604 research outputs found
On the Stability of the Implicit Prices of Housing Attributes: A Dynamic Theory and Some Evidence
Given the dramatic fluctuations in aggregate housing prices, this paper attempts to examine whether the implicit prices of different housing attributes are “stable.” Theoretically, this paper provides perhaps the first dynamic, general equilibrium model in which housing attributes’ implicit prices fluctuate. Empirically, this paper models the time paths of different implicit prices as auto-regressive processes by employing a hedonic pricing model on a large set of housing transaction data over a relatively long period of time. An endogenous structural break test is then performed. Except for a few attributes, structural breaks are not detected. Directions for future research are discussed.hedonic pricing; structural break; evolution of valuation; housing attributes
Toughening of epoxy carbon fibre composites using dissolvable phenoxy fibres.
PhDThe aim of this study is to investigate a novel toughening approach for liquid mouldable carbon fibre/epoxy composites. The toughening mechanism is based on the use of thermoplastics for the toughening of epoxy resins in which polymer blends are formed, leading to phase separated morphologies which allows for various toughening mechanisms to take place. Instead of standard melt or solution blending, the thermoplastic in this study is introduced as solid phenoxy fibres, which are combined with dry carbon fabric preforms. These phenoxy fibres remain solid during resin infusion and dissolve when the laminates are heated and phase separation takes place before curing completed. The main benefits of this approach are that the viscosity of matrix resin remains low, which makes liquid moulding of these laminates possible. Localised and selective toughening of particular regions within a structure can also be achieved. Process time and cost can also be reduced by eliminating the polymer blending process.
It was found that modification with phenoxy improved composite Mode-I interlaminar toughness significantly, with an increase of up to 10-folds for bifunctional epoxy composite and 100% for tetrafunctional epoxy composite, while tensile properties were not adversely affected. It was found that it is possible to combine the dissolvable phenoxy fibres with an undissolved aramid interleaf to improve toughness and damage properties. However, the phenoxy-epoxy systems had lowered environmental stability and degraded after hot-wet and solvent conditioning.School of Engineering and Materials Science, Queen Mary University of Londo
The impact of topical mupirocin on peritoneal dialysis infection rates in Singapore general hospital.
Background.
Peritonitis and exit-site infections (ESI) are major causes of technique failure and morbidity in peritoneal dialysis (PD) patients. Topical mupirocin on the exit-site has been shown to reduce such complications and prolong life in PD. Since the year 2000, such an approach has been adopted for our new incident PD population. We now report the results of this new protocol. We also studied the effect of co-morbidity on peritonitis occurrence.
Methods.
A total of 740 incident PD patients were studied. Patients were divided into two groups based on year of entry into PD (Group 1 from January 1998–December 1999 without topical mupirocin and Group 2 from January 2000–March 2004 with topical mupirocin). Variables studied included gender, age, diabetic status, ischaemic heart disease, peripheral vascular disease, cerebrovascular disease and serum albumin.
Results.
Topical mupirocin at the exit-site has led to a significant reduction in peritonitis rate (0.443 vs 0.339 episodes/patient-year; P<0.0005) and ESI (0.168 vs 0.156 episodes/patient-year; P<0.005) attributed primarily to the significant reduction in Staphylococcus aureus infections. There was an unexpected finding of lower Pseudomonas aeruginosa peritonitis in the mupirocin group (P<0.005). Stepwise multiple logistic regression analysis revealed that only mupirocin application and serum albumin were significant predictors of peritonitis.
Conclusions.
Our study, although limited by its retrospective nature, demonstrated that topical mupirocin was associated with a significant reduction in ESI and peritonitis with unexpected findings of lower Pseudomonas peritonitis. Serum albumin prior to the initiation of PD was a strong predictor of subsequent peritonitis. Mupirocin, with its low toxicity, ease of application and demonstrable beneficial effect in reducing ESI and peritonitis is now used on all incident PD patients
Applying Qualitative Approach in Business Research
Researchers and students in the business field are increasingly turning to qualitative methods to seek answers for complex research questions. Current literature presents a copious number of published qualitative research compared to previous decades, in which qualitative methods serve mainly as an exploratory inquiry toward more comprehensive quantitative studies. Although qualitative research is now widely adopted in both academia and practice, a dearth of germane literature that argues and discusses key challenges in applying qualitative methods continues to compound the scepticism and ambiguity of the research process. Moreover, details on the analysis process gleaned from research articles are often limited and thus offer little to learn from. Qualitative analysis thus resembles a black box, an analogy of intricacy and complexity. In this editorial, we discuss how to define the scope and goals of a qualitative study, examine current literature, and provide practical guidance for researchers in business to apply qualitative approach and methods. We also detail several steps for qualitative analysis and introduce Computer Assisted Qualitative Data Analysis (CAQDAS) software for this purpose. Finally, we draw from other disciplines to guide and encourage researchers to adopt qualitative research as part of their inquiry endeavour
- …