6,754 research outputs found
Does the anaesthetic influence behavioural transmission of the monogenean Gyrodactylus gasterostei Glaser, 1974 off the host?
The aim of this study was to investigate the use of the anaesthetic 2-phenoxyethanol on the transmission factors of gyrodactylid and to ascertain how this may affect in the colonisation of new hosts using the Gyrodactylus gasterostei Glaser, 1974 - Gasterosteus aculeatus L. model which is a simple and successful system to examine aspects of transmission of parasites from live and dead fish. Laboratory experiments include determining the maturity (presence of male copulate organ) and reproductive (presence of daughter) status of transmitting worms, in order to consider the factors that influence parasite option to migrate to a new individual of the same host species. This study demonstrates that parasites with a Male Copulate Organ (MCO) present are more likely to abandon the host and attempt a host transfer. The use of the anaesthetic 2-phenoxyethanol does not affect transmission of gyrodactylids which leave the host to colonise a new host. Finally, the use of other anaesthetic although its relative importance with respect to transmission remains uncertain.Department of the Environment, Food and Rural Affairs (Defra); Overseas Research Students Awards Scheme (ORSAS) UK; Consejo Nacional Ciencia y Tecnologia, Mexico CONACyT [171032]info:eu-repo/semantics/publishedVersio
Traveling wave solutions for wave equations with two exponential nonlinearities
We use a simple method that leads to the integrals involved in obtaining the
traveling wave solutions of wave equations with one and two exponential
nonlinearities. When the constant term in the integrand is zero, implicit
solutions in terms of hypergeometric functions are obtained while when that
term is nonzero all the basic traveling wave solutions of Liouville, Tzitzeica
and their variants, as well as sine/sinh-Gordon equations with important
applications in the phenomenology of nonlinear physics and dynamical systems
are found through a detailed study of the corresponding elliptic equationsComment: 9 pages, 7 figures, 42 references, version matching the published
articl
A binocular-type atmospheric interaction generating sequential exotic features
A cosmic-ray induced nuclear event is presented, which is of clear binocular-type and contains several exotic features through its passage in the atmosphere and the emulsion chamber
A halo event created at 200 m above the Chacaltaya emulsion chamber
The results of analysis on a cosmic-ray induced nuclear event with the total visible energy approx. = 1300 TeV which is characterized by the central (halo) part of a strong energy concentration and the outer part of a large lateral spread are presented. The event (named as P06) was detected in the 18th two-storied emulsion chamber exposed at Chacaltaya by Brasil-Japan Collaboration. As the nuclear emulsion plates were inserted at every layer of the concerned blocks in the upper and the lower chambers together with RR- and N-type X-ray films, it is possible to study the details of the event. Some results on P06 have already been reported 1 based on the general measurement of opacity on N-type X-ray films: (1) the total energy of halo is approx. = 1000 TeV; (2) the shower transition reaches its maximum at approx. 16 cu; and (3) the radius of halo is 6.5 mm (at the level of 10 to the 6th power electrons/sq.cm.). The results in more details will be described
Atmospheric interactions detected in both the upper and the lower chambers at Chacaltaya
The cosmic ray interactions in the energy region 10 to the 13th power to 10 to the 17th power eV were studied by emulsion chambers exposed at Chacaltaya, 5220 m above sea-level. The chambers have a two-storied structure, and the events observed in both chambers give important informations on these phenomena. The first Centauro event was detected as a small shower at the bottom of the upper chamber and as a big fraction of energy deposit in the lower chamber, which indicates a high contribution of hadronic showers. Results of the events with continuation in the rather low energy region are described
Linearly independent pure-state decomposition and quantum state discrimination
We put the pure-state decomposition mathematical property of a mixed state to
a physical test. We begin by characterizing all the possible decompositions of
a rank-two mixed state by means of the complex overlap between two involved
states. The physical test proposes a scheme of quantum state recognition of one
of the two linearly independent states which arise from the decomposition. We
find that the two states associated with the balanced pure-state decomposition
have the smaller overlap modulus and therefore the smallest probability of
being discriminated conclusively, while in the nonconclusive scheme they have
the highest probability of having an error. In addition, we design an
experimental scheme which allows to discriminate conclusively and optimally two
nonorthogonal states prepared with different a priori probabilities. Thus, we
propose a physical implementation for this linearly independent pure-state
decomposition and state discrimination test by using twin photons generated in
the process of spontaneous parametric down conversion. The information-state is
encoded in one photon polarization state whereas the second single-photon is
used for heralded detection.Comment: 6 pages, 5 figures, Submitted to Phys. Rev.
Systematic evaluation of software product line architectures
The architecture of a software product line is one of its most important artifacts as it represents an abstraction of the products that can be generated. It is crucial to evaluate the quality attributes of a product line architecture in order to: increase the productivity of the product line process and the quality of the products; provide a means to understand the potential behavior of the products and, consequently, decrease their time to market; and, improve the handling of the product line variability. The evaluation of product line architecture can serve as a basis to analyze the managerial and economical values of a product line for software managers and architects. Most of the current research on the evaluation of product line architecture does not take into account metrics directly obtained from UML models and their variabilities; the metrics used instead are difficult to be applied in general and to be used for quantitative analysis. This paper presents a Systematic Evaluation Method for UML-based Software Product Line Architecture, the SystEM-PLA. SystEM-PLA differs from current research as it provides stakeholders with a means to: (i) estimate and analyze potential products; (ii) use predefined basic UML-based metrics to compose quality attribute metrics; (iii) perform feasibility and trade-off analysis of a product line architecture with respect to its quality attributes; and, (iv) make the evaluation of product line architecture more flexible. An example using the SEI’s Arcade Game Maker (AGM) product line is presented as a proof of concept, illustrating SystEM-PLA activities. Metrics for complexity and extensibility quality attributes are defined and used to
perform a trade-off analysis
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