RESOURCE QUALITY AND AGRICULTURAL PRODUCTIVITY: A MULTI-COUNTRY COMPARISON

This paper builds on earlier studies of agricultural productivity by incorporating spatially referenced soil and climate data combined with high-resolution land-cover data. Econometric analysis of these data, along with panel data on agricultural inputs and outputs from 110 countries for 1961-1997, quantifies the significant impact that differences in land quality have on agricultural productivity.Productivity Analysis,

Eliminating Fruit and Vegetable Planting Restrictions: How Would Markets Be Affected?

Eighty-nine percent of American households were food secure throughout the entire year in 2005, meaning that they had access, at all times, to enough food for an active, healthy life for all household members. The remaining households were food insecure at least some time during that year. The prevalence of food insecurity declined from 11.9 percent of households in 2004 to 11.0 percent in 2005, while the prevalence of very low food security remained unchanged at 3.9 percent. This report, based on data from the December 2005 food security survey, provides the most recent statistics on the food security of U.S. households, as well as on how much they spent for food and the extent to which food-insecure households participated in Federal and community food assistance programs. Survey responses indicate that the typical food-secure household in the U.S. spent 34 percent more on food than the typical food-insecure household of the same size and household composition. Just over one-half of all food-insecure households participated in one or more of the three largest Federal food assistance programs during the month prior to the survey. About 22 percent of food-insecure households—3.5 percent of all U.S. households—obtained emergency food from a food pantry at some time during the year.Food security, food insecurity, food spending, food pantry, hunger, soup kitchen, emergency kitchen, material well-being, Food Stamp Program, National School, Crop Production/Industries,

Ionic composition of endolymph and perilymph in the inner ear of the oyster toadfish, Opsanus tau

Author Posting. © Marine Biological Laboratory, 2008. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 214 (2008): 83-90.The concentrations of free Na+, K+, Ca2+, and Cl-in endolymph and perilymph from the inner ear of the oyster toadfish, Opsanus tau, were measured in vivo using double-barreled ion-selective electrodes. Perilymph concentrations were similar to those measured in other species, while endolymph concentrations were similar to those measured previously in elasmobranch fish, though significantly different from concentrations reported in mammals. Perilymph concentrations (mean ± std. dev.) were as follows: Na+, 129 mmol l-1 ± 20; K+, 4.96 mmol l-1 ± 2.67; Ca2+, 1.83 mmol l-1 ± 0.27; and Cl-, 171 mmol l-1 ± 20. Saccular endolymph concentrations were Na+, 166 mmol l-1 ± 22; K+, 51.4 mmol l-1 ± 16.7; Ca2+, 2.88 mmol l-1 ± 0.27; and Cl-, 170 mmol l-1 ± 12; and semicircular canal (utricular vestibule) endolymph concentrations were Na+, 122 mmol l-1 ± 15; K+, 47.7 mmol l-1 ± 13.2; Ca2+, 1.78 mmol l-1 ± 0.48; Cl-, 176 mmol l-1 ± 27. The relatively high concentrations of Ca2+ and Na+ in the endolymph may have significant implications for the physiological function of the mechanoelectrical transduction channels in the vestibular hair cells of fish compared to those of their mammalian counterparts.This work was supported by the National Institute of Deafness and Other Communications Disorders P01 DC01837, R01 DC06685, R01 DC04928, NASA NNA-04CK67H, and NSF Igert DGE9987616

MANURE MANAGEMENT FOR WATER QUALITY COSTS TO ANIMAL FEEDING OPERATIONS OF APPLYING MANURE NUTRIENTS TO LAND

Nutrients from livestock and poultry manure are key sources of water pollution. Ever-growing numbers of animals per farm and per acre have increased the risk of water pollution. New Clean Water Act regulations compel the largest confined animal producers to meet nutrient application standards when applying manure to the land, and USDA encourages all animal feeding operations to do the same. The additional costs for managing manure (such as hauling manure off the farm) have implications for feedgrain producers and consumers as well. This report's farm-level analysis examines on-farm technical choice and producer costs across major U.S. production areas for hauling manure to the minimum amount of land needed to assimilate manure nutrients. A regional analysis then focuses on off-farm competition for land to spread surplus manure, using the Chesapeake Bay region as a case study. Finally, a sectorwide analysis addresses potential long-term structural adjustments at the national level and ultimate costs to consumers and producers.manure management costs, price and quantity adjustments, water quality, animal waste, manure nutrients, excess nutrients, confined animals, CAFO, manure nitrogen, manure phosphorus, manure use, assimilative capacity, nutrient management plan, Environmental Economics and Policy, Livestock Production/Industries,

Quasi-chemical study of Be2+^{2+}(aq) speciation

Be$^{2+}$(aq) hydrolysis can to lead to the formation of multi-beryllium clusters, but the thermodynamics of this process has not been resolved theoretically. We study the hydration state of an isolated Be$^{2+}$ ion using both the quasi-chemical theory of solutions and ab initio molecular dynamics. These studies confirm that Be$^{2+}$(aq) is tetra-hydrated. The quasi-chemical approach is then applied to then the deprotonation of Be(H_2O)_4^{2+}} to give BeOH(H_2O)_3{}^{+}}. The calculated pK$_a$ of 3.8 is in good agreement with the experimentally suggested value around 3.5. The calculated energetics for the formation of BeOHBe$^{3+}$ are then obtained in fair agreement with experiments.Comment: 11 pages, 3 figure

Observation of individual molecules trapped on a nanostructured insulator

For the first time, ordered polar molecules confined in monolayer-deep rectangular pits produced on an alkali halide surface by electron irradiation have been resolved at room temperature by non-contact atomic force microscopy. Molecules self-assemble in a specific fashion inside pits of width smaller than 15 nm. By contrast no ordered aggregates of molecules are observed on flat terraces. Conclusions regarding nucleation and ordering mechanisms are drawn. Trapping in pits as small as 2 nm opens a route to address single molecules

Near-Earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations.

Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeVelectron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L ∼ 5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ∼40 s and a dispersionless injection of electrons up to ∼3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front. Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons

Large Amplitude Whistler Waves and Electron Acceleration in the Earth's Radiation Belts: A Review of STEREO and Wind Observations

One of the critical problems for understanding the dynamics of Earth's radiation belts is determining the physical processes that energize and scatter relativistic electrons. We review measurements from the Wind/Waves and STEREO S/Waves waveform capture instruments of large amplitude whistler-mode waves. These observations have provided strong evidence that large amplitude (100s mV/m) whistler-mode waves are common during magnetically active periods. The large amplitude whistlers have characteristics that are different from typical chorus. They are usually nondispersive and obliquely propagating, with a large longitudinal electric field and significant parallel electric field. We will also review comparisons of STEREO and Wind wave observations with SAMPEX observations of electron microbursts. Simulations show that the waves can result in energization by many MeV and/or scattering by large angles during a single wave packet encounter due to coherent, nonlinear processes including trapping. The experimental observations combined with simulations suggest that quasilinear theoretical models of electron energization and scattering via small-amplitude waves, with timescales of hours to days, may be inadequate for understanding radiation belt dynamics