Effects of Water Acidity, Calcium, and Aluminum on Whole Body Ions of Brook Trout (Salvelinus fontinalis) Continuously Exposed from Fertilization to Swim-Up: A Study by Instrumental Neutron Activation Analysis

1990 ◽  
Vol 47 (8) ◽  
pp. 1593-1603 ◽  
Author(s):  
C. M. Wood ◽  
D. G. McDonald ◽  
C. G. Ingersoll ◽  
D. R. Mount ◽  
O. E. Johannsson ◽  
...  
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Negative Influence ◽  
Positive Influence ◽  
Whole Body ◽  
Healthy Development ◽  
Adverse Conditions ◽  
Aluminum Accumulation ◽  
Decreasing Ph ◽  
Water Acidity

Water Ca, rather than pH or Al, was the most important factor affecting whole body electrolyte levels in fry exposed from fertilization to swim-up (91 d) to 84 combinations of pH (6.5, 5.2, 4.8, 4.4, 4.0), Ca (0.5, 1, 2, 8 mg/L), and Al (0, 12, 37, 111, 333, 1000 μg/L) in flowing soft water. Aluminum accumulation occurred only at water Al levels > 111 μg/L; Al accumulation was inhibited both by increasing Ca and decreasing pH. Under control conditions (pH = 6.5, Ca = 2 mg/L, Al = 0 μg/L), whole body Na, Cl, K, and Ca levels all increased greatly during development, while Mg decreased. Body Ca levels were elevated up to 3-fold, and Na, Cl, and K up to 2-fold by increasing water Ca at the same pH and Al. Low pH had a small negative influence, intermediate levels of Al (37, 111) a slight positive influence, and higher levels of Al a negative influence on Na, Cl, K, and Ca levels. Whole body Mg showed opposite trends, reflecting delayed development under adverse conditions. At pH = 6.5, the positive influence of increasing water Ca on most whole body ions showed a clear threshold between 0.5 and 1 mg/L. At lower pH, this threshold was shifted to between 2 and 8 mg/L, indicating that Ca levels sufficient to support healthy development at circumneutral pH may prove inadequate under acidified conditions.

Whole Body Ions of Brook Trout (Salvelinus fontinalis) Alevins: Responses of Yolk-Sac and Swim-Up Stages to Water Acidity, Calcium, and Aluminum, and Recovery Effects

1990 ◽  
Vol 47 (8) ◽  
pp. 1604-1615 ◽  
Author(s):  
C. M. Wood ◽  
D. G. McDonald ◽  
C. G. Ingersoll ◽  
D. R. Mount ◽  
O. E. Johannsson ◽  
...  
Keyword(s):  
Brook Trout ◽  
Low Ph ◽  
Yolk Sac ◽  
Whole Body ◽  
Critical Stage ◽  
Adverse Conditions ◽  
Developmental Effects ◽  
Water Ph ◽  
Water Acidity ◽  
Dominant Influence

Water pH, rather than Ca or Al, was the most important factor affecting whole body ions in yolk-sac or swim-up fry exposed to a matrix of pH (6.5–4.0), Ca (0.5–8 mg/L), and Al (0–1000 μg/L). Fry were raised from fertilization (day 0) in flowing soft water (pH = 6.5, Ca = 2 mg/L, Al = 0 μg/L), exposed to pH/Ca/Al on day 49 (yolk-sac, 2 d post-hatch) or day 70 (swim-up) for 21 d, and then allowed to recover a further 20 d. Yolk-sac fry were extremely resistant at [Formula: see text]; developmental effects, as indicated by body weight and Mg, were negligible. However whole body Na, Cl, K, and Ca were depressed by low pH, while water Ca was protective. Aluminum (37–111 μg/L) raised most ions above control values, while higher Al lowered them. Swim-up fry were more sensitive, showing pronounced developmental inhibition (lower weight, higher Mg) under adverse conditions; mortality continued during recovery. Low pH was again the dominant influence on body ions, water Ca was protective, while Al (12–111 μg/L) was only protective and not stimulatory. These effects persisted significantly; indeed responses in body Ca were larger after recovery than after the exposure itself, in the field, emergence from the redd into ambient acidic water is probably the critical stage. Water pH will be the principal determinant of whole body ions in alevins surviving this emergence, in contrast to fry exposed continuously from fertilization.

Effects of the Polychlorinated Biphenyl Aroclor® 1254 on Growth, Survival, and Bone Development in Brook Trout (Salvelinus fontinalis)

1978 ◽  
Vol 35 (8) ◽  
pp. 1084-1088 ◽  
Author(s):  
Wilbur L. Mauck ◽  
Paul M. Mehrle ◽  
Foster L. Mayer
Keyword(s):  
Vitamin C ◽  
Brook Trout ◽  
Polychlorinated Biphenyl ◽  
Salvelinus Fontinalis ◽  
Bone Development ◽  
Whole Body ◽  
Aroclor 1254 ◽  
Egg Hatchability ◽  
Hatching Time ◽  
Phosphorous Concentration

Eyed eggs of brook trout (Salvelinus fontinalis) were exposed to Aroclor® 1254 (0.43–13 μg/L) for 10 d before hatching and the fry for 118 d after hatching. Median hatching time, egg hatchability, and sac fry survival were not affected by Aroclor 1254. At 48 d after hatching, growth was significantly (P < 0.05) decreased by Aroclor 1254 concentrations ≥ 1.5 μg/L, but no significant differences in growth of surviving fry were observed at the end of the 118-d exposure. Mortality occurred in fry exposed to 13 μg/L within 48 d of exposure, and after 118 d of exposure significant mortality occurred in the three highest concentrations. Biochemical constituents in brook trout fry related to growth and development were affected by Aroclor 1254. Hydroxyproline and vitamin C concentrations in sac fry (38 d old) were decreased by ≥ 3.1 μg/L. Backbone development in fry exposed for 118 d was significantly altered. Collagen was significantly decreased in the backbone as was the phosphorous concentration, while the calcium concentration increased. Hydroxyproline concentration in collagen isolated from the backbone was also decreased. The no-effect exposure concentration on backbone composition was < 0.43 μg/L. Whole body residues in fry exposed for 118 d were 40 000 to 47 000 times the concentration in water. Key words: brook trout, Salvelinus fontinalis, Aroclor® 1254, polychlorinated biphenyls, PCB, growth, bone development, vitamin C, collagen

Toxaphene Effects on Growth and Development of Brook Trout (Salvelinus fontinalis)

1975 ◽  
Vol 32 (5) ◽  
pp. 609-613 ◽  
Author(s):  
Paul M. Mehrle ◽  
Foster L. Mayer Jr.
Keyword(s):  
Growth And Development ◽  
Good Predictor ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Whole Body ◽  
Flow Through ◽  
Calcium And Phosphorus

Twenty-two days before hatching, eyed eggs of brook trout (Salvelinus fontinalis) were placed in a flow-through system and continuously exposed to toxaphene (0, 39, 68, 139, 288, and 502 ng/liter) until they hatched and the resulting fry were exposed for a further 90 days. Hatchability was not affected by toxaphene, but all of the fry exposed to 502 and 288 ng/liter of toxaphene died by 30 and 60 days after hatch, respectively. Growth of fry was significantly depressed at the 139 and 288 ng/liter concentrations 30 days after hatch and at all concentrations after 60 and 90 days of toxaphene exposure.Whole body collagen of fry, as estimated by hydroxyproline, was significantly decreased in the four higher concentrations of toxaphene within 7–15 days after hatch. Backbone collagen was significantly decreased (P < 0.05) in 30-, 60-, and 90-day-old fry exposed to toxaphene, whereas calcium and phosphorus concentrations in the backbone were increased (P < 0.05). The mineral: collagen ratio was significantly increased by toxaphene. The whole body collagen of sac-fry was a good predictor of later growth and development of brook trout.

Physiological Evidence of Acclimation to Acid/Aluminum Stress in Adult Brook Trout (Salvelinus fontinalis). 1. Blood Composition and Net Sodium Fluxes

1988 ◽  
Vol 45 (9) ◽  
pp. 1587-1596 ◽  
Author(s):  
C. M. Wood ◽  
D. G. McDonald ◽  
C. E. Booth ◽  
B. P. Simons ◽  
C. G. Ingersoll ◽  
...  
Keyword(s):  
Plasma Protein ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Blood Sampling ◽  
Prior Exposure ◽  
Whole Body ◽  
Aluminum Stress ◽  
Short Term ◽  
Flow Through

Brook trout (Salvelinus fontinalis) adapt to chronic sublethal acid/Al stress. The accompanying acclimation confers greater resistance to short-term increases in Al and acidity. Adult trout were exposed in flowing soft water to eight combinations of pH (6.5, 5.2) × Ca2+ (25, 400 μequiv/L) × Al (0, 75, 150 μg/L = 0, 2.8, 5.6 μmol/L). After 10 wk, blood sampling by caudal puncture revealed no significant variations in osmolality, plasma protein, or hemoglobin and only minor differences [Formula: see text] in plasma Na+ and Cl−. Overall, most electrolytes were higher in fish exposed to higher water Al and/or Ca2+; only plasma Ca2+ was directly depressed by low pH. Hematocrit was raised by both low pH and elevated Al. When trout naive to both acid and Al were challenged with pH = 4.8, Al = 333 μg/L under flow-through conditions, there were large negative whole-body Na+ fluxes and marked depressions of plasma Na+ and Cl−, hemoconcentration, and substantial mortality over 48 h. Prior exposure for 10 wk to pH = 5.2 plus either 75 or 150 μg Al/L prevented mortality and ameliorated or abolished these effects through a more rapid recovery of net Na+ balance. Prior exposure to pH = 5.2 alone ameliorated these effects only slightly.

Prolactin Cell Cytology, Plasma Electrolytes, and Whole-Body Sodium Efflux in Acid-Stressed Brook Trout (Salvelinus fontinalis)

1988 ◽  
Vol 45 (7) ◽  
pp. 1212-1221 ◽  
Author(s):  
J. N. Fryer ◽  
W. H. Tam ◽  
B. Valentine ◽  
R. E. Tikkala
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acid Exposure ◽  
Whole Body ◽  
Plasma Sodium ◽  
Prolactin Cells ◽  
Sodium Efflux ◽  
Male And Female ◽  
Prolactin Cell ◽  
Body Sodium

Twelve-month-old brook trout (Salvelinus fontinalis) of both sexes were exposed to acidified water (pH 4 5) for a period of 52 d. Ultrastructural morphometric studies of the prolactin cells of the pituitaries of acid-stressed female trout revealed a reduction, after a latent period of about 1 wk, in prolactin cell area, cytoplasmic area and nuclear area which gradually recovered to control values by day 52 of acid exposure. In both male and female trout, acid exposure resulted in significant decreases in plasma osmolarity, and plasma sodium, which gradually returned to control values by day 52 of the study. Total plasma calcium was not altered by acid exposure in either male or female trout. For both male and female trout, acid exposure resulted in transient elevations in haematocrit and a prolonged suppression of blood pH. The whole-body sodium efflux for trout introduced into dechlorinated tap water or distilled water was significantly greater at pH 4.5 than at pH 7.35. Possible relationships between the acid-induced inhibition of the secretory activity of the prolactin cells and impairments in osmotic and ionic regulation observed in acid-stressed trout are discussed.

Role of Exposure Duration in Hydrogen Ion Toxicity to Brook (Salvelinus fontinalis) and Rainbow Trout (Salmo gairdneri)

1989 ◽  
Vol 46 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Lawrence R. Curtis ◽  
Wayne K. Seim ◽  
Lisbeth K. Siddens ◽  
Debra A. Meager ◽  
Richard A. Carchman ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Exposure Duration ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Recovery Period ◽  
Whole Body ◽  
Toxicity Tests ◽  
Salmo Gairdneri ◽  
Electrolyte Balance ◽  
Toxicant Concentration

Acidification of streams and rivers associated with rainstorm or snowmelt events is often episodic as are many environmental introductions of toxic substances. We examined the toxicity of continuous or intermittent exposures to sulfuric acid (H+) to brook trout (Salvelinus fontinalis) embryos, alevins, and fry. Acute toxicity tests were conducted with juvenile rainbow trout (Salmo gairdneri). These studies permitted evaluation of key components of intermittent exposures (toxicant concentration, exposure duration, and recovery period) on mortality, reduced growth, and perturbed electrolyte balance. Lethality of H+ markedly changed with developmental stage of brook trout. Resistance of the chorion to H+ penetration probably protected embryonic fish, while hatching and onset of active swimming exacerbated H+ toxicity. Response surface methods demonstrated that between pH 4 and 7, time–concentration relationships for H+ toxicity were greatly influenced by exposure duration and peak concentration but little by length of recovery period. Daily pulses at pH 4 with duration as short 4.5 h produced marked mortality after 90 d. This did not occur after 4–60 d of testing. Whole-body Na+, K+, and Ca2+ concentrations of brook trout were negatively correlated with mean H+ concentrations after 90 d of exposure. Cation depletion appeared to be a more sensitive index of chronic, sublethal H+ toxicity than reduced growth.

Does Diversity in The Boardroom Add Value to a Firm?

2018 ◽  
Vol 18 (5) ◽  
Keyword(s):  
Firm Performance ◽  
Panel Data ◽  
Firm Size ◽  
Significant Influence ◽  
Negative Influence ◽  
Positive Influence ◽  
Future Research ◽  
Board Composition ◽  
Board Diversity

This study examines whether board diversity affects firm performance. We investigate this study using panel data of a sample of S&P 500 firms during a 12 year period. After controlling for industry, firm size, and other board composition variables, we find that all three board diversity variables of interest – gender, ethnicity, and age have a significant influence on firm performance. While ethnicity and age have a positive influence on firm performance, it was found that gender has a negative influence. Implications for future research are discussed.

scholarly journals Concerns or Desires Post-Pandemic: An Extended MGB Model for Understanding South Korean Residents’ Perceptions and Intentions to Travel to China

2021 ◽  
Vol 18 (5) ◽  
pp. 2542
Author(s):  
Guanghui Qiao ◽  
Xiao-li Zhao ◽  
Luqi Xin ◽  
Seokchool Kim
Keyword(s):  
Mass Media ◽  
Latent Variables ◽  
Structural Equation ◽  
Mainland China ◽  
Negative Influence ◽  
Positive Influence ◽  
Extended Model ◽  
South Korean ◽  
Structural Relationships ◽  
China Post

In this study, we examined South Korean residents’ travel-related behavioural intention for mainland China post-COVID-19 using an extended model of goal-directed behaviour. To do so, we integrated South Korean residents’ perceptions of country image (PCI), mass media, and concerns about travel into the framework of the original model of goal-directed behaviour (MGB). Structural equation modelling was used to identify the structural relationships among the latent variables. The results show that mass media had a positive influence on South Korean residents’ perception of China’s image, a negative influence on residents’ concerns, and a positive influence on residents’ behavioural intentions for travel overseas. Meanwhile, PCI had a positive influence on residents’ attitude towards travel overseas. The theoretical and practical implications of the study are discussed.

scholarly journals Filling the void of family leadership: institutional support to business model changes in the Italian Industry 4.0 experience

2021 ◽  
Author(s):  
Marco Cucculelli ◽  
Ivano Dileo ◽  
Marco Pini
Keyword(s):  
Business Model ◽  
Industry 4.0 ◽  
Manufacturing Industry ◽  
Business Models ◽  
Institutional Support ◽  
Negative Influence ◽  
Positive Influence ◽  
External Support ◽  
Family Management ◽  
Family Leadership

AbstractWe examine whether the probability of innovating a company’s business model towards the Industry 4.0 paradigm is affected by external institutional support and family leadership. Industry 4.0 is the information-intensive transformation of global manufacturing enabled by Internet technologies aimed at reinventing products and services from design and engineering to manufacturing. Using a sample of 3000 firms from a corporate survey on the manufacturing industry in Italy, our results showed that family leadership has a significant positive influence on the adoption of Industry 4.0 business models, but only in terms of family ownership. By contrast, family management has a negative influence on the probability of adopting a new business model. However, this negative influence is almost totally offset by the presence of the Triple Helix, i.e. the external support by public institutions and universities, which counterbalances the lower propensity of family managers to adopt Industry 4.0 business models. This supporting role only occurs when institutions and universities act together.

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