Dispersal and establishment both limit colonization during primary succession on a glacier foreland

Plant colonization can be limited by lack of seeds or by factors that reduce establishment. The role of seed limitation in community assembly is being increasingly recognized, but in early primary succession, establishment failure is still considered more important. We studied the factors limiting colonization on the foreland of Coleman Glacier, Washington, USA to determine the importance of seed and establishment limitation during primary succession. We also evaluated the effects of seed predation, drought and existing vegetation on establishment. We planted seeds of seven species into plots of four different ages and found evidence that both seed and establishment limitation are strong in early succession. We also found that seed and establishment limitation both remained high in later stages of succession. Seed predation reduced establishment for most species and some evidence suggested that drought and existing vegetation also limit establishment. Because both dispersal and establishment failure restrict colonization in recently exposed habitat, late-seral forest species may have a difficult time migrating upward in response to global climate change

Feeding selectivity of brown trout (Salmo trutta) in Loch Ness, Scotland

The aim of this study was to compare statistically the zooplankton assemblage ingested by brown trout (Salmo trutta) in Loch Ness with that of the zooplankton in the water column. This would allow the examination of the apparent paradox that very few copepods appear to be consumed by trout at a time of year when they are numerous and readily available as food. The investigation was limited to the crustacean zooplankters, since the Rotifera are generally so small that they are only of interest to fish in the first few days of life. 25 trout were obtained from anglers, and the stomach contents of non-"ferox" animals analysed. Samples of pelagic zooplankton were obtained approximately monthly from 30-m vertical net-hauls (mesh size 100 km). It is concluded that the variation in dietary composition with trout wet weight indicates an ontogenetic habitat shift producing spatial separation of young and older individuals

Analysis of Writing Inks on Paper Using Direct Analysis in Real Time Mass Spectrometry

Ink analysis is central to questioned document examination. We applied direct analysis in real time mass spectrometry (DART MS) to ballpoint, gel, and fluid writing ink analysis. DART MS acquires the mass spectrum of an ink while it is still on a document without altering the appearance of the document. Spectra were acquired from ink on a variety of papers, and the spectrum of the blank paper could be subtracted out to produce a cleanly isolated ink spectrum in most cases. Only certain heavy or heavily processed papers interfered. The time since an ink is written on paper has a large effect on its spectrum. DART spectra change radically during the first few months after an ink is written as the more volatile components evaporate, but the spectra stabilize after that. A library-search study involving 166 well-aged inks assessed the ability to identify inks from their DART spectra. The aggregate success rate was 92%

Quantitative Depth Profiling of Layered Samples Using Phase-Modulation FT-IR Photoacoustic Spectroscopy

In phase-modulation FT-IR spectroscopy, all wavelengths in a spectrum are modulated at the same frequency and in phase. This factor makes the use of photoacoustic phase data for depth profiling samples much easier in phase modulation than in rapid scan. A method to quantitatively measure layer thickness by using the phase of a substrate spectrum peak is demonstrated with a series of samples consisting of thin polymer films on substrates. Additions to the basic method are demonstrated that extend its application to cases where the substrate peak is overlapped by a spectrum peak of the surface film. A linear relationship between phase angle and layer thickness extending to thicknesses greater than twice the thermal diffusion length is demonstrated. Representations of phase modulation data as a family of angle-specific spectra, as magnitude vs. phase curves, and as a power spectrum and phase spectrum pair, each of which is useful for different aspects of depth profiling, are discussed. Calculating these representations from a single pair of orthogonal interferograms is described

Designing a virtual teacher for non-verbal children with autism: Pedagogical affordances and the influence of teacher voice

The prevalence of children with autism in Asia has been estimated as comparable to that in many other countries (Jeevanandam, 2009; William et al., 2005). Within this group, approximately one-third to one-half of these children will lack functional speech (Mirenda, 2003) and have severe learning difficulties. There have been recent technological developments for teaching children with autism, for example virtual worlds (Bignell, 2008) and socially intelligent agents (Dautenhahn & Werry, 2004). However, there has been relatively little research into the effectiveness of technologically supported approaches to language development for those children who are non-verbal. The Picture Exchange Communications System (PECS) is an augmentative and alternative communication (AAC) approach that has been used with children with little or no speech to develop language and communication skills. In essence the children gradually learn to communicate through exchanging pictures and symbols for desired items or outcomes. There is empirical evidence to support the value of this approach (Preston & Carter, 2009). This paper considers a technologically supported approach within this area: Computer Assisted Picture Exchange (CAPE). It examines the issue of teacher embodiment and the affordances arising from using an interactive virtual teacher avatar that responds to the child's manipulation of objects and symbols in the physical world. The paper discusses investigations to compare synthetic and natural teacher voices, and to assess their influence on the learning of communication skills by children with autism

The design and development of a constant-speed solar array drive

The design and development of a constant-speed solar array drive system for use in high power communications satellites is described. The relationship between continuity of motion in the solar array drive and spacecraft attitude disturbance is investigated. The selection of the system design based on the design requirements including spacecraft disturbance is discussed. The system comprises two main parts: the drive mechanism including small angle stepper motor and reduction gearing and the control electronics including ministepping drive circuits, such that a very small output step size is achieved. Factors contributing to discontinuities in motion are identified and discussed. Test methods for measurement of very small amplitudes of discontinuity at low rotational rates are described to assist in the testing of similar mechanisms

Valuing adaptation under rapid change

AbstractThe methods used to plan adaptation to climate change have been heavily influenced by scientific narratives of gradual change and economic narratives of marginal adjustments to that change. An investigation of the theoretical aspects of how the climate changes suggests that scientific narratives of climate change are socially constructed, biasing scientific narratives to descriptions of gradual as opposed rapid, non-linear change. Evidence of widespread step changes in recent climate records and in model projections of future climate is being overlooked because of this. Step-wise climate change has the potential to produce rapid increases in extreme events that can cross institutional, geographical and sectoral domains.Likewise, orthodox economics is not well suited to the deep uncertainty faced under climate change, requiring a multi-faceted approach to adaptation. The presence of tangible and intangible values range across five adaptation clusters: goods; services; capital assets and infrastructure; social assets and infrastructure; and natural assets and infrastructure. Standard economic methods have difficulty in giving adequate weight to the different types of values across these clusters. They also do not account well for the inter-connectedness of impacts and subsequent responses between agents in the economy. As a result, many highly-valued aspects of human and environmental capital are being overlooked.Recent extreme events are already pressuring areas of public policy, and national strategies for emergency response and disaster risk reduction are being developed as a consequence. However, the potential for an escalation of total damage costs due to rapid change requires a coordinated approach at the institutional level, involving all levels of government, the private sector and civil society.One of the largest risks of maladaptation is the potential for un-owned risks, as risks propagate across domains and responsibility for their management is poorly allocated between public and private interests, and between the roles of the individual and civil society. Economic strategies developed by the disaster community for disaster response and risk reduction provide a base to work from, but many gaps remain.We have developed a framework for valuing adaptation that has the following aspects: the valuation of impacts thus estimating values at risk, the evaluation of different adaptation options and strategies based on cost, and the valuation of benefits expressed as a combination of the benefits of avoided damages and a range of institutional values such as equity, justice, sustainability and profit.The choice of economic methods and tools used to assess adaptation depends largely on the ability to constrain uncertainty around problems (predictive uncertainty) and solutions (outcome uncertainty). Orthodox methods can be used where both are constrained, portfolio methodologies where problems are constrained and robust methodologies where solutions are constrained. Where both are unconstrained, process-based methods utilising innovation methods and adaptive management are most suitable. All methods should involve stakeholders where possible.Innovative processes methods that enable transformation will be required in some circumstances, to allow institutions, sectors and communities to prepare for anticipated major change.Please cite this report as: Jones, RN, Young, CK, Handmer, J, Keating, A, Mekala, GD, Sheehan, P 2013 Valuing adaptation under rapid change, National Climate Change Adaptation Research Facility, Gold Coast, pp. 192.The methods used to plan adaptation to climate change have been heavily influenced by scientific narratives of gradual change and economic narratives of marginal adjustments to that change. An investigation of the theoretical aspects of how the climate changes suggests that scientific narratives of climate change are socially constructed, biasing scientific narratives to descriptions of gradual as opposed rapid, non-linear change. Evidence of widespread step changes in recent climate records and in model projections of future climate is being overlooked because of this. Step-wise climate change has the potential to produce rapid increases in extreme events that can cross institutional, geographical and sectoral domains.Likewise, orthodox economics is not well suited to the deep uncertainty faced under climate change, requiring a multi-faceted approach to adaptation. The presence of tangible and intangible values range across five adaptation clusters: goods; services; capital assets and infrastructure; social assets and infrastructure; and natural assets and infrastructure. Standard economic methods have difficulty in giving adequate weight to the different types of values across these clusters. They also do not account well for the inter-connectedness of impacts and subsequent responses between agents in the economy. As a result, many highly-valued aspects of human and environmental capital are being overlooked.Recent extreme events are already pressuring areas of public policy, and national strategies for emergency response and disaster risk reduction are being developed as a consequence. However, the potential for an escalation of total damage costs due to rapid change requires a coordinated approach at the institutional level, involving all levels of government, the private sector and civil society.One of the largest risks of maladaptation is the potential for un-owned risks, as risks propagate across domains and responsibility for their management is poorly allocated between public and private interests, and between the roles of the individual and civil society. Economic strategies developed by the disaster community for disaster response and risk reduction provide a base to work from, but many gaps remain.We have developed a framework for valuing adaptation that has the following aspects: the valuation of impacts thus estimating values at risk, the evaluation of different adaptation options and strategies based on cost, and the valuation of benefits expressed as a combination of the benefits of avoided damages and a range of institutional values such as equity, justice, sustainability and profit.The choice of economic methods and tools used to assess adaptation depends largely on the ability to constrain uncertainty around problems (predictive uncertainty) and solutions (outcome uncertainty). Orthodox methods can be used where both are constrained, portfolio methodologies where problems are constrained and robust methodologies where solutions are constrained. Where both are unconstrained, process-based methods utilising innovation methods and adaptive management are most suitable. All methods should involve stakeholders where possible.Innovative processes methods that enable transformation will be required in some circumstances, to allow institutions, sectors and communities to prepare for anticipated major change

The marine ΔR For Nenumbo (Solomon Islands): A case study in calculating reservoir offsets form paired sample data

It is necessary to calculate location-specific marine ΔR values in order to calibrate marine samples using calibration curves such as those provided through the IntCal98 (Stuiver et al. 1998) data. Where known-age samples are available, this calculation is straightforward (i.e. Stuiver et al. 1986). In the case that a paired marine/terrestrial sample calculation is performed, however, the standard calculation (i.e. Stuiver and Braziunas 1993) requires that the samples are treated as relating to isochronous events. This may not be an appropriate assumption for many archaeological paired samples. In this paper, we present an approach to calculating marine ΔR values that does not require the dated events to be treated as isochronous. When archaeological evidence allows the dated events to be tightly temporally constrained, the approach presented here and that described by Stuiver and Braziunas (1993) give very similar results. However, where tight temporal constraints are less certain, the 2 approaches can give rise to differing results. The example analysis considered here shows that a ΔR of –81 ± 64 ¹⁴C yr is appropriate for samples in the vicinity of Nenumbo (Reef Islands, southeast Solomon Islands) around the period 2000–3000 BP

Real-Time Monitoring of Low-Level Mixed-Waste Loading during Polyethylene Microencapsulation using Transient Infrared Spectroscopy

In polyethylene microencapsulation, low-level mixed waste (LLMW) is homogenized with molten polyethylene and extruded into containers, resulting in a lighter, lower-volume waste form than cementation and grout methods produce. Additionally, the polyethylene-based waste form solidifies by cooling, with no risk of the waste interfering with cure, as may occur with cementation and grout processes. We have demonstrated real-time monitoring of the polyethylene encapsulation process stream using a noncontact device based on transient infrared spectroscopy (TIRS). TIRS can acquire mid-infrared spectra from solid or viscous liquid process streams, such as the molten, waste-loaded polyethylene stream that exits the microencapsulation extruder. The waste loading in the stream was determined from the TIRS spectra using partial least squares techniques. The monitor has been demonstrated during the polyethylene microencapsulation of nitrate-salt LLMW and its surrogate, molten salt oxidation LLMW and its surrogate, and flyash. The monitor typically achieved a standard error of prediction for the waste loading of about 1% by weight with an analysis time under 1 minute