2,563 research outputs found
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Extensive use of mesopelagic waters by a Scalloped hammerhead shark (Sphyrna lewini) in the Red Sea
Background: Despite being frequently landed in fish markets along the Saudi Arabian Red Sea coast, information regarding fundamental biology of the Scalloped hammerhead shark (Sphyrna lewini) in this region is scarce. Satellite telemetry studies can generate important data on life history, describe critical habitats, and ultimately redefine management strategies for sharks. To better understand the horizontal and vertical habitat use of S. lewini in the Red Sea and to aid with potential future development of zoning and management plans for key habitats, we deployed a pop-up satellite archival transmitting tag to track a single female specimen (240 cm total length) for a tracking period of 182 days.
Results: The tag was physically recovered after a deployment period of 6 months, thus providing the complete archived dataset of more than one million depth and temperature records. Based on a reconstructed, most probable track, the shark travelled a circular distance of approximately 1000 km from the central Saudi Arabian Red Sea southeastward into Sudanese waters, returning to the tagging location toward the end of the tracking period. Mesopelagic excursions to depths between 650 and 971 m occurred on 174 of the 182 days of the tracking period. Intervals between such excursions were characterized by constant oscillatory diving in the upper 100 m of the water column.
Conclusions: This study provides evidence that mesopelagic habitats might be more commonly used by S. lewini than previously suggested. We identified deep diving behavior throughout the 24-h cycle over the entire 6-month tracking period. In addition to expected nightly vertical habitat use, the shark exhibited frequent mesopelagic excursions during daytime. Deep diving throughout the diel cycle has not been reported before and, while dive functionality remains unconfirmed, our study suggests that mesopelagic excursions may represent foraging events within and below deep scattering layers. Additional research aimed at resolving potential ecological, physiological and behavioral mechanisms underpinning vertical movement patterns of S. lewini will help to determine if the single individual reported here is representative of S. lewini populations in the Red Sea
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Contact and channel modelling to support the early design of technical systems
The early design of mechanical systems is critical because it constrains options later in the design process. In this early stage of the design process, designers must consider customer requirements, how they are related to system functionality and how these requirements and functions are implemented in the physical interactions between components and sub-systems. This paper proposes an approach by which the Contact and Channel Model (C&CM) can be applied to support this stage of embodiment design. The proposed approach is implemented in a computer support tool and illustrated through a simple example. A number of opportunities for further work to extend and evaluate the approach are identified. We argue that our approach offers a unique way to consider the functionality of a design
alongside the parts, surfaces and physical effects which embody that functionality, and provides an intuitive representation which could help designers iteratively develop and express this relationship
The Role of Neighborhoods in the Receipt of Transcranial Doppler Screening among Children with Sickle Cell Disease
Summary: Although transcranial Doppler (TCD) screening assesses the need for stroke prevention efforts among children with sickle cell disease (SCD), screening rates remain low across many parts of the United States. We sought to identify neighborhoods with low TCD screening rates and neighborhood-level factors related to screening to inform the utility of community-level interventions to improve TCD screening. Children ages 2 to 16 years with SCD (HbSS/HbS/b-thalassemia) living in Wayne County, MI, were identified in Michigan Medicaid (2007 to 2011) through newborn screening records. Children were enrolled for Z1 year and could contribute multiple years. We determined receipt of Z1 TCD screening and neighborhood (census tract) each year. The proportion of children receiving TCD in the tract was calculated and investigated for spatial patterns across tracts (Moran's I). Median household income, % unemployment, % black residents, and % less than high school education within each tract were ascertained from the American Community Survey. Logistic regression with generalized estimating equations was used to model associations between TCD screening and neighborhood-level factors. Overall, 329 children contributed 532 person-years and screening rates increased from 7% to 36% from 2007 to 2011. Median screening rate in tracts was 0% (interquartile range=29%) and there was no spatial pattern of TCD screening across tracts (Moran's I Z-score= 0.94, P-value=0.35). No associations were found between neighborhood characteristics and receipt of TCD screening in this disadvantaged Michigan county. Additional research is needed to inform interventions to increase TCD screening in this high stroke-risk population
Multi-gluon helicity amplitudes with one off-shell leg within high energy factorization
Basing on the Slavnov-Taylor identities, we derive a new prescription to
obtain gauge invariant tree-level scattering amplitudes for the process g*g->Ng
within high energy factorization. Using the helicity method, we check the
formalism up to several final state gluons, and we present analytical formulas
for the the helicity amplitudes for N=2. We also compare the method with
Lipatov's effective action approach.Comment: 25 pages, quite a few figures, an appendix added, typos correcte
Ethics for civil indoor drones: a qualitative analysis
[EN] Drones face two main concerns: safety and security/privacy. Whilst safety has been broadly studied by literature, less research has been carried out into security/privacy. Moreover, current European regulations on drone flights apply to outdoor drones but not always to their indoor counterparts. However, several industrial sectors have started to use drones for indoor tasks such as surveillance, architecture, emergencies, and communication media. A qualitative study has been conducted in order to explore the concerns expressed by civil drone operators over the measures that manufacturers include in their products and information packages. Codes of conduct could also help these parties when there is no legal regulation that can be applied. We used content analysis as the method of analysis for three different sources: secondary data from a literature review and from public European documents, and primary data from focus groups. Results show that safety and security/privacy by design are seen as the best ethical measures, whilst codes of conduct could be used as complimentary information for professional users.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: The project leading to this application has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 732433. Project: AiRT, Technology transfer of RPAs for the creative industry, H2020-ICT-2016-2017.De-Miguel-Molina, M.; Santamarina-Campos, V.; Carabal-Montagud, M.; De-Miguel-Molina, B. (2018). Ethics for civil indoor drones: a qualitative analysis. International Journal of Micro Air Vehicles. 10(4):340-351. https://doi.org/10.1177/1756829318794004S34035110
Overcoming barriers to engaging socio-economically disadvantaged populations in CHD primary prevention: a qualitative study
<p><b>Background:</b> Preventative medicine has become increasingly important in efforts to reduce the burden of chronic disease in industrialised countries. However, interventions that fail to recruit socio-economically representative samples may widen existing health inequalities. This paper explores the barriers and facilitators to engaging a socio-economically disadvantaged (SED) population in primary prevention for coronary heart disease (CHD).</p>
<p><b>Methods:</b> The primary prevention element of Have a Heart Paisley (HaHP) offered risk screening to all eligible individuals. The programme employed two approaches to engaging with the community: a) a social marketing campaign and b) a community development project adopting primarily face-to-face canvassing. Individuals living in areas of SED were under-recruited via the social marketing approach, but successfully recruited via face-to-face canvassing. This paper reports on focus group discussions with participants, exploring their perceptions about and experiences of both approaches.</p>
<p><b>Results:</b> Various reasons were identified for low uptake of risk screening amongst individuals living in areas of high SED in response to the social marketing campaign and a number of ways in which the face-to-face canvassing approach overcame these barriers were identified. These have been categorised into four main themes: (1) processes of engagement; (2) issues of understanding; (3) design of the screening service and (4) the priority accorded to screening. The most immediate barriers to recruitment were the invitation letter, which often failed to reach its target, and the general distrust of postal correspondence. In contrast, participants were positive about the face-to-face canvassing approach. Participants expressed a lack of knowledge and understanding about CHD and their risk of developing it and felt there was a lack of clarity in the information provided in the mailing in terms of the process and value of screening. In contrast, direct face-to-face contact meant that outreach workers could explain what to expect. Participants felt that the procedure for uptake of screening was demanding and inflexible, but that the drop-in sessions employed by the community development project had a major impact on recruitment and retention.</p>
<p><b>Conclusion:</b> Socio-economically disadvantaged individuals can be hard-to-reach; engagement requires strategies tailored to the needs of the target population rather than a population-wide approach.</p>
Flavor in Minimal Conformal Technicolor
We construct a complete, realistic, and natural UV completion of minimal
conformal technicolor that explains the origin of quark and lepton masses and
mixing angles. As in "bosonic technicolor", we embed conformal technicolor in a
supersymmetric theory, with supersymmetry broken at a high scale. The exchange
of heavy scalar doublets generates higher-dimension interactions between
technifermions and quarks and leptons that give rise to quark and lepton masses
at the TeV scale. Obtaining a sufficiently large top quark mass requires strong
dynamics at the supersymmetry breaking scale in both the top and technicolor
sectors. This is natural if the theory above the supersymmetry breaking also
has strong conformal dynamics. We present two models in which the strong top
dynamics is realized in different ways. In both models, constraints from
flavor-changing effects can be easily satisfied. The effective theory below the
supersymmetry breaking scale is minimal conformal technicolor with an
additional light technicolor gaugino. We argue that this light gaugino is a
general consequence of conformal technicolor embedded into a supersymmetric
theory. If the gaugino has mass below the TeV scale it will give rise to an
additional pseudo Nambu-Goldstone boson that is observable at the LHC.Comment: 37 pages; references adde
Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation
To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences) was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance) as well as deactivation of limbic structures (that regulate motivation and emotional tone). This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity
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