2,268 research outputs found
Assessing schematic knowledge of introductory probability theory
[Abstract]: The ability to identify schematic knowledge is an important goal for both assessment
and instruction. In the current paper, schematic knowledge of statistical probability theory is
explored from the declarative-procedural framework using multiple methods of assessment.
A sample of 90 undergraduate introductory statistics students was required to classify 10
pairs of probability problems as similar or different; to identify whether 15 problems
contained sufficient, irrelevant, or missing information (text-edit); and to solve 10 additional
problems. The complexity of the schema on which the problems were based was also
manipulated. Detailed analyses compared text-editing and solution accuracy as a function of
text-editing category and schema complexity. Results showed that text-editing tends to be
easier than solution and differentially sensitive to schema complexity. While text-editing and
classification were correlated with solution, only text-editing problems with missing
information uniquely predicted success. In light of previous research these results suggest
that text-editing is suitable for supplementing the assessment of schematic knowledge in
development
Gambelia Wislizenii (Long-nosed Leopard Lizard). Arboreal behavior.
In the North American southwest, leopard lizards (genus Gambelia) are characteristically ground dwelling (Stebbins 2003. A Field Guide to Western Reptiles and Amphibians, 3rd ed., Houghton-Mifflin, New York. 533 pp.; Smith 1946. Handbook of Lizards, Comstock Publishing Co., Ithaca, New York. 557 pp.). In G. wislizenii, climbing is not mentioned in several substantive ecological studies of this species (Parker and Pianka 1976. Herpetologica 32:95-114; Tanner and Krogh 1974. Herpetologica 30:63-72), and to our knowledge, only a few seconds exist of climbing in this species. Clark (1974. Trans. Kansas Acad. Sci. 77:68) observed a G. wislizenii perched 30 cm off the ground in a shrub, and Miller and Stebbins (1964. The Lives of Desert Animals in Joshua Tree National Monument,. University of California Press, Berkeley. 452 pp.) mentioned collecting an individual on top of a massive rock 30 feet from the ground. Crowley and Pietruszka (1983. Anim. Behav. 31:1055-1060) commented that this species often climbs into shrubs or onto rocks, but did not provide additional information. For this reason, we augment the limited data on climbing in G. wislizenii with an observation from the Mojave Desert of California (USA)
Colocalization of neurons in optical coherence microscopy and Nissl-stained histology in Brodmann’s area 32 and area 21
Published in final edited form as:
Brain Struct Funct. 2019 January ; 224(1): 351–362. doi:10.1007/s00429-018-1777-z.Optical coherence tomography is an optical technique that uses backscattered light to highlight intrinsic structure, and when applied to brain tissue, it can resolve cortical layers and fiber bundles. Optical coherence microscopy (OCM) is higher resolution (i.e., 1.25 µm) and is capable of detecting neurons. In a previous report, we compared the correspondence of OCM acquired imaging of neurons with traditional Nissl stained histology in entorhinal cortex layer II. In the current method-oriented study, we aimed to determine the colocalization success rate between OCM and Nissl in other brain cortical areas with different laminar arrangements and cell packing density. We focused on two additional cortical areas: medial prefrontal, pre-genual Brodmann area (BA) 32 and lateral temporal BA 21. We present the data as colocalization matrices and as quantitative percentages. The overall average colocalization in OCM compared to Nissl was 67% for BA 32 (47% for Nissl colocalization) and 60% for BA 21 (52% for Nissl colocalization), but with a large variability across cases and layers. One source of variability and confounds could be ascribed to an obscuring effect from large and dense intracortical fiber bundles. Other technical challenges, including obstacles inherent to human brain tissue, are discussed. Despite limitations, OCM is a promising semi-high throughput tool for demonstrating detail at the neuronal level, and, with further development, has distinct potential for the automatic acquisition of large databases as are required for the human brain.Accepted manuscrip
An eccentrically perturbed Tonks-Girardeau gas
We investigate the static and dynamic properties of a Tonks-Girardeau gas in
a harmonic trap with an eccentric -perturbation of variable strength.
For this we first find the analytic eigensolution of the single particle
problem and use this solution to calculate the spatial density and energy
profiles of the many particle gas as a function of the strength and position of
the perturbation. We find that the crystal nature of the Tonks state is
reflected in both the lowest occupation number and momentum distribution of the
gas. As a novel application of our model, we study the time evolution of the
the spatial density after a sudden removal of the perturbation. The dynamics
exhibits collapses and revivals of the original density distribution which
occur in units of the trap frequency. This is reminiscent of the Talbot effect
from classical optics.Comment: Comments and suggestions are welcom
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