scholarly journals The interplay between demography and neutral evolution at the expansion front of a widespread conifer, Picea sitchensis

2018 ◽  
Author(s):  
Joane S. Elleouet ◽  
Sally N. Aitken
Keyword(s):  
Population Growth ◽  
Demographic History ◽  
Pollen Dispersal ◽  
Picea Sitchensis ◽  
Limiting Factors ◽  
Neutral Evolution ◽  
Long Distance ◽  
Evolutionary Trajectory ◽  
Genetic Structure And Diversity

AbstractTree species in the northern hemisphere have advanced and retreated with interglacial and glacial periods, and are currently subject to rapid anthropogenic climate change. These observations prompt questions about the mechanisms allowing tree populations to respond quickly to selection pressures when establishing into new areas. Focusing on the northern expanding range edge of Picea sitchensis, a widespread conifer of western North America, we ask how genetic structure and diversity develop during colonization, and assess the role of demographic history in shaping the evolutionary trajectory of a colonizing population. By combining nearly 500 years of tree-ring and genetic data at the expansion front on the Kodiak Archipelago, we show that allelic richness - but not expected heterozygosity - increased rapidly during early stages of establishment in the 1600s, while genetic differentiation from populations further from the front decreased. This trend ended in the 1700s, after an increase in population growth rate. These findings highlight the major role of long-distance pollen dispersal in the recovery of genetic diversity during initial stages of colonization, and suggest that demographic dynamics including an initial lag in population growth are likely limiting factors in the adaptation of tree populations tracking their niche in a changing climate.

Attachment Styles, Physical Proximity, and Relational Satisfaction

2014 ◽  
Vol 4 (2) ◽  
pp. 106-112
Author(s):  
Anita Shrivastava ◽  
Andrea Burianova
Keyword(s):  
Attachment Styles ◽  
Romantic Relationship ◽  
Distinct Type ◽  
Relational Satisfaction ◽  
Long Distance ◽  
Avoidant Attachment ◽  
Geographic Separation ◽  
Relationship Of ◽  
Attachment Dimensions

This study aimed to explore the relationships between attachment styles, proximity, and relational satisfaction. This was achieved by assessing a distinct type of long distance romantic relationship of flying crews, compared with proximal (non-flying crew) romantic relationships. The responses of 139 expatriate professionals revealed significant associations between proximity and anxious and avoidant attachment dimensions. The role of the avoidant dimension in comparison with that of the anxious dimension was found to be a significant predictor of relational satisfaction. This study contributes significantly toward addressing the role of proximity and attachment in relational satisfaction in a new context of geographic separation.

PERAN MASYARAKAT TERHADAP PEMBAYARAN RETRIBUSI SAMPAH DI KOTA SAMARINDA

2018 ◽  
Vol 2 (1) ◽  
pp. 33
Author(s):  
Abd Rachim AF,
Keyword(s):  
Waste Management ◽  
Population Growth ◽  
Frequency Analysis ◽  
Urban Areas ◽  
Relative Frequency ◽  
Environmental Problems ◽  
Living Standards ◽  
The Public ◽  
And Behavior

One of the environmental problems in urban areas is the pollution caused by garbage. The waste problem is caused by various factors such as population growth, living standards changes, lifestyles and behavior, as well as how the waste management system. This study aims to determine how the role of society to levy payments garbage in Samarinda. This research was descriptive; where the data is collected then compiled, described and analyzed used relative frequency analysis. The participation of the public to pay a "levy junk", which stated to pay 96.67%, for each month and the rates stated society cheap, moderate and fairly, respectively 46.08%, 21.21%, 21.04%. Base on the data , the role of the community to pay "levy junk" quite high.

Trade, Commerce, and the State in the Roman World

2017 ◽  
Keyword(s):  
Roman Empire ◽  
The State ◽  
Market Regulation ◽  
External Trade ◽  
Long Distance ◽  
Legal Structures ◽  
The City ◽  
Political Character ◽  
Different Sources

This interdisciplinary volume presents nineteen chapters by Roman historians and archaeologists, discussing trade in the Roman Empire in the period c.100 BC to AD 350, and in particular the role of the Roman state, in shaping the institutional framework for trade within and outside the Empire, in taxing that trade, and in intervening in the markets to ensure the supply of particular commodities, especially for the city of Rome and for the army. The chapters in this volume address facets of the subject on the basis of widely different sources of evidence—historical, papyrological, and archaeological—and are grouped in three sections: institutional factors (taxation, legal structures, market regulation, financial institutions); evidence for long-distance trade within the Empire, in wood, stone, glass, and pottery; and trade beyond the frontiers, with the East (as far as China), India, Arabia, and the Red Sea, and the Sahara. Rome’s external trade with realms to the east emerges as being of particular significance to the fisc. But in the eastern part of the Empire at least, the state appears, in collaboration with the elite holders of wealth, to have adapted the mechanisms of taxation, both direct and indirect, to support its need for revenue. On the other hand, the price of that collaboration, which was in effect a fiscal partnership, in slightly different forms in East and West, in the longer term fundamentally changed the political character of the Empire.

Agenda-Setting Dynamics during the Campaign Period

2017 ◽  
Author(s):  
Julia Partheymüller
Keyword(s):  
Political Parties ◽  
News Media ◽  
Agenda Setting ◽  
Information Environment ◽  
Limiting Factors ◽  
Media Content ◽  
Agenda Setter ◽  
Memory Decay ◽  
The Media

It is widely believed that the news media have a strong influence on defining what are the most important problems facing the country during election campaigns. Yet, recent research has pointed to several factors that may limit the mass media’s agenda-setting power. Linking news media content to rolling cross-section survey data, the chapter examines the role of three such limiting factors in the context of the 2009 and the 2013 German federal elections: (1) rapid memory decay on the part of voters, (2) advertising by the political parties, and (3) the fragmentation of the media landscape. The results show that the mass media may serve as a powerful agenda setter, but also demonstrate that the media’s influence is strictly limited by voters’ cognitive capacities and the structure of the campaign information environment.

scholarly journals Biogeochemical Controls on the Redox Evolution of Earth’s Oceans and Atmosphere

Elements ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Christopher T. Reinhard ◽  
Noah J. Planavsky
Keyword(s):  
Redox State ◽  
Modeling Tools ◽  
Evolutionary Trajectory ◽  
Geochemical Tracers ◽  
Atmosphere System ◽  
Ocean Atmosphere ◽  
Dramatic Shift ◽  
Redox Evolution

The redox state of Earth’s atmosphere has undergone a dramatic shift over geologic time from reducing to strongly oxidizing, and this shift has been coupled with changes in ocean redox structure and the size and activity of Earth’s biosphere. Delineating this evolutionary trajectory remains a major problem in Earth system science. Significant insights have emerged through the application of redox-sensitive geochemical systems. Existing and emerging biogeochemical modeling tools are pushing the limits of the quantitative constraints on ocean–atmosphere redox that can be extracted from geochemical tracers. This work is honing our understanding of the central role of Earth’s biosphere in shaping the long-term redox evolution of the ocean–atmosphere system.

Plant Resistance in Some Modern Soybean Varieties May Favor Population Growth and Modify the Stylet Penetration of Bemisia tabaci (Hemiptera: Aleyrodidae)

2021 ◽  
Author(s):  
Mauricélia F Almeida ◽  
Clébson S Tavares ◽  
Euires O Araújo ◽  
Marcelo C Picanço ◽  
Eugênio E Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Bemisia Tabaci ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Genetically Engineered ◽  
Population Increase ◽  
Net Reproductive Rate ◽  
Bt Toxin ◽  
Demographic Performance

Abstract Complaints of severe damage by whiteflies in soybean fields containing genetically engineered (GE) varieties led us to investigate the role of transgenic soybean varieties expressing resistance to some insects (Cry1Ac Bt toxin) and to herbicide (glyphosate) on the population growth and feeding behavior of Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae). In the laboratory, the whiteflies reared on the GE Bt soybeans had a net reproductive rate (R0) 100% higher and intrinsic rate of population increase (rm) 15% higher than those reared on non-GE soybeans. The increased demographic performance was associated with a higher lifetime fecundity. In electrical penetration graphs, the whiteflies reared on the GE soybeans had fewer probes and spent 50% less time before reaching the phloem phase from the beginning of the first successful probe, indicating a higher risk of transmission of whitefly-borne viruses. Data from Neotropical fields showed a higher population density of B. tabaci on two soybean varieties expressing glyphosate resistance and Cry1Ac Bt toxin. These results indicate that some GE soybean varieties expressing insect and herbicide resistances can be more susceptible to whiteflies than non-GE ones or those only expressing herbicide resistance. Most likely, these differences are related to varietal features that increase host-plant susceptibility to whiteflies. Appropriate pest management may be needed to deal with whiteflies in soybean fields, especially in warm regions, and breeders may want to consider the issue when developing new soybean varieties.

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