Merits Of Using Low U And G-Value Facades On Heating/cooling Demand And CO2 Emissions From Office Buildings

Office buildings are responsible for a significant amount of energy usage and CO2 emissions, undesirable because of resource depletion and/or climate change. A possible strategy for reducing energy consumption and hence CO2 emissions might be to specify high performance facades since they should reduce heat losses in cold conditions and conductive heat gains in hot conditions. This project reports on an investigation on energy demand and CO2 emissions in office buildings incorporating facades with U-values between 1.2 to 2.6 W/m2K and g-values between 0.3 to 0.5, in four locations: London, Hong Kong, Caribou and Abu Dhabi which experience, respectively, cool, sub-tropical, cold and hot climates. Other variables considered include office orientation, long working hours, low internal gains and climate change. Energy demand was calculated using a steady-state method and the dynamic simulation tool, EDSL Tas. The results show that low U-value facades can reduce both annual energy demand and CO2 emissions in locations with predominantly cold or predominantly hot environments such as those found in Caribou and Abu Dhabi. In Hong Kong U-value has a marginal effect on energy usage but savings can be achieved by specifying low g-value facades. In London, low U-value facades only decrease annual energy demand if internal gains are also low. However, reducing energy use does not necessarily reduce CO2 emissions and if this is the goal a second strategy which emerges is to select facades which minimise energy demand when solar irradiations are low and maximising the use of, for example, solar energy and air/ground source heat pumps at other times. The work further suggests that Building Regulations should include a lower limit on U-value, a higher set point temperature in winter and more guidance on internal heat gains if energy use and CO2 emissions are to be reduced in the UK

Withaferin A Suppresses Liver Tumor Growth in a Nude Mouse Model by Downregulation of Cell Signaling Pathway Leading to Invasion and Angiogenesis

Purpose: To investigate the effect of withaferin A on tumor growth and metastasis in liver in a nude mouse model.Methods: Withaferin A was injected through a portal vein to the orthotopic liver tumor in a nude mice model. Xenogen in vivo imaging system was used to monitor tumor growth and metastasis. The effect of withaferin A on tumor volume, invasive growth pattern, expression of Pyk2, upregulation of BAX/P53, apoptotic signaling and ROCK/IP10/VEGF pathway along with cytoskeletal protein actin projection formation was studied. Tumor/non-tumor margin was examined under electron microscopy. In addition, the direct effect of withaferin A on liver cancer cells and endothelial cells was further investigated.Results: A significant inhibition of tumor growth and lower incidence of lung metastasis was observed after withaferin A treatment. Withaferin A treatment led to a decrease in the incidence of intrahepatic metastasis from 90 (9 of 10) to 10 % (1 of 10, p = 0.041). There was decrease in macrophage infiltration in the liver tumors and vessels. Western blot analysis revealed inhibition of expression of Pyk2, ROCK1 protein and VEGF. Electron microscopy showed tumor vascular endothelial cell damage and significant necrosis of tumor tissues. It also suppressed formation of cytoskeletal protein actin projection involved in cell migration.Conclusion: Withaferin A inhibits liver tumor invasion and angiogenesis by downregulation of cell signalling pathway leading to invasion and angiogenesis. Therefore, withaferin A is a promising candidate for the treatment of liver tumor invasion and angiogenesis.Keywords: Withaferin A, Macrophage, Lung metastasis, Angiogenesis, Vascular endothelial growth factor, Rho kinase, Withania somnifer

Different response of phytochelatins in two aquatic macrophytes exposed to cadmium at environmentally relevant concentrations

Phytochelatins (PCs) have been proposed as potential biomarkers for an evaluation of metal toxicity. However, most studies have been generally limited to high concentrations of metals. In this study, two submerged macrophytes Ceratophyllum demersum L. and Elodea canadensis Michx. were adopted to investigate the response of phytochelatins (PCs) and its relationship with cadmium (Cd) toxicity upon exposure to low concentrations of Cd (0.01 to 0.64 μM) usually present in low or moderately polluted environments. It was observed that, 0.01 to 0.04 μM Cd had no obvious toxic effects on the growth of two plants compared with the control plants, whereas Cd toxicity is significantly seen in C. demersum at 0.08 to 0.64 μM and in E. canadensis at 0.16 to 0.64 μM, as indicated by the significant decreases of fresh weights. Two plants showed strong capacity to accumulate Cd present in low concentrations. PCs were produced in a dependent-species and-concentration manner. Response of PCs was strong in C. demersum exposed to Cd concentrations studied (0.02 to 0.64 μM) and dramatically increased with the increase of Cd concentrations in solutions. The maximum amount of PCs in C. demersum was found at 7 days and obviously decreased with the prolonged exposure to Cd. PC concentrations in C. demersum were positively correlated with Cd toxicity, as measured by the growth inhibition rate of fresh weight. By contrast, Cd concentrations studied slightly or mildly induced the production of PCs in E. canadensis. The results suggested that, positive responses of PCs in C. demersum can serve as early biomarkers for reflecting Cd toxicity in low or moderately polluted water environments.Key words: Biomarker, cadmium, Ceratophyllum demersum L., Elodea canadensis Michx., metal toxicity, phytochelatins

Using Lidar Elevation Data to Develop a Topobathymetric Digital Elevation Model for Sub-Grid Inundation Modeling at Langley Research Center

Technological progression in light detection and ranging permits the production of highly detailed digital elevation models, which are useful in sub-grid hydrodynamic modeling applications. Sub-grid modeling technology is capable of incorporating these high-resolution lidar-derived elevation measurements into the conventional hydrodynamic modeling framework to resolve detailed topographic features for inclusion in a hydrological transport model for runoff simulations. The horizontal resolution and vertical accuracy of the digital elevation model is augmented via inclusion of these lidar elevation values on a nested 5-m sub-grid within each coarse computational grid cell. This aids in resolving ditches and overland drainage infrastructure at Langley Research Center to calculate runoff induced by the heavy precipitation often accompanied with tropical storm systems, such as Hurricane Irene (2011) and Hurricane Isabel (2003). Temporal comparisons of model results with a NASA tide gauge during Hurricane Irene yielded a good R-2 correlation of 0.97, and root mean squared error statistic of 0.079 m. A rigorous point-to-point comparison between model results and wrack line observations collected at several sites after Hurricane Irene revealed that when soil infiltration was not accounted for in the model, the mean difference between modeled and observed maximum water levels was approximately 10%. This difference was reduced to 2-5% when infiltration was considered in the model formulation, ultimately resulting in the sub-grid model more accurately predicting the horizontal maximum inundation extents within 1.0-8.5 m of flood sites surveyed. Finally, sea-level rise scenarios using Hurricane Isabel as a base case revealed future storm-induced inundation could extend 0.5-2.5 km inland corresponding to increases in mean sea level of 37.5-150 cm

Design and fabrication of freeform reflector for automotive headlamp

Author name used in this publication: J. B. JiangAuthor name used in this publication: C. F. CheungAuthor name used in this publication: S. ToAuthor name used in this publication: K. W. ChengAdvanced Optics Manufacturing CentreRefereed conference paper2006-2007 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Neural network model of binaural hearing based on spatial feature extraction of the head related transfer function

In spatial hearing, complex valued head-related transfer function (HRTF) can be represented as a real valued head-related impulse response (HRIR). Using Karhunen-Loeve expansion, the spatial features of the normalized HRIRs on measurement space can be extracted as spatial character functions. A neural network model based on Von-Mises function is used to approximate the discrete spatial character function of HRIR. As a result, a time-domain binaural model is established and it fits the measured HRIRs well.published_or_final_versio

Enabling decision trend analysis with interactive scatter plot matrices visualization

© 2015 Elsevier Ltd. This paper presents a new interactive scatter plot visualization for multi-dimensional data analysis. We apply Rough Set Theory (RST) to reduce the visual complexity through dimensionality reduction. We use an innovative point-to-region mouse click concept to enable direct interactions with scatter points that are theoretically impossible. To show the decision trend we use a virtual Z dimension to display a set of linear flows showing approximation of the decision trend. We conducted case studies to demonstrate the effectiveness and usefulness of our new technique for analyzing the property of three popular data sets including wine quality, wages and cars. The paper also includes a pilot usability study to evaluate parallel coordinate visualization with scatter plot matrices visualization with RST results

A comparison of efficacy between conventional and modified methods of the chronic myocardial ischemia/reperfusion model

The objective of this study is to develop and compare the efficacy of a modified versus conventional rat model of chronic myocardial ischemia/reperfusion. Sixty Sprague Dawley (SD) rats were randomlydivided into two groups, a modified group (mask respiratory support and short-time chest-opening) and a conventional group (tracheal intubation and long-time chest-opening). Operation time, surgical success rate, survival rate and infarct size were investigated. In addition, the post-operative living state of the rats was observed. In the perioperative period, the surgical success rate was greater in the modified model (P 0.05). The modified method offers advantages of simplicity, efficiency and independent conduct. Its employment enhances the success rate of the chronic rat myocardial ischemia/reperfusion model

Fyn Kinase regulates GluN2B subunit-dominant NMDA receptors in human induced pluripotent stem cell-derived neurons

NMDA receptor (NMDAR)-mediated fast excitatory neurotransmission is implicated in a broad range of physiological and pathological processes in the mammalian central nervous system. The function and regulation of NMDARs have been extensively studied in neurons from rodents and other non-human species, and in recombinant expression systems. Here, we investigated human NMDARs in situ by using neurons produced by directed differentiation of human induced pluripotent stem cells (iPSCs). The resultant cells showed electrophysiological characteristics demonstrating that they are bona fide neurons. In particular, human iPSC-derived neurons expressed functional ligand-gated ion channels, including NMDARs, AMPA receptors, GABAA receptors, as well as glycine receptors. Pharmacological and electrophysiological properties of NMDAR-mediated currents indicated that these were dominated by receptors containing GluN2B subunits. The NMDAR currents were suppressed by genistein, a broad-spectrum tyrosine kinase inhibitor. The NMDAR currents were also inhibited by a Fyn-interfering peptide, Fyn(39-57), but not a Src-interfering peptide, Src(40-58). Together, these findings are the first evidence that tyrosine phosphorylation regulates the function of NMDARs in human iPSC-derived neurons. Our findings provide a basis for utilizing human iPSC-derived neurons in screening for drugs targeting NMDARs in neurological disorders