2,159 research outputs found
Broadband sensitivity enhancement of detuned dual-recycled Michelson interferometers with EPR entanglement
We demonstrate the applicability of the EPR entanglement squeezing scheme for
enhancing the shot-noise-limited sensitivity of a detuned dual-recycled
Michelson interferometers. In particular, this scheme is applied to the
GEO\,600 interferometer. The effect of losses throughout the interferometer,
arm length asymmetries, and imperfect separation of the signal and idler beams
are considered
Testicular infarction secondary to protein S deficiency: a case report
BACKGROUND: Protein S deficiency is an inherited cause of thrombophilia. We present the second reported case in the literature of a man developing testicular infarction secondary to protein S deficiency. CASE PRESENTATION: A 63 year old man presented with sudden onset of pain in his left hemi-scrotum. Despite oral warfarin therapy the plasma INR was only 1.4 at presentation. Doppler ultrasound scan of the scrotum confirmed absent blood flow to the left testis with increased echogenicity. Orchidectomy was performed to remove the necrotic testis. Post-operatively the patient did well and was referred to the Regional Haemophilia and Thrombosis Centre for further management. CONCLUSION: The case highlights a rare but potential complication of protein S deficiency and demonstrates the importance of adequate anticoagulation in these patients
Fundamental Limitations of Cavity-assisted Atom Interferometry
Atom interferometers employing optical cavities to enhance the beam splitter
pulses promise significant advances in science and technology, notably for
future gravitational wave detectors. Long cavities, on the scale of hundreds of
meters, have been proposed in experiments aiming to observe gravitational waves
with frequencies below 1 Hz, where laser interferometers, such as LIGO, have
poor sensitivity. Alternatively, short cavities have also been proposed for
enhancing the sensitivity of more portable atom interferometers. We explore the
fundamental limitations of two-mirror cavities for atomic beam splitting, and
establish upper bounds on the temperature of the atomic ensemble as a function
of cavity length and three design parameters: the cavity g-factor, the
bandwidth, and the optical suppression factor of the first and second order
spatial modes. A lower bound to the cavity bandwidth is found which avoids
elongation of the interaction time and maximizes power enhancement. An upper
limit to cavity length is found for symmetric two-mirror cavities, restricting
the practicality of long baseline detectors. For shorter cavities, an upper
limit on the beam size was derived from the geometrical stability of the
cavity. These findings aim to aid the design of current and future
cavity-assisted atom interferometers.Comment: 11 pages, 12 figure
Effects of Exercise Intensity on Postexercise Endothelial Function and Oxidative Stress
Purpose. To measure endothelial function and oxidative stress immediately, 90 minutes, and three hours after exercise of varying intensities. Methods. Sixteen apparently healthy men completed three exercise bouts of treadmill running for 30 minutes at 55% V˙O2max (mild); 20 minutes at 75% V˙O2max (moderate); or 5 minutes at 100% V˙O2max (maximal) in random order. Brachial artery flow-mediated dilation (FMD) was assessed with venous blood samples drawn for measurement of endothelin-1 (ET-1), lipid hydroperoxides (LOOHs), and lipid soluble antioxidants. Results. LOOH increased immediately following moderate exercise (P<0.05). ET-1 was higher immediately after exercise and 3 hours after exercise in the mild trial compared to maximal one (P<0.05). Transient decreases were detected for ΔFMD/ShearAUC from baseline following maximal exercise, but it normalised at 3 hours after exercise (P<0.05). Shear rate was higher immediately after exercise in the maximal trial compared to mild exercise (P<0.05). No changes in baseline diameter, peak diameter, absolute change in diameter, or FMD were observed following any of the exercise trials (P>0.05). Conclusions. Acute exercise at different intensities elicits varied effects on oxidative stress, shear rate, and ET-1 that do not appear to mediate changes in endothelial function measured by FMD
Bolstering Mission Success: Lessons Learned for Small Satellite Developers Adhering to Manned Spaceflight Requirements
This paper is meant to impart critical knowledge to new and upcoming spacecraft developers (universities, high schools, research centers, young commercial companies, etc.) regarding lessons learned that they can implement to create successful spacecraft missions. This perspective comes from NanoRacks, a “space access provider”, where we’ve gained enormous expertise on how to design and build to requirements driven by human-rated spaceflight. As we all know, operating in space is only half of the battle
A Systematic Review of the Acute Effects of Exercise on Immune and Inflammatory Indices in Untrained Adults
Feasibility of near-unstable cavities for future gravitational wave detectors
Near-unstable cavities have been proposed as an enabling technology for
future gravitational wave detectors, as their compact structure and large beam
spots can reduce the coating thermal noise of the interferometer. We present a
tabletop experiment investigating the behaviour of an optical cavity as it is
parametrically pushed to geometrical instability. We report on the observed
degeneracies of the cavity's eigenmodes as the cavity becomes unstable and the
resonance conditions become hyper-sensitive to mirror surface imperfections. A
simple model of the cavity and precise measurements of the resonant frequencies
allow us to characterize the stability of the cavity and give an estimate of
the mirror astigmatism. The significance of these results for gravitational
wave detectors is discussed, and avenues for further research are suggested.Comment: 11 pages, 8 figure
A Systematic Review of the Acute Effects of Exercise on Immune and Inflammatory Indices in Untrained Adults
BACKGROUND: Cardiovascular disease (CVD) is the leading cause of global mortality. Although the incidence may be reduced with regular exercise, the health benefits of a single bout of exercise on selected CVD risk factors are not well understood. The primary objective of this review is to consider the transient effects of exercise on immune (neutrophil count) and inflammatory (interleukin-6 [IL-6], C-reactive protein [CRP]) markers in untrained adults. METHODS: MEDLINE, EMBASE, CINAHL, Sports Discus and Cochrane were searched for relevant studies published from January 1946 to May 2013. Randomised controlled or crossover studies which measured any of these parameters in untrained but otherwise healthy participants in the 48 h following about of exercise, less than 1 h in duration were included. RESULTS: Ten studies met the inclusion criteria. The results indicate a single bout of aerobic or resistance exercise of moderate to high intensity promotes an increase in IL-6 (145 %) and neutrophil counts (51 %). It appears that 30–60 min of moderate to high intensity exercise is necessary to elicit such changes although variables such as the mode, intensity and pattern of exercise also affect the response. The acute response of CRP within the included studies is equivocal. CONCLUSIONS: Although responses to CRP are inconsistent, a single bout of exercise can increase the activity of both circulating IL-6 and neutrophil counts in untrained adults. These immune and inflammatory responses to a single bout of exercise may be linked to a range of health benefits
Partnered care: insights from economic theories of the firm
This paper offers ideas as to how economic theories of the firm might be used as a lens to inform the development of the Partnered Health Care Model of healthcare delivery in The Bahamas. The model is explained, concepts are offered and implications suggested
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Advances in therapeutic peptides targeting G protein-coupled receptors.
Dysregulation of peptide-activated pathways causes a range of diseases, fostering the discovery and clinical development of peptide drugs. Many endogenous peptides activate G protein-coupled receptors (GPCRs) - nearly 50 GPCR peptide drugs have been approved to date, most of them for metabolic disease or oncology, and more than 10 potentially first-in-class peptide therapeutics are in the pipeline. The majority of existing peptide therapeutics are agonists, which reflects the currently dominant strategy of modifying the endogenous peptide sequence of ligands for peptide-binding GPCRs. Increasingly, novel strategies are being employed to develop both agonists and antagonists, to both introduce chemical novelty and improve drug-like properties. Pharmacodynamic improvements are evolving to allow biasing ligands to activate specific downstream signalling pathways, in order to optimize efficacy and reduce side effects. In pharmacokinetics, modifications that increase plasma half-life have been revolutionary. Here, we discuss the current status of the peptide drugs targeting GPCRs, with a focus on evolving strategies to improve pharmacokinetic and pharmacodynamic properties.Wellcome Trust [WT107715/Z/15/Z], Cambridge Biomedical Research Centre Biomedical Resources Gran
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