Topological soliton-polaritons in 1D systems of light and fermionic matter

Quantum nonlinear optics is a quickly growing field with large technological promise, at the same time involving complex and novel many-body phenomena. In the usual scenario, optical nonlinearities originate from the interactions between polaritons, which are hybrid quasi-particles mixing matter and light degrees of freedom. Here we introduce a type of polariton which is intrinsically nonlinear and emerges as the natural quasi-particle in presence quantum degenerate fermionic matter. It is a composite object made of a fermion trapped inside an optical soliton forming a topological defect in a spontaneously formed crystalline structure. Each of these soliton-polaritons carries a $\textbf{Z}_2$ topological quantum number, as they create a domain wall between two crystalline regions with opposite dimerization so that the fermion is trapped in an interphase state. These composite objects are formally equivalent to those appearing in the Su-Schrieffer-Heeger (SSH) model for electrons coupled to lattice phonons.Comment: Edited version. 6+7 pages, 3 figure

Transforming mesoscale granular plasticity through particle shape

When an amorphous material is strained beyond the point of yielding it enters a state of continual reconfiguration via dissipative, avalanche-like slip events that relieve built-up local stress. However, how the statistics of such events depend on local interactions among the constituent units remains debated. To address this we perform experiments on granular material in which we use particle shape to vary the interactions systematically. Granular material, confined under constant pressure boundary conditions, is uniaxially compressed while stress is measured and internal rearrangements are imaged with x-rays. We introduce volatility, a quantity from economic theory, as a powerful new tool to quantify the magnitude of stress fluctuations, finding systematic, shape-dependent trends. For all 22 investigated shapes the magnitude $s$ of relaxation events is well-fit by a truncated power law distribution $P(s)\sim {s}^{-\tau} exp(-s/s^*)$, as has been proposed within the context of plasticity models. The power law exponent $\tau$ for all shapes tested clusters around $\tau=$ 1.5, within experimental uncertainty covering the range 1.3 - 1.7. The shape independence of $\tau$ and its compatibility with mean field models indicate that the granularity of the system, but not particle shape, modifies the stress redistribution after a slip event away from that of continuum elasticity. Meanwhile, the characteristic maximum event size $s^*$ changes by two orders of magnitude and tracks the shape dependence of volatility. Particle shape in granular materials is therefore a powerful new factor influencing the distance at which an amorphous system operates from scale-free criticality. These experimental results are not captured by current models and suggest a need to reexamine the mechanisms driving mesoscale plastic deformation in amorphous systems.Comment: 11 pages, 8 figures. v3 adds a new appendix and figure about event rates and changes several parts the tex

Complete Genome Sequences of vB_LmoS_188 and vB_LmoS_293, Two Bacteriophages with Specificity for Listeria monocytogenes Strains of Serotypes 4b and 4e

peer-reviewedListeria monocytogenes is responsible for the rare disease listeriosis, which is associated with the consumption of contaminated food products. We report here the complete genome sequences of vB_LmoS_188 and vB_LmoS_293, phages isolated from environmental sources and that have host specificity for L. monocytogenes strains of the 4b and 4e serotypes.This work was supported by the EU 7th Framework projects PROMISE (project no. 265877) and FOODSEG (project no. 266061) and by a safefood mini-project

Giant ultrafast Kerr effect in type-II superconductors

We study the ultrafast Kerr effect and high-harmonic generation in type-II superconductors by formulating a new model for a time-varying electromagnetic pulse normally incident on a thin-film superconductor. It is found that type-II superconductors exhibit exceptionally large $\chi^{(3)}$ due to the progressive destruction of Cooper pairs, and display high-harmonic generation at low incident intensities, and the highest nonlinear susceptibility of all known materials in the THz regime. Our theory opens up new avenues for accessible analytical and numerical studies of the ultrafast dynamics of superconductors

Social support, social control and health behavior change in spouses

Our work on support processes in intimate relationships has focused on how partners in committed relationships help one another contend with personal difficulties, and how partners elicit and provide support in their day-to-day interactions. We are particularly interested in how these support skills relate to marital outcomes (Pasch & Bradbury, 1998; Pasch, Harris, Sullivan, & Bradbury, 2004; Sullivan, Pasch, Eldridge, & Bradbury, 1998) and how they relate to behavior change in spouses (Sullivan, Pasch, Johnson, & Bradbury, 2006), especially health behavior changes. In this chapter, we review research examining the effects of social support and social control on spouses\u27 health behaviors, propose a theory to account for discrepancies in these findings, and report initial data examining the usefulness of this theory in understanding the relationship between social support, social control, and partner health behavior

A Geospatial Analysis of CDC-funded HIV Prevention Programs for African Americans in the United States

Given the increase in HIV/AIDS infection rates among racial and ethnic minorities, particularly African Americans, this study was undertaken as part of a larger research effort to examine the distribution of HIV prevention services focusing on African American populations within the United States. Data were gathered via a national survey of community-based organizations (CBOs) funded by the Centers for Disease Control and Prevention (CDC). A geocoded national database was constructed to identify, locate, and map these HIV prevention programs. A total of 1,020 CBOs responded to the survey, yielding a response rate of 70.3%. These CBOs administered a total of 3,028 HIV prevention programs. Data describing intervention types and persons served, combined with the address and service area of responding CBOs, were integrated with census data (2000) and analyzed by using a geographic information system (GIS). The results of our national level analysis show that HIV prevention services for African Americans have fair coverage where African Americans comprise a substantial proportion of the population in urban areas in northeastern states, but that HIV prevention services for African Americans are inadequately distributed in the southeastern states. A local-level analysis was conducted for Alabama, where 68% of HIV/AIDS cases are among African Americans. Specific interventions such as street and community outreach, health communications, and public information are fairly well provided to African Americans in more urban cities in Alabama, however, individual- and group-level interventions have poor coverage in rural areas where a large percentage of African-Americans live. Overall, our study illustrates that the use of GIS adds value when used with other data sources to provide prevention services that are accessible to the populations most in need

How I Organise my Research. ESRI Memorandum Series No. 96 1970

I give this talk with some trepidation. In the first place, I find it extremely egotistical to speak about the organisation of my own research, and I am nothing if not a modest man. More important, the general subject is one on which I never heard anybody lecture before. Thus, I do not have available many sources, the conventional prop of the professional research worker. Professor O'Connor, in organising these lectures, is providing for you a service which, in my experience, is not given anywhere else. Accordingly, I hope you will be patient with us if the first results are not too good

Partitioning of starter bacteria and added exogenous enzyme activities between curd and whey during Cheddar cheese manufacture

peer-reviewedPartitioning of starter bacteria and enzyme activities was investigated at different stages of Cheddar cheese manufacture using three exogenous commercial enzyme preparations added to milk or at salting. The enzyme preparations used were: Accelase AM317, Accelase AHC50, Accelerzyme CPG. Flow cytometric analysis indicated that AHC50 or AM317 consisted of permeabilised or dead cells and contained a range of enzyme activities. The CPG preparation contained only carboxypeptidase activity. Approximately 90% of starter bacteria cells partitioned with the curd at whey drainage. However, key enzyme activities partitioned with the bulk whey in the range of 22%–90%. An increased level of enzyme partitioning with the curd was observed for AHC50 which was added at salting, indicating that the mode of addition influenced partitioning. These findings suggest that further scope exists to optimise both bacterial and exogenous enzyme incorporation into cheese curd to accelerate ripening.Department of Agriculture, Food and the Marin

Welfare measurement and the national accounts. ESRI Memorandum Series 109

The stated objective of the author is "to lay a bridge between income accounting and welfare theory". There are two contrasting ways of pursuing this objective. The first, in the realm of pure theory, examines the relationship between welfare and hypothetical, perfect measures of national product, while the second lies in the domain of national income accounting with attempts to redefine concepts, extend data coverage and improve measurement. Professor Romans’s attempt at bridge-building begins in the realm of theory with the construction of a welfare maximisa tion model designed to establish the conditions in which it can be asserted without ambiguity that net national product and welfare are moving in the same direetion

Coherent polarimeter modules for the QUIET experiment

The Q/U Imaging Experiment (QUIET) is an experimental program to make very sensitive measurements of the Cosmic Background Radiation (CMB) polarization from the ground. A key component of this project is the ability to produce large numbers of detectors in order to achieve the required sensitivity. Using a breakthrough in mm-wave packaging at JPL, a polarimeter-on-a-chip has been developed which lends itself to the mass-production techniques used in the semiconductor industry. We describe the design, implementation and performance of these polarimeter modules for QUIET Phase I and briefly discuss the plans for further module development