The Quaternary pyroclastic succession of southeast Tenerife, Canary Islands: Explosive eruptions, related caldera subsidence, and sector collapse

A much-revised Quaternary stratigraphy is presented for ignimbrites and pumice fall deposits of the Bandas del Sur, in southern Tenerife. New Ar-41/Ar-39 data obtained for the Arico, Granadilla, Fasnia, Poris, La Caleta and Abrigo formations are presented, allowing correlation with previously dated offshore marine ashfall layers and volcaniclastic sediments. We also provide a minimum age of 287 +/- 7 ka for a major sector collapse event at the Gaimar valley. The Bandas del Sur succession includes more than seven widespread ignimbrite sheets that have similar characteristics, including widespread basal Plinian layers, predominantly phonolite composition, ignimbrites with similar extensive geographic distributions, thin condensed veneers with abundant diffuse bedding and complex lateral and vertical grading patterns, lateral gradations into localized massive facies within palaeo-wadis, and widespread lithic breccia layers that probably record caldera-forming eruptions. Each ignimbrite sheet records substantial bypassing of pyroclastic material into the ocean. The succession indicates that Las Canadas volcano underwent a series of major explosive eruptions, each starting with a Plinian phase followed by emplacement of ignimbrites and thin ash layers, some of coignimbrite origin. Several of the ignimbrite sheets are compositionally zoned and contain subordinate mafic pumices and banded pumices indicative of magma mingling immediately prior to eruption. Because passage of each pyroclastic density current was characterized by phases of non-deposition and erosion, the entire course of each eruption is incompletely recorded at any one location, accounting for some previously perceived differences between the units. Because each current passed into the ocean, estimating eruption volumes is virtually impossible. Nevertheless, the consistent widespread distributions and the presence of lithic breccias within most of the ignimbrite sheets suggest that at least seven caldera collapse eruptions are recorded in the Bandas del Sur succession and probably formed a complex, nested collapse structure. Detailed field relationships show that extensive ignimbrite sheets (e.g. the Arico, Poris and La Caleta formations) relate to previously unrecognized caldera collapse events. We envisage that the evolution of the nested Las Cahadas caldera is more complex than previously thought and involved a protracted history of successive ignimbrite-related caldera collapse events, and large sector collapse events, interspersed with edifice-building phases.

Knowledge, economy, technology and society: The politics of discourse

The WSIS is centrally interested in knowledge and has defined for itself a mission that is broadly humanitarian. Its development ‘talk’ is, rightly, replete with notions of equity, preserving culture, justice, human rights and so on. In incorporating such issues into knowledge society and economy discussions, WSIS has adopted a different posture towards knowledge than is seen in dominant discourses. This study analyses the dominant knowledge discourse using a large corpus of knowledge-related policy documents, discourse theory and an interrelational understanding of knowledge. I show that it is important to understand this dominant knowledge discourse because of its capacity to limit thought and action in relation to its central topic, knowledge. The results of this study demonstrate that the dominant knowledge discourse is technocratic, frequently insensitive to the humane mission at the core of the WSIS, and is based on a partial understanding of what knowledge is and how knowledge systems work. Moreover, I show that knowledge is inherently political, that the dominant knowledge discourse is politically oriented towards the concerns of business and technology, but that an emancipatory politics of knowledge is possible.

From radical to banal evil: Hannah Arendt against the justification of the unjustifiable

Two central strands in Arendt's thought are the reflection on the evil of Auschwitz and the rethinking in terms of politics of Heidegger's critique of metaphysics. Given Heidegger's taciturnity regarding Auschwitz and Arendt's own taciturnity regarding the philosophical implications of Heidegget's political engagement in 1933, to set out how these strands interrelate is to examine the coherence of Arendt's thought and its potential for a critique of Heidegger. By refusing to countenance a theological conception of the evil of Auschwitz, Arendt consolidates the break with theology that Heidegger attempts through his analysis of the essential finitude of Dasein. In the light of Arendt's account of evil, it is possible to see the theological vestiges in Heidegger's ontology. Heidegger's resumption of the question concerning the categorical interconnections of the ways of Being entails an abandonment of finitude: he accommodates and tacitly justifies that which can have no human justification.

Primary aldosteronism - actual epidemics or false alarm?

The prevalence of "primary aldosteronism" (PAL) cannot be precisely determined at this time, given 1) lack of a universally accepted definition, and 2) normotensive as well as normokalemic phases in the evolutionary development of a disease eventually characterized by hypertension and hypokalemia. The exception is fully genetically characterised forms such as glucocorticoid-suppressible hyperaldosteronism, the true prevalence of which could be proven today by universal screening using a single blood sample, but this is neither practical nor appropriate. Controversy has arisen regarding the rareness, or otherwise, of PAL because of 1) rediscovery in the last 12 years of the normokalemic phase described by Conn, 2) application of widely available methods for measurement of aldosterone and renin to "screening", 3) variable quality of these methods, and of their application, and 4) lack of the necessary "diagnostic", in addition to "screening", tests in some studies. PAL is significantly more common than previously thought, and a very important potentially curable form of hypertension. Early diagnosis and specific treatment avoids morbidity. The current focus on increased detection is essential, and will help to resolve the question of prevalence.

Greetings from the cybercaliphate: some notes on homeland insecurity

One of the paradoxical effects of the 7 July bombings in London was to expose the ambivalence in the British government's attempt to wage war on terror by forcefully prosecuting war against those who resort to jihad abroad, actively participating in coalitions of the wining whether in Afghanistan or Iraq, while affording some of Islamism's key ideologists and strategists a high degree of latitude in the United Kingdom itself. This indicates a number of contradictions in official policy that simultaneously recognizes the globalized threat from violent Islamic militancy while, under the rubric of multiculturalism, tolerating those very strains of Islamist radicalism, some of which draw upon the interdependent and transnational character of conflict, to render the UK vulnerable to those very same violent forces. Consequently, the British authorities displayed a studied indifference towards this developing transnational phenomenon both during the 1990s and in some respects even after the London bombings. To explore the curious character of the government's response to the Islamist threat requires the examination of the emergence of this radical ideological understanding and what it entails as a reaction to modernization and secularism in both thought and practice. The analysis explores how government policies often facilitated the non-negotiable identity politics of those promoting a pure, authentic and regenerated Islamic order both in the UK and abroad. This reflected a profound misunderstanding of the growing source and appeal of radical Islam that can be interpreted as a consequence of the slow-motion collision between modernity in its recent globalized form and an Islamic social character, which renders standard western modernization theory, and indeed, the notion of a 'social science' itself, deeply questionable.

Dynamic occupational therapy cognitive assessment for children: Perceived utility in Australian occupational therapy practice

Background and Aim: The Dynamic Occupational Therapy Cognitive Assessment for Children (DOTCA-Ch), recently developed in Israel, assesses the cognitive areas: orientation, spatial perception, praxis, visuomotor construction and thinking operations of 6- to 12-year-old children. The dynamic aspect, which incorporates mediation and prompting, has been presented as a valuable clinical feature of this new assessment. This study investigated the cultural suitability, dynamic nature and comprehensiveness of the DOTCA-Ch as a single cognitive assessment for occupational therapy practice in Australia. Methods: Twenty-three paediatric occupational therapists participated in three tutorial and video demonstrations, which were then followed by a group interview. Results and Conclusion: Thematic analysis of transcripts identified four main themes: appropriateness of assessment tasks, language, mediation and clinical utility. Within each theme, the participants raised both positive and negative features. This paper highlights occupational therapists' mixed views on the clinical utility of this assessment in Australia. Limitations of this study and areas for further research are suggested

Education for an ethical imagination

In response to the question, 'Education for what?', this article argues the case for an ethical imagination. It begins by illustrating different approaches to ethics - Greek antiquity, Kant s categorical imperative, Levinas's interhuman ethic of care, and Foucauldian genealogy. On the basis ofthis, it suggests that ethics may be understood as a disposition of continual questioning and adjusting of thought and action in relation to notions of human good and how to be and act in relation to others. It then briefly considers education as an ethical activity, and sets out three interrelated axes for an ethics of engagement in education: intellectual rigour, civility and care. Using examples ofcitizenship and statelessness in Australia, it argues that building an ethical imagination is a valuable goal for education.

A complex systems approach to the value of ecological resources

A theory of value sits at the core of every school of economic thought and directs the allocation of resources to competing uses. Ecological resources complicate the modem neoclassical approach to determining value due to their complex nature, considerable non-market values and the difficulty in assigning property rights. Application of the market model through economic valuation only provides analytical solutions based on virtual markets, and neither the demand nor supply-side techniques of valuation can adequately consider the complex set of biophysical and ecological relations that lead to the provision of ecosystem goods and services. This paper sets out a conceptual framework for a complex systems approach to the value of ecological resources. This approach is based on there being both an intrinsic quality of ecological resources and a subjective evaluation by the consumer. Both elements are necessary for economic value. This conceptual framework points the way towards a theory of value that incorporates both elements, so has implications for principles by which ecological resources can be allocated. (c) 2005 Elsevier B.V. All rights reserved.

Quality of Life in Chinese elderly people with depression

Background Depression is the most prevalent functional mental disorder of later life. It is estimated that about 5% of the elderly population of Hong Kong are suffering from depression. Aim To investigate the self-rated quality of life of community-dwelling elderly people diagnosed with depression, and to examine the relationships between quality of life and mental, physical health, functional status and social support. Methods and results A cross-sectional descriptive survey was conducted in psychiatric outpatient clinics. A convenience sample of 80 Chinese elderly people with a diagnosis of depressive disorder was recruited. Perception of quality of life was measured by the Hong Kong Chinese World Health Organization Quality of Life Scale-Brief Version. Participants' mental status, functional abilities, physical health condition, and social support status were assessed. Sixty-one (76.3%) participants were female. They were least satisfied with meaningfulness of life, life enjoyment, concentration and thinking, energy and work capacity. Functional abilities had a positive association with participants' perceived quality of life, level of depression and number of physical health conditions had a negative association. Participants had low ratings of quality of life when compared with healthy persons and persons with chronic physical problems. Findings are discussed in light of the socio-cultural environment in Hong Kong. Conclusion Comprehensive treatment and better control of depression, including different modes of medical and psychosocial intervention, could help to improve participants' perception of quality of life. A longitudinal study with a larger sample with various levels of depression and socio-demographic characteristics is recommended. Copyright © 2006 John Wiley & Sons, Ltd.