Quantifying minimum monolith size and solute dilution from multi-compartment percolation sampler data

Preferential flow affects solute transport in natural soils, leading to high spatiotemporal variation of concentration. A multicompartment solute sampler (MCS), yielding multiple breakthrough curves at a given depth, can monitor tracer movement in a heterogeneous soil. We present a technique to estimate from MCS data whether a soil monolith is sufficiently large to capture preferential flow, which is a necessity for tracer breakthrough curves to be representative. For several soils, we estimate that an MCS should be larger than 0.1 to 0.2 m². We also expand dilution theory to analyze the concentration variations of a tracer passing the control plane monitored by the MCS, in addition to the conventional plume spreading analysis. We characterize the set of locally observed breakthrough curves by the entropy-based dilution index. For given first and second-central moment, the spatially uniform log-normal breakthrough curve maximizes the dilution index. The ratio between observed and maximum dilution index is denoted reactor ratio. For a 300-compartment solute sampler, covering an area of 0.75 m², we compute a reactor ratio of 0.665, compared with 0.04 for stochastic-convective and 1 for convective-dispersive transport. With a single, large collector the reactor ratio would be 0.958, severely underestimating concentration variations. Large collector areas are clearly inadequate to estimate dilution. Values of the dilution index and the reactor ratio for individual sampling compartments indicate efficient longitudinal mixing in most but not all cases, and considerable spatial variation of the leaching process.

Quantifying the relationship between mechanical loading and the skeletal response in pre- and early-pubertal girls

PURPOSE
Before exercise prescription for bone health can be recommended, the relationship between mechanical loading characteristics and the skeletal response need to be quantified. We asked i) does moderate impact exercise result in a greater gain in BMC than low impact exercise, ii) what are the loading characteristics associated with a moderate and low impact exercise program and does this differ from non-structured play?, and iii) does loading history affect the osteogenic response to a moderate or low impact program?

METHODS
Sixty-eight pre- and early-pubertal girls (aged 8.9 +/- 0.2 yrs) were randomized to take part in a moderate or low impact exercise program 3 times/wk for 8.5 mnths. The number and type of loads associated with the exercise classes and non-structured play (recess) were assessed from video footage. The magnitude of load was assessed using a pedar in-sole mobile system. Hours of moderate and high impact organized sport were assessed from a physical activity questionnaire.

RESULTS
The moderate and low impact exercise programs consisted of -400 impacts per class, but the jumping, hopping and dynamic activities performed during the moderate impact program produced forces ranging from 2 to 4 times body weight (BW) compared to -1 BW for the low impact program. Moderate impact exercise resulted in a 2.7% greater gain in BMC at the tibia compared to the low impact exercise. The moderate impact exercise program consisted of fewer low impacts (1-2 BW) and a higher number of moderate impacts (2-4BW) compared to those typically performed during non-structured play. There were greater gains in BMC in subjects participating in the moderate versus the low impact exercise programs who participated in 2 to 3 hours of moderate impact sports outside school (2.5% to 4.5%, p

CONCLUSION
Approximately 400 impacts ranging 2-4 BW, 3 times/wk was enough stimuli to result in an osteogenic response in normally active girls; even in those actively involved in moderate impact sports outside school.

Quantifying the impact of transient joint symptoms, chronic joint symptoms, and arthritis : a population-based approach

Objective : To estimate the prevalence and co-occurrence of self-reported doctor-diagnosed arthritis, chronic joint symptoms (pain, aching, stiffness, or swelling on most days for a month), and transient joint symptoms (pain, aching, stiffness, or swelling but not on most days for a month), and to compare the sociodemographic characteristics, activity limitations, and health-related quality of life (HRQOL) of people with joint conditions with those who have no self-reported doctor-diagnosed arthritis and no joint symptoms.
Methods : Data from the 2004 population-based South Australian Health Omnibus Survey (n = 2,840, ages 18-96 years) were used in the study. Activity limitations were assessed using 10 activity limitations questions from the Short Form 36 health survey. HRQOL was assessed using the Assessment of Quality of Life scale.
Results : Half of all respondents reported having joint problems, with 26%, 11%, and 13% reporting self-reported doctor-diagnosed arthritis, chronic joint symptoms, and transient joint symptoms, respectively. Chronic joint conditions (self-reported doctor-diagnosed arthritis and chronic joint symptoms) accounted for 74% of all joint problems and were associated with higher odds of activity limitations and poorer HRQOL. The frequency of transient and chronic joint symptoms was highest among middle-aged participants (ages 45-54 years for transient and 45-64 years for chronic joint symptoms) and those who had a body mass index in the obese range. Prevalence of self-reported doctor-diagnosed arthritis increased with age and was higher among women and those who were overweight or obese.
Conclusion : This study documented the high prevalence and impact of joint conditions in the community. Chronic joint conditions affect daily life and are substantial barriers for effective public health interventions aimed at reducing obesity and inactivity.

MUSTe method for quantifying virtual environment training system efficacy

In the current era increased attention and interest of utilizing advanced computer technologies for training and education at all managerial levels and functional areas is apparent. One of such technologies, virtual environment (VE), is perceived to be effective in enhancing human abilities to learn abstract concept and complex procedural tasks. Despite its adaptation for training and fast-paced technological advancements, ways in which to evaluate efficacy of such technology are unclear. We have approached this problem by developed a new evaluation method focus on cognitive, affective and skillbased learning dimensions, based on traditional usability evaluation methods but tailored to specifically suit for the quantification of 3D VE system. We first describe the construct of the new method and then report a study utilizing the method in the context of quantifying a VE efficacy in an object assembly task. At last, we discuss the implications of such a method.

Quantifying rubber degradation using NMR

Ageing can lead to the degradation of the tensile properties of natural rubber. The ageing process causes changes in the polymer segmental motion as well as the chemical structure, both of which can be monitored using nuclear magnetic resonance (NMR) spectroscopy. This work demonstrates that NMR can quantify rubber degradation due to ageing, and also that relatively simple NMR equipment can be used. This simpler equipment can be made portable and so could give a simple and fast indication of the condition of rubber in service. The 1H NMR transverse relaxation time, T2, and the 13C NMR spectrum using cross polarization and magic angle spinning (CP MAS) for samples taken at various levels of a degraded natural rubber liner were compared. These experiments showed that, as the level of degradation increased, the 1H NMR transverse relaxation time decreased. The 13C spectra showed considerable peak broadening, indicative of decreased mobility with increased level of degradation as well as the presence of degradation products. Further investigations using lower powered NMR equipment to measure the 1H NMR transverse relaxation times of two different series of natural rubbers were also performed. This work has shown that this simpler method is also sensitive to structural and mechanical property changes in the rubber. This method of monitoring rubber degradation could lead to the non-destructive use of NMR to determine the condition of a part in service.

Quantifying urbanisation as a risk factor for non-communicable disease

Aim of this study was to investigate the poorly understood relationship between the process of urbanization and non-communicable diseases (NCDs) in Sri Lanka using a multi-component, quantitative measure of urbanicity.

NCD prevalence data were taken from the Sri Lankan Diabetes and Cardiovascular Study comprising a representative sample of people from seven of the nine provinces in Sri Lanka (n=4,485/5,000; response rate=89.7%). We constructed a measure of the urban environment for seven areas using a seven-item scale based on data from study clusters to develop an ―urbanicity” scale. The items were population size, population density, and access to markets, transportation, communications/media, economic factors, environment/sanitation, health, education, and housing quality. Linear and logistic regression models were constructed to examine the relationship between urbanicity and chronic disease risk factors.

Among men, urbanicity was positively associated with physical inactivity (OR: 3.22; 2.27 – 4.57), high body mass index (OR: 2.45; 95% CI: 1.88 – 3.20) and diabetes mellitus (OR: 2.44; 95% CI: 1.66 – 3.57). Among women, too, urbanicity was positively associated with physical inactivity (OR: 2.29; 95% CI: 1.64 – 3.21), high body mass index (OR: 2.92;95% CI: 2.41 – 3.55) and diabetes mellitus (OR: 2.10; 95% CI: 1.58 – 2.80).

There is a clear relationship between urbanicity and common modifiable risk factors for chronic disease in a representative sample of Sri Lankan adults.

Examining and quantifying the drivers behind alterations and extensions to commercial buildings in a central business district

The drive to undertake building adaptation has increased in momentum, the primary reason being adaptation can be less expensive than new build and conventionally result in faster project delivery times. The issue of sustainable development is another clear driver for adaptation and collectively buildings contribute around half of all greenhouse gas emissions. At the same time governments seek effective and efficient ways of reducing the contribution of cities to climate change and building adaptation appears to offer a practical means of reducing building-related emissions. One example is the ‘1200 building program’ which aims to increase adaptation rates with a target of 1200 city centre office adaptations by 2020 as part of the strategy to achieve carbon neutrality. Through a longitudinal examination of building adaptations it is possible to identify the nature and extent of typical levels of adaptation, as well as determining the inter-relationship between different types of adaptation and building attributes. Melbourne city centre was used for a case study which analysed 5290 building adaptation events between 1998 and 2008. The findings promote the adaptive reuse of buildings in specific circumstances and are directly applicable for increasing sustainability in the built environment. The case study focused on existing buildings in a global city to ensure relevance to urban centres where existing commercial buildings can become part of the solution to mitigate climate change.

Quantifying the potential impacts of increasing agricultural fragmentation on land value

Societal expectations from rural lands have traditionally focused on the production of food and fibre. Yet the perception of rural areas is changing and they are now seen in many instances to be capable of delivering multiple functions or non‐commodity outputs including land conservation and the preservation of biodiversity, contributing to the sustainable management of renewable natural resources and enhancing the socio‐economic viability of many areas . The overall multi‐functionality is constrained or favoured by biophysical and socio‐economic drivers. As these types of drivers vary spatially and temporally, so does the functionality of the landscape and heterogeneous patterns emerge. Associated with multiple functions at a single location are a variety of pressures which can manifest themselves as conflict between interacting land uses. One such conflict in rural zones is that between agricultural use and residential use. Warrnambool City Council (WCC) is a Local Government Area (LGA) in southwest Victoria where the debate surrounding the best use of rural land is currently being debated. In a region where agriculture has historically been the mainstay of the economy there is some resistance to unplanned conversion to residential use. Despite concerns and much strategy being discussed it appears an investigation quantifying the impacts of these conversions is yet to be done. This paper addresses the issue of the allocation of land by using GIS mapping to incorporate economic, social and environmental attributes, and applying a theoretical economic framework for the optimal allocation of land to the comprehensive data set. Marginal values of land for competing purposes are estimated and discussed. The method is relevant for other regions where the rural/residential interface and associated planning decisions are highly topical.

A panel regression method for quantifying the convergence of house prices

The convergence among house prices has attracted much attention from researchers. Previous research mainly utilised a time-series regression method to investigate convergences of house prices, which may ignore the heterogeneity of houses across cities. This research developed a panel regression method, by which the heterogeneity of house prices can be captured. Seemingly unrelated regression estimators were also adapted to deal with the contemporary correlations across cities. Investigation of the convergence among house prices in the Australian capital cities was carried out by using the developed panel regression method. Results suggested that house prices converge in Sydney, Adelaide and Hobart but diverge in Darwin.