2,276 research outputs found
KELT-12b: A P ~ 5 day, Highly Inflated Hot Jupiter Transiting a Mildly Evolved Hot Star
We announce the discovery of KELT-12b, a highly inflated Jupiter-mass planet transiting the mildly evolved, V = 10.64 host star TYC 2619-1057-1. We followed up the initial transit signal in the KELT-North survey data with precise ground-based photometry, high-resolution spectroscopy, precise radial velocity measurements, and high-resolution adaptive optics imaging. Our preferred best-fit model indicates that the host star has T_(eff) = 6279 ± 51 K, log gâ = 3.89 ± 0.05, [Fe/H] = 0.19^(+0.08)_(-0.09), M* = 1.59^(+0.07)_(-0.09)Mâ, and R* = 2.37 ± 0.17 Râ. The planetary companion has M_P = 0.95 ± 0.14 M_J, R_P = 1.78^(+0.17)_(-0.16)R_J, log g_P = 2.87^(+0.09)_(-0.10), and density Ï_P = 0.21^(+0.07)_(-0.05) g cm^(â3), making it one of the most inflated giant planets known. Furthermore, for future follow-up, we report a high-precision time of inferior conjunction in BJD_(TDB) of 2,457,083.660459 ± 0.000894 and period of P = 5.0316216 ± 0.000032 days. Despite the relatively large separation of ~0.07 au implied by its ~5.03-day orbital period, KELT-12b receives significant flux of 2.38^(+0.32)_(-0.29) x 10^9 erg s^(â1) cm^(â2) from its host. We compare the radii and insolations of transiting gas giant planets around hot (T_(eff) â©Ÿ 6250 K) and cool stars, noting that the observed paucity of known transiting giants around hot stars with low insolation is likely due to selection effects. We underscore the significance of long-term ground-based monitoring of hot stars and space-based targeting of hot stars with the Transiting Exoplanet Survey Satellite to search for inflated gas giants in longer-period orbits
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Evaluating forecasts of the evolution of the cloudy boundary layer using diurnal composites of radar and lidar observations
Observations of boundary-layer cloud have been made using radar and lidar at Chilbolton, Hampshire, UK. These have been compared with output from 7 different global and regional models. Fifty-five cloudy days have been composited to reveal the mean diurnal variation of cloud top and base heights, cloud thickness and liquid water path of the clouds. To enable like-for-like comparison between model and observations, the observations have been averaged on to the grid of each model. The composites show a distinct diurnal cycle in observed cloud; the cloud height exhibits a sinusoidal variation throughout the day with a maximum at around 1600 and a minimum at around 0700 UTC. This diurnal cycle is captured by six of the seven models analysed, although the models generally under-predict both cloud top and cloud base heights throughout the day. The two worst performing models in terms of cloud boundaries also have biases of around a factor of two in liquid water path; these were the only two models that did not include an explicit formulation for cloud-top entrainment
New sustainable ternary copper phosphide thermoelectrics
Funding: R. J. Q. and J.-W. G. B. acknowledge the Leverhulme Trust (RPG-2020-177). A. D. H. acknowledges the EPSRC (EP/ R013004/1).The thermoelectric performance of ACuP (A = Mg and Ca) with abundant elements and low gravimetric density is reported. Both systems are p-type doped by intrinsic Cu vacancy defects, have large power factors and promising figures of merit, reaching zT = 0.5 at 800 K. This demonstrates that copper phosphides are a potential new class of thermoelectric materials for waste heat harvesting.Publisher PDFPeer reviewe
Evidence of methodological bias in hospital standardised mortality ratios: retrospective database study of English hospitals
Objective To assess the validity of case mix adjustment methods used
to derive standardised mortality ratios for hospitals, by examining the
consistency of relations between risk factors and mortality across
hospitals
Social factors influencing utilization of home care in community-dwelling older adults: a scoping review
Background: Older adults want to live at home as long as possible, even in the face of circumstances that limit their autonomy. Home care services reflect this emergent preference, allowing older adults to âage in placeâ in familiar settings rather than receiving care for chronic health conditions or ageing needs in an institutionalized setting. Numerous social factors, generally studied in isolation, have been associated with home care utilization. Even so, social circumstances are complex and how these factors collectively influence home care use patterns remains unclear. Objectives: To provide a broad and comprehensive overview of the social factors influencing home care utilization; and to evaluate the influence of discrete social factors on patterns of home care utilization in community-dwelling older adults in high-income countries. Methods: A scoping review was conducted of six electronic databases for records published between 2010 and 2020; additional records were obtained from hand searching review articles, reference lists of included studies and documents from international organisations. A narrative synthesis was presented, complemented by vote counting per social factor, harvest plots and an evaluation of aggregated findings to determine consistency across studies. Results: A total of 2,365 records were identified, of which 66 met inclusion criteria. There were 35 discrete social factors grouped into four levels of influence using a socio-ecological model (individual, relationship, community and societal levels) and grouped according to outcome of interest (home care propensity and intensity). Across all studies, social factors consistently showing any association (positive, negative, or equivocal in pattern) with home care propensity were: age, ethnicity/race, self-assessed health, insurance, housing ownership, housing problems, marital status, household income, children, informal caregiving, social networks and urban/rural area. Age, education, personal finances, living arrangements and housing ownership were associated with home care intensity, also with variable patterns in utilization. Additional community and societal level factors were identified as relevant but lacking consistency across the literature; these included rurality, availability of community services, methods of financing home care systems, and cultural determinants. Conclusion: This is the first literature review bringing together a wide range of reported social factors that influence home care utilization. It confirms social factors do influence home care utilization in complex interactions, distinguishes level of influences at which these factors affect patterns of use and discusses policy implications for home care reform
Trends in the costs of drugs launched in the UK between 1981 and 2015: an analysis of the launch price of drugs in five disease areas
Vascular endothelial growth factor-A165b restores normal glomerular water permeability in a diphtheria-toxin mouse model of glomerular injury
BACKGROUND/AIMS:Genetic cell ablation using the human diphtheria toxin receptor (hDTR) is a new strategy used for analysing cellular function. Diphtheria toxin (DT) is a cytotoxic protein that leaves mouse cells relatively unaffected, but upon binding to hDTR it ultimately leads to cell death. We used a podocyte-specific hDTR expressing (Pod-DTR) mouse to assess the anti-permeability and cyto-protective effects of the splice isoform vascular endothelial growth factor (VEGF-A165b).
METHODS:The Pod-DTR mouse was crossed with a mouse that over-expressed VEGF-A165b specifically in the podocytes (Neph-VEGF-A165b). Wild type (WT), Pod-DTR, Neph-VEGF-A165b and Pod-DTR X Neph-VEGF-A165b mice were treated with several doses of DT (1, 5, 100, and 1,000 ng/g bodyweight). Urine was collected and the glomerular water permeability (LpA/Vi) was measured ex vivo after 14 days. Structural analysis and podocyte marker expression were also assessed.
RESULTS: Pod-DTR mice developed an increased glomerular LpA/Vi 14 days after administration of DT (all doses), which was prevented when the mice over-expressed VEGF-A165b. No major structural abnormalities, podocyte ablation or albuminuria was observed in Pod-DTR mice, indicating this to be a mild model of podocyte disease. However, a change in expression and localisation of nephrin within the podocytes was observed, indicating disruption of the slit diaphragm in the Pod-DTR mice. This was prevented in the Pod-DTR X Neph-VEGF-A165b mice.
CONCLUSION: Although only a mild model of podocyte injury, over-expression of the anti-permeability VEGF-A165b isoform in the podocytes of Pod-DTR mice had a protective effect. Therefore, this study further highlights the therapeutic potential of VEGF-A165b in glomerular disease
Can Inflation be Falsified?
Despite its central role in modern cosmology, doubts are often expressed as
to whether cosmological inflation is really a falsifiable theory. We
distinguish two facets of inflation, one as a theory of initial conditions for
the hot big bang and the other as a model for the origin of structure in the
Universe. We argue that the latter can readily be excluded by observations, and
that there are also a number of ways in which the former can find itself in
conflict with observational data. Both aspects of the theory are indeed
falsifiable.Comment: 7 pages LaTeX file with two figures incorporated by epsf. Fifth Prize
in Gravity Research Foundation Essay Competition. To appear, General
Relativity and Gravitatio
The Dilemma of Using Sward Height as a Management Tool for Intensively Grazed Sheep Pasture in Spring
Sward height is often used as a tool for both animal and pasture management, especially when continuously grazing pasture. For example, sward height has been used to define the conditions for optimal feed intake of multiple-bearing ewes, both before and after lambing (Everett-Hincks et al.2005; Morris and Kenyon 2004). Sward height is easily applied by the grazier and so becomes an effective tool. However, changes in the leaf distribution and relative species makeup of the sward both seasonally (Thomson et al. 2001) and in response to grazing management (Webby and Pengelly 1986) mean that the amount of pasture per unit height will change. When these changes occur a dilemma is presented to the grazier. How do they manage the trade-off between a simple indicator for management decisions and the lost opportunity of harvesting pasture mass that may be accumulating below the assigned sward height?
This paper presents data from an experiment that investigated the impacts of defoliation strategies on sward of differing starting masses, with defoliation management based on height rather than mass. The paper quantifies the accumulation of herbage below defoliation height and highlights the dilemma of using sward height as a management tool when aiming to maximise the utilisation of our pasture resource
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