scholarly journals Molecular Detection of Peronospora variabilis in Quinoa Seed and Phylogeny of the Quinoa Downy Mildew Pathogen in South America and the United States

2014 ◽  
Vol 104 (4) ◽  
pp. 379-386 ◽  
Author(s):  
Anna L. Testen ◽  
María del Mar Jiménez-Gasco ◽  
José B. Ochoa ◽  
Paul A. Backman
Keyword(s):  
United States ◽  
South America ◽  
Downy Mildew ◽  
Detection Method ◽  
Chenopodium Quinoa ◽  
The United States ◽  
Human Consumption ◽  
South American ◽  
Geographical Differences ◽  
Polymerase Chain

Quinoa (Chenopodium quinoa) is an important export of the Andean region, and its key disease is quinoa downy mildew, caused by Peronospora variabilis. P. variabilis oospores can be seedborne and rapid methods to detect seedborne P. variabilis have not been developed. In this research, a polymerase chain reaction (PCR)-based detection method was developed to detect seedborne P. variabilis and a sequencing-based method was used to validate the PCR-based method. P. variabilis was detected in 31 of 33 quinoa seed lots using the PCR-based method and in 32 of 33 quinoa seed lots using the sequencing-based method. Thirty-one of the quinoa seed lots tested in this study were sold for human consumption, with seed originating from six different countries. Internal transcribed spacer (ITS) and cytochrome c oxidase subunit 2 (COX2) phylogenies were examined to determine whether geographical differences occurred in P. variabilis populations originating from Ecuador, Bolivia, and the United States. No geographical differences were observed in the ITS-derived phylogeny but the COX2 phylogeny indicated that geographical differences existed between U.S. and South American samples. Both ITS and COX2 phylogenies supported the existence of a Peronospora sp., distinct from P. variabilis, that causes systemic-like downy mildew symptoms on quinoa in Ecuador. The results of these studies allow for a better understanding of P. variabilis populations in South America and identified a new causal agent for quinoa downy mildew. The PCR-based seed detection method allows for the development of P. variabilis-free quinoa seed, which may prove important for management of quinoa downy mildew.

scholarly journals Brazil and the institutionalization of South America: from hemispheric estrangement to cooperative hegemony

2011 ◽  
Vol 54 (2) ◽  
pp. 189-211 ◽  
Author(s):  
Carlos Gustavo Poggio Teixeira
Keyword(s):  
United States ◽  
South America ◽  
Free Trade ◽  
Free Trade Area ◽  
The United States ◽  
South American ◽  
The South ◽  
Trade Area

This article argues that Brazil went from a posture of estrangement in relation to the hemispheric project represented by the Free Trade Area of the Americas (FTAA) to a strategy of cooperative hegemony aimed at institutionalizing the South American space and increasing the costs of the FTAA for the United States. Although Brazil was initially isolated, US lack of leadership combined with events at the subregional level ended up turning the tide in the direction of Brazilian interests. These factors help to understand the current institutional configuration of South America.

scholarly journals International Surveillance of Bloodstream Infections Due to Candida Species: Frequency of Occurrence and Antifungal Susceptibilities of Isolates Collected in 1997 in the United States, Canada, and South America for the SENTRY Program

1998 ◽  
Vol 36 (7) ◽  
pp. 1886-1889 ◽  
Author(s):  
M. A. Pfaller ◽  
R. N. Jones ◽  
G. V. Doern ◽  
H. S. Sader ◽  
R. J. Hollis ◽  
...  
Keyword(s):  
United States ◽  
South America ◽  
Bloodstream Infections ◽  
The United States ◽  
South American ◽  
Frequency Of Occurrence ◽  
Species Frequency ◽  
International Program ◽  
Medical Centers ◽  
Geographic Differences

An international program of surveillance of bloodstream infections (BSIs) in the United States, Canada, and South America between January and December 1997 detected 306 episodes of candidemia in 34 medical centers (22 in the United States, 6 in Canada, and 6 in South America). Eighty percent of the BSIs were nosocomial and 50% occurred in patients hospitalized in an intensive care unit. Overall, 53.3% of the BSIs were due to Candida albicans, 15.7% were due toC. parapsilosis, 15.0% were due to C. glabrata, 7.8% were due to C. tropicalis, 2.0% were due to C. krusei, 0.7% were due to C. guilliermondii, and 5.8% were due to Candida spp. However, the distribution of species varied markedly by country. In the United States, 43.8% of BSIs were due to non-C. albicansspecies. C. glabrata was the most common non-C. albicans species in the United States. The proportion of non-C. albicans BSIs was slightly higher in Canada (47.5%), where C. parapsilosis, not C. glabrata, was the most common non-C. albicansspecies. C. albicans accounted for 40.5% of all BSIs in South America, followed by C. parapsilosis (38.1%) andC. tropicalis (11.9%). Only one BSI due to C. glabrata was observed in South American hospitals. Among the different species of Candida, resistance to fluconazole (MIC, ≥64 μg/ml) and itraconazole (MIC, ≥1.0 μg/ml) was observed with C. glabrata and C. krusei and was observed more rarely among other species. Isolates of C. albicans,C. parapsilosis, C. tropicalis, and C. guilliermondii were all highly susceptible to both fluconazole (99.4 to 100% susceptibility) and itraconazole (95.8 to 100% susceptibility). In contrast, 8.7% of C. glabrata isolates (MIC at which 90% of isolates are inhibited [MIC90], 32 μg/ml) and 100% of C. krusei isolates were resistant to fluconazole, and 36.9% of C. glabrata isolates (MIC90, 2.0 μg/ml) and 66.6% of C. kruseiisolates were resistant to itraconazole. Within each species there were no geographic differences in susceptibility to fluconazole or itraconazole.

Study on Mining Materials Products of Central and South America

2014 ◽  
Vol 484-485 ◽  
pp. 581-584
Author(s):  
Ying Li ◽  
Qi Shen Chen ◽  
Jian Wu Li ◽  
Qun Yi Liu
Keyword(s):  
United States ◽  
Economic Development ◽  
South America ◽  
Regional Economic Development ◽  
The United States ◽  
South American ◽  
Regional Economic ◽  
Export Strategy ◽  
The Future

There are rich resources in Central and South America, and mining products export plays an important role in the regional economic development. In this paper, the mining products trade information of more than ten years in Central and South America is collected, and then the authors point out that a "diversified export" strategy has been implemented by Central and South America in recent years for reducing the dependence on the economy of the United States, and the export of Central and South America is continuously rising to China but declining to the United States because they are benefited from the great demands of China's development on resources. However, along with the development of the industrialization in the countries of Central and South America, increasingly more resources will be consumed in this region. Therefore, some Central and South American countries will reduce their energy and mining products exports in the future in the condition of meeting their own needs.

Different Profiles, Different Choices: Mid-Nineteenth Century Hessians Who Emigrated to the Southern Hemisphere

2017 ◽  
Vol 41 (3) ◽  
pp. 415-444 ◽  
Author(s):  
Simone A. Wegge
Keyword(s):  
United States ◽  
Nineteenth Century ◽  
South America ◽  
Southern Hemisphere ◽  
The United States ◽  
South American ◽  
Migration Strategy ◽  
Socioeconomic Characteristic ◽  
Intact Families

Before 1890, German emigrants were one of the largest European groups to emigrate overseas in the middle of the nineteenth century. Most of them settled in North America, but a handful of Germans landed in countries south of the equator. This article examines those who chose uncommon paths and settled in the Southern Hemisphere, focusing on Hessians who went to either Australia or South America. Those who emigrated to the Southern Hemisphere were quite different from the Hessians who moved to the United States. More striking, however, are the contrasting backgrounds of the Australian-bound versus the South American–bound groups: These two groups were comparable in size, but in terms of any identifying socioeconomic characteristic they were poles apart from each other. Those bound for Australia were poorer, less skilled, and more likely to use a multiyear migration strategy to get their family members across the ocean, typical of the ways of those bound for the United States. In contrast, those who went to South America were wealthier, more skilled, and mostly emigrated as intact families without the use of such migration networks. This work shows that the choice of destination mattered for individuals and that certain destinations attracted particular types of individuals and groups, reemphasizing the role of self-selection in the migration experience.

scholarly journals Transmission of the Citrus Variegated Chlorosis Bacterium Xylella fastidiosa with the Sharpshooter Oncometopia nigricans

Plant Disease ◽  
2002 ◽  
Vol 86 (11) ◽  
pp. 1237-1239 ◽  
Author(s):  
R. H. Brlansky ◽  
V. D. Damsteegt ◽  
J. S. Hartung
Keyword(s):  
United States ◽  
Polymerase Chain Reaction ◽  
Xylella Fastidiosa ◽  
The United States ◽  
Reliable Indicator ◽  
Symptom Development ◽  
Chain Reaction ◽  
Citrus Variegated Chlorosis ◽  
Specific Polymerase Chain Reaction ◽  
Polymerase Chain

Citrus variegated chlorosis (CVC) is an economically important, destructive disease in Brazil and is caused by the bacterium Xylella fastidiosa Wells. The bacterium has been found to be transmitted in Brazil by sharpshooter leafhoppers (Cicadellidae). Sharpshooters are present in most citrus growing areas of the United States. The sharpshooter leafhopper, Oncometopia nigricans Walker, frequently is found feeding on citrus in Florida. This sharpshooter transmits the X. fastidiosa strains that cause Pierce's disease of grape and ragweed stunt. Research was initiated to determine if O. nigricans was capable of vectoring the X. fastidiosa that causes CVC. In 59 different transmission tests, using 1 to 57 insects per test, transmission of the bacterium was observed 12 times (20.3%). Symptom development in the greenhouse was not a reliable indicator of transmission. Transmission was verified by specific polymerase chain reaction-based assays. Individual insects were able to transmit the bacterium. This information on sharpshooter transmission of CVC is needed to assess the threat posed by the CVC disease to the citrus industries in the United States.

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