1522 research outputs found
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Changes in macular pigment optical density and serum concentrations of its constituent carotenoids following supplemental lutein and zeaxanthin: The LUNA Study
No full textMacular pigment (MP), consisting of lutein (L) and zeaxanthin (Z), is believed to protect the retina from photo-oxidative damage. The current study investigates, in terms of MP optical density (MPOD) and serum concentrations of its constituent carotenoids, response to supplemental L and Z, and co-antioxidants. An intervention (I) group, consisting of 108 subjects (mean [SD] age: 71.5 [7.1] years), of which 92.6% exhibited features of age-related macular degeneration (AMD), received a daily supplement consisting of 12 mg L and 1 mg Z, both provided as ester 120 mg vitamin C, 17.6 mg vitamin E, 10 mg zinc, 40 mg selenium (Ocuvite Lutein) for a period of 6 months. MPOD was measured, by 2-wavelength autofluorescence (AF), on five occasions during the period of supplementation, and once again 3 months following discontinuation of the supplement. A control (C) group of 28 subjects (mean [SD] age: 71.0 [8.1] years), who received no dietary supplementation or modification, was examined at baseline and once again after a mean of 29.4 (9.3) weeks. At baseline, mean (SD) MPOD (at 0.5) was 0.504 (0.197) and 0.525 (0.189) in the I and C groups, respectively. There was a statistically significant increase in MPOD (at 0.5) for the I group (0.1 [0.009]; p 0.05), over the period of supplementation. In order to classify supplemented subjects into quartiles, in terms of MPOD response, we calculated the difference between MPOD (at 0.5) at visit 6 and at baseline (visit 1). Quartile 1 (the ‘‘non-responder’’ quartile) displayed no increase in MPOD (at 0.5), in spite of rises seen in serum concentrations of L and Z. The three ‘‘responder’’ quartiles reached similar final plateaus of MPOD (at 0.5), reflected in final mean (SEM) values of 0.59 (0.04) optical density unit (ODU), 0.64 (0.03) ODU and 0.64 (0.03) ODU for quartiles 2, 3 and 4, respectively. Subjects with low baseline MPOD were more likely to exhibit a dramatic rise in MPOD, or to exhibit no rise in MPOD, in response to supplements than subjects with medium to high baseline MPOD values. Supplementation with 12 mg L and 1 mg Z, combined with co-antioxidants, resulted in an increase of MPOD at 0.5 eccentricity in a majority of subjects, including those afflicted with AMD. However, there remains a substantial proportion of subjects for whom, in spite of rises in serum concentrations of L and Z in these subjects, MPOD augmentation in response to supplemental L, Z and co-antioxidants could not be detected over the study period, thus indicating that intestinal malabsorption of these carotenoids is not responsible for the lack of a macular response to such supplements. Further, our results suggest that saturable mechanisms play a role in the retinal capture and/or stabilisation of the macular carotenoids
Semiconductor physics at WIT and Trinity College
Get PDFA WIT research group that studies the physics of semiconductors is coordinated by Dr. Cormac O’Raifeartaigh of the School of Science. Experimental research is carried out at the electron spin resonance (ESR) laboratory at Trinity College Dublin (TCD) in collaboration with Dr. Robert Barklie of TCD. Research data are analysed at WIT with theoretical support provided by Dr. Mohammad Alhourani and Mr. Frank Leonard. The group has participated in research projects funded by WIT (BEHEST Programme), Enterprise Ireland and the EU (5th Framework Programme), with the results published in international science journals
The Use of Weblogs as a Tool to Support Collaborative Learning and Reflective Practice in Third-Level Institutions
Get PDFWeblogs can be used as a tool for learning support, providing additional features that are lacking in many Learning Management Systems (LMSs). This research aims to demonstrate that weblogs can enhance the learning experience by allowing students to reflect on their learning, and by allowing students to easily collaborate with their tutors and with one another. Laurillard’s conversational framework is used a basis for describing how weblogs should be incorporated into the existing learning environment. In an initial study, students set up weblogs and created a weblog post each week over a 10-week period. Analysis of this study has begun, and preliminary results show that the use of weblogs with RSS (Rich Site Summary) helps to reduce tutor workload in comparison to the use of a Learning Management System, and helps to increase student involvement in learning
Synchronization and Clustering in a Multimode Quantum Dot Laser
No full textWe analyze experimentally the intensity oscillations of the longitudinal modes of quantum dot semiconductor lasers. We show that the modal intensities can oscillate chaotically with different average frequencies, but obey a highly organized antiphase dynamics leading to a constant total output power. The fluctuations are in the MHz range. We report the first experimental observation of frequency clustering associated with synchronization. We also observe the propagation of perturbations across the optical spectrum from blue to red
Major Tourism Network based at WIT School of Business
Get PDFThe School of Business at Waterford Institute of Technology has been engaged by Fáilte Ireland to develop and implement an active learning environment for tourism enterprises across a seven-county region stretching from Wexford to Kerry. The aim of the project is to assist the small tourism and hospitality enterprise owner in developing his/her business through providing access to a range of training and development supports at a flexible and local level. The mergo project is concerned with four aspects of knowledge transfer: local networks, regional events, research and web communications resources. Tourism providers will, through this project, be able to co-operate on issues such as county-based research and marketing. Up to 675 enterprises are set to benefit from the programme by the end of 2008
HOW LEARNING NETWORKS CAN BRIDGE THE TRAINING GAP
No full textEntrepreneurs could benefit from a radically different approach to their training needs
A learning framework for the small business environment
Get PDFPURPOSE-The aim of this article is to offer insight into the factors affecting individual and organisational learning in small businesses; specifically the identification of the learning relationships that are unique to the small business environment.
DESIGN/METHODOLOGY/APPROACH- The authors apply Crossan et al.'s (1997, 1999) Organisational Learning Framework. The proposed framework is supported by empirical evidence generated through a longitudinal case study carried out in a small business in the Republic of Ireland over a two-year period. A learning catalyst, in this case the implementation of a new information system(IS), offered an initial point from which to gauge subsequent learning within the studied case.
FINDINGS- This framework acknowledges the learning impact of a small workforce, an owner-centred culture and a simple organisational structure, as well as the time and resource constraints specific to small businesses which affect the learning dynamic. The framework also takes account of the learning challenges brought about by external influences unique to a small business environment, such as enforced organisational change created by powerful business partners' commercial requirements.
RESEARCH LIMITATIONS/IMPLICATIONS- As this framework was developed based on a single case, similar research may be conducted on additional case studies to determine the learning dynamic in alternative settings and business environments.
ORIGINALITY/VALUE- This research presents some valuable insights into the ways in which organistional learning can be facilitated and impeded in the largely ignored small business environment
A Review of the Development of Stent and Related Technologies
Get PDFThe relationship between the unique nature
of new stent technology and the development of
the stent industry is unclear. Previous research
has not characterised the term ‘new technology’,
and so could not investigate its unique impact on
the formation and activities of a new industry.
This paper reviews the historical
development of stent and related technologies,
including catheters and balloons. It describes the
development of interdependencies between the
related technologies and the growth of the stent
industry. It reports on this aspect of research
being performed in order to understand the
nature of the relationship between a new
technology and the strategic activities of a new
technology industry
George Barrett R.A. 1732-84, Tempietto del Clitunno
Get PDFAn article commissioned by the Gorry Gallery in Dublin to explain the background to and the meaning of an oil on canvas by George Barrett R.A. (1732 - 1734) based on two works by the Italian artist Piranesi. This work was for sale in the Gallery in March 2006