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The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
The Dark Energy Survey is undertaking an observational programme imaging 1/4 of the southern hemisphere sky with unprecedented photometric accuracy. In the process of observing millions of faint stars and galaxies to constrain the parameters of the dark energy equation of state, the Dark Energy Survey will obtain pre-discovery images of the regions surrounding an estimated 100 gamma-ray bursts over 5 yr. Once gamma-ray bursts are detected by, e.g., the Swift satellite, the DES data will be extremely useful for follow-up observations by the transient astronomy community. We describe a recently-commissioned suite of software that listens continuously for automated notices of gamma-ray burst activity, collates information from archival DES data, and disseminates relevant data products back to the community in near-real-time. Of particular importance are the opportunities that non-public DES data provide for relative photometry of the optical counterparts of gamma-ray bursts, as well as for identifying key characteristics (e.g., photometric redshifts) of potential gamma-ray burst host galaxies. We provide the functional details of the DESAlert software, and its data products, and we show sample results from the application of DESAlert to numerous previously detected gamma-ray bursts, including the possible identification of several heretofore unknown gamma-ray burst hosts.
In October 2012, an outbreak of gentamicin-resistant, ciprofloxacin non-susceptible extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae occurred in a neonatal intensive care unit in Ireland. In order to determine whether the outbreak strain was more widely dispersed in the country, 137 isolates of K. pneumoniae with this resistance phenotype collected from 17 hospitals throughout Ireland between January 2011 and July 2013 were examined. ESBL production was confirmed phenotypically and all isolates were screened for susceptibility to 19 antimicrobial agents and for the presence of genes encoding blaTEM, blaSHV, blaOXA, and blaCTX-M; 22 isolates were also screened for blaKPC, blaNDM, blaVIM, blaIMP and blaOXA-48 genes. All isolates harboured blaSHV and blaCTX-M and were resistant to ciprofloxacin, gentamicin, nalidixic acid, amoxicillin-clavulanate, and cefpodoxime; 15 were resistant to ertapenem, seven to meropenem and five isolates were confirmed as carbapenemase producers. Pulsed-field gel electrophoresis of all isolates identified 16 major clusters, with two clusters comprising 61% of the entire collection. Multilocus sequence typing of a subset of these isolates identified a novel type, ST1236, a single locus variant of ST48. Data suggest that two major clonal groups, ST1236/ST48 (CG43) and ST15/ST14 (CG15) have been circulating in Ireland since at least January 2011.
In pasture-based seasonal calving systems, failure to become pregnant during the breeding season results in important economic losses as maximum profit is attained by minimising costs and increasing the proportion of grass in the diet of the lactating dairy cow. In the United States, dairy producers primarily strive to maximise production potential but are becoming increasingly aware of the economic consequences of sub-optimal cow fertility and survival. For this reason, interest in crossbreeding is emerging. The objective of this paper is to review the fertility and survival outcomes reported from recent research studies and data analyses in Ireland, New Zealand and the United States. Research conducted in Ireland during the early 2000s concluded that of three ‘alternative’ dairy breeds the Norwegian Red was most suited to seasonal grass-based production. A key finding was favourable fertility and survival. A follow-up study confirmed a fertility advantage with Norwegian Red×Holstein-Friesian compared with Holstein-Friesian: proportion pregnant to first service; +0.08 and in-calf after 6 weeks breeding; +0.11. Another study found higher fertility with Jersey crossbreds: pregnant to first service; +0.21, and in-calf after 6 weeks breeding; +0.19. Studies conducted in Northern Ireland also found superior fertility performance with Jersey crossbred cows offered low and moderate concentrate diets. In New Zealand, crossbred dairy cattle (primarily Jersey×Friesian) are achieving similar rates of genetic gain for farm profit as the purebred populations, but creating additional gain derived from economic heterosis. In the United States, analysis of commercial data from California showed higher first-service conception rates for Scandinavian Red×Holstein (+6 percentage units) and Montbeliarde×Holstein (+10 percentage units) compared with Holstein (23%). They also exhibited fewer days open and greater survival. At Penn State University, Brown Swiss×Holstein cows had 17 fewer days open than Holstein cows during first lactation, and numerically fewer in second (12 days) and third lactation (6 days). At the University of Minnesota, crossbred cows had 21 percentage units higher first-service conception rates, 41 fewer days open and 12 percentage units higher in-calf rates compared with pure Holstein cows. They also had greater survival to second (+13 percentage units), third (+24 percentage units), fourth (+25 percentage units) and fifth (+17 percentage units) lactation. The literature clearly illustrates favourable animal performance benefits from crossbreeding, using a range of modern breeds, and within the context of both grass-based and high-input confinement production environments. Economic analyses generally indicate profitable performance owing to lower replacement cost and higher herd productivity.
The nitrogen-vacancy (NV) center in diamond offers the opportunity to develop quantum technologies that leverage the defect’s atom-like properties using established engineering techniques from the semiconductor industry. While many NV center applications are motivated by the remarkable properties of isolated NV centers in bulk diamond, realizing these technologies requires addressing a number of device and materials engineering challenges unique to creating and controlling individual semiconductor spins. We review recent advances in interfacing NV centers with on-chip electronics that enable control over the defect’s spin and orbital degrees of freedom and review fabrication techniques for creating single NV centers with nanometer-scale placement accuracies. We also discuss efforts, motivated by the success of diamond NV center applications, to identify defect spins with similar properties to the NV center in more technologically mature semiconductors such as SiC.
Background: Quality of life (QOL) is frequently assessed in persons with dementia (PWD) through self- and/or proxy-report. Determinants of QOL ratings are multidimensional and may differ between patients and caregiver proxies. This study compared self- and proxy-reported QOL ratings in a population-based study of PWD and their caregivers, and examined the extent to which discrepancies in reports were associated with characteristics of the PWD.
Methods: The sample consisted of 246 patient/caregiver dyads from the initial visit of the Cache County Dementia Progression Study, with both members of the dyad rating PWD QOL. PWD age, gender, cognitive impairment (Mini-Mental State Examination), neuropsychiatric symptoms (Neuropsychiatric Inventory; NPI), dementia severity (Clinical Dementia Rating), medical comorbidities (General Medical Health Rating), and functional impairment (Dementia Severity Rating Scale) were examined as correlates of self- and proxy-reported QOL ratings and the differences between the QOL reports.
Results: Self- and proxy-reported PWD QOL ratings were only modestly correlated. Medical comorbidity was associated with self-report whereas NPI was associated with proxy-report. Dementia severity was associated with discrepancies in self- and proxy-report, with worse patient cognition associated with poorer proxy-reported QOL ratings.
Conclusions: PWD self- and proxy-reported QOL ratings are associated with different variables. Discrepancies between PWD and caregiver perceptions of PWD QOL should be recognized, particularly in cases of more severe dementia.
Faecal specimens were collected at weekly intervals over the winter months from 141 new-born infants without diarrhoea. Contrary to the findings in other studies, no viruses were detected by electron microscopy or culturein any of these specimens. Over the same period faecal specimens were collected from 84 infants up to four yearsof age admitted to hospital. Rotaviruses or adenoviruses were found in 48% of infants with gastroenteritis. Enteroviruses and other small round virus-like particles were found in infants both with and without gastroenteritis.No viruses or pathogenic bacteria could be found in 34% of specimens from infants with gastroenteritis.
An overview is given of the development of advanced nanoporous carbons as storage ma-terials for natural gas (methane) and molecular hydrogen in on-board fuel tanks for next-generation clean automobiles. The carbons are produced in a multi-step process from corncob, have surface areas of up to 3500 m2/g, porosities of up to 0.8, and reversibly store, by physisorp-tion, record amounts of methane and hydrogen. Current best gravimetric and volumetric storage capacities are: 250 g CH4/kg carbon and 130 g CH4/liter carbon (199 V/V) at 35 bar and 293 K; and 80 g H2/kg carbon and 47 g H2/liter carbon at 47 bar and 77 K. This is the first time the DOE methane storage target of 180 V/V at 35 bar and ambient temperature has been reached and exceeded. The hydrogen values compare favorably with the 2010 DOE gravimetric and volu-metric targets for hydrogen. A prototype adsorbed natural gas (ANG) tank, loaded with carbon monoliths produced accordingly and currently undergoing a road test in Kansas City, is de-scribed. A preliminary analysis of the surface and pore structure is given that may shed light on the mechanisms leading to the extraordinary storage capacities of these materials. The analysis includes pore-size distributions from nitrogen adsorption isotherms; spatial organization of pores across the entire solid from small-angle x-ray scattering (SAXS); pore entrances from scanning electron microscopy (SEM) and transmission electron microscopy (TEM); H2 binding energies from temperature-programmed desorption (TPD); and analysis of surface defects from Raman spectra. For future materials, expected to have higher H2 binding energies via appropriate sur-face functionalization, preliminary projections of H2 storage capacities based on molecular dy-namics simulations of adsorption of H2 on graphite, are reported.