A study of the phosphorus responses of a wide range of accessions from the genus Stylosanthes

1974 ◽  
Vol 25 (6) ◽  
pp. 847 ◽  
Author(s):  
RK Jones
Keyword(s):  
Growth Rates ◽  
Dry Matter ◽  
Phosphorus Uptake ◽  
Numerical Classification ◽  
Foliar Symptoms ◽  
Severe Deficiency ◽  
Wide Range ◽  
Phosphorus Toxicity ◽  
High Concentrations ◽  
Phosphorus Levels

The effects of a wide range of phosphorus levels on the growth and uptake of phosphorus by 30 accessions of the legume genus Stylosanthes, representing seven species, were compared in a glasshouse experiment. The basic data from the experiment were subjected to a numerical classification, and accessions with similar patterns of response were grouped to simplify description and interpretation of the results. Differences in growth and phosphorus uptake under conditions of severe deficiency were fairly small, but there were appreciable differences between groups in the dry matter produced per unit phosphorus absorbed. With progressive improvement in the supply of phosphorus, large differences developed between the groups in growth and phosphorus uptake. One group, in which nodulation was partially or completely ineffective, responded poorly in growth and phosphorus uptake to additions of phosphorus. Other groups, however, were effectively nodulated, and appeared to differ considerably in their inherent growth rates and hence in their uptake of phosphorus during the 55 days of the experiment. At moderately high levels of applied phosphorus (equivalent to between 96 and 192 kg P/ha) accessions in several groups developed foliar symptoms resembling 'phosphorus toxicity', had depressed yields of dry matter, and accumulated phosphorus in their tops to high concentrations.

Effect of diet energy density and season on voluntary dry-matter and energy intake in male red deer

2000 ◽  
Vol 70 (3) ◽  
pp. 547-554 ◽  
Author(s):  
J.R. Webster ◽  
I.D. Corson ◽  
R.P. Littlejohn ◽  
B.M. Masters ◽  
J.M. Suttie
Keyword(s):  
Food Intake ◽  
Energy Density ◽  
Growth Rates ◽  
Dry Matter ◽  
Red Deer ◽  
Energy Requirement ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Wide Range ◽  
Pelleted Diet

AbstractFood intake and growth of red deer is lower in winter than in spring and this reduces the efficiency of venison production. Rumen capacity is also lower during winter and this may contribute to the reduced food intake and therefore growth. In the present study, we investigated the ability of deer to regulate food intake during winter and spring by feeding diets of differing energy densities.Six groups of eight male red deer calves were housed indoors in separate pens. Each group was given,ad libitum, a pelleted diet of a different energy density (8·5, 9·0, 9·5, 10·0, 10·5 and 11·0 MJ metabolizable energy (ME) per kg dry matter (DM) for groups 1 to 6 respectively) but the same amount of protein (156 g/kg DM). Food intake of each group was recorded every 2nd day and animals were weighed every 6 days from 17 May to 9 December. For seasonal comparisons, winter was defined as 24 May to 31 August and spring as 1 September to 9 December.There was no difference (P> 0·05) between the mean live weights of the groups at any time during the study. Live-weight gain (LWG) reached a minimum on 4 July and was lower in winter than spring (161 v. 308 g/day, s.e.d. = 10·0,P< 0·001). LWG was positively related (P< 0·001) to diet ME during winter. DM intake (g/kg M0·75per day) and ME intake (MJ ME per kg M0·75per day) decreased until 16 July and increased thereafter. Mean DM intake was lower in winter than spring (83·5 v. 97·2 g/kg M0·75per day, s.e.d. = 2·05,P< 0·001). DM intake increased as diet energy decreased (P< 0·001) in winter and spring with a steeper slope (P< 0·05) in spring than winter. ME intake was not related to diet ME (P> 0·005) and was lower in winter than spring (0·82 v. 0·95 MJ/kg M0·75per day, s.e.d. = 0·25,P< 0·001). Maintenance energy requirement (MEm) across groups and seasons was calculated to be 0·45 (s.e. 0·22) MJ ME per kg M0·75and the energy requirement for LWG (MEf) was 53 (s.e. 8·5) MJ/kg LWG. MEfwas related (P< 0·01) negatively to diet ME during winter.In summary, deer consuming diets with a wide range of energy densities, altered their DM intake, resulting in similar energy intakes and growth rates on all diets. Animals seemed less able to achieve this compensation in winter compared with spring when food intake increased to support the natural rise in growth rate at that time. These results indicate that deer have target growth rates and/or energy intakes that change with season, and are defended by adjusting food intake.

An Investigation on the Performance of an Oxidation Catalyst Using Two-dimensional Simulation with Detailed Reaction Mechanism

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sreeharsh Nair ◽  
Mayank Mittal
Keyword(s):  
Single Channel ◽  
Catalytic Converter ◽  
Oxidation Catalyst ◽  
Low Temperature Combustion ◽  
Wide Range ◽  
Detailed Reaction Mechanism ◽  
Temperature Combustion ◽  
High Concentrations ◽  
Dimensional Simulation ◽  
Surface Reaction Kinetics

AbstractThe advent of stricter emission standards has increased the importance of aftertreatment devices and the role of numerical simulations in the evolution of better catalytic converters in order to satisfy these emission regulations. In this paper, a 2-D numerical simulation of a single channel of the monolith catalytic converter is presented by using detailed surface reaction kinetics aiming to investigate the chemical behaviour inside the converter. The model has been developed to study the conversion of carbon monoxide (CO) in the presence of propene (C3H6) for low-temperature combustion (LTC) engine application. The inhibition effect of C3H6 over a wide range of CO inlet concentrations is investigated. Considering both low and high levels of CO concentration at the inlet, the 2-D model predicted better results than their corresponding 1-D counterparts when compared with the experimental data from literature. It was also observed that C3H6 inhibition at high temperatures was significant, particularly for high concentrations of CO compared to low concentrations of CO at the inlet.

Application of the EYTEX™ System to the Evaluation of Cosmetic Products and their Ingredients

1992 ◽  
Vol 20 (1) ◽  
pp. 146-163
Author(s):  
Francis H. Kruszewski ◽  
Laura H. Hearn ◽  
Kyle T. Smith ◽  
Janice J. Teal ◽  
Virginia C. Gordon ◽  
...  
Keyword(s):  
Double Blind ◽  
Eye Irritation ◽  
Ocular Irritation ◽  
Rabbit Eye ◽  
Wide Range ◽  
High Concentrations ◽  
Alkaline Membrane ◽  
Positive Agreement

465 cosmetic product formulations and raw ingredients were evaluated with the EYTEX™ system to determine the potential of this in vitro alternative for identifying eye irritation potential. The EYTEX™ system is a non-animal, biochemical procedure developed by Ropak Laboratories, Irvine, CA, that was designed to approximate the Draize rabbit eye irritation assay for the evaluation of ocular irritation. Avon Products Inc. provided all the test samples, which included over 30 different product types and represented a wide range of eye irritancy. All the EYTEX™ protocols available at the time of this study were used. Samples were evaluated double-blind with both the membrane partition assay (MPA) and the rapid membrane assay (RMA). When appropriate, the standard assay (STD) and the alkaline membrane assay (AMA) were used, as well as specific, documented protocol modifications. EYTEX™ results were correlated with rabbit eye irritation data which was obtained from the historical records of Avon Products Inc. A positive agreement of EYTEX™ results with the in vivo assay was demonstrated by an overall concordance of 80%. The assay error was 20%, of which 18% was due to an overestimation of sample irritancy (false positives) and 2% was attributed to underestimation (false negatives). Overestimation error in this study was due in part to the inability of the protocols to accurately classify test samples with very low irritation potential. Underestimation of sample irritancy was generally associated with ethoxylated materials and high concentrations of specific types of surfactants. 100% sensitivity and 85% predictability were described by the data, indicating the efficiency of EYTEX™ in identifying known irritants. A specificity rate of 39% showed the EYTEX™ assay to be weak in discerning non-irritants. However, the EYTEX™ protocols used in this study were not designed to identify non-irritants. A compatibility rate of 99% proved the effectiveness of the EYTEX™ assay in accommodating a diversity of product types. The EYTEX™ system protocols, when used appropriately, can provide a conservative means of assessing the irritant potential of most cosmetic formulations and their ingredients.

scholarly journals Oxygen Is Instrumental for Biological Signaling: An Overview

Oxygen ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 3-15
Author(s):  
John T. Hancock
Keyword(s):  
Oxidative Stress ◽  
Superoxide Anion ◽  
Nitrosative Stress ◽  
Redox Status ◽  
Complex Interplay ◽  
Wide Range ◽  
Form Part ◽  
High Concentrations ◽  
And Control ◽  
Signaling Components

Control of cellular function is extremely complex, being reliant on a wide range of components. Several of these are small oxygen-based molecules. Although reactive compounds containing oxygen are usually harmful to cells when accumulated to relatively high concentrations, they are also instrumental in the control of the activity of a myriad of proteins, and control both the upregulation and downregulation of gene expression. The formation of one oxygen-based molecule, such as the superoxide anion, can lead to a cascade of downstream generation of others, such as hydrogen peroxide (H2O2) and the hydroxyl radical (∙OH), each with their own reactivity and effect. Nitrogen-based signaling molecules also contain oxygen, and include nitric oxide (NO) and peroxynitrite, both instrumental among the suite of cell signaling components. These molecules do not act alone, but form part of a complex interplay of reactions, including with several sulfur-based compounds, such as glutathione and hydrogen sulfide (H2S). Overaccumulation of oxygen-based reactive compounds may alter the redox status of the cell and lead to programmed cell death, in processes referred to as oxidative stress, or nitrosative stress (for nitrogen-based molecules). Here, an overview of the main oxygen-based molecules involved, and the ramifications of their production, is given.

Relationship Between Gas Emissions and Dry Matter Intake in Mature Angus Cows

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 32-33
Author(s):  
Amanda Holder ◽  
Megan A Gross ◽  
Alexi Moehlenpah ◽  
Paul Beck
Keyword(s):  
Dry Matter ◽  
Significant Positive Correlation ◽  
Crossover Design ◽  
Dry Matter Intake ◽  
Data Set ◽  
Gas Emissions ◽  
Positive Correlation ◽  
Wide Range ◽  
Carbon Dioxide Co2 ◽  
Second Period

Abstract The objective of this study was to examine the effects of diet quality on greenhouse gas emissions and dry matter intake (DMI). We used 42 mature, gestating Angus cows (600±69 kg; and BSC 5.3±1.1) with a wide range in DMI EPD (-1.36 to 2.29). Cows were randomly assigned to 2 diet sequences forage-concentrate (FC) or concentrate-forage(CF) determined by the diet they consumed in each period (forage or concentrate). The cows were adapted to the diet and the SmartFeed individual intake units for 14 d followed by 45 d of intake data collection for each period. Body weight was recorded on consecutive weigh days at the beginning and end of each period and then once every two wk for the duration of a period. Cows were exposed to the GreenFeed Emission Monitoring (GEM) system for no less than 9 d during each period. The GEM system was used to measure emissions of carbon dioxide (CO2) and methane (CH4). Only cows with a minimum of 20 total &gt;3-m visits to the GEM were included in the data set. Data were analyzed in a crossover design using GLIMMIX in SASv.9.4. Within the CF sequence there was a significant, positive correlation between TMR DMI and CH4 (r=0.81) and TMR DMI and CO2 (r=0.69), however, gas emissions during the second period on the hay diet were not correlated with hay intake. There was a significant, positive correlation between hay DMI and CO2 (r=0.76) and hay DMI and CH4 (r=0.74) when cows first consumed forage (FC). In comparison to the CF sequence, cows on the FC sequence showed a positive correlation between CO2 and TMR DMI during the second period. There was also a significant positive correlation between hay and TMR DMI when assessed across (r=0.43) or within sequence (FC r=0.41, CF r=0.47).

scholarly journals PHOSPHORUS NUTRITION OF SOYBEANS AS AFFECTED BY PLACEMENT OF FERTILIZER PHOSPHORUS

1983 ◽  
Vol 63 (2) ◽  
pp. 199-210 ◽  
Author(s):  
C. W. BULLEN ◽  
R. J. SOPER ◽  
L. D. BAILEY
Keyword(s):  
Glycine Max ◽  
Total Phosphorus ◽  
Dry Matter ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Phosphorus Uptake ◽  
Growth Chamber ◽  
Grain Yields ◽  
Chamber Experiment ◽  
Glycine Max L

Growth chamber and field experiments were conducted on Southern Manitoba soils, low in available soil phosphorus, to investigate the effects of various placement methods and levels of phosphorus fertilizer on soybean (Glycine max (L.) Merrill ’Maple Presto’). It was found that soybean responded well to applied phosphorus on low-P soil in growth chamber studies. In the first growth chamber experiment, P was applied in solution to 100%, 50%, 25%, 12.5% and 1% of the total soil volume. Dry matter yields, total phosphorus uptake and utilization of fertilizer P increased at each level of applied P as the size of the phosphated band was decreased. The results were partly attributed to greater chemical availability of P in the smaller zones of P fertilizer reaction. In a second growth chamber experiment, soybeans responded differently to phosphorus banded in six different locations. Placement of the fertilizer 2.5 cm directly below the seed was more effective in increasing dry matter yield, total phosphorus uptake and fertilizer P utilization than placement 2.5 cm and 5 cm away at the same depth or placement 5 cm below the seed, whether the band was directly below, 2.5 cm away or 5 cm away. Soybean yield responses in the field were greatest with P banded 2.5 cm directly below the seed on low-P soils. Placement of P 2.5 cm below the seed resulted in grain yields that were 64% and 50% higher (at the two sites) than those obtained in control plots. Sidebanding P, 2.5 cm below and 2.5 cm away from the seed at the same level of application, improved grain yields of control plots by 40% and 39%. Seed placement and broadcast applications of P were not as effective in increasing grain yields. Broadcasting P in fall or in spring at rates of up to 52.38 kg P/ha did not result in significantly higher grain yields than those obtained in control plots. Placement of P in contact with the seed appeared to reduce seedling emergence, resulting in depressed yields when 52.38 kg P/ha were applied. Key words: Glycine max L. Merrill, ’Maple Presto’

Prostacyclin and cerebral vessel relaxation

1982 ◽  
Vol 57 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Kamal S. Paul ◽  
Eric T. Whalley ◽  
Christine Forster ◽  
Richard Lye ◽  
John Dutton
Keyword(s):  
Angiotensin Ii ◽  
Arterial Spasm ◽  
Cerebral Vessel ◽  
Content Type ◽  
Wide Range ◽  
Potent Vasodilator ◽  
Dose Dependent Fashion ◽  
Basilar Arteries ◽  
High Concentrations

✓ The authors have studied the ability of prostacyclin to reverse contractions of human basilar arteries in vitro that were induced by a wide range of substances implicated in the etiology of cerebral arterial spasm. Prostacyclin (10−10 to 10−6M) caused a dose-related reversal of contractions induced by 5-hydroxytryptamine, noradrenaline, angiotensin II, prostaglandin (PG)F2α, and U-46619 (a thromboxane-A2 mimetic). These agents were tested at concentrations or volumes that produced almost maximum or maximum responses and those that produced approximately 50% of the maximum response. Contractions induced by maximum concentrations of angiotensin II and U-46619 were least affected by prostacyclin. In addition, contractions induced by thromboxane-A2 generated from guinea-pig lung were reversed in a dose-dependent fashion by prostacyclin. This ability of prostacyclin to physiologically antagonize contractions of the human basilar artery in vitro induced by high concentrations of various spasmogenic agents suggests that such a potent vasodilator agent or more stable analogue may be of value in the treatment of such disorders as cerebral arterial spasm following subarachnoid hemorrhage.

Radiation absorption, growth and yield of cereals

1978 ◽  
Vol 91 (1) ◽  
pp. 47-60 ◽  
Author(s):  
J. N. Gallagher ◽  
P. V. Biscoe
Keyword(s):  
Dry Matter ◽  
Growing Season ◽  
Growth Efficiency ◽  
Growth And Yield ◽  
Radiation Absorption ◽  
Exponential Equation ◽  
Crop Cover ◽  
Crop Growth Rate ◽  
Wide Range ◽  
Total Crop

SummaryAnalysis of measurements of absorbed radiation and leaf area indices of wheat and barley crops showed that throughout most of growth the fraction of absorbed solar radiation could be described by a simple exponential equation.For several of these crops grown under a wide range of weather and husbandry at Sutton Bonington and Rothamsted, 2-weekly values of crop growth rate (C) were closely related to radiation absorbed until ear emergence and about 3·0 g of dry matter (D.M.) were produced by each MJ of photosynthetically active radiation (PAR) absorbed. Final crop weight was closelyrelated to total PAR absorbed during growth (SA); on average about 2·2 g D.M. were produced per MJ absorbed, equivalent to a growth efficiency (Eg) of approximately 3·9%. Unfertilized and drought-stressed crops had a smaller Eg.The fraction of total crop D.M. harvested as grain (harvest index) varied more for wheat than for barley. Calculations of a maximum realizable grain yield made using the largest values of Eg and SA for the crops measured and assuming a harvestindex of 0.53 (achieved in an experimental crop) showed a grain D.M. yield of 10·3 t D.M./ha to be possible. To achieve such a yield would require full crop cover from the beginning of April until the end of July in a typical English growing season.

scholarly journals Ozone damage, detoxification and the role of isoprenoids – new impetus for integrated models

2016 ◽  
Vol 43 (4) ◽  
pp. 324 ◽  
Author(s):  
Supriya Tiwari ◽  
Rüdiger Grote ◽  
Galina Churkina ◽  
Tim Butler
Keyword(s):  
Stomatal Conductance ◽  
Environmental Conditions ◽  
Economic Losses ◽  
Plant Responses ◽  
Damage Scenarios ◽  
Biochemical Processes ◽  
Wide Range ◽  
Defence Responses ◽  
High Concentrations ◽  
The Impact

High concentrations of ozone (O3) can have significant impacts on the health and productivity of agricultural and forest ecosystems, leading to significant economic losses. In order to estimate this impact under a wide range of environmental conditions, the mechanisms of O3 impacts on physiological and biochemical processes have been intensively investigated. This includes the impact on stomatal conductance, the formation of reactive oxygen species and their effects on enzymes and membranes, as well as several induced and constitutive defence responses. This review summarises these processes, discusses their importance for O3 damage scenarios and assesses to which degree this knowledge is currently used in ecosystem models which are applied for impact analyses. We found that even in highly sophisticated models, feedbacks affecting regulation, detoxification capacity and vulnerability are generally not considered. This implies that O3 inflicted alterations in carbon and water balances cannot be sufficiently well described to cover immediate plant responses under changing environmental conditions. Therefore, we suggest conceptual models that link the depicted feedbacks to available process-based descriptions of stomatal conductance, photosynthesis and isoprenoid formation, particularly the linkage to isoprenoid models opens up new options for describing biosphere-atmosphere interactions.

scholarly journals Chemical composition of leaves of a mangrove tree (Sonneratia apetala Buch.-Ham.) and their correlation with some soil variables

1970 ◽  
Vol 39 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Ashafaque Ahmed ◽  
Mikael Ohlson ◽  
Sirajul Hoque ◽  
Md Golam Moula
Keyword(s):  
Heavy Metals ◽  
Chemical Composition ◽  
Coastal Zone ◽  
Organic Matter Content ◽  
Matter Content ◽  
Sonneratia Apetala ◽  
Mangrove Tree ◽  
Soil Variables ◽  
Wide Range ◽  
High Concentrations

Chemical composition of leaves of Sonneratia apetala Buch.-Ham. collected from three islands (chars) representing three hydrological regimes in a segment of the coastal zone of Bangladesh was studied. Their relations to some soil chemical and physical variables have also been investigated. The results showed that concentrations of B, C, Fe, Ga, Li, Mg, Mn, N, Na, P, Zn and Sr in leaves of S. apetala grown in different islands differed significantly. It was also revealed that some heavy metals, viz. Mn, Fe, Al, Sr and Ti showed wide range of concentrations. The leaves from one of the locations in Motherbunia island were characterized by exceptional high concentrations of heavy metals such as Al, As, Cu, Fe, Li, Ni, Pb that may be due to local contamination. Leaves sampled in the most seaward locations of the same island had highest concentrations of Ba, Ca, Cu, Mn and Na. High Mn concentration was found in the leaves of S. apetala of Motherbunia island. Correlations among soil and plant samples were generally very weak and organic matter content of soil did not appear to play a significant role in the nutrient supply of S. apetala. Key words: Coastal zone; tidal inundation; elemental concentration; Sonneratia apetala DOI: 10.3329/bjb.v39i1.5528Bangladesh J. Bot. 39(1): 61-69, 2010 (June)

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