5,934 research outputs found
C3TM: CEI CCD charge transfer model for radiation damage analysis and testing
Radiation induced defects in the silicon lattice of Charge Couple Devices (CCDs) are able to trap electrons during read out and thus create a smearing effect that is detrimental to the scientific data. To further our understanding of the positions and properties of individual radiation-induced traps and how they affect space- borne CCD performance, we have created the Centre for Electronic Imaging (CEI) CCD Charge Transfer Model (C3TM). This model simulates the physical processes taking place when transferring signal through a radiation damaged CCD. C3TM is a Monte Carlo model based on Shockley-Read-Hall theory, and it mimics the physical properties in the CCD as closely as possible. It runs on a sub-electrode level taking device specific charge density simulations made with professional TCAD software as direct input. Each trap can be specified with 3D positional information, emission time constant and other physical properties. The model is therefore also able to simulate multi-level clocking and other complex clocking schemes, such as trap pumping
Lattice QCD Evidence that the Lambda(1405) Resonance is an Antikaon-Nucleon Molecule
For almost 50 years the structure of the Lambda(1405) resonance has been a
mystery. Even though it contains a heavy strange quark and has odd parity, its
mass is lower than any other excited spin-1/2 baryon. Dalitz and co-workers
speculated that it might be a molecular state of an antikaon bound to a
nucleon. However, a standard quark-model structure is also admissible. Although
the intervening years have seen considerable effort, there has been no
convincing resolution. Here we present a new lattice QCD simulation showing
that the strange magnetic form factor of the Lambda(1405) vanishes, signaling
the formation of an antikaon-nucleon molecule. Together with a Hamiltonian
effective-field-theory model analysis of the lattice QCD energy levels, this
strongly suggests that the structure is dominated by a bound antikaon-nucleon
component. This result clarifies that not all states occurring in nature can be
described within a simple quark model framework and points to the existence of
exotic molecular meson-nucleon bound states.Comment: Manuscript accepted for publication. 4 figures, 5 page
Changes in catch rates and length and age at maturity, but not growth, of an estuarine plotosid (Cnidoglanis macrocephalus) after heavy fishing
The hypothesis that heavy fishing pressure has led to changes in the biological characteristics of the estuary cobbler (Cnidoglanis macrocephalus) was tested in a large seasonally open estuary in southwestern Australia, where this species completes its life cycle and is the most
valuable commercial fish species. Comparisons were made between seasonal data collected for this plotosid
(eeltail catfish) in Wilson Inlet during 2005–08 and those recorded with the same fishery-independent sampling regime during 1987–89. These comparisons show that the proportions of larger and older individuals and the catch rates in the
more recent period were far lower, i.e., they constituted reductions of 40% for fish ≥430 mm total length, 62% for fish ≥4 years of age, and 80% for catch rate. In addition, total mortality and fishing-induced mortality estimates increased by factors of ~2 and 2.5, respectively. The indications that the abundance and proportion of older C. macrocephalus declined between the two periods are consistent with the perception of long-term commercial fishermen and their shift toward using a smaller maximum gill net mesh to target this species. The sustained heavy fishing pressure on C. macrocephalus between 1987–89 and 2005–08 was accompanied by a marked reduction in length and age at maturity of this species. The shift in probabilistic maturation reaction norms toward smaller fish in 2005–08
and the lack of a conspicuous change in growth between the two periods indicate that the maturity changes were related to fishery-induced evolution rather than to compensatory
responses to reduced fish densities
Artificial folklore for simulated religions
In this paper we use grammar-directed procedural content generation (PCG) techniques to develop folklore; based on the seven basic story plots, for a simulated religion. A hierarchy of values for a simulated community was first generated. Using these values, a variety of deities were procedurally generated, each with their own reflected values and persona. A Context-Free Grammar is then traversed in order to generate fables appropriate for each deities persona. The intention of this work is to generate fables which can be used to contextualize a given simulated culture's beliefs
Genetic Mutations as Risk Predictors of Atrial Fibrillation Recurrence After Catheter Ablation?**Editorials published in the Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACCor the American College of Cardiology.
Loss of the flagellum happened only once in the fungal lineage: phylogenetic structure of Kingdom Fungi inferred from RNA polymerase II subunit genes
BACKGROUND: At present, there is not a widely accepted consensus view regarding the phylogenetic structure of kingdom Fungi although two major phyla, Ascomycota and Basidiomycota, are clearly delineated. Regarding the lower fungi, Zygomycota and Chytridiomycota, a variety of proposals have been advanced. Microsporidia may or may not be fungi; the Glomales (vesicular-arbuscular mycorrhizal fungi) may or may not constitute a fifth fungal phylum, and the loss of the flagellum may have occurred either once or multiple times during fungal evolution. All of these issues are capable of being resolved by a molecular phylogenetic analysis which achieves strong statistical support for major branches. To date, no fungal phylogeny based upon molecular characters has satisfied this criterion. RESULTS: Using the translated amino acid sequences of the RPB1 and RPB2 genes, we have inferred a fungal phylogeny that consists largely of well-supported monophyletic phyla. Our major results, each with significant statistical support, are: (1) Microsporidia are sister to kingdom Fungi and are not members of Zygomycota; that is, Microsporidia and fungi originated from a common ancestor. (2) Chytridiomycota, the only fungal phylum having a developmental stage with a flagellum, is paraphyletic and is the basal lineage. (3) Zygomycota is monophyletic based upon sampling of Trichomycetes, Zygomycetes, and Glomales. (4) Zygomycota, Basidiomycota, and Ascomycota form a monophyletic group separate from Chytridiomycota. (5) Basidiomycota and Ascomycota are monophyletic sister groups. CONCLUSION: In general, this paper highlights the evolutionary position and significance of the lower fungi (Zygomycota and Chytridiomycota). Our results suggest that loss of the flagellum happened only once during early stages of fungal evolution; consequently, the majority of fungi, unlike plants and animals, are nonflagellated. The phylogeny we infer from gene sequences is the first one that is congruent with the widely accepted morphology-based classification of Fungi. We find that, contrary to what has been published elsewhere, the four morphologically defined phyla (Ascomycota, Basidiomycota, Zygomycota and Chytridiomycota) do not overlap with one another. Microsporidia are not included within kingdom Fungi; rather they are a sister-group to the Fungi. Our study demonstrates the applicability of protein sequences from large, slowly-evolving genes to the derivation of well-resolved and highly supported phylogenies across long evolutionary distances
Expanded Thruster Mass Model Incorporating Nested Hall Thrusters
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143089/1/6.2017-4729.pd
Development of a core outcome set for use in determining the overall success of gastroschisis treatment.
Background: Gastroschisis research is limited in quality by the presence of significant heterogeneity in outcome measure reporting (PloS One 10(1):e0116908, 2015). Using core outcome sets in research is one proposed method for addressing this problem (Trials 13:103, 2012; Clin Rheumatol 33(9):1313-1322, 2014; Health Serv Res Policy 17(1):1-2, 2012). Ultimately, standardising outcome measure reporting will improve research quality and translate into improvements in patient care.Methods/design: Candidate outcome measures have been identified through systematic reviews. These outcome measures will form the starting point for an online, three-phase Delphi process that will be carried out in parallel by three panels of experts. Panel 1 is a neonatal panel, panel 2 is a non-neonatal panel and panel 3 is a lay panel.In round 1, experts will be asked to score the previously identified outcome measures from 1–9 based on how important they think the measures are in determining the overall success of their/their child’s/their patient’s gastroschisis treatment.In round 2, experts will be presented with the same list of outcome measures and with graphical representations of how their panel scored that outcome in round 1. They will be asked to re-score the outcome measure taking into account how important other members of their panel felt it to be. In round 3, experts will again be asked to re-score each outcome measure, but this time they will receive a graphical representation of the distribution of scores from all three panels which they should take into account when re-scoring.Following round 3 of the Delphi process, 40 experts will be invited to attend a face-to-face consensus meeting. Participants will be invited in a purposive manner to obtain balance between the different panels. The results of the Delphi process will be discussed, and outcomes re-scored. Outcome measures where?>?70 % of the participants at the meeting scored them as 7–9 and?<?15 % scored them as 1–3 will form the core outcome set.Discussion: Development of a core outcome set will help to reduce the heterogeneity of the outcome measure reporting in gastroschisis. This will increase the quality of research taking place and ultimately improve care provided to infants with gastroschisis.<br/
Diffusion of Innovations and the Theory of Planned Behavior in Information Systems Research: A Metaanalysis
Diffusion of Innovations and the Theory of Planned Behavior provide the foundation on which a preponderance of information systems (IS) theory and research is built. IS scholars often assume that the basic factors proffered by these theories are significant determinants of innovation adoption. However, there has yet to be a meta-analytic examination of research in the IS field to validate this assumption. Herein, we use Tornatzky and Klein’s seminal 1982 meta-analysis of innovation characteristics as the starting point for our meta-analytic examination of Diffusion of Innovations and Theory of Planned Behavior models in IS research. In order to focus our investigation on a common criterion variable, adoption propensity, we use antecedents from both models to develop a model of innovation adoption-behavior (IAB). After describing the relationships encompassed by the IAB model, we step through a bare-bones meta-analysis. Considering the data reported in fifty-eight empirical articles, we calculate the estimated true correlations with the criterion variable to be .53 for attitude toward behavior, .33 for subjective norm, .41 for perceived behavioral control, .42 for relative advantage, .43 for compatibility, -.28 for complexity, .32 for trialability, and .38 for observability. With the exception of complexity, all correlations generalize across studies
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