Towards systolizing compilation

Summary A scheme for the compilation of imperative or functional programs into systolic programs is demonstrated on matrix composition/decomposition and Gauss-Jordan elimination. Using this scheme, programs for the processor network Warp and for several transputer networks have been generated. Christian Lengauer holds a Dipl. Math. (1976) from the Free University of Berlin, and an M.Sc (1978) and Ph.D. (1982) in Computer Science from the University of Toronto. He was an Assistant Professor of Computer Sciences at The University of Texas at Austin from 1982 to 1989 and is presently a Lecturer in Computer Science at the University of Edinburgh. His past research has been in the areas of systolic design, formal semantics and program construction, and automated theorem proving. Michael Barnett received a B.A. in Computer Science from Brooklyn College/City University of New York in 1985, and is currently a Ph.d. candidate at the University of Texas at Austin, where he has been since 1986. From 1985 to 1986 he worked at IBM's T.J. Watson Research Center. His current research interests include formal methods, programming methodology, and functional programming. Duncan G. Hudson III received the B.A. degree in computer sciences from The University of Texas at Austin in 1987 and the M.S.C.S. degree in computer sciences from The University of Texas at Austin in 1989. He has worked as a Graduate Research Assistant at The University of Texas at Austin in the areas of graphical parallel programming environments, parallel numerical algorithms, and objectoriented programming languages for parallel architectures and as a Software Design Engineer at Texas Instruments in the areas of objectoriented databases and parallel image understanding. He is currently a Ph.D. candidate in the Department of Computer Sciences at The University of Texas at Austin. His current research interests include parallel architectures and algorithms and parallelizing compilers.This research was supported in part by the following funding agencies: through Carnegie-Mellon University by the Defense Advanced Research Projects Agency monitored by the Space and Naval Warfare Systems Command under Contract N00039-87-C-0251 and by the Office of Naval Research under Contracts N00014-87-K-0385 and N00014-87-K-0533; through Oxford University by the Science and Engineering Research Council under Contract GR/E 63902; through the University of Texas at Austin by the Office of Naval Research under Contract N00014-86-K-0763 and by the National Science Foundation under Contract DCR-8610427     

The gene encoding protein-tyrosine phosphatase RPTP epsilon (PTPRE) is assigned to human chromosome 10q26

In suspected Horner's syndrome, cocaine eye drops are applied to verify the diagnosis. Subsequent application of hydroxyamphetamine or pholedrine eye drops allows localization of the site of the interruption in the oculosympathetic pathway. In the present study the influence of cocaine on subsequent pholedrine testing was examined. Cocaine 5% and pholedrine 5% eye drops were applied to eight (72-h interval only six) normal volunteers with light-colored irides. The ages of the subjects ranged from 23 to 40 years. Eye drops were applied to the same eye at varying intervals of up to 72 h, with the cocaine being given between 8:30 and 9:30 a.m. Pupil diameters were recorded by means of a frame-grabber card in a personal computer and were subsequently measured before and at 50-60 min after each drug application in 1.7 cd/m2 ambient light. In the absence of pretreatment with cocaine, pholedrine changed the mean pupil diameter from 6.89 to 8.57 mm. At 12 h after cocaine pretreatment the pupil remained dilated. Pholedrine dilated the pupil further, from 7.69 to 8.61 mm. When cocaine was given 24 h before pholedrine, the pupil dilated from 6.75 to 8.25 mm; at 48 h after cocaine application, pholedrine dilated the pupil from 6.14 to 8.20 mm; and at 72 h after cocaine pretreatment, pholedrine dilated the pupil from 5.74 to 8.00 mm. As compared with the mean diameter of the untreated contralateral pupil, the pholedrine-induced dilation amounted to 2.32 mm in the absence of cocaine pretreatment, 1.04 mm at 12 h after cocaine application, 1.29 mm at 24 h after cocaine administration, 1.89 mm at 48 h after cocaine pretreatment, and 2.18 mm at 72 h after cocaine application. The residual cocaine effect interfered with the mean pupil dilation produced by pholedrin for at least 48 h. To ensure that the sensitivity of the pholedrine test is maximal, the examiner should delay its use for more than 48 h after the cocaine test.     

In situ distribution of integrin alpha 2 beta 1 and alpha-actinin in melanocytic proliferations

Integrin alpha 2 beta 1 is a transmembrane protein receptor for collagen and laminin previously reported as a melanoma tumor progression antigen. alpha-Actinin is an actin-binding protein reported to interact with the cytoplasmic domain of the beta 1-integrin chain of alpha 2 beta 1. In vitro, both alpha 2 beta 1 and alpha-actinin play a role in melanoma cell motility. In turn, increased melanoma cell line motility (measured as mean migration rates), correlates with metastasis. To determine the in situ distribution of these proteins, we used monoclonal antibodies directed against the alpha 2-integrin subunit of alpha 2 beta 1 and alpha-actinin on frozen sections of 33 melanocytic proliferations, which included dermal nevi, primary melanomas, and metastatic melanomas. We found that the superficial portion of all of the melanocytic proliferations tested stained for alpha-actinin. In benign nevi and superficial spreading melanoma, there was a notable loss of staining for alpha-actinin in the cells in the deep reticular dermis. In contrast, alpha-actinin was present on almost all of the tumor cells in the nodular melanomas and the melanoma metastases. Tumors stained either uniformly positive or uniformly negative for alpha 2 beta 1; the expression of this protein correlated with the later stages of melanoma progression. Our findings suggest that alpha-actinin protein levels initially decrease and then increase during melanocytic tumor progression, whereas the alpha 2 subunit protein appears in the later stages of melanoma progression. The variable distribution of these proteins is evidence for the differential adhesive and motile properties of subpopulations of cells in melanocytic proliferations.     

Surface-enhanced Raman scattering spectroscopy as a sensitive and selective technique for the detection of folic acid in water and human serum

Surface-enhanced Raman scattering (SERS) is shown to give linear and sensitive concentration-dependent detection of folic acid using silver nanoparticles created via ethylene-diaminetetraacetic acid (EDTA) reduction. Optical detection by SERS overcomes the primary limitation of photodissociation encountered during the application of other shorter wavelength ultraviolet (UV)/near-UV techniques such as fluorescence based microscopy. The SERS approach in water-based samples was demonstrated and optimized using several longer wavelengths of excitation (514.5, 632.8, and 785 nm). Excitation in the green (514.5 nm) was found to achieve the best balance between photodissociation and SERS efficiency. Linear concentration dependence was observed in the range of 0.018 to 1 microM. The importance of folic acid in a clinical setting and the potential applications of this technique in a biological environment are highlighted. We demonstrate the potential to transfer this technique to real biological samples by the detection of folic acid in human serum samples by SERS.     

Optical head tracking for functional magnetic resonance imaging using structured light

An accurate motion-tracking technique is needed to compensate for subject motion during functional magnetic resonance imaging (fMRI) procedures. Here, a novel approach to motion metrology is discussed. A structured light pattern specifically coded for digital signal processing is positioned onto a fiduciary of the patient. As the patient undergoes spatial transformations in 6 DoF (degrees of freedom), a high-resolution CCD camera captures successive images for analysis on a computing platform. A high-speed image processing algorithm is used to calculate spatial transformations in a time frame commensurate with patient movements (10-100 ms) and with a precision of at least 0.5 microm for translations and 0.1 deg for rotations.     

C60 colloid formation in aqueous systems: effects of preparation method on size, structure, and surface charge

The discovery that negatively charged aggregates of C60 fullerene are stable in aqueous environments has elicited concerns regarding the potential environmental and health effects of these aggregates. Many previous studies have used aggregates synthesized using intermediate organic solvents. This work primarily employed an aggregate production method that more closely emulates the fate of C60 upon accidental release into the environment: extended mixing in water. The aggregates formed via this method (aqu/nC60) differ from those produced using the more common solvent exchange methods. The aqu/nC60 aggregates are heterogeneous in size (20 nm and larger) and shape (facetted to spherical), negatively charged, and crystalline in structure, exhibiting a face centered cubic (FCC) system. Solution characteristics such as aqu/nC60 aggregate size and concentration were found to be dependent upon preparation variables such as initial C60 concentration, initial particle size, and the presence or absence of natural organic matter. These results indicate that care should be taken when attempting to compare experimental results obtained with aqu/nC60 to nC60 produced by solvent exchange methods.