A combinatorial spanning tree model for knot Floer homology

We iterate Manolescu's unoriented skein exact triangle in knot Floer homology with coefficients in the field of rational functions over $\mathbb{Z}/2\mathbb{Z}$. The result is a spectral sequence which converges to a stabilized version of delta-graded knot Floer homology. The $(E_2,d_2)$ page of this spectral sequence is an algorithmically computable chain complex expressed in terms of spanning trees, and we show that there are no higher differentials. This gives the first combinatorial spanning tree model for knot Floer homology.Comment: 58 pages, 18 figures. Published version, with updated reference

The motel in the heart of every man: the transitional spaces of Don DeLillo

This work illustrates the spatial nature of Don DeLillo’s writing. Through a reading of his work a network of societal spaces repeatedly occur and are utilised as locations within which to raise questions of the relationship between identity and mass society. The spaces that predominate produce the topography of his work. A network begins to develop, a series of nodal points joined by a connective tissue of pathways through which the discussion of society and identity pass. By focusing on both the nodal points themselves and the pathways that connect them the roles of motion, control and a potential counter-narrative appear. The individual spaces that DeLillo chooses as locations in his novels are relevant. Their placing in society, their means of construction and the materials of which they are constituted all illustrate the form of society which created them. In turn these spaces are observed to shape the characters that pass through them, in the process further expanding the network of societal associations. The particular spatial forms that DeLillo focuses on reflect a transitional impulse, a desire for motion and speed rooted in anti-historicism. The suburb, the motel, and the highway are all born of the period which followed the Second World War which had a profound sociological, psychological and technological impact on society. The need to face the future, reject the past and repress the traumatic experiences of war led an experience of space and society which is transitional. The spaces are selected for their association with anxiety, trauma, nostalgia and consumption. The duality of these spaces epitomises the complexities of modern social identity. Due to the reflexive nature of transitionality cultural shifts impact upon its form, altering the way in which it appears and functions. The alleyway influences the development of the highway, the motel influences the development of the suburb, and the railway station affects the airport. The airport is an example of the manner in which technological advance change the appearance of these spaces but the themes and issues that are explored in them reflect consistent interests. Similarly, moments of great social import such as the Kennedy assassination and the attacks of 9/11 leave traces on these transitional spaces

Diversity of the parB and repA genes of the Burkholderia cepacia complex and their utility for rapid identification of Burkholderia cenocepacia

Background: Burkholderia cenocepacia is the most prominent species of the B. cepacia complex (Bcc), a group of nine closely related and difficult to identify bacteria that cause serious infections in patients with cystic fibrosis. Despite its clinical relevance, identification of B. cenocepacia as a single species is unavailable, as it splits by a widely used recA gene-based PCR identification method into discrete phylogenetic subgroups IIIA, IIIB, IIIC and IIID. With the aim of identifying gene targets suitable for unified detection of B. cenocepacia strains, we examined sequence polymorphisms in the repA and parB genes. These essential genes are involved in the replication and partitioning of bacterial replicons, hence we also had the opportunity for the first time to investigate the evolution of the multireplicon (three chromosome) structure of Bcc genomes. Results: Alignment of the repA and parB genes from publicly available Bcc genome sequences enabled the design of primers for their amplification and sequence analysis. Multilocus sequencing typing, a highly discriminatory method for Bcc species and strain discrimination, was used to select strains of unique sequence types (STs) that spanned the known Bcc genetic diversity. Sequence datasets of repA (83 isolates, 67 STs) and parB (120 isolates, 95 STs) genes from the second chromosome were aligned and examined phylogenetically to identify polymorphisms suitable for identification of B. cenocepacia. In contrast to parB, the Bcc repA sequences demonstrated distinct clustering of B. cenocepacia from other species, which enabled the design a species-specific multiplex PCR. The novel single-reaction B. cenocepacia detection method was tested on a panel of 142 different Bcc strains (142 STs) and distinguished recA groups IIIA, IIIB and IIID, from all other Bcc members with 100% sensitivity and 93% specificity. Conclusion: The repA-based multiplex PCR is a useful aid to the rapid identification of the most clinically relevant B. cenocepacia recA subgroups IIIA, IIIB and IIID. Phylogenetic analysis of repA and parB genes demonstrated that acquisition of the second and third replicons of Bcc genomes occurred prior to their differentiation into discrete species and that the sharing of replicons across species had not occurred

Terrorism ideology and perceptions of homeland security in Tennessee law enforcement

Homeland security is a concept that has become firmly embedded in American society since the events of September 11, 2001. While recent research has begun to study the implications of homeland security in state and local law enforcement, few have focused on perceptions of homeland security ideology, policy, and practice. Therefore, this study focuses on the impact that homeland security ideology, policy, and practice has had on the local law enforcement community by examining the varying levels of individual understanding, agreement, and support for the concept. Moderate levels of agreement were found regarding homeland security clarity at federal, state, and local levels of law enforcement. Variables measuring perceptions of consistency and departmental involvement in implementing homeland security strategies, post 9/11 funding, homeland security training, and number of agency collaborations and training activities were found to be the best predictors of perceived clarity. No demographic variables had a significant impact on perceptions of homeland security clarity

New World Orders: The Scientific Romances of George Griffith

This thesis aims to establish George Griffith (1857-1906) as an important writer of late nineteenth-century science fiction. Since Griffith’s death only a handful of his novels have been reprinted, despite their popularity during his lifetime. This has both led to and enabled Griffith’s near disappearance from modern critical consciousness, overlooked by most, dismissed as unimportant by others, with only a very few critics taking Griffith’s contribution to science fiction seriously. This thesis demonstrates that Griffith was instrumental in the creation of the newly emerging genre of the scientific romance, by drawing on different elements of pre-existing genres, such as the utopian novel, the future-war novel, and the adventure romance. This thesis argues that Griffith’s work is of interest and importance because his novels vividly articulate the dominant concerns of late-Victorian Britain: democracy and imperialism; the rise of commercialism; the New Woman; and the potential impact of scientific discoveries and innovative technologies on Britain and its empire. I demonstrate the importance of Griffith’s writing by undertaking close readings of six key works in their publishing, literary and historical context(s), including analyses of the vivid illustrations accompanying the stories. In the process, I explore how Griffith’s scientific romances represent and interrogate in popular narrative form the social contradictions of the 1890s

Multilocus sequence typing of Cronobacter sakazakii and Cronobacter malonaticus reveals stable clonal structures with clinical significance which do not correlate with biotypes

Background: The Cronobacter genus (Enterobacter sakazakii) has come to prominence due to its association with infant infections, and the ingestion of contaminated reconstituted infant formula. C. sakazakii and C. malonaticus are closely related, and are defined according their biotype. Due to the ubiquitous nature of the organism, and the high severity of infection for the immunocompromised, a multilocus sequence typing (MLST) scheme has been developed for the fast and reliable identification and discrimination of C. sakazakii and C. malonaticus strains. It was applied to 60 strains of C. sakazakii and 16 strains of C. malonaticus, including the index strains used to define the biotypes. The strains were from clinical and non-clinical sources between 1951 and 2008 in USA, Canada, Europe, New Zealand and the Far East. Results: This scheme uses 7 loci; atpD, fusA, glnS, gltB, gyrB, infB, and pps. There were 12 sequence types (ST) identified in C. sakazakii, and 3 in C. malonaticus. A third (22/60) of C. sakazakii strains were in ST4, which had almost equal numbers of clinical and infant formula isolates from 1951 to 2008. ST8 may represent a particularly virulent grouping of C. sakazakii as 7/8 strains were clinical in origin which had been isolated between 1977 - 2006, from four countries. C. malonaticus divided into three STs. The previous Cronobacter biotyping scheme did not clearly correspond with STs nor with species. Conclusion: In conclusion, MLST is a more robust means of identifying and discriminating between C. sakazakii and C. malonaticus than biotyping. The MLST database for these organisms is available online at http://pubmlst.org/cronobacter

Interaction of Co(II), Ni(II) and Cu(II) with dibenzo-substituted macrocyclic ligands incorporating both symmetrically and unsymmetrically arranged N, O and S donors

The synthesis and characterisation of four 17-membered, dibenzo-substituted macrocyclic ligands incorporating unsymmetrical arrangements of their N3S2, N3O2 and N3OS (two ligands) donor atoms are described; these rings complete the matrix of related macrocyclic systems incorporating both symmetric and unsymmetric donor sets reported previously. The X-ray structures of three of the new macrocycles are reported. In two of the Cu(II) structures only three of the possible five donor atoms present in the corresponding macrocyclic ligand bind to the Cu(II) site, whereas all five donors are coordinated in each of the remaining complexes. The interaction of Co(II), Ni(II) and Cu(II) with the unsymmetric macrocycle series has been investigated by potentiometric (pH) titration in 95% methanol; X-ray structures of two nickel and three copper complexes of these ligands, each exhibiting 1 : 1 (M :L) ratios, have been obtained. The results are discussed in the context of previous results for these metals with the analogous 17-membered ring systems incorporating symmetrical arrangements of their donor atoms, with emphasis being given to both the influence of the donor atom set, as well as the donor atom sequence, on the nature of the resulting complexes