scholarly journals Community genetics: what have we accomplished and where should we be going?

2011 ◽  
Vol 366 (1569) ◽  
pp. 1453-1460 ◽  
Author(s):  
Erika I. Hersch-Green ◽  
Nash E. Turley ◽  
Marc T. J. Johnson
Keyword(s):  
Genetic Variation ◽  
Ecological Factors ◽  
Ecosystem Processes ◽  
Community Genetics ◽  
Future Research ◽  
Ecosystem Ecology ◽  
Relative Importance ◽  
Genetic Mechanisms ◽  
Intraspecific Genetic Variation ◽  
Dynamic Interplay

Research in community genetics seeks to understand how the dynamic interplay between ecology and evolution shapes simple and complex communities and ecosystems. A community genetics perspective, however, may not be necessary or informative for all studies and systems. To better understand when and how intraspecific genetic variation and microevolution are important in community and ecosystem ecology, we suggest future research should focus on three areas: (i) determining the relative importance of intraspecific genetic variation compared with other ecological factors in mediating community and ecosystem properties; (ii) understanding the importance of microevolution in shaping ecological dynamics in multi-trophic communities; and (iii) deciphering the phenotypic and associated genetic mechanisms that drive community and ecosystem processes. Here, we identify key areas of research that will increase our understanding of the ecology and evolution of complex communities but that are currently missing in community genetics. We then suggest experiments designed to meet these current gaps.

scholarly journals Cryptic variation and its manifestation in the Lower Trentonian Rafinesquina lineage (Ordovician, New York State)

1992 ◽  
Vol 6 ◽  
pp. 292-292
Author(s):  
Robert Titus
Keyword(s):  
New York ◽  
Genetic Variation ◽  
Natural Selection ◽  
New York State ◽  
Ecological Factors ◽  
Stabilizing Selection ◽  
Rapid Population Growth ◽  
York State ◽  
Cryptic Variation ◽  
Adaptive Peak

Species populations commonly carry a great deal of genetic variation which is not expressed in individual phenotypes. Cryptic variation can be carried in recessive alleles, in cases of heterosis, or where modifier genes inhibit expression of the hidden trait. Other genetic and ecological factors also allow cryptic variation. Stabilizing selection prevents the expression of hidden traits; normalizing selection weeds out the deviants and canalizing selection suppresses their traits. Together the two keep the species near the top of the adaptive peak. Cryptic variation balances a species' need to be well-adapted to its environment and also for it to maintain a reserve of variation for potential environmental change. Expression of cryptic traits is rare and is usually associated with times of greatly reduced natural selection and rapid population growth, when the lower slopes of the adaptive peak are exposed.A possible example of the manifestation of cryptic traits occurs within the lower Trentonian Rafinesquina lineage of New York State. The two most commonly reported species of the genus have been reappraised in terms of cryptic variation. Extensive collections of Rafinesquina “lennoxensis” reveal far more intergrading morphotypes than had hitherto been recognized. The form which Salmon (1942) described is broadly U-shaped with sulcate margins. It grades into very convex forms as well as sharply-defined or convexly geniculate types. Of great importance, all forms grade into the flat, U-shaped, alate R. trentonensis, which is, by far, the most common and widespread lower Trentonian member of the genus. The R. “lennoxensis” assemblage has a very narrow biostratigraphy, being confined to a few locations in the upper Napanee Limestone. This places it in a quiet, protected, low stress, lagoonal setting behind the barrier shoal facies of the Kings Falls Limestone.The R. “lennoxensis” assemblage does not constitute a natural biologic species; it is reinterpreted as an assemblage of phenodeviants occupying a low stress, low natural selection lagoon facies. All such forms should be included within R. trentonensis. Given the evolutionary plasticity of this genus, extensive cryptic variation is not surprising.

Effectiveness of a Modified Version of Airflow Therapy

1982 ◽  
Vol 47 (2) ◽  
pp. 160-164
Author(s):  
Glenn L. Falkowski ◽  
Arthur M. Guilford ◽  
Jack Sandler
Keyword(s):  
Success Rate ◽  
Scientific Literature ◽  
Future Research ◽  
Relative Importance ◽  
Differential Effectiveness ◽  
History Of ◽  
One Year ◽  
Main Components

Utilizing airflow therapy, Schwartz (1976) has claimed an 89% success rate with stutterers following treatment and an 83% success rate at one year follow-up. Such claims have yet to be documented in the scientific literature. The purposes of this study were: (a) to investigate the effectiveness of a modified version of airflow therapy; (b) to examine the relative importance of its two main components—passive airflow and elongation of the first vowel spoken. The speech of two adult male stutterers with a lengthy history of stuttering, was assessed with spontaneous speaking and reading tasks. Results indicated marked improvement in both subjects' speech on the reading task was maintained at follow-up 10 weeks later. For spontaneous speech, results were generally weaker and less durable. Effects of the two treatment components were cumulative and did not allow determination of any differential effectiveness between components. Implications of these findings were considered and directions for future research discussed.

Competition theory — science and application in mixed forest stands: review of experimental and modelling methods and suggestions for future research

2013 ◽  
Vol 21 (2) ◽  
pp. 71-84 ◽  
Author(s):  
Guy R. Larocque ◽  
Nancy Luckai ◽  
Shailendra N. Adhikary ◽  
Arthur Groot ◽  
F. Wayne Bell ◽  
...  
Keyword(s):  
Mixed Forest ◽  
Single Species ◽  
Experimental Designs ◽  
Competitive Interactions ◽  
Future Research ◽  
Relative Importance ◽  
Forest Stands ◽  
Management Scenarios ◽  
Mixed Stands ◽  
Individual Tree

Competition in forest stands has long been of interest to researchers. However, much of the knowledge originates from empirical studies that examined the effects of competition. For instance, many studies were focused on the effects of the presence of herbaceous species on the development of tree seedlings or the decrease in individual tree growth with increases in stand density. Several models that incorporate competitive effects have been developed to predict tree and stand growth, but with simplified representations of competitive interactions. While these studies provided guidance useful for forest management, they contributed only partially to furthering our understanding of competitive mechanisms. Also, most competition studies were conducted in single-species stands. As competitive interactions occurring in mixed stands are characterized by a higher degree of complexity than those in single-species stands, a better understanding of these mechanisms can contribute to developing optimal management scenarios. The dynamics of forest stands with at least two species may be affected not only by competition, but also by facilitation or complementarity mechanisms. Thus, knowledge of the mechanisms may provide insight into the relative importance of intra- versus inter-specific competition and whether competition is symmetric or asymmetric. Special attention to the implementation of field experimental designs is warranted for mixed stands. While traditional spacing trials are appropriate for single-species stands, the examination of competitive interactions in mixed stands requires more complex experimental designs to examine the relative importance of species combinations. Forest productivity models allow resource managers to test different management scenarios, but again most of these models were developed for single-species stands. As competitive interactions are more complex in mixed stands, models developed to predict their dynamics will need to include more mechanistic representations of competition.

What does Solitude Mean to the Aged?

1988 ◽  
Vol 7 (4) ◽  
pp. 358-371 ◽  
Author(s):  
Marc-André Delisle
Keyword(s):  
Social Isolation ◽  
The Elderly ◽  
Complex Problem ◽  
Future Research ◽  
Relative Importance ◽  
Affective Needs ◽  
Quebec Literature ◽  
Comprehensive Study

AbstractThis article examines the extent and the meaning of solitude among the aged. A comprehensive study of the foreign, Canadian and Quebec literature was undertaken to prepare this document, but priority was given to the somewhat lesser known investigations originating from Quebec. First, the concepts most often utilized in discussing the phenomena under scrutiny were defined: solitude, social isolation and the feeling of loneliness. Then, the relative importance of each phenomenon was assessed, based on the available data. In order to fully understand the meaning of the facts observed, their causes were also examined. Finally, avenues for future research were proposed. This study suggests that solitude among the elderly is a more complex problem than believed. Even if the isolated and (or) lonely aged are in the minority, this does not mean that all their socio-affective needs are being met. These people spend long periods of time alone and this affects their lives. The problem as such is largely caused by the position the elderly occupy in the society and, in turn, this position probably influences their behaviour. However, gerontologists have scarcely studied this hypothesis. This article then highlights certain aspects of the solitude phenomenon which have so far been overlooked by gerontologists.

scholarly journals Adaptive genetic variation at three loci in South African vervet monkeys (Chlorocebus pygerythrus) and the role of selection within Primates

2018 ◽  
Author(s):  
Willem G Coetzer ◽  
Trudy R Turner ◽  
Christopher A Schmitt ◽  
J Paul Grobler
Keyword(s):  
Genetic Variation ◽  
South African ◽  
Vervet Monkey ◽  
Climatic Conditions ◽  
Primate Species ◽  
Annual Rainfall ◽  
Future Research ◽  
Vervet Monkeys ◽  
Adaptive Genetic Variation ◽  
Chlorocebus Pygerythrus

Vervet monkeys (Chlorocebus pygerythrus) are one of the most widely distributed non-human primate species found in South Africa. They occur across all the South African provinces, inhabiting a large variety of habitats. These habitats vary sufficiently that it can be assumed that various factors such as pathogen diversity could influence populations in different ways. In turn, these factors could lead to varied levels of selection at specific fitness linked loci. The Toll-like Receptor (TLR) gene family, which play an integral role in vertebrate innate immunity, is a group of fitness linked loci which has been the focus of much research. In this study, we assessed the level of genetic variation at partial sequences of two TLR loci (TLR4 and 7) and a reproductively linked gene, acrosin (ACR), across the different habitat types within the vervet monkey distribution range. Gene variation and selection estimates were also made among 11 – 21 primate species. Low levels of genetic variation for all three gene regions were observed within vervet monkeys , with only two polymorphic sites identified for TLR4, three sites for TLR7 and one site for ACR . TLR7 variation was positively correlated with high mean annual rainfall, which was linked to increased pathogen abundance. The observed genetic variation at TLR4 might have been influenced by numerous factors including pathogens and climatic conditions. The ACR exonic regions showed no variation in vervet monkeys, which could point to the occurrence of a selective sweep. The TLR4 and TLR7 results for the among primate analyses was mostly in line with previous studies, indicating a higher rate of evolution for TLR4. Within primates, ACR also showed signs of positive selection, which was congruent with previous reports on mammals. Important additional information to the already existing vervet monkey knowledge base was gained from this study, which can guide future research projects on this highly researched taxon as well as help conservation agencies with future management planning involving possible translocations of this species.

External Factors and the Pricing of Audit Services: A Systematic Review of the Archival Literature using a PESTLE Analysis

2021 ◽  
Author(s):  
Brigitte Eierle ◽  
Sven Hartlieb ◽  
David C Hay ◽  
Lasse Niemi ◽  
Hannu Ojala
Keyword(s):  
Systematic Review ◽  
Ecological Factors ◽  
External Factors ◽  
Future Research ◽  
Archival Studies ◽  
Audit Pricing ◽  
Regulatory Changes ◽  
Novel Structure ◽  
Audit Fee ◽  
Political Economic

Client- and auditor-related attributes are well-documented determinants of audit pricing but the number of empirical archival studies investigating the effects of external factors on audit pricing has grown rapidly in recent years. We extend the traditional framework used to classify audit fee research by adding a novel structure that focuses on political, economic, social, technological, legal, and environmental/ecological factors (a PESTLE analysis). We provide a systematic review of the literature on external factors and audit pricing, and we suggest opportunities for future research. Our review reveals that audit researchers focus on legal factors in terms of regulatory changes, and we find increased attention to political, economic, and social factors. However, despite increased public scrutiny, technological and environmental/ecological factors remain under-researched. Overall, our review demonstrates the importance of considering external factors to gain a more complete understanding of the audit pricing framework, especially in terms of global and regional variations.

Toward Web 2.0 Integration in Indonesian Education

2012 ◽  
pp. 198-221
Author(s):  
Agus Mutohar ◽  
Joan E. Hughes
Keyword(s):  
Professional Development ◽  
Developing Countries ◽  
Web 2.0 ◽  
Standardized Testing ◽  
Ecological Factors ◽  
Technology Leadership ◽  
Future Research ◽  
Government Organizations ◽  
Integration Of Technology ◽  
National Educational Policy

Numerous efforts have been made to reform education to address globalization both in developed and developing countries. The integration of technology in education has been one vital reform effort in developing countries to prepare graduates for 21st century workplaces, which are digitally robust. Web 2.0 technologies are becoming prominent educational and workplace tools. This literature review of Indonesian government policies, NGO initiative reports, and contemporary research explores the integration of Web 2.0 in Indonesian education using an ecological perspective by introducing the Indonesian national educational policy and laws, describing national and non-government organizations’ initiatives focused on Web 2.0 integration, identifying salient national and local challenges preventing Web 2.0 integration, and proposing strategies for future planning and research. Challenges identified include lack of technological facilities, an absence of technology standards in education, a standardized testing culture, lack of coordination between government levels (national to local), lack of professional development, and a need for strong school technology leadership. The authors recommend Indonesia engage in comprehensive, visionary planning for Web 2.0 integration with strategies to meet local needs, invest in professional development and technology specialist positions, and advance mobile Web 2.0 computing and BYOT/D initiatives. Future research could examine how ecological factors at the national, provincial, and local levels coordinate to best establish Web 2.0 integration in education at the school level.

Unified Framework II Ecosystem Processes: A Link Between Species and Landscape Diversity

2005 ◽  
Author(s):  
Robert Waide ◽  
Peter M. Groffman
Keyword(s):  
Landscape Ecology ◽  
Nutrient Cycling ◽  
Community Ecology ◽  
Energy Flow ◽  
Ecosystem Processes ◽  
Landscape Diversity ◽  
Ecosystem Ecology ◽  
Unified Framework ◽  
Ecosystem Diversity

The discipline of ecology can be subdivided into several subdisciplines, including community, ecosystem, and landscape ecology. While all the subdisciplines are important to the study of biodiversity, there is great variation in the extent to which their contributions have been analyzed. For example, the role of community ecology in biodiversity studies is well established. In community ecology, the entities of study are species that differ in their properties and generate a web of interactions that, in turn, organize the species into a community. Similar to community ecology, the contribution of landscape ecology to biodiversity is apparent. The entities of study, definable “patches,” are tangible. They differ in their properties and generate a web of interactions that organize the patches into a landscape mosaic. In contrast to community and landscape ecology, the role of ecosystem ecology in biodiversity is less apparent. In ecosystem ecology, it often is not clear what the entities are, and how they are organized. To the extent that ecosystem ecology focuses on energy flow and nutrient cycling, we can define fundamental entities as compartments and vectors in models that depict the flows of water, energy, and nutrients through communities. If we apply diversity criteria to these entities, we can use the term ecosystem diversity to refer to the number of compartments and vectors, the differences among them in type and size, and their organization in promoting energy flow or nutrient cycling. To our knowledge, ecosystem scientists have not yet developed criteria for ecosystem diversity similar to those used for species and landscape diversity. There has been some use of the term “ecosystem diversity” to refer to a diversity of ecosystems, implying a variety of habitats, landscapes, or biomes. As discussed above, we suggest that to define the role of ecosystem ecology in biodiversity studies, the approach should be to study the relationships among species, landscape, and ecosystem diversities (chapters 1 and 13). However, since the concept of ecosystem diversity awaits further development, we adopt a different approach for understanding the role of ecosystem science in biodiversity studies. In this chapter, we examine relationships among ecosystem processes, species diversity, and landscape diversity.

scholarly journals Patterns, Mechanisms and Genetics of Speciation in Reptiles and Amphibians

Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 646 ◽  
Author(s):  
Wollenberg Valero ◽  
Marshall ◽  
Bastiaans ◽  
Caccone ◽  
Camargo ◽  
...  
Keyword(s):  
Ecological Speciation ◽  
Integrative Taxonomy ◽  
Future Research ◽  
Phenotypic Traits ◽  
South American ◽  
Evolutionary Forces ◽  
Speciation Rates ◽  
Genetic Mechanisms ◽  
Genetics Of Speciation ◽  
Patterns And Processes

In this contribution, the aspects of reptile and amphibian speciation that emerged from research performed over the past decade are reviewed. First, this study assesses how patterns and processes of speciation depend on knowing the taxonomy of the group in question, and discuss how integrative taxonomy has contributed to speciation research in these groups. This study then reviews the research on different aspects of speciation in reptiles and amphibians, including biogeography and climatic niches, ecological speciation, the relationship between speciation rates and phenotypic traits, and genetics and genomics. Further, several case studies of speciation in reptiles and amphibians that exemplify many of these themes are discussed. These include studies of integrative taxonomy and biogeography in South American lizards, ecological speciation in European salamanders, speciation and phenotypic evolution in frogs and lizards. The final case study combines genomics and biogeography in tortoises. The field of amphibian and reptile speciation research has steadily moved forward from the assessment of geographic and ecological aspects, to incorporating other dimensions of speciation, such as genetic mechanisms and evolutionary forces. A higher degree of integration among all these dimensions emerges as a goal for future research.

scholarly journals Some ecological factors influencing the breeding success of the Brenton Blue butterfly, Orachrysops niobe (Trimen) (Lepidoptera: Lycaenidae)

Koedoe ◽  
2002 ◽  
Vol 45 (2) ◽  
Author(s):  
D.A. Edge
Keyword(s):  
Host Plant ◽  
Breeding Season ◽  
Breeding Success ◽  
Ecological Factors ◽  
Future Research ◽  
Plant Abundance ◽  
Factors Influencing ◽  
Nectar Sources ◽  
Management Techniques ◽  
Blue Butterfly

The Brenton Blue butterfly, Orachrysops niobe (Trimen, 1862) (Lepidoptera:Lycaenidae), is endemic to the southern Cape and is currently listed as Endangered. This study looks at some of the key ecological factors influencing the breeding success of the species—host plant abundance and condition, nectar sources, climate/ microclimate, and vegetation management techniques. The adult butterfly population was monitored over an entire breeding season; host plants were identified and individually monitored; and egg counts were done. This enabled the effects of a number of different management techniques to be evaluated (burning, cutting, physical removal of invasive elements, and combinations thereof). A fivefold increase in the population of O. niobe was observed over the breeding season. This increase was positively correlated to a similar increase in host plant abundance in the areas where cutting and physical removal of invasive elements was practiced. Burning, by contrast, appeared to have a negative impact on host plant and butterfly abundance over the same period. Impacts of other factors such as climate, nectar sources and the natural strength of the second brood are discussed. A hypothesis, of megaherbivore activity as the principal historical disturbance mechanism promoting locally favourable conditions for O. niobe to establish and maintain colonies, is proposed. Recommendations for reserve management and future research are made.

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