Integrating out the Dirac sea: Effective field theory approach to exactly solvable four-fermion models

We use 1+1 dimensional large N Gross-Neveu models as a laboratory to derive microscopically effective Lagrangians for positive energy fermions only. When applied to baryons, the Euler-Lagrange equation for these effective theories assumes the form of a non-linear Dirac equation. Its solution reproduces the full semi-classical results including the Dirac sea to any desired accuracy. Dynamical effects from the Dirac sea are encoded in higher order derivative terms and multi-fermion interactions with perturbatively calculable, finite coefficients. Characteristic differences between models with discrete and continuous chiral symmetry are observed and clarified.Comment: 13 pages, 11 figures; v2: typos corrected (Eqs. 4 and 44

A Bayesian Updating Framework for Simulating Marine Energy Converter Drive Train Reliability

This is the author accepted manuscript. The final version is available from METSINTRODUCTION: Accurately quantifying and assessing the reliability of Marine Energy Converters (MEC’s) is critical for the successful commercialization of the industry. Without improvements in reliability and hence reductions in operation & maintenance (O&M) costs, the industry will struggle to reach competitive Levelised Cost of Energy (LCoE). At present, due to the nascent stage of the industry and commercial sensitivities there is very little reliability field data available. This presents an issue: how can the reliability of MEC devices be accurately assessed and predicted with a lack of specific reliability data? [...]The support of the ETI and RCUK Energy Program funding for IDCORE (EP/J500847/1) is gratefully acknowledged

First results on a process-oriented rain area classification technique using Meteosat Second Generation SEVIRI nighttime data

A new technique for process-oriented rain area classification using Meteosat Second Generation SEVIRI nighttime data is introduced. It is based on a combination of the Advective Convective Technique (ACT) which focuses on precipitation areas connected to convective processes and the Rain Area Delineation Scheme during Nighttime (RADS-N) a new technique for the improved detection of stratiform precipitation areas (e.g. in connection with mid-latitude frontal systems). The ACT which uses positive brightness temperature differences between the water vapour (WV) and the infrared (IR) channels (ΔT<sub>WV-IR</sub>) for the detection of convective clouds and connected precipitating clouds has been transferred from Meteosat First Generation (MFG) Metesoat Visible and Infra-Red Imager radiometer (MVIRI) to Meteosat Second Generation (MSG) Spinning Enhanced Visible and InfraRed Imager (SEVIRI). RADS-N is based on the new conceptual model that precipitating cloud areas are characterised by a large cloud water path (<i>cwp</i>) and the presence of ice particles in the upper part of the cloud. The technique considers information about both parameters inherent in the channel differences ΔT<sub>3.9-10.8</sub>, ΔT<sub>3.9-7.3</sub>, ΔT<sub>8.7-10.8</sub>, and ΔT<sub>10.8-12.1</sub>, to detect potentially precipitating cloud areas. All four channel differences are used to gain implicit knowledge about the <i>cwp</i>. ΔT<sub>8.7-10.8</sub> and ΔT<sub>10.8-12.1</sub> are additionally considered to gain information about the cloud phase. First results of a comparison study between the classified rain areas and corresponding ground based radar data for precipitation events in connection with a cold front occlusion show encouraging performance of the new proposed process-oriented rain area classification scheme

Discriminating raining from non-raining clouds at mid-latitudes using Meteosat Second Generation daytime data

International audienceA new method for the delineation of precipitation during daytime using multispectral satellite data is proposed. The approach is not only applicable to the detection of mainly convective precipitation by means of the commonly used relation between infrared cloud top temperature and rainfall probability but enables also the detection of stratiform precipitation (e.g. in connection with mid-latitude frontal systems). The presented scheme is based on the conceptual model that precipitating clouds are characterized by a combination of particles large enough to fall, an adequate vertical extension (both represented by the cloud water path (cwp)), and the existence of ice particles in the upper part of the cloud. The technique considers the VIS0.6 and the NIR1.6 channel to gain information about the cloud water path. Additionally, the channel differences ?T8.7-10.8 and ?T10.8-12.1 are considered to supply information about the cloud phase. Rain area delineation is realized by using a minimum threshold of the rainfall confidence. To obtain a statistical transfer function between the rainfall confidence and the channel differences, the value combination of the four variables is compared to ground based radar data. The retrieval is validated against independent radar data not used for deriving the transfer function and shows an encouraging performance as well as clear improvements compared to existing optical retrieval techniques using only IR thresholds for cloud top temperature

Parathyroid localization

Twenty-nine consecutive patients with suspected primary hyperparathyroidism were examined preoperatively using ultrasound, sonographically guided fine needle aspiration, and aspirate immunostaining for PTH. In 25 patients, localization of enlarged parathyroid glands was successful. In 2 patients, the tumors were located retrosternally and, thus, could not be detected by ultrasound. One patient had a multinodular goiter which impeded localization. In 1 patient with renal osteodystrophy, 2 enlarged parathyroid glands in the neck were not visualized preoperatively. Cytology was not diagnostic, although some cytological features were suggestive of parathyroid cells. Immunostaining of the aspirated smears for PTH, however, correctly diagnosed all preoperatively localized lesions. Ultrasound should be the routine procedure of choice for preoperative localization of abnormal parathyroid glands in primary hyperparathyroidism. Fine needle aspiration and immunocytochemistry can supply confirmation, if necessary

Currents, Waves and Turbulence Measurement: A view from multiple Industrial-Academic Projects in Tidal Stream Energy

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordTidal Stream Energy is considered a regular, predictable and dense energy source with potential to make a significant contribution to our future energy needs. Development of the industry, from resource assessment to device design and operation, requires characterisation of the flow environment at a variety of spatial and temporal scales at tidal energy sites. Demand for flow characterisation arises from companies developing, installing and operating tidal turbine prototypes or small arrays in locations from Scotland to France to Canada. Flow characterisation for tidal stream applications relies on the measurement of water velocity at the relevant scales, yet given the non-uniformity of the flow field, no single instrument measures all the necessary data inputs required by the sector. This paper provides an overview of a variety of current, surface wave and turbulence metrics of industrial relevance to tidal stream and discusses methods employed to secure these datasets. The use of variants of acoustic current profilers is presented, which have been utilised and developed on previous and ongoing industrialacademic projects, including ReDAPT (ETI, UK), FloWTurb (EPSRC, UK) and RealTide (EC H2020, EU). These variants feature differing numbers of acoustic transducers and varying geometrical configurations with installations at both seabed locations and atop operating tidal stream energy converters. Ongoing development of advanced sensor configuration is discussed, aiming to achieve resilient, high resolution threedimensional measurement of mean and turbulent flow tailored for tidal energy applications. The paper gives practitioners and researchers an overview of tidal stream flow characterisation and practical lessons learnt.Engineering and Physical Sciences Research Council (EPSRC)European Union Horizon 202

Nd:YVO4 high-power master oscillator power amplifier laser system for second-generation gravitational wave detectors

Ultrastable high-power laser systems are essential components of the long baseline interferometers that detected the first gravitational waves from merging black holes and neutron stars. One way to further increase the sensitivity of current generation gravitational wave detectors (GWDs) is to increase the laser power injected into the interferometers. In this Letter, we describe and characterize a 72 W and a 114 W linearly polarized, single-frequency laser system at a wavelength of 1064 nm, each based on single-pass Nd:YVO4 power amplifiers. Both systems have low power and frequency noise and very high spatial purity with less than 10.7% and 2.9% higher order mode content, respectively. We demonstrate the simple integration of these amplifiers into the laser stabilization environment of operating GWDs and show stable low-noise operation of one of the amplifier systems in such an environment for more than 45 days

The Impact of Cannabis Use on Neuropsychological and Neural Biomarkers of Treatment Response in Schizophrenia Spectrum Disorders

Cannabis use among patients with schizophrenia-spectrum disorders (SSD) is at significantly greater levels than in healthy populations but the impact of cannabis on neural mechanisms of clinical improvement is poorly understood. Cognitive functioning and neural connectivity are disrupted as a result of both SSD and cannabis use, and research indicates that neuropsychological capacity and connectivity of the striatum, a region involved in salience and reward processing, may be integral to effective antipsychotic drug (AP) treatment response. Despite this overlap, no previous research has investigated the effect of cannabis on the brain functions implicated in AP treatment response. The present study aimed to explicate the influence of recent cannabis use on previously established predictors of effective AP treatment outcomes for patients with SSD. The study used a cohort of medication-naïve first-episode SSD patients who used cannabis at varying rates (i.e. both non-users (n=33) and users (n=43)). Patients were recruited from an ongoing treatment study that consisted of a baseline functional magnetic resonance imaging (fMRI) scan prior to beginning 12 weeks of standardized risperidone treatment, a common second-generation atypical AP drug. Clinical interview, urine toxicology screening, neuropsychological testing and resting-state fMRI were used to characterize the interaction between cannabis, cognitive functioning and striatal connectivity as related to clinical improvement. The study aimed to examine the extent to which the cumulative frequency of cannabis use prior to antipsychotic treatment influences previously established markers of treatment response, specifically: (1) neuropsychological functioning and (2) striatal connectivity. While the primary aims of the study were cross-sectional in nature, the longitudinal design of the parent study allowed us to explore the extent to which the cumulative frequency of cannabis use, prior to and over the course of AP treatment, impacted the prognostic utility of: (1) baseline neuropsychological functioning and (2) baseline resting-state striatal connectivity in predicting treatment response following 12 weeks of treatment. Our results demonstrated that there was no influence of cannabis use on baseline measures of neuropsychological functioning or striatal connectivity. There were also no differences between patients who responded to AP medications versus non-responders in neuropsychological functioning or striatal connectivity. However, there was evidence for a potential interaction effect between cannabis and striatal connectivity in regard to treatment response. Future research with a larger sample size is needed to further investigate the impact of cannabis on the utility of striatal connectivity in predicting treatment outcomes. As legalization of cannabis becomes increasingly widespread across the United States, it will be crucial to understand cannabis’ effect on treatment-related neural circuitry in order to create brain biomarkers that are generalizable to the large proportion of patients who use cannabis

Supercritical fluid explosion process to aid fractionation of lipids from biomass

Disclosed are processes for development and recovery of lipids from biomass. A plant or microorganism-based biomass can be developed to encourage a desired lipid profile. Following development, ecologically friendly normally gaseous fluids such as carbon dioxide can be pressurized to a supercritical state followed by rapid expansion. The fluid is first contacted with a biomass source including oil-containing microorganisms and/or agricultural products. For instance, fungi or algae can be bioconverted from another biomass sources such as canola seed or corn syrup and then contacted with the high pressure fluid. During a contact period, the fluid can diffuse into the biomass, and in particular through the cell walls of the biomass. The fluid undergoes rapid release of pressure and opens the cell structure for improved release of oil. The fluid can optionally be utilized for extraction following the explosion process. For instance, the fluid can be re-pressurized in the same vessel for extraction processes