Wrapper Maintenance: A Machine Learning Approach

The proliferation of online information sources has led to an increased use of wrappers for extracting data from Web sources. While most of the previous research has focused on quick and efficient generation of wrappers, the development of tools for wrapper maintenance has received less attention. This is an important research problem because Web sources often change in ways that prevent the wrappers from extracting data correctly. We present an efficient algorithm that learns structural information about data from positive examples alone. We describe how this information can be used for two wrapper maintenance applications: wrapper verification and reinduction. The wrapper verification system detects when a wrapper is not extracting correct data, usually because the Web source has changed its format. The reinduction algorithm automatically recovers from changes in the Web source by identifying data on Web pages so that a new wrapper may be generated for this source. To validate our approach, we monitored 27 wrappers over a period of a year. The verification algorithm correctly discovered 35 of the 37 wrapper changes, and made 16 mistakes, resulting in precision of 0.73 and recall of 0.95. We validated the reinduction algorithm on ten Web sources. We were able to successfully reinduce the wrappers, obtaining precision and recall values of 0.90 and 0.80 on the data extraction task

IPU or ITU? It all starts with PCT (palliative care training)

Background: Impending death is not well recognised. Due to improvements in technology and medicine, people are living longer with more complex health conditions and because of this, the death of a patient is an experience that many people entering a healthcare profession will have little of. As death occurs in any setting, at any time, it is vital that all healthcare professionals regardless of the setting they go on to work in, have adequate Palliative Care Training (PCT). / Aim: To understand what current training is available on the recognition of dying at undergraduate level. / Methods: An information gathering exercise of the following UK undergraduate courses: medicine, nursing, social work, physiotherapy, occupational therapy. All courses received an email asking what training was provided in recognising and communication of dying and what time was dedicated to this. / Results: 73/198 courses responded (37%). 18/20 medical courses provided training in recognising dying with a median of 2 hours dedicated, and 17/20 in the communication of dying with a median of 3 hours dedicated. 80% (43/54) of nursing and allied health professional courses provided some form of training in end-of-life care. Many of these courses expressed frustration at the lack of resources, funding, and time to include more training. Those with more time dedicated to PCT often had a ‘champion’ to advocate for it. / Conclusion: Training in end-of-life care was inconsistent and variable across courses and professions. Further work on how we can support the champions in progressing PCT input on the courses is needed

A New Approach for Sampling Ordered Parameters in Probabilistic Sensitivity Analysis

Background Probabilistic sensitivity analysis (PSA) in cost-effectiveness analysis involves sampling a large number of realisations of an economic model. For some parameters, we may be uncertain around the true mean values of the variables, but the ordering of the values is known. Typical sampling approaches lack either statistical or clinical validity. For example, sampling using a common number generator results in extreme dependence and independent sampling can lead to realisations with incorrect ordering. Methods We propose a new sampling approach for ordered parameters, the Difference Method approach, which samples the parameters of interest via a difference parameter. If the parameters of interest are bounded, it involves transforming the variables so that they are unbounded and then sampling via the difference parameter. We have provided an Excel workbook to implement the method. The proposed approach is illustrated with an example sampling ordered parameters for utility and cost. Results The DM approach has a number of advantages when comparing with the typical approaches used in practice. The DM approach generates PSA samples which have similar summary statistics as the given values in our examples whilst maintaining the constraint that one value was greater than another. The method also implies plausible positive correlation between the two ordered variables. Conclusions Both clinical and statistical validity should be checked when producing PSA samples. The DM approach should be considered as a solution to potential problems in generating PSA samples for ordered parameters

Palliative care training in undergraduate medical, nursing and allied health: a survey

OBJECTIVES: Impending death is poorly recognised. Many undergraduate healthcare professionals will not have experience of meeting or caring for someone who is dying. As death can occur in any setting, at any time, it is vital that all healthcare students, regardless of the setting they go on to work in, have end-of-life care (EOLC) training. The aim was to determine current palliative care training at the undergraduate level, in multiple professions, in recognising and communicating dying. METHODS: Current UK undergraduate courses in medicine, adult nursing, occupational therapy, social work and physiotherapy were included. All courses received an email asking what training is currently offered in the recognition and communication of dying, and what time was dedicated to this. RESULTS: A total of 73/198 (37%) courses responded to the request for information. 18/20 medical courses provided training in recognising when patients were dying (median 2 hours), and 17/20 provided training in the communication of dying (median 3 hours). 80% (43/54) of nursing and allied health professional courses provided some training in EOLC. Many of the course organisers expressed frustration at the lack of resources, funding and time to include more training. Those courses with more palliative care provision often had a 'champion' to advocate for it. CONCLUSIONS: Training in EOLC was inconsistent across courses and professions. Further research is needed to understand how to remove the barriers identified and to improve the consistency of current training

The Potential of Personalized Virtual Reality in Palliative Care: A Feasibility Trial

BACKGROUND: Virtual Reality can help alleviate symptoms in a non-palliative care population. Personalized therapy can further alleviate these symptoms. There is little evidence in a palliative care population. AIM: To understand the feasibility of repeated personalized virtual reality sessions in a palliative care population. DESIGN: A feasibility randomized control trial. Intervention: personalized virtual reality, Control: non-personalized virtual reality. All participants completed a 4-minute virtual reality session for 4 weeks. At each point, the Edmonton Symptom Assessment System-Revised (scored 0 = none up to 100 = worst) was completed pre- and post- each session. A time-series regression analysis was completed for the overall effect. SETTING/PARTICIPANTS: The research took place in one hospice. The main inclusion criteria was: (1) under the care of the hospice (2) advanced disease (3) over 18 years (4) physically able to use virtual reality set (5) capacity (6) proficient English. RESULTS: Twenty-six participants enrolled, of which 20 (77%) completed all sessions. At baseline, the intervention group had a mean pre- score of 26.3 (SD 15.1) which reduced to 11.5 (SD 12.6) after the first session. At the same time point, the control group had a mean pre- score of 37.9 (SD 21.6) which reduced to 25.5 (SD 17.4) post-session. The mean scores dropped following each session, however this was not significant (mean difference = -1.3, 95% CI: -6.4 to 3.7, p = 0.601). CONCLUSIONS: It is feasible to complete repeated virtual reality sessions within a palliative care population. Future research should explore the structure and effectiveness of virtual reality in a fully powered trial

On the Migration of Jupiter and Saturn: Constraints from Linear Models of Secular Resonant Coupling with the Terrestrial Planets

We examine how the late divergent migration of Jupiter and Saturn may have perturbed the terrestrial planets. We identify six secular resonances between the nu_5 apsidal eigenfrequency of Jupiter and Saturn and the four eigenfrequencies of the terrestrial planets (g_{1-4}). We derive analytic upper limits on the eccentricity and orbital migration timescale of Jupiter and Saturn when these resonances were encountered to avoid perturbing the eccentricities of the terrestrial planets to values larger than the observed ones. If Jupiter and Saturn migrated with eccentricities comparable to their present day values, smooth migration with exponential timescales characteristic of planetesimal-driven migration (\tau~5-10 Myr) would have perturbed the eccentricities of the terrestrial planets to values greatly exceeding the observed ones. This excitation may be mitigated if the eccentricity of Jupiter was small during the migration epoch, migration was very rapid (e.g. \tau<~ 0.5 Myr perhaps via planet-planet scattering or instability-driven migration) or the observed small eccentricity amplitudes of the j=2,3 terrestrial modes result from low probability cancellation of several large amplitude contributions. Further, results of orbital integrations show that very short migration timescales (\tau<0.5 Myr), characteristic of instability-driven migration, may also perturb the terrestrial planets' eccentricities by amounts comparable to their observed values. We discuss the implications of these constraints for the relative timing of terrestrial planet formation, giant planet migration, and the origin of the so-called Late Heavy Bombardment of the Moon 3.9+/-0.1 Ga ago. We suggest that the simplest way to satisfy these dynamical constraints may be for the bulk of any giant planet migration to be complete in the first 30-100 Myr of solar system history.Comment: Accepted for publication in The Astrophysical Journa

‘It should be more outspoken and not hushed away, not like put in a dark box’: An interpretative phenomenological analysis of experiences of menopause voiced by women with learning disabilities

Background: There is little research into experiences of menopause voiced by women with learning disabilities, who can be neglected in academic research. There is a particular lack of knowledge around the psychological and social experiences of menopause in this population, and how changes are managed. This study sought to explore these experiences. Methods: Experiences of five women with lived experience of menopause, being seen by community National Health Services specialising in learning disabilities, were captured with semistructured interviews and analysed using interpretive phenomenological analysis. Findings: Five superordinate themes were identified, involving the importance of having information about menopause, challenges of periods, observable changes in menopause, the importance of social connection, and managing menopause independently. Conclusions: This study highlights the need for clinicians and carers to understand the variety of impacts menopause can have on women with learning disabilities, including emotional and social aspects, and the need to initiate conversations regarding menopause and available treatments

The (un)availability of prognostic information in the last days of life: a prospective observational study.

OBJECTIVES: The aims of this study were (1) to document the clinical condition of patients considered to be in the last 2 weeks of life and (2) to compare patients who did or did not survive for 72 hours. DESIGN: A prospective observational study. SETTING: Two sites in London, UK (a hospice and a hospital palliative care team). PARTICIPANTS: Any inpatient, over 18 years old, English speaking, who was identified by the palliative care team as at risk of dying within the next 2 weeks was eligible. OUTCOME MEASURES: Prognostic signs and symptoms were documented at a one off assessment and patients were followed up 7 days later to determine whether or not they had died. RESULTS: Fifty participants were recruited and 24/50 (48%) died within 72 hours of assessment. The most prevalent prognostic features observed were a decrease in oral food intake (60%) and a rapid decline of the participant's global health status (56%). Participants who died within 72 hours had a lower level of consciousness and had more care needs than those who lived longer. A large portion of data was unavailable, particularly that relating to the psychological and spiritual well-being of the patient, due to the decreased consciousness of the patient. CONCLUSIONS: The prevalence of prognostic signs and symptoms in the final days of life has been documented between those predicted to die and those who did not. How doctors make decisions with missing information is an area for future research, in addition to understanding the best way to use the available information to make more accurate predictions

Investigation of the High-Energy Oxidation of FiberForm from DSMC Analysis of Molecular Beam Experiments

A collaborative effort between the University of Illinois at Urbana-Champaign (UIUC), NASA Ames Research Center (ARC) and Montana State University (MSU) succeeded at developing a new finite-rate carbon oxidation model from molecular beam scattering experiments on vitreous carbon (VC). We now aim to use the direct simulation Monte Carlo (DSMC) code SPARTA to apply the model to each fiber of the porous fibrous Thermal Protection Systems (TPS) material FiberForm (FF). The detailed micro-structure of FF was obtained from X-ray micro-tomography and then used in DSMC. Both experiments and simulations show that the CO/O products ratio increased at all temperatures from VC to FF. We postulate this is due to the larger number of collisions an O atom encounters inside the porous FF material compared to the flat surface of VC. For the simulations, we particularly focused on the lowest and highest temperatures studied experimentally, 1023 K and 1823 K, and found good agreement between the finite-rate DSMC simulations and experiments