Showing papers by "Macquarie University published in 2003"

A handbook of protocols for standardised and easy measurement of plant functional traits worldwide

Abstract: There is growing recognition that classifying terrestrial plant species on the basis of their function (into 'functional types') rather than their higher taxonomic identity, is a promising way forward for tackling important ecological questions at the scale of ecosystems, landscapes or biomes. These questions include those on vegetation responses to and vegetation effects on, environmental changes (e.g. changes in climate, atmospheric chemistry, land use or other disturbances). There is also growing consensus about a shortlist of plant traits that should underlie such functional plant classifications, because they have strong predictive power of important ecosystem responses to environmental change and/or they themselves have strong impacts on ecosystem processes. The most favoured traits are those that are also relatively easy and inexpensive to measure for large numbers of plant species. Large international research efforts, promoted by the IGBP–GCTE Programme, are underway to screen predominant plant species in various ecosystems and biomes worldwide for such traits. This paper provides an international methodological protocol aimed at standardising this research effort, based on consensus among a broad group of scientists in this field. It features a practical handbook with step-by-step recipes, with relatively brief information about the ecological context, for 28 functional traits recognised as critical for tackling large-scale ecological questions.

Does Rejection Hurt? An fMRI Study of Social Exclusion

Abstract: A neuroimaging study examined the neural correlates of social exclusion and tested the hypothesis that the brain bases of social pain are similar to those of physical pain. Participants were scanned while playing a virtual ball-tossing game in which they were ultimately excluded. Paralleling results from physical pain studies, the anterior cingulate cortex (ACC) was more active during exclusion than during inclusion and correlated positively with self-reported distress. Right ventral prefrontal cortex (RVPFC) was active during exclusion and correlated negatively with self-reported distress. ACC changes mediated the RVPFC-distress correlation, suggesting that RVPFC regulates the distress of social exclusion by disrupting ACC activity.

Correlation between Fitness and Genetic Diversity

Abstract: Genetic diversity is one of the three forms of biodiversity recognized by the World Conservation Union (IUCN) as deserving conservation. The need to conserve genetic diversity within populations is based on two arguments: the necessity of genetic diversity for evolution to occur, and the expected relation- ship between heterozygosity and population fitness. Because loss of genetic diversity is related to inbreed- ing, and inbreeding reduces reproductive fitness, a correlation is expected between heterozygosity and pop- ulation fitness. Long-term effective population size, which determines rates of inbreeding, should also be correlated with fitness. However, other theoretical considerations and empirical observations suggest that the correlation between fitness and heterozygosity may be weak or nonexistent. We used all the data sets we could locate (34) to perform a meta-analysis and resolve the issue. Data sets were included in the study, provided that fitness, or a component of fitness, was measured for three or more populations along with heterozygosity, heritability, and/or population size. The mean weighted correlation between measures of genetic diversity, at the population level, and population fitness was 0.4323. The correlation was highly sig- nificant and explained 19% of the variation in fitness. Our study strengthens concerns that the loss of het- erozygosity has a deleterious effect on population fitness and supports the IUCN designation of genetic di- versity as worthy of conservation.

The evolution of plant functional variation: traits, spectra, and strategies

Abstract: Variation in plant functional traits results from evolutionary and environmental drivers that operate at a variety of different scales, which makes it a challenge to differentiate among them. In this article we describe patterns of functional trait variation and trait correlations within and among habitats in relation to several environmental and trade‐off axes. We then ask whether such patterns reflect natural selection and can be considered plant strategies. In so doing we highlight evidence that demonstrates that (1) patterns of trait variation across resource and environmental gradients (light, water, nutrients, and temperature) probably reflect adaptation, (2) plant trait variation typically involves multiple‐correlated traits that arise because of inevitable trade‐offs among traits and across levels of whole‐plant integration and that must be understood from a whole‐plant perspective, and (3) such adaptation may be globally generalizable for like conditions; i.e., the set of traits (collections of t...

Climate change and Australia: Trends, projections and impacts

Abstract: This review summarizes recent research in Australia on: (i) climate and geophysical trends over the last few decades; (ii) projections for climate change in the 21st century; (iii) predicted impacts from modelling studies on particular ecosystems and native species; and (iv) ecological effects that have apparently occurred as a response to recent warming. Consistent with global trends, Australia has warmed ~ 0.8 � C over the last century with minimum temperatures warming faster than maxima. There have been significant regional trends in rainfall with the northern, eastern and southern parts of the continent receiving greater rainfall and the western region receiving less. Higher rainfall has been associated with an increase in the number of rain days and heavy rainfall events. Sea surface temperatures on the Great Barrier Reef have increased and are associated with an increase in the frequency and severity of coral bleaching and mortality. Sea level rises in Australia have been regionally variable, and considerably less than the global average. Snow cover and duration have declined significantly at some sites in the Snowy Mountains. CSIRO projections for future climatic changes indicate increases in annual average temperatures of 0.4-2.0 � C by 2030 (relative to 1990) and 1.0-6.0 � C by 2070. Considerable uncertainty remains as to future changes in rainfall, El Nino Southern Oscillation events and tropical cyclone activity. Overall increases in potential evaporation over much of the continent are predicted as well as continued reductions in the extent and duration of snow cover. Future changes in temperature and rainfall are predicted to have significant impacts on most vegetation types that have been modelled to date, although the interactive effect of continuing increases in atmospheric CO 2 has not been incorporated into most modelling studies. Elevated CO 2 will most likely mitigate some of the impacts of climate change by reducing water stress. Future impacts on particular ecosystems include increased forest growth, alterations in competitive regimes between C3 and C4 grasses, increasing encroachment of woody shrubs into arid and semiarid rangelands, continued incursion of mangrove communities into freshwater wetlands, increasing frequency of coral bleaching, and establishment of woody species at increasingly higher elevations in the alpine zone. Modelling of potential impacts on specific Australian taxa using bioclimatic analysis programs such as BIOCLIM consistently predicts contraction and/or fragmentation of species' current ranges. The bioclimates of some species of plants and vertebrates are predicted to disappear entirely with as little as 0.5-1.0 � C of warming. Australia lacks the long-term datasets and tradition of phenological monitoring that have allowed the detection of climate-change-related trends in the Northern Hemisphere. Long-term changes in Australian vegetation can be mostly attributed to alterations in fire regimes, clearing and grazing, but some trends, such as encroachment of rainforest into eucalypt woodlands, and establishment of trees in subalpine meadows probably have a climatic component. Shifts in species distributions toward the south (bats, birds), upward in elevation (alpine mammals) or along changing rainfall contours (birds, semiarid reptiles), have recently been documented and offer circumstantial evidence that temperature and rainfall trends are already affecting geographic ranges. Future research directions suggested include giving more emphasis to the study of climatic impacts and understanding the factors that control species distributions, incorporating the effects of elevated CO 2 into climatic modelling for vegetation and selecting suitable species as indicators of climate-induced change.

The evolution of, and revolution in, land surface schemes designed for climate models

Abstract: The land surface is a key component of climate models. It controls the partitioning of available energy at the surface between sensible and latent heat, and it controls the partitioning of available water between evaporation and runoff. The land surface is also the location of the terrestrial carbon sink. Evidence is increasing that the influence of the land surface is significant on climate and that changes in the land surface can influence regional- to global-scale climate on time scales from days to millennia. Further, there is now a suggestion that the terrestrial carbon sink may decrease as global temperatures increase as a consequence of rising CO2 levels. This paper provides the theoretical background that explains why the land surface should play a central role in climate. It also provides evidence, sourced from climate model experiments, that the land surface is of central importance. This paper then reviews the development of land surface models designed for climate models from the early, very simple models through to recent efforts, which include a coupling of biophysical processes to represent carbon exchange. It is pointed out that significant problems remain to be addressed, including the difficulties in parameterizing hydrological processes, root processes, sub-grid-scale heterogeneity and biogeochemical cycles. It is argued that continued development of land surface models requires more multidisciplinary efforts by scientists with a wide range of skills. However, it is also argued that the framework is now in place within the international community to build and maintain the latest generation of land surface models. Further, there should be considerable optimism that consolidating the recent rapid advances in land surface modelling will enhance our capability to simulate the impacts of land-cover change and the impacts of increasing CO2 on the global and regional environment. Copyright  2003 Royal Meteorological Society.

The Activist Teaching Profession

Abstract: Series editor's preface Teacher professionalism in transition Rethinking the practice of teacher professionalism The politics of professionalism Preparing activist teacher professionals Teacher research for professional renewal Professional in practice New professional identities for new times The activist teacher professional References Index.

Modularity of music processing.

Abstract: The music faculty is not a monolithic entity that a person either has or does not. Rather, it comprises a set of neurally isolable processing components, each having the potential to be specialized for music. Here we propose a functional architecture for music processing that captures the typical properties of modular organization. The model rests essentially on the analysis of music-related deficits in neurologically impaired individuals, but provides useful guidelines for exploring the music faculty in normal people, using methods such as neuroimaging.

Plant height and evolutionary games

Abstract: In plants, investment in height improves access to light, but incurs costs in construction and maintenance of the stem. Because the benefits of plant height depend on which other height strategies are present, competition for light can usefully be framed as a game-theoretic problem. The vertical structure of the world's vegetation, which is inefficient for plant growth, can then be understood as the outcome of evolutionary and ecological arms races. In addition, game-theoretic models predict taller vegetation on sites of higher leaf area index, and allocation to reproduction only after an initial period of height growth. However, of 14 game-theoretic models for height reviewed here, only one predicts coexistence of a mix of height strategies, a conspicuous feature of most vegetation. We suggest that game-theoretic models could help account for observed mixtures of height strategies if they incorporated processes for coexistence along spectra of light income and time since disturbance.

Genome scan meta-analysis of schizophrenia and bipolar disorder, part III: Bipolar disorder.

Abstract: Genome scans of bipolar disorder (BPD) have not produced consistent evidence for linkage. The rank-based genome scan meta-analysis (GSMA) method was applied to 18 BPD genome scan data sets in an effort to identify regions with significant support for linkage in the combined data. The two primary analyses considered available linkage data for "very narrow" (i.e., BP-I and schizoaffective disorder-BP) and "narrow" (i.e., adding BP-II disorder) disease models, with the ranks weighted for sample size. A "broad" model (i.e., adding recurrent major depression) and unweighted analyses were also performed. No region achieved genomewide statistical significance by several simulation-based criteria. The most significant P values (<.01) were observed on chromosomes 9p22.3-21.1 (very narrow), 10q11.21-22.1 (very narrow), and 14q24.1-32.12 (narrow). Nominally significant P values were observed in adjacent bins on chromosomes 9p and 18p-q, across all three disease models on chromosomes 14q and 18p-q, and across two models on chromosome 8q. Relatively few BPD pedigrees have been studied under narrow disease models relative to the schizophrenia GSMA data set, which produced more significant results. There was no overlap of the highest-ranked regions for the two disorders. The present results for the very narrow model are promising but suggest that more and larger data sets are needed. Alternatively, linkage might be detected in certain populations or subsets of pedigrees. The narrow and broad data sets had considerable power, according to simulation studies, but did not produce more highly significant evidence for linkage. We note that meta-analysis can sometimes provide support for linkage but cannot disprove linkage in any candidate region.

Leaf size and angle vary widely across species: what consequences for light interception?

Abstract: Summary •A rchitecture can vary widely across species. Both steeper leaf angles and increased self-shading are thought to reduce potential carbon gain by decreasing total light interception. An alternative hypothesis is that steeper leaf angles have evolved to improve day-long carbon gain by emphasising light interception from low angles. • Here we relate variation in architectural properties (leaf angle and leaf size) to cross-species patterns of leaf display, light capture and simulated carbon gain in branching-units of 38 perennial species occurring at two sites in Australian forest. Architectural comparison was made possible by combining 3D-digitising with the architecture model YPLANT. • Species with shallow angled leaves had greater daily light interception and potentially greater carbon gain. Self-shading, rather than leaf angle, explained most variance between species in light capture and potential carbon gain. Species average leaf size was the most important determinant of self-shading. • Our results provide the first cross-species evidence that steeper leaf angles function to reduce exposure to excess light levels during the middle of the day, more than to maximise carbon gain.

Nutrient concentration, resorption and lifespan: leaf traits of Australian sclerophyll species

Abstract: Summary 1. Most plants withdraw nutrients from leaves as they age, and redeploy them elsewhere in the plant. The proportion of nutrients resorbed and the residual nutrient concentration in senesced leaves are different but complementary indices of nutrient conservation via this process. A major spectrum of strategic variation runs from plant species with typically long leaf lifespan (LL), high leaf mass per area (LMA), low leaf nutrient concentrations, and low photosynthetic capacity, to species with the opposite characteristics. It is unknown to what extent either facet of resorption covaries with the LL‐LMA spectrum. 2. Green-leaf and senesced-leaf N and P concentrations were quantified for 73 evergreen species from four sites in eastern Australia (nutrient-rich and nutrient-poor sites in each of two rainfall zones). Leaf nutrient concentrations in green and senesced leaves were negatively correlated with LL across all species and at most sites, especially if N 2 fixing species were excluded from analyses involving leaf N. 3. Proportional resorption did not differ with soil nutrients, as has been found elsewhere, nor was it correlated with LL. Green-leaf and senesced-leaf nutrient concentrations were lower for species on poorer soils. A simple model was described in which the proportion of resorbed vs soil-derived nutrients deployed in new leaves is set by the relative cost of nutrients from the two sources. The model provides a prospective explanation for the observed differences between species from nutrient-rich and nutrientpoor habitats. 4. The results from this study provide support for the argument that selection to minimize nutrient losses has affected the residual nutrient concentration in senesced leaves, rather than proportional resorption per se . Further, variation among species in residual nutrient concentration was correlated with one of the key spectra of strategic variation between plant species, the leaf lifespan‐LMA axis of variation.

Implementing learning design : the Learning Activity Management System (LAMS)

Abstract: Learning Design has the potential to revolutionise e-learning by capturing the “process” of education, rather than simply content. By describing sequences of collaborative learning activities, Learning Design offers a new approach to re-use in e-learning. This paper describes the Learning Design approach, a detailed example, and its implementation in the Learning Activity Management System.

Determining the Value of Cultural Goods: How Much (or How Little) Does Contingent Valuation Tell Us?

Abstract: Contingent valuation methods (CVM) are now well established as a means of measuring the nonmarket demand for cultural goods and services. When combined with valuations provided through market processes (where relevant), an overall assessment of the economic value of cultural commodities can be obtained. Within a neoclassical framework, such assessments are thought to provide a complete picture of the value of cultural goods. But are there aspects of the value of cultural goods which are not fully captured, or not captured at all, within such a model? This paper argues that CVM provides an incomplete view of the nonmarket value of cultural goods, and that alternative measures need to be developed to provide a fuller account. of Sydney which sought to measure the community's willingness to pay (WTP) for the perceived public-good benefits of the arts. Around 825 respondents were questioned about the nature and extent of the nonmarket benefits they enjoyed from the existence of the subsidised arts in Australia - literature, visual arts, music, theatre, dance, etc. - and they were asked to nominate the dollar amounts they would be willing to pay out of their taxes to support the arts, under conditions of both liability and nonliability for actual payment. With appropriate caveats, we concluded from our research that aggregate WTP for the public-good benefits of the arts in Australia at that time exceeded the then-prevailing tax-price of cultural subsidy. What did we think we were measuring in this study and what did we actually measure? As far as the arts were concerned, our work was predicated on two princi- pal motivations, one theoretical and one practical. The theoretical drive came from a desire to test the longstanding proposition that the arts were a case of market failure. This hypothesis, first articulated in the 1960s (Baumol and Bowen, 1966; Peacock, 1969) and elaborated at length in our own book of 1979 (Throsby and

Customer relationship management: concepts and technologies

Abstract: Section A 1.Introduction to CRM 2.Understanding Relationships Section B: Strategic CRM 3.Managing the Customer Lifecycle: Customer Acquisition 4.Managing the Customer Lifecycle: Customer Retention and Development 5.Customer Portfolio Management 6.How to Deliver Customer-Experienced Value 7.Managing Customer Experience Section C: Operational CRM 8.Sales force automation 9.Marketing Automation 10.Service Automation Section D: Analytical CRM 11.Developing and Managing Customer-Related Databases 12.Using Customer-Related Data Section E: Realizing the Benefits of CRM 13.Planning to Succeed 14.Implementing CRM Section F: Looking to the Future 15.The Future

Cdk5 is essential for synaptic vesicle endocytosis

Abstract: Synaptic vesicle endocytosis (SVE) is triggered by calcineurin-mediated dephosphorylation of the dephosphin proteins. SVE is maintained by the subsequent rephosphorylation of the dephosphins by unidentified protein kinases. Here, we show that cyclin-dependent kinase 5 (Cdk5) phosphorylates dynamin I on Ser 774 and Ser 778 in vitro, which are identical to its endogenous phosphorylation sites in vivo. Cdk5 antagonists and expression of dominant-negative Cdk5 block phosphorylation of dynamin I, but not of amphiphysin or AP180, in nerve terminals and inhibit SVE. Thus Cdk5 has an essential role in SVE and is the first dephosphin kinase identified in nerve terminals.

Evidence for low sulphate and anoxia in a mid-Proterozoic marine basin

Abstract: Many independent lines of evidence document a large increase in the Earth's surface oxidation state 2,400 to 2,200 million years ago1,2,3,4, and a second biospheric oxygenation 800 to 580 million years ago, just before large animals appear in the fossil record5,6. Such a two-staged oxidation implies a unique ocean chemistry for much of the Proterozoic eon, which would have been neither completely anoxic and iron-rich as hypothesized for Archaean seas, nor fully oxic as supposed for most of the Phanerozoic eon7. The redox chemistry of Proterozoic oceans has important implications for evolution8, but empirical constraints on competing environmental models are scarce. Here we present an analysis of the iron chemistry of shales deposited in the marine Roper Basin, Australia, between about 1,500 and 1,400 million years ago, which record deep-water anoxia beneath oxidized surface water. The sulphur isotopic compositions of pyrites in the shales show strong variations along a palaeodepth gradient, indicating low sulphate concentrations in mid-Proterozoic oceans. Our data help to integrate a growing body of evidence favouring a long-lived intermediate state of the oceans, generated by the early Proterozoic oxygen revolution and terminated by the environmental transformation late in the Proterozoic eon.

The Delphi method and health research

Abstract: The Delphi method is well suited to the research needed to inform health education and health promotion campaigns. This paper measures the current interest in the method by way of a literature review. It then describes how the method has evolved from its inception in the 1950s, to its current form. The focus is on a Delphi variant that is particularly relevant to health education – the Policy Delphi. The benefits of the method for the developer of health education and health promotion campaigns are then discussed. The main benefits relate to the gaining of expert opinions without the time and geographical restraints involved in alternative methods. The anonymity that is central to the Delphi method also has benefits for the researcher. The last section of the paper deals with potential pitfalls in the Delphi method that might undermine the successful application of the method, and recommends steps the practitioner can take to address these pitfalls.

Least‐Cost Input Mixtures of Water and Nitrogen for Photosynthesis

Abstract: In microeconomics, a standard framework is used for determining the optimal input mix for a two‐input production process. Here we adapt this framework for understanding the way plants use water and nitrogen (N) in photosynthesis. The least‐cost input mixture for generating a given output depends on the relative cost of procuring and using nitrogen versus water. This way of considering the issue integrates concepts such as water‐use efficiency and photosynthetic nitrogen‐use efficiency into the more inclusive objective of optimizing the input mix for a given situation. We explore the implications of deploying alternative combinations of leaf nitrogen concentration and stomatal conductance to water, focusing on comparing hypothetical species occurring in low‐ versus high‐humidity habitats. We then present data from sites in both the United States and Australia and show that low‐rainfall species operate with substantially higher leaf N concentration per unit leaf area. The extra protein reflected i...

Latitude, seed predation and seed mass

Abstract: Aim We set out to test the hypothesis that rates of pre- and post-dispersal seed predation would be higher towards the tropics, across a broad range of species from around the world. We also aimed to quantify the slope and predictive power of the relationship between seed mass and latitude both within and across species. Methods Seed mass, pre-dispersal seed predation and post-dispersal seed removal data were compiled from the literature. Wherever possible, these data were combined with information regarding the latitude at which the data were collected. Analyses were performed using both cross-species and phylogenetic regressions. Results Contrary to expectations, we found no significant relationship between seed predation and latitude (log10 proportion of seeds surviving predispersal seed predation vs. latitude, P = 0.63; R2 = 0.02; n = 122 species: log10 proportion of seeds remaining after postdispersal seed removal vs. latitude, P = 0.54; R2 = 0.02; n = 205 species). These relationships remained non-significant after variation because of seed mass was accounted for. We also found a very substantial (R2 = 0.21) relationship between seed mass and latitude across 2706 species, with seed mass being significantly higher towards the tropics. Within-species seed mass decline with latitude was significant, but only about two-sevenths, as rapid as the cross-species decline with latitude. Results of phylogenetic analyses were very similar to cross-species analyses. We also demonstrated a positive relationship between seed mass and development time across ten species from dry sclerophyll woodland in Sydney (P < 0.001; R2 = 0.77; Standardized Major Axis slope = 0.14). These data lend support to the hypothesis that growing period might affect the maximum attainable seed mass in a given environment. Main conclusions There was no evidence that seed predation is higher towards the tropics. The strong relationship between seed mass and latitude shown here had been observed in previous studies, but had not previously been quantified at a global scale. There was a tenfold reduction in mean seed mass for every c. 23° moved towards the poles, despite a wide range of seed mass within each latitude.

Optimal Remote State Preparation

Abstract: We prove that it is possible to remotely prepare an ensemble of noncommuting mixed states using communication equal to the Holevo information for this ensemble. This remote preparation scheme may be used to convert between different ensembles of mixed states in an asymptotically lossless way, analogous to concentration and dilution for entanglement.

Leaf-size divergence along rainfall and soil-nutrient gradients: Is the method of size reduction common among clades?

Abstract: Summary 1Ecologists have long recognized that plants occurring in areas of low rainfall or soil nutrients tend to have smaller leaves than those in more favourable regions. 2Working with a large data set (690 species at 47 sites spread widely through south-east Australia) for which this reduction has been described previously, we investigated the morphology of leaf size reduction, asking whether any patterns observed were consistent across evolutionary lineages or between environmental gradients. 3Leaf length, width and surface areas were measured; leaf traits such as pubescence or lobing were also scored qualitatively. There was no correlation between soil phosphorus and rainfall across sites. Further, there was no evidence that pubescence, lobing or other traits assessed served as alternatives to reduction of leaf size at the low ends of either environmental gradient. 4Leaf size reduction occurred through many combinations of change in leaf width and length, even within lineages. Thus consistent patterns in the method of leaf size reduction were not found, although broad similarities between rainfall and soil P gradients were apparent.