Palladium-Catalyzed Enantioselective C_(sp)^3–C_(sp)^3 Cross-Coupling for the Synthesis of (Poly)fluorinated Chiral Building Blocks

A general method for the enantioselective synthesis of carbo- and heterocyclic carbonyl compounds bearing fluorinated α-tetrasubstituted stereocenters using palladium-catalyzed decarboxylative allylic alkylation is described. The stereoselective C_(sp)^3–C_(sp)^3 cross-coupling reaction delivers five- and six-membered ketone and lactam products bearing (poly)fluorinated tetrasubstituted chiral centers in high yields and enantioselectivities. These fluorinated, stereochemically rich building blocks hold potential value in medicinal chemistry and are prepared using an orthogonal and enantioselective approach into such chiral moieties compared to traditional approaches, often without the use of electrophilic fluorinating reagents

Relaxations and rheology near jamming

We determine the form of the complex shear modulus $G^*$ in soft sphere packings near jamming. Viscoelastic response at finite frequency is closely tied to a packing's intrinsic relaxational modes, which are distinct from the vibrational modes of undamped packings. We demonstrate and explain the appearance of an anomalous excess of slowly relaxing modes near jamming, reflected in a diverging relaxational density of states. From the density of states, we derive the dependence of $G^*$ on frequency and distance to the jamming transition, which is confirmed by numerics.Comment: 4 pages, 3 figure

A City within a City: Community Development and the Struggle over Harlem, 1961-2001

This dissertation examines the idea of community development in the last four decades of the twentieth century through the example of the Harlem neighborhood of New York City and, in doing so, explains the broader transformation of the American city in these decades. Frustration with top-down urban redevelopment and the rise of Black Power brought new demands to Harlem, as citizens insisted on the need for “community control” over their built environment. In attempting to bring this goal to life, Harlemites created new community-based organizations that promised to realize a radically inclusive, cooperative ideal of a neighborhood built by and for the benefit of its predominantly low-income, African-American residents. For several reasons, including continued reliance on the public sector, dominant leaders, changing sociological understandings of poverty, and the intransigence of activists, however, such organizations came to advance a narrower approach in Harlem in succeeding years. By the 1980s, they pursued a moderate vision of Harlem’s future, prioritizing commercial projects instead of development that served residents’ many needs, emphasizing economic integration, and eschewing goals of broad structural change. In examining community design centers, community development corporations, self-help housing, and other neighborhood-based strategies, I conclude that local actors achieved their longstanding aspiration that they could become central to the process of development in Harlem and similar places, but built a dramatically different reality than the idealistic hope that had fueled demands for community control in the late 1960s. This ironic outcome reveals the unexpected, radical roots of urban landscapes that by the end of the century were characterized by increasing privatization, economic gentrification, and commercial redevelopment. Likewise, it demonstrates that such dramatic changes in American cities were not simply imposed on unwitting neighborhoods by outsiders or the result of abstract forces, but were in part produced by residents themselves. Understanding the mutable nature of community development helps to explain both the complicated course of urban development in the aftermath of modernist planning and the lasting, often contradictory consequences of the radical demands that emerged from the 1960s, two areas that historians have only begun to examine in detail

Creating Test Score Bands for Assessments Involving Ratings using a Generalizability Theory Approach to Reliability Estimation

The selection of a method for estimating the reliability of ratings has considerable implications for the use of assessments in personnel selection. In particular, the accuracy of corrections to validity coefficients for unreliability and test score bands are completely dependent on the correct estimation of the reliability. In this paper, we discuss how generalizability theory can be used to estimate reliability for test score bands with assessments involving ratings. Using selection data from a municipal entity, we demonstrate the use of generalizability theory-based compare the implications of its use in test score banding compared to the traditional approach

Mitochondrial Association of a Plus End–Directed Microtubule Motor Expressed during Mitosis in Drosophila

The kinesin superfamily is a large group of proteins (kinesin-like proteins [KLPs]) that share sequence similarity with the microtubule (MT) motor kinesin. Several members of this superfamily have been implicated in various stages of mitosis and meiosis. Here we report our studies on KLP67A of Drosophila. DNA sequence analysis of KLP67A predicts an MT motor protein with an amino-terminal motor domain. To prove this directly, KLP67A expressed in Escherichia coli was shown in an in vitro motility assay to move MTs in the plus direction. We also report expression analyses at both the mRNA and protein level, which implicate KLP67A in the localization of mitochondria in undifferentiated cell types. In situ hybridization studies of the KLP67A mRNA during embryogenesis and larval central nervous system development indicate a proliferation-specific expression pattern. Furthermore, when affinity-purified anti-KLP67A antisera are used to stain blastoderm embryos, mitochondria in the region of the spindle asters are labeled. These data suggest that KLP67A is a mitotic motor of Drosophila that may have the unique role of positioning mitochondria near the spindle

Herpesviruses including novel gammaherpesviruses are widespread among phocid seal species in Canada

Little is known about herpesviruses in Canadian pinnipeds. We measured prevalence of antibodies to herpesviruses in the sera from Canadian phocid seals by an indirect enzyme-linked immunosorbent assay. Wild harbor seals (Phoca vitulina) and captive harbor seals were positive for antibodies to Phocid herpesvirus 1 (PhoHV-1) at prevalences of 91% and 100%, respectively. Sera from wild hooded seals (Cystophora cristata), harp seals (Pagophilus groenlandica), and grey seals (Halichoerus grypus) were positive for antibodies to PhoHV-1 antigenically related herpesvirus antigens at 73%, 79%, and 96%, respectively. We isolated new herpesviruses in cell culture from two hunter-harvested ringed seals (Pusa hispida) in poor body condition from Ulukhaktok, Northwest Territories, Canada; one lethargic hooded seal from the St. Lawrence Estuary, Québec, Canada; and one captive, asymptomatic harp seal from the Magdalen Islands, Québec. Partial sequencing of the herpesvirus DNA polymerase gene revealed that all four virus isolates were closely related to PhoHV-2, a member of the Gammaherpesvirinae subfamily, with nucleotide similarity ranging between 92.8% and 95.3%. The new seal herpesviruses were genetically related to other known pinniped herpesviruses, such as PhoHV-1, Otariid herpesvirus 3, Hawaiian monk (Monachus schauinslandi) seal herpesvirus, and Phocid herpesvirus 5 with 47–48%, 55%, 77%, and 70–77% nucleotide similarities, respectively. The harp seal herpesvirus and both ringed seal herpesviruses were almost identical to each other, whereas the hooded seal herpesvirus was genetically different from the three others (92.8% nucleotide similarity), indicating detection of at least two novel seal herpesviruses. These findings are the first isolation, partial genome sequencing, and identification of seal gammaherpesviruses in three species of Canadian phocid seals; two species of which were suspected of exposure to one or more antigenically related herpesviruses based on serologic analyses

Normalizing Resource Identifiers using Lexicons in the Global Change Information System: Linking Earth Science Identifiers, Concepts, and Communities

Earth Science informatics involves collaboration between multiple groups of people with diverse specializations and goals,often using variations in terminology to refer to common resources. The uniformity of the resource identifiers often does not cross organizational boundaries. Because of this, permanent, widely used, unambiguous identifiers for resources are elusive. We examine real world cases of changing and inconsistent identifiers which inherently work against persistence and uniformity. We also present a solution which mediates factors in these situations; namely the creation of lexicons:mappings of sets of terms to URIs which are curated within the Global Change Information System (GCIS). We discuss aspects of the GCIS which facilitate the use of lexicons: an information model which disambiguates resources, a RESTful API which provides metadata through content-negotiation, and a strategy for long term curation of URIs, including mechanisms for handling changes to URIs and variations in terms used by different communities while providing persistent URIs and preserving relationships between resources We provide working definitions of terms,contexts, and lexicons, and relate them to the practical challenges of disambiguation and curation. We also discuss the mechanisms employed and architecture of the GCIS, and how these choices facilitate representation of persistent identifiers and mappings of them to identifiers used colloquially within various earth science communities of practice