scholarly journals Growth, stoichiometry and cell size; temperature and nutrient responses in haptophytes

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3743 ◽  
Author(s):  
Lars Fredrik Skau ◽  
Tom Andersen ◽  
Jan-Erik Thrane ◽  
Dag Olav Hessen
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Cell Size ◽  
Marine Phytoplankton ◽  
Effect Of Temperature ◽  
Elemental Content ◽  
Specific Content ◽  
Batch Cultures ◽  
P Limitation ◽  
Effects Of Temperature

Temperature and nutrients are key factors affecting the growth, cell size, and physiology of marine phytoplankton. In the ocean, temperature and nutrient availability often co-vary because temperature drives vertical stratification, which further controls nutrient upwelling. This makes it difficult to disentangle the effects of temperature and nutrients on phytoplankton purely from observational studies. In this study, we carried out a factorial experiment crossing two temperatures (13°and 19°C) with two growth regimes (P-limited, semi-continuous batch cultures [“−P”] and nutrient replete batch cultures in turbidostat mode [“+P”]) for three species of common marine haptophytes (Emiliania huxleyi, Chrysochromulina rotalis and Prymnesium polylepis) to address the effects of temperature and nutrient limitation on elemental content and stoichiometry (C:N:P), total RNA, cell size, and growth rate. We found that the main gradient in elemental content and RNA largely was related to nutrient regime and the resulting differences in growth rate and degree of P-limitation, and observed reduced cell volume-specific content of P and RNA (but also N and C in most cases) and higher N:P and C:P in the slow growing −P cultures compared to the fast growing +P cultures. P-limited cells also tended to be larger than nutrient replete cells. Contrary to other recent studies, we found lower N:P and C:P ratios at high temperature. Overall, elemental content and RNA increased with temperature, especially in the nutrient replete cultures. Notably, however, temperature had a weaker–and in some cases a negative–effect on elemental content and RNA under P-limitation. This interaction indicates that the effect of temperature on cellular composition may differ between nutrient replete and nutrient limited conditions, where cellular uptake and storage of excess nutrients may overshadow changes in resource allocation among the non-storage fractions of biomass (e.g. P-rich ribosomes and N-rich proteins). Cell size decreased at high temperature, which is in accordance with general observations.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

scholarly journals Studies in the geotropism of the pteridophyta V—Some effects of temperature on growth and geotropism in Asplenium bulbiferium

1935 ◽  
Vol 116 (800) ◽  
pp. 479-493 ◽  
Keyword(s):  
Growth Rate ◽  
Effect Of Temperature ◽  
Horizontal Position ◽  
Present Position ◽  
Minimum Period ◽  
Plant Life ◽  
Latent Time ◽  
Presentation Time ◽  
Effects Of Temperature ◽  
The Given

Although temperature and gravity both influence plant life, and although both factors have been studied for many decades, there is surprisingly little literature decades, there is surprisingly little literature dealing with the relation between the two; and none, so far as I can discover, on the effect in any Pteridophyte. Navez (1929) who criticized the work of some investigators on the effect of temperature on the geotropism of a few seedlings, sums up the present position in his remark that the conclusions of workers are very different and often in opposition. The present paper gives the results of 1100 experiments carried out mainly between the years 1922 and 1927, and though it is realized that much remains to be done on the question, it is believed that the results which have been obtained are of some value. For general methods, reference may be made to previous “Studies” in this series. Geotropic sensitivity, as measured by presentation time at different stages in development of the frond, was fully worked out by Waight (1923) for 20°C, and is adopted here as a standard of reference. The growth rate recorded in the tables is that for the particular frond under investigation, or is the average of the fronds examined during the day of the experiment. Nearly all the experiments included in the tables were conducted during the months of April-October, as I have since been able to show that there is an annual rhythm in geotropic irritability. A decrease in sensitivity occurs in winter, and hence experiments performed in November-March are not strictly comparable with those carried out in the summer. The following abbreviations are used:- P.S. = period of stimulation. P.T. = presentation time, i. e ., the minimum period of stimulation in a horizontal position, which, under the given conditions, will cause a movement of approximately 5° in about 80% of the fronds. L.T. = latent time (Prankerd, 1925) in hours. N = “normal time,” i. e ., the P.T. For different stages of the frond at 20°C (see Waight, 1923).

Effects of temperature and nutritional conditions on the mitotic cell cycle of Saccharomyces cerevisiae

1978 ◽  
Vol 31 (1) ◽  
pp. 71-78
Author(s):  
M.N. Jagadish ◽  
B.L. Carter
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Growth Rates ◽  
Mitotic Cell ◽  
S Phase ◽  
Yeast Cells ◽  
Batch Cultures ◽  
Nutritional Conditions ◽  
Limiting Nutrient ◽  
Effects Of Temperature

Yeast cells were cultivated at different growth rates in a chemostat by alterations in the flow of the limiting nutrient glucose and in batch cultures where variations in growth rate were achieved by alterations in the composition of nutrients. It was observed that the stage in the cycle at which S-phase was completed varied with growth rate. The faster the growth rate, the earlier the stage in the cycle in which completion of S-phase occurred. When stage in the cycle is converted into time before division it was observed that the time from completion of S-phase to cell division varied only slightly with growth rate except at extremely slow growth rates. Expansion of cell cycle transit time as the growth rate was slowed was achieved primarily by an expansion in time of the period from division to the completion of S-phase. In contrast, when cells were grown at different rates by alterations in the temperature of cultivation, completion of S-phase occurred at approximately the same stage in the cell cycle at all growth rates.

The influence of nutrition on the response of wheat to above-optimal temperature

1984 ◽  
Vol 35 (2) ◽  
pp. 129 ◽  
Author(s):  
IA Dawson ◽  
IF Wardlaw
Keyword(s):  
High Temperature ◽  
Nutrient Availability ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Effect Of Temperature ◽  
Vegetative Organs ◽  
Two Temperatures ◽  
Effects Of Temperature ◽  
Phloem Mobility

Wheat plants (Triticum aestivum L. cv. Gabo) were grown at two temperatures (18/13 and 24/19�C, Day/night), either with full nutrient availability or deprived of nutrients after floral initiation or after anthesis, in order to identify possible interactions between nutrient availability and response to a temperature higher than the optimum for grain dry weight accumulation. Nutrient deprivation reduced levels of nitrogen, potassium and calcium in the vegetative organs of the plant at anthesis and maturity, and levels of nitrogen and calcium, but not potassium, in the grain. Differences in the distribution of nitrogen, potassium and calcium can be explained on the basis of their phloem mobility. An interaction was observed between nutrition and temperature in the time from seedling emergence to anthesis, the number of tillers at anthesis and the number of heads per plant at maturity. Within the main culm ear, high temperature and low nutrition reduced grain number. High temperature, but not low nutrition, reduced individual grain weights. However, there were no interactions between nutrition and temperature in regulating these responses. Therefore, although nutrition may be an important factor when considering the effect of temperature on tillering, there is no evidence from this study that nutritional status will mask the effects of temperature on the later stages of ear and grain development.

scholarly journals Effect of Temperature on In Vivo Protein Synthetic Capacity in Escherichia coli

1998 ◽  
Vol 180 (17) ◽  
pp. 4704-4710 ◽  
Author(s):  
Anne Farewell ◽  
Frederick C. Neidhardt
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
High Temperature ◽  
Low Temperature ◽  
Protein Degradation ◽  
Elongation Rate ◽  
Peptide Chain ◽  
Chain Elongation ◽  
Effect Of Temperature ◽  
Synthetic Capacity

ABSTRACT In this report, we examine the effect of temperature on protein synthesis. The rate of protein accumulation is determined by three factors: the number of working ribosomes, the rate at which ribosomes are working, and the rate of protein degradation. Measurements of RNA/protein ratios and the levels of individual ribosomal proteins and rRNA show that the cellular amount of ribosomal machinery in Escherichia coli is constant between 25 and 37°C. Within this range, in a given medium, temperature affects ribosomal function the same as it affects overall growth. Two independent methodologies show that the peptide chain elongation rate increases as a function of temperature identically to growth rate up to 37°C. Unlike the growth rate, however, the elongation rate continues to increase up to 44°C at the same rate as between 25 and 37°C. Our results show that the peptide elongation rate is not rate limiting for growth at high temperature. Taking into consideration the number of ribosomes per unit of cell mass, there is an apparent excess of protein synthetic capacity in these cells, indicating a dramatic increase in protein degradation at high temperature. Temperature shift experiments show that peptide chain elongation rate increases immediately, which supports a mechanism of heat shock response induction in which an increase in unfolded, newly translated protein induces this response. In addition, we find that at low temperature (15°C), cells contain a pool of nontranslating ribosomes which do not contribute to cell growth, supporting the idea that there is a defect in initiation at low temperature.

Aerobio Growth of Listeria monocytogenes on Beef Lean and Fatty Tissue: Equations Describing the Effects of Temperature and pH

1993 ◽  
Vol 56 (2) ◽  
pp. 96-101 ◽  
Author(s):  
FREDERICK H. GRAU ◽  
PAUL B. VANDERLINDE
Keyword(s):  
Growth Rate ◽  
Listeria Monocytogenes ◽  
Goodness Of Fit ◽  
Effect Of Temperature ◽  
Fatty Tissue ◽  
Lean Tissue ◽  
Generation Times ◽  
Lag Period ◽  
Effects Of Temperature ◽  
Lag Times

The aerobio growth rate and the duration of the lag period were determined for Listeria monocytogenes strain Murray B growing on ground beef lean and on pieces of fatty tissue. The organism grew at 0°C on lean tissue at pH ≥ 6 and on fatty tissue. It failed to grow at 0°C on lean at pH 5.6 but did grow at 2.5°C. The effect of temperature, between 0 and 30°C, on the growth rate on fatty tissue can be described by a modified Arrhenius equation Ln (gen/h) = −205.73 + 1.2939 × 105/K −2.0298 × 107/K2, where K = °Kelvin. This equation accounted for 99.7% of the variance. The combined effect of temperature and pH on the growth rate on beef lean was described by Ln (gen/h) = − 232.64 + 1.4041 × 105/K - 2.1908 × 107K2 + 1.1586 × 102/pH - 4.0952 × 102/pH2 (variance accounted for 99.5%). For lean at about pH 5.5–5.6, this equation applied between about 2.5 and 35°C; for lean of pH 6–7, it applied between about 0 and 35°C. Though the lag period increased with decrease in temperature and pH, measured lag times were more variable than generation times, and the goodness of fit of modified Arrhenius equations to lag times was relatively poor (variance accounted for 83–92%).

The Effects of Temperature on Rheology Properties and Filtrate after Using Lemongrass as Lost Circulation Materials for Oil Based Drilling Mud

2014 ◽  
Vol 911 ◽  
pp. 243-247 ◽  
Author(s):  
N.A. Ghazali ◽  
T.A.T. Mohd ◽  
N. Alias ◽  
M.Z. Shahruddin ◽  
A. Sauki ◽  
...  
Keyword(s):  
High Temperature ◽  
Filter Press ◽  
Effect Of Temperature ◽  
Drilling Mud ◽  
Lost Circulation ◽  
Water Based ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Mud Loss ◽  
Lost Circulation Materials

Lost circulation materials (LCM) are used to combat mud loss to the reservoir formation which can cause problems during drilling operation. Difficulties in handling and costly are those challenges faced by drilling operator. Mostly LCM can work better in water based mud compared to oil based mud due to characteristic of LCM itself. Nowadays, most of operator interested in the ultra-deep water due to the limitation of reservesand deals with high temperature and high pressure conditions.Oil based mud (OBM) is more preferable in high temperature conditions compared to water based mud hence a laboratory study was carried out to investigate the effect of temperature on the performance of lemongrass with different sizes in oil based mud. The oil based mud was formulated and tested with three different temperatures which are 250oF, 275oF and 350oF. The lemongrass LCM was prepared with three different sizes which are 150 microns, 250 microns and 500 microns. The sizes distribution of LCM is one of the main contributors to the success of LCM in the formation. The oil based mud samples were tested using Fann Viscometer to determine rheology properties and HPHT Filter Press to investigate the amount of filtrate. It was found that different temperatures and sizes have great effects on the lemongrass LCM in the oil based mud. The optimum temperature for lemongrass LCM is 275oF and with the sizes of 250 microns.

scholarly journals From individuals to populations: How intraspecific competition shapes thermal reaction norms

2019 ◽  
Author(s):  
François Mallard ◽  
Vincent Le Bourlot ◽  
Christie Le Coeur ◽  
Monique Avnaim ◽  
Romain Péronnet ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Intraspecific Competition ◽  
Thermal Reaction ◽  
Reaction Norms ◽  
Effect Of Temperature ◽  
Dominant Factor ◽  
List Type ◽  
Joint Effects ◽  
Effects Of Temperature

AbstractMost ectotherms follow the temperature-size rule (TSR): in cold environments individuals grow slowly but reach a large asymptotic length. Intraspecific competition can induce plastic changes of growth rate and asymptotic length and competition may itself be modulated by temperature.Our aim is to disentangle the joint effects of temperature and intraspecific competition on growth rate and asymptotic length.We used two distinct clonal lineages of the Collembola Folsomia candida, to describe thermal reaction norms of growth rate, asymptotic length and reproduction over 6 temperatures between 6°C and 29°C. In parallel, we measured the long-term size-structure and dynamics of populations reared under the same temperatures to measure growth rates and asymptotic lengths in populations and to quantify the joint effects of competition and temperature on these traits.We show that intraspecific competition modulates the temperature-size rule. In dense populations there is a direct negative effect of temperature on asymptotic length, but there is no temperature dependence of the growth rate, the dominant factor regulating growth being competition. We fail to demonstrate that the strength of competition varies with temperature except at the lowest temperature where competition is minimal. The two lineages responded differently to the joint effects of temperature and competition and these genetic differences have marked effects on population dynamics along our temperature gradient.Our results reinforce the idea that the TSR response of ectotherms can be modulated by biotic and abiotic stressors when studied in non-optimal laboratory experiments. Untangling complex interactions between environment and demography will help understanding how size will respond to environmental change and how climate change may influence population dynamics.

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