Critical levels and magnitude of effects

1984 ◽  
Vol 55 (3) ◽  
pp. 273-280
Author(s):  
David Navon
Keyword(s):  
Critical Levels

Critical Levels of Mineral Oil Affecting the Absorption of Vitamin A

1952 ◽  
Vol 20 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Frederick Steigmann ◽  
Hans Popper ◽  
Hattie Dyniewicz ◽  
Irene Maxwell
Keyword(s):  
Vitamin A ◽  
Mineral Oil ◽  
Critical Levels

Mineral nutrition, dinitrogen fixation, and growth of Alnuscrispa and Alnusglutinosa

1985 ◽  
Vol 15 (5) ◽  
pp. 855-861 ◽  
Author(s):  
G. Prégent ◽  
C. Camiré
Keyword(s):  
Mineral Nutrition ◽  
Dry Weight ◽  
Optimal Growth ◽  
Maximum Growth ◽  
Dinitrogen Fixation ◽  
Weight Basis ◽  
Critical Levels ◽  
N Status

Invitro cultures of Alnuscrispa (Ait.) Pursh and Alnusglutinosa (L.) Gaertn. were used to estimate critical foliage levels of selected nutrients for optimal growth and dinitrogen (N2) fixation. For A. crispa to obtain 90% of maximum growth and N2 fixation, foliar levels of 0.12% P, 0.13% Mg, <0.31% K, and <0.04% Ca on a dry weight basis were needed. For A. glutinosa, the critical levels were 0.138% P, 0.10% Mg, 0.29% Ca, and ~0.20% K. From all the deficiencies observed, P had the more pronounced effects on N status of both species.

scholarly journals WALANT–Epinephrine injection may lead to short term, reversible episodes of critical oxygen saturation in the fingertips

2021 ◽  
Vol 141 (3) ◽  
pp. 527-533
Author(s):  
P. Moog ◽  
M. Dozan ◽  
J. Betzl ◽  
I. Sukhova ◽  
H. Kükrek ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Substantial Reduction ◽  
Tissue Perfusion ◽  
Critical Levels ◽  
Short Term ◽  
Doppler Flowmetry ◽  
Epinephrine Injection ◽  
Venous Oxygen Saturation

Abstract Introduction Although the WALANT technique’s long-term safeness has been demonstrated in many studies, there are only few data investigating its short-term effects on tissue perfusion and oxygen levels. It was hypothesized that, temporarily, critical levels of tissue perfusion may occur. Methods Seventeen patients, who were scheduled for different procedures in WALANT technique, were injected with 5–7 ml of 1% Articain containing 1:200,000 epinephrine at the finger base. Capillary-venous oxygen saturation, hemoglobin volume in the capillaries, and relative blood flow in the fingertips were recorded once per second by white light spectrometry and laser Doppler flowmetry before, during and after injection for an average of 32 min. Results Clinically, no persistent tissue malperfusion was observed, and there were no postoperative complications. Capillary-venous oxygen saturation was reduced by ≥ 30% in seven patients. Critical levels of oxygen saturation were detected in four patients during 13 intervals, each lasting for 132.5 s on average. Oxygen saturation returned to noncritical values in all patients by the end of the observation period. Blood flow in the fingertips was reduced by more than 30% in nine patients, but no critical levels were observed, as with the hemoglobin. Three patients demonstrated a reactive increase in blood flow of more than 30% after injection. Conclusions Injection of tumescent local anesthesia containing epinephrine into finger base may temporarily cause a substantial reduction in blood flow and lead to critical levels of oxygen saturation in the fingertips. However, this was fully reversible within minutes and does not cause long-term complications.

Propagation of internal gravity waves in fluids with shear flow and rotation

1967 ◽  
Vol 30 (3) ◽  
pp. 439-448 ◽  
Author(s):  
Walter L. Jones
Keyword(s):  
Angular Momentum ◽  
Shear Flow ◽  
Gravity Waves ◽  
Shear Flows ◽  
Internal Gravity Waves ◽  
Vertical Transport ◽  
Wave Frequency ◽  
Slow Rotation ◽  
Critical Levels ◽  
Rotating System

In a rotating system, the vertical transport of angular momentum by internal gravity waves is independent of height, except at critical levels where the Doppler-shifted wave frequency is equal to plus or minus the Coriolis frequency. If slow rotation is ignored in studying the propagation of internal gravity waves through shear flows, the resulting solutions are in error only at levels where the Doppler-shifted and Coriolis frequencies are comparable.

Critical levels of iron, manganese and zinc in Egyptian soils

1986 ◽  
Vol 9 (3) ◽  
pp. 267-280 ◽  
Author(s):  
A. M. Elgala ◽  
A. S. Ismail ◽  
M. A. Ossman
Keyword(s):  
Critical Levels ◽  
Iron Manganese

Testing critical levels in product and geographic diversification: a structural threshold approach

2021 ◽  
Vol 16 (3) ◽  
pp. 529
Author(s):  
Pablo Garrido Prada ◽  
Maria Jesús Delgado Rodriguez ◽  
Desiderio Romero Jordán
Keyword(s):  
Critical Levels ◽  
Geographic Diversification ◽  
Threshold Approach

Manganese as a Micronutrient in Agriculture: Crop Requirement and Management

2021 ◽  
Vol 12 (1-2) ◽  
pp. 225-242
Author(s):  
MH Rashed ◽  
TS Hoque ◽  
MMR Jahangir ◽  
MA Hashem
Keyword(s):  
Growth And Development ◽  
Crop Production ◽  
Nutrient Elements ◽  
Biological Processes ◽  
Critical Levels ◽  
Plant Growth And Development ◽  
Safe Environment ◽  
Body Of Knowledge ◽  
Cell Compartments ◽  
Manganese Uptake

Manganese (Mn) as an essential plant micronutrient affects plant development, when at deficient or toxic levels. Manganese is used in several biological processes as an important contributor in plant growth and development. Manganese uptake depends on forms of Mn in soil solution, crop characteristics including growth rate, and ineteractions with other environmental factors. Its distribution in soils and requirement for crops vary from location to location, depending on soil type and reactions. Despite the metabolic roles of Mn in different plant cell compartments, the importance of Mn requirement in plants, distribution in soils and application to crops has been understated. As a micronutrient, judicious Mn management requires to critically evaluating its concentration in soils, biochemical functions, critical levels, soil availability and interactions with other nutrient elements is essential. This review has critically analysed the existing body of knowledge on Mn distribution in soils, dynamics, functions and management towards better crop production and safe environment. Environ. Sci. & Natural Resources, 12(1&2): 225-242, 2019

scholarly journals Comparative response to N, P and K of grain sorghum and corn: I. Distrophic quartz sand

1983 ◽  
Vol 40 (2) ◽  
pp. 865-889
Author(s):  
J. P. Dantas ◽  
E. Malavolta
Keyword(s):  
Nutritional Status ◽  
Quartz Sand ◽  
Fertilizer Application ◽  
Grain Sorghum ◽  
Critical Levels ◽  
Comparative Response

The comparative response of three sorghum (E-57, TEY 101 and C- 102) and of three corn cultivars (HMD-7974, Centralmex and Piranão) to N, P and K applications was studied in a soil from Anhembi, SP, classifield as Distrophic quartz sand (AQd) was studied. Leaf analyses were made to assess the nutritional status of the two crops. Main conclusions were the following. 1. Sorghum yieldel more than corn; 2. Both sorghum and corn varieties showed different capacities to absorb N, P and K from the soil and to fertilizer application; 3. There was no response to K2O fertilization; 4. Only Piranão increased yield when suplemented with a mixture of micronutrientes; 5. Direct relationships between rates of N and P2O5 and yield and leaf content were found; 6. Direct relationships between rates of N and P2O5 and yield and leaf content were found; 7. The following leaf levels were considered to be adequate, respectively for sorghum and corn: N - 2,00 - 2,25%, 3,25 - 3,50%; P - 0,30 - 0,40, 0,45 - 0,50; K -2,00 - 2,50, 2,20 - 2,40%; Ca - 0,20 - 0,40, 0,44- 0,72% Mg - 0,25 - 0,40, 0,34 - 0,60%; S - 0,50 - 0,70, 0,72 -0,80; Cu - 7 - 10, 11 - 15%; Fe - 84 - 170, 98 - 125%; Mn - 58 - 72, 66 - 85%; Zn - 10 - 14, 18 - 22; critical levels, however, do very depending upon cultivar.

scholarly journals Boron nutrition and yield of alfalfa cultivar crioula in relation to boron supply

2004 ◽  
Vol 61 (5) ◽  
pp. 496-500 ◽  
Author(s):  
Anacleto Ranulfo dos Santos ◽  
Waldssimiler Teixeira de Mattos ◽  
Ana Aparecida da Silva Almeida ◽  
Francisco Antonio Monteiro ◽  
Beatriz Dias Corrêa ◽  
...  
Keyword(s):  
Dry Matter ◽  
Boron Concentration ◽  
Critical Level ◽  
External Solution ◽  
Dry Mass ◽  
Dry Matter Accumulation ◽  
Critical Levels ◽  
Production And Distribution ◽  
Plant Data ◽  
South Brazil

Alfalfa cultivar Crioula (Medicago sativa cv. Crioula) is grown in South Brazil and only a few studies on the plants' boron requirement are available. A greenhouse experiment was carried out with alfalfa to measure boron acquisition, production and distribution in the plant; data on critical level and production potentials were recorded. Plants were grown in ground quartz added with 1 L of solution, with the following boron rates: 0, 0.0625, 0.125, 0.25, 0.50, 1.00, and 2.00 mg L-1. Plants were harvested at 46 days of growth. Forage dry mass was increased by boron supply and dry matter accumulation was considerably low in control. Boron concentration in the leaves was higher than in the stems or roots. Boron utilization from the external solution reached 90% at 0.0625 mg L-1 and sharply decreased with further increasing boron rates. Boron concentration and content in the leaves and in plant tops were at maximum when applied boron was between 1.5 and 1.6 mg L-1. Critical levels of boron in plant were 61 mg kg-1 in the leaves and 39 mg kg-1 in plant tops for this cultivar of alfalfa.

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