Exuberance, A Motivation for Language

The following is part of the presidential address from Allen Walker Read, given before LACUS (Linguistic Association of Canada and the United States) at its annual meeting, August 7, 1987, at York University, Toronto, Ontario, Canada. It is reprinted by permission from the proceedings, The Fourteenth LACUS Forum, 1987

Radial structure, inflow and central mass of stationary radiative galaxy clusters

We analyse the radial structure of self-gravitating spheres consisting of multiple interpenetrating fluids, such as the X-ray emitting gas and the dark halo of a galaxy cluster. In these dipolytropic models, the adiabatic dark matter sits in equilibrium, while the gas develops a gradual, smooth, quasi-stationary cooling flow. Both affect and respond to the collective gravitational field. We find that all subsonic, radially continuous, steady solutions require a non-zero minimum central point mass. For Mpc-sized haloes with 7–10 effective degrees of freedom (F2), the minimum central mass is compatible with observations of supermassive black holes. Smaller gas mass influxes enable smaller central masses for wider ranges of F2. The halo comprises a sharp spike around the central mass, embedded within a core of nearly constant density (at 101–102.5 kpc scales), with outskirts that attenuate and naturally truncate at finite radius (several Mpc). The gas density resembles a broken power law in radius, but the temperature dips and peaks within the dark core. A finite minimum temperature occurs due to gravitational self-warming, without cold mass dropout nor needing regulatory heating. X-ray emission from the intracluster medium mimics a β-model plus bright compact nucleus. Near-sonic points in the gas flow are bottlenecks to the allowed steady solutions; the outermost are at kpc scales. These sites may preferentially develop cold mass dropout during strong perturbations off equilibrium. Within the sonic point, the profile of gas specific entropy is flatter than s∝r1/2, but this is a shallow ramp and not an isentropic core. When F2 is large, the inner halo spike is only marginally Jeans stable in the central parsec, suggesting that a large non-linear disturbance could trigger local dark collapse on to the central object

Abortion Counselling in Britain: Understanding the Controversy

This article reviews literature from a number of disciplines in order to provide an explanation of the political controversy attached to the provision of abortion counselling. It will show how this is an area of health policy debate in which women's reproductive bodies have become a setting for political struggle. The issue of abortion counselling in Britain has undergone a number of discursive shifts in response to political manoeuvring and changing socio-legal framing of abortion. In particular, the article shows how much of the controversial reframing of abortion counselling was a tactical shift by political actors opposed to abortion per se, and this work is critiqued for not contextualising abortion. The article then focuses on women's abortion experiences and discusses research that shows how women's decision-making processes, and responses to an abortion, are related to gendered socio-cultural contexts: the extent to which women having an abortion feel they have transgressed societal norms and values, for example, is likely to affect their abortion experiences. Finally, it is suggested that providing a non-judgemental context, and challenging negative discourses on abortion, may be the most effective way of minimising the possibility of negative emotions

Ngā Whakāwhitinga (standing at the crossroads): How Māori understand what Western psychiatry calls “schizophrenia”

This project explored how Māori understand experiences commonly labelled “schizophrenic” or “psychotic”. Semi-structured interviews were conducted with 57 Māori participants who had either personal experiences labelled as “psychosis” or “schizophrenia”, or who work with people with such experiences; including tangata whaiora (users of mental health services), tohunga (traditional healers), kaumatua/kuia (elders), Māori clinicians, cultural support workers and students. Kaupapa Māori Theory and Personal Construct Theory guided the research within a qualitative methodology. The research found that participants held multiple explanatory models for experiences commonly labelled “psychotic” or “schizophrenic”. The predominant explanations were spiritual and cultural. It seems that cultural beliefs and practices related to mental health within Māori communities remain resilient, despite over a century of contact with mainstream education and health services. Other explanations included psychosocial constructions (interpersonal trauma and drug abuse), historical trauma (colonisation) and biomedical constructions (chemical brain imbalance). Participants (both tangata whaiora and health professionals) reported they were apprehensive about sharing their spiritual/cultural constructions within mainstream mental health settings due to fear of being ignored or pathologised. This study highlights the importance of asking users of mental health services about the meaning they place on their experiences and recognising that individuals can hold multiple explanatory models. Māori may hold both Māori and Pākehā (European) ways of understanding their experiences and meaningful recognition should be afforded to both throughout assessment and treatment planning in mental health services. Clinicians need to be aware that important personal and cultural meanings of experiences labelled psychotic may be withheld due to fear of judgement or stigmatisation

Novel Root-Fungus Symbiosis in Ericaceae: Sheathed Ericoid Mycorrhiza Formed by a Hitherto Undescribed Basidiomycete with Affinities to Trechisporales

Ericaceae (the heath family) are widely distributed calcifuges inhabiting soils with inherently poor nutrient status. Ericaceae overcome nutrient limitation through symbiosis with ericoid mycorrhizal (ErM) fungi that mobilize nutrients complexed in recalcitrant organic matter. At present, recognized ErM fungi include a narrow taxonomic range within the Ascomycota, and the Sebacinales, basal Hymenomycetes with unclamped hyphae and imperforate parenthesomes. Here we describe a novel type of basidiomycetous ErM symbiosis, termed ‘sheathed ericoid mycorrhiza’, discovered in two habitats in mid-Norway as a co-dominant mycorrhizal symbiosis in Vaccinium spp. The basidiomycete forming sheathed ErM possesses clamped hyphae with perforate parenthesomes, produces 1- to 3-layer sheaths around terminal parts of hair roots and colonizes their rhizodermis intracellularly forming hyphal coils typical for ErM symbiosis. Two basidiomycetous isolates were obtained from sheathed ErM and molecular and phylogenetic tools were used to determine their identity; they were also examined for the ability to form sheathed ErM and lignocellulolytic potential. Surprisingly, ITS rDNA of both conspecific isolates failed to amplify with the most commonly used primer pairs, including ITS1 and ITS1F + ITS4. Phylogenetic analysis of nuclear LSU, SSU and 5.8S rDNA indicates that the basidiomycete occupies a long branch residing in the proximity of Trechisporales and Hymenochaetales, but lacks a clear sequence relationship (>90% similarity) to fungi currently placed in these orders. The basidiomycete formed the characteristic sheathed ErM symbiosis and enhanced growth of Vaccinium spp. in vitro, and degraded a recalcitrant aromatic substrate that was left unaltered by common ErM ascomycetes. Our findings provide coherent evidence that this hitherto undescribed basidiomycete forms a morphologically distinct ErM symbiosis that may occur at significant levels under natural conditions, yet remain undetected when subject to amplification by ‘universal’ primers. The lignocellulolytic assay suggests the basidiomycete may confer host adaptations distinct from those provisioned by the so far investigated ascomycetous ErM fungi

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix