A Test Suite for High-Performance Parallel Java

The Java programming language has a number of features that make it attractive for writing high-quality, portable parallel programs. A pure object formulation, strong typing and the exception model make programs easier to create, debug, and maintain. The elegant threading provides a simple route to parallelism on shared-memory machines. Anticipating great improvements in numerical performance, this paper presents a suite of simple programs that indicate how a pure Java Navier-Stokes solver might perform. The suite includes a parallel Euler solver. We present results from a 32-processor Hewlett-Packard machine and a 4-processor Sun server. While speedup is excellent on both machines, indicating a high-quality thread scheduler, the single-processor performance needs much improvement

Protein engineering of Pseudomonas fluorescens peroxidase Dyp1B for oxidation of phenolic and polymeric lignin substrates

Directed evolution was applied to dye-decolourizing peroxidase Dyp1B from Pseudomonas fluorescens Pf-5, in order to enhance the activity for oxidation of phenolic and lignin substrates. Saturation mutagenesis was used to generate focused libraries at 7 active site residues in the vicinity of the heme cofactor, and the libraries were screened for activity towards 2,6-dichlorophenol. Mutants N193 L and H169 L were found to show 7–8 fold enhanced kcat/KM towards DCP, and replacements at Val205 and Ala209 also showed enhanced activity towards alkali Kraft lignin. Residues near the predicted Mn(II) binding site were also investigated by site-directed mutagenesis, and mutants S223 N and H127R showed 4-7-fold increased kcat/KM for Mn(II) oxidation. Mutant F128R also showed enhanced thermostability, compared to wild-type Dyp1B. Testing of mutants for low molecular weight product release from Protobind alkali lignin revealed that mutant H169 L showed enhanced product release, compared with WT enzyme, and the formation of three low molecular weight metabolites by this mutant was detected by reverse phase HPLC analysis

Substrate Stiffness Controls Osteoblastic and Chondrocytic Differentiation of Mesenchymal Stem Cells without Exogenous Stimuli

Stem cell fate has been linked to the mechanical properties of their underlying substrate, affecting mechanoreceptors and ultimately leading to downstream biological response. Studies have used polymers to mimic the stiffness of extracellular matrix as well as of individual tissues and shown mesenchymal stem cells (MSCs) could be directed along specific lineages. In this study, we examined the role of stiffness in MSC differentiation to two closely related cell phenotypes: osteoblast and chondrocyte. We prepared four methyl acrylate/methyl methacrylate (MA/MMA) polymer surfaces with elastic moduli ranging from 0.1 MPa to 310 MPa by altering monomer concentration. MSCs were cultured in media without exogenous growth factors and their biological responses were compared to committed chondrocytes and osteoblasts. Both chondrogenic and osteogenic markers were elevated when MSCs were grown on substrates with stiffnesschondrocytes, MSCs on lower stiffness substrates showed elevated expression of ACAN, SOX9, and COL2 and proteoglycan content; COMP was elevated in MSCs but reduced in chondrocytes. Substrate stiffness altered levels of RUNX2 mRNA, alkaline phosphatase specific activity, osteocalcin, and osteoprotegerin in osteoblasts, decreasing levels on the least stiff substrate. Expression of integrin subunits α1, α2, α5, αv, β1, and β3 changed in a stiffness- and cell type-dependent manner. Silencing of integrin subunit beta 1 (ITGB1) in MSCs abolished both osteoblastic and chondrogenic differentiation in response to substrate stiffness. Our results suggest that substrate stiffness is an important mediator of osteoblastic and chondrogenic differentiation, and integrin β1 plays a pivotal role in this process

Criminal Law and Procedure

This Article surveys recent developments in criminal procedure and law in Virginia. Because of space limitations, the authors have limited their discussion to the most significant published appellate decisions and legislation

An optical coherence microscope for 3-dimensional imaging in developmental biology

An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue. The design trade-offs for a 3-D OCM are discussed, and the fundamental photon noise limitation is measured and compared with theory. A rotating 3-D image of a frog embryo is presented to illustrate the capabilities of the instrument

Early Growth in Weight of Kemp\u27s Ridley Sea Turtles (Lepidochelys kempii) in Captivity

Growth in individual weight (w, kg) of Kemp’s ridley sea turtles (Lepidochelys kempii) in captivity was described for 15 year-classes (1978-1992) of turtles between ages (t) 0.17 to 1.22 yr, using In linear regression: Inw = lnc + dt1/2, where Inc is the intercept and d is the slope (growth rate index). There was significant (P \u3c 0.001) heterogeneity in d among year-classes, with slowest growth (d = 3.798) exhibited by the 1983 year-class and fastest growth (d = 6.929) by the 1985 year-class, but there was no significant trend in d (P = 0.307) over year-classes. The variance of residuals from regression, s2reg, ranged from 0.2032 for the 1978 year-class to 0.0075 for the 1992 year-class, and showed a significant (P = 0.0001) logarithmic decrease over the year-classes. This decline in variation among individuals was probably due to a a shift toward sex ratios dominated by one sex (females), improvements in rearing facilities, year-around control of seawater temperature which reduced disease incidence, improved diet, and reduced feeding levels. The relationship between w and scl (straight carapace length) was also described

Pediatric Cancer Genetics Research and an Evolving Preventive Ethics Approach for Return of Results after Death of the Subject

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115941/1/jlme12295.pd

The Frontier Fields Lens Modeling Comparison Project

Gravitational lensing by clusters of galaxies offers a powerful probe of their structure and mass distribution. Deriving a lens magnification map for a galaxy cluster is a classic inversion problem and many methods have been developed over the past two decades to solve it. Several research groups have developed techniques independently to map the predominantly dark matter distribution in cluster lenses. While these methods have all provided remarkably high precision mass maps, particularly with exquisite imaging data from the Hubble Space Telescope (HST), the reconstructions themselves have never been directly compared. In this paper, we report the results of comparing various independent lens modeling techniques employed by individual research groups in the community. Here we present for the first time a detailed and robust comparison of methodologies for fidelity, accuracy and precision. For this collaborative exercise, the lens modeling community was provided simulated cluster images -- of two clusters Ares and Hera -- that mimic the depth and resolution of the ongoing HST Frontier Fields. The results of the submitted reconstructions with the un-blinded true mass profile of these two clusters are presented here. Parametric, free-form and hybrid techniques have been deployed by the participating groups and we detail the strengths and trade-offs in accuracy and systematics that arise for each methodology. We note in conclusion that lensing reconstruction methods produce reliable mass distributions that enable the use of clusters as extremely valuable astrophysical laboratories and cosmological probes.Comment: 38 pages, 25 figures, submitted to MNRAS, version with full resolution images can be found at http://pico.bo.astro.it/~massimo/papers/FFsims.pd

Variation in Periodontal Diagnosis and Treatment Planning Among Clinical Instructors

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153684/1/jddj002203372005693tb03919x.pd

American Policy British Politics: Whole of Life Imprisonment and Transatlantic Influence

Since the abolition of the death penalty, life imprisonment in England and Wales has had a literal meaning with exceptional rarity. Now though, in the rejection of perceived interference by the European Court of Human Rights in domestic sentencing, the politics of whole of life imprisonment have become exposed, specifically, in the widening applicability of the tariff to those who kill police officers or prison guards. Borrowing from the politics of capital punishment in the USA, in both ‘acting out’ after a particular crime, and the prioritising of victim groups, the most severe penalty in England and Wales is increasingly beginning to mirror how the most severe punishment across the Atlantic is used, represented, and politicised