Growth and adaptation to sea water in 'underyearling' sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon subjected to regimes of constant or changing temperature and day length

1978 ◽  
Vol 56 (11) ◽  
pp. 2413-2421 ◽  
Author(s):  
W. C. Clarke ◽  
J. E. Shelbourn ◽  
J. R. Brett
Keyword(s):  
Growth Rate ◽  
Environmental Factors ◽  
Constant Temperature ◽  
Sea Water ◽  
Rate Of Change ◽  
Day Length ◽  
Artificial Photoperiod ◽  
Final Length ◽  
Temperature Controlled ◽  
Rate Of Response

Growth and hypoosmoregulatory ability of 'underyearling' sockeye and coho were studied in relation to the influence of constant as well as changing temperature and day length. Both environmental factors influenced growth and osmoregulatory performance. Temperature controlled the rate of response to photoperiod so that changes in growth rate caused by photoperiod treatments were apparent sooner at higher temperatures than at lower ones. Changing temperatures did not alter the final length or weight achieved in comparison with a constant temperature of the same mean.The sensitivity of the fry to photoperiod varied seasonally. The characteristics of photoperiod which formed the most important cues were direction of change and rate of change of day length.It is concluded that artificial photoperiod treatments are not required to produce 'underyearling' sockeye smolts in spring, provided that water temperatures are sufficient to allow growth to a weight of 3–4 g. However, coho smoltify at a larger size and thus would require a substantially greater thermal input to produce 'underyearling' smolts in spring.

scholarly journals Seasonal Changes in Reproductive Productivity, Growth Rate, and Food Intake in Mice Exposed to Different Regimes of day Length and Environmental Temperature

1972 ◽  
Vol 25 (3) ◽  
pp. 627 ◽  
Author(s):  
Pamela R Pennycuik
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Constant Temperature ◽  
Productivity Growth ◽  
Seasonal Changes ◽  
Environmental Temperature ◽  
Day Length ◽  
Seasonal Fluctuations

Groups of mice were maintained in three different environments: (1) constant day length and constant temperature; (2) seasonal fluctuations in day length and constant temperature; (3) seasonal fluctuations in day length and seasonal fluctua-tions in temperature.

Environmental Factors Affecting the Yield of Tea (Camellia sinensis). II. Effects of Soil Temperature, Day Length, and Dry Air

1982 ◽  
Vol 18 (1) ◽  
pp. 53-63 ◽  
Author(s):  
T. W. Tanton
Keyword(s):  
Growth Rate ◽  
Environmental Factors ◽  
Environmental Variable ◽  
Day Length ◽  
Daily Maximum ◽  
Temperature Model ◽  
Factors Affecting ◽  
Dry Air ◽  
Soil Temperatures ◽  
Short Days

SUMMARYTemperature is the major environmental variable affecting the yield of tea, but within the framework of a temperature model shoot extension is severely depressed when daily maximum vapour pressure deficits rise above 2.3 kPa. Day length does not affect shoot extension when the nights are cool (10°C), but growth rate is depressed by short days (11 h) when nights are warm (20°C). Soil temperatures between 18–25°C do not affect shoot extension.

A note on the stability of an infinite fluid heated from below

1967 ◽  
Vol 29 (3) ◽  
pp. 461-464 ◽  
Author(s):  
J. L. Robinson
Keyword(s):  
Growth Rate ◽  
Temperature Profile ◽  
Constant Temperature ◽  
Temperature Difference ◽  
Rate Of Change ◽  
Time Dependent ◽  
Initial Value ◽  
Horizontal Boundary ◽  
Boundary Case ◽  
The Stability

The problem of the stability of a fluid with time-dependent heating has been investigated by Morton (1957), Lick (1965) and Foster (1965). Morton and Lick assumed that the rate of change of the temperature profile is small compared with the growth rate of the disturbances (quasi-static assumption). This assumption is invalid near the onset of instability (as defined by ∂/∂t = 0), and Foster has therefore used an initial-value approach.In this paper the range of validity of the quasi-static assumption is discussed, and results of a time-scaled analysis and calculations based on this are compared with the work of Foster; the agreement is found to be good. We restrict our attention to a semi-infinite fluid initially at a constant temperature; at time t = 0 a temperature difference ΔT is applied at the (lower) horizontal boundary (case (A) of Foster).

scholarly journals Spatial-Temporal Patterns and Controls of Evapotranspiration across the Tibetan Plateau (2000–2012)

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Hao Zhang ◽  
Jian Sun ◽  
Junnan Xiong
Keyword(s):  
Tibetan Plateau ◽  
Environmental Factors ◽  
Vegetation Type ◽  
Middle Part ◽  
Rate Of Change ◽  
Ecological Indicator ◽  
The Tibetan Plateau ◽  
Grassland Ecosystems ◽  
Key Factor ◽  
Positive Correlations

Evapotranspiration (ET) is a key factor to further our understanding of climate change processes, especially on the Tibetan Plateau, which is sensitive to global change. Herein, the spatial patterns of ET are examined, and the effects of environmental factors on ET at different scales are explored from the years 2000 to 2012. The results indicated that a steady trend in ET was detected over the past decade. Meanwhile, the spatial distribution shows an increase of ET from the northwest to the southeast, and the rate of change in ET is lower in the middle part of the Tibetan Plateau. Besides, the positive effect of radiation on ET existed mainly in the southwest. Based on the environment gradient transects, the ET had positive correlations with temperature (R>0.85, p<0.0001), precipitation (R > 0.89, p < 0.0001), and NDVI (R > 0.75, p < 0.0001), but a negative correlation between ET and radiation (R = 0.76, p < 0.0001) was observed. We also found that the relationships between environmental factors and ET differed in the different grassland ecosystems, which indicated that vegetation type is one factor that can affect ET. Generally, the results indicate that ET can serve as a valuable ecological indicator.

Temperature/light interactions and the effect of seed source on germination of annual ryegrass (Lolium rigidum Gaud.) seeds

1976 ◽  
Vol 27 (6) ◽  
pp. 779 ◽  
Author(s):  
D Gramshaw
Keyword(s):  
Constant Temperature ◽  
Day Length ◽  
Maximum Temperature ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Average Temperature ◽  
Seed Sources ◽  
Alternating Temperature ◽  
Germinating Seeds ◽  
Temperature Optima

Germination of Lolium rigidum seeds, in the light (12 hr day length) and in the dark, was studied at constant and alternating (12/12 hr) temperatures in the range 8–35°C. Seeds had after-ripened for 22 weeks. Different constant temperature optima for germinability were found: 27° in light and 11° in dark. Germinability at alternating temperatures in darkness was determined solely by the minimum temperature of the alternation, and there was no response to thermoperiodicity per se. In contrast, light and alternating temperature appeared to interact to increase germinability, although the highest germinability occurred only when the maximum temperature was close to the optimum constant temperature, i.e. about 27°. Germination in both light and dark was most rapid where either the constant or the average temperature of an alternating regime was between 18 and 29°. Below 18° germination rates decreased markedly, and at 8°, rates were one-third of those at 18°. Seeds germinated more slowly in light than in darkness at all temperatures, but the differences were small relative to the effects of low temperatures.In another study, seeds collected from plants naturalized in eight different localities in the cereal belt of Western Australia and subsequently planted together in two contrasting environments were examined for germinability at 24/12°C in light and dark 18 weeks after harvest. Dark germinability differed between seed sources but not between planting sites, and ranged between 78 and 93%. Exposure of germinating seeds to light substantially alleviated dormancy in seeds from all sources.

Growth rate and habitat of Nautilus pompilius inferred from radioactive and stable isotope studies

Paleobiology ◽  
1981 ◽  
Vol 7 (4) ◽  
pp. 469-480 ◽  
Author(s):  
J. Kirk Cochran ◽  
Danny M. Rye ◽  
Neil H. Landman
Keyword(s):  
Growth Rate ◽  
Half Life ◽  
Activity Ratio ◽  
Sea Water ◽  
Tissue Growth ◽  
Carbon And Oxygen Isotopes ◽  
Nautilus Pompilius ◽  
Radioactive Disequilibrium ◽  
Horizontal Migration ◽  
Isotope Studies

The growth rate of Nautilus pompilius in its natural environment has been determined from radioactive disequilibrium between 210Pb (half-life 22.3 yr) and its granddaughter 210Po (half-life 138 d) in septa of two juvenile specimens. 210Pb and 210Po data from the most recently formed shell material of both specimens indicate that 210Pb from sea water is incorporated into septa during septal formation and 210Po is excluded. Therefore the 210Po/210Pb activity ratio serves as a chronometer to estimate the age of each septum and the time between formation of septa. In the specimens studied the average time between sucessive points in septal deposition is 75 d for the nine most recent septa of one specimen and 23 d for the six most recent septa of the other specimen. These different growth rates, if representative of the ontogeny of each animal, suggest that the timing of septal deposition probably is dependent on the rate of shell and tissue growth coupled with buoyancy requirements and is not a unique period for all Nautilus. The habitat and ontogeny of Nautilus may be inferred from the pattern of stable isotopes of oxygen and carbon in the septa. Both specimens show a pronounced break in δ18O from nearly uniform light values in the first seven septa to heavier values (∼1%) after the seventh septum. We interpret this break to correspond to the hatching of Nautilus. A temperature (i.e. water depth) interpretation of the δ18O data for septa after the eighth is complicated by a positive correlation between δ18O and δ13C. This may reflect horizontal migration of the animal or a kinetically controlled fractionation of carbon and oxygen isotopes during septal formation.

scholarly journals A Comparison of Psychophysical Dose-Response Behaviour across 16 Sweeteners

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1632 ◽  
Author(s):  
May Wee ◽  
Vicki Tan ◽  
Ciarán Forde
Keyword(s):  
Growth Rate ◽  
Dose Response ◽  
Rate Of Change ◽  
The Other ◽  
Rebaudioside A ◽  
Glycaemic Response ◽  
Sensory Panel ◽  
Response Behaviour ◽  
Sweetness Intensity ◽  
Sugar Replacement

Reduction or replacement of sucrose while maintaining sweetness in foods is challenging, but today there are many sweeteners with diverse physical and caloric compositions to choose from. The choice of sweetener can be adapted to match reformulation goals whether these are to reduce calories, lower the glycaemic response, provide bulk or meet criteria as a natural ingredient. The current study sought to describe and compare the sweetness intensity dose-response, sweetness growth rate, sweetness potency, and potential for calorie reduction across 16 different sweeteners including sucrose. Sweetness growth rate was defined as the rate of change in sweetness intensity per unit of sweetener concentration. Sweetness potency was defined as the ratio of the concentration of a sweetener to that of sucrose at equivalent sweetness intensity, whereas the potential for calorie reduction is the caloric value of a sweetener compared to sucrose at matched sweetness intensities. Sweeteners were drawn from a range of nutritive saccharide (sucrose, dextrose, fructose, allulose (d-psicose), palatinose (isomaltulose), and a sucrose–allulose mixture), nutritive polyol (maltitol, erythritol, mannitol, xylitol, sorbitol), non-nutritive synthetic (aspartame, acesulfame-K, sucralose) and non-nutritive natural sweeteners stevia (rebaudioside A), luo han guo (mogroside V). Sweetness intensities of the 16 sweeteners were compared with a sensory panel of 40 participants (n = 40; 28 females). Participants were asked to rate perceived sweetness intensity for each sweetener series across a range of concentrations using psychophysical ratings taken on a general labelled magnitude scale (gLMS). All sweeteners exhibited sigmoidal dose-response behaviours and matched the ‘moderate’ sweetness intensity of sucrose (10% w/v). Fructose, xylitol and sucralose had peak sweetness intensities greater than sucrose at the upper concentrations tested, while acesulfame-K and stevia (rebA) were markedly lower. Independent of sweetener concentration, the nutritive sweeteners had similar sweetness growth rates to sucrose and were greater than the non-nutritive sweeteners. Non-nutritive sweeteners on the other hand had higher potencies relative to sucrose, which decreases when matching at higher sweetness intensities. With the exception of dextrose and palatinose, all sweeteners matched the sweetness intensity of sucrose across the measured range (3.8–25% w/v sucrose) with fewer calories. Overall, the sucrose–allulose mixture, maltitol and xylitol sweeteners were most similar to sucrose in terms of dose-response behaviour, growth rate and potency, and showed the most potential for sugar replacement within the range of sweetness intensities tested.

The effect of supplementary light during winter on the growth, body composition and behaviour of steers and heifers

1997 ◽  
Vol 65 (2) ◽  
pp. 173-181 ◽  
Author(s):  
C. J. C. Phillips ◽  
P. N. Johnson ◽  
T. M. Arab
Keyword(s):  
Growth Rate ◽  
Body Composition ◽  
Food Intake ◽  
Day Treatment ◽  
Day Length ◽  
Fatty Tissue ◽  
Reduced Body ◽  
Entire Experiment ◽  
Female Cattle ◽  
Autumn And Winter

AbstractIn two experiments the growth, body composition and behaviour of steers and heifers kept in a building with natural day length only (average 9·7 h/day, treatment N) were compared with similar groups of animals kept in identical housing with the day length artificially extended to 16 h/day, (treatment L). The effects were recorded for 126 days in steers and 180 days in heifers, with both groups of animals being slaughtered in March when the two experiments ended. There were no effects over the entire experiment on the growth rate or food intake of either steers or heifers. The growth of the steers was reduced in the first 2 weeks after the lights were switched on but they gained more weight to compensate over the next 8 weeks. Over the whole experiment there was no treatment effect on food conversion ratio for either steers or heifers but it was reduced for steers on treatment L over the first 10 weeks. Steers in treatment N produced fatter carcasses than those on treatment L. Ultrasonic scanning of the heifers showed that those on treatment N deposited more fatty tissue between autumn and winter and less between winter and spring compared with those on treatment L.The behaviour of steers on treatment L did not vary over the experiment but steers on treatment N changed their behaviour with season. They slept for more time in winter and less in spring. Over the whole experiment steers on treatment L slept less and spent more time lying ruminating than those on treatment N but the total time spent lying was not affected by treatment. In contrast, the heifers on treatment L lay down for longer than those on treatment N, suggesting that the effect of supplementary light on lying time, which has been observed previously with dairy cows, is confined to female cattle. Heifers on treatment L started mounting each other earlier than heifers on treatment N and, like the steers, they spent less time sleeping It is concluded that extending the photoperiod for cattle in winter reduced body fatness in both steers and heifers and increased the time heifers spend lying down but that there were no major effects on growth rate or food intake.

scholarly journals The rooting, survival and growth of woody species on tailing dumps in the limestone quarry “Lafarge ciment”

2021 ◽  
Vol 13 (1(22)) ◽  
pp. 34-42
Author(s):  
Petru Cuza ◽  
◽  
Corina Certan ◽  
Constantin Bulimaga ◽  
◽  
...  
Keyword(s):  
Growth Rate ◽  
Environmental Factors ◽  
Slow Growth ◽  
Woody Species ◽  
Mineral Elements ◽  
Black Pine ◽  
Limestone Quarry ◽  
Survival And Growth ◽  
High Degree ◽  
Fast Growing Species

The rooting, the survival and dynamics of growths in the height and after the diameter of the seedlings, of a range of woody species, had investigated on the freshly formed sterile dump limestone quarry „Lafarge Ciment”. The seedlings of the woody species had a relatively good rooting (69-99%). A high degree of rooting can be ensured as a result of the maintenance of forest crops. After planting, the young seedlings must be cared for by hoeing as many times as necessary in order to control the weeds and maintain moisture in the soil, which increases the survival of the seedlings. Tree species have been characterized by a different growth rate. Acacia has showed a very rapid increase in height, but the black pine has been characterized by a slow growth. Acacia being a fast-growing species and unpretentious to the mineral elements in the soil can be used to afforest the limestone quarry land. In the fi rst year after planting, the young seedlings, otherwise sensitive to the action of the environmental factors, had an increase in height and in diameter slow and uneven. In the years that followed, the seedlings became more viable and less infl uenced by local and temporal fl uctuations of environmental factors.

scholarly journals Phytoremediation of Special Metals in Emerging Industries

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
T Y TEH ◽  
Min-Hao Wu ◽  
Kf Chen ◽  
Yp Peng
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Growth Rate ◽  
Environmental Factors ◽  
Contaminated Soil ◽  
Morphological Analysis ◽  
Energy Crop ◽  
Emerging Industries ◽  
Incremental Growth ◽  
Conventional Methods

This project is carried out to assess the remediation effect on soil contaminated by molybdenum (Mo), one of heavy metals, through the use of an energy crop, sunflowers. This project explores the integration of phytohormones and chelates in the phytoremediation of soils contaminated by heavy metals, and further assesses the operational measures of remedying heavy-metal contaminated soil with sunflowers, in addition to the related environmental factors. Then the project explores phytohormones and heavy metals on the growth scenario explants (explants morphological analysis) through the experiment. The results indicate that GA3 can increase the growth rate of the plants. The average incremental growth of the heavy-metal-added-only group is 21.0 cm; of the GA3-added group it is 21.9 cm; of the EDDS-added group, it is 20.3 cm; of the GA3+ EDDS-added group, it is 21.7 cm. Compared with the conventional methods of phytoremediation, these integrated measures can actually spur the growth of plants. 

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