Coping with Complexity. Keynes and International Economic Relations in the Aftermath of WWI

In the attempt to deepen the understanding of Keynes's thought as an international macroeconomist, we explore the hypothesis of consistency between his general methodological approach to the economic material and his way of reasoning about international economic relations as shaped by WWI. We argue that the methodology of "The Economic Consequences of the Peace" reflects Keynes's attempt to cope with the attributes of the complexity characterizing the European settlement for the post-war period, and particularly 1) organic interdependence among variables at play, 2) irreducible dilemmas and situations of conflict, as well as 3) the need for external, public assistance to overcome the impasse and promote a "shared responsibilities" approach to the imbalances. Striking similarities appearing with the method of Keynes's economic diplomacy in the Forties call for further research in this sense.Keynes; complexity; international economic relations

“Veiling The Controversies with Dubious Moral Attitudes”? Creditors and Debtors in Keynes’s Ethics of International Economic Relations

This paper addresses the enduring insistence on the moral dimension of international economic relations in Keynes’s economics and diplomacy. The issue has so far raised scarce attention in the literature, which tend to attribute some outstanding failures of Keynes’s economic diplomacy to the presumed instrumental use Keynes made of moral arguments. The paper provides a comprehensive account of the ethical arguments used by Keynes in his lifelong attempt to design a fair international order, and aims to demonstrate that this moral dimension is part of a well-defined ethics of international relations which privileges national policy space and freedom to choose.John Maynard Keynes, international economic relations, ethics, complexity

Chapter 18 of the General Theory “Further Analysed”: The Theory of Economics as A Method

In 1987, Greenwald and Stiglitz accused Keynes’s summary of the General Theory in chapter 18 of relying upon “neoclassical and Marshallian tools”. A number of contributions have on the contrary emphasized the methodological importance of this chapter, which this paper revisits in the light of A Treatise on Probability. It thereby shows that the notions of cause and dependence used to discuss the relationships between independent and dependent variables of the General Theory are related to the concept of “independence for knowledge”, which concerns logical connections between arguments rather than material connections between events. We demonstrate that such logical connections established in chapter 18 are rediscussed in chapters 19-21, where Keynes allows for probable repercussions between the factors and removes the simplifying assumptions previously introduced. After stressing the methodological continuity this method provides with the analysis of credit cycles in A Treatise on Money, we argue that chapter 18 is an indispensable tool to decode the internal text structure of the General Theory. We thus characterize the latter as a vademecum to the complex economic world, the author providing an analytical method allowing – and requiring – the readers to emulate his efforts to grasp the complexity and interdependence of the economic material.John Maynard Keynes, The General Theory, complexity, economic methodology

The Economic Problem of Happiness. Keynes on Happiness and Economics

In their latest book (2008), Bruno Frey and the members of the research group he chairs at the University of Zurich announce that happiness research is leading a revolution in economics. More precisely, the revolutionary character of happiness economics would draw on measurement, on how people value goods and social conditions, as well as on policies. This paper aims to discuss critically this claim and what we identified as five crucial issues of mainstream happiness economics, i.e.: 1. the ambiguous relationship between income and happiness, 2. the “back to Bentham” approach, 3. problems of incommensurability, 4. heterogeneity and multidimensionality, 5. the scope of economics in relation to happiness. In so doing, we attempt to review John Maynard Keynes’s vision about happiness and economics, starting from a revisiting of his essay Economic Possibilities for Our Grandchildren in the light of his early unpublished writings on ethics as well as of the whole bulk of his writings in economics. We then provide reasons to argue that the rediscovery of Keynes’s legacy in this respect can be of help to point out and examine the most controversial aspects of today’s happiness research.Happiness, Happiness economics, John Maynard Keynes, Economic Possibilities for Our Grandchildren

Microelectrode arrays of diamond-insulated graphitic channels for real time detection of exocytotic events from cultured chromaffin cells and slices of adrenal glands

A microstructured graphitic 4x4 multielectrode array was embedded in a single crystal diamond substrate (4x4 {uG-SCD MEA) for real-time monitoring of exocytotic events from cultured chromaffin cells and adrenal slices. The current approach relies on the development of a parallel ion beam lithographic technique, which assures the time effective fabrication of extended arrays with reproducible electrode dimensions. The reported device is suitable for performing amperometric and voltammetric recordings with high sensitivity and temporal resolution, by simultaneously acquiring data from 16 rectangularly shaped microelectrodes (20x3.5 um^2) separated by 200 um gaps. Taking advantage of the array geometry we addressed the following specific issues: i) detect both the spontaneous and KCl-evoked secretion simultaneously from several chromaffin cells directly cultured on the device surface, ii) resolve the waveform of different subsets of exocytotic events, iii) monitoring quantal secretory events from thin slices of the adrenal gland. The frequency of spontaneous release was low (0.12 Hz and 0.3 Hz respectively for adrenal slices and cultured cells) and increased up to 0.9 Hz after stimulation with 30 mM KCl in cultured cells. The spike amplitude as well as rise and decay time were comparable with those measured by carbon fiber microelectrodes and allowed to identify three different subsets of secretory events associated to "full fusion" events, "kiss and-run" and "kiss-and-stay" exocytosis, confirming that the device has adequate sensitivity and time resolution for real-time recordings. The device offers the significant advantage of shortening the time to collect data by allowing simultaneous recordings from cell populations either in primary cell cultures or in intact tissues

All-carbon multi-electrode array for real-time in vitro measurements of oxidizable neurotransmitters

We report on the ion beam fabrication of all-carbon multi electrode arrays (MEAs) based on 16 graphitic micro-channels embedded in single-crystal diamond (SCD) substrates. The fabricated SCD-MEAs are systematically employed for the in vitro simultaneous amperometric detection of the secretory activity from populations of chromaffin cells, demonstrating a new sensing approach with respect to standard techniques. The biochemical stability and biocompatibility of the SCD-based device combined with the parallel recording of multi-electrodes array allow: i) a significant time saving in data collection during drug screening and/or pharmacological tests over a large number of cells, ii) the possibility of comparing altered cell functionality among cell populations, and iii) the repeatition of acquisition runs over many cycles with a fully non-toxic and chemically robust bio-sensitive substrate.Comment: 24 pages, 5 figure

Nanodiamonds-induced effects on neuronal firing of mouse hippocampal microcircuits

Fluorescent nanodiamonds (FND) are carbon-based nanomaterials that can efficiently incorporate optically active photoluminescent centers such as the nitrogen-vacancy complex, thus making them promising candidates as optical biolabels and drug-delivery agents. FNDs exhibit bright fluorescence without photobleaching combined with high uptake rate and low cytotoxicity. Focusing on FNDs interference with neuronal function, here we examined their effect on cultured hippocampal neurons, monitoring the whole network development as well as the electrophysiological properties of single neurons. We observed that FNDs drastically decreased the frequency of inhibitory (from 1.81 Hz to 0.86 Hz) and excitatory (from 1.61 Hz to 0.68 Hz) miniature postsynaptic currents, and consistently reduced action potential (AP) firing frequency (by 36%), as measured by microelectrode arrays. On the contrary, bursts synchronization was preserved, as well as the amplitude of spontaneous inhibitory and excitatory events. Current-clamp recordings revealed that the ratio of neurons responding with AP trains of high-frequency (fast-spiking) versus neurons responding with trains of low-frequency (slow-spiking) was unaltered, suggesting that FNDs exerted a comparable action on neuronal subpopulations. At the single cell level, rapid onset of the somatic AP ("kink") was drastically reduced in FND-treated neurons, suggesting a reduced contribution of axonal and dendritic components while preserving neuronal excitability.Comment: 34 pages, 9 figure