A river of memory: landscape, narrative and identity in the Lee Valley, Co. Cork, Ireland

In moments of rapid social changes, as has been witnessed in Ireland in the last decade, the conditions through which people engage with their localities though memory, individually and collectively, remains an important cultural issue with key implications for questions of heritage, preservation and civic identity. In recent decades, cultural geographers have argued that landscape is more than just a view or a static text of something symbolic. The emphasis seems to be on landscape as a dynamic cultural process – an ever-evolving process being constructed and re-constructed. Hence, landscape seems to be a highly complex term that carries many different meanings. Material, form, relationships or actions have different meanings in different settings. Drawing upon recent and continuing scholarly debates in cultural landscapes and collective memory, this thesis sets out to examine the generation of collective memory and how it is employed as a cultural tool in the production of memory in the landscape. More specifically, the research considers the relationships between landscape and memory, investigating the ways in which places are produced, appropriated, experienced, sensed, acknowledged, imagined, yearned for, appropriated, re-appropriated, contested and identified with. A polyvocal-bricoleur approach aims to get below the surface of a cultural landscape, inject historical research and temporal depth into cultural landscape studies and instil a genuine sense of inclusivity of a wide variety of voices (role of monuments and rituals and voices of people) from the past and present. The polyvocal-bricoleur approach inspires a mixed method methodology approach to fieldsites through archival research, fieldwork and filmed interviews. Using a mixture of mini-vignettes of place narratives in the River Lee valley in the south of Ireland, the thesis explores a number of questions on the fluid nature of narrative in representing the story and role of the landscape in memory-making. The case studies in the Lee Valley are harnessed to investigate the role of the above questions/ themes/ debates in the act of memory making at sites ranging from an Irish War of Independence memorial to the River Lee’s hydroelectric scheme to the valley’s key religious pilgrimage site. The thesis investigates the idea that that the process of landscape extends not only across space but also across time – that the concept of historical continuity and the individual and collective human engagement and experience of this continuity are central to the processes of remembering on the landscape. In addition the thesis debates the idea that the production of landscape is conditioned by several social frames of memory – that individuals remember according to several social frames that give emphasis to different aspects of the reality of human experience. The thesis also reflects on how the process of landscape is represented by those who re-produce its narratives in various media.

Simplified decoding techniques for linear block codes

Error correcting codes are combinatorial objects, designed to enable reliable transmission of digital data over noisy channels. They are ubiquitously used in communication, data storage etc. Error correction allows reconstruction of the original data from received word. The classical decoding algorithms are constrained to output just one codeword. However, in the late 50’s researchers proposed a relaxed error correction model for potentially large error rates known as list decoding. The research presented in this thesis focuses on reducing the computational effort and enhancing the efficiency of decoding algorithms for several codes from algorithmic as well as architectural standpoint. The codes in consideration are linear block codes closely related to Reed Solomon (RS) codes. A high speed low complexity algorithm and architecture are presented for encoding and decoding RS codes based on evaluation. The implementation results show that the hardware resources and the total execution time are significantly reduced as compared to the classical decoder. The evaluation based encoding and decoding schemes are modified and extended for shortened RS codes and software implementation shows substantial reduction in memory footprint at the expense of latency. Hermitian codes can be seen as concatenated RS codes and are much longer than RS codes over the same aphabet. A fast, novel and efficient VLSI architecture for Hermitian codes is proposed based on interpolation decoding. The proposed architecture is proven to have better than Kötter’s decoder for high rate codes. The thesis work also explores a method of constructing optimal codes by computing the subfield subcodes of Generalized Toric (GT) codes that is a natural extension of RS codes over several dimensions. The polynomial generators or evaluation polynomials for subfield-subcodes of GT codes are identified based on which dimension and bound for the minimum distance are computed. The algebraic structure for the polynomials evaluating to subfield is used to simplify the list decoding algorithm for BCH codes. Finally, an efficient and novel approach is proposed for exploiting powerful codes having complex decoding but simple encoding scheme (comparable to RS codes) for multihop wireless sensor network (WSN) applications.

Functional metagenomic analysis of the human gut microbiome to identify novel salt tolerance genes

The ability to adapt to and respond to increases in external osmolarity is an important characteristic that enables bacteria to survive and proliferate in different environmental niches. When challenged with increased osmolarity, due to sodium chloride (NaCl) for example, bacteria elicit a phased response; firstly via uptake of potassium (K+), which is known as the primary response. This primary response is followed by the secondary response which is characterised by the synthesis or uptake of compatible solutes (osmoprotectants). The overall osmotic stress response is much broader however, involving many diverse cellular systems and processes. These ancillary mechanisms are arguably more interesting and give a more complete view of the osmotic stress response. The aim of this thesis was to identify novel genetic loci from the human gut microbiota that confer increased tolerance to osmotic stress using a functional metagenomic approach. Functional metagenomics is a powerful tool that enables the identification of novel genes from as yet uncultured bacteria from diverse environments through cloning, heterologous expression and phenotypic identification of a desired trait. Functional metagenomics does not rely on any previous sequence information to known genes and can therefore enable the discovery of completely novel genes and assign functions to new or known genes. Using a functional metagenomic approach, we have assigned a novel function to previously annotated genes; murB, mazG and galE, as well as a putative brp/blh family beta-carotene 15,15’-monooxygenase. Finally, we report the identification of a completely novel salt tolerance determinant with no current known homologues in the databases. Overall the genes identified originate from diverse taxonomic and phylogenetic groups commonly found in the human gastrointestinal (GI) tract, such as Collinsella and Eggerthella, Akkermansia and Bacteroides from the phyla Actinobacteria, Verrucomicrobia and Bacteroidetes, respectively. In addition, a number of the genes appear to have been acquired via lateral gene transfer and/or encoded on a prophage. To our knowledge, this thesis represents the first investigation to identify novel genes from the human gut microbiota involved in the bacterial osmotic stress response.