Mutations in Phytoene Desaturase Gene in Fluridone-Resistant Hydrilla (Hydrilla verticillata) Biotypes in Florida

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 412-420 ◽  
Author(s):  
Atul Puri ◽  
Gregory E. MacDonald ◽  
Fredy Altpeter ◽  
William T. Haller
Keyword(s):  
Herbicide Resistance ◽  
Single Point ◽  
Hydrilla Verticillata ◽  
The United States ◽  
Phytoene Desaturase ◽  
Day Length ◽  
Single Point Mutation ◽  
Aquatic Weed ◽  
Systemic Control

Hydrilla is one of the most serious aquatic weed problems in the United States, and fluridone is the only U.S. Environment Protection Agency (USEPA)–approved herbicide that provides relatively long-term systemic control. Recently, hydrilla biotypes with varying levels of fluridone resistance have been documented in Florida. One susceptible and five fluridone-resistant biotypes of hydrilla varying in resistance levels were maintained in 950-L tanks under ambient sunlight and day-length conditions from September 2004 to September 2005 in absence of fluridone. Because fluridone is an inhibitor of the enzyme phytoene desaturase (PDS), the gene for PDS (pds) was cloned from fluridone-susceptible and -resistant hydrilla biotypes. Somatic mutations in amino acid 304 of hydrilla PDS are known to confer herbicide resistance. We determinedpdssequence from these hydrilla biotypes at planting and 12-mo after planting. Two independent mutations at the arginine 304 codon ofpdswere found in the resistant hydrilla plants. The codon usage for arginine 304 is CGT, and a single point mutation yielding either serine (AGT) or histidine (CAT) was identified in different resistant hydrilla biotypes. There were no differences at codon 304 in the PDS protein of any hydrilla biotype 12-mo after planting. Several other mutations were also found in resistantpdsalleles, though their possible role in herbicide resistance is unclear.

Growth and Reproductive Physiology of Fluridone-Susceptible and -resistant Hydrilla (Hydrilla verticillata) Biotypes

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 441-445 ◽  
Author(s):  
Atul Puri ◽  
Gregory E. MacDonald ◽  
William T. Haller ◽  
Megh Singh
Keyword(s):  
United States ◽  
Hydrilla Verticillata ◽  
The United States ◽  
Reproductive Physiology ◽  
Day Length ◽  
Aquatic Weed ◽  
Environment Protection ◽  
Economic Problems ◽  
Systemic Control

Hydrilla is one of the most serious aquatic weed problems in the United States, and fluridone is the only U.S. Environment Protection Agency (USEPA)–approved herbicide that provides relatively long-term systemic control. Recently, hydrilla biotypes with varying levels of fluridone resistance have been documented in Florida. Several biotypes of hydrilla varying in resistance levels were maintained in 950-L tanks under ambient sunlight and day-length conditions from September 2004 to September 2005 in absence of fluridone. Phenotypic measurements were performed during this 1-yr period to monitor differences in growth and reproductive physiology. All fluridone-resistant biotypes (except R3) were growing at the same rate or greater than the susceptible hydrilla. These data suggested that there are no deleterious effects on growth and reproductive physiology because of development of fluridone resistance. Aggressive spread of fluridone-resistant dioecious hydrilla in aquatic ecosystems can severely affect hydrilla management and, consequently, cause substantial and long-lasting ecological and economic problems throughout the southern United States.

Ploidy Variations in Floridone-Susceptible and -Resistant Hydrilla (Hydrilla verticillata) Biotypes

Weed Science ◽  
2007 ◽  
Vol 55 (6) ◽  
pp. 578-583 ◽  
Author(s):  
Atul Puri ◽  
Gregory E. MacDonald ◽  
William T. Haller
Keyword(s):  
Nuclear Dna ◽  
Flow Cytometric Analysis ◽  
Nuclear Dna Content ◽  
Hydrilla Verticillata ◽  
The United States ◽  
Day Length ◽  
Aquatic Weed ◽  
Ploidy Levels ◽  
Systemic Control ◽  
Dna Contents

Hydrilla is one of the most serious aquatic weed problems in the United States, and fluridone is the only U.S. Environment Protection Agency (USEPA)–approved herbicide that provides relatively long-term systemic control. Recently, hydrilla biotypes with varying levels of fluridone resistance have been documented in Florida. Fluridone-susceptible (S) and several fluridone-resistant (R1 to R5) hydrilla biotypes varying in resistance levels were maintained in 950-L tanks under ambient sunlight and day-length conditions. To correlate varying levels of fluridone resistance to ploidy in hydrilla, flow cytometric analysis was performed. Differential ploidy levels (diploid, 2n = 2x = 16; triploid, 2n = 3x = 24; and tetraploid, 2n = 4x = 32) were reported among different hydrilla biotypes, plants within each biotype, and within shoot tissues of the same plant. Triploid plants were predominant in all biotypes. Diploid plants were observed in all hydrilla biotypes except the susceptible hydrilla (S). Plants with tetraploidy were rare within biotypes. The diploid, triploid, and tetraploid plants had nuclear DNA contents of 2.43 to 2.73 pg, 3.44 to 3.71 pg, and 4.64 to 4.90 pg, respectively, and no differences were observed among plants with same ploidy for nuclear DNA content in different hydrilla biotypes. Endoreduplication patterns were observed in diploid plants of R1 and R3 biotypes. However, no plant with higher ploidy levels (triploid or tetraploid) in any hydrilla biotypes showed endoreduplication.

Stability of Fluridone-Resistant Hydrilla (Hydrilla verticillata) Biotypes over Time

Weed Science ◽  
2007 ◽  
Vol 55 (1) ◽  
pp. 12-15 ◽  
Author(s):  
Atul Puri ◽  
G. E. MacDonald ◽  
W. T. Haller
Keyword(s):  
Hydrilla Verticillata ◽  
The United States ◽  
Time Interval ◽  
Aquatic Weed ◽  
Atmospheric Conditions ◽  
Carotene Content ◽  
Systemic Control ◽  
Β Carotene ◽  
Over Time

Hydrilla is one of the most serious aquatic weed problems in the United States, and fluridone is the only herbicide approved by the U.S. Environment Protection Agency that provides systemic control. Recently, hydrilla biotypes with varying levels of fluridone resistance have been documented in Florida. Hydrilla biotypes of varying fluridone resistance levels were maintained in 900-L tanks under natural atmospheric conditions from September 2004 to September 2005 in the absence of fluridone. Hydrilla shoot tips were collected from each biotype during September 2004 (at planting), December 2004 (3 mo after planting [MAP]), March 2005 (6 MAP), June 2005 (9 MAP), and September 2005 (12 MAP) and exposed to 5, 10, 15, 20, 30, and 50 µg L−1fluridone to assess changes in susceptibility to this herbicide over time. Nonlinear regression analysis was used to calculate EC50values for phytoene and β-carotene (effective fluridone concentration to increase/decrease the phytoene/β-carotene content in hydrilla plant tissue by 50% over the untreated control) at each time interval. EC50values did not change in the susceptible hydrilla biotype over time. The EC50values for phytoene and β-carotene for the susceptible biotype were 7.5 and 8.9 µg L−1, respectively, at planting and 7.6 and 9.4 µg L−1, respectively, at 12 MAP. Resistant hydrilla biotypes (R1–R5) also showed no change in EC50phytoene values over time. Although, EC50β-carotene values in resistant biotypes R1, R3, R4, and R5 did not change over time, R2 recorded a reduction in EC50β-carotene at 12 MAP. Also, a 0.5-point decrease in resistance factor was observed for all resistant biotypes. Future long-term studies are needed to evaluate stability of resistant hydrilla biotypes in the absence of fluridone selection pressure.

Point mutation in acetolactate synthase confers sulfonylurea and imidazolinone herbicide resistance in spiny annual sow-thistle [Sonchus asper (L.) Hill]

2012 ◽  
Vol 92 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Kee Woong Park ◽  
Judith M. Kolkman ◽  
Carol A. Mallory-Smith
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Herbicide Resistance ◽  
Single Point ◽  
Acetolactate Synthase ◽  
Amino Acid Sequences ◽  
Cross Resistance ◽  
Single Point Mutation ◽  
Sonchus Asper

Park, K. W., Kolkman, J. M. and Mallory-Smith, C. A. 2012. Point mutation in acetolactate synthase confers sulfonylurea and imidazolinone herbicide resistance in spiny annual sow-thistle [Sonchus asper (L.) Hill]. Can. J. Plant Sci. 92: 303–309. Suspected thifensulfuron resistant spiny annual sow-thistle was identified near Colfax, Washington, in two fields with a winter wheat and lentil rotation. Therefore, studies were conducted to examine resistance of spiny annual sow-thistle to thifensulfuron and cross-resistance to other acetolactate synthase inhibitors and to determine the physiological and molecular basis for herbicide resistance. Whole-plant bioassay confirmed that the biotype was highly resistant to the sulfonylurea (SU) herbicides, thifensulfuron, metsulfuron, and prosulfuron. The resistant (R) biotype was also highly resistant to the imidazolinone (IMI) herbicides, imazamox and imazethapyr. An in vivo acetolactate synthase (ALS) assay indicated that the concentrations of SU and IMI herbicides required for 50% inhibition (I50) were more than 10 times greater for R biotype compared with susceptible (S) biotype. Analysis of the nucleotide and predicted amino acid sequences for ALS genes demonstrated a single-point mutation from C to T at the als1 gene, conferring the substitution of the amino acid leucine for proline in the R biotype at position197. The results of this research indicate that the resistance of spiny annual sow-thistle to SU and IMI herbicides is due to on altered target site and caused by a point mutation in the als1 gene.

Speech-Language Pathology in the Peace Corps: Necessity and Sustainability

2012 ◽  
Vol 2 (1) ◽  
pp. 11-18
Author(s):  
Melissa A. Pierce
Keyword(s):  
United States ◽  
Special Education ◽  
Peace Corps ◽  
People With Disabilities ◽  
Communication Disorders ◽  
The United States ◽  
Speech Language Pathology ◽  
Speech Language Pathologists ◽  
Language Pathology

In countries other than the United States, the study and practice of speech-language pathology is little known or nonexistent. Recognition of professionals in the field is minimal. Speech-language pathologists in countries where speech-language pathology is a widely recognized and respected profession often seek to share their expertise in places where little support is available for individuals with communication disorders. The Peace Corps offers a unique, long-term volunteer opportunity to people with a variety of backgrounds, including speech-language pathologists. Though Peace Corps programs do not specifically focus on speech-language pathology, many are easily adapted to the profession because they support populations of people with disabilities. This article describes how the needs of local children with communication disorders are readily addressed by a Special Education Peace Corps volunteer.

Multidisciplinary Evidence to Treat Bilingual Individuals with Aphasia

2008 ◽  
Vol 15 (3) ◽  
pp. 66-72 ◽  
Author(s):  
José G. Centeno
Keyword(s):  
Stroke Rehabilitation ◽  
Culturally Diverse ◽  
Treatment Strategies ◽  
The United States ◽  
Intervention Strategies ◽  
Steady Increase ◽  
Clinical Procedures ◽  
Bilingual Speakers ◽  
Aphasic Clients

Abstract The steady increase in linguistic and cultural diversity in the country, including the number of bilingual speakers, has been predicted to continue. Minorities are expected to be the majority by 2042. Strokes, the third leading cause of death and the leading cause of long-term disability in the U.S., are quite prevalent in racial and ethnic minorities, so population estimates underscore the imperative need to develop valid clinical procedures to serve the predicted increase in linguistically and culturally diverse bilingual adults with aphasia in post-stroke rehabilitation. Bilingualism is a complex phenomenon that interconnects culture, cognition, and language; thus, as aphasia is a social phenomenon, treatment of bilingual aphasic persons would benefit from conceptual frameworks that exploit the culture-cognition-language interaction in ways that maximize both linguistic and communicative improvement leading to social re-adaptation. This paper discusses a multidisciplinary evidence-based approach to develop ecologically-valid treatment strategies for bilingual aphasic individuals. Content aims to spark practitioners' interest to explore conceptually broad intervention strategies beyond strictly linguistic domains that would facilitate linguistic gains, communicative interactions, and social functioning. This paper largely emphasizes Spanish-English individuals in the United States. Practitioners, however, are advised to adapt the proposed principles to the unique backgrounds of other bilingual aphasic clients.

Traumatic Brain Injury: A Trauma Surgeon's Perspective

2012 ◽  
Vol 22 (3) ◽  
pp. 82-89
Author(s):  
Oscar D. Guillamondegui
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Multidisciplinary Approach ◽  
Trauma Team ◽  
The United States ◽  
Long Term Outcomes ◽  
Term Care ◽  
Injured Brain ◽  
The Moment

Traumatic brain injury (TBI) is a serious epidemic in the United States. It affects patients of all ages, race, and socioeconomic status (SES). The current care of these patients typically manifests after sequelae have been identified after discharge from the hospital, long after the inciting event. The purpose of this article is to introduce the concept of identification and management of the TBI patient from the moment of injury through long-term care as a multidisciplinary approach. By promoting an awareness of the issues that develop around the acutely injured brain and linking them to long-term outcomes, the trauma team can initiate care early to alter the effect on the patient, family, and community. Hopefully, by describing the care afforded at a trauma center and by a multidisciplinary team, we can bring a better understanding to the armamentarium of methods utilized to treat the difficult population of TBI patients.

Mafias on the Move

2011 ◽  
Author(s):  
Federico Varese
Keyword(s):  
United States ◽  
New York ◽  
Organized Crime ◽  
The United States ◽  
The West ◽  
Market Expansion ◽  
The North ◽  
Economic Transformations ◽  
At Will

Organized crime is spreading like a global virus as mobs take advantage of open borders to establish local franchises at will. That at least is the fear, inspired by stories of Russian mobsters in New York, Chinese triads in London, and Italian mafias throughout the West. As this book explains, the truth is more complicated. The author has spent years researching mafia groups in Italy, Russia, the United States, and China, and argues that mafiosi often find themselves abroad against their will, rather than through a strategic plan to colonize new territories. Once there, they do not always succeed in establishing themselves. The book spells out the conditions that lead to their long-term success, namely sudden market expansion that is neither exploited by local rivals nor blocked by authorities. Ultimately the inability of the state to govern economic transformations gives mafias their opportunity. In a series of matched comparisons, the book charts the attempts of the Calabrese 'Ndrangheta to move to the north of Italy, and shows how the Sicilian mafia expanded to early twentieth-century New York, but failed around the same time to find a niche in Argentina. The book explains why the Russian mafia failed to penetrate Rome but succeeded in Hungary. A pioneering chapter on China examines the challenges that triads from Taiwan and Hong Kong find in branching out to the mainland. This book is both a compelling read and a sober assessment of the risks posed by globalization and immigration for the spread of mafias.

Russian-Japanese Relations: Long-Term Development Factors

2020 ◽  
Vol 13 (3) ◽  
pp. 68-85
Author(s):  
D. V. Streltsov
Keyword(s):  
Security Policy ◽  
The United States ◽  
Peace Treaty ◽  
Strategic Decisions ◽  
Chinese Market ◽  
External Energy ◽  
Economic Relations ◽  
Bilateral Relations ◽  
Personal Diplomacy

The article analyzes long-term external and internal factors determining the course of development of Russian-Japanese relations in 2019-2020. On the one hand, the anti-Russian component in Tokyo's foreign policy is shaped by its membership in the Security Treaty with the United States and its solidarity with the sanctions policy of the Group of Seven towards Russia. On the other hand, Japan and Russia are both interested interest in political cooperation in creating multilateral dialog mechanisms of international security in East Asia, resolving the nuclear issue on the Korean Peninsula, and easing tensions around territorial disputes in the East China and South China seas. Among the economic factors, the author focuses on the significant place of Russia in the context of Japan's task of diversifying sources of external energy supplies, as well as on Russia's desire to avoid unilateral dependence on the Chinese market while reorienting the system of foreign economic relations from the West to the East. Personal diplomacy of political leaders plays a significant role in relations between Russia and Japan, and, above all, close personal relationships and frequent meetings between Prime Minister Abe and President Putin, which make it possible to partially compensate the unfavorable image of the partner country in the public opinion of both Russia and Japan. Against the background of a deadlock in the Peace Treaty talks which emerged in 2019, the search for a way out of the diplomatic impasse is on the agenda. In the author's opinion, it would be appropriate at the first stage to proceed to the conclusion of a basic agreement on the basis bilateral relations, which would be "untied" from the Peace Treaty. In addition, Russia could stop criticizing Japan for its security policy and show greater understanding of the Japanese initiative in the field of quality infrastructure. In turn, Japan could take a number of strategic decisions on cooperation with Russia and announce them in the Prime Minister's keynote speech. In addition, Tokyo could stop positioning the issue of the peace Treaty as the main issue in relations with Russia, which would allow our countries to "untie" bilateral relations from the problem of border demarcation and focus on their positive agenda.

Leaded Aviation Fuel May Present Long-Term Effects on Campus Life from the Adjacent Albert Whitted Airport

2020 ◽  
Author(s):  
Joseph Matthews ◽  
Madhu Pandey
Keyword(s):  
United States ◽  
Particulate Matter ◽  
The United States ◽  
Aviation Fuel ◽  
University Campus ◽  
Long Term Effects ◽  
Aviation Gasoline ◽  
Suspended Particulate ◽  
Descent Line

Propeller planes and small engine aircraft around the United States, legally utilize leaded aviation gasoline. The purpose of this experiment was to collect suspended particulate matter from a university campus, directly below an airport’s arriving flight path’s descent line, and to analyze lead content suspended in the air. Two collection sets of three separate samples were collected on six separate days, one set in July of 2018 and the second set in January 2019.

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