The effects of agglomeration economies on the productivity of manufacturing local units in Ireland

The purpose of this study is to examine the effects of agglomeration economies on the productivity of manufacturing local units in Ireland. Four types of agglomeration economies are considered in this study. These are internal economies of scale, localization economies, related variety and urbanization economies. This study makes a number of contributions to the literature. Firstly, this is the first study to conduct an investigation of the effects of agglomeration economies on the productivity of manufacturing local units operating in Ireland. Secondly, this study distinguishes between indigenous and foreign-owned local units which is important given the dual nature of the Irish economy (Krugman, 1997). Thirdly, in addition to considering the effects of agglomeration economies, this study examines the impact of spurious agglomeration on the productivity of foreign-owned local units. Using data from the Census of Industrial Local Units and a series of IV GMM estimators to control for endogeneity, the results of the analysis conducted in Chapter 6 reveal that there are differences in the effects of agglomeration economies on the productivity of indigenous and foreign-owned local units. In Chapter 7 the Census of Industrial Local Units is supplemented by additional data sources and more in-depth measures are generated to capture the features of each of the external agglomeration economies considered in this analysis. There is some evidence to suggest that the availability of local inputs has a negative and significant impact on productivity. The NACE based measures of related variety reveal that the availability of local inputs and knowledge spillovers for related sectors have a negative and significant impact on productivity. There is clear evidence to suggest that urbanization economies are important for increasing the productivity of indigenous local units. The findings reveal that a 1% increase in population density in the NUTS 3 region leads to an increase in the productivity of indigenous local units of approximately 0.07% to 0.08%. The results also reveal that there is a significant difference in the effects of agglomeration economies on the productivity of low-tech and medium/high-tech indigenous local units. The more in-depth measures of agglomeration economies used in Chapter 7 are also used in Chapter 8. A series of IV GMM regressions are estimated in order to identify the impact of agglomeration economies and spurious agglomeration on the productivity of foreign-owned local units operating in Ireland. There is some evidence found to suggest that the availability of a pool of skilled labour has a positive and significant on productivity of foreign-owned local units. There is also evidence to suggest that localization knowledge spillovers have a negative impact on the productivity of foreign-owned local units. There is strong evidence to suggest that the availability of local inputs has a negative impact on the productivity. The negative impact is not confined to the NACE 4-digit sector but also extends into related sectors as determined by Porter’s (2003) cluster classification. The cluster based skills measure of related variety has a positive and significant impact on the productivity of foreign-owned local units. Similar to Chapter 7, there is clear evidence to suggest that urbanization economies are important for increasing the productivity of foreign-owned local units. Both the summary measure and each of the more in-depth measures of agglomeration economies have a positive and significant impact on productivity. Spurious agglomeration has a positive and significant impact on the productivity of foreign-owned local units. The results indicate that the more foreign-owned local units of the same nationality in the country the greater the levels of productivity for the local unit. From a policy perspective, urbanization economies are clearly important for increasing the productivity of both indigenous and foreign-owned local units. Furthermore, the availability of a pool of skilled labour appears to be important for increasing the productivity of foreign-owned local units. Another policy implication that arises from these results relates to the differences observed between indigenous local units and foreign-owned local units and also between low-tech and medium/high-tech indigenous local units. These findings indicate that ‘one-size-fits-all’ type policies are not appropriate for increasing the productivity of local units operating in Ireland. Policies should be tailored to the needs of either indigenous or foreign-owned local units and also to specific sectors. This positive finding for own country spurious agglomeration is important from a policy perspective and is one that IDA Ireland should take on board.

New weapons to fight old enemies: novel strategies for the (bio)control of bacterial biofilms in the food industry

Biofilms are microbial communities characterized by their adhesion to solid surfaces and the production of a matrix of exopolymeric substances, consisting of polysaccharides, proteins, DNA and lipids, which surround the microorganisms lending structural integrity and a unique biochemical profile to the biofilm. Biofilm formation enhances the ability of the producer/s to persist in a given environment. Pathogenic and spoilage bacterial species capable of forming biofilms are a significant problem for the healthcare and food industries, as their biofilm-forming ability protects them from common cleaning processes and allows them to remain in the environment post-sanitation. In the food industry, persistent bacteria colonize the inside of mixing tanks, vats and tubing, compromising food safety and quality. Strategies to overcome bacterial persistence through inhibition of biofilm formation or removal of mature biofilms are therefore necessary. Current biofilm control strategies employed in the food industry (cleaning and disinfection, material selection and surface preconditioning, plasma treatment, ultrasonication, etc.), although effective to a certain point, fall short of biofilm control. Efforts have been explored, mainly with a view to their application in pharmaceutical and healthcare settings, which focus on targeting molecular determinants regulating biofilm formation. Their application to the food industry would greatly aid efforts to eradicate undesirable bacteria from food processing environments and, ultimately, from food products. These approaches, in contrast to bactericidal approaches, exert less selective pressure which in turn would reduce the likelihood of resistance development. A particularly interesting strategy targets quorum sensing systems, which regulate gene expression in response to fluctuations in cell-population density governing essential cellular processes including biofilm formation. This review article discusses the problems associated with bacterial biofilms in the food industry and summarizes the recent strategies explored to inhibit biofilm formation, with special focus on those targeting quorum sensing.

Studies relating to the population dynamics of the European badger (Meles meles) in Ireland

European badgers (Meles meles) are an important part of the Irish ecosystem; they are a component of Ireland’s native fauna and are afforded protection by national and international laws. The species is also a reservoir host for bovine tuberculosis (bTB) and implicated in the epidemiology of bTB in cattle. Due to this latter point, badgers have been culled in the Republic of Ireland (ROI) in areas where persistent cattle bTB outbreaks exist. The population dynamics of badgers are therefore of great pure and applied interest. The studies within this thesis used large datasets and a number of analytical approaches to uncover essential elements of badger populations in the ROI. Furthermore, a review and meta-analysis of all available data on Irish badgers was completed to give a framework from which key knowledge gaps and future directions could be identified (Chapter 1). One main finding suggested that badger densities are significantly reduced in areas of repeated culling, as revealed through declining trends in signs of activity (Chapter 2) and capture numbers (Chapter 2 and Chapter 3). Despite this, the trappability of badgers was shown to be lower than previously thought. This indicates that management programmes would require repeated long-term efforts to be effective (Chapter 4). Mark-recapture modelling of a population (sample area: 755km2) suggested that mean badger density was typical of continental European populations, but substantially lower than British populations (Chapter 4). Badger movement patterns indicated that most of the population exhibited site fidelity. Long-distance movements were also recorded, the longest of which (20.1km) was the greatest displacement of an Irish badger currently known (Chapter 5). The studies presented in this thesis allows for the development of more robust models of the badger population at national scales (see Future Directions). Through the use of large-scale datasets future models will facilitate informed sustainable planning for disease control.

Investigation of the genetic susceptibility to osteoporosis in the Irish population

Osteoporosis is a complex skeletal disorder characterized by compromised bone strength. Variation in bone mineral density (BMD) is a contributing factor. The aim of this research as to select informative single nucleotide polymorphisms (SNPs) in potential candidate genes from loci suggestively linked to BMD variation for fine mapping. The gene regulated by oestrogen in breast cancer 1 (GREB1), located at 2p25.1, was selected. GREB1 transcription is initiated early in the oestrogen receptor alpha regulated pathway. There was significant association between GREB1_03 and BMD variation at the lumbar spine and femoral neck (FN) in the discovery cohort. Significant association was observed between GREB1_04 and FN BMD in the replication cohort. The development and differentiation enhancing factor 2, the integrin cytoplasmic domain associated protein 1 and A-disintegrin and metalloprotease 17 were selected due to their respective roles in cell mobility and adhesion. There was no linkage or association observed between the Chr2 cluster SNPs and BMD. Two factors in bone remodelling are the attraction of bone cell precursors and endocrine regulation of the process, primarily through the action of parathyroid hormone (PTH). The C-C chemokine receptor type 3 (CCR3) encodes a CC chemokine receptor expressed in osteoclast precursors. The PTH receptor type 1 (PTHR1) encodes a G-protein coupled receptor for PTH. Association was observed between CCR3 haplotypes and BMD variation at the FN. There was no linkage or association observed between PTHR1 SNPs and BMD variation. Population genetic studies with complex phenotypes endeavour to elucidate the traits genetic architecture. This study presents evidence of association between GREB1 and BMD variation and as such, introduces GREB1 as a novel gene target for osteoporosis genetics studies. It affirms that common genomic variants in PTHR1 are not associated with BMD variation in Caucasians and supports the evidence that CCR3 may be contributing to BMD variation

A craniometric study of population dynamics and social organisation in the European upper Palaeolithic and Mesolithic

The purpose of this study is to explore aspects of social organisation during the Upper Palaeolithic and Mesolithic periods using craniometric data. Different hypotheses were tested using geometric morphometrics, alongside traditional craniometric data. The clustering of individuals from the same site, as well as a correspondence to an isolation-by-distance model—particular in the Mesolithic samples—points to population structure within these groups. Moreover, discontinuities in cranial traits between the early Upper Palaeolithic and later periods could suggest that the Last Glacial Maximum had a disruptive effect on populations in Europe. Differences in social organisation can often result from cultural norms regarding post-marital residence. Such differences can be tested by comparing cranial data to that of geographic information. Greater variation in male cranial traits relative to females, after controlling for location, suggests that the overall pattern of residence during the Upper Palaeolithic and Mesolithic was one of matrilocality. It has been suggested that coastal occupation was density dependent and these populations show a greater degree of sedentism than their inland counterparts. Moreover, it has been proposed that coastal areas were not continuously occupied until the Late Pleistocene due to spatial restrictions that would adversely affect reproductive opportunities. This study corroborates the pattern seen in cranial traits corresponded with that of a more sedentary population. The results are consistent with the hypothesis that coastal populations are more sedentary than inland populations during these periods. This study adds new information regarding the social dynamics of prehistoric populations in Europe and sheds light on some of the conditions that may have paved the way for the transition to agriculture