Randomized controlled trial of supported employment in England: 2 year follow-up of the Supported Work and Needs (SWAN) study

Studies from North America have concluded that supported employment using the Individual Placement and Support (IPS) model is effective in helping individuals with severe and persistent mental illness gain competitive employment. The aim of this study was to investigate the effectiveness and cost-effectiveness of IPS in England in patients followed up for 2 years. Patients with severe mental illness were randomised to IPS or local vocational services (treatment as usual). Service use and costs were measured. Two hundred-nineteen participants were randomised, and 86% re-assessed 2 years later. In the multivariate analysis, relatively low rates of competitive employment were found in both the intervention group and the treatment as usual group, although significantly more patients obtained competitive employment in the treatment arm (22% vs. 11%, p=0.041). There were no significant differences in costs. The employment rate among participants receiving IPS was lower than in previously published reports, and the number needed to treat to obtain the benefit of IPS was relatively high. This may reflect difficulties in the implementation of IPS where it is not structurally integrated within mental health teams, as well as economic disincentives which lead to lower levels of motivation for patients and mental health professionals.     

Rooting down the aphid's tree – the oldest record of the Aphidomorpha lineage from Palaeozoic (Insecta: Hemiptera)

The new genus and species Lutevanaphis permiana gen.n. et sp.n. , represents the oldest Aphidomorpha, new superfamily Lutevanaphidoidea superfam.n. and new family Lutevanaphididae. This taxon is described from the Middle Permian of the Lodève Basin, southern France. The presence of very small Aphidomorpha in the Middle Permian contradicts the hypothesis of the ‘Lilliput effect’ that is presumed to have affected the insect fauna during the Early to Middle Triassic, after the end‐Permian crisis. Very small insects were present well before the end of the Permian; their relative rarity is attributable probably to taphonomic biases.     

Inhibition of lactic streptococcus bacteriophage by crystal violet and other agents

Ninety-nine selected compounds and eleven antibiotic-producing organisms were tested for antiphage activity and host toxicity. A paper disc-agar diffusion method was used for primary screening and quantitative methods were employed for confirmatory investigation. Most of the agents tested, although previously reported as inhibitory to one or more other virus-host systems, did not selectively prevent multiplication of lactic streptococcus bacteriophage. Several compounds which prevented mass lysis were extremely toxic to host bacteria. Crystal violet suppressed growth of two phage strains at a level (1.0 x 10(-7)M) which permitted normal growth of the host cells. Failure of crystal violet to prevent multiplication of many phage strains suggested possible variations in the multiplication mechanisms of different strains of virus. Virustatic levels of crystal violet did not destroy unadsorbed virus, reduce adsorption, or prevent invasion; increase of virus was reduced in one-step growth experiments; mass lysis was prevented or delayed in long time experiments. Addition and removal of crystal violet at various intervals during the latent period resulted in virus yields directly related to the portion of the latent period during which no dye was present. Duration of the latent period was unaffected. Single burst experiments indicated that the yield of plaque-forming particles per infected bacterium was reduced; the proportion of infected bacteria giving rise to active progeny did not appear to be influenced to a significant degree. Crystal violet apparently interferes with intracellular multiplication of the virus, possibly by combination of the dye with phage DNA or fractions thereof at some critical stage in the incorporation of DNA into the virus particle.     

Fidelity of molluscan life and death assemblages on sublittoral hard substrata around granitic islands of the Seychelles

This study quantified the degree of coincidence between living and dead molluscan faunas in a shallow-water coral reef environment in the Indian Ocean. The results were compared with those from a similar life:death study in the northern Red Sea, and with those published for reef corals and soft substrata molluscs. The proportions of quantitatively important taxa are robust to sampling intensity, but fidelity indices and rank-order correlations are strongly influenced by quantitatively unimportant taxa. Distinct differences between life and death assemblages were recognized, which are due to distinct biases in the death assemblage. Bivalves that lived in close contact with living corals are preferentially overgrown after death and should provide considerable temporal and ecological information in a potential fossil record, as they will be preserved within a rapidly growing reef framework. Some gastropod taxa are preferentially transported into surrounding soft substrata postmortem. Here they will be affected by time-averaging and taphonomic disintegration typically occurring in sediments resulting in the associated loss of much temporal information. Most gastropod shells, however, are inhabited by hermit crabs postmortem, which may strongly alter the fossil gastropod community structure. The results are similar to a comparable study in the northern Red Sea, with a major exception being the strong dominance of hermit crab-inhabited gastropod shells in the death assemblage of the Seychelles. Comparison of life:death assemblages between hard and soft substrata, in keeping with the northern Red Sea study, showed the strong dominance of dead shells in the soft substrata with the converse on the hard substrata. This results from different accumulation conditions for dead shells in soft substrata. Fidelity indices are well suited to demonstrate that sedimentary death assemblages are typically remarkably robust reflections of local community composition but they do not record the strong biases in death assemblages of coral reef associated hard substrata molluscs and are therefore unsuitable for comparisons of life and death assemblages in reef environments.     

Indole-3-Acetic Acid (IAA) Oxidation by Leghemoglobin form Soybean

Leghemoglobin from nudules of soybean prepated by ammonium sulfate frationation appeared to be able to destroy substantial quantities of IAA, Degradation still occurred in purified leghemoglobin preparations isolated by G-100 Sephadex chromatography. Nicotinic acid and acetate affecting the conformation of leghemoglobin both inhibited IAA oxidation by this hemoprotein. The ferric form was found to be the most active in this catabolism. This oxication, related to the psedudoperocidase activity of leghemoghlobin, is undoubtedly restricted in vivo by the very low level of the ferric form present in efficient nodules.     

Pattern, process and prediction in aquatic ecology. A limnological view of some general ecological problems

1. New scientific concepts such as models of chaos, complex dynamics and non-linear interactions have the potential to contribute to an improved understanding of ecological patterns and processes. This paper discusses some of the known dynamics of phytoplankton, pelagic food chains and nutrient cycles in the light of some of these new concepts. The paper brings these new conceptual models together with data from a wide range of sources in an attempt to produce a synthesis of system behaviour which allows us to understand why some things are inherently more predictable than others. In particular it looks at the limnological management tools of empirical biomass models and biomanipulation and at the need for prediction of species composition. 2. The structures observed in ecosystems (nutrient pools, sizes, species, temporal/spatial patterns) show properties at a spectrum of scales, as do the processes (fluxes, grazing, competition). Both respond to a spectrum of external perturbations that may be climatologically or anthropogenically induced. Empirical biomass models work because of the annual averaging of pattern and process and because of some inherent properties of the functioning of pelagic ecosystems. Many aspects of ecosystem pattern and process vary in a regular way with trophic state. Examination of empirical data sets can lead to an improved understanding of system behaviour if questions are asked about why things happen the way they do. 3. Feedbacks between pattern, process and periodicity are seen to be an inherent property of the system. Understanding the fundamental dynamics of non-linear interactions in ecosystems may make it possible to exploit the external spectrum of environmental perturbations and to control system function. For example, by imposing external physical perturbations on pelagic systems it may be possible to manipulate the species composition of the phytoplankton community. Because of the complexity of possible interactions both ‘horizontally’ between species and ‘vertically’ within the food chain, any prediction of species composition will necessarily be probabilistic.