PSR J1740−3052: a pulsar with a massive companion

We report on the discovery of a binary pulsar, PSR J1740−3052, during the Parkes multibeam survey. Timing observations of the 570-ms pulsar at Jodrell Bank and Parkes show that it is young, with a characteristic age of 350 kyr, and is in a 231-d, highly eccentric orbit with a companion whose mass exceeds 11 M_⊙. An accurate position for the pulsar was obtained using the Australia Telescope Compact Array. Near-infrared 2.2-μm observations made with the telescopes at the Siding Spring observatory reveal a late-type star coincident with the pulsar position. However, we do not believe that this star is the companion of the pulsar, because a typical star of this spectral type and required mass would extend beyond the orbit of the pulsar. Furthermore, the measured advance of periastron of the pulsar suggests a more compact companion, for example, a main-sequence star with radius only a few times that of the Sun. Such a companion is also more consistent with the small dispersion measure variations seen near periastron. Although we cannot conclusively rule out a black hole companion, we believe that the companion is probably an early B star, making the system similar to the binary PSR J0045−7319.     

Simultaneous multifrequency single-pulse properties of AXP XTE J1810–197

We have used the 76-m Lovell, 94-m equivalent Westerbork Synthesis Radio Telescope (WSRT) and 100-m Effelsberg radio telescopes to investigate the simultaneous single-pulse properties of the radio emitting magnetar Anomalous X-ray Pulsar (AXP) XTE J1810−197 at frequencies of 1.4, 4.8 and 8.35 GHz during 2006 May and July. We study the magnetar's pulse-energy distributions which are found to be very peculiar as they are changing on time-scales of days and cannot be fit by a single statistical model. The magnetar exhibits strong spiky single giant-pulse-like subpulses, but they do not fit the definition of the giant pulse or giant micropulse phenomena. Measurements of the longitude-resolved modulation index reveal a high degree of intensity fluctuations on day-to-day time-scales and dramatic changes across pulse phase. We find the frequency evolution of the modulation index values differs significantly from what is observed in normal radio pulsars. We find that no regular drifting subpulse phenomenon is present at any of the observed frequencies at any observing epoch. However, we find a quasi-periodicity of the subpulses present in the majority of the observing sessions. A correlation analysis indicates a relationship between components from different frequencies. We discuss the results of our analysis in light of the emission properties of normal radio pulsars and a recently proposed model which takes radio emission from magnetars into consideration.     

Maser maps and magnetic field of OH 300.969+1.147

The southern maser site OH 300.969+1.147 has been studied using the Long Baseline Array of the Australia Telescope National Facility. The 1665- and 1667-MHz hydroxyl ground-state transitions were observed simultaneously. A series of maps with 0.1-arcsec spatial resolution, at velocity spacing  0.09 km s⁻¹  , and in both senses of circular polarization reveals 59 small diameter maser spots. The spots are scattered over 2 arcsec, coincident with a strong ultracompact H  ii region, at a distance of 4.3 kpc. 17 Zeeman pairs of oppositely polarized spots were found, all yielding magnetic field estimates towards us (negative), ranging from −1.1 to −4.7 mG, with a median value of −3.5 mG. Excited state masers of OH at 6035 and 6030 MHz at this site also display Zeeman pairs revealing a magnetic field of −5.0 mG. Weak methanol maser emission is intermingled with the OH masers, but there is no detectable closely related water maser. The consistent magnetic field direction found within this site is a striking feature of several other maser sites associated with strong H  ii regions studied in comparable detail. We interpret the site as a mature region nearing the end of the brief evolutionary stage that can support maser emission.     

Searching for high alumina mare basalts using Clementine UVVIS and Lunar Prospector GRS data: Mare Fecunditatis and Mare Imbrium

In the context of sample evidence alone, the high-alumina (HA) basalts appear to be an unique, and rare variety of mare basalt. In addition to their distinct chemistry, radiometric dating reveals these basalts to be among the oldest sampled mare basalts. Yet, HA basalts were sampled by four missions spanning a lateral range of ∼2400 km, with ages demonstrating that aluminous volcanism lasted at least 1 billion years. This evidence suggests that HA basalts may be a widespread phenomenon on the Moon. Knowing the distribution of HA mare basalts on the lunar surface has significance for models of the origin and the evolution of the Lunar Magma Ocean. Surface exposures of HA basalts can be detected with compositional remote sensing data from Lunar Prospector Gamma Ray Spectrometer and Clementine. We searched the lunar surface for regions of interest (ROIs) that correspond to the intersection of three compositional constraints taken from values of sampled HA basalts: 12-18 wt% FeO, 1.5-5 wt% TiO₂, and 0-4 ppm Th. We then determined the “true” (unobscured by regolith) composition of basalt units by analyzing the rims and proximal ejecta of small impacts (0.4-4 km in diameter) into the mare surface of these ROIs. This paper focuses on two ROIs that are the best candidates for sources of sampled HA basalts: Mare Fecunditatis, the landing site of Luna 16; and northern Mare Imbrium, hypothesized origin of the Apollo 14 HA basalts. We demonstrate our technique's ability for delineating discrete basalt units and determining which is the best compositional match to the HA basalts sampled by each mission. We identified two units in Mare Fecunditatis that spectrally resemble HA basalts, although only one unit (Iltm) is consistent with the compositional and relative age of the Luna 16 HA samples. Northern Mare Imbrium also reveals two units that are within the compositional constraints of HA basalts, with one (Iltm) best matching the composition of the basalts sampled by Apollo 14.     

Nd, Pb, and Sr isotope composition of juvenile magmatism in the Mesozoic large magmatic province of northern Chile (18–27°S): indications for a uniform subarc mantle

The Jurassic to Early Cretaceous magmatic arc of the Andes in northern Chile was a site of major additions of juvenile magmas from the subarc mantle to the continental crust. The combined effect of extension and a near stationary position of the Jurassic to lower Cretaceous arc favoured the emplacement and preservation of juvenile magmatic rocks on a large vertical and horizontal scale. Chemical and Sr, Nd, and Pb isotopic compositions of mainly mafic to intermediate volcanic and intrusive rock units coherently indicate the generation of the magmas in a subduction regime and the dominance of a depleted subarc mantle source over contributions of the ambient Palaeozoic crust. The isotopic composition of the Jurassic (²⁰⁶Pb/²⁰⁴Pb: ∼ 18.2; ²⁰⁷Pb/²⁰⁴Pb: ∼ 15.55; ¹⁴³Nd/¹⁴⁴Nd: ∼ 0.51277; ⁸⁷Sr/⁸⁶Sr: ∼ 0.703–0.704) and Present (²⁰⁶Pb/²⁰⁴Pb: ∼ 18.5; ²⁰⁷Pb/²⁰⁴Pb: ∼ 15.57; 143Nd/144Nd: ∼ 0.51288; ⁸⁷Sr/⁸⁶Sr: ∼ 0.703–0.704) depleted subarc mantle beneath the Central and Southern Andes (18°–40°S) was likely uniform over the entire region. Small differences of isotope ratios between Jurassic and Cenozoic to Recent of subarc mantle-derived could be explained by radiogenic growth in a still uniform mantle source.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at .     

Improvement of a Monoclonal Antibody-based Immunoassay for the Determination of Terbutryn Verbesserung eines Immunassays mit monoklonalen Antikörpern zur Bestimmung von Terbutryn

The performance of an existing enzyme immunoassay (EIA) with monoclonal antibodies (mAb) for the determination of terbutryn was improved by the application of a new enzyme tracer. For this purpose the triazine derivative 6-chloro-2-(tert-butylamino)-1,3,5-triazine-4-(6-aminohexane carboxylic acid) was coupled to horseradish peroxidase (HRP). The competitive EIA on microwell plates made it possible to determine terbutryn in the range from 0.05 to 1 μg/L with a 50% B/B₀ value of the test at 0.2 μg/L. The application of the EIA to determine terbutryn in spiked surface waters provided good recoveries of terbutryn without matrix effects.     

Use of nuclear magnetic resonance microscopy for noninvasive observations of root-soil water relations

Summary As part of our strategy to study root-soil water relationships, it was necessary to develop a nondestructive technique to detect small changes in water distribution in and near the root. Nuclear magnetic resonance imaging (MRI), clinically used to nondestructively and noninvasively acquire anatomical information, can also be used to observe water distribution in roots, soils and other plant tissues. In MRI, a sample is placed in a strong magnetic field and a sequence of radio frequency (rf) pulses and magnetic field gradients is used to measure the concentration and relaxation properties of protons, chiefly those associated with water. This information is then reconstructed into a digital image representing the spatial distribution of water in plant tissues and soil. Today, intact roots less than 1 mm in diameter growing in soil or synthetic media can be clearly imaged in less than 4 minutes at resolutions typically less than 30µm. This permits rapid production of images that simultaneously distinguish temporal changes in water distribution in root tissue, the rhizosphere and the adjacent soil at microscopic levels. Applications of this technique for investigating plant-soil water relationships will be discussed.With 3 Figures     

A new certified reference material for the quality control of trace elements in marine monitoring: Cod muscle (CRM 422)

Analyses of fish tissues are routinely carried out by a number of laboratories to monitor the levels of contamination of the marine environment and food by toxic elements, e.g. by heavy metals. To improve and control the quality of such determinations, the Community Bureau of Reference (BCR) has organized a certification campaign which enabled us to produce a reference material (cod muscle CRM 422) certified for its contents of As, Cd, Cu, Fe, Hg, I, Mn, Pb, Se, and Zn. This material was collected in the southern part of the North Sea, carefully prepared (filleted and crushed under liquid nitrogen) and its homogeneity and long term stability were verified. This paper presents the certification work performed.     

Fluid inclusion study of the Fiumarella barite deposit (Catanzaro — S. Italy)

Samples from a barite vein deposit, located in the Catanzaro Fiumarella (Calabria) were examined by fluid inclusion and ore minerographic techniques. The barite vein occur in plutonic rocks of the Stilo Unit, where some Mo mineralizations were reported. The purpose of the study was to determine the characteristics of the fluid inclusions and to compare them to those of typical porphyry Cu/Mo systems. The ore minerographic study shows that the sulfides, associated to the barite, are clearly post-barite. The fluid inclusion results indicate that the average minimum temperature of the barite formation can be assumed to be about 210°C, with a range of 190–235°C. The salinity of the barite forming solutions is in the range 0–19.5 wt% NaCl and the average minimum pressure on the system was of 18.04 bars equivalent to a minimum depth of 201 m of barite formation below the paleowatertable. No genetic link is suggested to exist between the fluid inclusions of the Fiumarella barite deposit and those characteristic of typical porphyry Cu/Mo systems, whereas a close relation with epithermal precious metal (with base metals) vein deposits or with their distant cousins, the Kuroko deposits, is suggested to exist.Work carried out with the financial assistance of the "Progetto Finalizzato Geodinamica" (n^o 79.00597.89.115.6291). Publ. n^o 353     

Sensitivity of FORGRO to climatic change scenarios: A case study on Betula pubescens, Fagus sylvatica and Quercus robur in The Netherlands

The impacts of the climate change predictions of four general circulation models (GFDL, GISS, OSU and UKMO) on net primary production (NPP) ofBetula pubescens, Fagus sylvatica and Quercus robur in The Netherlands were analysed using the process-based model FORGRO. FORGRO is a model suitable to simulate growth of managed mono-species stands. For the GCMs mentioned, both transient and equilibrium 2 × CO₂ scenarios of temperature and precipitation change were evaluated and compared with responses under current climate. It was found that the NPP increases in the transient scenarios, but remains the same or declines in the 2 × CO₂ scenarios. This is because respiration increases more with rising temperature than photosynthesis. During the transient scenarios this effect gradually increases, while in the 2 × CO₂ scenario this effect is operating over the entire simulation period.If water limitation is taken into account, then the NPP of the reference scenario is reduced. In both the transient and 2 × CO₂ scenarios mis water limitation is annulated, resulting in a stronger response of NPP compared to the situation without water limitation. This enhancement of the response is most pronounced in the transient scenario due to the gradual effect of temperature on respiration.Similar results were obtained with a version of FORGRO in which the photosynthesis module of HYBRID (PGEN) is incorporated, although the response in FORGRO-PGEN is usually higher than that of FORGRO. This is because the response of photosynthesis to CO₂ rises with increasing temperature as defined in the PGEN-model, but not according to FORGRO.