1,393 research outputs found
Bivariate stochastic modeling of functional response with natural mortality
A correction due to Abbott (1925) is the standard method of dealing with control mortality in insect bioassay to estimate the mortality of an insect conditional on control mortality not having occurred. In this article a bivariate stochastic process for overall mortality is developed in which natural mortality and predation are jointly modeled to take account of the competing-risks associated with prey loss. The total mortality estimate from this model is essentially identical with that from more classical modeling. However, when predation loss is estimated in the absence of control mortality the results are somewhat different, with the estimate from the bivariate model being lower than that from using Abbottâs formula in conjunction with the classical model. It is argued that overdispersion in observed mortality data corresponds to correlated outcomes (death or survival) for the prey initially present, while Abbottâs correction relies implicitly on independence
Influence of MWCNT/surfactant dispersions on the mechanical properties of Portland cement pastes
This work studies the reinforcing effect of Multi Walled Carbon Nanotubes (MWCNT) on cement pastes. A 0.35% solid concentration of MWCNT in powder was dispersed in deionized water with sodium dodecyl sulfate (cationic surfactant), cetylpyridinium chloride (anionic surfactant) and triton X-100 (amphoteric surfactant) using an ultrasonic tip processor. Three concentrations of each surfactant (1mM, 10mM and 100mM) were tested, and all samples were sonicated until an adequate dispersion degree was obtained. Cement pastes with additions of carbon nanotubes of 0.15% by mass of cement were produced in two steps; first the dispersions of MWCNT were combined with the mixing water using an ultrasonic tip processor to guarantee homogeneity, and then cement was added and mixed until a homogeneous paste was obtained. Direct tensile strength, apparent density and open porosity of the pastes were measured after 7 days of curing. It was found that the MWCNT/surfactants dispersions decrease the mechanical properties of the cement based matrix due to an increased porosity caused by the presence of surfactants. © Published under licence by IOP Publishing Ltd
Cladding mode coupling in highly localized fiber Bragg gratings: modal properties and transmission spectra
The spectral characteristics of a fiber Bragg grating (FBG) with a
transversely inhomogeneous refractive index profile, differs con- siderably
from that of a transversely uniform one. Transmission spectra of inhomogeneous
and asymmetric FBGs that have been inscribed with focused ultrashort pulses
with the so-called point-by-point technique are investigated. The cladding mode
resonances of such FBGs can span a full octave in the spectrum and are very
pronounced (deeper than 20dB). Using a coupled-mode approach, we compute the
strength of resonant coupling and find that coupling into cladding modes of
higher azimuthal order is very sensitive to the position of the modification in
the core. Exploiting these properties allows precise control of such
reflections and may lead to many new sensing applications.Comment: Submission to OE, 16 pages, 6 figure
Tandem high dose therapy with hematopoietic progenitor cell rescue in children with high-risk solid tumors
A Hybrid Sequencing Approach Completes the Genome Sequence of Thermoanaerobacter ethanolicus JW 200
This is the final version. Available on open access from American Society for Microbiology via the DOI in this recordData availability.The complete genome sequence of T. ethanolicus JW 200 is deposited in GenBank under the accession number CP033580. Illumina and Oxford Nanopore DNA sequence reads have been deposited in the NCBI Sequence Read Archive (accession numbers SRR8113455 and SRR8113456).Thermoanaerobacter ethanolicus JW 200 has been identified as a potential sustainable biofuel producer due to its ability to readily ferment carbohydrates to ethanol. A hybrid sequencing approach, combining Oxford Nanopore and Illumina DNA sequence reads, was applied to produce a single contiguous genome sequence of 2,911,280âbp.Shell Research Ltd
Probing the Space of Toric Quiver Theories
We demonstrate a practical and efficient method for generating toric Calabi-Yau quiver theories, applicable to both D3 and M2 brane world-volume physics. A new analytic method is presented at low order parametres and an algorithm for the general case is developed which has polynomial complexity in the number of edges in the quiver. Using this algorithm, carefully implemented, we classify the quiver diagram and assign possible superpotentials for various small values of the number of edges and nodes. We examine some preliminary statistics on this space of toric quiver theories
Children and young peopleâs perspectives from UK lockdown: leisure-less experiences
If researchers are to understand the impacts of lockdown on children and young people, then the experiences of lockdown need to be explored from the perspective of the child. Young people participate in leisure for a multitude of reasons, yet, within the UK, children were largely unable to access their regular leisure activities for a six-month period during the first national lockdown. Within the context of this paper, leisure includes outdoor sports and physical activities within blue spaces. Following interviews with parents and young people (aged 11â16) focused on experiences of leisure during the Covid-19 pandemic, this qualitative study identified that children felt an intense sense of missing out on opportunities and found day-to-day life without leisure monotonous. However, there were some positive impacts of reduced leisure, such as a greater appreciation for what was once a regular activity. This research empowered the voice of children, so their distinct experiences were made visible to those who aim to support their wellbeing. Findings suggest that the promotion of leisure activities in the current climate could mitigate poor wellbeing among children associated with the Covid-19 pandemic
Item Development and Face Validity of the Rheumatoid Arthritis Patient Priorities in Pharmacological Interventions Outcome Measures
© 2015, Springer International Publishing Switzerland. Background: The assessment of rheumatoid arthritis (RA) is dominated by core sets and indices that have been developed by RA professionals. Previous research developed a set of eight priority treatment outcomes generated by patients to complement the professionally developed core sets for RA. Objective: This study aimed to facilitate quantitative measurement of these outcomes. Methods: Two consultation meetings with patient research partners diagnosed with RA (n=18) were held to identify face validity in existing instruments (Phase 1) at the Bristol Royal Infirmary. Where validated measures did not exist, new numerical rating scales (NRS) were constructed and discussed at two focus groups with patients diagnosed with RA (n=8) at the Bristol Royal Infirmary and the Royal National Hospital for Rheumatic Diseases (Phase 2). Feedback on the stem question, time frame, anchors and layout was recorded and transcribed verbatim. Results: Of the eight priorities, existing NRS for pain, activities of daily living and fatigue were voted as acceptable (Phase 1), but new NRS were required for five priorities. The partners strongly recommended that the three separate domains of severity, effect and ability to cope in each measurement area be assessed, as in the existing validated fatigue NRS. Focus group participants (Phase 2) made significant contributions to the phrasing of questions, for example how to ensure âmobilityâ could be uniformly understood and how changes in valued activities be judged appropriately. Conclusion: Through extensive patient feedback, 24 NRS were constructed based on priorities identified by patients and encompassing domains where existing questionnaires contain many more items and do not address three important concepts endorsed by patients: severity, effect and coping. The Rheumatoid Arthritis Patient Priorities in Pharmacological Interventions patient-reported outcome measures are now ready for the evaluation of comprehension, construct validity and sensitivity through an observational study
The Peaceful Atom Comes to Campus
Youthful idealism, institutional ambition, and Cold War sensibilities all helped shape the Michigan MemorialâPhoenix Project, the University of Michiganâs tribute to fallen World War II soldiers.</jats:p
Polymerase chain reaction evidence for human immunodeficiency virus 1 neutralization by passive immunization in patients with AIDS and AIDS-related complex.
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