Now showing items 2022-2041 of 2096

    • Validation of a Model of a Resonant Optothermoacoustic Trace Gas Sensor 

      Petra, N.; Zweck, J.; Minkoff, S. E.; Kosterev, A. A.; Doty, J. H. (OSA, 2011-06)
      A model for a resonant optothermoacoustic sensor is validated by comparison with experiments performed with 0.5% acetylene in nitrogen. At low concentrations, the molecular dynamics of the trace gas do not influence the signal.
    • Validity of a two-item screen for early psychosis 

      Phalen, Peter L.; Rouhakhtar, Pamela Rakhshan; Millman, Zachary B.; Thompson, Elizabeth; DeVylder, Jordan; Mittal, Vijay; Carter, Evan; Reeves, Gloria; Schiffman, Jason (Elsevier B.V., 2018-12)
      Well-validated screening tools have been developed to identify people at high risk for psychosis, but these are rarely used outside of specialty clinics or research settings. The development of extremely brief and simple ...
    • Valuing ecological systems and services 

      Costanza, Robert; Kubiszewski, Ida; Ervin, David; Bluffstone, Randy; Boyd, James; Brown, Darrell; Chang, Heejun; Dujon, Veronica; Granek, Elise; Polasky, Stephen; Shandas, Vivek; Yeakley, J. Alan (F1000, 2011)
      Making trade-offs between ecological services and other contributors to human well-being is a difficult but critical process that requires valuation. This allows both better recognition of the ecological, social, and ...
    • Variability and Proper Motion of X-ray Knots in the Jet of Centaurus A 

      Snios, Bradford; Wykes, Sarka; Nulsen, Paul E. J.; Kraft, Ralph P.; Meyer, Eileen T.; Birkinshaw, Mark; Worrall, Diana M.; Hardcastle, Martin J.; Roediger, Elke; Forman, William R.; Jones, Christine (2019-01-22)
      We report results from Chandra observations analyzed for evidence of variability and proper motion in the X-ray jet of Centaurus A. Using data spanning 15 years, collective proper motion of 11.3±3.3 mas yr We report results ...
    • Variable light environments induce plastic spectral tuning by regional opsin coexpression in the African cichlid fish, Metriaclima zebra 

      Dalton, Brian E.; Lu, Jessica; Leips, Jeff; Cronin, Thomas W.; Carleton, Karen L. (Wiley Periodicals, 2015-08-06)
      Critical behaviors such as predation and mate choice often depend on vision. Visual systems are sensitive to the spectrum of light in their environment, which can vary extensively both within and among habitats. Evolutionary ...
    • Variation in spectral reflectance among populations of Dendrobates pumilio, the strawberry poison frog, in the Bocas del Toro Archipelago, Panama 

      Summers, Kyle; Cronin, Thomas W.; Kennedy, Timothy (John Wiley & Sons, 2003-01-14)
      Aim: The goal of this study was to quantify levels of variation in spectral reflectance within and among populations of Dendrobates pumilio, the strawberry poison frog from the Bocas del Toro Archipelago. Location: This ...
    • Velocity-dependent optical forces and Maxwell’s demon 

      Franson, J. D. (Nature, 2019-09-24)
      An atom placed in a focused laser beam will experience a dipole force due to the gradient in the interaction energy, which is analogous to the well-known optical tweezers effect. This force will be dependent on the velocity ...
    • VERITAS and Fermi-LAT Observations of TeV Gamma-Ray Sources Discovered by HAWC in the 2HWC Catalog 

      Ojha, Roopesh; et al. (The American Astronomical Society, 2018-10-05)
      The High Altitude Water Cherenkov (HAWC) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100 GeV) gamma-ray sources based on 507 days of observation. Among these, 19 sources are not ...
    • Vertical migration behavior and larval transport in brachyuran crabs 

      Garrison, Lance P. (Inter-Research, 1999-01-18)
      documented the patterns of vertical distribution and abundance of zoeae from 3 families of brachyuran crabs in the York River, a sub-estuary in southern Chesapeake Bay (USA). The family groups included species from Ocypodidae. ...
    • Video Summarization of Laparoscopic Cholecystectomies 

      Grasso, Michael A.; Finin, Tim; Zhu, Xianshu; Joshi, Anupam; Yesha, Yelena (2009-11-14)
      We compared image features with a distance metric and support vector machine to identify the critical view of a laparoscopic cholecystectomy. Our accuracy was up to 91%. We are currently experimenting with particle analysis, ...
    • Viewpoint: Equilibration in Quantum Systems 

      Deffner, Sebastian (American Physical Society, 2019-11-13)
      Two research groups show that specific contributions to entropy may be the key to understanding how and when quantum systems equilibrate.
    • Vigil: Providing Trust for Enhanced Security in Pervasive Systems 

      Kagal, Lalana; Undercoffer, Jeffrey; Perich, Filip; Joshi, Anupam; Finin, Tim; Yesha, Yelena (2002-08-12)
      Computing today is moving away from the desktop, becoming diffused into our surroundings and onto our personal digital devices. Moreover, ad-hoc networks such as Bluetooth provide for spontaneous connectivity between ...
    • Violating Bell’s inequality using a number state and a beam splitter 

      Shringarpure, S.U.; Franson, J.D. (2019-11-06)
      Passing a photon number state through a balanced beam splitter will produce an entangled state in which the phases of the two output modes are highly correlated. We show that Bell’s inequality can be violated using this ...
    • Virtual Reality and Photogrammetry for Improved Reproducibility of Human-Robot Interaction Studies 

      Murnane, Mark; Breitmeyer, Max; Matuszek, Cynthia; Engel, Don (IEEE, 2019-08-15)
      Collecting data in robotics, especially human-robot interactions, traditionally requires a physical robot in a prepared environment, which presents substantial scalability challenges. First, robots provide many possible ...
    • Virtual Schools and eLearning: Planning for Success 

      Clark, Tom; Berge, Zane (University of Wisconsin, 2003-01)
      Virtual schools are a rapidly growing phenomenon in American elementary and secondary (K-12) education. They are the latest and potentially the most controversial manifestation of the elearning revolution in schools. The ...
    • Virtual Worlds : Corporate Early Adopters Pave the Way 

      Lithgow, Catherine M. J.; Wolf, Judi L. Davidson; Berge, Zane L. (IGI Global Disseminator of Knowledge, 2011)
      Multi-user virtual environments (MUVEs), the most popular of which is Second Life, have great potential to provide engaging, interactive content to today’s students using both synchronous and asynchronous delivery. ...
    • Visual Deficits and Dysfunctions Associated with Traumatic Brain Injury: A Systematic Review and Meta-analysis 

      Merezhinskaya, Natalya; Mallia, Rita K.; Park, DoHwan; Bryden, Daniel W.; Mathur, Karan; Barker II, Felix M (American Academy of Optometry, 2019-05-04)
      SIGNIFICANCE This study reports prevalence data combined independently for accommodative dysfunction, convergence insufficiency, visual field loss, and visual acuity loss in patients with traumatic brain injury in the ...
    • Visual mate choice in poison frogs 

      Summers, Kyle; Symula, Rebecca; Clough, Mark; Cronin, Thomas (The Royal Society, 1999-11-07)
      We investigated female mate choice on the basis of visual cues in two populations of Dendrobates pumilio, the strawberry poison frog, from the Bocas del Toro Archipelago in Panama, Central America. Mate choice experiments ...
    • Visual Optics: Accommodation in a Splash 

      Cronin, Thomas W. (Elsevier B.V., 2012-10-23)
      Gannets are large seabirds that hunt fish from the air, making a plunge dive followed by active swimming pursuit of prey. A recent study shows that they convert from aerial to aquatic vision nearly instantly.
    • Visual phototransduction components in cephalopod chromatophores suggest dermal photoreception 

      Kingston, Alexandra C. N.; Kuzirian, Alan M.; Hanlon, Roger T.; Cronin, Thomas W. (The Company of Biologists Ltd, 2015-04-08)
      Cephalopodmollusks are renowned for their colorful and dynamic body patterns, produced by an assemblage of skin components that interact with light.Thesemay include iridophores, leucophores, chromatophores and (in some ...