The importance of temperature and lipid accumulation for initiation and duration of Calanus hyperboreus spawning

2020 ◽  
Vol 42 (2) ◽  
pp. 159-171
Author(s):  
Mads Schultz ◽  
Torkel Gissel Nielsen ◽  
Eva Friis Møller
Keyword(s):  
Population Dynamics ◽  
Lipid Metabolism ◽  
Lipid Content ◽  
Egg Production ◽  
Arctic Ecosystems ◽  
Calanus Hyperboreus ◽  
Higher Temperature ◽  
The Mean ◽  
Increasing Temperature ◽  
The Impact

Abstract Large, lipid-storing copepods play a central role in marine Arctic ecosystems. Knowledge of the mechanisms that control their oogenesis is important for understanding their phenology and population dynamics. We investigated the impact of female lipid content on the timing and cumulative egg production (EP) of Calanus hyperboreus at 0, 3 and 6°C. The lipid content of females in early autumn was a good predictor of their EP potential. However, we saw no indication of a threshold in lipid content for initiation of spawning. Higher temperature resulted in 17 and 24 days earlier spawning at 3 and 6°C compared with 0°C, and the mean spawning duration was 8 and 30 days shorter, respectively. This illustrates that temperature affects the phenology of C. hyperboreus. When EP began, lipid metabolism increased 2–4 times. The females allocated 1.3 μg lipid per egg independent of temperature. However, the basic metabolism increased with increasing temperature; consequently, a smaller fraction of lipid was allocated for EP when the temperature increased.

scholarly journals Radical Response: Effects of Heat Stress-Induced Oxidative Stress on Lipid Metabolism in the Avian Liver

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 35
Author(s):  
Nima K. Emami ◽  
Usuk Jung ◽  
Brynn Voy ◽  
Sami Dridi
Keyword(s):  
Oxidative Stress ◽  
Heat Stress ◽  
Lipid Metabolism ◽  
Egg Production ◽  
Well Being ◽  
Enzymatic Reactions ◽  
Poultry Production ◽  
Hepatic Lipid Metabolism ◽  
Hepatic Lipid ◽  
The Impact

Lipid metabolism in avian species places unique demands on the liver in comparison to most mammals. The avian liver synthesizes the vast majority of fatty acids that provide energy and support cell membrane synthesis throughout the bird. Egg production intensifies demands to the liver as hepatic lipids are needed to create the yolk. The enzymatic reactions that underlie de novo lipogenesis are energetically demanding and require a precise balance of vitamins and cofactors to proceed efficiently. External stressors such as overnutrition or nutrient deficiency can disrupt this balance and compromise the liver’s ability to support metabolic needs. Heat stress is an increasingly prevalent environmental factor that impairs lipid metabolism in the avian liver. The effects of heat stress-induced oxidative stress on hepatic lipid metabolism are of particular concern in modern commercial chickens due to the threat to global poultry production. Chickens are highly vulnerable to heat stress because of their limited capacity to dissipate heat, high metabolic activity, high internal body temperature, and narrow zone of thermal tolerance. Modern lines of both broiler (meat-type) and layer (egg-type) chickens are especially sensitive to heat stress because of the high rates of mitochondrial metabolism. While this oxidative metabolism supports growth and egg production, it also yields oxidative stress that can damage mitochondria, cellular membranes and proteins, making the birds more vulnerable to other stressors in the environment. Studies to date indicate that oxidative and heat stress interact to disrupt hepatic lipid metabolism and compromise performance and well-being in both broilers and layers. The purpose of this review is to summarize the impact of heat stress-induced oxidative stress on lipid metabolism in the avian liver. Recent advances that shed light on molecular mechanisms and potential nutritional/managerial strategies to counteract the negative effects of heat stress-induced oxidative stress to the avian liver are also integrated.

SIMULATION MODEL FOR THE POPULATION DYNAMICS OF THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (LECONTE) (COLEOPTERA: CURCULIONIDAE)

1991 ◽  
Vol 123 (1) ◽  
pp. 63-76 ◽  
Author(s):  
D.X. Zhao ◽  
G. Boivin ◽  
R.K. Stewart
Keyword(s):  
Population Dynamics ◽  
Simulation Model ◽  
Mortality Rates ◽  
Egg Parasitoid ◽  
Adult Density ◽  
Larval Population ◽  
Listronotus Oregonensis ◽  
The Mean ◽  
Carrot Weevil ◽  
The Impact

AbstractA simulation model was developed for the population dynamics of a carrot weevil, Listronotus oregonensis (LeConte), population on muck-grown carrots. The model includes mortality rates of eggs, larvae, and pupae for different sowing dates of carrots. It also incorporates the overwintered adult density, the temperature-dependent growth rates of the above-mentioned life stages, the age-, temperature-, and phenology-dependent oviposition rates, and the impact of an egg parasitoid, Anaphes sordidatus (Girault), on egg mortality rates. Model output was evaluated by comparing simulated results with observed results on the seasonal totals and time of population peaks of the egg and larval populations. The mean percentage differences between the simulated and observed seasonal egg totals were 3.1 ± 0.66 (SE) in 1987 and 1988, and 4.2 ± 0.05 in 1989. They were not statistically different. The mean percentage differences between the simulated and observed seasonal larval totals were 10 ± 3.33 in 1987 and 1988 and 29.8 ± 0.66 in 1989. Independent data sets (i.e. field data in 1989) showed a significant increase in the simulation error of the larval population. Sensitivity analysis indicated that A. sordidatus had a large influence on the population dynamics of L. oregonensis.

scholarly journals Modeling the Effects of Temperature and Photosynthetic Daily Light Integral on Growth and Flowering of Salvia splendens and Tagetes patula

2007 ◽  
Vol 132 (3) ◽  
pp. 283-288 ◽  
Author(s):  
Lee Ann Moccaldi ◽  
Erik S. Runkle
Keyword(s):  
Dry Weight ◽  
Tagetes Patula ◽  
Flower Number ◽  
Daily Light Integral ◽  
Salvia Splendens ◽  
The Mean ◽  
Increasing Temperature ◽  
The Impact ◽  
Light Integral ◽  
Changing Light

Photosynthetic daily light integral (DLI) and temperature are two environmental factors that profoundly influence plant growth and development. Two common ornamental annual crops, salvia (Salvia splendens F. Sello ex Roem & Schult.) and marigold (Tagetes patula L.), were grown in glass greenhouses under a mean DLI of 5 to 25 mol·m−2·d−1 at temperatures from 14 to 27 °C. Growth (e.g., plant dry weight at flowering) and flowering characteristics (e.g., time to flowering and flower number) were modeled in response to the mean daily temperature and DLI by using multiple regression analysis. The rate of progress to flowering of salvia and marigold was primarily influenced by the mean air temperature. For example, time from seedling transplant to flowering of salvia decreased from 42 days to 24 days as temperature increased from 15 to 25 °C, with a mean DLI of 10 mol·m−2·d−1. Flower number and plant dry weight on the date of first flowering generally decreased with increasing temperature and decreasing DLI in both species. For example, marigold plants grown at 15 °C and a mean DLI of 25 mol·m−2·d−1 were 2.45 times greater in dry weight, had 2.12 more flowers, and had 49% larger flowers at flowering compared with plants grown at 25 °C and a mean DLI of 5 mol·m−2·d−1. The models can be used to predict the impact of changing light and temperature conditions on plant quality and flowering of these two crops.

L'enneigement hivernal : un facteur de variation du recrutement chez l'isard (Rupicapra pyrenaica pyrenaica)

2002 ◽  
Vol 80 (7) ◽  
pp. 1306-1312 ◽  
Author(s):  
J -P Crampe ◽  
J -M Gaillard ◽  
A Loison
Keyword(s):  
Population Dynamics ◽  
Climatic Conditions ◽  
Snow Accumulation ◽  
Yearly Variation ◽  
Rupicapra Pyrenaica ◽  
Winter Snow ◽  
Population Recruitment ◽  
The Mean ◽  
Mountain Ungulates ◽  
The Impact

To assess the relationships between winter climatic conditions and population dynamics of mountain ungulates, we monitored over the long term an unhunted isard (Rupicapra pyrenaica pyrenaica) population living in the Pyrénées National Park. We used general linear modelling to assess (i) the influence of the observation date (between November and April) of the transect sampled and of the year on population recruitment (proportion of females 2 years of age and older with kids at heel) and (ii) the impact of snow accumulation during winter (cumulated snow fall from November to April) on kid mortality. As expected, the mean number of kids per female decreased over the observation period. The mean number of kids per female showed marked among-year differences in initial recruitment (measured on 31 October) as well as in kid mortality (measured as the decrease in recruitment between 31 October and 31 March). This model accounted for 80% of the variability observed in the field data. Among-year differences in snow accumulation accounted for most (86%) of the yearly variation observed in kid mortality. Our study demonstrates that winter snow may severely affect juvenile survival, and thereby population dynamics of mountain ungulates.

scholarly journals Temperature changes alter the acute toxicity responses of cypermethrin in Zebrafish

2018 ◽  
Vol 29 (1) ◽  
pp. 64-70 ◽  
Author(s):  
MH Uddin ◽  
MS Alim ◽  
SMM Islam ◽  
H Rashid ◽  
M Shahjahan
Keyword(s):  
Blood Glucose ◽  
Acute Toxicity ◽  
Probit Analysis ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Temperature Regimes ◽  
Higher Temperature ◽  
T1 And T2 ◽  
Increasing Temperature ◽  
The Impact

The study was carried out to determine the effect of temperature changes on acute toxicity of pyrethroid pesticide cypermethrin in zebrafish. A two-day renewal bioassay system for 96h was conducted to find out LC50 value of cypermethrin at two temperature regimes i.e. 25°C and 30°C considering as T1 and T2, respectively. During the determination of LC50 in both temperatures, blood glucose (mg/dL) levels were measured at lower concentration (0.25 µg/L) of cypermethrin. The results of acute toxicity test at 96h LC50 values were calculated through probit analysis. It was found that 96h LC50 for T1 and T2 groups were about 2.1 and 1.4 µg/L, respectively. Significantly lower LC50 of cypermethrin at T2 compared to T1 showed that higher temperature increased the toxicity of cypermethrin. There was a significant increase (P<0.05) in blood glucose level (mg/dL) in 0.25 µg/L compared to 0 µg/L concentration of cypermethrin at both treatments. Dissolved oxygen decreased and free CO2 increased significantly (P<0.05) with increasing temperature, while the pH of the water was almost unchanged throughout the study period. The present study indicated the impact of increased temperature on pesticide toxicity in the aquatic ecosystem.Progressive Agriculture 29 (1): 64-70, 2018 

scholarly journals Soil <i>δ</i><sup>15</sup>N is a better indicator of ecosystem nitrogen cycling than plant <i>δ</i><sup>15</sup>N: A global meta-analysis

SOIL ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 733-742
Author(s):  
Kaihua Liao ◽  
Xiaoming Lai ◽  
Qing Zhu
Keyword(s):  
Meta Analysis ◽  
Global Scale ◽  
N Cycling ◽  
Mean Annual Temperature ◽  
Experimental Warming ◽  
Analysis Method ◽  
Higher Temperature ◽  
The Mean ◽  
Increasing Temperature ◽  
Soil Δ15n

Abstract. The nitrogen-15 (15N) natural abundance composition (δ15N) in soils or plants is a useful tool to indicate the openness of ecosystem N cycling. This study aimed to evaluate the influence of the experimental warming on soil and plant δ15N. We applied a global meta-analysis method to synthesize 79 and 76 paired observations of soil and plant δ15N from 20 published studies, respectively. Results showed that the mean effect sizes of the soil and plant δ15N under experimental warming were −0.524 (95 % CI (confidence interval): −0.987 to −0.162) and 0.189 (95 % CI: −0.210 to 0.569), respectively. This indicated that soil δ15N had negative response to warming at the global scale, where warming had no significant effect on plant δ15N. Experimental warming significantly (p<0.05) decreased soil δ15N in Alkali and medium-textured soils, in grassland/meadow, under air warming, for a 4–10-year warming period and for an increase of >3 ∘C in temperature, whereas it significantly (p<0.05) increased soil δ15N in neutral and fine-textured soils and for an increase of 1.5–3 ∘C in temperature. Plant δ15N significantly (p<0.05) increased with increasing temperature in neutral and fine-textured soils and significantly (p<0.05) decreased in alkali soil. Latitude did not affect the warming effects on both soil and plant δ15N. However, the warming effect on soil δ15N was positively controlled by the mean annual temperature, which is related to the fact that the higher temperature can strengthen the activity of soil microbes. The effect of warming on plant δ15N had weaker relationships with environmental variables compared with that on soil δ15N. This implied that soil δ15N was more effective than plant δ15N in indicating the openness of global ecosystem N cycling.

scholarly journals Assessment of Changes in Lipids Metabolism in Patients with Degenerative Joints and Discs Diseases Subjected to Spa Therapy

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Michał Kasperczak ◽  
Jadwiga Kuciel-Lewandowska ◽  
Jan Gnus ◽  
Małgorzata Paprocka-Borowicz
Keyword(s):  
Lipid Metabolism ◽  
Colorimetric Assay ◽  
Lifestyle Changes ◽  
Control Group ◽  
Spa Therapy ◽  
Health Resort ◽  
Disc Disease ◽  
Scientific Publications ◽  
The Mean ◽  
The Impact

Introduction. High levels of total cholesterol, triglycerides, and, connected with them, lipoprotein fractions may result in atherosclerosis. There are various forms of therapy used to prevent cardiovascular diseases, such as balneophysiotherapy, the effectiveness of which is confirmed by numerous scientific publications. Objective. The objective of this study was to assess the impact of balneophysiotherapeutic procedures on the systemic metabolism of lipids in patients suffering from osteoarthritis of the motor organ. Material and Methods. The study was conducted in the Health Resort Świeradów-Zdrój. Observation included patients undergoing radon water therapy. Before therapy and after 21 days of treatment, lipid profile was assessed with the use of standard colorimetric assay. Study group consisted of n=34 patients with degenerative joints and disc disease. The mean age of patients was 56.5l. The control group consisted of 17 people selected among the employees of the spa also suffering from osteoarthritis. The mean age was 54.2 years. Results. The results of the study are based on a single, 21-day health resort stay period in April/May. A statistically significant increase in HDL cholesterol levels was observed in female patients having undergone health resort treatment (P<0.01). Statistically significant drops in LDL cholesterol and TG levels were observed in the control group (P<0.01). An increase in HDL levels was observed in the male and female control subjects, with P<0.05. Conclusions. (1) After the end of therapy, there were no changes in lipid metabolism in men, while in the group of women an increase in HDL level was observed. (2) In the control group, statistically significant changes in the field of lipid metabolism may be related to lifestyle changes as a result of educational activities conducted prior to the research. (3) Due to the divergent results, it is advisable to conduct randomized studies in a larger population. This trial is registered with NCT03274128.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Sound Production Treatment for Acquired Apraxia of Speech: An Examination of Dosage in Relation to Probe Performance

2020 ◽  
pp. 1-16
Author(s):  
Julie L. Wambaugh ◽  
Lydia Kallhoff ◽  
Christina Nessler
Keyword(s):  
Retrospective Analysis ◽  
Sound Production ◽  
Apraxia Of Speech ◽  
Practice Schedule ◽  
Practice Schedules ◽  
Baseline Performance ◽  
The Mean ◽  
Number Of Treatment ◽  
The Impact

Purpose This study was designed to examine the association of dosage and effects of Sound Production Treatment (SPT) for acquired apraxia of speech. Method Treatment logs and probe data from 20 speakers with apraxia of speech and aphasia were submitted to a retrospective analysis. The number of treatment sessions and teaching episodes was examined relative to (a) change in articulation accuracy above baseline performance, (b) mastery of production, and (c) maintenance. The impact of practice schedule (SPT-Blocked vs. SPT-Random) was also examined. Results The average number of treatment sessions conducted prior to change was 5.4 for SPT-Blocked and 3.9 for SPT-Random. The mean number of teaching episodes preceding change was 334 for SPT-Blocked and 179 for SPT-Random. Mastery occurred within an average of 13.7 sessions (1,252 teaching episodes) and 12.4 sessions (1,082 teaching episodes) for SPT-Blocked and SPT-Random, respectively. Comparisons of dosage metric values across practice schedules did not reveal substantial differences. Significant negative correlations were found between follow-up probe performance and the dosage metrics. Conclusions Only a few treatment sessions were needed to achieve initial positive changes in articulation, with mastery occurring within 12–14 sessions for the majority of participants. Earlier occurrence of change or mastery was associated with better follow-up performance. Supplemental Material https://doi.org/10.23641/asha.12592190

Long-term population dynamics of the red deer and European roe deer at the protected and not-protected areas in Mountain Crimea

2017 ◽  
Vol 7 (4) ◽  
pp. 65-72
Author(s):  
V. N. Shmagol' ◽  
V. L. Yarysh ◽  
S. P. Ivanov ◽  
V. I. Maltsev
Keyword(s):  
Population Dynamics ◽  
Protected Areas ◽  
Red Deer ◽  
Nature Reserve ◽  
Roe Deer ◽  
Precipitation Amount ◽  
Annual Precipitation ◽  
Population Number ◽  
The Impact

<p>The long-term population dynamics of the red deer (<em>Cervus elaphus</em> L.) and European roe deer (<em>Capreolus</em> <em>capreolus</em> L.) at the mountain and forest zone of Crimea during 1980-2017 is presented. Fluctuations in numbers of both species are cyclical and partly synchronous. Period of oscillations in the population of red deer is about 25 years, the average duration of the oscillation period of number of roe deer is 12.3 years. During the fluctuations in the number the increasing and fall in population number of the red deer had been as 26-47 %, and roe deer – as 22-34 %. Basing on the dada obtained we have assumed that together with large-scale cycles of fluctuations in population number of both red deer and roe deer the short cycles of fluctuations in the number of these species with period from 3.5 to 7.5 years take place. Significant differences of the parameters of cyclical fluctuations in the number of roe deer at some sites of the Mountainous Crimea: breaches of synchronicity, as well as significant differences in the duration of cycles are revealed. The greatest deviations from the average values of parameters of long-term dynamics of the number of roe deer in Crimea are noted for groups of this species at two protected areas. At the Crimean Nature Reserve the cycle time of fluctuations of the numbers of roe deer was 18 years. At the Karadag Nature Reserve since 1976 we can see an exponential growth in number of roe deer that is continued up to the present time. By 2016 the number of roe deer reached 750 individuals at a density of 437 animals per 1 thousand ha. Peculiarity of dynamics of number of roe deer at some sites proves the existence in the mountain forest of Crimea several relatively isolated groups of deer. We assumed that "island" location of the Crimean populations of red deer and European roe deer, their relatively little number and influence of permanent extreme factors of both natural and anthropogenic origination have contributed to a mechanism of survival of these populations. The elements of such a mechanism include the following features of long-term dynamics of the population: the reduction in the period of cyclic population fluctuations, while maintaining their amplitude and the appearance of additional small cycles, providing more flexible response of the population to the impact of both negative and positive environmental factors. From the totality of the weather conditions for the Crimean population of roe deer the recurring periods of increases and downs in the annual precipitation amount may have relevance. There was a trend of increase in the roe deer population during periods of increasing annual precipitation.</p>

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