3,437 research outputs found
Data Stewardship: Environmental Data Curation and a Web-of-Repositories
Scientific researchers today frequently package measurements and associated metadata as digital datasets in anticipation of storage in data repositories. Through the lens of environmental data stewardship, we consider the data repository as an organizational element central to data curation. One aspect of non-commercial repositories, their distance-from-origin of the data, is explored in terms of near and remote categories. Three idealized repository types are distinguished â local, center, and archive - paralleling research, resource, and reference collection categories respectively. Repository type characteristics such as scope, structure, and goals are discussed. Repository similarities in terms of roles, activities and responsibilities are also examined. Data stewardship is related to care of research data and responsible scientific communication supported by an infrastructure that coordinates curation activities; data curation is defined as a set of repeated and repeatable activities focusing on tending data and creating data products within a particular arena. The concept of âsphere-of-contextâ is introduced as an aid to distinguishing repository types. Conceptualizing a âweb-of-repositoriesâ accommodates a variety of repository types and represents an ecologically inclusive approach to data curation
A Preliminary Review of the Operation and Effect of the NAFTA Rules of Origin
This PDF contains a central article and response articles, these are then followed by a short discussion piece
Towards Standardization: A Participatory Framework for Scientific Standard-Making
In contemporary scientific research, standard-making and standardization are key processes for the sharing and reuse of data. The goals of this paper are twofold: 1) to stress that collaboration is crucial to standard-making, and 2) to urge recognition of metadata standardization as part of the scientific process. To achieve these goals, a participatory framework for developing and implementing scientific metadata standards is presented. We highlight the need for ongoing, open dialogue within and among research communities at multiple levels. Using the Long Term Ecological Research network adoption of the Ecological Metadata Language as a case example in the natural sciences, we illustrate how a participatory framework addresses the need for active coordination of the evolution of scientific metadata standards. The participatory framework is contrasted with a hierarchical framework to underscore how the development of scientific standards is a dynamic and continuing process. The roles played by âbest practicesâ and âworking standardsâ are identified in relation to the process of standardization
High Radiation Resistant DC-DC Converter Regulators for use in Magnetic fields for LHC High Luminosity Silicon Trackers
For more efficient power transport to the electronics embedded inside large colliding beam detectors, we explore the feasibility of supplying higher DC voltage and using local DC-DC conversion to 1.3 V (or lower, depending upon on the lithography of the embedded electronics) using switch mode regulators located very close to the front end electronics. These devices will be exposed to high radiation and high magnetic fields, 10 â 100 Mrads and 2 - 4 Tesla at the SLHC
Progress on DC-DC Converters for a Silicon Tracker for the sLHC Upgrade
There is a need for DC-DC converters which can operate in the extremely harsh environment of the sLHC Si Tracker. The environment requires radiation qualification to a total ionizing radiation dose of 50 Mrad and a displacement damage fluence of 5 x 1014 /cm2 of 1 MeV equivalent neutrons. In addition a static magnetic field of 2 Tesla or greater prevents the use of any magnetic components or materials. In February 2007 an Enpirion EN5360 was qualified for the sLHC radiation dosage but the converter has an input voltage limited to a maximum of 5.5V. From a systems point of view this input voltage was not sufficient for the application. Commercial LDMOS FETs have developed using a 0.25 ÎŒm process which provided a 12 volt input and were still radiation hard. These results are reported here and in previous papers. Plug in power cards with Ă10 voltage ratio are being developed for testing the hybrids with ABCN chips. These plug-in cards have air coils but use commercial chips that are not designed to be radiation hard. This development helps in evaluating system noise and performance. GaN FETs are tested for radiation hardness to ionizing radiation and displacement damage and preliminary results are given
Fluoroquinolones and isoniazid-resistant tuberculosis: implications for the 2018 WHO guidance.
INTRODUCTION: 2018 World Health Organization (WHO) guidelines for the treatment of isoniazid (H)-resistant (Hr) tuberculosis recommend a four-drug regimen: rifampicin (R), ethambutol (E), pyrazinamide (Z) and levofloxacin (Lfx), with or without H ([H]RZE-Lfx). This is used once Hr is known, such that patients complete 6â
months of Lfx (â„6[H]RZE-6Lfx). This cohort study assessed the impact of fluoroquinolones (Fq) on treatment effectiveness, accounting for Hr mutations and degree of phenotypic resistance. METHODS: This was a retrospective cohort study of 626 Hr tuberculosis patients notified in London, 2009-2013. Regimens were described and logistic regression undertaken of the association between regimen and negative regimen-specific outcomes (broadly, death due to tuberculosis, treatment failure or disease recurrence). RESULTS: Of 594 individuals with regimen information, 330 (55.6%) were treated with (H)RfZE (Rf=rifamycins) and 211 (35.5%) with (H)RfZE-Fq. The median overall treatment period was 11.9â
months and median Z duration 2.1â
months. In a univariable logistic regression model comparing (H)RfZE with and without Fqs, there was no difference in the odds of a negative regimen-specific outcome (baseline (H)RfZE, cluster-specific odds ratio 1.05 (95% CI 0.60-1.82), p=0.87; cluster NHS trust). Results varied minimally in a multivariable model. This odds ratio dropped (0.57, 95% CI 0.14-2.28) when Hr genotype was included, but this analysis lacked power (p=0.42). CONCLUSIONS: In a high-income setting, we found a 12-month (H)RfZE regimen with a short Z duration to be similarly effective for Hr tuberculosis with or without a Fq. This regimen may result in fewer adverse events than the WHO recommendations
The CSF in neurosarcoidosis contains consistent clonal expansion of CD8 T cells, but not CD4 T cells
The tissue-specific drivers of neurosarcoidosis remain poorly defined. To identify cerebrospinal fluid (CSF) specific, antigen-driven T and B cell responses, we performed single-cell RNA sequencing of CSF and blood cells from neurosarcoid participants coupled to T and B cell receptor sequencing. In contrast to pulmonary sarcoidosis, which is driven by CD4 T cells, we found CD8 T cell clonal expansion enriched in the neurosarcoid CSF. These CSF-enriched CD8 T cells were composed of two subsets with differential expression of EBI2, CXCR3, and CXCR4. Lastly, our data suggest that IFNÎł signaling may distinguish neurosarcoidosis from other neurological disorders
From Quantum Systems to L-Functions: Pair Correlation Statistics and Beyond
The discovery of connections between the distribution of energy levels of
heavy nuclei and spacings between prime numbers has been one of the most
surprising and fruitful observations in the twentieth century. The connection
between the two areas was first observed through Montgomery's work on the pair
correlation of zeros of the Riemann zeta function. As its generalizations and
consequences have motivated much of the following work, and to this day remains
one of the most important outstanding conjectures in the field, it occupies a
central role in our discussion below. We describe some of the many techniques
and results from the past sixty years, especially the important roles played by
numerical and experimental investigations, that led to the discovery of the
connections and progress towards understanding the behaviors. In our survey of
these two areas, we describe the common mathematics that explains the
remarkable universality. We conclude with some thoughts on what might lie ahead
in the pair correlation of zeros of the zeta function, and other similar
quantities.Comment: Version 1.1, 50 pages, 6 figures. To appear in "Open Problems in
Mathematics", Editors John Nash and Michael Th. Rassias. arXiv admin note:
text overlap with arXiv:0909.491
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Motifs in bipartite ecological networks: uncovering indirect interactions
Indirect interactions play an essential role in governing population, community and coevolutionary dynamics across a diverse range of ecological communities. Such communities are widely represented as bipartite networks: graphs depicting interactions between two groups of species, such as plants and pollinators or hosts and parasites. For over thirty years, studies have used indices, such as connectance and species degree, to characterise the structure of these networks and the roles of their constituent species. However, compressing a complex network into a single metric necessarily discards large amounts of information about indirect interactions. Given the large literature demonstrating the importance and ubiquity of indirect effects, many studies of network structure are likely missing a substantial piece of the ecological puzzle. Here we use the emerging concept of bipartite motifs to outline a new framework for bipartite networks that incorporates indirect interactions. While this framework is a significant departure from the current way of thinking about bipartite ecological networks, we show that this shift is supported by analyses of simulated and empirical data. We use simulations to show how consideration of indirect interactions can highlight differences missed by the current index paradigm that may be ecologically important. We extend this finding to empirical plant-pollinator communities, showing how two bee species, with similar direct interactions, differ in how specialised their competitors are. These examples underscore the need to not rely solely on network- and species-level indices for characterising the structure of bipartite ecological networks
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