Model-Based Cross-Correlation Search for Gravitational Waves from Scorpius X-1

We consider the cross-correlation search for periodic GWs and its potential application to the LMXB Sco X-1. This method coherently combines data from different detectors at the same time, as well as different times from the same or different detectors. By adjusting the maximum time offset between a pair of data segments to be coherently combined, one can tune the method to trade off sensitivity and computing costs. In particular, the detectable signal amplitude scales as the inverse fourth root of this coherence time. The improvement in amplitude sensitivity for a search with a coherence time of 1hr, compared with a directed stochastic background search with 0.25Hz wide bins is about a factor of 5.4. We show that a search of 1yr of data from Advanced LIGO and Advanced Virgo with a coherence time of 1hr would be able to detect GWs from Sco X-1 at the level predicted by torque balance over a range of signal frequencies from 30-300Hz; if the coherence time could be increased to 10hr, the range would be 20-500Hz. In addition, we consider several technical aspects of the cross-correlation method: We quantify the effects of spectral leakage and show that nearly rectangular windows still lead to the most sensitive search. We produce an explicit parameter-space metric for the cross-correlation search in general and as applied to a neutron star in a circular binary system. We consider the effects of using a signal template averaged over unknown amplitude parameters: the search is sensitive to a combination of the intrinsic signal amplitude and the inclination of the neutron star rotation axis, and the peak of the expected detection statistic is systematically offset from the true signal parameters. Finally, we describe the potential loss of SNR due to unmodelled effects such as signal phase acceleration within the Fourier transform timescale and gradual evolution of the spin frequency.Comment: 27 pages, 12 figures, 4 tables, pdflatex; synchronized to final version published in Phys Rev

Using meta-networks to identify key intervention points in nuclear WMD development

The ability to identify key intervention points in the nuclear WMD development process is vital for the development of effective intervention strategies against nuclear proliferation efforts. This paper describes research in progress to investigate nuclear weapons development as a meta-network of people, knowledge, resources, locations and tasks, and to design a software tool which will be capable of identifying the key intervention points of the process based upon the available information

The presence of 5-HT in myenteric varicosities is not due to uptake of 5-HT released from the mucosa during dissection: use of a novel method for quantifying 5-HT immunoreactivity in myenteric ganglia

Author version made available according to Publisher copyright policy. This is the accepted version of the following article: 
Keating, D. J., Peiris, H., Kyloh, M., Brookes, S. J. H. and Spencer, N. J. (2013), The presence of 5-HT in myenteric varicosities is not due to uptake of 5-HT released from the mucosa during dissection: use of a novel method for quantifying 5-HT immunoreactivity in myenteric ganglia. Neurogastroenterology & Motility, 25: 849–853, 

which has been published in final form at 
http://dx.doi.org/10.1111/nmo.12189. 

In addition, authors may also transmit, print and share copies with colleagues, provided that there is no systematic distribution of the submitted version, e.g. posting on a listserve, network or automated delivery

The β-cell/EC axis: how do islet cells talk to each other?

Author version made available in accordance with the publisher's policy.Within the pancreatic islet, the beta cell represents the ultimate biosensor. Its central function is to accurately sense glucose levels in the blood, and consequently release appropriate amounts of insulin. As the only cell type capable of insulin production, the beta cell must balance this crucial workload with self-preservation and, when required, regeneration. Evidence suggests that the beta cell has an important ally in intra-islet endothelial cells. As well as providing a conduit for delivery of the primary input stimulus (glucose) and dissemination of its most important effector (insulin), intra-islet blood vessels deliver oxygen to these dense clusters of metabolically active cells. Furthermore, it appears that endothelial cells directly impact insulin gene expression, secretion and beta cell survival. This review discusses the molecules and pathways involved in the crosstalk between beta cells and intra-islet endothelial cells. The evidence supporting the intra-islet endothelial cell as an important partner for beta cell function is examined to highlight the relevance of this axis in the context of type 1 and type 2 diabetes. Recent work which has established the potential of endothelial cells or their progenitors to enhance the reestablishment of glycaemic control following pancreatic islet transplantation in animal models is discussed

RCAN1 regulates vesicle recycling and quantal release kinetics via effects on calcineurin activity

Author version made available in accordance with the publisher's policy.We have previously shown that Regulator of Calcineurin 1 (RCAN1) regulates multiple stages of vesicle exocytosis. However, the mechanisms by which RCAN1 affects secretory vesicle exocytosis and quantal release kinetics remain unknown. Here we use carbon fiber amperometry to detect exocytosis from chromaffin cells and identify these underlying mechanisms. We observe reduced exocytosis with repeated stimulations in chromaffin cells overexpressing RCAN1 (RCAN1ox), but not in wild type (WT) cells, indicating a negative effect of RCAN1 on vesicle recycling and endocytosis. Acute exposure to calcineurin inhibitors, cyclosporine A and FK-506, replicates this effect in WT cells but has no additional effect in RCAN1ox cells. When we chronically expose WT cells to cyclosporine A and FK-506 we find that catecholamine release per vesicle and pre-spike foot (PSF) signal parameters are decreased, similar to that in RCAN1ox cells. Inhibiting calcineurin activity in RCAN1ox cells has no additional effect on the amount of catecholamine release per vesicle but further reduces PSF signal parameters. Electron microscopy studies indicate these changes are not due to altered vesicle number or distribution in RCAN1ox cells but reduced vesicle release may be cause by decreased vesicle and dense core size in RCAN1ox cells. Thus, our results indicate that RCAN1 may negatively affects vesicle recycling and quantal release kinetics via the inhibition of calcineurin activity

Wellbeing and healthcare access for sexuality and gender minority secondary school students with long-term health conditions

Peer reviewedPublisher PD

Identifying risks related to road traffic accidents among vulnerable population in Moneragala district, Sri Lanka

Objectives: To identify individual and environmental risks related to road traffic accidents(RTA) among elderly (>60years) and disabled people (>5years living with physical, sensory or mobility impairment) in Moneragala district.Methods: Study was designed as community based participatory research. Participants were vulnerable road users (elderly and disabled). Eight focus group discussions (8-10 in each) were conducted with elderly and disabled to identify local and regional destinations that were most important to access, perceived risks related to RTA and needs/suggestions for road safety. Participants were encouraged to photograph the environment barriers and facilitators for road safety. ‘Photovoice’ is increasingly used as valuable adjunct in participatory research-a voice better heard through.Results: Frequently visited places identified by older people were the hospital, temple, village houses, community hall and bank. For disabled it varied by age, as vocational training centre, special needs school and community hall. Mostly used travel modes were public bus, three wheeled-vehicles or walking. Transportation barriers for the elderly were identified as poor road conditions, lack of disability-friendly transportation system, financial constraints and negative human factors. Disabled found accessibility to public places a major barrier. These facts were supported by photographs. Suggestions for improvement included awareness programs among people involved in transportation, cost effective transportation modes, mass media acknowledgments of rights of elderly and disabled, more effective legislation and improved road infrastructure.Conclusions: It is evident that many places the study population frequently travels are located in the city. They face many risks when travelling to these destinations. It is proposed to improve road conditions, modify modes of transportation, rigorous law enforcement and awareness programs among public to minimize the road related risks faced by disabled and elderl

Results of the 1st external quality assurance for SARS new coronavirus diagnostic PCR and serology : talk

Background The detection of the new Coranavirus (CoV) causing agent of the severe acute respiratory syndrome (SARS) for diagnostic purposes is still a critical step in prevention of secondary hospital infections. In this respect the PCR for SARS diagnostic is the fastest and most sensitive method and was published very early after the description of the new pathogen by different groups. To evaluate the quality and sensitivity of the SARS PCR performed in diagnostic laboratories all over the world an external quality assurance (EQA) for SARS PCR was initiated by the WHO, the European Network for Diagnostics of "Imported" Viral Diseases (ENIVD) and the Robert Koch-Institut. Methods Therefore 10 samples of inactivated SARS CoV strains isolated in Frankfurt and Hong Kong in different dilutions and negative controls were prepared. The freeze dried samples were send by mail to 62 different laboratories, in 37 countries in Europe and Israel (35), Asia (11), The Americas (11), Australia and New Zealand (4) and Africa (1). The results were returned by email or fax 1 week (13), 2 weeks (14), 3 weeks (6) and later (29) after receiving the material which does not mimic at all the possible speed of this fast method. But this was not considered in the evaluation of these first SARS EQA. Results 44 laboratories showed good or excellent results (26 = 100%, 18 = 90%) and even the 14 laboratories which archived only 80% (10) or 70% (4) correct results are mostly lacking sensitivity. The results of the other 4 laboratories show basic problems in regard to sensitivity, specificity and consistency of results and must be overcome as soon as possible. 4 laboratories seem to have problems with the specificity finding a positive signal in negative samples. The different methods used for preparation of the SARS CoV genome and diagnostic PCR test procedure used by the participating laboratories will be discussed in more detail in the presentation. Conclusion However, in contrast to previous EQAs for Ebola, Lassa and Orthopoxviruses the quality of PCR results was rather good which might be caused by the early publication and distribution of well developed PCR methods. An EQA for evaluation of SARS specific serology is still ongoing, first results will be available beginning of April 2004