2,914 research outputs found
Indians and Equal Protection
This article analyzes the recent Indian equal protection cases in an attempt to formulate the equal protection doctrine as applied to Indians, to examine the theoretical foundation for that doctrine, and to indicate how that doctrine will likely be applied in situations not yet addressed by the courts
Indians and Equal Protection
This article analyzes the recent Indian equal protection cases in an attempt to formulate the equal protection doctrine as applied to Indians, to examine the theoretical foundation for that doctrine, and to indicate how that doctrine will likely be applied in situations not yet addressed by the courts
AGC Team\u27s Rock Design, Heavy Civil and PreConstruction Skills at 2020 ASC Competition
MT Tech Represented:
• AGC (Associated General Contractors) Club heads to Nevada
• Represents the construction industry in: heavy civil, design build, and preconstructio
Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens
Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators
Alternate Refactoring Paths Reveal Usability Problems
Modern Integrated Development Environments (IDEs) support many refactorings. Yet, programmers greatly underuse automated refactorings. Recent studies have applied traditional usability testing methodologies such as surveys, lab studies, and interviews to find the usability problems of refactoring tools. However, these methodologies can identify only certain kinds of usability problems. The critical incident technique (CIT) is a general methodology that uncovers usability problems by analyzing troubling user interactions. We adapt CIT to refactoring tools and show that alternate refactoring paths are indicators of the usability problems of refactoring tools. We define an alternate refactoring path as a sequence of user interactions that contains cancellations, reported messages, or repeated invocations of the refactoring tool. We evaluated our method on a large corpus of refactoring usage data, which we collected during a field study on 36 programmers over three months. This method revealed 15 usability problems, 13 of which were previously unknown. We reported these problems and proposed design improvements to Eclipse developers. The developers acknowledged all of the problems and have already fixed four of them. This result suggests that analyzing alternate paths is effective at discovering the usability problems of interactive program transformation (IPT) tools
Simulation of alnico coercivity
Micromagnetic simulations of alnico show substantial deviations from
Stoner-Wohlfarth behavior due to the unique size and spatial distribution of
the rod-like Fe-Co phase formed during spinodal decomposition in an external
magnetic field. The maximum coercivity is limited by single-rod effects,
especially deviations from ellipsoidal shape, and by interactions between the
rods. Both the exchange interaction between connected rods and magnetostatic
interaction between rods are considered, and the results of our calculations
show good agreement with recent experiments. Unlike systems dominated by
magnetocrystalline anisotropy, coercivity in alnico is highly dependent on
size, shape, and geometric distribution of the Fe-Co phase, all factors that
can be tuned with appropriate chemistry and thermal-magnetic annealing
A Model for Ferromagnetic Nanograins with Discrete Electronic States
We propose a simple phenomenological model for an ultrasmall ferromagnetic
grain, formulated in terms of the grain's discrete energy levels. We compare
the model's predictions with recent measurements of the discrete tunneling
spectrum through such a grain. The model can qualitatively account for the
observed features if we assume (i) that the anisotropy energy varies among
different eigenstates of one grain, and (ii) that nonequilibrium spin
accumulation occurs.Comment: 4 pages, 2 figure
Generating rewritable abstract syntax trees - A foundation for the rapid development of source code transformation tools
Abstract. Building a production-quality refactoring engine or similar source code transformation tool traditionally requires a large amount of hand-written, language-specific support code. We describe a system which reduces this overhead by allowing both a parser and a fully rewritable AST to be generated automatically from an annotated grammar, requiring little or no additional handwritten code. The rewritable AST is ideal for implementing program transformations that preserve the formatting of the original sources, including spacing and comments, and the system can be augmented to allow transformation of Cpreprocessed sources even when the target language is not C or C++. Moreover, the AST design is fully customizable, allowing it to resemble a hand-coded tree. The amount of required annotation is typically quite small, and the annotated grammar is often an order of magnitude smaller than the generated code
Deep Chandra Observations of Abell 2199: the Interplay between Merger-Induced Gas Motions and Nuclear Outbursts in a Cool Core Cluster
We present new Chandra observations of Abell 2199 that show evidence of gas
sloshing due to a minor merger, as well as impacts of the radio source, 3C 338,
hosted by the central galaxy, NGC 6166, on the intracluster gas. The new data
are consistent with previous evidence of a Mach 1.46 shock 100" from the
cluster center, although there is still no convincing evidence for the expected
temperature jump. Other interpretations of this feature are possible, but none
is fully satisfactory. Large scale asymmetries, including enhanced X-ray
emission 200" southwest of the cluster center and a plume of low entropy,
enriched gas reaching 50" to the north of the center, are signatures of gas
sloshing induced by core passage of a merging subcluster about 400 Myr ago. An
association between the unusual radio ridge and low entropy gas are consistent
with this feature being the remnant of a former radio jet that was swept away
from the AGN by gas sloshing. A large discrepancy between the energy required
to produce the 100" shock and the enthalpy of the outer radio lobes of 3C 338
suggests that the lobes were formed by a more recent, less powerful radio
outburst. Lack of evidence for shocks in the central 10" indicates that the
power of the jet now is some two orders of magnitude smaller than when the 100"
shock was formed.Comment: 17 pages, 20 figures, accepted for publication in Ap
Poorly Controlled Homocystinuria: A Rare Cause of Ischemic Priapism?
We report on the 1st case of ischemic priapism secondary to poorly controlled homocystinuria. Homocystinuria is a rare, autosomal recessive, inherited disorder of metabolism that is caused by a deficiency of cystathionine synthase, leading to marked hyperhomocysteinemia. Arterial and/or venous thromboemboli are a major cause of mortality and morbidity in patients with homocystinuria. Untreated patients have a 50% chance of having a vascular event by 30 years of age. Increased homocysteine levels have been reported to upregulate prothrombotic factors and downregulate antithrombotic factors; in particular, increased homocystinuria has been found to downregulate nitric oxide (NO). Mice that are deficient in NO synthase in the cavernosal smooth muscles have a higher incidence of priapism. Decrease in NO synthase causes downregulation of cyclic guanosine monophosphate, phosphodiesterase type 5A, and Rho A/Rho-kinase. Because persistently increased homocysteine also downregulates NO, a similar mechanism could be proposed for priapism secondary to homocystinuria. In patients presenting with priapism, specific features of homocystinuria should be sought; in selected patients, screening with plasma total homocysteine might be appropriate. Ischemic priapism secondary to homocystinuria appears to respond well to the standard treatment options of aspiration, intracavernosal injection with phenylephrine, and, if required, a shunting procedure
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