Grain-supply response in Ethiopia: An error-correction approach

This paper quantifies the responsiveness of producers of teff, wheat, maize and sorghum to incentives using an error-correction model (ECM). It is found that planned supply of these crops is positively affected by own price, negatively by prices of substitute crops and variously by structural breaks related to policy changes and the occurrence of natural calamities. It has found significant long-run price elasticities for all crop types and insignificant short-run price elasticities for all crops but maize. Higher and significant long-run price elasticities as compared to lower and insignificant short-run price elasticities are attributable to various factors, namely structural constraints, the theory of supply and the conviction that farmers respond when they are certain that price changes are permanent. The paper concludes that farmers do respond to incentive changes. Thus attempts, which directly or indirectly tax agriculture with the belief that the sector is non-responsive to incentives, harm its growth and its contribution to growth in other sectors of the economy.Crop Production/Industries,

Simulation based Bayesian econometric inference: principles and some recent computational advances

In this paper we discuss several aspects of simulation based Bayesian econometric inference. We start at an elementary level on basic concepts of Bayesian analysis; evaluating integrals by simulation methods is a crucial ingredient in Bayesian inference. Next, the most popular and well-known simulation techniques are discussed, the MetropolisHastings algorithm and Gibbs sampling (being the most popular Markov chain Monte Carlo methods) and importance sampling. After that, we discuss two recently developed sampling methods: adaptive radial based direction sampling [ARDS], which makes use of a transformation to radial coordinates, and neural network sampling, which makes use of a neural network approximation to the posterior distribution of interest. Both methods are especially useful in cases where the posterior distribution is not well-behaved, in the sense of having highly non-elliptical shapes. The simulation techniques are illustrated in several example models, such as a model for the real US GNP and models for binary data of a US recession indicator.

Methodology of the biological risk classification of animal pathogens in Belgium

The biological hazards posed by micro-organisms have lead to their categorisation into risk groups and the elaboration of classification lists. Current classification systems rely on criteria defined by the World Health Organization, which cover the severity of the disease the micro-organism might cause, its ability to spread and the availability of prophylaxis or efficient treatment. Animal pathogens are classified according to the definitions of the World Organization of Animal Health, which also consider economic aspects of disease. In Europe, classification is often directly linked to containment measures. The Belgian classification system however, only considers the inherent characteristics of the micro-organism, not its use, making the risk classification independent of containment measures. A common classification list for human and animal pathogens has been developed in Belgium using as comprehensive an approach as possible. Evolution of scientific knowledge will demand regular updating of classification lists. This paper describes the Belgian risk classification system and the methodology that was used for its peer-reviewed revision (with a focus on animal pathogens)

Private Sector and Climate Change A Case Study of Carbon-Based Governance

Global greenhouse gas emissions are the main contributor to anthropocentrically-induced climate change and have risen 41% since 1990. We are still yet to reach peak emissions. A large share of those emissions result from private sector activity. At the same time, the private sector possesses major resources which should be harnessed to scale up funding and emissions reduction technologies to benefit the 3 climate. Since the Paris Climate Agreement in 2015, there has been an upsurge in private sector activity on climate change, especially in the corporate sector. Researchers have suggested that this groundswell of private sector activity especially in reduction of carbon emissions holds out the promise of plugging conspicuous public governance gaps. But while this surge in private action since the Paris Climate Agreement is to be encouraged, and indeed has been formally welcomed by global public climate governance actors under the UNFCCC, the measurable success of private, public-private and “hybrid” climate governance arrangements on reducing emissions remains unclear. Through an in depth empirical investigation of the actors and initiatives that play a key role in this emerging domain of bottom-up climate change governance, this study finds that, despite a groundswell in private activity, zones of fragmentation among a multiplicity of private actors, initiatives and standards is stymying progress: while key actors are increasingly networked, key metrics remain severely fragmented; while substantial resources have been dedicated to governing carbon emissions, greenhouse gas emissions keep rising. These observations are demonstrated through an empirical analysis of the “carbon-based” governance regime, which we define as the governance of climate change through a unitary focus on carbon measurement, disclosure, and verification. So far, the ultimate goal of carbon-based governance to reduce emissions is far from being realized. Whether this regime can be repurposed to fulfil this crucial function remains an open question

Induction of Plant Defense Gene Expression by Plant Activators and Pseudomonas syringae pv. tomato in Greenhouse-Grown Tomatoes

Plant activators provide an appealing management option for bacterial diseases of greenhouse-grown tomatoes. Two types of plant activators, one that induces systemic acquired resistance (SAR) and a second that activates induced systemic resistance (ISR), were evaluated for control of Pseudomonas syringae pv. tomato and effect on plant defense gene activation. Benzothiadiazole (BTH, SAR-inducing compound) effectively reduced bacterial speck incidence and severity, both alone and in combination with the ISR-inducing product. Application of BTH also led to elevated activation of salicylic acid and ethylene-mediated responses, based on real-time polymerase chain reaction analysis of marker gene expression levels. In contrast, the ISR-inducing product (made up of plant growth-promoting rhizobacteria) inconsistently modified defense gene expression and did not provide disease control to the same level as did BTH. No antagonism was observed by combining the two activators as control of bacterial speck was similar to or better than BTH alone

Superconducting and structural properties of plasma sprayed YBaCuO layers deposited on metallic substrates

The properties of plasma sprayed Y-Ba-Cu-O coatings deposited on metallic substrates are studied. Stainless steel, nickel steels and pure nickel are used as substrate. Y-Ba-Cu-O deposited on stainless steel and nickel steel reacts with the substrate. This interaction can be suppressed by using an yttria-stabilized zirconia (YsZ) diffusion barrier. However, after heat treatment the Y-Ba-Cu-O layers on YsZ show cracks perpendicular to the surface. As a result the critical current density is very low. The best results are obtained for Y-Ba-Cu-O deposited on pure nickel; here no cracks perpendicular to the surface are observed. The critical current increases with the anneal temperature but annealing for longer than 10 h does not seem to improve the superconducting properties any further

Removing black-hole singularities with nonlinear electrodynamics

We propose a way to remove black hole singularities by using a particular nonlinear electrodynamics Lagrangian that has been recently used in various astrophysics and cosmological frameworks. In particular, we adapt the cosmological analysis discussed in a previous work to the black hole physics. Such analysis will be improved by applying the Oppenheimer-Volkoff equation to the black hole case. At the end, fixed the radius of the star, the final density depends only on the introduced quintessential density term $\rho_{\gamma}$ and on the mass.Comment: In this last updated version we correct two typos which were present in Eqs. (21) and (22) in the version of this letter which has been published in Mod. Phys. Lett. A 25, 2423-2429 (2010). In the present version, both of Eqs. (21) and (22) are dimensionally and analytically correc

The Nuclear X-Ray Emission-line Structure in NGC 2992 Revealed by

We present the narrow emission-line structure revealed by a 135 ks Chandra observation of Seyfert galaxy NGC 2992, using the High Energy Transmission Grating Spectrometer. The source was observed in an historically low-flux state. Using a Bayesian Block search technique, we detected neutral Si Kα and S Kα fluorescence and two additional lines that are consistent with redshifted, ionized Si emission. The latter two features are indicative of a photoionized outflow with a velocity of ∼ 2500 km s⁻¹. We also observed prominent, unresolved line emission at the rest energy of Fe Kα, with a 90% confidence FWHM velocity width of < 2000 km s⁻¹ ( < 2800 km s⁻¹) and equivalent width of 406-1148 eV (288-858 eV) when broad Fe Kα line emission, as detected by Suzaku, was (was not) included in the model