20 research outputs found
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Methods for assessing the effects of spatial luminance patterns on perceived qualities of concert lighting
This paper presents experimental approaches for evaluating concert lighting from the viewpoints of audience members and performers in Cambridge King's College Chapel. We develop image zoning and abstraction techniques to quantify and interpret photometric data acquired under four different electric lighting conditions. Assessed by 78 participants, these lighting scenarios are compared across six different viewing positions using a set of structured questionnaires. Ordered logistic regression modelling shows that the ratios and functions describing uniformity, brightness and light patterns are common explanatory variables for predicting perceived visual clarity, visual uniformity, brightness and spatial intimacy. Uniformity-related attributes are observed to be among the strongest variables for all these perceived qualities, except for visual clarity, which is better explained by acuity-related measures. These experimental results confirm the applicability of our approaches, highlighting the importance of combining multiple methods and integrating complex architectural situations into the process of understanding luminous appearance. Cambridge Trus
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Measuring light in field experiments using dummies and objects: A study of concert lighting
Lighting experiments were performed in a real context populated with dummies and objects. Using the King’s College Chapel in Cambridge as a case study, two field surveys of concert lighting were performed, one with the chapel empty and one with it occupied. In each survey, photometric data were collected under three electric lighting conditions and from six different viewing positions. A comparative analysis indicates that the data gathered from the occupied space represent the luminances more accurately, present a more detailed description of the light distribution, and provide a more extensive set of variables characterising the geometrical details of the visual scene. This study demonstrates the importance of using occupied spaces and considering the presence of occupants in field studies, which could be useful for obtaining a more complete understanding of complex luminous environments. </jats:p
Modelling Building Users’ Space Preferences for Group Work: A Discrete-Choice Experiment
Accurate space-use prediction helps architects to optimise space efficiency in buildings, thereby achieving economic and environmental sustainability. However, current space-use prediction models and approaches either disregard or oversimplify the role of building users’ space preferences in spatial-choice behaviour, thereby compromising prediction accuracy. The aim of this study was thus to develop a space-preference model of spatial choice behaviour with a focus on group work-related activities. A total of 2,464 observations of spatial choices were collected using a discrete-choice experiment. The data were modelled using a conditional logit model and then validated in a predictive success test. The resulting model clearly explains space preferences for group work-related activities and predicts spatial-choice behaviour by generating space-use probabilities for given spaces. The model is compared to a space preference model for individual work-related activities. Lastly, the application of the model was demonstrated in a case example.This work was supported by Hong Kong Polytechnic University: [grant number 1-ZE5H]
Another tool in the genome-wide association study arsenal: population-based detection of somatic gene conversion
The hunt for the genetic contributors to complex disease has used a number of strategies, resulting in the identification of variants associated with many of the common diseases affecting society. However most of the genetic variants detected to date are single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) and fall far short of explaining the full genetic component of any given disease. An as yet untapped genomic mechanism is somatic gene conversion and deletion, which could be complicit in disease risk but has been challenging to detect in genome-wide datasets. In a recent publication in BMC Medicine by Kenneth Ross, the author uses existing datasets to look at somatic gene conversion and deletion in human disease. Here, we describe how Ross's recent efforts to detect such occurrences could impact the field going forward
Complex nature of SNP genotype effects on gene expression in primary human leucocytes
<p>Abstract</p> <p>Background</p> <p>Genome wide association studies have been hugely successful in identifying disease risk variants, yet most variants do not lead to coding changes and how variants influence biological function is usually unknown.</p> <p>Methods</p> <p>We correlated gene expression and genetic variation in untouched primary leucocytes (n = 110) from individuals with celiac disease – a common condition with multiple risk variants identified. We compared our observations with an EBV-transformed HapMap B cell line dataset (n = 90), and performed a meta-analysis to increase power to detect non-tissue specific effects.</p> <p>Results</p> <p>In celiac peripheral blood, 2,315 SNP variants influenced gene expression at 765 different transcripts (< 250 kb from SNP, at FDR = 0.05, <it>cis </it>expression quantitative trait loci, eQTLs). 135 of the detected SNP-probe effects (reflecting 51 unique probes) were also detected in a HapMap B cell line published dataset, all with effects in the same allelic direction. Overall gene expression differences within the two datasets predominantly explain the limited overlap in observed <it>cis</it>-eQTLs. Celiac associated risk variants from two regions, containing genes <it>IL18RAP </it>and <it>CCR3</it>, showed significant <it>cis </it>genotype-expression correlations in the peripheral blood but not in the B cell line datasets. We identified 14 genes where a SNP affected the expression of different probes within the same gene, but in opposite allelic directions. By incorporating genetic variation in co-expression analyses, functional relationships between genes can be more significantly detected.</p> <p>Conclusion</p> <p>In conclusion, the complex nature of genotypic effects in human populations makes the use of a relevant tissue, large datasets, and analysis of different exons essential to enable the identification of the function for many genetic risk variants in common diseases.</p
Numerical evaluation of thermal comfort in traditional courtyards to develop new microclimate design in a hot and dry climate
The growing interest in thermal comfort of outdoor environments yields in different analysis on courtyards as a common space between urban and architectural scales. However, there is a limited knowledge regarding the microclimatic behavior of such spaces. Using ENVI-met simulations, this paper aims to numerically discuss the thermal performance of different configurations of traditionally designed courtyards in Shiraz, Iran, which experiences hot summers and cold winters. The geometrical effects such as orientation and H/W (height to width ratio) of courtyards are considered as potential parameters to improve the microclimatic conditions. In this paper, PMV and UTCI are used as thermal comfort indices. The obtained results indicate mean radiant temperature and wind speed as the most effective parameters for thermal comfort of courtyards. In addition, the aforementioned geometrical parameters might not be able to solely create a desirable condition, but they could significantly improve the thermal comfort of courtyards during summer and winter. To achieve a desirable thermal comfort level, the results suggest using configurations of a high H/W rate and southward orientation in order to obtain better shading during summer as well as allowing the solar radiation in while regulating the wind speed in winter
Evaluating the overall impression of concert lighting: An integrated approach
Using experimental data from four electric lighting scenarios at King’s College Chapel in Cambridge, we developed an integrated approach to evaluating the overall impression of concert lighting. First, we performed a group analysis based on the aggregated response from the audience, conductor and musician respondents, followed by an overall analysis accounting for all 624 responses. Ordered logistic regression analysis revealed the absence of statistically significant subjective–objective relationships for perceived visual balance, appropriateness, comfort and the overall impression. There were, however, significant results when the variables were correlated with subjective attributes. This suggests that the perceptual process was bi-level. To gain a more complete understanding of the perceived qualities, it is necessary for an approach to consider not only the intercorrelations between the subjective and objective measures, but also the intracorrelations among the subjective attributes. Further analysis of variance showed that increasing the overall lighting intensity was more likely to lead to a lower level of satisfaction. Nevertheless, providing peripheral and directional lights appeared to be the key to improving the overall impression. This paper confirms that combining detailed and generalised approaches to evaluate subjective responses can yield more meaningful interpretations, enabling relations with measures to be established with greater confidence.This study was supported by the Cambridge Trust, Emmanuel College and the Cambridge Department of Architecture
A non-synonymous SNP within membrane metalloendopeptidase-like 1 (MMEL1) is associated with multiple sclerosis.
Several single-nucleotide polymorphism (SNP) genome-wide association studies (GWASs) have been completed in multiple sclerosis (MS). Follow-up studies of the variants with the most promising rankings, especially when supplemented by informed candidate gene selection, have proven to be extremely successful. In this study we report the results of a multi-stage replication analysis of the putatively associated SNPs identified in the Wellcome Trust Case Control Consortium non-synonymous SNP (nsSNP) screen. In total, the replication sample consisted of 3444 patients and 2595 controls. A combined analysis of the nsSNP screen and replication data provides evidence implicating a novel additional locus, rs3748816 in membrane metalloendopeptidase-like 1 (MMEL1; odds ratio=1.16, P=3.54 × 10⁻⁶) in MS susceptibility