The influence of climatic factors on the demography of the terrestrial isopod Tracheoniscus rathkei Brandt

1976 ◽  
Vol 54 (12) ◽  
pp. 2185-2199 ◽  
Author(s):  
Donald J. McQueen
Keyword(s):  
Life Cycle ◽  
Simulation Model ◽  
Field Data ◽  
Climatic Factors ◽  
Laboratory Data ◽  
Day Length ◽  
Model Output ◽  
Population Limitation ◽  
Growth And Survival ◽  
Rates Of Growth

A field population of the isopod Tracheoniscus rathkei was monitored during 1971, 1972, and 1973. At the same time, laboratory data related to growth, reproduction, and survival were collected and combined to produce a simulation model. The model output was compared with the field data. In the laboratory, T. rathkei required humidities very near 100% relative humidity, day length had no effect on growth rates, and temperature altered rates of growth and survival and determined the periodicity of reproduction. In the field, T. rathkei exhibited a 2-year life cycle, breeding occurred in the spring and summer, and about 83% of the population bred once and 42% bred twice during each year. Juveniles grew throughout the fall, overwintered, reproduced at 1 year of age, continued to grow, overwintered a second time, reproduced again, and died. The simulation model mimicked this pattern with considerable precision. Both the field data and the simulated output suggested that the population expanded during 1971, 1972, and 1973. No mechanisms for population limitation were found.

Porcellio spinicornis Say (Isopoda) demography. III. A comparison between field data and the results of a simulation model

1976 ◽  
Vol 54 (12) ◽  
pp. 2174-2184 ◽  
Author(s):  
Donald James McQueen
Keyword(s):  
Population Growth ◽  
Simulation Model ◽  
Field Data ◽  
Survival Rates ◽  
Laboratory Data ◽  
Individual Growth ◽  
Growth And Survival ◽  
Life History Stages ◽  
Demographic Rates ◽  
Rates Of Growth

A simulation model for a Porcellio spinicornis Say population was constructed using laboratory data for rates of growth, reproduction, and survival and using winter survival rates observed in the field. The simulated output was compared with field data collected from 1971 to 1973. The expected and observed weight distributions and reproductive periodicities showed good agreement. The expected and observed patterns of numerical change also agreed for all life-history stages, except 18-month-old individuals, which disappeared from the field counts more quickly than expected. Sensitivity analysis showed that the time at which reproduction began each year was not as critical to population growth as were the effects of minor shifts in temperature on individual growth and survival rates. Furthermore, individual growth rate emerged as the factor having the greatest effect on patterns of population growth. Since the laboratory data on growth was reasonably accurate it is probable that the simulation model adequately describes the processes that determine the changes observed in the field population monitored during this study. All of the evidence indicated that during the period of study the population did not increase or decrease and that temperature conditions modifying demographic rates could have accounted for this observation.

Porcellio spinicornis Say (Isopoda) demography. II. A comparison between field and laboratory data

1976 ◽  
Vol 54 (6) ◽  
pp. 825-842 ◽  
Author(s):  
Donald J. McQueen
Keyword(s):  
Field Data ◽  
Laboratory Data ◽  
Field Population ◽  
Laboratory Studies ◽  
The Third ◽  
Terrestrial Isopod ◽  
Independent Laboratory ◽  
Demographic Study ◽  
June July ◽  
Rates Of Growth

Field data from a demographic study of the terrestrial isopod Porcellio spinicornis Say were analyzed and compared with laboratory data reported by McQueen and Carnio. On the study area, which covered 482.8 m2, it was observed that reproduction began when average temperatures were > 13 °C, and that about 86% of the individuals produced one brood and about 30% produced two broods. During 1972, 25 654 offspring were produced and during 1973, 27 664 offspring resulted from reproduction, which took place during May, June, July, and August. By October of both years, these animals attained sizes ranging from 10 to 30 mg and exhibited 42 to 47% survivorship. During the next summer, females grew to between 30 and 50 mg and males to between 20 and 40 mg, and survivorship ranged from 15% in May to 2% in August. During the third summer, females attained sizes ranging from 80 to 100 mg and males from 40 to 70 mg. Survivorship during this period ranged from 1% in May to 0% in August. All rates of growth, reproduction, and survival, as well as reproductive periodicity, agreed with independent laboratory studies conducted under controlled conditions. During the 3 years studied the field population remained relatively constant and appeared to be limited by temperature conditions.

Sanguivory in leeches and its effects on growth, survivorship, and reproduction of Theromyzon rude

1984 ◽  
Vol 62 (4) ◽  
pp. 589-593 ◽  
Author(s):  
Ronald W. Davies
Keyword(s):  
Population Dynamics ◽  
Body Weight ◽  
Life Cycle ◽  
Blood Meal ◽  
Sexual Maturity ◽  
Field Data ◽  
Size Structure ◽  
Laboratory Data ◽  
Blood Meals ◽  
Take All

The trophic effects of the timing of the blood meals of Theromyzon rude on its population dynamics and life cycle were determined in the laboratory and compared with field data based only on the population size structure. It was found that a minimum of three full blood meals are necessary before T. rude reaches sexual maturity. The laboratory data show that the majority (> 80%) of the population take all three meals in the first 6 months after hatching. The remainder of the population overwinters after two meals and take their third meal in the spring so that all the population reproduces within approximately 12 months of hatching. Some individuals overwintering after three meals decline in weight to below 150 mg before spring and these individuals require a fourth blood meal before reproduction commences. After each blood meal there is a further increase in body weight as a result of water uptake. It is suggested that this dilution of the blood facilitates the faster digestive rates shown by T. rude compared with other sanguivorous species which rapidly eliminate water from their guts after feeding. Sanguivory in T. rude is compared with sanguivory in other Glossiphoniidae and Hirudinidae.

scholarly journals Simulation Model for Time to Flowering with Climatic and Genetic Inputs for Wild Chickpea

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1389
Author(s):  
Andrey Ageev ◽  
Abdulkadir Aydogan ◽  
Eric Bishop-von Wettberg ◽  
Sergey V. Nuzhdin ◽  
Maria Samsonova ◽  
...  
Keyword(s):  
Simulation Model ◽  
Flowering Time ◽  
Climatic Factors ◽  
Analytic Form ◽  
Day Length ◽  
Climate Change Scenarios ◽  
Data Set ◽  
Lower Elevation ◽  
River Valleys ◽  
The Impact

Accurate prediction of flowering time helps breeders to develop new varieties that can achieve maximal efficiency in a changing climate. A methodology was developed for the construction of a simulation model for flowering time in which a function for daily progression of the plant from one to the next phenological phase is obtained in analytic form by stochastic minimization. The resulting model demonstrated high accuracy on the recently assembled data set of wild chickpeas. The inclusion of genotype-by-climatic factors interactions accounted to 77% of accuracy in terms of root mean square error. It was found that the impact of minimal temperature is positively correlated with the longitude at primary collection sites, while the impact of day length is negatively correlated. It was interpreted as adaptation of accessions from highlands to lower temperatures and those from lower elevation river valleys to shorter days. We used bootstrap resampling to construct an ensemble of models, taking into account the influence of genotype-by-climatic factors interactions and applied it to forecast the time to flowering for the years 2021–2099, using generated daily weather in Turkey, and for different climate change scenarios. Although there are common trends in the forecasts, some genotypes and SNP groups have distinct trajectories.

scholarly journals Interaction of Plasmodium falciparum apicortin with α- and β-tubulin is critical for parasite growth and survival

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malabika Chakrabarti ◽  
Nishant Joshi ◽  
Geeta Kumari ◽  
Preeti Singh ◽  
Rumaisha Shoaib ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Life Cycle ◽  
Specific Protein ◽  
Parasite Growth ◽  
Growth And Survival ◽  
Apicomplexan Parasites ◽  
Parasite Replication ◽  
Main Components ◽  
Β Tubulin

AbstractCytoskeletal structures of Apicomplexan parasites are important for parasite replication, motility, invasion to the host cell and survival. Apicortin, an Apicomplexan specific protein appears to be a crucial factor in maintaining stability of the parasite cytoskeletal assemblies. However, the function of apicortin, in terms of interaction with microtubules still remains elusive. Herein, we have attempted to elucidate the function of Plasmodium falciparum apicortin by monitoring its interaction with two main components of parasite microtubular structure, α-tubulin-I and β-tubulin through in silico and in vitro studies. Further, a p25 domain binding generic drug Tamoxifen (TMX), was used to disrupt PfApicortin-tubulin interactions which led to the inhibition in growth and progression of blood stage life cycle of P. falciparum.

scholarly journals Evolutionary dynamics of spore killers.

Genetics ◽  
1993 ◽  
Vol 135 (3) ◽  
pp. 923-930 ◽  
Author(s):  
M J Nauta ◽  
R F Hoekstra
Keyword(s):  
Life Cycle ◽  
Segregation Distortion ◽  
Population Genetic ◽  
Field Data ◽  
Evolutionary Dynamics ◽  
Natural Populations ◽  
Additional Advantage ◽  
Genetic Modeling ◽  
Spore Killing ◽  
Ascospore Formation

Abstract Spore killing in ascomycetes is a special form of segregation distortion. When a strain with the Killer genotype is crossed to a Sensitive type, spore killing is expressed by asci with only half the number of ascospores as usual, all surviving ascospores being of the Killer type. Using population genetic modeling, this paper explores conditions for invasion of Spore killers and for polymorphism of Killers, Sensitives and Resistants (which neither kill, nor get killed), as found in natural populations. The models show that a population with only Killers and Sensitives can never be stable. The invasion of Killers and stable polymorphism only occur if Killers have some additional advantage during the process of spore killing. This may be due to the effects of local sib competition or some kind of "heterozygous" advantage in the stage of ascospore formation or in the short diploid stage of the life cycle. This form of segregation distortion appears to be essentially different from other, well-investigated forms, and more field data are needed for a better understanding of spore killing.

Computer Simulation Applied to Facility Design and Performance Evaluation

1969 ◽  
Vol 6 (03) ◽  
pp. 318-324
Author(s):  
Thomas P. Dunn
Keyword(s):  
Computer Simulation ◽  
Performance Evaluation ◽  
Simulation Model ◽  
Model Output ◽  
Facility Design ◽  
Newport News ◽  
Dry Dock ◽  
Computerized Simulation ◽  
Steel Fabrication ◽  
And Performance

This paper describes how a computerized simulation model was utilized to evaluate initially the design and later the performance of the new Steel Fabrication Shop of the Newport News Shipbuilding and Dry Dock Company. Included are descriptions of the model and its development, the shop, and exhibits which are illustrative of model output.

A Life Cycle Simulation Model for Transportation System consisting of Automobile and Public Transportation

2020 ◽  
Vol 2020.30 (0) ◽  
pp. 1206
Author(s):  
Hiroki NITTA ◽  
Taro KAWAGUCHI ◽  
Hidenori MURATA ◽  
Shinichi FUKUSHIGE ◽  
Hideki KOBAYASHI
Keyword(s):  
Life Cycle ◽  
Simulation Model ◽  
Public Transportation ◽  
Transportation System ◽  
Cycle Simulation

Robust Life-Cycle Production Optimization With a Support-Vector-Regression Proxy

SPE Journal ◽  
2018 ◽  
Vol 23 (06) ◽  
pp. 2409-2427 ◽  
Author(s):  
Zhenyu Guo ◽  
Albert C. Reynolds
Keyword(s):  
Life Cycle ◽  
Simulation Model ◽  
Support Vector Regression ◽  
Reservoir Simulation ◽  
Production Optimization ◽  
Forward Model ◽  
Support Vector ◽  
Well Control ◽  
Steepest Ascent ◽  
Reservoir Simulation Model

Summary We design a new and general work flow for efficient estimation of the optimal well controls for the robust production-optimization problem using support-vector regression (SVR), where the cost function is the net present value (NPV). Given a set of simulation results, an SVR model is built as a proxy to approximate a reservoir-simulation model, and then the estimated optimal controls are found by maximizing NPV using the SVR proxy as the forward model. The gradient of the SVR model can be computed analytically so the steepest-ascent algorithm can easily and efficiently be applied to maximize NPV. Then, the well-control optimization is performed using an SVR model as the forward model with a steepest-ascent algorithm. To the best of our knowledge, this is the first SVR application to the optimal well-control problem. We provide insight and information on proper training of the SVR proxy for life-cycle production optimization. In particular, we develop and implement a new iterative-sampling-refinement algorithm that is designed specifically to promote the accuracy of the SVR model for robust production optimization. One key observation that is important for reservoir optimization is that SVR produces a high-fidelity model near an optimal point, but at points far away, we only need SVR to produce reasonable approximations of the predicting output from the reservoir-simulation model. Because running an SVR model is computationally more efficient than running a full-scale reservoir-simulation model, the large computational cost spent on multiple forward-reservoir-simulation runs for robust optimization is significantly reduced by applying the proposed method. We compare the performance of the proposed method using the SVR runs with the popular stochastic simplex approximate gradient (StoSAG) and reservoir-simulations runs for three synthetic examples, including one field-scale example. We also compare the optimization performance of our proposed method with that obtained from a linear-response-surface model and multiple SVR proxies that are built for each of the geological models.

Short-Term Change in a Population of the Meat Ant Iridomyrmex Purpureus (Hymenoptera: Formicidae).

1975 ◽  
Vol 23 (4) ◽  
pp. 511 ◽  
Author(s):  
PJM Greenslade
Keyword(s):  
Seasonal Variation ◽  
Colony Size ◽  
Critical Factor ◽  
Nest Entrance ◽  
Short Term ◽  
Growth And Survival ◽  
Short Term Change ◽  
Term Change ◽  
Rates Of Growth ◽  
Size And Structure

A population of the mound-building meat ant, Iridomyrmex purpureus s. s., was studied from 1971 to 1974 near the cool, wet end of its South Australian range. Seasonal variation in the numbers of nest mounds, and in number of nest entrance holes used by the population, indicate that it is under climatic stress in winter and summer. It is also subject to human interference and many mounds have been damaged; the fate of such colonies suggests that the mounds affect nest temperatures and are important in reducing winter stress. Comparison of parts of the population from areas differing in aspect and drainage shows that colony size and structure are controlled by rates of growth and survival of nests, depending largely on summer and winter stress respectively. The latter appears to be the critical factor in this population.

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