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Tail docking of pigs is commonly performed to reduce the incidence of unwanted tail-biting behaviour. Two docking methods are commonly used: blunt trauma cutting (i.e. using side clippers), or cutting and concurrent cauterisation using a hot cautery iron. A potential consequence of tail amputation is the development of neuromas at the docking site. Neuromas have been linked to neuropathic pain, which can influence the longer-term welfare of affected individuals. To determine whether method of tail docking influences the extent of neuroma formation, 75 pigs were allocated to one of three treatments at birth: tail docked using clippers; tail docked using cautery iron; tail left intact. Tail docking was performed at 2 days of age and pigs were kept under conventional conditions until slaughter at 21 weeks of age. Tails were removed following slaughter and subjected to histological examination. Nerve histomorphology was scored according to the following scale: 1=discrete well-organised nerve bundles; 2=moderate neural proliferation and disorganisation affecting more than half of the circumference of the tail; 3=marked neural proliferation to form almost continuous disorganised bundles or non-continuous enlarged bundles compressing the surrounding connective tissue. Scores of 2 or 3 indicated neuroma formation. Scores were higher in docked pigs than undocked pigs (P<0.001), but did not differ between pigs docked using clippers and those docked using cautery (P=0.23). The results indicate that tail docking using either clippers or cautery results in neuroma formation, thus having the potential to affect long-term pig welfare.
Acute kidney injury after cardiac surgery is a frequent and serious complication among children with congenital heart disease (CHD) and adults with acquired heart disease; however, the significance of kidney injury in adults after congenital heart surgery is unknown. The primary objective of this study was to determine the incidence of acute kidney injury after surgery for adult CHD. Secondary objectives included determination of risk factors and associations with clinical outcomes.
This single-centre, retrospective cohort study was performed in a quaternary cardiovascular ICU in a paediatric hospital including all consecutive patients ⩾18 years between 2010 and 2013.
Data from 118 patients with a median age of 29 years undergoing cardiac surgery were analysed. Using Kidney Disease: Improving Global Outcome creatinine criteria, 36% of patients developed kidney injury, with 5% being moderate to severe (stage 2/3). Among higher-complexity surgeries, incidence was 59%. Age ⩾35 years, preoperative left ventricular dysfunction, preoperative arrhythmia, longer bypass time, higher Risk Adjustment for Congenital Heart Surgery-1 category, and perioperative vancomycin use were significant risk factors for kidney injury development. In multivariable analysis, age ⩾35 years and vancomycin use were significant predictors. Those with kidney injury were more likely to have prolonged duration of mechanical ventilation and cardiovascular ICU stay in the univariable regression analysis.
We demonstrated that acute kidney injury is a frequent complication in adults after surgery for CHD and is associated with poor outcomes. Risk factors for development were identified but largely not modifiable. Further investigation within this cohort is necessary to better understand the problem of kidney injury.
Background: NCSE dramatically increases morbidity and mortality. It is clinically subtle, which makes it difficult to diagnose without EEG. StatNet EEG provides a quick alternative to conventional EEG, which is often unavailable after hours. Methods: Each patient received a StatNet EEG by a neurology resident and a conventional EEG by an EEG technologist. Blinded studies were compared for delay between the studies, setup time, artifact, and abnormality detection using conventional EEG as controls. Nonparametric Mann-Whitney two-sample T-test was used. Results are expressed in mean minutes +/- SD. Kappa score assessed inter-observer reliability. Results: 19 patients were collected. Two StatNet EEGs were not interpretable and excluded. The mean delay between studies was 26h53min. Electrode placement is significantly shorter: 13:14±5:24 StatNet EEG vs 18:07±5:35 conventional EEG (p=0.02).
Conclusions: There is high inter-rater reliability between the conventional and StatNet EEG groups (table 1) demonstrating that StatNet is a reliable and effective tool, aiding in early recognition and management of NCSE.
We describe the search for δ Scuti stars in the MACHO database of bulge fields. Concentrating on a sample of high amplitude δ Scutis, we examine the light curves and pulsation modes. We also discuss their spatial distribution and evolutionary status using mean colors and absolute magnitudes.
Real-time detection of microlensing has moved from proof of concept in 1994 (Udalski et al. 1994a, Alcock et al. 1994) to a steady stream of events this year. Global dissemination of these events by the MACHO and OGLE collaborations has made possible intensive photometric and spectroscopic follow up from widely dispersed sites confirming the microlensing hypothesis (Benetti 1995). Improved photometry and increased temporal resolution from follow up observations greatly increases the possibility of detecting deviations from the standard point-source, point-lens, inertial motion microlensing model. These deviations are crucial in understanding individual lensing systems by breaking the degeneracy between lens mass, position and velocity. We report here on GMAN (Global Microlensing Alert Network), the coordinated follow up of MACHO alerts.
Wolf-Rayet galaxies are a subset of blue emission-line galaxies, whose spectra show the signature of large numbers of WR stars, with ages in the range 1-10 x 106 yr. Mid infra-red observations are well suited to the study of their hot, massive stars since this spectral region contains many fine-structure nebular lines which depend very sensitively on stellar content. The observations of ISO have opened-up this window, which we are exploiting through a Guest Observer program with the Short Wavelength Spectrometer (sws), that includes NGC 5253, a nearby (4 Mpc) WR galaxy. NGC 5253 contains several young super-star clusters, no older than a few million years and has been the focus of many recent studies which have shown that the extinction is very high and patchy in the UV and optical. ISO observations of NGC 5253 are particularly important since the interstellar extinction at mid-IR wavelengths is low and because of its remarkably hot and young stellar population.
Gravitational microlensing is the most straightforward interpretation of the stellar brightenings that have been observed by our team and other experiments. These data have provided some of the most stringent limits to date on the nature of the Galaxy's dark matter halo. The number of events seen towards the LMC indicate that our Galaxy is not surrounded by a “standard” halo of MACHOs in the mass range of 10–6 to 0.3 solar masses. The observed optical depth towards the Galactic Center is an important constraint on the distribution of mass in the plane of the Galaxy.
The MACHO data base has been used to examine light curves of all red giant stars brighter than Mbol ∼ −2 in a 0.5° × 0.5° area of the LMC bar. Periods, often multiple, have been searched for in all stars found to be variable. Five distinct period-luminosity sequences have been found on the low mass (M ≲ 2.25M⊙) giant branch. Comparison of observed periods, luminosities and period ratios with theoretical models identifies Miras unambiguously as radial fundamental mode pulsators, while semi-regular variables can be pulsating in the 1st, 2nd or 3rd overtone, or even the fundamental. All these variables lie on just 3 of the 5 distinct sequences, and they all appear to be on the AGB.
The fourth sequence contains red giants on the first giant branch (FGB) or at the red end of the core-helium burning loops of intermediate mass stars (M ≳ 2.25M⊙). The light curves of these stars strongly suggest that they are contact binaries, and they make up ∼0.5% of stars within 1 mag. of the FGB tip. Stars on the fifth sequence show semi-regular, eclipse-like light curves. The light curves and periods of these stars suggest that they are in semi-detached binaries, transfering mass to an invisible companion via a stellar wind or Roche lobe overflow. They make up ∼25% of AGB stars. If the existence of these red giant contact and semi-detached binaries is confirmed, then extant theories of binary star evolution will require substantial modification.
We have analyzed a sample of 1150 type ab, and 550 type c RR Lyrae stars found in 24 of 94 bulge fields of the MACHO database. These fields cover a range in Galactocentric distances from 0.3 to 1.6 kpc. In combination with the data on the outer bulge fields of Alard (1997) and Wesselink (1987), here we present the surface density distribution of bulge RR Lyrae between 0.3 and 3 kpc.
The MACHO microlensing experiment's time-sampled photometry database contains blue and red lightcurves for nearly 9 million stars in the central bar region of the Large Magellanic Cloud (LMC). We have identified known LMC Planetary Nebulae (PN) in the database and find one, Jacoby 5, to be variable. We additionally present data on the “parent populations” of LMC PN, and discuss the star formation history of the LMC bar.
Ultraluminous IRAS Galaxies (ULIRGs) are unusual galaxies with luminosities > 1012L⊙ (H0 = 75 kms−1 Mpc−1), comparable to optically selected quasars, with up to 90% of this emitted in the 8-1000 μm region. Initial work on nearby ULIRGs suggested that all of these objects were in interacting or merging systems. Larger samples (e.g. Leech et al 1994) suggested that this might only be true for 2/3 of the objects. The triggering of ULIRG-type activity in the non-merging galaxies would then be difficult to understand.
A review of the properties of Type II Cepheids and RV Tauri stars in the Magellanic Clouds is presented. In the behaviour of their light and colour curves, the RV Tauri stars appear to be a direct extension of the Type II Cepheids to longer periods. A single P – L – C relationship describes both the Type II Cepheids and RV Tauri stars in the LMC. The derived high intrinsic magnitudes for the RV Tauri variables supports the proposition that these objects are luminous stars evolving off the AGB. Preliminary analysis of the long time-series MACHO photometry indicates one star (MACHO*05:37:45.0–69:54:16) has an obvious ‘period-quadrupled’ periodicity, which is supporting evidence for a period-doubling bifurcation transition to chaotic pulsations.
In the past few years, the Magellanic Clouds have been the targets for several major variable star surveys. The results of these surveys are now becoming available and it is clear that a Renaissance in LMC and SMC variable star research will result. In this review, I will describe the results of such surveys and review the questions that are likely to be answered by further work.
With respect to results, I will concentrate on LMC MACHO Project data, including beat Cepheids, discovery statistics, mode identification, Fourier decomposition of lightcurves, and the differences between the LMC and galactic sample.
We present optical photometry of the eclipsing supersoft source, CAL 87. We find the eclipse structure to be stable over ~ 4 y, derive an improved ephemeris of To = HJD 2450111.5144(3)+0.442674(7)E, and see new structure in the light curve morphology.
The MACHO Collaboration’s search for baryonic dark matter via its gravitational microlensing signature has generated a massive database of time ordered photometry of millions of stars in the LMC and the bulge of the Milky Way. The search’s experimental design and capabilities are reviewed and the dark matter results are briefly noted. Preliminary analysis of the ~ 39,000 variable stars discovered in the LMC database is presented and examples of periodic variables are shown. A class of a periodically variable Be star is described which is the closest background to microlensing which has been found. Plans for future work on variable stars using the MACHO data are described.
We present the first results of the analysis of 22 Blazhko stars. We find: 1) Blazhko RRab stars that are nearly pure amplitude modulators; 2) Blazhko RRab stars that have both amplitude and phase modulation; 3) A Blazhko RRab star that has an abrupt period change; 4) Proof of the Blazhko effect in RRc stars. Our data show the character of the amplitude and phase modulations of the light curves over the Blazhko cycles far better than has been previously possible.
We present the preliminary results of a frequency analysis of 1457 fundamental mode RR Lyrae (RR0) stars in the Large Magellanic Cloud (LMC) from MACHO Project photometry. We find the same classes of pulsational behavior as were found in our earlier survey of first overtone RR Lyrae (RR1) stars. Variables whose prewhitened power spectra contain one or two peaks close to the main frequency component in the original power spectra are commonly known as Blazhko-type variables. The present analysis shows the overall frequency of Blazhko-type stars in the total RR0 population analysed to date to be ≈ 10%. This is lower than the often cited Galactic field/globular rate of 20-30% (Szeidl, 1988).
The incidence rate of Blazhko-type variability in the LMC appears to be about three times higher in RR0 stars than in RR1 stars. This puts important constraints on possible models of the Blazhko effect.
We present the first massive frequency analysis of the 1200 first overtone RR Lyrae stars in the Large Magellanic Cloud observed in the first 4.3 yr of the MACHO project. Besides the many new double-mode variables, we also discovered stars with closely spaced frequencies. These variables are most probably nonradial pulsators.
Gem minerals at Lava Plains, northeast Queensland, offer further insights into mantle-crustal gemformation under young basalt fields. Combined mineralogy, U-Pb age determination, oxygen isotope and petrological data on megacrysts and meta-aluminosilicate xenoliths establish a geochemical evolution in sapphire, zircon formation between 5 to 2 Ma. Sapphire megacrysts with magmatic signatures (Fe/Mg ∼100–1000, Ga/Mg 3–18) grew with ∼3 Ma micro-zircons of both mantle (δ18O 4.5–5.6%) and crustal (δ18O 9.5–10.1‰) affinities. Zircon megacrysts (3±1 Ma) show mantle and crustal characteristics, but most grew at crustal temperatures (600–800°C). Xenolith studies suggest hydrous silicate melts and fluids initiated from amphibolized mantle infiltrated into kyanite+sapphire granulitic crust (800°C, 0.7 GPa). This metasomatized the sapphire (Fe/Mg ∼50–120, Ga/Mg ∼3–11), left relict metastable sillimanite-corundum-quartz and produced minerals enriched in high field strength, large ion lithophile and rare earth elements. The gem suite suggests a syenitic parentage before its basaltic transport. Geographical trace-element typing of the sapphire megacrysts against other eastern Australian sapphires suggests a phonolitic involvement.
Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone.