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1. ConSmax: Hardware-Friendly Alternative Softmax with Learnable Parameters

Author

Liu, Shiwei, Tao, Guanchen, Zou, Yifei, Chow, Derek, Fan, Zichen, Lei, Kauna, Pan, Bangfei, Sylvester, Dennis, Kielian, Gregory, and Saligane, Mehdi

Subjects
Computer Science - Hardware Architecture, Computer Science - Artificial Intelligence, Computer Science - Machine Learning
Abstract

The self-attention mechanism distinguishes transformer-based large language models (LLMs) apart from convolutional and recurrent neural networks. Despite the performance improvement, achieving real-time LLM inference on silicon remains challenging due to the extensive use of Softmax in self-attention. In addition to the non-linearity, the low arithmetic intensity significantly limits processing parallelism, especially when working with longer contexts. To address this challenge, we propose Constant Softmax (ConSmax), a software-hardware co-design that serves as an efficient alternative to Softmax. ConSmax utilizes differentiable normalization parameters to eliminate the need for maximum searching and denominator summation in Softmax. This approach enables extensive parallelization while still executing the essential functions of Softmax. Moreover, a scalable ConSmax hardware design with a bitwidth-split look-up table (LUT) can achieve lossless non-linear operations and support mixed-precision computing. Experimental results show that ConSmax achieves a minuscule power consumption of 0.2mW and an area of 0.0008mm^2 at 1250MHz working frequency in 16nm FinFET technology. For open-source contribution, we further implement our design with the OpenROAD toolchain under SkyWater's 130nm CMOS technology. The corresponding power is 2.69mW and the area is 0.007mm^2. ConSmax achieves 3.35x power savings and 2.75x area savings in 16nm technology, and 3.15x power savings and 4.14x area savings with the open-source EDA toolchain. In the meantime, it also maintains comparable accuracy on the GPT-2 model and the WikiText103 dataset. The project is available at https://github.com/ReaLLMASIC/ConSmax

Published
2024

3. Flat beam plasma wakefield accelerator

Author

Manwani, Pratik, Majernik, Nathan, Mann, Joshua, Kang, Yunbo, Chow, Derek, Ancelin, Havyn, Andonian, Gerard, and Rosenzweig, James

Subjects
Physics - Accelerator Physics, Physics - Plasma Physics
Abstract

Particle beams with highly asymmetric emittance ratios are expected at the interaction point of high energy colliders. These asymmetric beams can be used to drive high gradient wakefields in dielectrics and plasma. In the case of plasma, the high aspect ratio of the drive beam creates a transversely elliptical blowout cavity and the asymmetry in the ion column creates asymmetric focusing in the two transverse planes. The ellipticity of the blowout depends on the ellipticity and normalized charge density of the beam. In this paper, simulations are performed to investigate the ellipticity of the wakefield based on the initial driver beam parameters. The matching conditions for this elliptical cavity are discussed. Example cases for employment using the attainable parameter space at the AWA and FACET facilities are also presented., Comment: 5 Pages, 4 Figures

Published
2023

4. LSST: From Science Drivers to Reference Design and Anticipated Data Products

Author

Ivezić, Željko, Kahn, Steven M, Tyson, J Anthony, Abel, Bob, Acosta, Emily, Allsman, Robyn, Alonso, David, AlSayyad, Yusra, Anderson, Scott F, Andrew, John, Angel, James Roger P, Angeli, George Z, Ansari, Reza, Antilogus, Pierre, Araujo, Constanza, Armstrong, Robert, Arndt, Kirk T, Astier, Pierre, Aubourg, Éric, Auza, Nicole, Axelrod, Tim S, Bard, Deborah J, Barr, Jeff D, Barrau, Aurelian, Bartlett, James G, Bauer, Amanda E, Bauman, Brian J, Baumont, Sylvain, Bechtol, Ellen, Bechtol, Keith, Becker, Andrew C, Becla, Jacek, Beldica, Cristina, Bellavia, Steve, Bianco, Federica B, Biswas, Rahul, Blanc, Guillaume, Blazek, Jonathan, Blandford, Roger D, Bloom, Josh S, Bogart, Joanne, Bond, Tim W, Booth, Michael T, Borgland, Anders W, Borne, Kirk, Bosch, James F, Boutigny, Dominique, Brackett, Craig A, Bradshaw, Andrew, Brandt, William Nielsen, Brown, Michael E, Bullock, James S, Burchat, Patricia, Burke, David L, Cagnoli, Gianpietro, Calabrese, Daniel, Callahan, Shawn, Callen, Alice L, Carlin, Jeffrey L, Carlson, Erin L, Chandrasekharan, Srinivasan, Charles-Emerson, Glenaver, Chesley, Steve, Cheu, Elliott C, Chiang, Hsin-Fang, Chiang, James, Chirino, Carol, Chow, Derek, Ciardi, David R, Claver, Charles F, Cohen-Tanugi, Johann, Cockrum, Joseph J, Coles, Rebecca, Connolly, Andrew J, Cook, Kem H, Cooray, Asantha, Covey, Kevin R, Cribbs, Chris, Cui, Wei, Cutri, Roc, Daly, Philip N, Daniel, Scott F, Daruich, Felipe, Daubard, Guillaume, Daues, Greg, Dawson, William, Delgado, Francisco, Dellapenna, Alfred, de Peyster, Robert, de Val-Borro, Miguel, Digel, Seth W, Doherty, Peter, Dubois, Richard, Dubois-Felsmann, Gregory P, Durech, Josef, Economou, Frossie, Eifler, Tim, Eracleous, Michael, Emmons, Benjamin L, and Neto, Angelo Fausti

Subjects
Astronomical Sciences, Physical Sciences, astrometry, cosmology: observations, Galaxy: general, methods: observational, stars: general, surveys, astro-ph, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract

We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the solar system, exploring the transient optical sky, and mapping the Milky Way. LSST will be a large, wide-field ground-based system designed to obtain repeated images covering the sky visible from Cerro Pachón in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg 2 field of view, a 3.2-gigapixel camera, and six filters (ugrizy) covering the wavelength range 320-1050 nm. The project is in the construction phase and will begin regular survey operations by 2022. About 90% of the observing time will be devoted to a deep-wide-fast survey mode that will uniformly observe a 18,000 deg 2 region about 800 times (summed over all six bands) during the anticipated 10 yr of operations and will yield a co-added map to r ∼27.5. These data will result in databases including about 32 trillion observations of 20 billion galaxies and a similar number of stars, and they will serve the majority of the primary science programs. The remaining 10% of the observing time will be allocated to special projects such as Very Deep and Very Fast time domain surveys, whose details are currently under discussion. We illustrate how the LSST science drivers led to these choices of system parameters, and we describe the expected data products and their characteristics.

Published
2019

5. LSST: from Science Drivers to Reference Design and Anticipated Data Products

Author

Ivezić, Željko, Kahn, Steven M., Tyson, J. Anthony, Abel, Bob, Acosta, Emily, Allsman, Robyn, Alonso, David, AlSayyad, Yusra, Anderson, Scott F., Andrew, John, Angel, James Roger P., Angeli, George Z., Ansari, Reza, Antilogus, Pierre, Araujo, Constanza, Armstrong, Robert, Arndt, Kirk T., Astier, Pierre, Aubourg, Éric, Auza, Nicole, Axelrod, Tim S., Bard, Deborah J., Barr, Jeff D., Barrau, Aurelian, Bartlett, James G., Bauer, Amanda E., Bauman, Brian J., Baumont, Sylvain, Becker, Andrew C., Becla, Jacek, Beldica, Cristina, Bellavia, Steve, Bianco, Federica B., Biswas, Rahul, Blanc, Guillaume, Blazek, Jonathan, Blandford, Roger D., Bloom, Josh S., Bogart, Joanne, Bond, Tim W., Borgland, Anders W., Borne, Kirk, Bosch, James F., Boutigny, Dominique, Brackett, Craig A., Bradshaw, Andrew, Brandt, William Nielsen, Brown, Michael E., Bullock, James S., Burchat, Patricia, Burke, David L., Cagnoli, Gianpietro, Calabrese, Daniel, Callahan, Shawn, Callen, Alice L., Chandrasekharan, Srinivasan, Charles-Emerson, Glenaver, Chesley, Steve, Cheu, Elliott C., Chiang, Hsin-Fang, Chiang, James, Chirino, Carol, Chow, Derek, Ciardi, David R., Claver, Charles F., Cohen-Tanugi, Johann, Cockrum, Joseph J., Coles, Rebecca, Connolly, Andrew J., Cook, Kem H., Cooray, Asantha, Covey, Kevin R., Cribbs, Chris, Cui, Wei, Cutri, Roc, Daly, Philip N., Daniel, Scott F., Daruich, Felipe, Daubard, Guillaume, Daues, Greg, Dawson, William, Delgado, Francisco, Dellapenna, Alfred, de Peyster, Robert, de Val-Borro, Miguel, Digel, Seth W., Doherty, Peter, Dubois, Richard, Dubois-Felsmann, Gregory P., Durech, Josef, Economou, Frossie, Eracleous, Michael, Ferguson, Henry, Figueroa, Enrique, Fisher-Levine, Merlin, Focke, Warren, Foss, Michael D., Frank, James, Freemon, Michael D., Gangler, Emmanuel, Gawiser, Eric, Geary, John C., Gee, Perry, Geha, Marla, Gessner, Charles J. B., Gibson, Robert R., Gilmore, D. Kirk, Glanzman, Thomas, Glick, William, Goldina, Tatiana, Goldstein, Daniel A., Goodenow, Iain, Graham, Melissa L., Gressler, William J., Gris, Philippe, Guy, Leanne P., Guyonnet, Augustin, Haller, Gunther, Harris, Ron, Hascall, Patrick A., Haupt, Justine, Hernandez, Fabio, Herrmann, Sven, Hileman, Edward, Hoblitt, Joshua, Hodgson, John A., Hogan, Craig, Huang, Dajun, Huffer, Michael E., Ingraham, Patrick, Innes, Walter R., Jacoby, Suzanne H., Jain, Bhuvnesh, Jammes, Fabrice, Jee, James, Jenness, Tim, Jernigan, Garrett, Jevremović, Darko, Johns, Kenneth, Johnson, Anthony S., Johnson, Margaret W. G., Jones, R. Lynne, Juramy-Gilles, Claire, Jurić, Mario, Kalirai, Jason S., Kallivayalil, Nitya J., Kalmbach, Bryce, Kantor, Jeffrey P., Karst, Pierre, Kasliwal, Mansi M., Kelly, Heather, Kessler, Richard, Kinnison, Veronica, Kirkby, David, Knox, Lloyd, Kotov, Ivan V., Krabbendam, Victor L., Krughoff, K. Simon, Kubánek, Petr, Kuczewski, John, Kulkarni, Shri, Ku, John, Kurita, Nadine R., Lage, Craig S., Lambert, Ron, Lange, Travis, Langton, J. Brian, Guillou, Laurent Le, Levine, Deborah, Liang, Ming, Lim, Kian-Tat, Lintott, Chris J., Long, Kevin E., Lopez, Margaux, Lotz, Paul J., Lupton, Robert H., Lust, Nate B., MacArthur, Lauren A., Mahabal, Ashish, Mandelbaum, Rachel, Marsh, Darren S., Marshall, Philip J., Marshall, Stuart, May, Morgan, McKercher, Robert, McQueen, Michelle, Meyers, Joshua, Migliore, Myriam, Miller, Michelle, Mills, David J., Miraval, Connor, Moeyens, Joachim, Monet, David G., Moniez, Marc, Monkewitz, Serge, Montgomery, Christopher, Mueller, Fritz, Muller, Gary P., Arancibia, Freddy Muñoz, Neill, Douglas R., Newbry, Scott P., Nief, Jean-Yves, Nomerotski, Andrei, Nordby, Martin, O'Connor, Paul, Oliver, John, Olivier, Scot S., Olsen, Knut, O'Mullane, William, Ortiz, Sandra, Osier, Shawn, Owen, Russell E., Pain, Reynald, Palecek, Paul E., Parejko, John K., Parsons, James B., Pease, Nathan M., Peterson, J. Matt, Peterson, John R., Petravick, Donald L., Petrick, M. E. Libby, Petry, Cathy E., Pierfederici, Francesco, Pietrowicz, Stephen, Pike, Rob, Pinto, Philip A., Plante, Raymond, Plate, Stephen, Price, Paul A., Prouza, Michael, Radeka, Veljko, Rajagopal, Jayadev, Rasmussen, Andrew P., Regnault, Nicolas, Reil, Kevin A., Reiss, David J., Reuter, Michael A., Ridgway, Stephen T., Riot, Vincent J., Ritz, Steve, Robinson, Sean, Roby, William, Roodman, Aaron, Rosing, Wayne, Roucelle, Cecille, Rumore, Matthew R., Russo, Stefano, Saha, Abhijit, Sassolas, Benoit, Schalk, Terry L., Schellart, Pim, Schindler, Rafe H., Schmidt, Samuel, Schneider, Donald P., Schneider, Michael D., Schoening, William, Schumacher, German, Schwamb, Megan E., Sebag, Jacques, Selvy, Brian, Sembroski, Glenn H., Seppala, Lynn G., Serio, Andrew, Serrano, Eduardo, Shaw, Richard A., Shipsey, Ian, Sick, Jonathan, Silvestri, Nicole, Slater, Colin T., Smith, J. Allyn, Smith, R. Chris, Sobhani, Shahram, Soldahl, Christine, Storrie-Lombardi, Lisa, Stover, Edward, Strauss, Michael A., Street, Rachel A., Stubbs, Christopher W., Sullivan, Ian S., Sweeney, Donald, Swinbank, John D., Szalay, Alexander, Takacs, Peter, Tether, Stephen A., Thaler, Jon J., Thayer, John Gregg, Thomas, Sandrine, Thukral, Vaikunth, Tice, Jeffrey, Trilling, David E., Turri, Max, Van Berg, Richard, Berk, Daniel Vanden, Vetter, Kurt, Virieux, Francoise, Vucina, Tomislav, Wahl, William, Walkowicz, Lucianne, Walsh, Brian, Walter, Christopher W., Wang, Daniel L., Wang, Shin-Yawn, Warner, Michael, Wiecha, Oliver, Willman, Beth, Winters, Scott E., Wittman, David, Wolff, Sidney C., Wood-Vasey, W. Michael, Wu, Xiuqin, Xin, Bo, Yoachim, Peter, and Zhan, Hu

Subjects
Astrophysics
Abstract

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world., Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overview

Published
2008
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6. Simulating Enhanced Focusing Effects of Ion Motion in Adiabatic Plasmas

Author

Chow, Derek, Apsimon, Oznur, Hansel, Claire, Manwani, Pratik, Rosenzweig, James, Welsch, Carsten, and Yadav, Monika

Subjects
MC3: Novel Particle Sources and Acceleration Techniques, Physics::Plasma Physics, Physics::Accelerator Physics, Accelerator Physics
Abstract

The FACET-II facility offers the unique opportunity to study low emittance, GeV beams and their interactions with high density plasmas in plasma wakefield acceleration (PWFA) scenarios. One of the experiments relevant to PWFA research at FACET-II is the ion collapse experiment E-314, which aims to study how ion motion in a PWFA can produce dual-focused equilibrium. As nonlinear focusing effects due to nonuniform ion distributions have not been extensively studied; we explore the difficulties of inducing ion motion in an adiabatic plasma and examines the effect an ion column has on beam focusing. A case study is performed on a system containing a plasma lens and adiabatic PWFA. Ions in the lens section are assumed to be static, while simulations of an adiabatic matching section are modified to include the effects of ion column collapse and their nonlinear focusing fields. Using the parameters of the FACET-II beam, we find that a collapsed ion column amplifies the focusing power of a plasma without compromising emittance preservation. This led to a spot size orders of magnitude less than that of a simply matched beam., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Published
2022

7. A bioinspired synthetic soft hydrogel for the treatment of dry eye

Author

Yu, Yu, Chow, Derek Wai Yee, Lau, Chi Ming Laurence, Zhou, Guanqun, Back, Woo Jin, Xu, Jing, Carim, Sean, Chau, Ying, Yu, Yu, Chow, Derek Wai Yee, Lau, Chi Ming Laurence, Zhou, Guanqun, Back, Woo Jin, Xu, Jing, Carim, Sean, and Chau, Ying

Abstract

Natural soft hydrogels are unique elastic soft materials utilized by living organisms for protecting delicate tissues. Under a theoretical framework derived from the Blob model, we chemically crosslinked high molecular weight hyaluronic acid at a concentration close to its overlap concentration (c*), and created synthetic soft hydrogels that exhibited unique rheological properties similar to a natural soft hydrogel: being dominantly elastic under low shear stress while being viscous when the stress is above a small threshold. We explored a potential application of the hyaluronic acid-based soft hydrogel as a long-acting ocular surface lubricant and evaluated its therapeutic effects for dry eye. The soft hydrogel was found to be biocompatible after topical instillation on experimental animals' and companion dogs' eyes. In a canine clinical study, twice-a-day ocular instillation of the soft hydrogel in combination with cyclosporine for 1 month improved the clinical signs in more than 65% of dog patients previously unresponsive to cyclosporine treatment. © 2021 The Authors. Bioengineering & Translational Medicine published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.

Published
2021

11. Comparison of two bupivacaine delivery methods to control postoperative pain after enucleation in dogs

Author

Chow, Derek W.Y., Wong, Manyu, Westermeyer, Hans D., Chow, Derek W.Y., Wong, Manyu, and Westermeyer, Hans D.

Abstract

Objective: To compare the efficacy of a preoperative retrobulbar injection of bupivacaine to an intraoperative splash block of bupivacaine in controlling postoperative pain following enucleation in dogs. Animals studied: Prospective, randomized, double-masked clinical study of 31 client owned dogs with end-stage ophthalmic disease requiring enucleation. Procedures: Dogs admitted for unilateral enucleation were randomly assigned to receive bupivacaine 0.5% (1 mL/kg) into the retrobulbar space either via an inferior-temporal palpebral (ITP) injection preoperatively or an intraoperative splash block. Pain was assessed prior to pre-anesthetic sedation and at 0, 0.25, 0.5, 1, 2, 4 6, 8, and 24 hours (H) after extubation by masked observers using a previously described subjective pain scoring system. Rescue analgesia was initiated if overall pain score was >9 or if the score in any category at any time point was >3. Results: There were no adverse reactions. One of 15 dogs that received bupivacaine via a preoperative retrobulbar ITP injection required rescue analgesia. There was no significant difference between groups with regard to the need for rescue analgesia or pain scores at any time point or overall. Conclusions and Clinical Relevance: Pain control using an intraoperative orbital splash administration of bupivacaine is not significantly different to a preoperative retrobulbar injection of bupivacaine. © 2015 American College of Veterinary Ophthalmologists.

Published
2015

12. In vitro evaluation of the inhibitory effect of canine serum, canine fresh frozen plasma, freeze-thaw-cycled plasma, and Solcoseryl (TM) on matrix metalloproteinases 2 and 9

Author

Chow, Derek W.Y., Chau, Ying, Yeung, Wai Kit, Westermeyer, Hans D., Chow, Derek W.Y., Chau, Ying, Yeung, Wai Kit, and Westermeyer, Hans D.

Abstract

ObjectiveCompare the efficacy of canine serum, fresh frozen plasma (FFP), freeze-thaw-cycled plasma (FTCP), and Solcoseryl at inhibiting matrix metalloproteinases (MMP) 2 and 9 in vitro. ProcedureMatrix metalloproteinases 2 and 9 activity in the presence of serum, FFP, FTCP, or Solcoseryl was assayed using a commercially available fluorogenic gelatinase activity kit. ResultsMatrix metalloproteinases 2 activity in the presence of serum, FFP, FTCP, and Solcoseryl was 20.84%, 5.76%, 8.10%, and 83.03%, respectively of uninhibited MMP 2 activity. MMP 9 activity in the presence of serum, FFP, FTCP, and Solcoseryl was 57.36%, 58.35%, 49.35%, and -8.69%, respectively of uninhibited MMP 9 activity. ConclusionSerum, FFP, and FTCP exhibit similar levels of MMP 2 and 9 inhibitions. Solcoseryl causes minimal MMP 2 inhibition, but profound MMP 9 inhibition.

Published
2015

18. Unilateral ventral strabismus in an aquarium Silver Arowana ( Osteoglossum bicirrhosum).

Author

Chow, Derek W.Y., Westermeyer, Hans D., Fernando, Nimal, Hoey, Seamus, and Dubielzig, Richard R.

Subjects
*STRABISMUS, *OSTEOGLOSSUM, *CYSTS (Pathology), *CONJUNCTIVA, *EYE, *VETERINARY histopathology, *MAGNETIC resonance imaging
Abstract

An adult silver arowana ( Osteoglossum bicirrhosum) presented with a 2-month history of acute onset ventral strabismus of the right eye associated with a cystic structure overlying the dorsal aspect of the globe. Aspiration of the cyst, removal of redundant conjunctival tissue, and apposition of the surgical edges of the conjunctiva did not correct the strabismus. Magnetic resonance imaging of the head and histopathology of the eye did not reveal significant differences between affected and unaffected eyes except for a more posterior dorsal rectus muscle insertion site in the affected eye. This case report documents and describes a syndrome well known among arowana hobbyists as 'drop eye'. [ABSTRACT FROM AUTHOR]

Published
2016
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19. Retrospective evaluation of corneal reconstruction using ACell Vet™ alone in dogs and cats: 82 cases.

Author

Chow, Derek W.Y. and Westermeyer, Hans D.

Subjects
*CORNEA surgery, *CYCLOSPORINE, *MUCOUS membranes, *RETROSPECTIVE studies, *DOG physiology, *CAT physiology, *TACROLIMUS, CORNEAL ulcer
Abstract

Objectives To retrospectively evaluate the complications, graft clarity, and outcomes associated with the use of commercially available porcine urinary bladder submucosa ( ACell Vet™) alone for corneal reconstruction in dogs and cats. Procedures Dogs or cats receiving an ACell Vet™ graft for corneal reconstruction due to severe ulcerative keratitis or after a keratectomy to remove a corneal sequestrum were included. All received a single layer of ACell Vet™, bandage contact lens, and temporary tarsorrhaphy. Bandage contact lens and temporary tarsorrhaphy were removed after graft vascularization or epithelialization. Topical steroids, cyclosporine, tacrolimus were started after epithelialization. Based on their last examination, outcomes were categorized into five groups based on the presence of corneal vessels, appearance of the scar, and the ability to visualize the posterior and/or the anterior segment through the grafted area. Results There were 82 eyes included in the study, with 68 eyes with sufficient follow-up time for final assessment. Scarring was minimal in 47 eyes, moderate but not enough to obscure visualization of the posterior segment in 12, and severe in nine. There were five eyes that developed phthisis bulbi, glaucoma or were enucleated and nine that were lost to follow up. Graft dehiscence occurred in 19 eyes. Twelve healed without additional surgical intervention while three required a second graft, two became phthisical, and two were enucleated. Conclusions and Clinical Relevance Corneal reconstruction with ACell Vet™ alone is a viable alternative and results in minimal scarring and complications in cats. In dogs, scarring is more pronounced than in cats and graft dehiscence rate is higher compared to conventional techniques. [ABSTRACT FROM AUTHOR]

Published
2016
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22. In vitro evaluation of the inhibitory effect of canine serum, canine fresh frozen plasma, freeze-thaw-cycled plasma, and Solcoseryl™ on matrix metalloproteinases 2 and 9.

Author

Chow, Derek W. Y., Chau, Ying, Yeung, Wai Kit, and Westermeyer, Hans D.

Subjects
*IN vitro studies, *CANIDAE, *BLOOD serum analysis, *MATRIX metalloproteinases, *GELATINASES, *ENZYME inhibitors
Abstract

Objective Compare the efficacy of canine serum, fresh frozen plasma ( FFP), freeze-thaw-cycled plasma ( FTCP), and Solcoseryl™ at inhibiting matrix metalloproteinases (MMP) 2 and 9 in vitro. Procedure Matrix metalloproteinases 2 and 9 activity in the presence of serum, FFP, FTCP, or Solcoseryl™ was assayed using a commercially available fluorogenic gelatinase activity kit. Results Matrix metalloproteinases 2 activity in the presence of serum, FFP, FTCP, and Solcoseryl™ was 20.84%, 5.76%, 8.10%, and 83.03%, respectively of uninhibited MMP 2 activity. MMP 9 activity in the presence of serum, FFP, FTCP, and Solcoseryl™ was 57.36%, 58.35%, 49.35%, and −8.69%, respectively of uninhibited MMP 9 activity. Conclusion Serum, FFP, and FTCP exhibit similar levels of MMP 2 and 9 inhibitions. Solcoseryl™ causes minimal MMP 2 inhibition, but profound MMP 9 inhibition. [ABSTRACT FROM AUTHOR]

Published
2015
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23. Lake Washington Ship Canal, Seattle, Washington. Master Plan (DM 9)

Author

CORPS OF ENGINEERS SEATTLE WA SEATTLE DISTRICT, Chow, Derek J., CORPS OF ENGINEERS SEATTLE WA SEATTLE DISTRICT, and Chow, Derek J.

Abstract

This February 1994 Lake Washington Ship Canal Master Plan (Design Memorandum 9), has been prepared to guide the use and development of the natural and manmade resources at the project, which is administered by the Seattle District, US Army Corps of Engineers. Project resource development and management actions are measured against a management framework which includes resource objectives and concise land management measures for individual project sites and features. The Master Plan will serve to increase resource management effectiveness and provide the basis for the preparation of follow-on operation management plans (OMP), prescribed by ER 1130-2-400, and feature design memorandums (FDM). Master plan, Land allocation, Land classification.

Published
1994

25. Pendent Polyimides using Mellitic Acid Dianhydride. IV. Effect of Increased Zirconium-Pendent Group Content on Polymer Properties.

Author

Chow, Derek, Wei Cheng, Huixiong Dai, Wagner, Shawn R., Luzzi, Scott D., Landi, Brian J., Liling He, Illingsworth, Marvin L., and Siochi, Emilie J.

Subjects
*POLYIMIDES, *POLYMER analysis, *HYDRIDES, *SPECTRUM analysis, *ZIRCONIUM, *MOLECULAR weights, *PHYSICAL & theoretical chemistry
Abstract

For co-polyimides (PIs) of mellitic acid dianhydride, 1,3-aminophenoxybenzene and 4,4′- oxydiphthalic anhydride, Zr-pendent group content could be increased to 50% (mol) improving atomic oxygen (AO) resistance while retaining good film properties. Spectral data are consistent with expected structures. Intrinsic viscosities of 0.54-0.60 dL g-1 and average molecular weights of 111 000-122 000 gmol-1 estimated from gel permeation chromatography confirm the polymeric nature of co-polyamic acid precursors. Nuclear magnetic resonance integrations and amounts of thermogravimetric analysis residue verify pendent group concentrations. Increasing Zr-pendent group concentration from 10 to 50% (mol) caused glass transition temperatures to increase (198-245 °C), decomposition temperatures to decrease (518-455 °C), and the number of film layers able to be fabricated prior to crack formation to decrease (10 to 8). These numbers of layers were much higher than those for other PIs with comparable Zr-pendent group concentrations. Increased pendent group concentration caused the amount of protective oxide layer formed upon AO exposure to increase. [ABSTRACT FROM AUTHOR]

Published
2009
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26. China.

Author

Chow, Derek

Subjects
FOREIGN exchange accounting, TAXATION, RENMINBI, BALANCE of payments, RESERVES (Accounting), ACCOUNTING standards
Abstract

The article explores some of the accounting and tax considerations for foreign exchange differences in China. On June 17, 2008, the renminbi (Rmb) extended its gains to 20%. A number of factors have brought about the appreciation. Externally, China has been under pressure to revalue its currency to redress the balance of payments trade surplus on the current account since joining the World Trade Organization (WTO). Internally, China's cumulative foreign exchange reserve is the largest in the world. This rapid rise in the value of the Rmb brought about challenges in the way which foreign exchange differences should be accounted for under the new Professional Regulation Commission (PRC) Generally Accepted Accounting Principles (GAAP).

Published
2008

27. China opens for foreign institutional investors.

Author

Chow, Derek and Zhang, William

Subjects
FOREIGN investments, INVESTORS
Abstract

Reports on the restrictions and pitfalls of the opening of China's A-share market to foreign investors through the qualified foreign institutional investors scheme, which took effect on December 1, 2003. Allowable investment activities; Tax-withholding responsibilities; Restrictions; Double-tax treaty provisions.

Published
2003

28. Atomic oxygen resistant Zr pendent polyimide based on 1,3-aminophenoxybenzene

Author

Chow, Derek

Subjects
Chemistry, Zr pendent
Abstract

We wish to evaluate Zr pendent aromatic polyimides based on oxydiphthalic anhydride (ODPA), 1,3-aminophenoxybenzene (APB) and mellitic dianhydride (MADA) as atomic oxygen resistant materials. Eight poly(amic acid) solutions in Nmethylpyrrolidone (NMP) with different anhydrides ratios were synthesized, and four of the eight poly(amic) acids allowed to react with the complex (4-amino-N,N '- disalicylidene- l,2-phenylenediaminato)(N.N '-disalicylidene- 1,2- phenylenediaminato)zirconium(IV), Zr(adsp)(dsp), in the presence of dicyclohexylcarbodiimide (DCC). The resulting non-pendent polyamic acids and Zr pendent polyamic acids were cast onto glass substrate followed by thermal imidization. Characterization of polyamic acids and polyimides were accomplished by Thin Layer Chromatography (TLC), Fourier Transform Infrared (FT-IR), Proton Nuclear Magnetic Resonance (!H NMR) and Gel Permeation Chromatography (GPC). Their thermal properties were investigated by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). TLC results indicate that no free Zr complex remains following the DCC reaction. Spectroscopic results of Zr(adsp)(dsp), polyamic acids and polyimides were consistent with their proposed structures. GPC results indicate that a moderate degree of polymerization occurred. The incorporation of the ether groups and meta amino position along the polymer backbone decreased the glass transition temperatures vs. analogous polymers without APB. Their Tg's fell in the ranges 64.1 to 74.6 C, 57.6 to 83.1C, 188.3 to 242.9C and 198.5 to 245.3C for polyamic acids, pendent polyamic acids, polyimides, pendent polyimides, respectively. The zirconium pendent polyimides were less thermally stable than the parent polyimides, being stable up to 455.53- 518. 15C and 525.61- 555.43C, respectively, and affording char yields of 0.993-12.52 % for pendent polymers and 0% for non-pendent polymers at 700C in air. Multilayer films of the Zr complex pendent polyimides were made. The maximum number of layers that were made were 10, 10, 8 and 8 for PI(ODPA/APB/10 mol % MADA), PI(ODPA/APB/20 mol % MADA), PI(ODPA/APB/30 mol % MADA) and PI(ODPA/APB/50 mol % MADA), respectively. All fully imidized films passed the solvent resistance test which involved immersion in acetone, methyl ethyl ketone, toluene, 1-mefhyl-pyrrolidinone (NMP), dimethylsulfoxide (DMSO) and chloroform for one hour followed by a fingernail crease. Their atomic oxygen resistance was studied by Scanning Electronic Microscopy (SEM) before and after atomic oxygen erosion in a plasma asher. The SEM of Zr pendent polyimide film shows substantial erosion occurred in select regions, giving a "pitted" appearance.

Published
2000

29. Retrospective evaluation of corneal reconstruction using ACell Vet(™) alone in dogs and cats: 82 cases.

Author

Chow DW and Westermeyer HD

Subjects
Animals, Cats, Corneal Diseases surgery, Corneal Diseases veterinary, Corneal Ulcer surgery, Dogs, Postoperative Complications veterinary, Retrospective Studies, Urinary Bladder, Cat Diseases surgery, Cornea surgery, Corneal Ulcer veterinary, Dog Diseases surgery, Mucous Membrane transplantation
Abstract

Objectives: To retrospectively evaluate the complications, graft clarity, and outcomes associated with the use of commercially available porcine urinary bladder submucosa (ACell Vet(™) ) alone for corneal reconstruction in dogs and cats., Procedures: Dogs or cats receiving an ACell Vet(™) graft for corneal reconstruction due to severe ulcerative keratitis or after a keratectomy to remove a corneal sequestrum were included. All received a single layer of ACell Vet(™) , bandage contact lens, and temporary tarsorrhaphy. Bandage contact lens and temporary tarsorrhaphy were removed after graft vascularization or epithelialization. Topical steroids, cyclosporine, tacrolimus were started after epithelialization. Based on their last examination, outcomes were categorized into five groups based on the presence of corneal vessels, appearance of the scar, and the ability to visualize the posterior and/or the anterior segment through the grafted area., Results: There were 82 eyes included in the study, with 68 eyes with sufficient follow-up time for final assessment. Scarring was minimal in 47 eyes, moderate but not enough to obscure visualization of the posterior segment in 12, and severe in nine. There were five eyes that developed phthisis bulbi, glaucoma or were enucleated and nine that were lost to follow up. Graft dehiscence occurred in 19 eyes. Twelve healed without additional surgical intervention while three required a second graft, two became phthisical, and two were enucleated., Conclusions and Clinical Relevance: Corneal reconstruction with ACell Vet(™) alone is a viable alternative and results in minimal scarring and complications in cats. In dogs, scarring is more pronounced than in cats and graft dehiscence rate is higher compared to conventional techniques., (© 2015 American College of Veterinary Ophthalmologists.)

Published
2016
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30. In vitro evaluation of the inhibitory effect of canine serum, canine fresh frozen plasma, freeze-thaw-cycled plasma, and Solcoseryl™ on matrix metalloproteinases 2 and 9.

Author

Chow DW, Chau Y, Yeung WK, and Westermeyer HD

Subjects
Animals, Dogs, Actihaemyl, Matrix Metalloproteinase 2 metabolism, Matrix Metalloproteinase 9 metabolism, Matrix Metalloproteinase Inhibitors pharmacology, Plasma, Serum
Abstract

Objective: Compare the efficacy of canine serum, fresh frozen plasma (FFP), freeze-thaw-cycled plasma (FTCP), and Solcoseryl(™) at inhibiting matrix metalloproteinases (MMP) 2 and 9 in vitro., Procedure: Matrix metalloproteinases 2 and 9 activity in the presence of serum, FFP, FTCP, or Solcoseryl(™) was assayed using a commercially available fluorogenic gelatinase activity kit., Results: Matrix metalloproteinases 2 activity in the presence of serum, FFP, FTCP, and Solcoseryl(™) was 20.84%, 5.76%, 8.10%, and 83.03%, respectively of uninhibited MMP 2 activity. MMP 9 activity in the presence of serum, FFP, FTCP, and Solcoseryl(™) was 57.36%, 58.35%, 49.35%, and -8.69%, respectively of uninhibited MMP 9 activity., Conclusion: Serum, FFP, and FTCP exhibit similar levels of MMP 2 and 9 inhibitions. Solcoseryl(™) causes minimal MMP 2 inhibition, but profound MMP 9 inhibition., (© 2014 American College of Veterinary Ophthalmologists.)

Published
2015
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