scholarly journals Correlation between the spatial distribution and colony size was common for monogenetic bacteria in laboratory conditions

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Heng Xue ◽  
Masaomi Kurokawa ◽  
Bei-Wen Ying
Keyword(s):  
Spatial Distribution ◽  
Population Growth ◽  
Colony Size ◽  
Size Variation ◽  
Morphological Characteristics ◽  
Laboratory Conditions ◽  
Structured Population ◽  
Microbial Ecosystems ◽  
Universal Correlation ◽  
Spatial Resources

Abstract Background Geographically separated population growth of microbes is a common phenomenon in microbial ecology. Colonies are representative of the morphological characteristics of this structured population growth. Pattern formation by single colonies has been intensively studied, whereas the spatial distribution of colonies is poorly investigated. Results The present study describes a first trial to address the questions of whether and how the spatial distribution of colonies determines the final colony size using the model microorganism Escherichia coli, colonies of which can be grown under well-controlled laboratory conditions. A computational tool for image processing was developed to evaluate colony density, colony size and size variation, and the Voronoi diagram was applied for spatial analysis of colonies with identical space resources. A positive correlation between the final colony size and the Voronoi area was commonly identified, independent of genomic and nutritional differences, which disturbed the colony size and size variation. Conclusions This novel finding of a universal correlation between the spatial distribution and colony size not only indicated the fair distribution of spatial resources for monogenetic colonies growing with identical space resources but also indicated that the initial localization of the microbial colonies decided by chance determined the fate of the subsequent population growth. This study provides a valuable example for quantitative analysis of the complex microbial ecosystems by means of experimental ecology.

scholarly journals Correlation between the Spatial Distribution and Colony size Was Common for Monogenetic Bacteria in Laboratory Conditions.

2020 ◽  
Author(s):  
Heng Xue ◽  
Masaomi Kurokawa ◽  
Bei-Wen YING
Keyword(s):  
Spatial Distribution ◽  
Population Growth ◽  
Colony Size ◽  
Size Variation ◽  
Morphological Characteristics ◽  
Laboratory Conditions ◽  
Structured Population ◽  
Microbial Ecosystems ◽  
Universal Correlation ◽  
Spatial Resources

Abstract Background: Geographically separated population growth of microbes is a common phenomenon in microbial ecology. Colonies are representative of the morphological characteristics of this structured population growth. Pattern formation by single colonies has been intensively studied, whereas the spatial distribution of colonies is poorly investigated. Results: The present study describes a first trial to address the questions of whether and how the spatial distribution of colonies determines the final colony size using the model microorganism Escherichia coli, colonies of which can be grown under well-controlled laboratory conditions. A computational tool for image processing was developed to evaluate colony density, colony size and size variation, and the Voronoi diagram was applied for spatial analysis of colonies with identical space resources. A positive correlation between the final colony size and the Voronoi area was commonly identified, independent of genomic and nutritional differences, which disturbed the colony size and size variation. Conclusions: This novel finding of a universal correlation between the spatial distribution and colony size not only indicated the fair distribution of spatial resources for monogenetic colonies growing with identical space resources but also indicated that the initial localization of the microbial colonies decided by chance determined the fate of the subsequent population growth. This study provides a valuable example for quantitative analysis of the complex microbial ecosystems by means of experimental ecology.

scholarly journals The influence of subcolony-scale nesting habitat on the reproductive success of Adélie penguins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Annie E. Schmidt ◽  
Grant Ballard ◽  
Amélie Lescroël ◽  
Katie M. Dugger ◽  
Dennis Jongsomjit ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Colony Size ◽  
Nest Predation ◽  
Size Variation ◽  
Area Ratio ◽  
Slope Aspect ◽  
Nesting Habitat ◽  
Terrain Attributes ◽  
Small Colony ◽  
Adélie Penguins

AbstractGroup-size variation is common in colonially breeding species, including seabirds, whose breeding colonies can vary in size by several orders of magnitude. Seabirds are some of the most threatened marine taxa and understanding the drivers of colony size variation is more important than ever. Reproductive success is an important demographic parameter that can impact colony size, and it varies in association with a number of factors, including nesting habitat quality. Within colonies, seabirds often aggregate into distinct groups or subcolonies that may vary in quality. We used data from two colonies of Adélie penguins 73 km apart on Ross Island, Antarctica, one large and one small to investigate (1) How subcolony habitat characteristics influence reproductive success and (2) How these relationships differ at a small (Cape Royds) and large (Cape Crozier) colony with different terrain characteristics. Subcolonies were characterized using terrain attributes (elevation, slope aspect, slope steepness, wind shelter, flow accumulation), as well group characteristics (area/size, perimeter-to-area ratio, and proximity to nest predators). Reproductive success was higher and less variable at the larger colony while subcolony characteristics explained more of the variance in reproductive success at the small colony. The most important variable influencing subcolony quality at both colonies was perimeter-to-area ratio, likely reflecting the importance of nest predation by south polar skuas along subcolony edges. The small colony contained a higher proportion of edge nests thus higher potential impact from skua nest predation. Stochastic environmental events may facilitate smaller colonies becoming “trapped” by nest predation: a rapid decline in the number of breeding individuals may increase the proportion of edge nests, leading to higher relative nest predation and hindering population recovery. Several terrain covariates were retained in the final models but which variables, the shapes of the relationships, and importance varied between colonies.

scholarly journals Reproduction and survival of Muscina stabulans under laboratory conditions

2010 ◽  
Vol 40 (3) ◽  
pp. 674-677 ◽  
Author(s):  
Rodrigo Ferreira Krüger ◽  
Paulo Bretanha Ribeiro ◽  
Simone Giehl Erthal ◽  
Og DeSouza
Keyword(s):  
Population Growth ◽  
Quantitative Estimate ◽  
Intrinsic Rate ◽  
Reproduction Rate ◽  
Rapid Population Growth ◽  
Artificial Diets ◽  
Adaptation Capacity ◽  
Laboratory Conditions ◽  
Published Report ◽  
Rearing Conditions

This is the first published report concerning reproduction and survival using life table analyses of fertility and survival for Muscina stabulans maintained under laboratory conditions with artificial diets. The intrinsic rate of growth, reproduction rate and average generational time were obtained, suggesting a rapid population growth under these rearing conditions. These findings permitted the creation of time models of survival and oviposition, as well as a quantitative estimate of the adaptation capacity of this species.

scholarly journals The impact of highways on population redistribution: the role of land development restrictions

2019 ◽  
Vol 20 (3) ◽  
pp. 783-808 ◽  
Author(s):  
Or Levkovich ◽  
Jan Rouwendal ◽  
Jos van Ommeren
Keyword(s):  
Spatial Distribution ◽  
The Netherlands ◽  
Population Growth ◽  
Land Development ◽  
Apparent Effect ◽  
Population Redistribution ◽  
Interaction Variables ◽  
Peripheral Areas ◽  
The Impact

Abstract We study the role of land development restrictions for the effects of highway expansion on the spatial distribution of population for the Netherlands. Introducing an IV approach to address multiple endogenous interaction variables, our findings show that new highways accelerated population growth in peripheral areas, but had no apparent effect in suburban municipalities, in line with the presence of development restrictions. Highway expansions caused a ‘leapfrog’ pattern in which suburban growth skipped development-restricted areas and expanded into farther located peripheral areas.

Contraception of prepubertal young can increase cost effectiveness of management of overabundant koala populations

2019 ◽  
Vol 46 (4) ◽  
pp. 317
Author(s):  
Emily F. Hynes ◽  
Geoff Shaw ◽  
Marilyn B. Renfree ◽  
Kathrine A. Handasyde
Keyword(s):  
Cost Effectiveness ◽  
Population Growth ◽  
Wildlife Management ◽  
Sexual Maturation ◽  
Limited Resources ◽  
Management Scenarios ◽  
Structured Population ◽  
Population Reduction ◽  
Contraceptive Implants ◽  
Management And Conservation

Context With limited resources for wildlife management and conservation, it is vital that the effectiveness of management programs is maximised and costs reduced. Koala populations need to be reduced in locations where they are locally overabundant and over-browsing their food trees. Subcutaneous contraceptive implants containing levonorgestrel are currently used to control koala fertility to assist in reducing population densities. Dependent young are caught with their mothers, so are also available for contraception. Aims The overall aim was to investigate whether the effectiveness of koala contraception programs can be improved by administering levonorgestrel implants to female young along with their mothers. This was achieved by: (1) determining if implanting females before sexual maturation affects their fertility, growth and pouch development; and (2) developing a stage-structured population growth model to compare two management scenarios. Methods Juvenile female koalas (11–17 months old) were treated with either a control (n = 5) or 70 mg levonorgestrel implant (n = 5). Koalas were caught every 4 to 6 weeks for 15 months, then every 3 to 12 months for 5 years. Koalas were weighed and head length measured. Pouches were checked for young. Pouch development was assessed as a proxy for sexual maturation. A stage-based population model simulating koala population growth was developed to compare different management scenarios: no treatment; treatment of adults only; and treatment of adults plus their dependent young. Key results Levonorgestrel implants prevented births with no effect on growth, survival or timing of sexual maturation. Population growth simulations indicate that treating dependent young with their mothers results in earlier population reduction. Conclusions The treatment of prepubertal female koalas with levonorgestrel implants is a safe and effective method that increases the effectiveness of koala contraception programs. Implications Development of novel strategies may provide opportunities to increase the efficiency and cost-effectiveness of management programs with constrained resources.

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