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Identifying factors that contribute to the preservation of cognitive function is imperative to maintaining quality of life in advanced years. Of modifiable risk factors, diet quality has emerged as a promising candidate to make an impact on cognition. The objective of this study was to evaluate associations between empirically derived dietary patterns and cognitive function. This study included 18 080 black and white participants aged 45 years and older from the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. Principal component analysis on data from the Block98 FFQ yielded five dietary patterns: convenience, plant-based, sweets/fats, Southern, and alcohol/salads. Incident cognitive impairment was defined as shifting from intact cognitive status (score >4) at first assessment to impaired cognitive status (score ≤4) at latest assessment, measured by the Six-Item Screener. Learning, memory and executive function were evaluated with the Word List Learning, Word List Delayed Recall, and animal fluency assessments. In fully adjusted models, greater consumption of the alcohol/salads pattern was associated with lower odds of incident cognitive impairment (highest quintile (Q5) v. lowest quintile (Q1): OR 0·68; 95 % CI 0·56, 0·84; P for trend 0·0005). Greater consumption of the alcohol/salads pattern was associated with higher scores on all domain-specific assessments and greater consumption of the plant-based pattern was associated with higher scores in learning and memory. Greater consumption of the Southern pattern was associated with lower scores on each domain-specific assessment (all P < 0·05). In conclusion, dietary patterns including plant-based foods and alcohol intake were associated with higher cognitive scores, and a pattern including fried food and processed meat typical of a Southern diet was associated with lower scores.
We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
Light curve analysis by MDW of the photometry and RV data accumulated to date on HD 209458 has made use of a simulations database created for an 8-day HST observing project led by RLG to look for transits in 47 Tuc. We report progress in developing a consistent set of parameters obtained with our versions of the Wilson-Devinney program, WD98 and wd98k93, specially modified to treat large grid sizes, corresponding to objects with radii exceeding 0.7RJ and masses greater than 0.1 MJ.
This work is supported in part by grants to EFM by Canadian NSERC and by the Univ. of Calgary Research Grants Committee.
Primordial binaries in globular clusters are important both because their properties are an integral part of the description of the stellar population and because they can strongly influence the dynamical evolution of the cluster (see Hut, this volume).
The movements of fluid–fluid interfaces and the common curve are an important aspect of two-fluid-phase flow through porous media. The focus of this work is to develop, apply and evaluate methods to simulate two-fluid-phase flow in porous medium systems at the microscale and to demonstrate how these results can be used to support evolving macroscale models. Of particular concern is the problem of spurious velocities that confound the accurate representation of interfacial dynamics in such systems. To circumvent this problem, a combined level-set and lattice-Boltzmann method is advanced to simulate and track the dynamics of the fluid–fluid interface and of the common curve during simulations of two-fluid-phase flow in porous media. We demonstrate that the interface and common curve velocities can be determined accurately, even when spurious currents are generated in the vicinity of interfaces. Static and dynamic contact angles are computed and shown to agree with existing slip models. A resolution study is presented for dynamic drainage and imbibition in a sphere pack, demonstrating the sensitivity of averaged quantities to resolution.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
The future of centimetre and metre-wave astronomy lies with the Square Kilometre Array (SKA), a telescope under development by a consortium of 17 countries that will be 50 times more sensitive than any existing radio facility. Most of the key science for the SKA will be addressed through large-area imaging of the Universe at frequencies from a few hundred MHz to a few GHz. The Australian SKA Pathfinder (ASKAP) is a technology demonstrator aimed in the mid-frequency range, and achieves instantaneous wide-area imaging through the development and deployment of phased-array feed systems on parabolic reflectors. The large field-of-view makes ASKAP an unprecedented synoptic telescope that will make substantial advances in SKA key science. ASKAP will be located at the Murchison Radio Observatory in inland Western Australia, one of the most radio-quiet locations on the Earth and one of two sites selected by the international community as a potential location for the SKA. In this paper, we outline an ambitious science program for ASKAP, examining key science such as understanding the evolution, formation and population of galaxies including our own, understanding the magnetic Universe, revealing the transient radio sky and searching for gravitational waves.
A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (H i) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of H i emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b| < 10°) at all declinations south of δ = +40°, spanning longitudes 167° through 360°to 79° at b = 0°, plus the entire area of the Magellanic Stream and Clouds, a total of 13 020 deg2. The brightness temperature sensitivity will be very good, typically σT≃ 1 K at resolution 30 arcsec and 1 km s−1. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream.
Micro- and Macro-photoluminescence techniques were employed in this research to investigate the role of nitrogen-doping on the optical spectra of chemical vapor deposited diamond films and to determine whether the origin of the broadband luminescence is due to vibronic interaction of the nitrogen centers. The temperature behavior of the broadband PL and of the 1.681 eV silicon related optical center were analyzed. The intensity of the broadband was found to exhibit a temperature dependence characteristic of optical emission from a continuous distribution of gap states while the temperature dependence of the 1.681 eV band followed the Boltzmann quenching process.
The methanol multi-beam (MMB) survey has produced the largest and most complete catalogue of Galactic 6.7-GHz methanol masers to date. 6.7-GHz methanol masers are exclusively associated with high-mass star formation, and as such provide invaluable insight into the Galactic distribution and properties of high-mass star formation regions. I present the statistical properties of the MMB catalogue and, through the calculation of kinematic distances, investigate the resolution of distance ambiguities and explore the Galactic distribution.
The results of the first complete survey for 6668-MHz CH3OH and 6035-MHz excited-state OH masers in the Small and Large Magellanic Clouds are presented. A new 6668-MHz CH3OH maser in the Large Magellanic Cloud has been detected towards the star-forming region N 160a, together with a new 6035-MHz excited-state OH maser detected towards N 157a. We also re-observed the previously known 6668-MHz CH3OH masers and the single known 6035-MHz OH maser. Neither maser transition was detected above ~0.13 Jy in the Small Magellanic Cloud. All observations were initially made using the CH3OH Multibeam (MMB) survey receiver on the 64-m Parkes radio telescope as part of the overall MMB project. Accurate positions were measured with the Australia Telescope Compact Array (ATCA). In a comparison of the star formation maser populations in the Magellanic Clouds and our Galaxy, the LMC maser populations are demonstrated to be smaller than their Milky Way counterparts. CH3OH masers are under-abundant by a factor of ~50, whilst OH and H2O masers are a factor of ~10 less abundant than our Galaxy.
A new 7-beam methanol multibeam receiver is being used to survey the Galaxy for newly forming massive stars, that are pinpointed by strong methanol maser emission at 6.668 GHz. The receiver, jointly constructed by Jodrell Bank Observatory (JBO) and the Australia Telescope National Facility (ATNF), was successfully commissioned at Parkes in January 2006. The Parkes-Jodrell survey of the Milky Way for methanol masers is two orders of magnitude faster than previous systematic surveys using 30-m class dishes, and is the first systematic survey of the entire Galactic plane. The first 53 days of observations with the Parkes telescope have yielded 518 methanol sources, of which 218 are new discoveries. We present the survey methodology as well as preliminary results and analysis.
A new 7-beam methanol multibeam receiver was successfully commissioned at Parkes Observatory in January 2006, and has begun surveying the Milky Way for newly forming massive stars, that are pinpointed by strong methanol maser emission at 6.7 GHz. The receiver was jointly constructed by Jodrell Bank Observatory and the Australia Telescope National Facility for use on the Parkes and Lovell Telescopes. The whole galactic plane is being surveyed within latitudes ±2°, with a velocity resolution of 0.1 km s−1 and a 5-σ sensitivity of ~0.7 Jy. Altogether 200 days of observing will be required.
Suicide rates for England and Wales have been decreasing recently, but rates for young adult males remain high.
To review changes in suicide rates for children and adolescents in England and Wales between 1970 and 1998.
Rates for suicide, ‘accidental’ death by causes similar to suicide and ‘undetermined’ death for 10–14- and 15–19-year-olds are calculated between 1970 and 1998 using suicide data and estimated mid-year populations obtained from the Office for National Statistics.
There has been a substantial increase in suicide rate between the 1970s and the 1990s for males aged 15–19 years. This remains true even when ‘undetermined’ and ‘accidental’ death rates for causes similar to suicide are examined. The increase was associated with an increase in self-poisoning with vehicle exhaust gas in the 1980s and an increase in hanging which has continued into the 1990s. Although there was a slight decrease in the official suicide rate for females aged 15–19 years, ‘undetermined’ deaths increased. There is no indication of a major change in suicide rate in 10–14-year-olds.
The substantial increase in suicide rate in 15–19-year-old males may indicate increased psychosocial stress, particularly affecting this group.
Methods of suicide and suicide rates in England and Wales have fluctuated considerably since the 1960s.
To review the changes that have occurred in suicide rates in England and Wales between 1960 and 1997.
Suicide rates, derived from total annual suicides and the estimated annual resident population, were obtained from the Office for National Statistics.
Suicide rates decreased in both genders between the early 1960s and the mid-1970s. The rate for males then increased between 1975 and 1990, while the rate for females continued to fall. Between 1990 and 1997, the rate decreased for males and females in all age groups, particularly for those using motor vehicle exhaust gas; the latter finding is associated with increasing use of catalytic converters.
Following the increase in suicide among males until 1990 there was a decrease for both genders between 1990 and 1997, consistent with the ‘Health of the Nation’ target.
Following reports of recent increases in adult male suicides in England and Wales, suicide rates for children and adolescents are reviewed.
By using estimated mid-year populations for five-year age bands, the suicide rates for 10–14 year-olds and 15–19 year-olds are calculated between 1960–1990. The same method is used to obtain rates for ‘undetermined’ death and ‘accidental’ death by causes comparable to suicide.
The only group to show an increase in suicide rate since the 1970s has been males aged 15–19 years. This increase persists even when ‘undetermined’ and ‘accidental’ death rates for causes similar to suicide are examined. The increase is associated with an increase in hanging and self-poisoning with vehicle exhaust gas.
The increase in suicide rate in 15–19 year-old males may indicate increased psychosocial stress, particularly affecting this age/gender group.