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265 results on '"Tai, Y. C."'

6. Initial Results of a Prototype AWSM-PET Device for Augmented Whole-body PET Imaging

Author

Chen, Y., primary, Hambdi, M., additional, Komarov, S., additional, Mintzer, R. A., additional, Cho, S., additional, Pocci, D., additional, Thomas, A., additional, Corbeil, J., additional, Breuer, J., additional, Judenhofer, M., additional, Wu, N., additional, Frye, J., additional, Dehdashti, F., additional, O’Sullivan, J. A., additional, Laforest, R., additional, Siegel, S. B., additional, and Tai, Y.-C., additional

Published
2023
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8. MicroPET II: design, development and initial performance of an improved microPET scanner for small-animal imaging

Author

Tai, Y C, Chatziioannou, A F, Yang, Y F, Silverman, R W, Meadors, K, Siegel, S, Newport, D F, Stickel, J R, and Cherry, Simon R

Abstract

MicroPET II is a second-generation animal PET scanner designed for high-resolution imaging of small laboratory rodents. The system consists of 90 scintillation detector modules arranged in three contiguous axial rings with a ring diameter of 16.0 cm and an axial length of 4.9 cm. Each detector module consists of a 14 x 14 array of lutetium oxyorthosilicate (LSO) crystals coupled to a multi-channel photomultiplier tube (MC-PMT) through a coherent optical fibre bundle. Each LSO crystal element measures 0.975 mm x 0.975 mm in cross section by 12.5 mm in length. A barium sulphate reflector material was used between LSO elements leading to a detector pitch of 1.15 mm in both axial and transverse directions. Fused optical fibre bundles were made from 90 mum diameter glass fibres with a numerical aperture of 0.56. Interstitial extramural absorber was added between the fibres to reduce optical cross talk. A charge-division readout circuit was implemented on printed circuit boards to decode the 196 crystals in each array from the outputs of the 64 anode signals of the MC-PMT. Electronics from Concorde Microsystems Inc. (Knoxville, TN) were used for signal amplification, digitization, event qualification, coincidence processing and data capture. Coincidence data were passed to a host PC that recorded events in list mode. Following acquisition, data were sorted into sinograms and reconstructed using Fourier rebinning and filtered backprojection algorithms. Basic evaluation of the system has been completed. The absolute sensitivity of the microPET II scanner was 2.26% at the centre of the field of view (CFOV) for an energy window of 250-750 keV and a timing window of 10 ns. The intrinsic spatial resolution of the detectors in the system averaged 1.21 mm full width at half maximum (FWHM) when measured with a Na-22 point source 0.5 mm in diameter. Reconstructed image resolution ranged from 0.83 mm FWHM at the CFOV to 1.47 mm FWHM in the radial direction, 1.17 mm FWHM in the tangential direction and 1.42 mm FWHM in the axial direction at 1 cm offset from the CFOV. These values represent highly significant improvements over our earlier microPET scanner (approximately fourfold sensitivity increase and 25-35% improvement in linear spatial resolution under equivalent operating conditions) and are expected to be further improved when the system is fully optimized.

Published
2003

11. Dense Granular Avalanches: Mathematical Description and Experimental Validation

Author

Tai, Y.-C., Hutter, K., Gray, J.M.N.T., Beig, R., editor, Ehlers, J., editor, Frisch, U., editor, Hepp, K., editor, Hillebrandt, W., editor, Imboden, D., editor, Jaffe, R. L., editor, Kippenhahn, R., editor, Lipowsky, R., editor, Löhneysen, H. v., editor, Ojima, I., editor, Weidenmüller, H. A., editor, Wess, J., editor, Zittartz, J., editor, Balmforth, N. J., editor, and Provenzale, A., editor

Published
2001
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15. Ion Chromatography-on-a-chip for Water Quality Analysis

Author

Kidd, R. D, Noell, A, Kazarians, G, Aubrey, A. D, Scianmarello, N, and Tai, Y.-C

Subjects
Inorganic, Organic And Physical Chemistry
Abstract

We report progress towards developing a Micro-Electro-Mechanical Systems (MEMS)- based ion chromatograph (IC) for crewed spacecraft water analysis. This IC-chip is an offshoot of a NASA-funded effort to produce a high performance liquid chromatograph (HPLC)-chip. This HPLC-chip system would require a desalting (i.e. ion chromatography) step. The complete HPLC instrument consists of the Jet Propulsion Labortory's (JPL's) quadrupole ion trap mass spectrometer integrated with a state-of-the-art MEMS liquid chromatograph (LC) system developed by the California Institute of Technology's (Caltech's) Micromachining Laboratory. The IC version of the chip consist of an electrolysis-based injector, a separation column, two electrolysis pumps for gradient generation, mixer, and a built-in conductivity detector. The HPLC version of the chip also includes a nanospray tip. The low instrument mass, coupled with its high analytical capabilities, makes the LC chip ideally suitable for wide range of applications such as trace contaminant, inorganic analytical science and, when coupled to a mass spectrometer, a macromolecular detection system for either crewed space exploration vehicles or robotic planetary missions.

Published
2015

17. Wafer-level parylene packaging with integrated RF electronics for wireless retinal prostheses

Author

Li, W., Rodger, D. C., Meng, E., Weiland, J. D., Humayun, M. S., and Tai, Y.-C.

Subjects
Microelectromechanical systems -- Design and construction, Parylenes -- Electric properties, Parylenes -- Thermal properties, Embedded systems -- Design and construction, Embedded system, System on a chip, Engineering and manufacturing industries, Science and technology
Published
2010

26. A hybrid attenuation correction technique to compensate for lung density in 3-D total body PET

Author

Tai, Y.-C., Lin, K.-P., Dahlbom, M., and Hoffman, E.J.

Subjects
Body, Human, PET imaging -- Methods, Image processing -- Digital techniques, Business, Electronics, Electronics and electrical industries
Abstract

A hybrid attenuation correction technique (ACT) is under development for 18F-FDG total body positron emission tomography (PET). With a short transmission scan of the thorax, any time within a few days of the imaging session, this technique can correct for attenuation in the entire body. Segmentation, registration, and active contour finding techniques are applied to both emission and short transmission images to locate and map the major attenuating structures in the body. This technique eliminates the need for the patient to remain still from the start of the transmission scan to the end of the emission scan without the added noise of simultaneous or post emission transmission scan measurements. The results of volunteer studies are comparable to standard measured ACT, both visually and quantitatively. The efficient use of scanner time and improved patient comfort make this technique particularly suitable for clinical imaging.

Published
1996

27. Development of Gas Permeable Parylene HT as a Substrate for Cell-Culture-on-a-Chip Applications

Author

Scianmarello, Nicholas, Cook, Colin, Shang, Kuang-Ming, Tai, Y. C., Scianmarello, Nicholas, Cook, Colin, Shang, Kuang-Ming, and Tai, Y. C.

Abstract

Here we report on the production of highly gas permeable Parylene HT through a cryogenic deposition process. The unique combination of biological and chemical inertness of Parylene, and gas permeability of this porous variant make it interesting for cell culture and biology-on-a-chip applications. The dependence of porosity, density, and permeability on the deposition temperature allows for tunable control of material properties. Culture of HEK-293 cells on cryogenically deposited Parylene HT demonstrates viability for biological applications.

Published
2019

32. Modeling Shallow Over-Saturated Mixtures on Arbitrary Rigid Topography

Author

Luca, I., Kuo, C. Y., Hutter, K., and Tai, Y. C.

Abstract

In this paper a system of depth-integrated equations for over-saturated debris flows on three-dimensional topography is derived. The lower layer is a saturated mixture of density preserving solid and fluid constituents, where the pore fluid is in excess, so that an upper fluid layer develops above the mixture layer. At the layer interface fluid mass exchange may exist and for this a parameterization is needed. The emphasis is on the description of the influence on the flow by the curvature of the basal surface, and not on proposing rheological models of the avalanching mass. To this end, a coordinate system fitted to the topography has been used to properly account for the geometry of the basal surface. Thus, the modeling equations have been written in terms of these coordinates, and then simplified by using (1) the depth-averaging technique and (2) ordering approximations in terms of an aspect ratio ϵ which accounts for the scale of the flowing mass. The ensuing equations have been complemented by closure relations, but any other such relations can be postulated. For a shallow two-layer debris with clean water in the upper layer, flowing on a slightly curved surface, the equilibrium free surface is shown to be horizontal

Published
2017

33. Multi-scales Approximations of Thin Flows for Curved Topography

Author

Nkonga, B., Tai,Y-C., Kuo, C-Y., and Kuratorium für Forschung im Küsteningenieurwesen (KFKI)

Subjects
Wasserbau (627), Ingenieurwissenschaften (620)
Abstract

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive/

Published
2016

34. Thermal conductivity of heavily doped low-pressure chemical vapor deposited polycrystalline silicon films.

Author

Tai, Y. C., Mastrangelo, C. H., and Muller, R. S.

Subjects
*CHEMICAL vapor deposition, *POLYCRYSTALLINE semiconductors, *SILICON, *THIN films, *DOPED semiconductors
Abstract

Presents a study which measured the thermal conductivity of heavily doped low-pressure chemical vapor deposited polycrystalline silicon films. Fabrication process for the bridges; Theoretical considerations; Experimental details.

Published
1988
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35. Study of Parylene penetration into microchannel

Author

Wang, W., Kang, D., Tai, Y. C., Wang, W., Kang, D., and Tai, Y. C.

Abstract

This study reports the penetration properties of various Parylenes (i.e., C, N and HT) inside long microchannels. The work broadly covers the effects of the dimer type, loaded dimer mass, substrate temperature and channel size on the penetration length, i.e., the length that Parylene can be deposited into the microchannel from the inlet. Understanding the mechanism of Parylene penetration into microchannel helps to develop mass-producible inner surface protection design and process for microfluidic devices.

Published
2015

36. Top-Down Control Of Phytoplankton By Zooplankton In Tropical Reservoirs In Singapore?

Author

Low, E. W., Clews, E., Todd, P. A., Tai, Y. C., and Ng, Peter K. L.

Subjects
Biodiversity, Taxonomy
Abstract

Low, E. W., Clews, E., Todd, P. A., Tai, Y. C., Ng, Peter K. L. (2010): Top-Down Control Of Phytoplankton By Zooplankton In Tropical Reservoirs In Singapore? Raffles Bulletin of Zoology 58 (2): 311-322, DOI: http://doi.org/10.5281/zenodo.5342886, {"references":["Abrantes, N., S. C. Antunes, M. J. Pereira & F. Goncalves, 2006. Seasonal succession of cladocerans and phytoplankton and their interactions in a shallow eutrophic lake (Lake Vela, Portugal). Acta Oecologica, 29: 54-64.","Agrawal, A. A. 1998. Algal defense, grazers and their interactions in aquatic trophic cascades. Acta Oecologica, 19(4): 331-337.","Attayde, J. L.& R. L. Bozelli, 1998. Assessing the indicator properties of zooplankton assemblages to disturbance gradients by canonical correspondence analysis. Canadian Journal of Fisheries and Aquatic Science, 55: 1789-1797","Auer, B., U. Elzer & H. Arndt, 2004. Comparison of pelagic food webs in lakes along a trophic gradient and with seasonal aspects: influences of resource and predation. Journal of Plankton Research, 26(6): 697-709.","Balseiro, E., B. Modenutti & C. P. Queimalino, 1997. Nutrient recycling and shifts in N P ratio by different zooplankton structure in a South Andes lake. Journal of Plankton Research, 19(7): 805-817.","Becker, C., H. Feuchtmayr, D. Brepohl, B. Santer & M. Boersma, 2004. Differential impacts of copepods and cladocerans on lake seston, and resulting effects on zooplankton growth. Hydrobiologia, 526: 197-207.","Bergquist, A. M., S. R. Carpenter & J. C. Latino, 1985. Shifts in phytoplankton size structure and community composition during grazing by contrasting zooplankton assemblages. Limnology and Oceanography, 30(5): 1037-1045.","Bergquist, A. M. & S. R. Carpenter, 1986. Limnetic herbivory: effects on phytoplankton populations and primary production. Ecology, 67(5):1351-1360.","Brooks, J. L. 1969. Eutrophication and changes in the composition of the zooplankton. In: Eutrophication: causes, consequences, correctives. National Academy of Sciences, Washington, D.C.: 236-255.","Brooks, J. L. & S. I. Dodson, 1965. Predation, body size and composition of plankton. Science, 150: 28-35.","Burns, C. W., 1979. Population dynamics and production of Boekella dilatata (Copepoda: Calanoida) in Lake Hayes, New Zealand. Archiv fur Hydrobiologie Supplement, 54: 409-465.","Burns, C. W., 1987. Insights into zooplankton-cyanobacteria interactions derived from enclosure studies. New Zealand Journal of Marine and Freshwater Research, 21: 477-482.","Burns, C. W. & Z. K. Xu, 1990. Calanoid copepods feeding on algae and filamentous cyanobacteria: rates of ingestion, defaecation and effects on trichome length. Journal of Plankton Research, 12(1): 201-213.","Butler, N. M., C. A. Suttle & W. E. Neill, 1989. Discrimination by freshwater zooplankton between single algal cells differing in nutritional status. Oecologia, 78: 368-372.","Carpenter, S. R., J. F. Kitchell, K. L. Cottingham, D. E. Schindler, D. L. Christensen, D. M. Post & N. Voichick, 1996. Chlorophyll variability, nutrient input and grazing: evidence from wholelake experiments. Ecology, 77(3): 725-735.","Carvalho, L. 1994. Top-down control of phytoplankton in a shallow hypertrophic lake: Little Mere (England). Hydrobiologia, 275- 276: 53-63.","Christoffersen, K., B. Riemann, A. Klysner & M. Sondergaard, 1993. Potential role of fish predation and natural populations of zooplankton in structuring a plankton community in eutrophci lake water. Limnology and Oceanography, 38(3): 561-573.","DeMott, W. R. & W. C. Kerfoot, 1982. Competiion among cladocerans: nature of the interaction between Bosmina and Daphnia. Ecology, 63(6): 1949-1966.","DeMott, W. R., 1986. The role of taste in food selection by freshwater zooplankton. Oecologia, 69: 334-340.","DeMott, W. R. & F. Moxter, 1991. Foraging on cyanobacteria by copepods: responses to chemical defences and resource abundance. Ecology, 72(5): 1820-1834.","DeMott, W. R., Q. X. Zhang & W. W. Carmichael, 1991. Effects of toxic cyanobacteria and purified toxins on the survival and feeding of a copepod and three species of Daphnia. Limnology and Oceanography, 36(7): 1346-1357.","DeMott, W. R. & D. Muller-Navarra, 1997. The importance of highly unsaturated fatty acides in zooplankton nutrition: evidence from experiments with Daphnia, a cyanobacterium and lipid emulsions. Freshwater Biology, 38(3): 649-664.","Dumont, H. J., 1994. On the diversity of Cladocera in the tropics. Hydrobiologia, 272: 27-38.","Dumont, H. J., J. Green & H. Masundire, 1994. The Kariba Discussion. In: Studies on the Ecology of Tropical Zooplankton. Hydrobiologia, 272: 293-295.","Dussart, B. H., C. H. Fernando, T. Matsumura-Tundisi & R. J. Shiel, 1984. A review of the systematic, distribution and ecology of tropical freshwater zooplankton. Hydrobiologia, 113: 77-91.","Edgar, N. B. & J. D. Green, 1994. Calanoid copepod grazing on phytoplankton: seasonal experiments on natural communities. Hydrobiologia, 273: 147-161.","Elser, J. J., M. M. Elser, N. A. MacKay & S. R. Carpenter, 1988. Zooplankton-mediated transitions between N- and P-limited algal growth. Limnology and Oceanography, 33(1): 1-14.","Elser, J. J., 1999. The pathway to noxious cyanobacteria blooms in lakes: the food web as the final turn. Freshwater Biology, 42: 537-543.","Elser, J. J., L. Gudex, M. Kyle, T. Ishikawa & J. Urabe, 2001. Effects of zooplankton on nutrient availability and seston C: N: P stoichiometry in inshore waters of Lake Biwa, Japan. Limnology, 2: 91-100.","Fernando, C. H., 1980. The species and size composition of tropical freshwater zooplankton with special reference to the Oriental region (Southeast Asia). Internationale Revue der gesamten Hydrobiologie und Hydrographie, 65(3): 411-426.","Forsberg, C. & S. O. Ryding, 1980. Eutrophication parameters and trophic state indices in 30 Swedish waste-receiving lakes. Archiv fur Hydrobiologie, 89(1/2): 189-207.","Fryer, G., 1957. The food of some freshwater cyclopoid copepods and its ecological significance. Journal of Animal Ecology, 26(2): 263-286.","Gannon, J. E. & R. S. Stemberger, 1978. Zooplankton (especially crustaceans and rotifers) as indicators of water quality. Transactions of the American Microscopical Society, 97(1): 16-35.","Hair, J. F., W. C. Black, B. J. Babin, R. E. Anderson & R. L. Tatham, 2005. Multivariate Data Analysis. 6th Edition. Pearson Prentice Hall, New Jersery, United States of America.","Haney, J. F., 1987. Field studies on zooplankton-cyanobacteria interactions. New Zealand Journal of Marine and Freshwater Research, 21: 467-475.","Hansson, L. A., S. Gustafsson, K. Rengefors, & L. Bomark, 2007. Cyanobacterial chemical warfare affects zooplankton community composition. Freshwater Biology, 52: 1290-1301.","Holm, N. P., G. G. Ganf & J. Sharpiro, 1983. Feeding and assilimation rates of Daphnia pulex fed with Aphanizomenon flos-aquae. Limnology and Oceanography, 28(4): 677-687.","Huszar, V. L. M., L. H. S. Silva, P. Domingos, M. Marinho, & S. Melo, 1998. Phytoplankton species composition is more sensitive than OECD criteria to the trophic status of three Brazilian tropical lakes. Hydrobiologia, 369/370: 59-71.","Jeppesen, E., M. Sondergaard, N. Mazzeo, M. Meerhoff, C. Branco, V. Huszar & F. Scasso, 2005. Lake restoration and biomanipulation in temperate lakes: relevance for subtropical and tropical lakes. In: Reddy, M. V. (ed.), Restoration and Management of Tropical Eutrophic Lakes. Science Publishers.","Jeppesen, E., M. Meerhoff, B. A. Jacobson, R. S. Hansen, M. Sondergaard, J. P. Jensen, T. L. Lauridsen, N. Mazzeo & C. W. C. Branco, 2007. Restoration of shallow lakes by nutrient control and biomanipulation - the successful strategy varies with lake size and climate. Hydrobiologia, 581: 269-285.","Jutter, F., 2005. Evidence that polyunsaturated aldehydes of diatoms are repellents for pelagic crustacean grazers. Aquatic Ecology, 39(3): 271-282.","Kasprzak, P. & R. Koschel, 2000. Lake trophic status, community structure and biomass of crustacean plankton. Verhandlungen Internationale Vereinigung fur Theoretische und Angewandte Limnologie, 27: 773-777.","Kilham, S. S., D. A. Kreeger, C. E. Goulden & S. G. Lynn, 1997. Effects of algal food quality on fecundity and population growth rates of Daphnia. Freshwater Biology, 38: 639-647.","Knisely, K. & W. Geller, 1986. Selective feeding of four zooplankton species on natural lake phytoplankton. Oecologia, 69: 86-94.","Lair, N., 1991. Grazing and assimilation rates of natural populations of planktonic cladocerans in a eutrophic lake. Hydrobiologia, 215: 51-61.","Lampert, W., 1974. A method for determining food selection by zooplankton. Limnology and Oceanography, 19(6): 995-998.","Lampert, W., 1981. Inhibitory and toxic effects of blue-green algae on Daphnia. Internationale Revue der gesamten Hydrobiologie und Hydrographie, 66(3): 285-298.","Lampert, W., W. Fleckner, H. Rai & B. E. Taylor, 1986. Phytoplankton control by grazing zooplankton: a study on the spring clear-water phase. Limnology and Oceanography, 31(3): 478-490.","Lampert, W., 1987. Laboratory studies on zooplankton-cyanobacteria interactions. New Zealand Journal of Marine and Freshwater Research, 21: 483-490.","Leflaive, J. & L. Ten-Hage, 2009. Chemical interactions in diatoms: role of polyunsaturated aldehydes and precursors. New Phytologist, 184(4): 794-805.","Lehman, J. T., 1980. Release and cycling of nutrients between planktonic algae and herbivores. Limnology and Oceanography, 25(4): 620-632.","Lehman, J. T. & C. D. Sandgren, 1985. Species-specific rates of growth and grazing loss among freshwater algae. Limnology and Oceanography, 30(1): 34-46.","Low, E. W., E. Clews, P. A. Todd, Y. C. Tai & P. K. L. Ng, 2010. Multivariate analysis of water quality and phytoplankton data from 14 tropical urban reservoirs in Singapore: a 12 year study: under review.","Lurling, M., H. J. de Lange & E. van Dook, 1997. Changes in food quality of the green alga Scenedesmus induced by Daphnia infochemical: biochemical composition and morphology. Freshwater Biology, 38: 619-628.","Lurling, M. & E. van Donk, 1997. Morphological changes in Scenedesmus induced by infochemicals released in situ from zooplankton grazers. Limnology and Oceanography, 42(4): 783-788.","Lynch, M. & J. Sharpiro, 1981. Predation, enrichment and phytoplankton community structure. Limnology and Oceanography, 26(1): 86-102.","Macedo, C. F. R. M. Pinto-Coelho, 2001. Nutritional status response of Daphnia laevis and Moina micrura from a tropical reservoir to different algal diets: Scenedesmus quadricauda and Ankistrodesmus gracilis. Brazilian Journal of Biology, 61(4): 555-562.","MacKay, N. A. & J. J. Elser, 1998. Nutrient recycling by Daphnia reduces N2 fixation by cyanobacteria. Limnology and Oceanography, 43(2): 347-354.","McGill, B. J., B. J. Enquist, E. Wieher & M. Westoby, 2006. Rebuilding community ecology from functional traits. Trends in Ecology and Evolution, 21(4): 178-185.","McMarigal, K., S. Cushman & S. Stafford, 2000. Multivariate Statistics for Wildlife and Ecology Research. Springer Science + Business Media, Inc., New York, USA.","McNaught, D. C. 1975. A hypothesis to explain the succession from calanoids to cladocerans during eutrophication. Verhandlungen, Internationale Vereinigung fuer Theoretische und Angewandte Limnologie, 19: 724-731.","Mitrovic, S. & R. Croome, 2009. A guide to the sampling and identification of the phytoplankton of reservoirs in Singapore. Report submitted to PUB, Technology and Water Quality Office for Raffles Museum of Biodiversity Research, Department of Biological Sciences, National University of Singapore. 116 pp.","Naselli-Flores, L. & R. Barone, 1994. Relationships between trophic state and plankton community structure in 21 Sicilian dam reservoirs. Hydrobiologia, 275-276: 197-205.","Pace, M. L., 1986. An empirical analysis of zooplankton community size structure across lake of trophic gradients. Limnology and Oceanography, 31(1): 45-55.","Pace, M. L. & J. D. Orcutt Jr., 1981. The relative importance of protozoans, rotifers and crustaceans in freshwater zooplankton community. Limnology and Oceanography, 31(5): 45-55.","Pedrozo, C. D. S. & O. Rocha, 2005. Zooplankton and water quality of lakes of the Northern Coast of Rio Grande do Sul State, Brazil. Acta Limnologica Brasiliensia, 17(4): 445-464.","Peters, R. H. & J. A. Downings, 1984. Empirical analysis of zooplankton filtering and feeding rates. Limnology and Oceanography, 29(4): 763-784.","Pinto-Coelho, R. M., A. Giani, C. A. Morasis-Jr, E. R. Carvalho-Jr., & J. F. Bezerro-Neto, 2005. The nutritional status of zooplankton in a tropical reservoir: effects of food quality and community structure. Brazilian Journal of Biology, 65(2): 313-324.","Porter, K. G., 1972. A method for the in situ study of zooplankton grazing effects on algal species composition and standing crop. Limnology and Oceanography, 17(6): 913-917.","Reynolds, C. S., 1998. What factors influence the species composition of phytoplankton in lakes of different trophic status? Hydrobiologia, 369-370: 11-26.","Reynolds, C. S., V. Huszar, C. Kruk, L. Naselli-Flores & S. Melo, 2002. Towards a functional classification of the freshwater phytoplankton. Journal of Plankton Research, 24(5): 417-428.","Ruckert, G. & A. Giani, 2008. Biological interactions in the plankton community of a tropical eutrophic reservoir: is the phytoplankton controlled by zooplankton? Journal of Plankton Research, 30(10): 1157-1168.","Scheffer, M., S. H. Hosper, M.-L. Meijer, B. Moss & E. Jeppesen, 1993. Alternative equilibria in shallow lakes. Trends in Ecology and Evolution, 8(8): 275-279.","Schoenberg, S. A. & R. E. Carlson, 1984. Direct and indirect effects of zooplankton grazing on phytoplankton in a hypereutrophic lake. Oikos, 42(3): 291-302.","Sommer, U. & F. Sommer, 2006. Cladocerans versus copepods: the cause of contrasting top-down controls on freshwater and marine phytoplankton. Oecologia, 147: 183-194.","Stemberger, R. S. & J. J. Gilbert, 1985. Body size, food concentration and population growth in planktonic rotifers. Ecology, 66(4): 1151-1159.","Sterner, R. W., 1990. The ratio of nitrogen to phosphorus resupplied by herbivores: zooplankton and the algal competitive arena. The American Naturalist, 136(2): 209-229.","Sterner, R. W., J. J. Elser, & D. O. Hessen, 1992. Stoichiometric relationshops among producers, consumers and nutrient cycling in pelagic ecosystems. Biogeochemistry, 17: 49-67.","Sterner, R. W., 1993. Daphnia growth on varying quality of Scenedesmus: mineral limitation of zooplankton. Ecology. 74(8): 2351-2360.","Timms, R. M. & B. Moss, 1984. Prevention of growth of potentially dense phytoplankton populations by zooplankton grazing, in the presence of zooplanktivorous fish, in a shallow wetland ecosystem. Limnology and Oceanography, 29(3): 472-486.","Vanderploeg, H. A., G. A. Paffenhofer & J. R. Liebig, 1988. Diaptomus vs. net phytoplankton: effects of algal size and morphology on selectivity of a behaviourally flexible, omnivorous copepod. Bulletin of Marine Science, 43(3): 377-394.","Vanni, M. J. 1987. Effects of nutrients and zooplankton size on the structure of a phytoplankton community. Ecology, 68(3): 624-635.","Vanni, M. J. & D. Layne, 1997. Nutrient recycling and herbivory as mechanisms in the \"Top-Down\" effect of fish on algae in lakes. Ecology, 78(1): 21-40.","Wang, X., B. Qin, G. Gao & H. W. Paerl, 2010. Nutrient enrichment and selective predation by zooplankton promote Microcystis (Cyanobacteria) bloom formation.Journal of Plankton Research, 32(4): 457-470.","Webster, K. E. & R. H. Peters, 1978. Size-dependent inhibitions of larger cladocerans filterers in filamentous suspensions. Limnology and Oceanography, 23(6): 1238-1245.","Wee, Y. C. & R. T. Corlett, 1986. The City and the Forest: Plant Life in Urban Singapore. Singapore University Press, Singapore. Pp. 130-131.","Yang, Y., X. Huang & J. Liu, 1999. Long-term changes in crustacean zooplankton and water quality in a shallow, eutrophic Chinese lake densely stocked with fish. Hydrobiologia, 391: 195-203.","Zhao, J., M. Ramin, V. Cheng & G. B. Arhonditsis, 2008. Plankton community patterns across a trophic gradient: the role of zooplankton functional groups. Ecological Modelling, 213(3-4): 417-436."]}

Published
2010
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39. Gryphon M^3 system: integration of MEMS for flight control

Author

Huang, A., Folk, C., Ho, C.-M., Liu, Z., Chu, W. W., Xu, Y., Tai, Y.-C., Helvajian, Henry, Janson, Siegfried W., and Lärmer, Franz

Subjects
Computer Science::Other
Abstract

By using distributed arrays of micro-actuators as effectors, micro-sensors to detect the optimal actuation location, and microelectronics to provide close loop feedback decisions, a low power control system has been developed for controlling a UAV. Implementing the Microsensors, Microactuators, and Microelectronics leads to what is known as a M^3 (M-cubic) system. This project involves demonstrating the concept of using small actuators (approximately micron-millimeter scale) to provide large control forces for a large-scale system (approximately meter scale) through natural flow amplification phenomenon. This is theorized by using fluid separation phenomenon, vortex evolution, and vortex symmetry on a delta wing aircraft. By using MEMS actuators to control leading edge vortex separation and growth, a desired aerodynamic force can be produced about the aircraft for flight control. Consequently, a MEMS shear stress sensor array was developed for detecting the leading edge separation line where leading edge vortex flow separation occurs. By knowing the leading edge separation line, a closely coupled micro actuation from the effectors can cause the required separation that leads to vortex control. A robust and flexible balloon type actuator was developed using pneumatic pressure as the actuation force. Recently, efforts have started to address the most elusive problem of amplified distributed control (ADC) through data mining algorithms. Preliminary data mining results are promising and this part of the research is ongoing. All wind tunnel data used the baseline 56.5 degree(s) sweepback delta wing with root chord of 31.75 cm.

Published
2001

40. Recovery of control of posture and locomotion after a spinal cord injury: solutions staring us in the face

Author

Fong, Andy J., Roy, Roland R., Ichiyama, Ronaldo M., Lavrov, Igor, Courtine, Grégoire, Gerasimenko, Yury, Tai, Y. C., Burdick, Joel, Edgerton, V. Reggie, Fong, Andy J., Roy, Roland R., Ichiyama, Ronaldo M., Lavrov, Igor, Courtine, Grégoire, Gerasimenko, Yury, Tai, Y. C., Burdick, Joel, and Edgerton, V. Reggie

Abstract

Over the past 20 years, tremendous advances have been made in the field of spinal cord injury research. Yet, consumed with individual pieces of the puzzle, we have failed as a community to grasp the magnitude of the sum of our findings. Our current knowledge should allow us to improve the lives of patients suffering from spinal cord injury. Advances in multiple areas have provided tools for pursuing effective combination of strategies for recovering stepping and standing after a severe spinal cord injury. Muscle physiology research has provided insight into how to maintain functional muscle properties after a spinal cord injury. Understanding the role of the spinal networks in processing sensory information that is important for the generation of motor functions has focused research on developing treatments that sharpen the sensitivity of the locomotor circuitry and that carefully manage the presentation of proprioceptive and cutaneous stimuli to favor recovery. Pharmacological facilitation or inhibition of neurotransmitter systems, spinal cord stimulation, and rehabilitative motor training, which all function by modulating the physiological state of the spinal circuitry, have emerged as promising approaches. Early technological developments, such as robotic training systems and high-density electrode arrays for stimulating the spinal cord, can significantly enhance the precision and minimize the invasiveness of treatment after an injury. Strategies that seek out the complementary effects of combination treatments and that efficiently integrate relevant technical advances in bioengineering represent an untapped potential and are likely to have an immediate impact. Herein, we review key findings in each of these areas of research and present a unified vision for moving forward. Much work remains, but we already have the capability, and more importantly, the responsibility, to help spinal cord injury patients now.

Published
2012
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41. Leukocyte 5-part differential count using a microfluidic cytometer

Author

Shi, W., Guo, L. W., Kasdan, H., Fridge, A., Tai, Y. C., Shi, W., Guo, L. W., Kasdan, H., Fridge, A., and Tai, Y. C.

Abstract

A portable leukocyte differential count is especially desirable for the emerging needs from bedside and NASA spaceflight healthcare. However, previous efforts to miniaturize the test using microfluidics have shown only a 3-part differential of leukocyte including lymphocyte, monocyte, and neutrophil, whereas the 5-part differential is still lacking. Here we report a complete 5-part differential leukocyte count, where lymphocyte, monocyte, neutrophil, eosinophil, and basophil are counted and classified on a microfluidic cytometer. This is done using a dye-staining assay with a two-color fluorescence detection scheme. The differential results are further validated by spiking whole blood samples with purified leukocyte cells.

Published
2011

42. A MEMS intraocular origami coil

Author

Zhao, Y., Nandra, M. S., Tai, Y. C., Zhao, Y., Nandra, M. S., and Tai, Y. C.

Abstract

This work presents a MEMS intraocular coil which is designed to be flexible, biocompatible and electrically efficient as the secondary power coil of inductive coupling links for retinal prostheses applications. A microfabricated structure of parylene-gold-parylene is combined with a folding technique to create a conducting strip with increased cross-section and length than is possible without folding, which is then wound to form a single-layer coil. Compared with the wire-wound coil and MEMS planar coil, our strip-fold-and-wound origami coil can better fulfill the size, mass, and flexibility requirements of an intraocular implant, and also reduce the proximity effect and achieve high quality factor at the targeted frequency. As an example, a 5-turn prototype coil of 10 mm outer diameter, 1 mm thickness and 10 mg weight in saline, has an inductance of 480 nH and reaches a maximum Q factor of 12.5 at 30 MHz. A further increase of Q factor can be achieved by increasing the equivalent cross-sectional area by depositing thicker metal.

Published
2011

43. A microfluidic blood-clogging valve for on-chip blood analysis

Author

Shi, W., Guo, L. W., Tai, Y. C., Shi, W., Guo, L. W., and Tai, Y. C.

Abstract

The lack of simple but reliable microvalves is still a serious problem for many lab-on-a-chip applications. This work studied the use of blood coagulation, the transformation of liquid blood into solid coagulum, as a possible valving mechanism for microfluidic control and demonstrated a one-time open-to-close valve. This is done by creating a solidified blood coagulum, which clogs a normally-open fluidic channel as a closed valve. Local thermal coagulation is demonstrated using a focused laser for blood heating. This clogging valve can withstand a back pressure of 22 psig or higher and its simple structure is well-suited for disposable devices.

Published
2011

44. Leukocyte count and two-part differential in whole blood based on a portable microflow cytometer

Author

Shi, W., Zheng, S., Kasdan, H. L., Fridge, A., Tai, Y. C., Shi, W., Zheng, S., Kasdan, H. L., Fridge, A., and Tai, Y. C.

Abstract

This work demonstrated leukocyte count and two-part leukocyte differential from the whole blood based on a portable microflow cytometer system. Leukocytes are selectively stained with a fluorescent dye, Acridine Orange (AO). The blood sample is then pumped through a disposable microfluidic device for fluorescence sensing. Under blue LED excitation (460nm), the green fluorescence from DNA and the red fluorescence from RNA are detected simultaneously with two photomultiplier tubes (PMT). Leukocytes are counted and differentiated into two parts, lymphocyte versus non-lymphocyte, based on their fluorescence signatures. The results, including leukocyte absolute count and lymphocyte ratio, matched well with the commercial hemacytometer counts (maximal error 9.0%, correlation coefficient ~0.8). We also tested the system for the first time under a zero-gravity (zero-G) environment that facilitated its application in space missions.

Published
2009

45. A 3-D Microfluidic Combinatorial Cell Culture Array

Author

Liu, M. C., Tai, Y. C., Liu, M. C., and Tai, Y. C.

Abstract

We present the development of a three-dimensional (3-D), on-glass combinatorial cell culture array chip featured with integrated three-input, eight-output combinatorial mixers and cell culture chambers. The device is designed to simultaneously screen for the effects of multiple compounds and concentrations on cultured cells. Experimentally, we first developed a precise way to characterize the combined compound concentration profile at each chamber with a fluorescence method. We then successfully demonstrated the functionality of the cell assay by culturing neuron cells on this device and screening the ability of three chemicals to attenuate cell death caused by cytotoxic hydrogen peroxide. Based on the same technology, the number of inputs and outputs of the combinatorial mixer can be scaled-up to construct labon-chip devices for performing high-throughput cell-based assay and highly parallel and combinatorial chemical or biochemical reactions with reduced labors, reagents, and time.

Published
2009

46. Electrolysis-based parylene-balloon actuators

Author

Giacchino, L., Tai, Y. C., Giacchino, L., and Tai, Y. C.

Abstract

This work reports the design, fabrication, testing and modeling of electrolysis-based fully encapsulated parylene balloon actuators. The proposed actuators have the advantage of high force at low power and low voltage. The main issues are low actuation speed and limited number of actuation cycles due to loss of water by permeation through the balloon membrane. In our case, the actuators are targeted to move neuroprobes after implantation, where slow movement is acceptable but low power consumption is of demand.

Published
2009

47. Recovery of control of posture and locomotion after a spinal cord injury: solutions staring us in the face

Author

Verhaagen, J., Hol, Elly, Huitinga, Inge, Wijnholds, Jan, Bergen, Arthur, Boer, Gerard, Swaab, Dick, Fong, Andy J., Roy, Roland R., Ichiyama, Ronaldo M., Lavrov, Igor, Courtine, Grégoire, Gerasimenko, Yury, Tai, Y. C., Burdick, Joel, Edgerton, V. Reggie, Verhaagen, J., Hol, Elly, Huitinga, Inge, Wijnholds, Jan, Bergen, Arthur, Boer, Gerard, Swaab, Dick, Fong, Andy J., Roy, Roland R., Ichiyama, Ronaldo M., Lavrov, Igor, Courtine, Grégoire, Gerasimenko, Yury, Tai, Y. C., Burdick, Joel, and Edgerton, V. Reggie

Abstract

Over the past 20 years, tremendous advances have been made in the field of spinal cord injury research. Yet, consumed with individual pieces of the puzzle, we have failed as a community to grasp the magnitude of the sum of our findings. Our current knowledge should allow us to improve the lives of patients suffering from spinal cord injury. Advances in multiple areas have provided tools for pursuing effective combination of strategies for recovering stepping and standing after a severe spinal cord injury. Muscle physiology research has provided insight into how to maintain functional muscle properties after a spinal cord injury. Understanding the role of the spinal networks in processing sensory information that is important for the generation of motor functions has focused research on developing treatments that sharpen the sensitivity of the locomotor circuitry and that carefully manage the presentation of proprioceptive and cutaneous stimuli to favor recovery. Pharmacological facilitation or inhibition of neurotransmitter systems, spinal cord stimulation, and rehabilitative motor training, which all function by modulating the physiological state of the spinal circuitry, have emerged as promising approaches. Early technological developments, such as robotic training systems and high-density electrode arrays for stimulating the spinal cord, can significantly enhance the precision and minimize the invasiveness of treatment after an injury. Strategies that seek out the complementary effects of combination treatments and that efficiently integrate relevant technical advances in bioengineering represent an untapped potential and are likely to have an immediate impact. Herein, we review key findings in each of these areas of research and present a unified vision for moving forward. Much work remains, but we already have the capability, and more importantly, the responsibility, to help spinal cord injury patients now.

Published
2009

48. Corrosion Behavior of Parylene-Metal-Parylene Thin Films in Saline

Author

Li, W., Rodger, D. C., Menon, P. R., Tai, Y. C., Li, W., Rodger, D. C., Menon, P. R., and Tai, Y. C.

Abstract

In this paper, we study the corrosion behavior of parylene-metal-parylene thin films using accelerated-lifetime soak tests. The samples under test are thin film resistors with a 200 nm layer of Au sandwiched by parylene-C on both sides, fabricated with parylene-metal skin technology. The samples are tested in hot saline both passively and actively, and different failure modes are observed using optical and electron-beam metrologies. Bubbles and delamination are first seen in the samples after 2 days of soaking under passive conditions, and followed by metal corrosion. While under active conditions, either bubbles or parylene breakdowns are observed depending on the thickness of parylene packaging. These results contribute to a better understanding of the failure mechanisms of parylene packaging in body fluids.

Published
2008

49. Integrated parylene-cabled silicon probes for neural prosthetics

Author

Huang, R., Pang, C., Tai, Y. C., Emken, J., Ustun, C., Andersen, R., Burdick, J., Huang, R., Pang, C., Tai, Y. C., Emken, J., Ustun, C., Andersen, R., and Burdick, J.

Abstract

Recent advances in the field of neural prosthetics have demonstrated the thought control of a computer cursor. This capability relies primarily on electrode array surgically implanted into the brain as an acquisition source of neural activity. Various technologies have been developed for signal extraction; however most suffer from either fragile electrode shanks and bulky cables or inefficient use of surgical site areas. Here we present a design and initial testing results from high electrode density, silicon based arrays system with an integrated parylene cable. The greatly reduced flexible rigidity of the parylene cable is believed to relief possible mechanical damages due to relative motion between a brain and its skull.

Published
2008

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