1,629 research outputs found

    Reputation and competition: evidence from the credit rating industry

    Get PDF
    The credit rating industry has historically been dominated by just two agencies, Moody’s and S&P, leading to longstanding legislative and regulatory calls for increased competition. The material entry of a third rating agency (Fitch) to the competitive landscape offers a unique experiment to empirically examine how in fact increased competition affects the credit ratings market. Increased competition from Fitch coincides with lower quality ratings from the incumbents: rating levels went up, the correlation between ratings and market-implied yields fell, and the ability of ratings to predict default deteriorated. We offer several possible explanations for these findings that are linked to existing theories.

    Genetic Population Structure of the Plains Spadefoot Toad (Scaphiopus (Spea) bombifrons) On the Northern Plains

    Get PDF
    In this study, I examined genetic population structure in spadefoot toads (Scaphiopus bombifrons) living in western North Dakota. Spadefoct toads have a very unique life history among amphibians. They are generally limited to being active only during nocturnal wet periods. Because of this, and other factors such as philopatry, it is expected that migration and dispersal rates should be relatively low. I hypothesize that this low rate of movement, along with fairly short dispersal distances when individuals do move, should lead to the structuring of genetic variation at relatively fine scales. Five microsatellite loci were used to examine population structure at 9 temporary breeding ponds. Distances between ponds ranged from \u3c500m to 14 km. The data showed evidence of significant genetic variation occurring between ponds even at the shortest interpond distances. A strong heterozygote deficiency was observed for 4 out of the 5 microsatellite loci, suggesting that inbreeding may be occurring in the system. A pattern of isolation by distance was also observed but was not statistically significant. High Fst and Rst values at short interpond distances deviated from the pattern predicted by isolation by distance, and may be driven by stochastic processes such as drift, bottlenecks, and founder events

    Attorney-Client Privilege Versus the PTO\u27s Duty of Candor: Resolving the Clash in Simultaneous Patent Representations

    Get PDF
    Patent attorneys play dual roles: they are simultaneously attorneys and patent practitioners. Their dual role causes problems when the rules that govern one role conflict with the rules that govern the other. One such problem is illustrated in Molins PLC v. Textron, Inc., where a patent attorney simultaneously representing two clients was caught between the Patent & Trademark Office\u27s duty of candor and the attorney\u27s duty of confidentiality imposed by the rules of professional responsibility. The Molins decision presents a problem because it creates uncertainty about whether confidentiality can be maintained by using the attorney-client privilege to defeat the duty of candor. This Comment examines the contours of the duty of candor and the attorney-client privilege, concludes that in some situations there is a conflict between the two, and argues that, when a conflict does exist policy considerations dictate that the attorney-client privilege override the duty of candor

    The yield strength and flow stress anomaly in B2 yttrium copper

    Get PDF
    The apparent yield strength anomaly in the B2 YCu intermetallic compound is shown not to be a yield point anomaly at all, but rather a phenomenon resulting from the work hardening behavior in YCu, which was found to rise with rising temperature and to drop with increases in strain rate. This effect is shown to occur over temperature ranges where YCu has negative strain rate sensitivity, result in dynamic strain ageing behavior, and the effect is shown to be irreversible when the testing temperature is changed. Neutron diffraction experiments utilizing SMARTS and HIPPO show the evolution of texture and the change in plastic deformation behavior as the temperature is raised

    How did increased competition affect credit ratings?

    Get PDF
    The credit rating industry has historically been dominated by just two agencies, Moody’s and S&P, leading to longstanding legislative and regulatory calls for increased competition. The material entry of a third rating agency (Fitch) to the competitive landscape offers a unique experiment to empirically examine how in fact increased competition affects the credit ratings market. Increased competition from Fitch coincides with lower quality ratings from the incumbents: rating levels went up, the correlation between ratings and market-implied yields fell, and the ability of ratings to predict default deteriorated. We offer several possible explanations for these findings that are linked to existing theories.

    Hybrid 3-D Euler/Navier-Stokes calculations of transonic vortex flows over the NTF delta wing

    Get PDF
    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989.Includes bibliographical references (leaves 104-106).by Todd M. Becker.M.S

    High magnitude and rapid incision from river capture: Rhine River, Switzerland

    Full text link
    Landscape evolution is controlled by the development and organization of drainage basins. As a landscape evolves, drainage reorganization events can occur via river capture or piracy, whereby one river basin grows at the expense of another. The river downstream of a capture location will generate a transient topographic response as the added water discharge increases sediment transport and erosion efficiency. This erosional response will propagate upstream through both the captured and original river basins. Here we focus on quantifying the impact of drainage reorganization along the Rhine/Aare River system (~45,000 km 2 ) during the late Pliocene/early Pleistocene, where gravel remnants indicate total incision of ~650 m during the last ~4.2 Myr in the region of the recent Aare‐Rhine confluence. We develop a numerical model of drainage capture to quantify the range of possible magnitudes of erosion and the transient river response resulting from the reorganization of the Rhine River. The model accounts for both fluvial incision and sediment transport. Our model estimates 400–800 m of river elevation change (lowering profiles) during the last ~4 Myr due to river capture events, providing an important component to the recent exhumation budget of the Swiss Alpine Foreland. The model indicates a rapid response to capture events (re‐equilibration timescale of ~1 Myr). The predicted incision magnitudes are consistent with incision measured from the elevation of Pliocene and early Pleistocene river gravels, suggesting that across northern Switzerland, a significant amount of incision can be explained by drainage reorganization. Key Points Drainage capture has caused significant erosion along the Rhine River The transient erosional wave propagates quickly through the landscape The incision is a significant fraction of Plio‐Pleistocene erosion in the regionPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99064/1/jgrf20056.pd

    Lithologic Effects on Landscape Response to Base Level Changes: A Modeling Study in the Context of the Eastern Jura Mountains, Switzerland

    Full text link
    Landscape evolution is a product of the forces that drive geomorphic processes (e.g., tectonics and climate) and the resistance to those processes. The underlying lithology and structural setting in many landscapes set the resistance to erosion. This study uses a modified version of the Channel‐Hillslope Integrated Landscape Development (CHILD) landscape evolution model to determine the effect of a spatially and temporally changing erodibility in a terrain with a complex base level history. Specifically, our focus is to quantify how the effects of variable lithology influence transient base level signals. We set up a series of numerical landscape evolution models with increasing levels of complexity based on the lithologic variability and base level history of the Jura Mountains of northern Switzerland. The models are consistent with lithology (and therewith erodibility) playing an important role in the transient evolution of the landscape. The results show that the erosion rate history at a location depends on the rock uplift and base level history, the range of erodibilities of the different lithologies, and the history of the surface geology downstream from the analyzed location. Near the model boundary, the history of erosion is dominated by the base level history. The transient wave of incision, however, is quite variable in the different model runs and depends on the geometric structure of lithology used. It is thus important to constrain the spatiotemporal erodibility patterns downstream of any given point of interest to understand the evolution of a landscape subject to variable base level in a quantitative framework.Key PointsA landscape evolution model is used to show how topographic history is influenced by regional geologyExhumation of different lithologies modulates the transient response to base level changes over millions of yearsSignificantly different erosion and topographic histories result depending on the stratigraphic architecture, even over a small range in erodibilityPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141336/1/jgrf20766_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141336/2/jgrf20766.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141336/3/jgrf20766-sup-0001-Data_S1.pd

    “Dermal Dendritic Cells” Comprise Two Distinct Populations: CD1+ Dendritic Cells and CD209+ Macrophages

    Get PDF
    A key cell type of the resident skin immune system is the dendritic cell (DC), which in normal skin is located in two distinct microanatomical compartments: Langerhans cells (LCs), mainly in the epidermis, and dermal DCs (DDCs), in the dermis. Here, the lineage of DDCs was investigated using monoclonal antibodies and immunohistology. We provide evidence that “DDC” comprise at least two major phenotypic populations of dendritic-appearing cells, immature DC expressing CD1, CD11c and CD208; and macrophages expressing CD209, CD206, CD163, and CD68. These data suggest that dermal dendritic-appearing macrophages comprise a novel part of the innate immune response in the resident skin immune system

    Interleukin 15 Is Required for Proliferative Renewal of Virus-specific Memory CD8 T Cells

    Get PDF
    The generation and efficient maintenance of antigen-specific memory T cells is essential for long-lasting immunological protection. In this study, we examined the role of interleukin (IL)-15 in the generation and maintenance of virus-specific memory CD8 T cells using mice deficient in either IL-15 or the IL-15 receptor α chain. Both cytokine- and receptor-deficient mice made potent primary CD8 T cell responses to infection with lymphocytic choriomeningitis virus (LCMV), effectively cleared the virus and generated a pool of antigen-specific memory CD8 T cells that were phenotypically and functionally similar to memory CD8 T cells present in IL-15+/+ mice. However, longitudinal analysis revealed a slow attrition of virus-specific memory CD8 T cells in the absence of IL-15 signals.This loss of CD8 T cells was due to a severe defect in the proliferative renewal of antigen-specific memory CD8 T cells in IL-15−/− mice. Taken together, these results show that IL-15 is not essential for the generation of memory CD8 T cells, but is required for homeostatic proliferation to maintain populations of memory cells over long periods of time
    • 

    corecore