Automated seismic waveform location using multichannel coherency migration (MCM)–I: theory

With the proliferation of dense seismic networks sampling the full seismic wavefield, recorded seismic data volumes are getting bigger and automated analysis tools to locate seismic events are essential. Here, we propose a novel Multichannel Coherency Migration (MCM) method to locate earthquakes in continuous seismic data and reveal the location and origin time of seismic events directly from recorded waveforms. By continuously calculating the coherency between waveforms from different receiver pairs, MCM greatly expands the available information which can be used for event location. MCM does not require phase picking or phase identification, which allows fully automated waveform analysis. By migrating the coherency between waveforms, MCM leads to improved source energy focusing. We have tested and compared MCM to other migration-based methods in noise-free and noisy synthetic data. The tests and analysis show that MCM is noise resistant and can achieve more accurate results compared with other migration-based methods. MCM is able to suppress strong interference from other seismic sources occurring at a similar time and location. It can be used with arbitrary 3D velocity models and is able to obtain reasonable location results with smooth but inaccurate velocity models. MCM exhibits excellent location performance and can be easily parallelized giving it large potential to be developed as a real-time location method for very large datasets

Analogue Cosmological Particle Creation: Quantum Correlations in Expanding Bose Einstein Condensates

We investigate the structure of quantum correlations in an expanding Bose Einstein Condensate (BEC) through the analogue gravity framework. We consider both a 3+1 isotropically expanding BEC as well as the experimentally relevant case of an elongated, effectively 1+1 dimensional, expanding condensate. In this case we include the effects of inhomogeneities in the condensate, a feature rarely included in the analogue gravity literature. In both cases we link the BEC expansion to a simple model for an expanding spacetime and then study the correlation structure numerically and analytically (in suitable approximations). We also discuss the expected strength of such correlation patterns and experimentally feasible BEC systems in which these effects might be detected in the near future.Comment: Reference adde

A chromosomal analysis of Nepa cinerea Linnaeus, 1758 and Ranatra linearis (Linnaeus, 1758) (Heteroptera, Nepidae)

An account is given of the karyotypes and male meiosis of the Water Scorpion Nepa cinerea Linnaeus, 1758 and the Water Stick Insect Ranatra linearis (Linnaeus, 1758) (Heteroptera, Nepomorpha, Nepidae). A number of different approaches and techniques were tried: the employment of both male and female gonads and mid-guts as the sources of chromosomes, squash and air-drying methods for chromosome preparations, C-banding and fluorescence in situ hybridization (FISH) for chromosome study. We found that N. cinerea had a karyotype comprising 14 pairs of autosomes and a multiple sex chromosome system, which is X1X2X3X4Y (♂) / X1X1X2X2X3X3X4X4 (♀), whereas R. linearis had a karyotype comprising 19 pairs of autosomes and a multiple sex chromosome system X1X2X3X4Y (♂) / X1X1X2X2X3X3X4X4 (♀). In both N. cinerea and R. linearis, the autosomes formed chiasmate bivalents in spermatogenesis, and the sex chromosome univalents divided during the first meiotic division and segregated during the second one suggesting thus a post-reductional type of behaviour. These results confirm and amplify those of Steopoe (1925, 1927, 1931, 1932) but are inconsistent with those of other researchers. C-banding appeared helpful in pairing up the autosomes for karyotype assembly; however in R. linearis the chromosomes were much more uniform in size and general appearance than in N. cinerea. FISH for 18S ribosomal DNA (major rDNA) revealed hybridization signals on two of the five sex chromosomes in N. cinerea. In R. linearis, rDNA location was less obvious than in N. cinerea; however it is suggested to be similar. We have detected the presence of the canonical “insect” (TTAGG)n telomeric repeat in chromosomes of these species. This is the first application of C-banding and FISH in the family Nepidae.Copyright Robert B. Angus et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.NHM Repositor

Home versus hospital-based cardiac rehabilitation: A systematic review

Comprehensive cardiac rehabilitation has positive effects on many cardiac risk factors (physical activity, smoking status, cholesterol, anxiety and depression) and can lead to improvements in mortality, morbidity and quality of life. Most formal cardiac rehabilitation in the UK is offered within a hospital or centre setting, although this may not always be convenient or accessible for many cardiac patients, especially those in remote areas. The proportion of eligible patients who successfully complete a cardiac rehabilitation program remains low. There are many reasons for this but geographical isolation and transport issues are important. This systematic review examines the current evidence for home- versus hospital-based cardiac rehabilitation. Home-based cardiac rehabilitation offers greater accessibility to cardiac rehabilitation and has the potential to increase uptake. While there have been fewer studies of home-based cardiac rehabilitation, the available data suggest that it has comparable results to hospital-based programs. Many of these studies are small and heterogeneous in terms of interventions but home-based cardiac rehabilitation appears both safe and effective. Available evidence suggests that it results in longer lasting maintenance of physical activity levels compared with hospital-based rehabilitation and is equally effective in improving cardiac risk factors. Furthermore, it has the potential to be a more cost-effective intervention for patients who cannot easily access their local centre or hospital. Currently home-based cardiac rehabilitation is not offered routinely to all patients but it appears to have the potential to increase uptake in patients who are unable, or less likely, to attend more traditional hospital-based cardiac rehabilitation programs

Neutrinos as galactic dark matter in the Ursa Major galaxy group?

We present the analysis of 23 published rotation curves of disk galaxies belonging to the Ursa Major group of galaxies, with kinematics free of irregularities. The rotation curves are analysed in the context of MOND (Modified Newtonian Dynamics). We add an extra component to the rotation curve fits, in addition to the stellar and gaseous disks: a speculative halo of constant density made of, e.g., neutrinos, which would solve the bulk of the problem currently faced by MOND on rich galaxy clusters scales. We find that this additional unseen mass density is poorly constrained (as expected a priori, given that a neutrino halo never dominates the kinematics), but we also find that the best-fit value is non-zero: rho = 3.8 x 10^{-27} g/cm^3, and that a zero-density is marginally excluded with 87% confidence; also, the 95% confidence upper limit for the density is rho = 9.6 x 10^{-27} g/cm^3. These limits are slightly above the expectations from the Tremaine-Gunn phase space constraints on ordinary 2 eV neutrinos, but in accordance with the maximum density expected for one or two species of 5 eV sterile neutrinos.Comment: Accepted for publication in MNRAS Letters. 5 pages, 2 figure

Insufficient Reporting of Factors Associated with Exercise Referral Scheme Uptake, Attendance, and Adherence: A Systematic Review of Reviews

Background: Exercise Referral Schemes (ERS) are prescribed programmes aimed at tackling physical inactivity and associated non-communicable disease. Inconsistencies in reporting, recording and delivering ERS make it challenging to identify what works, why, and for whom. Methods: PRISMA guided this narrative review of reviews. Fifteen electronic databases were searched for systematic reviews of ERS. Reviewers applied inclusion criteria and quality assessed via the AMSTAR tool. Data on uptake, attendance and adherence were extracted. Results: Eleven reviews met the inclusion criteria. AMSTAR quality was medium. Definitions of uptake varied within reviews. Uptake ranged from 35%-81%. Groups reported as more likely to take up ERS included, (i) females and (ii) older adults. Attendance was defined variably but ranged from 12%-49%. Men were more likely to attend ERS. Effect of medical diagnosis upon uptake and attendance was inconsistent. Exercises prescribed were unreported and therefore, adherence to exercise prescriptions was unreported. The influence of theoretically-informed approaches on uptake, attendance and adherence was generally lacking, however, self-determination, peer support and supervision support were reported as influencing attendance. Conclusions: There was insufficient reporting across studies about uptake, attendance and adherence. Complex interventions like ERS require consistent definitions, recording and reporting of these key facets, but this is not evident from the existing literature

Spiral Galaxies Rotation Curves with a Logarithmic Corrected Newtonian Gravitational Potential

We analyze the rotation curves of 10 spiral galaxies with a newtonian potential corrected with an extra logarithmic term, using a disc modelization for the spiral galaxies. There is a new constant associated with the extra term in the potential. The rotation curve of the chosen sample of spiral galaxies is well reproduced for a given range of the new constant. It is argued that this correction can have its origin from string configurations. The compatibility of this correction with local physics is discussed.Comment: Latex file, 6 pages, 20 figure

The Effect of Pulmonary Artery Catheter Use on Costs and Long-Term Outcomes of Acute Lung Injury

Background: The pulmonary artery catheter (PAC) remains widely used in acute lung injury (ALI) despite known complications and little evidence of improved short-term mortality. Concurrent with NHLBI ARDS Clinical Trials Network Fluid and Catheters Treatment Trial (FACTT), we conducted a prospectively-defined comparison of healthcare costs and long-term outcomes for care with a PAC vs. central venous catheter (CVC). We explored if use of the PAC in ALI is justified by a beneficial cost-effectiveness profile. Methods: We obtained detailed bills for the initial hospitalization. We interviewed survivors using the Health Utilities Index Mark 2 questionnaire at 2, 6, 9 and 12 m to determine quality of life (QOL) and post-discharge resource use. Outcomes beyond 12 m were estimated from federal databases. Incremental costs and outcomes were generated using MonteCarlo simulation. Results: Of 1001 subjects enrolled in FACTT, 774 (86%) were eligible for long-term follow-up and 655 (85%) consented. Hospital costs were similar for the PAC and CVC groups ($96.8k vs.$89.2k, p = 0.38). Post-discharge to 12 m costs were higher for PAC subjects ($61.1k vs. 45.4k, p = 0.03). One-year mortality and QOL among survivors were similar in PAC and CVC groups (mortality: 35.6$14.4k and mean loss of 0.3 quality-adjusted life years (QALYs)) and a 94.2% probability of being higher than the $100k/QALY willingness-to-pay threshold. Conclusion: PAC use increased costs with no patient benefit and thus appears unjustified for routine use in ALI. Trial Registration: www.clinicaltrials.gov NCT00234767. © 2011 Clermont et al