Interaction between effects of low pH and low ion concentration on mortality during early development of medaka, Oryzias latipes

1989 ◽  
Vol 67 (9) ◽  
pp. 2158-2168 ◽  
Author(s):  
Weerawan Chulakasem ◽  
Jay A. Nelson ◽  
John J. Magnuson
Keyword(s):  
Ionic Strength ◽  
Oryzias Latipes ◽  
Calcium Content ◽  
Explanatory Models ◽  
Low Ph ◽  
Ion Concentration ◽  
Physiological Mechanisms ◽  
Effects Of Ph ◽  
Independent Effects ◽  
Patterns Of Interaction

Eggs and fry of medaka, Oryzias latipes, were incubated continuously from shortly after fertilization until 7 days after hatching using a factorial design with four water conductivities (9, 16, 28, and 49 μS/cm) and four pH levels (4.2, 4.5, 5.6, or 6.6). Results on survival suggest that only during hatching can independent effects of pH and ionic strength be statistically separated. Mortalities of encapsulated embryos and fry were determined by interactions between pH and ionic strength. Sensitivity to dilute, low pH water was greatest in freshly fertilized eggs and 1- to 4-day-old fry. Egg mortality occurred within a day after water hardening, whereas fry mortality occurred more gradually over the 3 days following hatching. Dilute, low pH water did not influence oxygen consumption or calcium content of eggs, yet impeded normal developmental increases in both calcium content and metabolic rate in fry. Results are discussed mechanistically with respect to causes of the mortality, and two explanatory models are proposed. Speculation that patterns of interaction in multivariate analyses can be indicative of physiological mechanisms also is entertained.

Residual phase lignin in haft cooking related to the conditions in the cook

1997 ◽  
Vol 12 (4) ◽  
pp. 225-229
Author(s):  
Cart-in A-S. Gustavsson ◽  
Chritofer T. Lindgren ◽  
Mikael E. Lindström
Keyword(s):  
Hydrogen Sulfide ◽  
Ionic Strength ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Constant Composition ◽  
Hydroxide Ion ◽  
Sulfide Ion ◽  
Residual Phase ◽  
Kraft Cooking ◽  
Very High

Abstract The amount of lignin reacting according to the slow residual phase, i.e. the residual phase lignin, is in many perspectives an interesting issue. The purpose of the present investigation was to develop a mathematical model to show how the amount of residual phase lignin in the kraft cooking of spruce chips (Picm ahies) depends on the conditions in the earlier phases of the cook. The variables studied were hydroxide ion concentration, hydrogen sulfide ion concentration and ionic strength. The liquor-to-wood ratio during pulping was very high to maintain approximately constant chemical concentrations throughout each experiment (so called "constant composition" cooks). An increase in hydroxide ion concentration andtor hydrogen sulfide ion concentration leads to a decrease in the amount of residual phase lignin, while an increase in ionic strength, i.e. sodium ion concentration, leads to an increase. A signiticant result is that the hydrogen sulfide ion concentration has a pronounced influence on the amount of residual phase lignin during a cook at a low hydroxide ion concentration. The amount of residual phase lignin expressed as % lignin on wood, L,, can be described by the following equation developed for "constant composition" cooks (when cooking with a constant sodium ion concentration of 2 mol/L): LT=0,55-0.32*[HO-](-1,3)*ln[HS-] This equation is valid for a concentration of HO- in the range from 0.17 to 1.4, and a hydrogen sulfide ion concentration from 0.07 to 0.6 mol/L.

Decolorisation of natural organic matter by Phanerochaete chrysosporium: the effect of environmental conditions

2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Phanerochaete Chrysosporium ◽  
Fungal Growth ◽  
Low Ph ◽  
Colour Removal ◽  
Humic Material ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Content

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.

Effects of pH and ionic strength on the cation exchange capacity of soils with variable charge

Soil Research ◽  
1981 ◽  
Vol 19 (1) ◽  
pp. 93 ◽  
Author(s):  
GP Gillman
Keyword(s):  
Ionic Strength ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Surface Soils ◽  
Ph Values ◽  
Variable Charge ◽  
Effects Of Ph ◽  
Variable Charge Soils

The cation exchange capacity of six surface soils from north Queensland and Hawaii has been measured over a range of pH values (4-6) and ionic strength values (0.003-0.05). The results show that for variable charge soils, modest changes in electrolyte ionic strength are as important in their effect on caton exchange capacity as are changes in pH values.

Evaluation of effects of pH and ionic strength on colloidal stability of IgG solutions by PEG-induced liquid-liquid phase separation

2016 ◽  
Vol 145 (18) ◽  
pp. 185101 ◽  
Author(s):  
Ronald W. Thompson ◽  
Ramil F. Latypov ◽  
Ying Wang ◽  
Aleksey Lomakin ◽  
Julie A. Meyer ◽  
...  
Keyword(s):  
Phase Separation ◽  
Ionic Strength ◽  
Liquid Phase ◽  
Colloidal Stability ◽  
Liquid Phase Separation ◽  
Effects Of Ph ◽  
Liquid Liquid Phase Separation

The effects of pH on force and stiffness development in mouse muscles

1987 ◽  
Vol 65 (8) ◽  
pp. 1798-1801 ◽  
Author(s):  
J. M. Renaud ◽  
R. B. Stein ◽  
T. Gordon
Keyword(s):  
High Frequency ◽  
Small Amplitude ◽  
Force Production ◽  
Muscle Length ◽  
Low Ph ◽  
Muscle Stiffness ◽  
Average Force ◽  
Cross Bridge ◽  
Effects Of Ph ◽  
Cross Bridges

Changes in force and stiffness during contractions of mouse extensor digitorum longus and soleus muscles were measured over a range of extracellular pH from 6.4 to 7.4. Muscle stiffness was measured using small amplitude (<0.1% of muscle length), high frequency (1.5 kHz) oscillations in length. Twitch force was not significantly affected by changes in pH, but the peak force during repetitive stimulation (2, 3, and 20 pulses) was decreased significantly as the pH was reduced. Changes in muscle stiffness with pH were in the same direction, but smaller in extent. If the number of attached cross-bridges in the muscle can be determined from the measurement of small amplitude, high frequency muscle stiffness, then these findings suggest that (a) the number of cross-bridges between thick and thin filaments declines in low pH and (b) the average force per cross-bridge also declines in low pH. The decline in force per cross-bridge could arise from a reduction in the ability of cross-bridges to generate force during their state of active force production and (or) in an increased percentage of bonds in a low force, "rigor" state.

Effects of pH, aluminium, and soft water on larvae of the amphibians Bufo bufo and Triturus vulgaris

2006 ◽  
Vol 84 (11) ◽  
pp. 1668-1677 ◽  
Author(s):  
Jon K. Skei ◽  
Dag Dolmen
Keyword(s):  
Ionic Strength ◽  
High Mortality ◽  
Bufo Bufo ◽  
Soft Water ◽  
Internal Environment ◽  
Triturus Vulgaris ◽  
Effects Of Ph ◽  
Low Ionic Strength

Larval Bufo bufo (L., 1758) and Triturus vulgaris (L., 1758) were exposed to soft water (0.5 mg·L–1 Ca2+) experimentally acidified to pH 3.9 to 5.9 and total aluminium concentrations of <10, 150, and 300 µg·L–1. Below pH 4.5 both species experienced increased mortality. The LC50 (168 h) for <10 and 150 µg·L–1 Al was pH 4.3 and 4.1 for B. bufo and 4.2 and 4.1 for T. vulgaris. However, Al3+ increased the survival of both species, which may be due to the contribution of Al3+ to the ionic strength. No B. bufo larvae died at pH >4.5, whereas T. vulgaris at higher Al concentrations suffered relatively high mortality at pH 5.1–5.9, where Al occurs mainly as Al(OH)2+ and Al(OH)2+. Unlike external gills (T. vulgaris), internal gills (B. bufo) have their own internal environment and are probably better protected against the presence of these toxic Al species in the water. These Al species thus seem to be toxic to T. vulgaris larvae but not to B. bufo. Chloride was seen to be important for survival in water of low ionic strength, since the survival of T. vulgaris larvae, particularly at low Al concentration, increased at pH levels down to pH 4.3 when the water was acidified with HCl.

scholarly journals Comparison of Flocculation Characteristics of Humic Acid by Inorganic and Organic Coagulants: Effects of pH and Ionic Strength

2005 ◽  
Vol 14 (8) ◽  
pp. 723-737
Author(s):  
Mei-Lan Xu ◽  
Min-Gyu Lee ◽  
Sang-Kyu Kam
Keyword(s):  
Humic Acid ◽  
Ionic Strength ◽  
Effects Of Ph ◽  
Inorganic And Organic

Rheology and structure of ovalbumin gels at low pH and low ionic strength

2002 ◽  
Vol 16 (3) ◽  
pp. 269-276 ◽  
Author(s):  
M Weijers ◽  
L.M.C Sagis ◽  
C Veerman ◽  
B Sperber ◽  
E van der Linden
Keyword(s):  
Ionic Strength ◽  
Low Ph ◽  
Low Ionic Strength
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