Can the binding of GABA,glycine and β-alanine to synaptic receptors be determined in the presence of a physiological concentration of Na+?

Summary Bicuculline- and strychnine-sensitive components of the binding of GABA, glycine and -alanine, which can be demonstrated in the presence of a physiological concentration of Na⁺, might be related to synaptic receptors.     

The presence of β-phenylethylamine,p-tyramine,m-tyramine and tryptamine in ganglia and foot muscle of the garden snail (Helix aspersa)

Summary The concentrations of -phenylethylamine,p-tyramine,m-tyramine,m-octopamine and tryptamine in the ganglia or foot muscle ofHelix aspersa range from <0.6 to 11 ng/g.p-Octopamine levels are higher in ganglia (327 ng/g) than in foot muscle (4.1 ng/g). Dopamine and 5-hydroxytryptamine range from 840 to 2710 ng/g while their acid metabolites, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylacetic acid and 5-hydroxyindoleacetic acid range from <20 to 130 ng/g.Acknowledgments. We thank Dr A.A. Boulton for helpful discus sion, Dr D.A. Durden for supervising the mass spectrometric analyses, Dr B.A. Davis for the synthesis of the deuterated standards, G.H. Wheatley, E.P. Zarycki and M. Mizuno for expert technical assistance, and Saskatchewan Health and the MRC of Canada for providing financial support.     

The epistemological virtues of assumptions: towards a coming of age of Boltzmann and Meinong’s objections to ‘the prejudice in favour of the actual’?

Two complementary debates of the turn of the nineteenth and twentieth century are examined here: the debate on the legitimacy of hypotheses in the natural sciences and the debate on intentionality and ‘representations without object’ in philosophy. Both are shown to rest on two core issues: the attitude of the subject and the mode of presentation chosen to display a domain of phenomena. An orientation other than the one which contributed to shape twentieth-century philosophy of science is explored through the analysis of the role given to assumptions in Boltzmann’s research strategy, where assumptions are contrasted to hypotheses, axioms, and principles, and in Meinong’s criticism of the privileged status attributed to representations in mental activities. Boltzmann’s computational style in mathematics and Meinong’s criticism of the confusion between representation and judgment give prominence to an indirect mode of presentation, adopted in a state of suspended belief which is characteristic of assumptions and which enables one to grasp objects that cannot be reached through direct representation or even analogies. The discussion shows how assumptions and the movement to fiction can be essential steps in the quest for objectivity. The conclusion restates the issues of the two debates in a contemporary perspective and shows how recent developments in philosophy of science and philosophy of language and mind can be brought together by arguing for a twofold conception of reference.     

The tumor necrosis factor α of the bony fish seabream exhibits the in vivo proinflammatory and proliferative activities of its mammalian counterparts,yet it functions in a species-specific manner

Information on the bioactivities of non-mammalian cytokines is scant due to the lack of the recombinant molecules and specific antibodies. We produced the mature predicted peptide of tumor necrosis factor (TNF) from the bony fish gilthead seabream (Sparus aurata L.) (sbTNF), and its biological role was determined in vitro and in vivo. We first demonstrated by analytical size-exclusion chromatography that sbTNF is an oligomeric protein but the dimer appears to predominate over the trimeric form, in contrast to mammalian TNF. Intraperitoneal injection of native sbTNF resulted in (i) priming of the respiratory burst of the peritoneal exudate and head-kidney (HK) leukocytes, the latter being the bone marrow equivalent in fish; (ii) rapid recruitment of phagocytic granulocytes to the injection site, and (iii) induction of granulopoiesis in the HK. Interestingly, sbTNF was able to induce a strong proliferation of HK cells in vitro, whereas human TNF did not. Conversely, sbTNF was not cytotoxic for murine L929 fibroblasts.Received 12 February 2004; received after revision 15 March 2004; accepted 29 March 2004     

The Hybrid Expert in the ‘Bergstaat’: Anton von Ruprecht as a Professor of Chemistry and Mining and as a Mining Official, 1779–1814

Summary

In the course of the 18th century a new type of scientifically educated functional elites developed, who were trained to administer mines. The educational project that led to the formation of a corps of mining engineers was part of a programme of administrative and economic reforms that led to a new configuration of bonds between state, economy and science. At the same time the status of this new group of experts was predicated substantially by the new emerging corpora of the scientific, technological and cameralist knowledge of the period between 1760 and 1800. The aim of this paper is to discuss this group using the example of a leading expert in the context of the mining and metallurgy of this period. Anton von Ruprecht (1748–1814) was strongly grounded in the social and epistemic context of the Habsburg mining bureaucracy, which employed his scientific and technical savoir faire to serve their mercantile goals in several areas of mining expertise.