Entanglement temperature in molecular magnets composed of S-spin dimers

In the present work, we investigate the quantum thermal entanglement in molecular magnets composed of dimers of spin S, using an Entanglement Witness built from measurements of magnetic susceptibility. An entanglement temperature, T(e), is then obtained for some values of spin S. From this, it is shown that T(e) is proportional to the intradimer exchange interaction J and that entanglement appears only for antiferromagnetic coupling. The results are compared to experiments carried on three isostructural materials: KNaMSi(4)O(10) (M=Mn, Fe or Cu). Copyright (C) EPLA, 2009

Temporal changes in macroinvertebrate assemblages following experimental flooding in permanent and temporary wetlands in an Australian floodplain forest

The River Murray, Australia, is a highly regulated river from which almost 80% of mean annual flow is removed for human use, primarily irrigated agriculture. Consequent changes to the pattern and volume of river flow are reflected in floodplain hydrology and, therefore, the wetting/drying patterns of floodplain wetlands. To explore the significance of these changes, macroinvertebrate samples were compared between permanent and temporary wetlands following experimental flooding in a forested floodplain of the River Murray. Weekly samples from two permanent wetlands and four associated temporary sites were used to track changes in macroinvertebrate assemblage composition. Non-metric multidimensional scaling was used to ordinate the macroinvertebrate data, indicating consistent differences between the biota of permanent and temporary wetlands and between the initial and later assemblages in the temporary sites. There were marked changes over time, but little sign that the permanent and temporary assemblages were becoming more alike over the 25-week observation period. The apparent heterogeneity of these systems is of particular importance in developing river management plans which are likely to change flooding patterns. Such plans need to maintain a mosaic of wetland habitats if floodplain biodiversity is to be supported.

On rapid vector alignment in permanent magnet brushless motor

A software replacement for the commutation signals of a permanent magnet brushless motor is presented. The feedback observed acceleration loop or equivalently the high-order position polynomial controller allows finding the initial relative orientation between the two magnetic fields of the motors within a fraction of a second. Also, using the proposed method allows a considerable cost saving, since the transducer that is usually used for this purpose can be eliminated. The cost saving is most obvious in the case of linear motors and angle motors with large diameters. The way the problem is posed is an essential part of this work and it is the reason behind the apparent simplicity of the solution. The method has been tested when a relative encoder was used and the motor current was regulated.

Are oil shocks permanent or temporary? panel data evidence from crude oil and NGL production in 60 countries

This paper examines the unit root properties of crude oil production for 60 countries employing a range of panel data unit root tests for the period 1971 to 2003. The study first employs a number of panel data tests that do not accommodate structural breaks and then proceeds to apply the Lagrange Multiplier (LM) panel unit root test with one structural break. The results of the panel data tests without a structural break are inconclusive with at best mixed support for joint stationarity. The findings from the LM panel unit root test with a structural break, however, are conclusive, suggesting that for a world panel and smaller regional-based panels, crude oil and NGL production are jointly stationary.

Are shocks to real effective exchange rates permanent or transitory? evidence from Pacific Island countries

In this article, we consider the stability of the real effective exchange rates for four Pacific Island countries using the Lee and Strazicich (2003a, b) unit root test, which allows one to incorporate at most two structural breaks in the data series. Our main finding is that for Papua New Guinea and Samoa, exchange rates are stable, implying that shocks will have a transitory effect on real effective exchange rates, while for Fiji and the Solomon Islands we find exchange rates to be unstable, implying that shocks will have a permanent effect on real effective exchange rates.

Do shocks to G7 stock prices have a permanent effect? : evidence from panel unit root tests with structural change

There is a plethora of studies that investigate evidence for the behaviour of stock prices using univariate techniques for unit roots. Whether or not stock prices are characterised by a unit root have implications for the efficient market hypothesis, which asserts that returns of a stock market are unpredictable from previous price changes. The extant literature has found mixed evidence on the integrational properties of stock prices. In this paper, for the first time, we provide evidence on the unit root hypothesis for G7 stock price indices using the Lagrangian multiplier panel unit root test that allows for structural breaks. Our main finding is that stock prices are stationary processes, inconsistent with the efficient market hypothesis.

Understanding the importance of permanent and transitory shocks at business cycle horizons for the UK

The goal of this paper is to examine the relative importance of permanent and transitory shocks in explaining variations in macroeconomic aggregates for the UK at business cycle horizons. Using the common trend–common cycle restrictions, we estimate a variance decomposition of shocks, and find that over short horizons the bulk of the variations in income and consumption were due to permanent shocks while transitory shocks explain the bulk of the variations in investment. Our findings for income and consumption are consistent with real business cycle models which emphasize the role of aggregate supply shocks, while our findings for investment are consistent with the Keynesian school of thought, which emphasizes the role of aggregate demand shocks in explaining business cycles.

Do permanent shocks explain income levels? a common cycle-common trend analysis of regional income levels for China

In this paper, we analyse per capita income levels of China's three main regions: the western region, the eastern region and the central region using common cycle and common trend tests. Our main contribution is that we impose the common cycle and common trend restrictions in decomposing shocks into permanent and transitory components. We find that: (i) there is evidence for two cointegrating relationships and one common cycle; and (ii) the variance decomposition analysis of shocks provides evidence that over short horizons, permanent shocks play a large role in explaining variations in regional per capita incomes.

Are shocks to energy consumption permanent or temporary? evidence from 182 countries

This article applies univariate and panel data unit root tests to annual panel data for 182 countries over the period 1979–2000 to examine the stationarity properties of per capita energy consumption. The univariate unit root test can only reject the unit root null for 56 countries or 31% of the sample at the 10% level or better. However, univariate unit root tests have low power with short spans of data and therefore failure to reject the unit root null should be treated with caution. When we apply the panel data unit root test we find overwhelming evidence that energy consumption is stationary. We discuss the policy implications of these findings and offer suggestions for future research.

Permanent genetic resources added to molecular ecology resources database 1 August 2010 – 30 September 2010

This article documents the addition of 229 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acacia auriculiformis · Acacia mangium hybrid, Alabama argillacea, Anoplopoma fimbria, Aplochiton zebra, Brevicoryne brassicae, Bruguiera gymnorhiza, Bucorvus leadbeateri, Delphacodes detecta, Tumidagena minuta, Dictyostelium giganteum, Echinogammarus berilloni, Epimedium sagittatum, Fraxinus excelsior, Labeo chrysophekadion, Oncorhynchus clarki lewisi, Paratrechina longicornis, Phaeocystis antarctica, Pinus roxburghii and Potamilus capax. These loci were cross-tested on the following species: Acacia peregrinalis, Acacia crassicarpa, Bruguiera cylindrica, Delphacodes detecta, Tumidagena minuta, Dictyostelium macrocephalum, Dictyostelium discoideum, Dictyostelium purpureum, Dictyostelium mucoroides, Dictyostelium rosarium, Polysphondylium pallidum, Epimedium brevicornum, Epimedium koreanum, Epimedium pubescens, Epimedium wushanese and Fraxinus angustifolia.

Are shocks to real output permanent or transitory? Evidence from a panel of Pacific Island countries

Panel unit root and stationarity tests without structural breaks suggest that for eight Pacific island economies real gross domestic product (GDP) per capita contains a unit root. The panel stationarity test that accommodates structural change in the trend function, however, finds evidence in favour of regimewise trend stationarity. This result points to the importance of taking structural breaks into account. The finding implies that, for the period considered, the permanent secular component of output is dominated by transitory fluctuations accompanied by infrequent changes in the trend function. The only exceptions are Fiji and Kiribati, for which individual stationarity tests with multiple structural breaks suggest that real GDP per capita contains a unit root.