipps, Hans J

    2012-06-01

    Nonviral episomal vectors represent attractive alternatives to currently used virus-based expression systems. In the late 1990s, it was shown that a plasmid containing an expression cassette linked to a scaffold/matrix attached region (S/MAR) replicates as a low copy number episome in all cell lines tested, as well as primary cells, and can be used for the genetic modification of higher animals. Once established in the cell, the S/MAR vector replicates early during S-phase and, in the absence of selection, is stably retained in the cells for an unlimited period of time. This vector can therefore be regarded as a minimal model system for studying the epigenetic regulation of replication and functional nuclear architecture. In theory, this construct represents an almost "ideal" expression system for gene therapy. In practice, S/MAR-based vectors stably modify mammalian cells with efficiencies far below those of virus-based constructs. Consequently, they have not yet found application in gene therapy trials. Furthermore, S/MAR vector systems are not trivial to handle and several critical technical issues have to be considered when modifying these vectors for various applications.

  14. Decays of the vector glueball

    Giacosa, Francesco; Janowski, Stanislaus

    2016-01-01

    We calculate two- and three-body decays of the (lightest) vector glueball into (pseudo)scalar, (axial-)vector, as well as pseudovector and excited vector mesons. By setting the mass of this yet hypothetical vector glueball to 3.8 GeV as predicted by Lattice QCD, many branching ratios can be computed and represent a parameter-free prediction of our approach. We find that the decay mode $\\omega\\pi\\pi$ should be one of the largest (both through the decay chain $\\mathcal{O}\\rightarrow b_{1}\\pi\\rightarrow$ $\\omega\\pi\\pi$ and through the direct coupling $\\mathcal{O}\\rightarrow\\omega\\pi\\pi$)$.$ Similarly, the (direct and indirect) decay into $\\pi KK^{\\ast}(892)$ is sizable. Moreover, the decays into $\\rho\\pi$ and $K^{\\ast}(892)K$ are, although subleading, possible and could play a role in explaining the $\\rho\\pi$ puzzle of the charmonium state $\\psi(2S)$ thank to a (small) mixing with the vector glueball. The vector glueball can be directly formed at the ongoing BESIII experiment as well as at the future PANDA exper...

  15. 永磁电动机转子偏心空载气隙磁场矢量位解析法%Analytical Method with Vector Magnetic Potential for Open-Circuit Air-Gap Magnetic Field Computation in Permanent Magnet Motors with Rotor Eccentricity

    刘蓉晖; 章跃进; 李琛; 周晓燕

    2013-01-01

    The analytical method with vector magnetic potential was proposed to calculate the open-circuit air-gap magnetic field distribution in surface-mounted permanent magnet motors with rotor eccentricity,and the method was applicable to both internal and external rotor eccentric structure.The Laplace' s or Poisson' s equations and associated boundary conditions were formulated and solved by a perturbation method.The analytical eccentric air-gap flux density expressions were deduced by the use of vector magnetic potential.The proposed method was verified by comparing flux density of the analytical results with the finite element analysis results.%提出了矢量磁位解析法用于分析转子偏心表贴式永磁电动机的空载气隙磁场,该方法适用于内转子偏心和外转子偏心结构.解析模型的求解场域分为气隙区域和转子永磁体区域,两类子区域的矢量磁位拉普拉斯方程或泊松方程根据交界条件建立关联,利用边界摄动理论,通过矢量位解析法求解转子偏心表贴式永磁电动机在定子坐标系下和转子坐标系下的气隙磁通密度表达式,实例计算结果与有限元法分析波形作比较,验证了矢量位解析法的有效性和正确性.

  16. Structural Learning of Attack Vectors for Generating Mutated XSS Attacks

    Yi-Hsun Wang

    2010-09-01

    Full Text Available Web applications suffer from cross-site scripting (XSS attacks that resulting from incomplete or incorrect input sanitization. Learning the structure of attack vectors could enrich the variety of manifestations in generated XSS attacks. In this study, we focus on generating more threatening XSS attacks for the state-of-the-art detection approaches that can find potential XSS vulnerabilities in Web applications, and propose a mechanism for structural learning of attack vectors with the aim of generating mutated XSS attacks in a fully automatic way. Mutated XSS attack generation depends on the analysis of attack vectors and the structural learning mechanism. For the kernel of the learning mechanism, we use a Hidden Markov model (HMM as the structure of the attack vector model to capture the implicit manner of the attack vector, and this manner is benefited from the syntax meanings that are labeled by the proposed tokenizing mechanism. Bayes theorem is used to determine the number of hidden states in the model for generalizing the structure model. The paper has the contributions as following: (1 automatically learn the structure of attack vectors from practical data analysis to modeling a structure model of attack vectors, (2 mimic the manners and the elements of attack vectors to extend the ability of testing tool for identifying XSS vulnerabilities, (3 be helpful to verify the flaws of blacklist sanitization procedures of Web applications. We evaluated the proposed mechanism by Burp Intruder with a dataset collected from public XSS archives. The results show that mutated XSS attack generation can identify potential vulnerabilities.

  17. Adjuvants and vector systems for allergy vaccines.

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

    2011-05-01

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

  18. 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.

  19. Phased-array vector velocity estimation using transverse oscillations

    Pihl, Michael Johannes; Marcher, Jønne; Jensen, Jørgen Arendt

    2012-01-01

    A method for estimating the 2-D vector velocity of blood using a phased-array transducer is presented. The approach is based on the transverse oscillation (TO) method. The purposes of this work are to expand the TO method to a phased-array geometry and to broaden the potential clinical applicabil......A method for estimating the 2-D vector velocity of blood using a phased-array transducer is presented. The approach is based on the transverse oscillation (TO) method. The purposes of this work are to expand the TO method to a phased-array geometry and to broaden the potential clinical...

  20. Containment of arthropod disease vectors.

    Scott, Thomas W

    2005-01-01

    Effective containment of arthropod vectors of infectious diseases is necessary to prevent transmission of pathogens by released, infected vectors and to prevent vectors that escape from establishing populations that subsequently contribute to increased disease. Although rare, past releases illustrate what can go wrong and justify the need for guidelines that minimize risks. An overview of recommendations for insectary facilities, practices, and equipment is provided, and features of four recently published and increasingly rigorous arthropod containment levels (ACLs 1-4) are summarized. ACL-1 is appropriate for research that constitutes the lowest risk level, including uninfected arthropods or vectors that are infected with micro-organisms that do not cause disease in humans, domestic animals, or wildlife. ACL-2 is appropriate for indigenous and exotic arthropods that represent a moderate risk, including vectors infected or suspected of being infected with biosafety level (BSL)-2 infectious agents and arthropods that have been genetically modified in ways that do not significantly affect their fecundity, survival, host preference, or vector competence. ACL-3 is recommended for arthropods that are or may be infected with BSL-3 infectious agents. ACL-3 places greater emphasis on pathogen containment and more restricted access to the insectary than ACL-2. ACL-4 is intended for arthropods that are infected with the most dangerous BSL-4 infectious agents, which can cause life-threatening illness by aerosol or arthropod bite. Adherence to these guidelines will result in laboratory-based arthropod vector research that minimizes risks and results in important new contributions to applied and basic science.

  1. Project Physics Programmed Instruction, Vectors 1.

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    This programmed instruction booklet is an interim version of instructional materials being developed by Harvard Project Physics. It is the first in a series of three booklets on vectors and covers the definitions of vectors and scalars, drawing vector quantities to scale, and negative vectors. For others in this series, see SE 015 550 and SE 015…

  2. Project Physics Programmed Instruction, Vectors 2.

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    This is the second of a series of three programmed instruction booklets on vectors developed by Harvard Project Physics. It covers adding two or more vectors together, and finding a third vector that could be added to two given vectors to make a sum of zero. For other booklets in this series, see SE 015 549 and SE 015 551. (DT)

  3. The Duality on Vector Optimization Problems

    HUANG Long-guang

    2012-01-01

    Duality framework on vector optimization problems in a locally convex topological vector space are established by using scalarization with a cone-strongly increasing function.The dualities for the scalar convex composed optimization problems and for general vector optimization problems are studied.A general approach for studying duality in vector optimization problems is presented.

  4. A NOTE ON VECTOR CASCADE ALGORITHM

    Qiu-hui Chen; Jin-zhao Liu; Wen-sheng Zhang

    2002-01-01

    The focus of this paper is on the relationship between accuracy of multivariate refinable vector and vector cascade algorithm. We show that, if the vector cascade algorithm (1.5) with isotropic dilation converges to a vector-valued function with regularity, then the initial function must satisfy the Strang-Fix conditions.

  5. The biological control of disease vectors.

    Okamoto, Kenichi W; Amarasekare, Priyanga

    2012-09-21

    Vector-borne diseases are common in nature and can have a large impact on humans, livestock and crops. Biological control of vectors using natural enemies or competitors can reduce vector density and hence disease transmission. However, the indirect interactions inherent in host-vector disease systems make it difficult to use traditional pest control theory to guide biological control of disease vectors. This necessitates a conceptual framework that explicitly considers a range of indirect interactions between the host-vector disease system and the vector's biological control agent. Here we conduct a comparative analysis of the efficacy of different types of biological control agents in controlling vector-borne diseases. We report three key findings. First, highly efficient predators and parasitoids of the vector prove to be effective biological control agents, but highly virulent pathogens of the vector also require a high transmission rate to be effective. Second, biocontrol agents can successfully reduce long-term host disease incidence even though they may fail to reduce long-term vector densities. Third, inundating a host-vector disease system with a natural enemy of the vector has little or no effect on reducing disease incidence, but inundating the system with a competitor of the vector has a large effect on reducing disease incidence. The comparative framework yields predictions that are useful in developing biological control strategies for vector-borne diseases. We discuss how these predictions can inform ongoing biological control efforts for host-vector disease systems.

  6. Implementing Bayesian Vector Autoregressions Implementing Bayesian Vector Autoregressions

    Richard M. Todd

    1988-03-01

    Full Text Available Implementing Bayesian Vector Autoregressions This paper discusses how the Bayesian approach can be used to construct a type of multivariate forecasting model known as a Bayesian vector autoregression (BVAR. In doing so, we mainly explain Doan, Littermann, and Sims (1984 propositions on how to estimate a BVAR based on a certain family of prior probability distributions. indexed by a fairly small set of hyperparameters. There is also a discussion on how to specify a BVAR and set up a BVAR database. A 4-variable model is used to iliustrate the BVAR approach.

  7. Vector Encoding in Biochemical Networks

    Potter, Garrett; Sun, Bo

    Encoding of environmental cues via biochemical signaling pathways is of vital importance in the transmission of information for cells in a network. The current literature assumes a single cell state is used to encode information, however, recent research suggests the optimal strategy utilizes a vector of cell states sampled at various time points. To elucidate the optimal sampling strategy for vector encoding, we take an information theoretic approach and determine the mutual information of the calcium signaling dynamics obtained from fibroblast cells perturbed with different concentrations of ATP. Specifically, we analyze the sampling strategies under the cases of fixed and non-fixed vector dimension as well as the efficiency of these strategies. Our results show that sampling with greater frequency is optimal in the case of non-fixed vector dimension but that, in general, a lower sampling frequency is best from both a fixed vector dimension and efficiency standpoint. Further, we find the use of a simple modified Ornstein-Uhlenbeck process as a model qualitatively captures many of our experimental results suggesting that sampling in biochemical networks is based on a few basic components.

  8. Ensemble Dynamics and Bred Vectors

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

    2011-01-01

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

  9. Modification to the Capsid of the Adenovirus Vector That Enhances Dendritic Cell Infection and Transgene-Specific Cellular Immune Responses

    Worgall, Stefan; Busch, Annette; Rivara, Michael; Bonnyay, David; Leopold, Philip L.; Merritt, Robert; Hackett, Neil R.; Rovelink, Peter W.; Joseph T Bruder; Wickham, Thomas J.; Kovesdi, Imi; Crystal, Ronald G.

    2004-01-01

    Adenovirus (Ad) gene transfer vectors can be used to transfer and express antigens and function as strong adjuvants and thus are useful platforms for the development of genetic vaccines. Based on the hypothesis that Ad vectors with enhanced infectibility of dendritic cells (DC) may be able to evoke enhanced immune responses against antigens encoded by the vector in vivo, the present study analyzes the vaccine potential of an Ad vector expressing β-galactosidase as a model antigen and genetica...

  10. MAR characteristic motifs mediate episomal vector in CHO cells.

    Lin, Yan; Li, Zhaoxi; Wang, Tianyun; Wang, Xiaoyin; Wang, Li; Dong, Weihua; Jing, Changqin; Yang, Xianjun

    2015-04-01

    An ideal gene therapy vector should enable persistent transgene expression without limitations in safety and reproducibility. Recent researches' insight into the ability of chromosomal matrix attachment regions (MARs) to mediate episomal maintenance of genetic elements allowed the development of a circular episomal vector. Although a MAR-mediated engineered vector has been developed, little is known on which motifs of MAR confer this function during interaction with the host genome. Here, we report an artificially synthesized DNA fragment containing only characteristic motif sequences that served as an alternative to human beta-interferon matrix attachment region sequence. The potential of the vector to mediate gene transfer in CHO cells was investigated. The short synthetic MAR motifs were found to mediate episomal vector at a low copy number for many generations without integration into the host genome. Higher transgene expression was maintained for at least 4 months. In addition, MAR was maintained episomally and conferred sustained EGFP expression even in nonselective CHO cells. All the results demonstrated that MAR characteristic sequence-based vector can function as stable episomes in CHO cells, supporting long-term and effective transgene expression.

  11. 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.

  12. [Transfection of HL-60 cells by Venus lentiviral vector].

    Li, Zheng; Hu, Shao-Yan; Cen, Jian-Nong; Chen, Zi-Xing

    2013-06-01

    In order to study the potential of Venus, lentiviral vector, applied to acute myeloid leukemia, the recombinant vector Venus-C3aR was transfected into 293T packing cells by DNA-calcium phosphate coprecipitation. All virus stocks were collected and transfected into HL-60, the GFP expression in HL-60 cells was measured by flow cytometry. The expression level of C3aR1 in transfected HL-60 cells was identified by RT-PCR and flow cytometry. The lentiviral toxicity on HL-60 was measured by using CCK-8 method and the ability of cell differentiation was observed. The results indicated that the transfection efficacy of lentiviral vector on HL-60 cells was more than 95%, which meets the needs for further study. C3aR1 expression on HL-60 cells increased after being transfected with recombinant lentiviral vector. Before and after transfection, the proliferation and differentiation of cells were not changed much. It is concluded that the lentiviral vector showed a high efficacy to transfect AML cells and can be integrated in genome of HL-60 cells to realize the stable expression of interest gene. Meanwhile, lentiviral vector can not affect HL-60 cell ability to proliferate and differentiate.

  13. Feline Foamy Virus-Based Vectors: Advantages of an Authentic Animal Model

    Martin Löchelt

    2013-07-01

    Full Text Available New-generation retroviral vectors have potential applications in vaccination and gene therapy. Foamy viruses are particularly interesting as vectors, because they are not associated to any disease. Vector research is mainly based on primate foamy viruses (PFV, but cats are an alternative animal model, due to their smaller size and the existence of a cognate feline foamy virus (FFV. The potential of replication-competent (RC FFV vectors for vaccination and replication-deficient (RD FFV-based vectors for gene delivery purposes has been studied over the past years. In this review, the key achievements and functional evaluation of the existing vectors from in vitro cell culture systems to out-bred cats will be described. The data presented here demonstrate the broad application spectrum of FFV-based vectors, especially in pathogen-specific prophylactic and therapeutic vaccination using RD vectors in cats and in classical gene delivery. In the cat-based system, FFV-based vectors provide an advantageous platform to evaluate and optimize the applicability, efficacy and safety of foamy virus (FV vectors, especially the understudied aspect of FV cell and organ tropism.

  14. 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.

  15. 3-D Vector Flow Imaging

    Holbek, Simon

    studies and in vivo. Phantom measurements are compared with their corresponding reference value, whereas the in vivo measurement is validated against the current golden standard for non-invasive blood velocity estimates, based on magnetic resonance imaging (MRI). The study concludes, that a high precision......, if this significant reduction in the element count can still provide precise and robust 3-D vector flow estimates in a plane. The study concludes that the RC array is capable of estimating precise 3-D vector flow both in a plane and in a volume, despite the low channel count. However, some inherent new challenges......For the last decade, the field of ultrasonic vector flow imaging has gotten an increasingly attention, as the technique offers a variety of new applications for screening and diagnostics of cardiovascular pathologies. The main purpose of this PhD project was therefore to advance the field of 3-D...

  16. Skyrmions with vector mesons revisited

    Oh, Yongseok

    2014-01-01

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

  17. Quantum contextuality for rational vectors

    Cabello, Adan

    2010-01-01

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

  18. 3D vector flow imaging

    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...... on 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 on 5...

  19. Multi-Center Vector Field Methods for Wave Equations

    Soffer, Avy; Xiao, Jianguo

    2016-12-01

    We develop the method of vector-fields to further study Dispersive Wave Equations. Radial vector fields are used to get a-priori estimates such as the Morawetz estimate on solutions of Dispersive Wave Equations. A key to such estimates is the repulsiveness or nontrapping conditions on the flow corresponding to the wave equation. Thus this method is limited to potential perturbations which are repulsive, that is the radial derivative pointing away from the origin. In this work, we generalize this method to include potentials which are repulsive relative to a line in space (in three or higher dimensions), among other cases. This method is based on constructing multi-centered vector fields as multipliers, cancellation lemmas and energy localization.

  20. Regional and seasonal response of a West Nile virus vector to climate change

    Cory W Morin; Comrie, Andrew C.

    2013-01-01

    The potential impacts of climate change on human health are possibly large and not yet well understood, especially for vector-borne diseases. This study provides projections of how climate change may affect the population of a West Nile virus mosquito vector across the southern United States. Using a climate-driven mosquito population model, we simulate vector abundance under base and future climate. Under future climate, many locations exhibit a lengthening of the mosquito season with a decr...

  1. Vector competence of selected North American Culex and Coquillettidia mosquitoes for West Nile virus.

    Sardelis, M. R.; Turell, M.J.; Dohm, D. J.; O'Guinn, M. L.

    2001-01-01

    To control West Nile virus (WNV), it is necessary to know which mosquitoes are able to transmit this virus. Therefore, we evaluated the WNV vector potential of several North American mosquito species. Culex restuans and Cx. salinarius, two species from which WNV was isolated in New York in 2000, were efficient laboratory vectors. Cx. quinquefasciatus and Cx. nigripalpus from Florida were competent but only moderately efficient vectors. Coquillettidia perturbans was an inefficient laboratory v...

  2. 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.

  3. 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

  4. Requirements for airborne vector gravimetry

    Schwarz, K. P.; Colombo, O.; Hein, G.; Knickmeyer, E. T.

    1992-01-01

    The objective of airborne vector gravimetry is the determination of the full gravity disturbance vector along the aircraft trajectory. The paper briefly outlines the concept of this method using a combination of inertial and GPS-satellite data. The accuracy requirements for users in geodesy and solid earth geophysics, oceanography and exploration geophysics are then specified. Using these requirements, accuracy specifications for the GPS subsystem and the INS subsystem are developed. The integration of the subsystems and the problems connected with it are briefly discussed and operational methods are indicated that might reduce some of the stringent accuracy requirements.

  5. Vector Theory in Relativistic Thermodynamics

    刘泽文

    1994-01-01

    It is pointed out that five defects occur in Planck-Einstein’s relativistic thermodynamics (P-E theory). A vector theory in relativistic thermodynamics (VTRT) is established. Defining the internal energy as a 4-vector, and supposing the entropy and the number of. particles to be invariants we have derived the transformations of all quantities, and subsequently got the Lagrangian and 4-D forms of thermodynamic laws. In order to test the new theory, several exact solutions with classical limits are given. The VTRT is free from the defects of the P-E theory.

  6. Plant Virus Expression Vector Development: New Perspectives

    Kathleen Hefferon

    2014-01-01

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

  7. Vectors for gene therapy of skin diseases.

    Pfützner, Wolfgang

    2010-08-01

    The success of gene therapy mainly depends on the gene vector (GV) responsible for the efficient transport of genetic information. The qualities of a GV have a profound influence on the method of application, the efficiency of gene transfer in the target tissue, the amount and persistence of gene expression and the potential side effects and safety risks. Clinical gene therapy studies over the past 20 years have contributed to the development and testing of different GV systems, some of which also show great potential for the treatment of skin diseases. In this review the structures, methods of application, characteristics, clinical uses and possibilities for optimization of these GV will be discussed with regard to their cutaneous applications.

  8. Scalar Calibration of Vector Magnetometers

    Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz;

    2000-01-01

    The calibration parameters of a vector magnetometer are estimated only by the use of a scalar reference magnetometer. The method presented in this paper differs from those previously reported in its linearized parametrization. This allows the determination of three offsets or signals in the absence...

  9. 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 ...

  10. SCALAR AND VECTOR IN COMPULATION

    Valery F. Ochkov

    2013-01-01

    Full Text Available The article deals with two fundamental data types – scalar and vector (array, without the ability of working with them one cannot solve using computer school or university tasks in mathematics, physics, chemistry and other technical training courses. Some fundamentals of teaching computer science at school and university are covered as well. 

  11. Vector-valued fuzzy multifunctions

    Ismat Beg

    2001-01-01

    Full Text Available Some of the properties of vector-valued fuzzy multifunctions are studied. The notion of sum fuzzy multifunction, convex hull fuzzy multifunction, close convex hull fuzzy multifunction, and upper demicontinuous are given, and some of the properties of these fuzzy multifunctions are investigated.

  12. 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…

  13. Sparse Matrix Vector Processing Formats

    Stathis, P.T.

    2004-01-01

    In this dissertation we have identified vector processing shortcomings related to the efficient storing and processing of sparse matrices. To alleviate existent problems we propose two storage formats denoted as Block Based Compression Storage (BBCS) format and Hierarchical Sparse Matrix (HiSM) stor

  14. Bifurcations of optimal vector fields

    Kiseleva, T.; Wagener, F.

    2015-01-01

    We study the structure of the solution set of a class of infinite-horizon dynamic programming problems with one-dimensional state spaces, as well as their bifurcations, as problem parameters are varied. The solutions are represented as the integral curves of a multivalued optimal vector field on sta

  15. Phlebotomine Vectors of Human Disease.

    1983-12-30

    different. We refrain from naming this specimen until more material becomes available. 12. Lutzomyia olmeca bicolor Fairchild and Theodor 1971...Castillo (1958) and Arzube (1960). Lutzomyia olmeca bicolor is the suspected vector of Leishmania mexicana aristedesi among rodents and marsupials in

  16. 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.

  17. Phase transitions in Vector Quantization

    Witoelar, Aree; Ghosh, Anarta; Biehl, Michael; Verleysen, Michel

    2008-01-01

    We study Winner-Takes-All and rank based Vector Quantization along the lines of the statistical physics of off-line learning. Typical behavior of the system is obtained within a model where high-dimensional training data are drawn from a mixture of Gaussians. The analysis becomes exact in the simpli

  18. 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...

  19. The consequences of poor vectorization

    CERN. Geneva

    2016-01-01

    This talk briefly discusses the vectorization problem and how it impacts scientific and engineering systems. A simple cost model of designing such system in context of different phases of software lifetime is considered. Finally a concept for scalable solution is presented.

  20. Vector Bundles over Elliptic Fibrations

    Friedman, R; Witten, Edward; Friedman, Robert; Morgan, John W.; Witten, Edward

    1997-01-01

    This paper gives various methods for constructing vector bundles over elliptic curves and more generally over families of elliptic curves. We construct universal families over generalized elliptic curves via spectral cover methods and also by extensions, and then give a relative version of the construction in families. We give various examples and make Chern class computations.

  1. Large N Expansion. Vector Models

    Nissimov, E; Nissimov, Emil; Pacheva, Svetlana

    2006-01-01

    Preliminary version of a contribution to the "Quantum Field Theory. Non-Perturbative QFT" topical area of "Modern Encyclopedia of Mathematical Physics" (SELECTA), eds. Aref'eva I, and Sternheimer D, Springer (2007). Consists of two parts - "main article" (Large N Expansion. Vector Models) and a "brief article" (BPHZL Renormalization).

  2. 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.

  3. 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.

  4. Global transcriptional analysis reveals surface remodeling of anaplasma marginale in the tick vector

    Background: Pathogens dependent upon vectors for transmission to new hosts undergo environment specific changes in gene transcription dependent on whether they are replicating in the vector or the mammalian host. Differential gene transcription, especially of potential vaccine candidates, is of inte...

  5. Wildlife as reservoirs for vector borne diseases in a warmer Scandinavian climate

    Bødker, Rene; Kristensen, Birgit

    The distribution of vector borne diseases is highly determined by environmental and climatic parameters. As the climate becomes warmer the potential for spread of exotic vector borne diseases may therefore increase in the Nordic countries. But this does not mean that all new outbreaks of diseases...

  6. Larvicidal effects of a neem (Azadirachta indica) oil formulation on the malaria vector Anopheles gambiae

    Okumu, F.O.; Knols, B.G.J.; Fillinger, U.

    2007-01-01

    Background - Larviciding is a key strategy used in many vector control programmes around the world. Costs could be reduced if larvicides could be manufactured locally. The potential of natural products as larvicides against the main African malaria vector, Anopheles gambiae s.s was evaluated. Method

  7. Vector competence of selected North American Culex and Coquillettidia mosquitoes for West Nile virus.

    Sardelis, M R; Turell, M J; Dohm, D J; O'Guinn, M L

    2001-01-01

    To control West Nile virus (WNV), it is necessary to know which mosquitoes are able to transmit this virus. Therefore, we evaluated the WNV vector potential of several North American mosquito species. Culex restuans and Cx. salinarius, two species from which WNV was isolated in New York in 2000, were efficient laboratory vectors. Cx. quinquefasciatus and Cx. nigripalpus from Florida were competent but only moderately efficient vectors. Coquillettidia perturbans was an inefficient laboratory vector. As WNV extends its range, exposure of additional mosquito species may alter its epidemiology.

  8. An Extrapolation Method of Vector Magnetic Field via Surface Integral Technique

    YAN Hui; XIAO Chang-han; ZHOU Guo-hua

    2009-01-01

    According to the integral relationship between the vector magnetic flux density on a spatial point and that over a closed surface around magnetic sources, a technique for the extrapolation of vector magnetic field of a ferromagnetic object is given without computing scalar potential and its gradient. The vector magnetic flux density on a remote spatial point can be extrapolated by surface integral from the vector values over a closed measureed surface around the ferromagnetic object. The correctness of the technique testified by a special example and simulation. The experimented result shows that its accuracy is satisfying and the execution time is less than 1 second.

  9. 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.

  10. 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\

  11. Pre-existing vector immunity does not prevent replication deficient adenovirus from inducing efficient CD8 T-cell memory and recall responses

    Steffensen, Maria Abildgaard; Jensen, Benjamin Anderschou Holbech; Holst, Peter Johannes

    2012-01-01

    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 invariant chain (Ii). To further evaluate the potential of this system, the concept of pre-existing inhibitory......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...... immunity to adenoviral vectors was revisited to investigate whether the inhibition previously seen with the Ad5 vector also applied to the optimized vector system. We found this to be the case, and antibodies dominated as the mechanism underlying inhibitory vector immunity. However, presence of CD8 T cells...

  12. Epidemiological Implications of Host Biodiversity and Vector Biology: Key Insights from Simple Models.

    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.

  13. 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.

  14. Looking forward by looking back: using historical calibration to improve forecasts of human disease vector distributions.

    Acheson, Emily Sohanna; Kerr, Jeremy Thomas

    2015-03-01

    Arthropod disease vectors, most notably mosquitoes, ticks, tsetse flies, and sandflies, are strongly influenced by environmental conditions and responsible for the vast majority of global vector-borne human diseases. The most widely used statistical models to predict future vector distributions model species niches and project the models forward under future climate scenarios. Although these methods address variations in vector distributions through space, their capacity to predict changing distributions through time is far less certain. Here, we review modeling methods used to validate and forecast future distributions of arthropod vectors under the effects of climate change and outline the uses or limitations of these techniques. We then suggest a validation approach specific to temporal extrapolation models that is gaining momentum in macroecological modeling and has great potential for epidemiological modeling of disease vectors. We performed systematic searches in the Web of Science, ScienceDirect, and Google Scholar to identify peer-reviewed English journal articles that model arthropod disease vector distributions under future environment scenarios. We included studies published up to and including June, 2014. We identified 29 relevant articles for our review. The majority of these studies predicted current species niches and projected the models forward under future climate scenarios without temporal validation. Historically calibrated forecast models improve predictions of changing vector distributions by tracking known shifts through recently observed time periods. With accelerating climate change, accurate predictions of shifts in disease vectors are crucial to target vector control interventions where needs are greatest.

  15. 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

  16. Vector-Boson Fusion and Vector-Boson Scattering

    Rauch, Michael

    2016-01-01

    Vector-boson fusion and vector-boson scattering are an important class of processes for the Large Hadron Collider at CERN. It is characterized by two high-energetic jets in the forward regions of the detector and reduced jet activity in the central region. The higher center-of-mass energy during the current and subsequent runs strongly boosts the sensitivity in these processes and allows to test the predictions of the Standard Model to a high precision. In this review, we first present the main phenomenological features of vector-boson fusion and scattering processes. Then we discuss the effects of higher-order corrections, which are available at NLO QCD for all processes and up to N3LO QCD and NLO electro-weak for VBF-H production. An additional refinement is the addition of parton-shower effects, where recently a lot of progress has been made. The appearance of triple and quartic gauge vertices in the production processes enables us to probe anomalous gauge couplings. We introduce and compare the different ...

  17. Graphical representations of vector functions in upper-division E&M

    Gire, Elizabeth; Price, Edward

    2012-02-01

    In upper division electricity and magnetism, the manipulation and interpretation of vector functions is pervasive and a significant challenge to students. At CSU San Marcos, using in-class activities adapted from the Oregon State University Paradigms in Physics Curriculum, students' difficulties with vector functions become evident in two types of in-class activities: sketching vector functions and relating vector and scalar functions (e.g., electric field and electric potential). For many students, the cause of these difficulties is a failure to fully distinguish between the components of a vector function and its coordinate variables. To address this difficulty, we implement an additional inclass activity requiring students to translate between graphical and algebraic representations of vector functions. We present our experience with these issues, how to address them, and how in-class activities can provide evidence of student thinking that facilitates curricular refinement.

  18. 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.

  19. Improved NYVAC-based vaccine vectors.

    Karen V Kibler

    Full Text Available While as yet there is no vaccine against HIV/AIDS, the results of the phase III Thai trial (RV144 have been encouraging and suggest that further improvements of the prime/boost vaccine combination of a poxvirus and protein are needed. With this aim, in this investigation we have generated derivatives of the candidate vaccinia virus vaccine vector NYVAC with potentially improved functions. This has been achieved by the re-incorporation into the virus genome of two host range genes, K1L and C7L, in conjunction with the removal of the immunomodulatory viral molecule B19, an antagonist of type I interferon action. These novel virus vectors, referred to as NYVAC-C-KC and NYVAC-C-KC-ΔB19R, have acquired relevant biological characteristics, giving higher levels of antigen expression in infected cells, replication-competency in human keratinocytes and dermal fibroblasts, activation of selective host cell signal transduction pathways, and limited virus spread in tissues. Importantly, these replication-competent viruses have been demonstrated to maintain a highly attenuated phenotype.

  20. Comment on "Electromagnetic potential vectors and spontaneous symmetry breaking"

    Dvoeglazov, V V

    1993-01-01

    The appearance of terms, which are analogous to ones required for symmetry breaking, in Lagrangian of Ref.~\\cite{Shebalin} is shown to be caused by gauge invariance of quantum electrodynamics (QED) and by inaccuracy of the author in a choice of canonical variables. These terms in the Lagrangian (18) of~\\cite{Shebalin} do not have physical meaning.

  1. 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

  2. On third order integrable vector Hamiltonian equations

    Meshkov, A. G.; Sokolov, V. V.

    2017-03-01

    A complete list of third order vector Hamiltonian equations with the Hamiltonian operator Dx having an infinite series of higher conservation laws is presented. A new vector integrable equation on the sphere is found.

  3. SYSTEM OF GENERALIZED VECTOR VARIATIONAL INEQUALITIES

    Fang Yaping; Huang Nanjing

    2005-01-01

    In this paper, the authors introduce and study system of generalized vector variational inequalities. Under suitable conditions, the existence of solutions for system of generalized vector variational inequalities is presented by Kakutani-Fan-Glicksberg fixed point theorem.

  4. 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.

  5. 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.

  6. Jet Vectoring Control Using a Novel Synthetic Jet Actuator

    2007-01-01

    A primary air jet vectoring control system with a novel synthetic jet actuator (SJA) is presented and simulated numerically. The results show that, in comparison with an existing traditional synthetic jet actuator, which is able to perform the duty of either "push" or "pull", one novel synthetic jet actuator can fulfill both "push" and "pull" functions to vector the primary jet by shifting a slide block inside it. Therefore, because the new actuator possesses greater efficiency, it has potentiality to replace the existing one in various applications, such as thrust vectoring and the reduction of thermal signature. Moreover, as the novel actuator can fulfill those functions that the existing one can not, it may well be expected to popularize it into more flow control systems.

  7. In-vivo examples of synthetic aperture vector flow imaging

    Oddershede, Niels; Hansen, Kristoffer Lindskov; Nielsen, Michael Bachmann;

    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 our RASMUS experimental ultrasound scanner. The first data set covers the femoral artery and the confluence of the femoral and saphenous vein of a healthy 26-year-old male volunteer. The second shows the carotid bifurcation of a healthy 32-year-old male volunteer. Both 2 second long data sets...... are processed, and movies of full vector flow images are generated. This paper presents still frames from different time instances of these movies. The movie from the femoral data tracks the accelerating velocity in the femoral artery during systole and a backwards flow at the end of the systole. A complex flow...

  8. Diffractive photoproduction of vector mesons at the LHC

    Armesto, Néstor

    2014-01-01

    We confront saturation-based results for diffractive $\\psi(2s)$ and $\\rho$ production at HERA and $J/\\psi$ photoproduction with all available data including recent ones from HERA, ALICE and LHCb, finding a good agreement. We show that the $t$-distribution of differential cross-section of photoproduction of vector mesons offers a unique opportunity to discriminate among saturation and non-saturation models. This is due to emergence of a pronounced dip (or multiple dips) in the $t$-distribution of diffractive photoproduction of vector mesons at relatively large, but potentially accessible $|t|$ that can be traced back to the unitarity features of colour dipole amplitude in the saturation regime. We provide various predictions for exclusive (photo)-production of different vector mesons including the ratio of $\\psi(2s)/J/\\psi$ at HERA, the LHC and at future colliders.

  9. Clinical Observation of 5-fluorouracil Ultrasonic Atomizing Inhalation Combined with MVP Chemotherapy for Ⅲb-Ⅳ Stage Non-small Cell Lung Cancer%5-氟尿嘧啶超声雾化吸入联合MVP方案治疗Ⅲb~Ⅳ期非小细胞肺癌的临床观察

    邹泽; 刘恩强; 岳建农

    2014-01-01

    目的:观察5-氟尿嘧啶超声雾化吸入联合丝裂霉素、长春地辛、顺铂(MVP)方案治疗Ⅲb~Ⅳ期非小细胞肺癌(NSCLC)的疗效和安全性.方法:160例NSCLC患者按随机数字表法均分为5-氟尿嘧啶超声雾化吸入组(HTP组),丝裂霉素、长春地辛、顺铂静脉化疗组(MVP组),HTP联合MVP组(联合组)和5-氟尿嘧啶静脉化疗组(对照组).HTP组患者给予5-氟尿嘧啶5 mg/kg+α-糜蛋白酶10 mg加入0.9%氯化钠注射液中配成20 ml混合溶液,装入雾化器中雾化吸入0.5h,bid,d1-3/周,治疗12周;MVP组患者给予丝裂霉素8 mg/m2,d1、d8静脉滴注,qd+长春地辛2.5 mg/m2,d1、d8静脉滴注,qd+顺铂30 mg/m2,d1-3静脉滴注,qd,28 d为1个周期,共3个周期;联合组患者给予HTP组+MVP组方案联合治疗;对照组患者给予α-糜蛋白酶10 mg加入0.9%氯化钠注射液中配成20 ml混合溶液雾化吸入+5-氟尿嘧啶5mg/kg,静脉滴注,bid,d1-3/周,治疗12周.所有患者治疗12周后评价疗效.观察4组患者的总有效率、毒性反应及随访1年、2年的生存率.结果:联合组患者总有效率> MVP组>HTP组>对照组,联合组患者1年、2年生存率> MVP组>HTP组>对照组,对照组患者毒性反应总发生例次<联合组<MVP组<HTP组,4组比较差异均有统计学意义(P<0.05).结论:5-氟尿嘧啶超声雾化吸入联合MVP方案治疗Ⅲb~Ⅳ期NSCLC较单用MVP或HTP方案疗效和安全性更好,对于一般情况较好的患者,可显著提高生存率.

  10. Vectors and translations in mathematics and physics

    Dorier, Jean-Luc

    2016-01-01

    In mathematics, students learn about vectors and translation, in physics they model forces, speed, acceleration, etc. with vectors and study movements of translation. Do they make the connection between these concepts introduced in different disciplines or do they put things in separate boxes? In this paper we will start with some partial considerations on the history of vectors and we will give some references. Then we will show some examples of naïve illustrations of vectors from physics in...

  11. NEVILLE-TYPE VECTOR VALUED RATIONAL INTERPOLANTS

    陈之兵; 顾传青; 徐晨

    2004-01-01

    A new kind of vector valued rational interpolants is established by means of Samelson inverse, with scalar numerator and vector valued denominator. It is essen tially different from that of Graves-Morris(1983), where the interpolants are constructed by Thiele-type continued fractions with vector valued numerator and scalar denominator. The new approach is more suitable to calculate the value of a vector valued function for a given point. And an error formula is also given and proven.

  12. Clinical applications of power vectors.

    Miller, Joseph M

    2009-06-01

    The study of infant vision is closely coupled to the study of the refraction, change in refraction over time, and the effect of spectacle correction on visual development. Frequently, reports are limited to descriptions of spherical equivalent or cylinder power without regard to axis, as data are frequently collected in the clinical format of sphere, cylinder, and axis (S, C, A). Conversion from clinical notation to a power vector representation of refraction allows unambiguous description of how refractions change over time and differ between repeated measurements. This article presents a series of examples of Microsoft Excel spreadsheet formulas that make the conversion from clinical notation to power vector format, and provides examples of useful applications of these methods.

  13. ELVIS - ELectromagnetic Vector Information Sensor

    Bergman, J E S; Thidé, B; Ananthakrishnan, S; Wahlund, J E; Karlsson, R L; Puccio, W; Carozzi, T D; Kale, P

    2005-01-01

    The ELVIS instrument was recently proposed by the authors for the Indian Chandrayaan-1 mission to the Moon and is presently under consideration by the Indian Space Research Organisation (ISRO). The scientific objective of ELVIS is to explore the electromagnetic environment of the moon. ELVIS samples the full three-dimensional (3D) electric field vector, E(x,t), up to 18 MHz, with selective Nyqvist frequency bandwidths down to 5 kHz, and one component of the magnetic field vector, B(x,t), from a few Hz up to 100 kHz.As a transient detector, ELVIS is capable of detecting pulses with a minimum pulse width of 5 ns. The instrument comprises three orthogonal electric dipole antennas, one magnetic search coil antenna and a four-channel digital sampling system, utilising flexible digital down conversion and filtering together with state-of-the-art onboard digital signal processing.

  14. Ultrasonic Dynamic Vector Stress Sensor

    Heyman, Joseph S.; Froggatt, Mark

    1992-01-01

    Stress inferred from measurements in specimens rather than in bonded gauges. Ultrasonic dynamic vector stress sensor (UDVSS) measures changes in dynamic directional stress occurring in material or structure at location touched by device when material or structure put under cyclic load. Includes phase-locked loop, synchronous amplifier, and contact probe. Useful among manufacturers of aerospace and automotive structures for stress testing and evaluation of designs.

  15. Biological rhythms and vector insects

    Mirian David Marques

    2013-01-01

    Full Text Available The adjustment of all species, animals and plants, to the Earth’s cyclic environments is ensured by their temporal organisation. The relationships between parasites, vectors and hosts rely greatly upon the synchronisation of their biological rhythms, especially circadian rhythms. In this short note, parasitic infections by Protozoa and by microfilariae have been chosen as examples of the dependence of successful transmission mechanisms on temporal components.

  16. Structural Learning of Attack Vectors for Generating Mutated XSS Attacks

    Wang, Yi-Hsun; Lee, Hahn-Ming; 10.4204/EPTCS.35.2

    2010-01-01

    Web applications suffer from cross-site scripting (XSS) attacks that resulting from incomplete or incorrect input sanitization. Learning the structure of attack vectors could enrich the variety of manifestations in generated XSS attacks. In this study, we focus on generating more threatening XSS attacks for the state-of-the-art detection approaches that can find potential XSS vulnerabilities in Web applications, and propose a mechanism for structural learning of attack vectors with the aim of generating mutated XSS attacks in a fully automatic way. Mutated XSS attack generation depends on the analysis of attack vectors and the structural learning mechanism. For the kernel of the learning mechanism, we use a Hidden Markov model (HMM) as the structure of the attack vector model to capture the implicit manner of the attack vector, and this manner is benefited from the syntax meanings that are labeled by the proposed tokenizing mechanism. Bayes theorem is used to determine the number of hidden states in the model...

  17. Vector and tensor analysis with applications

    Borisenko, A I; Silverman, Richard A

    1979-01-01

    Concise and readable, this text ranges from definition of vectors and discussion of algebraic operations on vectors to the concept of tensor and algebraic operations on tensors. It also includes a systematic study of the differential and integral calculus of vector and tensor functions of space and time. Worked-out problems and solutions. 1968 edition.

  18. Project Physics Programmed Instruction, Vectors 3.

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    This is the third of a series of three programmed instruction booklets on vectors developed by Harvard Project Physics. Separating vectors into components and obtaining a vector from its components are the topics covered. For other booklets in this series, see SE 015 549 and SE 015 550. (DT)

  19. Some Remarks on a Generalized Vector Product

    Acosta-Humánez, Primitivo B; Núñez, Reinaldo

    2011-01-01

    In this paper we use a generalized vector product to construct an exterior form $\\wedge :(\\mathbb{R}^{n}) ^{k}\\to \\mathbb{R}^{\\binom{n}{k}}$, where $\\binom{n}{k}=\\frac{n!}{(n-k)!k!}$, $k\\leq n$. Finally, for $n=k-1$ we introduce the reversing operation to study this generalized vector product over palindromic and antipalindromic vectors.

  20. Vector Fields and Flows on Differentiable Stacks

    A. Hepworth, Richard

    2009-01-01

    This paper introduces the notions of vector field and flow on a general differentiable stack. Our main theorem states that the flow of a vector field on a compact proper differentiable stack exists and is unique up to a uniquely determined 2-cell. This extends the usual result on the existence...... of vector fields....

  1. Alpharetroviral Vectors: From a Cancer-Causing Agent to a Useful Tool for Human Gene Therapy

    Julia D. Suerth

    2014-12-01

    Full Text Available 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 this review, we provide a short overview of the history of alpharetroviruses and explain how they can be converted into state-of-the-art gene delivery tools with improved safety features. We discuss development of alpharetroviral vectors in compliance with regulatory requirements for clinical translation, and provide an outlook on possible future gene therapy applications. Taken together, this review is a broad overview of alpharetroviral vectors spanning the bridge from their parental virus discovery to their potential applicability in clinical settings.

  2. Integrated multi vector vortex beam generator

    Schulz, Sebastian A; Karimi, Ebrahim; Boyd, Robert W

    2013-01-01

    A novel method to generate and manipulate vector vortex beams in an integrated, ring resonator based geometry is proposed. We show numerically that a ring resonator, with an appropriate grating, addressed by a vertically displaced access waveguide emits a complex optical field. The emitted beam possesses a specific polarization topology, and consequently a transverse intensity profile and orbital angular momentum. We propose a combination of several concentric ring resonators, addressed with different bus guides, to generate arbitrary orbital angular momentum qudit states, which could potentially be used for classical and quantum communications. Finally, we demonstrate numerically that this device works as an orbital angular momentum sorter with an average cross-talk of -10 dB between different orbital angular momentum channels.

  3. Supernova Recognition using Support Vector Machines

    Romano, Raquel A.; Aragon, Cecilia R.; Ding, Chris

    2006-10-01

    We introduce a novel application of Support Vector Machines(SVMs) to the problem of identifying potential supernovae usingphotometric and geometric features computed from astronomical imagery.The challenges of this supervised learning application are significant:1) noisy and corrupt imagery resulting in high levels of featureuncertainty,2) features with heavy-tailed, peaked distributions,3)extremely imbalanced and overlapping positiveand negative data sets, and4) the need to reach high positive classification rates, i.e. to find allpotential supernovae, while reducing the burdensome workload of manuallyexamining false positives. High accuracy is achieved viaasign-preserving, shifted log transform applied to features with peaked,heavy-tailed distributions. The imbalanced data problem is handled byoversampling positive examples,selectively sampling misclassifiednegative examples,and iteratively training multiple SVMs for improvedsupernovarecognition on unseen test data. We present crossvalidationresults and demonstrate the impact on a largescale supernova survey thatcurrently uses the SVM decision value to rank-order 600,000 potentialsupernovae each night.

  4. On the Distribution of Norm of Vector Projection and Rejection of Two Complex Normal Random Vectors

    Mehdi Maleki

    2015-01-01

    Full Text Available Vector projection and vector rejection are highly common and useful operations in mathematics, information theory, and signal processing. In this paper, we find the distribution of the norm of projection and rejection vectors when the original vectors are standard complex normally distributed.

  5. Development of Fungal Applications on Netting Substrates for Malaria Vector Control

    Farenhorst, M.; Hilhorst, A.; Thomas, M.B.; Knols, B.G.J.

    2011-01-01

    Mosquito resistance to chemical insecticides is considered a serious threat for the sustainable use of contemporary malaria vector control methods. Fungal entomopathogens show potential as alternative biological control agents against (insecticide-resistant) anophelines. This study was designed to t

  6. Problems and worked solutions in vector analysis

    Shorter, LR

    2014-01-01

    ""A handy book like this,"" noted The Mathematical Gazette, ""will fill a great want."" Devoted to fully worked out examples, this unique text constitutes a self-contained introductory course in vector analysis for undergraduate and graduate students of applied mathematics.Opening chapters define vector addition and subtraction, show how to resolve and determine the direction of two or more vectors, and explain systems of coordinates, vector equations of a plane and straight line, relative velocity and acceleration, and infinitely small vectors. The following chapters deal with scalar and vect

  7. The role of remote sensing and GIS for spatial prediction of vector-borne diseases transmission: a systematic review.

    Palaniyandi, M

    2012-12-01

    There have been several attempts 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 for spatial prediction of vector-borne diseases transmission. The nature of the presence and the abundance of vectors and vector-borne diseases, disease infection and the disease transmission are not ubiquitous and are confined with geographical, environmental and climatic factors, and are localized. The presence of vectors and vector-borne diseases is most complex in nature, however, it is confined and fueled by the geographical, climatic and environmental factors including man-made factors. The usefulness of the present day availability of the information derived from the satellite data including vegetation indices of canopy cover and its density, soil types, soil moisture, soil texture, soil depth, etc. is integrating the information in the expert GIS engine for the spatial analysis of other geoclimatic and geoenvironmental variables. The present study gives the detailed information on the classical studies of the past and present, and the future role of remote sensing and GIS for the vector-borne diseases control. The ecological modeling directly gives us the relevant information to understand the spatial variation of the vector biodiversity, vector presence, vector abundance and the vector-borne diseases in association with geoclimatic and the environmental variables. The probability map of the geographical distribution and seasonal variations of horizontal and vertical distribution of vector abundance and its association with vector -borne diseases can be obtained with low cost remote sensing and GIS tool with reliable data and speed.

  8. DBSC-Based Grayscale Line Image Vectorization

    Konstantin Melikhov; Feng Tian; Jie Qiu; Quan Chen; Hock Soon Seah

    2006-01-01

    Vector graphics plays an important role in computer animation and imaging technologies. However present techniques and tools cannot fully replace traditional pencil and paper. Additionally, vector representation of an image is not always available. There is not yet a good solution for vectorizing a picture drawn on a paper. This work attempts to solve the problem of vectorizing grayscale line drawings. The solution proposed uses Disk B-Spline curves to represent strokes of an image in vector form. The algorithm builds a vector representation from a grayscale raster image, which can be a scanned picture for instance. The proposed method uses a Gaussian sliding window to calculate skeleton and perceptive width of a stroke. As a result of vectorization, the given image is represented by a set of Disk B-Spline curves.

  9. The vector algebra war: A historical perspective

    Chappell, James M; Hartnett, John G; Abbott, Derek

    2015-01-01

    There are a wide variety of different vector formalisms currently utilized in science. For example, Gibbs three-vectors, spacetime four-vectors, complex spinors for quantum mechanics, quaternions used for rigid body rotations and Clifford multivectors. With such a range of vector formalisms in use, it thus appears that there is as yet no general agreement on a vector formalism suitable for the whole of science. This surprising situation exists today, despite the fact that one of the main goals of nineteenth century science was to correctly describe vectors and the algebra of three-dimensional space. This situation has also had the unfortunate consequence of fragmenting knowledge across many disciplines and requiring a very significant amount of time and effort in learning the different formalisms. We thus review historically the development of our various vector systems and conclude that the Clifford algebra multivector fulfills the goal of correctly describing vectorial quantities in three dimensions.

  10. Lentiviral Vectors for Cancer Immunotherapy and Clinical Applications

    David Escors

    2013-07-01

    Full Text Available The success of immunotherapy against infectious diseases has shown us the powerful potential that such a treatment offers, and substantial work has been done to apply this strategy in the fight against cancer. Cancer is however a fiercer opponent than pathogen-caused diseases due to natural tolerance towards tumour associated antigens and tumour-induced immunosuppression. Recent gene therapy clinical trials with viral vectors have shown clinical efficacy in the correction of genetic diseases, HIV and cancer. The first successful gene therapy clinical trials were carried out with onco(g-retroviral vectors but oncogenesis by insertional mutagenesis appeared as a serious complication. Lentiviral vectors have emerged as a potentially safer strategy, and recently the first clinical trial of patients with advanced leukemia using lentiviral vectors has proven successful. Additionally, therapeutic lentivectors have shown clinical efficacy for the treatment of HIV, X-linked adrenoleukodystrophy, and b-thalassaemia. This review aims at describing lentivectors and how they can be utilized to boost anti-tumour immune responses by manipulating the effector immune cells.

  11. Lentiviral Vectors for Cancer Immunotherapy and Clinical Applications

    Liechtenstein, Therese, E-mail: t.liechtenstein.12@ucl.ac.uk [University College London, 5 University Street, London, WC1E 6JF (United Kingdom); Perez-Janices, Noemi; Escors, David [University College London, 5 University Street, London, WC1E 6JF (United Kingdom); Navarrabiomed Fundacion Miguel Servet, 3 Irunlarrea St., Hospital Complex of Navarra, 31008 Pamplona, Navarra (Spain)

    2013-07-02

    The success of immunotherapy against infectious diseases has shown us the powerful potential that such a treatment offers, and substantial work has been done to apply this strategy in the fight against cancer. Cancer is however a fiercer opponent than pathogen-caused diseases due to natural tolerance towards tumour associated antigens and tumour-induced immunosuppression. Recent gene therapy clinical trials with viral vectors have shown clinical efficacy in the correction of genetic diseases, HIV and cancer. The first successful gene therapy clinical trials were carried out with onco(γ-)retroviral vectors but oncogenesis by insertional mutagenesis appeared as a serious complication. Lentiviral vectors have emerged as a potentially safer strategy, and recently the first clinical trial of patients with advanced leukemia using lentiviral vectors has proven successful. Additionally, therapeutic lentivectors have shown clinical efficacy for the treatment of HIV, X-linked adrenoleukodystrophy, and β-thalassaemia. This review aims at describing lentivectors and how they can be utilized to boost anti-tumour immune responses by manipulating the effector immune cells.

  12. Some theoretical comparisons of refined Ritz vectors and Ritz vectors

    JIA Zhongxiao

    2004-01-01

    Refined projection methods proposed by the author have received attention internationally. We are concerned with a conventional projection method and its refined counterpart for computing approximations to a simple eigenpair (λ,x)of a large matrix A. Given a subspace w that contains anapproximation to x, these two methods compute approximations(μ(x~)) and (μ(x^)) to (λ,x),respectively. We establish three results. First, the refinedeigenvector approximation or simply the refined Ritz vector (x^) is unique as the deviation of x from w approaches zero if λ is simple. Second, interms of residual norm of the refined approximate eigenpair (μ,(x^)), we derive lower and upper bounds for the sine of the angle betweenthe Ritz vector (x~) and the refined eigenvector approximation (x^), and we prove that (x~)≠(x^) unless (x^)=x. Third, we establish relationships between theresidual norm ‖A(x~)-μ(x^)‖ of the conventionalmethods and the residual norm ‖A(x^)-μ(x^)‖ of therefined methods, and we show that the latter is always smallerthan the former if (μ,(x^)) is not an exact eigenpair ofA, indicating that the refined projection method is superiorto the corresponding conventional counterpart.

  13. Some theoretical comparisons of refined Ritz vectors and Ritz vectors

    JIA; Zhongxiao

    2004-01-01

    Refined projection methods proposed by the author have received attention internationally. We are concerned with a conventional projection method and its refined counterpart for computing approximations to a simple eigenpair (λ,x)of a large matrix A. Given a subspace w that contains anapproximation to x, these two methods compute approximations(μ(x~)) and (μ(x)) to (λ,x),respectively. We establish three results. First, the refinedeigenvector approximation or simply the refined Ritz vector (x) is unique as the deviation of x from w approaches zero if λ is simple. Second, interms of residual norm of the refined approximate eigenpair (μ,(x)), we derive lower and upper bounds for the sine of the angle betweenthe Ritz vector (x~) and the refined eigenvector approximation (x), and we prove that (x~)≠(x) unless (x)=x. Third, we establish relationships between theresidual norm ‖A(x~)-μ(x)‖ of the conventionalmethods and the residual norm ‖A(x)-μ(x)‖ of therefined methods, and we show that the latter is always smallerthan the former if (μ,(x)) is not an exact eigenpair ofA, indicating that the refined projection method is superiorto the corresponding conventional counterpart.

  14. Possible impact of rising sea levels on vector-borne infectious diseases

    Surendran Sinnathamby N

    2011-01-01

    Full Text Available Abstract Background Vector-borne infectious diseases are a significant cause of human and animal mortality and morbidity. Modeling studies predict that changes in climate that accompany global warming will alter the transmission risk of many vector-borne infectious diseases in different parts of the world. Global warming will also raise sea levels, which will lead to an increase in saline and brackish water bodies in coastal areas. The potential impact of rising sea levels, as opposed to climate change, on the prevalence of vector-borne infectious diseases has hitherto been unrecognised. Presentation of the hypothesis Mosquito species possessing salinity-tolerant larvae and pupae, and capable of transmitting arboviruses and parasites are found in many parts of the world. An expansion of brackish and saline water bodies in coastal areas, associated with rising sea levels, can increase densities of salinity-tolerant vector mosquitoes and lead to the adaptation of freshwater vectors to breed in brackish and saline waters. The breeding of non-mosquito vectors may also be influenced by salinity changes in coastal habitats. Higher vector densities can increase transmission of vector-borne infectious diseases in coastal localities, which can then spread to other areas. Testing the hypothesis The demonstration of increases in vector populations and disease prevalence that is related to an expansion of brackish/saline water bodies in coastal areas will provide the necessary supportive evidence. However the implementation of specific vector and disease control measures to counter the threat will confound the expected findings. Implications of the hypothesis Rising sea levels can act synergistically with climate change and then interact in a complex manner with other environmental and socio-economic factors to generate a greater potential for the transmission of vector-borne infectious diseases. The resulting health impacts are likely to be particularly

  15. Quantifying and resolving multiple vector transformants in S. cerevisiae plasmid libraries

    Gray Elizabeth C

    2009-11-01

    Full Text Available Abstract Background In addition to providing the molecular machinery for transcription and translation, recombinant microbial expression hosts maintain the critical genotype-phenotype link that is essential for high throughput screening and recovery of proteins encoded by plasmid libraries. It is known that Escherichia coli cells can be simultaneously transformed with multiple unique plasmids and thusly complicate recombinant library screening experiments. As a result of their potential to yield misleading results, bacterial multiple vector transformants have been thoroughly characterized in previous model studies. In contrast to bacterial systems, there is little quantitative information available regarding multiple vector transformants in yeast. Saccharomyces cerevisiae is the most widely used eukaryotic platform for cell surface display, combinatorial protein engineering, and other recombinant library screens. In order to characterize the extent and nature of multiple vector transformants in this important host, plasmid-born gene libraries constructed by yeast homologous recombination were analyzed by DNA sequencing. Results It was found that up to 90% of clones in yeast homologous recombination libraries may be multiple vector transformants, that on average these clones bear four or more unique mutant genes, and that these multiple vector cells persist as a significant proportion of library populations for greater than 24 hours during liquid outgrowth. Both vector concentration and vector to insert ratio influenced the library proportion of multiple vector transformants, but their population frequency was independent of transformation efficiency. Interestingly, the average number of plasmids born by multiple vector transformants did not vary with their library population proportion. Conclusion These results highlight the potential for multiple vector transformants to dominate yeast libraries constructed by homologous recombination. The

  16. Vector meson electroproduction in QCD

    Lu, Juan; Cai, Xian-Hao; Zhou, Li-Juan

    2012-08-01

    Based on the generalized QCD vector meson dominance model, we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model. Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for ρ, ω and varphi meson electroproduction in this paper. Since gluons interact among themselves (self-interaction), two gluons can form a glueball with quantum numbers IG, JPC = 0+,2++, decay width Γt ≈ 100 MeV, and mass of mG = 2.23 GeV. The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C = -1, called the Odderon. The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon. Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully, which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton. It should be emphasized that our mechanism is different from the theoretical framework of Block et al. We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies, as well as for searching for new particles such as tensor glueballs and Odderons, which have been predicted by QCD and the color glass condensate model (CGC). Therefore, in return, it can test the validity of QCD and the CGC model.

  17. Vector meson electroproduction in QCD

    LU Juan; CAI Xian-Hao; ZHOU Li-Juan

    2012-01-01

    Based on the generalized QCD vector meson dominance model,we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model.Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for p,ω and φ meson electroproduction in this paper.Since gluons interact among themselves (self-interaction),two gluons can form a glueball with quantum numbers IG,JPC =0+,2++,decay width Γt ≈ 100 MeV,and mass of mG=2.23 GeV.The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C =-1,called the Odderon.The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon.Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully,which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton.It should be emphasized that our mechanism is different from the theoretical framework of Block et al.We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies,as well as for searching for new particles such as tensor glueballs and Odderons,which have been predicted by QCD and the color glass condensate model (CGC).Therefore,in return,it can test the validity of QCD and the CGC model.

  18. Incorporating double copies of a chromatin insulator into lentiviral vectors results in less viral integrants

    Rosenqvist Nina

    2009-02-01

    Full Text Available Abstract 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 elements that can prevent enhancer-promoter interactions, if placed between these elements, and protect transgene cassettes from silencing and positional effects. It has been suggested that insulators can improve the safety and performance of lentiviral vectors. Therefore insulators have been incorporated 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 β-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 reverse transcription but before integration of the viral DNA. This non-integrated viral DNA could be detected by PCR and, importantly, prevented efficient transduction of target cells. Conclusion These results have importance for the future use of insulator sequences in lentiviral vectors and might limit the use of insulators in vectors for in vivo use. Therefore, a careful analysis of the optimal design must be performed before insulators are included into clinical lentiviral vectors.

  19. 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...... the differences and similarities of the two types of weights by demonstrating the connection between the Least Absolute Shrinkage and Selection Operator (LASSO) and the SVR. We show that an SVR problem can be transformed to a LASSO problem plus a linear constraint and a box constraint. We demonstrate...

  20. Probability Ranking in Vector Spaces

    Melucci, Massimo

    2011-01-01

    The Probability Ranking Principle states that the document set with the highest values of probability of relevance optimizes information retrieval effectiveness given the probabilities are estimated as accurately as possible. The key point of the principle is the separation of the document set into two subsets with a given level of fallout and with the highest recall. The paper introduces the separation between two vector subspaces and shows that the separation yields a more effective performance than the optimal separation into subsets with the same available evidence, the performance being measured with recall and fallout. The result is proved mathematically and exemplified experimentally.

  1. Nonviral Vectors for Gene Delivery

    Baoum, Abdulgader Ahmed

    2011-12-01

    The development of nonviral vectors for safe and efficient gene delivery has been gaining considerable attention recently. An ideal nonviral vector must protect the gene against degradation by nuclease in the extracellular matrix, internalize the plasma membrane, escape from the endosomal compartment, unpackage the gene at some point and have no detrimental effects. In comparison to viruses, nonviral vectors are relatively easy to synthesize, less immunogenic, low in cost, and have no limitation in the size of a gene that can be delivered. Significant progress has been made in the basic science and applications of various nonviral gene delivery vectors; however, the majority of nonviral approaches are still inefficient and often toxic. To this end, two nonviral gene delivery systems using either biodegradable poly(D,L-lactide- co-glycolide) (PLG) nanoparticles or cell penetrating peptide (CPP) complexes have been designed and studied using A549 human lung epithelial cells. PLG nanoparticles were optimized for gene delivery by varying particle surface chemistry using different coating materials that adsorb to the particle surface during formation. A variety of cationic coating materials were studied and compared to more conventional surfactants used for PLG nanoparticle fabrication. Nanoparticles (˜200 nm) efficiently encapsulated plasmids encoding for luciferase (80-90%) and slowly released the same for two weeks. After a delay, moderate levels of gene expression appeared at day 5 for certain positively charged PLG particles and gene expression was maintained for at least two weeks. In contrast, gene expression mediated by polyethyleneimine (PEI) ended at day 5. PLG particles were also significantly less cytotoxic than PEI suggesting the use of these vehicles for localized, sustained gene delivery to the pulmonary epithelium. On the other hand, a more simple method to synthesize 50-200 nm complexes capable of high transfection efficiency or high gene knockdown was

  2. Listeria monocytogenes as a vector for anti-cancer therapies.

    Tangney, Mark

    2012-01-31

    The intracellular pathogen Listeria monocytogenes represents a promising therapeutic vector for the delivery of DNA, RNA or protein to cancer cells or to prime immune responses against tumour-specific antigens. A number of biological properties make L. monocytogenes a promising platform for development as a vector for either gene therapy or as an anti-cancer vaccine vector. L. monocytogenes is particularly efficient in mediating internalization into host cells. Once inside cells, the bacterium produces specific virulence factors which lyse the vaculolar membrane and allow escape into the cytoplasm. Once in the cytosol, L. monocytogenes is capable of actin-based motility and cell-to-cell spread without an extracellular phase. The cytoplasmic location of L. monocytogenes is significant as this potentiates entry of antigens into the MHC Class I antigen processing pathway leading to priming of specific CD8(+) T cell responses. The cytoplasmic location is also beneficial for the delivery of DNA (bactofection) by L. monocytogenes whilst cell-to-cell spread may facilitate access of the vector to cells throughout the tumour. Several preclinical studies have demonstrated the ability of L. monocytogenes for intracellular gene or protein delivery in vitro and in vivo, and this vector has also displayed safety and efficacy in clinical trial. Here, we review the features of the L. monocytogenes host-pathogen interaction that make this bacterium such an attractive candidate with which to induce appropriate therapeutic responses. We focus primarily upon work that has led to attenuation of the pathogen, demonstrated DNA, RNA or protein delivery to tumour cells as well as research that shows the efficacy of L. monocytogenes as a vector for tumour-specific vaccine delivery.

  3. Combination recombinant simian or chimpanzee adenoviral vectors for vaccine development.

    Cheng, Cheng; Wang, Lingshu; Ko, Sung-Youl; Kong, Wing-Pui; Schmidt, Stephen D; Gall, Jason G D; Colloca, Stefano; Seder, Robert A; Mascola, John R; Nabel, Gary J

    2015-12-16

    Recombinant adenoviral vector (rAd)-based vaccines are currently being developed for several infectious diseases and cancer therapy, but pre-existing seroprevalence to such vectors may prevent their use in broad human populations. In this study, we investigated the potential of low seroprevalence non-human primate rAd vectors to stimulate cellular and humoral responses using HIV/SIV Env glycoprotein (gp) as the representative antigen. Mice were immunized with novel simian or chimpanzee rAd (rSAV or rChAd) vectors encoding HIV gp or SIV gp by single immunization or in heterologous prime/boost combinations (DNA/rAd; rAd/rAd; rAd/NYVAC or rAd/rLCM), and adaptive immunity was assessed. Among the rSAV and rChAd tested, rSAV16 or rChAd3 vector alone generated the most potent immune responses. The DNA/rSAV regimen also generated immune responses similar to the DNA/rAd5 regimen. rChAd63/rChAd3 and rChAd3 /NYVAC induced similar or even higher levels of CD4+ and CD8+ T-cell and IgG responses as compared to rAd28/rAd5, one of the most potent combinations of human rAds. The optimized vaccine regimen stimulated improved cellular immune responses and neutralizing antibodies against HIV compared to the DNA/rAd5 regimen. Based on these results, this type of novel rAd vector and its prime/boost combination regimens represent promising candidates for vaccine development.

  4. Construction and Characterization of an in-vivo Linear Covalently Closed DNA Vector Production System

    2012-01-01

    Background While safer than their viral counterparts, conventional non-viral gene delivery DNA vectors offer a limited safety profile. They often result in the delivery of unwanted prokaryotic sequences, antibiotic resistance genes, and the bacterial origins of replication to the target, which may lead to the stimulation of unwanted immunological responses due to their chimeric DNA composition. Such vectors may also impart the potential for chromosomal integration, thus potentiating oncogenesis. We sought to engineer an in vivo system for the quick and simple production of safer DNA vector alternatives that were devoid of non-transgene bacterial sequences and would lethally disrupt the host chromosome in the event of an unwanted vector integration event. Results We constructed a parent eukaryotic expression vector possessing a specialized manufactured multi-target site called “Super Sequence”, and engineered E. coli cells (R-cell) that conditionally produce phage-derived recombinase Tel (PY54), TelN (N15), or Cre (P1). Passage of the parent plasmid vector through R-cells under optimized conditions, resulted in rapid, efficient, and one step in vivo generation of mini lcc—linear covalently closed (Tel/TelN-cell), or mini ccc—circular covalently closed (Cre-cell), DNA constructs, separated from the backbone plasmid DNA. Site-specific integration of lcc plasmids into the host chromosome resulted in chromosomal disruption and 105 fold lower viability than that seen with the ccc counterpart. Conclusion We offer a high efficiency mini DNA vector production system that confers simple, rapid and scalable in vivo production of mini lcc DNA vectors that possess all the benefits of “minicircle” DNA vectors and virtually eliminate the potential for undesirable vector integration events. PMID:23216697

  5. Vector-tensor and vector-vector decay amplitude analysis of B0-->phiK*0.

    Aubert, B; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Pegna, D Lopes; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Sanchez, P del Amo; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Cheng, C H; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Vetere, M Lo; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Lee, C L; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Vazquez, W Panduro; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y; Gritsan, A V; Guo, Z J; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Diberder, F Le; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Clarke, C K; Lodovico, F Di; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; Nardo, G De; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Potter, C T; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Buono, L Del; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; del Re, D; Marco, E Di; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Gioi, L Li; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Tehrani, F Safai; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; Franek, B; Olaiya, E O; Ricciardi, S; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Ricca, G Della; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihalyi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2007-02-02

    We perform an amplitude analysis of the decays B(0)-->phiK*(2)(1430)(0), phiK*(892)(0), and phi(Kpi)(0)(S-wave) with a sample of about 384x10(6) BB[over ] pairs recorded with the BABAR detector. The fractions of longitudinal polarization f(L) of the vector-tensor and vector-vector decay modes are measured to be 0.853(-0.069+0.061)+/-0.036 and 0.506+/-0.040+/-0.015, respectively. Overall, twelve parameters are measured for the vector-vector decay and seven parameters for the vector-tensor decay, including the branching fractions and parameters sensitive to CP violation.

  6. Therapeutic and prophylactic applications of alphavirus vectors.

    Atkins, Gregory J; Fleeton, Marina N; Sheahan, Brian J

    2008-11-11

    Alphavirus vectors are high-level, transient expression vectors for therapeutic and prophylactic use. These positive-stranded RNA vectors, derived from Semliki Forest virus, Sindbis virus and Venezuelan equine encephalitis virus, multiply and are expressed in the cytoplasm of most vertebrate cells, including human cells. Part of the genome encoding the structural protein genes, which is amplified during a normal infection, is replaced by a transgene. Three types of vector have been developed: virus-like particles, layered DNA-RNA vectors and replication-competent vectors. Virus-like particles contain replicon RNA that is defective since it contains a cloned gene in place of the structural protein genes, and thus are able to undergo only one cycle of expression. They are produced by transfection of vector RNA, and helper RNAs encoding the structural proteins. Layered DNA-RNA vectors express the Semliki Forest virus replicon from a cDNA copy via a cytomegalovirus promoter. Replication-competent vectors contain a transgene in addition to the structural protein genes. Alphavirus vectors are used for three main applications: vaccine construction, therapy of central nervous system disease, and cancer therapy.

  7. Current progress of polymeric gene vectors

    ZENG Xuan; SUN YunXia; ZHUO RenXi; ZHANG XianZheng

    2011-01-01

    After over 40 years ot progress,gene therapy provides great opportunities for treating diseases from various genetic disorders,infections and cancers.The success of gene therapy largely depends on the availability of suitable gene vectors.As an attractive alternative to virus-based gene therapy,non-viral gene delivery system has been developed and investigated due to their merits including low immunogenecity,convenient operability,and large-scale manufacturability [1].Because polycations can condense with DNA as a result of electrostatic interactions,form nanosize polyplexes,and protect DNA from degradation by DNase,cationic polymer becomes a major type of non-viral gene delivery vectors (Figure 1) [2].A wide range of polymeric vectors have been developed and investigated in the past decade,such as polyethylenimine (PEI)-based vectors,poly(L-lysine) (PLL)-based vectors,dendrimer-based vectors,polypeptide-based vectors,and chitosan-based vectors [3].However,unlike viral vectors that have the ability to infect host cells and overcome cellular barriers through the course of evolution,nonviral gene vectors exhibit Significantly reduced transfection efficiency as they are obstructed by various extra- and intracellular barriers,including serum proteins in blood stream,cell membrane,endosomal compartment and nuclear membrane [4].

  8. Vector-Resonance-Multimode Instability

    Sergeyev, S. V.; Kbashi, H.; Tarasov, N.; Loiko, Yu.; Kolpakov, S. A.

    2017-01-01

    The modulation and multimode instabilities are the main mechanisms which drive spontaneous spatial and temporal pattern formation in a vast number of nonlinear systems ranging from biology to laser physics. Using an Er-doped fiber laser as a test bed, here for the first time we demonstrate both experimentally and theoretically a new type of a low-threshold vector-resonance-multimode instability which inherits features of multimode and modulation instabilities. The same as for the multimode instability, a large number of longitudinal modes can be excited without mode synchronization. To enable modulation instability, we modulate the state of polarization of the lasing signal with the period of the beat length by an adjustment of the in-cavity birefringence and the state of polarization of the pump wave. As a result, we show the regime's tunability from complex oscillatory to periodic with longitudinal mode synchronization in the case of resonance matching between the beat and cavity lengths. Apart from the interest in laser physics for unlocking the tunability and stability of dynamic regimes, the proposed mechanism of the vector-resonance-multimode instability can be of fundamental interest for the nonlinear dynamics of various distributed systems.

  9. Ecological niche modelling of Rift Valley fever virus vectors in Baringo, Kenya

    Alfred O. Ochieng

    2016-11-01

    Full Text Available Background: Rift Valley fever (RVF is a vector-borne zoonotic disease that has an impact on human health and animal productivity. Here, we explore the use of vector presence modelling to predict the distribution of RVF vector species under climate change scenario to demonstrate the potential for geographic spread of Rift Valley fever virus (RVFV. Objectives: To evaluate the effect of climate change on RVF vector distribution in Baringo County, Kenya, with an aim of developing a risk map for spatial prediction of RVF outbreaks. Methodology: The study used data on vector presence and ecological niche modelling (MaxEnt algorithm to predict the effect of climatic change on habitat suitability and the spatial distribution of RVF vectors in Baringo County. Data on species occurrence were obtained from longitudinal sampling of adult mosquitoes and larvae in the study area. We used present (2000 and future (2050 Bioclim climate databases to model the vector distribution. Results: Model results predicted potential suitable areas with high success rates for Culex quinquefasciatus, Culex univitattus, Mansonia africana, and Mansonia uniformis. Under the present climatic conditions, the lowlands were found to be highly suitable for all the species. Future climatic conditions indicate an increase in the spatial distribution of Cx. quinquefasciatus and M. africana. Model performance was statistically significant. Conclusion: Soil types, precipitation in the driest quarter, precipitation seasonality, and isothermality showed the highest predictive potential for the four species.

  10. The role of Remote Sensing and GIS for spatial prediction of vector-borne diseases transmission: A systematic review

    M. Palaniyandi

    2012-12-01

    Full Text Available 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 disease transmission are not ubiquitous and are confined withgeographical, environmental and climatic factors, and are localized. The presence of vectors and vector-bornediseases is most complex in nature, however, it is confined and fueled by the geographical, climatic andenvironmental factors including man-made factors. The usefulness of the present day availability of the informationderived from the satellite data including vegetation indices of canopy cover and its density, soil types, soil moisture,soil texture, soil depth, etc. is integrating the information in the expert GIS engine for the spatial analysis of othergeoclimatic and geoenvironmental variables. The present study gives the detailed information on the classicalstudies of the past and present, and the future role of remote sensing and GIS for the vector-borne diseasescontrol. The ecological modeling directly gives us the relevant information to understand the spatial variation ofthe vector biodiversity, vector presence, vector abundance and the vector-borne diseases in association withgeoclimatic and the environmental variables. The probability map of the geographical distribution and seasonalvariations of horizontal and vertical distribution of vector abundance and its association with vector-borne diseasescan be obtained with low cost remote sensing and GIS tool with reliable data and speed.

  11. The Influence of Delivery Vectors on HIV Vaccine Efficacy

    Beatrice Omusiro Ondondo

    2014-08-01

    Full Text Available Development of an effective HIV/AIDS vaccine remains a big challenge, largely due to the enormous HIV diversity which propels immune escape. Thus novel vaccine strategies are targeting multiple variants of conserved antibody and T cell epitopic regions which would incur a huge fitness cost to the virus in the event of mutational escape. Besides immunogen design, the delivery modality is critical for vaccine potency and efficacy, and should be carefully selected in order to not only maximise transgene expression, but to also enhance the immuno-stimulatory potential to activate innate and adaptive immune systems. To date, five HIV vaccine candidates have been evaluated for efficacy and protection from acquisition was only achieved in a small proportion of vaccinees in the RV144 study which used a canarypox vector for delivery. Conversely, in the STEP study (HVTN 502 where human adenovirus serotype 5 (Ad5 was used, strong immune responses were induced but vaccination was more associated with increased risk of HIV acquisition than protection in vaccinees with pre-existing Ad5 immunity. The possibility that pre-existing immunity to a highly promising delivery vector may alter the natural course of HIV to increase acquisition risk is quite worrisome and a huge setback for HIV vaccine development. Thus, HIV vaccine development efforts are now geared towards delivery platforms which attain superior immunogenicity while concurrently limiting potential catastrophic effects likely to arise from pre-existing immunity or vector-related immuno-modulation. However, it still remains unclear whether it is poor immunogenicity of HIV antigens or substandard immunological potency of the safer delivery vectors that has limited the success of HIV vaccines. This article discusses some of the promising delivery vectors to be harnessed for improved HIV vaccine efficacy.

  12. Transversals of Complex Polynomial Vector Fields

    Dias, Kealey

    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......, an important step was proving that the transversals possessed a certain characteristic. Understanding transversals might be the key to proving other polynomial vector fields are generic, and they are important in understanding bifurcations of polynomial vector fields in general. We consider two important...... examples of rotated families to argue this. There will be discussed several open questions concerning the number of transversals that can appear for a certain degree d of a polynomial vector field, and furthermore how transversals are analyzed with respect to bifurcations around multiple equilibrium points....

  13. A Modified Moist Ageostrophic Q Vector

    YUE Caijun; SHOU Shaowen

    2008-01-01

    The quasi-geostrophic Q vector is an important diagnostic tool for studying development of surface rainfall associated with large-scale weather systems and is calculated using data at single vertical level. When ageostrophic Q vector was introduced, it required data at two vertical levels. In this study, moist ageostrophic Q vector is modified so that it can be calculated using data at a single vertical level. The comparison study between the original and modified moist ageostrophic Q vectors is conducted using the data from 5 to 6 July 1991 during the torrential rainfall event associated with the Changjiang-Huaihe mei-yu front in China. The results reveal that divergences of original and modified moist ageostrophic Q vectors have similar horizontal distributions and their centers are almost located in the precipitation centers. This indicates that modified moist ageostrophic Q vector can be used to diagnose convective development with reasonable accuracy.

  14. Dengue Prevention and 35 Years of Vector Control in Singapore

    Ooi, Eng-Eong; Goh, Kee-Tai; Duane J Gubler

    2006-01-01

    After a 15-year period of low incidence, dengue has reemerged in Singapore in the past decade. We identify potential causes of this resurgence. A combination of lowered herd immunity, virus transmission outside the home, an increase in the age of infection, and the adoption of a case-reactive approach to vector control contribute to the increased dengue incidence. Singapore's experience with dengue indicates that prevention efforts may not be sustainable. For renewed success, Singapore needs ...

  15. WHAT CAN WE LEARN FROM VIRUS IN DESIGNING NONVIRAL GENE VECTORS

    Chun-hong Xu; Mei-hua Sui; Jian-bin Tang; You-qing Shen

    2011-01-01

    Gene therapy has emerged as a potential new approach to treat genetic disorders by delivering therapeutic genes to target diseased tissues. However, its clinical use has been impeded by gene delivery systems. The viral vectors are very efficient in delivering and expressing their carried genes, but they have safety issues in clinical use. While nonviral vectors are much safer with very low risks after careful material design, but their gene transcription efficiency is too low to be clinically used. Thus, rational design of nonviral vectors mimicking the viral vectors would be a way to break this bottleneck. This review compares side-by-side how viral/nonviral gene vectors transcend these biological barriers in terms of blood circulation, cellular uptake, endosome escape, nucleus import and gene transcription.

  16. Higgs Decays and Brane Gravi-vectors

    Clark, T. E.; Liu, B. Y.; Love, S. T.; Xiong, C.; ter Veldhuis, T.

    2008-01-01

    Higgs boson decays in flexible brane world models with stable, massive gravi-vectors are considered. Such vectors couple bilinearly to the Standard Model fields through either the Standard Model energy-momentum tensor, the weak hypercharge field strength or the Higgs scalar. The role of the coupling involving the extrinsic curvature is highlighted. It is found that within the presently allowed parameter space, the decay rate of the Higgs into two gravi-vectors (which would appear as an invisi...

  17. [Research progress on malaria vector control].

    Zhu, Guo-Ding; Cao, Jun; Zhou, Hua-Yun; Gao, Qi

    2013-06-01

    Vector control plays a crucial role in the stages of malaria control and elimination. Currently, it mainly relies on the chemical control methods for adult mosquitoes in malaria endemic areas, however, it is undergoing the serious threat by insecticide resistance. In recent years, the transgenic technologies of malaria vectors have made a great progress in the laboratory. This paper reviews the challenges of the traditional methods and the rapid developed genetic modified technology in the application of vector control.

  18. Integrated epidemiology for vector-borne zoonoses

    2016-01-01

    The development and application of interventions for the control of vector-borne zoonoses requires broad understanding of epidemiological linkages between vector, animal infection and human infection. However, there are significant gaps in our understanding of these linkages and a lack of appropriate data poses a considerable barrier to addressing this issue. A move towards strengthened surveillance of vectors and disease in both animal and human hosts, in combination with linked human-animal...

  19. Construction of shRNA lentiviral vector

    Hong Song

    2010-12-01

    Full Text Available Lentiviruses have been adapted as gene delivery vehicles. This article summarized shRNA lentiviral vector methods generally used in research laboratories. The main procedures of shRNA lentiviral vector include that (1 Target sequences screening and shRNA oligonucleotides designing, (2 insert designed oligonucleotides into lentiviral vectors, (3 using packaging cells to produce shRNA lentivirus, and (4 transducing target cells with shRNA lentivirus.

  20. Genetic manipulation of endosymbionts to control vector and vector borne diseases

    Jay Prakash Gupta

    Full Text Available Vector borne diseases (VBD are on the rise because of failure of the existing methods of control of vector and vector borne diseases and the climate change. A steep rise of VBDs are due to several factors like selection of insecticide resistant vector population, drug resistant parasite population and lack of effective vaccines against the VBDs. Environmental pollution, public health hazard and insecticide resistant vector population indicate that the insecticides are no longer a sustainable control method of vector and vector-borne diseases. Amongst the various alternative control strategies, symbiont based approach utilizing endosymbionts of arthropod vectors could be explored to control the vector and vector borne diseases. The endosymbiont population of arthropod vectors could be exploited in different ways viz., as a chemotherapeutic target, vaccine target for the control of vectors. Expression of molecules with antiparasitic activity by genetically transformed symbiotic bacteria of disease-transmitting arthropods may serve as a powerful approach to control certain arthropod-borne diseases. Genetic transformation of symbiotic bacteria of the arthropod vector to alter the vector’s ability to transmit pathogen is an alternative means of blocking the transmission of VBDs. In Indian scenario, where dengue, chikungunya, malaria and filariosis are prevalent, paratransgenic based approach can be used effectively. [Vet World 2012; 5(9.000: 571-576