15,110 research outputs found

    A new look at NICMOS transmission spectroscopy of HD189733, GJ-436 and XO-1: no conclusive evidence for molecular features

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    We present a re-analysis of archival HST/NICMOS transmission spectroscopy of three exoplanet systems; HD 189733, GJ-436 and XO-1. Detections of several molecules, including H20, CH4 and CO2, have been claimed for HD 189733 and XO-1, but similarly sized features are attributed to systematic noise for GJ-436. The data consist of time-series grism spectra covering a planetary transit. After extracting light curves in independent wavelength channels, we use a linear decorrelation technique account for instrumental systematics (which is becoming standard in the field), and measure the planet-to-star radius ratio as a function of wavelength. For HD 189733, the uncertainties in the transmission spectrum are significantly larger than those previously reported. We also find the transmission spectrum is considerably altered when using different out-of-transit orbits to remove the systematics, when some parameters are left out of the decorrelation procedure, or when we perform the decorrelation with quadratic functions rather than linear functions. Given that there is no physical reason to believe the baseline flux should be modelled as a linear function of any particular set of parameters, we interpret this as evidence that the linear decorrelation technique is not a robust method to remove systematic effects from the light curves for each wavelength channel. For XO-1, the parameters measured to decorrelate the light curves would require extrapolation to the in-transit orbit to remove the systematics, and we cannot reproduce the previously reported results. We conclude that the resulting NICMOS transmission spectra are too dependent on the method used to remove systematics to be considered robust detections of molecular species in planetary atmospheres, although the presence of these molecules is not ruled out.Comment: 17 pages, 28 figures, accepted in MNRA

    Identifying patient concerns during consultations in tertiary burns services: development of the Adult Burns Patient Concerns Inventory

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    ObjectivesIdentifying the issues and concerns that matter most to burns survivors can be challenging. For a number of reasons, but mainly relating to patient empowerment, some of the most pressing concerns patients may have during a clinical encounter may not naturally be the focal point of that encounter. The Patient Concerns Inventory (PCI) is a tried and tested concept initially developed in the field of head and neck cancer that empowers patients during a clinical encounter through provision of a list of prompts that allows patients to self-report concerns prior to consultation. The aim of this study was to develop a PCI for adult burns patients.DesignContent for the PCI was generated from three sources: burns health-related quality of life tools, thematic analysis of one-to-one interviews with 12 adult burns patients and 17 multidisciplinary team (MDT) members. Content was refined using a Delphi consensus technique, with patients and staff members, using SurveyMonkey.SettingWithin outpatient secondary care.ParticipantsTwelve adult burns patients and MDT members from two regional burns centres.ResultsA total of 111 individual items were generated from the three sources. The Delphi process refined the total number of items to 58. The main emergent domains were physical and functional well-being (18 items), psychological, emotional and spiritual well-being (22 items), social care and social well-being (7 items) and treatment-related concerns (11 items).ConclusionsThe Adult Burns Patient Concerns Inventory is a 58-item, holistic prompt list, designed to be used in the outpatient clinic. It offers a new tool in burn care to improve communication between healthcare professionals and patients, empowering them to identify their most pressing concerns and hence deliver a more focused and targeted patient-centred clinical encounter

    Modes of cyberstalking and cyberharassment: measuring the negative effects in the lives of victims in the UK

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    Cyberstalking may occur solely in the digital realm, or may form part of a wider campaign targeting individuals on and off-line. The impact cyberstalking has on victims may differ depending on the type. In this paper, we use Sheridan and Grant's (2007) classifications of, "Proximal with offline", "Online only" and "Cross-over" stalking types. These classifications are applied to responses gathered from 278 victims of cyberstalking and cyberharassment through the 2011-2014 ECHO survey. We analyse the responses to first classify the type of stalking experienced and then the reported number and types of effects in the life of the victims on a per-group basis. Using chi-square analysis, we identify that victims in the case of proximal and Cross-over stalking are significantly more likely to report negative changes to their work, relationships and financial lives and to report more negative changes in these areas than those experiencing online only. In addition, in the relationship category Cross-over cases provoke significantly more changes than proximal cases. This indicates that cases where the stalker moves from being an online presence to a proximal presence have an extreme impact and therefore should be treated with the utmost concern, both in terms of support and safeguarding strategies

    Maximizing Agents\u27 Effectiveness: Virginia Cooperative Extension’s Answer to Training New Extension Agents

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    The New Agent Training Program is required for all new Extension agents employed by Virginia Cooperative Extension (VCE). The New Agent Training Program is based on the programming skills inventory and the background they bring to VCE. This article is to shares with other Extension or related professionals the efforts that VCE is taking to train new Extension agents in necessary skills outside their subject matter training

    In silico design of context-responsive mammalian promoters with user-defined functionality

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    Comprehensive de novo-design of complex mammalian promoters is restricted by unpredictable combinatorial interactions between constituent transcription factor regulatory elements (TFREs). In this study, we show that modular binding sites that do not function cooperatively can be identified by analyzing host cell transcription factor expression profiles, and subsequently testing cognate TFRE activities in varying homotypic and heterotypic promoter architectures. TFREs that displayed position-insensitive, additive function within a specific expression context could be rationally combined together in silico to create promoters with highly predictable activities. As TFRE order and spacing did not affect the performance of these TFRE-combinations, compositions could be specifically arranged to preclude the formation of undesirable sequence features. This facilitated simple in silico-design of promoters with context-required, user-defined functionalities. To demonstrate this, we de novo-created promoters for biopharmaceutical production in CHO cells that exhibited precisely designed activity dynamics and long-term expression-stability, without causing observable retroactive effects on cellular performance. The design process described can be utilized for applications requiring context-responsive, customizable promoter function, particularly where co-expression of synthetic TFs is not suitable. Although the synthetic promoter structure utilized does not closely resemble native mammalian architectures, our findings also provide additional support for a flexible billboard model of promoter regulation

    Heterocyst placement strategies to maximize growth of cyanobacterial filaments

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    Under conditions of limited fixed-nitrogen, some filamentous cyanobacteria develop a regular pattern of heterocyst cells that fix nitrogen for the remaining vegetative cells. We examine three different heterocyst placement strategies by quantitatively modelling filament growth while varying both external fixed-nitrogen and leakage from the filament. We find that there is an optimum heterocyst frequency which maximizes the growth rate of the filament; the optimum frequency decreases as the external fixed-nitrogen concentration increases but increases as the leakage increases. In the presence of leakage, filaments implementing a local heterocyst placement strategy grow significantly faster than filaments implementing random heterocyst placement strategies. With no extracellular fixed-nitrogen, consistent with recent experimental studies of Anabaena sp. PCC 7120, the modelled heterocyst spacing distribution using our local heterocyst placement strategy is qualitatively similar to experimentally observed patterns. As external fixed-nitrogen is increased, the spacing distribution for our local placement strategy retains the same shape while the average spacing between heterocysts continuously increases.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Physical Biology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version will be available onlin

    Scaling laws in the spatial structure of urban road networks

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    The urban road networks of the 20 largest German cities have been analysed, based on a detailed database providing the geographical positions as well as the travel-times for network sizes up to 37,000 nodes and 87,000 links. As the human driver recognises travel-times rather than distances, faster roads appear to be 'shorter' than slower ones. The resulting metric space has an effective dimension d>2, which is a significant measure of the heterogeneity of road speeds. We found that traffic strongly concentrates on only a small fraction of the roads. The distribution of vehicular flows over the roads obeys a power law, indicating a clear hierarchical order of the roads. Studying the cellular structure of the areas enclosed by the roads, the distribution of cell sizes is scale invariant as well

    Regeneration characteristics of a swamp forest in northwestern Tasmania

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    The botanical composition and regeneration characteristics are described for a Melaleuca ricifoliaLeptospermum lanigerum forest from northwestern Tasmania. The size classes of the two dominant species are highly correlated with tree age. Size class analysis shows that the dominants are regenerating continuously. The relationship of this forest type to rainforest and wet sclerophyll forest are discussed
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