7 resultados para Cluster Analysis. Information Theory. Entropy. Cross Information Potential. Complex Data
em CORA - Cork Open Research Archive - University College Cork - Ireland
Resumo:
This thesis describes two newly sequenced B. longum subsp. longum genomes and subsequent comparative analysis with publicly available B. longum subsp. longum, B. longum subsp. infantis and B. longum subsp. suis genomes (Chapter 2). The acquired data revealed a closed pan-genome for this bifidobacterial species and furthermore facilitated the definition of the B. longum core genome. The comparative analysis also highlights differences in the potential metabolic abilities of all three sub-species. Interestingly, phylogenetic analysis of the B. longum core genome indicated the existence of a novel B. longum subspecies. Characterisation of restriction-modification systems from two B. longum subsp. longum strains is described in Chapter 3. These defence mechanisms limit the uptake of genetic material, which was successfully demonstrated for some of the identified systems. When these systems were by-passed by methylation of DNA prior to the transformation procedure, the resulting transformation efficiency of both B. longum subsp. longum strains was increased to a level that allowed for the generation of mutants via homologous recombination. Arabinoxylan metabolism by B. longum subsp. longum NCIMB 8809 was investigated in Chapter 4 of this thesis. Transcriptome analysis allowed the identification of a number of genes involved in the degradation, uptake and utilisation of arabinoxylan. Biochemical analysis revealed that three of the identified genes encode arabinofuranosidase activity. Phenotypic assessment of a number of insertion mutants in genes identified by the transcriptome analysis revealed the essential role of two of these enzymes in arabinoxylan metabolism, and a third enzyme in the metabolism of debranched arabinan. Furthermore, this investigation revealed that B. longum subsp. longum NCIMB 8809 does not completely degrade arabinoxylan, but utilises the arabinose substitutions only, while leaving the xylan backbone untouched.Finally, Chapter 5 outlines that B. longum subsp. longum NCIMB 8809 is capable of removing ferulic and p-coumaric acid substitutions that originate from arabinoxylan. Analysis of the genome sequence led to the identification of a candidate gene for this activity, which was subsequently cloned and expressed in E. coli. Biochemical analysis revealed that the enzyme, designated here as FaeA, is indeed capable of releasing both ferulic and p-coumaric acid from arabinoxylan. Furthermore, it is shown that a derivative of B. longum subsp. longum NCIMB 8809 carrying an insertion mutation in faeA had lost the ability to release ferulic and p-coumaric acid from arabinoxylan, and that growth of this mutant strain is negatively affected when cultivated on growth-limiting levels of arabinoxylan.
Resumo:
As the Internet has changed communication, commerce, and the distribution of information, so it is changing Information Systems Research (ISR). The goal of this paper is to put the topic of application and reliability of online research into the focus of ISR by exploring the extension of online research methods (ORM) into its popular publication outlets. 513 articles from high ranked ISR publication outlets from the last decade have been analyzed using online content analysis. The findings show that in ISR online research methods are applied despite the missing discussion on the validity of the theories and methods that were defined offline within the new environment and the associated challenges.
Resumo:
It is recognized that young people experience difficulties in accessing mainstream mental health services particularly because of the stigma that remains associated with mental health problems. One potential solution is to use the many websites available offering information and support for mental health problems, such support and information could be offered by Psychiatric Nurses. However, young peoples' usage and views on using the Internet for this purpose has yet to be examined. This quantitative descriptive study aimed to elicit the views of 922 University students, aged between 18 and 24 years, on using the Internet for mental health information and support. Data were collected using a 30-item self-designed questionnaire and analysed using descriptive statistics. The findings indicated that 72.4% of participants used the Internet several times a day. In addition, 30.8% had previously searched for mental health information online, predominantly on depression. While it was found that 68% of participants indicated that they would use the Internet for mental health support if they needed to, 79.4% would still prefer face to face support. It is concluded that young people are willing to use the Internet for mental health information and that it represents a viable source of support for this age group.
Resumo:
This report evaluates the existing situation in the Celtic Seas sub-region and determines the current state of preparedness for transboundary management of marine ecosystems and MSFD implementation. Recommendations for capacity building are provided through the analysis of the existing conflicts and potential synergies between relevant policies, institutions and information resources for MSFD implementation across the region. This report strives to empower stakeholders through the provision of a sound baseline with accurate and up-to-date information on the current status of MSFD implementation, potential opportunities and suggested approaches for building capacities in their region and across the Celtic Seas. It is evident that there are a number of national marine planning processes currently underway and at different stages throughout the United Kingdom and the pre-planning context for MSP in Ireland. On a similar note, this evaluation of MSFD implementation progress to-date in the United Kingdom, Ireland and France highlights that each Member State has implemented the legal and procedural requirements of preparatory steps in differing manners and using different time scales. This variance across the sub-region has the potential to impact the achievement of GES by 2020 across the Celtic Seas.
Resumo:
Background: Most cardiovascular disease (CVD) occurs in the presence of traditional risk factors, including hypertension and dyslipidemia, and these in turn are influenced by behavioural factors such as diet and lifestyle. Previous research has identified a group at low risk of CVD based on a cluster of inter-related factors: body mass index (BMI) < 25 Kg/m2, moderate exercise, alcohol intake, non-smoking and a favourable dietary pattern. The objective of this study was to determine whether these factors are associated with a reduced prevalence of hypertension and dyslipidemia in an Irish adult population. Methods: The study was a cross-sectional survey of 1018 men and women sampled from 17 general practices. Participants completed health, lifestyle and food frequency questionnaires and provided fasting blood samples for analysis of glucose and insulin. We defined a low risk group based on the following protective factors: BMI <25 kg/m2; waist-hip ratio (WHR) <0.85 for women and <0.90 for men; never smoking status; participants with medium to high levels of physical activity; light alcohol consumption (3.5–7 units of alcohol/week) and a "prudent" diet. Dietary patterns were assessed by cluster analysis. Results: We found strong significant inverse associations between the number of protective factors and systolic blood pressure, diastolic blood pressure and dyslipidemia. The prevalence odds ratio of hypertension in persons with 1, 2, 3, ≥ 4 protective factors relative to those with none, were 1.0, 0.76, 0.68 and 0.34 (trend p < 0.01). The prevalence odds ratio of dyslipidemia in persons with 1, 2, 3, ≥ 4 protective factors relative to those with none were 0.83, 0.98, 0.49 and 0.24 (trend p = 0.001). Conclusion: Our findings of a strong inverse association between low risk behaviours and two of the traditional risk factors for CVD highlight the importance of 'the causes of the causes' and the potential for behaviour modification in CVD prevention at a population level.
Resumo:
This paper takes some of Melanie Klein’s ideas, which Bion (1961/1998) previously used to understand group dynamics, to analyse the discipline of management studies since its ‘birth’ in the United States in the late 19th century. Specifically, it focuses on the idealisation of work and play, and argues that at its inception, for idiosyncratic historical reasons, the discipline was rooted in a ‘paranoid-schizoid’ position in which work was idealised as good and play as bad. The paper maps out the peculiar set of factors and influences that brought this about. It then examines how and if, again following Klein, the discipline has evolved to the ‘depressive’ position, where the idealisations are replaced by a more ambiguous, holistic semantic frame. Seven different relationships between work and play are then described. The paper contends that the originary splitting and idealisation is foundational to the discipline, and provides an enduring basis for analysing management theory and practice. It concludes by using this splitting to map out five potential future trajectories for the discipline.
Resumo:
This work considers the static calculation of a program’s average-case time. The number of systems that currently tackle this research problem is quite small due to the difficulties inherent in average-case analysis. While each of these systems make a pertinent contribution, and are individually discussed in this work, only one of them forms the basis of this research. That particular system is known as MOQA. The MOQA system consists of the MOQA language and the MOQA static analysis tool. Its technique for statically determining average-case behaviour centres on maintaining strict control over both the data structure type and the labeling distribution. This research develops and evaluates the MOQA language implementation, and adds to the functions already available in this language. Furthermore, the theory that backs MOQA is generalised and the range of data structures for which the MOQA static analysis tool can determine average-case behaviour is increased. Also, some of the MOQA applications and extensions suggested in other works are logically examined here. For example, the accuracy of classifying the MOQA language as reversible is investigated, along with the feasibility of incorporating duplicate labels into the MOQA theory. Finally, the analyses that take place during the course of this research reveal some of the MOQA strengths and weaknesses. This thesis aims to be pragmatic when evaluating the current MOQA theory, the advancements set forth in the following work and the benefits of MOQA when compared to similar systems. Succinctly, this work’s significant expansion of the MOQA theory is accompanied by a realistic assessment of MOQA’s accomplishments and a serious deliberation of the opportunities available to MOQA in the future.