66,250 research outputs found
Repeat and first time visitation in an experience specific context: The Valley of the Giants Tree Top Walk.
Communication with the public is a primary consideration in
the design of natural area tourist attractions (Manfredo & Bright,1991; Roggenbuck, 1992; Vogt & Stewart, 1998). In a management context, communication is essential in ensuring a relevant and enjoyable experience on the part of the visiting tourists (Magill, 1995). Communication also serves as an important management aid in reminding visitors of appropriate behaviour while ensuring continued visitor interest in the attraction (Moscardo, 1998; Moscardo & Woods,2001). This paper presents the results of a .survey examining motivations and attitudes of repeat and first time visitors to the Tree Top Walk site in the context of the communication strategy used at the site
Impact of trail-side interpretive signs on visitor knowledge
Interpretive signs provide an important tool for enhancing visitor knowledge and understanding during a natural area experience. The Tree Top Walk (TTW) site in Western Australia adopted a minimal approach to interpretive signs to reduce distractions and allow the site to speak for itself. A 1999 pilot visitor survey indicated that many visitors were frustrated at this approach and wanted more signs installed along the walk trails despite the presence of information displays around the visitor kiosk. An interpretive sign trial was carried out in 2001 to assess the impact on visitor knowledge of the natural aspects of the site. While the trail-side interpretive signs provided no additional improvement in visitor knowledge, there appeared to be a positive increase in the perception of the site as providing a learning experience. The addition of trail-side interpretive signs also provided a point of interest for repeat visitors already familiar with the unique experience of the Tree Top Walk
Orbital evolution of a test particle around a black hole: higher-order corrections
We study the orbital evolution of a radiation-damped binary in the extreme
mass ratio limit, and the resulting waveforms, to one order beyond what can be
obtained using the conservation laws approach. The equations of motion are
solved perturbatively in the mass ratio (or the corresponding parameter in the
scalar field toy model), using the self force, for quasi-circular orbits around
a Schwarzschild black hole. This approach is applied for the scalar model.
Higher-order corrections yield a phase shift which, if included, may make
gravitational-wave astronomy potentially highly accurate.Comment: 4 pages, 3 Encapsulated PostScript figure
The Co-ordination of Swimmeret Movements in the Crayfish, Procambarus Clarkii (Girard)
1. Electrical activity recorded in the first roots of the abdominal nerve cord show bursts of activity which accompany rhythmic movements of the swimmerets. These bursts persist when a root is cut distal to the electrodes.
2. Proprioceptive impulses have been recorded from the distal portion of these nerves during passive movements of the swimmerets. They have also been recorded in the connectives during both passive and active movements.
3. Cutting all second and third roots of the abdominal ganglia does not interfere with the rhythmic swimmeret movements of the isolated abdomen. Rhythmic efferent bursts persist in first roots even when only a single first root remains intact in such a preparation.
4. Intermittent bursts are also found in the first roots of a completely isolated cord but their pattern, frequency and phase relationships differ from those recorded in the same roots before isolation was completed. Such bursts are very rare in second and third roots.
5. Stimulation of small bundles of fibres in the circumoesophageal commissure produces well-defined inhibitory and excitatory effects on the discharge of single units in the first roots.
6. One specific bundle found in many preparations, when stimulated at 50/sec., caused a tonic retraction of all the swimmerets which then began to beat rhythmically and continued to do so when stimulation was discontinued.
7. Intermittent bursts in the first roots took place with correct phasing during this stimulation even when the abdominal ganglia were isolated except for their connexion with the last thoracic ganglion. Again, such bursts were absent in the second and third roots.
8. It is concluded that both the inflow from peripheral proprioceptors and intrinsic properties of the central ganglia play essential parts in the co-ordination of the metachronal movements of the swimmerets
Neuronal Pathways and Synaptic Connexions in the Abdominal Cord of the Crayfish
1. An investigation has been made into the function and distribution of nerve fibres in the abdominal ganglion chain and its roots in the crayfish, Procambarus clarkii, by leading off action potentials from small prepared bundles following sensory stimulation.
2 .The sensory fields belonging to the first and second roots of each abdominal ganglion were determined, and the antero-posterior pathway of sensory fibres within the cord noted. It was found that the primary sensory fibres of the dorsal muscle receptor organs, entering through the second root, send out an anterior branch to the brain and a posterior one to the last ganglion. For most other sensory fibres much shorter intracentral branches are indicated, though some of them extend for two ganglia in the anterior direction and for one posteriorly. All sensory fibres in the connectives run on the same side as they enter.
3. The segmental divisions of the external skeleton and of the nervous system do not coincide, the neural segment slants in a posterior dorsal direction with respect to the skeletal one.
4. For the majority of the interneurones which innervate more than two abdominal segments it has been proved that they synapse with primary sensory fibres in each of the ganglia that these enter. Depending on the segment stimulated with respect to the leading-off position, both ascending and descending impulses are obtained in such interneurones and collision of the impulses has been observed. Some consequences of this type of integration are discussed.
5. For interneurones responding to bilateral or heterolateral stimulation the course of the impulses proved to be of at least two types. In some, cutting the fibre prevents the arrival of impulses except those set up on the side of the cut from which the recording is made. In others, recording from either side of the cut fibre does not exclude any of the sensory fields to which the fibre normally responded.
6. At least one interneurone is present in which all primary sensory fibres from the different segments to whose activity it responds collect in one ganglion
On the falloff of radiated energy in black hole spacetimes
The goal of much research in relativity is to understand gravitational waves
generated by a strong-field dynamical spacetime. Quantities of particular
interest for many calculations are the Weyl scalar , which is simply
related to the flux of gravitational waves far from the source, and the flux of
energy carried to distant observers, . Conservation laws guarantee
that, in asympotically flat spacetimes, and as . Most calculations extract these quantities at
some finite extraction radius. An understanding of finite radius corrections to
and allows us to more accurately infer their asymptotic
values from a computation. In this paper, we show that, if the final state of
the system is a black hole, then the leading correction to is , and that to the energy flux is --- not and as one might naively guess. Our argument only
relies on the behavior of the curvature scalars for black hole spacetimes.
Using black hole perturbation theory, we calculate the corrections to the
leading falloff, showing that it is quite easy to correct for finite extraction
radius effects.Comment: 5 pages, no figures, accepted to Phys. Rev. D. This version corrects
several typos and minor errors in the earlier submissio
AGAPEROS: Searching for variable stars in the LMC Bar with the Pixel Method. I. Detection, astrometry and cross-identification
We extend the work developed in previous papers on microlensing with a
selection of variable stars. We use the Pixel Method to select variable stars
on a set of 2.5 x 10**6 pixel light curves in the LMC Bar presented elsewhere.
The previous treatment was done in order to optimise the detection of long
timescale variations (larger than a few days) and we further optimise our
analysis for the selection of Long Timescale and Long Period Variables
(LT&LPV). We choose to perform a selection of variable objects as comprehensive
as possible, independent of periodicity and of their position on the colour
magnitude diagram. We detail the different thresholds successively applied to
the light curves, which allow to produce a catalogue of 632 variable objects.
We present a table with the coordinate of each variable, its EROS magnitudes at
one epoch and an indicator of blending in both colours, together with a finding
chart.
A cross-correlation with various catalogues shows that 90% of those variable
objects were undetected before, thus enlarging the sample of LT&LPV previously
known in this area by a factor of 10. Due to the limitations of both the Pixel
Method and the data set, additional data -- namely a longer baseline and near
infrared photometry -- are required to further characterise these variable
stars, as will be addressed in subsequent papers.Comment: 11 pages with 10 figure
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