Potential Competitive Effects of Vertical Mergers: A How-To Guide for Practitioners

The purpose of this short article is to aid practitioners in analyzing the competitive effects of vertical and complementary product mergers. It is also intended to assist the agencies if and when they undertake revision of the 1984 U.S. Vertical Merger Guidelines. Those Guidelines are out of date and do not reflect current enforcement or economic thinking about the potential competitive effects of vertical mergers. Nor do they provide the tools needed to carry out a modern competitive effects analysis. This article is intended to partially fill the gap by summarizing the various potential competitive harms and benefits that can occur in vertical mergers and the types of economic and factual analysis of competitive effects that can be applied to those mergers during the HSR review process. The analysis in the article also identifies several legal and policy issues that the agencies would consider when they undertake the process of revising the Vertical Merger Guidelines. The Appendix contains a listing and summary of the vertical merger cases challenged by the DOJ and FTC since 1994

Vertical Merger Enforcement Actions: 1994–April 2020

We have revised our earlier listing of vertical merger enforcement actions by the Department of Justice and Federal Trade Commission since 1994. This revised listing includes 66 vertical matters beginning in 1994 through April 2020. It includes challenges and certain proposed transactions that were abandoned in the face of Agency concerns. This listing can be treated as an Appendix to Steven C. Salop and Daniel P. Culley, Revising the Vertical Merger Guidelines: Policy Issues and an Interim Guide for Practitioners, 4 JOURNAL OF ANTITRUST ENFORCEMENT 1 (2016)

Resonator-induced dissipation of transverse nuclear-spin signals in cold nanoscale samples

The back action of typical macroscopic resonators used for detecting nuclear magnetic resonance can cause a reversible decay of the signal, known as radiation damping. A mechanical resonator that is strongly coupled to a microscopic sample can in addition induce an irreversible dissipation of the nuclear-spin signal, distinct from radiation damping. We provide a theoretical description of resonator-induced transverse relaxation that is valid for samples of a few nuclear spins in the low-temperature regime, where quantum fluctuations play a significant role in the relaxation process, as well as for larger samples and at higher temperatures. Transverse relaxation during free evolution and during spin locking are analyzed, and simulations of relaxation in example systems are presented. In the case where an isolated spin 1/2 interacts with the resonator, transverse relaxation is exponential during free evolution, and the time constant for the relaxation is T_2=2/R_h, where R_h is the rate constant governing the exchange of quanta between the resonator and the spin. For a system of multiple spins, the time scale of transverse relaxation during free evolution depends on the spin Hamiltonian, which can modify the relaxation process through the following effects: (1) changes in the structure of the spin-spin correlations present in the energy eigenstates, which affect the rates at which these states emit and absorb energy, (2) frequency shifts that modify emission and absorption rates within a degenerate manifold by splitting the energy degeneracy and thus suppressing the development of resonator-induced correlations within the manifold, and (3) frequency shifts that introduce a difference between the oscillation frequencies of single-quantum coherences ρ_(ab) and ρ_(cd) and average to zero the transfers between them. This averaging guarantees that the spin transitions responsible for the coupling between ρ_(ab) and ρ_(cd) cause irreversible loss of order rather than a reversible interconversion of the coherences. In systems of a few spins, transverse relaxation is accelerated by a dipolar Hamiltonian that is either the dominant term in the internal spin Hamiltonian or a weak perturbation to the chemical-shift Hamiltonian. A pure chemical-shift Hamiltonian yields exponential relaxation with T_2=2/R_h in the case where the Larmor frequencies of the spins are distinct and sufficiently widely spaced. During spin locking with a nutation frequency fast enough to average the evolution under the internal spin Hamiltonian but not the interactions occurring during the correlation time of the resonator, relaxation of the spin-locked component is exponential with time constant T_(1ρ)=2/R_h

Revising the U.S. Vertical Merger Guidelines: Policy Issues and an Interim Guide for Practitioners

Mergers and acquisitions are a major component of antitrust law and practice. The U.S. antitrust agencies spend a majority of their time on merger enforcement. The focus of most merger review at the agencies involves horizontal mergers, that is, mergers among firms that compete at the same level of production or distribution. Vertical mergers combine firms at different levels of production or distribution. In the simplest case, a vertical merger joins together a firm that produces an input (and competes in an input market) with a firm that uses that input to produce output (and competes in an output market). Over the years, the agencies have issued Merger Guidelines that outline the type of analysis carried out by the agencies and the agencies’ enforcement intentions in light of state of the law. These Guidelines are used by agency staff in evaluating mergers, as well as by outside counsel and the courts. Guidelines for vertical mergers were issued in 1968 and revised in 1984. However, the Vertical Merger Guidelines have not been revised since 1984. Those Guidelines are now woefully out of date. They do not reflect current economic thinking about vertical mergers. Nor do they reflect current agency practice. Nor do they reflect the analytic approach taken in the 2010 Horizontal Merger Guidelines. As a result, practitioners and firms lack the benefits of up-to-date guidance from the U.S. enforcement agencies

Polarization of nuclear spins by a cold nanoscale resonator

A cold nanoscale resonator coupled to a system of nuclear spins can induce spin relaxation. In the low-temperature limit where spin-lattice interactions are “frozen out,” spontaneous emission by nuclear spins into a resonant mechanical mode can become the dominant mechanism for cooling the spins to thermal equilibrium with their environment. We provide a theoretical framework for the study of resonator-induced cooling of nuclear spins in this low-temperature regime. Relaxation equations are derived from first principles, in the limit where energy donated by the spins to the resonator is quickly dissipated into the cold bath that damps it. A physical interpretation of the processes contributing to spin polarization is given. For a system of spins that have identical couplings to the resonator, the interaction Hamiltonian conserves spin angular momentum, and the resonator cannot relax the spins to thermal equilibrium unless this symmetry is broken by the spin Hamiltonian. The mechanism by which such a spin system becomes “trapped” away from thermal equilibrium can be visualized using a semiclassical model, which shows how an indirect spin-spin interaction arises from the coupling of multiple spins to one resonator. The internal spin Hamiltonian can affect the polarization process in two ways: (1) By modifying the structure of the spin-spin correlations in the energy eigenstates, and (2) by splitting the degeneracy within a manifold of energy eigenstates, so that zero-frequency off-diagonal terms in the density matrix are converted to oscillating coherences. Shifting the frequencies of these coherences sufficiently far from zero suppresses the development of resonator-induced correlations within the manifold during polarization from a totally disordered state. Modification of the spin-spin correlations by means of either mechanism affects the strength of the fluctuating spin dipole that drives the resonator. In the case where product states can be chosen as energy eigenstates, spontaneous emission from eigenstate populations into the resonant mode can be interpreted as independent emission by individual spins, and the spins relax exponentially to thermal equilibrium if the development of resonator-induced correlations is suppressed. When the spin Hamiltonian includes a significant contribution from the homonuclear dipolar coupling, the energy eigenstates entail a correlation specific to the coupling network. Simulations of dipole-dipole coupled systems of up to five spins suggest that these systems contain weakly emitting eigenstates that can trap a fraction of the population for time periods ≫100/R_0, where R_0 is the rate constant for resonator-enhanced spontaneous emission by a single spin 1/2. Much of the polarization, however, relaxes with rates comparable to R_0. A distribution of characteristic high-field chemical shifts tends to increase the relaxation rates of weakly emitting states, enabling transitions to states that can quickly relax to thermal equilibrium. The theoretical framework presented in this paper is illustrated with discussions of spin polarization in the contexts of force-detected nuclear-magnetic-resonance spectroscopy and magnetic-resonance force microscopy

Competitive Effects of Partial Ownership: Financial Interest and Corporate Control

In this article, we set up an economic framework for analyzing the competitive effects of partial ownership interests. We have three main goals. First, we conceptually derive and explain the competitive effects of partial ownership, explaining its key elements and drawing analogies to the key ideas behind the analysis of horizontal mergers. Second, we present a general framework for evaluating the competitive effects of partial ownership that is analogous to, but at the same time recognizes key differences in the standard analysis for evaluating horizontal mergers. Third, we examine several methods of quantifying these competitive effects

Assessment of Effectiveness of Buffer Zones in Removing Impurities in Runoff from Areas Treated with Poultry Litter. Part II: Source Areas to Buffer Areas Ratio Effects

Vegetative filter strips (VFS) are known to reduce runoff losses of nutrients. solids. and other materials from land areas treated with fertilizers . Although VFS effectiveness is known to depend partially on the relative lengths of filter and pollutant source areas. there is little experimental evidence available to quantify this dependence. This is particularly the case when VFS are implemented down-slope of pasture areas treated with animal manures such as poultry litter. This study assessed the influences of pollutant source area (treated with poultry litter) and VFS lengths on VFS removal of total Kjeldahl nitrogen (TKN). ammonia nitrogen (NH3 -N ). nitrate nitrogen (N03-N). ortho-phosphorus (P04-P). total phosphorus (TP). total organic carbon (TOC). total suspended solids (TSS). and fecal coliform (FC) fromincoming runoff for a silt loam soil with fescue cover. Litter-treated lengths of 6.1. 12.2. and 18.3 m with corresponding VFS lengths of up to 18.3 m. 12.2 m. and 6.1 m. respectively, were examined. Runoff was produced from simulated rainfall applied at 50 mm/h for 1 h of runoff. Concentrations of the parameters analyzed were unaffected by litter treated length but demonstrated a first-order decrease with increasing VFS length except in the cases of TSS and FC. Mass transport of TKN. NH3-N. P04-P. and TP increased with increasing litter-treated length (due to increased runoff) and decreased (approximately first-order) with increasing VFS length. Effectiveness of the VFS in terms of TKN. NH3-N. P04 -P. and TP removal from runoff ranged from 6.5 to 96.3% depending on the particular parameter. litter-treated length. and VFS length. The data collected during this study can be helpful in developing and testing simulation models of VFS performance and can thus aid in design of VFS for pasture areas treated with poultry litter

Lysine Biosynthesis in Bacteria: A Metallodesuccinylase as a Potential Antimicrobial Target

In this review, we summarize the recent literature on dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) enzymes, with an emphasis on structure–function studies that provide insight into the catalytic mechanism. Crystallographic data have also provided insight into residues that might be involved in substrate and hence inhibitor recognition and binding. These data have led to the design and synthesis of several new DapE inhibitors, which are described along with what is known about how inhibitors interact with the active site of DapE enzymes, including the efficacy of a moderately strong DapE inhibitor