Effects of time of day, moisture stress, and frosting on the alkaloid content of Phalaris tuberosa

1972 ◽  
Vol 23 (4) ◽  
pp. 611 ◽  
Author(s):  
JD Williams
Keyword(s):  
Environmental Conditions ◽  
Leaf Tissue ◽  
Moisture Stress ◽  
Time Of Day ◽  
Alkaloid Content ◽  
Experimental Results ◽  
Field Conditions ◽  
Field Observations ◽  
Slight Effect ◽  
Related Compounds

Time of day had a slight effect on the level of N,N-dimethylated indolealkylamines in leaf tissue of plants of Phalaris tuberosa L. grown under controlled environmental conditions, and a somewhat larger effect on plants grown under field conditions. The alkaloid content was not affected significantly by moderate increases in moisture stress, but severe wilting caused an increase in the alkaloid content. The immediate regrowth from plants previously stressed had a higher alkaloid content than regrowth from unstressed plants. Severe moisture stress also caused an increase in certain related compounds, as yet unidentified. Frosting increased the alkaloid content more in plants receiving adequate nitrogen, and even more in plants grown at 21/16°C compared with plants grown at 15/10°. Changes in alkaloid content are discussed in relation to field observations and previous experimental results on the toxicity of P. tuberosa pastures to sheep.

scholarly journals The Application of Visual Environmental Economics in the Study of Public Preference and Urban Greenspace

2009 ◽  
Vol 36 (2) ◽  
pp. 355-375 ◽  
Author(s):  
Richard Laing ◽  
Anne-Marie Davies ◽  
David Miller ◽  
Anna Conniff ◽  
Stephen Scott ◽  
...  
Keyword(s):  
Environmental Economic ◽  
Environmental Economics ◽  
Environmental Conditions ◽  
Three Dimensional ◽  
Computer Models ◽  
Time Of Day ◽  
Public Preference ◽  
Daily Lives ◽  
Urban Greenspace ◽  
Physical Variables

Urban greenspace has consistently been argued to be of great importance to the wellbeing, health, and daily lives of residents and users. This paper reports results from a study that combined the visualisation of public results from a study that combined the visualisation of public greenspace with environmental economics, and that aimed to develop a method by which realistic computer models of sites could be used within preference studies. As part of a methodology that employed contingent rating to establish the values placed on specific greenspace sites, three-dimensional computer models were used to produce visualisations of particular environmental conditions. Of particular importance to the study was the influence of variables including lighting, season, time of day, and weather on the perception of respondents. This study followed previous work that established a suitable approach to the modelling and testing of entirely moveable physical variables within the built environment. As such, the study has established firmly that computer-generated visualisations are appropriate for use within environmental economic surveys, and that there is potential for a holistic range of attributes to be included in such studies.

FIELD OBSERVATIONS OF SEA SALT SPRAY AT THE HOKURIKU AND TOHOKU AREA AND EFFECTS OF ENVIRONMENTAL CONDITIONS

2021 ◽  
Vol 77 (2) ◽  
pp. I_445-I_450
Author(s):  
Fuminori NAKAMURA ◽  
Chimedtseren OTGONBILEG ◽  
Takeru MASUDA ◽  
Keiichi KANDA ◽  
Takumi SHIMOMURA
Keyword(s):  
Environmental Conditions ◽  
Salt Spray ◽  
Sea Salt ◽  
Field Observations

Dynamic Analysis of a Floating Offshore Wind Turbine Under Extreme Environmental Conditions

2012 ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Shigeo Yoshida ◽  
Hiroshi Ookubo ◽  
Iku Sato ◽  
Shigesuke Ishida
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Environmental Conditions ◽  
Aerodynamic Force ◽  
Experimental Results ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Analysis Tool ◽  
Simulation Code ◽  
Floating Offshore Wind Turbine

This paper is concerned with the development of a Floating Offshore Wind Turbine (FOWT) utilizing spar-type floating foundation. In order to design such a structure, it is essential to evaluate the dynamic response under extreme environmental conditions. In this study, therefore, a dynamic analysis tool has been developed. The dynamic analysis tool consists of a multi-body dynamics solver (MSC.Adams), aerodynamic force evaluation library (NREL/AeroDyn), hydrodynamic force evaluation library (In-house program named SparDyn), and mooring force evaluation library (In-house program named Moorsys). In this paper, some details of the developed dynamic analysis tool are given. In order to validate the program, comparison with the experimental results, where the wind, current and wave are applied simultaneously, has been made. The comparison shows that satisfactory agreements between the simulation and the experimental results are obtained. However, when VIM (Vortex Induced Motion) occurs, the current loads and cross flow responses (sway and roll) are underestimated by the simulation since the simulation code does not account for the effect of VIM.

scholarly journals The sources of sex differences in aging in annual fishes

2020 ◽  
Author(s):  
Martin Reichard ◽  
Radim Blažek ◽  
Jakub Žák ◽  
Petr Kačer ◽  
Oldřich Tomášek ◽  
...  
Keyword(s):  
Sex Differences ◽  
Social Environment ◽  
Social Factors ◽  
Environmental Conditions ◽  
Natural Populations ◽  
Experimental Results ◽  
Survival Difference ◽  
Captive Populations ◽  
Baseline Mortality ◽  
In The Wild

AbstractSex differences in lifespan and aging are widespread among animals, with males usually the shorter-lived sex. Despite extensive research interest, it is unclear how lifespan differences between the sexes are modulated by genetic, environmental and social factors. We combined comparative data from natural populations of annual killifishes with experimental results on replicated captive populations, showing that females consistently outlived males in the wild. This sex-specific survival difference persisted in social environment only in two most aggressive species, and ceased completely when social and physical contacts were prevented. Demographically, neither an earlier start nor faster rate of aging accounted for shorter male lifespans, but increased baseline mortality and the lack of mortality deceleration in the oldest age shortened male lifespan. The sexes did not differ in any measure of functional aging we recorded. Overall, we demonstrate that sex differences in lifespan and aging may be ameliorated by modulating social and environmental conditions.

EFFECTS OF SOIL MOISTURE TENSIONS ON GROWTH OF WHEAT

1962 ◽  
Vol 42 (1) ◽  
pp. 180-188 ◽  
Author(s):  
J. J. Lehane ◽  
W. J. Staple
Keyword(s):  
Soil Moisture ◽  
Early Stage ◽  
Moisture Stress ◽  
Field Conditions ◽  
Grain Production ◽  
Optimum Conditions ◽  
High Soil Moisture ◽  
Early Stress ◽  
Moisture Supply ◽  
Favorable Conditions

Greenhouse experiments in which wheat was grown on a limited amount of soil moisture showed that crops subjected to moisture stress at an early stage of growth yielded well on all soils tested, but that crops with moisture stress late in the season yielded poorly on loam soils. Late stress was less damaging on clay because high soil moisture tension in this soil resulted in better distribution of moisture use during the critical period.Crops grown under early stress used less moisture, but were equally as efficient in grain production as those grown under optimum conditions. Crops with moisture shortage during heading and filling were inefficient in moisture use.Similar variations in moisture efficiency caused by seasonal trends in available moisture supply have been observed under field conditions. For example, good yields of wheat were produced with a minimum of rainfall in Saskatchewan in 1958 when a shortage of moisture in May and June was followed by more favorable conditions in July.

Picloram Absorption by Broom Snakeweed (Gutierrezia sarothrae) Leaf Tissue

Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 390-394 ◽  
Author(s):  
Tracy M. Sterling ◽  
Norman K. Lownds
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Leaf Tissue ◽  
Axillary Bud ◽  
Solution Ph ◽  
Simple Diffusion ◽  
Foliar Absorption ◽  
Ph Dependent ◽  
Gutierrezia Sarothrae ◽  
Diffusion Absorption

Foliar absorption of picloram by broom snakeweed, a rangeland shrub, was investigated. Picloram uptake into leaf, axillary bud, and stem tissues was similar. In addition, picloram uptake by leaf tissue from greenhouse- and field-grown broom snakeweed did not differ. Picloram accumulated rapidly and absorption saturated between 15 min and 1 h of application; no further absorption occurred through 72 h with maximum uptake ca. 15% of applied picloram. Picloram content increased linearly with increasing external picloram concentration, implying that movement of the herbicide across the cuticle is via diffusion. Absorption was dependent on relative humidity and temperature with the greatest uptake at 94% relative humidity and 35 C, respectively. Absorption was pH dependent; picloram absorption was greatest at pH 4 and least at pH 8. In addition, picloram absorption was less at pH 3 compared to pH 4. These results provide evidence that picloram is absorbed across the cuticle via simple diffusion and absorption is dependent on environmental conditions and solution pH at and following application.

Variability of Peak Hour Factor at Intersections

2005 ◽  
Vol 1920 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Andrew P. Tarko ◽  
Rafael I. Perez-Cartagena
Keyword(s):  
Flow Rate ◽  
Field Measurements ◽  
Past Research ◽  
Time Of Day ◽  
Strong Impact ◽  
Field Observations ◽  
Average Value ◽  
The Common ◽  
Multiple Field ◽  
Over Time

A peak hour factor (PHF) is used to convert hourly traffic volume into the flow rate that represents the busiest 15 min of the rush hour. Past research indicated that PHF had a strong impact on traffic analysis results. The common practice is to use a default value recommended by national or local guidelines or to use limited field observations. This paper investigates the variability of PHF over time and across locations. The day-to-day variability of PHF was found to be as strong as the site-to-site variability. This finding prompts estimation of the PHF on the basis of multiple field measurements or, when it is not possible to obtain measurements, for the use of a model that returns the average value of PHF. This paper presents such a model, which links PHF with the hourly volume, population, and time of day. The paper demonstrates that a large portion of the variability in the sample of observations either can be explained with the model or can be attributed to the day-to-day fluctuation.

Operation and regulation of the lutein epoxide cycle in seedlings of Ocotea foetens

2010 ◽  
Vol 37 (9) ◽  
pp. 859 ◽  
Author(s):  
Raquel Esteban ◽  
Shizue Matsubara ◽  
María Soledad Jiménez ◽  
Domingo Morales ◽  
Patricia Brito ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Higher Plants ◽  
Daily Basis ◽  
Field Conditions ◽  
Photochemical Quenching ◽  
Complete Restoration ◽  
Non Photochemical Quenching ◽  
First Time

Two xanthophyll cycles are present in higher plants: the ubiquitous violaxanthin (V) cycle and the taxonomically restricted lutein epoxide (Lx) cycle. Conversions of V to zeaxanthin (Z) in the first and Lx to lutein (L) in the second happen in parallel under illumination. Unlike the V cycle, in which full epoxidation is completed overnight, in the Lx cycle, this reaction has been described as irreversible on a daily basis in most species (the ‘truncated’ Lx cycle). However, there are some species that display complete restoration of Lx overnight (‘true’ Lx cycle). So far, little is known about the physiological meaning of these two versions of the Lx cycle. Therefore, in the present work, the ‘true’ Lx cycle operation was studied in seedlings of Ocotea foetens (Aiton) Benth. under controlled and field conditions. Complete overnight recovery of the Lx pool in the presence of norfluorazon suggested that the inter-conversions between Lx and L represent a true cycle in this species. Furthermore, Lx responded dynamically to environmental conditions during long-term acclimation. Our data demonstrate the operation of a ‘true’ Lx cycle and, for the first time, its potential involvement in the regulation of non-photochemical quenching in situ. We propose dual regulation of Lx cycle in O. foetens, in which the extent of Lx restoration depends on the intensity and duration of illumination.

Climatic effects on Salmonella survival in plant and soil irrigated with artificially inoculated wastewater: preliminary results

2001 ◽  
Vol 43 (12) ◽  
pp. 103-108 ◽  
Author(s):  
M. P. Palacios ◽  
P. Lupiola ◽  
M. T. Tejedor ◽  
E. Del-Nero ◽  
A. Pardo ◽  
...  
Keyword(s):  
Health Risk ◽  
Environmental Conditions ◽  
Management Practices ◽  
Disease Incidence ◽  
Field Conditions ◽  
Natural Soil ◽  
Wastewater Management ◽  
Secondary Effluent ◽  
Waterborne Diseases ◽  
Agricultural Field

The use of wastewater to replace other water resources for irrigation is highly dependent on whether the health risk and environmental impacts entailed are acceptable or not. Total count and species of microorganisms found in wastewater vary widely because of climatic conditions, season, population sanitary habits and disease incidence. Salmonella, one of the genera associated with waterborne diseases, lives in the intestine. Thus, it is widely accepted that they have a limited survival period under environmental conditions. Wastewater management practices and the ability of Salmonella to survival under field conditions would determine the health risk associated with its presence in wastewater. Although chlorination is widely used, there are situations in which Salmonella is able to survive the sudden stress imposed by this technique. The aim of this experiment was to contribute to the study of the climatic and soil effects on pathogen survival under agricultural field conditions in order to assess which were the best wastewater management practices from both health and economic points of view. Five pots filled with soil seeded with Medicago sativa and an automatic weather station were used. A secondary effluent was artificially inoculated with Salmonella. In addition, open plates (filled with sterilised soil) and ultraviolet radiation isolated plates (filled with non-sterilised soil) were used. As soil heat emission contributes to the environmental conditions around the bacteria, standardised meteorological temperature data had to be carefully used in the bacterial survival studies under agricultural conditions. Radiation was the main cause of Salmonella mortality as its effect was more important than natural soil bacteria competence. Higher reduction of Salmonella counts could have been associated with longer spring days. Soil was able to effectively remove Salmonella. Subsurface drip irrigation methods could provide an effective tool to prevent health risk associated with wastewater irrigation.

Sign in / Sign up

Export Citation Format

Share Document