330 research outputs found
A 3D stereo camera system for precisely positioning animals in space and time
PLT was supported by the Scottish Funding Council (grant HR09011) through the Marine Alliance for Science and Technology for Scotland.Here, we describe a portable stereo camera system that integrates a GPS receiver, an attitude sensor and 3D stereo photogrammetry to rapidly estimate the position of multiple animals in space and time. We demonstrate the performance of the system during a field test by simultaneously tracking the individual positions of six long-finned pilot whales, Globicephala melas. In shore-based accuracy trials, a system with a 50-cm stereo baseline had an average range estimation error of 0.09 m at a 5-m distance increasing up to 3.2 at 50 m. The system is especially useful in field situations where it is necessary to follow groups of animals travelling over relatively long distances and time periods whilst obtaining individual positions with high spatial and temporal resolution (up to 8 Hz). These positions provide quantitative estimates of a variety of key parameters and indicators for behavioural studies such as inter-animal distances, group dispersion, speed and heading. This system can additionally be integrated with other techniques such as archival tags, photo-identification methods or acoustic playback experiments to facilitate fieldwork investigating topics ranging from natural social behaviour to how animals respond to anthropogenic disturbance. By grounding observations in quantitative metrics, the system can characterize fine-scale behaviour or detect changes as a result of disturbance that might otherwise be difficult to observe.PostprintPeer reviewe
The choreography of belonging : toothed whale spatial cohesion and acoustic communication
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2016To maintain the benefits of group membership, social animals need mechanisms to stay
together and reunite if separated. This thesis explores the acoustic signals that dolphins
use to overcome this challenge and mediate their complex relationships in a dynamic 3D
environment. Bottlenose dolphins are the most extensively studied toothed whale, but
research on acoustic behavior has been limited by an inability to identify the vocalizing
individual or measure inter-animal distances in the wild. This thesis resolves these
problems by simultaneously deploying acoustic tags on closely-associated pairs of known
animals. These first reported deployments of acoustic tags on dolphins allowed me to
characterize temporal patterns of vocal behavior on an individual level, uncovering large
variation in vocal rates and inter-call waiting time between animals. Looking more
specifically at signature whistles, a type of call often linked to cohesion, I found that
when one animal produced its own signature whistle, its partner was more likely to
respond with its own whistle. To better evaluate potential cohesion functions for
signature whistles, I then modeled the probability of an animal producing a signature
whistle at different times during a temporary separation and reunion from its partner.
These data suggest that dolphins use signature whistles to signal a motivation to reunite
and to confirm identity prior to rejoining their partner. To examine how cohesion is
maintained during separations that do not include whistles, I then investigated whether
dolphins could keep track of their partners by passively listening to conspecific
echolocation clicks. Using a multi-pronged approach, I demonstrated that the passive
detection range of echolocation clicks overlaps with the typical separation ranges of
Sarasota mother-calf pairs and that the amount of time since an animal was last able to
detect a click from its partner helped explain its probability of producing a signature
whistle. Finally, this thesis developed a portable stereo camera system to study cohesion
in situations where tagging is not possible. Integrating a GPS receiver, an attitude sensor
and 3D stereo photogrammetry, the system rapidly positions multiple animals, grounding
behavioral observations in quantitative metrics and characterizing fine-scale changes that
might otherwise be missed.This work was supported by the Office of Naval Research (N000140910528 and
N000141210417), the WHOI Marine Mammal Center, WHOI Biology Department,
WHOI Academic Programs Endowed Funds, the MIT Martin Family Foundation for
Sustainability, the MIT Graduate Student Government, the Grossman Family Foundation,
and the Danish Council for Independent Research (11-107628)
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A study of the information needs of the users of a folk music library and the implications for the design of a digital library system
A qualitative study of user information needs is reported, based on a purposive sample of users and potential users of the Vaughan Williams Memorial Library, a small specialist folk music library in North London. The study set out to establish what the user’s (both existing and potential) information needs are, so that the library’s online service may take them into account with its design. The information needs framework proposed by Nicholas (2000) is used as an analytical tool to achieve this end. The demographics of the users were examined in order to establish four user groups: Performer, Academic, Professional and Enthusiast. Important information needs were found to be based on social interaction, and key resources of the library were its staff, the concentration of the collection and the library’s social nature. A collection of broad design requirements are proposed based on the analysis and this study also provided some insights into the issue of musical relevance, which are discussed
Mathematical models and time-frequency heat maps for surface gravity waves generated by thin ships
Recent research suggests that studying the time-frequency response of ship
wave signals has potential to shed light on a range of applications, such as
inferring the dynamical and geometric properties of a moving vessel based on
the surface elevation data detected at a single point in space. We continue
this line of research here with a study of mathematical models for thin ships
using standard Wigley hulls and Wigley transom-stern hulls as examples.
Mathematical models of varying sophistication are considered. These include
basic minimal models which use applied pressure distributions as proxies for
the ship hull. The more complicated models are Michell's thin ship theory and
the Hogner model, both of which explicitly take into account the shape of the
hull. We outline a methodology for carefully choosing the form and parameter
values in the minimal models such that they reproduce the key features of the
more complicated models in the time-frequency domain. For example, we find that
a two-pressure model is capable of producing wave elevation signals that have a
similar time-frequency profile as that for Michell's thin ship theory applied
to the Wigley hull, including the crucially important features caused by
interference between waves created at the bow and stern of the ship. One of the
key tools in our analysis is the spectrogram, which is a heat-map visualisation
in the time-frequency domain. Our work here extends the existing knowledge on
the topic of spectrograms of ship waves. The theoretical results in this study
are supported by experimental data collected in a towing tank at the Australian
Maritime College using model versions of the standard Wigley hulls and Wigley
transom-stern hulls
Access to scientific literature by the conservation community
Access to the scientific literature is perceived to be a challenge to the biodiversity conservation community, but actual level of literature access relative to needs has never been assessed globally. We examined this question by surveying the constituency of the International Union for Conservation of Nature (IUCN) as a proxy for the conservation community, generating 2,285 responses. Of these respondents, ∼97% need to use the scientific literature in order to support their IUCN-related conservation work, with ∼50% needing to do so at least once per week. The crux of the survey revolved around the question, “How easy is it for you currently to obtain the scientific literature you need to carry out your IUCN-related work?” and revealed that roughly half (49%) of the respondents find it not easy or not at all easy to access scientific literature. We fitted a binary logistic regression model to explore factors predicting ease of literature access. Whether the respondent had institutional literature access (55% do) is the strongest predictor, with region (Western Europe, the United States, Canada, Australia and New Zealand) and sex (male) also significant predictors. Approximately 60% of respondents from Western Europe, the United States, Canada, Australia and New Zealand have institutional access compared to ∼50% in Asia and Latin America, and ∼40% in Eastern Europe and in Africa. Nevertheless, accessing free online material is a popular means of accessing literature for both those with and without institutional access. The four journals most frequently mentioned when asked which journal access would deliver the greatest improvements to the respondent’s IUCN-related work were Conservation Biology, Biological Conservation, Nature, and Science. The majority prefer to read journal articles on screen but books in hard copy. Overall, it is apparent that access to the literature is a challenge facing roughly half of the conservation community worldwide
Making Sense of a New Transport System: An Ethnographic Study of the Cambridgeshire Guided Busway
An increase in public transport use has the potential to contribute to improving population health, and there is growing interest in innovative public transport systems. Yet how new public transport infrastructure is experienced and integrated (or not) into daily practice is little understood. We investigated how the Cambridgeshire Guided Busway, UK, was used and experienced in the weeks following its opening, using the method of participant observation (travelling on the busway and observing and talking to passengers) and drawing on Normalization Process Theory to interpret our data. Using excerpts of field notes to support our interpretations, we describe how the ease with which the new transport system could be integrated into existing daily routines was important in determining whether individuals would continue to use it. It emerged that there were two groups of passengers with different experiences and attitudes. Passengers who had previously travelled frequently on regular bus services did not perceive the new system to be an improvement; consequently, they were frustrated that it was differentiated from and not coherent with the regular system. In contrast, passengers who had previously travelled almost exclusively by car appraised the busway positively and perceived it to be a novel and superior form of travel. Our rich qualitative account highlights the varied and creative ways in which people learn to use new public transport and integrate it into their everyday lives. This has consequences for the introduction and promotion of future transport innovations. It is important to emphasise the novelty of new public transport, but also the ways in which its use can become ordinary and routine. Addressing these issues could help to promote uptake of other public transport interventions, which may contribute to increasing physical activity and improving population health. © 2013 Jones et al
Improving the normalization of complex interventions: measure development based on normalization process theory (NoMAD): study protocol
<b>Background</b> Understanding implementation processes is key to ensuring that complex interventions in healthcare are taken up in practice and thus maximize intended benefits for service provision and (ultimately) care to patients. Normalization Process Theory (NPT) provides a framework for understanding how a new intervention becomes part of normal practice. This study aims to develop and validate simple generic tools derived from NPT, to be used to improve the implementation of complex healthcare interventions.<p></p>
<b>Objectives</b> The objectives of this study are to: develop a set of NPT-based measures and formatively evaluate their use for identifying implementation problems and monitoring progress; conduct preliminary evaluation of these measures across a range of interventions and contexts, and identify factors that affect this process; explore the utility of these measures for predicting outcomes; and develop an online users’ manual for the measures.<p></p>
<b>Methods</b> A combination of qualitative (workshops, item development, user feedback, cognitive interviews) and quantitative (survey) methods will be used to develop NPT measures, and test the utility of the measures in six healthcare intervention settings.<p></p>
<b>Discussion</b> The measures developed in the study will be available for use by those involved in planning, implementing, and evaluating complex interventions in healthcare and have the potential to enhance the chances of their implementation, leading to sustained changes in working practices
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Perinatal health monitoring in Europe: results from the EURO-PERISTAT project
Data about deliveries, births, mothers and newborn babies are collected extensively to monitor the health and care of mothers and babies during pregnancy, delivery and the post-partum period, but there is no common approach in Europe. We analysed the problems related to using the European data for international comparisons of perinatal health. We made an inventory of relevant data sources in 25 European Union (EU) member states and Norway, and collected perinatal data using a previously defined indicator list. The main sources were civil registration based on birth and death certificates, medical birth registers, hospital discharge systems, congenital anomaly registers, confidential enquiries and audits. A few countries provided data from routine perinatal surveys or from aggregated data collection systems. The main methodological problems were related to differences in registration criteria and definitions, coverage of data collection, problems in combining information from different sources, missing data and random variation for rare events. Collection of European perinatal health information is feasible, but the national health information systems need improvements to fill gaps. To improve international comparisons, stillbirth definitions should be standardised and a short list of causes of fetal and infant deaths should be developed
Left Ventricular Noncompaction:Anatomical Phenotype or Distinct Cardiomyopathy?
The present study was funded by the Souter Charitable Foundation and the Chest, Heart and Stroke Scotland Charity. Dr. Weir-McCall is supported by the Wellcome Trust through the Scottish Translational Medicine and Therapeutics Initiative (Grant no. WT 085664) in the form of a Clinical Research Fellowship.Background: There is considerable overlap between left ventricular noncompaction (LVNC) and other cardiomyopathies. LVNC has been reported in up to 40% of the general population, raising questions about whether it is a distinct pathological entity, a remodeling epiphenomenon, or merely an anatomical phenotype. Objectives: The authors determined the prevalence and predictors of LVNC in a healthy population using 4 cardiac magnetic resonance imaging diagnostic criteria. Methods: Volunteers >40 years of age (N = 1,651) with no history of cardiovascular disease (CVD), a 10-year risk of CVD < 20%, and a B-type natriuretic peptide level greater than their gender-specific median underwent magnetic resonance imaging scan as part of the TASCFORCE (Tayside Screening for Cardiac Events) study. LVNC ratios were measured on the horizontal and vertical long axis cine sequences. All individuals with a noncompaction ratio of ≥2 underwent short axis systolic and diastolic LVNC ratio measurements, and quantification of noncompacted and compacted myocardial mass ratios. Those who met all 4 criteria were considered to have LVNC. Results: Of 1,480 participants analyzed, 219 (14.8%) met ≥1 diagnostic criterion for LVNC, 117 (7.9%) met 2 criteria, 63 (4.3%) met 3 criteria, and 19 (1.3%) met all 4 diagnostic criteria. There was no difference in demographic or allometric measures between those with and without LVNC. Long axis noncompaction ratios were the least specific, with current diagnostic criteria positive in 219 (14.8%), whereas the noncompacted to compacted myocardial mass ratio was the most specific, only being met in 61 (4.4%). Conclusions: A significant proportion of an asymptomatic population free from CVD satisfy all currently used cardiac magnetic resonance imaging diagnostic criteria for LVNC, suggesting that those criteria have poor specificity for LVNC, or that LVNC is an anatomical phenotype rather than a distinct cardiomyopathy.Publisher PDFPeer reviewe
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