scholarly journals Hidden patterns of colony size variation in seabirds: a logarithmic point of view

Oikos ◽  
2008 ◽  
Vol 117 (12) ◽  
pp. 1774-1781 ◽  
Author(s):  
Roger Jovani ◽  
Roddy Mavor ◽  
Daniel Oro
Keyword(s):  
Colony Size ◽  
Size Variation ◽  
Point Of View ◽  
Hidden Patterns

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 Fluctuating survival selection explains variation in avian group size

2016 ◽  
Vol 113 (18) ◽  
pp. 5113-5118 ◽  
Author(s):  
Charles R. Brown ◽  
Mary Bomberger Brown ◽  
Erin A. Roche ◽  
Valerie A. O’Brien ◽  
Catherine E. Page
Keyword(s):  
Group Size ◽  
Colony Size ◽  
Information Transfer ◽  
Size Variation ◽  
Directional Selection ◽  
Net Benefit ◽  
First Case ◽  
Survival Selection ◽  
Wide Range ◽  
Directional Change

Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark–recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population.

CuDia Slug Size Variation Analysis on Heat Dissipation of High Power LED

2014 ◽  
Vol 487 ◽  
pp. 33-36 ◽  
Author(s):  
Rajendaran Vairavan ◽  
Vithyacharan Retnasamy ◽  
Zaliman Sauli
Keyword(s):  
Natural Convection ◽  
High Power ◽  
Heat Dissipation ◽  
Size Variation ◽  
Simulation Method ◽  
Point Of View ◽  
Junction Temperature ◽  
Variation Analysis ◽  
Single Chip ◽  
Simulation Results

The current advancement of LED has prompt thermal challenges from the packaging point of view. The reliability of the LED is significantly influenced by each of its packaging component. This paper presents the investigation of heat slug size effect on the junction temperature and stress of single chip LED through simulation method. Ansys version 11 was utilized and the analysis was done with copper diamond rectangular heat slug under natural convection condition at ambient temperature of 25 °C.The simulation results indicated that junction temperature and the stress of the single chip LED is influenced by the size of heat slug.

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 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 The spatial and metabolic basis of colony size variation

2018 ◽  
Vol 12 (3) ◽  
pp. 669-680 ◽  
Author(s):  
Jeremy M. Chacón ◽  
Wolfram Möbius ◽  
William R. Harcombe
Keyword(s):  
Colony Size ◽  
Size Variation ◽  
Metabolic Basis

scholarly journals Extracting hidden patterns from dates' product data using a machine learning technique

2019 ◽  
Vol 8 (3) ◽  
pp. 205
Author(s):  
Mohammed Abdullah Al-Hagery
Keyword(s):  
Machine Learning ◽  
Nutritional Value ◽  
Health Benefits ◽  
Point Of View ◽  
Apriori Algorithm ◽  
Machine Learning Technique ◽  
Arab Region ◽  
Learning Technique ◽  
Important Health ◽  
Hidden Patterns

<div style="’text-align: justify;">Mining in data is an important step for knowledge discovery, which leads to extract new patterns from datasets. It is a widespread methodology that has the capability to help ministries, companies, and experts for diving into the data to find important insights and patterns to help them take suitable decisions. The farmers and marketers of the date product in the production regions lack to discover the most important characteristics of dates types from the economically, healthy, and the type of consumers point of view to achieve the highest profits by choosing the best types and the most consumed. The research objective is to extract interesting patterns from the dates’ product dataset, using Machine Learning, based on association rules generation. This, in turn, will support the farmers, and marketers to discover new features related to the production, consumption, and marketing processes. This research used a real dataset collected from KSA, Qassim region, which is the first region of cultivation of palm, that produces the best types of dates in the Arab region. The data preprocessed and analyzed by the Apriori algorithm. The results show important features and insights related to the health benefits of dates, production, its consumption, consumers types, and marketing. Consequently, these results can be employed, for instance, to encourage individuals to consume dates for their nutritional value and their important health benefits., furthermore, the results encourage producers to focus on the production of preferable types and to improve the marketing policies of the other types.</div>

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