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Search Results: 1 - 10 of 192102 matches for " Kimberly D. Belfry "
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Responses of Four Types of Winter Wheat to Fenoxaprop-p-ethyl  [PDF]
Kimberly D. Belfry, Peter H. Sikkema
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.62018
Abstract: Fenoxaprop-p-ethyl is a selective grass herbicide that if registered will provide winter wheat growers with an additional weed control option. Field experiments were established in the fall of 2011, 2012 and 2013 at Ridgetown and Exeter, Ontario, to determine the sensitivity of four market classes of winter wheat [Soft white winter wheat (SWWW), soft red winter wheat (SRWW), hard white winter wheat (HWWW) and hard red winter wheat (HRWW)] to 1X and 2X fenoxaprop-p-ethyl/safener at early-(EPOST) or late-post emergence (LPOST) application timings. Fenoxaprop-p-ethyl/safener applied LPOST at 1X and 2X the manufacturer’s proposed label rate caused 4% and 5% injury 1 week after application (WAA), respectively. The injury observed was transient with 1% injury 2 WAA. Winter wheat height ranged from 91 to 95, 76 to 77, 76 to 79 and 90 to 93 cm while grain yield was 6.2 to 6.4, 6.1 to 7.1, 5.5 to 5.8 and 5.6 to 6.2 t?ha?1 for SWWW, SRWW, HRWW and HRWW, respectively. Exeter sites were not affected by fenoxaprop-p-ethyl/ safener treatment. At Ridgetown and Exeter, no market class-specific response was identified for the cultivars evaluated. Based on this study, fenoxaprop-p-ethyl/safener has the potential to cause only minor and transient injury in winter wheat that will not decrease yield. Furthermore, this research supports the registration of fenoxaprop-p-ethyl/safener for spring POST application in winter wheat in Ontario.
Preplant and Postemergence Control of Glyphosate-Resistant Giant Ragweed in Corn  [PDF]
Kimberly D. Belfry, Peter H. Sikkema
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.62026
Abstract: Glyphosate-resistant (GR) giant ragweed has recently been identified in southwestern Ontario and has the potential to be a significant problem for regional corn producers. Eight field trials [four with preplant (PP) and four with postemergence (POST) herbicides] were conducted from 2013 to 2014 on various Ontario farms infested with GR giant ragweed to determine the efficacy of PP and POST tank-mixes in corn. Glyphosate tank-mixed with atrazine, dicamba, dicamba/atrazine, mesotrione plus atrazine, flumetsulam, isoxaflutole plus atrazine, saflufenacil/dimethenamid-P, S-metolachlor/atrazine and rimsulfuron applied PP provided up to 54%, 95%, 93%, 95%, 40%, 89%, 91%, 50% and 93% control of GR giant ragweed and reduced dry weight 69%, 100%, 99%, 100%, 30%, 92%, 98%, 66% and 99%, respectively. POST application of glyphosate alone and tank-mixed with 2,4-D ester, atrazine, dicamba, dicamba/diflufenzopyr, dicamba/atrazine, bromoxynil plus atrazine, prosulfuron plus dicamba, mesotrione plus atrazine, topramezone plus atrazine, tembotrione/thiencarbazone-methyl and glufosinate provided up to 31%, 84%, 39%, 94%, 89%, 86%, 83%, 78%, 72%, 43%, 63% and 58% GR giant ragweed and reduced dry weight 55%, 99%, 72%, 99%, 99%, 98%, 96%, 96%, 93%, 89%, 91% and 95%, respectively. In general, PP control of GR giant ragweed was greater than POST applied herbicides evaluated. Based on these results, glyphosate tank-mixes containing dicamba or mesotrione plus atrazine applied PP, and dicamba applied POST will provide the most consistent control of GR giant ragweed in corn.
Evaluation of Delayed Glyphosate Burndown in No-Till Soybean  [PDF]
Kimberly D. Belfry, Christy Shropshire, Peter H. Sikkema
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.63035
Abstract: Application of a preplant or preemergence glyphosate burndown is routine in most no-tillage production systems of annual crops, however, time of application may influence overall weed control and grain yield. Six field trials were conducted over a three-year period (2008, 2009 and 2010) near Ridgetown, Ontario, Canada to determine the effect of glyphosate burndown application timing in glyphosate-resistant (GR) no-tillage soybean [Glycine max (L.) Merr.]. Soybean growth was reduced 5%, 10% and 20% when the burndown was delayed to 1, 5 and 12 days after planting (DAP), when evaluated one week after application (WAA), respectively. By 8 WAA, predicted burndown timing increased to 9, 14 and 23 DAP, and was 10, 17 and 26 DAP at 12 WAA, to reduce soybean growth by 5%, 10% and 20%, respectively. Similarly, burndown application at 14, 21 and 30 DAP corresponded to a soybean yield reduction of 5%, 10% and 20%. Seed moisture content was generally insensitive to burndown timing; 80 and 140 DAP were required to increase moisture by 5% and 10%, respectively. This research indicates that delaying glyphosate burndown by up to 14 DAP, approximately VE to VC growth stage, has the potential to result in a modest reduction in soybean yield (5%).
Creating a Supportive Environment to Enhance Computer Based Learning for Underrepresented Minorities in College Algebra Classrooms
Kimberly D. Kendricks
The Journal of Scholarship of Teaching and Learning , 2011,
Abstract:
Nanotechnology, Closed Captioned videos and ESL students
David D. KUMAR,Kimberly SCAROLA
Asia-Pacific Forum on Science Learning and Teaching , 2006,
Abstract: This paper argues in favor of Closed Captioned Video technology for incorporating nanotechnology as part of teaching science to English as a Second Language (ESL) students. Nanotechnology deals with particles with diameters 1-50 nm and provides a macro-context for science instruction. Closed Captioned Videos provide an effective tool for presenting nanotechnology information in a meaningful way to ESL students. Implications for science curriculum and instruction are discussed.
Movement of Soil-Applied Imidacloprid and Thiamethoxam into Nectar and Pollen of Squash (Cucurbita pepo)
Kimberly A. Stoner, Brian D. Eitzer
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0039114
Abstract: There has been recent interest in the threat to bees posed by the use of systemic insecticides. One concern is that systemic insecticides may translocate from the soil into pollen and nectar of plants, where they would be ingested by pollinators. This paper reports on the movement of two such systemic neonicotinoid insecticides, imidacloprid and thiamethoxam, into the pollen and nectar of flowers of squash (Cucurbita pepo cultivars “Multipik,” “Sunray” and “Bush Delicata”) when applied to soil by two methods: (1) sprayed into soil before seeding, or (2) applied through drip irrigation in a single treatment after transplant. All insecticide treatments were within labeled rates for these compounds. Pollen and nectar samples were analyzed using a standard extraction method widely used for pesticides (QuEChERS) and liquid chromatography mass spectrometric analysis. The concentrations found in nectar, 10±3 ppb (mean ± s.d) for imidacloprid and 11±6 ppb for thiamethoxam, are higher than concentrations of neonicotinoid insecticides in nectar of canola and sunflower grown from treated seed, and similar to those found in a recent study of neonicotinoids applied to pumpkins at transplant and through drip irrigation. The concentrations in pollen, 14±8 ppb for imidacloprid and 12±9 ppb for thiamethoxam, are higher than those found for seed treatments in most studies, but at the low end of the range found in the pumpkin study. Our concentrations fall into the range being investigated for sublethal effects on honey bees and bumble bees.
Special considerations in the treatment of patients with bipolar disorder and medical co-morbidities
Kimberly D McLaren, Lauren B Marangell
Annals of General Psychiatry , 2004, DOI: 10.1186/1475-2832-3-7
Abstract: A review of the literature was conducted and papers addressing this topic were selected by the authors.Common medical comorbidities and treatment-emergent illnesses, including obesity, diabetes mellitus, dyslipidemia, cardiac disease, hepatic disease, renal disease, pulmonary disease and cancer are reviewed with respect to concomitant use of mood stabilizers. Guidance to clinicians regarding effective monitoring and treatment is offered.Mood-stabilizing medications are necessary in treating patients with bipolar disorder and often must be used in the face of medical illness. Their safe use is possible, but requires increased vigilance in monitoring for treatment-emergent illnesses and effects on comorbid medical illness.Patients with bipolar disorder are among the most challenging to treat pharmacologically, especially in the presence of medical comorbidity. Although the rates of medical comorbidity are high in patients with bipolar disorder (20–80%), medical illnesses are frequently underdiagnosed and inadequately treated in psychiatric patients. For example, Cradock-O'Leary and colleagues reviewed centralized Veterans Affairs data and examined the use of medical services by 175,653 veterans during fiscal year 2000 [1]. They identified 3,694 veterans with a primary diagnosis of bipolar disorder and compared the care that these veterans received to that of all veterans. Among all veterans with diabetes and hypertension, those with a comorbid diagnosis of bipolar disorder (as well as those with diagnoses of anxiety disorder, schizophrenia, post-traumatic stress disorder, or a substance use disorder) were less likely to have more than one medical visit in one year. This is especially concerning given that veterans are afforded medical and psychiatric treatment within one comprehensive health care system, seemingly making care more accessible. Patients with bipolar disorder in the general population are likely receiving even less medical care. The significance of this
Using a Hazard Quotient to Evaluate Pesticide Residues Detected in Pollen Trapped from Honey Bees (Apis mellifera) in Connecticut
Kimberly A. Stoner, Brian D. Eitzer
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0077550
Abstract: Analysis of pollen trapped from honey bees as they return to their hives provides a method of monitoring fluctuations in one route of pesticide exposure over location and time. We collected pollen from apiaries in five locations in Connecticut, including urban, rural, and mixed agricultural sites, for periods from two to five years. Pollen was analyzed for pesticide residues using a standard extraction method widely used for pesticides (QuEChERS) and liquid chromatography/mass spectrometric analysis. Sixty pesticides or metabolites were detected. Because the dose lethal to 50% of adult worker honey bees (LD50) is the only toxicity parameter available for a wide range of pesticides, and among our pesticides there were contact LD50 values ranging from 0.006 to >1000 μg per bee (range 166,000X), and even among insecticides LD50 values ranged from 0.006 to 59.8 μg/bee (10,000X); therefore we propose that in studies of honey bee exposure to pesticides that concentrations be reported as Hazard Quotients as well as in standard concentrations such as parts per billion. We used both contact and oral LD50 values to calculate Pollen Hazard Quotients (PHQ = concentration in ppb ÷ LD50 as μg/bee) when both were available. In this study, pesticide Pollen Hazard Quotients ranged from over 75,000 to 0.01. The pesticides with the greatest Pollen Hazard Quotients at the maximum concentrations found in our study were (in descending order): phosmet, Imidacloprid, indoxacarb, chlorpyrifos, fipronil, thiamethoxam, azinphos-methyl, and fenthion, all with at least one Pollen Hazard Quotient (using contact or oral LD50) over 500. At the maximum rate of pollen consumption by nurse bees, a Pollen Hazard Quotient of 500 would be approximately equivalent to consuming 0.5% of the LD50 per day. We also present an example of a Nectar Hazard Quotient and the percentage of LD50 per day at the maximum nectar consumption rate.
Genetics and Molecular Biology of the Electron Flow for Sulfate Respiration in Desulfovibrio
Kimberly L. Keller,Judy D. Wall
Frontiers in Microbiology , 2011, DOI: 10.3389/fmicb.2011.00135
Abstract: Progress in the genetic manipulation of the Desulfovibrio strains has provided an opportunity to explore electron flow pathways during sulfate respiration. Most bacteria in this genus couple the oxidation of organic acids or ethanol with the reduction of sulfate, sulfite, or thiosulfate. Both fermentation of pyruvate in the absence of an alternative terminal electron acceptor, disproportionation of fumarate and growth on H2 with CO2 during sulfate reduction are exhibited by some strains. The ability to produce or consume H2 provides Desulfovibrio strains the capacity to participate as either partner in interspecies H2 transfer. Interestingly the mechanisms of energy conversion, pathways of electron flow and the parameters determining the pathways used remain to be elucidated. Recent application of molecular genetic tools for the exploration of the metabolism of Desulfovibrio vulgaris Hildenborough has provided several new datasets that might provide insights and constraints to the electron flow pathways. These datasets include (1) gene expression changes measured in microarrays for cells cultured with different electron donors and acceptors, (2) relative mRNA abundances for cells growing exponentially in defined medium with lactate as carbon source and electron donor plus sulfate as terminal electron acceptor, and (3) a random transposon mutant library selected on medium containing lactate plus sulfate supplemented with yeast extract. Studies of directed mutations eliminating apparent key components, the quinone-interacting membrane-bound oxidoreductase (Qmo) complex, the Type 1 tetraheme cytochrome c3 (Tp1-c3), or the Type 1 cytochrome c3:menaquinone oxidoreductase (Qrc) complex, suggest a greater flexibility in electron flow than previously considered. The new datasets revealed the absence of random transposons in the genes encoding an enzyme with homology to Coo membrane-bound hydrogenase. From this result, we infer that Coo hydrogenase plays an important role in D. vulgaris growth on lactate plus sulfate. These observations along with those reported previously have been combined in a model showing dual pathways of electrons from the oxidation of both lactate and pyruvate during sulfate respiration. Continuing genetic and biochemical analyses of key genes in Desulfovibrio strains will allow further clarification of a general model for sulfate respiration.
Linuron Biologically Effective Dose for Glyphosate-Resistant Giant Ragweed (Ambrosia trifida L.) Control in Soybean (Glycine max L.)  [PDF]
Kimberly D. Walsh, Nader Soltani, Lynette R. Brown, Peter H. Sikkema
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.518285
Abstract:

Glyphosate-resistant (GR) giant ragweed (Ambrosia trifida L.) was first identified in Canada in 2008 and has since been found throughout southwestern Ontario. Six field trials were conducted over a two-year period (2012, 2013) on Ontario farms with GR giant ragweed to evaluate the efficacy of linuron applied pre-plant (PP) in soybean (Glycine max (L.) Merr.). The dose required for 50%, 80%, and 95% GR giant ragweed control was 1238, 2959, and 6018 g·ai·ha-1 four weeks after application (WAA), respectively. The linuron dose needed for 50%, 80%, and 95% reduction in density was 1554, 3181, and 5643 g·ai·ha-1 and 1204, 2496, and 4452 g·ai·ha-1 for dry weight, respectively. Application of 7874 g·ai·ha-1 linuron was needed to obtain soybean yields that were 90% of the weed-free control; approximately 3.5 times the maximum field recommended dose. To achieve 95% and 98% yields, greater than 8640 g·ai·ha-1 linuron was required. Application of linuron plus glyphosate PP in soybean will help to control GR giant ragweed as well as reduce GR selection pressure.

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