793 research outputs found

    Property in the Fifth Amendment: A Quest for Common Ground in the Maze of Regulatory Takings

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    In 1922, the Supreme Court embarked on its first decision to protect property owners from unbridled, uncompensated government regulation. Prior to Pennsylvania Coal Co. v. Mahon, the courts applied the Just Compensation Clause of the Fifth Amendments only to \u27direct appropriation[s]\u27 of property ... or the functional equivalent of a \u27practical ouster of [the owner\u27s] possession.\u27 Mahon established that governmental regulation that affects an owner\u27s use of his land may constitute a taking under the Fifth Amendment. In Mahon, Justice Holmes recognized the need for constitutional limits on the government\u27s power to impair certain rights inherent in the ownership of property, especially when abolishing those rights has the same effect as appropriating or destroying the property itself. Justice Holmes understood that human nature gradually would lead government officials to qualify the rights of ownership under the guise of police power until, at last, private property disappeared.\u27 Without a check on their powers, officials may use regulation as an off-the-books method in lieu of taxation and compensation to achieve certain goals, particularly when funds are unavailable or when it appears that taxpayers will not support such a use of available funds. This abuse of the police power, Justice Holmes observed, amounts to petty larceny. The Just Compensation Clause of the Fifth Amendment provided the protection necessary to check this natural Hobbesian tendency.\u2

    Kaon and Hyperon Form Factors in Kaon Electroproduction on the Nucleon

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    The electromagnetic form factors of strange mesons and baryons are studied by means of kaon electroproduction on the nucleon. The response functions that are sensitive to the K0, Lambda, Sigma, and KK*\gamma transition form factors are systematically explored. The effects of these form factors on several response functions are discussed.Comment: 10 pages, Latex2e, 12 postscript figures. Invited talk given at the International Conference on Hypernuclear and Strange Particle Physics (HYP97), Brookhaven National Laboratory, USA, October 13-18, 1997. To be published in Nucl. Phys.

    Bromethalin toxicosis--evaluation of aminophylline treatment and an epidemiolgic assessment

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    The compound bromethalin is described and characterized in terms of mode of action when used as a rodenticide. It is hypothesized that an antimetabolite which inhibits the conversion of bromethalin to its desmethylbromethalin metabolite could represent a potential treatment for bromethalin toxicosis. An ideal antimetabolite of bromethalin is described, and based on these considerations, aminophylline (theophylline ethylenediamine) was chosen as a potential antimetabolite. In lab trials, aminophylline was administered to rats given a lethal dose of bromethalin, but it was not effective in prolonging rat survival. However, it did result in mean survival time being increase to nearly double. Further studies aminophylline or similar drugs may results in identifying a suitable treatment for bromethalin-induced toxic syndrome

    Timing as a sexually selected trait: the right mate at the right moment

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    Sexual selection favours the expression of traits in one sex that attract members of the opposite sex for mating. The nature of sexually selected traits such as vocalization, colour and ornamentation, their fitness benefits as well as their costs have received ample attention in field and laboratory studies. However, sexually selected traits may not always be expressed: coloration and ornaments often follow a seasonal pattern and behaviours may be displayed only at specific times of the day. Despite the widely recognized differences in the daily and seasonal timing of traits and their consequences for reproductive success, the actions of sexual selection on the temporal organization of traits has received only scant attention. Drawing on selected examples from bird and mammal studies, here we summarize the current evidence for the daily and seasonal timing of traits. We highlight that molecular advances in chronobiology have opened exciting new opportunities for identifying the genetic targets that sexual selection may act on to shape the timing of trait expression. Furthermore, known genetic links between daily and seasonal timing mechanisms lead to the hypothesis that selection on one timescale may simultaneously also affect the other. We emphasize that studies on the timing of sexual displays of both males and females from wild populations will be invaluable for understanding the nature of sexual selection and its potential to act on differences within and between the sexes in timing. Molecular approaches will be important for pinpointing genetic components of biological rhythms that are targeted by sexual selection, and to clarify whether these represent core or peripheral components of endogenous clocks. Finally, we call for a renewed integration of the fields of evolution, behavioural ecology and chronobiology to tackle the exciting question of how sexual selection contributes to the evolution of biological clocks.This article is part of the themed issue 'Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals'

    Superhydrophobic Thin Films Fabricated by Reactive Layer-by-Layer Assembly of Azlactone-Functionalized Polymers

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    We report an approach to the fabrication of superhydrophobic thin films that is based on the reactive layer-by-layer assembly of azlactone-containing polymer multilayers. We demonstrate that films fabricated from alternating layers of the azlactone functionalized polymer poly(2-vinyl- 4,4-dimethylazlactone) (PVDMA) and poly(ethyleneimine) (PEI) exhibit micro- and nanoscale surface features that result in water contact angles in excess of 150°. Our results reveal that the formation of these surface features is (i) dependent upon film thickness (i.e., the number of layers of PEI and PVDMA deposited) and (ii) that it is influenced strongly by the presence (or absence) of cyclic azlactone-functionalized oligomers that can form upon storage of the 2-vinyl-4,4-dimethylazlactone (VDMA) used to synthesize PVDMA. For example, films fabricated using polymers synthesized in the presence of these oligomers exhibited rough, textured surfaces and superhydrophobic behavior (i.e., advancing contact angles in excess of 150°). In contrast, films fabricated from PVDMA polymerized in the absence of this oligomer (e.g., using freshly distilled monomer) were smooth and only moderately hydrophobic (i.e., advancing contact angles of ̃75°). The addition of authentic, independently synthesized oligomer to samples of distilled VDMA at specified and controlled concentrations permitted reproducible fabrication of superhydrophobic thin films on the surfaces of a variety of different substrates. The surfaces of these films were demonstrated to be superhydrophobic immediately after fabrication, but they became hydrophilic after exposure to water for 6 days. Additional experiments demonstrated that it was possible to stabilize and prolong the superhydrophobic properties of these films (e.g., advancing contact angles in excess of 150° even after complete submersion in water for at least 6 weeks) by exploiting the reactivity of residual azlactones to functionalize the surfaces of the films using hydrophobic amines (e.g., aliphatic or semifluorinated aliphatic amines). Our results demonstrate a straightforward and substrate-independent approach to the design of superhydrophobic and reactive polymer-based coatings of potential use in a broad range of fundamental and applied contexts

    Social cognition in schizophrenia: factor structure, clinical and functional correlates

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    Social cognition is consistently impaired in people with schizophrenia, separable from general neurocognition, predictive of real-world functioning, and amenable to psychosocial treatment. Few studies have empirically examined its underlying factor structure

    NONDESTRUCTIVE DETECTION OF AN UNDESERABLE METALLIC PHASE, T1, DURING PROCESSING OF ALUMNUM-L THUMALLOYS

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    A method is disclosed for detecting the T1 phase in aluminum-lithium alloys through simultaneous measurement of conductivity and hardness. In employing eddy current to measure conductivity, when the eddy current decreases with aging of the alloy, while the hardness of the material continues to increase, the presence of the T1 phase may be detected

    Strength and Ultrasonic Characterization of Metallic Interfaces

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    In recent years, the process of diffusion bonding has found considerable usage in both the nuclear power and aerospace industries. This process requires the compression of mating surfaces at an elevated temperature for a given time. If optimum conditions of time, temperature, pressure and surface cleanliness are achieved, diffusion of material across the interface will occur, yielding interfacial mechanical properties identical to those of the bulk material. The use of insufficient bonding conditions may result in void formation, precipitation of undesired phases or lack of grain growth across the interface. The consequence will be an interface that is less than fully bonded, which will result in severe degradation of the mechanical properties. Applications of diffusion bonding to nuclear reactor fuel elements, helicopter rotor hubs, jet engine turbine blades, etc., thus make the ability to characterize the strength of these interfaces highly desirable

    Glory Oscillations in the Index of Refraction for Matter-Waves

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    We have measured the index of refraction for sodium de Broglie waves in gases of Ar, Kr, Xe, and nitrogen over a wide range of sodium velocities. We observe glory oscillations -- a velocity-dependent oscillation in the forward scattering amplitude. An atom interferometer was used to observe glory oscillations in the phase shift caused by the collision, which are larger than glory oscillations observed in the cross section. The glory oscillations depend sensitively on the shape of the interatomic potential, allowing us to discriminate among various predictions for these potentials, none of which completely agrees with our measurements

    Comparative Genomics of Cryptosporidium

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    Until recently, the apicomplexan parasites, Cryptosporidium hominis andC. parvum, were considered the same species. However, the two parasites, now considered distinct species, exhibit significant differences in host range, infectivity, and pathogenicity, and their sequenced genomes exhibit only 95–97% identity. The availability of the complete genome sequences of these organisms provides the potential to identify the genetic variations that are responsible for the phenotypic differences between the two parasites. We compared the genome organization and structure, gene composition, the metabolic and other pathways, and the local sequence identity between the genes of these two Cryptosporidium species. Our observations show that the phenotypic differences between C. hominisand C. parvum are not due to gross genome rearrangements, structural alterations, gene deletions or insertions, metabolic capabilities, or other obvious genomic alterations. Rather, the results indicate that these genomes exhibit a remarkable structural and compositional conservation and suggest that the phenotypic differences observed are due to subtle variations in the sequences of proteins that act at the interface between the parasite and its host
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