Alternative Model Selection Using Forecast Error Variance Decompositions in Wholesale Chicken Markets

Although Vector Autoregressive models are commonly used to forecast prices, specification of these models remains an issue. Questions that arise include choice of variables and lag length. This article examines the use of Forecast Error Variance Decompositions to guide the econometrician’s model specification. Forecasting performance of Variance Autoregressive models, generated from Forecast Error Variance Decompositions, is analyzed within wholesale chicken markets. Results show that the Forecast Error Variance Decomposition approach has the potential to provide superior model selections to traditional Granger Causality tests.broiler markets, DAGs, forecasting, market structure, VAR, Agribusiness, Demand and Price Analysis, Livestock Production/Industries, Risk and Uncertainty, C53, D4, L1, Q00,

Prepared for Bioterrorism Events? A Study of the Grain and Oilseed Sector

One of the most crucial problems facing the U.S. economy is the possibility of a terrorist attack on its food sector. The implications can be profound for its stakeholders, who are highly dependent on this sector for their economic livelihood as well as their food supplies. The U.S. Bioterrorism Act of 2002 was enacted to improve the ability of the United States to prevent, prepare for and respond to bioterrorism and other public health emergencies. One of the important features of the U.S. Bioterrorism Act of 2002 is its emphasis on prevention, a change from prior legislation that focused on punishments after an incidence had occurred. The U.S. Bioterrorism Act does not address food safety issues in general; its focus is to prevent intentional contamination. The objective of this study was to assess the preparedness to potential bioterrorism in the grain and oilseed sector based on facility security expenditures and history of security breaches. The study was conducted as a research activity under the multistate project NC-1016 “Economic Assessment of Changes in Trade Arrangements, Bio-terrorism Threats and Renewable Fuels Requirements on the U.S. Grain and Oilseed Sector.” In addition to assessing preparedness, the study investigated the relationship between adoption of security measures and breaches in facility security. Finally the study documents, for a small sample, the extent to which grain and oilseed facilities appear to be following regulations that implement the U.S. Bioterrorism Act.bioterrorism, grain and oilseed sector, Bioterrorism Act of 2002, NC-1016, Agribusiness, Agricultural and Food Policy, Marketing, Political Economy, I18, K23, Q13, Q18,

Attitudes of College Students towards Agriculture, Food and the Role of Government

In 2002 and 2007 we surveyed Agribusiness students’ attitudes about agriculture, farming, food and agricultural policies. Responses were analyzed by year and student characteristics including farm background, citizenship and gender. Citizenship was a significant variable explaining differences in agreement with statements. Year and interactions with year were not significant.agricultural policy, farming, logistic regression, student attitudes, Agricultural and Food Policy, Teaching/Communication/Extension/Profession, A13, A22, C42, Q18,

COVID-19 e alojamento local em Portugal: Futuros imprevisíveis

This article presents the results of a pioneering online survey of short-term rental (STR) hosts (N=879) in Portugal about the impact of Covid on their activity, with a sample structured into four areas (Lisbon, Porto, Algarve and the rest of the country). Despite the very high losses, especially in the cities, most of the respondents intend to continue operating in the STR sector. A massive migration from STR to long-term rental is not predicted for a number of reasons, including financial, those related to the nature of this type of supply – more temporary – and the high level of distrust of the state, specifically in terms of guaranteeing legislative stability. In the cities, medium-term rental is the alternative most commonly considered, suggesting there may be a possible restructuring of the sector. Survival capacity over the medium term will depend on the degree of losses and type of public support received during the pandemic, which has benefited hosts constituted as companies more than the sole proprietorships.Este artigo apresenta os resultados de um pioneiro inquérito online aos anfitriões de Alojamento Local (AL) em Portugal (N=879), com uma amostra estruturada territorialmente em quatro áreas áreas (Lisboa, Porto, Algarve e resto do país), sobre os impactos da COVID na sua atividade. Apesar das enormes perdas, sobretudo nas cidades, a maioria dos inquiridos tenciona continuar a operar no sector do AL. Não se prevê uma migração massiva do AL para o arrendamento de longa duração por várias razões: desde as financeiras, às relativas à natureza deste tipo de oferta –mais temporária –ou a elevada desconfiança em relação ao Estado, especificamente em termos de estabilidade legis-lativa. Nas cidades, o arrendamento de média duração é a alternativa mais considerada, sugerindo a possibilidade de alguma reestruturação do sector. A capacidade de sobrevivência a médio prazo dependerá do grau das perdas e do tipo de apoio público recebido durante a pandemia o qual bene-ficiou mais os anfitriões constituídos como empresas do que os empresários em nome individual.info:eu-repo/semantics/publishedVersio

Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO). In these conditions, NO promotes proliferation of neural stem cells (NSC) in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA) induced seizuremouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.Foundation for Science and Technology (FCT, Portugal); COMPETE; FEDER [PTDC/SAU-NEU/102612/2008, PTDC/NEU-OSD/0473/2012, PEst-C/SAU/LA0001/2013-2014, PEst-OE/EQB/LA0023/2013-2014]; FCT, Portugal [SFRH/BPD/78901/2011, SFRH/BD/77903/2011

EXFI: a low cost Fault Injection System for embedded Microprocessor-based Boards

Evaluating the faulty behavior of low-cost embedded microprocessor-based boards is an increasingly important issue, due to their adoption in many safety critical systems. The architecture of a complete Fault Injection environment is proposed, integrating a module for generating a collapsed list of faults, and another for performing their injection and gathering the results. To address this issue, the paper describes a software-implemented Fault Injection approach based on the Trace Exception Mode available in most microprocessors. The authors describe EXFI, a prototypical system implementing the approach, and provide data about some sample benchmark applications. The main advantages of EXFI are the low cost, the good portability, and the high efficienc

Inverse Ising inference using all the data

We show that a method based on logistic regression, using all the data, solves the inverse Ising problem far better than mean-field calculations relying only on sample pairwise correlation functions, while still computationally feasible for hundreds of nodes. The largest improvement in reconstruction occurs for strong interactions. Using two examples, a diluted Sherrington-Kirkpatrick model and a two-dimensional lattice, we also show that interaction topologies can be recovered from few samples with good accuracy and that the use of $l_1$-regularization is beneficial in this process, pushing inference abilities further into low-temperature regimes.Comment: 5 pages, 2 figures. Accepted versio