4,544 research outputs found
Eminent Domain after Kelo v. City of New London: Compensating for the Supreme Court’s Refusal to Enforce the Fifth Amendment
Governments, both state and federal, have the right to take private property for public use, provided that just compensation is paid. The Fifth Amendment to the United States Constitution sets the legal standard for these propositions; this power is known as the right of eminent domain. In the landmark decision, Kelo v. City of New London, the Supreme Court held that the taking of a citizen’s private property for economic development qualified as a public use within the meaning of the Fifth Amendment. Several scholars, legislatures, and individuals, have objected to Kelo’s extension of the power of eminent domain. The ruling has extended the government’s power of eminent domain to areas once thought unimaginable
Gyrokinetic studies of the effect of beta on drift-wave stability in NCSX
The gyrokinetic turbulence code GS2 was used to investigate the effects of
plasma beta on linear, collisionless ion temperature gradient (ITG) modes and
trapped electron modes (TEM) in National Compact Stellarator Experiment (NCSX)
geometry. Plasma beta affects stability in two ways: through the equilibrium
and through magnetic fluctuations. The first was studied here by comparing ITG
and TEM stability in two NCSX equilibria of differing beta values, revealing
that the high beta equilibrium was marginally more stable than the low beta
equilibrium in the adiabatic-electron ITG mode case. However, the high beta
case had a lower kinetic-electron ITG mode critical gradient. Electrostatic and
electromagnetic ITG and TEM mode growth rate dependencies on temperature
gradient and density gradient were qualitatively similar. The second beta
effect is demonstrated via electromagnetic ITG growth rates' dependency on
GS2's beta input parameter. A linear benchmark with gyrokinetic codes GENE and
GKV-X is also presented.Comment: Submitted to Physics of Plasmas. 9 pages, 27 figure
Threshold photoproduction of neutral pions off protons in nuclear model with explicit mesons
We apply the nuclear model with explicit mesons to photoproduction of neutral
pions off protons at the threshold. In this model the nucleons do not interact
with each other via a potential but rather emit and absorb mesons that are
treated explicitly on equal footing with the nucleons. We calculate the total
cross section of the reaction for energies close to threshold and compare the
calculations with available experimental data. We show that the model is able
to reproduce the experimental data and determine the range of the parameters
where the model is compatible with the experiment
Novel α-L-Fucosidases from a Soil Metagenome for Production of Fucosylated Human Milk Oligosaccharides
This paper describes the discovery of novel α-L-fucosidases and evaluation of their potential to catalyse the transglycosylation reaction leading to production of fucosylated human milk oligosaccharides. Seven novel α-L-fucosidase-encoding genes were identified by functional screening of a soil-derived metagenome library and expressed in E. coli as recombinant 6xHis-tagged proteins. All seven fucosidases belong to glycosyl hydrolase family 29 (GH 29). Six of the seven α-L-fucosidases were substrate-inhibited, moderately thermostable and most hydrolytically active in the pH range 6-7, when tested with para-nitrophenyl-α-L-fucopyranoside (pNP-Fuc) as the substrate. In contrast, one fucosidase (Mfuc6) exhibited a high pH optimum and an unusual sigmoidal kinetics towards pNP-Fuc substrate. When tested for trans-fucosylation activity using pNP-Fuc as donor, most of the enzymes were able to transfer fucose to pNP-Fuc (self-condensation) or to lactose. With the α-L-fucosidase from Thermotoga maritima and the metagenome-derived Mfuc5, different fucosyllactose variants including the principal fucosylated HMO 2'-fucosyllactose were synthesised in yields of up to ~6.4%. Mfuc5 was able to release fucose from xyloglucan and could also use it as a fucosyl-donor for synthesis of fucosyllactose. This is the first study describing the use of glycosyl hydrolases for the synthesis of genuine fucosylated human milk oligosaccharides
Projectile-shape dependence of impact craters in loose granular media
We report on the penetration of cylindrical projectiles dropped from rest
into a dry, noncohesive granular medium. The cylinder length, diameter,
density, and tip shape are all explicitly varied. For deep penetrations, as
compared to the cylinder diameter, the data collapse onto a single scaling law
that varies as the 1/3 power of the total drop distance, the 1/2 power of
cylinder length, and the 1/6 power of cylinder diameter. For shallow
penetrations, the projectile shape plays a crucial role with sharper objects
penetrating deeper.Comment: 3 pages, 3 figures; experimen
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