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We describe 14 yr of public data from the Parkes Pulsar Timing Array (PPTA), an ongoing project that is producing precise measurements of pulse times of arrival from 26 millisecond pulsars using the 64-m Parkes radio telescope with a cadence of approximately 3 weeks in three observing bands. A comprehensive description of the pulsar observing systems employed at the telescope since 2004 is provided, including the calibration methodology and an analysis of the stability of system components. We attempt to provide full accounting of the reduction from the raw measured Stokes parameters to pulse times of arrival to aid third parties in reproducing our results. This conversion is encapsulated in a processing pipeline designed to track provenance. Our data products include pulse times of arrival for each of the pulsars along with an initial set of pulsar parameters and noise models. The calibrated pulse profiles and timing template profiles are also available. These data represent almost 21 000 h of recorded data spanning over 14 yr. After accounting for processes that induce time-correlated noise, 22 of the pulsars have weighted root-mean-square timing residuals of
in at least one radio band. The data should allow end users to quickly undertake their own gravitational wave analyses, for example, without having to understand the intricacies of pulsar polarisation calibration or attain a mastery of radio frequency interference mitigation as is required when analysing raw data files.
This study presents two years of characterization of a warm temperate rhodolith bed in order to analyse how certain environmental changes influence the community ecology. The biomass of rhodoliths and associated species were analysed during this period and in situ experiments were conducted to evaluate the primary production, calcification and respiration of the dominant species of rhodoliths and epiphytes. The highest total biomass of rhodoliths occurred during austral winter. Lithothamnion crispatum was the most abundant rhodolith species in austral summer. Epiphytic macroalgae occurred only in January 2015, with Padina gymnospora being the most abundant. Considering associated fauna, the biomass of Mollusca increased from February 2015 to February 2016. Population densities of key reef fish species inside and around the rhodolith beds showed significant variations in time. The densities of grouper (carnivores/piscivores) increased in time, especially from 2015 to 2016. On the other hand, grunts (macroinvertebrate feeders) had a modest decrease over time (from 2014 to 2016). Other parameters such as primary production and calcification of L. crispatum were higher under enhanced irradiance, yet decreased in the presence of P. gymnospora. Community structure and physiological responses can be explained by the interaction of abiotic and biotic factors, which are driven by environmental changes over time. Biomass changes can indicate that herbivores play a role in limiting the growth of epiphytes, and this is beneficial to the rhodoliths because it decreases competition for environmental resources with fleshy algae.
For nutrition practitioners and researchers, assessing dietary intake of children and adults with a high level of accuracy continues to be a challenge. Developments in mobile technologies have created a role for images in the assessment of dietary intake. The objective of this review was to examine peer-reviewed published papers covering development, evaluation and/or validation of image-assisted or image-based dietary assessment methods from December 2013 to January 2016. Images taken with handheld devices or wearable cameras have been used to assist traditional dietary assessment methods for portion size estimations made by dietitians (image-assisted methods). Image-assisted approaches can supplement either dietary records or 24-h dietary recalls. In recent years, image-based approaches integrating application technology for mobile devices have been developed (image-based methods). Image-based approaches aim at capturing all eating occasions by images as the primary record of dietary intake, and therefore follow the methodology of food records. The present paper reviews several image-assisted and image-based methods, their benefits and challenges; followed by details on an image-based mobile food record. Mobile technology offers a wide range of feasible options for dietary assessment, which are easier to incorporate into daily routines. The presented studies illustrate that image-assisted methods can improve the accuracy of conventional dietary assessment methods by adding eating occasion detail via pictures captured by an individual (dynamic images). All of the studies reduced underreporting with the help of images compared with results with traditional assessment methods. Studies with larger sample sizes are needed to better delineate attributes with regards to age of user, degree of error and cost.
We describe the first X-ray observations of binary millisecond pulsars PSR J0023+0923, J1810+1744, J2215+5135, and J2256−1024. All are Fermi gamma-ray sources and three are ‘black-widow’ pulsars, with companions of mass < 0.1 M⊙. Data were taken using the Chandra X-Ray Observatory and covered a full binary orbit for each pulsar. PSRs J2215+5135 and J2256−1024, show significant orbital variability and X-ray flux minima coinciding with eclipses seen at radio wavelengths. This is consistent with intrabinary shock emission characteristic of black-widow pulsars. The other two pulsars, PSRs J0023+0923 and J1810+1744, do not demonstrate significant variability, but are fainter than the other two sources. Spectral fits yield power-law indices that range from 1.4 to 2.3 and blackbody temperatures in the hundreds of eV. The spectrum for PSR J2215+5135 shows a significant hard X-ray component (41% of counts are above 2 keV), which is additional evidence for the presence of intrabinary shock emission.
Proton dissociation and transfer are investigated with ab initio molecular dynamics (AIMD) simulations of carbon nanotubes (CNT) functionalized with perfluorosulfonic acid (-CF2SO3H) groups with 3 H2O/–SO3H. The CNT systems were constructed both with and without fluorine atoms covalently bound to the inner walls to determine the effects of the presence of fluorine on proton dissociation, hydration, and stabilization. The results of the AIMD trajectories show that decreasing the separation of sulfonic acid groups increases the propensity for proton dissociation. The simulations also revealed that the dissociated proton was preferentially stabilized as a hydrated hydronium (H3O+) cation in the CNT systems with the fluorine. This feature is attributed to the fluorine atoms providing a localized negative charge that promotes hydrogen bonding of the water molecules coordinated to the central hydronium ion. The hydrated H3O+ ion differed from a traditional Eigen cation (H9O4+) as it donated hydrogen bonds to sulfonate oxygen atoms, as well as water molecules.
This qualitative study investigated the positive and negative outcomes of a home-based strength-training programme for young people with cerebral palsy (CP). Eleven young people with spastic diplegic CP (seven females, four males; mean age 12 years 9 months, SD 2 years 10 months; range 8 to 18 years) and their parents were interviewed. Gross Motor Function Classification System scores ranged from I (walks without limitations) to III (walks with assistive device), with a mode of III. The strength-training programme, which was conducted in the participants' homes three times per week for 6 weeks (total of 18 prescribed sessions), comprised three exercises targeting the major support muscles of the lower limbs. Exercises were bilateral half squats, heel raises, and step-ups. The training load was increased by adding free weights to a backpack so that 8 to 10 repetitions of each exercise could be performed. Using thematic coding, three categories of outcome emerged: body function and structure, activity, and participation, which were influenced by environmental and personal contextual factors. The programme generated overwhelmingly positive outcomes with only minor negative responses about some equipment and the need for parental involvement. Benefits included perceptions that strength, flexibility, posture, walking, and the ability to negotiate steps had improved. In addition, participants reported psychological benefits such as a feeling of increased well-being and improved participation in school and leisure activities. The contextual factors highlighted the fact that sufficient clinician resources must be allocated to solve individual exercise and equipment problems. As well as providing further evidence that strength training can be beneficial, this study provides useful indicators to guide future quantitative studies of outcomes that are meaningful for people with CP.
This randomized clinical trial evaluated the effects of a home-based, six-week strength-training programme on lower limb strength and physical activity of 21 young people (11 females, 10 males; mean age 13 years 1 month, SD 3 years 1 month; range 8 to 18 years) with spastic diplegic cerebral palsy (CP) with independent ambulation, with or without gait aids; (Gross Motor Function Classification System levels I to III). Compared with the 10 controls, the 11 participants in the strength-training programme increased their lower limb strength (combined ankle plantarflexor and knee extensor strength as measured by a hand-held dynamometer) at 6 weeks (F(1,19)=4.58, p=0.046) and at a follow-up 12 weeks later (F(1,18)=6.25, p=0.041). At 6 weeks, trends were also evident for improved scores in Gross Motor Function Measure dimensions D and E for standing, running and jumping, and faster stair climbing. A relatively short clinically feasible home-based training programme can lead to lasting changes in the strength of key lower-limb muscles that may impact on the daily function of young people with CP.
Continuously grazed rye grassl clover swards with surface heights of 8 to 10 cm at 5 weeks before a synchronized mating and 7·5 cm at mating were grazed by 151 Greyface ewes stocked at 12 per ha until mating. The effects of two stocking rates (eight and 16 ewes per ha) for 6 weeks over the mating and post-mating period were then studied on live weight, body condition and reproductive peformance. Sward height fell more rapidly post mating when stocked at 16 ewes per ha than at eight ewes per ha, but remained above 3·5 cm until 4 weeks after first mating under both rates. Ewes stocked at 16 per ha became significantly lighter and leaner than ewes stocked at eight per ha. There was no significant effect of post-mating stocking rate on reproductive performance in terms of conception rate and lambing rate to first mating or lambing rate to all matings. Reproductive performance of Greyface ewes is therefore unlikely to be adversely affected by post-mating stocking rate on swards of 7 to 8 cm which do not fall below 3·5 to 4·0 cm until 3 to 4 weeks after mating.
Bleeding is the major source of morbidity and mortality of tonsillectomy and most operative time is spent securing haemostasis. Calcium alginate reduces experimental wound blood loss. This study assessed the efficacy of alginate swabs during tonsillectomy and inferior tonsillar pole ligation in the control of blood loss during tonsillectomy.
Ninety-nine tonsillectomy patients were randomized to gauze or alginate swab use. A haemoglobinometer measured blood losses collected by suction during dissection and by swab until haemostasis was secured. Operative time, complications and healing were also assessed.
Mean total blood losses and operative times were similar for the two groups. Swab blood loss was significantly lower for surgeons who ligated the lower tonsillar pole, compared with surgeons who used a snare. This finding was independent of swab type. Independent assessment showed no difference in the healing rate.
Alginate swabs offer no advantage over gauze in terms of blood loss, operative time or complications of tonsillectomy. The results show that routine lower pole ligation significantly reduces post-dissection blood loss. We suggest that this technique should be more widely adopted.
A 64-year-old man with right aural discharge presented complaining of progressive deafness. Other otological symptoms were absent and specifically there was no seventh nerve paresis. A right aural polyp was identified and biopsied. Histology showed the polyp to be a schwannoma.
Subsequent temporal bone computed tomography showed expansion of the distal facial canal. At operation, the schwannoma filled the middle ear cleft and extended from the genu to the region of the stylomastoid foramen. The floor of the middle ear had been eroded, exposing the jugular bulb.
Facial paresis is the usual presenting feature of a facial schwannoma, while deafness, ageusia and reduced lacrimation are variable, dependent upon the site of the lesion. The absence of facial palsy as a presenting feature is very rare and this case illustrates the need for histological examination of all abnormal aural material.
Whereas the I.A.U. standard values of the constants Ro, ⊙o, A, and B, differ from those currently considered best, the errors of current determinations are still rather large. Although the means of recent determinations lead to a fairly consistent set of values for the four main constants, the agreement may be largely coincidental. However, a case can be made for agreeing on a new pair of standard values for Ro and ⊙o as a matter of practical convenience.
At the IAU General Assembly in Patras in August 1982, Commission 33 set up a Working Group on the Galactic Constants. The Working Group is charged with developing a critical review of the values of the main galactic constants, for publication before the General Assembly in 1985. It has not been specifically charged to come up with a proposal for a revised set of values, although it can do so if it wishes.
The structure and kinematics of the neutral hydrogen associated with Gould's Belt have been studied using data of high velocity resolution and large latitude extent covering ℓ = 10o − 350°. The data comprise the Berkeley Survey of Neutral Hydrogen (Weaver and Williams 1973, 1974), and an unpublished survey by Kerr, Bowers, Kerr, and Jackson (1983) using the 60-foot Parkes telescope. The latter is a fully-sampled survey of the region ℓ = 240° to 350°, b = −10° to +10°.
As usual, this report contains contributions from a number of authors, as follows: § 2, P. D. Jackson and M. P. FitzGerald; §§ 3 and 4, F. J. Kerr and D. L. Crawford; §5, P. O. Lindblad; §§ 6A and C, R. Wielen; §§ 6B and 7, J. Einasto; §§ 6D and E, K. C. Freeman, § 6F, M Fujimoto. The layout follows previous practice, except that a new Section 7 on the galactic environment has been added. A longer version of the Report will be published by the University of Maryland and will be distributed to all members of Commission 33 and to astronomical institutions.
This review of 21-cm studies of the galactic disk will be rather short, because several aspects of such studies are being covered by other speakers. These include the galactic rotation curve, the warp, the outer limits of the hydrogen layer, high-velocity clouds, large supernova remnants and comparisons between observations and theory with respect to density waves.