6,053 research outputs found
RIDI: Robust IMU Double Integration
This paper proposes a novel data-driven approach for inertial navigation,
which learns to estimate trajectories of natural human motions just from an
inertial measurement unit (IMU) in every smartphone. The key observation is
that human motions are repetitive and consist of a few major modes (e.g.,
standing, walking, or turning). Our algorithm regresses a velocity vector from
the history of linear accelerations and angular velocities, then corrects
low-frequency bias in the linear accelerations, which are integrated twice to
estimate positions. We have acquired training data with ground-truth motions
across multiple human subjects and multiple phone placements (e.g., in a bag or
a hand). The qualitatively and quantitatively evaluations have demonstrated
that our algorithm has surprisingly shown comparable results to full Visual
Inertial navigation. To our knowledge, this paper is the first to integrate
sophisticated machine learning techniques with inertial navigation, potentially
opening up a new line of research in the domain of data-driven inertial
navigation. We will publicly share our code and data to facilitate further
research
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The role of the Boudouard and water–gas shift reactions in the methanation of CO or CO<inf>2</inf> over Ni/γ-Al<inf>2</inf>O<inf>3</inf> catalyst
The Boudouard and the water–gas shift reactions were studied at different temperatures between 453 and 490 K over a Ni/γ-AlO catalyst in a Carberry batch reactor using various mixtures of CO, H and CO. The activity of the Boudouard reaction was found to be low, compared to the water–gas shift reaction, and diminished over time, suggesting that the temperature was too low for significant activity after an initiation period of CO adsorption. Furthermore, the rate of the Boudouard reaction has been reported to decrease in the presence of HO and H. The water–gas shift reaction was found to be the main reaction responsible for the production of CO in a mixture of CO, H and HO in the batch reactor. The ratio of the total amount of CO consumed to the total amount of CO produced showed that the catalyst was also active towards hydrogenation, where the rate of the hydrogenation reaction was very much faster than the water–gas shift reaction. The resulting ratio of to was found to be extremely low, probably leading to the production of long-chain hydrocarbons. The stoichiometry of the overall reaction was such that for every mole of CO produced, 1.5 mol of CO was consumed in the batch reactor. Kinetic studies were performed in the batch reactor. An Eley-Rideal mechanism was found to provide a good agreement with the experimental results over a wide range of partial pressures of steam and CO.JYL was funded by the Cambridge International Scholarship Scheme. The Cambridge Philosophical Society, the Lundgren Research Award and Corpus Christi College are also gratefully thanked for contributing to the support of his PhD studies. We are grateful for the assistance of Dr A.P.E. York, Johnson Matthey Technology Centre, Sonning Common, Reading RG4 9NH, United Kingdom, for his valuable input to this research.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ces.2016.06.04
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Kinetic studies of CO<inf>2</inf> methanation over a Ni/γ-Al<inf>2</inf>O<inf>3</inf> catalyst using a batch reactor
The methanation of CO₂ was investigated over a wide range of partial pressures of products and reactants using a gradientless, spinning-basket reactor operated in batch mode. The rate and selectivity of CO₂ methanation, using a 12 wt% Ni/γ-Al₂O₃ catalyst, were explored at temperatures 453 – 483 K and pressures up to 20 bar. The rate was found to increase with increasing partial pressures of H₂ and CO₂ when the partial pressures of these reactants were low; however, the rate of reaction was found to be insensitive to changes in the partial pressures of H₂ and CO₂ when their partial pressures were high. A convenient method of determining the effect of H₂O on the rate of reaction was also developed using the batch reactor and the inhibitory effect of H₂O on CO₂ methanation was quantified. The kinetic measurements were compared with a mathematical model of the reactor, in which different kinetic expressions were explored. The kinetics of the reaction were found to be consistent with a mechanism in which adsorbed CO₂ dissociated to adsorbed CO and O on the surface of the catalyst with the rate-limiting step being the subsequent dissociation of adsorbed CO.JYL was funded by the Cambridge International Scholarship Scheme. The Cambridge Philosophical Society, the Lundgren Research Award and Corpus Christi College are also gratefully thanked for contributing to the support of his PhD studies.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ces.2015.10.02
The human gC1qR/p32 gene, C1qBP. Genomic organization and promoter analysis
gC1qR is an ubiquitously expressed cell protein that interacts with the globular heads of C1q (gC1q) and many other ligands. In this study, the 7.8-kilobase pair (kb) human gC1qPJp32 (C1qBP) gene was cloned and found to consist of 6 exons and 5 introns. Analysis of a 1.3-kb DNA fragment at the 5′-flanking region of this gene revealed the presence of multiple TATA, CCAAT, and Sp1 binding sites. Luciferase reporter assays performed in different human cell lines demonstrated that the reporter gene was ubiquitously driven by this 1.3-kb fragment. Subsequent 5′ and 3′ deletion of this fragment confined promoter elements to within 400 base pairs (bp) upstream of the translational start site. Because the removal of the 8-bp consensus TATATATA at -399 to -406 and CCAAT at -410 to -414 did not significantly affect the transcription efficiency of the promoter, GC-rich sequences between this TATA box and the translation start site may be very important for the promoter activity of the C1qBP gene. One of seven GC-rich sequences in this region binds specifically to PANC-1 nuclear extracts, and the transcription factor Sp1 was shown to bind to this GC-rich sequence by the supershift assay. Primer extension analysis mapped three major transcription start regions. The farthest transcription start site is 49 bp upstream of the ATG translation initiation codon and is in close proximity of the specific SP1 binding site.postprin
Flight performance of actively foraging honey bees is reduced by a common pathogen
ArticleSudden and severe declines in honey bee (Apis mellifera) colony health in the US and Europe have been attributed, in part, to emergent microbial pathogens, however, the mechanisms behind the impact are unclear. Using roundabout flight mills, we measured the flight distance and duration of actively foraging, healthy-looking honey bees sampled from standard colonies, before quantifying the level of infection by Nosema ceranae and Deformed Wing Virus complex (DWV) for each bee. Neither the presence nor quantity of N. ceranae at low, natural levels of infection had any effect on flight distance or duration, but presence of DWV reduced flight distance by two thirds and duration by one half. Quantity of DWV was shown to have a significant, but weakly positive relation with flight distance and duration, however, the low amount of variation that was accounted for suggests further investigation by dose-response assays is required. We conclude that widespread, naturally occurring levels of infection by DWV weaken the flight ability of honey bees and high levels of within-colony prevalence are likely to reduce efficiency and increase the cost of resource acquisition. Predictions of implications of pathogens on colony health and function should take account of sub-lethal effects on flight performance.This work was funded by the Insect Pollinators Initiative (IPI) grants BB/I000100/1,
BB/I000097/1 and BB/I000097/2, C.B. Dennis British Beekeepers' Research Trust and the
High Wycombe Beekeepers’ Association. The IPI is funded jointly by the BBSRC, Defra,
NERC, The Scottish Government and The Wellcome Trust, under the LWEC Partnership.
Rothamsted Research is a national institute of bioscience strategically funded by the BBSRC
Evidence for a pervasive 'idling-mode' activity template in flying and pedestrian insects
This is the final version. Available on open access from the Royal Society via the DOI in this recordUnderstanding the complex movement patterns of animals in natural environments is a key objective of 'movement ecology'. Complexity results from behavioural responses to external stimuli but can also arise spontaneously in their absence. Drawing on theoretical arguments about decision-making circuitry, we predict that the spontaneous patterns will be scale-free and universal, being independent of taxon and mode of locomotion. To test this hypothesis, we examined the activity patterns of the European honeybee, and multiple species of noctuid moth, tethered to flight mills and exposed to minimal external cues. We also reanalysed pre-existing data for Drosophila flies walking in featureless environments. Across these species, we found evidence of common scale-invariant properties in their movement patterns; pause and movement durations were typically power law distributed over a range of scales and characterized by exponents close to 3/2. Our analyses are suggestive of the presence of a pervasive scale-invariant template for locomotion which, when acted on by environmental cues, produces the movements with characteristic scales observed in nature. Our results indicate that scale-finite complexity as embodied, for instance, in correlated random walk models, may be the result of environmental cues overriding innate behaviour, and that scale-free movements may be intrinsic and not limited to 'blind' foragers as previously thought.Rothamsted research receives grant aided support from the Biotechnology and Biological Sciences Research
Council. S.W. was funded jointly by a grant from BBSRC, Defra, NERC, the Scottish Government and the Wellcome
Trust, under the Insect Pollinators Initiative (grant nos. BB/I00097/1). A.J.P. was funded by a BBSRC Doctoral Training
Partnership in Food Security awarded to K.W. and J.W.C. H.B.C.J. was funded by a BBSRC Quota studentship
awarded to J.W.C. and J.K.
Interpreting and acting upon home blood pressure readings: A qualitative study
This article is made available through the Brunel Open Access Publishing Fund. Copyright @ 2013 Vasileiou et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.Background: Recent guidelines recognize the importance of home blood pressure monitoring (HBPM) as an adjunct to clinical measurements. We explored how people who have purchased and use a home blood pressure (BP) monitor make sense of, and act upon, readings and how they communicate with their doctor about the practice of home monitoring.
Methods: A qualitative study was designed and participants were purposively recruited from several areas in England, UK. Semi-structured in-depth interviews were conducted with 18 users of home BP monitors. The transcribed data were thematically analysed.
Results: Interpretation of home BP readings is complex, and is often characterised by uncertainty. People seek to assess value normality using ‘rules of thumb’, and often aim to identify the potential causes of the readings. This is done by drawing on lay models of BP function and by contextualising the readings to personal circumstances. Based on the perceived causes of the problematic readings, actions are initiated, mostly relating to changes in daily routines. Contacting the doctor was more likely when the problematic readings persisted and could not be easily explained, or when participants did not succeed in regulating their BP through their other interventions. Most users had notified their doctor of the practice of home monitoring, but medical involvement varied, with some participants reporting disinterest or reservations by doctors.
Conclusions: Involvement from doctors can help people overcome difficulties and resolve uncertainties around the interpretation of home readings, and ensure that the rules of thumb are appropriate. Home monitoring can be used to strengthen the patient-clinician relationship
A Quantitative Metric to Identify Critical Elements within Seafood Supply Networks
A theoretical basis is required for comparing key features and critical elements in wild fisheries and aquaculture
supply chains under a changing climate. Here we develop a new quantitative metric that is analogous to indices used to
analyse food-webs and identify key species. The Supply Chain Index (SCI) identifies critical elements as those elements with
large throughput rates, as well as greater connectivity. The sum of the scores for a supply chain provides a single metric that
roughly captures both the resilience and connectedness of a supply chain. Standardised scores can facilitate crosscomparisons
both under current conditions as well as under a changing climate. Identification of key elements along the
supply chain may assist in informing adaptation strategies to reduce anticipated future risks posed by climate change. The
SCI also provides information on the relative stability of different supply chains based on whether there is a fairly even
spread in the individual scores of the top few key elements, compared with a more critical dependence on a few key
individual supply chain elements. We use as a case study the Australian southern rock lobster Jasus edwardsii fishery, which
is challenged by a number of climate change drivers such as impacts on recruitment and growth due to changes in largescale
and local oceanographic features. The SCI identifies airports, processors and Chinese consumers as the key elements in
the lobster supply chain that merit attention to enhance stability and potentially enable growth. We also apply the index to
an additional four real-world Australian commercial fishery and two aquaculture industry supply chains to highlight the
utility of a systematic method for describing supply chains. Overall, our simple methodological approach to empiricallybased
supply chain research provides an objective method for comparing the resilience of supply chains and highlighting
components that may be critical
Risk factors for delay in symptomatic presentation: a survey of cancer patients
Background: Delay in symptomatic presentation leading to advanced stage at diagnosis may contribute to poor cancer survival. To inform public health approaches to promoting early symptomatic presentation, we aimed to identify risk factors for delay in presentation across several cancers.
Methods: We surveyed 2371 patients with 15 cancers about nature and duration of symptoms using a postal questionnaire. We calculated relative risks for delay in presentation (time from symptom onset to first presentation >3 months) by cancer, symptoms leading to diagnosis and reasons for putting off going to the doctor, controlling for age, sex and deprivation group.
Results: Among 1999 cancer patients reporting symptoms, 21% delayed presentation for >3 months. Delay was associated with greater socioeconomic deprivation but not age or sex. Patients with prostate (44%) and rectal cancer (37%) were most likely to delay and patients with breast cancer least likely to delay (8%). Urinary difficulties, change of bowel habit, systemic symptoms (fatigue, weight loss and loss of appetite) and skin symptoms were all common and associated with delay. Overall, patients with bleeding symptoms were no more likely to delay presentation than patients who did not have bleeding symptoms. However, within the group of patients with bleeding symptoms, there were significant differences in risk of delay by source of bleeding: 35% of patients with rectal bleeding delayed presentation, but only 9% of patients with urinary bleeding. A lump was a common symptom but not associated with delay in presentation. Twenty-eight percent had not recognised their symptoms as serious and this was associated with a doubling in risk of delay. Embarrassment, worry about what the doctor might find, being too busy to go to the doctor and worry about wasting the doctor’s time were also strong risk factors for delay, but were much less commonly reported (<6%).
Interpretation: Approaches to promote early presentation should aim to increase awareness of the significance of cancer symptoms and should be designed to work for people of the lowest socioeconomic status. In particular, awareness that rectal bleeding is a possible symptom of cancer should be raised
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