Invasive Species Management: Foot-and-Mouth Disease in the U.S. Beef Industry

A conceptual bioeconomic framework that integrates dynamic epidemiological-economic processes was designed to analyze the effects of invasive species introduction on decision making in a livestock sector (e.g., production and feeding). The framework integrates an epidemiological model, a dynamic livestock production model, domestic consumption, and international trade. The integrated approach captures producer and consumer responses and welfare outcomes of livestock disease outbreaks, as well as alternative invasive species management policies. Scenarios of foot-and-mouth disease are simulated to demonstrate the usefulness of the framework in facilitating invasive species policy design.livestock, invasive species, foot-and-mouth disease, beef cattle production, Livestock Production/Industries,

Invasive Species Management: Foot-and-Mouth Disease in the U.S. Beef Industry

A conceptual bio-economic framework that integrates dynamic epidemiologicaleconomic processes was designed to analyze the effects of invasive species introduction on decision-making in a livestock sector (e.g., production and feeding). The framework integrates an epidemiological model, a dynamic livestock production model, domestic consumption, and international trade. The integrated approach captures producer and consumer responses to, and welfare outcomes of, livestock disease outbreaks, as well as alternative invasive species management policies. Scenarios of foot-and-mouth disease are simulated to demonstrate the usefulness of the framework in facilitating invasive species policy design.bio-economics, livestock, invasive species, foot-and-mouth disease, beef cattle production, Livestock Production/Industries,

Experimental study of open-channel flow with partial double-layered vegetation

Many rivers and wetlands have vegetation. The effect of riparian vegetation on ecological and flow process in channels has become increasingly important in river flood risk and aquatic environmental management. Most previous studies have been done on the flow structure of vegetation of the same height which is not realistic in natural rivers. There are only a few studies on flows with a mixing array of short and tall vegetation under either submerged or emergent flow condition. This paper is to undertake a novel experimental study on a flow with double-layered vegetation under submerged and emergent conditions, which often occur in most rivers. Two different heights of dowels, 10 cm and 20 cm, were used in the water flume to represent the short and tall vegetation respectively, and they were allocated on one side of the flume. Experiments in two flow depths were undertaken to represent different submergence ratios of vegetation, and velocities at various locations were measured by Acoustic Doppler Velocimetry (ADV) and propeller velocimetry. Experimental results show that the velocity profile is almost uniform within the depth of short vegetation in different configurations. The velocity starts to increase in the region near the edge of short vegetation, and then followed by a rapid increase through the height of tall vegetation to the free surface. Meanwhile, a strange shear layer exists laterally between vegetation and non-vegetation, showing that the vegetation significantly reduces the velocity of flow

Experimental study of open-channel flow with partial double-layered vegetation

Many rivers and wetlands have vegetation. The effect of riparian vegetation on ecological and flow process in channels has become increasingly important in river flood risk and aquatic environmental management. Most previous studies have been done on the flow structure of vegetation of the same height which is not realistic in natural rivers. There are only a few studies on flows with a mixing array of short and tall vegetation under either submerged or emergent flow condition. This paper is to undertake a novel experimental study on a flow with double-layered vegetation under submerged and emergent conditions, which often occur in most rivers. Two different heights of dowels, 10 cm and 20 cm, were used in the water flume to represent the short and tall vegetation respectively, and they were allocated on one side of the flume. Experiments in two flow depths were undertaken to represent different submergence ratios of vegetation, and velocities at various locations were measured by Acoustic Doppler Velocimetry (ADV) and propeller velocimetry. Experimental results show that the velocity profile is almost uniform within the depth of short vegetation in different configurations. The velocity starts to increase in the region near the edge of short vegetation, and then followed by a rapid increase through the height of tall vegetation to the free surface. Meanwhile, a strange shear layer exists laterally between vegetation and non-vegetation, showing that the vegetation significantly reduces the velocity of flow

Alterations in brain morphology and functional connectivity mediate cognitive decline in carotid atherosclerotic stenosis

BackgroundPatients with carotid atherosclerotic stenosis (CAS) often have varying degrees of cognitive decline. However, there is little evidence regarding how brain morphological and functional abnormalities impact the cognitive decline in CAS patients. This study aimed to determine how the brain morphological and functional changes affected the cognitive decline in patients with CAS.MethodsThe brain morphological differences were analyzed using surface and voxel-based morphometry, and the seed-based whole-brain functional connectivity (FC) abnormalities were analyzed using resting-state functional magnetic resonance imaging. Further, mediation analyses were performed to determine whether and how morphological and FC changes affect cognition in CAS patients.ResultsThe CAS-MCI (CAS patients with mild cognitive impairment) group performed worse in working memory, verbal fluency, and executive time. Cortical thickness (CT) of the left postcentral and superiorparietal were significantly reduced in CAS-MCI patients. The gray matter volume (GMV) of the right olfactory, left temporal pole (superior temporal gyrus) (TPOsup.L), left middle temporal gyrus (MTG.L), and left insula (INS.L) were decreased in the CAS-MCI group. Besides, decreased seed-based FC between TPOsup.L and left precuneus, between MTG.L and TPOsup.L, and between INS.L and MTG.L, left middle frontal gyrus, as well as Superior frontal gyrus, were found in CAS-MCI patients. Mediation analyses demonstrated that morphological and functional abnormalities fully mediated the association between the maximum degree of carotid stenosis and cognitive function.ConclusionMultiple brain regions have decreased GMV and CT in CAS-MCI patients, along with disrupted seed-based FC. These morphological and functional changes play a crucial role in the cognitive impairment in CAS patients

The Effects of Exchange Rate Fluctuations on the Live Hog Trade Between the U.S. and Canada

In 1998, the U.S. hog price hit its lowest level since World War IT at the same time the U.S. dollar reached its 100-year high against the Canadian dollar. The U.S. dollar appreciation was blamed as a factor that caused the hog price crisis and increasing trade deficit of live hogs, which directs our interest to the effects of exchange rate fluctuations on the live hog trade between the U.S. and Canada. We examine both the live hog trade market and the U.S. pork market with Vector Auto-Regression (VAR) models to find out how and to what extent the exchange rate fluctuations affect the prices and trade flow. The results show that an appreciation of the U.S. dollar does lower the U.S. live hog price, but not directly. The hog price is lower because the appreciation drives down the pork price. The exchange rates do not have much influence on the trade flow. On the contrary, the widening gap between Canadian hog production and slaughter capacity causes the Canadian hog producers to send an increasing number of their hogs to the U.S

MODELING THE IMPACTS OF ALTERNATIVE INVASIVE SPECIES MANAGEMENT POLICIES ON LIVESTOCK PRODUCTION

In this paper, a dynamic optimization modeling framework for livestock production is developed for the purpose of evaluating the welfare effects of the introduction of invasive species. A beef production model implemented based on the conceptual framework shows that the model is valid and stable. The modeling framework can be used to assess the welfare effects under alternative IS management policies and optimal resource allocation schemes for policymakers

MODELING THE IMPACTS OF ALTERNATIVE INVASIVE SPECIES MANAGEMENT POLICIES ON LIVESTOCK PRODUCTION

In this paper, a dynamic optimization modeling framework for livestock production is developed for the purpose of evaluating the welfare effects of the introduction of invasive species. A beef production model implemented based on the conceptual framework shows that the model is valid and stable. The modeling framework can be used to assess the welfare effects under alternative IS management policies and optimal resource allocation schemes for policymakers.Research Methods/ Statistical Methods,

THE EFFECTS OF EXCHANGE RATE FLUCTUATIONS ON LIVE HOG TRADE BETWEEN THE U.S. AND CANADA

The real exchange rate is often blamed as a main reason for the increased imports of live hogs from Canada. This study uses co-integration of weekly data from Jan 1997 to Jun 2000 to examine the real exchange rate fluctuations and their effects on live hog trade between the two countries

Modeling the Effects of Mitigating Apple Maggot Spread into Apple Production Region of Washington State

Crop Production/Industries,