Entrepreneurial urbanism, state restructuring and civilizing 'New' East Manchester

This paper draws on the 'entrepreneurial turn' literatures to examine the current redevelopment of East Manchester. It makes three contributions to our existing empirical and theoretical understanding of what is termed here 'entrepreneurial urbanism'. First, attention is drawn to the spatially selective nature of entrepreneurial urbanism within cities; second, it argues that entrepreneurial urbanism actually demands a qualitative shift in the state's role in urban redevelopment and third, using the example of East Manchester, these two theoretical issues are explored empirically.     

Controlling introduced predators in the Gibson Desert of Western Australia

Three introduced predators, the dingo (Canis lupus dingo), the fox (Vulpes vulpes) and the feral cat (Felis catus) are widespread throughout the arid interior of Western Australia. While the dingo has been present for an estimated 3500–4000 years, the fox and the feral cat are relatively recent arrivals and have been implicated in the modern decline and in some cases extinction of arid zone fauna, especially medium size mammals. This paper reports on a long-term, large-scale project aimed at developing control strategies for these introduced predators. Broad area control of foxes and dingoes in the Gibson Desert using 40–60 g dried meat baits impregnated with the poison sodium monofluoroacetate (1080) and delivered by aircraft at a density of 5 baits km⁻² proved to be highly effective. Following a single aerial baiting of some 1600 km², foxes and dingoes were virtually eradicated from a core area for up to 15 months, but feral cats appeared to increase in abundance. Two aerial baitings (each 400 km²) carried out during periods of below average rainfall using a small (about 30 g) fresh meat bait developed to be attractive to feral cats reduced their abundance by an estimated 75% and 100% when baits were delivered at a density of 10 and 22 km⁻², respectively. A third aerial baiting at a density of 11 baits km⁻² carried out during a period of above average rainfall reduced feral cat density by only 25% when surveyed 3 months after baiting. Baiting density, frequency and season are key factors likely to affect the impact of baiting on feral cat populations. Preliminary studies reveal that the home range of feral cats in this environment varies from about 700 to 1200 ha. Reptiles and small native mammals form the major dietary items of feral cats and the seasonal variation in abundance of these items is likely to affect bait uptake. These observations have important implications for control strategies.     

On the consistency of earthquake moment release and space geodetic strain rates: Europe

In this paper, approximately 100 VLBI/SLR/GPS velocities map European strain rates from <0.09 × 10⁻⁸ to >9.0 × 10⁻⁸ yr⁻¹ with regional uncertainties of 20 to 40 per cent. Kostrov's formula translates these strain-rate values into regional geodetic moment rates M¯˙ _geodetic . Two other moment rates, M¯˙ _seismic , extracted from a 100-year historical catalogue and M¯˙ _plate , taken from plate-tectonic models, contrast the geodetic rates. In Mediterranean Europe, the ratios of M¯˙ _seismic to M¯˙ _geodetic are between 0.50 and 0.71. In Turkey the ratio falls to 0.22. Although aseismic deformation may contribute to the earthquake deficit ( M¯˙ _seismic values less than M¯˙ _geodetic ), the evidence is not compelling because the magnitudes of the observed shortfalls coincide with the random variations expected in a 100-year catalogue. If the lack of aseismic deformation inferred from the 100-year catalogue holds true for longer periods, then much of Europe's strain budget would have to be accommodated by more frequent or larger earthquakes than have been experienced this century to raise the ratios of M¯˙ _seismic to M¯˙ _geodetic to unity. Improved geological fault data bases, longer historical earthquake catalogues, and densification of the continent's space geodetic network will clarify the roles of aseismic deformation versus statistical quiescence.     

Near-infrared luminosity function and colours of dwarf galaxies in the Coma cluster

We present K -band observations of the low-luminosity galaxies in the Coma cluster, which are responsible for the steep upturn in the optical luminosity function at M _R∼−16, discovered recently. The main results of this study are as follows.
(i) The optical–near-infrared colours of these galaxies imply that they are dwarf spheroidal galaxies. The median B − K colour for galaxies with −19.3< M_K <−16.3 is 3.6 mag.
(ii) The K -band luminosity function in the Coma cluster is not well constrained, because of the uncertainties due to the field-to-field variance of the background. However, within the estimated large errors, this is consistent with the R -band luminosity function, shifted by ∼3 mag.
(iii) Many of the cluster dwarfs lie in a region of the B − K versus B − R colour–colour diagram where background galaxies are rare ( B − K <5; 1.2< B − R <1.6). Local dwarf spheroidal galaxies lie in this region too. This suggests that a better measurement of the K -band cluster luminosity can be made if the field-to-field variance of the background can be measured as a function of colour, even if it is large.
(iv) If we assume that none of the galaxies in the region of the B − K versus B − R plane given in (iii) in our cluster fields are background, and that all the cluster galaxies with 15.5< K <18.5 lie in this region of the plane, then we measure α=−1.41^+0.34_−0.37 for −19.3< M_K −16.3, where α is the logarithmic slope of the luminosity function. The uncertainties in this number come from counting statistics.     

Stellar populations in active galactic nuclei — I. The observations

Recent observations supported by theoretical models have led to the view that giant and supergiant stars are overabundant, and/or a high-metallicity component may be present, in the stellar populations at the centres of active galaxies. Here we attempt to quantify these effects by observing the strengths of the stellar absorption lines of Mg b, Na  i and the Ca  ii triplet, as well as molecular bands such as CN and TiO. Using long-slit spectroscopic data we are able to separate the stellar populations in and around the nucleus, for a sample including normal, LINER, starburst and Seyfert galaxies.   In this paper we present the data, namely spectra of the nucleus and of a number of circumnuclear regions. Comparisons reveal gradients in both the reddening and the stellar population within the central regions of most galaxies. Detailed stellar population synthesis will be presented in a companion paper.     

Skill and reproducibility of seasonal rainfall patterns in the tropics in ECHAM-4 GCM simulations with prescribed SST

 The ECHAM4 atmospheric general circulation model (GCM) has been integrated at T30 resolution through the period 1960–1994 forced with the observed sea-surface temperatures (SSTs) as compiled at the Hadley Centre (GISST2.2). Three experiments were made starting from different initial conditions. The large-scale tropical precipitation patterns simulated by the model have been studied, focusing on the skill (i.e. the capability to simulate the observed anomaly over land areas) and reproducibility (i.e. the GCM’s interannual rainfall variance that is independent from the initial conditions). Analysis of variance is used to estimate the reproducibility amongst ensemble members at each grid-box, but most emphasis is placed on large-scale patterns, as revealed by various singular value decomposition analyses (SVDAs), between observed and model fields (OM analyses) and amongst the different model runs (MM analyses). Generally, it is found that the first model mode in the MM analysis is very similar to that in the OM analysis, suggesting the model mode with strongest reproducibility is also the mode which tallies best with observations. For the global tropics, the first MM mode is highly reproducible (external variance above 90%) and the first OM couplet is very skillful (correlation between observed and model SVDA time series is over 0.84). The extent to which skill and reproducibility is related to El Nino/Southern Oscillation (ENSO) has been investigated by comparing the OM and MM time series with the Southern Oscillation Index (SOI). For the global tropics, most of the OM and MM variance is common with the SOI, though in boreal summer, the first modes do also have some clear independence from the SOI. The analyses were repeated at the regional scale for Oceania, tropical America, tropical Africa and tropical Southeast Asia. A highly reproducible mode is found in all cases except October-December in Africa. Skill, while always positive, is more variable, strongest for Oceania and tropical America and weakest for Africa. Comparisons with the SOI suggest skill in tropical America and tropical Africa has substantial components that are independent of the SOI, especially in boreal spring and summer when the tropical Atlantic SSTs are strongly related to the leading OM and MM time series. Received: 1 January 1997 / Accepted: 28 July 1997     

Recharge and groundwater models: an overview

Recharge is a fundamental component of groundwater systems, and in groundwater-modeling exercises recharge is either measured and specified or estimated during model calibration. The most appropriate way to represent recharge in a groundwater model depends upon both physical factors and study objectives. Where the water table is close to the land surface, as in humid climates or regions with low topographic relief, a constant-head boundary condition is used. Conversely, where the water table is relatively deep, as in drier climates or regions with high relief, a specified-flux boundary condition is used. In most modeling applications, mixed-type conditions are more effective, or a combination of the different types can be used. The relative distribution of recharge can be estimated from water-level data only, but flux observations must be incorporated in order to estimate rates of recharge. Flux measurements are based on either Darcian velocities (e.g., stream baseflow) or seepage velocities (e.g., groundwater age). In order to estimate the effective porosity independently, both types of flux measurements must be available. Recharge is often estimated more efficiently when automated inverse techniques are used. Other important applications are the delineation of areas contributing recharge to wells and the estimation of paleorecharge rates using carbon-14. Electronic Publication     

D/H ratios in speleothem fluid inclusions: A guide to variations in the isotopic composition of meteoric precipitation?

D/H ratios of fluid inclusion waters extracted from²³⁰Th/²³⁴U-dated speleothems that were originally deposited under conditions of isotopic equilibrium should provide a direct estimate of the hydrogen isotopic composition of ancient meteoric waters. We present here D/H ratios for 47 fluid inclusion samples from thirteen speleothems deposited over the past 250,000 years at cave sites in Iowa, West Virginia, Kentucky and Missouri. At each site glacial-age waters are depleted in deuterium relative to those of interglacial age. The average interglacial/glacial shift in the hydrogen isotopic composition of meteoric precipitation over ice-free areas of east-central North America is estimated to be ?12‰. This shift is consistent with the present climatic models and can be explained in terms of the prevailing pattern of atmospheric circulation and an increased ocean-continent temperature gradient during glacial times which more than compensated for the increase in deuterium content of the world ocean.