1,405 research outputs found
Climate change and the Great Barrier Reef: a vulnerability assessment
The combination of sensitivity and exposure to climate change render the GBR ecosystem highly vulnerable to climate change. While the components and processes that comprise the ecosystem vary in their vulnerability, the implications of climate change are far-reaching and, in many cases, severe. Overall, the GBR ecosystem has features that will afford it some protection from climate change compared with tropical marine reef ecosystems. These features include its immense size, its location adjacent to a relatively sparsely populated and developed country, and its protection under a management regime that is recognised as the best in the world. However, coral reefs are one of the most vulnerable of all of the earth’s ecosystems to climate change, and the GBR will continue to be affected. Even under the most optimistic climate change scenarios, the GBR is destined for significant change over this century; under pessimistic scenarios, catastrophic impacts are possible. In this section, we provide an overview of the exposure of the GBR to climate factors, including a summary of predicted changes to the GBR climate, followed by a review of the reasons for the sensitivity of the GBR to climate change. We then provide a synopsis of current and emerging knowledge about the vulnerability of GBR species groups and habitats to climate change.This is Chapter 24 of Climate change and the Great Barrier Reef: a vulnerability assessment. The entire book can be found at http://hdl.handle.net/11017/137
ID: 7
Determinantes del Precio del Vino en el Mercado Chileno: Un Estudio de Precios Hedónicos.
Published by Asociación de Economistas Agrarios de ChileConsumer/Household Economics, Production Economics,
Climate change and the Great Barrier Reef: a vulnerability assessment
The Great Barrier Reef is renowned internationally for its ecological importance and the beauty of its seascapes and landscapes. These natural values also provide important ecosystem services, which underpin Australian $6.9 billion worth of economic activity and incalculable social values. In combination, the social-ecological system centred on the reef is extraordinary in its importance, and in its complexity. Understanding the vulnerability of such a large and intricate system to climate change is a particularly difficult challenge. A first step in meeting this challenge is to describe the general characteristics of the system and the environment in which they interact. Toward this end, this chapter introduces the Great Barrier Reef and the human systems that interact with it, providing a context for the detailed chapters that follow.This is Chapter 1 of Climate change and the Great Barrier Reef: a vulnerability assessment. The entire book can be found at http://hdl.handle.net/11017/13
Biophysical assessment of reefs in Keppel Bay: a baseline study (April 2007)
The Keppel Islands are a group of 16 continental islands lying 18 km off the coastal town of Yeppoon in the southern Great Barrier Reef. Located in the shallow basin to the north of Keppel Bay, the islands are host to a patchwork of fringing reefs in various forms of development. Coral communities are abundant in some locations, and coral cover is high (60 to 70%) relative to the average at sites surveyed by the Australian Institute of Marine Science’s Long-Term Monitoring Program (~35%), and are often dominated by extensive stands of branching Acropora that extend into shallow water. These ‘staghorn’ corals are vulnerable to impacts caused by environmental stresses such as elevated sea temperature (causing coral bleaching events), degraded water quality (associated with hyposaline floods events) and physical damage (from cyclones, storms and anchoring). The Fitzroy River, one of the largest catchments in Queensland, is about 40 km to the south of the Keppel Islands. Large flood plumes occur approximately every 10 years, and the soft riverine sediments are regularly re-suspended in the shallow bay by wind and tide action causing high turbidity. Heavy rainfall also affects the shallow reef flat habitats, with reported incidences of coral mortality caused by heavy rain at times of extreme low tidesID: 176
Participation in devolved commons management: multiscale socioeconomic factors related to individuals' participation in community-based management of marine protected areas in Indonesia
Management of common-pool natural resources is commonly implemented under institutional models promoting devolved decision-making, such as co-management and community-based management. Although participation of local people is critical to the success of devolved commons management, few studies have empirically investigated how individuals' participation is related to socioeconomic factors that operate at multiple scales. Here, we evaluated how individual- and community-scale factors were related to levels of individual participation in management of community-based marine protected areas in Indonesia. In addressing this aim, we drew on multiple bodies of literature on human behaviour from economics and social science, including the social-ecological systems framework from the literature on common-pool resources, the theory of planned behaviour from social psychology, and public goods games from behavioural economics. We found three key factors related to level of participation of local people: subjective norms, structural elements of social capital, and nested institutions. There was also suggestive evidence that participation was related to people's cooperative behavioural disposition, which we elicited using a public goods game. These results point to the importance of considering socioeconomic factors that operate at multiple scales when examining individual behaviour. Further, our study highlights the need to consider multiscale mechanisms other than those designed to appeal to self interested concerns, such as regulations and material incentives, which are typically employed in devolved commons management to encourage participation. Increased understanding of the factors related to participation could facilitate better targeting of investments aimed at encouraging cooperative management
Polarization Measurements of the Polluted White Dwarf G29-38
We have made high-precision polarimetric observations of the polluted white dwarf G29-38 with the HIgh Precision Polarimetric Instrument 2. The observations were made at two different observatories – using the 8.1-m Gemini North Telescope and the 3.9-m Anglo-Australian Telescope – and are consistent with each other. After allowing for a small amount of interstellar polarization, the intrinsic linear polarization of the system is found to be 275.3 ± 31.9 parts per million at a position angle of 90.8 ± 3.8◦ in the SDSS g
band. We compare the observed polarization with the predictions of circumstellar disc models. The measured polarization is small in the context of the models we develop, which only allows us to place limits on disc inclination and Bond albedo for optically thin disc geometries. In this case, either the inclination is near-face-on or the albedo is small – likely in the range 0.05–0.15 – which is in line with other debris disc measurements. A preliminary search for the effects of G29-38’s pulsations in the polarization signal produced inconsistent results. This may be caused by beating effects, indicate a clumpy dust distribution, or be a consequence of measurement systematics
Feature Neighbourhood Mutual Information for multi-modal image registration: An application to eye fundus imaging
© 2014 Elsevier Ltd. All rights reserved. Multi-modal image registration is becoming an increasingly powerful tool for medical diagnosis and treatment. The combination of different image modalities facilitates much greater understanding of the underlying condition, resulting in improved patient care. Mutual Information is a popular image similarity measure for performing multi-modal image registration. However, it is recognised that there are limitations with the technique that can compromise the accuracy of the registration, such as the lack of spatial information that is accounted for by the similarity measure. In this paper, we present a two-stage non-rigid registration process using a novel similarity measure, Feature Neighbourhood Mutual Information. The similarity measure efficiently incorporates both spatial and structural image properties that are not traditionally considered by MI. By incorporating such features, we find that this method is capable of achieving much greater registration accuracy when compared to existing methods, whilst also achieving efficient computational runtime. To demonstrate our method, we use a challenging medical image data set consisting of paired retinal fundus photographs and confocal scanning laser ophthalmoscope images. Accurate registration of these image pairs facilitates improved clinical diagnosis, and can be used for the early detection and prevention of glaucoma disease
Thermodynamics of Random Ferromagnetic Antiferromagnetic Spin-1/2 Chains
Using the quantum Monte Carlo Loop algorithm, we calculate the temperature
dependence of the uniform susceptibility, the specific heat, the correlation
length, the generalized staggered susceptibility and magnetization of a
spin-1/2 chain with random antiferromagnetic and ferromagnetic couplings, down
to very low temperatures. Our data show a consistent scaling behavior in all
the quantities and support strongly the conjecture drawn from the approximate
real-space renormalization group treatment.A statistical analysis scheme is
developed which will be useful for the search of scaling behavior in numerical
and experimental data of random spin chains.Comment: 13 pages, 13 figures, RevTe
The Carboniferous carbon isotope record from sedimentary organic matter: can we disentangle the carbon cycle?
A comprehensive analysis of the 13C composition of sedimentary organic matter from Euramerican
Carboniferous successions indicates there are significant shifts in 13C through this key time interval.
Our studies have revealed that, at an individual location, the source and delivery mechanism of the
sediment contribute to the type of organic matter preserved and, in turn this influences the
measured 13C values from bulk sedimentary organic matter of organic matter
The fermi arc and fermi pocket in cuprates in a short-range diagonal stripe phase
In this paper we studied the fermi arc and the fermi pocket in cuprates in a
short-range diagonal stripe phase with wave vectors , which
reproduce with a high accuracy the positions and sizes of the fermi arc and
fermi pocket and the superstructure in cuprates observed by Meng et
al\cite{Meng}. The low-energy spectral function indicates that the fermi pocket
results from the main band and the shadow band at the fermi energy. Above the
fermi energy the shadow band gradually departs away from the main band, leaving
a fermi arc. Thus we conclude that the fermi arc and fermi pocket can be fully
attributed to the stripe phase but has nothing to do with pairing.
Incorporating a d-wave pairing potential in the stripe phase the spectral
weight in the antinodal region is removed, leaving a clean fermi pocket in the
nodal region.Comment: 5 pages, 6 figure
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