scholarly journals Long-term variability of CO2and O in the Mars upper atmosphere from MRO radio science data

2015 ◽  
Vol 120 (5) ◽  
pp. 849-868 ◽  
Author(s):  
Antonio Genova ◽  
Sander Goossens ◽  
Frank G. Lemoine ◽  
Erwan Mazarico ◽  
Susan K. Fricke ◽  
...  
Keyword(s):  
Upper Atmosphere ◽  
Science Data ◽  
Radio Science

Using long-term citizen science data to understand distribution and habitat use of an irruptive species

2021 ◽  
pp. 101377
Author(s):  
Anant Deshwal ◽  
Pooja Panwar ◽  
Joseph C. Neal ◽  
Matthew A. Young
Keyword(s):  
Habitat Use ◽  
Citizen Science ◽  
Science Data

scholarly journals Inferring thermospheric composition from ionogram profiles: a calibration with the TIMED spacecraft

2021 ◽  
Vol 39 (2) ◽  
pp. 309-319
Author(s):  
Christopher J. Scott ◽  
Shannon Jones ◽  
Luke A. Barnard
Keyword(s):  
Dissociative Recombination ◽  
Molecular Ions ◽  
Upper Atmosphere ◽  
Global Network ◽  
G Factor ◽  
Important Region ◽  
Term Change ◽  
Ion Production ◽  
Sensitive Function

Abstract. We present a method for augmenting spacecraft measurements of thermospheric composition with quantitative estimates of daytime thermospheric composition below 200 km, inferred from ionospheric data, for which there is a global network of ground-based stations. Measurements of thermospheric composition via ground-based instrumentation are challenging to make, and so details about this important region of the upper atmosphere are currently sparse. The visibility of the F1 peak in ionospheric soundings from ground-based instrumentation is a sensitive function of thermospheric composition. The ionospheric profile in the transition region between F1 and F2 peaks can be expressed by the “G” factor, a function of ion production rate and loss rates via ion–atom interchange reactions and dissociative recombination of molecular ions. This in turn can be expressed as the square of the ratio of ions lost via these processes. We compare estimates of the G factor obtained from ionograms recorded at Kwajalein (9∘ N, 167.2∘ E) for 25 times during which the Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) spacecraft recorded approximately co-located measurements of the neutral thermosphere. We find a linear relationship between G and the molecular-to-atomic composition ratio, with a gradient of 2.55±0.40. Alternatively, using hmF1 values obtained by ionogram inversion, this gradient was found to be 4.75±0.4. Further, accounting for equal ionisation in molecular and atomic species yielded a gradient of 4.20±0.8. This relationship has potential for using ground-based ionospheric measurements to infer quantitative variations in the composition of the neutral thermosphere via a relatively simple model. This has applications in understanding long-term change and the efficacy of the upper atmosphere on satellite drag.

Digital Preservation Challenges, Infrastructures and Evaluations

2013 ◽  
pp. 74-86
Author(s):  
David Giaretta
Keyword(s):  
Information Structure ◽  
Reference Model ◽  
Digital Rights Management ◽  
Digital Preservation ◽  
Science Data ◽  
Data Infrastructure ◽  
Loosely Coupled ◽  
Digital Objects ◽  
Historical Resources

To preserve digitally encoded information over a long term following the OAIS Reference Model requires that the information remains accessible, understandable and usable by a specified Designated Community. These are significant challenges for repositories. It will be argued that infrastructure which is needed to support this preservation must be seen in the context of the broader science data infrastructure which international and national funders seek to put in place. Moreover aspects of the preservation components of this infrastructure must themselves be preservable, resulting in a recursive system which must also be highly adaptable, loosely coupled and asynchronous. Even more difficult is to be able to judge whether any proposal is actually likely to be effective. From the earliest discussions of concerns about the preservability of digital objects there have been calls for some way of judging the quality of digital repositories. In this chapter several interrelated efforts which contribute to solutions for these issues will be outlined. Evidence about the challenges which must be overcome and the consistency of demands across nations, disciplines and organisations will be presented, based on extensive surveys which have been carried out by the PARSE.Insight project (http://www.parse-insight.eu). The key points about the revision of the OAIS Reference Model which is underway will be provided; OAIS provides many of the key concepts which underpin the efforts to judge solutions. In the past few years the Trustworthy Repositories Audit and Certification: Criteria and Checklist (TRAC) document has been produced, as well as a number of related checklists. These efforts provide the background of the international effort (the RAC Working Group http://wiki.digitalrepositoryauditandcertification.org) to produce a full ISO standard on which an accreditation and certification process can be built. If successful this standard and associated processes will allow funders to have an independent evaluation of the effectiveness of the archives they support and data producers to have a basis for deciding which repository to entrust with their valuable data. It could shape the digital preservation market. The CASPAR project (http://www.casparpreserves.eu) is an EU part funded project with total spend of 16MEuros which is trying to faithfully implement almost all aspects of the OAIS Reference Model in particular the Information Model. The latter involves tools for capturing all types of Representation Information (Structure, Semantics and all Other types), and tools for defining the Designated Community. This chapter will describe implementations of tools and infrastructure components to support repositories in their task of long term preservation of digital resources, including the capture and preservation of digital rights management and evidence of authenticity associated with digital objects. In order to justify their existence, most repositories must also support contemporaneous use of contemporary as well as “historical” resources; the authors will show how the same techniques can support both, and hence link to the fuller science data infrastructure.

scholarly journals Hypertension and Experimental Stroke Therapies

2013 ◽  
Vol 33 (8) ◽  
pp. 1141-1147 ◽  
Author(s):  
Victoria E O'Collins ◽  
Geoffrey A Donnan ◽  
Malcolm R Macleod ◽  
David W Howells
Keyword(s):  
Basic Science ◽  
Meta Analysis ◽  
Experimental Stroke ◽  
Science Data ◽  
Anesthetic Agents ◽  
Superior Efficacy ◽  
Lower Treatment ◽  
Tissue Plasminogen ◽  
The Impact

Hypertension is an established target for long-term stroke prevention but procedures for management of hypertension in acute stroke are less certain. Here, we analyze basic science data to examine the impact of hypertension on candidate stroke therapies and of anti-hypertensive treatments on stroke outcome. Methods: Data were pooled from 3,288 acute ischemic stroke experiments (47,899 animals) testing the effect of therapies on infarct size (published 1978-2010). Data were combined using meta-analysis and meta-regression, partitioned on the basis of hypertension, stroke model, and therapy. Results: Hypertensive animals were used in 10% of experiments testing 502 therapies. Hypertension was associated with lower treatment efficacy, especially in larger infarcts. Overall, anti-hypertensives did not provide greater benefit than other drugs, although benefits were evident in hypertensive animals even when given after stroke onset. Fifty-eight therapies were tested in both normotensive and hypertensive animals: some demonstrated superior efficacy in hypertensive animals (hypothermia) while others worked better in normotensive animals (tissue plasminogen activator, anesthetic agents). Discussion: Hypertension has a significant effect on the efficacy of candidate stroke drugs: standard basic science testing may overestimate the efficacy which could be reasonably expected from certain therapies and for hypertensive patients with large or temporary occlusions.

scholarly journals Butterfly declines in protected areas of Illinois: Assessing the influence of two decades of climate and landscape change

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0257889
Author(s):  
Nicole B. Kucherov ◽  
Emily S. Minor ◽  
Philip P. Johnson ◽  
Doug Taron ◽  
Kevin C. Matteson
Keyword(s):  
North America ◽  
Protected Areas ◽  
Functional Groups ◽  
Impervious Surface ◽  
Urban Landscapes ◽  
Migratory Species ◽  
Science Data ◽  
Larval Host ◽  
Variable Influence

Despite increasing concern regarding broad-scale declines in insects, there are few published long-term, systematic butterfly surveys in North America, and fewer still that have incorporated the influence of changing climate and landscape variables. In this study, we analyzed 20 years of citizen science data at seven consistently monitored protected areas in Illinois, U.S.A. We used mixed models and PERMANOVA to evaluate trends in butterfly abundance, richness, and composition while also evaluating the effects of temperature and land use. Overall butterfly richness, but not abundance, increased in warmer years. Surprisingly, richness also was positively related to percent impervious surface (at the 2 km radius scale), highlighting the conservation value of protected areas in urban landscapes (or alternately, the potential negative aspects of agriculture). Precipitation had a significant and variable influence through time on overall butterfly abundance and abundance of resident species, larval host plant specialists, and univoltine species. Importantly, models incorporating the influence of changing temperature, precipitation, and impervious surface indicated a significant overall decline in both butterfly abundance and species richness, with an estimated abundance decrease of 3.8%/year and richness decrease of 1.6%/year (52.5% and 27.1% cumulatively from 1999 to 2018). Abundance and richness declines were also noted across all investigated functional groups except non-resident (migratory) species. Butterfly community composition changed through time, but we did not find evidence of systematic biotic homogenization, perhaps because declines were occurring in nearly all functional groups. Finally, at the site-level, declines in either richness or abundance occurred at five of seven locations, with only the two largest locations (>300 Ha) not exhibiting declines. Our results mirror those of other long-term butterfly studies predominantly in Europe and North America that have found associations of butterflies with climate variables and general declines in butterfly richness and abundance.

scholarly journals Nitrate Fluctuations in Antarctic Snow and Firn: Potential Sources and Mechanisms of Formation

1982 ◽  
Vol 3 ◽  
pp. 243-248 ◽  
Author(s):  
Bruce C. Parker ◽  
Edward J. Zeller ◽  
Anthony J. Gow
Keyword(s):  
Solar Activity ◽  
Upper Atmosphere ◽  
South Pole ◽  
Ion Concentrations ◽  
Potential Sources ◽  
Long Term Changes ◽  
Antarctic Snow ◽  
Mechanisms Of Formation

We summarize here data on in situ nitrate ion concentrations in snow pits and firn cores over the last ∼3 250 a. Nitrate fluctuations show seasonal, 11 and 22 a periodicities, and long-term changes both at South Pole station and Vostok. High nitrate levels conform to winter darkness and solar activity peaks. Long-term lows and highs conform to solar activity minima and maxima. The data available support the hypothesis that nitrate is fixed in the upper atmosphere by some solar-mediated phenomenon causing a periodicity in East Antarctica snow. Background levels and non-periodic spikes in nitrate come from other sources.

scholarly journals Coastline evolution of Portuguese low-lying sandy coast in the last 50 years: an integrated approach

2016 ◽  
Author(s):  
Cristina Ponte Lira ◽  
Ana Nobre Silva ◽  
Rui Taborda ◽  
Cesar Freire de Andrade
Keyword(s):  
Coastal Management ◽  
Holistic Approach ◽  
Integrated Approach ◽  
Beach Erosion ◽  
Science Data ◽  
Coastal System ◽  
Dune Systems ◽  
Management Actions ◽  
Coastline Evolution

Abstract. Regional/global-scale information on coastline rates of change and trends is extremely valuable, but national-scale studies are scarce. A widely accepted standardized methodology for analysing long-term coastline change has been difficult to achieve, but is essential to conduct an integrated and holistic approach to coastline evolution and hence support coastal management actions. Additionally, databases providing knowledge on coastline evolution are of key importance to support both coastal management experts and users. The main objective of this work is to present the first systematic, global and consistent long-term coastline evolution data of Portuguese mainland low-lying sandy. The methodology used quantifies coastline evolution using an unique and robust coastline indicator (the foredune toe), which is independent of short-term changes. The dataset presented comprises: 1) two polyline sets, mapping the 1958 and 2010 sandy beach-dune systems coastline, both optimized for working at 1:50 000 scale or smaller, and 2) one polyline set representing long-term change rates between 1958 and 2010, estimated at each 250 m. The science data produced here are in Open Access at doi:10.1594/PANGAEA.853654 and can be used in other studies. Results show beach erosion as the dominant trend, with a mean change rate of −0.24 ± 0.01 m/year for all mainland Portuguese beach-dune systems. Although erosion is dominant, this evolution is variable in signal and magnitude in different coastal sediment cell and also within each cell. The most relevant beach erosion issues were found in the coastal stretches of Espinho – Torreira and Costa Nova – Praia da Mira, both at sub-cell 1b; Cova Gala – Leirosa, at sub-cell 1c and Cova do Vapor – Costa da Caparica, at cell 4. Cells 1 and 4 exhibit a history of major human interventions interfering with the coastal system, many of which originated and maintained a sediment deficit. In contrast, cells 5 and 6 have been less intervened and show stable or moderate accretion behaviour.

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