FARM LEVEL EFFECTS AN INCREASE IN FEDERAL CIGARETTE TAXES UNDER TWO SCENARIOS: KEEP VS ELIMINATE THE TOBACCO PROGRAM

Agricultural and Food Policy,

PRICE VERSUS QUOTA REDUCTIONS: U.S. FLUE-CURED TOBACCO POLICY

Declining domestic cigarette consumption, increased global competition, and loss of import restrictions indicate decreased demand for U.S. flue-cured tobacco. The effects of 10% declines in domestic and export demand are evaluated under a policy of reducing quota to maintain price versus a policy of allowing price to fall to maintain quota. Changes in prices, quantities, revenues, and economic rents are simulated. Losses to nonfarming quota owners are minimized under a policy of price maintenance, while losses in revenues to tobacco-producing areas are minimized by a policy of quota maintenance. Aggregate losses to tobacco growers are greater under a policy of quota maintenance.Flue-cured, Policy, Price reduction, Quota, Tobacco, Agricultural and Food Policy,

Molecular Identification of Eimeria Species in Broiler Chickens in Trinidad, West Indies

Coccidiosis is an intestinal disease of chickens of major economic importance to broiler industries worldwide. Species of coccidia found in chickens include Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, and Eimeria tenella. In recent years, polymerase chain reaction (PCR) has been developed to provide accurate and rapid identification of the seven known Eimeria species of chickens. The aim of this study was to use species-specific real-time PCR (qPCR) to identify which of the seven Eimeria species are present in Trinidad poultry. Seventeen pooled fecal samples were collected from 6 broiler farms (2–5 pens per farm) across Trinidad. Feces were also collected from birds showing clinical signs of coccidiosis in two live bird markets (pluck shops). qPCR revealed the presence of five species of Eimeria (E. acervulina, E. maxima, E. mitis, E. necatrix, and E. tenella), but not E. brunetti or E. praecox. Mixed infections were detected on all broiler farms, and DNA of two highly pathogenic Eimeria species (E. tenella and E. necatrix) was detected in feces taken from clinically sick birds sampled from the two pluck shops

Near-Infrared Spectroscopy of the Bright Kuiper Belt Object 2000 EB173

We have obtained a near-infrared spectrum of the bright Kuiper Belt object 2000 EB173; the spectrum appears featureless. The spectrum has a sufficient signal-to-noise ratio to rule out the 1.5 and 2.0 μm absorption from water ice even at the low level seen in the Centaur Chariklo. In addition, we can rule out a 2.3 μm absorption at the level seen in the Centaur Pholus

CO Rovibrational Emission as a Probe of Inner Disk Structure

We present an analysis of CO emission lines from a sample of T Tauri, Herbig Ae/Be, and transitional disks with known inclinations in order to study the structure of inner disk molecular gas. We calculate CO inner radii by fitting line profiles with a simple parameterized model. We find that, for optically thick disks, CO inner radii are strongly correlated with the total system luminosity (stellar plus accretion) and consistent with the dust sublimation radius. Transitional disk inner radii show the same trend with luminosity, but are systematically larger. Using rotation diagram fits, we derive, for classical T Tauri disks, emitting areas consistent with a ring of width ~0.15 AU located at the CO inner radius; emitting areas for transitional disks are systematically smaller. We also measure lower rotational temperatures for transitional disks, and disks around Herbig Ae/Be stars, than for those around T Tauri stars. Finally, we find that rotational temperatures are similar to, or slightly lower than, the expected temperature of blackbody grains located at the CO inner radius, in contrast to expectations of thermal decoupling between gas and dust

THE END OF SUPPLY CONTROLS: THE ECONOMIC EFFECTS OF RECENT CHANGE IN FEDERAL PEANUT POLICY

The paper analyzes recent changes in U.S. peanut policy as enacted in the 2002 Farm Security Act. A model representing the impact of the 2002 farm bill on the domestic and foreign prices of edible peanuts is constructed and the gains and losses to peanut producing states are measured.Agricultural and Food Policy,

Mammalian Sperm Motility: Observation and Theory

Mammalian spermatozoa motility is a subject of growing importance because of rising human infertility and the possibility of improving animal breeding. We highlight opportunities for fluid and continuum dynamics to provide novel insights concerning the mechanics of these specialized cells, especially during their remarkable journey to the egg. The biological structure of the motile sperm appendage, the flagellum, is described and placed in the context of the mechanics underlying the migration of mammalian sperm through the numerous environments of the female reproductive tract. This process demands certain specific changes to flagellar movement and motility for which further mechanical insight would be valuable, although this requires improved modeling capabilities, particularly to increase our understanding of sperm progression in vivo. We summarize current theoretical studies, highlighting the synergistic combination of imaging and theory in exploring sperm motility, and discuss the challenges for future observational and theoretical studies in understanding the underlying mechanics.\ud Acronyms and Definitions\ud Acrosome: the cap of the sperm head containing enzymes allowing penetration of the zona pellucida via the acrosome reaction\ud Adenosine triphosphate (ATP): the currency unit of chemical energy transfer in living cells\ud Axoneme: a phylogenetically conserved structure within the eukaryotic flagellum consisting of a ring of nine microtubule doublets and a central pair, frequently referred to as 9 + 2\ud Bending moment density: the moment per unit length associated with flagellar bending; it can be divided into a hydrodynamic moment, an elastic moment (from the flagellar bending stiffness), an active moment (generated by dyneins exerting forces between adjacent microtubule doublets), and a passive moment resisting shear\ud Capacitation: the physiological state of a sperm required for fertilization, which is accompanied by the motility patterns associated with hyperactivation, characterized in saline by high-amplitude asymmetric beating\ud Central pair: a pair of microtubules along the length of the axoneme, symmetrically and slightly offset from the axoneme centerline\ud Cumulus oophorus: the outer vestment of the mammalian egg consisting of hundreds of cells radiating out from the egg embedded within a non-Newtonian hyaluronic acid gel\ud Dynein: a molecular motor within the axoneme, attached between adjacent microtubule doublets, that exerts a shearing force to induce axonemal bending\ud Flagellum: a motile cellular appendage that drives the swimming of sperm and other cells; this article focuses on the eukaryotic flagellum\ud Microtubule doublet: a pair of proteinaceous filament structures running the length of the axoneme; dyneins drive their bending, which induces flagellar motion\ud Mid-piece: the region of a sperm flagellum with a mitochondrial sheath, where ATP is generated\ud Oocyte: the egg\ud Outer dense fibers and fibrous sheath: accessory structures reinforcing the mammalian sperm flagellum; the combined axoneme and accessory structures are referred to as 9+9+2\ud Resistive-force theory: an approximation for the local drag of a slender filament element in Stokes flow (or a viscoelastic generalization thereof)\ud Rheotaxis: directed motility in response to the influence of fluid flow\ud Shear: in the context of the flagellum, the relative movement of adjacent microtubule doublets\ud Slender-body theory: an improved approximation for the local drag on a slender filament element in Stokes flow (or a viscoelastic generalization thereof)\ud Zona pellucida: a tough glycoprotein coat between the human egg and the cumulus oophorus, which a sperm must penetrate for successful fertilizatio

Imaging the Haro 6-10 Infrared Companion

We present an infrared imaging study of the low-mass pre-main-sequence binary system Haro 6-10. This system is one of a handful in which the optically visible primary has the characteristics of a normal T Tauri star, while the secondary is a so-called "infrared companion" (IRC), a strongly extincted object that emits most of its luminosity in the infrared. A speckle holographic technique was used to produce nearly diffraction-limited images on three nights over a 1 yr period starting in late 1997. The images show that the IRC is obscured and surrounded by a compact, irregular, and variable nebula. This structure is in striking contrast to the well-ordered edge-on disk associated with HK Tauri B, the extincted companion to another T Tauri star of similar age. A new, resolved intensity peak was found 0".4 southwest of the IRC. We suggest that it may represent light scattered by a clump of dusty material illuminated by starlight escaping along an outflow-carved cavity in the IRC envelope. The primary star became fainter and the companion became more extended during the observing period

Irradiation Products On Dwarf Planet Makemake

The dark, reddish tinged surfaces of icy bodies in the outer solar system are usually attributed to the long term irradiation of simple hydrocarbons leading to the breaking of C–H bonds, loss of hydrogen, and the production of long carbon chains. While the simple hydrocarbon methane is stable and detected on the most massive bodies in the Kuiper Belt, evidence of active irradiation chemistry is scant except for the presence of ethane on methane-rich Makemake and the possible detections of ethane on more methane-poor Pluto and Quaoar. We have obtained deep high signal-to-noise spectra of Makemake from 1.4 to 2.5 μm in an attempt to trace the radiation chemistry in the outer solar system beyond the initial ethane formation. We present the first astrophysical detection of solid ethylene and evidence for acetylene and high-mass alkanes—all expected products of the continued irradiation of methane, and use these species to map the chemical pathway from methane to long-chain hydrocarbons