Abstract:
Worldwide, wild birds play a vital role in the dispersal of ticks that harbour tick-borne pathogens, including Borrelia burgdorferi, the Lyme disease bacterium. Using PCR testing, we found 124 (31%) of 405 ticks (4 species), which were collected from 21 species of birds in far-western Canada, to be infected with B. burgdorferi. Transstadial transmission of B. burgdorferi occurred from larva to nymph, plus nymph to adult, in the avian coastal tick, Ixodes auritulus, collected from songbirds in British Columbia (B.C). Collectively, all 3 motile life stages (larva, nymph, adult) of this tick had an infection prevalence of 31% for B. burgdorferi, which suggests vector competency. A Pacific Wren was highly infested with I. auritulus immatures, and 20 (44%) of 45 ticks (2 nymphs, 43 larvae) were infected with B. burgdorferi. This heavy infestation shows the high potential to initiate a new population of ticks and to disseminate Lyme spirochetes. Epidemiologically, B. burgdorferi-infected I. auritulus larvae collected from the Spotted Towhee, Swainson’s Thrush, Pacific Wren, and Fox Sparrow suggest that these avian hosts act as reservoirs for B. burgdorferi. In this study, the western blacklegged tick, Ixodes pacificus, and Ixodes spinipalpis played a limited role in the enzootic transmission cycle of B. burgdorferi along coastal B.C. We document the first record of I.spinipalpis on a bird in Alberta. Because songbirds widely disperse Lyme disease vector ticks, primary health providers and the general public must be vigilant that outdoors people may be bitten by B. burgdorferi-infected ticks throughout far-western Canada.

Abstract:
non-linear functional representation of the aerodynamic response provides a convenient mathematical model for motion-induced unsteady transonic aerodynamic loads response, that accounts for both complex non-linearities and time-history effects. a recent development, based on functional approximation theory, has established a novel functional form; namely, the multi-layer functional. for a large class of non-linear dynamic systems, such multi-layer functional representations can be realised via finite impulse response (fir) neural networks. identification of an appropriate fir neural network model is facilitated by means of a supervised training process in which a limited sample of system input-output data sets is presented to the temporal neural network. the present work describes a procedure for the systematic identification of parameterised neural network models of motion-induced unsteady transonic aerodynamic loads response. the training process is based on a conventional genetic algorithm to optimise the network architecture, combined with a simplified random search algorithm to update weight and bias values. application of the scheme to representative transonic aerodynamic loads response data for a bidimensional airfoil executing finite-amplitude motion in transonic flow is used to demonstrate the feasibility of the approach. the approach is shown to furnish a satisfactory generalisation property to different motion histories over a range of mach numbers in the transonic regime.

Abstract:
Non-linear functional representation of the aerodynamic response provides a convenient mathematical model for motion-induced unsteady transonic aerodynamic loads response, that accounts for both complex non-linearities and time-history effects. A recent development, based on functional approximation theory, has established a novel functional form; namely, the multi-layer functional. For a large class of non-linear dynamic systems, such multi-layer functional representations can be realised via finite impulse response (FIR) neural networks. Identification of an appropriate FIR neural network model is facilitated by means of a supervised training process in which a limited sample of system input-output data sets is presented to the temporal neural network. The present work describes a procedure for the systematic identification of parameterised neural network models of motion-induced unsteady transonic aerodynamic loads response. The training process is based on a conventional genetic algorithm to optimise the network architecture, combined with a simplified random search algorithm to update weight and bias values. Application of the scheme to representative transonic aerodynamic loads response data for a bidimensional airfoil executing finite-amplitude motion in transonic flow is used to demonstrate the feasibility of the approach. The approach is shown to furnish a satisfactory generalisation property to different motion histories over a range of Mach numbers in the transonic regime.

Abstract:
Let $\ast$ be a star operation on an integral domain $D$. Let $\f(D)$ be the set of all nonzero finitely generated fractional ideals of $D$. Call $D$ a $\ast$--Pr\"ufer (respectively, $(\ast, v)$--Pr\"ufer) domain if $(FF^{-1})^{\ast}=D$ (respectively, $(F^vF^{-1})^{\ast}=D$) for all $F\in \f(D)$. We establish that $\ast$--Pr\"ufer domains (and $(\ast, v)$--Pr\"ufer domains) for various star operations $\ast $ span a major portion of the known generalizations of Pr\"{u}fer domains inside the class of $v$--domains. We also use Theorem 6.6 of the Larsen and McCarthy book [Multiplicative Theory of Ideals, Academic Press, New York--London, 1971], which gives several equivalent conditions for an integral domain to be a Pr\"ufer domain, as a model, and we show which statements of that theorem on Pr\"ufer domains can be generalized in a natural way and proved for $\ast$--Pr\"ufer domains, and which cannot be. We also show that in a $\ast $--Pr\"ufer domain, each pair of $\ast $-invertible $\ast $-ideals admits a GCD in the set of $\ast $-invertible $\ast $-ideals, obtaining a remarkable generalization of a property holding for the "classical" class of Pr\"ufer $v$--multiplication domains. We also link $D$ being $\ast $--Pr\"ufer (or $(\ast, v)$--Pr\"ufer) with the group Inv$^{\ast}(D)$ of $\ast $-invertible $\ast $-ideals (under $\ast$-multiplication) being lattice-ordered.

Abstract:
forty-three specimens of umbrina canosai captured in the littoral of the state of the rio grande do sul, brazil, were examined between august 1991 and february 1992. forty fishes (93%) showed infection by the acanthocephalan corynosoma sp. (cistacanth) in the abdominal cavity and intestinal mesentery, with a mean intensity of 43.3, and relative density of 40.3 corynosoma sp showed a overdispersed distribution. the intensity of corynosoma was positively correlated with the host total length, but, the prevalence was not. the prevalence and intensity of corynosoma sp. was not influenced by the host sex.

Abstract:
Quarenta e três espécimes de Umbrina canosai capturados no litoral do Estado do Rio Grande do Sul, Brasil, foram examinados entre agosto de 1991 e fevereiro de 1992. Quarenta peixes (93%) estavam infectados pelo acantocéfalo Corynosoma sp. (cistacanto) na cavidade abdominal e no mesentério intestinal, com uma intensidade média de 43,3 e uma densidade relativa de 40,3. Corynosoma sp. foi positivamente correlacionada com o comprimento total dos hospedeiros, mas, a prevalência n o apresentou correla o. A prevalência e a intensidade parasitária de Corynosoma sp. n o foram influenciadas pelo sexo dos hospedeiros Forty-three specimens of Umbrina canosai captured in the littoral of the State of the Rio Grande do Sul, Brazil, were examined between August 1991 and February 1992. Forty fishes (93%) showed infection by the acanthocephalan Corynosoma sp. (cistacanth) in the abdominal cavity and intestinal mesentery, with a mean intensity of 43.3, and relative density of 40.3 Corynosoma sp showed a overdispersed distribution. The intensity of Corynosoma was positively correlated with the host total length, but, the prevalence was not. The prevalence and intensity of Corynosoma sp. was not influenced by the host sex.

Abstract:
Given any subgroup H of a group G, let Γ H (G) be the directed graph with vertex set G such that x is the initial vertex and y is the terminal vertex of an edge if and only if x ≠ y and ${xy\in H}$ . Furthermore, if ${xy\in H}$ and ${yx\in H}$ for some ${x,y\in G}$ with x ≠ y, then x and y will be regarded as being connected by a single undirected edge. In this paper, the structure of the connected components of Γ H (G) is investigated. All possible components are provided in the cases when |H| is either two or three, and the graph Γ H (G) is completely classified in the case when H is a normal subgroup of G and G/H is a finite abelian group.

Abstract:
The principal aim of the study was to determine the relationship between flow (optimal experience) and quality of work life in a diverse workforce. The sample comprised 307 managers, middle-managers and junior officials from a private company. The sample was drawn from all organisational functions and cultural groups within the organisation. A questionnaire was developed to measure flow experience. The flow factors correlated statistically significantly with the quality of work life factors. The implications of these findings are discussed. Opsomming Die hoofdoel van die studie was om die verhouding tussen psigologiese vloei (optimale ervaring) en gehalte van werklewe in 'n diverse werksmag vas te stel. Die steekproef het uit 307 bestuurders, middelbestuurders en junior amptenare van 'n privaatmaatskappy bestaan. Die steekproef is uit alle organisasiefunksies en kultuurgroepe binne die organisasie getrek. 'n Vraelys wat psigologiese vloei-ervarings meet, is ontwikkel. Die psigologiese vloei-faktore het statisties beduidend met gehalte van werklewe-faktore gekorreleer. Die implikasies van die bevindinge word bespreek.

Abstract:
Two scenarios for the penetration of relativistically intense laser radiation into an overdense plasma, accessible by self-induced transparency, are presented. For supercritical densities less than 1.5 times the critical one, penetration of laser energy occurs by soliton-like structures moving into the plasma. At higher background densities laser light penetrates over a finite length only, that increases with the incident intensity. In this regime plasma-field structures represent alternating electron layers separated by about half a wavelength by depleted regions.

Abstract:
It is shown that penetration of relativistically intense laser light into an overdense plasma, accessible by self-induced transparency, occurs over a finite length only. The penetration length depends crucially on the overdense plasma parameter and increases with increasing incident intensity after exceeding the threshold for self-induced transparency. Exact analytical solutions describing the plasma-field distributions are presented.