Sustainability: meaning and measurement with application to agriculture

Sustainability refers to having the ability to meet present needs without impacting on future generations to meet their needs. It incorporates social, economic and environmental aspects, and as a measure of sustainability, a range of sustainability indicators at the economy, regional, and individual level, have been suggested. However, given the complex and multidisciplinary nature of the concept, an interdisciplinary approach is necessary. Sustainability is not something that is easily measurable, and the aim of this paper is to present a conceptual framework for quantifying sustainability on the basis of social economic efficiency. According to neoclassical economic theory, economic activity will only be sustained by the private sector as long as it is profitable. However, private economic decisions do not always ensure long-term sustainability of environmental resources or production. The approach suggested here is to derive a measure of social economic efficiency as a measure of sustainability. For dairy farmers, increased productivity has been emphasized, while recognizing the need to reduce greenhouse emissions, pests and disease, nutrient run-off into the environment and degradation of the soil structure. By incorporating environmental and economic impacts, a fuller measure of efficiency, social economic efficiency, and sustainability of the farming practice can be developed.

DNA repair deficiencies increase the resistance of Arabidopsis Thaliana to Hyaloperonospora Parasitica

We have found that UV-C treatment of Arabidopsis thaliana induces resistance to the biotrophic pathogen Hyaloperonospora parasitica, and our data suggest UV induced DNA photoproducts are involved (see accompanying abstract by K.G. McKenzie et al.). To address the potential role of DNA damage, we have examined the effect of mutations in nucleotide excision repair (uvr1-1), photoreactivation of cyclobutane pyrimidine dimers (uvr2-1) or flavonoid production (tt5) on the resistance of Arabidopsis to the pathogen with or without pre-inoculation treatment with UV-C. In the mutant backgrounds, UV-C induced pathogen resistance (as measured by decreased conidiophore formation) to the same degree as in the wildtype plants, but much lower UV doses were required (e.g., 100 Jm-2 in the mutant vs. 400 Jm-2 in the wildtype). This is the result expected if damage to DNA rather than a non DNA target is involved. Interestingly, in the absence of UV-C, the tt5 mutation alone resulted in a slight increase in resistance. However, when coupled with uvr1-1, resistance was enhanced to an even greater extent. Remarkably, the tt5 uvr1-1 uvr2-1 triple mutant was completely resistant to the pathogen. Since tt5 mutants are sensitive to reactive oxygen species, which can cause DNA damage susceptible to nucleotide excision repair, our results suggest that in addition to UV photoproducts, an accumulation of endogenous oxidative DNA damage may also trigger resistance to the pathogen. We are currently examining pathogen resistance in other DNA repair deficient mutants, and quantifying UV-C-induced DNA damage in Arabidopsis in order to assess the relationship between damage levels and the extent of resistance.

Activated calcineurin ameliorates contraction-induced injury to skeletal muscles of mdx dystrophic mice

Utrophin expression is regulated by calcineurin and up-regulating utrophin can decrease the susceptibility of dystrophic skeletal muscle to contraction-induced injury. We overexpressed the constitutively active calcineurin-A α in skeletal muscle of mdx dystrophic mice (mdx CnA*) and examined the tibialis anterior muscle to determine whether the presence of activated calcineurin promotes resistance to muscle damage after lengthening contractions. Two stretches (10 s apart) of 40% strain relative to muscle fibre length were initiated from the plateau of a maximal isometric tetanic contraction. Muscle damage was assessed 1, 5 and 15 min later by the deficit in maximum isometric force and by quantifying the proportion of muscle fibres staining positive for intracytoplasmic albumin. The force deficit at all time points after the lengthening contractions was approximately 80% in mdx muscles and 30% in mdxCnA* muscles. The proportion of albumin-positive fibres was significantly less in control and injured muscles from mdxCnA* mice than from mdx mice. Compared with mdx mice, mean fibre cross-sectional area was 50% less in muscles from mdxCnA* mice. Furthermore, muscles frommdxCnA* mice exhibited a higher proportion of fibres expressing the slow(er) myosin heavy chain (MyHC) I and IIa isoforms, prolonged contraction and relaxation times, lower absolute and normalized maximum forces, and a clear leftward shift of the frequency–force relationship with greater force production at lower stimulation frequencies. These are structural and functional markers of a slower muscle phenotype. Taken together, our findings show that muscles from mdxCnA* mice have a smaller mean fibre cross-sectional area, a greater sarcolemmal to cytoplasmic volume ratio, and an increase in utrophin expression, promoting an attenuated susceptibility to contraction-induced injury. We conclude that increased calcineurin activity may confer functional benefits to dystrophic skeletal muscles.

Color signals in the Black Grouse (Tetrao tetrix) : signal properties and their condition dependency

Recent progress in techniques of quantifying between‐individual differences of color‐based ornaments has revealed undiscovered possibilities for research in sexual selection. We present how the color spectra data can be comprehensively used for studying the importance of sexual ornaments in the black grouse and how these ornaments are related to a male condition. For this, we used both correlative field and experimental data. Field data indicated that older males had more chromatic coloration than yearlings. Blue chroma of males was correlated with male mating success. We experimentally manipulated yearling birds with testosterone implants and found that testosterone‐implanted males had impaired expression of several sexual ornaments: 10 months after the implantation, both structural‐based blue and carotenoid‐based red eye comb coloration were diminished, as well as lyre (tail) length. However, the manipulation did not affect vital traits under natural selection (wing length or body mass). Our data indicate that structural color is an important trait in sexual selection in this lekking species. Importantly, the data also indicate that male sexual ornaments are more susceptible to environmental conditions than the other male traits, thus showing their heightened condition dependency compared with the other traits mediating the honesty of signaling.

Windfarms, powerlines and phone masts : the changing face of stigma

Previous research has identified varying degrees of stigma attached to high voltage overhead transmission lines (HVOTLs) depending upon characteristics such as visibility, size, location and the potential impact on house value. In addition to HVOTLs there are other common types of infrastructure, namely mobile phone towers and windfarms, that are also large highly visible
structures and can exhibit similar characteristics. These similarities include varying levels of visibility from properties in the immediate vicinity, a high general profile in society and varying perceptions from surrounding residents about possible side effects. This research broadens the framework originally developed to study HVOTLs to encompass mobile phone towers and windfarms. It undertakes a literature review of research in this area and proposes a research methodology for identifying and quantifying the varying levels of stigma attached to these three forms of infrastructure. The final results will enable the resulting effect on property values to be better understood, and assist developers to fully understand their effect on devaluing land prices.

Energy analysis of the construction of office buildings /by Graham J. Treloar

Buildings have a significant impact on the environment due to the energy required for the manufacture of construction materials. The method of assessing the energy embodied in a product is known as energy analysis. Detailed office building embodied energy case studies are very rare. However, there is evidence to suggest that the energy requirements for the construction phase of commercial buildings, including the energy embodied in materials, is a significant component of the life cycle energy requirements. This thesis sets out to examine the current state of energy analysis, determine the national average energy intensities < i.e. embodied energy rates < for building materials and assess the significance of using national average energy intensities for the energy analysis of a case study office building. Likely ranges of variation in the building material embodied energy rates from the national averages are estimated and the resulting distribution for total embodied energy in the case study building simulated. Strategies for improving the energy analysis methods and data are suggested. Detailed energy analysis is shown to be a useful indicative method of quantifying the energy required for the construction of buildings.

The trophic effect of dietary fibre is not associated with a change in total crypt number in the distal colon of rats

Soluble fibres, such as guar gum, promote and wheat bran or methylcellulose protect from chemically induced colon carcinogenesis, relative to the effect of a fibre-free diet in rats. Mechanisms are poorly understood. Whereas all fibres are trophic to the colonic epithelium, the heterogeneity of effects on carcinogenesis may reflect different effects on the total number of crypts and, therefore, the size of the stem cell population. This study aimed to assess this hypothesis. Sprague–Dawley rats were fed one of fibre-free diets with or without 10% wheat bran, methylcellulose or guar gum for 4 weeks. The distal colons were stained with methylene blue and quantified for the number and density of crypts using an image analysis system. Epithelial proliferative kinetics was measured stathmokinetically. Methodology for quantifying crypts was valid and reproducible. Rats fed a fibre-free diet had atrophic distal colon, as shown by a decrease in crypt column height and a lower mitotic index. Fibre supplementation prevented the atrophy and was associated with crypt mouth areas that were 30–60% larger than those in the fibre-free group (P < 0.001, ANOVA), with the methylcellulose group being the largest (1.16 µm2). The crypt density of the fibre-free group was 16–19% greater than those in fibre fed groups (P + 0.006), due to the smaller size of the crypts. However, there was no difference in the total number of crypts across the four dietary groups (P > 0.1). Distal colons in all of the dietary groups contained ~105 crypts. In conclusion, although variation in the amount or type of dietary fibre exerts heterogeneous effects on the growth of the colonic epithelium and on colon carcinogenesis, the total number of crypts in the distal colon remains constant. It is, therefore, unlikely that fibres influence carcinogenic events by altering the size of the stem cell population.

User-centered evaluation of a virtual environment training system : utility of user perception measures

This study assessed the utility of measures of Self-efficacy (SelfEfficacy) and Perceived VE efficacy (PVEefficacy) for quantifying how effective VEs are in procedural task training. SelfEfficacy and PVEefficacy have been identified as affective construct potentially underlying VE efficacy that is not evident from user task performance. The motivation for this study is to establish subjective measures of VE efficacy and investigate the relationship between PVEefficacy, SelfEfficacy and User task performance. Results demonstrated different levels of prior experience in manipulating 3D objects in gaming or computer environment (LOE3D) effects on task performance and user perception of VE efficacy. Regression analysis revealed LOE3D, SelfEfficacy,
PVEefficacy explain significant portions of the variance in VE efficacy. Results of the study provide further evidence that task performance may share relationships with PVEefficacy and SelfEfficacy, and that affective constructs, such as PVEefficacy, and SelfEfficacy may serve as alternative, subjective measures of task performance that account for VE efficacy.

Systematic evaluation of a virtual environment-based training systems

This paper explores the application of three constructs that deemed to be essential to quantify virtual environments (VE) efficacy: cognitive, skill-based, and affective learning outcomes. The authors discuss the implementation of these constructs in a user-centered evaluation of a VE training system. By transforming both the conceptual and operational cohorts for training evaluation the authors illustrate the benefits of the development of a Multi-dimensional User-centered Systematic Training Evaluation (MUSTe) method for quantifying VEs efficacy. Importantly, MUSTe acknowledges the importance of combining holistic and analytical approaches in conducting systematic user-based evaluation. Furthermore, it also emphasizes that quantifying VEs efficacy must reflect the perception and preferences of the users rather than the imposition of efficacy on single measures of task outcome. An empirical study that applied MUSTe evaluation method in quantifying a VE training system efficacy provided valuable evidence of the theoretical construct and content validity of the method.

On the concept of ionicity in ionic liquids

Ionic liquids are liquids comprised totally of ions. However, not all of the ions present appear to be available to participate in conduction processes, to a degree that is dependent on the nature of the ionic liquid and its structure. There is much interest in quantifying and understanding this ‘degree of ionicity’ phenomenon. In this paper we present transport data for a range of ionic liquids and evaluate the data firstly in terms of the Walden plot as an approximate and readily accessible approach to estimating ionicity. An adjusted Walden plot that makes explicit allowance for differences in ion sizes is shown to be an improvement to this approach for the series of ionic liquids described. In some cases, where diffusion measurements are possible, it is feasible to directly quantify ionicity via the Nernst–Einstein equation, confirming the validity of the adjusted Walden plot approach. Some of the ionic liquids studied exhibit ionicity values very close to ideal; this is discussed in terms of a model of a highly associated liquid in which the ion correlations have similar impact on both the diffusive and conductive motions. Ionicity, as defined, is thus a useful measure of adherence to the Nernst–Einstein equation, but is not necessarily a measure of ion availability in the chemical sense.

Reliability and variability of day-to-day vault training measures in artistic gymnastics

Inter-day training reliability and variability in artistic gymnastics vaulting was determined using a customised infra-red timing gate and contact mat timing system. Thirteen Australian high performance gymnasts (eight males and five females) aged 11-23 years were assessed during two consecutive days of normal training. Each gymnast completed a number of vault repetitions per daily session. Inter-day variability of vault run-up velocities (at -18 to -12 m, -12 to -6 m, -6 to -2 m, and -2 to 0 m from the nearest edge of the beat board), and board contact, pre-flight, and table contact times were determined using mixed modelling statistics to account for random (within-subject variability) and fixed effects (gender, number of subjects, number of trials). The difference in the mean (Mdiff) and Cohen's effect sizes for reliability assessment and intra-class correlation coefficients, and the coefficient of variation percentage (CV%) were calculated for variability assessment. Approach velocity (-18 to -2 m, CV = 2.4-7.8%) and board contact time (CV = 3.5%) were less variable measures when accounting for day-to-day performance differences, than pre-flight time (CV = 17.7%) and table contact time (CV = 20.5%). While pre-flight and table contact times are relevant training measures, approach velocity and board contact time are more reliable when quantifying vaulting performance.

Evidence for the direct interaction between methylene blue and guanine bases using DNA-modified carbon paste electrodes

It is explored that methylene blue interacts with the guanine bases specifically, rather than the bases of ss-DNA in general. This interaction can be used as a method of quantifying the amount of oligonucleotide that is immobilized onto an electrode surface.

Inexplicable inefficiency of avian molt? Insights from an opportunistically breeding arid-zone species, Lichenostomus penicillatus

The majority of bird species studied to date have molt schedules that are not concurrent with other energy demanding life history stages, an outcome assumed to arise from energetic trade-offs. Empirical studies reveal that molt is one of the most energetically demanding and perplexingly inefficient growth processes measured. Furthermore, small birds, which have the highest mass-specific basal metabolic rates (BMR_m), have the highest costs of molt per gram of feathers produced. However, many small passerines, including white-plumed honeyeaters (WPHE; Lichenostomus penicillatus), breed in response to resource availability at any time of year, and do so without interrupting their annual molt. We examined the energetic cost of molt in WPHE by quantifying weekly changes in minimum resting metabolic rate (RMR_min) during a natural-molt period in 7 wild-caught birds. We also measured the energetic cost of feather replacement in a second group of WPHEs that we forced to replace an additional 25% of their plumage at the start of their natural molt period. Energy expenditure during natural molt revealed an energy conversion efficiency of just 6.9% (±0.57) close to values reported for similar-sized birds from more predictable north-temperate environments. Maximum increases in RMR_min during the molt of WPHE, at 82% (±5.59) above individual pre-molt levels, were some of the highest yet reported. Yet RMR_min maxima during molt were not coincident with the peak period of feather replacement in naturally molting or plucked birds. Given the tight relationship between molt efficiency and mass-specific metabolic rate in all species studied to date, regardless of life-history pattern (Efficiency (%) = 35.720•10^-0.494BMRm; r² = 0.944; p =<0.0001), there appears to be concomitant physiological costs entrained in the molt period that is not directly due to feather replacement. Despite these high total expenditures, the protracted molt period of WPHE significantly reduces these added costs on a daily basis.

New housing supply and residential construction costs in Australia : a panel ECM approach

The supply of new housing in Australia has been experiencing a low increase rate since the 1990s in conjunction with an increasingly strong housing demand. On the contrary, residential construction costs across Australia?s states maintained dramatic increases simultaneously. Economic theory suggests that new housing supply is correlated to the costs of residential constructions. However, few empirical studies have focused on examining this relationship for Australian housing markets. To comprehensively investigate the relationship between the supply of new housing and residential construction costs a function for new housing supply considering the effects of regional heterogeneities is introduced in this study. By estimating a panel error correction model (ECM) applicable for quantifying the correlation with regional heterogeneities, this research identifies that a causal link and a strong correlation exist in between new housing supply and residential construction costs in Australia.

Edge evaluation using necessary components

We classify all the different kinds of errors that can occur in edge detection and then develop measures for quantifying these errors. It is shown that these sets of measures are complete and independent and form necessary components of an edge-evaluation scheme. The principle that an edge-evaluation measure should have certain qualitative properties is used to develop a method for combining these error components into a single combined measure.