801 resultados para Human Milk, PCDDs, PCDFs, PCBs, Australia


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work is concerned with the genetic basis of normal human pigmentation variation. Specifically, the role of polymorphisms within the solute carrier family 45 member 2 (SLC45A2 or membrane associated transporter protein; MATP) gene were investigated with respect to variation in hair, skin and eye colour ― both between and within populations. SLC45A2 is an important regulator of melanin production and mutations in the gene underly the most recently identified form of oculocutaneous albinism. There is evidence to suggest that non-synonymous polymorphisms in SLC45A2 are associated with normal pigmentation variation between populations. Therefore, the underlying hypothesis of this thesis is that polymorphisms in SLC45A2 will alter the function or regulation of the protein, thereby altering the important role it plays in melanogenesis and providing a mechanism for normal pigmentation variation. In order to investigate the role that SLC45A2 polymorphisms play in human pigmentation variation, a DNA database was established which collected pigmentation phenotypic information and blood samples of more than 700 individuals. This database was used as the foundation for two association studies outlined in this thesis, the first of which involved genotyping two previously-described non-synonymous polymorphisms, p.Glu272Lys and p.Phe374Leu, in four different population groups. For both polymorphisms, allele frequencies were significantly different between population groups and the 272Lys and 374Leu alleles were strongly associated with black hair, brown eyes and olive skin colour in Caucasians. This was the first report to show that SLC45A2 polymorphisms were associated with normal human intra-population pigmentation variation. The second association study involved genotyping several SLC45A2 promoter polymorphisms to determine if they also played a role in pigmentation variation. Firstly, the transcription start site (TSS), and hence putative proximal promoter region, was identified using 5' RNA ligase mediated rapid amplification of cDNA ends (RLM-RACE). Two alternate TSSs were identified and the putative promoter region was screened for novel polymorphisms using denaturing high performance liquid chromatography (dHPLC). A novel duplication (c.–1176_–1174dupAAT) was identified along with other previously described single nucleotide polymorphisms (c.–1721C>G and c.–1169G>A). Strong linkage disequilibrium ensured that all three polymorphisms were associated with skin colour such that the –1721G, +dup and –1169A alleles were associated with olive skin in Caucasians. No linkage disequilibrium was observed between the promoter and coding region polymorphisms, suggesting independent effects. The association analyses were complemented with functional data, showing that the –1721G, +dup and –1169A alleles significantly decreased SLC45A2 transcriptional activity. Based on in silico bioinformatic analysis that showed these alleles remove a microphthalmia-associated transcription factor (MITF) binding site, and that MITF is a known regulator of SLC45A2 (Baxter and Pavan, 2002; Du and Fisher, 2002), it was postulated that SLC45A2 promoter polymorphisms could contribute to the regulation of pigmentation by altering MITF binding affinity. Further characterisation of the SLC45A2 promoter was carried out using luciferase reporter assays to determine the transcriptional activity of different regions of the promoter. Five constructs were designed of increasing length and their promoter activity evaluated. Constitutive promoter activity was observed within the first ~200 bp and promoter activity increased as the construct size increased. The functional impact of the –1721G, +dup and –1169A alleles, which removed a MITF consensus binding site, were assessed using electrophoretic mobility shift assays (EMSA) and expression analysis of genotyped melanoblast and melanocyte cell lines. EMSA results confirmed that the promoter polymorphisms affected DNA-protein binding. Interestingly, however, the protein/s involved were not MITF, or at least MITF was not the protein directly binding to the DNA. In an effort to more thoroughly characterise the functional consequences of SLC45A2 promoter polymorphisms, the mRNA expression levels of SLC45A2 and MITF were determined in melanocyte/melanoblast cell lines. Based on SLC45A2’s role in processing and trafficking TYRP1 from the trans-Golgi network to stage 2 melanosmes, the mRNA expression of TYRP1 was also investigated. Expression results suggested a coordinated expression of pigmentation genes. This thesis has substantially contributed to the field of pigmentation by showing that SLC45A2 polymorphisms not only show allele frequency differences between population groups, but also contribute to normal pigmentation variation within a Caucasian population. In addition, promoter polymorphisms have been shown to have functional consequences for SLC45A2 transcription and the expression of other pigmentation genes. Combined, the data presented in this work supports the notion that SLC45A2 is an important contributor to normal pigmentation variation and should be the target of further research to elucidate its role in determining pigmentation phenotypes. Understanding SLC45A2’s function may lead to the development of therapeutic interventions for oculocutaneous albinism and other disorders of pigmentation. It may also help in our understanding of skin cancer susceptibility and evolutionary adaptation to different UV environments, and contribute to the forensic application of pigmentation phenotype prediction.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

CPNS’ new Working Paper examines the latest findings from a national survey of professional advisers on the topic of philanthropy assistance to high-net-worth individuals. Findings confirm a growing willingness within the Australian advisory sector to provide philanthropy advice to clients with means, although the rate of change has slowed since 2005. Advisers are now more likely to see benefits in providing this type of counselling, as well as benefits for their clients in engaging in philanthropy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The PMBOK Guide is one of the most influential publications concerning the knowledge of the project manangement. Moreover, the pervasion of this guide seems to be set to increase as the basis of accreditation - in conjunction with the increasing global trend toward obtaining project management professional status. However, despite the influence and strengthening profile of this guide, reports continue to be published that detail numerous project failures in a wide range of different industries. The PMBOK Guide comprises mainly declarative (know-what) and procedural (know-how) information. In this sense, the guide is largely normative and provides a very good example of the limitations of this approach as highlighted by proponents of a move to the genuine application of positibe theory in project management.----- The aim of this paper is to determine the applicability of the guide in Australia and to determine the extent to which project success can be attributed to the guide. Project Managers from a variety of organisations were surveyed. This postal survey yielded 48 replies. Descriptive statistics was used to assess the incidence and effectivieness of all the processes in the guide. The results indicate that there were no processes that could be considered as peripheral or as a candidate for elimination from the guide. More specifically, all the processes were identified as either a key routine process or a key selective process and positively related to the level of project success. However, the results also indicated that other major factors pertaining to causal knowledge (know-why) are, at least, equally important determinants of project success. It is concluded that declarative, procedural and causal knowledge are all valuable, and given the preponderance of the first two types of knowledge, there seems to be an urgent need to now ensure an equal quest for causal knowledge. In terms of developing causal knowledge, a good starting point would appear to be both positive theory from production and economics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper reports on progress in developing new design and measurement concepts, and translating these concepts into practical applications. This research addresses gaps in ‘best practice’ green building, and is aimed ultimately at replacing green buildings with sustainable urban environments. Building on the author’s previously articulated concepts of Design for Eco-services and Positive Development, this research will demonstrate how to eco-retrofit cities so that they reverse the negative impacts of past design and generate net positive ecological impacts, at no extra cost. In contrast to ‘restorative’ design,this means increasing ecological carrying capacity and natural and social capital through built environment design. Some exemplars for facilitating Positive development will be presented in this talk,such as Green Scaffolding for retrofits, and Green Space Walls for new construction. These structures have been designed to grow and change over time, be easily deconstructed, and entail little waste. The frames support mini-ecospheres that provide a wide range of ecosystem services and biodiversity habitats, as well as heating, cooling and ventilating. In combination, the modules serve to improve human and environmental health. Current work is focused on developing a range of such space frame walls, optimised through an innovative marriage of eco-logical design and virtual modelling.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To assess extent of coder agreement for external causes of injury using ICD-10-AM for injury-related hospitalisations in Australian public hospitals. Methods: A random sample of 4850 discharges from 2002 to 2004 was obtained from a stratified random sample of 50 hospitals across four states in Australia. On-site medical record reviews were conducted and external cause codes were assigned blinded to the original coded data. Code agreement levels were grouped into the following agreement categories: block level, 3-character level, 4-character level, 5th-character level, and complete code level. Results: At a broad block level, code agreement was found in over 90% of cases for most mechanisms (eg, transport, fall). Percentage disagreement was 26.0% at the 3-character level; agreement for the complete external cause code was 67.6%. For activity codes, the percentage of disagreement at the 3-character level was 7.3% and agreement for the complete activity code was 68.0%. For place of occurrence codes, the percentage of disagreement at the 4-character level was 22.0%; agreement for the complete place code was 75.4%. Conclusions: With 68% agreement for complete codes and 74% agreement for 3-character codes, as well as variability in agreement levels across different code blocks, place and activity codes, researchers need to be aware of the reliability of their specific data of interest when they wish to undertake trend analyses or case selection for specific causes of interest.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper describes a series of design games, specifically aimed at exploring shifts in human agency, how they are managed, and the impact this will have on the design of future context-aware applications. The games focussed on understanding information handling issues in dental practice with participants from the University of Queensland Dental School playing an active role in the activities. Participatory design activities reveal how technology solution impact on dental practices. By finding methods of representing technological possibilities in ways which can easily be understood we enhance the contribution that dentists can make to the design process.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents aspects of a longitudinal study in the design and practice of Internet meetings between farmer their advisors and researchers in rural Australia. It reports on the use of Microsoft NetMeeting (NM) by a group of agricultural researchers from Australia's CSIRO (Commonwealth Scientific and Industrial Research Organisation) for regular meetings, over nine years, with farmers and the commercial advisers. It describes lessons drawn from this experience about the conditions under which telecollaborative tools, such as NM and video conferencing, are likely to be both useful and used.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The murine ghrelin gene (Ghrl), originally sequenced from stomach tissue, contains five exons and a single transcription start site in a short, 19 bp first exon (exon 0). We recently isolated several novel first exons of the human ghrelin gene and found evidence of a complex transcriptional repertoire. In this report, we examined the 5' exons of the murine ghrelin orthologue in a range of tissues using 5' RACE. -----FINDINGS: 5' RACE revealed two transcription start sites (TSSs) in exon 0 and four TSSs in intron 0, which correspond to 5' extensions of exon 1. Using quantitative, real-time RT-PCR (qRT-PCR), we demonstrated that extended exon 1 containing Ghrl transcripts are largely confined to the spleen, adrenal gland, stomach, and skin. -----CONCLUSION: We demonstrate that multiple transcription start sites are present in exon 0 and an extended exon 1 of the murine ghrelin gene, similar to the proximal first exon organisation of its human orthologue. The identification of several transcription start sites in intron 0 of mouse ghrelin (resulting in an extension of exon 1) raises the possibility that developmental-, cell- and tissue-specific Ghrl mRNA species are created by employing alternative promoters and further studies of the murine ghrelin gene are warranted.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research explores gestures used in the context of activities in the workplace and in everyday life in order to understand requirements and devise concepts for the design of gestural information applicances. A collaborative method of video interaction analysis devised to suit design explorations, the Video Card Game, was used to capture and analyse how gesture is used in the context of six different domains: the dentist's office; PDA and mobile phone use; the experimental biologist's laboratory; a city ferry service; a video cassette player repair shop; and a factory flowmeter assembly station. Findings are presented in the form of gestural themes, derived from the tradition of qualitative analysis but bearing some similarity to Alexandrian patterns. Implications for the design of gestural devices are discussed.