807 research outputs found

    Methane observations from the Greenhouse Gases Observing SATellite: Comparison to ground‐based TCCON data and model calculations

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    We report new short-wave infrared (SWIR) column retrievals of atmospheric methane (X_(CH4)) from the Japanese Greenhouse Gases Observing SATellite (GOSAT) and compare observed spatial and temporal variations with correlative ground-based measurements from the Total Carbon Column Observing Network (TCCON) and with the global 3-D GEOS-Chem chemistry transport model. GOSAT X_(CH4) retrievals are compared with daily TCCON observations at six sites between April 2009 and July 2010 (Bialystok, Park Falls, Lamont, Orleans, Darwin and Wollongong). GOSAT reproduces the site-dependent seasonal cycles as observed by TCCON with correlations typically between 0.5 and 0.7 with an estimated single-sounding precision between 0.4–0.8%. We find a latitudinal-dependent difference between the X_(CH4) retrievals from GOSAT and TCCON which ranges from 17.9 ppb at the most northerly site (Bialystok) to −14.6 ppb at the site with the lowest latitude (Darwin). We estimate that the mean smoothing error difference included in the GOSAT to TCCON comparisons can account for 15.7 to 17.4 ppb for the northerly sites and for 1.1 ppb at the lowest latitude site. The GOSAT X_(CH4) retrievals agree well with the GEOS-Chem model on annual (August 2009 – July 2010) and monthly timescales, capturing over 80% of the zonal variability. Differences between model and observed X_(CH4) are found over key source regions such as Southeast Asia and central Africa which will be further investigated using a formal inverse model analysis

    Perplexity – a new predictor of cognitive changes in spoken language? – results of the Interdisciplinary Longitudinal Study on Adult Development and Aging (ILSE)

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    Abstract: In addition to memory loss, progressive deterioration of speech and language skills is among the main symptoms at the onset of Alzheimer’s disease (AD) as well as in mild cognitive impairment (MCI). Detailed interview analyses demonstrated early symptoms years before the onset of AD/MCI. Automatic speech processing could be a promising approach to identifying underlying mechanisms in larger studies or even support diagnostics. Perplexity as a measure of predictability of text could be a sensitive indicator of cognitive deterioration. Therefore, voice recordings from the Interdisciplinary Longitudinal Study on Adult Development and Aging were analyzed with regard to neuropsychological parameters in participants that develop MCI/AD or remain cognitively healthy. Preliminary results indicate that perplexity predicts severity of cognitive deficits and information processing speed obtained 10–12 years later in participants who developed MCI/AD in contrast to those who stayed healthy. Findings support the heuristic value of research on the diagnostic potential of automatic speech processing

    Satellite Remote Sensing of Atmospheric SO_2: Volcanic Eruptions and Anthropogenic Emissions

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    In this article, we present satellite data analysis of atmospheric Sulfur Dioxide (SO_2) from volcanic eruptions and anthropogenic activities. Data from Global Ozone Monitoring Experiment (GOME) on board ERS-2 for the years 1996 to 2002 is analyzed using a DOAS based algorithm with the aim of retrieving SO_2 Slant Column Densities (SCDs). Difficulties in the retrieval of SO_2 SCDs due to instrumental effects are investigated in detail and significantly improved. The retrieved SCDs can be used to identify and monitor several volcanic eruptions. A brief introduction of different volcanic eruptions around the globe is presented Also informations about the anthropogenic SO_2 emissions can be easily achieved from the retrieved data set. A time series of anthropogenic SO_2 emissions over Eastern Europe is presented in this study. The time series showed high SO_2 SCDs over Eastern Europe during the winter months. The results demonstrate a high sensitivity of GOME instrument towards SO_2 emissions

    Application of Pulsed Field Gel Electrophoresis to Determine Îł-ray-induced Double-strand Breaks in Yeast Chromosomal Molecules

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    The frequency of DNA double-strand breaks (dsb) was determined in yeast cells exposed to Îł-rays under anoxic conditions. Genomic DNA of treated cells was separated by pulsed field gel electrophoresis, and two different approaches for the evaluation of the gels were employed: (1) The DNA mass distribution profile obtained by electrophoresis was compared to computed profiles, and the number of DSB per unit length was then derived in terms of a fitting procedure; (2) hybridization of selected chromosomes was performed, and a comparison of the hybridization signals in treated and untreated samples was then used to derive the frequency of dsb

    Reviews

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    The following publications have been reviewed by the mentioned authors;Art and Society One. War by Ken Baynes, reviewed by Ronald FrankenbergArt and Society Two. Work by Ken Baynes and Alan Robinson, reviewed by Ronald FrankenbergArt and Society Three. Worship by Ken and Kate Baynes, reviewed by Ronald FrankenbergArt and Science by Dolf Rieser, reviewed by M. K. PaffardA COMMON SYSTEM OF EXAMINING AT 16+ by the Schols Council Examinations Bulletin No.23, reviewed by W. G. SkinnerSchool Resource Centres, the Schools Council Working Paper 43, reviewed by L. BroughA History of English Furniture by John Harrison, reviewed by S. J. EgglestonTrends in School Design by Eric Pearson, reviewed by P. K. BodenWorking Space, A Place to Paint, Language Aeas by Jason Dean, reviewed by P. K. BodenAlive to Art by Jose Llobera, reviewed by John LancasterVisual Education in the primary school by John M. Pickering, reviewed by L. BroughArt & Design Cards. Packs 1 & 2 by Ian Pillinger, reviewed by Francis ZankerWorkshop Assignments, Book One by S. Dunkerley & A. Huxton, reviewed by L. BroughStep By Step Metalwork, Book 3 by Kenneth Wells, reviewed by M. SayerIntroducing Jewellery Making by John Crawford, reviewed by John DecorteMaggie Hayes Jewellery Book by Maggie Hayes, reviewed by S. J. Egglesto

    Capturing Complete Spatial Context in Satellite Observations of Greenhouse Gases

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    Scientific consensus from a 2015 pre-Decadal Survey workshop highlighted the essential need for a wide-swath (mapping) low earth orbit (LEO) instrument delivering carbon dioxide (CO_2), methane (CH_4), and carbon monoxide (CO) measurements with global coverage. OCO-2 pioneered space-based CO_2 remote sensing, but lacks the CH_4, CO and mapping capabilities required for an improved understanding of the global carbon cycle. The Carbon Balance Observatory (CARBO) advances key technologies to enable high-performance, cost-effective solutions for a space-based carbon-climate observing system. CARBO is a compact, modular, 15-30° field of view spectrometer that delivers high-precision CO_2, CH_4, CO and solar induced chlorophyll fluorescence (SIF) data with weekly global coverage from LEO. CARBO employs innovative immersion grating technologies to achieve diffraction-limited performance with OCO-like spatial (2x2 km^2) and spectral (λ/Δλ ≈ 20,000) resolution in a package that is >50% smaller, lighter and more cost-effective. CARBO delivers a 25- to 50-fold increase in spatial coverage compared to OCO-2 with no loss of detection sensitivity. Individual CARBO modules weigh < 20 kg, opening diverse new space-based platform opportunities

    Methane retrievals from Greenhouse Gases Observing Satellite (GOSAT) shortwave infrared measurements: Performance comparison of proxy and physics retrieval algorithms

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    We compare two conceptually different methods for determining methane column-averaged mixing ratios image from Greenhouse Gases Observing Satellite (GOSAT) shortwave infrared (SWIR) measurements. These methods account differently for light scattering by aerosol and cirrus. The proxy method retrieves a CO_2 column which, in conjunction with prior knowledge on CO_2 acts as a proxy for scattering effects. The physics-based method accounts for scattering by retrieving three effective parameters of a scattering layer. Both retrievals are validated on a 19-month data set using ground-based X_CH_4 at 12 stations of the Total Carbon Column Observing Network (TCCON), showing comparable performance: for the proxy retrieval we find station-dependent retrieval biases from −0.312% to 0.421% of X_CH_4 a standard deviation of 0.22% and a typical precision of 17 ppb. The physics method shows biases between −0.836% and −0.081% with a standard deviation of 0.24% and a precision similar to the proxy method. Complementing this validation we compared both retrievals with simulated methane fields from a global chemistry-transport model. This identified shortcomings of both retrievals causing biases of up to 1ings and provide a satisfying validation of any methane retrieval from space-borne SWIR measurements, in our opinion it is essential to further expand the network of TCCON stations

    Retelling racialized violence, remaking white innocence: the politics of interlocking oppressions in transgender day of remembrance

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    Transgender Day of Remembrance has become a significant political event among those resisting violence against gender-variant persons. Commemorated in more than 250 locations worldwide, this day honors individuals who were killed due to anti-transgender hatred or prejudice. However, by focusing on transphobia as the definitive cause of violence, this ritual potentially obscures the ways in which hierarchies of race, class, and sexuality constitute such acts. Taking the Transgender Day of Remembrance/Remembering Our Dead project as a case study for considering the politics of memorialization, as well as tracing the narrative history of the Fred F. C. Martinez murder case in Colorado, the author argues that deracialized accounts of violence produce seemingly innocent White witnesses who can consume these spectacles of domination without confronting their own complicity in such acts. The author suggests that remembrance practices require critical rethinking if we are to confront violence in more effective ways. Description from publisher's site: http://caliber.ucpress.net/doi/abs/10.1525/srsp.2008.5.1.2
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