STRUCTURE OF SOUTH CENTRAL AGRICULTURAL PRODUCTION

Using a dual economic specification of a multiproduct technology, the structure of agricultural production was tested for five South Central states (Texas, Oklahoma, Arkansas, Mississippi, and Louisiana). A comprehensive set of output supplies and input demands comprised the estimation equations in each state. Evidence of nonjoint production in a subset of commodities was detected in four of the five states. Several commodities also satisfied sufficient conditions for consistent aggregations. However, the specific outputs satisfying each structural property varied by state. Sufficient conditions for consistent geographic aggregation across the states were not satisfied. These results provide empirical guidance and important cautions for legitimately simplifying state-level model specifications of southern agricultural production.Industrial Organization,

Organizing to Win: Introduction

[Excerpt] The American labor movement is at a watershed. For the first time since the early years of industrial unionism sixty years ago, there is near-universal agreement among union leaders that the future of the movement depends on massive new organizing. In October 1995, John Sweeney, Richard Trumka, and Linda Chavez-Thompson were swept into the top offices of the AFL-CIO, following a campaign that promised organizing at an unprecedented pace and scale. Since taking office, the new AFL-CIO leadership team has created a separate organizing department and has committed $20 million to support coordinated large-scale industry-based organizing drives. In addition, in the summer of 1996, the AFL-CIO launched the Union Summer program, which placed more than a thousand college students and young workers in organizing campaigns across the country

Red-Cockaded Woodpeckers and Silvicultural Practice: is Uneven-Aged? Silviculture Preferable to Even-Aged

The endangered red-cockaded woodpecker (Picoides borealis) has become a high-profile management issue in the southeastern United States. Suitable habitat consists of mature to old pine, or mixed pine-hardwood forest, with minimal hardwood midstory vegetation. Loss of habitat, detrimental silvicultural practices, and changes in the fire regime have resulted in small fragmented populations, most of which have been declining precipitously in recent decades (Costa and Escano 1989, Conner and Rudolph 1989). The current population of l0-12 thousand birds occurs across much of the original range from Virginia and Florida west to Oklahoma and Texas (James 1995). However, populations are restricted to isolated tracts of suitable habitat, primarily on public lands. Consequently, the debate over the future of this once abundant species, characteristic of fire climax pine forests, has focused primarily on management strategies for the species by the U.S. Forest Service (USFS), the agency responsible for the majority of the public forest lands in the region

Red-cockaded Woodpecker Colony Status and Trends On the Angelina, Davy Crockett and Sabine National Forests

Abundant hardwood midstory, colony isolation, and habitat fragmentation are believed to be the causes for severe population declines of red-cockaded woodpeckers on three national forests in eastern Texas

Trapped-ion quantum error-correcting protocols using only global operations

Quantum error-correcting codes are many-body entangled states that are prepared and measured using complex sequences of entangling operations. Each element of such an entangling sequence introduces noise to delicate quantum information during the encoding or reading out of the code. It is important therefore to find efficient entangling protocols to avoid the loss of information. Here we propose an experiment that uses only global entangling operations to encode an arbitrary logical qubit to either the five-qubit repetition code or the five-qubit code, with a six-ion Coulomb crystal architecture in a Penning trap. We show that the use of global operations enables us to prepare and read out these codes using only six and ten global entangling pulses, respectively. The proposed experiment also allows the acquisition of syndrome information during readout. We provide a noise analysis for the presented protocols, estimating that we can achieve a six-fold improvement in coherence time with noise as high as $\sim 1\%$ on each entangling operation.Comment: 7 pages, 4 figures, published version, comments are welcom

Red-Cockaded Woodpecker Nesting Success, Forest Structure, and Southern Flying Squirrels in Texas

For several decades general opinion has suggested that southern flying squirrels (Gluucomys volans) have a negative effect on Red-cockaded Woodpeckers (Picoides borealis) through competition for cavities and egg/nestling predation. Complete removal of hardwood trees from Red-cockaded Woodpecker cavity tree clusters has occurred on some forests because southern flying squirrel abundance was presumed to be associated with the presence and abundance of hardwood vegetation. In some locations, southern flying squirrels have been captured and either moved or killed in the name of Red-cockaded Woodpecker management. We determined southern flying squirrel occupancy of Red-cockaded Woodpecker cavities in loblolly (Pinus taeda)-shortleaf (P. echinata) pine habitat (with and without hardwood midstory vegetation) and longleaf pine (P. pulustris) habitat (nearly devoid of hardwood vegetation) during spring, late summer, and winter during 1990 and 1991. Flying squirrel use of Red-cockaded Woodpecker cavities was variable and was not related to presence or abundance of hardwood vegetation. Woodpecker nest productivity was not correlated with flying squirrel use of woodpecker cavities within clusters. In addition, we observed six instances where Red-cockaded Woodpeckers successfully nested while flying squirrels occupied other cavities in the same tree. Our results suggest that complete removal of hardwoods from woodpecker cluster areas in loblolly and shortleaf pine habitat may not provide benefits to the woodpeckers through reduction of flying squirrel numbers. Reduction of hardwood midstory around cavity trees, however, is still essential because of the woodpecker\u27s apparent innate intolerance of hardwood midstory foliage

Red-Cockaded Woodpecker Nestling Provisioning and Reproduction in Two Different Pine Habitats

We obtained nestling provisioning and reproductive data from 24 Red-cockaded Woodpecker (Picoides borealis) groups occupying two different pine habitats-longleaf pine (Pinus palustris) and a mixture of loblolly (P. taeda) and shortleaf pine (P. echinata)--in eastern Texas during 1990 and 1901. Habitat data were collected within 800 m of each group\u27s cavity-tree cluster. Feeding trips per nest and prey biomass per feeding trip were significantly greater in lohlolly-shortleaf pine habitat. There were few significant correlations between reproductive/provisioning and habitat variables in either pine habitat. Pines dying from infestation by southern pine beetles (Dendroctonus frontalis) were more common in loblolly-shortleaf than in longleaf pine habitat. In addition, adult male Red-cockaded Woodpeckers weighed more in loblolly-shortleaf pine habitat. Indices of southern pine beetle abundance in loblolly-shortleaf pine habitat were negatively correlated with but positively correlated with prey biomass delivered to nestlings. We number of feeding trips per nestling, hypothesize that the greater abundance of southern pine beetles and associated arthropods in loblolly-shortleaf pine habitat, ancl the resulting higher frequency of dying pines containing an abundant food source, were associated with an elevated prey biomass available to both nestling and adult Red-cockaded Woodpeckers

Species Using Red-Cockaded Woodpecker Cavities in Eastern Texas

Because of its ability to excavate cavities in living pines, the Red-cockaded Woodpecker (Picoides borealis) is a keystone species in the fire-disclimax, pine ecosystems of the southeastern United States. Many species representing multiple taxonomic classes are dependent on this woodpecker species for the cavities it creates. We examined the occupants of Red-cockaded Woodpecker cavities during spring, late summer, and winter. Cavities enlarged by other species of woodpeckers and unenlarged cavities were examined in two habitat conditions: loblolly (Pinus taeda) -shortleaf (P. echinata) pine and longleaf pine (P. palustris) habitats. Red-cockaded Woodpecker cavities provided cavity habitat for seven species of birds, two species of squirrels, skinks, frogs, spiders, moths, and numerous species of Hymenoptera