782 research outputs found
SWEEPFINDER2: Increased sensitivity, robustness, and flexibility
SweepFinder is a popular program that implements a powerful likelihood-based
method for detecting recent positive selection, or selective sweeps. Here, we
present SweepFinder2, an extension of SweepFinder with increased sensitivity
and robustness to the confounding effects of mutation rate variation and
background selection, as well as increased flexibility that enables the user to
examine genomic regions in greater detail and to specify a fixed distance
between test sites. Moreover, SweepFinder2 enables the use of invariant sites
for sweep detection, increasing both its power and precision relative to
SweepFinder
Impacts of the local environment on recruitment: a comparative study of North Sea and Baltic Sea fish stocks
Abstract
While the impact of environmental forcing on recruitment variability in marine populations remains largely elusive, studies spanning large spatial areas and many stocks are able to identify patterns common to different regions and species. In this study, we investigate the effects of the environment on the residuals of a Ricker stock–recruitment (SR) model, used as a proxy of prerecruits' survival, of 18 assessed stocks in the Baltic and North Seas. A probabilistic principal components (PCs) analysis permits the identification of groups of stocks with shared variability in the prerecruits' survival, most notably a group of pelagics in the Baltic Sea and a group composed of gadoids and herring in the North Sea. The first two PCs generally grouped the stocks according to their localizations: the North Sea, the Kattegat–Western Baltic, and the Baltic Sea. This suggests the importance of the local environmental variability on the recruitment strength. Hence, the prerecruits' survival variability is studied according to geographically disaggregated and potentially impacting abiotic or biotic variables. Time series (1990–2009) of nine environmental variables consistent with the spawning locations and season for each stock were extracted from a physical–biogeochemical model to evaluate their ability to explain the survival of prerecruits. Environmental variables explained &gt;70% of the survival variability for eight stocks. The variables water current, salinity, temperature, and biomass of other fish stocks are regularly significant in the models. This study shows the importance of the local environment on the dynamics of SR. The results provide evidence of the necessity of including environmental variables in stock assessment for a realistic and efficient management of fisheries.</jats:p
Location-Quality-aware Policy Optimisation for Relay Selection in Mobile Networks
Relaying can improve the coverage and performance of wireless access
networks. In presence of a localisation system at the mobile nodes, the use of
such location estimates for relay node selection can be advantageous as such
information can be collected by access points in linear effort with respect to
number of mobile nodes (while the number of links grows quadratically).
However, the localisation error and the chosen update rate of location
information in conjunction with the mobility model affect the performance of
such location-based relay schemes; these parameters also need to be taken into
account in the design of optimal policies. This paper develops a Markov model
that can capture the joint impact of localisation errors and inaccuracies of
location information due to forwarding delays and mobility; the Markov model is
used to develop algorithms to determine optimal location-based relay policies
that take the aforementioned factors into account. The model is subsequently
used to analyse the impact of deployment parameter choices on the performance
of location-based relaying in WLAN scenarios with free-space propagation
conditions and in an measurement-based indoor office scenario.Comment: Accepted for publication in ACM/Springer Wireless Network
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Challenges in Implementing Assessment and Management of Data Limited Stocks and Fisheries: IIFET Open Session & Stakeholder Perspectives
A series of session stakeholder presentations will address the current status, challenges, needs and future perspectives for implementation of management and ecological / economic assessment of data poor fish stocks and fisheries in management advice. This covers methods, simulation models and management strategy evaluation (MSE) tools to conduct assessment and evaluate economic efficiency and risks in exploiting data poor stocks caught in mixed, small scale, and indigenous fisheries. Focus is on accessibility of models and their development to ensure widespread and open access availability, user-friendly model operation, and efficient widespread adoption and implementation of those by scientists, stakeholders, and managers. Additional focus is on the data requirements for those models. The presentations will also address ways to link economic assessments, risk assessment and MSE with biological (ecological) assessment of stock status according to sustainable harvest levels in those data limited situations and systems to provide robust assessment and advice – and maybe even integrated ecological-economic advice? Invited stakeholder representatives from fishing industry, fisheries management, fisheries advice (ICES) and fisheries biological and economic science will present their perspectives and views on the above challenges.
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