We have developed a multiscale structure identification algorithm for the detection of overdensities in galaxy data that identifies structures having radii within a user-defined range. Our 'multiscale probability mapping' technique combines density estimation with a shape statistic to identify local peaks in the density field. This technique takes advantage of a user-defined range of scale sizes, which are used in constructing a coarse-grained map of the underlying fine-grained galaxy distribution, from which overdense structures are then identified. In this study we have compiled a catalogue of groups and clusters at 0.025 < z < 0.24 based on the Sloan Digital Sky Survey (SDSS), Data Release 7, quantifying their significance and comparing with other catalogues. Most measured velocity dispersions for these structures lie between 50 and 400 km s −1 . A clear trend of increasing velocity dispersion with radius from 0.2 to 1 h −1 Mpc is detected, confirming the lack of a sharp division between groups and clusters. A method for quantifying elongation is also developed to measure the elongation of group and cluster environments. By using our group and cluster catalogue as a coarse-grained representation of the galaxy distribution for structure sizes of 1 h −1 Mpc, we identify 53 filaments (from an algorithmically derived set of 100 candidates) as elongated unions of groups and clusters at 0.025 < z < 0.13. These filaments have morphologies that are consistent with previous samples studied.

Reported rates of referral by individual general practitioners to hospitals range from less than 1% of all consultations to more than 20%. Research on variations in rates of referral by general practitioners in the UK is reviewed here. Studies have largely failed to account for variation either in terms of differences in the characteristics of patients or differences in the doctors and their practices. It is argued that this failure arises because most studies do not distinguish between different types of referral or reasons for making a referral. In order to begin to explain variations it is necessary to identify the stages in the complex process of decision making. A theoretical model of the referral decision is advanced, which is intended to provide a framework for further research on the referral process.

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Cisplatin, used to treat ovarian, bladder, and testicular cancers, causes a sensory dose-limiting neuropathy. Preliminary observations in humans and animals suggest that nerve damage may be prevented by ACTH analogs, particularly those belonging to the melanocortin class, and by nerve growth factor (NGF). We established a rat embryo dorsal root ganglion model to study cisplatin neurotoxicity. The drug reproducibly inhibited axonal growth at concentrations similar to that known to produce toxicity in neurons. The inhibition was prevented in a dose-dependent fashion by simultaneous exposure to alpha-melanocyte stimulating hormone (alpha-MSH) or ACTH but not by excess NGF or ciliary neurotrophic factor (CNTF). The ACTH peptides were not effective in preventing suramin-induced neurotoxicity in the same model. Drug interaction and dose-response studies showed that ACTH and alpha-MSH do not act by potentiation of NGF action. ACTH analogs appear to protect against cisplatin-induced neurotoxicity directly at the cellular level.

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