Rufford Foundation

Animal body size influences key ecological processes across biological hierarchies. For instance, densities (N) and community biomass (B) are allometric functions of body mass (M). Energetic equivalence predicts that density scales with body size as N ∝ M-0.75 and that biomass scales with body size as B ∝ M0.25. However, the way fish size-spectra are influenced by external processes, such as ecological subsidies (e.g. nutrients from upwelling zones) and fisheries management, is not well understood. We investigated the relationship of body size with density and biomass of reef fishes associated with subtidal kelp forests of Lessonia trabeculata that were influenced by the separate and interactive effects of management (Territorial Use Rights for Fisheries [TURF] or open access) and upwelling regimes (upwelling or non-upwelling zones). Fish densities and lengths were recorded using underwater visual censuses. Within each of 4 locations, paired TURF and open-access sites were surveyed. We surveyed 18 fish species, encompassing 1511 individuals ranging between 2 and 6639 g. We observed that fish size-spectra deviated from energetic equivalence, as N ∝ M-0.32 and B ∝ M2.2, indicating that the contribution of large-sized fishes to community density and biomass was greater than that predicted by energetic equivalence. Multi-model inference suggested that TURF and upwelling scenarios had weak effects on fish size-spectra. Results indicated that fish communities may have access to external food sources beyond local kelp forests. In addition, size-spectra may be a spatially persistent attribute of these fish communities.

The aim of this study was to compare the results of healthy volunteers with patients in chronic pain, in terms of acupuncture needle sensation. The search for a credible mechanism that underpins the effect of acupuncture in pain has recently involved the use of brain imaging techniques in an attempt to identify the neural correlates involved in pain control. Such studies have usually enrolled healthy participants rather than patients. This practice might be inappropriate as we are unsure if we can generalize from healthy volunteers to patients in chronic pain. This paper describes a comparison of data obtained from 2 small randomized controlled studies, 1 involving patients with chronic pain and the other which recruited healthy volunteers. Both studies used real acupuncture and a nonpenetrating "placebo" needle in a crossover design. The outcome studied in this paper was a comprehensive needling sensation questionnaire. There was a difference in the sensations experienced by patients as compared with healthy volunteers. Patients tended to feel much stronger sensation. Neither group differed in distinguishing between real and placebo needling. However, patients were more likely to state that both needles were real, whereas healthy participants were more likely to suggest that neither were real. It is concluded that if the nature of the sensation felt is of importance, then it might be inappropriate to recruit healthy volunteers in lieu of patients and a larger study is required to clarify this.