264 research outputs found

    Spatial and Temporal Stability of Airglow Measured in the Meinel Band Window at 1191.3 nm

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    We report on the temporal and spatial fluctuations in the atmospheric brightness in the narrow band between Meinel emission lines at 1191.3 nm using an R=320 near-infrared instrument. We present the instrument design and implementation, followed by a detailed analysis of data taken over the course of a night from Table Mountain Observatory. The absolute sky brightness at this wavelength is found to be 5330 +/- 30 nW m^-2 sr^-1, consistent with previous measurements of the inter-band airglow at these wavelengths. This amplitude is larger than simple models of the continuum component of the airglow emission at these wavelengths, confirming that an extra emissive or scattering component is required to explain the observations. We perform a detailed investigation of the noise properties of the data and find no evidence for a noise component associated with temporal instability in the inter-line continuum. This result demonstrates that in several hours of ~100s integrations the noise performance of the instrument does not appear to significantly degrade from expectations, giving a proof of concept that near-IR line intensity mapping may be feasible from ground-based sites.Comment: 15 figures, submitted to PAS

    The Review of Economic Performance and Social Progress 2001: The Longest Decade: Canada in the 1990s

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    One of the most (if not the most) highly charged public debates in this country over the past decade has been about the role of economic imperatives in dismantling the foundations of the welfare state set out in the universalist model adopted in the post-war years. Ken Battle in his chapter is critical of the ongoing public discourse on this issue, which he considers as lacking both in substance and subtlety. He argues that this has led to a polarization of views and produced persistent mythologies which in his estimation have served to insulate government from effective criticism and prevented the occurrence of a truly needed, open and informed public debate on the present and future course of social policy. Battle describes the overall process of reform and developments in social policy in the last two decades as one of "relentless incrementalism" where cumulative, purposeful and patterned change has produced a substantial shift in the structure of the Canadian income security system. He concludes that on the whole the emerging post-welfare state will better serve Canada's evolving social, economic and political needs and sees little cause for continuing nostalgia over the fading universalist welfare state, which in his estimation never worked all that well.Social Policy, Income Support, Income Security, Economic Security, Welfare State, Welfare System, Social Safet Net, Welfare Policy, Social Security, Canada

    Siamese Neural Networks for Skin Cancer Classification and New Class Detection using Clinical and Dermoscopic Image Datasets

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    Skin cancer is the most common malignancy in the world. Automated skin cancer detection would significantly improve early detection rates and prevent deaths. To help with this aim, a number of datasets have been released which can be used to train Deep Learning systems - these have produced impressive results for classification. However, this only works for the classes they are trained on whilst they are incapable of identifying skin lesions from previously unseen classes, making them unconducive for clinical use. We could look to massively increase the datasets by including all possible skin lesions, though this would always leave out some classes. Instead, we evaluate Siamese Neural Networks (SNNs), which not only allows us to classify images of skin lesions, but also allow us to identify those images which are different from the trained classes - allowing us to determine that an image is not an example of our training classes. We evaluate SNNs on both dermoscopic and clinical images of skin lesions. We obtain top-1 classification accuracy levels of 74.33% and 85.61% on clinical and dermoscopic datasets, respectively. Although this is slightly lower than the state-of-the-art results, the SNN approach has the advantage that it can detect out-of-class examples. Our results highlight the potential of an SNN approach as well as pathways towards future clinical deployment.Comment: 10 pages, 5 figures, 5 table

    Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models

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    Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined into a tracer known as atmospheric potential oxygen (APO ≈ O2/N2 + CO2) that is conservative with respect to terrestrial biological activity. Consequently, APO reflects primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. (1998), we present a set of APO observations for the years 1996-2003 with unprecedented spatial coverage. Combining data from the Princeton and Scripps air sampling programs, the data set includes new observations collected from ships in the low-latitude Pacific. The data show a smaller interhemispheric APO gradient than was observed in past studies, and different structure within the hemispheres. These differences appear to be due primarily to real changes in the APO field over time. The data also show a significant maximum in APO near the equator. Following the approach of Gruber et al. (2001), we compare these observations with predictions of APO generated from ocean O2 and CO2 flux fields and forward models of atmospheric transport. Our model predictions differ from those of earlier modeling studies, reflecting primarily the choice of atmospheric transport model (TM3 in this study). The model predictions show generally good agreement with the observations, matching the size of the interhemispheric gradient, the approximate amplitude and extent of the equatorial maximum, and the amplitude and phasing of the seasonal APO cycle at most stations. Room for improvement remains. The agreement in the interhemispheric gradient appears to be coincidental; over the last decade, the true APO gradient has evolved to a value that is consistent with our time-independent model. In addition, the equatorial maximum is somewhat more pronounced in the data than the model. This may be due to overly vigorous model transport, or insufficient spatial resolution in the air-sea fluxes used in our modeling effort. Finally, the seasonal cycles predicted by the model of atmospheric transport show evidence of an excessive seasonal rectifier in the Aleutian Islands and smaller problems elsewhere. Copyright 2006 by the American Geophysical Union

    Glutamate efflux mediated by Corynebacterium glutamicum MscCG, Escherichia coli MscS, and their derivatives

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    AbstractCorynebacterium glutamicum is used in microbial biotechnology for the production of amino acids, in particular glutamate. The mechanism of glutamate excretion, however, is not yet fully understood. Recently, evidence was provided that the NCgl1221 gene product from C. glutamicum ATCC 13869, a MscS-type mechanosensitive efflux channel, is responsible for glutamate efflux [1]. The major difference of NCgl1221 and the homologous protein MscCG of C. glutamicum ATCC 13032 from Escherichia coli MscS and most other MscS-type proteins is the presence of an additional, 247 amino acid long C-terminal domain. By topology analysis, we show that this domain in MscCG carries a transmembrane segment. We have generated selected C-terminal truncations of MscCG, gain-of-function and loss-of-function constructs of both E. coli MscS and C. glutamicum MscCG, as well as fusion constructs of the two proteins. These mutant proteins were investigated for mechanosensitive efflux, MS channel activity, glutamate excretion and their impact on membrane potential. We provide evidence that the channel domain of MscCG mediates glutamate efflux in response to penicillin treatment, and that the E. coli MscS channel is to some extent able to function in a similar manner. We further show that the C-terminal domain of MscCG has a significant impact for function and/or regulation of MscCG. Significantly, a positive effect on glutamate efflux of the C-terminal extension of MscCG from C. glutamicum was also observed when fused to the E. coli MscS channel

    Patient and physician discordance of global disease assessment in juvenile dermatomyositis: Findings from the Childhood Arthritis & Rheumatology Research Alliance Legacy Registry

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    © 2020 The Author(s). Background: Global disease activity scores (gVAS) capture patient or family (PF) and physician (MD) assessments of disease. This study sought to measure discordance between PF and MD global activity scores in juvenile dermatomyositis (JDM), and determine factors associated with discordance. Methods: Patients with JDM were included from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry (N = 563). PF and MD gVAS were assessed for discordance, defined as a ≄ 2-point difference. Factors associated with discordant gVAS were compared in univariate analysis. Multivariable regression analysis was used to identify predictors of discordance. Results: Almost 40% (N = 219) of PF and MD gVAS were discordant. Among discordant scores, 68% of PF rated gVAS ≄2-points above MD, which was associated with calcinosis and lower quality of life and functional scores (p \u3c 0.01). MD gVAS rated ≄2-points above PF in 32%, which was associated with abnormal laboratory results, weakness, arthritis, rash and other skin changes, and current intravenous steroid treatment (p \u3c 0.01). In multivariate analysis, predictors for higher PF rating included calcinosis, lower quality of life and functional scores, while predictors for higher MD rating included rash, calcinosis, nailfold capillaroscopy changes, and current intravenous steroid treatment. Conclusions: Discordance between PF and MD gVAS was common in this JDM cohort. Overall, higher PF rating was associated with poorer patient reported outcome (PRO) scores, while higher MD rating was associated with poorer objective measures. This suggests PF and MD assessments of gVAS may be measuring different aspects of disease, highlighting the importance of integrating PROs into clinical practice and research

    Contextual Fear Conditioning Alter Microglia Number and Morphology in the Rat Dorsal Hippocampus

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    Contextual fear conditioning is a Pavlovian conditioning paradigm capable of rapidly creating fear memories to contexts, such as rooms or chambers. Contextual fear conditioning protocols have long been utilized to evaluate how fear memories are consolidated, maintained, expressed, recalled, and extinguished within the brain. These studies have identified the lateral portion of the amygdala and the dorsal portion of the hippocampus as essential for contextual fear memory consolidation. The current study was designed to evaluate how two different contextual fear memories alter amygdala and hippocampus microglia, brain derived neurotrophic factor (BDNF), and phosphorylated cyclic-AMP response element binding (pCREB). We find rats provided with standard contextual fear conditioning to have more microglia and more cells expressing BDNF in the dentate gyrus as compared to a context only control group. Additionally, standard contextual fear conditioning altered microglia morphology to become amoeboid in shape – a common response to central nervous system insult, such as traumatic brain injury, infection, ischemia, and more. The unpaired fear conditioning procedure (whereby non-reinforced and non-overlapping auditory tones were provided at random intervals during conditioning), despite producing equivalent levels of fear as the standard procedure, did not alter microglia, BDNF or pCREB number in any dorsal hippocampus or lateral amygdala brain regions. Despite this, the unpaired fear conditioning protocol produced some alterations in microglia morphology, but less compared to rats provided with standard contextual fear conditioning. Results from this study demonstrate that contextual fear conditioning is capable of producing large alterations to dentate gyrus plasticity and microglia, whereas unpaired fear conditioning only produces minor changes to microglia morphology. These data show, for the first time, that Pavlovian fear conditioning protocols can induce similar responses as trauma, infection or other insults within the central nervous system

    Delays to Care in Pediatric Lupus Patients: Data From the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry.

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    OBJECTIVE: Prompt treatment for lupus is important to prevent morbidity. A potential barrier to early treatment of pediatric lupus is delayed presentation to a pediatric rheumatologist. To better understand factors contributing to delayed presentation among pediatric lupus patients, we examined differences in demographic and clinical characteristics of lupus patients within the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry with regard to time between symptom onset and presentation to a pediatric rheumatologist. METHODS: We analyzed data from 598 CARRA Legacy Registry participants for differences between those who presented early (withinonset), between 1-3 months (typical presentation), with moderate delays (3-12 months), and with severe delays (≄1 year). Factors associated with early presentation, moderate delay, and severe delay were determined by multinomial logistic regression. RESULTS: Forty-four percent of patients presented early, while 23% had moderate delays and 9% had severe delays. Family history of lupus, absence of discoid rash, and location in a state with a higher density of pediatric rheumatologists were associated with earlier presentation. Younger age, low household income ( CONCLUSION: Delays to care ≄1 year exist in a notable minority of pediatric lupus patients from the CARRA Legacy Registry. In this large and diverse sample of patients, access to care and family resources played an important role in predicting time to presentation to a pediatric rheumatologist

    CMB polarimetry with BICEP: instrument characterization, calibration, and performance

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    BICEP is a ground-based millimeter-wave bolometric array designed to target the primordial gravity wave signature on the polarization of the cosmic microwave background (CMB) at degree angular scales. Currently in its third year of operation at the South Pole, BICEP is measuring the CMB polarization with unprecedented sensitivity at 100 and 150 GHz in the cleanest available 2% of the sky, as well as deriving independent constraints on the diffuse polarized foregrounds with select observations on and off the Galactic plane. Instrument calibrations are discussed in the context of rigorous control of systematic errors, and the performance during the first two years of the experiment is reviewed.Comment: 12 pages, 15 figures, updated version of a paper accepted for Millimeter and Submillimeter Detectors and Instrumentation for Astronomy IV, Proceedings of SPIE, 7020, 200
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