1,325 research outputs found
The question of gendered voice in some contemporary Irish novels by Brian Moore and John McGahern
No full textThis thesis questions the use of the 'voice' metaphor in contemporary Irish cultural studies in order to examine
the ways in which gendered identities are constructed in some Irish Catholic communities in twentieth-century
Ireland. With reference to novels by Brian Moore and
John McGahern as well as to Judith Butler's theories of performativity and citational practices, it argues that gendered identities are constructed through the repetitive citation of hegemonic cultural discourses. This thesis
focuses on the ways in which gendered identities are produced and maintained through the citation of the official discourses of the Catholic Church and the State as
well as the more mundane discourses related to popular nationalism and the family.
The first two chapters concentrate on novels whose protagonists are trying to construct powerful identities in urban Irish society through the manipulation of gendered discourses. The discussion of Moore's The Lonely Passion of Judith Hearne identifies some of the strategies through which conventional Irish women's voices are constructed
and questions the validity of the category of 'authentic' women's voices. In the chapter relating to McGahem's The
Pornographer, the powerful, abstract male voice is exposed as a performative construct which is sustained only through the abjection of those elements which disrupt the narrator's performance of masculinity.
The remaining chapters concentrate on the use of idealised images such as those of the 'woman-as-nation' and the iconised mother in novels by Moore and McGahem. Moore's The
Mangan Inheritance provides the basis for a discussion of whether or not voices attributed to women in texts by Irish men can be read in ways that disrupt the apparent authority of Irish men's voices. This thesis discusses the issues
raised when men participate in the deconstruction
of idealised images of Irish women. The final chapter examines the processes through which conventional identities are discursively constructed and maintained in two novels by John McGahem: The Dark and Amongst Women. This thesis contends that through the strategic
redeployment of those voices attributed to idealised images of Irish women, voices which are conventionally regarded
as silent, patriarchal gendered identities can be destabilised or displaced
Brian Ferneyhough : the logic of the figure
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
A scoping and consensus building model of a toxic blue-green algae bloom
No full textNuisance blooms of Lyngbya muiuscula have been occurring with increasing frequency in tropical coastal waters around the world. Outbreaks of this cyanobacterium (blue-green algae) threaten water quality, coastal ecosystems, and can be harmful in instances of human contact. While scientific and popular theories abound regarding Lyngbya bloom initiation and growth, a clear research agenda has not emerged. This article offers a scoping and consensus building model for the development of research directions. The model is based on the hypothesis that Lyngbya is iron limited and that blooms are initiated and perpetuated in response to increased bioavailable iron concentrations. Interacting model sectors for Lyngbya, bioavailable iron, dissolved oxygen, and seagrass have been developed. Simulations show that the occurrence of Lyngby a bloom is sensitive to a number of uncertain parameters and model structures, including inflows and decay times of organically complexed iron, Lyngbya maximum growth rate and half-saturation constant for bioavailable iron, and bioturbation. Development of the first stage scoping model is reported here, as are simulation results that are instrumental in setting priorities for empirical investigations and future simulation-based research. It is expected that this model, after additional empirical work is completed, will lead to research and management models that will help set policy for community response to Lyngbya blooms
Trophic level decoupling drives future changes in phytoplankton bloom phenology
No full text© 2022, The Author(s), under exclusive licence to Springer Nature Limited.Climate change can drive shifts in the seasonality of marine productivity, with consequences for the marine food web. However, these alterations in phytoplankton bloom phenology (initiation and peak timing), and the underlying drivers, are not well understood. Here, using a 30-member Large Ensemble of climate change projections, we show earlier bloom initiation in most ocean regions, yet changes in bloom peak timing vary widely by region. Shifts in both initiation and peak timing are induced by a subtle decoupling between altered phytoplankton growth and zooplankton predation, with increased zooplankton predation (top-down control) playing an important role in altered bloom peak timing over much of the global ocean. Only in limited regions is light limitation a primary control for bloom initiation changes. In the extratropics, climate-change-induced phenological shifts will exceed background natural variability by the end of the twenty-first century, which may impact energy flow in the marine food webs.11Nsciessciscopu
Dynamics of particulate and dissolved organic and inorganic phosphorus during the peak and declining phase of an iron-induced phytoplankton bloom in the eastern subarctic Pacific
No full textPhosphorus (P) is an essential element for all organisms and thus the P cycle plays a key role in determining the dynamics of lower trophic levels in marine ecosystems. P in seawater occurs conceptually in particulate and dissolved organic and inorganic (POP, PIP, DOP, and DIP, respectively) pools and clarification of the dynamics in these P pools is the basis to assess the biogeochemical cycle of P. Despite its importance, behaviors of each P pool with phytoplankton dynamics have not been fully examined. We measured the four operationally defined P pools (POPop, PIPop, DOPop, and SRP) during an iron-induced phytoplankton bloom (as part of the subarctic ecosystem response to iron enrichment study (SERIES)) in the eastern subarctic Pacific in summer 2002. During our observations of the iron-enriched patch from day 15 to day 26 after the iron infusion, chlorophyll-alpha concentration in the surface layer decreased from 6.3 to 1.2 mu g L-1, indicating the peak through decline phase of the phytoplankton bloom. At the bloom peak, P was partitioned into POPop, PIPop, and DOPop in proportions of 60, 27, and 13%, respectively. While chlorophyll-alpha and POPop showed similar temporal variations during the declining phase, PIPop showed a different peak timing with a 2 day delay compared to POPop, resulting in a rapid change in the relative proportion of PIPop to total particulate P (TPP = POPop + PIPop) at the peak (25%) and during the declining phase of the bloom (50%). A part of POPop was replaced by PIPop just after slowing down of phytoplankton growth. This process may have a significant role in the subsequent regeneration of P. We conclude that measurement of TPP alone is insufficient to show the interaction between P and phytoplankton dynamics and fractionation of TPP into POPop and PIPop provides useful insights to clarify the biogeochemical cycle of P
Short-term changes in population structure and vertical distribution of mesopelagic copepods during the spring phytoplankton bloom in the Oyashio region
No full textTo evaluate the responses to the spring phytoplankton bloom, short-term changes in population structure and vertical distribution of mesopelagic copepods (Gaetanus simplex, Gaidius variabilis, Pleuromamma scutullata, Paraeuchaeta elongata, P. birostrata, Heterorhabdus tanneri and Heterostylites major) were studied in the Oyashio region. Samples were collected with a 60 mu m mesh VMPS from 9 strata between 0 and 1000 m both day and night on five occasions during March-April 2007. All the species except Heterorhabdidae species performed reproduction during the spring phytoplankton bloom, while no recruitment to copepodid stages was detected because the newly born individuals were eggs or nauplii. The shallower-living species, G. simplex, P. scutullata and P. elongata had nocturnal ascent did l vertical migration (DVM). While suspension feeding copepods cease DVM after 11 April (P. scutullata) or 23 April (G. simplex), carnivorous P. elongata continued DVM over the study period. Since the gut contents of G. simplex showed a nocturnal increment even in the period of no DVM (23 and 29 April), they might be feeding at depth without DVM. Thus, the cessation of DVM in mesopelagic suspension feeding copepods would be induced by the increase of sinking particles (e.g. food for suspension feeders) during the spring phytoplankton bloom. (C) 2012 Elsevier Ltd. All rights reserved
Monitoring of Harmful Algal Bloom (HAB) of Noctiluca scintillans (Macartney) along the Gulf of Mannar, India using in-situ and satellite observations and its impact on wild and maricultured finfishes
No full textIn the Gulf of Mannar, Noctiluca scintillans blooms have been observed three times in September 2019, September and October 2020, and October 2021. It was determined and measured how the bloom period affects ichthyo-diversity. Noctiluca cell density varied slightly from year to year, ranging from1.8433 × 103 cells/L to 1.3824 x 106cells/L. In surface and sea bottom waters, high ammonia levels and low dissolved oxygen levels were noted. During the bloom period a significant increase in chlorophyll concentration was found. The amount of chlorophyll in GOM was extremely high, according to remote sensing photos made using MODIS-Aqua 4 km data. Acute hypoxia caused the death of wild fish near coral reefs and also in fish reared in sea cages. The decay of the bloom resulted in significant ammonia production, a dramatic drop in the amount of dissolved oxygen in the water, and ultimately stress, shock, and mass mortality of fishes
Comparative studies on phosphate utilization of two bloom-forming Microcystis spp. (cyanobacteria) isolated from Lake Taihu (China)
No full textMicrocystis is a common freshwater bloom-dominating cyanobacterial genus. However, the crucial factors that affect the seasonal succession and extent of dominance of different species remain largely unknown. This study investigated inorganic phosphorus (P) uptake, growth, and P utilization of two dominant Microcystis species from Lake Taihu (China) at different P concentrations and temperatures. Compared with Microcystis wesenbergii, Microcystis flos-aquae had higher maximum uptake rate and luxury storage coefficient. However, M. flos-aquae also had a higher P demand for growth. Under P-rich conditions (64.5 to 174.5 mu M), M. flos-aquae had a higher growth rate (0.16 to 0.21 d(-1)) than M. wesenbergii (0.06 to 0.19 d(-1)) at 22 to 30 A degrees C. M. wesenbergii, with higher phosphate affinity, had a lower P demand to sustain its growth, and yielded a higher growth rate of 0.10 d(-1) at low P concentration (6.5 mu M) at 34 A degrees C, whereas M. flos-aquae had a lower growth rate of 0.03 d(-1). Therefore, M. flos-aquae was dominant in late spring under P-rich conditions, whereas M. wesenbergii prevailed in hot summer after M. flos-aquae decreased under P-limited conditions. These results agree well with their succession patterns in the field. Overall, succession and dominance of M. flos-aquae and M. wesenbergii in Lake Taihu are regulated by P concentration and water temperature.Microcystis is a common freshwater bloom-dominating cyanobacterial genus. However, the crucial factors that affect the seasonal succession and extent of dominance of different species remain largely unknown. This study investigated inorganic phosphorus (P) uptake, growth, and P utilization of two dominant Microcystis species from Lake Taihu (China) at different P concentrations and temperatures. Compared with Microcystis wesenbergii, Microcystis flos-aquae had higher maximum uptake rate and luxury storage coefficient. However, M. flos-aquae also had a higher P demand for growth. Under P-rich conditions (64.5 to 174.5 mu M), M. flos-aquae had a higher growth rate (0.16 to 0.21 d(-1)) than M. wesenbergii (0.06 to 0.19 d(-1)) at 22 to 30 A degrees C. M. wesenbergii, with higher phosphate affinity, had a lower P demand to sustain its growth, and yielded a higher growth rate of 0.10 d(-1) at low P concentration (6.5 mu M) at 34 A degrees C, whereas M. flos-aquae had a lower growth rate of 0.03 d(-1). Therefore, M. flos-aquae was dominant in late spring under P-rich conditions, whereas M. wesenbergii prevailed in hot summer after M. flos-aquae decreased under P-limited conditions. These results agree well with their succession patterns in the field. Overall, succession and dominance of M. flos-aquae and M. wesenbergii in Lake Taihu are regulated by P concentration and water temperature
Nitrogen fixation in the western English Channel (NE Atlantic Ocean)
No full textIn temperate Atlantic waters (18.8 to 20.1°C), biological nitrogen fixation has beendemonstrated by 2 independent measurements: 15N-N2 incorporation and nifH identification in theDNA and expressed messenger RNA (mRNA). At 2 stations in the western English Channel, bulkwaters were incubated with 15N-N2. At the high levels of particulate nitrogen (?11.5 ?mol N l–1),absolute fixation rates of 18.9 ± 0.01 and 20.0 nmol N l–1d–1 were determined. While a caveat mustaccompany the magnitude of the rates presented due to the limited number of data, the presence andactivity of diazotrophic organisms in these waters is of ecological significance and may affect currentattitudes to nitrogen and carbon budgets. In particular, our estimate of the rate of N fixation(0.35 mmol N m–2 d–1) is comparable to that of denitrification rates in UK shelf seas. Molecular analysisidentified a diversity of expressed nifH genes, and 21 different prokaryotic nifH transcripts wereidentified
A niche model to predict Microcystis bloom decline in Chaohu Lake, China
No full textCyanobacterial blooms occur frequently in lakes due to eutrophication. Although a number of models have been proposed to forecast algal blooms, a good and applicable method is still lacking. This study explored a simple and effective mathematical-ecological model to evaluate the growth status and predict the population dynamics of Microcystis blooms. In this study, phytoplankton were collected and identified from 8 sampling sites in Chaohu Lake every month from July to October, 2010. The niche breadth and niche overlap of common species were calculated using standard equations, and the potential relative growth rates of Microcystis were calculated as a weighted-value of niche overlap. In July, the potential relative growth rate was 2.79 (a.u., arbitrary units) but then rapidly declined in the following months to -3.99 a.u. in September. A significant correlation (R =0.998, P < 0.01) was found in the model between the net-increase in biomass of Microcystis in the field and the predicted values calculated by the niche model, we concluded that the niche model is suitable for forecasting the dynamics of Microcystis blooms. Redundancy analysis indicated that decreases in water temperature, dissolved oxygen and total dissolved phosphorus might be major factors underlying bloom decline. Based on the theory of community succession being caused by resource competition, the growth and decline of blooms can be predicted from a community structure. This may provide a basis for early warning and control of algal blooms.Cyanobacterial blooms occur frequently in lakes due to eutrophication. Although a number of models have been proposed to forecast algal blooms, a good and applicable method is still lacking. This study explored a simple and effective mathematical-ecological model to evaluate the growth status and predict the population dynamics of Microcystis blooms. In this study, phytoplankton were collected and identified from 8 sampling sites in Chaohu Lake every month from July to October, 2010. The niche breadth and niche overlap of common species were calculated using standard equations, and the potential relative growth rates of Microcystis were calculated as a weighted-value of niche overlap. In July, the potential relative growth rate was 2.79 (a.u., arbitrary units) but then rapidly declined in the following months to -3.99 a.u. in September. A significant correlation (R =0.998, P < 0.01) was found in the model between the net-increase in biomass of Microcystis in the field and the predicted values calculated by the niche model, we concluded that the niche model is suitable for forecasting the dynamics of Microcystis blooms. Redundancy analysis indicated that decreases in water temperature, dissolved oxygen and total dissolved phosphorus might be major factors underlying bloom decline. Based on the theory of community succession being caused by resource competition, the growth and decline of blooms can be predicted from a community structure. This may provide a basis for early warning and control of algal blooms
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