3,254 research outputs found
Ecological segregation of the Late Jurassic stegosaurian and iguanodontian dinosaurs of the Morrison Formation in North America: pronounced or subtle ?
Age, Growth, and Mortality of Atlantic Croaker, Micropogonias undulatus, in the Chesapeake Bay Region
Cost factors in software maintenance.
SIGLEAvailable from British Library Document Supply Centre- DSC:DX176739 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Ground Beetles From a Remnant Oak-Maple-Beech Forest and Its Surroundings in Northeastern Ohio (Coleoptera: Carabidae)
We report 66 ground beetle species in 14 tribes from a natural preserve in northeastern Ohio (Stark County). Six species are new state records. Data from pitfall trap transects across adjoining habitats suggest narrow habitat preferences in some species and broad tolerances in others.
Trends toward flightlessness in forest species and macroptery in the fauna of disturbed agricultural sites are apparent
Alarm Pheromone in a Gregarious Poduromorph Collembolan (Collembola: Hypogastruridae)
We report an alarm pheromone in the gregarious poduromorph collembolan, Hypogastrura pannosa. Cuticular rupture results in emission of a rapidly vaporizing hexane-soluble material with an active space diameter of ca. 1 cm. Conspecifics encountering the vapor front respond with stereotypic aversion and dispersal behaviors. This is the first report on the presence of an alarm pheromone in the order Collembola
Bistability in a simple fluid network due to viscosity contrast
We study the existence of multiple equilibrium states in a simple fluid
network using Newtonian fluids and laminar flow. We demonstrate theoretically
the presence of hysteresis and bistability, and we confirm these predictions in
an experiment using two miscible fluids of different viscosity--sucrose
solution and water. Possible applications include bloodflow, microfluidics, and
other network flows governed by similar principles
Acoustic, psychophysical, and neuroimaging measurements of the effectiveness of active cancellation during auditory functional magnetic resonance imaging
Functional magnetic resonance imaging (fMRI) is one of the principal neuroimaging techniques for studying human audition, but it generates an intense background sound which hinders listening performance and confounds measures of the auditory response. This paper reports the perceptual effects of an active noise control (ANC) system that operates in the electromagnetically hostile and physically compact neuroimaging environment to provide significant noise reduction, without interfering with image quality. Cancellation was first evaluated at 600 Hz, corresponding to the dominant peak in the power spectrum of the background sound and at which cancellation is maximally effective. Microphone measurements at the ear demonstrated 35 dB of acoustic attenuation [from 93 to 58 dB sound pressure level (SPL)], while masked detection thresholds improved by 20 dB (from 74 to 54 dB SPL). Considerable perceptual benefits were also obtained across other frequencies, including those corresponding to dips in the spectrum of the background sound. Cancellation also improved the statistical detection of sound-related cortical activation, especially for sounds presented at low intensities. These results confirm that ANC offers substantial benefits for fMRI research
Improved Performance of the ECR Waveguide Plasma Cathode with Permanent Magnets
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83622/1/AIAA-2010-6519-570.pd
Characterization of a Waveguide ECR Plasma Source
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76786/1/AIAA-2008-4535-674.pd
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