458 research outputs found
Nondaily Deposition Of Striae In The Bay Scallop Argopecten Irradians (Concentricus) In The Laboratory
Small (similar to 15 mm) and large (similar to 30 mm) calcein-marked bay scallops, Argopecten irradians, held for 2, 4, and 6 wk in the laboratory under natural illumination and conditions of high and low flow rates deposited significantly more striae on the surface of the left (dark) shell valve compared with the right (light) shell valve. Small scallops deposited an average of 0.55 stria per day, 0.42 stria per day, and 0.34 stria per day, respectively, during the 2-, 4-, and 6-wk experiments, whereas large scallops had a lower frequency of stria formation (0.20 stria per day, 0.18 stria per day, and 0.17 stria per day, respectively). Striae deposition and interstria distance were highly variable among small A. irradians. No relationship in interstria distance was obvious in A. irradians that deposited the same number of striae during 6 wk (0.45 striae per day) and held under conditions of high flow rate, indicating that stria formation is not synchronous with changes in the environment. Our results demonstrate unequivocally that in, A. irradians, stria formation is nondaily and is related to shell growth rate. The largest and oldest scallops (similar to 30 mm and 1.4 y old) formed striae at a rate of 0.17-0.2 stria per day whereas smaller and younger fast-growing A. irradians formed between 0.34 striae per day and 0.55 stria per day-clear evidence of nondaily and nonrhythmic deposition of striae in this pectinid species. Thus, striae cannot be used as a chronological marker with which environmental conditions can be compared
Hierarchies Everywhere -- Managing & Measuring Uncertainty in Hierarchical Time Series
We examine the problem of making reconciled forecasts of large collections of
related time series through a behavioural/Bayesian lens. Our approach
explicitly acknowledges and exploits the 'connectedness' of the series in terms
of time-series characteristics and forecast accuracy as well as hierarchical
structure. By making maximal use of the available information, and by
significantly reducing the dimensionality of the hierarchical forecasting
problem, we show how to improve the accuracy of the reconciled forecasts. In
contrast to existing approaches, our structure allows the analysis and
assessment of the forecast value added at each hierarchical level. Our
reconciled forecasts are inherently probabilistic, whether probabilistic base
forecasts are used or not
Innovative use of sclerochronology in marine resource management
In recent years, technical and analytical developments in sclerochronology, based on the analysis of accretionary hard tissues, have improved our ability to assess the life histories of a wide range of marine organisms. This Theme Section on the innovative use of sclerochronology was motivated by the cross-disciplinary session ‘Looking backwards to move ahead—how the wider application of new technologies to interpret scale, otolith, statolith and other biomineralised age-registering structures could improve management of natural resources’ convened at the 2016 ICES Annual Science Conference in Riga, Latvia. The contributions to this Theme Section provide examples of applications to improve the assessment and management of populations and habitats, or showcase the potential for sclerochronology to provide a deeper understanding of the interaction between marine life and its environment, including the effects of changing climate
Cellular targets of Kaposi's sarcoma-associated herpesvirus latency-associated nuclear antigen.
The latency-associated nuclear antigen (LANA1) of Kaposi's sarcoma-associated herpesvirus (KSHV) is a multi-function protein involved in maintenance of the viral episome and has been shown to interact with several proteins including p53 and pRB. It is likely that the multifunctional role of LANA1 exceeds these observations therefore the work in this thesis aimed to study LANA1 at both the transcription and protein-protein interaction level. I developed a lentiviral system for the infection of primary endothelial cells with LANA1, to analyse changes in gene expression profiles by gene expression microarrays. While the system was successfully developed, no significant changes in gene expression could be attributed to LANA1. Subsequently, using the yeast two-hybrid system and large-scale immunoaffinity purification coupled to mass spectrometry, I identified 26 novel binding partners of the KSHV LANA1 complex. The majority of these proteins have functions in splicing or mRNA processing and further analysis lead to the discovery of predominant protein domains. Several of the identified proteins, including heterogeneous nuclear ribonucleoprotein (hnRNP) A1, A2/B1, D and I, constitute members of the human H-complex. hnRNP A1, A2/B1 and D are also implicated in telomere biogenesis. I show that LANA1 binds UP1, the proteolytic derivative of hnRNP A1, which modulates telomere elongation and maintenance. Furthermore, I show an in vivo interaction between LANA1 and human telomerase reverse transcriptase (hTERT) and the ability of LANA1 to recover telomerase activity from cell lysates. These findings suggest a function for LANA1 in the maintenance of telomeres and may have important implications for the role of LANA1 in KSHV-related tumours. I propose models for the role of these complexes in splicing and telomere biogenesis
Effect of temperature on the growth of the commercially fished common whelk (Buccinum undatum, L.): a regional analysis within the Irish Sea
In response to increased demand in Asian markets, the commercial fishery for the common whelk (Buccinum undatum, L) has expanded in north-eastern Europe. In the Irish Sea region (ICES Area 20 VHa), increased effort and landings have raised concerns about long-term stability of the fishery amongst stakeholders. Fisheries in Welsh waters and the Isle of Man territorial sea are now subject to an increased minimum landing size according to the best available scientific data. This study addresses key knowledge gaps by investigating the size-at-age relationship of the species across the latitudinal extent of the fisheries management region. Our findings show that growth parameters, modelled using growth rings observed in the statolith, vary between populations and show a broadly latitudinal pattern. Thermal-time (expressed as sea bottom temperature degree-days) showed a significant negative linear relationship with the asymptotic size reach by whelk populations (L-infinity), where whelk grew to a larger maximum size in cooler waters. Other parameters, including maximum growth rates and the age at which growth rate begins to decrease, showed clear trends with sea-bottom temperature but linear modelling failed to detect significant relationships, where warmer waters increase the rate of growth in the early life stages of whelk but cooler waters allow growth to continue until later in life. Whilst there are substantial requirements to further validate and refine the relationship between growth and sea-bottom temperature, extrapolation of these data to other regions in Northeast Europe may provide a valuable tool in approximating important life-history characteristics in stock assessments, such as L-infinity, age-at-L-50 and age-at-recruitment
Statoliths of the whelk Buccinum undatum: a novel age determination tool
Sustainability within the fisheries of the commercially important European whelk Buccinum undatum has become a major concern because of over-exploitation and increased landings in many European coastal shelf seas due to the expansion of export markets to East Asian countries. Current management of B. undatum populations is difficult to achieve as several life history traits are problematic to accurately monitor. The current method of age determination for stock assessment has a low success rate and focuses on the use of putative annual rings on the surface of the organic operculum. Here, we validate an annual periodicity of growth ring formation in B. undatum statoliths that provides an alternative, reliable and accurate method for determining a whelk’s age. Laboratory-reared juvenile B. undatum of known provenance and age deposited a hatching ring at the time of emergence from their egg capsule and a clearly defined growth ring during February of their first and second years. Stable oxygen isotope profiles from the shells of 2 adult whelks confirmed annual growth ring deposition by demonstrating seasonal cycles of δ18O in the shell that matched the relative position and number of visible growth rings in the statolith. Validation of annually resolved statolith growth rings will, for the first time, provide fisheries scientists with a tool to determine the age structure of B. undatum populations and allow analytical stock assessments that will enable informed decisions for future management practices of whelk fisheries
The self-begetting novel: metafiction in the twenty-first century
The thesis examines the potentialities offered by social networking websites for
constructing original metafictional narratives. It comprises a novel, a critical exegesis,
and three Facebook pages which are attributed to fictional characters and used as a
plot-development tool. Readers ‘befriend’ the characters and place themselves within
the fabric of the fictional narrative. The result is a collaborative storytelling
experience which evolves in real time and forms the basis of the print novel
Esc&Ctrl.
The exegesis places the creative piece into a contemporary research context.
In chapter one I provide an account of the evolution of metafiction and the selfbegetting
novel with reference to the works of William H. Gass, Steven Kellman and
Patricia Waugh. I also account for the problem of authenticity in fiction, and use Paul
Ricoeur’s Time and Narrative to demonstrate the ways in which the temporal
spectrum of an online narrative differs from that of traditional print text.
Chapter two argues that the evolution of the internet offers a new set of
conditions that necessitate a radical overhaul of the ways in which postmodernity
tends to be theorised, and according to which postmodern theories may be
reconfigured. Referencing Jean-Francois Lyotard, I discuss the micronarratives of the
internet and how these lead to the formation of an online ‘self’ which is necessarily
different from a self located in the offline realm. Jean Baudrillard’s concept of the
loss of the real is extrapolated in order to show that the internet, and particularly
social networking sites, are representative of a simulated culture. The chapter ends
with a definition of what I have called ‘metafictional virtuality’ and a summary of
how it could be said to impact postmodern consciousness.
Chapter three examines the new creative vistas opened up by hypertext, social
networking and transmedia fiction for metafiction and the self-begetting novel.
Referencing the works of Wayne C. Booth, Wolfgang Iser and Stanley Fish, I explore
the role of the reader in attributing meaning to hypertext. I then examine the
advantages and shortcomings of using social networking to tell stories, with specific
reference to the critical work of Ruth Page and the practical example of the online
counterpart to Esc&Ctrl.
Chapter four provides an account of the mechanics of setting up, maintaining
and operating the Facebook pages I used in the project. It ends with a statistical
analysis of reader-engagement throughout the eight days that the project was live.
I conclude by evaluating the strengths and shortcomings of the social
networking narrative and account for how its basic principles might be applied to
newly-emerging technologies such as the soon-to-be-released Google Glass
Limited impact of an invasive oyster on intertidal assemblage structure and biodiversity:the importance of environmental context and functional equivalency with native species
- …