A discrete choice model of dividend reinvestment plans: classification and prediction

We study 852 companies with dividend reinvestment plans in 1999 matched by total assets to 852 companies without such plans. We use discrete choice methods to predict the classification of these companies. We interpret the misclassified companies as being likely to switch their plan status. That is, if a firm's financial data suggest that a company should have had a dividend reinvestment plan in 1999 but did not, then we expect that it would be more likely to institute a plan than the other companies in the sample. Conversely, if it did have a plan but the financial data suggest that it should not, then we expect that the company would be more likely to drop the plan. We use data from 2004 to explore this conjecture and find evidence supporting it. Our model is an economically and statistically reliable predictor of changes in plan status. We also identify which variables have the most influence on a company's decision whether or not to offer a plan.

Population genomic inference of ecology, conservation, evolution, and demographic history of Atlantic seahorses and pipefishes (Syngnathidae)

In the Atlantic Ocean powerful directional ocean currents can play a significant role in the formation and persistence of marine species. Syngnathidae fishes have a sparse fossil record, high morphological plasticity, and many of these species are difficult to observe in the wild, therefore they frequently lack life history information and the status of regional lineages and species designations are often obscure. In this dissertation I explore the ecology, evolution, and conservation of primarily Atlantic seahorses (Hippocampus) and pipefish (Syngnathus) in four core chapters, using differing genetic datasets ranging from mitochondrial DNA to genome-wide RAD sequences. Most Synganthids have the potential to disperse passively by rafting on floating vegetation, and are direct developers, which is thought to limit their active mobility, yet many species have widespread distributions. The majority of genetic research on Syngnathids fishes has focused on Indo-Pacific species, however the Atlantic Ocean is home to dozens of species of pipefishes from nine genera and roughly 1/5th of the world\u27s seahorses species. In Chapter 1, I use six loci to infer the species tree for all Atlantic seahorses and infer the demographic history and evolution of the Hippocampus erectus complex. The results of this study support the establishment of an ancestral population of the H. erectus complex in the Americas, followed by the Amazon River outflow splitting it into Caribbean/North American H. erectus and South American H. patagonicus at a time of increased sedimentation and outflow. Following this split, colonization occurred across the Atlantic via the Gulf Stream currents with subsequent trans-Atlantic isolation. Based on the results of Chapter 1, the species H. erectus exhibited a panmictic genetic structure from Latin America to temperate New York waters. However, inhabitants of the temperate region are considered by some ecologists to be tropical vagrants that only arrive during warm seasons from the southern provinces and perish as temperatures decline. Contrary to the findings of Chapter 1, in Chapter 2, I use thousands of RADseq loci and show strong support that temperate inhabitants are genetically diverged from southern populations and are composed of an isolated and persistent ancestral gene pool. The aim of Chapter 3 is to investigate how major current forces as well as climatic and geographic processes have shaped the evolutionary and demographic history of western Atlantic seahorses (Hippocampus) and pipefishes (Syngnathus). This Chapter takes a comparative approach across five codistributed species (two seahorses and three pipefishes). Genomic patterns of subpopulation divergence and post-divergence gene flow may be shared amongst fish species with similar life history traits, however ecological differences (i.e., macroclimatic tolerance and rafting propensity) may impact the rates of gene exchange and/or isolation times between subpopulations. The result of this study show how directional ocean currents and the life history trait of rafting propensity impacts population divergence and connectivity, and predicts gene flow directionality and magnitude in four out of five of the focal taxa. Lastly in Chapter 4, I use a molecular forensics approach to track the U.S. dried seahorse trade. Due to global exploitation, the genus Hippocampus are the only fish to have all species listed under the Convention of International trade of endangered species (CITES). Millions of individuals are traded each year for the use in traditional Chinese medicine as well as for souvenirs and crafts. Using DNA barcoding, while mentoring high school and undergraduate students, we identified and compared specimens collected from two primary U.S. dried seahorse end-markets: 1) traditional Chinese medicine and, 2) Internet and coastal souvenir retailers. The results of this study found a significant contrast in both the species composition and size of individuals being sold between each market

Is there discrimination in mortgage pricing? the case of overages

We conduct an empirical investigation to explain observed differentials in mortgage overage pricing. Our analysis makes several contributions. First, we study an area of mortgage pricing that is little understood by consumers and has received little scrutiny in the literature. Second, we consider the impact of the market power of individual loan officers on overages paid by borrowers, particularly minorities. Third, we include a number of borrower and lender characteristics not available in previous analysis. ; Importantly, we introduce a new direct measure of the market power of individual loan officers. We also incorporate the interactive effects of loan officer market power and the race of the borrower in determining the rate of the mortgage loan. Through the use of these new variables and employing proprietary data from different branches of a nationwide mortgage lending institution, we conclude that the market power of the lender and the bargaining or negotiating ability of the borrower are important determinants of overages. We find that overages paid by minorities who purchase homes are larger than those paid by whites. Our evidence suggests that this is due to differences in the pools of borrowers rather than to racial discrimination. Indeed, tests show that the pool of refinancings is more homogeneous across races than the pool for purchases, and we find no differences by race for refinancings. We conclude that a more effective way to eliminate racial differences in overages is to pursue policies designed to increase the ability of minorities to bargain more effectively rather than to enact additional antidiscrimination laws.Discrimination in mortgage loans ; Mortgages

Primordial Black Holes, Hawking Radiation and the Early Universe

The 511 keV gamma emission from the galactic core may originate from a high concentration ($\sim 10^{22}$) of primordial black holes (PBHs) in the core each of whose Hawking radiation includes $\sim 10^{21}$ positrons per second. The PBHs we consider are taken as near the lightest with longevity greater than the age of the universe (mass $\sim 10^{12}$ kg; Schwarzschild radius $\sim 1$ fm). These PBHs contribute only a small fraction of cold dark matter, $\Omega_{PBH} \sim 10^{-8}$. This speculative hypothesis, if confirmed implies the simultaneous discovery of Hawking radiation and an early universe phase transition.Comment: 4 Page

Everything in Its Place

In this issue of Immunity, Griffith et al. (2009) define the thymic midcortex as a functionally inert zone between subcapsular and cortico-medullary regions, and Ehrlich et al. (2009) infer that structural features of the cortex and medulla regulate migration of thymocytes

Computational Fluid Dynamics: Hemodynamic Changes in Abdominal Aortic Aneurysm After Stent-Graft Implantation

The aim of this study was to demonstrate quantitatively and qualitatively the hemodynamic changes in abdominal aortic aneurysms (AAA) after stent-graft placement based on multidetector CT angiography (MDCT-A) datasets using the possibilities of computational fluid dynamics (CFD). Eleven patients with AAA and one patient with left-side common iliac aneurysm undergoing MDCT-A before and after stent-graft implantation were included. Based on the CT datasets, three-dimensional grid-based models of AAA were built. The minimal size of tetrahedrons was determined for grid-independence simulation. The CFD program was validated by comparing the calculated flow with an experimentally generated flow in an identical, anatomically correct silicon model of an AAA. Based on the results, pulsatile flow was simulated. A laminar, incompressible flow-based inlet condition, zero traction-force outlet boundary, and a no-slip wall boundary condition was applied. The measured flow volume and visualized flow pattern, wall pressure, and wall shear stress before and after stent-graft implantation were compared. The experimentally and numerically generated streamlines are highly congruent. After stenting, the simulation shows a reduction of wall pressure and wall shear stress and a more equal flow through both external iliac arteries after stenting. The postimplantation flow pattern is characterized by a reduction of turbulences. New areas of high pressure and shear stress appear at the stent bifurcation and docking area. CFD is a versatile and noninvasive tool to demonstrate changes of flow rate and flow pattern caused by stent-graft implantation. The desired effect and possible complications of a stent-graft implantation can be visualized. CFD is a highly promising technique and improves our understanding of the local structural and fluid dynamic conditions for abdominal aortic stent placemen

The Further Education Maturity Model: Development and Implementation of a Maturity Model for the Selection of Further Education Offerings in the Field of IT Management and IT Consulting

The permanently changing information and communication technology (IT) makes it inevitable for IT professionals to keep up-to-date. However, the market for further education presents itself as being diversified and opaque at the same time. Especially for young professionals, the selection of the “right” training offering is difficult. This entails the necessity to develop methods and models to create the further education market in a more comprehensible and transparent way. This article describes the development of the Further Education Maturity Model (FEMM). It enables users to assign IT training offerings to certain maturity levels and consequently to make decisions about the quality of the further education offering. A proven procedure is used to develop the FEMM, implement it into an online tool, and evaluate it. Results show the appropriateness of the proposed model

A discrete choice model of dividend reinvestment plans: Classification and prediction

We study 852 companies with dividend reinvestment plans in 1999 matched by total assets to 852 companies without such plans. We use discrete choice methods to predict the classification of these companies. We interpret the misclassified companies as being likely to switch their plan status. That is, if a firm's financial data suggest that a company should have had a dividend reinvestment plan in 1999 but did not, then we expect that it would be more likely to institute a plan than the other companies in the sample. Conversely, if it did have a plan but the financial data suggest that it should not, then we expect that the company would be more likely to drop the plan. We use data from 2004 to explore this conjecture and find evidence supporting it. Our model is an economically and statistically reliable predictor of changes in plan status. We also identify which variables have the most influence on a company's decision whether or not to offer a plan

An investigation on effectiveness of temperature treatment for fluorine-based reactive plasma jet machining of N-BK7®

In this study, a fluorine-based reactive plasma jet is investigated as a promising tool for ultraprecise surface machining of N-BK7®. Plasma-generated particles react with an N-BK7 surface to create volatile and nonvolatile compounds. The desorption of volatile compounds results in an etched surface, whereas nonvolatile compounds form a residual layer in the etched area, causing unpredictable effects on the etching rate. Surface temperature treatment is proposed to improve the machining procedure with respect to deterministic material removal, leading to predictable results. It is shown that, at an elevated surface temperature, the residual layer properties are modified in favor of improved etching performance. The etching behavior of N-BK7 is compared with fused silica to verify the optimality of the obtained results