"Candidatus phytoplasma australiense," a new phytoplasma taxon associated with Australian grapevine yellows

A phytoplasma was detected in naturally diseased 'Chardonnay' grapevines exhibiting symptoms of Australian grapevine yellows disease. The use of PCR designed to amplify phytoplasma DNA resulted in detection of phytoplasma DNA in all of the diseased plants examined; no phytoplasma DNA was detected in healthy seedling grapevines. The collective restriction fragment length polymorphism (RFLP) patterns of amplified 16S ribosomal DNA differed from the patterns described previously for other phytoplamas. On the basis of the RFLP patterns, Australian grapevine yellows phytoplasma was classified as a representative of a new subgroup, designated subgroup 16SrI-J, in phytoplasma 16S rRNA group 16SrI (aster yellows and related phytoplasmas). A phylogenetic analysis in which parsimony of 16S rRNA gene sequences from this and other group 16SrI phytoplasmas was used identified the Australian grapevine yellows phytoplasma as a member of a distinct subclade (subclade xii) in the phytoplasma clade of the class Mollicutes. A phylogenetic tree constructed on the basis of 16S rRNA gene sequences was consistent with the hypothesis that there was divergent evolution of Australian grapevine yellows phytoplasma and its closet known relative, European stolbur phytoplasma (subgroup 16SrI-G), from a common ancestor. The unique properties of the DNA from the Australian grapevine yellows phytoplasma clearly establish that it represents a new taxon, "Candidatus Phytoplasma australiense."     

Trends in Mysis diluviana abundance in the Great Lakes, 2006–2016

With the large Diporeia declines in lakes Michigan, Huron, and Ontario, there is concern that a similar decline of Mysis diluviana related to oligotrophication and increased fish predation may occur. Mysis density and biomass were assessed from 2006 to 2016 using samples collected by the Great Lakes National Program Office's biomonitoring program in April and August in all five Great Lakes. Summer densities and biomasses were generally greater than spring values and both increased with bottom depth. There were no significant time trends during these 10–11 years in lakes Ontario, Michigan, or Huron, but there was a significant increase in Lake Superior. Density and biomass were highest in lakes Ontario and Superior, somewhat lower in Lake Michigan, and substantially lower in Lake Huron. A few Mysis were collected in eastern Lake Erie, indicating a small population in the deep basin of that lake. On average, mysids contributed 12–18% (spring-summer, Michigan), 18–14% (spring-summer, Superior), 30–13% (spring-summer, Ontario), and 3% (Huron) of the total open-water crustacean biomass. Size distributions consisted of two peaks, indicating a 2-year life cycle in all four of the deep lakes. Mysis were larger in Lake Ontario than in lakes Michigan, Superior, and Huron. Comparisons with available historic data indicated that mysid densities were higher in the 1960s–1990s (5 times higher in Huron, 2 times higher in Ontario, and around 40% higher in Michigan and Superior) than in 2006–2016.     

Patterns of long-term dynamics of aquatic communities and water quality parameters in the Great Lakes: Are they synchronized?

Long time series data can provide insights into dynamics of large lakes. We use the USEPA-GLNPO biological monitoring dataset (phytoplankton, benthos, zooplankton and water quality), collected from 1996 through 2016, to identify whether there is evidence of concordant linear or non-linear trends in community composition, density/biomass/biovolume and major environmental parameters. We show changes in biotic assemblages and water quality variables, particularly in Lakes Michigan and Huron. These include changes in phytoplankton biovolume and zooplankton biomass, increasing invasive Dreissena abundance and decreasing densities of other benthos. Biotic changes are accompanied by pronounced changes in water quality and nutrient ratios. Species change-points, identified using threshold indicator taxon analysis, are often less abrupt, but there are clear shifts in a large proportion of species in each assemblage. The concordance of breakpoints among assemblages or lack thereof provides valuable insight into potential drivers of ecosystem change.     

Ozonation of swine manure wastes to control odors and reduce the concentrations of pathogens and toxic fermentation metabolites

The use of ozone for the remediation of nuisance odorous chemicals in liquid swine manure slurry was investigated. Gaseous ozone was bubbled directly into stored swine manure slurry in a continuously stirred batch reactor. One‐liter samples of swine slurry were ozonated to achieve ozone dosages of 1.0, 2.0 and 3.0 g ozone/liter of waste. Olfactometric determinations demonstrated a significant reduction in odors in ozonated samples as compared to raw and oxygenated samples. Volatile fatty acids, nitrate, phosphate and ammonia concentrations were unchanged by ozonation. The biochemical oxygen demand (BOD) and the chemical oxygen demand (COD) were essentially unaffected by ozonation. The concentrations of odorous phenolic microbial metabolites (e.g., phenol, p‐cresol and p‐ethylphenol) and odorous indolic microbial metabolites (e.g., 3‐methylindole and indole) were reduced to non‐detectable levels by ozonation. Hydrogen sulfide concentrations were reduced slightly by the process, with a concurrent increase in the sulfate concentration. E. coli counts were reduced by a factor of three log units and total coliforms showed a one log decrease in concentration after treatment with ozone at 1.0 g/L.

The results of this study demonstrate clearly that at the pH values studied (ca. 7), ozonation is effective for the elimination of the malodors associated with stored swine slurry and for killing potentially pathogenic bacteria, without increasing the concentrations of major pollutants of current concern, (i.e., nitrate and phosphate) and without oxidizing ammonia, which is a major plant nutrient.     

Microdissection of peripheral nerve: collagen and lipid distribution with morphological correlation

Peripheral nerve is a complex tissue composed of endoneurial fascicles surrounded by perineurium and epineurium. We separated endoneurium from peri- and epineurium in human sural nerves by "endoneurial plucking", a method of microdissection. Endoneurial contents (axons, myelin sheaths, Schwann cells, vessels, and interstitial collagen) were cleanly separated in high yield from enveloping connective tissue, by both microscopic and biochemical criteria. Most of the nerve sulfatide and unesterified sterol was found in the endoneurial fraction while most of the collagen was in the peri-epineurial fraction. This microdissection method should prove useful in biochemical investigations of peripheral nerve.     

Deposits on the surface of intraocular lenses: a pathologic study

The clinical course of implanted intraocular lenses is frequently complicated by the formation of deposits or "precipitates" on the lens surfaces. These lesions are related to the amount of inflammation in the eye, the use of pilocarpine, and the presence of lens cortex in extracapsular procedures. Corticosteroids cause the lesions to diminish or disappear. Similar lesions seen in the course of lens implantation in laboratory animals are found on histologic examination to be accumulations of inflammatory cells. In the chronic state the cells are macrophages, epithelioid cells, and giant cells, accompanied in the early stages by acute inflammatory leukocytes. The relationships between these cells, inflammation, the presence of the foreign body, and the chemistry of methacrylate are difficult to sort out.     

Effect of Shear Stress on Sintering

The effect of small uniaxial stresses on the sintering of CdO powder compacts was studied using a loading dilatometer. Compacts of two different green densities were sintered at 1123 K and subjected to stresses between 0 and 0.25 MPa. Densification and creep occur simultaneously, and the effects of these two processes can be separated. Between relative densities of 0.5 and 0.9, the dependence of the uniaxial creep rate on density can be described in terms of a stress intensification factor which depends exponentially on the porosity but is independent of the grain size. Comparison of the densification and creep rates permits definition of the sintering stress, which is found to decrease with increasing density, and verification of the Zener relation. The stress and grain size dependence of the creep rate, and the grain size dependence of the densification rate, support grain-boundary diffusion as the rate-controlling step in both processes.     

Mullite Development from Fibrous Kaolin Mineral

The development of mullite from kaolin minerals was studied using transmission electron microscopy and X-ray powder diffraction methods on the unusual long-fibered kaolin from Piedade, Sao Paulo, Brazil. The mullite crystals observed at ≥ 1200°C initially exhibited an elliptical shape and were randomly oriented inside the tubes; at 1250°C their shape changed to laths oriented either parallel to the tube length or at 120° to the adjacent lath. At 1300°C, the shape changed to a bipointed lath and the crystals developed a hexagonal configuration with preferred orientation at 120°, similar to mullite developed from kaolinite plates. Thus, the temperature at which mullite begins to develop from this tubular kaolin is ∼200°C above that normally observed in well-crystallized kaolinites and is 100°C above b axis disordered kaolinite. Cristobalite was not observed in the electron microscope in the range 1000° to 1300°C.     

核电循环冷却水一氯胺反应动力学规律

核电站循环冷却水系统的消毒是核电水系统的研究重点．以法国丹皮尔核电站冷却塔模型为研究对象,进行一氯胺消毒剂的消耗动力学研究,确定以天然原水为循环水介质的一氯胺消耗动力学符合一级反应的动力学模型,其反应速率常数为0．002min^-1;以人工模拟投加Fe^3＋进行一氯胺消耗分析表明,Fe^3＋对一氯胺的消耗无显著影响．     

Incorporation of La3+ into a Pt/CeO2/Al2O3 catalyst

The effects of La³⁺ incorporation into a Pt/CeO₂/Al₂O₃ catalyst were investigated by a combination of activity, temperature-programmed reduction (TPR), oxygen storage capacity (OSC), noble-metal surface area, and X-ray diffraction (XRD) measurements. Incorporation of La³⁺ ions into the Al₂O₃, before CeO₂ is added, promoted higher Pt and CeO₂ dispersions. The oxygen storage capacity was also higher in the presence of La³⁺. This is attributed to a combination of Pt and CeO₂ particle-size effects and possible blockage of the reaction between Al₂O₃ and CeO₂. The XRD data show that La³⁺ forms LaAlO₃ with Al₂O₃ and prevents -Al₂O₃ formation after various heat treatments.