Some intertemporal and informational aspects of economic theory

I present several theoretical models in which agents participate in environments where some relevant economic data is not known perfectly and decisions are taken within an intertemporal setting. In all the models I make extensive use of game theoretic concepts because agents are strategically interdependent. In other words in each model I describe, the action of one agent is known to affect at least one other agent and vice versa. I therefore commence with a description of the theoretical tools applied throughout. In particular, I focus on the refinements of the Nash equilibrium in games of incomplete or imperfect information. The first model I describe is one where a consumer is unable to discern the quality of a good at a particular store prior to consumption. I show that when a consumer locates a good match store the store will exercise price discrimination by increasing its price in the future. The model characterizes introductory offers. A number of extensions are considered, including the idea of interrelated prices. This is the theme of the next chapter where I show how price matching refunds can act as a price discriminatory mechanism if consumers differ over costs of acquiring information about prices. In the next chapter I present a model of multidimensional signalling, where refund promises or free trial periods when combined with the selling price can signal quality for certain. In the final chapter I analyse a bargain between a country and a foreign company and focus on the design of an incentive compatible tax schedule. The aim of the models is to provide new insights about economic relationships that feature intertemporal and informational aspects

The First Step Act: Filling the Gap in Missouri

Although the federal government’s First Step Act is a move in the right direction when it comes to addressing criminal justice in America, states bear the responsibility of doing their part. In this article, Christopher Doyle-Lohse addresses the gaps Missouri must fill to achieve criminal justice reform.https://scholarship.law.slu.edu/lawjournalonline/1004/thumbnail.jp

Catecholaminergic innervation of the cat spinal cord

The organization of catecholamine (CA)-containing nerve terminals in the cat spinal dorsal horn was examined in an immunocytochemical study employing antisera against tyrosine hydroxylase and dopamine-B-hydroxylase. Light microscopic analysis revealed that varicose axons were concentrated in laminae I, II & IV. Correlated ultrastructural analysis showed that these terminals usually formed single synapses with dendrites or somata, but not with other axon terminals. This suggests that descending catecholaminergic axons regulate sensory transmission through the dorsal horn via a postsynaptic action upon dorsal horn neurons.Using the retrograde tracer horseradish peroxidase to label particular groups of dorsal horn neurons, it was shown that the postsynaptic dorsal column (PSDC) pathway is a major projection target of CA-containing axons. Over 60% of these cells were found to have dopamine-Bhydroxylase immunostained varicosities closely apposed to their somata and/or proximal dendrites, and correlated electron microscopic analysis confirmed that many of these contacts were regions of synaptic association. In contrast, the cells of the spinocervical tract (SCT) did not receive a major innervation from these axons when viewed with the light microscope.The lateral cervical nucleus (LCN), the termination site of SCT cells, was found to possess a dense innervation from CA-containing axons. These fibres were 7 present throughout the nucleus and synapsed with dendrites and somata, including those of large cells in the lateral region, but not with other axon terminals. This suggests that catecholaminergic axons in the LCN regulate the activity of LCN neurons but not the terminals of SCT cells.It has been suggested that many catecholaminergic axons in the dorsal horn may contain neuropeptide Y (NPY), and an examination was made of NPY-immunoreactive axons to test this hypothesis. Light microscopy revealed a heavy concentration of NPY-positive profiles in laminae I-II but only low to moderate numbers in III-VI. Fine structural examination showed most of these profiles to be axon terminals but a few structures were observed which may have been NPY vesicle-containing dendrites. The postsynaptic targets of NPY terminals were mostly dendrites or somata, but many (27%) formed axo-axonic synaptic junctions. In laminae I-III, the postsynaptic axon terminals were sometimes the central boutons of glomeruli. These findings suggest that NPY axons regulate sensory transmission by a postsynaptic action upon dorsal horn neurons and a presynaptic action upon primary afferent terminals. NPY boutons often formed more than one synapse and some of these arrangements were confirmed to be triads. Clearly, NPY profiles are organized in a much more complex way than those containing CA, which suggests that co-1oca1ization between the two neurotransmitters in the spinal dorsal horn is, at best, limited

Union College Flying Dutchman Micro Team

SAE Aero Lift is an intercollegiate competition where mechanical, electrical engineering, and computer science students from Union College design and build a remote controlled and autonomous aircraft system to meet specified mission objectives and then compete with their design against engineering students from around the world. The objective of the Micro Class is to design a RC airplane that carries maximal payload with minimal vehicle weight. The plane must also packable into a 12 by 3.5 by 13.5 box, and be able to be assembled to loaded, flight ready, status in fewer than 2 minutes from unboxing. This year\u27s Micro Event team was led by junior students, and involved several sophomores and first year students as well. The Micro event team had intended to travel to Fort Worth, Texas for competition during the first week of April, 2020. Our presentation will consist of an overview of our design and build of the aircraft

Untying Knotted DNA with Elongational Flows

We present Brownian dynamics simulations of initially knotted double-stranded DNA molecules untying in elongational flows. We show that the motions of the knots are governed by a diffusion–convection equation by deriving scalings that collapse the simulation data. When being convected, all knots displace nonaffinely, and their rates of translation along the chain are topologically dictated. We discover that torus knots “corkscrew” when driven by flow, whereas nontorus knots do not. We show that a simple mechanism can explain a coupling between this rotation and the translation of a knot, explaining observed differences in knot translation rates. These types of knots are encountered in nanoscale manipulation of DNA, occur in biology at multiple length scales (DNA to umbilical cords), and are ubiquitous in daily life (e.g., hair). These results may have a broad impact on manipulations of such knots via flows, with applications to genomic sequencing and polymer processing.Singapore-MIT Alliance for Research and Technology (SMART)National Science Foundation (U.S.) (Grant CBET-1335938

Enantioselective synthesis and application to the allylic imidate rearrangement of amine-coordinated palladacycle catalysts of cobalt sandwich complexes

The reaction of (η5-(N,N-dimethylaminomethyl)cyclopentadien-yl)(η4-tetraphenylcyclobutadiene)cobalt with sodium tetrachloropalladate and (R)-N-acetylphenylalanine gave planar chiral palladacycle di-μ-chloridebis[(η5-(Sp)-2-(N,N-dimethylaminomethyl)cyclopentadienyl,1-C,3′-N)(η4-tetraphenylcyclobutadiene)cobalt]dipalladium [(Sp)-Me2-CAP-Cl] in 92 % ee and 64 % yield. Enantiopurity (>98 % ee) was achieved by purification of the monomeric (R)-proline adducts and conversion back to the chloride dimer. Treatment with AgOAc gave (Sp)-Me2-CAP-OAc which was applied to asymmetric transcyclopalladation (up to 78 % ee). The (R)-N-acetylphenylalanine mediated palladation methodology was applicable also to the corresponding N,N-diethyl (82 % ee, 39 % yield) and pyrrolidinyl (>98 % ee, 43 % yield) cobalt sandwich complexes. A combination of 5 mol % of the latter [(Sp)-Pyrr-CAP-Cl] and AgNO3 (3.8 equiv) is a catalyst for the allylic imidate rearrangement of an (E)-N-aryltrifluoroacetimidate (up to 83 % ee), and this catalyst system is also applicable to the rearrangement of a range of (E)-trichloroacetimidates (up to 99 % ee). This asymmetric efficiency combined with the simplicity of catalyst synthesis provides accessible solutions to the generation of non-racemic allylic amine derivatives

Metastable Tight Knots in Semiflexible Chains

Knotted structures can spontaneously occur in polymers such as DNA and proteins, and the formation of knots affects biological functions, mechanical strength and rheological properties. In this work, we calculate the equilibrium size distribution of trefoil knots in linear DNA using off-lattice simulations. We observe metastable knots on DNA, as predicted by Grosberg and Rabin. Furthermore, we extend their theory to incorporate the finite width of chains and show an agreement between our simulations and the modified theory for real chains. Our results suggest localized knots spontaneously occur in long DNA and the contour length in the knot ranges from 600 to 1800 nm.National Science Foundation (U.S.) (NSF Grant No. 1335938)Singapore. National Research FoundationSingapore-MIT Alliance for Research and Technology (SMART

Origin of Metastable Knots in Single Flexible Chains

Recent theoretical progress has explained the physics of knotting of semiflexible polymers, yet knotting of flexible polymers is relatively unexplored. We herein develop a new theory for the size distribution of knots on a flexible polymer and the existence of metastable knots. We show the free energy of a flexible molecule in a tube can be mapped to quantitatively reproduce the free energy distribution of a knot on a flexible chain. The size distribution of knots on flexible chains is expected to be universal and might be observed at a macroscopic scale, such as a string of hard balls.Singapore-MIT Alliance for Research and TechnologyNational Science Foundation (U.S.) (Grant 1335938

Translocation dynamics of knotted polymers under a constant or periodic external field

We perform Brownian dynamics simulations to examine how knots alter the dynamics of polymers moving through nanopores under an external field. In the first part of this paper, we study the situation when the field is constant. Here, knots halt translocation above a critical force with jamming occurring at smaller forces for twist topologies compared to non-twist topologies. Slightly below the jamming transition, the polymer's transit times exhibit large fluctuations. This phenomenon is an example of the knot's molecular individualism since the conformation of the knot plays a large role in the chain's subsequent dynamics. In the second part of the paper, we study the motion of the chain when one cycles the field on and off. If the off time is comparable to the knot's relaxation time, one can adjust the swelling of the knot at the pore and hence design strategies to ratchet the polymer in a controllable fashion. We examine how the off time affects the ratcheting dynamics. We also examine how this strategy alters the fluctuations in the polymer's transit time. We find that cycling the force field can reduce fluctuations near the knot's jamming transition, but can enhance the fluctuations at very high forces since knots get trapped in metastable states during the relaxation process. The latter effect appears to be more prominent for non-torus topologies than torus ones. We conclude by discussing the feasibility of this approach to control polymer motion in biotechnology applications such as sequencing.Singapore-MIT Alliance for Research and Technology (SMART)National Science Foundation (U.S.) (Grant CBET-1335938

Private labels, buyer power and competition policy.

Private labels - products controlled by retailers instead of suppliers - are an increasingly important market segment for firms worldwide. They, and the closely related concept of buyer power, have become a topic of major interest and concern for competition authorities around the world. Firstly we explain the growth of private labels as retailers taking over the role of quality certification from suppliers. Consumers, wary about product quality, seek reassurance in a brand they can trust, and this role of certifying quality is moving downstream from manufacturers to distributors. We explain this by modelling the negotiations that takes place within the production chain, and demonstrate that by establishing a private label a retailer improves his sourcing options and hence his bargaining position, and increases his profits. Next we examine how the presence of private labels in a market affects non-price competition between firms, in particular incentives to invest, an area which the literature has neglected in favour of a simple focus on prices. We demonstrate that, while under certain conditions the conventional wisdom the private labels can reduce suppliers' investment incentives can be correct, the outcome is more complex than traditionally thought. Private labels can also potentially spur suppliers to increase investment, which ultimately benefits consumers. Thirdly we examine the implications of private labels for an argument of great significance in competition policy: the countervailing buyer power merger defence. We discuss several major cases where this idea - that buyer power downstream can prevent wholesale prices rising following an upstream merger - has been crucial in determining the outcome. We present a formal model of this argument - to our knowledge the first and demonstrate some limitations to the validity of this defence, but also highlight circumstances where it may be unexpectedly applicable