Use of a load carriage assistance device for specialist police

Aim: to examine the effectiveness of a load carriage assistance device (LCAD) on specialist police mobility and marksmanship.Design: A randomized counter-balanced study.Method: Six specialist police officers (age = 41.1±6.2 years, weight = 88.4±9.2 kg) completed 2x2 trials of a tactical course as quickly as possible with and without a Reaper™ LCAD (randomised), worn to support the load of their ballistic shield (±20 kg). Heart rate was measured via an Equivital™ harnesses and marksmanship via distance from centre of target (DCOT). Perceived LCAD impacts were measured with a visual analogue scale (VAS). Bond University Human Research Ethics Committee provided ethics approval (RO1585).Results: No significant differences were found for heart rate (non-Reaper™=152.20±7.29 bpm; Reaper™=152.01±12.97 bpm, p=0.910) or completion time (non-Reaper™=80.46±13.98 secs, Reaper™=76.82±11.23 secs, p=0.130); although a trend towards faster times wearing the ReaperTM was found. Marksmanship was not significantly different between trials however officers lowered the shield on the ground during the non-Reaper™ trials to engage the target. The VAS results were significantly poorer (p&lt;0.001) in non-Reaper™ (-5.58±1.93 mm) versus Reaper™ (2.88±4.90 mm) trials.Conclusion: Officers considered the riot shield to negatively impact their performance to a lesser degree when assisted by the LCAD. The ability to support the shield on the LCAD allowed officers to maintain protection behind a riot shield.</div

Anti-atherogenic function of LPL in human and porcine coronary endothelial cells [abstract]

Abstract only availableMultiple epidemiological studies concluded that lipoprotein lipase (LPL) function is inversely related to the incidence and severity of coronary artery disease. There is debate, however, because those seeking to identify the responsible mechanisms have reported higher than normal levels of LPL in the arteries of diseased mouse models. This confusion could be clarified by beginning to identify the LPL responses in pigs as a large animal model and determining the phenotypic effects of experimentally altering LPL on cultured endothelial cells and isolated vascular tissue. PURPOSE: We tested the hypothesis that LPL activity regulates the expression of thrombospondin-1 (TSP-1), eNOS, VCAM1, and the PPAR promoter activity in endothelial cells. METHODS: LPL activity and protein were measured in the plasma and heart of pigs fed a normal or high fat diet. The cellular effects of changing LPL activity were determined in primary porcine and human endothelial cells. Studies of VCAM1 were performed in cultured cells and isolated aortic segments. Northern and Western blots were used for mRNA and protein measurements, respectively. RESULTS: LPL-dependent lipolysis of VLDL suppressed TSP-1 expression several fold in endothelial cells (PNational Institutes of Healt

GaAs-based distributed feedback laser at 780 nm for 87

Summary form only given. The UK Quantum Technology Hub in Sensors and Metrology [1] has the aim of developing integrated, small and practical cold atom systems for a range of sensor and timing applications which includes rotation, magnetism, gravity and atomic clocks. The approach is similar to that pioneered by the chip scale atomic clock [2] where atoms held in microfabricated vacuum chambers have atomic transitions excited and probed by diodes lasers [3] and photodetectors. That system used coherent population trapping for the clock transitions whilst we are aiming to first produce lasers for cooling and trapping ions inside vacuum chambers before microwave pulses or controlled lasers are used to create superposition states, recombine them and measure the interference from the final state populations. For cooling 87Rb atoms, 780.24 nm lasers with linewidths below ~5 MHz are required whilst the lasers for controlling and measuring superposition states typically external cavity lasers have been used to achieve linewidths from 20 kHz [3] down to a few Hz [4]. Most single mode diode lasers aimed at laser cooling have used DBR gratings with regrowth [5] but this is challenging when using AlGaAs materials due to oxidation.Here we present single mode 780.24 nm DFB AlGaAs/GaAs lasers with output powers up to 50 mW and sidemode suppression ratios above 46 dB (Fig. 1(a)) using sidewall etched gratings (Fig. 1(b)) and no regrowth. The lasers demonstrate clear DFB performance allowing tuning through the required 780.24 nm without any mode hopping. Initial tests for short ridge devices indicate linewidths of ~10 MHz and initial lifetime tests have exceeded 200 hours. We will discuss methods being pursued to increasing the power and reducing the linewidth through longer ridges [5], coupled cavities and by integrating SOAs. Control of the population of electrons in hyperfine split states requires two laser outputs spaced by ~3.617 GHz. Fig 1(c) demonstrates the principle of two DFB lasers operated on the same waveguide where the present line spacing has been increased to 30 GHz to allow a clear measurement by our OSA. Careful control of the gratings and the current enable 3. 617 GHz to be achieved. We will present results comparing two coupled DFB lasers (Fig. 1(c)), direct modulation, external AOMs and integrated AOM approaches and discuss which are best suited for integrated cold atom systems

Evolution of the Solar Activity over Time and Effects on Planetary Atmospheres: I. High-energy Irradiances (1-1700 A)

We report on the results of the Sun in Time multi-wavelength program (X-rays to the UV) of solar analogs with ages covering ~0.1-7 Gyr. The chief science goals are to study the solar magnetic dynamo and to determine the radiative and magnetic properties of the Sun during its evolution across the main sequence. The present paper focuses on the latter goal, which has the ultimate purpose of providing the spectral irradiance evolution of solar-type stars to be used in the study and modeling of planetary atmospheres. The results from the Sun in Time program suggest that the coronal X-ray-EUV emissions of the young main-sequence Sun were ~100-1000 times stronger than those of the present Sun. Similarly, the transition region and chromospheric FUV-UV emissions of the young Sun are expected to be 20-60 and 10-20 times stronger, respectively, than at present. When considering the integrated high-energy emission from 1 to 1200 A, the resulting relationship indicates that the solar high-energy flux was about 2.5 times the present value 2.5 Gyr ago and about 6 times the present value about 3.5 Gyr ago (when life supposedly arose on Earth). The strong radiation emissions inferred should have had major influences on the thermal structure, photochemistry, and photoionization of planetary atmospheres and also played an important role in the development of primitive life in the Solar System. Some examples of the application of the Sun in Time results on exoplanets and on early Solar System planets are discussed.Comment: 20 pages, 8 figures, accepted for publication in Ap

A statistical review of light curves and the prevalence of contact binaries in the Kuiper Belt

We investigate what can be learned about a population of distant Kuiper Belt Objects (KBOs) by studying the statistical properties of their light curves. Whereas others have successfully inferred the properties of individual, highly variable KBOs, we show that the fraction of KBOs with low amplitudes also provides fundamental information about a population. Each light curve is primarily the result of two factors: shape and orientation. We consider contact binaries and ellipsoidal shapes, with and without flattening. After developing the mathematical framework, we apply it to the existing body of KBO light curve data. Principal conclusions are as follows. (1) When using absolute magnitude H as a proxy for the sizes of KBOs, it is more accurate to use the maximum of the light curve (minimum H) rather than the mean. (2) Previous investigators have noted that smaller KBOs tend to have higher-amplitude light curves, and have interpreted this as evidence that they are systematically more irregular in shape than larger KBOs; we show that a population of flattened bodies with uniform proportions, independent of size, could also explain this result. (3) Our method of analysis indicates that prior assessments of the fraction of contact binaries in the Kuiper Belt may be artificially low. (4) The pole orientations of some KBOs can be inferred from observed changes in their light curves over time scales of decades; however, we show that these KBOs constitute a biased sample, whose pole orientations are not representative of the population overall. (5) Although surface topography, albedo patterns, limb darkening, and other surface properties can affect individual light curves, they do not have a strong influence on the statistics overall. (6) Photometry from the Outer Solar System Origins Survey (OSSOS) survey is incompatible with previous results and its statistical properties defy easy interpretation. We also discuss the promise of this approach for the analysis of future, much larger data sets such as the one anticipated from the upcoming Vera C. Rubin Observatory

A statistical review of light curves and the prevalence of contact binaries in the Kuiper Belt

We investigate what can be learned about a population of distant Kuiper Belt Objects (KBOs) by studying the statistical properties of their light curves. Whereas others have successfully inferred the properties of individual, highly variable KBOs, we show that the fraction of KBOs with low amplitudes also provides fundamental information about a population. Each light curve is primarily the result of two factors: shape and orientation. We consider contact binaries and ellipsoidal shapes, with and without flattening. After developing the mathematical framework, we apply it to the existing body of KBO light curve data. Principal conclusions are as follows. (1) When using absolute magnitude H as a proxy for the sizes of KBOs, it is more accurate to use the maximum of the light curve (minimum H) rather than the mean. (2) Previous investigators have noted that smaller KBOs tend to have higher-amplitude light curves, and have interpreted this as evidence that they are systematically more irregular in shape than larger KBOs; we show that a population of flattened bodies with uniform proportions, independent of size, could also explain this result. (3) Our method of analysis indicates that prior assessments of the fraction of contact binaries in the Kuiper Belt may be artificially low. (4) The pole orientations of some KBOs can be inferred from observed changes in their light curves over time scales of decades; however, we show that these KBOs constitute a biased sample, whose pole orientations are not representative of the population overall. (5) Although surface topography, albedo patterns, limb darkening, and other surface properties can affect individual light curves, they do not have a strong influence on the statistics overall. (6) Photometry from the Outer Solar System Origins Survey (OSSOS) survey is incompatible with previous results and its statistical properties defy easy interpretation. We also discuss the promise of this approach for the analysis of future, much larger data sets such as the one anticipated from the upcoming Vera C. Rubin Observatory

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 9 Spectroscopic Galaxy Sample

We present measurements of galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). These use the Data Release 9 (DR9) CMASS sample, which contains 264,283 massive galaxies covering 3275 square degrees with an effective redshift z=0.57 and redshift range 0.43 < z < 0.7. Assuming a concordance Lambda-CDM cosmological model, this sample covers an effective volume of 2.2 Gpc^3, and represents the largest sample of the Universe ever surveyed at this density, n = 3 x 10^-4 h^-3 Mpc^3. We measure the angle-averaged galaxy correlation function and power spectrum, including density-field reconstruction of the baryon acoustic oscillation (BAO) feature. The acoustic features are detected at a significance of 5\sigma in both the correlation function and power spectrum. Combining with the SDSS-II Luminous Red Galaxy Sample, the detection significance increases to 6.7\sigma. Fitting for the position of the acoustic features measures the distance to z=0.57 relative to the sound horizon DV /rs = 13.67 +/- 0.22 at z=0.57. Assuming a fiducial sound horizon of 153.19 Mpc, which matches cosmic microwave background constraints, this corresponds to a distance DV(z=0.57) = 2094 +/- 34 Mpc. At 1.7 per cent, this is the most precise distance constraint ever obtained from a galaxy survey. We place this result alongside previous BAO measurements in a cosmological distance ladder and find excellent agreement with the current supernova measurements. We use these distance measurements to constrain various cosmological models, finding continuing support for a flat Universe with a cosmological constant.Comment: 33 page