Variation in tolerance to low environmental pH by the crayfish Orconectes rusticus, O. propinquus, and Cambarus robustus

1985 ◽  
Vol 63 (11) ◽  
pp. 2586-2589 ◽  
Author(s):  
Michael Berrill ◽  
Lois Hollett ◽  
Arlene Margosian ◽  
Jeff Hudson
Keyword(s):  
Life Cycle ◽  
Laboratory Experiments ◽  
Low Ph ◽  
Soft Water ◽  
Stage Iii ◽  
Aluminum Concentration ◽  
Orconectes Rusticus ◽  
Juvenile Stages ◽  
Ph Range ◽  
Crayfish Species

We compared the tolerance of three common Ontario crayfish species to low pH under natural and laboratory conditions in water varying in aluminum concentration and hardness. Both transplant and laboratory experiments indicated that exposure to a pH range of 5.4–6.1 in soft water was toxic to attached juvenile stages of Orconectes rusticus and O. propinquus but not to females carrying the broods. In contrast, stage III juveniles of Cambarus robustus molted and survived in soft water at pH 4. Cambarus robustus is clearly far less sensitive to low pH stress than the two Orconectes species. No increased mortality due to the presence of elevated aluminum occurred among stage III juveniles of the three species exposed to pH 4.5–5.0 in soft water. Physiological differences, augmented by differences in life cycle, may account for the continued presence of C. robustus in acid-stressed lakes and streams.

Variation in Major Ion Concentration of Cambarus robustus and Orconectes rusticus Following Exposure to Low pH

1986 ◽  
Vol 43 (10) ◽  
pp. 2040-2044 ◽  
Author(s):  
Lois Hollett ◽  
Michael Berrill ◽  
Locke Rowe
Keyword(s):  
Chronic Exposure ◽  
Low Ph ◽  
Ion Concentration ◽  
Acute Exposure ◽  
Stage Iii ◽  
Orconectes Rusticus ◽  
Ion Regulation ◽  
Major Ion ◽  
Acid Tolerant ◽  
Total Body

Cambarus robustus is more tolerant of low environmental pH than Orconectes rusticus and this tolerance reflects a difference in ion regulation physiology. Chronic exposure (96 h) of the acid-tolerant C. robustus to pH 3.8 soft water did not significantly change haemolymph [Na+] or [Ca2+] of the adults or total body [Na+] of the juveniles relative to the control (pH 6.5). In contrast, the intolerant O. rusticus showed a significant decrease in [Na+] and increase in [Ca2+] in adult haemolymph (Wood and Rogano. 1986. Can. J. Fish. Aquat. Sci. 43: 1017–1026) and an increase in total body [Na+] of stage III juveniles following acute exposure to pH 3.8 compared with the pH 6.5 control.

Comparative tolerance to low pH of three life stages of the crayfish Orconectes virilis

1984 ◽  
Vol 62 (12) ◽  
pp. 2360-2363 ◽  
Author(s):  
R. L. France
Keyword(s):  
Life Cycle ◽  
Acid Stress ◽  
Low Ph ◽  
Stage Iii ◽  
Life Stages ◽  
Orconectes Virilis ◽  
Old Adults ◽  
Population Extinction ◽  
Life Cycle Stages

The response of three life cycle stages of Orconectes virilis to acidification was investigated in the laboratory. Chronic lethality tests revealed that compared with 2-week-old stage III hatchlings, 2.5-month-old juveniles were seven times more tolerant to acid but only one-twentieth as tolerant as 2- to 3-year-old adults. Juvenile crayfish recovered following exposure to acid stress (pH < 3.5). Comparison of laboratory survival results with data from the literature concerning the magnitude and duration of chemical fluctuations indicates that lentic populations of O. virilis are not likely to decline as a result of episodic acid events. Nevertheless, gradual acidification of a lake to an average annual pH below 5.5 could result in eventual population extinction as a result of mortality of the young.

Aluminum Bioaccumulation and Toxicity to Daphnia magna in Soft Water at Low pH

1985 ◽  
Vol 42 (11) ◽  
pp. 1741-1748 ◽  
Author(s):  
Magda Havas
Keyword(s):  
Daphnia Magna ◽  
Negative Correlation ◽  
Laboratory Experiments ◽  
Low Ph ◽  
Al Toxicity ◽  
Soft Water ◽  
Consistent Pattern ◽  
Additional Source ◽  
Zooplanktivorous Fish ◽  
Al Content

Aluminum may be either harmful or beneficial to Daphnia magna (Straus) depending on pH and on the Al concentration in the water. My results are based on laboratory experiments conducted at various concentrations of total Al (0.02–1.02 mg/L) in soft water (2.5 and 12.5 mg Ca/L) adjusted from pH 6.5 to 4.5. Maximum Al toxicity and maximum Al bioaccumulation were observed at pH 6.5 (at and above 0.32 mg total Al/L). At lower pHs ([Formula: see text]), H+ was toxic to D. magna. Aluminum (1.02 mg/L) temporarily ameliorated H+ toxicity at pH 4.5. Calcium reduced H+ toxicity at pH 5.0 and Al toxicity at pH 6.5. Mortality in the presence of Al and also at low pH was associated with a net loss of Na and Cl from the daphnids. The Ca content of the daphnids was highly variable and showed no consistent pattern apart from a negative correlation with the Al content of the daphnids at pH 5.0 and 5.5. The 24-h bioconcentration ratio for Al was 10 000 at pH 6.5,4000 at pH 5.0, and negligible at pH 4.5. The rapid uptake of Al, particularly at circumneutral pHs, may be an additional source of Al for zooplanktivorous fish and other predators.

scholarly journals Common Loon, Gavia immer, Breeding Success in Relation to Lake pH and Lake Size Over 25 Years

2009 ◽  
Vol 123 (2) ◽  
pp. 146 ◽  
Author(s):  
Robert Alvo
Keyword(s):  
Breeding Success ◽  
Low Ph ◽  
Single Pair ◽  
Gavia Immer ◽  
Common Loon ◽  
Sulphur Deposition ◽  
Acidic Lakes ◽  
Ph Range ◽  
Lake Size ◽  
Critical Ph

I monitored Common Loon (Gavia immer) breeding success in relation to lake pH (range 4.0–8.5) between 1982 and 2007 on 38 single-pair lakes (5–88 ha) in the Sudbury, Ontario, area. No chicks fledged on lakes with pH < 4.4. Chicks fledged on lakes with slightly higher pH only if the lakes were relatively large. Acidic lakes became less acidic as sulphur dioxide emissions from the Sudbury smelters and sulphur deposition from other long-range sources decreased. Two lakes initially too acidic to support successful loon reproduction eventually had successful reproduction. One loon pair used two large acidic lakes (combined area 140 ha) connected by shallow rapids, and one of the adults made extremely long dives (average = 99 s) while foraging for the chicks. One chick died on that lake after apparently ingesting a very large food item; the lack of smaller items was attributed to the lake’s acidity. My results suggest that a shortage of food for chicks is the main reason why low pH reduces breeding success. I suggest that, for lakes without high levels of dissolved organic carbon (DOC), the critical pH for loon breeding success is approximately 4.3, and the suboptimal pH is approximately 4.4–6.0.

scholarly journals THE ABSORPTION SPECTRUM OF VISUAL PURPLE

1938 ◽  
Vol 21 (4) ◽  
pp. 411-430 ◽  
Author(s):  
Aurin M. Chase ◽  
Charles Haig
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Light Transmission ◽  
Low Ph ◽  
The Other ◽  
Distilled Water ◽  
Color Purity ◽  
Chemical Combination ◽  
Ph Range ◽  
Sensitive Group

The absorption spectra of visual purple solutions extracted by various means were measured with a sensitive photoelectric spectrophotometer and compared with the classical visual purple absorption spectrum. Hardening the retinas in alum before extraction yielded visual purple solutions of much higher light transmission in the blue and violet, probably because of the removal of light-dispersing substances. Re-extraction indicated that visual purple is more soluble in the extractive than are the other colored retinal components. However, the concentration of the extractive did not affect the color purity of the extraction but did influence the keeping power. This suggests a chemical combination between the extractive and visual purple. The pH of the extractive affected the color purity of the resulting solution. Over the pH range from 5.5 to 10.0, the visual purple color purity was greatest at the low pH. Temperature during extraction was also effective, the color purity being greater the higher the temperature, up to 40°C. Drying and subsequent re-dissolving of visual purple solutions extracted with digitalin freed the solution of some protein impurities and increased its keeping power. Dialysis against distilled water seemed to precipitate visual purple from solution irreversibly. None of the treatments described improved the symmetry of the unbleached visual purple absorption spectrum sufficiently for it to resemble the classical absorption spectrum. Therefore it is very likely that the classical absorption spectrum is that of the light-sensitive group only and that the absorption spectra of our purest unbleached visual purple solutions represent the molecule as a whole.

Experimental Work with the Tsetse-fly, Glossina palpalis, in Uganda

1936 ◽  
Vol 27 (4) ◽  
pp. 611-632 ◽  
Author(s):  
Kenneth Mellanby
Keyword(s):  
Life Cycle ◽  
East Africa ◽  
Experimental Work ◽  
Laboratory Experiments ◽  
Climatic Conditions ◽  
Tsetse Fly ◽  
London School ◽  
East African ◽  
Laboratory Assistant ◽  
Glossina Palpalis

This is an account of laboratory experiments made with the tsetse Glossina palpalis. The results deal mainly with the effects of climatic conditions, temperature and humidity in particular, on the metabolism and life-cycle. Some work was also done on the activity and behaviour of the fly, but this is very incomplete, though it shows the importance of the problem and the need for further study.The work was done during a visit of just over a year to East Africa, in 1935-36, as Wandsworth Scholar of the London School of Hygiene and Tropical Medicine. I spent most of the time at the Human Trypanosomiasis Institute, Entebbe, Uganda, and also visited tsetse areas in Kenya and Tanganyika. I am grateful to all those who helped to make my visit profitable. Among others, to the Directors of Medical Services of the East African territories, in particular the Hon. W. H. Kauntze of Uganda, and many members of their departments. To Mr. C. B. Symes, Medical Entomologist, Kenya, and to Mr. W. H. Potts, of the Department of Tsetse Research, Tanganyika. I am especially grateful to Dr. H. Lyndhurst Duke, Director of the Human Trypanosomiasis Institute, for many kindnesses. Considerable assistance was received from Mrs. Helen Mellanby, who was working on allied problems at Entebbe. And mention must be made of the intelligent and conscientious help of my laboratory assistant, Omw. Bonaventure Semalwadde.

scholarly journals Effect of pH on the interaction of botulinum neurotoxins A, B and E with liposomes

1989 ◽  
Vol 259 (1) ◽  
pp. 47-53 ◽  
Author(s):  
C Montecucco ◽  
G Schiavo ◽  
B R Dasgupta
Keyword(s):  
Fatty Acid ◽  
Botulinum Neurotoxin ◽  
Structural Changes ◽  
Polar Region ◽  
Low Ph ◽  
Hydrophobic Core ◽  
Head Groups ◽  
Botulinum Neurotoxins ◽  
Ph Range ◽  
Lipid Interaction

The interaction of botulinum neurotoxin serotypes A, B and E with membranes of different lipid compositions was examined by photolabelling with two photoreactive phosphatidylcholine analogues that monitor the polar region and the hydrophobic core of the lipid bilayer. At neutral pH the neurotoxins interacted both with the polar head groups and with fatty acid chains of phospholipids. At acidic pHs the neurotoxins underwent structural changes characterized by a more extensive interaction with lipids. Both the heavy and light chain subunits of the neurotoxins were involved in the process. The change in the nature and extent of toxin-lipid interaction occurred in the pH range 4-6 and was not influenced by the presence of polysialogangliosides. The present data are in agreement with the idea that botulinum neurotoxins enter into nerve cells from a low pH intracellular compartment.

Reproductive Success of Amnicola limosa (Gastropoda) in Low Alkalinity Lakes in South-Central Ontario

1989 ◽  
Vol 46 (5) ◽  
pp. 863-869 ◽  
Author(s):  
Margo A. Shaw ◽  
Gerald L. Mackie
Keyword(s):  
Life Cycle ◽  
Reproductive Success ◽  
Hatching Success ◽  
Low Ph ◽  
Critical Stage ◽  
Percent Survival ◽  
South Central ◽  
Order Of Magnitude ◽  
Magnitude Difference

The reproductive success of the gastropod Amnicola limosa was examined in six lakes ranging in pH from 4.62 to 7.42 to determine which stages in the life cycle were most sensitive to acidification. Although fecundity was significantly greater (p < 0.01) for adults reared at pH 7.42 than at pH 5.89–6.64, a failure to oviposit was documented only at pH 4.62. Hatching success was uniformly high (88–97%) at pH 5.59 to 7.42, while embryos incubated at pH 4.62 suffered complete mortality. The most critical stage in the life cycle is the newly hatched stage. Survival during the 20 d post hatch ranged from 23% at pH 5.59 to 69% at pH 7.42. There was an order of magnitude difference in the cumulative percent survival of recruits in lakes ranging in pH from 5.59 (5.1%) to 7.42 (44.0%). Juveniles raised at low pH (5.59–5.70) were on average 0.20 mm (20%) smaller than those in circumneutral lakes (pH 6.64–7.42). The present low densities of Amnicola limosa in Heney Lake (pH 5.59) can be explained by low recruitment since 1980. Evidence presented suggests that the disappearance of this species from clear low pH lakes (pH < 5.8) is due to reductions in fecundity and hatchling survival.

scholarly journals Chemoenzymatic synthesis of the pH responsive surfactant octyl β-D-glucopyranoside uronic acid

2019 ◽  
Vol 104 (3) ◽  
pp. 1055-1062 ◽  
Author(s):  
Ngoc T. N. Ngo ◽  
Carl Grey ◽  
Patrick Adlercreutz
Keyword(s):  
Substrate Concentration ◽  
Uronic Acid ◽  
Catalyst System ◽  
Low Ph ◽  
Chemoenzymatic Synthesis ◽  
Ph Responsive ◽  
Ph Values ◽  
Wide Ph Range ◽  
Carboxyl Derivative ◽  
Ph Range

AbstractMethodology was developed to expand the range of benign alkyl glycoside surfactants to include also anionic types. This was demonstrated possible through conversion of the glycoside to its carboxyl derivative. Specifically, octyl β-D-glucopyranoside (OG) was oxidised to the corresponding uronic acid (octyl β-D-glucopyranoside uronic acid, OG-COOH) using the catalyst system T. versicolor laccase/2,2,6,6-tetramethylpiperidinyloxy (TEMPO) and oxygen from air as oxidant. The effects of oxygen supply methodology, concentrations of laccase, TEMPO and OG as well as reaction temperature were evaluated. At 10 mM substrate concentration, the substrate was almost quantitatively converted into product, and even at a substrate concentration of 60 mM, 85% conversion was reached within 24 h. The surfactant properties of OG-COOH were markedly dependent on pH. Foaming was only observed at low pH, while no foam was formed at pH values above 5.0. Thus, OG-COOH can be an attractive low-foaming surfactant, for example for cleaning applications and emulsification, in a wide pH range (pH 1.5–10.0).

An aminoquinoline based biocompatible fluorescent and colourimetric pH sensor designed for cancer cell discrimination

2018 ◽  
Vol 42 (24) ◽  
pp. 19818-19826 ◽  
Author(s):  
Jayanta Mandal ◽  
Pravat Ghorai ◽  
Paula Brandão ◽  
Kunal Pal ◽  
Parimal Karmakar ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cancer Cell ◽  
Low Cost ◽  
Ph Sensor ◽  
Low Ph ◽  
Cell Permeability ◽  
Ph Range ◽  
Cell Discrimination

A simple, low cost aminoquinoline based pH sensor,HLwas prepared and it works at a low pH range.HLexhibits cell permeability and used as an effective tool for differentiating between normal and cancer cells.

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