168 research outputs found
Overcoming the Challenges Associated with Image-based Mapping of Small Bodies in Preparation for the OSIRIS-REx Mission to (101955) Bennu
The OSIRIS-REx Asteroid Sample Return Mission is the third mission in NASA's
New Frontiers Program and is the first U.S. mission to return samples from an
asteroid to Earth. The most important decision ahead of the OSIRIS-REx team is
the selection of a prime sample-site on the surface of asteroid (101955) Bennu.
Mission success hinges on identifying a site that is safe and has regolith that
can readily be ingested by the spacecraft's sampling mechanism. To inform this
mission-critical decision, the surface of Bennu is mapped using the OSIRIS-REx
Camera Suite and the images are used to develop several foundational data
products. Acquiring the necessary inputs to these data products requires
observational strategies that are defined specifically to overcome the
challenges associated with mapping a small irregular body. We present these
strategies in the context of assessing candidate sample-sites at Bennu
according to a framework of decisions regarding the relative safety,
sampleability, and scientific value across the asteroid's surface. To create
data products that aid these assessments, we describe the best practices
developed by the OSIRIS-REx team for image-based mapping of irregular small
bodies. We emphasize the importance of using 3D shape models and the ability to
work in body-fixed rectangular coordinates when dealing with planetary surfaces
that cannot be uniquely addressed by body-fixed latitude and longitude.Comment: 31 pages, 10 figures, 2 table
Effect of cottonseed meal consumption on performance of female fallow deer
Last updated: 6/12/200
Cost-effectiveness of tiotropium versus usual care and glycopyrronium in the treatment of chronic obstructive pulmonary disease in Sweden
BACKGROUND: Tiotropium (TIO) is a well-established bronchodilator, LAMA (long-acting anticholinergic), for the treatment of moderate to very severe chronic obstructive pulmonary disease (COPD). Clinical evidence suggests that tiotropium is superior to usual non-LAMA care (UC) but may also have benefits compared to other LAMAs in preventing and limiting the effects of severe exacerbations. The primary objective of this study was to undertake a cost-effectiveness analysis of adding tiotropium to usual care versus usual care alone. A secondary objective was to assess the cost-effectiveness of tiotropium compared to glycopyrronium (GLY), another LAMA. The study was conducted with a Swedish setting in mind. METHODS: A Markov cohort model, incorporating the effects of exacerbations, was populated with efficacy data from the UPLIFT and SPARK trials and epidemiological data relevant for a Swedish patient population. Treatment efficacy of tiotropium was modelled as a lowering of the risk of exacerbations and as a slow-down of overall disease progression. The model followed patients over their remaining life-time. RESULTS: The base case analysis showed that patients treated with tiotropium gained 0.07 quality-adjusted life years (QALYs) compared to usual care alone at an incremental cost of SEK 15,041, resulting in a cost per QALY gained of SEK 224,850. Compared to glycopyrronium the QALY gained was estimated to 0.23 QALYs in favour of tiotropium at an incremental cost of SEK 2423, yielding a cost per QALY gained of SEK 10,456. The results were mainly driven by differences in the risk of severe exacerbations. CONCLUSION: At the current implicit willingness-to-pay (WTP) per QALY threshold in Sweden, the results from this study indicate that tiotropium is a highly cost-effective intervention when added to usual non-LAMA care in the treatment of moderate to very severe COPD in Sweden. In addition, tiotropium is a highly cost-effective intervention when compared to glycopyrronium monotherapy
The natural history of chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality in the USA, and it remains one of the few diseases that continues to increase its numbers. The development and progression of COPD can vary dramatically between individuals. A low level of lung function remains the cornerstone of COPD diagnosis and is a key predictor of prognosis. Lung function, however, is not the only factor in determining morbidity and mortality related to COPD, with factors such as body mass index, exercise capability and comorbid disease being important predictors of poor outcomes. Exacerbations of COPD are additional important indicators of both quality of life and outcomes in COPD patients. Definitions of exacerbations can vary, ranging from an increase in symptoms to COPD-related hospitalisations and death. COPD exacerbations are more common in patients with lower levels of lung function and may lead to more rapid declines in lung function. Better understanding of the natural history of COPD may lead to better definitions of specific COPD phenotypes, better interventions and improved outcomes
External validation of a COPD prediction model using population-based primary care data: a nested case-control study
Emerging models for predicting risk of chronic obstructive pulmonary disease (COPD) require external validation in order to assess their clinical value. We validated a previous model for predicting new onset COPD in a different database. We randomly drew 38,597 case-control pairs (total N = 77,194) of individuals aged ≥35 years and matched for sex, age, and general practice from the United Kingdom Clinical Practice Research Datalink database. We assessed accuracy of the model to discriminate between COPD cases and non-cases by calculating area under the receiver operator characteristic (ROC(AUC)) for the prediction scores. Analogous to the development model, ever smoking (OR 6.70; 95%CI 6.41–6.99), prior asthma (OR 6.43; 95%CI 5.85–7.07), and higher socioeconomic deprivation (OR 2.90; 95%CI 2.72–3.09 for highest vs. lowest quintile) increased the risk of COPD. The validated prediction scores ranged from 0–5.71 (ROC(AUC) 0.66; 95%CI 0.65–0.66) for males and 0–5.95 (ROC(AUC) 0.71; 95%CI 0.70–0.71) for females. We have confirmed that smoking, prior asthma, and socioeconomic deprivation are key risk factors for new onset COPD. Our model seems externally valid at identifying patients at risk of developing COPD. An impact assessment now needs to be undertaken to assess whether this prediction model can be applied in clinical care settings
Introducing the national COPD resources and outcomes project
<p>Abstract</p> <p>Background</p> <p>We report baseline data on the organisation of COPD care in UK NHS hospitals participating in the National COPD Resources and Outcomes Project (NCROP).</p> <p>Methods</p> <p>We undertook an initial survey of participating hospitals in 2007, looking at organisation and performance indicators in relation to general aspects of care, provision of non-invasive ventilation (NIV), pulmonary rehabilitation, early discharge schemes, and oxygen. We compare, where possible, against the national 2003 audit.</p> <p>Results</p> <p>100 hospitals participated. These were typically larger sized Units. Many aspects of COPD care had improved since 2003. Areas for further improvement include organisation of acute care, staff training, end-of-life care, organisation of oxygen services and continuation of pulmonary rehabilitation.</p> <p>Conclusion</p> <p>Key Points: positive change occurs over time and repeated audit seems to deliver some improvement in services. It is necessary to assess interventions such as the Peer Review used in the NCROP to achieve more comprehensive and rapid change.</p
Pragmatic Evaluation of an Improvement Program for People Living With Modifiable High-Risk COPD Versus Usual Care: Protocol for the Cluster Randomized PREVAIL Trial
Background: The burden of chronic obstructive pulmonary disease (COPD) is well established, but opportunities for earlier diagnosis and improved management are still missed. Compared to the general COPD population, patients with a history of exacerbations and suboptimal treatment (“modifiable high-risk”) are at greater risk of future exacerbations and adverse health outcomes. To date there is no systematic approach for identifying and treating this patient group. Methods: Two cluster randomized controlled trials (CRTs) in the United Kingdom and United States will assess the impact of a primary care-based quality improvement program (COllaboratioN on QUality improvement initiative for achieving Excellence in STandards of COPD care [CONQUEST]), compared to routine care. In each trial, 126 primary care clusters will be randomized 1:1 to intervention or control arms. Three groups of modifiable high-risk patients will be identified using electronic medical records: undiagnosed with potential COPD, newly diagnosed COPD, and already diagnosed COPD. Eligible patients will be aged ≥40 years, have experienced ≥2 moderate/≥1 severe exacerbation(s) in the prior 24 months, including ≥1 in the last 12 months, and not be prescribed inhaled triple therapy. Patients in the undiagnosed group will also be required to have a positive smoking history. Primary trial outcomes will be the annual rate of exacerbations and the annual rate of major adverse cardiac or respiratory events, comparing the quality improvement program against routine care. Discussion: These will be the first CRTs assessing such a comprehensive primary care-based COPD quality improvement program. Intention-to-treat analysis of trial outcomes after 24 months will inform its effectiveness in targeting the identification, assessment, treatment, and follow-up of patients with modifiable high-risk COPD
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Overcoming the Challenges Associated with Image-Based Mapping of Small Bodies in Preparation for the OSIRIS-REx Mission to (101955) Bennu
The OSIRIS‐REx Asteroid Sample Return Mission is the third mission in National Aeronautics and Space Administration (NASA)'s New Frontiers Program and is the first U.S. mission to return samples from an asteroid to Earth. The most important decision ahead of the OSIRIS‐REx team is the selection of a prime sample‐site on the surface of asteroid (101955) Bennu. Mission success hinges on identifying a site that is safe and has regolith that can readily be ingested by the spacecraft's sampling mechanism. To inform this mission‐critical decision, the surface of Bennu is mapped using the OSIRIS‐REx Camera Suite and the images are used to develop several foundational data products. Acquiring the necessary inputs to these data products requires observational strategies that are defined specifically to overcome the challenges associated with mapping a small irregular body. We present these strategies in the context of assessing candidate sample sites at Bennu according to a framework of decisions regarding the relative safety, sampleability, and scientific value across the asteroid's surface. To create data products that aid these assessments, we describe the best practices developed by the OSIRIS‐REx team for image‐based mapping of irregular small bodies. We emphasize the importance of using 3‐D shape models and the ability to work in body‐fixed rectangular coordinates when dealing with planetary surfaces that cannot be uniquely addressed by body‐fixed latitude and longitude.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Association between Variations in Cell Cycle Genes and Idiopathic Pulmonary Fibrosis
Idiopathic pulmonary fibrosis (IPF) is a devastating and progressive lung disease. Its aetiology is thought to involve damage to the epithelium and abnormal repair. Alveolar epithelial cells near areas of remodelling show an increased expression of proapoptotic molecules. Therefore, we investigated the role of genes involved in cell cycle control in IPF. Genotypes for five single nucleotide polymorphisms (SNPs) in the tumour protein 53 (TP53) gene and four SNPs in cyclin-dependent kinase inhibitor 1A (CDKN1A), the gene encoding p21, were determined in 77 IPF patients and 353 controls. In peripheral blood mononuclear cells (PBMC) from 16 healthy controls mRNA expression of TP53 and CDKN1A was determined
Near-field Electrical Detection of Optical Plasmons and Single Plasmon Sources
Photonic circuits can be much faster than their electronic counterparts, but
they are difficult to miniaturize below the optical wavelength scale. Nanoscale
photonic circuits based on surface plasmon polaritons (SPs) are a promising
solution to this problem because they can localize light below the diffraction
limit. However, there is a general tradeoff between the localization of an SP
and the efficiency with which it can be detected with conventional far-field
optics. Here we describe a new all-electrical SP detection technique based on
the near-field coupling between guided plasmons and a nanowire field-effect
transistor. We use the technique to electrically detect the plasmon emission
from an individual colloidal quantum dot coupled to an SP waveguide. Our
detectors are both nanoscale and highly efficient (0.1 electrons/plasmon), and
a plasmonic gating effect can be used to amplify the signal even higher (up to
50 electrons/plasmon). These results enable new on-chip optical sensing
applications and are a key step towards "dark" optoplasmonic nanocircuits in
which SPs can be generated, manipulated, and detected without involving
far-field radiation.Comment: manuscript followed by supplementary informatio
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