501 research outputs found
Gun Law History in the United States and Second Amendment Rights
The plethora of early gun laws herein described establish their prolific existence, but also validate the argument that gun rules and gun rights are by no means at odds. If the Supreme Court was indeed serious in saying that the provenance of gun regulations is relevant to the evaluation of contemporary laws, then this examination advances the Court's stated objective. The common notions that gun laws are largely a function of modern, industrial (or postindustrial) America, that gun laws are incompatible with American history and its practices or values, and that gun laws fundamentally collide with American legal traditions or individual rights, are all patently false. Following this introduction in part I, part II establishes that gun laws are as old as the nation. Part III summarizes the different categories into which early gun laws are categorized, and the frequency distributions within each category divided into time periods from 1607 to 1934. Part IV examines illustrative laws within each category and considers their nature and consequences. Part V offers a brief conclusion
Lost and Found: Researching the Second Amendment
The recent proliferation of writings on the Second Amendment makes numerous claims including: (1) there has been little or no legal scholarship on the Second Amendment until recent times; (2) the individualist view of the Second Amendment is the dominant or mainstream paradigm; (3) the courts have committed a dereliction of duty insofar as they have been silent on, or indifferent to, interpretation of the Second Amendment; and (4) since three of the four Supreme Court cases concerning the Second Amendment were decided in the nineteenth century, the court doctrine is somehow defective, irrelevant, outdated, unclear, or embarrassing. In this Article, Spitzer rebuts these claims based on his detailed study of law journal literature on the Second Amendment and suggests that law journals provide a breeding ground for occasionally wayward theories of constitutional meaning
Optimal Occulter Design for Finding Extrasolar Planets
One proposed method for finding terrestrial planets around nearby stars is to
use two spacecraft--a telescope and a specially shaped occulter that is
specifically designed to prevent all but a tiny fraction of the starlight from
diffracting into the telescope. As the cost and observing cadence for such a
mission will be driven largely by the separation between the two spacecraft, it
is critically important to design an occulter that can meet the observing goals
while flying as close to the telescope as possible. In this paper, we explore
this tradeoff between separation and occulter diameter. More specifically, we
present a method for designing the shape of the outer edge of an occulter that
is as small as possible and gives a shadow that is deep enough and large enough
for a 4m telescope to survey the habitable zones of many stars for Earth-like
planets. In particular, we show that in order for a 4m telescope to detect in
broadband visible light a planet 0.06 arcseconds from a star shining
times brighter than the planet requires a specially-shaped occulter 50m in
diameter positioned about km in front of the telescope.Comment: 14 pages, 4 figures, 15 subfigure
Surface materials of the Viking landing sites
Martian surface materials viewed by the two Viking landers (VL-1 and VL-2) range from fine-grained nearly cohesionless soils to rocks. Footpad 2 of VL-1, which landed at 2.30 m/s, penetrated 16.5 cm into very fine grained dunelike drift material; footpad 3 rests on a rocky soil which it penetrated ≈3.6 cm. Further penetration by footpad 2 may have been arrested by a hard substrate. Penetration by footpad 3 is less than would be expected for a typical lunar regolith. During landing, retroengine exhausts eroded the surface and propelled grains and rocks which produced craters on impact with the surface. Trenches excavated in drift material by the sampler have steep walls with up to 6 cm of relief. Incipient failure of the walls and failures at the end of the trenches are compatible with a cohesion near 10–10^2 N/m^2. Trenching in rocky soil excavated clods and possibly rocks. In two of five samples, commanded sampler extensions were not achieved, a situation indicating that buried rocks or local areas with large cohesions (≥10 kN/m^2) or both are present. Footpad 2 of VL-2, which landed at a velocity between 1.95 and 2.34 m/s, is partly on a rock, and footpad 3 appears to have struck one; penetration and leg strokes are small. Retroengine exhausts produced more erosion than occurred for VL-1 owing to increased thrust levels just before touchdown. Deformations of the soil by sampler extensions range from doming of the surface without visible fracturing to doming accompanied by fracturing and the production of angular clods. Although rocks larger than 3.0 cm are abundant at VL-1 and VL-2, repeated attempts to collect rocks 0.2–1.2 cm across imbedded in soil indicate that rocks in this size range are scarce. There is no evidence that the surface sampler of VL-2, while it was pushing and nudging rocks ≈25 cm across, spalled, chipped, or fractured the rocks. Preliminary analyses of surface sampler motor currents (≈25 N force resolution) during normal sampling are consistent with cohesionless frictional soils (ϕ ≈ 36°) or weakly cohesive frictionless soils (C < 2 kN/m^2). The soil of Mars has both cohesion and friction
On the and as Bound States and Approximate Nambu-Goldstone Bosons
We reconsider the two different facets of and mesons as
bound states and approximate Nambu-Goldstone bosons. We address several topics,
including masses, mass splittings between and and between and
, meson wavefunctions, charge radii, and the wavefunction overlap.Comment: 15 pages, late
Functional and Pharmacological Analysis of Cardiomyocytes Differentiated from Human Peripheral Blood Mononuclear-Derived Pluripotent Stem Cells
SummaryAdvances in induced pluripotent stem cell (iPSC) technology have set the stage for routine derivation of patient- and disease-specific human iPSC-cardiomyocyte (CM) models for preclinical drug screening and personalized medicine approaches. Peripheral blood mononuclear cells (PBMCs) are an advantageous source of somatic cells because they are easily obtained and readily amenable to transduction. Here, we report that the electrophysiological properties and pharmacological responses of PBMC-derived iPSC CM are generally similar to those of iPSC CM derived from other somatic cells, using patch-clamp, calcium transient, and multielectrode array (MEA) analyses. Distinct iPSC lines derived from a single patient display similar electrophysiological features and pharmacological responses. Finally, we demonstrate that human iPSC CMs undergo acute changes in calcium-handling properties and gene expression in response to rapid electrical stimulation, laying the foundation for an in-vitro-tachypacing model system for the study of human tachyarrhythmias
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