Campus & alumni news

Boston University Medicine was published by the Boston University Medical Campus, and presented stories on events and topics of interest to members of the BU Medical Campus community. It followed the discontinued publication Centerscope as Boston University Medicine from 1991-2005, and was continued as Campus & Alumni News from 2006-2013 before returning to the title Boston University Medicine from 2014-present

A comparison of shrinkage due to laundering of cotton, linen and rayon fabrics pressed under controlled tensions

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Ice Formation in the Arctic Ocean: Observed Processes and Climate Feedbacks

The Arctic seasonal ice zone undergoes dramatic changes throughout the year. In the summer, ice cover melts off, leaving the ocean surface exposed to the atmosphere. Incident solar radiation warms the surface mixed layer. At the end of the summer season, the mixed layer must then cool to the freezing point in order for ice to form at the surface. This thesis explores the impact of that heat throughout the annual cycle, but especially on first-year ice growth. Through analysis of CTD profiles and buoy data, it is found that summer heat gets into the summer halocline, where it is trapped through the fall season cooling process. The mixed layer heat (estimated from an empirical relationship derived from direct measurements and atmospheric and geographic parameters along with sea surface temperatures) is well correlated with freeze-up date. The results presented herein suggest that delayed freeze-up does result in thinner ice cover at the end of the winter season, in part because the maximum ice growth rate is consistent (approximately 12 cm/day) between observations from Antarctic polynyas with exceptionally high ice production and the few observations that exist in the Arctic. Finally, from analysis of end-of-season first year ice thickness distributions, it is clear that the summer heat trapped in the summer halocline is released over the course of the winter, limiting ice growth in addition to that caused by the delay in freeze-up. In all, it is likely that as the Arctic becomes increasingly dominated by first-year ice, the thinning trend will continue though at a slower rate than in the current transition from multi- to first-year ice cover

using thermal inertia of buildings with phase change material for demand response

Abstract: In recent years, demand response programs have proved useful in managing peak demand and meeting sustainability goals, enabling an efficient use of the smart grid. Heating, ventilation, and air conditioning (HVAC) loads in buildings constitute a large proportion of the total energy consumption of households, and accordingly, a flexible and efficient operation of these devices can aid power utilities in meeting load management objectives while reducing consumer's electricity bills. With the emergence of promising new technologies, such as phase change materials (PCM), buildings can serve as a virtual thermal energy storage, which improves energy efficiency and also allows occupants to offer grid services like peak demand reduction. The objective of this paper is to establish the effectiveness of PCM as a demand response resource, demonstrating the extent to which it can be used for peak demand reduction. A wide range of scenarios are considered to investigate the impacts of geographical location, PCM melting point, duration of precooling and preheating, setting points of HVAC system, thickness and location of PCM, on the capability of the PCM in reducing or shifting the cooling and heating load. All simulations are performed using the EnergyPlus platform, examining typical residential buildings in five Australian cities: Brisbane, Sydney, Melbourne, Hobart and Perth. The simulation results showed a decrease in the HVAC demand in the buildings with PCM, in all cities, with the highest reductions observed in Hobart and Melbourne. The integration of a 20mm thick PCM in the roof, wall and floor of the building yielded a 21.8% and 16.7% reduction in annual HVAC demand in Hobart and Melbourne respectively, when compared to the building without PCM. However, this is with the assumption that the HVAC system is operating 24 hours a day for a whole year. The PCM-integrated building showed a shift in the HVAC demand in all cities except Perth. A shift by 9 minutes, 3 minutes, 60 minutes and 103 minutes was recorded in the cities of Brisbane, Sydney, Melbourne and Hobart respectively. The simulation results will be used in subsequent research to schedule the HVAC demand using a home energy management system

Molecular genetics of developmental dyslexia

Developmental Dyslexia (DD) is a complex, cognitive disorder which is characterised by an impairment in reading despite adequate educational, motivational and intellectual opportunities. Family and twin studies have shown that this common neurodevelopmental disorder has a highly heritable component. The aim of this thesis was to identify novel susceptibility variants for DD using several approaches. A candidate gene study was conducted, testing variants within the genes CDC42, PRTG, KIAA0319L, DCDC2b and RIOK3 for association with DD in the Cardiff case-control sample. None of the variants within these genes showed a significant association withDD. A genome-wide association study (GWAS) was conducted in collaboration with other groups as part of the NeuroDys consortium, using DD cases from Europe and population controls. 27 of the most significant SNPs identified were selected and genotyped in a larger replication sample. 8 of these showed a significant association with DD, with the most interesting SNPs within the gene SNX29. An additional GWAS was conducted by the NeuroDys consortium in the form of a pooling study using a larger array. 38 of the most significant SNPs identified were selected for individual genotyping after which 14 remained significant, with the most interesting within the genes TMC1 and WDR78. Another GWAS was conducted in the form of a pooling study using the Cardiff cases and screened controls only. 57 of the most significant SNPs identified were selected for individual genotyping of which 54 remained significant. This study highlighted a number of interesting genes and demonstrated the effect of using a homogeneous case-control sample when conducting pooling studies. Analysis of copy number variants (CNVs) was also conducted using data from the initial NeuroDys GWAS. This study highlighted the technical issues that can affect the outcome of such studies. As such, the CNVs in this study need to be validated before these results can be relied upon. To conclude, some interesting variants have been identified in this thesis but further work is required to confirm these findings