The Odonata of Isle Royale, Michigan

This paper presents a list of the Odonata recorded from Isle Royale National Park, located in northwestern Lake Superior. Collections from Isle Royale include 38 species of Anisoptera and 12 species of Zygoptera. The list is typical of the boreal regions of North America, and includes nine new records for Isle Royale and one new record for the state of Michigan

Non-interactive multiple predator effects on tadpole survival

Interactions among and within three species of predators were estimated in terms of their effects on prey survival using short-term predation experiments. The prey were tadpoles (Rana temporaria), and the predators were dragonfly larvae (Anax imperator), newts (Triturus alpestris), and backswimmers (Notonecta glauca). Mortality rate per predator imposed by Triturus and Notonecta did not decline with predator density, whereas the predation rate of Anax was strongly reduced when the number of predator individuals increased. Impacts of all three predators were not altered by the presence of other species in pairwise combinations. This system is therefore characterized by interference between individual dragonflies but relatively independent effects of predator species. These results were largely predictable based on the natural history of the predators and are encouraging for attempts to model communities as assemblages of interacting specie

Effort and catch estimates for northern and central California marine recreational fisheries, 1981-1986

Nearly 200 species of finfish are taken by the marine recreational fishery along the northern and central California coast. This data report provides estimates of total effort, total catch, and fishery demographics for the years 1981 through 1986 for that fishery. Catch estimate data are presented by number and weight of species, by disposition of the fish caught (e.g. kept or thrown back), by type of access and fishing gear used, and by geographic zone. (311pp.

Gas volume contents within a container, smart volume instrument

A method for determining the volume of an incompressible gas in a system including incompressible substances in a zero-gravity environment. The method includes inducing a volumetric displacement within a container and measuring the resulting pressure change. From this data, the liquid level can be determined

Variability of contour line alignment on sequential images with the Heidelberg Retina Tomograph

•Background: The influence of the contour line alignment software algorithm on the variability of the Heidelberg Retina Tomograph (HRT) parameters remains unclear. •Methods: Nine discrete topographic images were acquired with the HRT from the right eye in six healthy, emmetropic subjects. The variability of topometric data obtained from the same topographic image, analyzed within different samples of images, was evaluated. A total of four mean topographic images was computed for each subject from: all nine discrete images (A), the first six of those images (B), the last six of those nine images (C), and the first three combined with the last three images (D). A contour line was computed on the mean topographic image generated from the nine discrete topographic images (A). This contour line was then applied to the three other mean topographic images (B, C, and D), using the contour line alignment in the HRT software. Subsequently, the contour line on the mean topographic images was applied to each of the discrete members of the particular images subsets used to compute the mean topographic image, and the topometric data for these discrete topographic images was computed successively for each subset. Prior to processing each subset, the contour line on the discrete topographic images was deleted. This strategy provided a total of three analyses on each discrete topographic image: as a member of the nine images (mean topographic image A), and as a member of two subsets of images (mean topographic image B, C, and/or D). The coefficient of variation (100×SD/mean) of the topographic parameters within those three analyses was calculated for each discrete topographic image in each subject ("intraimage” coefficient of variation). In addition, a coefficient of variation between the nine discrete topographic images ("interimage” coefficient of variation) was calculated. •Results: The "intraimage” and "interimage” variability for the various topographic parameters ranged between 0.03% and 3.10% and between 0.03% and 24.07% respectively. The "intraimage” coefficients of variation and "interimage” coefficients of variation correlated significant (r 2=0.77;P<0.0001). •Conclusion: A high "intraimage” variability, i.e. a high variability in contour line alignment between sequential images, might be an important source of test re-test variability between sequential image

Analysis, Design and Fabrication of centimeter-wave Dielectric Fresnel Zone Plate Lens and reflector

Fresnel lens has a long history in optics. This concept at non-optical wavelengths is also applicable. In this paper we report design and fabrication of a half and quarter wave dielectric Fresnel lens made of Plexiglas, and a Fresnel reflector at 11.1 GHz frequency. We made two lenses and one reflector at same frequency and compare their gain and radiation pattern to simulated results. Some methods for better focusing action will be introduced

Drugs and the internet.

Key findings: The number of retailers on the Silk Road increased (from 282 at time 1 to 374 at the last time point), while the number of retailers on the surface web remained relatively stable (92 at time 1 and 101 at the last time point). The increase on the Silk Road is largely driven by international rather than domestic retailers. • On the Silk Road, cannabis and EPS were sold by the largest number of retailers consistently across all time points, followed by MDMA (3,4-methylenedioxy-Nmethylamphetamine) and pharmaceuticals (primarily benzodiazepines and sildenafil). • The type of EPS available from surface web retailers differed substantially from the EPS available from those selling on the Silk Road. EPS sold on the Silk Road more closely mirrored those most commonly used by EDRS participants (i.e. people who regularly use psychostimulants) including drugs from the 2C-x and NBOMe categories, followed by DMT (dimethyltryptamine), Mephedrone and Methylone. • Average prices of methamphetamine, cocaine and ecstasy being sold on the Silk Road remained stable across the time period. Average domestic prices for common quantities of these substances were comparable to prices paid for these same quantities by 2012 EDRS participants. Average international prices for these substances were substantially lower

Responses of common diving petrel chicks (Pelecanoides urinatrix) to burrow and colony specific odours in a simple wind tunnel

Researchers have previously assumed that common diving petrels (Pelecanoides urinatrix) have a limited sense of smell since they have relatively small olfactory bulbs. A recent study, however, showed that adult diving petrels prefer the scent of their own burrow compared to burrows of other diving petrels, implying that personal scents contribute to the burrow’s odour signature. Because diving petrels appear to be adapted to use olfaction in social contexts, they could be a useful model for investigating how chemically mediated social recognition develops in birds. A first step is to determine whether diving petrel chicks can detect familiar and unfamiliar odours. We compared behavioural responses of chicks to three natural stimuli in a wind tunnel: soil collected from their burrow or colony, and a blank control. During portions of the experiment, chicks turned the least and walked the shortest distances in response to odours from the nest, which is consistent with their sedentary behaviour within the burrow. By contrast, behaviours linked to olfactory search increased when chicks were exposed to blank controls. These results suggest that common diving petrel chicks can detect natural olfactory stimuli before fledging, and lay the foundation for future studies on the role of olfaction in social contexts for this species

A test of the risk allocation hypothesis: tadpole responses to temporal change in predation risk

The risk allocation hypothesis predicts that temporal variation in predation risk can influence how animals allocate feeding behavior among situations that differ in danger. We tested the risk allocation model with tadpoles of the frog Rana lessonae, which satisfy the main assumptions of this model because they must feed to reach metamorphosis within a single season, their behavioral defense against predators is costly, and they can respond to changes in risk integrated over time. Our experiment switched tadpoles between artificial ponds with different numbers of caged dragonfly larvae and held them at high and low risk for different portions of their lives. Tadpoles responded strongly to predators, but they did not obey the risk allocation hypothesis: as the high-risk environment became more dangerous, there was no tendency for tadpoles to allocate more feeding to the low-risk environment, and as tadpoles spent more time at risk, they did not increase feeding in both environments. Our results suggest that the model might be more applicable when the time spent under high predation risk is large relative to the time required to collect resource

Unbalanced-flow, fluid-mixing plug with metering capabilities

A fluid mixer plug has holes formed therethrough such that a remaining portion is closed to fluid flow. The plug's inlet face defines a central circuit region and a ring-shaped region with the ring-shaped region including at least some of the plug's remaining portion so-closed to fluid flow. This remaining portion or closed region at each radius R of the ring shaped region satisfies a radius independent, flow-based relationship. Entry openings are defined in the plug's inlet face in correspondence with the holes. The entry openings define an open flow area at each radius of the ring-shaped region. The open flow area at each such radius satisfies the inverse of the flow-based relationship defining the closed regions of the plug