5,977 research outputs found
Conflict between International Treaties: failing to mitigate the effects of introduced marine species.
Humans have changed the face of the earth - we have intentionally altered the locations of species in order to achieve food and economic security (eg, aquaculture of the freshwater fish Tilapia and the marine algae Kappaphycus) while also appealing to our cultural and aesthetic values (eg, the introduction of gorse to New Zealand and Australia). We have accidentally spread pathogens and diseases beyond their natural ranges1 and we have improved our technologies (such as shipping) to such an extent that we can transit our planet in shorter and shorter timeframes.
All of these activities have occurred over many hundreds of years and have led in one way or another, to an increasing number of species being introduced beyond their natural ranges. Such introductions are now considered one of the top five threats to native biological diversity.
This paper examines how humans have impacted upon the marine environment through the introduction of species beyond their native ranges. Introduced species impact upon native biodiversity, spread diseases and pathogens, and have had economic and social impacts in their ânewâ ecosystems. Because of the range and extent of introduced species impacts, numerous methods to mitigate the effects of
introduced species have been developed and implemented. Within this paper we will examine how two international legal instruments, the Convention on Biological Diversity, 1992 (CBD) and the World Trade Organizationâs General Agreement on Tariffs and Trade 1994 (GATT), in particular its associated Agreement on the Application of Sanitary and Phytosanitary Measures (SPS), deal with introduced species. In this context, the paper focuses on the potential for conflict that may arise with the application of these international legal instruments, thus causing a failure to
effectively mitigate for the effects of introduced species
An overview of risk assessment in a marine biosecurity context
Our ability to manage the variety of human induced stresses in the marine environment
is hampered by limited resources, a lack of fundamental knowledge and the
absence of appropriate tools (Lubchenco et al. 1991; Norse 1993). This is particularly
true when faced with introduced marine species. Structured and transparent
evaluation techniques that both determine and justify management decisions are
needed to effectively deal with introduced marine species in both an ecological and
socio-political sense (as discussed by Hewitt et al., Chap. 33). Coupling this need
with knowledge, resource and data limitations has led decision makers and management
to use risk assessment as a means to direct their actions.
In simple terms, risk assessment is a method of evaluating the likelihood that an
event may occur and the consequences of such an event. In general, ecological risk
assessment proceeds by establishing the context (e.g., introduced species in a
region; hazard analysis); identifying the risk, hazards and effects (e.g., impacts on
core values); assessing those risks (analyse and evaluate the risks); and treating the
risk(s) (e.g., incursion response activity, mitigation, Australian Risk Management
Guidelines; Standards Australia 2000, 2004). A measure of risk is derived by multiplying
likelihood by consequence. Hazard analysis (a technique often confused
with risk assessment) determines the actions, events, substances, environmental
conditions, or species that could result in an undesired event, but does not identify
the likelihood or the level of consequence. Introduced species, vectors or transport
pathways are all examples of hazards.
Likelihood is the probability that an event may occur. Typically, likelihood will
range from rare occurrence to highly likely (or frequent). Consequence, on the
other hand, measures the impact an event may have on the values being assessed
and can be derived by measuring the change in value from a pre- and post impacted
system. Although monetary units are often used to measure change in value
(because they are easily understood and facilitate comparison) this does not have to
be the unit of measure; semi-quantitative categorical ranking (e.g., low, medium,
high value) is also possible
Revisiting the relativistic ejection event in XTE J1550-564 during the 1998 outburst
We revisit the discovery outburst of the X-ray transient XTE J1550â564 during which relativistic jets were observed in 1998 September, and review the radio images obtained with the Australian Long Baseline Array, and light curves obtained with the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array. Based on Hi spectra, we constrain the source distance to between 3.3 and 4.9 kpc. The radio images, taken some 2 d apart, show the evolution of an ejection event. The apparent separation velocity of the two outermost ejecta is at least 1.3c and may be as large as 1.9c; when relativistic effects are taken into account, the inferred true velocity is â„ 0.8c. The flux densities appear to peak simultaneously during the outburst, with a rather flat (although still optically thin) spectral index of â0.2
An ecological role for assortative mating under infection?
ReviewThis is the final version of the article. Available from Springer Verlag via the DOI in this record.Wildlife diseases are emerging at a higher rate than ever before meaning that understanding their potential impacts is essential, especially for those species and populations that may already be of conservation concern. The link between population genetic structure and the resistance of populations to disease is well understood: high genetic diversity allows populations to better cope with environmental changes, including the outbreak of novel diseases. Perhaps following this common wisdom, numerous empirical and theoretical studies have investigated the link between disease and disassortative mating patterns, which can increase genetic diversity. Few however have looked at the possible link between disease and the establishment of assortative mating patterns. Given that assortative mating can reduce genetic variation within a population thus reducing the adaptive potential and long-term viability of populations, we suggest that this link deserves greater attention, particularly in those species already threatened by a lack of genetic diversity. Here, we summarise the potential broad scale genetic implications of assortative mating patterns and outline how infection by pathogens or parasites might bring them about. We include a review of the empirical literature pertaining to disease-induced assortative mating. We also suggest future directions and methodological improvements that could advance our understanding of how the link between disease and mating patterns influences genetic variation and long-term population viability.Funding was provided by Marie Curie Fellowship and NERC PhD Studentship
Analysis of Bone Architecture in Rodents Using Micro-Computed Tomography.
This chapter describes the use of micro-computed tomography scanning for analyzing bone structure, focussing on rodent bone. It discusses sample preparation, the correct setup of the scanner, the impact of some of the important scanner settings and new applications
MINLO: Multi-scale improved NLO
In the present work we consider the assignment of the factorization and
renormalization scales in hadron collider processes with associated jet
production, at next-to-leading order (NLO) in perturbation theory. We propose a
simple, definite prescription to this end, including Sudakov form factors to
consistently account for the distinct kinematic scales occuring in such
collisions. The scheme yields results that are accurate at NLO and, for a large
class of observables, it resums to all orders the large logarithms that arise
from kinematic configurations involving disparate scales. In practical terms
the method is most simply understood as an NLO extension of the matrix element
reweighting procedure employed in tree level matrix element-parton shower
merging algorithms. By way of a proof-of-concept, we apply the method to Higgs
and Z boson production in association with up to two jets.Comment: 27 pages, 17 figure
Cross Section Ratios between different CM energies at the LHC: opportunities for precision measurements and BSM sensitivity
The staged increase of the LHC beam energy provides a new class of
interesting observables, namely ratios and double ratios of cross sections of
various hard processes. The large degree of correlation of theoretical
systematics in the cross section calculations at different energies leads to
highly precise predictions for such ratios. We present in this letter few
examples of such ratios, and discuss their possible implications, both in terms
of opportunities for precision measurements and in terms of sensitivity to
Beyond the Standard Model dynamics.Comment: 19 pages, 9 figure
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