Rapid metabolism increases the level of 2,4-D resistance at high temperature in common waterhemp (Amaranthus tuberculatus)

Abstract Common waterhemp emerges throughout the crop growing season in the Midwestern United States, and as a result, the seedlings are exposed to a wide range of temperature regimes. Typically, 2,4-D is used in the Midwest to control winter annual broad-leaf weeds before planting soybean and in an early post-emergence application in corn and sorghum; however, the evolution of 2,4-D-resistant common waterhemp in several Midwestern states may limit the use of 2.4-D for controlling this problem weed. Moreover, temperature is one of the crucial factors affecting weed control efficacy of 2,4-D. This research investigated the effect of temperature on efficacy of 2,4-D to control 2,4-D susceptible (WHS) and -resistant (WHR) common waterhemp. Do se-response of WHS and WHR to 2,4-D was assessed at two temperature regimes, high (HT; 34/20 °C, d/n) and low (LT; 24/10 °C, d/n). Whole plant dose response study indicated an increased level of 2,4-D resistance in WHR at HT compared to LT. Additional investigation of the physiological mechanism of this response indicated that both WHS and WHR common waterhemp plants rapidly metabolized 14C 2,4-D at HT compared to LT. In conclusion, a rapid metabolism of 2,4-D conferred increased level of resistance to 2,4-D in WHR at HT. Therefore, application of 2,4-D when temperatures are cooler can improve control of 2,4-D resistant common waterhemp.

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Isotope Gauges: An Analysis of Some Errors in Hot Metal Thickness Measurement

Measurement and Control ◽

10.1177/002029407100400703 ◽

1971 ◽

Vol 4 (7) ◽

pp. T117-T124

Author(s):

F. X. Macedo ◽

F. Seredynski

Keyword(s):

Temperature Distribution ◽

Thickness Measurement ◽

Carbon Steels ◽

Effect Of Temperature ◽

Measuring Instruments ◽

Hot Metal ◽

Theoretical Evaluation ◽

Factors Affecting ◽

Statistical Variation ◽

Wide Range

Isotope gauges are particularly suitable as thickness measuring instruments for hot metal above 5 cm. thick and their application for this purpose is continuing to increase. The paper discusses some of the factors affecting the accuracy of these gauges and, in particular attempts a theoretical evaluation of the errors due to steel composition, temperature distribution and statistical variation. These errors are evaluated for three carbon steels. Errors in thickness measurement due to the different compositions of these steels are evaluated for the two isotope sources most commonly used for gauging purposes namely, Americium 241 and Caesium 137. These isotope sources are representative of those used for the entire practical range of thickness measurement. The paper considers the effect of temperature distribution across the depth of metal on the mass attenuating the γ-rays and the thickness measurements so evaluated are compared with those determined assuming a homogenous stock temperature. The principle of constant absorption is described and also some of its limitations where a wide range of measurements is required. Finally an artifice is discussed whereby some of the limitations may be overcome.

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Factors affecting pitfall capture rates of small ground vertebrates in arid South Australia. I. The influence of weather and moon phase on capture rates of reptiles

Wildlife Research ◽

10.1071/wr99057 ◽

2001 ◽

Vol 28 (1) ◽

pp. 53 ◽

Cited By ~ 26

Author(s):

J. L. Read ◽

K. E. Moseby

Keyword(s):

Cloud Cover ◽

Arid Zone ◽

South Australia ◽

Major Change ◽

Effect Of Temperature ◽

Representative Sampling ◽

Factors Affecting ◽

Wide Range ◽

Maximum Temperatures ◽

Capture Rates

The effect of temperature, humidity, cloud cover, wind and rainfall on capture rates of small reptiles in pitfall traps was assessed in the South Australian arid zone. Capture rates increased significantly with increased ambient temperature. Captures of diurnal reptiles were highest when the minimum temperature was greater than 26°C, while captures of nocturnal reptiles peaked when maximum temperatures exceeded 34°C. Dark nights, particularly those with cloud cover, yielded higher captures of nocturnal reptiles than moonlit or cloudless nights. Representative sampling periods to record a wide range of reptile species should extend for at least 8 days, which is the modal period of a major change in daily temperature during the summer months.

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Effect of temperature on the germination of common waterhemp (Amaranthus tuberculatus), giant foxtail (Setaria faberi), and velvetleaf (Abutilon theophrasti)

Weed Science ◽

10.1614/p2002-172 ◽

2004 ◽

Vol 52 (1) ◽

pp. 67-73 ◽

Cited By ~ 34

Author(s):

Ramon G. Leon ◽

Allen D. Knapp ◽

Micheal D. K. Owen

Keyword(s):

Seed Germination ◽

Abutilon Theophrasti ◽

Effect Of Temperature ◽

Common Waterhemp ◽

Setaria Faberi ◽

Giant Foxtail ◽

Germination Temperature ◽

Percent Germination ◽

Amaranthus Tuberculatus ◽

Response To Temperature

Common waterhemp, giant foxtail, and velvetleaf seed germination in response to temperature was studied with a two-way thermogradient plate. Seeds were maintained under dark and wet conditions at 4 C for 12 wk, and velvetleaf seeds were scarified before the experiments were conducted. The seeds were germinated at 25 different temperature treatments. Minimum and optimum temperatures for velvetleaf germination were approximately 8 and 24 C, respectively. Temperature alternation did not affect the germination of this species. The minimum germination temperature was 10 C for common waterhemp and 14 C for giant foxtail. The optimum germination of giant foxtail occurred at approximately 24 C, but common waterhemp optimum germination was variable depending on temperature alternation. Increased amplitude of the diurnal temperature alternation increased percent germination of these two species, and this was more evident at lower temperatures. In the case of common waterhemp, the temperature required to reach specific germination percentages was reduced by increasing the amplitude of the temperature alternation.

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Rapid Assay Evaluation of Plant Response to Protoporphyrinogen Oxidase (Protox)-Inhibiting Herbicides

Weed Technology ◽

10.1614/wt-04-302r.1 ◽

2006 ◽

Vol 20 (1) ◽

pp. 104-112 ◽

Cited By ~ 6

Author(s):

Jeanne S. Falk ◽

Kassim Al-Khatib ◽

Dallas E. Peterson

Keyword(s):

Dose Response ◽

Electrolyte Leakage ◽

Visible Injury ◽

Protoporphyrinogen Oxidase ◽

Common Waterhemp ◽

Leaf Discs ◽

Rapid Assay ◽

Wild Mustard ◽

Whole Plant ◽

Dose Response Study

Protoporphyrinogen oxidase (protox)-inhibiting herbicides damage cell membranes, resulting in electrolyte leakage. A whole-plant dose-response study and a rapid assay that measured electrolyte leakage was used to determine the response of wild mustard, soybean, and protox inhibitor–susceptible and protox inhibitor–resistant common waterhemp to increasing doses of three protox inhibitors: acifluorfen, fomesafen, and sulfentrazone. For the dose-response study, whole plants were treated with the three protox-inhibitor herbicides. Electroconductivity assay 1 consisted of cutting discs from leaf tissue and submerging them in an incubation medium containing concentrations of acifluorfen, fomesafen, or sulfentrazone. In electroconductivity assay 2, the entire leaf was treated with solutions containing acifluorfen, fomesafen, or sulfentrazone. The whole-plant dose-response study showed increasing visible injury with increasing herbicide rates for all species and all herbicides. The order of visible injury was wild mustard > susceptible common waterhemp > resistant common waterhemp > soybean. In assay 1, electrolyte leakage from leaf discs treated with acifluorfen or fomesafen increased with increasing herbicide concentrations, and was similar for all species. In contrast, electrolyte leakage from leaf discs treated with sulfentrazone did not increase with increasing herbicide concentrations for any species. In assay 2, only wild mustard leaf discs increased in electrolyte leakage with increasing herbicide rates of acifluorfen, fomesafen, and sulfentrazone and followed the regression curves established by the whole-plant dose-response study. However, assay 2 was not able to distinguish between susceptible wild mustard and tolerant soybean, or between susceptible and resistant waterhemp.

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Factors Affecting Molecular Self-Assembly and Its Mechanism

Scientific Research Journal ◽

10.24191/srj.v9i1.5385 ◽

2012 ◽

Vol 9 (1) ◽

pp. 43 ◽

Cited By ~ 1

Author(s):

Hueyling Tan

Keyword(s):

Self Assembly ◽

Building Blocks ◽

Molecular Engineering ◽

Molecular Structures ◽

Polymer Science ◽

New Approach ◽

Factors Affecting ◽

Dna Structures ◽

Self Assembling ◽

Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

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Uphoff Norman, Priti Ramamurthy, and Roy Steiner. Managing Irrigation: Analysing and Improving the Performance of Bureaucracies. New Delhi/Newbury Park/London: Sage Publications. 1991. Hardbound. Price not given.

The Pakistan Development Review ◽

10.30541/v32i2pp.226-228 ◽

1993 ◽

Vol 32 (2) ◽

pp. 226-228

Author(s):

Zakir Hussain

Keyword(s):

Water Distribution ◽

Irrigation System ◽

Irrigation Management ◽

Performance Criterion ◽

New Delhi ◽

Irrigation Performance ◽

Factors Affecting ◽

Wide Range ◽

Resource Mobilisation ◽

Management Issues

The book; under review provides a valuable account of the issues and factors in managing the irrigation system, and presents a lucid and thorough discussion on the performance of the irrigation bureaucracies. It comprises two parts: the first outlines the factors affecting irrigation performance under a wide range of topics in the first five chapters. In Chapter One, the authors have attempted to assess the performance of the irrigation bureaucracies, conceptualise irrigation management issues, and build an empirical base for analysis while drawing upon the experience of ten country cases in Asia, Africa, and Latin America. The Second Chapter focuses on the variations in the management structures identified and the types of irrigation systems; and it defines the variables of the management structures. The activities and objectives of irrigation management are discussed in Chapter Three. The objectives include: greater production and productivity of irrigation projects; improved water distribution; reduction in conflicts; greater resource mobilisation and a sustained system performance. The authors also highlight the performance criterion in this chapter. They identify about six contextual factors which affect the objectives and the performance of irrigation, which are discussed in detail in Chapter Four. In Chapter Five, some organisational variables, which would lead to improvements in irrigation, are examined.

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Business Aviation in Russia: Specific Features and Prospects of Development

Economics and Management ◽

10.35854/1998-1627-2020-1-86-93 ◽

2020 ◽

Vol 26 (1) ◽

pp. 86-93

Author(s):

D. V. Slivinsky ◽

I. A. Fomina ◽

D. G. Menshikh

Keyword(s):

Systems Approach ◽

National Policy ◽

Civil Aviation ◽

Economic Growth Rate ◽

Factors Affecting ◽

Organization And Management ◽

Transport Services ◽

Business Aviation ◽

Wide Range

The presented study determines the role of business aviation in the modern economy and examines the specific features of its development in Russia.Aim. The study aims to analyze the development of business aviation in Russia and its correlation with economic development in general.Tasks. The authors determine the benefits of business aviation as a business tool, examine the specific features of the Russian business aviation market and problems of its development, and identify factors that affect the development of business aviation in Russia.Methods. This study uses the methods of comparative and retrospective analysis, cross-country comparison, systems approach, and expert analytics.Results. Business aviation is a new segment of civil aviation for Russia. Therefore, it is advisable to rely on foreign practices in the management of its development. In many countries, business aviation is a separate industry that specializes in providing transport services to a wide range of corporate clients and/or individuals. The development of this industry is associated with the economic growth rate and the development level of the national economy, and also depends on the national institutional specifics. This study describes the specific features of development of business aviation in Russia and problems arising in the organization and management of this type of business.Conclusions. The authors develop a system of factors affecting the development of business aviation in Russia, describe the major problems of this industry, and propose solutions. The results of this study can be used in the development (adjustment) of business aviation development strategies in Russia both at the industrial and corporate level, and in the implementation of the national policy in this field.

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Qualitative Analysis of Underlying Factors Affecting Vaccine Hesitancy in Iran- A Study Protocol (Preprint)

10.2196/preprints.22746 ◽

2020 ◽

Author(s):

Salime Goharinezhad

Keyword(s):

Vaccine Coverage ◽

Deep Understanding ◽

World Health ◽

Vaccine Hesitancy ◽

Slight Reduction ◽

Cultural Variation ◽

Global Public Health ◽

Factors Affecting ◽

Wide Range ◽

Context Specific

BACKGROUND World Health Organization declared the vaccine hesitancy as a global public health threat in 2019. Since even a slight reduction in vaccine coverage rates can lead to a decrease in herd immunity, it is imperative to explore the underlying factors affecting vaccine hesitancy. in specific contexts, considering socioeconomic and cultural variation, to ensure interventions targeting hesitancy are well formulated and intervened. OBJECTIVE The main objective of this study is to identify underlying factors affecting vaccine hesitancy in Iran. METHODS A framework qualitative study will be conducted in the west of Tehran province in 2020. Participants in the study will be recruited hesitance-parents who extracted from the SIB system (an electronic health record in Iran) to maximize diversity. Interviews will be analyzed based on ''Determinants of Vaccine Hesitancy Matrix'' which developed by the WHO-SAGE Working Group. RESULTS deep understanding from the context-specific reasons for vaccine hesitancy cause to formulate better strategies to address them. The ultimate goal of this study is to inform future policies to increase the uptake of the vaccine in Iran. CONCLUSIONS This result of study will show variety opinions about vaccination among different types of socioeconomic and demographic households. The wide range of reasons related to vaccine hesitancy imply to more comprehensive, context-specific interventions. Today, the most important intervention issues focus on improving information about effectiveness and safety of vaccines, while other interventions for promoting vaccination is need to addressed.

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Factors Affecting Acoustic Properties of Natural-Fiber-Based Materials and Composites: A Review

Textiles ◽

10.3390/textiles1010005 ◽

2021 ◽

Vol 1 (1) ◽

pp. 55-85

Author(s):

Tufail Hassan ◽

Hafsa Jamshaid ◽

Rajesh Mishra ◽

Muhammad Qamar Khan ◽

Michal Petru ◽

...

Keyword(s):

Sound Absorption ◽

Natural Fiber ◽

Volume Fraction ◽

Fiber Type ◽

Alkali Treatment ◽

Acoustic Properties ◽

Synthetic Fiber ◽

Sound Insulation ◽

Factors Affecting ◽

Wide Range

Recently, very rapid growth has been observed in the innovations and use of natural-fiber-based materials and composites for acoustic applications due to their environmentally friendly nature, low cost, and good acoustic absorption capability. However, there are still challenges for researchers to improve the mechanical and acoustic properties of natural fiber composites. In contrast, synthetic fiber-based composites have good mechanical properties and can be used in a wide range of structural and automotive applications. This review aims to provide a short overview of the different factors that affect the acoustic properties of natural-fiber-based materials and composites. The various factors that influence acoustic performance are fiber type, fineness, length, orientation, density, volume fraction in the composite, thickness, level of compression, and design. The details of various factors affecting the acoustic behavior of the fiber-based composites are described. Natural-fiber-based composites exhibit relatively good sound absorption capability due to their porous structure. Surface modification by alkali treatment can enhance the sound absorption performance. These materials can be used in buildings and interiors for efficient sound insulation.

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Membrane Lipid Composition of the Moderately Thermophilic Ammonia-Oxidizing Archaeon “Candidatus Nitrosotenuis uzonensis” at Different Growth Temperatures

Applied and Environmental Microbiology ◽

10.1128/aem.01332-19 ◽

2019 ◽

Vol 85 (20) ◽

Cited By ~ 4

Author(s):

Nicole J. Bale ◽

Marton Palatinszky ◽

W. Irene C. Rijpstra ◽

Craig W. Herbold ◽

Michael Wagner ◽

...

Keyword(s):

Lipid Composition ◽

Strong Influence ◽

Thermal Spring ◽

Membrane Lipid ◽

Effect Of Temperature ◽

Environmental Niche ◽

Membrane Lipid Composition ◽

Moderately Thermophilic ◽

Wide Range ◽

Membrane Spanning

ABSTRACT “Candidatus Nitrosotenuis uzonensis” is the only cultured moderately thermophilic member of the thaumarchaeotal order Nitrosopumilales (NP) that contains many mesophilic marine strains. We examined its membrane lipid composition at different growth temperatures (37°C, 46°C, and 50°C). Its lipids were all membrane-spanning glycerol dialkyl glycerol tetraethers (GDGTs), with 0 to 4 cyclopentane moieties. Crenarchaeol (cren), the characteristic thaumarchaeotal GDGT, and its isomer (crenʹ) were present in high abundance (30 to 70%). The GDGT polar headgroups were mono-, di-, and trihexoses and hexose/phosphohexose. The ratio of glycolipid to phospholipid GDGTs was highest in the cultures grown at 50°C. With increasing growth temperatures, the relative contributions of cren and crenʹ increased, while those of GDGT-0 to GDGT-4 (including isomers) decreased. TEX86 (tetraether index of tetraethers consisting of 86 carbons)-derived temperatures were much lower than the actual growth temperatures, further demonstrating that TEX86 does not accurately reflect the membrane lipid adaptation of thermophilic Thaumarchaeota. As the temperature increased, specific GDGTs changed relative to their isomers, possibly representing temperature adaption-induced changes in cyclopentane ring stereochemistry. Comparison of a wide range of thaumarchaeotal core lipid compositions revealed that the “Ca. Nitrosotenuis uzonensis” cultures clustered separately from other members of the NP order and the Nitrososphaerales (NS) order. While phylogeny generally seems to have a strong influence on GDGT distribution, our analysis of “Ca. Nitrosotenuis uzonensis” demonstrates that its terrestrial, higher-temperature niche has led to a lipid composition that clearly differentiates it from other NP members and that this difference is mostly driven by its high crenʹ content. IMPORTANCE For Thaumarchaeota, the ratio of their glycerol dialkyl glycerol tetraether (GDGT) lipids depends on growth temperature, a premise that forms the basis of the widely applied TEX86 paleotemperature proxy. A thorough understanding of which GDGTs are produced by which Thaumarchaeota and what the effect of temperature is on their GDGT composition is essential for constraining the TEX86 proxy. “Ca. Nitrosotenuis uzonensis” is a moderately thermophilic thaumarchaeote enriched from a thermal spring, setting it apart in its environmental niche from the other marine mesophilic members of its order. Indeed, we found that the GDGT composition of “Ca. Nitrosotenuis uzonensis” cultures was distinct from those of other members of its order and was more similar to those of other thermophilic, terrestrial Thaumarchaeota. This suggests that while phylogeny has a strong influence on GDGT distribution, the environmental niche that a thaumarchaeote inhabits also shapes its GDGT composition.

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