793 research outputs found
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Investigating the Distribution and Source(s) of Lunar Volatiles
Following the renewed interest in the volatile inventory of the Moon witnessed in the last decade, from both sample studies and data from orbital missions, it is timely to reassess the distribution and likely source(s) of light element volatiles (C, N, He, Ne, and Ar) in a diverse suite of lunar mare basalts and soils, providing new insights about volatiles indigenous to the lunar interior, volatiles produced in situ at the lunar surface, and volatiles delivered to and implanted into the lunar surface. Simultaneous static-mode mass spectrometric measurements of these key volatiles, extracted from the same aliquot of sample by high-resolution stepped combustion, enable a more detailed identification of the different volatile components present by comparing their varying release patterns across a range of temperature steps. Taken in context with other studies of different volatile elements, this new data contributes towards a greater understanding of the Earth-Moon system, with additional implications for future in situ resource utilisation at the lunar surface.
With an average Ī“15N value of +0.93 Ā± 9.39 ā°, the indigenous N component measured in mare basalts is most compatible with a CO carbonaceous chondrite source for nitrogen in the lunar interior, although some caveats exist. Variations in abundance and isotopic composition of indigenous nitrogen imply a heterogeneous lunar mantle. Assuming up to ~50 % loss of solar wind 36Ar from lunar soils, nitrogen trapped in soils can be reconciled with up to 87 % being contributed from a non-solar source with an isotopic composition
of between +87 ā° and +160 ā°.
Noble gases in soils are dominated by solar wind components, with only minor amounts of cosmogenic neon being released at the highest temperature steps. In mare basalts, noble gases are a mixture of trapped, radiogenic, and cosmogenic components (from which cosmogenic production rates can be calculated and exposure ages for previously undated samples suggeste
The Port Norfolk Project: Improved Raster Navigation Products From High Resolution Source Data
With increasing capabilities in technology, modern hydrographic surveys are comprised of similarly increasing amounts of data, only a minute fraction of which is currently available in the nautical charts produced by the NOAA Office of Coast Survey (OCS). Simultaneously, a tremendous amount of effort goes into the generalization and optimal cartographic representation of the hydrographic data onto raster products, from which the vector products are digitized. Preserving and maintaining a single database of high-resolution vector source data will retainā and make accessibleāmuch more of the hydrographic data collected, alleviate the burden of generalization, and would allow for delivery of high-resolution vector products, as well as a very wide selection of raster products. From high-resolution source data, raster output could be generated at customer specifications. These āuser-definedā raster products could be suitably tailored to meet anyoneās needs, regardless if they are a mariner, a scientist, a fisherman, a student, or a casual ācommon manā customer. The āuser-definedā concept will ultimately improve our ability to meet the highly variable needs of our customers. This paper is intended as an exploratory endeavor, specifically, using the Paper Chart Editor component of CARIS HPD to create examples of the kinds of raster products one can create from high-resolution source data, how this process could optimize the current raster chart production workflow within OCS, while also providing a stronger focus on customer service. Finally, the capabilities and lessons learned from the experimentation with HPD will be applied toward the NOAA-wide implementation of Nautical Chart System II (NCSII)
The Cooking and Pneumonia Study (CAPS) in Malawi: Implementation of Remote Source Data Verification
Background
Source data verification (SDV) is a data monitoring procedure which compares the original records with the Case Report Form (CRF). Traditionally, on-site SDV relies on monitors making multiples visits to study sites requiring extensive resources. The Cooking And Pneumonia Study (CAPS) is a 24- month village-level cluster randomized controlled trial assessing the effectiveness of an advanced cook-stove intervention in preventing pneumonia in children under five in rural Malawi (www.capstudy.org). CAPS used smartphones to capture digital images of the original records on an electronic CRF (eCRF). In the present study, descriptive statistics are used to report the experience of electronic data capture with remote SDV in a challenging research setting in rural Malawi.
Methods
At three monthly intervals, fieldworkers, who were employed by CAPS, captured pneumonia data from the original records onto the eCRF. Fieldworkers also captured digital images of the original records. Once Internet connectivity was available, the data captured on the eCRF and the digital images of the original records were uploaded to a web-based SDV application. This enabled SDV to be conducted remotely from the UK. We conducted SDV of the pneumonia data (occurrence, severity, and clinical indicators) recorded in the eCRF with the data in the digital images of the original records.
Result
664 episodes of pneumonia were recorded after 6 months of follow-up. Of these 664 episodes, 611 (92%) had a finding of pneumonia in the original records. All digital images of the original records were clear and legible.
Conclusion
Electronic data capture using eCRFs on mobile technology is feasible in rural Malawi. Capturing digital images of the original records in the field allows remote SDV to be conducted efficiently and securely without requiring additional field visits. We recommend these approaches in similar settings, especially those with health endpoints
Remote file access over low-speed lines
A link between microcomputer and mainframe can be useful in several ways, even when, as is usually the case, the link is only a normal terminal line. One interesting example is the āIntegrated applicationā, which divides a task between microcomputer and mainframe and can offer several benefits; in particular, reducing load on the mainframe and permitting a more advanced user interface than possible on a conventional terminal.
Because integrated applications consist of two co-operating programs, they are much more difficult to construct than a single program. It would be much easier to implement integrated applications concerned with the display and/or modification of data in mainframe files if the microcomputer could confine its dealings with the mainframe to a suitable file server. However, file servers do not appear practical for use over slow (compared to disc access speed) terminal lines.
It was proposed to alleviate the problems caused by the slow link with extended file operations, which would allow time-consuming file operations such as searching or copying between files to be done in the file server. It was discovered after attempting such a system that extended file operations are not, by themselves, sufficient; but, allied to a record-based file model and asynchronous operations (i.e. file operations that do not suspend the user program until they complete), useful results could be obtained.
This thesis describes FLAP, a file server for use over terminal lines which incorporates these ideas, and MMMS, an inter-application transport protocol used by FLAP for communication between the microcomputer file interface and the mainframe server.
Two simple FLAP applications are presented, a customer records maintenance program and a screen editor. Details are given of their construction and response time in use at various line speeds
Enantioselective one-carbon expansion of aromatic rings by simultaneous formation and chromoselective irradiation of a transient coloured enolate
Enantioenriched seven-membered carbocycles are motifs in many molecules of structural and biological interest. We report a simple, practical, transition metal-free and mechanistically unusual method for the enantioselective synthesis of substituted cycloheptatrienes. By forming a coloured enolate with an appropriate absorption band and selectively irradiating in situ, we to initiate a tandem, asymmetric anionic and photochemical ring expansion of readily accessible N-benzylbenzamides. The cascade of reactions leading to the products entails enantioselective benzylic deprotonation with a chiral lithium amide, dearomatizing cyclization of the resulting configurationally defined organolithium to give an extended amide enolate, and photochemically induced formal [1,7]-sigmatropic rearrangement and 6Ļ-electrocyclic ring-opening ā the latter all evidently being stereospecific ā to deliver enantioenriched cycloheptatrienes with embedded benzylic stereocentres
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Using stable isotope geochemistry to investigate the source(s) of volatiles in the lunar regolith
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Physical exercise and activity may be important in reducing dementia risk at any age
Lifestyle interventions such as physical exercise may provide inexpensive and effective ways to delay the onset of cognitive decline and dementia. If we are able to reduce Alzheimer neuropathology in the future as now appears possible,1 combining pharmacologic and lifestyle interventions will likely provide the best prevention for cognitive decline and dementia. In this respect, prevention of dementia and cognitive impairment would be similar to current preventive treatments for diabetes and vascular disease, where both types of interventions are used
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Preparing and Characterizing Carbonaceous Chondrite Standards for Verification of ESAāS āProspectā Package
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An Experimental Approach to Understanding Sublimation Water Ice Losses from Planetary Regolith Analogue Mixtures for ESAās PROSPECT Package
A promising Start? The Local Network Fund for Children and Young People: Interim Findings from the National Evaluation
This is a summary of the interim evaluation report of the National Evaluation of the Local Network Fund (LNF) for Children and Young People. It is based on data gathered during the first phase of the evaluation (between October 2002 to December 2003). A final report of the National Evaluation will be available early in 2005. A consortium of research organisations, led by the University of Hull and including BMRB Social
Research, The University of York and the University of Sheffield were commissioned in August 2002 by the-then Children and Young Peopleās Unit (CYPU) to carry out the evaluation
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