589 research outputs found

    Comparison of diverse methods for the correction of atmospheric effects on LANDSAT and SKYLAB images

    Get PDF
    Earth's atmosphere reduces a sensors ability in currently discriminating targets. Using radiometric correction to reduce the atmospheric effects may improve considerably the performance of an automatic image interpreter. Several methods for radiometric correction from the open literature are compared leading to the development of an atmospheric correction system

    A decision aid to support family carers of people living with dementia towards the end-of-life: Coproduction process, outcome and reflections

    Get PDF
    BACKGROUND: Family carers of people living with dementia often need support with making decisions about care. Many find end-of-life care decisions particularly difficult. The aim of this article is to present an evidence- and theoretical-based process for developing a decision aid to support family carers of people with dementia towards the end-of-life. METHODS: Following a systematic process, we developed a decision aid using coproduction methods and matrices to synthesize data from a systematic review and qualitative interviews with people living with dementia and family carers. Data were presented to coproduction workshops of people living with dementia, family carers, practitioners and professionals. Development was guided by the Ottawa Decision Support Framework and a modified Interprofessional Shared Decision-Making model. RESULTS: The decision aid covers four decision areas: (1) changes in care; (2) eating and drinking difficulties; (3) everyday well-being; and (4) healthcare, tests and medication. We present an interactive decision aid, using a variety of approaches including written text, Frequently Asked Questions, top tips and illustrative quotes from people living with dementia and family carers. CONCLUSION: This is the first decision aid that focusses on multiple decisions towards the end-of-life in dementia care. The process offers a template for others to develop decision aids or similar interventions, and how to include people living with dementia in coproduction. PATIENT OR PUBLIC CONTRIBUTION: Family carers provided feedback on data collection, data analysis and the decision aid, and one is a coauthor. People living with dementia and family carers were integral to the coproduction workshops

    Correlations in Nuclear Arrhenius-Type Plots

    Full text link
    Arrhenius-type plots for multifragmentation process, defined as the transverse energy dependence of the single-fragment emission-probability, -ln(p_{b}) vs 1/sqrt(E_{t}), have been studied by examining the relationship of the parameters p_{b} and E_{t} to the intermediate-mass fragment multiplicity . The linearity of these plots reflects the correlation of the fragment multiplicity with the transverse energy. These plots may not provide thermal scaling information about fragment production as previously suggested.Comment: 12 pages, Latex, 3 Postscript figures include

    Predictors of the need for an extracervical approach to intrathoracic goitre

    Get PDF
    Background: Sternotomy and lateral thoracotomy are required infrequently to remove an intrathoracic goitre (ITG). As few studies have explored the need for an extracervical approach (ECA), the aim of this study was to examine this in a large cohort of patients. Methods: A prospective database of all patients who had surgery for ITG between 2004 and 2016 was interrogated. Patient demographics, preoperative characteristics and type of operation were analysed to identify factors associated with an ECA. Results: Of 237 patients who had surgery for ITG, 29 (12·2 per cent) required an ECA. ITGs below the aortic arch (odds ratio (OR) 10·84; P = 0·004), those with an iceberg shape (OR 59·30; P < 0·001) and revisional surgery (OR 4·83; P = 0·022) were significant preoperative predictors of an ECA. Conclusion: The extent of intrathoracic extension in relation to the aortic arch, iceberg goitre shape and revisional surgery were independent risk factors for ECA. Careful preoperative assessment should take these factors into consideration when determining the optimal surgical approach to ITG

    Use of neoadjuvant chemotherapy prior to radical hysterectomy in cervical cancer: monitoring tumour shrinkage and molecular profile on magnetic resonance and assessment of 3-year outcome

    Get PDF
    Use of neoadjuvant chemotherapy prior to radical hysterectomy in cervical cancer: monitoring tumour shrinkage and molecular profile on magnetic resonance and assessment of 3-year outcome The objective of this study is to assess tumour response to neoadjuvant chemotherapy prior to radical hysterectomy in cervical cancer using magnetic resonance (MR) to monitor tumour volume and changes in molecular profile and to compare the survival to that of a control group. Eligibility included Stage Ib-IIb previously untreated cervical tumours >10 cm(3). Neoadjuvant chemotherapy in 22 patients ( methotrexate 300 mg m(-2) (with folinic acid rescue), bleomycin 30 mg m(-2), cisplatin 60 mg m(-2)) was repeated twice weekly for three courses and followed by radical hysterectomy. Post-operative radiotherapy was given in 14 cases. A total of 23 patients treated either with radical surgery or chemoradiotherapy over the same time period comprised the nonrandomised control group. MR scans before and after neoadjuvant chemotherapy and in the control group documented tumour volume on imaging and metabolites on in vivo spectroscopy. Changes were compared using a paired t-test. Survival was calculated using the Kaplan-Meier method. There were no significant differences between the neoadjuvant chemotherapy and control groups in age ( mean, s.d. 43.3 +/- 10, 44.7 +/- 8.5 years, respectively, P = 0.63) or tumour volume (medians, quartiles 35.8, 17.8, 57.7 cm(3) vs 23.0, 15.0, 37.0 cm(3), respectively, P = 0.068). The reduction in tumour volume post-chemotherapy (median, quartiles 7.5, 3.0, 19.0 cm(3)) was significant ( P = 0.002). The reduction in - CH2 triglyceride approached significance ( P = 0.05), but other metabolites were unchanged. The 3-year survival in the chemotherapy group (49.1%) was not significantly different from the control group (46%, P = 0.94). There is a significant reduction in tumour volume and - CH2 triglyceride levels after neoadjuvant chemotherapy, but there is no survival advantage

    A statistical interpretation of the correlation between intermediate mass fragment multiplicity and transverse energy

    Full text link
    Multifragment emission following Xe+Au collisions at 30, 40, 50 and 60 AMeV has been studied with multidetector systems covering nearly 4-pi in solid angle. The correlations of both the intermediate mass fragment and light charged particle multiplicities with the transverse energy are explored. A comparison is made with results from a similar system, Xe+Bi at 28 AMeV. The experimental trends are compared to statistical model predictions.Comment: 7 pages, submitted to Phys. Rev.

    Transient peak-strain matching partially recovers the age-impaired mechanoadaptive cortical bone response

    Get PDF
    Mechanoadaptation maintains bone mass and architecture; its failure underlies age-related decline in bone strength. It is unclear whether this is due to failure of osteocytes to sense strain, osteoblasts to form bone or insufficient mechanical stimulus. Mechanoadaptation can be restored to aged bone by surgical neurectomy, suggesting that changes in loading history can rescue mechanoadaptation. We use non-biased, whole-bone tibial analyses, along with characterisation of surface strains and ensuing mechanoadaptive responses in mice at a range of ages, to explore whether sufficient load magnitude can activate mechanoadaptation in aged bone. We find that younger mice adapt when imposed strains are lower than in mature and aged bone. Intriguingly, imposition of short-term, high magnitude loading effectively primes cortical but not trabecular bone of aged mice to respond. This response was regionally-matched to highest strains measured by digital image correlation and to osteocytic mechanoactivation. These data indicate that aged bone’s loading response can be partially recovered, non-invasively by transient, focal high strain regions. Our results indicate that old murine bone does respond to load when the loading is of sufficient magnitude, and bones’ age-related adaptation failure may be due to insufficient mechanical stimulus to trigger mechanoadaptation

    Circumstantial Evidence for a Critical Behavior in Peripheral Au + Au Collisions at 35 MeV/nucleon

    Full text link
    The fragmentation resulting from peripheral Au + Au collisions at an incident energy of E = 35 MeV/nucleon is investigated. A power-law charge distribution, AτA^{-\tau} with τ2.2\tau \approx 2.2, and an intermittency signal are observed for events selected in the region of the Campi scatter plot where "critical" behavior is expected.Comment: 11 pages, RevTex file, 4 postscript figures available upon request from [email protected]

    Reactive direction control for a mobile robot: A locust-like control of escape direction emerges when a bilateral pair of model locust visual neurons are integrated

    Get PDF
    Locusts possess a bilateral pair of uniquely identifiable visual neurons that respond vigorously to the image of an approaching object. These neurons are called the lobula giant movement detectors (LGMDs). The locust LGMDs have been extensively studied and this has lead to the development of an LGMD model for use as an artificial collision detector in robotic applications. To date, robots have been equipped with only a single, central artificial LGMD sensor, and this triggers a non-directional stop or rotation when a potentially colliding object is detected. Clearly, for a robot to behave autonomously, it must react differently to stimuli approaching from different directions. In this study, we implement a bilateral pair of LGMD models in Khepera robots equipped with normal and panoramic cameras. We integrate the responses of these LGMD models using methodologies inspired by research on escape direction control in cockroaches. Using ‘randomised winner-take-all’ or ‘steering wheel’ algorithms for LGMD model integration, the khepera robots could escape an approaching threat in real time and with a similar distribution of escape directions as real locusts. We also found that by optimising these algorithms, we could use them to integrate the left and right DCMD responses of real jumping locusts offline and reproduce the actual escape directions that the locusts took in a particular trial. Our results significantly advance the development of an artificial collision detection and evasion system based on the locust LGMD by allowing it reactive control over robot behaviour. The success of this approach may also indicate some important areas to be pursued in future biological research

    Interferometric imaging with the 32 element Murchison Wide-field Array

    Get PDF
    The Murchison Wide-field Array (MWA) is a low frequency radio telescope, currently under construction, intended to search for the spectral signature of the epoch of re-ionisation (EOR) and to probe the structure of the solar corona. Sited in Western Australia, the full MWA will comprise 8192 dipoles grouped into 512 tiles, and be capable of imaging the sky south of 40 degree declination, from 80 MHz to 300 MHz with an instantaneous field of view that is tens of degrees wide and a resolution of a few arcminutes. A 32-station prototype of the MWA has been recently commissioned and a set of observations taken that exercise the whole acquisition and processing pipeline. We present Stokes I, Q, and U images from two ~4 hour integrations of a field 20 degrees wide centered on Pictoris A. These images demonstrate the capacity and stability of a real-time calibration and imaging technique employing the weighted addition of warped snapshots to counter extreme wide field imaging distortions.Comment: Accepted for publication in PASP. This is the draft before journal typesetting corrections and proofs so does contain formatting and journal style errors, also has with lower quality figures for space requirement
    corecore