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The use of titanium dioxide (TiO2) as an additive in food has been a subject of ongoing debate in Europe due to its potential toxicity. To inform and support toxicological assessment of this additive, a better understanding of the physicochemical characteristics of TiO2 added to food is needed. For this reason, recent research efforts have focused on method development for the physicochemical characterisation of TiO2 in food and, as a raw material, in a regulatory context. Despite the significant progress made so far, more information is needed about the size-resolved quantification of titania nanoparticles in the fraction below 100 nm. Here, we report the development of a multi-method analytical platform for the characterisation of TiO2 in food. It is based on single particle ICP-MS (spICP-MS), supported by asymmetrical flow field-flow fractionation (AF4) coupled on-line to ICP-MS and multi-angle light scattering (MALS). spICP-MS was optimised to detect TiO2 with sizes down to 15 nm. This enabled us to detect and quantify a fraction of TiO2 particles with sizes below 35 nm, which has not been reported in the literature so far. The presence of this size fraction was confirmed by AF4/MALS/ICP-MS in the raw E171 additive. The relative percentage of particles in this fraction (from the total particle number detected) ranged from 48 to 61% in a range of food products purchased from a local grocery store, with a number concentration range of 2.9 1010–7.13 1013 kg−1, depending on the product. These findings will help bridge the gap with regard to lack of data comparability between orthogonal measurement methods and provide further scientific evidence supporting policy makers and regulators. [ABSTRACT FROM AUTHOR]

We report the independent discovery of PSR J0026-1955 with the Murchison Widefield Array (MWA) in the ongoing Southern-sky MWA Rapid Two-metre pulsar survey. J0026-1955 has a period of ∼1.306 s, a dispersion measure of ∼20.869 pc cmâˆ'3, and a nulling fraction of ∼77%. This pulsar highlights the advantages of the survey's long dwell times (∼80 minutes), which, when fully searched, will be sensitive to the expected population of similarly bright, intermittent pulsars with long nulls. A single-pulse analysis in the MWA's 140â€"170 MHz band also reveals a complex subpulse drifting behavior, including both rapid changes of the drift rate characteristic of mode switching pulsars, as well as a slow, consistent evolution of the drift rate within modes. In some longer drift sequences, interruptions in the otherwise smooth drift rate evolution occur preferentially at a particular phase, typically lasting a few pulses. These properties make this pulsar an ideal test bed for prevailing models of drifting behavior such as the carousel model. [ABSTRACT FROM AUTHOR]

The objective of this study is to attempt to understand predictors of health among adult migrants from Myanmar to Thailand and predictors of development among their children. EQ5D5L scores and sociodemographic data were obtained among adult household members of children from two schools on the Thai/Myanmar border. Children were administered Ages and Stages questionnaires (ASQs). OLS and logistic regressions were used to examine predictors (e.g., witnessing gunfire) of various outcome measures (e.g., ASQ scores among children). In logistic regression analyses, maternal literacy proved to be a very strong predictor of the child's ASQ communication [17 ASQ points out of 60; 95 % confidence interval (CI) 3, 31 points], problem solving (25 points; 95 % CI 4, 45 points), and social skills (12 points; 95 % CI 1, 23 points) scores. A lower number of habitants/room predicted significantly better dentition among children [odds ratio (OR) 1.08, 95 % CI 1.01, 1.67] and better social skills on the child's ASQ (12 points; 95 % CI 1, 23 points). Appliance ownership was a weak predictor of adult health, with those who own a refrigerator having about an 8 % higher score on the EQ5D5L (1.08; 95 % CI 1.01, 1.16). Finally, parents who witnessed gunfire tended to have children with ASQ scores that were 14 points lower than average in problem solving (95 % CI −24, −4). Maternal education programs may have a very large impact on the development of their children. However, identifying those households at greatest need of resources is not a simple task, and will require a more complete census of communities at risk. [ABSTRACT FROM AUTHOR]

Abstract: The cyclisation of mono-protected and bis-protected guanidines 8a–j under standard iodocyclisation conditions (I2/K2CO3) gave the guanidine heterocycles 9–25 via either a direct cyclisation or by a cyclisation/ring-contraction process, which could be controlled by careful selection of conditions. [Copyright &y& Elsevier]

We present some first results on the variability, polarization and general properties of radio sources selected at 20 GHz, the highest frequency at which a sensitive radio survey has been carried out over a large area of sky. Sources with flux densities above 100 mJy in the Australia Telescope Compact Array 20 GHz pilot survey at declination −60° to −70° were observed at up to three epochs during 2002–04, including near-simultaneous measurements at 5, 8 and 18 GHz in 2003. Of the 173 sources detected, 65 per cent are candidate QSOs or BL Lac objects, 20 per cent galaxies and 15 per cent faint optical objects or blank fields. On a 1–2 yr time-scale, the general level of variability at 20 GHz appears to be low. For the 108 sources with good-quality measurements in both 2003 and 2004, the median variability index at 20 GHz was 6.9 per cent and only five sources varied by more than 30 per cent in flux density. Most sources in our sample show low levels of linear polarization (typically 1–5 per cent), with a median fractional polarization of 2.3 per cent at 20 GHz. There is a trend for fainter 20 GHz sources to have higher fractional polarization. At least 40 per cent of sources selected at 20 GHz have strong spectral curvature over the frequency range 1–20 GHz. We use a radio ‘two-colour diagram’ to characterize the radio spectra of our sample, and confirm that the flux densities of radio sources at 20 GHz (which are also the foreground point-source population for cosmic microwave background anisotropy experiments like Wilkinson Microwave Anisotropy Probe and Planck) cannot be reliably predicted by extrapolating from surveys at lower frequencies. As a result, direct selection at 20 GHz appears to be a more efficient way of identifying 90 GHz phase calibrators for Atacama Large Millimeter Array (ALMA) than the currently proposed technique of extrapolation from radio surveys at 1–5 GHz. [ABSTRACT FROM AUTHOR]