scholarly journals Crop-associated virus infection in a native perennial grass: reduction in plant fitness and dynamic patterns of virus detection

2017 ◽  
Vol 105 (4) ◽  
pp. 1021-1031 ◽  
Author(s):  
Helen M. Alexander ◽  
Emily Bruns ◽  
Hayley Schebor ◽  
Carolyn M. Malmstrom
Keyword(s):  
Virus Infection ◽  
Perennial Grass ◽  
Virus Detection ◽  
Plant Fitness ◽  
Dynamic Patterns ◽  
Native Perennial Grass

Atypical Bacterial Infections Explained by a Concomitant Virus Infection

PEDIATRICS ◽  
1985 ◽  
Vol 76 (3) ◽  
pp. 411-414
Author(s):  
Ron Dagan ◽  
Caroline B. Hall ◽  
Marilyn A. Menegus
Keyword(s):  
Early Childhood ◽  
Virus Infection ◽  
Bacterial Infection ◽  
Clinical Manifestation ◽  
Bacterial Infections ◽  
Recent Progress ◽  
Clinical Presentation ◽  
Virus Detection ◽  
Dual Infection ◽  
Dual Infections

Because both viral and bacterial infections are common during early childhood, dual infections are not unexpected. However, the clinical manifestation of such combined infections may be, difficult to interpret, and they are often misdiagnosed as "atypical bacterial infection." Five patients with concomitant viral-bacterial infections are described. In all five cases, virus detection enabled the physicians to better understand an otherwise puzzling clinical presentation. In view of the recent progress in rapid viral diagnoses and the potential of antiviral drugs, the possibility of dual infection should be investigated more often.

Indirect effects of an invasive annual grass on seed fates of two native perennial grass species

Oecologia ◽  
2014 ◽  
Vol 174 (4) ◽  
pp. 1401-1413 ◽  
Author(s):  
Susan E. Meyer ◽  
Katherine T. Merrill ◽  
Phil S. Allen ◽  
Julie Beckstead ◽  
Anna S. Norte
Keyword(s):  
Indirect Effects ◽  
Perennial Grass ◽  
Grass Species ◽  
Annual Grass ◽  
Seed Fates ◽  
Native Perennial Grass

Correlations between environmental factors, the biomass of exotic annual grasses and the frequency of native perennial grasses

2006 ◽  
Vol 54 (7) ◽  
pp. 655 ◽  
Author(s):  
Tanja I. Lenz ◽  
José M. Facelli
Keyword(s):  
Species Composition ◽  
Soil Fertility ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Annual Rainfall ◽  
Grass Species ◽  
Soil Factors ◽  
Annual Grasses ◽  
Exotic Annual Grasses ◽  
Native Perennial Grass

The species composition of temperate grasslands in the mid-north of South Australia has been radically altered from a system dominated by native perennial grasses to a system dominated by Mediterranean annual grasses. This study investigated the importance of chemical and physical soil characteristics, topographical features and climatic variables on the abundance of native and exotic grass species in nine ungrazed grasslands. Overall, climatic and other abiotic factors were highly variable. In addition, past management practices and original species composition are generally unknown, leading to further unexplained variation in the data. On a large spatial scale (among sites), the abundance of exotic annual grasses was positively correlated with mean annual rainfall, and on any scale, with finer soil textures and higher soil organic carbon levels. The most abundant annual grass, Avena barbata (Pott ex Link), was generally associated with soil factors denoting higher soil fertility. The abundance of native perennial grass species was not correlated with any environmental variables at any scale. The various native perennial grass species did not show clear associations with soil factors, although they tended to be associated with factors denoting lower soil fertility. However, at small spatial scales (within some sites) and among sites, the abundances of exotic annual and native perennial grasses were strongly negatively correlated. The results suggest that at the present time, rainfall and soil properties are important variables determining the abundance of annual grasses. The driving variables for the abundance of perennial grasses are less clear. They may be controlled by other factors or extreme rainfall events, which were not surveyed. In addition, they are likely to be controlled by competitive interactions with the annual grasses.

scholarly journals Integrated Management of Perennial Pepperweed (Lepidium latifolium)

2008 ◽  
Vol 1 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Rob G. Wilson ◽  
Debra Boelk ◽  
Guy B. Kyser ◽  
Joseph M. DiTomaso
Keyword(s):  
Integrated Management ◽  
Perennial Grass ◽  
Management Strategies ◽  
Site Preparation ◽  
Perennial Grasses ◽  
Flower Bud ◽  
No Till ◽  
Wide Range ◽  
Grass Establishment ◽  
Native Perennial Grass

AbstractPerennial pepperweed is invasive throughout California. It thrives in a wide range of environments and is a common weed in floodplains, pastures, wetlands, and roadsides. In disturbed areas, perennial pepperweed rapidly forms monotypic stands with a thick litter layer. These infestations not only out-compete other vegetation, but prevent re-establishment of desirable species even after perennial pepperweed control. This experiment examined integrated management strategies with the goal of maximizing perennial pepperweed control and establishment of desirable native vegetation. The experiment was conducted at two sites in Lassen County, CA. Both sites were heavily infested with perennial pepperweed and lacked competing vegetation. The experimental design was a split-split-randomized block with four replications. Site preparation treatments included winter burning, summer and fall mowing, winter grazing, and fall disking. These treatments were designed to remove thatch to facilitate herbicide application and reseeding of desirable perennial grasses. Herbicide treatments included chlorsulfuron, 2,4-D, or glyphosate applied at the flower bud stage. Revegetation treatments included no seeding and no-till seeding of native perennial grasses. Most site preparation plus herbicide combinations reduced perennial pepperweed cover > 85% compared to the untreated control, although treatment efficacy was variable between sites and years. Burning, grazing, mowing, or disking in combination with herbicide treatment and no-till seeding was necessary for successful native perennial grass establishment. Burning or mowing with yearly 2,4-D applications for 3 yr gave the best combination of perennial pepperweed control and native grass establishment. Chlorsulfuron caused chlorosis and stunting to western wheatgrass, basin wildrye, and beardless wildrye at both sites when applied the spring before seeding. No treatment offered complete weed control, suggesting follow-up spot herbicide applications are needed for long-term perennial pepperweed suppression. These results provide several successful integrated strategies for control of perennial pepperweed and revegetation to a desired native perennial grass community.

Investigation of a Computer Virus Outbreak in the Pharmacy of a Tertiary Care Teaching Hospital

1992 ◽  
Vol 13 (10) ◽  
pp. 594-598
Author(s):  
Thomas C. Bailey ◽  
Richard M. Reichley
Keyword(s):  
Virus Infection ◽  
Personal Computer ◽  
Tertiary Care ◽  
Virus Detection ◽  
Computer Virus ◽  
Personal Computers ◽  
Control Approach ◽  
Care Teaching ◽  
Wilcoxon Rank Sum Test ◽  
Detection Software

AbstractObjective:A computer virus outbreak was recognized, verified, defined, investigated, and controlled using an infection control approach. The pathogenesis and epidemiology of computer virus infection are reviewed.Design:Case-control study.Setting:Pharmacy of a tertiary care teaching institution.Results:On October 28, 1991, 2 personal computers in the drug information center manifested symptoms consistent with the “Jerusalem” virus infection. The same day, a departmental personal computer began playing ‘Yankee Doodle,” a sign of “Doodle” virus infection. An investigation of all departmental personal computers identified the “Stoned” virus in an additional personal computer. Controls were functioning virus-free personal computers within the department. Cases were associated with users who brought diskettes from outside the department (5/5 cases versus 5/13 controls, p = .04) and with College of Pharmacy student users (3/5 cases versus 0/13 controls, p = .012). The detection of a virus-infected diskette or personal computer was associated with the number of 5 1/4-inch diskettes in the files of personal computers, a surrogate for rate of media exchange (mean= 17.4 versus 152.5, p = .018, Wilcoxon rank sum test). After education of departmental personal computer users regarding appropriate computer hygiene and installation of virus protection software, no further spread of personal computer viruses occurred, although 2 additional Stoned-infected and 1 Jerusalem-infected diskettes were detected.Conclusions:We recommend that virus detection software be installed on personal computers where the interchange of diskettes among computers is necessary, that write-protect tabs be placed on all program master diskettes and data diskettes where data are being read and not written, that in the event of a computer virus outbreak, all available diskettes be quarantined and scanned by virus detection software, and to facilitate quarantine and scanning in an outbreak, that diskettes be stored in organized files.

Response of a Native Perennial Grass Stand to Disturbance in California's Coast Range Grassland

2004 ◽  
Vol 12 (2) ◽  
pp. 279-289 ◽  
Author(s):  
James W. Bartolome ◽  
Jeffrey S. Fehmi ◽  
Randall D. Jackson ◽  
Barbara Allen-Diaz
Keyword(s):  
Perennial Grass ◽  
Coast Range ◽  
Grass Stand ◽  
Native Perennial Grass

Grassland Response to Herbicides and Seeding of Native Grasses 6 Years Posttreatment

2012 ◽  
Vol 5 (3) ◽  
pp. 311-316 ◽  
Author(s):  
Bryan A. Endress ◽  
Catherine G. Parks ◽  
Bridgett J. Naylor ◽  
Steven R. Radosevich ◽  
Mark Porter
Keyword(s):  
Invasive Plant ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Grassland Restoration ◽  
Exotic Grasses ◽  
Exotic Invasive ◽  
Successful Establishment ◽  
Exotic Invasive Plants ◽  
Exotic Grass ◽  
Native Perennial Grass

AbstractHerbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We found the timing of picloram applications to be important to the native forb community. Plots with picloram applied in the fall had greater native forb cover. However, without the addition of native perennial grass seeds, the sites became dominated by exotic grasses. Seeding resulted in a 20% decrease in exotic grass cover. Successful establishment of native perennial grasses was not apparent until 6 yr after seeding. Our study found integrating herbicide application and the addition of native grass seed to be an effective grassland restoration strategy, at least in the case where livestock are excluded.

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