Will Gravitational Wave Sirens Determine the Hubble Constant?

Lack of knowledge about the background expansion history of the Universe from independent observations makes it problematic to obtain a precise and accurate estimation of the Hubble constant $H_0$ from gravitational wave standard sirens, even with electromagnetic counterpart redshifts. Simply fitting simultaneously for the matter density in a flat \lcdm\ model can reduce the precision on $H_0$ from 1\% to 5\%, while not knowing the actual background expansion model of the universe (e.g.\ form of dark energy) can introduce substantial bias in estimation of the Hubble constant. When the statistical precision is at the level of 1\% uncertainty on $H_0$, biases in non-\lcdm\ cosmologies that are consistent with current data could reach the 3$\sigma$ level. To avoid model-dependent biases, statistical techniques that are appropriately agnostic about model assumptions need to be employed.Comment: 7 pages, 7 figure

The particle interpretation of N = 1 supersymmetric spin foams

We show that N = 1 supersymmetric BF theory in 3d leads to a supersymmetric spin foam amplitude via a lattice discretisation. Furthermore, by analysing the supersymmetric quantum amplitudes, we show that they can be re-interpreted as 3d gravity coupled to embedded fermionic Feynman diagrams.Comment: Pages: 16+1

Higher physical fitness levels are associated with less language decline in healthy ageing

Healthy ageing is associated with decline in cognitive abilities such as language. Aerobic fitness has been shown to ameliorate decline in some cognitive domains, but the potential benefits for language have not been examined. In a cross-sectional sample, we investigated the relationship between aerobic fitness and tip-of-the-tongue states. These are among the most frequent cognitive failures in healthy older adults and occur when a speaker knows a word but is unable to produce it. We found that healthy older adults indeed experience more tip-of-the-tongue states than young adults. Importantly, higher aerobic fitness levels decrease the probability of experiencing tip-of-the-tongue states in healthy older adults. Fitness-related differences in word finding abilities are observed over and above effects of age. This is the first demonstration of a link between aerobic fitness and language functioning in healthy older adults

Development of explosive welding techniques for fabrication of regeneratively cooled thrust chambers for large rocket engine requirements Final report, 28 Jun. 1967 - 15 Sep. 1970

Explosive welding techniques in fabricating regeneratively cooled thrust chambers for large rocket engine requirements including ultrasonic inspection, metallography, and burst testin

Nutritional intervention and impact of polyphenol on glycohaemoglobin (HbA1c) in non-diabetic and type 2 diabetic subjects: systematic review and meta-analysis

Polyphenols have been extensively studied for their antioxidant and anti-inflammatory properties. Recently, their antiglycative actions by oxidative stress modulation have been linked to prevention of diabetes and associated complications. This paper assesses the evidence for polyphenol interventions on glycohaemoglobin (HbA1c) in non-diabetic, pre-diabetic and type 2 diabetes mellitus (T2DM) subjects. A systematic review of polyphenols clinical trials on HbA1c in humans was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis. Thirty-six controlled randomized trials with HbA1c values were included. Polyphenols (extracts, supplements, foods), were supplemented (28 mg to 1.5g) for 0.7 to 12 months. Combining all subjects (n=1954, mean baseline HbA1c=7.03%, 53 mmol/mol), polyphenol supplementation significantly (p<0.001) lowered HbA1c% by -0.53±0.12 units (-5.79±0.13 mmol/mol). This reduction was significant (p<0.001) in T2DM subjects, specifically (n=1426, mean baseline HbA1c=7.44%, 58 mmol/mol), with HbA1c% lowered by -0.21±0.04 units (-2.29±0.4 mmol/mol). Polyphenol supplementation had no significant effect (p>0.21) in the non-diabetic (n=258, mean baseline HbA1c=5.47%, 36 mmol/mol) and the pre-diabetic subjects (n=270, mean baseline HbA1c=6.06%, 43 mmol/mol) strata: -0.39±0.27 HbA1c% units (-4.3±0.3 mmol/mol), and -0.38±0.31 units (-4.2±0.31 mmol/mol), respectively. In conclusion, polyphenols can successfully reduce HbA1c in T2DM, without any intervention at glycaemia, and could contribute to the prevention of diabetes complications

[OII] emitters in the GOODS field at z~1.85: a homogeneous measure of evolving star formation

We present the results of a deep, near-infrared, narrow band imaging survey at a central wavelength of 1.062 microns (FWHM=0.01 microns) in the GOODS-South field using the ESO VLT instrument, HAWK-I. The data are used to carry out the highest redshift search for [OII]3727 emission line galaxies to date. The images reach an emission line flux limit (5 sigma) of 1.5 x 10^-17 erg cm^-2 s^-1, additionally making the survey the deepest of its kind at high redshift. In this paper we identify a sample of [OII]3727 emission line objects at redshift z~1.85 in a co-moving volume of ~4100 Mpc^3. Objects are selected using an observed equivalent width (EW_obs) threshold of EW_obs = 50 angstroms. The sample is used to derive the space density and constrain the luminosity function of [OII] emitters at z=1.85. We find that the space density of objects with observed [OII] luminosities in the range log(L_[OII]) > 41.74 erg s^-1 is log(rho)=-2.45+/-0.14 Mpc^-3, a factor of 2 greater than the observed space density of [OII] emitters reported at z~1.4. After accounting for completeness and assuming an internal extinction correction of A_Halpha=1 mag (equivalent to A_[OII]=1.87), we report a star formation rate density of rho* ~0.38+/-0.06 Msun yr^-1 Mpc^-3. We independently derive the dust extinction of the sample using 24 micron fluxes and find a mean extinction of A_[OII]=0.98+/-0.11 magnitudes (A_Halpha=0.52). This is significantly lower than the A_Halpha=1 (A[OII]=1.86) mag value widely used in the literature. Finally we incorporate this improved extinction correction into the star formation rate density measurement and report rho*~0.24+/-0.06 Msun yr^-1 Mpc^-3.Comment: 11 pages, 10 figures, accepted for publication in MNRA