1,081 research outputs found

    Digital Preservation and Access of Natural Resources Documents

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    Digitization and preservation of natural resource documents were reviewed and the current status of digitization presented for a North American university. It is important to present the status of the digitation process for natural resources and to advocate for increased collections of digital material for ease of reference and exchange of information. Digital collections need to include both published documents and ancillary material for research projects and data for future use and interpretation. The methods in this paper can be applied to other natural resource collections increasing their use and distribution. The process of decision making for documents and their preservation and inclusion in ScholarWorks is presented as a part of the Forest Sciences Commons as a subset of the Life Sciences Commons of the Digital Commons Open Network launched and maintained by bepress. Digitization has increased the roles and skillsets needed for librarians and from libraries. This creates new challenges and opportunities for the library as publisher and as an advocate for open access. Digital curation melds together digitization and knowledge management and enhances community engagement. Digitization of collections are reviewed and natural resource documentation presented for faculty publications, Research Projects and Centers, eBooks, Journals, Galleries and electronic Theses and Dissertations (ETDs). Recommendations are made to increase the digital curation of the collection by encouraging community participation and use. Digital archives are important to natural resource professionals as society-ready natural resource graduates need to deal effectively with complex ecological, economic and social issues of current natural resources management. Natural resource research for the future needs to ensure that professionals have a greater breath of knowledge as they interpret and apply new knowledge, understanding, and technology to complex, transdisciplinary social and biological issues and challenges

    Multidimensional Scaling of Cognitive Ability and Academic Achievement Scores

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    Multidimensional scaling (MDS) was used as an alternate multivariate procedure for investigating intelligence and academic achievement test score correlations. Correlation coefficients among Wechsler Intelligence Scale for Children, Fifth Edition (WISC-5) and Wechsler Individual Achievement Test, Third Edition (WIAT-III) validity sample scores and among Kaufman Assessment Battery for Children, Second Edition (KABC-II) and Kaufman Test of Educational Achievement, Second Edition (KTEA-2) co-norming sample scores were analyzed using multidimensional scaling (MDS). Three-dimensional MDS configurations were the best fit for interpretation in both datasets. Subtests were more clearly organized by CHC ability and academic domain instead of complexity. Auditory-linguistic, figural-visual, reading-writing, and quantitative-numeric regions were visible in all models. Results were mostly similar across different grade levels. Additional analysis with WISC-V and WIAT-III tests showed that content (verbal, numeric, figural) and response process facets (verbal, manual, paper-pencil) were also useful in explaining test locations. Two implications from this study are that caution may be needed when interpreting fluency scores across academic areas, and MDS provides more empirically based validity evidence regarding content and response mode processes

    Experimental Synthetic Aperture Radar with Dynamic Metasurfaces

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    We investigate the use of a dynamic metasurface as the transmitting antenna for a synthetic aperture radar (SAR) imaging system. The dynamic metasurface consists of a one-dimensional microstrip waveguide with complementary electric resonator (cELC) elements patterned into the upper conductor. Integrated into each of the cELCs are two diodes that can be used to shift each cELC resonance out of band with an applied voltage. The aperture is designed to operate at K band frequencies (17.5 to 20.3 GHz), with a bandwidth of 2.8 GHz. We experimentally demonstrate imaging with a fabricated metasurface aperture using existing SAR modalities, showing image quality comparable to traditional antennas. The agility of this aperture allows it to operate in spotlight and stripmap SAR modes, as well as in a third modality inspired by computational imaging strategies. We describe its operation in detail, demonstrate high-quality imaging in both 2D and 3D, and examine various trade-offs governing the integration of dynamic metasurfaces in future SAR imaging platforms

    Predicting the whispering gallery mode spectra of microresonators

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    The whispering gallery modes (WGMs) of optical resonators have prompted intensive research efforts due to their usefulness in the field of biological sensing, and their employment in nonlinear optics. While much information is available in the literature on numerical modeling of WGMs in microspheres, it remains a challenging task to be able to predict the emitted spectra of spherical microresonators. Here, we establish a customizable Finite- Difference Time-Domain (FDTD)-based approach to investigate the WGM spectrum of microspheres. The simulations are carried out in the vicinity of a dipole source rather than a typical plane-wave beam excitation, thus providing an effective analogue of the fluorescent dye or nanoparticle coatings used in experiment. The analysis of a single dipole source at different positions on the surface or inside a microsphere, serves to assess the relative efficiency of nearby radiating TE and TM modes, characterizing the profile of the spectrum. By varying the number, positions and alignments of the dipole sources, different excitation scenarios can be compared to analytic models, and to experimental results. The energy flux is collected via a nearby disk-shaped region. The resultant spectral profile shows a dependence on the configuration of the dipole sources. The power outcoupling can then be optimized for specific modes and wavelength regions. The development of such a computational tool can aid the preparation of optical sensors prior to fabrication, by preselecting desired the optical properties of the resonator.Comment: Approved version for SPIE Photonics West, LASE, Laser Resonators, Microresonators and Beam Control XV

    Footprints and human evolution: Homeostasis in foot function?

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    Human, and hominin tracks, occur infrequently within the geological record as rare acts of sedimentary preservation. They have the potential, however, to reveal important information about the locomotion of our ancestors, especially when the tracks pertain to different hominin species. The number of known track sites is small and in making inter-species comparisons, one has to work with small track populations that are often from different depositional settings, thereby complicating our interpretations of them. Here we review several key track sites of palaeoanthropological significance across one of the most important evolutionary transitions (Australopithecus to Homo) which involved the development of anatomy and physiology better-suited to endurance running and walking. The sites include the oldest known hominin track site at Laetoli (3.66 Ma; Tanzania) and those at Ileret (1.5 Ma; Kenya). Tracks from both sites are compared with modern tracks made by habitually unshod individuals using a whole-foot analysis. We conclude that, contrary to some authors, foot function has remained relatively unchanged, perhaps experiencing evolutionary homeostasis, for the last 3.66 Ma. These data suggest that the evolutionary development of modern biomechanical locomotion pre-dates the earliest human tracks and also the transition from the genus Australopithecus to Homo

    Method for predicting whispering gallery mode spectra of spherical microresonators

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    A full three-dimensional Finite-Difference Time-Domain (FDTD)-based toolkit is developed to simulate the whispering gallery modes of a microsphere in the vicinity of a dipole source. This provides a guide for experiments that rely on efficient coupling to the modes of microspheres. The resultant spectra are compared to those of analytic models used in the field. In contrast to the analytic models, the FDTD method is able to collect flux from a variety of possible collection regions, such as a disk-shaped region. The customizability of the technique allows one to consider a variety of mode excitation scenarios, which are particularly useful for investigating novel properties of optical resonators, and are valuable in assessing the viability of a resonator for biosensing.Comment: Published 10 Apr 2015 in Opt. Express Vol. 23, Issue 8, pp. 9924-9937; The FDTD toolkit supercomputer scripts are hosted at: http://sourceforge.net/projects/npps/files/FDTD_WGM_Simulator

    Transfer of the brachialis to the anterior interosseous nerve as a treatment strategy for cervical spinal cord injury: Technical note

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    Study Design Technical report. Objective To provide a technical description of the transfer of the brachialis to the anterior interosseous nerve (AIN) for the treatment of tetraplegia after a cervical spinal cord injury (SCI). Methods In this technical report, the authors present a case illustration of an ideal surgical candidate for a brachialis-to-AIN transfer: a 21-year-old patient with a complete C7 spinal cord injury and failure of any hand motor recovery. The authors provide detailed description including images and video showing how to perform the brachialis-to-AIN transfer. Results The brachialis nerve and AIN fascicles can be successfully isolated using visual inspection and motor mapping. Then, careful dissection and microsurgical coaptation can be used for a successful anterior interosseous reinnervation. Conclusion The nerve transfer techniques for reinnervation have been described predominantly for the treatment of brachial plexus injuries. The majority of the nerve transfer techniques have focused on the upper brachial plexus or distal nerves of the lower brachial plexus. More recently, nerve transfers have reemerged as a potential reinnervation strategy for select patients with cervical SCI. The brachialis-to-AIN transfer technique offers a potential means for restoration of intrinsic hand function in patients with SCI

    In-situ measurements of the optical absorption of dioxythiophene-based conjugated polymers

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    Conjugated polymers can be reversibly doped by electrochemical means. This doping introduces new sub-bandgap optical absorption bands in the polymer while decreasing the bandgap absorption. To study this behavior, we have prepared an electrochemical cell allowing measurements of the optical properties of the polymer. The cell consists of a thin polymer film deposited on gold-coated Mylar behind which is another polymer that serves as a counterelectrode. An infrared transparent window protects the upper polymer from ambient air. By adding a gel electrolyte and making electrical connections to the polymer-on-gold films, one may study electrochromism in a wide spectral range. As the cell voltage (the potential difference between the two electrodes) changes, the doping level of the conjugated polymer films is changed reversibly. Our experiments address electrochromism in poly(3,4-ethylene-dioxy-thiophene) (PEDOT) and poly(3,4-dimethyl-propylene-dioxy-thiophene) (PProDOT-Me2_2). This closed electrochemical cell allows the study of the doping induced sub-bandgap features (polaronic and bipolaronic modes) in these easily oxidized and highly redox switchable polymers. We also study the changes in cell spectra as a function of polymer thickness and investigate strategies to obtain cleaner spectra, minimizing the contributions of water and gel electrolyte features
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