425 research outputs found
Birth of a station: the impact of Nova on the Perth radio market
At the end of 2002 a new player entered the Perth radio market. The launch of Nova threatened to create ripples in the relatively calm waters of the radio pool which had become comfortably settled since the last new entrant twenty years before. Researchers had a chance to observe the impact on the market, the products, the formats and the audiences and this paper describes the highs and lows of the market players during Nova's first year
Surface normal photonic crystal waveguide coupling for N^3 distributed optoelectronic crossbar
The realization of the N^3 distributed optoelectronic crossbar requires the incorporation of bidirectional transceiver modules. The current design philosophy of these modules in their single wavelength configuration consist of the integration of VCSEL and RCE detection devices monolithically integrated with a bidirectional common waveguide. Coupling into this common waveguide is currently under investigation utilizing two methods 1.) surface normal coupling using a buried grating coupler external but monolithic surface normal coupling utilizing photonic crystal. This paper will briefly discuss the first method and its drawbacks which motivate the second photonic crystal implementation method. Our initial design work has been accomplished at 980 nm. The measure reflectance spectrum of the VCSEL/PD epitaxy structure prior to the fabrication of the photonic crystal coupler and waveguide layer
Irish Marine Projects supported by the EU INTERREG IV Programme in 2007 - 2008
The EU INTERREG-IV Programme (2007-2013) is an important source of external competitive funding for a range of knowledge-based marine projects promoting regional and cross-border co-operation and development. During the period 2007-2008, fifteen marine INTERREG-IV projects (including two preparatory actions) with Irish participation were approved for funding. The total value of these projects is circa €35m with over €4m in grant-aid going to the Irish partners. This directory provides a summary of each of these fifteen projects. These projects in turn contribute to the implementation of research, development and innovation priorities identified in the national Strategy for Science, Technology and Innovation (SSTI: 2006-2013) and its marine component, the Sea Change Strategy (2007-2013).Funder: European Unio
Evaluating Safety and Productivity Relationship in Human-Robot Collaboration
Collaborative robots can improve ergonomics on factory floors while allowing a higher level of flexibility in production. The evolution of robotics and cyber-physical systems in size and functionality has enabled new applications which were never foreseen in traditional industrial robots. However, the current human-robot collaboration (HRC) technologies are limited in reliability and safety, which are vital in risk-critical scenarios. Certainly, confusion about European safety regulations has led to situations where collaborative robots operate behind security barriers, thus negating their advantages while reducing overall application productivity.Despite recent advances, developing a safe collaborative robotic system for performing complex industrial or daily tasks remains a challenge. Multiple influential factors in HRC make it difficult to define a clear classification to understand the depth of collaboration between humans and robots. In this article, we review the state of the art in reliable collaborative robotic work cells and propose a reference model to combine influential factors such as robot autonomy, collaboration, and safety modes to redefine HRC categorization
Neutral perfect fluids of Majumdar-type in general relativity
We consider the extension of the Majumdar-type class of static solutions for
the Einstein-Maxwell equations, proposed by Ida to include charged perfect
fluid sources. We impose the equation of state and discuss
spherically symmetric solutions for the linear potential equation satisfied by
the metric. In this particular case the fluid charge density vanishes and we
locate the arising neutral perfect fluid in the intermediate region defined by
two thin shells with respective charges and . With its innermost flat
and external (Schwarzschild) asymptotically flat spacetime regions, the
resultant condenser-like geometries resemble solutions discussed by Cohen and
Cohen in a different context. We explore this relationship and point out an
exotic gravitational property of our neutral perfect fluid. We mention possible
continuations of this study to embrace non-spherically symmetric situations and
higher dimensional spacetimes.Comment: 9 page
Matrix Metalloproteinase Expression in Contusional Traumatic Brain Injury: A Paired Microdialysis Study.
Matrix metalloproteinases (MMPs) are extracellular enzymes that have been implicated in the pathophysiology of blood-brain barrier (BBB) breakdown, contusion expansion, and vasogenic edema after traumatic brain injury (TBI). Specifically, in focal injury models, increased MMP-9 expression has been observed in pericontusional brain, and MMP-9 inhibitors reduce brain swelling and final lesion volume. The aim of this study was to examine whether there is a similarly localized increase of MMP concentrations in patients with contusional TBI. Paired microdialysis catheters were inserted into 12 patients with contusional TBI (with or without associated mass lesion) targeting pericontusional and radiologically normal brain defined on admission computed tomography scan. Microdialysate was pooled every 8 h and analyzed for MMP-1, -2, -7, -9, and -10 using a multiplex immunoassay. Concentrations of MMP-1, -2, and -10 were similar at both monitoring sites and did not show discernible temporal trends. Overall, there was a gradual increase in MMP-7 concentrations in both normal and injured brain over the monitoring period, although this was not consistent in every patient. MMP-9 concentrations were elevated in pericontusional, compared to normal, brain, with the maximal difference at the earliest monitoring times (i.e., <24 h postinjury). Repeated-measures analysis of variance showed that MMP-9 concentrations were significantly higher in pericontusional brain (p=0.03) and within the first 72 h of injury, compared with later in the monitoring period (p=0.04). No significant differences were found for the other MMPs assayed. MMP-9 concentrations are increased in pericontusional brain early post-TBI and may represent a potential therapeutic target to reduce hemorrhagic progression and vasogenic edema.M.R.G. was supported by a National Institute for Health Research
(NIHR) Academic Clinical Fellowship, a Royal College of
Surgeons/Philip King Research Fellowship, and a Beverley and
Raymond Sackler Fellowship. A.H. was supported by a joint
Medical Research Council/ Royal College of Surgeons of England
Clinical Research Training Fellowship. K.L.H.C. is supported by
the NIHR Biomedical Research Center, Cambridge (Neuroscience
Theme; Brain Injury and Repair Theme). J.D.P. is supported by the
Traumatic Brain Injury NIHR Health Technology Cooperative.
D.K.M. is supported by an NIHR Senior Investigator Award.
P.J.A.H. is supported by the Cambridge NIHR BRC and an NIHR
Research Professorship.This is the final published version. It was first made available by Mary Ann Liebert at http://dx.doi.org/10.1089/neu.2014.376
Surface normal photonic crystal waveguide coupling for N^3 distributed optoelectronic crossbar
The realization of the N^3 distributed optoelectronic crossbar requires the incorporation of bidirectional transceiver modules. The current design philosophy of these modules in their single wavelength configuration consist of the integration of VCSEL and RCE detection devices monolithically integrated with a bidirectional common waveguide. Coupling into this common waveguide is currently under investigation utilizing two methods 1.) surface normal coupling using a buried grating coupler external but monolithic surface normal coupling utilizing photonic crystal. This paper will briefly discuss the first method and its drawbacks which motivate the second photonic crystal implementation method. Our initial design work has been accomplished at 980 nm. The measure reflectance spectrum of the VCSEL/PD epitaxy structure prior to the fabrication of the photonic crystal coupler and waveguide layer
Photoelectron spectroscopy of manganese-based Heusler alloys
Ultraviolet-photoemission spectroscopy has been employed to investigate the valence-band electronic structures of the magnetic alloys Co2MnSn, Cu2MnAl, and Pd2MnSn.The valence band of Co2MnSn extends to approximately 5 eV below the Fermi level with a high density of states immediately below the Fermi edge. Cu2MnAl and Pd2MnSn have valence-band widths of 6 and 7 eV, respectively, with the highest density of states lying some 3 eV below the Fermi level in each case. Photoemission measurements in the region of the Mn 3p threshold indicate that Mn 3d character extends across the full width of the valence band for all three alloys. For Pd2MnSn, additional photoemission measurements in the region of the Pd 4d Cooper minimum confirm this conclusion. Modulations in photocurrent resulting from Mn 3p-to-3d resonances across the valence band of Co2MnSn are most intense towards the bottom of the band. This is discussed in terms of possible variations in initial-state hybridization. The experimental photoemission spectra are compared with calculated spectra derived from theoretical band structures. Although there are some differences in shape, the bandwidths of the calculated spectra agree very well with the experimental results
(In)finite extent of stationary perfect fluids in Newtonian theory
For stationary, barotropic fluids in Newtonian gravity we give simple
criteria on the equation of state and the "law of motion" which guarantee
finite or infinite extent of the fluid region (providing a priori estimates for
the corresponding stationary Newton-Euler system). Under more restrictive
conditions, we can also exclude the presence of "hollow" configurations. Our
main result, which does not assume axial symmetry, uses the virial theorem as
the key ingredient and generalises a known result in the static case. In the
axially symmetric case stronger results are obtained and examples are
discussed.Comment: Corrections according to the version accepted by Ann. Henri Poincar
Characterising the dynamics of cerebral metabolic dysfunction following traumatic brain injury: A microdialysis study in 619 patients.
Funder: National Institute for Health Research (NIHR)Traumatic brain injury (TBI) is a major cause of death and disability, particularly amongst young people. Current intensive care management of TBI patients is targeted at maintaining normal brain physiology and preventing secondary injury. Microdialysis is an invasive monitor that permits real-time assessment of derangements in cerebral metabolism and responses to treatment. We examined the prognostic value of microdialysis parameters, and the inter-relationships with other neuromonitoring modalities to identify interventions that improve metabolism. This was an analysis of prospective data in 619 adult TBI patients requiring intensive care treatment and invasive neuromonitoring at a tertiary UK neurosciences unit. Patients had continuous measurement of intracranial pressure (ICP), arterial blood pressure (ABP), brain tissue oxygenation (PbtO2), and cerebral metabolism and were managed according to a standardized therapeutic protocol. Microdialysate was assayed hourly for metabolites including glucose, pyruvate, and lactate. Cerebral perfusion pressure (CPP) and cerebral autoregulation (PRx) were derived from the ICP and ABP. Outcome was assessed with the Glasgow Outcome Score (GOS) at 6 months. Relationships between monitoring variables was examined with generalized additive mixed models (GAMM). Lactate/Pyruvate Ratio (LPR) over the first 3 to 7 days following injury was elevated amongst patients with poor outcome and was an independent predictor of ordinal GOS (p70mmHg, PRx 18mmHg, and brain glucose >1mM. Deranged cerebral metabolism is an important determinant of patient outcome following TBI. Variations in cerebral perfusion, oxygenation and glucose supply are associated with changes in cerebral LPR and suggest therapeutic interventions to improve cerebral metabolism. Future prospective studies are required to determine the efficacy of these strategies
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