Genomic organization of the mouse T-cell receptor β-chain gene family

We have combined three different methods, deletion mapping of T-cell lines, field-inversion gel electrophoresis, and the restriction mapping of a cosmid clone, to construct a physical map of the murine T-cell receptor β-chain gene family. We have mapped 19 variable (Vβ) gene segments and the two clusters of diversity (Dβ) and joining (Jβ) gene segments and constant (Cβ) genes. These members of the β-chain gene family span ~450 kilobases of DNA, excluding one potential gap in the DNA fragment alignments

Coronal heating in multiple magnetic threads

Context. Heating the solar corona to several million degrees requires the conversion of magnetic energy into thermal energy. In this paper, we investigate whether an unstable magnetic thread within a coronal loop can destabilise a neighbouring magnetic thread. Aims. By running a series of simulations, we aim to understand under what conditions the destabilisation of a single magnetic thread can also trigger a release of energy in a nearby thread. Methods. The 3D magnetohydrodynamics code, Lare3d, is used to simulate the temporal evolution of coronal magnetic fields during a kink instability and the subsequent relaxation process. We assume that a coronal magnetic loop consists of non-potential magnetic threads that are initially in an equilibrium state. Results. The non-linear kink instability in one magnetic thread forms a helical current sheet and initiates magnetic reconnection. The current sheet fragments, and magnetic energy is released throughout that thread. We find that, under certain conditions, this event can destabilise a nearby thread, which is a necessary requirement for starting an avalanche of energy release in magnetic threads. Conclusions. It is possible to initiate an energy release in a nearby, non-potential magnetic thread, because the energy released from one unstable magnetic thread can trigger energy release in nearby threads, provided that the nearby structures are close to marginal stability

Phase-Mixing and Dissipation of Standing Shear Alfven waves

We study the phase mixing and dissipation of a packet of standing shear Alfv\'en waves localized in a region with non-uniform Alfv\'en background velocity. We investigate the validity of the exponential damping law in time, $\exp(-At^3)$, presented by Heyvaerts & Priest (1983) for different ranges of Lundquist, $S$, and Reynolds, $R$, numbers. Our numerical results shows that it is valid for $(R,S)\geq 10^7$.Comment: 11 pages, 8 figure

Finding the Boundaries of Equitable Disgorgement

The disgorgement of “ill-gotten gains” is a significant mechanism for enforcing the securities laws. By compelling a violator of the securities laws to forfeit their illegal proceeds, disgorgement serves as a strong deterrent for securities fraud and an important method by which investors are compensated for unjust losses in the market—and today accounts for the recovery of billions of dollars annually. Despite its importance, commentators in recent years began to call into question theavailability of the disgorgement remedy for the SEC. The SEC purses disgorgement under the agency’s grant for seeking equitable relief for the benefit of investors; however, courts have arguably applied disgorgement in a manner that renders it a penalty—and thus beyond the scope of SEC enforcement. In June 2020, the Supreme Court stepped in to provide clarity as to the future of disgorgement as an equitable remedy. In Liu v. SEC, the Court held that while disgorgement remains available for the SEC, a disgorgement award cannot exceed the net proceeds that result from a violation of the securities laws. More specifically, the Court took issue with three instances in which lower court applications of disgorgement had tested the line between equity and penalty. First was the common practice of returning disgorged funds to the Treasury rather than to harmed investors. Second was through the imposition of joint-and-several liability, and third was the practice of denying cost and expense deductions from disgorgement awards. This Note proposes a method for navigating the boundary of equitable disgorgement. In particular, this Note argues that disgorged funds can be equitably returned to the Treasury to the extent that the method of remittance reflects a focus on investor compensation and an expansive view of “benefitting investors.” Further, joint-and-several liability may be appropriate in the context of a fraudster’s claim toproceeds held by another; and finally, equity requires that legitimate deductions include more than legitimate costs and expenses, but the subsequent disposal of profits as well. This approach to applying disgorgement can result in an equitable imposition of the remedy and the continued efficacy of an important enforcement mechanism for policing securities markets

Lunar magnetization concentrations (MAGCONS) antipodal to young large impact basins

Electron reflection measurements from Apollo 15 and 16 subsatellites show that patches of strong surface magnetic fields ranging in size from less than about 7 km to greater than 500 km are distributed over the surface of the Moon. With the exception of a few regions, no obvious association to surface geology has been found. Researchers examined the antipodes of 23 winged impact basins for which electron reflection measurements are available. It was concluded that the apparent temporal variations for the basin antipodes may reflect real variations in the lunar magnetic field

The Determinants of Home Ownership: An Application of Human Capital Investment Theory To the Home Ownership Decision

The decision to purchase a home is one of the most important financial decisions made by young adults today. This decision is influenced by several factors including the individual\u27s demographics and family characteristics. The purpose of this study is to focus on the influence of these factors on the probability of home ownership for young adults

The effect of the relative orientation between the coronal field and new emerging flux: I Global Properties

The emergence of magnetic flux from the convection zone into the corona is an important process for the dynamical evolution of the coronal magnetic field. In this paper we extend our previous numerical investigations, by looking at the process of flux interaction as an initially twisted flux tube emerges into a plane parallel, coronal magnetic field. Significant differences are found in the dynamical appearance and evolution of the emergence process depending on the relative orientation between the rising flux system and any preexisting coronal field. When the flux systems are nearly anti-parallel, the experiments show substantial reconnection and demonstrate clear signatures of a high temperature plasma located in the high velocity outflow regions extending from the reconnection region. However, the cases that have a more parallel orientation of the flux systems show very limited reconnection and none of the associated features. Despite the very different amount of reconnection between the two flux systems, it is found that the emerging flux that is still connected to the original tube, reaches the same height as a function of time. As a compensation for the loss of tube flux, a clear difference is found in the extent of the emerging loop in the direction perpendicular to the main axis of the initial flux tube. Increasing amounts of magnetic reconnection decrease the volume, which confines the remaining tube flux.Comment: 21 pages, 16 figures Accepted for Ap

Building one molecule from a reservoir of two atoms

Chemical reactions typically proceed via stochastic encounters between reactants. Going beyond this paradigm, we combine exactly two atoms into a single, controlled reaction. The experimental apparatus traps two individual laser-cooled atoms (one sodium and one cesium) in separate optical tweezers and then merges them into one optical dipole trap. Subsequently, photoassociation forms an excited-state NaCs molecule. The discovery of previously unseen resonances near the molecular dissociation threshold and measurement of collision rates are enabled by the tightly trapped ultracold sample of atoms. As laser-cooling and trapping capabilities are extended to more elements, the technique will enable the study of more diverse, and eventually more complex, molecules in an isolated environment, as well as synthesis of designer molecules for qubits