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Search Results: 1 - 10 of 25293 matches for " Lee Tarpley "
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Compartmentation of sucrose during radial transfer in mature sorghum culm
Lee Tarpley, Donald M Vietor
BMC Plant Biology , 2007, DOI: 10.1186/1471-2229-7-33
Abstract: On the day after culm infusion of the tracer sucrose, the specific radioactivity of sucrose recovered from the intracellular compartment of growing axillary-branch tissue was greater (nearly twice) than that in the free space, indicating that sucrose was preferentially transferred through symplasmic routes. In contrast, the sucrose specific radioactivity in the intracellular compartment of the mature (ripening) culm tissue was probably less (about 3/4's) than that in free space indicating that sucrose was preferentially transferred through routes that included an apoplasmic step. In growing internodes of the axillary branch of sorghum, the tritium label initially provided in the fructose moiety of sucrose molecules was largely (81%) recovered in the fructose moiety, indicating that a large portion of sucrose molecules is not hydrolysed and resynthesized during radial transfer.During radial transfer of sucrose in ripening internodes of intact sorghum plants, much of the sucrose is transferred intact (without hydrolysis and resynthesis) and primarily through a path that includes an apoplasmic step. In contrast, much of the sucrose is transferred through a symplasmic path in growing internode (axillary branch) tissue. These results contrast with the probable symplasmic path in mature culm of the closely related species, sugarcane. Phylogenetic variability exists in the compartmental path of radial transfer of sucrose in culms of the andropogonoid grasses.The Andropogoneae tribe of grasses includes a number of large tropical grasses, several of which are widely cultivated for either their grain (sorghum [Sorghum bicolor (L.) Moench] and maize [Zea mays L.]) or for the sucrose accumulated in the culm (sugarcane [Saccharum officinarum L.] and sorghum). The examined species contain sucrose in the culms. This sucrose can support grain filling in some circumstances by buffering the supply of photoassimilate. This study contributes to improved understanding of processes of su
Instrumentation enabling study of plant physiological response to elevated night temperature
Abdul R Mohammed, Lee Tarpley
Plant Methods , 2009, DOI: 10.1186/1746-4811-5-7
Abstract: The described system uses overhead infrared heaters that are relatively inexpensive and are accurate and precise in rapidly controlling the temperature. Remote computer-based data acquisition and control via the internet provides the ability to use complex temperature regimes and real-time monitoring. Due to its easy mobility, the heating system can randomly be allotted in the open field or in the greenhouse within the experimental setup. The apparatus has been successfully applied to study the response of rice to high night temperatures. Air temperatures were maintained within the set points ± 0.5°C. The incorporation of the combination of air-situated thermocouples, autotuned proportional integrative derivative temperature controllers and phase angled fired silicon controlled rectifier power controllers provides very fast proportional heating action (i.e. 9 ms time base), which avoids prolonged or intense heating of the plant material.The described infrared heating system meets the utilitarian requirements of a heating system for plant physiology studies in that the elevated temperature can be accurately, precisely, and reliably controlled with minimal perturbation of other environmental factors.Global climate warming can affect functioning of crops and of plants in the natural environment. Increased night temperatures have been implicated in decreased crop yields throughout the world and are predicted to warm more than the daytime temperatures in the future [1]. The effects of high night temperatures are diverse, including, for example, increased coincidence of intervals of unusually high night temperature with sensitive reproductive stages eventually resulting in poor seed set and a decline in vegetative reserves due to increased respiration and alteration in phenology, or, in the case of natural populations, altered quantity and seasonal distribution of reproductive units.Precise and accurate control of the temperatures of and immediately surrounding small popu
Characterization of Rice (Oryza sativa L.) Physiological Responses to a-Tocopherol, Glycine Betaine or Salicylic Acid Application
Abdul Razack Mohammed,Lee Tarpley
Journal of Agricultural Science , 2011, DOI: 10.5539/jas.v3n1p3
Abstract: The impacts of a-tocopherol, glycine betaine (GB) and salicylic acid (SA) applications on higher plants have been the subject of many studies, with special emphasis on oxidative stress tolerance under adverse conditions. However, little work has been carried out on rice responses to a-tocopherol, GB or SA under non-stress conditions, in which yield could potentially increased. This study determined the effects of a-tocopherol (2.3 kg ha-1), GB (2.0 kg ha-1) or SA (12.9 g ha-1) application on rice morphology, phenology and physiology under non-stress conditions. The applications did not affect production of tillers, biomass, phenology, or pollen germination; however, plant height, leaf characteristics and physiology, spikelet fertility (SF), panicle and grain characteristics and yield were affected. Plants treated with ?-tocopherol, GB or SA showed 6%, 13% and 13.5% increases in grain yield as a result of decreased respiration and increased membrane integrity and SF.
Confirmation of Pearl Millet-Napiergrass Hybrids Using EST-Derived Simple Sequence Repeat (SSR) Markers  [PDF]
Charlie D. Dowling, Byron L. Burson, Jamie L. Foster, Lee Tarpley, Russell W. Jessup
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.45124
Abstract:

Prospects for deploying perennial grasses that are currently considered leading candidates for dedicated energy crops over large acreages are debatable because of several limitations, including vegetative propagation or small seed size, low biomass production during the first growing season, and incomplete assessments of crop invasiveness risk. Pearl Millet-Napiergrass hybrids (PMN; Pennisetum glaucum [L.] R. Br. × P. purpureum Schumach.), in contrast, are large-seeded, sterile feedstocks capable of high biomass production during establishment year. Novel methods are warranted for confirmation of PMN hybrids, as traditional morphological observations can be inconclusive and chromosome number determination using cytological methods is laborious and time consuming. Six putative PMN lines were produced in this study, and 10 progeny from each line were evaluated using morphological traits, seed fertility, flow cytometry, and expressed sequence tag-simple sequence repeat (EST-SSR) markers. All putative hybrid lines were sterile and failed to produce seed. The PMN hybrids could not be distinguished from either parent using flow cytometry due to highly similar nuclear genome DNA contents. A number of paternal napiergrass-specific EST-SSRs were identified for each PMN line, and four paternal-specific EST-SSRs conserved across all napiergrass accessions were selected to screen the putative PMN hybrids. These EST-SSRs confirmed that all F1 individuals analyzed were PMN hybrids. The use of paternal-specific markers therefore provides a valuable tool in the development of both

Encyclopedia of Pentecostal and Charismatic Christianity
Margaret Tarpley
Theological Librarianship , 2008,
Abstract:
Biomarker metabolites capturing the metabolite variance present in a rice plant developmental period
Lee Tarpley, Anthony L Duran, Tesfamichael H Kebrom, Lloyd W Sumner
BMC Plant Biology , 2005, DOI: 10.1186/1471-2229-5-8
Abstract: An appropriate set of biomarker metabolites to represent the plant developmental period including the initiation and early growth of rice tillering (branching) was obtained by: (1) determining principal components of the comprehensive metabolomic profile, then (2) identifying clusters of metabolites representing variation in loading on the first three principal components, and finally (3) selecting individual metabolites from these clusters that were known to be common among diverse organisms. The resultant set of 21 biomarker metabolites was reliable (P = 0.001) in capturing 83% of the metabolite variation in development. Furthermore, a subset of the biomarker metabolites was successful (P = 0.05) in correctly predicting metabolite change in response to environment as determined in another rice metabolomics study.The ability to define a set of biomarker metabolites that reliably captures the metabolite variance of a plant developmental event was established. The biomarker metabolites are all commonly present in diverse organisms, so studies of their quantitative relationships can provide comparative information concerning metabolite profiles in relation to change in plant development, environment, or genotype.Variation in crop development due to genotype and environment strongly impacts yield. Increases in crop production efficiency are needed on a global basis because of projected expanding human populations coincident with regional decreases in area of arable land [1,2]. "An understanding of crop responses to environment will provide the fundamental basis for developing methods for achieving these increases in efficiency" (Hall,[2]). Plants interact with environment in both chemical and physical ways, but we have very little systematic understanding of how the plant responds chemically during development and in developmental response to environment [3,4]. This lack of knowledge of the broad changes in metabolite patterns during development limits our efficiency t
Encyclopedia of African Religion
Margaret Tarpley,D'Anna Shotts
Theological Librarianship , 2009,
Abstract:
Genome Wide Association Mapping of Grain Arsenic, Copper, Molybdenum and Zinc in Rice (Oryza sativa L.) Grown at Four International Field Sites
Gareth J. Norton, Alex Douglas, Brett Lahner, Elena Yakubova, Mary Lou Guerinot, Shannon R. M. Pinson, Lee Tarpley, Georgia C. Eizenga, Steve P. McGrath, Fang-Jie Zhao, M. Rafiqul Islam, Shofiqul Islam, Guilan Duan, Yongguan Zhu, David E. Salt, Andrew A. Meharg, Adam H. Price
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0089685
Abstract: The mineral concentrations in cereals are important for human health, especially for individuals who consume a cereal subsistence diet. A number of elements, such as zinc, are required within the diet, while some elements are toxic to humans, for example arsenic. In this study we carry out genome-wide association (GWA) mapping of grain concentrations of arsenic, copper, molybdenum and zinc in brown rice using an established rice diversity panel of ~300 accessions and 36.9 k single nucleotide polymorphisms (SNPs). The study was performed across five environments: one field site in Bangladesh, one in China and two in the US, with one of the US sites repeated over two years. GWA mapping on the whole dataset and on separate subpopulations of rice revealed a large number of loci significantly associated with variation in grain arsenic, copper, molybdenum and zinc. Seventeen of these loci were detected in data obtained from grain cultivated in more than one field location, and six co-localise with previously identified quantitative trait loci. Additionally, a number of candidate genes for the uptake or transport of these elements were located near significantly associated SNPs (within 200 kb, the estimated global linkage disequilibrium previously employed in this rice panel). This analysis highlights a number of genomic regions and candidate genes for further analysis as well as the challenges faced when mapping environmentally-variable traits in a highly genetically structured diversity panel.
Cost comparison of microscopy vs. empiric treatment for malaria in southwestern nigeria: a prospective study
Ravi Parikh, Isaac Amole, Margaret Tarpley, Daniel Gbadero, Mario Davidson, Sten H Vermund
Malaria Journal , 2010, DOI: 10.1186/1475-2875-9-371
Abstract: Patients with a diagnosis of clinical malaria were recruited from a mission/university teaching hospital in southwestern Nigeria. The patients underwent free Giemsa thick (diagnosis) and thin (differentiation) smears, but paid for all anti-malarial drugs. Clinical diagnosis was made on clinicians' judgments based on symptoms, including fever, diarrhoea, headache, and body aches. The paediatric regimen was artesunate (6-9 tablets of 3 mg/kg on day one and 1.5 mg/kg for the next four days) plus amodiaquine (10 mg/kg day 1-2 and 5 mg/kg on day three in suspension). Adults were given two treatment options: option one (four and one-half 50 mg artesunate tablets on day one and nine tablets for the next four days, plus three 500 mg sulphadoxine/25 mg pyrimethamine tablets) and option two (same artesunate regimen plus nine 200 mg tablets of amodiaquine at 10 mg/kg day 1-2 and 5 mg/kg on day three). The researchers calculated the costs of smears/drugs from standard hospital charges.Doctors diagnosed 304 patients (170 adults ages >16 years and 134 pediatric) with clinical malaria, prescribing antimalarial drugs to all. Giemsa thick smears were positive in 115/304 (38%). The typical patient cost for a Giemsa smear was 550 Naira (US$3.74 in 2009). For children, the cost of testing all, but treating only Giemsa positives was N888 ($6.04)/child; the cost of empiric treatment of all who were clinically diagnosed was lower, N660 ($4.49)/child. For adults, the cost of testing all, but treating only Giemsa positives was N711 ($4.84)/adult for treatment option one (artesunate and sulphadoxine/pyrimethamine) and N730 ($4.97)/adult for option two (artesunate and amodiaquine). This contrasts to lower costs of empiric treatment for both options one (N610 = $4.14/adult) and two (N680=$4.63/adult).Empiric treatment of all suspected cases of malaria was cheaper (at the end of the dry to the beginning of the rainy season) than only treating those who had microscopy-confirmed diagnoses of mala
The Relationship between Visual Satisfaction and Water Clarity and Quality Management in Tourism Fishing Ports  [PDF]
Lee-Hsueh Lee
Journal of Water Resource and Protection (JWARP) , 2016, DOI: 10.4236/jwarp.2016.88064
Abstract: Visual satisfaction of the tourists with a water body is strongly influenced by water clarity, which is in turn influenced by a number of water quality parameters. Visual satisfaction thus stands to benefit from having a water quality management tool that results in better water clarity. A Clarity Suitability Index of Water Quality (CSIWQ), derived from clarity suitability curves of selected water quality parameters, can allow estimation of optimal values for these parameters, while ensuring high visual satisfaction among tourists. The present study used sampling and survey methodologies to investigate water clarity and quality at five tourism fishing ports; simultaneously, tourists’ visual satisfaction with a water body was assessed through a questionnaire based on their perceptions. The relationship between tourists’ visual satisfaction and water clarity was found to be positive and strong, with water clarity having predictive power of 74.2%. The study showed that DO, BOD, TP, and SS were the most critical parameters for water clarity. A continued product approach of CSIWQ was found to be most appropriate for describing the relationship between water clarity and these four parameters. This enabled a CSIWQ Index value to be calculated. With a CSIWQ value of 0.6, water clarity would be more than 2.08 m, and tourists would experience very high satisfaction. CSI curves showed that DO would preferably be 9.0 mg/L, and BOD, TP, and SS less than 0.5 mg/L, 0.12 mg/L, and 45.0 mg/L, respectively. The model thus produced valuable insights for assessing and improving water quality and ensuring high levels of visual satisfaction among tourists in tourism fishing ports. This model identified only four parameters but could be improved by ensuring that other water quality parameters were included, to encourage an increase in the number of tourists and to include monitoring of more pollutant sources.
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