Austin Owen Lecture: The National Export Strategy

The Honorable Raymond E. Vickery, Jr., presented this address as The Fourth Annual Austin Owen Lecture on October 5, 1995. The Honorable Austin E. Owen attended Richmond College from 1946-47 and received his law degree from the T.C. Williams School of Law in 1950. During his distinguished career, Judge Owen served as the Assistant U.S. Attorney for the Eastern District of Virginia, was a partner in Owen, Guy, Rhodes, Betz, Smith and Dickerson and was appointed Judge of the Second Judicial Circuit of Virginia where he served until his retirement in 1990. In 1991, Judge Owen\u27s daughter, Dr. Judith O. Hopkins, W\u2774, and son-in-law, Dr. Marbry B. Hopkins, R\u2774, established the Austin Owen Lecture which is held each fall at the Law School. The Law School community grieved the loss of this distinguishedalumnus upon his death in March, 1995

Impact of the Agricultural Sector on the Arkansas Economy in 2001

Agriculture has historically been one of Arkansas’ primary economic sectors. Agriculture is defined as the sum of agricultural production and processing activities unless otherwise specified. Agriculture contributes to the economy through direct agricultural production and value-added processing which generates economic activity in other parts of the economy

Impact of the Agricultural Sector on the Arkansas Economy

Agriculture historically has been one of the primary sectors of the Arkansas economy. Agriculture is defined as the sum of agricultural, forestry, and fisheries production and processing activities unless otherwise specified. Not only does agriculture contribute to the economy through direct agricultural production and added value processing, it also plays an important role through the economy’s other sectors. Utilizing data from the United States Bureau of Economic Affairs and the State of Arkansas, the economic impact of agriculture on the Arkansas economy was estimated for the latest year available, 1999. Gross State Product (GSP) information for Arkansas was compared with that of other states in the southeastern U.S. to give a measure of the relative importance of agriculture in Arkansas compared with other states. The total impact of agriculture (direct, indirect, and induced effects) on added value, employment, and wage income was estimated by employing the Impact Analysis for Planning System (IMPLAN). Economic impacts of agricultural production and processing were estimated for agriculture as a whole and also separately for the crop sector, the livestock sector, and the forestry sector

Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus

Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing—observation, approach and usually harassment of a predator—being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing (Vanellus vanellus). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax, hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo, white stork Ciconia ciconia, black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory

Structural bases for the interaction of frataxin with the central components of iron–sulphur cluster assembly

Reduced levels of frataxin, an essential protein of as yet unknown function, are responsible for causing the neurodegenerative pathology Friedreich's ataxia. Independent reports have linked frataxin to iron–sulphur cluster assembly through interactions with the two central components of this machinery: desulphurase Nfs1/IscS and the scaffold protein Isu/IscU. In this study, we use a combination of biophysical methods to define the structural bases of the interaction of CyaY (the bacterial orthologue of frataxin) with the IscS/IscU complex. We show that CyaY binds IscS as a monomer in a pocket between the active site and the IscS dimer interface. Recognition does not require iron and occurs through electrostatic interactions of complementary charged residues. Mutations at the complex interface affect the rates of enzymatic cluster formation. CyaY binding strengthens the affinity of the IscS/IscU complex. Our data suggest a new paradigm for understanding the role of frataxin as a regulator of IscS functions

Avian Use of Perennial Biomass Feedstocks as Post-Breeding and Migratory Stopover Habitat

Increased production of biomass crops in North America will require new agricultural land, intensify the cultivation of land already under production and introduce new types of biomass crops. Assessing the potential biodiversity impacts of novel agricultural systems is fundamental to the maintenance of biodiversity in agricultural landscapes, yet the consequences of expanded biomass production remain unclear. We evaluate the ability of two candidate second generation biomass feedstocks (switchgrass, Panicum virgatum, and mixed-grass prairie) not currently managed as crops to act as post-breeding and fall migratory stopover habitat for birds. In total, we detected 41 bird species, including grassland specialists and species of state and national conservation concern (e.g. Henslow's Sparrow, Ammodramus henslowii). Avian species richness was generally comparable in switchgrass and prairie and increased with patch size in both patch types. Grassland specialists were less abundant and less likely to occur in patches within highly forested landscapes and were more common and likely to occur in larger patches, indicating that this group is also area-sensitive outside of the breeding season. Variation in the biomass and richness of arthropod food within patches was generally unrelated to richness and abundance metrics. Total bird abundance and that of grassland specialists was higher in patches with greater vegetation structural heterogeneity. Collectively, we find that perennial biomass feedstocks have potential to provide post-breeding and migratory stopover habitat for birds, but that the placement and management of crops will be critical factors in determining their suitability for species of conservation concern. Industrialization of cellulosic bioenergy production that results in reduced crop structural heterogeneity is likely to dramatically reduce the suitability of perennial biomass crops for birds

Investigation of the Interaction between the Large and Small Subunits of Potato ADP-Glucose Pyrophosphorylase

ADP-glucose pyrophosphorylase (AGPase), a key allosteric enzyme involved in higher plant starch biosynthesis, is composed of pairs of large (LS) and small subunits (SS). Current evidence indicates that the two subunit types play distinct roles in enzyme function. Recently the heterotetrameric structure of potato AGPase has been modeled. In the current study, we have applied the molecular mechanics generalized born surface area (MM-GBSA) method and identified critical amino acids of the potato AGPase LS and SS subunits that interact with each other during the native heterotetrameric structure formation. We have further shown the role of the LS amino acids in subunit-subunit interaction by yeast two-hybrid, bacterial complementation assay and native gel. Comparison of the computational results with the experiments has indicated that the backbone energy contribution (rather than the side chain energies) of the interface residues is more important in identifying critical residues. We have found that lateral interaction of the LS-SS is much stronger than the longitudinal one, and it is mainly mediated by hydrophobic interactions. This study will not only enhance our understanding of the interaction between the SS and the LS of AGPase, but will also enable us to engineer proteins to obtain better assembled variants of AGPase which can be used for the improvement of plant yield