Pseudo-Goodwin cycles in a Minsky model

© The Author 2016. Published by Oxford University Press on behalf of the Cambridge Political Economy Society. All rights reserved. Goodwin cycles result from the dynamic interaction between a profit-led demand regime and a reserve army effect in income distribution. The paper proposes the concept of a pseudo-Goodwin cycle. We define this as a counter-clockwise movement in output and wage share space which is not generated by the usual Goodwin mechanism. In particular, it does not depend on a profit-led demand regime. As a demonstration, a simple Minsky model is extended by adding a reserve army distribution mechanism such that the wage share responds positively to output. In the extended Minsky model, cycles are generated purely through the interaction between financial fragility and demand. In a first step we assume no feedback from income distribution to demand. We demonstrate that the model generates a pseudo- Goodwin cycle in output-wage share space. In a second step, we show that the result continues to hold even if a wage-led demand regime is introduced, although this can introduce instability. Our models demonstrate that the existence of a counter- clockwise movement of output and the wage share cannot be regarded as proof of the existence of a Goodwin cycle and a profit-led demand regime

How to state general qualitative facts in Psychology?

International audienceIn what form should qualitative psychological statements have to be in order to be general and falsifiable? I show how basic qualitative measurement systems can be defined that allow for the detection and testing of general relational facts of the if-then form in a well-defined range of potential qualitative, static or dynamic, multivariate observations. The formal framework permits the pointing out of general research problems falling under the scope of empirical investigation

On the Persistent Shape and Coherence of Pulsating Auroral Patches

The pulsating aurora covers a broad range of fluctuating shapes that are poorly characterized. The purpose of this paper is therefore to provide objective and quantitative measures of the extent to which pulsating auroral patches maintain their shape, drift and fluctuate in a coherent fashion. We present results from a careful analysis of pulsating auroral patches using all-sky cameras. We have identified four well-defined individual patches that we follow in the patch frame of reference. In this way we avoid the space-time ambiguity which complicates rocket and satellite measurements. We find that the shape of the patches is remarkably persistent with 85-100% of the patch being repeated for 4.5-8.5 min. Each of the three largest patches has a temporal correlation with a negative dependence on distance, and thus does not fluctuate in a coherent fashion. A time-delayed response within the patches indicates that the so-called streaming mode might explain the incoherency. The patches appear to drift differently from the SuperDARN-determined $\stackrel{\rightarrow}{E}$ X $\stackrel{\rightarrow}{B}$ convection velocity. However, in a nonrotating reference frame the patches drift with 230-287 m/s in a north eastward direction, which is what typically could be expected for the convection return flow

High time resolution PFISR and optical observations of naturally enhanced ion acoustic lines

Observations of naturally enhanced ion acoustic lines (NEIALs) taken with the Poker Flat Incoherent Scatter Radar (PFISR) using a mode with very high time resolution are presented. The auroral event took place over Poker Flat, Alaska on 8 February 2007 at 09:35 UT (~22:00 MLT), and the radar data are complemented by common-volume high-resolution auroral imaging. The NEIALs occurred during only one of the standard 15-s integration periods. The raw data of this time show very intermittent NEIALs which occur only during a few very short time intervals (≤1 s) within the 15-s period. The time sampling of the raw data, ~19 ms on average, allows study of the time development of the NEIALs, though there are indications that even finer time resolution would be of interest. The analysis is based on the assumption that the NEIAL returns are the result of Bragg scattering from ion-acoustic waves that have been enhanced significantly above thermal levels. The spectra of the raw data indicate that although the up- and down-shifted shoulders can both become enhanced at the same time, (within 19 ms), they are most often enhanced individually. The overall power in the up-and down-shifted shoulders is approximately equal throughout the event, with the exception of one time, when very large up-shifted power was observed with no corresponding down-shifted power. This indicates that during the 480 μs pulse, the strongly enhanced ion-acoustic waves were only traveling downward and not upward. The exact time that the NEIALs occurred was when the radar beam was on the boundary of a fast-moving (~10 km/s), bright auroral structure, as seen in the high resolution auroral imaging of the magnetic zenith. When viewed with high time resolution, the occurrence of NEIALs is associated with rapid changes in auroral luminosity within the radar field of view due to fast-moving auroral fine structures

PFISR Nightside Observations of Naturally Enhanced Ion Acoustic Lines, and Their Relation to Boundary Auroral Features

We present results from a coordinated camera and radar study of the auroral ionosphere conducted during March of 2006 from Poker Flat, Alaska. The campaign was conducted to coincide with engineering tests of the first quarter installation of the Poker Flat Incoherent Scatter Radar (PFISR). On 31 March 2006, a moderately intense auroral arc, (~10 kR at 557.7 nm), was located in the local magnetic zenith at Poker Flat. During this event the radar observed 7 distinct periods of abnormally large backscattered power from the F-region. These were only observed in the field-aligned radar beam, and radar spectra from these seven times show naturally enhanced ion-acoustic lines (NEIALs), the first observed with PFISR. These times corresponded to (a) when the polar cap boundary of the auroral oval passed through the magnetic zenith, and (b) when small-scale filamentary dark structures were visible in the magnetic zenith. The presence of both (a) and (b) was necessary for their occurrence. Soft electron precipitation occurs near the magnetic zenith during these same times. The electron density in the vicinity where NEIALs have been observed by previous studies is roughly between 5 and 30×1010 m−3. Broad-band extremely low frequency (BBELF) wave activity is observed in situ by satellites and sounding rockets to occur with similar morphology, during active auroral conditions, associated with the poleward edge of the aurora and soft electron precipitation. The observations presented here suggest further investigation of the idea that NEIALs and BBELF wave activity are differently-observed aspects of the same wave phenomenon. If a connection between NEIALs and BBELF can be established with more data, this could provide a link between in situ measurements of downward current regions (DCRs) and dynamic aurora, and ground-based observations of dark auroral structures and NEIALs. Identification of in situ processes, namely wave activity, in ground-based signatures could have many implications. One specific example of interest is identifying and following the temporal and spatial evolution of regions of potential ion outflow over large spatial and temporal scales using ground-based optical observations

LAKE PHELPS DUGOUT LOG CANOES: CONSERVATION, RETREATMENT, AND PUBLIC DISPLAY

During the latter part of the 1980s, nearly thirty prehistoric dugout log canoes were discovered at Lake Phelps, in eastern North Carolina. Of those reported, four of these canoes were retrieved and conserved with a sugar solution while the rest were left in situ. Two of the canoes were stored and displayed at the Information Center at Pettigrew State Park located near the lake. The environment in which they were stored was not conducive for their long-term storage and display, and over time, crystallized surface deposits developed, contributing to their further degradation. They were relocated to the East Carolina University (ECU) West Research campus under the management of North Carolina Department of Cultural Resources Underwater Archaeology Branch (NCDCR UAB) for analyses and stabilization until they could be re-conserved. In fall 2014, a formal study was developed focusing on their re-conservation and eventual return to their "home" at Pettigrew State Park. Several chemical and mechanical conservation techniques were tested and results indicated further trials would be beneficial. While collaborating with conservators how to best proceed with this study, a misting technique modeled after the ultrasonic misting method was developed. Ultrasonic misting was developed as a way to consolidate artworks and other artifacts where unstable pigment was present and had not been previously tested to conserve wooden artifacts where crystallized sugars had leached onto the surface. The technique developed in this study was tested and shown to substantially improve the condition of the wooden objects used for testing. Further improvement and testing of this technique could add to conservators' selection of techniques for those wishing to conserve objects such as those presented in this thesis

Endozoicomonas genomes reveal functional adaptation and plasticity in bacterial strains symbiotically associated with diverse marine hosts

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 7 (2017): 40579, doi:10.1038/srep40579.Endozoicomonas bacteria are globally distributed and often abundantly associated with diverse marine hosts including reef-building corals, yet their function remains unknown. In this study we generated novel Endozoicomonas genomes from single cells and metagenomes obtained directly from the corals Stylophora pistillata, Pocillopora verrucosa, and Acropora humilis. We then compared these culture-independent genomes to existing genomes of bacterial isolates acquired from a sponge, sea slug, and coral to examine the functional landscape of this enigmatic genus. Sequencing and analysis of single cells and metagenomes resulted in four novel genomes with 60–76% and 81–90% genome completeness, respectively. These data also confirmed that Endozoicomonas genomes are large and are not streamlined for an obligate endosymbiotic lifestyle, implying that they have free-living stages. All genomes show an enrichment of genes associated with carbon sugar transport and utilization and protein secretion, potentially indicating that Endozoicomonas contribute to the cycling of carbohydrates and the provision of proteins to their respective hosts. Importantly, besides these commonalities, the genomes showed evidence for differential functional specificity and diversification, including genes for the production of amino acids. Given this metabolic diversity of Endozoicomonas we propose that different genotypes play disparate roles and have diversified in concert with their hosts.This research was supported by a KAUST-WHOI Post-doctoral Partnership Award to M.J.N. and a KAUST-WHOI Special Academic Partnership Funding Reserve Award to C.R.V. and A.A. Additional research was supported from baseline funds to C.R.V. by the King Abdullah University of Science and Technology (KAUST)

Scale size-dependent characteristics of the nightside aurora

We have determined the spatiotemporal characteristics of the magnetosphere-ionosphere (M-I) coupling using auroral imaging. Observations at fixed positions for an extended period of time are provided by a ground-based all-sky imager measuring the 557.7 nm auroral emissions. We report on a single event of nightside aurora ($\sim$22 magnetic local time) preceding a substorm onset. To determine the spatiotemporal characteristics, we perform an innovative analysis of an all-sky imager movie (19 min duration, images at 3.31 Hz) that combines a two-dimensional spatial fast Fourier transform with a temporal correlation. We find a scale size-dependent variability where the largest scale sizes are stable on timescales of minutes while the small scale sizes are more variable. When comparing two smaller time intervals of different types of auroral displays, we find a variation in their characteristics. The characteristics averaged over the event are in remarkable agreement with the spatiotemporal characteristics of the nightside field-aligned currents during moderately disturbed times. Thus, two different electrodynamical parameters of the M-I coupling show similar behavior. This gives independent support to the claim of a system behavior that uses repeatable solutions to transfer energy and momentum from the magnetosphere to the ionosphere