Shared teaching with multimedia‐enhanced video‐conferencing

Video‐conferencing was used to share a short series of lectures between several universities. A high bandwidth network (155Mbit/s) permitted near broadcast TV quality video to be combined with fully mixed, high‐quality audio. The lectures were supported by visual aids made available using Microsoft NetMeeting to provide multipoint, shared applications. NetMeeting is shown to be a stable and effective platform for distributing multimedia material at a much higher resolution than is possible using the video signals common in most video‐conference lectures, although care must be taken when constructing animated material

Kinematic strangeness production in cluster hadronization

We present a modification to the non-perturbative strangeness production mechanisms in the Monte-Carlo event generator Herwig in order to make the processes more dynamic and collective. We compare the model to a series of observables for soft physics at both LEP and LHC

The Linear-Size Evolution of Classical Double Radio Sources

Recent investigations of how the median size of extragalactic radio sources change with redshift have produced inconsistent results. Eales compared the radio and optical properties of a bright 3C and faint 6C sample and concluded that $D\propto(1+z)^{-1.1\pm0.5}$ ($\Omega_0 = 0$), with $D$ being the median size of the radio sources at a given epoch and z the redshift. Oort, Katgert, and Windhorst, on the other hand, from a comparison of the properties of a number of radio samples, found much stronger evolution, with $D\propto(1+z)^{-3.3 \pm0.5}$. In this paper we attempt to resolve the difference. We have repeated the analysis of Eales using the virtually complete redshift information that now exists for the 6C sample. Confining our analysis to FR2 sources, which we argue is the best-understood class of radio sources and the least likely to be affected by selection effects, we find $D\propto(1+z)^{-1.2\pm0.5}$ ($\Omega_0 = 0$) and $D\propto(1+z)^{-1.7\pm0.4}$ ($\Omega_0 = 1$). Our complete redshift information allows us to gain insight into our result by plotting a radio luminosity-size (P-D) diagram for the 6C sample. The most obvious difference between the 3C and 6C P-D diagrams is the clump of sources in the 6C diagram at $D\sim 100 kpc, P_{151}\sim 5x10^{27} WHz^{-1}sr^{-1}$. These clump sources have similar sizes to the emission-line regions found around high-redshift radio galaxies, suggesting that the presence of dense line-emitting gas around high-redshift radio galaxies is responsible for the size evolution. We show that this explanation can quantitatively explain the observed size evolution, as long as there is either little X-ray emitting gas around these objects or, if there is, it is distributed in a similar way to the emission-line gas: highly anisotropic and inhomogeneous.Comment: compressed and uuencoded postscript file. 33 pages including 5 figures (441951 bytes). Accepted for publication in September Ap

FINDCHIRP: an algorithm for detection of gravitational waves from inspiraling compact binaries

Matched-filter searches for gravitational waves from coalescing compact binaries by the LIGO Scientific Collaboration use the FINDCHIRP algorithm: an implementation of the optimal filter with innovations to account for unknown signal parameters and to improve performance on detector data that has nonstationary and non-Gaussian artifacts. We provide details on the FINDCHIRP algorithm as used in the search for subsolar mass binaries, binary neutron stars, neutron star-black hole binaries, and binary black holes.Comment: 19 pages, 1 figure, journal version with Creative Commons 4.0 open-access license adde

An experimental 2D-Var retrieval using AMSR2

A two-dimensional variational retrieval (2D-Var) is presented for a passive microwave imager. The overlapping antenna patterns of all frequencies from the Advanced Microwave Scanning Radiometer 2 (AMSR2) are explicitly simulated to attempt retrieval of near-surface wind speed and surface skin temperature at finer spatial scales than individual antenna beams. This is achieved, with the effective spatial resolution of retrieved parameters judged by analysis of 2D-Var averaging kernels. Sea surface temperature retrievals achieve about 30 km resolution, with wind speed retrievals at about 10 km resolution. It is argued that multi-dimensional optimal estimation permits greater use of total information content from microwave sensors than other methods, with no compromises on target resolution needed; instead, various targets are retrieved at the highest possible spatial resolution, driven by the channels\u27 sensitivities. All AMSR2 channels can be simulated within near their published noise characteristics for observed clear-sky scenes, though calibration and emissivity model errors are key challenges. This experimental retrieval shows the feasibility of 2D-Var for cloud-free retrievals and opens the possibility of stand-alone 3D-Var retrievals of water vapour and hydrometeor fields from microwave imagers in the future. The results have implications for future satellite missions and sensor design, as spatial oversampling can somewhat mitigate the need for larger antennas in the push for higher spatial resolution

Telehealth on Advanced Networks

We address advanced Internet for complex telehealth applications by reviewing four hospital-based broadband telehealth projects and identifying common threads. These projects were conducted in Australia under a 6-year research project on broadband Internet applications. Each project addressed specific clinical needs and its development was guided by the clinicians involved. Each project was trialed in the field and evaluated against the initial requirements. The four projects covered remote management of a resuscitation team in a district hospital, remote guidance and interpretation of echocardiography, virtual-reality-based instructor-student surgical training, and postoperative outpatient consultations following pediatric surgery. Each was characterized by a high level of interpersonal communication, a high level of clinical expertise, and multiple participants. Each made use of multiple high-quality video and audio links and shared real-time access to clinical data. Four common threads were observed. Each application provided a high level of usability and task focus because the design and use of broadband capability was aimed directly to meet the clinicians' needs. Each used the media quality available over broadband to convey words, gestures, body movements, and facial expressions to support communication and a sense of presence among the participants. Each required a complex information space shared among the participants, including real-time access to stored patient data and real-time interactive access to the patients themselves. Finally, each application supported the social and organizational aspects of their healthcare focus, creating and maintaining relationships between the various participants, and this was done by placing the telehealth application into a wider functioning clinical context. These findings provide evidence for a significantly enhanced role for appropriate telemedicine systems running on advanced networks, in a wider range of clinical applications, more deeply integrated into healthcare systems

Generation and Genetic Characterization of Avian Reovirus Temperature-Sensitive Mutants

AbstractThere currently is little known about the genetic and biological functions of avian reovirus (ARV), an atypical member of the family Reoviridae and the prototype of all nonenveloped viruses that induce syncytia formation. In this study, we created ARV temperature-sensitive (ts) mutants by chemical mutagenesis of ARV strain 138. We developed a novel efficiency of lysis (EOL) screening technique and used it and the classical efficiency of plating (EOP) assay to identify 17 ARV ts mutants. Pairwise mixed infections of these mutants and evaluation of recombinant progeny ts status led to their organization into seven recombination groups. This indicates that these new groups of mutants represent the majority of the ARV genome. To phenotypically characterize the ts mutants, progeny double-stranded RNA (dsRNA) produced at permissive and nonpermissive temperature was measured. Some mutants were capable of dsRNA synthesis at the restrictive temperature (RNA+), which indicates the effects of their ts lesions occur after RNA replication. Most mutants were RNA−, which suggests their mutations affect stages in viral replication that precede progeny genome synthesis

Ultrasound-guided percutaneous thrombin for the management of superior mesenteric artery pseudoaneurysm

Visceral aneurysms are a well-recognized and potentially fatal occurrence in the event of rupture. Endovascular occlusion using stent grafting or embolization is often favorable over high-risk open surgical repair. However, interventional mesenteric angiography may not always be feasible or successful. We present an emergency case of successful occlusion of a large peripancreatic pseudoaneurysm using a single percutaneous injection of thrombin under ultrasound guidance alone after both laparotomy and mesenteric angiography had failed to identify and control bleeding. In this case and review of the current evidence, we propose an effective alternative first-line treatment strategy in these complex patients