5,975 research outputs found
Mechanisms of growth and sex determination in the Atlantic silverside, Menidia menidia, and the spatial scale of local adaptation
No full textLocal adaptation in widely-dispersed marine species may result from strong selection on multiple life history traits that differ among populations. This results in unique sets of traits that maximize fitness of individuals within populations along the species' range. The Atlantic silverside, Menidia menidia, is a fish that exhibits high gene flow potential, but differences in growth and sexual differentiation among populations demonstrate strong local adaptation. To better understand the spatial pattern of local adaptation in this species, I compared the form of sex determination, which shifts from genetic to environmental sex determination, across this species' range and quantified the rate of gonad development across populations. Strong local selection in this species drives genetic differences among populations, but few of the mechanisms that control these differences have been studied. Therefore, I also quantified the activity of a major sex-determining gene during gonad differentiation in populations with different forms of sex determination and assessed the role of a major growth protein in structuring growth differences among populations with unique life-history traits. Finally, widely-dispersed marine species come into contact with many anthropogenic stressors within their ranges, and there may be differential interactions between these stressors and local populations. I addressed how locally-adapted differences in sex determination contribute to population-level susceptibility to estrogenic contaminants in the wild.Advisor(s): David O. Conover. Anne E. McElroy. Committee Member(s): Stephan Munch; Mark Fast; Russell Borski.Stony Brook University Libraries. SBU Graduate School in Department of Marine and Atmospheric Science. Lawrence Martin (Dean of Graduate School)
Local Adaptation along a Latitudinal Gradient in Pacific versus Atlantic-Coast Fishes
No full textUnderstanding how species adapt to spatial climate gradients can provide clues to potential evolutionary responses to climate change. Species distributed across broad environmental gradients, such as those that occur along latitudes or altitudes, often exhibit adaptive genetic variation. However, little attention has been given to how the type of environmental gradient shapes adaptive responses. To provide insight into this, local adaptation is compared in related fish species across two very different environmental gradients: the Atlantic and Pacific coasts of North America. Local adaptation is first examined in the California grunion (Leuresthes tenuis) and then results are compared to previous work on the Atlantic silverside. Common garden experiments and wild fish studies were used to test for local adaptation among several traits (growth capacity, sex determination, and vertebral number) of the California grunion across three latitudinal populations: Monterey, CA (36.6øN), Malibu, CA (34.0øN), and Ensenada, MX (31.9øN). Consistent genetic differences in growth capacity between latitudinal populations were not observed. Wild southern grunion were slightly larger and grew faster than more northern grunion, likely due to environmental effects. Temperature (p<0.001) and photoperiod (p=0.011) were found to significantly affect sex ratios of laboratory reared fish, indicating that grunion have environmental sex determination (ESD); however the level of ESD did not differ among populations. Mean vertebral numbers in wild grunion were nearly identical for all populations. The lack of latitudinal variation in these traits of the grunion is in direct contrast to the Atlantic silverside, which exhibits a high degree of genetic differentiation in all of the above traits. Results also differ from recent work on the topsmelt, another Pacific coast silverside species. Failure to observe latitudinal variation in the grunion unlike its other taxonomic relatives may be due to its oceanic rather than estuarine habitat, which provides a greater opportunity for broad-scale gene flow and results in a more homogenous environment. Implications for climate change are discussed.Advisor(s): David O. Conover. Committee Member(s): Stephan B. Munch; Michael G. Frisk.Stony Brook University Libraries. SBU Graduate School in Department of Marine and Atmospheric Science. Lawrence Martin (Dean of Graduate School)
Local Adaptation along a Latitudinal Gradient in Pacific versus Atlantic-Coast Fishes
No full textUnderstanding how species adapt to spatial climate gradients can provide clues to potential evolutionary responses to climate change. Species distributed across broad environmental gradients, such as those that occur along latitudes or altitudes, often exhibit adaptive genetic variation. However, little attention has been given to how the type of environmental gradient shapes adaptive responses. To provide insight into this, local adaptation is compared in related fish species across two very different environmental gradients: the Atlantic and Pacific coasts of North America. Local adaptation is first examined in the California grunion (Leuresthes tenuis) and then results are compared to previous work on the Atlantic silverside. Common garden experiments and wild fish studies were used to test for local adaptation among several traits (growth capacity, sex determination, and vertebral number) of the California grunion across three latitudinal populations: Monterey, CA (36.6_N), Malibu, CA (34.0_N), and Ensenada, MX (31.9_N). Consistent genetic differences in growth capacity between latitudinal populations were not observed. Wild southern grunion were slightly larger and grew faster than more northern grunion, likely due to environmental effects. Temperature (p<0.001) and photoperiod (p=0.011) were found to significantly affect sex ratios of laboratory reared fish, indicating that grunion have environmental sex determination (ESD); however the level of ESD did not differ among populations. Mean vertebral numbers in wild grunion were nearly identical for all populations. The lack of latitudinal variation in these traits of the grunion is in direct contrast to the Atlantic silverside, which exhibits a high degree of genetic differentiation in all of the above traits. Results also differ from recent work on the topsmelt, another Pacific coast silverside species. Failure to observe latitudinal variation in the grunion unlike its other taxonomic relatives may be due to its oceanic rather than estuarine habitat, which provides a greater opportunity for broad-scale gene flow and results in a more homogenous environment. Implications for climate change are discussed.Advisor(s): David O. Conover. Committee Member(s): Stephan B. Munch; Michael G. Frisk.Stony Brook University Libraries. SBU Graduate School in Department of Marine and Atmospheric Science. Lawrence Martin (Dean of Graduate School)
Local Adaptation in the Atlantic silverside (Menidia menidia): Fine-scaled geographic variation in vertebral number and the adaptive significance of Jordan's Rule
No full textThe Atlantic silverside, Menidia menidia, is a widely distributed marine species along the east coast of North America that has been shown to exhibit local adaptation, despite evidence of high gene flow. This species displays a very strong and spatially fine scale increase in vertebral number with latitude, consistent with Jordan's Rule. Spatial and temporal variability can be seen on a microgeographic scale, potentially due to differences in site-specific developmental temperature and/or mixing among nearby locales. Most of the vertebral number variation is genetic however, and such tight clinal patterns implicate natural selection as the cause but its adaptive significance is unclear. Laboratory experiments show vertebral number responds to artificial selection on size, with populations with the largest size classes removed showing a decrease in vertebral number and vice versa. Natural selection on vertebral number is also evident in the wild, with vertebral numbers higher in juvenile populations compared to the same populations as adults. High latitude populations are thought to have evolved a greater number of vertebrae to allow for increased body flexibility in colder, move viscous water, however empirical evidence is limited. To test this theory, I hypothesized that at high temperatures, southern Atlantic silverside populations would show significantly higher critical swimming speeds than northern populations, but the reverse would be true at lower temperatures. Swimming speed experiments were conducted on southern (South Carolina) and northern (Nova Scotia) populations reared in a common environment. Each population was tested at a range of larval sizes and experimental temperatures. Vertebral number was negatively correlated with swimming speed at 28øC but such correlations at lower temperatures were non-significant. Few studies have investigated the link between vertebral number and swimming ability experimentally. The results of my research suggest extreme fine-tuning of vertebral number to natural selection in the wild and provide evidence for potential agents of selection.Advisor(s): David Conover. Committee Member(s): Stephan Munch; Glenn Lopez; Kathryn Kavanagh; Douglas Swain.Stony Brook University Libraries. SBU Graduate School in Department of Marine and Atmospheric Science. Lawrence Martin (Dean of Graduate School)
Thermal reaction norms of growth in Atlantic and Pacific silverside fishes
No full textHow organisms may adapt to rising global temperatures is uncertain, but concepts can emerge from studying adaptive physiological trait variations across existing spatial climate gradients. Many ectotherms, particularly fish, have evolved increasing genetic growth capacities with latitude (i.e. countergradient variation (CnGV) in growth), which are thought to be an adaptation primarily to strong gradients in seasonality. In contrast, evolutionary responses to gradients in mean temperature are often assumed to involve an alternative mode, 'thermal adaptation'. We measured thermal growth reaction norms in Pacific silverside populations (Atherinops affinis) occurring across a weak latitudinal temperature gradient with invariant seasonality along the North American Pacific coast. Instead of thermal adaptation, we found novel evidence for CnGV in growth, suggesting that CnGV is a ubiquitous mode of reaction-norm evolution in ectotherms even in response to weak spatial and, by inference, temporal climate gradients. A novel, large-scale comparison between ecologically equivalent Pacific versus Atlantic silversides (Menidia menidia) revealed how closely growth CnGV patterns reflect their respective climate gradients. While steep growth reaction norms and increasing growth plasticity with latitude in M. menidia mimicked the strong, highly seasonal Atlantic coastal gradient, shallow reaction norms and much smaller, latitude-independent growth plasticity in A. affinis resembled the weak Pacific latitudinal temperature gradient
O foco narrativo na ficção contemporânea : uma leitura de Author, Author, de David Lodge
No full textOrientador : Prof. Dr. Caetano Waldrigues GalindoAutor não autorizou a divulgação do arquivo digitalDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Letras e Artes, Programa de Pós-Graduação em Letras. Defesa: Curitiba, 26/06/2013Bibliografia: fls. 158-161Área de concentração: Estudos LiteráriosResumo: O propósito deste trabalho é refletir sobre a construção do foco narrativo em Author, Author (2004), de David Lodge, romance biográfico sobre o escritor Henry James (1843-1916). O narrador não se limita a situar o leitor na narrativa: o seu posicionamento em relação aos aspectos factuais da vida e do percurso literário do romancista norte-americano desempenha papel fundamental na discussão das estratégias narrativas da prosa de ficção de James. Na construção ficcional do malogro na noite de estreia de Guy Domville, em Londres, em 1895, por exemplo, é possível perceber a bipartição desse narrador, capaz de contar e mostrar dois episódios que se passam em dois lugares diferentes, simultaneamente. Em outros momentos do romance, a voz autoral embaralha-se com a voz do sujeito da enunciação a tal ponto, que o leitor menos atento encontra certa dificuldade para colocar ordem nos discursos. O abandono gradual da prosa de ficção em busca de uma identidade como dramaturgo, a falta de êxito na dramaturgia, a lenta recuperação psicológica, a retomada da prosa de ficção e o resultado insatisfatório da revisão e escrita de prefácios para as suas obras, para compor The novels and tales of Henry James:The New York Edition (1905), são alguns dos desdobramentos da trajetória de James, discutidos em Author, Author.Abstract: The purpose of this dissertation is to think over the construction process of narrative focus in Author, Author (2004), by David Lodge, a biographical novel about the writer Henry James (1843-1916). The narrator does not limit himself to guiding the reader through the narrative; rather, his attitude towards factual aspects of the life and literary course of the North-American novelist seems to play a fundamental role in the novel. In the fictional construction of the débâcle of "Guy Domville", in London, 1895 for instance it is possible to distinguish the narrator's bipartition, in order to tell and show two different episodes which happen in two different places, simultaneously. In other moments, the authorial voice blends with that of the subject of the enunciation to such a degree that the less attentive reader may not be capable of organizing the discourse, in a first moment. James' gradual movement away from prose fiction so as to find his playwright identity; the lack of success as a playwright; his subsequent slow psychological recovery; the return to prose fiction; and, finally, the weak result of writing and revising prefaces to his literary works in order to put together The Novels and Tales of Henry James: The New York Edition (1905), are some of the most conspicuous events in James' trajectory discussed in Author, Author
Recommended from our members
Russian Trio, Voice of America, 1977 December 28
No full textRecording of the "Voice of America Jazz Hour," hosted by Willis Conover and of a small jazz combo with pianist Jim McNeely. The program in the first recording focuses on Soviet Union jazz musicians. There is a lot of radio interference in this recording. The second recording features a jazz combo. All musicians are announced around the 1:30 mark on the second recording
Thermal reaction norms of growth capacity in Atherinops affinis and Menidia menidia (Atherinopsidae) determined by common garden experiments in 2008-2009
No full textThermal reaction norms of growth capacity in Atherinops affinis and Menidia menidia (Atherinopsidae) determined by common garden experiments in 2008-200
Cult: A Composite Novel
No full textCult (redacted)
The first component of the thesis is a composite novel called Cult which falls into two parts with seven narratives in each. Part 1 tracks the protagonist, Ellen, from her first involvement with the cult through to her eventually leaving it. Although fiction, the first half of the book answers the kinds of questions the author is asked when people discover that she was once a sannyasin (a follower of the guru Bhagwan Shree Rajneesh). While the experiences of meditation, group therapy and communal living are all faithfully rendered within the stories, the need for strong characters, narrative drive and a lightness of touch takes precedence.
Part 2 picks up Ellen’s story some twenty or so years later and explores what becomes of her in middle age. It also looks at other groups in society, such as academia, the law and the internet dating community which each have their own jargon, hierarchies, rituals and rules but are not considered to be cults.
The book examines the question raised in the Epigraph, ‘how do we be together when we feel so alone’ with a focus on relationships other than the familial and the romantic.
Collisions, Chasms and Connections: a Performative Exploration of the Composite Novel Form
The second part of the thesis is both a critical and creative response to three contemporary American books: Olive Kitteridge by Elizabeth Strout; A Visit from the Goon Squad by Jennifer Egan; and Legend of a Suicide by David Vann. The critical element comprises a close reading of the three books; a chronological reconstruction of their overarching storylines; and a consideration of what their authors have said about writing the books. It concludes that, in the composite novel, the simultaneous presentation of multiple views and storylines operate much like a 3D image to give the impression of depth to the characters and situations rendered. The creative element of the essay is a playful and personal response to the texts
(Re)Making of Identity: A Socio-Cultural Analysis of David Mamet’s American Buffalo
No full textThis article delves into the assertion of identity in David Mamet’s famous play American Buffalo. Mamet has revealed a rich variety of possible variations of identity in his creative opus, not only in the field of drama and theatre but also in the film, through the portrayal of a variety of different characters and situations. The identity will be discussed in his play as a unique cultural text outside of which there is nothing. America, its myths and contemporary cultural industry, its class, racial, and gender conflicts, and the author establish a mutual set of influences that help characters formulate their identities. By using Stuart Hall’s idea of identity in flux, this qualitative research explores the effects of industrialization on psychology, the concept of success of the people, and their identity in general. The change from ‘Who am I’ to ‘What do I have’ is the concern of the American people in this post-modern era so it has been given special focus. To some extent, the identity of the characters, if it means material success in his plays, is linked with the American Dream. The research also aims at the means i.e. language, lies, maltreatment, double-crossing, and cheating, the Mametian characters adopt to formulate their identity. The analysis shows that if identity means material success, they never succeed in making their identity. They keep on making, remaking, and re-remaking their identity proving that identity in the world of Mamet is in flux
- …
