Off-shell superconformal nonlinear sigma-models in three dimensions

We develop superspace techniques to construct general off-shell N=1,2,3,4 superconformal sigma-models in three space-time dimensions. The most general N=3 and N=4 superconformal sigma-models are constructed in terms of N=2 chiral superfields. Several superspace proofs of the folklore statement that N=3 supersymmetry implies N=4 are presented both in the on-shell and off-shell settings. We also elaborate on (super)twistor realisations for (super)manifolds on which the three-dimensional N-extended superconformal groups act transitively and which include Minkowski space as a subspace.Comment: 67 pages; V2: typos corrected, one reference added, version to appear on JHE

Scheme for generating entangled states of two field modes in a cavity

This paper considers a two-level atom interacting with two cavity modes with equal frequencies. Applying a unitary transformation, the system reduces to the analytically solvable Jaynes-Cummings model. For some particular field states, coherent and squeezed states, the transformation between the two bare basis's, related by the unitary transformation, becomes particularly simple. It is shown how to generate, the highly non-classical, entangled coherent states of the two modes, both in the zero and large detuning cases. An advantage with the zero detuning case is that the preparation is deterministic and no atomic measurement is needed. For the large detuning situation a measurement is required, leaving the field in either of two orthogonal entangled coherent states.Comment: Accepted in J. Mod. Opt.; 12 pages; Replaced with revised version. Extended discussion of experimental realizations, earlier studies in the field and on the frequency dependence in the adiabatic eliminatio

The Far-Infrared Properties of Spatially Resolved AKARI Observations

We present the spatially resolved observations of IRAS sources from the Japanese infrared astronomy satellite AKARI All-Sky Survey during the performance verification (PV) phase of the mission. We extracted reliable point sources matched with IRAS point source catalogue. By comparing IRAS and AKARI fluxes, we found that the flux measurements of some IRAS sources could have been over or underestimated and affected by the local background rather than the global background. We also found possible candidates for new AKARI sources and confirmed that AKARI observations resolved IRAS sources into multiple sources. All-Sky Survey observations are expected to verify the accuracies of IRAS flux measurements and to find new extragalactic point sources.Comment: 11 pages, 7 figures, accepted publication in PASJ AKARI special issu

String theoretic QCD axions in the light of PLANCK and BICEP2

The QCD axion solving the strong CP problem may originate from antisymmetric tensor gauge fields in compactified string theory, with a decay constant around the GUT scale. Such possibility appears to be ruled out now by the detection of tensor modes by BICEP2 and the PLANCK constraints on isocurvature density perturbations. A more interesting and still viable possibility is that the string theoretic QCD axion is charged under an anomalous U(1)_A gauge symmetry. In such case, the axion decay constant can be much lower than the GUT scale if moduli are stabilized near the point of vanishing Fayet-Illiopoulos term, and U(1)_A-charged matter fields get a vacuum value far below the GUT scale due to a tachyonic SUSY breaking scalar mass. We examine the symmetry breaking pattern of such models during the inflationary epoch with the Hubble expansion rate 10^{14} GeV, and identify the range of the QCD axion decay constant, as well as the corresponding relic axion abundance, consistent with known cosmological constraints. In addition to the case that the PQ symmetry is restored during inflation, there are other viable scenarios, including that the PQ symmetry is broken during inflation at high scales around 10^{16}-10^{17} GeV due to a large Hubble-induced tachyonic scalar mass from the U(1)_A D-term, while the present axion scale is in the range 10^{9}-5\times 10^{13} GeV, where the present value larger than 10^{12} GeV requires a fine-tuning of the axion misalignment angle. We also discuss the implications of our results for the size of SUSY breaking soft masses.Comment: 29 pages, 1 figure; v3: analysis updated including the full anharmonic effects, references added, version accepted for publication in JHE

Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes

The Kondo-effect is a many-body phenomenon arising due to conduction electrons scattering off a localized spin. Coherent spin-flip scattering off such a quantum impurity correlates the conduction electrons and at low temperature this leads to a zero-bias conductance anomaly. This has become a common signature in bias-spectroscopy of single-electron transistors, observed in GaAs quantum dots as well as in various single-molecule transistors. While the zero-bias Kondo effect is well established it remains uncertain to what extent Kondo correlations persist in non-equilibrium situations where inelastic processes induce decoherence. Here we report on a pronounced conductance peak observed at finite bias-voltage in a carbon nanotube quantum dot in the spin singlet ground state. We explain this finite-bias conductance anomaly by a nonequilibrium Kondo-effect involving excitations into a spin triplet state. Excellent agreement between calculated and measured nonlinear conductance is obtained, thus strongly supporting the correlated nature of this nonequilibrium resonance.Comment: 21 pages, 5 figure

Systematic review of the incidence, presentation and management of gastroduodenal artery pseudoaneurysm after pancreatic resection.

Background: Gastroduodenal artery (GDA) pseudoaneurysm is a serious complication following pancreatic resection, associated with high morbidity and mortality rates. This review aimed to report the incidence of GDA pseudoaneurysm after pancreatic surgery, and describe clinical presentation and management. Methods: MEDLINE and Embase were searched systematically for clinical studies evaluating postoperative GDA pseudoaneurysm. Incidence was calculated by dividing total number of GDA pseudoaneurysms by the total number of pancreatic operations. Additional qualitative data related to GDA pseudoaneurysm presentation and management following pancreatic resection were extracted and reviewed from individual reports. Results: Nine studies were selected for systematic review involving 4227 pancreatic operations with 55 GDA pseudoaneurysms, with a reported incidence of 1·3 (range 0·2-8·3) per cent. Additional data were extracted from 39 individual examples of GDA pseudoaneurysm from 14 studies. The median time for haemorrhage after surgery was at 15 (range 4-210) days. A preceding complication in the postoperative period was documented in four of 21 patients (67 per cent), and sentinel bleeding was observed in 14 of 20 patients (70 per cent). Postoperative complications after pseudoaneurysm management occurred in two-thirds of the patients (14 of 21). The overall survival rate was 85 per cent (33 of 39). Conclusion: GDA pseudoaneurysm is a rare yet serious cause of haemorrhage after pancreatic surgery, with high mortality. The majority of the patients had a preceding complication. Sentinel bleeding was an important clinical indicator

Determination of Pericardial Adipose Tissue Increases the Prognostic Accuracy of Coronary Artery Calcification for Future Cardiovascular Events

Objectives: Pericardial adipose tissue (PAT) is associated with coronary artery plaque accumulation and the incidence of coronary heart disease. We evaluated the possible incremental prognostic value of PAT for future cardiovascular events. Methods: 145 patients (94 males, age 60 10 years) with stable coronary artery disease underwent coronary artery calcification (CAC) scanning in a multislice CT scanner, and the volume of pericardial fat was measured. Mean observation time was 5.4 years. Results: 34 patients experienced a severe cardiac event. They had a significantly higher CAC score (1,708 +/- 2,269 vs. 538 +/- 1,150, p 400, 3.5 (1.9-5.4; p = 0.007) for scores > 800 and 5.9 (3.7-7.8; p = 0.005) for scores > 1,600. When additionally a PAT volume > 200 cm(3) was determined, there was a significant increase in the event rate and relative risk. We calculated a relative risk of 2.9 (1.9-4.2; p = 0.01) for scores > 400, 4.0 (2.1-5.0; p = 0.006) for scores > 800 and 7.1 (4.1-10.2; p = 0.005) for scores > 1,600. Conclusions:The additional determination of PAT increases the predictive power of CAC for future cardiovascular events. PAT might therefore be used as a further parameter for risk stratification. Copyright (C) 2012 S. Karger AG, Base

Remote Manipulation of Droplets on a Flexible Magnetically Responsive Film

The manipulation of droplets is used in a wide range of applications, from lab-on-a-chip devices to bioinspired functional surfaces. Although a variety of droplet manipulation techniques have been proposed, active, fast and reversible manipulation of pure discrete droplets remains elusive due to the technical limitations of previous techniques. Here, we describe a novel technique that enables active, fast, precise and reversible control over the position and motion of a pure discrete droplet with only a permanent magnet by utilizing a magnetically responsive flexible film possessing actuating hierarchical pillars on the surface. This magnetically responsive surface shows reliable actuating capabilities with immediate field responses and maximum tilting angles of ???90??. Furthermore, the magnetic responsive film exhibits superhydrophobicity regardless of tilting angles of the actuating pillars. Using this magnetically responsive film, we demonstrate active and reversible manipulation of droplets with a remote magnetic force.open0

Classification of non-Riemannian doubled-yet-gauged spacetime

Assuming $\mathbf{O}(D,D)$ covariant fields as the `fundamental' variables, Double Field Theory can accommodate novel geometries where a Riemannian metric cannot be defined, even locally. Here we present a complete classification of such non-Riemannian spacetimes in terms of two non-negative integers, $(n,\bar{n})$, $0\leq n+\bar{n}\leq D$. Upon these backgrounds, strings become chiral and anti-chiral over $n$ and $\bar{n}$ directions respectively, while particles and strings are frozen over the $n+\bar{n}$ directions. In particular, we identify $(0,0)$ as Riemannian manifolds, $(1,0)$ as non-relativistic spacetime, $(1,1)$ as Gomis-Ooguri non-relativistic string, $(D{-1},0)$ as ultra-relativistic Carroll geometry, and $(D,0)$ as Siegel's chiral string. Combined with a covariant Kaluza-Klein ansatz which we further spell, $(0,1)$ leads to Newton-Cartan gravity. Alternative to the conventional string compactifications on small manifolds, non-Riemannian spacetime such as $D=10$, $(3,3)$ may open a new scheme of the dimensional reduction from ten to four.Comment: 1+41 pages; v2) Refs added; v3) Published version; v4) Sign error in (2.51) correcte

Protease-activated receptor-2 mediates the expression of inflammatory cytokines, antimicrobial peptides, and matrix metalloproteinases in keratinocytes in response to Propionibacterium acnes

Propionibacterium acnes (P. acnes) has been known to produce various exogenous proteases, however, their role in acne pathogenesis remains largely unknown. Proteases elicit cellular responses, at least in part, via proteinase-activated receptor-2 (PAR-2), which is known to mediate inflammation and immune response. In this study, we investigated whether proteases from P. acnes could activate PAR-2 on keratinocytes and induce pro-inflammatory cytokines, antimicrobial peptides (AMPs), and matrix metalloproteinases (MMPs) via PAR-2 signaling. We examined PAR-2 expression and protease activity in acne lesions using immunofluorescence staining and in situ zymography. The effect of the culture supernatant of P. acnes on Ca2+ signaling in immortalized keratinocytes (HaCaT) was measured using a fluorescence method. HaCaT cells were treated with P. acnes strain ATCC 6919 culture supernatant, with or without pretreatment with serine protease inhibitor or selective PAR-2 antagonist and the gene expression of pro-inflammatory cytokines, AMPs, and MMPs was detected using real-time reverse transcription-polymerase chain reaction. We found that the protease activity and PAR-2 expression were increased in acne lesions. The P. acnes culture supernatant induced calcium signaling in keratinocytes via PAR-2 and stimulated the mRNA expression of interleukin (IL)-1α, -8, tumor necrosis factor (TNF)-α, human beta defensin (hBD)-2, LL-37, MMP-1, -2, -3, -9, and -13 in keratinocytes, which was significantly inhibited by serine protease inhibitor as well as selective PAR-2 specific antagonist. These results indicate that PAR-2 plays an important role in the pathogenesis of acne by inducing inflammatory mediators in response to proteases secreted from P. acnes