86 research outputs found
Absolute magnitudes for late-type dwarf stars for Sloan photometry
We present a new formula for absolute magnitude determination for late-type
dwarf stars as a function of (g-r) and (r-i) for Sloan photometry. The absolute
magnitudes estimated by this approach are brighter than those estimated by
colour-magnitude diagrams, and they reduce the luminosity function rather close
to the luminosity function of Hipparcos.Comment: 11 pages, 9 figures and 5 tables, accepted for publication in A
Transformations between 2MASS, SDSS and BVRI photometric systems: bridging the near infrared and optical
We present colour transformations for the conversion of the {\em 2MASS}
photometric system to the Johnson-Cousins system and further into the
{\em SDSS} system. We have taken {\em SDSS} magnitudes of stars
measured with the 2.5-m telescope from Data Release 5 (DR5), and
and magnitudes from Stetson's catalogue and \citet{Cu03},
respectively. We matched thousands of stars in the three photometric systems by
their coordinates and obtained a homogeneous sample of 825 stars by the
following constraints, which are not used in previous transformations: 1) the
data are de-reddened, 2) giants are omitted, and 3) the sample stars selected
are of the highest quality. We give metallicity, population type, and
transformations dependent on two colours. The transformations provide absolute
magnitude and distance determinations which can be used in space density
evaluations at short distances where some or all of the {\em SDSS}
magnitudes are saturated. The combination of these densities with those
evaluated at larger distances using {\em SDSS} photometry will supply
accurate Galactic model parameters, particularly the local space densities for
each population.Comment: 11 pages, including 10 figures and 7 tables, accepted for publication
in MNRA
Gene Ontology: Pitfalls, Biases, and Remedies.
The Gene Ontology (GO) is a formidable resource, but there are several considerations about it that are essential to understand the data and interpret it correctly. The GO is sufficiently simple that it can be used without deep understanding of its structure or how it is developed, which is both a strength and a weakness. In this chapter, we discuss some common misinterpretations of the ontology and the annotations. A better understanding of the pitfalls and the biases in the GO should help users make the most of this very rich resource. We also review some of the misconceptions and misleading assumptions commonly made about GO, including the effect of data incompleteness, the importance of annotation qualifiers, and the transitivity or lack thereof associated with different ontology relations. We also discuss several biases that can confound aggregate analyses such as gene enrichment analyses. For each of these pitfalls and biases, we suggest remedies and best practices
Methods for specifying the target difference in a randomised controlled trial : the Difference ELicitation in TriAls (DELTA) systematic review
Peer reviewedPublisher PD
A strategy to incorporate prior knowledge into correlation network cutoff selection
Correlation networks are frequently used to statistically extract biological interactions between omics markers. Network edge selection is typically based on the statistical significance of the correlation coefficients. This procedure, however, is not guaranteed to capture biological mechanisms. We here propose an alternative approach for network reconstruction: a cutoff selection algorithm that maximizes the overlap of the inferred network with available prior knowledge. We first evaluate the approach on IgG glycomics data, for which the biochemical pathway is known and well-characterized. Importantly, even in the case of incomplete or incorrect prior knowledge, the optimal network is close to the true optimum. We then demonstrate the generalizability of the approach with applications to untargeted metabolomics and transcriptomics data. For the transcriptomics case, we demonstrate that the optimized network is superior to statistical networks in systematically retrieving interactions that were not included in the biological reference used for optimization
Rationale and design of the United Kingdom Heart Failure with Preserved Ejection Fraction Registry
\ua9 Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.Objective: Heart failure with preserved ejection fraction (HFpEF) is a common heterogeneous syndrome that remains imprecisely defined and consequently has limited treatment options and poor outcomes. Methods: The UK Heart Failure with Preserved Ejection Fraction Registry (UK HFpEF) is a prospective data-enabled cohort and platform study. The study will develop a large, highly characterised cohort of patients with HFpEF. A biobank will be established. Deep clinical phenotyping, imaging, multiomics and centrally held national electronic health record data will be integrated at scale, in order to reclassify HFpEF into distinct subgroups, improve understanding of disease mechanisms and identify new biological pathways and molecular targets. Together, these will form the basis for developing diagnostics and targeted therapeutics specific to subgroups. It will be a platform for more effective and efficient trials, focusing on subgroups in whom targeted interventions are expected to be effective, with consent in place to facilitate rapid recruitment, and linkage for follow-up. Patients with a diagnosis of HFpEF made by a heart failure specialist, who have had natriuretic peptide levels measured and a left ventricular ejection fraction >40% are eligible. Patients with an ejection fraction between 40% and 49% will be limited to no more than 25% of the cohort. Conclusions: UK HFpEF will develop a rich, multimodal data resource to enable the identification of disease endotypes and develop more effective diagnostic strategies, precise risk stratification and targeted therapeutics. Trial registration number: NCT05441839
The apicomplexan plastid and its evolution
Protistan species belonging to the phylum Apicomplexa have a non-photosynthetic secondary plastid—the apicoplast. Although its tiny genome and even the entire nuclear genome has been sequenced for several organisms bearing the organelle, the reason for its existence remains largely obscure. Some of the functions of the apicoplast, including housekeeping ones, are significantly different from those of other plastids, possibly due to the organelle’s unique symbiotic origin
Introduction: new research in monetary history - A map
This handbook aims to provide a comprehensive (though obviously not exhaustive) picture of state-of-the-art international scholarship on the history of money and currency. The chapters of this handbook cover a wide selection of research topics. They span chronologically from antiquity to nowadays and are geographically stretched from Latin America to Asia, although most of them focus on Western Europe and the USA, as a large part of the existing research does. The authors of these chapters constitute, we hope, a balanced sample of various generations of scholars who contributed to what Barry Eichengreen defined as "the new monetary and financial history" – an approach that combines the analysis of monetary aggregates and policies with the structure and dynamics of the banking sector and financial markets. We have structured this handbook in ten broad thematic parts: the historical origins of money; money, coinage, and the state; trade, money markets, and international currencies; money and metals; monetary experiments; Asian monetary systems; exchange rate regimes; monetary integration; central banking and monetary policy; and aggregate price shocks. In this introduction, we offer for each part some historical context, a few key insights from the literature, and a brief analytical summary of each chapter. Our aim is to draw a map that hopefully will help readers to organize their journey through this very wide and diverse research area
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