Post-Katrina Reconstruction Liability: Exposing the Inferior Risk-Bearer

This Article describes the doctrinal, functional, and moral flaws inherent in the Gulf Coast Recovery Act (GCRA), a United States Senate bill that would provide liability protection to government contractors engaged in disaster relief work in the areas devastated by Hurricane Katrina, as well as in future disaster areas. First, the Article discusses the history of the government contractor defense and finds that the protection provided by the GCRA is quite unlike the traditional government contractor defense. This Article further argues that this doctrinal departure cannot be justified on grounds of efficiency or fairness, as the GCRA allocates risk away from government contractors and the government and towards the disaster area residents and relief workers who are potential victims. Finally, this Article notes that even if the sort of protection provided by the GCRA may be justified under some conditions of market failure, there is no empirical evidence that government contractors in the Gulf Coast have experienced such conditions, and there are superior alternatives to the GCRA that could provide such protection while preserving a path for victim compensation. This Article concludes that the GCRA is an untenable solution to a problem that has not been proven to exist, and one that violates the basic principles of good government

Post-Katrina Reconstruction Liability: Exposing the Inferior Risk-Bearer

This Article describes the doctrinal, functional, and moral flaws inherent in the Gulf Coast Recovery Act (GCRA), a United States Senate bill that would provide liability protection to government contractors engaged in disaster relief work in the areas devastated by Hurricane Katrina, as well as in future disaster areas. First, the Article discusses the history of the government contractor defense and finds that the protection provided by the GCRA is quite unlike the traditional government contractor defense. This Article further argues that this doctrinal departure cannot be justified on grounds of efficiency or fairness, as the GCRA allocates risk away from government contractors and the government and towards the disaster area residents and relief workers who are potential victims. Finally, this Article notes that even if the sort of protection provided by the GCRA may be justified under some conditions of market failure, there is no empirical evidence that government contractors in the Gulf Coast have experienced such conditions, and there are superior alternatives to the GCRA that could provide such protection while preserving a path for victim compensation. This Article concludes that the GCRA is an untenable solution to a problem that has not been proven to exist, and one that violates the basic principles of good government

Electron Spin Decoherence in Bulk and Quantum Well Zincblende Semiconductors

A theory for longitudinal (T1) and transverse (T2) electron spin coherence times in zincblende semiconductor quantum wells is developed based on a non-perturbative nanostructure model solved in a fourteen-band restricted basis set. Distinctly different dependences of coherence times on mobility, quantization energy, and temperature are found from previous calculations. Quantitative agreement between our calculations and measurements is found for GaAs/AlGaAs, InGaAs/InP, and GaSb/AlSb quantum wells.Comment: 11 pages, 3 figure

A full descriptive definition of the BV-integral

summary:We present a Cauchy test for the almost derivability of additive functions of bounded BV sets. The test yields a full descriptive definition of a coordinate free Riemann type integral

TIP47 is a key effector for Rab9 localization

The human genome encodes ∼70 Rab GTPases that localize to the surfaces of distinct membrane compartments. To investigate the mechanism of Rab localization, chimeras containing heterologous Rab hypervariable domains were generated, and their ability to bind seven Rab effectors was quantified. Two chimeras could bind effectors for two distinctly localized Rabs; a Rab5/9 hybrid bound both Rab5 and Rab9 effectors, and a Rab1/9 hybrid bound to certain Rab1 and Rab9 effectors. These unusual chimeras permitted a test of the importance of effector binding for Rab localization. In both cases, changing the cellular concentration of a key Rab9 effector, which is called tail-interacting protein of 47 kD, moved a fraction of the proteins from their parental Rab localization to that of Rab9. Thus, relative concentrations of certain competing effectors could determine a chimera's localization. These data confirm the importance of effector interactions for Rab9 localization, and support a model in which effector proteins rely on Rabs as much as Rabs rely on effectors to achieve their correct steady state localizations

From Mirrors to Wallpapers: A Virtual Math Circle Module on Symmetry

Symmetry is a natural property that children see in their everyday lives; it also has deep mathematical connections to areas like tiling and objects like wallpaper groups. The Tucson Math Circle (TMC) presents a 7-part module on symmetry that starts with reflective symmetry and culminates in the deconstruction of wallpapers into their ‘generating tiles’. This module utilizes a scaffolded, hands-on approach to cover old and new mathematical topics with various interactive activities; all activities are made available through free web-based platforms. In this paper, we provide lesson plans for the various activities used, and discuss their online implementation with Zoom, Miro, and the TMC Widget. We touch on the benefits and disadvantages of the online environment, and provide suggestions for moving these activities to an in-person format. We also include links to files in our Google Drive, where members of the Math Circle community can download our worksheets and Miro board templates

Anisotropic splitting of intersubband spin plasmons in quantum wells with bulk and structural inversion asymmetry

In semiconductor heterostructures, bulk and structural inversion asymmetry and spin-orbit coupling induce a k-dependent spin splitting of valence and conduction subbands, which can be viewed as being caused by momentum-dependent crystal magnetic fields. This paper studies the influence of these effective magnetic fields on the intersubband spin dynamics in an asymmetric n-type GaAs/AlGaAs quantum well. We calculate the dispersions of intersubband spin plasmons using linear response theory. The so-called D'yakonov-Perel' decoherence mechanism is inactive for collective intersubband excitations, i.e., crystal magnetic fields do not lead to decoherence of spin plasmons. Instead, we predict that the main signature of bulk and structural inversion asymmetry in intersubband spin dynamics is a three-fold, anisotropic splitting of the spin plasmon dispersion. The importance of many-body effects is pointed out, and conditions for experimental observation with inelastic light scattering are discussed.Comment: 8 pages, 6 figure