Stable isotope values in modern bryozoan carbonate from New Zealand and implications for paleoenvironmental interpretation

Bryozoan carbonate contains useful geochemical evidence of temperate shelf paleoenvironments. Stable isotope values were determined for 103 modern marine bryozoan skeletons representing 30 species from New Zealand. δ18O values range from -1.4 to 2.8 VPDB, while δ13C range from -4.5 to 2.8 VPDB (values uncorrected for mineralogical variation). These values are distinct from those of both tropical marine skeletons and New Zealand Tertiary fossils. Most bryozoans secrete carbonate in or near isotopic equilibrium with sea water, except for Celleporina and Steginoporella. The complex and variable mineralogies of the bryozoans reported here make correction for mineralogical effects problematic. Nevertheless, mainly aragonitic forms display higher isotope values, as anticipated. Both temperature and salinity constrain δ18O and δ13C values, and vary with latitude and water depth. Ten samples from a single branch of Cinctipora elegans from the Otago shelf cover a narrow range, although the striking difference in carbon isotope values between the endozone and exozone probably reflects different mineralisation histories. Our stable isotope results from three different laboratories on a single population from a single location are encouragingly consistent. Monomineralic bryozoans, when carefully chosen to avoid species suspected of vital fractionation, have considerable potential as geochemical paleoenvironmental indicators, particularly in temperate marine environments where bryozoans are dominant sediment producers

Computer memories: the history of computer form

This paper looks at the computer as a truly global form. The similar beige boxes found in offices across the world are analysed from the perspective of design history rather than that of the history of science and technology. Through the exploration of an archive of computer manufacturer's catalogues and concurrent design texts, this paper examines the changes that have occurred in the production and consumption of the computer in the context of the workplace, from its inception as a room-sized mainframe operated through a console of flashing lights, to the personal computer as a 'universal' form, reproduced by many manufacturers. It shows how the computer in the past has been as diverse as any other product, and asks how and why it now appears as a standardised, sanitised object. In doing so our relationship with the office computer, past and present is explored, revealing a complex history of vicissitude.</p

Discourse or dialogue? Habermas, the Bakhtin Circle, and the question of concrete utterances

This is the author's accepted manuscript. The final publication is available at Springer via the link below.This article argues that the Bakhtin Circle presents a more realistic theory of concrete dialogue than the theory of discourse elaborated by Habermas. The Bakhtin Circle places speech within the “concrete whole utterance” and by this phrase they mean that the study of everyday language should be analyzed through the mediations of historical social systems such as capitalism. These mediations are also characterized by a determinate set of contradictions—the capital-labor contradiction in capitalism, for example—that are reproduced in unique ways in more concrete forms of life (the state, education, religion, culture, and so on). Utterances always dialectically refract these processes and as such are internal concrete moments, or concrete social forms, of them. Moreover, new and unrepeatable dialogic events arise in these concrete social forms in order to overcome and understand the constant dialectical flux of social life. But this theory of dialogue is different from that expounded by Habermas, who tends to explore speech acts by reproducing a dualism between repeatable and universal “abstract” discursive processes (commonly known as the ideal speech situation) and empirical uses of discourse. These critical points against Habermas are developed by focusing on six main areas: sentences and utterances; the lifeworld and background language; active versus passive understandings of language; validity claims; obligation and relevance in language; and dialectical universalism

How can power discourses be changed? - Contrasting the ‘daughter deficit’ policy of the Delhi government with Gandhi and King’s transformational reframing

Social policy impact is partly determined by how policy is articulated and advocated, including which values are highlighted and how. In this paper, we examine the influence of policy framing and reframing on outcomes, with particular reference to the policies of the Delhi state government in India that target the practices of female feticide, infanticide and neglect that underlie the ‘daughter deficit’. Using Snow and Benford’s categories for understanding reframing processes, the paper outlines and applies a ‘model’ of reframing disputed issues derived from looking at two famous campaigns – Gandhi’s 1930 Salt March in the struggle for Indian freedom from British rule and the African-American civil rights struggle of the 1950s and 1960s. It argues that ‘carrot and stick’ policy measures, such as financial incentives and legal prohibitions, to counteract the ‘daughter deficit’ must be complemented by well crafted discursive interventions

Designing effective public participation

This paper reviews the various connections that can exist between the design of participatory processes and the different kind of results that they can entail. It details how effective participatory processes can be designed, whatever are the results that participation is deemed to elicit. It shows the main trends pertaining to design choicesand considers how to classify different arrangements in order to choose from among them. Then the paper deals with the main dilemmas that tend to arise when designing participatory processes. Thanks to this review, the paper argues that participatory processes tend to display a certain degree of ambivalence that cannot be completely overcome through the design choices