Factors influencing the growth rate of juvenile rock lobsters, Jasus lalandii

2001 ◽  
Vol 52 (8) ◽  
pp. 1367 ◽  
Author(s):  
R. W. Anthony Hazell ◽  
Andrew C. Cockcroft ◽  
Stephen Mayfield ◽  
Mark Noffke
Keyword(s):  
Growth Rates ◽  
Limb Regeneration ◽  
Somatic Growth ◽  
Seasonal Temperature ◽  
Ambient Conditions ◽  
Growth Increments ◽  
Factors Influencing ◽  
Seasonal Temperature Variation ◽  
In The Wild ◽  
Aquarium Experiment

Environmental conditions for juvenile spiny lobsters can vary spatially, interannually, and seasonally. We examined both field and aquarium data to elucidate some of the most important factors influencing somatic growth rates of juvenile Jasus lalandii. Growth increments of juveniles were determined at two sites in Table Bay, South Africa. Premoult individuals were captured and held in aquaria until they moulted. In addition, growth rates of small, medium, and large juvenile lobsters were monitored in aquaria under approximately ambient conditions for nine months. A separate aquarium experiment addressed effects of temperature. Moult increments at the two field sites varied significantly with season (highest in winter, lowest in spring), and month and site interacted. Temperature and diet affected grow-out significantly. Tagging and limb regeneration slowed grow-out. The 10˚C and the 15˚C experimental groups did not differ significantly in mean moult increment, but intermoult period at 15˚C was 50% shorter, so lobsters at 15˚C grew faster. Temperature affects intermoult period but, provided food is not limiting, does not appear to affect moult increment (within normal temperature range). In the wild, however, moult increments can vary up to twofold with season, probably at least in part because of seasonal temperature variation.

scholarly journals The effects of oscillating boundary conditions on thermal ignition

2020 ◽  
Vol 61 ◽  
pp. C45-C58
Author(s):  
Matthew Berry ◽  
Mark Nelson ◽  
Brian Monaghan ◽  
Ben Whale
Keyword(s):  
Temperature Variation ◽  
Filter Cake ◽  
Seasonal Temperature ◽  
Ambient Conditions ◽  
Ambient Temperatures ◽  
Temperature Oscillations ◽  
Seasonal Temperature Variation ◽  
Oscillating Boundary ◽  
Diurnal Temperature Variation ◽  
Ignition Times

We investigate the effect that oscillating ambient temperatures have on the ignition times of supercritical stockpiles. Large stockpiles are exposed to seasonal and diurnal temperature variation. We analyse the effects of seasonal temperature variation. When considering ignition within a year of construction, stockpiles built in spring ignited with a lower critical parameter than those built at other times. Consequently, seasonal temperature variation needs to be accounted for when predicting stockpile ignition times. References P. C. Bowes. Self-heating: evaluating and controlling the hazards. Dept. of the Environment, Building Research Establishment, 1984. R. J. Longbottom, B. J. Monaghan, G. Zhang, D. J. Pinson, and S. J. Chew. Self-sintering of BOS filter cake for improved recyclability. ISIJ Int., 59(3):432–441, 2019. doi:10.2355/isijinternational.ISIJINT-2018-627. V. Novozhilov. Thermal explosion in oscillating ambient conditions. Sci. Rep., 6:29730, 07 2016. doi:10.1038/srep29730. N. C. Roy. Convection characteristics in a closed vessel in the presence of exothermic combustion and ambient temperature oscillations. Int. J. Heat Mass Trans., 116:655–666, 2018. doi:10.1016/j.ijheatmasstransfer.2017.09.058.

Responsiveness to seasonal temperature and nitrogen among genotypes of kikuyu, paspalum and bermuda grass pastures of coastal New South Wales

1985 ◽  
Vol 25 (1) ◽  
pp. 109 ◽  
Author(s):  
CJ Pearson ◽  
H Kemp ◽  
AC Kirby ◽  
TE Launders ◽  
C Mikled
Keyword(s):  
Growth Rates ◽  
Bermuda Grass ◽  
Base Temperature ◽  
Seasonal Temperature ◽  
Potential Productivity ◽  
Average Growth ◽  
South Wales ◽  
Nitrogen Concentrations ◽  
Calcium Magnesium ◽  
Phosphorus And Potassium

Three experiments were carried out to test the hypotheses that (a) there are quantitative differences in growth rate and quality between newly registered cultivars and older cultivars in response to changes in temperature and fertility, and (b) responsiveness to temperature varies between sites because cultivars acclimatize to their current environment. Performance in simulated swards indicated that potential productivity was highest from bermuda grass (Cynodon x Burton Pearson). This was, however, a poor indicator of performance in the field, where yield of bermuda grass was depressed by weeds whereas that of kikuyu (Pennisetum clandestinum) was unaffected. In the field, a newly registered kikuyu, cv. Crofts, outyielded bermuda grass and paspalum (Paspalum dilatatum) either alone or when combined with lucerne. A further experiment compared cvv. Crofts, Whittet and common kikuyu at three levels of nitrogen at three sites. Peak growth rates were the same at all locations but Crofts outyielded the other genotypes by 60, 13 and 18% at Bega (37�S.), Camden (34�S.) and Taree (32�S.) respectively. Average growth rates varied seasonally and were correlated with temperature (r > 0.9). Analysis of temperature responsiveness (kg/ha.�C) indicated that responsiveness varied consistently between genotypes at any location. Furthermore, the base temperature (the temperature below which there was negligible growth) was the same for all genotypes at any location but it increased with increasing latitude. That is, there was a tendency to greater dormancy with increasing coldness of location. Nitrogen responsiveness was the same for all genotypes and sites. Seasonal variations in digestibility and mineral concentrations in kikuyu, bermuda grass and paspalum were similar in the field and in simulated swards; quality was the same in all kikuyu genotypes. Calcium, magnesium and nitrogen concentrations of plant tops (but not phosphorus and potassium concentrations) increased with increasing rates of application of nitrogen fertilizer.

Warming affects seasonal dynamics of microorganisms and reduces the N storage capacity of soil microbes in winter

2021 ◽  
Author(s):  
Philipp Gündler ◽  
Alberto Canarini ◽  
Sara Marañón Jiménez ◽  
Gunnhildur Gunnarsdóttir ◽  
Páll Sigurðsson ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Growth Rates ◽  
Seasonal Dynamics ◽  
Soil Microbes ◽  
Storage Capacity ◽  
Ambient Conditions ◽  
Soil Warming ◽  
Carbon Use Efficiency ◽  
Use Efficiency ◽  
C And N

<p>Seasonality of soil microorganisms plays a critical role in terrestrial carbon (C) and nitrogen (N) cycling. The asynchrony of immobilization by microbes and uptake by plants may be important for N retention during winter, when plants are inactive. Meanwhile, the known warming effects on soil microbes (decreasing biomass and increasing growth rates) may affect microbial seasonal dynamics and nutrient retention during winter.</p><p>We sampled soils from a geothermal warming site in Iceland (www.forhot.is) which includes three in situ warming levels (ambient, +3 °C, +6 °C). We harvested soil samples at 9 time points over one year and measured the seasonal variation in microbial biomass carbon (Cmic) and nitrogen (Nmic) and microbial physiology (growth and carbon use efficiency) by an <sup>18</sup>O-labelling technique.</p><p>We observed that Cmic and Nmic peaked in winter, followed by a decline in spring and summer. In contrast growth and respiration rates were higher in summer than winter. The observed biomass peak at lower growth rates, suggests that microbial death rates must have declined even more than growth rates. Soil warming increased biomass-specific microbial activity (i.e., growth, respiration, and turnover rates per unit of microbial biomass), prolonging the period of higher microbial activity found in summer into autumn and winter. Microbial carbon use efficiency was unaltered by soil warming. Throughout the seasons, warming reduced Cmic and Nmic, albeit with a stronger effect in winter than summer and restrained winter biomass accumulation by up to 78% compared to ambient conditions. We estimated a reduced microbial winter N storage capacity by 45.5 and 94.6 kg ha<sup>-1</sup> at +3 °C and +6 °C warming respectively compared to ambient conditions. This reduction represents 1.57% and 3.26% of total soil N stocks, that could potentially be lost per year from these soils.</p><p>Our results clearly demonstrate that soil warming strongly decreases microbial C and N immobilization when plants are inactive, potentially leading to higher losses of C and N from warmed soils over winter. These results have important implications as increased N losses may restrict increased plant growth in a future climate.</p>

scholarly journals Factors Influencing the Chlorine Susceptibility of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum

2003 ◽  
Vol 69 (9) ◽  
pp. 5685-5689 ◽  
Author(s):  
Joseph O. Falkinham
Keyword(s):  
Growth Rate ◽  
Mycobacterium Avium ◽  
Growth Phase ◽  
Growth Rates ◽  
Growth Stage ◽  
Tween 80 ◽  
Culture Conditions ◽  
C Cells ◽  
Mycobacterium Intracellulare ◽  
Factors Influencing

ABSTRACT The susceptibility of representative strains of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum (the MAIS group) to chlorine was studied to identify factors related to culture conditions and growth phase that influenced susceptibility. M. avium and M. intracellulare strains were more resistant to chlorine than were strains of M. scrofulaceum. Transparent and unpigmented colony variants were more resistant to chlorine than were their isogenic opaque and pigmented variants (respectively). Depending on growth stage and growth rate, MAIS strains differed in their chlorine susceptibilities. Cells from strains of all three species growing in early log phase at the highest growth rates were more susceptible than cells in log and stationary phase. Rapidly growing cells were more susceptible to chlorine than slowly growing cells. The chlorine susceptibility of M. avium cells grown at 30°C was increased when cells were exposed to chlorine at 40°C compared to susceptibility after exposure at 30°C. Cells of M. avium grown in 6% oxygen were significantly more chlorine susceptible than cells grown in air. Chlorine-resistant MAIS strains were more hydrophobic and resistant to Tween 80, para-nitrobenzoate, hydroxylamine, and nitrite than were the chlorine-sensitive strains.

Factors Influencing the Growth Rates of Three Commercial Eucheumoids at Coastal Sites in Southern Kenya

2006 ◽  
Vol 18 (3-5) ◽  
pp. 565-573 ◽  
Author(s):  
J. G. Wakibia ◽  
J. J. Bolton ◽  
D. W. Keats ◽  
L. M. Raitt
Keyword(s):  
Growth Rates ◽  
Factors Influencing ◽  
Commercial Eucheumoids

scholarly journals Growth rates and morphological measurements of Porcupine caribou calves

Rangifer ◽  
1989 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Katherine L. Parker
Keyword(s):  
Surface Area ◽  
Growth Rates ◽  
Rangifer Tarandus ◽  
Type I ◽  
Feeding Regime ◽  
Barren Ground ◽  
Body Weights ◽  
In The Wild

<p>Body weights, leg lengths, and surface area were monitored for bottle-raised barren-ground caribou calves (Rangifer tarandus granti) from the Porcupine herd up to 1 year of age. Body weights were compared with maternally-raised calves from the same cohort in the wild and from the Delta herd. A successful feeding regime for bottle-raising caribou calves is presented.</p><p>Veksthastigheter og morfologiske m&aring;l hos Porcupine karibu-kalver.</p><p>Abstract in Norwegian / Sammendrag: Kroppsvekter, visse knokkel-lengder og kropps-overflate areal ble m&aring;lt hos flaske-oppf&oslash;dde kalver av barren-ground karibu (Rangifer tarandus granti) fra Porcupine-stammen opp til 1 &aring;rs alder. Kroppsvekter ble sammelignet med normalt oppf&oslash;dde kalver av samme type i det fri og fra Delta-stam-men. Det presenteres et vellykket system for flaske-oppforing av karibu-kalver.</p><p>Porcupine-lauman karibuvasojen kasvunopeus ja morfologiset mitat.</p><p>Abstract in Finnish / Yhteenveto: Porcupine -lauman pulloruokinnalla olleiden tundrakaribuvasojen ruumiinpainot, jalanpituu-det ja ruumiin pinta-alat mitattiin 1 vuoden ik&auml;&auml;&auml;n saakka. Ruumiinpainoja verrattiin vastaaviin luonnon-oloissa kasvaneisiin saman lauman ja Delta -lauman vasoihin. Tutkimus kuvaa toimivan vasojen pulloruo-kintamenetelm&auml;n.</p>

scholarly journals Metagenomic Insights into the Effects of Seasonal Temperature Variation on the Activities of Activated Sludge

2019 ◽  
Vol 7 (12) ◽  
pp. 713 ◽  
Author(s):  
Chenbing Ai ◽  
Zhang Yan ◽  
Han Zhou ◽  
Shanshan Hou ◽  
Liyuan Chai ◽  
...  
Keyword(s):  
Microbial Community ◽  
Glutamine Synthetase ◽  
Activated Sludge ◽  
Temperature Variation ◽  
Nitrogen Metabolism ◽  
Metagenomic Data ◽  
Seasonal Temperature ◽  
Simulated Temperature ◽  
Genes Encoding ◽  
Seasonal Temperature Variation

It is well acknowledged that the activities of activated sludge (AS) are influenced by seasonal temperature variation. However, the underlying mechanisms remain largely unknown. Here, the activities of activated sludge under three simulated temperature variation trends were compared in lab-scale. The TN, HN3-H, and COD removal activities of activated sludge were improved as temperature elevated from 20 °C to 35 °C. While, the TN, HN3-H, COD and total phosphorus removal activities of activated sludge were inhibited as temperature declined from 20 °C to 5 °C. Both the extracellular polymer substances (EPS) composition (e.g., total amount, PS, PN and DNA) and sludge index of activated sludge were altered by simulated seasonal temperature variation. The variation of microbial community structures and the functional potentials of activated sludge were further explored by metagenomics. Proteobacteria, Actinobacteria, Acidobacteria and Bacteroidetes were the dominant phyla for each activated sludge sample under different temperatures. However, the predominant genera of activated sludge were significantly modulated by simulated temperature variation. The functional genes encoding enzymes for nitrogen metabolism in microorganisms were analyzed. The enzyme genes related to ammonification had the highest abundance despite the changing temperature, especially for gene encoding glutamine synthetase. With the temperature raising from 20 °C to 35 °C. The abundance of amoCAB genes encoding ammonia monooxygenase (EC:1.14.99.39) increased by 305.8%. Meanwhile, all the enzyme genes associate with denitrification were reduced. As the temperature declined from 20 °C to 5 °C, the abundance of enzyme genes related to nitrogen metabolism were raised except for carbamate kinase (EC:2.7.2.2), glutamate dehydrogenase (EC:1.4.1.3), glutamine synthetase (EC:6.3.1.2). Metagenomic data indicate that succession of the dominant genera in microbial community structure is, to some extent, beneficial to maintain the functional stability of activated sludge under the temperature variation within a certain temperature range. This study provides novel insights into the effects of seasonal temperature variation on the activities of activated sludge.

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