3,041 research outputs found
Using the UM dynamical cores to reproduce idealised 3D flows
We demonstrate that both the current (New Dynamics), and next generation
(ENDGame) dynamical cores of the UK Met Office global circulation model, the
UM, reproduce consistently, the long-term, large-scale flows found in several
published idealised tests. The cases presented are the Held-Suarez test, a
simplified model of Earth (including a stratosphere), and a hypothetical
tidally locked Earth. Furthermore, we show that using simplifications to the
dynamical equations, which are expected to be justified for the physical
domains and flow regimes we have studied, and which are supported by the
ENDGame dynamical core, also produces matching long-term, large-scale flows.
Finally, we present evidence for differences in the detail of the planetary
flows and circulations resulting from improvements in the ENDGame formulation
over New Dynamics.Comment: 34 Pages, 23 Figures. Accepted for publication in Geoscientific Model
Development (pre-proof version
A glimpse into the diversity of Colombian Acanthaceae
Summary: A short visit to four Colombian herbaria in 2022 is highlighted as an example of modern-day herbarium plant hunting which resulted in the discovery of 14 new species: Aphelandra guacharorum J.R.I.Wood, A. montis-tusae J.R.I.Wood & Hoyos-Gómez, Justicia betancurii J.R.I.Wood, J. chloroleuca J.R.I.Wood, J. cristalina J.R.I.Wood & Hoyos-Gómez, J. daironcardenasii J.R.I.Wood & Hoyos-Gómez, J. ipanorensis J.R.I.Wood, J. lutescens J.R.I.Wood & Hoyos-Gómez, J. macuirensis J.R.I.Wood, J. perijaensis J.R.I.Wood, J. reniformis J.R.I.Wood, J. rheophytica J.R.I.Wood & Hoyos-Gómez J. santanderana J.R.I.Wood & Hoyos-Gómez and Ruellia rheophytica J.R.I.Wood & Hoyos-Gómez. These are described and illustrated with line drawings. Additionally, a full description and line drawings of two poorly known species, Justicia hochreutineri J.F.Macbr. and J. trianae (Leonard) J.R.I.Wood are provided. Notes are provided on 21 other species drawing attention to new records for Colombia, rediscoveries and taxonomic issues. Justicia hochreutineri J.F.Macbr., J. pilosa (Ruiz ex Nees) Lindau, J. zamorensis Wassh. and Stenostephanus lasiostachyus Nees are recorded for the first time for Colombia. Justicia pampolystachys Leonard is treated as a synonym of J. hyperdasya Leonard. Poikilacanthus moritzianus (Nees) Lindau is shown to be restricted to Venezuela. Adhatoda pilosa Ruiz ex Nees is lectotypified. Attention is drawn to the number of rheophytes in Colombian Acanthaceae and to the importance of the Río Claro and Río Samaná Norte area of Antioquia as a centre of plant diversity
Estimating the Porosity of the Interstellar Medium from Three-Dimensional Photoionization Modeling of H II Regions
We apply our three dimensional photoionization code to model Wisconsin
H-alpha Mapper observations of the H II region surrounding the O9.5V star Zeta
Oph. Our models investigate the porosity of the interstellar medium around zeta
Oph and the effects of 3D densities on the H-alpha surface brightness and
variation in the [N II]/H-alpha line ratio. The Zeta Oph H II region has a well
characterized ionizing source, so it is an excellent starting point for 3D
models of diffuse ionized gas. We investigate various hierarchically clumped
density structures, varying the overall smoothness within the clumping
algorithm. By simulating the observations, we can estimate the porosity of the
medium in the vicinity of Zeta Oph and find that within the context of our
hierarchically clumped models, around 50% to 80% of the volume is occupied by
clumps surrounded by a low density smooth medium. We also conclude that in
order for O stars to ionize the diffuse Warm Ionized Medium, the O star
environment must be more porous than that surrounding Zeta Oph, with clumps
occupying less than one half of the interstellar volume. Our clumpy models have
irregular boundaries, similar to observed H II regions. However, in observed H
II regions it is difficult to identify the precise location of the boundary
because of the foreground and/or background emission from the widespread Warm
Ionized Medium. This complicates the interpretation of the predicted rapid rise
of some emission line ratios near the edge of uniform density H II regions and
combined with the three dimensional clumpy nature of the interstellar medium
may explain the apparent lack of distinctive emission line ratios near H I -- H
II interfaces.Comment: Accepted for publication in Ap
Misapplied names, synonyms and new species of Ipomoea (Convolvulaceae) from South America
The identities of plants treated under the names Ipomoea goyazensis Gardner, I. bignonioides Sims, I. patula Choisy, I. fiebrigii Hassl. ex O’Donell, I. hirsutissima Gardner and I. carajasensis D. F. Austin are evaluated. It is shown that the name I. goyazensis should be used for the cerrado species often known under the name I. decora Meisn., rather than a plant from southern Brazil which is here described as a new species I. austrobrasiliensis J. R. I. Wood and Scotland. I. bignonioides Sims is synonymised with I. mauritiana Jacq., and an epitype is selected to fix the application of this name and ensure it is not confused with I. goyazensis. I. patula is lectotypified and treated as a synonym of the African I. crassipes Hook. The different recognised varieties of I. patula are evaluated; var. monticola Meisn. is treated as a species under the name I. langsdorffii Choisy; var. villosa Meisn. is shown to be a synonym of I. guaranitica Chodat and Hassl., in which is included the little-known species I. cornucopia Chodat and Hassl. Specimens from Paraguay, originally also treated as I. patula var. villosa or I. malvaeoides Meisn. var. ovata Hallier f., are treated as a distinct species named I. cordillerae J. R. I. Wood and Scotland. Plants from Brazil treated in various herbaria under the name of the Paraguayan species I. fiebrigii are shown to be a distinct species, which is described as new under the name I. angustissima J. R. I. Wood and Scotland. Species sometimes included in I. hirsutissima are discussed and a key to distinguish them is provided. I. pyrenea Taub. is illustrated and shown to be distinct and a plant from Paraguay sometimes named I. hirsutissima is described as new under the name I. megalantha J. R. I. Wood and Scotland. I. carajasensis D. F. Austin is shown to be a synonym of I. maurandioides Meisn. and plants from the cerrados of central Brazil often identified as this species are described as new under the name I. aequiloba J. R. I. Wood and Scotland. Two other commonly misunderstood species I. elegans A. Dietr. and I. serpens Meisn. are also discussed. All new species and some little-known species are illustrated, maps of contrasting distributions are provided and various lectotypifications are made to fix the concepts of several species discussed in this paper
Whole-genome sequencing to understand the genetic architecture of common gene expression and biomarker phenotypes.
Initial results from sequencing studies suggest that there are relatively few low-frequency (<5%) variants associated with large effects on common phenotypes. We performed low-pass whole-genome sequencing in 680 individuals from the InCHIANTI study to test two primary hypotheses: (i) that sequencing would detect single low-frequency-large effect variants that explained similar amounts of phenotypic variance as single common variants, and (ii) that some common variant associations could be explained by low-frequency variants. We tested two sets of disease-related common phenotypes for which we had statistical power to detect large numbers of common variant-common phenotype associations-11 132 cis-gene expression traits in 450 individuals and 93 circulating biomarkers in all 680 individuals. From a total of 11 657 229 high-quality variants of which 6 129 221 and 5 528 008 were common and low frequency (<5%), respectively, low frequency-large effect associations comprised 7% of detectable cis-gene expression traits [89 of 1314 cis-eQTLs at P < 1 × 10(-06) (false discovery rate ∼5%)] and one of eight biomarker associations at P < 8 × 10(-10). Very few (30 of 1232; 2%) common variant associations were fully explained by low-frequency variants. Our data show that whole-genome sequencing can identify low-frequency variants undetected by genotyping based approaches when sample sizes are sufficiently large to detect substantial numbers of common variant associations, and that common variant associations are rarely explained by single low-frequency variants of large effect
Risk assessment for hospital admission in patients with COPD; a multi-centre UK prospective observational study.
In chronic obstructive pulmonary disease (COPD), acute exacerbation of COPD requiring hospital admission is associated with mortality and healthcare costs. The ERICA study assessed multiple clinical measures in people with COPD, including the short physical performance battery (SPPB), a simple test of physical function with 3 components (gait speed, balance and sit-to-stand). We tested the hypothesis that SPPB score would relate to risk of hospital admissions and length of hospital stay. Data were analysed from 714 of the total 729 participants (434 men and 280 women) with COPD. Data from this prospective observational longitudinal study were obtained from 4 secondary and 1 tertiary centres from England, Scotland, and Wales. The main outcome measures were to estimate the risk of hospitalisation with acute exacerbation of COPD (AECOPD and length of hospital stay derived from hospital episode statistics (HES). In total, 291 of 714 individuals experienced 762 hospitalised AECOPD during five-year follow up. Poorer performance of SPPB was associated with both higher rate (IRR 1.08 per 1 point decrease, 95% CI 1.01 to 1.14) and increased length of stay (IRR 1.18 per 1 point decrease, 95% CI 1.10 to 1.27) for hospitalised AECOPD. For the individual sit-to-stand component of the SPPB, the association was even stronger (IRR 1.14, 95% CI 1.02 to 1.26 for rate and IRR 1.32, 95% CI 1.16 to 1.49 for length of stay for hospitalised AECOPD). The SPPB, and in particular the sit-to-stand component can both evaluate the risk of H-AECOPD and length of hospital stay in COPD. The SPPB can aid in clinical decision making and when prioritising healthcare resources
Learning to mark: a qualitative study of the experiences and concerns of medical markers
BACKGROUND: Although there is published research on the methods markers use in marking various types of assessment, there is relatively little information on the processes markers use in approaching a marking exercise. This qualitative paper describes the preparation and experiences of general practice (GP) teachers who undertake marking a written assessment in an undergraduate medical course. METHODS: Semi-structured interviews were conducted with seven of the 16 GP tutors on an undergraduate course. The purposive sample comprised two new markers, two who had marked for a couple of years and three experienced markers. Each respondent was interviewed twice, once following a formative assessment of a written case study, and again after a summative assessment. All interviews were audio-taped and analysed for emerging themes. A respondent validation exercise was conducted with all 16 GP tutors. RESULTS: Markers had internal concerns about their ability to mark fairly and made considerable efforts to calibrate their marking. They needed guidance and coaching when marking for the first time and adopted a variety of marking styles, reaching a decision through a number of routes. Dealing with pass/fail borderline scripts and the consequences of the mark on the student were particular concerns. Even experienced markers felt the need to calibrate their marks both internally and externally CONCLUSION: Previous experience of marking appears to improve markers' confidence and is a factor in determining the role which markers adopt. Confidence can be improved by giving clear instructions, along with examples of marking. The authors propose that one method of providing this support and coaching could be by a process of peer review of a selection of papers prior to the main marking. New markers in particular would benefit from further guidance, however they are influenced by others early on in their marking career and course organisers should be mindful of this when arranging double marking
Radiocaesium transfer and radiation exposure of frogs in Fukushima Prefecture
The International Commission on Radiological Protection has proposed an environmental assessment framework. This includes ionising radiation exposure assessment for different frog life-stages, but radiocaesium transfer parameters are unavailable. We collate data from the Fukushima Prefecture (contaminated by the Fukushima accident) and estimate radiocaesium concentration ratio (CR ) values for tadpoles and adult frogs, presenting the largest available amphibian CR dataset. In total, 513 adult frogs and 2540 tadpoles were analysed in 62 and 59 composite samples respectively. Results suggest that equilibrium was reached between water and amphibian radiocaesium activity concentrations circa one-year after the accident. Radiocaesium transfer to tadpoles was higher than to adult frogs. Dose rates were estimated for different life-stages and species in both the aquatic and terrestrial environment. Estimated dose rates to adults and tadpoles were typically similar because external exposure dominated for both organisms; frogspawn dose rates were estimated to be orders of magnitude lower than other life-stages. For the two sites assessed, which were outside of the most contaminated areas of the Fukushima Prefecture, estimated dose rates were below those anticipated to present a risk to wildlife populations; it is likely that dose rates in more contaminated areas were in excess of some effects benchmark values
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