Global Anomalies in Canonical Gravity

In this note we study the structure of diffeomorphism anomalies in 3+1 canonical gravity coupled to a chiral massless fermion. We find that when the spatial manifold is S^3 or a Lens space L(p,q), the first homotopy group of the related diffeomorphism group can be nontrivial and hence the question of global anomalies becomes relevant. Here we show that for gravity coupled to SU(2) chiral fermions, assuming the strong form of the Hatcher conjecture, SU(2)-induced diffeomorphism anomalies do not occur whenever the spatial manifold is S^3 or a Lens space.Comment: 17 pages, LaTeX, uses packages amstex, amssymb. One reference added, one sign error corrected. Conclusions unchanged. To appear in Nucl. Phys.

Who am I and what am I doing here? : Becoming and being a project manager

Purpose - This paper aims to empirically explore the nature of tensions that emerge within the process of becoming a manager in the post-bureaucratic organisation, by focusing on the emergence of project management as a key carrier of post-bureaucracy. The paper seeks to address two aspects of individual transformation into project manager; first, it aims to understand the specific factors, which drive the transformation of technical specialists into project managers and, second, to illuminate the tensions and challenges experienced in this new position. Design/methodology/approach - The empirical base for the study is a series of structured group discussions with project managers from a range of distinct industrial sectors and organisations. Findings - The paper illustrates the tensions implicit in the process of becoming a project manager. It identifies a number of conflicts that arise between the overarching philosophy of project management and the process of enacting the role of project manager around the themes of status, organisational value, power, influence and ambiguity. Research limitations/implications - The research approach is empirically rich yet exploratory, providing directions and inspiration for more extensive research in specific contexts. Originality/value - The research points to an understanding of how new managerial roles are created and embedded in organisational contexts, and the pressures, which are brought to bear on the incumbents of these new roles through this process

Antiferromagnetic Zigzag Spin Chain in Magnetic Fields at Finite Temperatures

We study thermodynamic behaviors of the antiferromagnetic zigzag spin chain in magnetic fields, using the density-matrix renormalization group method for the quantum transfer matrix. We focus on the thermodynamics of the system near the critical fields in the ground-state magnetization process($M$-$H$ curve): the saturation field, the lower critical field associated with excitation gap, and the field at the middle-field cusp singularity. We calculate magnetization, susceptibility and specific heat of the zigzag chain in magnetic fields at finite temperatures, and then discuss how the calculated quantities reflect the low-lying excitations of the system related with the critical behaviors in the $M$-$H$ curve.Comment: accepted for publication in Physical Review

Middle-Field Cusp Singularities in the Magnetization Process of One-Dimensional Quantum Antiferromagnets

We study the zero-temperature magnetization process (M-H curve) of one-dimensional quantum antiferromagnets using a variant of the density-matrix renormalization group method. For both the S=1/2 zig-zag spin ladder and the S=1 bilinear-biquadratic chain, we find clear cusp-type singularities in the middle-field region of the M-H curve. These singularities are successfully explained in terms of the double-minimum shape of the energy dispersion of the low-lying excitations. For the S=1/2 zig-zag spin ladder, we find that the cusp formation accompanies the Fermi-liquid to non-Fermi-liquid transition.Comment: 4 pages, RevTeX, 3 figures, some mistakes in references are correcte

An rf cavity for the B-Factory

The paper describes the proposed design for the 476 MHz accelerating cavity for the SLAC/LBL/LLNL B-Factory. This machine will require a high power throughput to the beam because of the large synchrotron radiation losses, and very low impedances for the higher order modes because of the high current proposed. Use of conventional construction in copper means that careful consideration has to be paid to the problem of cooling. The need for a high shunt impedance for the accelerating mode dictated the use of a re-entrant shape. This maximized the impedance of the fundamental mode with respect to the troublesome longitudinal and deflecting higher order modes, when compared to open or bell shaped'' designs. A specialized damping scheme was employed to reduce the higher order mode impedances while sacrificing as little of the fundamental mode power as possible. This was required to suppress the growth of coupled bunch beam instabilities and minimize the workload of the feedback system needed to control them. A window design capable of handling the high power was also required. 8 refs., 1 fig., 2 tabs

Reduced Diversity and High Sponge Abundance on a Sedimented Indo-Pacific Reef System: Implications for Future Changes in Environmental Quality

Although coral reef health across the globe is declining as a result of anthropogenic impacts, relatively little is known of how environmental variability influences reef organisms other than corals and fish. Sponges are an important component of coral reef fauna that perform many important functional roles and changes in their abundance and diversity as a result of environmental change has the potential to affect overall reef ecosystem functioning. In this study, we examined patterns of sponge biodiversity and abundance across a range of environments to assess the potential key drivers of differences in benthic community structure. We found that sponge assemblages were significantly different across the study sites, but were dominated by one species Lamellodysidea herbacea (42% of all sponges patches recorded) and that the differential rate of sediment deposition was the most important variable driving differences in abundance patterns. Lamellodysidea herbacea abundance was positively associated with sedimentation rates, while total sponge abundance excluding Lamellodysidea herbacea was negatively associated with rates of sedimentation. Overall variation in sponge assemblage composition was correlated with a number of variables although each variable explained only a small amount of the overall variation. Although sponge abundance remained similar across environments, diversity was negatively affected by sedimentation, with the most sedimented sites being dominated by a single sponge species. Our study shows how some sponge species are able to tolerate high levels of sediment and that any transition of coral reefs to more sedimented states may result in a shift to a low diversity sponge dominated system, which is likely to have subsequent effects on ecosystem functioning. © 2014 Powell et al

INTRA-Disciplinary Care: Can Mental Health Professionals Work Together in Primary Care?

Excerpt: Last fall, I sat through an uncomfortable board meeting. I was charged to work with a Clinical Social Worker, Licensed Practicing Counselor, a Counseling Psychologist, and a Licensed Nurse Practitioner to develop an integrated care training program as part of a rural workforce development project