Phonon dispersions of fcc delta-plutonium-gallium by inelastic x-ray scattering

We report an experimental determination of the phonon dispersion curves in a face-centered cubic (fcc) delta-plutonium-0.6 weight % gallium alloy. Several unusual features, including a large elastic anisotropy, a small-shear elastic modulus C', a Kohn-like anomaly in the T1[011] branch, and a pronounced softening of the [111] transverse modes, are found. These features can be related to the phase transitions of plutonium and to strong coupling between the lattice structure and the 5f valence instabilities. Our results also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory calculations for delta-plutonium.     

NONHUMAN PRIMATE EXCRETORY UROGRAPHY*

Survey radiographs have not accurately identified renal contour or location in nonhuman primates. Excretory urography using 786 to 1193 mg iodinelkg body weight resulted in dense opacification of the renal parenchyma and pelvis. Abdominal compression improved visu- alization of the renal pelvis. Interpretation of the nonhuman primate excretory urogram was compromised by several anatomic characteristics of this animal group. Superimposition of the kidneys on the lateral radiograph limited evaluation of the renal contour. Since the renal pelvis in most species of nonhuman primates does not possess diverticula (as in the dog and cat) or a caliceal system (as in the pig and man), the diagnosis of pyelonephritis or renal mass lesions was difficult. Severe irregularities in the renal contour, size of the renal pelvis, or areas of deficient concentrating ability were identifiable in nonhuman primate excretory urograms, but the diagnosis of small cysts was not possible in smaller nonhuman primates. The presence of a caliceal collecting system in the spider monkey (Ateles sp.) suggests this animal as a potential model for the evaluation of human renal disease.     

Chemical cotton stalk destruction for maintenance of host-free periods for the control of overwintering boll weevil in tropical and subtropical climates

In the Lower Rio Grande Valley (LRGV) of Texas, cotton regrows and produces fruit from undestroyed stalks throughout the winter, and in spring weevils from such locations become a serious threat. The success of the boll weevil eradication program, which was reintroduced in the LRGV in 2005, will be dependent on thorough stalk destruction following harvest. However, adverse weather conditions and conservation tillage often impede immediate and complete stalk destruction using typical tool implements, and alternative stalk control methods are needed. This study provides an examination of the efficacy for cotton stalk destruction of different herbicides (thifensulfuron-methyl + tribenuron-methyl, dicamba-diolamine, 2,4-D-dimethylammonium, flumioxazin, 2,4-DB-dimethylammonium and carfentrazone-ethyl) and their rates, spray volumes and application timings on shredded or standing cotton stalks after stripper or picker harvest. None of the tested herbicides, except 2,4-D-dimethylammonium, stopped post-harvest cotton regrowth and fruiting. 2,4-D-dimethylammonium sprayed once (0 or 7 days) after cotton was harvested at 1 lb AE acre(-1) (1.12 kg ha(-1)), in a spray volume of 10 gal water acre(-1) (93.5 L ha(-1)) with 5 mL L(-1) surfactant, was highly effective in stalk destruction (72-90%). The best results were achieved when the herbicide was applied immediately after the cotton was shredded, followed by standing stripper-harvested and standing picker-harvested cotton. 2,4-D-dimethylammonium applied twice, 0 and 14 (or 21) days after cotton harvest, was 100% effective in killing stalks, regardless of whether they were shredded or standing, or whether harvest was by stripper or picker. These findings showed that 2,4-D-dimethylammonium cotton stalk destruction eliminated food and reproductive opportunities for managing overwintering boll weevils [Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae)].     

Characteristics of the urban forests in arctic and near-arctic cities

The urban forest of three arctic and near-arctic cities (Murmansk in Russia, Nuuk in Greenland, and Reykjavik in Iceland) were surveyed to determine tree species composition and structure. Interviews with local authorities were conducted to learn about the history of urban tree planting. The urban forests of all three cities were composed of a limited number of trees and tree species due to abiotic constraints of the arctic and near-arctic environment. These limitations include: low temperature, short growing season, high wind velocity and permafrost. A total of 28 species were observed in the three cities. Only three of these (Alnus incana (L.) Moench, Picea abies (L.) Karst., Betula pubescens Ehrh., and Salix glauca L.) were observed in all three of the cities. Planting designs that created windbreaks for pedestrians were common along streets in Murmansk and Reykjavik. Street trees have not yet been introduced in Nuuk, but trees were found in cemeteries, parks, and on private property. Older portions of cemeteries in all three cities were characterized by trees planted directly on graves. These grave trees were the first trees to be introduced in these cities. Subsequently, ‘trial and error’ was used by local residents to plant trees. Much of these plantings failed. In recent times arboreta were established near all three cities to identify species suited for planting under arctic and near-arctic conditions. Trees identified in these test gardens are now being planted in Murmansk and Reykjavik.     

Tail Muscle Free Amino Acid Concentration of Pacific White Shrimp,Litopenaeus vannamei,Fed Diets Containing Protein‐bound versus Crystalline Amino Acids

Tail muscle tissue free amino acids (FAA) concentration is reported for subadult (4.3 g) Litopenaeus vannamei fed diets containing only protein‐bound amino acids, crystalline lysine as a supplement to protein‐bound lysine, and only crystalline amino acids (CAA). FAA were determined in shrimp at 0.00, 0.25, 0.5, 1, 2, 4, and 8 h postfeeding. Highest total tissue concentrations of essential amino acids and individual amino acids were typically observed 4 h postfeeding for shrimp fed intact and crystalline lysine‐supplemented feeds. Those shrimp offered diets containing only CAA showed no tissue maxima. Similar uptake patterns for lysine shown by shrimp fed the intact and crystalline lysine‐supplemented diet indicate the potential use of small amounts of crystalline lysine in shrimp feeds.