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

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

A short report examining the introduction of routine use of patient reported outcome measures in a mixed oncology population

Aims: People living with treatable but not curable cancer often experience a range of symptoms related to their cancer and its treatment. During the COVID-19 pandemic, face-to-face consultations were reduced and so remote monitoring of these needs was necessary. University Hospitals Sussex implemented the routine use of electronic remote patient-reported outcome measures (PROMs) in a mixed oncology population, focusing on those with treatable but not curable cancers. Materials and methods: Over a 9-month period, patients were invited to register with My Clinical Outcomes (MCO) – a secure online platform for the collection of electronic PROMs. They were prompted by e-mail to complete assessments (EORTC QLQ-C30, EQ-5D-3L and EQ-5D VAS) routinely every 2 weeks. The team monitored patient scores and changes in these prompted clinical interventions. Results: In total, 324 patients completed at least one assessment. The median number of assessments completed by each patient was eight. The most represented tumour groups were secondary breast (28%), prostate (25%) and other (32%). Median scores for the assessments did not deteriorate in a clinically or numerically significant way for patients living with non-curable conditions for the majority of patients monitored. Conclusion: Routine collection of electronic remote PROMs is an effective and useful strategy to provide real-time clinical feedback to teams. With integration into existing systems, online platforms (such as MCO) could provide efficient and patient-centred information for those providing care for people with cancer

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

The eventization of leisure and the strange death of alternative Leeds

The communicative potential of city spaces as leisure spaces is a central assumption of political activism and the creation of alternative, counter-cultural and subcultural scenes. However, such potential for city spaces is limited by the gentrification, privatization and eventization of city centres in the wake of wider societal and cultural struggles over leisure, work and identity formation. In this paper, we present research on alternative scenes in the city of Leeds to argue that the eventization of the city centre has led to a marginalization and of alternative scenes on the fringes of the city. Such marginalization has not caused the death of alternative Leeds or political activism associated with those scenes—but it has changed the leisure spaces (physical, political and social) in which alternative scenes contest the mainstream

Astrophysical and Astrobiological Implications of Gamma-Ray Burst Properties

Combining results for the local cosmic rate and mean peak luminosity of GRBs with the cosmic history of the star formation rate, we provide estimates for the local GRB rate per unit blue luminosity in galaxies. We find a typical GRB rate per unit B luminosity of 2.4x10^-17 h_{70}^2/Lsun/yr. The corresponding mean rate in the Milky Way is 5.5x10^-7 h_{70}^2/yr. We conclude: 1) the ratio of supernova rate to isotropic equivalent GRB rate is large: more than 6000 SNIbc per GRB or 30,000 SNII per GRB. GRBs could arise in a large fraction of black hole-forming events only with collimation in the range 0.01 - 0.001 and a steep enough slope of the IMF; 2) GRBs cannot account for the majority of large HI holes observed in galaxies; 3) the probability that the solar system was exposed to a fluence large enough to melt the chondrules during the first 10^7 yr of solar system history is negligibly small; 4) Even for very opaque atmospheres, a significant fraction of the GRB energy is transmitted as UV lines due to excitation by secondary electrons. For eukaryotic-like organisms in thin atmospheres (e.g. contemporary Mars), or for UV line exposure in thick atmospheres (e.g. Earth), biologically significant events occur at a rate of about 100--500 /Gyr. The direct contribution of these "jolts" to mutational evolution may, however, be negligible because of the short duration of the GRBs. Evolutionary effects due to partial sterilizations and to longer-lived disruptions of atmospheric chemistry should be more important. (Abridged)Comment: 36 pages, no figures Accepted by Astrophysical Journal Oct. 2001. First submitted December,1999. Substantially rewritten discussion of burst source count distributions and of biological implication

β2-Adrenergic receptor promoter haplotype influences the severity of acute viral respiratory tract infection during infancy: a prospective cohort study.

BACKGROUND: Despite the significant interest in β2-Adrenergic receptor (ADRB2) polymorphisms related to asthma, whether ADRB2 genetic variants are similarly associated with acute respiratory tract infections have not been studied. We hypothesized that genetic variants in ADRB2 associated with a response to asthma therapy during an asthma exacerbation were also associated with severity of acute respiratory tract infections. METHODS: To test this hypothesis, we genotyped 5 common polymorphisms in the promoter region and coding block of the ADRB2 gene (loci -2387, -2274, -1343, +46, and +79) from 374 Caucasian and African American term infants who were enrolled at the time of acute respiratory illness over four respiratory viral seasons. Severity of respiratory tract infections was measured using a bronchiolitis severity score (BSS; range = 0-12, clinically significant difference = 0.5) with a higher score indicating more severe disease. We assigned the promoter, coding and combined promoter and coding haplotypes to the unphased genotype data. The associations between each of these five single-nucleotide polymorphisms (SNPs) as well as the haplotypes and infant BSS were analyzed using nonparametric univariate analysis and multivariable proportional odds model separately in Caucasians and African Americans. RESULTS: There was no significant association between infant BSS and each of the SNPs in both Caucasians and African Americans. However, promoter haplotype CCA was associated with a decreased BSS in African Americans in a dose dependent manner. The median (interquartile range) BSS of infants with no copies of the CCA haplotype, one copy, and two copies of the CCA haplotype were 5.5 (2.0, 8.0), 4.0 (1.0, 7.5), and 3.0 (1.0, 4.0), respectively. This dose dependent relationship persisted after adjusting for infant age, gender, daycare exposure, secondhand smoke exposure, prior history of breastfeeding, siblings at home, and enrollment season (adjusted odds ratio: 0.59, 95 % confidence interval: 0.36, 0.98). There was no similar protective relationship of haplotype CCA on severity of respiratory tract infections identified in Caucasians. CONCLUSIONS: ADRB2 genotype may be predictive of severity of acute respiratory tract infections in African Americans, and potentially identify a subset of infants who may respond to beta-agonist therapy

Depletion forces near curved surfaces

Based on density functional theory the influence of curvature on the depletion potential of a single big hard sphere immersed in a fluid of small hard spheres with packing fraction \eta_s either inside or outside of a hard spherical cavity of radius R_c is calculated. The relevant features of this potential are analyzed as function of \eta_s and R_c. There is a very slow convergence towards the flat wall limit R_c \to \infty. Our results allow us to discuss the strength of depletion forces acting near membranes both in normal and lateral directions and to make contact with recent experimental results