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

On Non-Abelian Symplectic Cutting

We discuss symplectic cutting for Hamiltonian actions of non-Abelian compact groups. By using a degeneration based on the Vinberg monoid we give, in good cases, a global quotient description of a surgery construction introduced by Woodward and Meinrenken, and show it can be interpreted in algebro-geometric terms. A key ingredient is the `universal cut' of the cotangent bundle of the group itself, which is identified with a moduli space of framed bundles on chains of projective lines recently introduced by the authors.Comment: Various edits made, to appear in Transformation Groups. 28 pages, 8 figure

Mathematical thinking: studying the notion of 'transfer'.

These analyses form part of a three-year project* looking at mathematical thinking as a socially organised activity. We revisit data from a University Calculus class using tools from two theoretical perspectives, used increasingly in mathematics education research: (1) semiotic mediation and (2) discursive practices. We highlight how different theory-driven analyses taking a sociocultural view of thinking and learning can offer insights into the conceptualisation of the 'transfer' of learning

The withdrawal from oncogenetic counselling and testing for hereditary and familial breast and ovarian cancer. A descriptive study of an Italian sample

<p>Abstract</p> <p>Background</p> <p>Oncogenetic counselling is seldom followed through, even when individuals are eligible according to the test criteria. The basic variables which influence the decision to undergo the genetic counselling process are: risk perception, expected benefit or limitations of genetic testing, general psychological distress or cancer-specific distress, lack of trust in one's emotional reactions when faced with negative events, expected level of family support and communications within the family. The aim of this study was to describe the psychosocial variables of an Italian sample that forgoes genetic counselling.</p> <p>Methods</p> <p>From May 2002 to December 2006 a psychological questionnaire was sent out to one hundred and six subjects, who freely requested a first genetic informative consultation, and never asked to have a second visit and the family tree drawn up in order to inquire about their eligibility for genetic testing. Statistical analysis was performed by Pearson chi-square test, t-test and Spearman RHO coefficient.</p> <p>Results</p> <p>The survey presents a lack of emotional cohesion and structured roles and rules within the family system and a positive correlation between the number of children, anxiety and risk perception. The main reasons for giving up on counselling were a sense that testing was a waste of time and the inability to emotionally handle the negative consequences of the test outcome. The subjects who maintained that test and an early diagnosis were a "waste of time" experienced more anxiety.</p> <p>Conclusion</p> <p>The study revealed the importance to ac knowledging the whole persona and their family system as well as provide information highlighting usefulness of early diagnosis.</p

The Old Farm-House On The Hill : Song And Refrain

https://digitalcommons.library.umaine.edu/mmb-vp/2297/thumbnail.jp

Iterative forcing and hyperimmunity in reverse mathematics

The separation between two theorems in reverse mathematics is usually done by constructing a Turing ideal satisfying a theorem P and avoiding the solutions to a fixed instance of a theorem Q. Lerman, Solomon and Towsner introduced a forcing technique for iterating a computable non-reducibility in order to separate theorems over omega-models. In this paper, we present a modularized version of their framework in terms of preservation of hyperimmunity and show that it is powerful enough to obtain the same separations results as Wang did with his notion of preservation of definitions.Comment: 15 page

First year engineering mathematics: the London South Bank University experience

This short article describes an innovative approach to teaching mathematics to first year undergraduates on a variety of B. Eng. courses offered in the Faculty of Engineering, Science and Built Environment (FESBE) of London South Bank University (LSBU)

Patients with Carotid Intraplaque Hemorrhage Have Higher Incidence of Cerebral Microbleeds

Aims: Carotid intraplaque hemorrhage (IPH) is considered a marker of plaque vulnerability. Cerebral microbleeds (CMBs) are recognized on magnetic resonance imaging (MRI) in patients with cerebrovascular disease. Any connection between carotid IPH and CMBs remains scantly investigated. This study aimed to determine whether the histologic evidence of carotid IPH is related to CMBs. Methods: We retrospectively enrolled 101 consecutive patients undergoing carotid endarterectomy with symptomatic (ischemic stroke, TIA, and amaurosis fugax) or asymptomatic ipsilateral carotid artery disease. The presence and the extent (%) of IPH were identified on carotid plaques stained with Movat Pentachrome. CMBs were localized on T2*-weighted gradient-recalled echo or susceptibility-weighted imaging sequence on brain MRI before surgery. The degree of carotid stenosis was measured by neck CTA. Results: IPH was identified in 57 (56.4%) patients, and CMBs were found in 24 (23.7%) patients. CMBs were more commonly observed in patients with carotid IPH compared to those without [19 (33.3%) vs 5 (11.4%); P=0.010]. The carotid IPH extent was significantly higher in patients with CMBs than in those without [9.0 % (2.8-27.1%) vs 0.9% (0.0-13.9%); P=0.004] and was associated with the number of CMBs (P=0.004). Logistic regression analysis demonstrated an independent association between carotid IPH extent and the presence of CMBs [OR 1.051 (95% CI 1.012-1.090); P=0.009]. Additionally, patients with CMBs had a lower degree of ipsilateral carotid stenosis compared to those without [40% (35-65%) vs 70% (50-80%); P=0.049]. Conclusions: CMBs may be potential markers of the ongoing process of carotid IPH, especially in those with nonobstructive plaques