The repression of siderophore synthesis by Mt. St. Helens' ash and silicate rock standards

Summary Mt. St. Helens' ash or U.S. Geological Survey silicate rock standards would replace FeCl₃ as the limiting nutrient and repress the synthesis of rhodotorulic acid inRhodotorulia pilimanae cultures.     

The siderophore mediated release of iron and magnesium from Mt St. Helens' ash and silicate rock standards

Summary Substantial amounts of iron and magnesium were observed to be released from ash from Mt St. Helens' and US Geological Survey Silicate Rock Standards by the siderophore rhodotorulic acid.This project was supported by the Robert A. Welch Foundation (Y-773) and the Lamar Research Council. We are grateful to S. Arnow, W. Matthews III, V. Pullen and M. Akers for their interest and assistance in obtaining Mt St. Helens' ash samples.     

Action and interaction of two 888-1888-1888-1agonists,methoxamine and St 587, on the rabbit's blood pressure and EEG

Summary In rabbits methoxamine reversed the vasopressor effect of St 587 and abolished the EEG synchronizing action of St 587. The interaction on the blood pressure could be ascribed either to the different chemical structures of St 587 and methoxamine or to partial agonistic properties of St 587. The interaction on the EEG appears to be more complex.     

On the existence of cytokines in invertebrates

Based on the assumption that invertebrates, like vertebrates, possess factors regulating responses to infection or wounding, studies dealing with the evolution of immunity have focussed on the isolation and characterisation of putative cytokine-related molecules from invertebrates. Until recently, most of our knowledge of cytokine- and cytokine receptor-like molecules in invertebrates relies on functional assays and similarities at the physicochemical level. As such, a phylogenetic relationship between invertebrate cytokine-like molecules and vertebrate counterparts could not be convincingly demonstrated. Recent genomic sequence analyses of interleukin-1-receptor-related molecules, that is Toll-like receptors, and members of the transforming growth factor-β superfamily suggest that the innate immune system of invertebrates and vertebrates evolved independently. In addition, data from protochordates and annelids suggest that invertebrate cytokine-like molecules and vertebrate factors do not have the same evolutionary origin. We propose instead that the convergence of function of invertebrate cytokine-like molecules and vertebrate counterparts involved in innate immune defences may be based on similar lectin-like activities. Received 27 November 2000; received after revision 11 December 2000; accepted 13 December 2000     

On the distribution of phytoecdysteroids in plants

The occurrence and levels of phytoecdysteroids in the seeds and other parts of plants grown from the seeds of 180 randomly selected plant species were assessed and compared. Ecdysteroids are frequently detectable in leaves and flowers, but less so in stems, roots and seeds. The seeds of 290 species were assessed for the presence of hydrolysable ecdysteroid conjugates. Low levels of conjugates were detected in a significant number of species, large amounts being present only when levels of free ecdysteroids were high. Individual plants of Arabidopsis thaliana were assessed for the presence of phytoecdysteroids. While plants of this species are generally ecdysteroid negative, individual plants in the population accumulate low levels of ecdysteroids. Extracts of seeds of 50 "ecdysteroid-negative" species were concentrated and partially purified to determine if they possess ecdysteroids at levels below the usual detection levels. Ecdysteroids were detectable by radioimmunoassay in almost all of these concentrated samples. Thus, all lines of evidence point to the conclusion that all species of plants have the capacity to produce at least low levels of phytoecdysteroids. This has important implications for the protection of crop species through enhancing ecdysteroid levels by breeding/genetic modification strategies. Received 2 April 2001; received after revision 4 May 2001; accepted 22 May 2001     

Instruments and rules: R. B. Woodward and the tools of twentieth-century organic chemistry

The paper illustrates how organic chemists dramatically altered their practices in the middle part of the twentieth century through the adoption of analytical instrumentation — such as ultraviolet and infrared absorption spectroscopy and nuclear magnetic resonance spectroscopy — through which the difficult process of structure determination for small molecules became routine. Changes in practice were manifested in two ways: in the use of these instruments in the development of ‘rule-based’ theories; and in an increased focus on synthesis, at the expense of chemical analysis. These rule-based theories took the form of generalizations relating structure to chemical and physical properties, as measured by instrumentation. This ‘Instrumental Revolution’ in organic chemistry was two-fold: encompassing an embrace of new tools that provided unprecedented access to structures, and a new way of thinking about molecules and their reactivity in terms of shape and structure. These practices suggest the possibility of a change in the ontological status of chemical structures, brought about by the regular use of instruments. The career of Robert Burns Woodward (1917–1979) provides the central historical examples for the paper. Woodward was an organic chemist at Harvard from 1937 until the time of his death. In 1965, he won the Nobel Prize in Chemistry.     

Forecasting contemporaneous aggregates and the combination of forecasts: The case of the U.K. monetary aggregates

A number of papers in recent years have investigated the problems of forecasting contemporaneously aggregated time series and of combining alternative forecasts of a time series. This paper considers the integration of both approaches within the example of assessing the forecasting performance of models for two of the U.K. monetary aggregates, £M3 and MO. It is found that forecasts from a time series model for aggregate £M3 are superior to aggregated forecasts from individual models fitted to either the components or counterparts of £M3 and that an even better forecast is obtained by forming a linear combination of the three alternatives. For MO, however, aggregated forecasts from its components prove superior to either the forecast from the aggregate itself or from a linear combination of the two.     

On the physiology of metazoa

The problem of integration and control of the various processes of the metazoan organism is a major challenge to the physiologist. The traditional research strategy in dealing with the problem is neuron-oriented and its roots extend back into the last century when knowledge of hormones was lacking. In the present article, the traditional strategy is analyzed in the light of available data and its logical basis is questioned. Different levels of communication are supposed to occur in the animal or human body. Circulating hormones are responsible for the highest level of communication that occurs between organs or tissues. The central concept in the article is that regulation of circulating hormones constitutes a higher level of control relative to regulation of intercellular hormones. This is regardless of whether the latter occurs in the nervous system or elsewhere. The approach is utilized in defining the mechanism that integrates and controls the part processes of the body. The mechanism is defined as endothelial; the vascular endothelial system is the controlling part and the nervous system is one of the subordinate parts. Thanks to the new approach, meaningful biological explanations of major psychiatric disorders are now possible.     

Estimation and prediction under structural instability: The case of the U.S. pulp and paper market

The objectives of this paper are: first, to show empirically the relevance of using adaptive estimation techniques over more traditional estimation approaches when economic systems are believed to be structurally unstable over time; and secondly, to compare in an empirical framework two adaptive estimation techniques: Kalman filtering and the Carbone–Longini filter. For that purpose, an econometric model for the U.S. pulp and paper market is examined under the assumption of structural instability and, hence, constitutes the basis for comparing forecasting performances and estimation accuracy achieved by each technique. A version of Kalman filtering, modified in line with the basic idea of ‘tracking’ characterizing the Carbone–Longini filter, is also presented and applied. The analysis of the results shows that it may be worth using adapative estimation methods to estimate structurally unstable models, even if there is no prior knowledge about the patterns of variation of the parameters. Also, it shows the Carbone–Longini filter and Kalman filtering as being complementary estimation techniques. An estimation/forecasting methodology involving a sequential application mode of these two techniques is suggested.     

Galilean argumentation and the inauthenticity of the Cigoli letter on painting vs. sculpture

This essay is partly a case study of the role of logic in historiography. It is also partly a test case for the thesis of a Galilean correspondence between aesthetic attitude and scientific thought, advanced by Panofsky, Koyré, and Heilbron. Intrinsically, it is a discussion of the authenticity of the letter to Cigoli dated 26 June 1612, widely attributed to Galileo, containing argumentation about the relative aesthetic merits of painting and sculpture. I undertake a systematic analysis of the letter’s method of argument, comparing and contrasting it with Galileo’s. I argue that the letter does have some Galilean characteristics: critical reasoning; ad hominem argumentation, in the seventeenth-century sense; and appeal to experimentation. However, the letter falls short of the typical Galilean open-mindedness, fair-mindedness, and clarity; crucially, it uses several illative terms which Galileo never uses, and does not use the one he uses most often. The latter features outweigh the former. Moreover, I discuss some aspects of the letter’s substantive content, primarily a theory of vision that disregards the dynamics of perspective and the faculty of binocularity, which Galileo understood and exploited very well. My novel argument vindicates an old judgment of Favaro, who doubted the letter’s authenticity.     

I am knowledge. Get me out of here! On localism and the universality of science

It has become increasingly common in historiography of science to understand science and its products as inherently local. However, this orientation is faced with three problems. First, how can one explain the seeming universality of contemporary science? Second, if science is so reflective of its local conditions of production, how can it travel so effortlessly to other localities and even globally? And third, how can scientific knowledge attain validity outside its context of origin? I will argue that the notion of standardization and theories of delocalization manage to explain the ‘globality’ of science, but that localism denies ‘universality’ if it is understood non-spatially. Further, localism limits the validity of scientific knowledge unacceptably inside the laboratory walls or other boundaries of knowledge creation. This is not consistent with scientific practice. I will consider on what grounds extra-local knowledge inferences that transcend the boundaries of locality could be seen as justified.     

Cytogenetic studies of Hynobiidae (Urodela). XIV. Analysis of the chromosome of a Chinese salamander, Batrachuperus pinchonii (David)

The chromosome number of a Chinese salamander, Batrachuperus pinchonii, was re-examined. Adults and embryonic specimens had a diploid number of 66, with 33 bivalents during meiosis, in contrast to previous reported results. Furthermore, when C-banding analysis was performed with embryos, chromosomes with banding patterns homoeologous to those of Salamandrella keyserlingii and Hynobius species were found. It appears, therefore, that Batrachuperus, Salamandrella and Hynobius might be derived from a common ancestral species in eastern Asia. Received 22 August 1997; received after revision 14 October 1997; accepted 20 November 1997     

Friedrich Miescher Prize awardee lecture review. A conserved family of nuclear export receptors mediates the exit of messenger RNA to the cytoplasm

The distinguishing feature of eukaryotic cells is the segregation of RNA biogenesis and DNA replication in the nucleus, separate from the cytoplasmic machinery for protein synthesis. As a consequence, messenger RNAs (mRNAs) and all cytoplasmic RNAs from nuclear origin need to be transported from their site of synthesis in the nucleus to their final cytoplasmic destination. Nuclear export occurs through nuclear pore complexes (NPCs) and is mediated by saturable transport receptors, which shuttle between the nucleus and cytoplasm. The past years have seen great progress in the characterization of the mRNA export pathway and the identification of proteins involved in this process. A novel family of nuclear export receptors (the NXF family), distinct from the well-characterized family of importin β-like proteins, has been implicated in the export of mRNA to the cytoplasm. Received 23 January 2001; received after revision 12 April 2001; accepted 12 April 2001     

Oxidative modifications of low-density lipoproteins (LDL) by the human endothelial cell line EA.hy 926

Modifications of LDL by the EA.hy 926 cell line were compared to those generated by human umbilical vein endothelial cells (HUVEC). Thiobarbituric acid reactive substances (TBARS) index values (TBARS sample/TBARS cell-free control ratio) were 2.64±0.18 (m±SE, n=11) and 3.12±0.24 (n=11), for HUVEC and EA.hy 926, respectively. The percentage of the most electronegative modified LDL fraction (fraction C), assessed by using an ion-exchange chromatographic method based on fast protein liquid chromatography (FPLC), represented 14±3% (n=34) and 22±13% (n=10) of total modified LDL in HUVEC and EA.hy 926, respectively. LDL modified by both cell lines showed increased agarose electrophoretic mobility and apo B100 fragmentation on SDS-PAGE. None of the results were significantly different between the two cell lines. Superoxide anion production was 0.12±0.04 (n=11) and 0.07±0.01 nmol/min/mg cell protein (n=11) in HUVEC and EA.hy 926, respectively. Cell-specific effects on LDL were abrogated in cysteine-free medium. Moreover, cell-modified LDL were similarly degraded by J774 macrophage-like cells. We conclude that EA.hy 926 cells are a good model for investigating endothelial cell-induced modifications of LDL. Advantages include ready availability and less individual variability than with HUVEC.     

Forecasting the economic recession in the U.K. 1979-1982: A comparison of model-based ex ante Forecasts

This paper compares the forecasts of recession and recovery made by five non-government U.K. teams modelling the economy (Cambridge Econometrics, the London Business School, the National Institute of Economic and Social Research, the Cambridge Economic Policy Group and the Liverpool Research Group). The paper concentrates on annual ex ante projections as published over the period 1978-1982, i.e. forecasts made, before the event, of the onset, length, depth and character of the economic recession in the U.K. which began in 1979. The comparison is in terms of year by year changes in production, unemployment, prices and other variables. It concludes that no group was systematically better or worse than other groups (confirming U.S. experience) and that the groups tended to perform better in their chosen areas of specialization, e.g. medium-term groups did better at forecasting the medium-term outcome.     

Relevance of chlorine-substituent for the antifungal activity of syringomycin and syringotoxin,metabolites of the phytopathogenic bacteriumPseudomonas syringae pv.syringae

Structural analogues of syringomycin and syringotoxin were produced by fermentation, characterized by FAB-MS and amino acid analysis and compared to the parent compounds in the antibiosis test againstRhodotorula pilimanae. The C-terminal residue was shown to be important for the activity.     

Putting pragmatism to work in the Cold War: Science, technology, and politics in the writings of James B. Conant

This paper examines James Conant’s pragmatic theory of science—a theory that has been neglected by most commentators on the history of 20^th-century philosophy of science—and it argues that this theory occupied an important place in Conant’s strategic thinking about the Cold War. Conant drew upon his wartime science policy work, the history of science, and Quine’s epistemological holism to argue that there is no strict distinction between science and technology, that there is no such thing as “the scientific method,” and that theories are better interpreted as policies rather than creeds. An important consequence that he drew from these arguments is that science is both a thoroughly value-laden, and an intrinsically social, enterprise. These results led him to develop novel proposals for reorganizing scientific and technological research—proposals that he believed could help to win the Cold War. Interestingly, the Cold War had a different impact upon Conant’s thinking than it did upon many other theorists of science in postwar America. Instead of leading him to “the icy slopes of logic,” it led him to develop a socially- and politically-engaged theory that was explicitly in the service of the American Cold War effort.