Integrin-mediated Cell Attachment Induces a PAK4-dependent Feedback Loop Regulating Cell Adhesion through Modified Integrin αvβ5 Clustering and Turnover

This article presents a novel mechanism deployed by cells to tune cell adhesion levels through the autoinhibitory regulation of integrin adhesion involving the activation of PAK4

Helicobacter pylori Adapts to Chronic Infection and Gastric Disease via pH-Responsive BabA-Mediated Adherence

International audienceThe BabA adhesin mediates high-affinity binding of Helicobacter pylori to the ABO blood group antigen-glycosylated gastric mucosa. Here we show that BabA is acid responsive-binding is reduced at low pH and restored by acid neutralization. Acid responsiveness differs among strains; often correlates with different intragastric regions and evolves during chronic infection and disease progression; and depends on pH sensor sequences in BabA and on pH reversible formation of high-affinity binding BabA multimers. We propose that BabA's extraordinary reversible acid responsiveness enables tight mucosal bacterial adherence while also allowing an effective escape from epithelial cells and mucus that are shed into the acidic bactericidal lumen and that bio-selection and changes in BabA binding properties through mutation and recombination with babA-related genes are selected by differences among individuals and by changes in gastric acidity over time. These processes generate diverse H. pylori subpopulations, in which BabA's adaptive evolution contributes to H. pylori persistence and overt gastric disease

Compression moulding of SMC : coupling between the flow and the local void contents

During compression moulding of sheet moulding compound (SMC), voids are formed that can deteriorate the properties of the final product. Here, experimental work and CFD-simulations have been carried out in order to increase the knowledge of the SMC compression moulding behaviour which highly affects the quality of the final products.Godkänd; 2009; Bibliografisk uppgift: CD-ROM; 20090826 (jimols

Process study on compression moulding of SMC using factorial design

During compression moulding of sheet moulding compounds, voids are formed that can deteriorate the properties of the final product. A large number of processing and material parameters can however be tuned in order to reduce the amount of voids. A factorial design is here applied to plan an experimental series where, in particular, vacuum assisted mouldings are carried out in a circular shaped mould. One result is that the electrical insulation can be considerably improved by choosing optimal processing conditions. Another is that the size of weld lines can be reduced in the same fashion.Godkänd; 2008; Bibliografisk uppgift: CD-ROM; 20080828 (ysko

Process study on compression moulding of SMC using factorial design

During compression moulding of sheet moulding compounds, voids are formed that can deteriorate the properties of the final product. A large number of processing and material parameters can however be tuned in order to reduce the amount of voids. A factorial design is here applied to plan an experimental series where, in particular, vacuum assisted mouldings are carried out in a circular shaped mould. One result is that the electrical insulation can be considerably improved by choosing optimal processing conditions. Another is that the size of weld lines can be reduced in the same fashion.Godkänd; 2008; Bibliografisk uppgift: CD-ROM; 20080828 (ysko

Method to estimate the ground loads for missing periods in a monitored GSHP

Monitoring a ground source heat pump can provide important insights into its working, but to study the behaviour of the borehole heat exchanger (BHE) we require monitored data for the whole period of operation. In practice, the monitored data often has periods of missing data. We propose a method to estimate the load during the periods of missing data based on the fluid temperature after that period. The method determined the missing load with negligible error, for the case of a BHE that behaves exactly like the model describing it. A sensitivity analysis showed that the estimated load is highly sensitive to errors in measured load and fluid temperature. The method was applied to a real monitored BHE, the magnitude of estimated loads were unreasonably high, but the overall deviation between the measured and simulated values of fluid temperature decreased. Therefore, the high magnitude of missing load compensates for the lack of agreement between the model and the measured data

Environmental Performance Measures to Assess Building Refurbishment from a Life Cycle Perspective

Energy efficiency investments in existing buildings are an effective way of reducing the environmental impact of the building stock. Even though policies in the European Union and elsewhere promote a unilateral focus on operational energy reduction, scientific studies highlight the importance of applying a life cycle perspective to energy refurbishment. However, life cycle assessment is often perceived as being complicated and the results difficult to interpret by the construction sector. There is also a lack of guidelines regarding the sustainable ratio between the embodied and accumulated operational impact. The scope of this study is to introduce a life cycle assessment method for building refurbishment that utilizes familiar economic performance tools, namely return on investment and annual yield. The aim is to use the introduced method to analyze a case building with a sustainability profile. The building was refurbished in order to reduce its operational energy use. The introduced method is compatible with a theory of minimum sustainable environmental performance that may be developed through backcasting from defined energy and GHG emissions objectives. The proposed approach will hopefully allow development of sustainable refurbishment objectives that can support the choice of refurbishment investments

Building performance based on measured data

With increasing liability for builders, the need for evaluation methods that focuses on the building’s performance and thus excludes the impact from residents’ behavior increases. This is not only of interest for new buildings but also when retrofitting existing buildings in order to reduce energy end-use. The investigation in this paper is based on extensive measurements on two fairly representative type of buildings, a single family building in Ekerö, Stockholm built 2000 and two apartment buildings in Umeå (1964) in order to extract key energy performance parameters such as the building’s heat loss coefficient, heat transfer via the ground and heat gained from the sun and used electricity. With access to pre-processed daily data from a 2-month periods, located close to the winter solstice, a robust estimate of the heat loss coefficient was obtained based on a regression analysis. For the single family building the variation was within 1% and for the two heavier apartment buildings an average variation of 2%, with a maximum of 4%, between different analyzed periods close to the winter solstice. The gained heating from the used electricity in terms of a gain factor could not be unambiguously extracted and therefore could only a range for the heat transfer via ground be estimated. The estimated range for the transfer via ground for the two apartment buildings were in very good agreement with those calculated according to EN ISO 13 370 and corresponded to almost 10% of the heating demand at the design temperature. For the single family building with an insulated slab and parts of the walls below ground level, the calculations gave slightly higher transfer than what was obtained from the regression analysis. For the estimated gained solar radiation no comparison has been possible to make, but the estimated gain exhibited an expected correlation with the global solar radiation data that was available for the two apartment buildings