Prefabricated modular housing: research vs practice

 Abstract: Prefabricated and modular solutions have formed a small part of the overall housing industry. This is particularly evident in Australia, where the market is dominated by hand-built housing using traditional construction techniques built by large-scale builders. This paper evaluates the ideal and the reality of prefabricated modular housing procurement in China for the Australian market. While there have been prefabricated components for the housing industry, primarily, most solutions are of volumetric nature. The findings question our understanding and methodology to prefabrication for Australia. The experiences of introducing building services into modules (pods) from overseas fabrication also have shortcomings. The case study presented indicates several of these problems and suggests a hybrid solution to volumetric delivery.

Frequency-domain beamformers using conjugate gradient techniques for speech enhancement

A multiple-iteration constrained conjugate gradient (MICCG) algorithm and a single-iteration constrained conjugate gradient (SICCG) algorithm are proposed to realize the widely used frequency-domain minimum-variance-distortionless-response (MVDR) beamformers and the resulting algorithms are applied to speech enhancement. The algorithms are derived based on the Lagrange method and the conjugate gradient techniques. The implementations of the algorithms avoid any form of explicit or implicit autocorrelation matrix inversion. Theoretical analysis establishes formal convergence of the algorithms. Specifically, the MICCG algorithm is developed based on a block adaptation approach and it generates a finite sequence of estimates that converge to the MVDR solution. For limited data records, the estimates of the MICCG algorithm are better than the conventional estimators and equivalent to the auxiliary vector algorithms. The SICCG algorithm is developed based on a continuous adaptation approach with a sample-by-sample updating procedure and the estimates asymptotically converge to the MVDR solution. An illustrative example using synthetic data from a uniform linear array is studied and an evaluation on real data recorded by an acoustic vector sensor array is demonstrated. Performance of the MICCG algorithm and the SICCG algorithm are compared with the state-of-the-art approaches.

The effect of surgical timing on the outcome of patients with neck of femur fracture

Aims: To investigate the effect of surgical timing (in hours versus after hours and weekdays versus weekends) on the outcome of patients with neck of femur fracture. Methods: Patients who were admitted to a single tertiary referral hospital for surgical management of femoral neck fractures over a continuous period from 1/11/2002 to 12/7/2012 were identified from medical records and the operating theatre database. Results: A consecutive series of 2334 patients were included in the study. Of the patients who underwent surgery during the weekday and during usual hours, 18 % (207/1135) experienced an adverse event, compared to 16 % (193/1199) outside of these times. The difference between the two groups was not significant (p = 0.17). The same conclusion was made for the comparison between those who had surgery during the week with those who had surgery on the weekend (17 %, 267/1546 and 17 %, 133/788, respectively, p > 0.05). The proportion of patients who underwent surgery during hours that experienced an adverse event was significantly higher than those undergoing surgery out of hours (18 %, 327/1789 and 13 %, 73/545, respectively, p = 0.0081). When adjusted for age, ASA score and pre-operative stay, there was no statistical difference between those different sub-groups. Conclusions: There was no difference in the rates of adverse events between patients who had surgery during hours and weekdays with those who had surgery after hours or weekends. The careful selection of patients with appropriate hospital staff, resources and adequate theatre access, surgery during after hours and weekends may be safely considered to prevent a delay in surgical treatment for patient with neck of femur fracture.

Monitoring and evaluating surgical care: defining perioperative mortality rate and standardising data collection

BACKGROUND: Case volume per 100 000 population and perioperative mortality rate (POMR) are key indicators to monitor and strengthen surgical services. However, comparisons of POMR have been restricted by absence of standardised approaches to when it is measured, the ideal denominator, need for risk adjustment, and whether data are available. We aimed to address these issues and recommend a minimum dataset by analysing four large mixed surgical datasets, two from well-resourced settings with sophisticated electronic patient information systems and two from resource-limited settings where clinicians maintain locally developed databases. METHODS: We obtained data from the New Zealand (NZ) National Minimum Dataset, the Geelong Hospital patient management system in Australia, and purpose-built surgical databases in Pietermaritzburg, South Africa (PMZ) and Port Moresby, Papua New Guinea (PNG). Information was sought on inclusion and exclusion criteria, coding criteria, and completeness of patient identifiers, admission, procedure, discharge and death dates, operation details, urgency of admission, and American Society of Anesthesiologists (ASA) score. Date-related errors were defined as missing dates and impossible discrepancies. For every site, we then calculated the POMR, the effect of admission episodes or procedures as denominator, and the difference between in-hospital POMR and 30-day POMR. To determine the need for risk adjustment, we used univariate and multivariate logistic regression to assess the effect on relative POMR for each site of age, admission urgency, ASA score, and procedure type. FINDINGS: 1 365 773 patient admissions involving 1 514 242 procedures were included, among which 8655 deaths were recorded within 30 days. Database inclusion and exclusion criteria differed substantially. NZ and Geelong records had less than 0·1% date-related errors and greater than 99·9% completeness. PMZ databases had 99·9% or greater completeness of all data except date-related items (94·0%). PNG had 99·9% or greater completeness for date of birth or age and admission date and operative procedure, but 80-83% completeness of patient identifiers and date related items. Coding of procedures was not standardised, and only NZ recorded ASA status and complete post-discharge mortality. In-hospital POMR range was 0·38% in NZ to 3·44% in PMZ, and in NZ it underestimated 30-day POMR by roughly a third. The difference in POMR by procedures instead of admission episodes as denominator ranged from 10% to 70%. Age older than 65 years and emergency admission had large independent effects on POMR, but relatively little effect in multivariate analysis on the relative odds of in-hospital death at each site. INTERPRETATION: Hospitals can collect and provide data for case volume and POMR without sophisticated electronic information systems. POMR should initially be defined by in-hospital mortality because post-discharge deaths are not usually recorded, and with procedures as denominator because details allowing linkage of several operations within one patient's admission are not always present. Although age and admission urgency are independently associated with POMR, and ASA and case mix were not included, risk adjustment might not be essential because the relative odds between sites persisted. Standardisation of inclusion criteria and definitions is needed, as is attention to accuracy and completeness of dates of procedures, discharge and death. A one-page, paper-based form, or alternatively a simple electronic data collection form, containing a minimum dataset commenced in the operating theatre could facilitate this process. FUNDING: None.

Quantitation of ascorbic acid in Arabidopsis thaliana reveals distinct differences between organs and growth phases

Optimal plant growth is the result of the interaction of a complex network of plant hormones and environmental signals. Ascorbic acid (AsA) is a crucial antioxidant in plants and is involved in the regulation of cell division, cell expansion, photosynthesis and hormone biosynthesis. Quantitative analysis of AsA in Arabidopsis thaliana organs was conducted using HPLC with d -isoascorbic acid (Iso-AsA) as an internal standard. Analysis revealed Àuctuations in the levels of AsA in different organs and growth phases when plants were grown under standard conditions. AsA concentrations increased in leaves in direct proportion to leaf size and age. Young siliques (seed set stage) and Àowering buds (open and unopened) showed the highest levels of AsA. A relationship was found between the level of AsA and indole acetic acid (IAA) in leaves, stems, Àowers, and siliques and the highest level of IAA and AsAwere found in the Àowers. In contrast, the lowest level of the plant hormone, salicylic acid, was found in the Àowers and the highest quantity measured in the leaves. Consequently, AsA has been found to be a multifunctional molecule that is involved as a key regulator of plant growth and development.