Antarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) compares ice-sheet model responses to decrease in buttressing by investigating the ‘end-member’ scenario of total and sustained loss of ice shelves. Although unrealistic, this scenario enables gauging the sensitivity of an ensemble of 15 ice-sheet models to a total loss of buttressing, hence exhibiting the full potential of marine ice-sheet instability. All models predict that this scenario leads to multi-metre (1–12 m) sea-level rise over 500 years from present day. West Antarctic ice sheet collapse alone leads to a 1.91–5.08 m sea-level rise due to the marine ice-sheet instability. Mass loss rates are a strong function of the sliding/friction law, with plastic laws cause a further destabilization of the Aurora and Wilkes Subglacial Basins, East Antarctica. Improvements to marine ice-sheet models have greatly reduced variability between modelled ice-sheet responses to extreme ice-shelf loss, e.g. compared to the SeaRISE assessments.

Mössbauer spectroscopy obtained with the sample at low temperatures and subject to large magnetic fields is discussed in terms of its use in analysing the naturally occurring polymorphs of FeOOH and the common growth precursor, ferrihydrite. Experiments on well-characterized synthetic samples provided benchmark results. A relatively simple means of quantitative analysis was used, in which sextets of Voigtian-shaped lines were summed and least-squares fitted. The results are discussed in terms of the magnetic structures of each compound.

Comparison of the infrared spectra of georgeite and a phase which can be reproducibily synthesised in the laboratory shows that the mineral is an amorphous analogue of malachite, Cu2CO3(OH)2. Synthetic studies also explain the chemical conditions under which georgeite may form, as well as those which can cause it to react to either malachite or chalconatronite. Parallels may be drawn between the laboratory observations and known mineral associations of georgeite.

Predictions of marine ice-sheet behaviour require models able to simulate grounding-line migration. We present results of an intercomparison experiment for plan-view marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no buttressing effects from lateral drag). Perturbation experiments specifying spatial variation in basal sliding parameters permitted the evolution of curved grounding lines, generating buttressing effects. The experiments showed regions of compression and extensional flow across the grounding line, thereby invalidating the boundary layer theory. Steady-state grounding-line positions were found to be dependent on the level of physical model approximation. Resolving grounding lines requires inclusion of membrane stresses, a sufficiently small grid size (<500 m), or subgrid interpolation of the grounding line. The latter still requires nominal grid sizes of <5 km. For larger grid spacings, appropriate parameterizations for ice flux may be imposed at the grounding line, but the short-time transient behaviour is then incorrect and different from models that do not incorporate grounding-line parameterizations. The numerical error associated with predicting grounding-line motion can be reduced significantly below the errors associated with parameter ignorance and uncertainties in future scenarios.

Eta Carinae is one of the most massive observable binaries. Yet determination of its orbital and physical parameters is hampered by obscuring winds. However the effects of the strong, colliding winds changes with phase due to the high orbital eccentricity. We wanted to improve measures of the orbital parameters and to determine the mechanisms that produce the relatively brief, phase-locked minimum as detected throughout the electromagnetic spectrum. We conducted intense monitoring of the He ii λ4686 line in η Carinae for 10 months in the year 2014, gathering ~300 high S/N spectra with ground- and space-based telescopes. We also used published spectra at the FOS4 SE polar region of the Homunculus, which views the minimum from a different direction. We used a model in which the He ii λ4686 emission is produced by two mechanisms: a) one linked to the intensity of the wind-wind collision which occurs along the whole orbit and is proportional to the inverse square of the separation between the companion stars; and b) the other produced by the ‘bore hole’ effect which occurs at phases across the periastron passage. The opacity (computed from 3D SPH simulations) as convolved with the emission reproduces the behavior of equivalent widths both for direct and reflected light. Our main results are: a) a demonstration that the He ii λ4686 light curve is exquisitely repeatable from cycle to cycle, contrary to previous claims for large changes; b) an accurate determination of the longitude of periastron, indicating that the secondary star is ‘behind’ the primary at periastron, a dispute extended over the past decade; c) a determination of the time of periastron passage, at ~4 days after the onset of the deep light curve minimum; and d) show that the minimum is simultaneous for observers at different lines of sight, indicating that it is not caused by an eclipse of the secondary star, but rather by the immersion of the wind-wind collision interior to the inner wind of the primary.

We carried out an extensive photometric and spectroscopic investigation of the SPB binary, HD 25558 (see Fig. 1 for the time and geographic distribution of the observations). The ~2000 spectra obtained at 13 observatories during 5 observing seasons, the ground-based multi-colour light curves and the photometric data from the MOST satellite revealed that this object is a double-lined spectroscopic binary with a very long orbital period of about 9 years. We determined the physical parameters of the components, and have found that both lie within the SPB instability strip. Accordingly, both components show line-profile variations consistent with stellar pulsations. Altogether, 11 independent frequencies and one harmonic frequency were identified in the data. The observational data do not allow the inference of a reliable orbital solution, thus, disentangling cannot be performed on the spectra. Since the lines of the two components are never completely separated, the analysis is very complicated. Nevertheless, pixel-by-pixel variability analysis of the cross-correlated line profiles was successful, and we were able to attribute all the frequencies to the primary or secondary component. Spectroscopic and photometric mode-identification was also performed for several of these frequencies of both binary components. The spectroscopic mode-identification results suggest that the inclination and rotation of the two components are rather different. While the primary is a slow rotator with ~6 d rotation period, seen at ~60° inclination, the secondary rotates fast with ~1.2 d rotation period, and is seen at ~20° inclination. Our spectropolarimetric measurements revealed that the secondary component has a magnetic field with at least a few hundred Gauss strength, while no magnetic field was detected in the primary.

The detailed analysis and results of this study will be published elsewhere.

An injection of influenza vaccine was offered to approximately 60 000 Postal and Telecommunications staff at the beginning of five successive winters. The sickness absence of this group, which included those who accepted the offer of vaccine as well as those who did not, was compared throughout the winter with that of a similar number of employees who were not offered vaccine. The two groups, ‘vaccinated’ and control, comprised the staff of nearly 400 Post Office units scattered throughout Great Britain, the units of the two groups being matched as far as practicable for numbers employed, type of work, region and type of location.

The proportion who accepted vaccine fell from 42% in the first year (when only 26 000 Telecommunications employees were offered vaccine) to 35% in the second year, and 25% by the fifth year.

With the exception of Telecommunications employees in 1972–73, the sickness absence rate of the group offered vaccine was less than that of the group not offered vaccine, and the difference was evident during the winter observation periods both when influenza was prevalent and when it was not. In the last four years of the study the average difference in sickness absence between the ‘vaccinated’ and control groups was 1.26 days per 100 employees per week during and 1.12 days outside the influenza periods. Moreover, the difference during the influenza periods was greater than could be expected from the acceptance rate of vaccine and the estimated attack rate of influenza. The apparent reduction in sickness absence of the group offered vaccine in comparison with the groupnot offered vaccine represented an appreciable saving in cost.

It is suggested than an annual influenza vaccination campaign in industry may produce financial benefit, but that only a proportion of the benefit is due to an improvement in health.

An experiment on spring barley (cvs Impala and Julia) on sandy loam soil near Oxford was made from 1969 to 1973 to compare mouldboard ploughing, deep and shallow tined cultivation followed by conventional seed-bed preparation, and direct-drilling.

In 1969 fewer barley plants on the direct-drilled plots than on cultivated plots gave fewer fertile ears/m2 and significantly less grain. In 1970, 1972 and 1973 yields did not differ between treatments. In 1971 there were more ears/m2 and more grain was obtained from direct-drilled than from ploughed plots. Mean grain yields over 5 years did not differ significantly between cultivation treatments. Ploughing and deep tine cultivation resulted in better shoot growth early in the season, more straw and more dicotyledonous weeds than direct-drilling. In comparable tillage operations on the same farm considerably less energy was needed for direct-drilling than for mouldboard ploughing and conventional seed-bed preparation.

The results are reported of two experiments made on a silt loam soil over chalk on downland in southern England. Three primary tillage treatments (ploughing, deep or shallow tine cultivation) were compared with direct drilling for their effects on the growth of spring barley during the years 1969–74 and winter wheat during 1974–8.

No significant differences in barley population density or early growth were recorded. In the first 2 years more grain was produced on the shallow tined and direct-drilled plots than on those that were ploughed, but the differences did not persist into subsequent years. The mean yield of each treatment over the 4 years did not differ.

Significant differences in population density and winter mortality of wheat occurred but these were not consistently associated with differences in yield. In this crop also the mean yields of the cultivation treatments over the 4 years were not significantly different.

It is concluded that choice of primary tillage system on this chalk downland soil was not a significant factor in the production of either spring barley or winter wheat.

Mouldboard ploughing, deep and shallow tined cultivation followed by conventional seed-bed preparation, and direct drilling were compared from 1972 to 1976 on a calcareous clay soil in two experiments, one on winter wheat and the other on spring barley.

At sowing the moisture content, bulk density and resistance to penetration in the surface layer of soil of uncultivated land were all greater than in soil that had been ploughed or cultivated deeply. Below 10 cm moisture content was less and root penetration was greater in the uncultivated soil. In all years winter wheat established and yielded well following direct drilling and shallow cultivation. In two dry autumns wheat establishment following ploughing was slower and less complete than with direct drilling, and in 1 year the yield was less. Spring barley established and yielded well without consistent differences in all years with all treatments.

PLANET, the Probing Lensing Anomaly NETwork, is an international teamconducting observations of on-going gravitational microlensingevents from five sites in the southern hemisphere. Our primary goal is todetect or to put constraints on sub-stellar companions of M dwarfs from the galactic disk. We report the current status and discuss the future prospects.A 2 m robotic telescope at Dome C which would benefit from continuous coverage and dream like seeing (median of 0.27 arcsec) is currently the best option for aground based aggressive search for Earth-mass planets in the habitable zone.

The dense phytoplankton blooms observed in earlier studies in the Southern Ocean Marginal Ice Zone (MIZ) may not be representative of all regions, so that some previous assessments of the overall importance of this system in total primary production may have been overestimated. Recent observations have shown that increased phytoplankton production may not always be associated with the retreating ice-edge, due to the unpredictability of meltwater-induced stability. Complex interactions between the MIZ and hydrographic fronts have also been indicated. A range of simple simulations, based on biomass inventories for the major biogeochemical systems in the Southern Ocean, show that the greater part of chlorophyll biomass is located in the extensive regions between the major fronts. Consideration of the fronts and the MIZ only, which we surmize may be the principal sites of export production, indicates that the MIZ is clearly the most important single feature. Even if the occurrence of MIZ blooms in the simulations is reduced dramatically, such blooms still appear to make a substantial contribution to production and, by implication, carbon export.

Due to their extremely small luminosity compared to the stars they orbit, planets outside our own Solar System are extraordinarily difficult to detect directly in optical light. Careful photometric monitoring of distant stars, however, can reveal the presence of exoplanets via the microlensing or eclipsing effects they induce. The international PLANET collaboration is performing such monitoring using a cadre of semi-dedicated telescopes around the world. Their results constrain the number of gas giants orbiting 1–7 AU from the most typical stars in the Galaxy. Upgrades in the program are opening regions of “exoplanet discovery space” – toward smaller masses and larger orbital radii – that are inaccessible to the Doppler velocity technique.

Summary

Background and objective: In October 2000, we conducted a national postal survey of consultant day case anaesthetists in the UK to explore the range and variation in the practice of anaesthetizing a patient for day case surgery (paediatrics, urology and orthopaedics). The survey was carried out as part of a larger study that comprised a major two-centre randomized controlled trial designed to investigate the costs and outcome of several anaesthetic techniques during day care surgery in paediatric and adult patients (cost-effectiveness study of anaesthesia in day case surgery). We report the findings of this national survey of adult urology and orthopaedic day case anaesthetic practice in the UK.

Methods: The survey used a structured postal questionnaire and collected data on the duration of the surgical procedure; the use of premedication; the anaesthetic agents used for induction and maintenance; the fresh gas flows used for anaesthesia; the use of antiemetics; and the administration of local anaesthesia and analgesia.

Results: The overall response rate for the survey was 74% (63% for urology, 67% for orthopaedics). The survey indicated the following practice in adult urology and adult orthopaedic day case surgery: 6 and 12% used premedication; propofol was the preferred induction agent (96 and 97%) and isoflurane the preferred maintenance agent (56 and 58%); 32 and 41% used prophylactic antiemetics; 86 and 93% used a laryngeal mask.

Conclusions: This survey identifies the variation in current clinical practice in adult day surgery anaesthesia in the UK and discusses this variation in the context of current published evidence.

Nectivory was studied in 90 species from the spider family Salticidae. Observations of 31 of these species feeding on nectar from flowers in nature was the impetus for laboratory tests in which all 90 species fed from flowers. That sugar, not just water, is relevant to salticids was implied by choice tests where salticids spent more time drinking from a simulated nectar source (30% sucrose solution) than from distilled water. Our findings suggest that nectar feeding may be widespread, if not routine, in salticid spiders.

Prolongation of the QT interval may produce potentially hazardous arrhythmias. The effects of midazolam or propofol, followed by suxamethonium on the QT interval have been investigated. Thirty patients, ASA I or II, without cardiovascular disease, electrolyte abnormalities or receiving any medication were studied. All patients were premedicated with midazolam 0.08 mg kg−1 i.m., 30–60 min prior to surgery. Anaesthesia was induced with either midazolam 0.4 mg kg−1 i.v., (15 patients) or propofol 1 mg kg−1 i.v. bolus, followed by a continuous infusion (15 patients). ECG, heart rate and arterial pressure were measured before induction of anaesthesia and at 1 and 3 min after the bolus of midazolam or propofol. Further recordings were obtained at 1 and 3 min after a bolus of suxamethonium 1.5 mg kg−1 i.v. and also immediately after tracheal intubation and 1 min later. Neither midazolam nor propofol had any significant effect on QTc interval. Prolongation of QTc was observed in both groups after suxamethonium and this was further prolonged following intubation. Heart rate and arterial pressure were also increased significantly in both groups following intubation.