Reactor Searches for Neutrino Magnetic Moment as a Probe of Extra Dimensions

We present calculations of the magnetic moment contribution to neutrino electron scattering in large extra dimension brane-bulk models (LED) with three bulk neutrinos. We discuss the cases with two and three large extra dimensions of sizes $R$. The calculations are done using reactor flux from Uranium, $^{235}U$ as the neutrino source. We find that if the electron neutrino mass is chosen to be in the range of one eV, the differential cross section for $\bar{\nu}-e$ scattering for low electron recoil energy can be of the same order as the presently explored values in reactor experiments. Furthermore the spectral shape for the LED models is different from the four dimensional case. Future higher precision reactor experiments can therefore be used to provide new constraints on a class of large extra dimension theories.Comment: 8 pages; 3 figure

Do Individual Investors Drive Post-Earnings Announcement Drift? Direct Evidence from Personal Trades

This study examines whether individual investors are the source of post- earnings announcement drift (PEAD). We provide evidence on how individual investors trade in response to extreme quarterly earnings surprises and on the relation between individual investors' trades and subsequent abnormal returns. We find no evidence that either individuals or any sub-category of individuals in our sample cause PEAD. Individuals are significant net buyers after both negative and positive earnings surprises. There is no indication that trading by any of our investor sub-categories explains the concentration of drift at subsequent earnings announcement dates. While post-announcement individual net buying is a significant negative predictor of stock returns over the next three quarters, individual investor trading fails to subsume any of the power of extreme earnings surprises to predict future abnormal returns.post earnings-announcement drift, trading activity, individual investors, market efficiency

What is the real impact of acute kidney injury?

Background: Acute kidney injury (AKI) is a common clinical problem. Studies have documented the incidence of AKI in a variety of populations but to date we do not believe the real incidence of AKI has been accurately documented in a district general hospital setting. The aim here was to describe the detected incidence of AKI in a typical general hospital setting in an unselected population, and describe associated short and long-term outcomes. Methods: A retrospective observational database study from secondary care in East Kent (adult catchment population of 582,300). All adult patients (18 years or over) admitted between 1st February 2009 and 31st July 2009, were included. Patients receiving chronic renal replacement therapy (RRT), maternity and day case admissions were excluded. AKI was defined by the acute kidney injury network (AKIN) criteria. A time dependent risk analysis with logistic regression and Cox regression was used for the analysis of in-hospital mortality and survival. Results: The incidence of AKI in the 6 month period was 15,325 pmp/yr (adults) (69% AKIN1, 18% AKIN2 and 13% AKIN3). In-hospital mortality, length of stay and ITU utilisation all increased with severity of AKI. Patients with AKI had an increase in care on discharge and an increase in hospital readmission within 30 days. Conclusions: This data comes closer to the real incidence and outcomes of AKI managed in-hospital than any study published in the literature to date. Fifteen percent of all admissions sustained an episode of AKI with increased subsequent short and long term morbidity and mortality, even in those with AKIN1. This confers an increased burden and cost to the healthcare economy, which can now be quantified. These results will furnish a baseline for quality improvement projects aimed at early identification, improved management, and where possible prevention, of AKI

Proteins that contain a functional Z-DNA-binding domain localize to cytoplasmic stress granules

Long double-stranded RNA may undergo hyper-editing by adenosine deaminases that act on RNA (ADARs), where up to 50% of adenosine residues may be converted to inosine. However, although numerous RNAs may undergo hyper-editing, the role for inosine-containing hyper-edited double-stranded RNA in cells is poorly understood. Nevertheless, editing plays a critical role in mammalian cells, as highlighted by the analysis of ADAR-null mutants. In particular, the long form of ADAR1 (ADAR1(p150)) is essential for viability. Moreover, a number of studies have implicated ADAR1(p150) in various stress pathways. We have previously shown that ADAR1(p150) localized to cytoplasmic stress granules in HeLa cells following either oxidative or interferon-induced stress. Here, we show that the Z-DNA-binding domain (Zα(ADAR1)) exclusively found in ADAR1(p150) is required for its localization to stress granules. Moreover, we show that fusion of Zα(ADAR1) to either green fluorescent protein (GFP) or polypyrimidine binding protein 4 (PTB4) also results in their localization to stress granules. We additionally show that the Zα domain from other Z-DNA-binding proteins (ZBP1, E3L) is likewise sufficient for localization to stress granules. Finally, we show that Z-RNA or Z-DNA binding is important for stress granule localization. We have thus identified a novel role for Z-DNA-binding domains in mammalian cells

Variational approximation for mixtures of linear mixed models

Mixtures of linear mixed models (MLMMs) are useful for clustering grouped data and can be estimated by likelihood maximization through the EM algorithm. The conventional approach to determining a suitable number of components is to compare different mixture models using penalized log-likelihood criteria such as BIC.We propose fitting MLMMs with variational methods which can perform parameter estimation and model selection simultaneously. A variational approximation is described where the variational lower bound and parameter updates are in closed form, allowing fast evaluation. A new variational greedy algorithm is developed for model selection and learning of the mixture components. This approach allows an automatic initialization of the algorithm and returns a plausible number of mixture components automatically. In cases of weak identifiability of certain model parameters, we use hierarchical centering to reparametrize the model and show empirically that there is a gain in efficiency by variational algorithms similar to that in MCMC algorithms. Related to this, we prove that the approximate rate of convergence of variational algorithms by Gaussian approximation is equal to that of the corresponding Gibbs sampler which suggests that reparametrizations can lead to improved convergence in variational algorithms as well.Comment: 36 pages, 5 figures, 2 tables, submitted to JCG

Partial discharge detection and location for HVDC polymeric cables

This poster is concerned with use of partial discharge monitoring to provide information about the condition of the insulation of electrical cables used for HVDC transmission systems. Electrical cables are among the most fundamental components of any electrical grid, from large subsea international interconnectors, to the ‘last mile’ providing consumers with their electrical supply. The size, cost and current carrying capability are the main considerations when designing and selecting a cable, and in this regard the insulation of these cables is as fundamental as the conductor. Partial discharge (PD) measurement is becoming increasingly vital in monitoring the condition of cable insulation, providing valuable information about the health of the insulation, and predicting when insulation is likely to fail. The majority of this PD monitoring is performed on cable operating under AC conditions, however, with the increasing use of high voltage DC links, for subsea, or long land-based connections provides motivation for the increased use of PD monitoring on cables operating under HVDC. However, despite the increased intensity of research into PD in HVDC cables, there are significant knowledge gaps, preventing the practical application of PD monitoring techniques to HVDC cables. This poster describes the initial stages of a project to partially address these gaps in knowledge, by seeking to obtain results from PD measurements on cables of different insulation types under both AC and DC conditions. From this, recommendations on the use of PD monitoring for HVDC cables, with emphasis on insulation type, are will be provided, as well as recommendations for future research at both an academic and industrial level. The poster will detail the results of the initial literature review, as well as the design for the planned experimentation, and test rig

External lightning protection system for wind turbine blades - power performance

Previous studies conducted by the authors on the aerodynamic performance of turbine blades have shown unfavourable effects of externally mounted lightning down conductors. Owing to this, one could ask whether or not externally mounted lightning down conductors could linearly affect the power performance of the whole wind turbine as well. Therefore, this paper presents a study of the power performance of one wind turbine with an externally mounted lightning down conductor. An untwisted blade profile of NACA 4418 with and without external conductor was used on the full wind turbine model. Numerical simulations were carried out on turbine power output derived from Blade Element Momentum (BEM) theory. The results are compared and discussed. The preliminary results indicate that degradation in power performance may not be significant

Pre-determination of partial discharge inception voltage in power cables using electrode gaps in air under AC voltage

The breakdown of insulation in cables while in service can cause considerable damage to equipment and the accessories to which they are connected. PD in cables arises due to the overstressing of cable insulation resulting from electric field enhancement caused by imperfections in cable core and screen. The nature and magnitude of PD activity depends upon the type of defect, aging, environmental factors, applied voltage and cable loading. Reduction in system voltage can potentially reduce PD, which will correspondingly extend the service life of the cable. Currently, industry voltage statutory requirements permit ±6% tolerance setting on nominal voltage on distribution networks. This ±6% voltage reduction on may have little or an adverse effect on PD magnitude depending on the nature of defect present in the cable. Hence there is a clear requirement to pre-determine the PD inception voltage in cables through laboratory experiments to understand the significance of voltage reduction. This means to verify the effect of voltage reduction on extinguishing or minimizing PD activity in cables. In this paper, range of voltages at which PD incepts termed as partial discharge inception voltage(PDIV) is measured using a test cell containing different types of electrode configuration having different spacing. PDIV measured using the test cell is verified by conducting partial discharge testing in paper insulated lead covered (PILC) and cross-linked poly ethylene(XLPE) cables. It has been found that PDIV measured using the test cell and cable are in good agreement

Nanoscale broadband transmission lines for spin qubit control

The intense interest in spin-based quantum information processing has caused an increasing overlap between two traditionally distinct disciplines, such as magnetic resonance and nanotechnology. In this work we discuss rigourous design guidelines to integrate microwave circuits with charge-sensitive nanostructures, and describe how to simulate such structures accurately and efficiently. We present a new design for an on-chip, broadband, nanoscale microwave line that optimizes the magnetic field driving a spin qubit, while minimizing the disturbance on a nearby charge sensor. This new structure was successfully employed in a single-spin qubit experiment, and shows that the simulations accurately predict the magnetic field values even at frequencies as high as 30 GHz.Comment: 18 pages, 8 figures, 1 table, pdflate