We develop a new identification strategy to evaluate the impact of the geographic expansion of a bank holding company (BHC) across US metropolitan statistical areas (MSAs) on BHC risk. For the ...average BHC, the instrumental variable results suggest that geographic expansion materially reduces risk. Geographic diversification does not affect loan quality. The results are consistent with arguments that geographic expansion lowers risk by reducing exposure to idiosyncratic local risks and inconsistent with arguments that expansion, on net, increases risk by reducing the ability of BHCs to monitor loans and manage risks.
This paper assesses the impact of the geographic diversification of bank holding company (BHC) assets across the United States on their market valuations. Using two new identification strategies ...based on the dynamic process of interstate bank deregulation, we find that exogenous increases in geographic diversity reduced BHC valuations. We also find that the geographic diversification of BHC assets increased insider lending and reduced loan quality. Taken together, these findings are consistent with theories predicting that geographic diversity intensifies agency problems.
We demonstrate coherent control over the photoelectron circular dichroism in randomly oriented chiral molecules, based on quantum interference between multiple photoionization pathways. To ...significantly enhance the chiral signature, we use a finite manifold of indistinguishable (1+1^{'}) resonantly enhanced multiphoton ionization pathways interfering at a common photoelectron energy but probing different intermediate states. We show that this coherent control mechanism maximizes the number of molecular states that constructively contribute to the dichroism at an optimal photoelectron energy and thus outperforms other schemes, including interference between opposite-parity pathways driven by bichromatic (ω, 2ω) fields as well as sequential pump-probe ionization.
Particle stimulated nucleation was incorporated into a cellular automata dynamic recrystallization model to determine the effect of PSN on DRX kinetics. CA DRX kinetics with PSN resulted in larger ...Avrami exponents than typically found with DRX. The Avrami exponents were similar to those of a Waspaloy ingot undergoing PSN.
► Denver, Colorado is expanding its rail transit system. ► Denver has experienced a large amount of transit-oriented development (TOD). ► Downtown Denver has experienced the majority of the TOD. ► ...TOD locations are denser than non-TOD locations in Denver. ► Regional TOD in Denver varies by corridor and station type.
As large cities seek to expand their transit systems to accommodate increasing travel demand, provide alternatives to growing road traffic congestion, and improve accessibility, more research attention has been focused on the land use effects of transit, most notably in the form of transit-oriented development (TOD). Many cities in the USA are starting or expanding rail transit systems with objectives that include more focused economic development near transit stations and along transit corridors. Denver, Colorado is one of the cities that is aggressively expanding its rail transit system and encouraging high-density, mixed-use development in the station areas. This study analyzes TOD data from the Denver Regional Transportation District and the Denver Regional Council of Governments for 0.5-mile areas around current and proposed rail transit stations. Early evidence indicates that the scope of transit-oriented development in Denver is considerable, resulting in nearly 18,000 residential dwelling units, 5.3 million square feet of retail space, 5.4 million square feet of office space, and 6.2 million square feet of medical space within one-half mile of existing or planned transit stations from 1997 to 2010. As one of the critical elements of the regional land use and transportation plan, the rail transit system and the emphasis on transit-oriented development is contributing to an increase in the average density of the Denver urbanized area.
Effective ecological restoration requires empirical assessment to determine outcomes of projects, but conclusions regarding the effects of restoration treatments on the whole ecosystem remain rare. ...Control of invasive shrubs and trees in the genus Tamarix and associated riparian restoration in the American Southwest has been of interest to scientists and resource managers for decades; dozens of studies have reported highly variable outcomes of Tamarix control efforts, as measured by a range of response variables, temporal and spatial scales and monitoring strategies. We conducted a literature search and review, meta-analysis and vote count (comparison of numerical outcomes lacking reported variances and/or sample sizes) on published papers that quantitatively measured a variety of responses to control of Tamarix . From 96 publications obtained through a global search on terms related to Tamarix control, we found 52 publications suitable for a meta-analysis (n = 777 comparisons) and 63 publications suitable for two vote counts (n = 1,460 comparisons total; 622 comparisons reported as statistically significant) of response to Tamarix control. We estimated responses to control by treatment type (e.g. cut-stump treatment, burning, biocontrol) and ecosystem component (e.g. vegetation, fauna, fluvial processes). Finally, we compared results of the various synthesis methods to determine whether the increasingly stringent requirements for inclusion led to biased outcomes. Vegetation metrics, especially measures of Tamarix response, were the most commonly assessed. Ecosystem components other than vegetation, such as fauna, soils and hydrogeomorphic dynamics, were under-represented. The meta-analysis showed significantly positive responses by vegetation overall to biocontrol, herbicide and cut-stump treatments. This was primarily due to reduction of Tamarix cover; impacts on replacement vegetation were highly variable. We found concordance amongst our varied synthesis approaches, indicating that increased granularity from stricter quantitative techniques does not come at the cost of a biased sample. Overall, our results indicate that common control methods are generally effective for reducing Tamarix , but the indirect effects on other aspects of the ecosystem are variable and remain understudied. Given that this is a relatively well-studied invasive plant species, our results also illustrate the limitations of not only individual studies, but also of reviews for measuring the impact of invasive species control. We call on researchers to investigate the less commonly studied responses to Tamarix control and riparian restoration including the effects on fauna, soil and hydrogeomorphic characteristics.
tervening pro
, or inteins, are mobile genetic elements that are translated within host polypeptides and removed at the protein level by splicing. In protein splicing, a self-mediated reaction ...removes the intein, leaving a peptide bond in place. While protein splicing can proceed in the absence of external cofactors, several examples of conditional protein splicing (CPS) have emerged. In CPS, the rate and accuracy of splicing are highly dependent on environmental conditions. Because the activity of the intein-containing host protein is compromised prior to splicing and inteins are highly abundant in the microbial world, CPS represents an emerging form of posttranslational regulation that is potentially widespread in microbes. Reactive chlorine species (RCS) are highly potent oxidants encountered by bacteria in a variety of natural environments, including within cells of the mammalian innate immune system. Here, we demonstrate that two naturally occurring RCS, namely, hypochlorous acid (the active compound in bleach) and
-chlorotaurine, can reversibly block splicing of DnaB inteins from Mycobacterium leprae and Mycobacterium smegmatis
. Further, using a reporter that monitors DnaB intein activity within M. smegmatis, we show that DnaB protein splicing is inhibited by RCS in the native host. DnaB, an essential replicative helicase, is the most common intein-housing protein in bacteria. These results add to the growing list of environmental conditions that are relevant to the survival of the intein-containing host and influence protein splicing, as well as suggesting a novel mycobacterial response to RCS. We propose a model in which DnaB splicing, and therefore replication, is paused when these mycobacteria encounter RCS.
Inteins are both widespread and abundant in microbes, including within several bacterial and fungal pathogens. Inteins are domains translated within host proteins and removed at the protein level by splicing. Traditionally considered molecular parasites, some inteins have emerged in recent years as adaptive posttranslational regulatory elements. Several studies have demonstrated CPS, in which the rate and accuracy of protein splicing, and thus host protein functions, are responsive to environmental conditions relevant to the intein-containing organism. In this work, we demonstrate that two naturally occurring RCS, including the active compound in household bleach, reversibly inhibit protein splicing of Mycobacterium leprae and Mycobacterium smegmatis DnaB inteins. In addition to describing a new physiologically relevant condition that can temporarily inhibit protein splicing, this study suggests a novel stress response in Mycobacterium, a bacterial genus of tremendous importance to humans.