Unitary irreducible representations of SL(2,C) in discrete and continuous SU(1,1) bases

We derive the matrix elements of generators of unitary irreducible representations of SL(2,C) with respect to basis states arising from a decomposition into irreducible representations of SU(1,1). This is done with regard to a discrete basis diagonalized by J^3 and a continuous basis diagonalized by K^1, and for both the discrete and continuous series of SU(1,1). For completeness we also treat the more conventional SU(2) decomposition as a fifth case. The derivation proceeds in a functional / differential framework and exploits the fact that state functions and differential operators have a similar structure in all five cases. The states are defined explicitly and related to SU(1,1) and SU(2) matrix elements.Comment: 21 pages, no figures; v2: published versio

Nonlinear radiation pressure dynamics in an optomechanical crystal

Utilizing a silicon nanobeam optomechanical crystal, we investigate the attractor diagram arising from the radiation pressure interaction between a localized optical cavity at $\lambda = 1552$nm and a mechanical resonance at $\omega/2\pi = 3.72$GHz. At a temperature of $T \approx 10$K, highly nonlinear driving of mechanical motion is observed via continuous wave optical pumping. Introduction of a time-dependent (modulated) optical pump is used to steer the system towards an otherwise inaccessible dynamically stable attractor in which mechanical self-oscillation occurs for an optical pump red-detuned from the cavity resonance. An analytical model incorporating thermo-optic effects due to optical absorption heating is developed, and found to accurately predict the measured device behavior.Comment: 5 pages, 3 figure

A Fully-Integrated Quad-Band GSM/GPRS CMOS Power Amplifier

Concentric distributed active transformers (DAT) are used to implement a fully-integrated quad-band power amplifier (PA) in a standard 130 nm CMOS process. The DAT enables the power amplifier to integrate the input and output matching networks on the same silicon die. The PA integrates on-chip closed-loop power control and operates under supply voltages from 2.9 V to 5.5 V in a standard micro-lead-frame package. It shows no oscillations, degradation, or failures for over 2000 hours of operation with a supply of 6 V at 135° under a VSWR of 15:1 at all phase angles and has also been tested for more than 2 million device-hours (with ongoing reliability monitoring) without a single failure under nominal operation conditions. It produces up to +35 dBm of RF power with power-added efficiency of 51%

MADNESS: A Multiresolution, Adaptive Numerical Environment for Scientific Simulation

MADNESS (multiresolution adaptive numerical environment for scientific simulation) is a high-level software environment for solving integral and differential equations in many dimensions that uses adaptive and fast harmonic analysis methods with guaranteed precision based on multiresolution analysis and separated representations. Underpinning the numerical capabilities is a powerful petascale parallel programming environment that aims to increase both programmer productivity and code scalability. This paper describes the features and capabilities of MADNESS and briefly discusses some current applications in chemistry and several areas of physics

A spin foam model for general Lorentzian 4-geometries

We derive simplicity constraints for the quantization of general Lorentzian 4-geometries. Our method is based on the correspondence between coherent states and classical bivectors and the minimization of associated uncertainties. For spacelike geometries, this scheme agrees with the master constraint method of the model by Engle, Pereira, Rovelli and Livine (EPRL). When it is applied to general Lorentzian geometries, we obtain new constraints that include the EPRL constraints as a special case. They imply a discrete area spectrum for both spacelike and timelike surfaces. We use these constraints to define a spin foam model for general Lorentzian 4-geometries.Comment: 27 pages, 1 figure; v4: published versio

A single domain antibody fragment that recognizes the adaptor ASC defines the role of ASC domains in inflammasome assembly

Myeloid cells assemble inflammasomes in response to infection or cell damage; cytosolic sensors activate pro–caspase-1, indirectly for the most part, via the adaptors ASC and NLRC4. This leads to secretion of proinflammatory cytokines and pyroptosis. To explore complex formation under physiological conditions, we generated an alpaca single domain antibody, VHH[subscript ASC], which specifically recognizes the CARD of human ASC via its type II interface. VHH[subscript ASC] not only impairs ASC[subscript CARD] interactions in vitro, but also inhibits inflammasome activation in response to NLRP3, AIM2, and NAIP triggers when expressed in living cells, highlighting a role of ASC in all three types of inflammasomes. VHH[subscript ASC] leaves the Pyrin domain of ASC functional and stabilizes a filamentous intermediate of inflammasome activation. Incorporation of VHH[subscript ASC]-EGFP into these structures allowed the visualization of endogenous ASC[superscript PYD] filaments for the first time. These data revealed that cross-linking of ASC[superscript PYD] filaments via ASC[superscript CARD] mediates the assembly of ASC foci.National Institutes of Health (U.S.) (Pioneer Award

Efficient occupancy grid computation on the GPU with lidar and radar for road boundary detection

Abstract—Accurate maps of the static environment are essential for many advanced driver-assistance systems. In this paper a new method for the fast computation of occupancy grid maps with laser range-finders and radar sensors is proposed. The approach utilizes the Graphics Processing Unit to overcome the limitations of classical occupancy grid computation in auto-motive environments. It is possible to generate highly accurate grid maps in just a few milliseconds without the loss of sensor precision. Moreover, in the case of a lower resolution radar sensor it is shown that it is suitable to apply super-resolution algorithms to achieve the accuracy of a higher resolution laser-scanner. Finally, a novel histogram based approach for road boundary detection with lidar and radar sensors is presented. I

Generalizability and Validation of PROMIS Scores to Predict Surgical Success in Foot and Ankle Patients: A Tale of Two Academic Centers

Introduction/Purpose: Patient-reported outcomes are advancing clinical care by improving patient satisfaction and engagement. A recent publication reported preoperative PROMIS scores to be highly predictive in selecting patients who would and would not benefit from foot and ankle (F/A) surgery. Although this publication used the data from 5 fellowship trained foot and ankle surgeons at one institution, the generalizability to other patient populations and geographic areas is unknown. This validation study assesses the pre-operative PROMIS physical function (PF) and pain interference (PI) t-scores as a predictor of post-operative success from a separate geographic area