Studies on controlled potassium fertilizers

Three K silicates having SiO₂/K₂O ratios of 4, 5, and 6 were compared with single and split applications of KCI, (KPO₃)n, and sulfur-coated KCI (SCK-34) for their availability to four cuttings of common bermudagrass. At the rate of 200 mg of K/pot, all silicates applied in fine particles gave the same pattern of yield and K uptake as readily soluble KCl; however, less response to these finely sized K silicates at applications from 200 to 500 mg of K/pot suggests that they supply K more slowly than do soluble sources. K₂O.6SiO₂, when granulated in the size of 0.41-1.2 or 1.65-2.36 rom gave typical yieiJ and K uptake patterns of slowrelease sources similar to those for SCK-34 at both rates of application. (KPO₃) ⁿ supplied K in the same pattern as KCl and no effect of granulation was observed. A better balanced K supply through the whole period and the production of forage of more stable mineral composition is expected by the use of these slow-release K sources.     

Ecoenzymes as Indicators of Compost to Suppress Rhizoctonia Solani

Reports of disease suppression by compost are inconsistent likely because there are no established standards for feedstock material, maturity age for application, and application rate. The overall goal of the study was to evaluate a suite of biological indicators for their ability to predict disease suppression. Indicators included both commercial available methods for compost stability (Solvita?, respiration) and metrics of soil ecology not yet adopted by the compost industry (e.g., ecoenzymes, nematode community index). Damping-off by Rhizoctonia solani on radish was chosen as a model system given its global importance, competitiveness affected by carbon quality, and lack of disease management options for organic production. Biological indicators were evaluated for their ability to consistently differentiate among curing process, maturity, and feedstock material as a function of disease severity of a seedling bioassay and a compost extract assay to test competition with R. solani growth. Compost processed as vermicompost and anaerobic digestate were more suppressive against R. solani than windrow or aerated static pile. Mature composts were more suppressive than immature components. Feedstocks containing dairy manure and/or hardwood bark tended to have suppressive qualities. In contrast, poultry manure-based components were conducive to disease. Microbial ecoenzymes active on chitin and cellulose and nematode community indices were better predictors of disease suppressiveness than microbial respiration. These indicators are quicker than plant bioassays and could be adopted as tools to certify commercial products.     

Cell-assisted growth of a fastidious spiroplasma

The Colorado potato beetle spiroplasma, which is not cultivable in conventional cell-free media, grew in tissue culture media in the presence of several coleopteran and lepidopteran insect cell lines. The cultured organisms attained titers of 1.2 x 10(9) spiroplasmas per milliliter of culture at the 100th passage and retained infectivity and a high capacity for translational motility at the 15th passage. Cell culture systems may facilitate the isolation of other presently uncultivable microorganisms and may be useful in the study of the role of microbial physiology and behavior in pathogenicity.     

Massive CO₂ ice deposits sequestered in the south polar layered deposits of Mars

Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO(2)) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO(2) volatile release. If released into the atmosphere at times of high obliquity, the CO(2) reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling.     

Japanese research and technology policy

Until recently the Japanese did not spend much on research and what they did spend was concentrated on the commercial development of technology. As a result there have so far been few Japanese breakthroughs in either science or technology. Dramatic changes have recently occurred, however, and Japan now trails only the United States and the Soviet Union in research spending. Beyond this, Japanese policy-makers are making a determined effort to overcome Japan's social and institutional barriers to scientific creativity.     

A mutation in the TRPC6 cation channel causes familial focal segmental glomerulosclerosis

Focal and segmental glomerulosclerosis (FSGS) is a kidney disorder of unknown etiology, and up to 20% of patients on dialysis have been diagnosed with it. Here we show that a large family with hereditary FSGS carries a missense mutation in the TRPC6 gene on chromosome 11q, encoding the ion-channel protein transient receptor potential cation channel 6 (TRPC6). The proline-to-glutamine substitution at position 112, which occurs in a highly conserved region of the protein, enhances TRPC6-mediated calcium signals in response to agonists such as angiotensin II and appears to alter the intracellular distribution of TRPC6 protein. Previous work has emphasized the importance of cytoskeletal and structural proteins in proteinuric kidney diseases. Our findings suggest an alternative mechanism for the pathogenesis of glomerular disease.     

An overview of potentially life-threatening poisonous plants in dogs and cats

Objectives: This article discusses the toxicity of the most common poisonous plants known to cause life‐threatening systemic effects or death in dogs and cats as reported to the ASPCA Animal Poison Control Center (APCC). Data sources: The article presents an overview of geographic distribution, toxic principle, clinical signs, clinical chemistry alterations, and treatment of intoxication as reported in the literature and based upon data retrieved from the APCC between January 2001 and December 2003. Summary: Most plant exposures in dogs or cats result in mild to moderate signs of vomiting and diarrhea while liver, kidney, central nervous system, or cardiovascular effects are rare. Some garden or household plants can cause serious systemic effects or death when a small amount of plant material has been ingested. Based on APCC records, the most frequently reported poisonous plants causing serious systemic effects include Lily (Lilium and Hemerocallis spp.), Azalea (Rhododendron spp.), Oleander (Nerium oleander), Sago palm (Cycas spp.), Castor bean (Ricinus communis), Kalanchoe (Kalanchoe spp.), and Autumn Crocus (Colchicum autumnale). Conclusion: Despite the variety of toxins present in the plants listed above, early clinical signs of toxicosis in dogs and cats can be nonspecific and can include vomiting, lethargy, anorexia, salivation, or diarrhea. Cardiac arrhythmias may be present with oleander, azalea, or kalanchoe ingestion. Evidence of liver or kidney damage (Cycas, Lilium, Hemerocallis spp., Ricinus communis) may occur 1–2 days after the exposure. Treatment consists of early decontamination and supportive care and may vary according to the type of plant involved and clinical signs present.     

Shoot growth,plant tissue elemental composition,and soil salinity following irrigation of alfalfa and tall fescue with high‐sulfate waters 1

Groundwater contaminated with sulfate (SO₄ ^2‐) at concentrations higher than allowable for drinking water might still be usable for irrigation. Objectives were to determine the growth response and mineral uptake of two forage crops irrigated with waters containing SO₄ ^2‐ at concentrations ranging from 175 to 1743 mg/L, and with electrical conductivities (EC) ranging from 1.2 to 3.6 dS/m. Plants were grown for 12 weeks in 8‐L pots containing a calcareous sandy loam and were harvested at 4, 8, or 12 weeks for plant growth measurements and tissue analysis. Digested leaves, stems, and reproductive tissues were analyzed by inductively coupled plasma (ICP) spectroscopy at each harvest, as were saturated soil paste extracts. Shoot growth of tall fescue (Festuca arundinacea Schreb.) was not affected by irrigation water treatment, whereas shoot growth of alfalfa (Medicago sativa L.) was increased by a moderate level of soil solution SO₄ ^2‐ Sulfur (S), boron (B), magnesium (Mg), sodium (Na), and zinc (Zn) concentrations in shoot tissues of both species showed a tendency to increase with increasing SO₄ ^2‐ content of irrigation water. Shoot tissue concentration of molybdenum (Mo) increased with maturation in both species, while the concentrations of B, potassium (K), manganese (Mn), Na, and Zn decreased. Soil saturated paste extract concentrations of Mg and Na increased with irrigation water Mg and Na concentrations, while Ca and S concentrations in the soil solution became saturated at the higher irrigation water concentrations of these elements.