Studies on soil potassium. III. The intensity of soil potassium following exhaustion by different plants

Soil Research ◽  
1973 ◽  
Vol 11 (2) ◽  
pp. 209 ◽  
Author(s):  
AE Martin ◽  
IF Fergus
Keyword(s):  
Calcium Chloride ◽  
Activity Ratio ◽  
Mean Value ◽  
Soil Potassium ◽  
Peculiar Behaviour ◽  
The Mean ◽  
Differential Ability ◽  
Equilibrium Activity

Exhaustive cropping of four soils by four species revealed only small differences in the limiting intensity (expressed as the equilibrium activity ratio, ARo) of soil potassium, for which the mean value was 5.0 x 10-4 mole1/2 L 1/2. Replanting of depleted soils led to slightly lower values. With a fifth soil, which contained significant amounts of potassium felspar in both clay and sand fractions, grasses reduced the intensity to a lower level (3.8 x 10-4 mole1/2 L 1/2) than did legumes (21.0 x 10-4 mole1/2 L 1/2), and these values were substantially reproducible with replantings of the same species. It was suggested that the peculiar behaviour of this soil may have been associated with the differential ability of the various plants to use potassium from orthoclase. The intensity at which potassium was first absorbed from sources not initially in equilibrium with 0.001M calcium chloride varied from 8 to 29 x 10-4 depending on the soil, and, in the case of the felspathic soil, depending on the plant.

Potassium in soils under different cropping systems:1. Behaviour of K remaining in soils from classical and rotation experiments at Rothamsted and Woburn and evaluation of methods of measuring soil potassium

1971 ◽  
Vol 76 (3) ◽  
pp. 539-552 ◽  
Author(s):  
A. E. Johnston ◽  
T. M. Addiscott
Keyword(s):  
Buffer Capacity ◽  
Activity Ratio ◽  
Cropping Systems ◽  
Crop Rotations ◽  
Exchangeable K ◽  
Soil Potassium ◽  
Ratio Equilibrium ◽  
Equilibrium Activity ◽  
Exchange Behaviour ◽  
Classical Experiment

SUMMARYMeasurements made on soils from the Ley–Arable rotation experiments and some of the Classical experiments at Rothamsted and Woburn are described. Values of exchangeable K, equilibrium activity ratio, equilibrium K potential, and buffer capacity are given for each plot. Potassium quantity/intensity relationships measured for each plot showed that no differences in K exchange behaviour have arisen as a result of manuring or of ley or arable treatments. The only fundamental variation was in the quantity of K in the soils. Continuous ley plots, whether given N fertilizer or containing clover, contained much more K than plots carrying crop rotations. In the Classical experiment soils, quantity of K depended largely on manuring.Potassium uptakes by ryegrass grown on the soils from the various plots are discussed. Potassium uptake was well-related to quantity of K, better so than to the other K parameters. The release of non-exchangeable K to the crop was non-linearly related to the fall in exchangeable K in the soils from the Rothamsted Ley-Arable experiments.Drying and re-wetting the cropped soils released K in amounts inversely proportional to the amount of K in the moist cropped soil. This release of K was unrelated to the original exchangeable K contents of the soils.

scholarly journals Ion Activities and Electrochemical Gradients in the Mealworm Rectal Complex

1991 ◽  
Vol 155 (1) ◽  
pp. 375-402 ◽  
Author(s):  
M. J. O'DONNELL ◽  
J. MACHIN
Keyword(s):  
Active Transport ◽  
Mean Value ◽  
Ph Values ◽  
Tubule Lumen ◽  
Perinephric Space ◽  
Ion Sensitive Microelectrodes ◽  
Ion Activities ◽  
The Mean ◽  
Equilibrium Activity ◽  
Electrochemical Equilibrium

Ion activities and potential differences in cellular and extracellular compartments of the rectal complex of Tenebrio molitor L. larvae have been recorded simultaneously using double-barrelled ion-sensitive microelectrodes. On average, the tubule lumen (TL) was 44mV positive to the haemolymph. Values of aK in the posterior rectal complex exceeding 2700 mmol l−1 were measured, sufficient to account for much of the osmolality of 6.8 osmol kg−1 driving uptake of water from the rectal lumen. The mean value of 797 mmol l−1 exceeded the Nernst equilibrium activity more than 75-fold, indicating active transport of K+. Intracellular potassium activities in the tubules (153 mmol l−1) were high relative to the values in other insect cells, but moderate relative to TL values. Tubule lumen Na+ activities as high as 400 mmol l−1 and pH values of 6.8 were well above the equilibrium values of 11 mmol l−1 and 7.9, respectively, indicating active transport of these cations as well. The ease and frequency of impaling a perinephric space (PNS) surrounding the tubules established it as a functional compartment. On average, the PNS was 22 mV negative to the haemolymph. Potassium activities in the PNS were close to electrochemical equilibrium with the haemolymph, whereas mean aNa and pH were reduced fivefold and 0.5 units, respectively, below the corresponding Nernst equilibrium values. The results suggest that cations move from haemolymph to PNS, and that the PNS is the immediate source for cation transport into the tubule lumen. Cl− was close to electrochemical equilibrium with the haemolymph in both compartments, and presumably enters the tubule lumen as a passive consequence of positive potential differences (PDs) in the tubule lumen.

Potassium (Q/I) relationships as influenced by calcium and magnesium treated as separate ionic species, and by soil submergence

1985 ◽  
Vol 104 (3) ◽  
pp. 577-581
Author(s):  
N. S. Pasricha
Keyword(s):  
Activity Ratio ◽  
Sandy Loam ◽  
Ionic Species ◽  
Mean Value ◽  
Buffering Capacity ◽  
Exchangeable K ◽  
Simple Ratio ◽  
Gains And Losses ◽  
Equilibrium Activity ◽  
Soil Submergence

SummaryThe quantity–intensity relationships between gains and losses of exchangeable K of the soil, and the K-intensity in the equilibrium solution, were determined for two soils incubated at 25 ± 1 °C for 0, 2, 4, 6 and 8 weeks under submerged conditions. The Kintensity modified to include the factor (F) by which Mg differs from Ca in its behaviour on the exchange complex, i. e. aK/(a½Ca + F.a½Mg), gave significantly lower values of equilibrium activity ratio, , and higher values of linear buffering capacity (LBCK), than when measured by the simple ratio, aK/(aCa + aMg)½. The mean value of the factor, F, was 0·46 for Conlubang sandy loam and 0–49 for Luisiana clay. Submergence up to 2 weeks resulted in an increase in the equilibrium activity ratio, , by 43–3% in Conlubang sandy loam. In Luisiana clay, , increased slightly after an initial decrease. In both soils, the readily exchangeable K, , increased with submergence, more so in Conlubang sandy loam than in Luisiana clay. Linear buffering capacity, LBCk, which is a measure of the rate of release of K to the soil solution, increased markedly with soil submergence.

Studies on soil potassium. II. The Q/I relation and other parameters compared with plant uptake of potassium

Soil Research ◽  
1972 ◽  
Vol 10 (1) ◽  
pp. 95 ◽  
Author(s):  
IF Fergus ◽  
AE Martin ◽  
IP Little ◽  
KP Haydock
Keyword(s):  
Exchange Resin ◽  
Clay Fraction ◽  
Cation Exchange Resin ◽  
Mean Value ◽  
Potassium Uptake ◽  
Exchangeable Potassium ◽  
Soil Potassium ◽  
Setaria Sphacelata ◽  
Total Potassium ◽  
Equilibrium Activity

Setaria (Setaria sphacelata cv. Nandi) was grown in 10 surface soils, of contrasting properties, in pots until (after repeated harvesting of tops) plant growth virtually ceased. Uptake of potassium by tops and roots was correlated with change in exchangeable potassium during cropping, initial exchangeable potassium, and with quantities of potassium predicted from the immediate Q/I relations of the soils. Some initially non-exchangeable potassium was absorbed from seven of the soils by the plants, such that these soil quantity parameters (which were statistically equivalent) predicted two-thirds of the total potassium uptake averaged over all soils. Potassium uptake was also correlated with soil potassium soluble in constant-boiling hydrochloric acid, and with potassium extracted by a cation exchange resin (both of which predicted about twice the plant absorption). For six of the soils, uptake of initially non-exchangeable potassium was correlated with the quantity of total potassium present in each pot in the 1 0 . 1 pm clay fraction. The intensity of soil potassium (measured in dilute calcium chloride solution from the immediate Q/I relation) was reduced on all soils by exhaustive cropping to a mean value for the equilibrium activity ratio (AR0) of 4.7 10-4 mole1/2 L.-1/2 (�G = -4500 cal equiv.-1); it was suggested that the observed variations in this value were unlikely to prohibit its use for practical soil testing, except for the prediction of the quantity parameter for those soils for which the form of the isotherm is altered by cropping. A tentative value for the potential of soil potassium at which setaria has an adequate average potassium concentration in its tops was - 3600 cal equiv.-1 (AR0 2.1 x 10-4 mole1/2 L.-1/2).

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

Partition Coefficient Ratios and Tumour Perfusion Studied with 85mKr and 133Xe

1987 ◽  
Vol 26 (06) ◽  
pp. 253-257
Author(s):  
M. Mäntylä ◽  
J. Perkkiö ◽  
J. Heikkonen
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Regional Blood Flow ◽  
Blood Perfusion ◽  
Compartmental Analysis ◽  
Malignant Tumour ◽  
Mean Value ◽  
Perfusion Rate ◽  
Biological Variables ◽  
The Mean

The relative partition coefficients of krypton and xenon, and the regional blood flow in 27 superficial malignant tumour nodules in 22 patients with diagnosed tumours were measured using the 85mKr- and 133Xe-clearance method. In order to minimize the effect of biological variables on the measurements the radionuclides were injected simultaneously into the tumour. The distribution of the radiotracers was assumed to be in equilibrium at the beginning of the experiment. The blood perfusion was calculated by fitting a two-exponential function to the measuring points. The mean value of the perfusion rate calculated from the xenon results was 13 ± 10 ml/(100 g-min) [range 3 to 38 ml/(100 g-min)] and from the krypton results 19 ± 11 ml/(100 g-min) [range 5 to 45 ml/(100 g-min)]. These values were obtained, if the partition coefficients are equal to one. The equations obtained by using compartmental analysis were used for the calculation of the relative partition coefficient of krypton and xenon. The partition coefficient of krypton was found to be slightly smaller than that of xenon, which may be due to its smaller molecular weight.

Detection of Soluble Fibrin Monomer Complexes in Blood by Means of Protamine Sulphate Test

1968 ◽  
Vol 20 (01/02) ◽  
pp. 044-049 ◽  
Author(s):  
B Lipiński ◽  
K Worowski
Keyword(s):  
Human Subjects ◽  
Coronary Thrombosis ◽  
Mean Value ◽  
Healthy Human ◽  
Protamine Sulphate ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
Dog Plasma ◽  
The Mean ◽  
Precipitable Protein

SummaryIn the present paper described is a simple test for detecting soluble fibrin monomer complexes (SFMC) in blood. The test consists in mixing 1% protamine sulphate with diluted oxalated plasma or serum and reading the optical density at 6190 Å. In experiments with dog plasma, enriched with soluble fibrin complexes, it was shown that OD read in PS test is proportional to the amount of fibrin recovered from the precipitate. It was found that SFMC level in plasma increases in rabbits infused intravenously with thrombin and decreases after injection of plasmin with streptokinase. In both cases PS precipitable protein in serum is elevated indicating enhanced fibrinolysis. In healthy human subjects the mean value of OD readings in plasma and sera were found to be 0.30 and 0.11, while in patients with coronary thrombosis they are 0.64 and 0.05 respectively. The origin of SFMC in circulation under physiological and pathological conditions is discussed.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Determination of Plasminogen in Clots and Thrombi

1966 ◽  
Vol 16 (01/02) ◽  
pp. 038-050 ◽  
Author(s):  
Ulla Hedner ◽  
Inga Marie Nilsson ◽  
B Robertson
Keyword(s):  
Mean Value ◽  
Main Mechanism ◽  
Clot Lysis ◽  
Post Mortem ◽  
Digestion Time ◽  
Normal Volunteers ◽  
Casein Solution ◽  
The Mean

SummaryThe plasminogen content was determined by a casein method in plasma and serum from 20 normal volunteers. The mean plasminogen content was found to be 10.1 ACU (the arbitrary caseinolytic unit defined in such a way that using a 3% casein solution and a digestion time of 20 min. at 37°C, 10 ACU gave an extinction of 0.300). No difference between serum and plasma regarding the plasminogen content was found.Plasminogen was determined in drained and drained plus washed clots prepared from 2 ml plasma. The highest values found in the drained clots were 0.9 ACU/clot and 0.2 ACU/clot in the drained plus washed clots.Plasminogen was also determined in drained and drained plus washed clots prepared from plasma with added purified plasminogen. The plasminogen was recovered in the washing fluid. According to these tests, then, purified added plasminogen is washed out of the clots.The plasminogen content of 20 thrombi obtained post mortem was also determined. The mean value was found to be 0.7 ACU/cm thrombus. Judging from our results, the “intrinsic clot lysis theory” is not the main mechanism of clot dissolution.

Perbedaan Pengetahuan Siswa Tentang Penyakit Hepatitis A Sebelum Dan Sesudah Penyuluhan Di MTsN 02 Bondowoso Tahun 2015

2017 ◽  
Vol 4 (2) ◽  
pp. 14
Author(s):  
Putri Megasari
Keyword(s):  
Hepatitis A ◽  
Hepatitis Virus ◽  
Sampling Technique ◽  
Mean Value ◽  
Test Design ◽  
The World ◽  
Before And After ◽  
Post Test ◽  
The Mean ◽  
Paired T Test

Hepatitis has become a health problem in the world. The hepatitis virus infected many people. According to the teacher of MTsN 02 Bondowoso more than 20 students have hepatitis A viral infection. The purpose of this research was to know the differences of students' knowledge about hepatitis A before and after counseling in MTsN 02 Bondowoso 2015. This study used pre-experimental (pre-post test design). This study used stratified random sampling technique, 127 students from 270 sample involved this research,and 143 students was excluded. We used questionnaires to collect data. The results showed that the mean value of the students 'knowledge about hepatitis A before counseling in MTsN 02 Bondowoso 2015 was 83.96 with the lowest value of 37.5 and the highest value was 100. The mean value of the students' knowledge about hepatitis A after counseling in MTsN 02 Bondowoso 2015 was 93.21 with the lowest value waf 62.5 and the highest value was 100. Paired t test showed that t (-9.07) > t table (1.98), the null hypothesis (H0) was rejected. There was a difference between students' knowledge about hepatitis A before and after counseling in MTsN 02 Bondowoso 2015. This study showed that routine counseling by healthcare provider was important to prevent hepatitis A infection.; Keywords: counseling, knowledge of students, hepatitis

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