Carbon-rich dust is known to form in the atmosphere of the semiregular variable star R Sculptoris. Such stardust, as well as the molecules and gas produced during the lifetime of the star, will be spread into the Galaxy via the mass-loss process. Probing this process is crucial to understand the chemical enrichment of the Galaxy. R Scl was observed using the ESO/VLTI MATISSE instrument in December 2018. Here we show the first images of the star between 3 and 10 R*. Using the complementary MIRA 3D image reconstruction and the RHAPSODY 1D intensity profile reconstruction code, we reveal the location of molecules and dust in the close environment of the star. Indeed, the C2H2 and HCN molecules are spatially located between 1 and 3.4 R* which is much closer to the star than the location of the dust. The R Scl spectrum is fitted by molecules and a dust mixture of 90% of amorphous carbon and 10% of silicone carbide. The inner boundary of the dust envelope is estimated by DUSTY at about 4.6 R*. We derive a mass-loss rate of 1.2 ± 0.4 × 10−6M⊙ yr−1however no clear SiC forming region has been detected in the MATISSE data.

Complete BVRCIC light curves of V1187 Her were obtained in May 2017 at the Dark Sky Observatory in North Carolina with the 0.81-m reflector of Appalachian State University. Earlier, spectra were taken at the Dominion Astrophysical Observatory with the 1.8-m telescope. The spectral type was found to be F8±1 V (6250 K), so the binary is of solar-type. V1187 Her was previously identified as a low amplitude (V < 0.2 mag), short period, overcontact eclipsing binary (EW) with a period of 0.310726 d. Strikingly, despite its low amplitude, the early light curves show total eclipses (eclipse duration ≍31.5 minutes), which is a characteristic of an extreme mass ratio binary. A period study covering 11 years reveals a continuous period decrease dP/dt=–4.7×10–9 d yr–1. The multi-band Wilson-Devinney light curve solution gives a fill-out of 79% and a mass ratio of only 0.0440±0.0001. There is a cool spot region on the secondary component, which is 400 K hotter than the primary. The inclination is only 66.85±0.05 despite the system’s total eclipses.

Wildlife reservoir hosts of bovine tuberculosis (bTB) include Eurasian badgers (Meles meles) and brushtail possum (Trichosurus vulpecula) in the UK and New Zealand, respectively. Similar species warrant further investigation in the northern lower peninsula of Michigan, USA due to the continued presence of bTB on cattle farms. Most research in Michigan, USA has focused on interactions between white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus) for the transmission of the infectious agent of bTB, Mycobacterium bovis, due to high deer densities and feeding practices. However, limited data are available on medium-sized mammals such as Virginia opossum (Didelphis virginiana; hereafter referred to as opossum) and their movements and home range in Michigan near cattle farms. We conducted surveillance of medium-sized mammals on previously depopulated cattle farms for presence of M. bovis infections and equipped opossum with Global Positioning System (GPS) technology to assess potential differences in home range between farms inside and outside the bTB core area that has had cattle test positive for M. bovis. On farms inside the bTB core area, prevalence in opossum was comparable [6%, 95% confidence interval (CI) 2·0–11·0] to prevalence in raccoon (Procyon lotor; 4%, 95% CI 1·0–9·0, P = 0·439) whereas only a single opossum tested positive for M. bovis on farms outside the bTB core area. The prevalence in opossum occupying farms that had cattle test positive for M. bovis was higher (6·4%) than for opossum occupying farms that never had cattle test positive for M. bovis (0·9%, P = 0·01). Mean size of home range for 50% and 95% estimates were similar by sex (P = 0·791) both inside or outside the bTB core area (P = 0·218). Although surveillance efforts and home range were not assessed on the same farms, opossum use of farms near structures was apparent as was selection for farms over surrounding forested habitats. The use of farms, stored feed, and structures by opossum, their ability to serve as vectors of M. bovis, and their propensity to ingest contaminated sources of M. bovis requires additional research in Michigan, USA.

In laboratory experiments adults and nymphs of the western conifer seed bug, Leptoglossus occidentalis Heidemann, were allowed to feed on mature seeds of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco. Weight-loss measurements and scanning electron microscopy provided strong supporting evidence for the use of simple radiographic diagnosis as a method of classifying feeding damage to seeds into four categories: light (greater than two thirds of seed contents remaining), moderate (one third to two thirds of seed contents remaining), severe (less than one third of seed contents remaining), and extreme (seed empty). Scanning electron micrographs showed the apparent depletion of lipid and protein storage reserves which was verified by quantitative analyses that showed significant loss of lipid and buffer-insoluble (crystalloid) storage protein from seeds in all damage categories. The amount of buffer-soluble (matrix) protein was reduced in seeds from the severe and extreme damage categories. The increase in buffer-soluble protein observed in lightly damaged seeds was likely due to the solubilization of crystalloid storage protein, as a result of its breakdown into smaller peptides. Our results suggest that through the action of both lipases and proteases, L. occidentalis can have a serious impact on the major storage reserves of conifer seeds. Moreover, our data suggest that L. occidentalis feeds in a different manner than the laceration and flushing method found in other seed-feeding Hemiptera.

An isolated stand of western white pine, Pinus monticola Dougl. ex D. Don, on Texada Island (49°40′N, 124°10′W), British Columbia, is extremely valuable as a seed-production area for progeny resistant to white pine blister rust, Cronartium ribicola J.C. Fisch. (Cronartiaceae). During the past 5 years, cone beetles, Conophthorus ponderosae Hopkins (= C. monticolae), have severely limited crops of western white pine seed from the stand. Standard management options for cone beetles in seed orchards are not possible on Texada Island. A control program in wild stands such as the one on Texada Island requires alternate tactics such as a semiochemical-based trapping program. Females of the related species, Conophthorus coniperda (Schwarz) and Conophthorus resinosae Hopkins, produce (+)-pityol, (2R,5S)-2-(1-hydroxyl-l-methylethyl)-5-methyl-tetrahydrofurana, sex pheromone that attracts males of both species (Birgersson et al. 1995; Pierce et al. 1995). The host compound a-pinene significantly increases attraction of male C. coniperda to pityol-baited traps in stands of eastern white pine, Pinus strobus L. (de Groot et al. 1998).

1. The habits of five Tanganyika Shorthorn zebus and their suckling calves were studied during periods of 72 consecutive hours at monthly intervals in each of the first 6 months of the calves' lives, during the ‘dry’ season of the year.

2. Cows grazed for 7·16 hr. per day while grass was green and plentiful, but, as grazing became dry and sparse, they ate silage at night for up to 3 hr., and reduced their grazing time by about 2 hr. The ratio of rumination time to eating time tended to increase as grazing became drier and as silage eating increased. The average ratio was 1·01 to 1.

3. All calves were actively grazing for 4·0 hr. per day by the second month, and for 5·6 hr. per day by the fifth month. They ate silage diffidently in the second month, but they were eating silage for 1·7 hr. per night at 6 months. Rumination was observed in a calf at 18 days of age, but was consistently observed in the second month when calves ruminated for 6·1 hr. per day. The ratio of rumination time to grazing time for calves declined from 1·5 to 1 in the second month to 1·1 to 1 in the fifth month. Rumination time among calves was more closely related to silage eating than to grazing time.

4. The calves acted as individuals in the first month, and thereafter their eating habits were determined more by their dam than by their age. Day-time rumination pattern was a characteristic of the age of calf, but night-time rumination by calves was more closely correlated to that of their dams.

5. Calves suckled for an average period of 9·2 min. per suckle. There was very little variation with age, but frequency of suckles decreased from 9·5 times per day at 1 month to 5·6 times per day at 6 months. The fastest-growing calf suckled less frequently for shorter periods, suggesting readier availabilty of more milk.

6. Suckling intensity was evenly spread over the 24 hr. during the first 2 months, but thereafter suckling became increasingly confined to nighttime while the cattle were yarded.

7. It was concluded that artificial feeding divided into three equal feeds per day at 05.00, 13.00 and 21.00 hr. for the first 2 months, followed by two equal feeds per day at 05.00 and 18.00 hr., would be reasonably consistent with natural suckling activities if restrictive feeding has to be applied. But further work is required to determine the cost, in terms of reduced efficiency of milk utilization, incurred by concentration of intake to restricted feeding times.

Cold environments are common throughout the Galaxy. We are conducting a series of experiments designed to probe the low-temperature limits for growth in selected methanogenic and halophilic Archaea. This paper presents initial results for two mesophiles, a methanogen, Methanosarcina acetivorans, and a halophile, Halobacterium sp. NRC-1, and for two Antarctic cold-adapted Archaea, a methanogen, Methanococcoides burtonii, and a halophile, Halorubrum lacusprofundi. Neither mesophile is active at temperatures below 5 °C, but both cold-adapted microorganisms show significant growth at sub-zero temperatures (−2 °C and −1 °C, respectively), extending previous low-temperature limits for both species by 4–5 °C. At low temperatures, both H. lacusprofundi and M. burtonii form multicellular aggregates, which appear to be embedded in extracellular polymeric substances. This is the first detection of this phenomenon in Antarctic species of Archaea at cold temperatures. The low-temperature limits for both psychrophilic species fall within the temperature range experienced on present-day Mars and could permit survival and growth, particularly in sub-surface environments. We also discuss the results of our experiments in the context of known exoplanet systems, several of which include planets that intersect the Habitable Zone. In most cases, those planets follow orbits with significant eccentricity, leading to substantial temperature excursions. However, a handful of the known gas giant exoplanets could potentially harbour habitable terrestrial moons.

DE CVn is a relatively unstudied eclipsing binary where one of the components is an M dwarf and the other is a white dwarf. Its brightness makes it an ideal system for a detailed study in the context of common-envelope evolution of a detached white dwarf – red dwarf binary with a relatively short orbital period (∼8.7 hours). We present a detailed study of the basic parameters (e.g. orbital period, components' masses and spectral types) for this system from photometric and spectroscopic studies. The eclipses observed during several photometric observing runs were used to derive the ephemeris. We have used spectroscopic data to derive the radial velocity variations of the emission lines and these are used to determine the components' masses and the orbital separation. The secondary component in DE CVn is an M3 main-sequence star and the primary star, which only contributes to the blue continuum, is a cool white dwarf with a temperature of ∼8000 K. From the photometry and spectroscopy together, we have set a limit on the binary inclination. This system is a post-common-envelope system where the progenitor of the present day white dwarf was a low-mass star (M≤2M⊙). The time before DE CVn becomes a semi-detached system is longer than the Hubble time.

Two models are presented for the motion of vortices near gaps in infinitely long barriers. The first model considers a line vortex for which the exact nonlinear trajectories satisfying the governing two-dimensional Euler equations are obtained analytically. The second model considers a finite-area patch of constant vorticity and is based on conformal mapping and the numerical method of contour surgery. The two models enable a comparison of the trajectories of line vortices and vortex patches. The case of a double gap formed by an island lying between two headlands is considered in detail. It is noted that Kelvin's theorem constrains the circulation around the island to be a constant and thus forces a time-dependent volume flux between the islands and the headlands. When the gap between the island and a headland is small this flux requires arbitrarily large flow speeds through the gap. In most examples the centroid of the patch is constrained to follow closely the trajectory of a line vortex of the same circulation. Exceptions occur when the through-gap flow forces the vortex patch close to an edge of the island where it splits into two with only part of the vortex passing through the gap. In general the part squeezing through a narrow gap returns to near-circular to have a diameter significantly larger than the gap width.

This paper describes a coronagraphic nulling interferometer called KEOPS (Kiloparsec Explorer for Optical Planet Search) to be placed on the Dome C plateau of Antarctica. KEOPS is an interferometric array of 39 1 m–2 m telescopes spread over kilometric baselines and operated in the thermal IR region. It could search and characterize all potential exoEarths within the 1 kpc diameter region observable from Dome C. We argue that even in the very difficult operation conditions of Antarctica, such a facility can compete at a much lower cost with the non-zero risk space missions, both for for ExPNs search and their spectroscopic characterization plus sub-mas snap-shot imaging of galactic and extra-galactic compact sources.

The problem of vortical motions in the surf zone is simplified by taking the bottom topography to be piecewise flat while allowing finite-height jumps in depth between flat regions. The motion of an arbitrary number of singular vortices is cast into Hamiltonian form and the rule for relating Hamiltonians in conformally equivalent domains derived. Examples are given of a singular vortex pair colliding head-on with a step, of a vortex propagating along a curved coast to cross a step, and of a vortex being swept past a circular island straddling a step. Surf-zone vortices are then modelled as finite-area vortex patches and their motion followed by contour dynamics. It is shown that the paths of singular vortices can yield highly accurate explicit predictions of the paths of the centroids of vortex patches. Possible applications to surf-zone rip currents are noted.

This paper describes our strategy and presents the specific additional calibration tool added to the near-infrared focal instrument AMBER of the Very Large Telescope Interferometer, to achieve the direct detection of extrasolar planets with color-differential interferometry. The measurement of the angular orbits, masses and spectra of hot giant extra solar planets can be achieved for Jupiter size planets up to 0.2 a.u. away from a 10 pc distant star, if it is limited only by photon, detector and background noises. However, this requires an extremely good control and calibration of the atmospheric and instrumental stability.

The feasibility of paediatric day-case tonsillectomy (PDCT) depends on its safety and acceptance by parents and patients. The purpose of our retrospective study of paediatric day-case tonsillectomy was to review the role of the home care team (HCT) in improving the safety and acceptance of the procedure.

Between January 1997 and June 1999, 352 consecutive children underwent day-case tonsillectomy. The notes and HCT assessment sheets were reviewed for telephone calls made by HCT or by parents, home visit by HCT, types of complication and their outcome.

The primary haemorrhage rate was 0.6 per cent. The effective day-case rate was 97 per cent. The unplanned admission rate was three per cent. The HCT visited about 25 per cent of patients at home. We conclude that paediatric day-case tonsillectomy is associated with high morbidity and considerable parental anxiety that can be dealt with by timely reassurance, support and advice by a dedicated HCT.

The Lebowa Granite Suite of the Bushveld Complex is a large, 2054 Ma old, A-type batholith, characterised by numerous relatively small magmato-hydrothermal, polymetallic ore deposits. The mineralisation is represented by a three-stage paragenetic sequence: early magmatic Sn-W-Mo-F ores (600°C > T > 400°C), followed by a Cu-Pb-Zn-As-Ag-Au paragenesis (400°C > T > 200°C) and then late-stage Fe-F-U mineralisation (< 200°C). The first stage of mineralisation (typified by the endogranitic Zaaiplaats tin deposit) is related to incompatible trace element concentration during crystal fractionation and subsequent fluid saturation of the magma. Evolution of the late magmatic fluids as they were channelled along fractures, as well as mingling with externally derived connate or meteoric fluids, resulted in the deposition of the second stage of mineralisation (typified by the fracture-related, endogranitic Spoedwel and Albert deposits and the exogranitic, sediment-hosted Rooiberg mine) which is dominated by polymetallic sulphide ores. As the externally derived fluid component became progressively more dominant, oxidation of the polymetallic sulphide assemblage and precipitation of hematite, pitchblende and fluorite occurred generally along the same fracture systems that hosted the earlier sulphide paragenesis.

Small hydrothermal zircons trapped along quartz growth zones from the Spoedwel deposit yield a U-Pb concordia age of 1957 ± 15 Ma. Whole-rock Rb-Sr age determinations from the Lebowa Granite Suite fall in the range 1790 ± 114 Ma to 1604 ± 70 Ma and are interpreted to reflect alkali element mobility and isotopic resetting during exhumation of the Bushveld granite. In contrast to thermal modelling which indicates that hydrothermal activity should have ceased within 4 my of emplacement, isotopic evidence suggests that mineralisation was long-lived, but episodic, and that fluid flow events were linked to major periods of Palaeo- and Mesoproterozoic orogenic activity along the margins of the Kaapvaal Craton. During these orogenic episodes, fluid flow was enhanced by tectonically induced fluid over-pressuring and/or exhumation of the Bushveld Complex.