209 research outputs found

    Making Self-Help Infrastructure Finance Regional: Promises and Perils of a Multi-Jurisdictional Approach.

    Full text link
    In recent decades, Congress has failed to raise transportation revenues to keep pace with inflation and growth in traffic volume. Insufficient funding for transportation programs has induced many local governments to fund new road and transit infrastructure themselves, using ballot initiatives known as local option transportation taxes. While localized taxing decisions have become more politically expedient than raising federal and state motor fuel taxes, local funding comes with inherent drawbacks for developing regional transportation, which crosses into multiple taxing jurisdictions. This creates a potentially serious impediment to dealing with crucial problems like air quality, job access for the economically disadvantaged, and promotion of economic growth. In response, some regions have chosen to make local funding decisions using multi-jurisdictional, rather than local, taxes. These places have voted across an entire region, allowing them to develop comprehensive, systemic solutions to transportation problems. This study identifies barriers to the implementation of regional self-help strategies, and approaches that have worked in overcoming them. Using interviews and archival evidence, this study examines seven cases in Atlanta, the San Francisco Bay Area, Seattle, and Denver, focusing on how state authorizing legislation shaped each process. This study develops a typology of multi-jurisdictional transportation funding mechanisms and identifies appropriate state and local policy approaches for situations that vary according to features of the authorizing legislation. The political cost of developing a multi-jurisdictional option tax can be reduced by the existence of robust regional policy making institution, though these rarely exist in U.S. regions. The cost may also be lowered by permissive legislation. Such legislation can lift a major political obstacle to regional funding initiatives but can also make local collaboration more costly due to absence of legislation forcing rival jurisdictions to cooperate. Nevertheless, both possibilities are much less costly than the lack of any pre-approved authorizing legislation. This situation requires special legislation for each tax measure, which can result in elevated influence by state legislators in developing the transportation plan, and difficulty repeating the process.PHDUrban and Regional PlanningUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/135871/1/dpwein_1.pd

    16-08 Does Location Matter? Performance Analysis of the Affordable Housing Programs in Dallas-Fort Worth

    Get PDF
    On June 2015, the Texas Department of Housing and Community Affairs lost a case in the U.S. Supreme Court due to their failure to provide equitable affordable housing under the Low Income Housing Tax Credit (LIHTC) program. The U.S. Supreme Court decision has shaken the affordable housing definition by highlighting the importance of location in housing affordability. To best assist low-income families, what should ā€˜high-opportunity areasā€™ concretely provide? First and foremost is transportation affordability. Transportation is more than a sheer convenience for Americans. Looking solely at housing costs is a misleading measure of affordability and a disservice to low-income families. A recent study by the PI, found that, households in 44% of all Multifamily Section 8 properties in the nation, spend on average more than 15 percent of their income on transportation costs, making these properties effectively unaffordable. According to this methodology, more than 73% of Section 8 Multifamily properties in Dallas Fort Worth (DFW) are unaffordable. This study has received extensive media attention by The Dallas Morning News, CityLab and other media outlets. Yet there is little understanding on the affordability and effectiveness of other rental assistance programs such as Public Housing, LIHTC and the Housing Choice Voucher Program. There is also little understanding about the long term effects of location on low income households in terms of providing accessibility to opportunities and, as a result, affecting the chance of upward mobility. This study seeks to address these gaps by developing an innovative approach to evaluate the short-term and long-term affordability of all state and federal rental assistance programs in the Dallas-Fort Worth metropolitan area. We used disaggregated data at the property level and measured built environment variables around each property. We then estimated transportation costs for a typical household that qualifies under these programs using solid transportation costs modeling tailored for low-income households. This study sheds light on the relative merit of each program in ensuring affordability when factoring in transportation costs. Second, this research seeks to identify long term affordability and opportunities for upward mobility for all census blocks in the Dallas-Fort Worth metropolitan region. We produced a series of ā€œCatalyst Areasā€ maps. Catalyst Areas represent areas with adequate access (by modes other than driving) to major destinations such as educational facilities, healthy food, health care facilities, public transit, and job opportunities. This would help low-income households to not only spend less on transportation, but also, by providing access to opportunities, increase their chance of upward mobility. Finally, this study provides recommendations to further federal and state initiatives in coordinating housing and transportation and is designed to inform regional and local planners on location-efficient investments. This study also recommends that the priority in affordable housing investments for low-income households should be given to Catalyst Areas

    Interleukin-1Ī² induced vascular permeability is dependent on induction of endothelial Tissue Factor (TF) activity

    Get PDF
    IL-1Ī² is a pleotropic cytokine that may mediate increased procoagulant activity and permeability in endothelial tissue during inflammatory conditions. The procoagulant effects of IL-1Ī² are mediated through induction of tissue factor (TF) but its alterations on vascular permeability are not well characterized. We found that IL-1Ī² induced a rapid and dose-dependent increase in TF activity in human umbilical vein endothelial cells (ECs) under routine culture conditions. However, IL-1Ī² caused a rapid and marked increase in permeability across confluent EC monolayers using a two-compartment in vitro model only in the presence of factor VIII-deficient plasma that was completely abrogated by neutralizing anti-TF antibody pre-treatment. In vitro permeability was associated with loss of EC surface expression of VE-cadherin and contraction of F-actin cytoskeletal elements that resulted in EC intercellular gap formation. These data demonstrate that IL-1Ī² induces marked changes in permeability across activated endothelium via a TF dependent mechanism and suggest that modulation of TF activity may represent a strategy to treat various acute and chronic inflammatory conditions mediated by this cytokine

    Evolutionary dynamics of the most populated genotype on rugged fitness landscapes

    Full text link
    We consider an asexual population evolving on rugged fitness landscapes which are defined on the multi-dimensional genotypic space and have many local optima. We track the most populated genotype as it changes when the population jumps from a fitness peak to a better one during the process of adaptation. This is done using the dynamics of the shell model which is a simplified version of the quasispecies model for infinite populations and standard Wright-Fisher dynamics for large finite populations. We show that the population fraction of a genotype obtained within the quasispecies model and the shell model match for fit genotypes and at short times, but the dynamics of the two models are identical for questions related to the most populated genotype. We calculate exactly several properties of the jumps in infinite populations some of which were obtained numerically in previous works. We also present our preliminary simulation results for finite populations. In particular, we measure the jump distribution in time and find that it decays as tāˆ’2t^{-2} as in the quasispecies problem.Comment: Minor changes. To appear in Phys Rev

    Role of conservative mutations in protein multi-property adaptation

    Get PDF
    Protein physicochemical properties must undergo complex changes during evolution, as a response to modifications in the organism environment, the result of the proteins taking up new roles or because of the need to cope with the evolution of molecular interacting partners. Recent work has emphasized the role of stability and stabilityā€“function trade-offs in these protein adaptation processes. In the present study, on the other hand, we report that combinations of a few conservative, high-frequency-of-fixation mutations in the thioredoxin molecule lead to largely independent changes in both stability and the diversity of catalytic mechanisms, as revealed by single-molecule atomic force spectroscopy. Furthermore, the changes found are evolutionarily significant, as they combine typically hyperthermophilic stability enhancements with modulations in function that span the ranges defined by the quite different catalytic patterns of thioredoxins from bacterial and eukaryotic origin. These results suggest that evolutionary protein adaptation may use, in some cases at least, the potential of conservative mutations to originate a multiplicity of evolutionarily allowed mutational paths leading to a variety of protein modulation patterns. In addition the results support the feasibility of using evolutionary information to achieve protein multi-feature optimization, an important biotechnological goal

    Dbf4-dependent kinase (DDK)-mediated proteolysis of CENP-A prevents mislocalization of CENP-A in Saccharomyces cerevisiae

    Get PDF
    The evolutionarily conserved centromeric histone H3 variant (Cse4 in budding yeast, CENP-A in humans) is essential for faithful chromosome segregation. Mislocalization of CENP-A to non-centromeric chromatin contributes to chromosomal instability (CIN) in yeast, fly, and human cells and CENP-A is highly expressed and mislocalized in cancers. Defining mechanisms that prevent mislocalization of CENP-A is an area of active investigation. Ubiquitin-mediated proteolysis of overexpressed Cse4 (GALCSE4)byE3 ubiquitin ligases such as Psh1 prevents mislocalization of Cse4, and psh1D strains display synthetic dosage lethality (SDL) with GALCSE4. We previously performed a genome-wide screen and identified five alleles of CDC7 and DBF4 that encode the Dbf4-dependent kinase (DDK) complex, which regulates DNA replication initiation, among the top twelve hits that displayed SDL with GALCSE4. We determined that cdc7-7 strains exhibit defects in ubiquitin-mediated proteolysis of Cse4 and show mislocalization of Cse4. Mutation of MCM5 (mcm5-bob1) bypasses the requirement of Cdc7 for replication initiation and rescues replication defects in a cdc7-7 strain. We determined that mcm5-bob1 does not rescue the SDL and defects in proteolysis of GALCSE4 in a cdc7-7 strain, suggesting a DNA replication-independent role for Cdc7 in Cse4 proteolysis. The SDL phenotype, defects in ubiquitin-mediated proteolysis, and the mislocalization pattern of Cse4 in a cdc7-7 psh1D strain were similar to that of cdc7-7 and psh1D strains, suggesting that Cdc7 regulates Cse4 in a pathway that overlaps with Psh1. Our results define a DNA replication initiation-independent role of DDK as a regulator of Psh1-mediated proteolysis of Cse4 to prevent mislocalization of Cse4.Fil: Eisenstatt, Jessica R.. National Institutes of Health; Estados UnidosFil: Boeckmann, Lars. National Institutes of Health; Estados UnidosFil: Au, Wei Chun. National Institutes of Health; Estados UnidosFil: Garcia, Valerie. National Institutes of Health; Estados UnidosFil: Bursch, Levi. National Institutes of Health; Estados UnidosFil: Ocampo, Josefina. Consejo Nacional de Investigaciones Cientƭficas y TƩcnicas. Instituto de Investigaciones en Ingenierƭa GenƩtica y Biologƭa Molecular "Dr. HƩctor N. Torres"; Argentina. National Instituto of Child Health & Human Development; Estados UnidosFil: Costanzo, Michael. National Institutes of Health; Estados Unidos. University of Toronto; CanadƔFil: Weinreich, Michael. Van Andel Research Institute; Estados UnidosFil: Sclafani, Robert A.. University of Colorado; Estados UnidosFil: Baryshnikova, Anastasia. University of Princeton; Estados UnidosFil: Myers, Chad L.. University of Minnesota; Estados UnidosFil: Boone, Charles. University of Toronto; CanadƔ. National Institutes of Health; Estados UnidosFil: Clark, David J.. National Institutes of Health; Estados UnidosFil: Baker, Richard. University of Massachusetts; Estados UnidosFil: Basrai, Munira A.. National Institutes of Health; Estados Unido

    Overcoming Local Barriers to Regional Transportation: Understanding Transit System Fragmentation from an Institutionalist Framework [Policy Brief]

    Get PDF
    69A3551747134In this study we trace the development of a transit governance geodatabase for the 200 most populous metropolitan statistical areas in the United States. We use this database to describe thoroughly the metropolitan public transportation systems serving these regions, which include general-purpose local governments, multi-jurisdictional special-purpose governments, public and private transit agencies, and metropolitan planning organizations. From our data, we develop measures of the fragmentation and regionalization of the formal governance of these metropolitan public transportation systems. We discuss national patterns evident in these measures, and we use case studies of four metropolitan statistical areas\u2014two in California, one in Michigan, and one in Texas\u2014to illustrate in more detail the calculation of fragmentation and regionalization

    The global bacterial regulator H-NS promotes transpososome formation and transposition in the Tn5 system

    Get PDF
    The histone-like nucleoid structuring protein (H-NS) is an important regulator of stress response and virulence genes in gram-negative bacteria. In addition to binding regulatory regions of genes in a structure-specific manner, H-NS also binds in a structure-specific manner to sites in the Tn10 transpososome, allowing it to act as a positive regulator of Tn10 transposition. This is the only example to date of H-NS regulating a transposition system by interacting directly with the transposition machinery. In general, transposition complexes tend to include segments of deformed DNA and given the capacity of H-NS to bind such structures, and the results from the Tn10 system, we asked if H-NS might regulate another transposition system (Tn5) by directly binding the transposition machinery. We show in the current work that H-NS does bind Tn5 transposition complexes and use hydroxyl radical footprinting to characterize the H-NS interaction with the Tn5 transpososome. We also show that H-NS can promote Tn5 transpososome formation in vitro, which correlates with the Tn5 system showing a dependence on H-NS for transposition in vivo. Taken together the results suggest that H-NS might play an important role in the regulation of many different bacterial transposition systems and thereby contribute directly to lateral gene transfer

    Maximally-localized generalized Wannier functions for composite energy bands

    Full text link
    We discuss a method for determining the optimally-localized set of generalized Wannier functions associated with a set of Bloch bands in a crystalline solid. By ``generalized Wannier functions'' we mean a set of localized orthonormal orbitals spanning the same space as the specified set of Bloch bands. Although we minimize a functional that represents the total spread sum_n [ _n - _n^2 ] of the Wannier functions in real space, our method proceeds directly from the Bloch functions as represented on a mesh of k-points, and carries out the minimization in a space of unitary matrices U_mn^k describing the rotation among the Bloch bands at each k-point. The method is thus suitable for use in connection with conventional electronic-structure codes. The procedure also returns the total electric polarization as well as the location of each Wannier center. Sample results for Si, GaAs, molecular C2H4, and LiCl will be presented.Comment: 22 pages, two-column style with 4 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/index.html#nm_wan

    Entangled Stories: The Red Jews in Premodern Yiddish and German Apocalyptic Lore

    Get PDF
    ā€œFar, far away from our areas, somewhere beyond the Mountains of Darkness, on the other side of the Sambatyon Riverā€¦there lives a nation known as the Red Jews.ā€ The Red Jews are best known from classic Yiddish writing, most notably from Mendele's Kitser masoes Binyomin hashlishi (The Brief Travels of Benjamin the Third). This novel, first published in 1878, represents the initial appearance of the Red Jews in modern Yiddish literature. This comical travelogue describes the adventures of Benjamin, who sets off in search of the legendary Red Jews. But who are these Red Jews or, in Yiddish, di royte yidelekh? The term denotes the Ten Lost Tribes of Israel, the ten tribes that in biblical times had composed the Northern Kingdom of Israel until they were exiled by the Assyrians in the eighth century BCE. Over time, the myth of their return emerged, and they were said to live in an uncharted location beyond the mysterious Sambatyon River, where they would remain until the Messiah's arrival at the end of time, when they would rejoin the rest of the Jewish people. This article is part of a broader study of the Red Jews in Jewish popular culture from the Middle Ages through modernity. It is partially based on a chapter from my book, Umstrittene Erlƶser: Politik, Ideologie und jĆ¼disch-christlicher Messianismus in Deutschland, 1500ā€“1600 (Gƶttingen: Vandenhoeck & Ruprecht, 2011). Several postdoctoral fellowships have generously supported my research on the Red Jews: a Dr. Meyer-Struckmann-Fellowship of the German Academic Foundation, a Harry Starr Fellowship in Judaica/Alan M. Stroock Fellowship for Advanced Research in Judaica at Harvard University, a research fellowship from the Heinrich Hertz-Foundation, and a YIVO Dina Abramowicz Emerging Scholar Fellowship. I thank the organizers of and participants in the colloquia and conferences where I have presented this material in various forms as well as the editors and anonymous reviewers of AJS Review for their valuable comments and suggestions. I am especially grateful to Jeremy Dauber and Elisheva Carlebach of the Institute for Israel and Jewish Studies at Columbia University, where I was a Visiting Scholar in the fall of 2009, for their generous encouragement to write this article. Sue Oren considerably improved my English. The style employed for Romanization of Yiddish follows YIVO's transliteration standards. Unless otherwise noted, translations from the Yiddish, Hebrew, German, and Latin are my own. Quotations from the Bible follow the JPS translation, and those from the Babylonian Talmud are according to the Hebrew-English edition of the Soncino Talmud by Isidore Epstein
    • ā€¦
    corecore