RX J0744−52: a probable new intermediate polar

We present optical and X-ray data of the cataclysmic variable RX 0744−52 discovered using ROSAT by Motch et al. High-resolution spectroscopy centred on the Hα line indicates a probable orbital period of 3.60 h. From its distance (obtained using polarimetry), its X-ray luminosity, its X-ray colour and its X-ray/UV+optical ratio, we suggest that RX 0744−52 is a new intermediate polar. The absence of a significant coherent modulation in the X-ray light curve suggests either that RX 0744−52 has a low inclination or that the rotational and magnetic axes must be closely aligned. This is consistent with its small radial velocity amplitude.     

A comparison of white dwarf mass estimators using the intermediate polar XY Ari

We determine the mass of the white dwarf in the eclipsing intermediate polar XY Ari following the method given in Cropper, Ramsay &38; Wu using a multitemperature bremsstrahlung model. By fitting X-ray spectra from Ginga RXTE and ASCA we find that the mean of the best fits to the data taken using different detectors is M _wd = 1.28 ± 0.04 M⊙. This figure is too high to be consistent with the mass of the white dwarf found by Hellier from X-ray eclipse timings. There are also small systematic differences between the masses derived using different X-ray satellites.     

Disruption of magnesium regulation in the crab Cancer productus exposed to chlorinated seawater

Exposure of the crab Cancer productus to chlorinated seawater resulted in alterations in haemolymph sodium and magnesium concentrations. At the highest chlorination levels, which approached the 96-h LC₅₀, regulation of both ions was essentially abolished. Reciprocal changes in the sodium and magnesium levels suggested an effect on the activity of the bladder wall, which has been implicated in the regulation of haemolymph magnesium in crustaceans.Additionally, exposure to 1·19 μg/ml applied Cl (0·68 μg/ml TRO) for 96 h resulted in a fourfold increase in the ammonia excretion rate. Crabs also contributed considerable chlorine demand to the exposure seawater. Measurements of TRO in the inhalant seawater and water exiting the crabs' branchial chambers indicated a reduction in TRO equivalent to 57% of that initially present in the inhalant water (0·51 μg/ml TRO).Measurements of ammonia concentrations in the exposure water indicated that ammonia in seawater was consumed in reactions with oxidants. This was especially evident at higher levels of chlorination. At 0·58 μg/ml applied Cl and above, chlorination resulted in near disappearance of ammonia from the water.     

Data-driven estimation of building interior plans

This work investigates constructing plans of building interiors using learned building measurements. In particular, we address the problem of accurately estimating dimensions of rooms when measurements of the interior space have not been captured. Our approach focuses on learning the geometry, orientation and occurrence of rooms from a corpus of real-world building plan data to form a predictive model. The trained predictive model may then be queried to generate estimates of room dimensions and orientations. These estimates are then integrated with the overall building footprint and iteratively improved using a two-stage optimisation process to form complete interior plans.

The approach is presented as a semi-automatic method for constructing plans which can cope with a limited set of known information and constructs likely representations of building plans through modelling of soft and hard constraints. We evaluate the method in the context of estimating residential house plans and demonstrate that predictions can effectively be used for constructing plans given limited prior knowledge about the types of rooms and their topology.     

Environmental economic geography: A sympathetic critique

In this article I examine the objectives and substantive claims of a body of work that has come to be known as ‘environmental economic geography’ (EEG). I characterize this loose grouping of research activities as a topical contrivance: often what unites EEG researchers is simply a desire to apply the theories and methods of economic geography to environmental issues. The article explores an alternative rationale for doing EEG: the development of a distinctive intellectual project out of the encounter between economic geography and environment. Such a project extends beyond an assessment of the environmental impacts of economic activity, to examine the ways in which many ‘economic’ processes are environmentally constituted.     

Global Resource Assessments of Primary Metals: An Optimistic Reality Check

The mining of primary metals is critical for a range of modern infrastructure and goods and the continuing growth in global population and consumption means that these primary metals are expected to remain in high demand. However, metallic deposits are, in essence, finite and non-renewable—leading to some concern that we may run out of a given metal in the future. Here, we address this concern by presenting a brief review of the reporting of mineral resource estimates, compiling detailed datasets for national and global trends in mineral resources for numerous metals, and present detailed case studies of major mining projects or fields. The evidence clearly shows strong growth in known mineral resources and cumulative production over time rather than any evidence of gradual resource depletion. In addition, the key factors that already govern existing mining projects and mineral resources are certainly social, environmental and economic in nature rather than geological or related to physical resource depletion. Overall, there is great room for optimism in terms of humankind’s ability to supply future generations with the metals they will require.