Anomaly Inflow and Membrane Dynamics in the QCD Vacuum

Large $N_c$ and holographic arguments, as well as Monte Carlo results, suggest that the topological structure of the QCD vacuum is dominated by codimension-one membranes which appear as thin dipole layers of topological charge. Such membranes arise naturally as $D6$ branes in the holographic formulation of QCD based on IIA string theory. The polarizability of these membranes leads to a vacuum energy $\propto \theta^2$, providing the origin of nonzero topological susceptibility. Here we show that the axial U(1) anomaly can be formulated as anomaly inflow on the brane surfaces. A 4D gauge transformation at the brane surface separates into a 3D gauge transformation of components within the brane and the transformation of the transverse component. The in-brane gauge transformation induces currents of an effective Chern-Simons theory on the brane surface, while the transformation of the transverse component describes the transverse motion of the brane and is related to the Ramond-Ramond closed string field in the holographic formulation of QCD. The relation between the surface currents and the transverse motion of the brane is dictated by the descent equations of Yang-Mills theory.Comment: 22 pages, 3 figure

A genetic perspective on leopard (Panthera pardus) conservation units across southern Africa

Conservation units are a tool to guide policy such that conservation goals can be achieved. These units should ideally synthesise a wide array of data – genetic, ecological, demographic – to identify the appropriate scales at which conservation actions can then be directed. Despite being the most widespread of all felids in Africa, and facing numerous threats across its range, it has been proposed that the entirety of southern Africa be considered one conservation unit for leopards (Panthera pardus pardus). This proposal does not take into consideration the likelihood of existing population genetic structure across an increasingly fragmented landscape. Further complicating regional leopard conservation is the variability in conservation policies among the geopolitical leopard-range states. Within this single proposed conservation unit, the patchwork of different legislation does not support a unified policy for leopard conservation. Using a population genetic perspective, this study explores and tests the values and shortcomings of southern Africa as a single conservation unit, and explores the importance of leopard range states within the context of conservation units. Parallel investigations of leopard microsatellite genotype data within the framework of a genetic population study spanning eight countries across southern Africa were carried out. This study presents consilient evidence supporting the finding that southern Africa contains six clusters of unique genetic lineages, and as such does not constitute a single genetic unit. Furthermore, it is shown here that the spatial genetic structure that exists does not correlate with the separate geopolitical range states. Leopard range states within southern Africa instead capture varying levels of unique genetic structure and thus are not of equal value with respect to the conservation of genetic lineages. These findings have several implications for leopard conservation across the region. While the data presented here specifically consider a genetic element of conservation units, they do suggest shortcomings in adopting either the entirety of southern Africa as a single unit or separate geopolitical range states as conservation units. The variability in leopard conservation policy across southern Africa is unlikely to sufficiently protect their existing regional genetic structure. If conservation units are indeed a tool to guide conservation policy, then the southern Africa unit for leopards is potentially less effective than a smaller unit whose spatial scale more accurately captures the discrete variation in population genetic structure. Genetic diversity and population structure is an important component of conservation units and should not be neglected. Currently, however, an appropriate framework allowing for conservation policy to be informed at the necessary scale does not exist; although the establishment of Transfrontier Conservation Areas speaks to the growing acknowledgement that conservation needs to evolve beyond the historical confines of geopolitical range states. The evidence presented here further supports the need for a rethinking of existing policy structures

Factors associated with physical activity participation in adults with chronic cervical spine pain: a systematic review

Objective: To determine the factors associated with physical activity participation in adults with chronic cervical spine pain. Methods: A systematic review was conducted including searches of PubMed (MEDLINE), EMBASE and CINAHL from inception to June 12th, 2016. Grey literature and reference checking was also undertaken. Quantitative studies including factors related to physical activity participation in adults with chronic cervical spine pain were included. Two independent authors conducted the searches, extracted data and completed methodological quality assessment. Results: A total of seven studies met the selection criteria, however, four papers were finally included in the final review. A modified Downs and Black criteria was used to assess methodological quality, each study included was classed as moderate quality. A total of six factors were assessed against physical activity participation for people with chronic neck pain. These included: pain, fear of movement, smoking habits, socioeconomic status, gender, leisure and work time habits. A significant relationship was demonstrated between pain, leisure and work time habits and physical activity. Subjects were less likely to participate in physical activity if they were in pain. Subjects with neck pain were less likely to participate in physical activity in their leisure and work time. Conclusion: This review, based on a small number of heterogeneous studies demonstrated key factors that are likely to affect physical activity in people with chronic neck pain, most notably, pain levels, leisure and work habits. This review suggests that more in-depth, high quality studies are required to fully understand the impact of chronic pain on physical activity

Randomized sham controlled trial of cranial microcurrent stimulation for symptoms of depression, anxiety, pain, fatigue and sleep disturbances in women receiving chemotherapy for early-stage breast cancer

Purpose Women with breast cancer may experience symptoms of depression, anxiety, pain, fatigue and sleep disturbances during chemotherapy. However, there are few modalities that address multiple, commonly occurring symptoms that may occur in individuals receiving cancer treatment. Cranial electrical stimulation (CES) is a treatment that is FDA cleared for depression, anxiety and insomnia. CES is applied via electrodes placed on the ear that deliver pulsed, low amplitude electrical current to the head. Methods This phase III randomized, sham-controlled study aimed to examine the effects of cranial microcurrent stimulation on symptoms of depression, anxiety, pain, fatigue, and sleep disturbances in women receiving chemotherapy for early-stage breast cancer. Patients were randomly assigned to either an actual or sham device and used the device daily for 1 h. The study was registered at clinicaltrials.gov, NCT00902330. Results The sample included N = 167 women with early-stage breast cancer. Symptom severity of depression, anxiety, and fatigue and sleep disturbances were generally mild to moderate. Levels of pain were low. Anxiety was highest prior to the initial chemotherapy and decreased over time. The primary outcome assessment (symptoms of depression, anxiety, fatigue, pain, sleep disturbances) revealed no statistically significant differences between the two groups, actual CES vs. sham. Conclusion In this study, women receiving chemotherapy for breast cancer experienced multiple symptoms in the mild to moderate range. Although there is no evidence for the routine use of CES during the chemotherapy period for symptom management in women with breast cancer, further symptom management modalities should be evaluated to mitigate symptoms of depression, anxiety, fatigue, pain and sleep disturbances over the course of chemotherapy

Coherent Topological Charge Structure in CPN−1CP^{N-1} Models and QCD

In an effort to clarify the significance of the recent observation of long-range topological charge coherence in QCD gauge configurations, we study the local topological charge distributions in two-dimensional $CP^{N-1}$ sigma models, using the overlap Dirac operator to construct the lattice topological charge. We find long-range sign coherence of topological charge along extended one-dimensional structures in two-dimensional spacetime. We discuss the connection between the long range topological structure found in $CP^{N-1}$ and the observed sign coherence along three-dimensional sheets in four-dimensional QCD gauge configurations. In both cases, coherent regions of topological charge form along membrane-like surfaces of codimension one. We show that the Monte Carlo results, for both two-dimensional and four-dimensional gauge theory, support a view of topological charge fluctuations suggested by Luscher and Witten. In this framework, the observed membranes are associated with boundaries between ``k-vacua,'' characterized by an effective local value of $\theta$ which jumps by $\pm 2\pi$ across the boundary.Comment: 26 page

Star Formation, Supernovae Feedback and the Angular Momentum Problem in Numerical CDM Cosmogony: Half Way There?

We present a smoothed particle hydrodynamic (SPH) simulation that reproduces a galaxy that is a moderate facsimile of those observed. The primary failing point of previous simulations of disk formation, namely excessive transport of angular momentum from gas to dark matter, is ameliorated by the inclusion of a supernova feedback algorithm that allows energy to persist in the model ISM for a period corresponding to the lifetime of stellar associations. The inclusion of feedback leads to a disk at a redshift $z=0.52$, with a specific angular momentum content within 10% of the value required to fit observations. An exponential fit to the disk baryon surface density gives a scale length within 17% of the theoretical value. Runs without feedback, with or without star formation, exhibit the drastic angular momentum transport observed elsewhere.Comment: 4 pages, 3 figures, accepted for publication in ApJ Letter