Species Limits and Phylogeography of North American Cricket Frogs (Acris: Hylidae)

Cricket frogs are widely distributed across the eastern United States and two species, the northern cricket frog (Acris crepitans) and the southern cricket frog (A. gryllus) are currently recognized. We generated a phylogenetic hypothesis for Acris using fragments of nuclear and mitochondrial genes in separate and combined phylogenetic analyses. We also used distance methods and fixation indices to evaluate species limits within the genus and the validity of currently recognized subspecies of A. crepitans. The distributions of existing A. crepitans subspecies, defined by morphology and call types, do not match the distributions of evolutionary lineages recovered using our genetic data. We discuss a scenario of call evolution to explain this disparity. We also recovered distinct phylogeographic groups within A. crepitans and A. gryllus that are congruent with other codistributed taxa. Under a lineage-based species concept, we recognize Acris blanchardi as a distinct species. The importance of this revised taxonomy is discussed in light of the dramatic declines in A. blanchardi across the northern and western portions of its range

The Effect of Particle Strength on the Ballistic Resistance of Shear Thickening Fluids

The response of shear thickening fluids (STFs) under ballistic impact has received considerable attention due to its field-responsive nature. While efforts have primarily focused on the response of traditional ballistic fabrics impregnated with fluids, the response of pure STFs to penetration has received limited attention. In the present study, the ballistic response of pure STFs is investigated and the effect of fluid density and particle strength on ballistic performance is isolated. The loss of ballistic resistance of STFs at higher impact velocities is governed by particle strength, indicating the range of velocities over which they may provide effective armor solutions.Comment: 4 pages, 4 figure

Automated Mobile System for Accurate Outdoor Tree Crop Enumeration Using an Uncalibrated Camera.

This paper demonstrates an automated computer vision system for outdoor tree crop enumeration in a seedling nursery. The complete system incorporates both hardware components (including an embedded microcontroller, an odometry encoder, and an uncalibrated digital color camera) and software algorithms (including microcontroller algorithms and the proposed algorithm for tree crop enumeration) required to obtain robust performance in a natural outdoor environment. The enumeration system uses a three-step image analysis process based upon: (1) an orthographic plant projection method integrating a perspective transform with automatic parameter estimation; (2) a plant counting method based on projection histograms; and (3) a double-counting avoidance method based on a homography transform. Experimental results demonstrate the ability to count large numbers of plants automatically with no human effort. Results show that, for tree seedlings having a height up to 40 cm and a within-row tree spacing of approximately 10 cm, the algorithms successfully estimated the number of plants with an average accuracy of 95.2% for trees within a single image and 98% for counting of the whole plant population in a large sequence of images

Different germanium dopant concentration and the thermoluminescence characteristics of flat Ge-doped optical fibres

The influence of elevated germanium concentration on the thermoluminesence characteristics of a novel form of fabricated flat optical fibre was examined. All the samples were irradiated with two nominal photon energies (6 MV and 10 MV) and 1.25 MeV gamma energy. Flat fibres with 10 mol % Ge concentration provided the superior TL yield compared against that of 6 and 8 mol % Ge-doped optical fibres for both 6 MV and 10 MV energy. Interpretation of the results has been aided by study of the glow curves, revealing in particular new generation of defects in the flat fibres due to strain-generation at the collapsed surfaces. The strain represent deep-energy defects

Interactive Digital Support for Concept Design Teams

This thesis develops a design method, the ICR (Inform, Create, Reflect) Grid, for improved utilisation of information during concept design. Although concept design is information intensive and critical to project direction, the effective management and use of digital information has not been adequately addressed. The ICR Grid is a prescriptive method which requires design teams to find and build information resources in parallel with creating solutions. As a solution-based approach it allows designers to freely explore ideas, while encouraging flexible thinking by using different modes of conceptual working (analysis, synthesis and evaluation). The output of the method is a linked grid of concepts and information sources. The exploratory phase of the research examined current design process models and concept design methods, with team information use patterns explored through protocol analyses of a design task. This was followed by an examination of literature relating to digital information and a class study on technological support for student designers. The outcome of these explorations was an understanding that to enhance digital information use in concept design, a new approach was necessary. Development began by correlating characteristics of computer games to concept design, with a view to applying new techniques to the structure and management of information. A number of scenarios were subsequently outlined, with one selected and developed using paper-based prototyping. This was eventually formalised as the ICR Grid. Initial evaluation of the new method was carried out through a comparative study with the 6-3-5 Method, which revealed that although fewer concepts were produced with the ICR Grid, they were of a higher quality, variety and detail. Three different companies then used the ICR Grid to address relevant industrial problems, with generally positive feedback obtained on its performance. Several areas are identified for future work and the further enhancement of information use

Open Notebook Science Challenge: Solubilities of Organic Compounds in Organic Solvents

This book contains the results of the Open Notebook Science Solubility Challenge. All experimental measurements are provided with a link to either the laboratory notebook page where the experiment was carried out or to a literature reference. The Challenge was sponsored by Submeta, Nature and Sigma-Aldrich

Open Notebook Science Challenge: Solubilities of Organic Compounds in Organic Solvents

This book contains the results of the Open Notebook Science Solubility Challenge. All experimental measurements are provided with a link to either the laboratory notebook page where the experiment was carried out or to a literature reference. The Challenge was sponsored by Submeta, Nature and Sigma-Aldrich