94 research outputs found

    Passive acoustic tracking of the three-dimensional movements and acoustic behaviour of toothed whales in close proximity to static nets

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    Funding: Department for Environment, Food and Rural Affairs, UK Government (Grant Number(s): ME6052; Grant recipient(s): Jamie Macaulay, Allen Kingston, Simon Northridge, Alexander Coram). University of St Andrews.1. Entanglement in net fisheries (static and drift) is the largest known cause of direct anthropogenic mortality to many small cetacean species, including harbour porpoise (Phocoena phocoena), in UK waters. Despite this, little is known about the behaviour of small cetaceans in proximity to nets. 2. We have developed a passive acoustic monitoring (PAM) system for tracking the fine-scale three-dimensional (3D) movements of echolocating cetaceans around actively fishing nets by localising their acoustic clicks. The system consists of two compact four-channel acoustic recorders with sample-synchronised sensor packages that use 3D motion tracking technology to accurately calculate log orientation, depth, water temperature and ambient light level. Two recorders were used in tandem, with each one attached to and floating above the net floatline. The system can be deployed during normal fishing operations by a trained researcher or experienced fisheries observer. Recordings were analysed in PAMGuard software and the 3D positions of echolocating animals in the vicinity of the system were calculated using an acoustic particle filter-based localisation method. 3. We present findings from four deployments in UK waters (each 1–2 days in duration) in which 12 distinct harbour porpoise encounters yielded a sufficient number of detected clicks to track their movements around the net. The tracks show a variety of behaviours, including multiple instances of animals actively foraging in close proximity to the fishing net. 4. We show that a relatively inexpensive PAM system, which is practical to deploy from active fishing vessels, is capable of providing highly detailed data on harbour porpoise behaviour around nets. As harbour porpoises are the one of the most difficult species to localise, this methodology is likely to be suitable for elucidating the behaviour of many other toothed whale species in a variety of situations.Publisher PDFPeer reviewe

    The role of water, sanitation and hygiene interventions in reducing soil-transmitted helminths: interpreting the evidence and identifying next steps.

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    The transmission soil transmitted helminths (STH) occurs via ingestion of or contact with infective stages present in soil contaminated with human faeces. It follows therefore that efforts to reduce faecal contamination of the environment should help to reduce risk of parasite exposure and improvements in water, sanitation and hygiene (WASH) are seen as essential for the long-term, sustainable control of STH. However, the link between WASH and STH is not always supported by the available evidence from randomised controlled trials, which report mixed effects of WASH intervention on infection risk. This review critically summarises the available trial evidence and offers an interpretation of the observed heterogeneity in findings. The review also discusses the implications of findings for control programmes and highlights three main issues which merit further consideration: intervention design, exposure assessment, and intervention fidelity assessment

    The Physics of the B Factories

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    This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

    Ethnicity and Special Education Research: Identifying Questions and Methods

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    This article presents questions, offers ideas, and solicits input regarding hypotheses and methodologies needed to extend our understanding of the ethnic representation of students identified as having serious emotional disturbance (SED). Technical methods are discussed to ensure that estimates of the extent of disproportionate representation are accurate, technically defensible, and interpretable for purposes of further research and policy decisions. Research questions and analyses needed to produce a better conceptual understanding of why disproportionality occurs are explored. Societal issues are described that influence definitions, methods, and interpretations and will continue to influence capacity to respond to the problem of disproportionate ethnic representation of students with SED