Manipulation of the Sediment-Water Interface of Extremely Acidic Mining Lakes with Potatoes: Laboratory Studies with Intact Sediment Cores

The water of flooded, abandoned, open-cast pits (Tagebauseen) in the Lusatia region of eastern Germany is characterised by a high acidity (Fe3+/H+), low pH (2.5-3.5) and low concentrations of dissolved phosphorus (SRP) and carbon (DIC). Investigations are investigating the use of amendments to assist in removal of acidity from Tagebauseen through controlled eutrophication. A simple system has been developed to investigate the effects of amendments on water chemistry around the sediment-water interface. Intact, little-disturbed sediment cores (diameter 5.5 cm) with overlying water (total volume 1.5 1) from one Tagebausee (Koschen: pH 3.1, Fe 15-20 mg/l) have been incubated at low temperature (6-10 °C) to investigate the effects of organic amendments (potato) on the concentrations of some major ions in the system. In particular, the dynamics of Fe, P, N and C over time in the presence or absence of organic amendment (potato) have been investigated. Addition of potatoes results in the rising of a sharp pH gradient from near the sediment surface, and an overall increase in dissolved Fe, P and C in the system. The Fe eventually precipitated as black particulates but the SRP remained in solution. Intact sediment cores provide a useful tool for studying changes in water column and sediment pore water chemistry and the potential effects of amendments on the sediments of Tagebauseen.     

Plasma diagnosis from thermal noise and limits on dust flux or mass in comet giacobini-zinner

Thermal noise spectroscopy was used to measure the density and temperature of the main (cold) electron plasma population during 2 hours (1.5x10(5) kilometers perpendicular to the tail axis) around the point of closest approach of the International Cometary Explorer (ICE) to Comet Giacobini-Zinner. The time resolution was 18 seconds (370 kilometers) in the plasma tail and 54 seconds (1100 kilometers) elsewhere. Near the tail axis, the maximum plasma density was 670 per cubic centimeter and the temperature slightly above 1 electron volt. Away from the axis, the plasma density dropped to 100 per cubic centimeter (temperature, 2x 10(4) K) over 2000 kilometers, then decreased to 10 (1.5x 10(5)K) over 15,000 kilometers; outside that region (plasma tail), the density fluctuated between 10 and 30 per cubic centimeter and the temperature between 1x 10(5) and 4 x10(5) K. The relative density of the hot population rarely exceeded a few percent. The tail was highly asymmetrical and showed much structure. On the other antenna, shot noise was recorded from the plasma particle impacts on the spacecraft body. No evidence was found of grain impacts on the antennas or spacecraft in the plasma tail. This yields an upper limit for the dust flux or particle mass, indicating either fluxes or masses in the tail smaller than implied by the models or an anomalous grain structure. This seems to support earlier suggestions that these grains are featherlike. Outside the tail, and particularly near 10(5) kilometers from its axis, impulsive noises indicating plasma turbulence were observed.     

Primary glossal squamous-cell carcinoma in a Spanish Cochin hen

A primary glossal squamous-cell carcinoma was diagnosed in an adult Spanish Cochin hen. Grossly, there was locally extensive ulceration of the tongue. Histologically, the submucosa was diffusely infiltrated by islands, nests, and fronds of variably differentiated squamous epithelial cells. Neoplastic cells extended into the underlying muscular layer and stimulated intense scirrhous and inflammatory reactions.     

Use of anti-coronavirus antibody testing of cerebrospinal fluid for diagnosis of feline infectious peritonitis involving the central nervous system in cats

OBJECTIVE: To assess the use of measuring anti-coronavirus IgG in CSF for the diagnosis of feline infectious peritonitis (FIP) involving the CNS in cats. DESIGN: Prospective study. SAMPLE POPULATION: CSF and serum samples from 67 cats. PROCEDURES: CSF and serum samples were allocated into 4 groups: cats with FIP involving the CNS (n = 10), cats with FIP not involving the CNS (13), cats with CNS disorders caused by diseases other than FIP (29), and cats with diseases other than FIP and not involving the CNS (15). Cerebrospinal fluid was evaluated for concentrations of erythrocytes, leukocytes, and total protein. Anti-coronavirus IgG was measured in CSF and serum by indirect immunofluorescence assay. RESULTS: CSF IgG (range of titers, 1:32 to 1:4,096) was detected in 12 cats, including 6 cats with neurologic manifestation of FIP, 4 cats with FIP not involving the CNS, and 2 cats with brain tumors. Cerebrospinal fluid IgG was detected only in cats with correspondingly high serum IgG titers (range, 1:4,096 to 1:16,384) and was positively correlated with serum IgG titers (r = 0.652; P < 0.01), but not with any other CSF parameter. Blood contamination of CSF resulted in < or = 333 erythrocytes/microL in cats with CSF IgG. CONCLUSIONS AND CLINICAL RELEVANCE: The correlation between serum and CSF IgG and the fact that CSF IgG was detected only in strongly seropositive cats suggested that CSF anti-coronavirus IgG was derived from blood. Measurement of anti-coronavirus IgG in CSF was of equivocal clinical use.     

Populations of Nonpathogenic Fusarium oxysporum Associated with Roots of Four Plant Species Compared to Soilborne Populations

ABSTRACT The effect of the plant on the diversity of soilborne populations of Fusarium oxysporum was assessed after successive cultures of flax, melon, tomato, and wheat in separate samples of the same soil. Forty soil-borne isolates of F. oxysporum and forty root-colonizing isolates of each plant species were sampled during the first (T0) and fourth (T1) cultures. The population structures were assessed by a genotypic method based on restriction fragment analysis of polymerase chain reaction-amplified ri-bosomal intergenic spacer (IGS) DNA. Sixteen IGS types were defined among the four hundred isolates analyzed. The distributions of soil isolates among IGS types were similar at both sampling times. The structure of F. oxysporum populations associated with the roots of flax or melon did not differ from the structure of soilborne populations. In contrast, the structure of F. oxysporum populations associated with roots of wheat or tomato differed from the structure of soilborne populations. High frequencies were found for IGS type 4 among wheat isolates at both T0 and T1 and for IGS type 11 among tomato isolates at T1. Moreover, a high level of genetic divergence was obtained between IGS types 4 and 11. Our results suggest that tomato and wheat have a selective effect on soilborne populations of F. oxysporum and that this effect seems to be plant specific.     

Fungal-based bioherbicides for weed control: a myth or a reality?

The use of bioherbicides containing fungal active ingredients or natural fungal molecules is one of the possible solutions to reduce the use of chemical products. This paper focuses on studies of bioherbicides, including both living fungi and natural fungal molecules, published in the last 45 years, and their associated weed targets; current problems in the development of bioherbicides are also discussed. Bibliometric methods based on the Web of Science database were used to analyse relevant articles published between 1973 and 2018. Overall analysis suggested that interest in bioherbicides extends over the preceding thirty years, when many potential microorganisms and natural fungal molecules were proposed. Furthermore, analysis of about 229 articles indicated an encouraging exploitable potential, although there is a real gap between the number of experimental studies and the small number of products currently on the market. A dozen fungal-based bioherbicides are on the market in the United States and Canada, while countries, such as China and South Africa, have one, and none is available in Europe. The active ingredients in these bioherbicides are living fungi, but no fungal molecule-based product is thus far on the market. Reasons for this gap include production hurdles, formulation process, ecological fitness, duration of herbicidal effects, and costly and time-consuming registration procedures. However, it is clear that analysis of fungus–plant interactions provides a promising source of bioherbicides that may be applied to appropriate cropping systems for environment-friendly, sustainable weed control.     

Isolation and characterization of nonpathogenic Fusarium oxysporum isolates from the rhizosphere of healthy banana plants

One of the most serious diseases of banana is fusarium wilt, caused by Fusarium oxysporum f.sp. cubense ( Foc ). The objectives of this study were to isolate and identify nonpathogenic F. oxysporum strains from soils suppressive to banana wilt, and to determine the diversity of these isolates. More than 100 Fusarium strains were isolated from the rhizosphere of banana plants and identified to species level. Pathogenicity testing was carried out to confirm that these isolates were nonpathogens of banana. A PCR-based RFLP analysis of the intergenic spacer region of the ribosomal RNA operon was used to characterize the nonpathogens. The isolates were also compared with isolates of Foc from South Africa and the known biological control isolate of F. oxysporum , Fo47. The species-specific primers FOF1 and FOR1, in addition to morphological features, were used to confirm the identity of F. oxysporum isolates included in the PCR-RFLP analysis. Twelve different genotypes could be distinguished, identified by a six-letter code allocated to each isolate following digestion with the restriction enzymes Hae III, Hha I, Hin fI, Msp I, Rsa I and Scrf I. Eleven of these included nonpathogenic F. oxysporum isolates, and these groups could all be distinguished from the genotype that included Foc . Fo47 was included in one of the genotype groups consisting of nonpathogenic F. oxysporum isolates from South Africa.