Field Evaluations of Herbicides on Vegetable, Small Fruit, and Ornamental Crops, 2000, 2001, & 2002

Field evaluations of herbicides provide the chemical industry, governmental agencies, such as IR-4, and the Arkansas Agricultural Experiment Station with an evaluation of herbicide performance on small fruit, vegetable, and ornamental crops grown under Arkansas conditions. This report provides a means for disseminating information to interested private and public service weed scientists

COMBINED EFFECT OF LARGE CRABGRASS AND SMOOTH PIGWEED DENSITIES ON SNAP BEAN YIELD

COMBINED EFFECT OF LARGE CRABGRASS AND SMOOTH PIGWEED DENSITIES ON SNAP BEAN YIEL

Distance of Interference of Red Rice (Orya sativa) in Rice (O. sativa)

Three rice cultivars were grown to determine the distance at which red rice affects growth and grain yield. Red rice reduced grain yield of Lemont when rice plants grew within 71 and 53 cm of red rice in 1986 and 1988, respectively. Grain yield of Newbonnet was reduced when grown within 53 cm of red rice in both years. Grain yield of Tebonnet was reduced when grown within 53 and 36 cm of red rice in 1986 and 1988, respectively. Grain yield reduction in influenced areas averaged 35, 26 and 21% for Lemont, Newbonnet, and Tebonnet, respectively. As the distance increased at 10-cm increments from the red rice row, Lemont, Newbonnet, and Teboment grain yields increased 49 to 85, 32 to 40, and 24 to 33 g/m2, respectively. Rice straw dry weight was reduced when Lemont and Tebonnet were grown within71 and 36 cm of red rice in 1986 and 1988, respectively. Straw dry weight of Newbonnet was reduced when grown within 36 cm of red rice in both years. As the distance increased at 10-cm increments from the red rice row, Lemont, Newbonnet and Tebonnet straw biomass increased 22 to 46, 10 to 18, and 12 to 20 g/m2,respectively. Rice panicles/ m2 were reduced when Lemont, Newbonnet, and Tebonnet were grown within 36, 18, and 18 cm of red rice, respectively. Rice grains/panicle were reduced when rice was grown within 71, 71, and 36 cm of red rice for Lemont, Newbonnet, and Tebonnet, respectively

Field Evaluation of Herbicides on Small Fruit, Vegetable, and Ornamental Crops, 1999

Growers generally use herbicides to efficiently produce high-quality fruit and vegetables for processing or fresh market sales. Because of the smaller acreage of these crops compared with major field crops, fewer herbicides are registered for use in fruit and vegetable crops than for field crops. Each year, new herbicides are evaluated under Arkansas growing conditions with the objective of improving the herbicide technology for the grower, processor, and ultimately the consumer. This report includes studies on the control of many of the more serious weed problems in important crops of this region, including snapbeans, spinach and other greens, southernpeas, tomatoes, and grapes

Water Quality as Affected by Pesticides in Rice Production

Studies were conducted to determine the environmental persistence of the rice pesticides triclopyr, 2,4-D, benomyl and quinclorac. Triclopyr half-lives ranged from \u3c7 d to \u3e100 d depending on depth within the soil profile and clay content. Triclopyr persistence increased as depth within the profile increased and clay content increased. The benomyl metabolite MBC was present at greater than 50% of the initial amount after 9 months in the field. In simulated carryover field studies quinclorac exhibited the greatest potential for injury to subsequent rotational crops. Cotton and soybean growth was reduced when planted at four weeks after quinclorac application. The adsorption of triclopyr to three soils was measured by the batch equilibrium technique. Freundlich isotherms were linear and resulted in Kf values of 1.60, 1.41, and 2.75 for Crowley silt loam soil from depths of 0, 0.2, and 0.6 m, respectively, within soil profile. Soil thin-layer chromatography of triclopyr resulted in Rf values of 0.42, 0.69, and 0.40 for the Crowley silt loam soil from 0, 0.2, and 0.6 m depths. In controlled temperature and water potential degradation studies, triclopyr and 2,4-D degraded more rapidly at 3 0 C than at 15 C. The degradation rates of the two herbicides responded oppositely to water potential. 2,4-D degraded more rapidly under anaerobic conditions, whereas triclopyr degraded more rapidly under aerobic conditions

Spontaneous Isomerization of Long-Lived Proteins Provides a Molecular Mechanism for the Lysosomal Failure Observed in Alzheimer's Disease.

Proteinaceous aggregation is a well-known observable in Alzheimer's disease (AD), but failure and storage of lysosomal bodies within neurons is equally ubiquitous and actually precedes bulk accumulation of extracellular amyloid plaque. In fact, AD shares many similarities with certain lysosomal storage disorders though establishing a biochemical connection has proven difficult. Herein, we demonstrate that isomerization and epimerization, which are spontaneous chemical modifications that occur in long-lived proteins, prevent digestion by the proteases in the lysosome (namely, the cathepsins). For example, isomerization of aspartic acid into l-isoAsp prevents digestion of the N-terminal portion of Aβ by cathepsin L, one of the most aggressive lysosomal proteases. Similar results were obtained after examination of various target peptides with a full series of cathepsins, including endo-, amino-, and carboxy-peptidases. In all cases peptide fragments too long for transporter recognition or release from the lysosome persisted after treatment, providing a mechanism for eventual lysosomal storage and bridging the gap between AD and lysosomal storage disorders. Additional experiments with microglial cells confirmed that isomerization disrupts proteolysis in active lysosomes. These results are easily rationalized in terms of protease active sites, which are engineered to precisely orient the peptide backbone and cannot accommodate the backbone shift caused by isoaspartic acid or side chain dislocation resulting from epimerization. Although Aβ is known to be isomerized and epimerized in plaques present in AD brains, we further establish that the rates of modification for aspartic acid in positions 1 and 7 are fast and could accrue prior to plaque formation. Spontaneous chemistry can therefore provide modified substrates capable of inducing gradual lysosomal failure, which may play an important role in the cascade of events leading to the disrupted proteostasis, amyloid formation, and tauopathies associated with AD

Multilevel Deconstruction of the In Vivo Behavior of Looped DNA-Protein Complexes

Protein-DNA complexes with loops play a fundamental role in a wide variety of cellular processes, ranging from the regulation of DNA transcription to telomere maintenance. As ubiquitous as they are, their precise in vivo properties and their integration into the cellular function still remain largely unexplored. Here, we present a multilevel approach that efficiently connects in both directions molecular properties with cell physiology and use it to characterize the molecular properties of the looped DNA-lac repressor complex while functioning in vivo. The properties we uncover include the presence of two representative conformations of the complex, the stabilization of one conformation by DNA architectural proteins, and precise values of the underlying twisting elastic constants and bending free energies. Incorporation of all this molecular information into gene-regulation models reveals an unprecedented versatility of looped DNA-protein complexes at shaping the properties of gene expression.Comment: Open Access article available at http://www.plosone.org/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1371%2Fjournal.pone.000035

Esperanto for histones : CENP-A, not CenH3, is the centromeric histone H3 variant

The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres