Finding keywords amongst noise: Automatic text classification without parsing

Copyright © 2007 SPIE - The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. Copyright 2007 Society of Photo-Optical Instrumentation Engineers. This paper was published in Noise and Stochastics in Complex Systems and Finance, edited by János Kertész, Stefan Bornholdt, Rosario N. Mantegna, Proc. of SPIE Vol. 6601, 660113 and is made available as an electronic reprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, application of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.The amount of text stored on the Internet, and in our libraries, continues to expand at an exponential rate. There is a great practical need to locate relevant content. This requires quick automated methods for classifying textual information, according to subject. We propose a quick statistical approach, which can distinguish between 'keywords' and 'noisewords', like 'the' and 'a', without the need to parse the text into its parts of speech. Our classification is based on an F-statistic, which compares the observed Word Recurrence Interval (WRI) with a simple null hypothesis. We also propose a model to account for the observed distribution of WRI statistics and we subject this model to a number of tests.Andrew G. Allison, Charles E. M. Pearce and Derek Abbot

Indoor and outdoor context-specific contributions to early adolescent MVPA as measured by combined diary, accelerometer and GPS

Background: The distribution of adolescent moderate to vigorous physical activity (MVPA) across multiple contexts is unclear. This study examined indoor and outdoor leisure time in terms of being structured or unstructured and explored relationships with total daily MVPA. Methods: Between September 2012 and January 2014, 70 participants (aged 11–13 y) from 4 schools in Edinburgh wore an accelerometer and global positioning system receiver over 7 days, reporting structured physical activity using a diary. Time spent and MVPA were summarized according to indoor/outdoor location and whether activity was structured/unstructured. Independent associations between context-specific time spent and total daily MVPA were examined using a multivariate linear regression model. Results: Very little time or MVPA was recorded in structured contexts. Unstructured outdoor leisure time was associated with an increase in total daily MVPA almost twice that of unstructured indoor leisure time [b value (95% confidence interval), 8.45 (1.71 to 14.48) vs 4.38 (0.20 to 8.22) minute increase per hour spent]. The association was stronger for time spent in structured outdoor leisure time [35.81 (20.60 to 52.27)]. Conclusions: Research and interventions should focus on strategies to facilitate time outdoors during unstructured leisure time and maximize MVPA once youth are outdoors. Increasing the proportion of youth engaging in structured activity may be beneficial given that, although time spent was limited, association with MVPA was strongest.</jats:p

Herd-level risk factors associated with the presence of Phage type 21/28 E. coli O157 on Scottish cattle farms

&lt;p&gt;Background: E. coli O157 is a bacterial pathogen that is shed by cattle and can cause severe disease in humans. Phage type (PT) 21/28 is a subtype of E. coli O157 that is found across Scotland and is associated with particularly severe human morbidity.&lt;/p&gt; &lt;p&gt;Methods: A cross-sectional survey of Scottish cattle farms was conducted in the period Feb 2002-Feb 2004 to determine the prevalence of E. coli O157 in cattle herds. Data from 88 farms on which E. coli O157 was present were analysed using generalised linear mixed models to identify risk factors for the presence of PT 21/28 specifically.&lt;/p&gt; &lt;p&gt;Results: The analysis identified private water supply, and northerly farm location as risk factors for PT 21/28 presence. There was a significant association between the presence of PT 21/28 and an increased number of E. coli O157 positive pat samples from a farm, and PT 21/28 was significantly associated with larger E. coli O157 counts than non-PT 21/28 E. coli O157.&lt;/p&gt; &lt;p&gt;Conclusion: PT 21/28 has significant risk factors that distinguish it from other phage types of E. coli O157. This finding has implications for the control of E. coli O157 as a whole and suggests that control could be tailored to target the locally dominant PT.&lt;/p&gt

Ingestible Oxygen Supplementation does NOT Impact Maximal Aerobic Performance Measures

Oxygen supplementation has been used to improve physical performances for decades, most commonly in the form of bottled oxygen. Other forms of inhalable and/or ingestible oxygen have been investigated more recently with mixed results. An ingestible oxygen supplement (Ox66TM) consisting of oxygen molecules contained within an aluminum ion clathrate structure has been shown to increase SaO2 at rest and reduce inflammation in clinical settings. This ingestible oxygen enters through the portal vein rather than the pulmonary system. It is unclear whether this oxygen supplement would have an impact on factors related to maximal aerobic capacity (VO2max). PURPOSE: The purpose of this study was to evaluate the ergogenic impact of acute Ox66TM ingestion on factors related to maximal aerobic performance. METHODS: 36 apparently healthy, college age participants completed the study (20 men, 16 women). Participants attended three testing sessions separated by at least 72 hours. During the first session, participants were familiarized with the Bruce protocol GXT and baseline measures were taken for VO2max, max blood lactate, max HR, time to exhaustion, max VE and RPE. Participants were then randomly assigned to double-blind placebo or oxygen supplementation during their second and third testing sessions. RESULTS: VO2max was significantly higher among all participants combined in the Ox66TM condition (p=.04). When separated by sex, the difference in VO2max was evident among women (p=.05), with no differences among the men. There were no other differences between placebo and supplement conditions for any other variables. CONCLUSION: Given that VO2max was determined using indirect calorimetry which assumes that VO2 is the difference between inspired and expired oxygen volumes, oxygen not taken in through the pulmonary system would not be measurable. Hypothetically, improvements would more likely be seen in time to exhaustion, blood lactate, heart rate, or RPE. In a post-hoc review, 10 of the 16 women completed the placebo condition first. Motivation to exceed their previous performance could explain improvement. Though statistically significant, the marginal improvement in VO2max among the women with Ox66TM (45.02 v. 45.82 ml*kg-1*min-1) would have little impact on overall aerobic performance

Repeated Maximal Exercise Measures are Very Reliable Among Healthy College-aged Individuals

The most common way to assess cardiovascular fitness is with a maximal graded exercise test (GXT) to determine the maximal rate of oxygen consumption (VO2 max). Maximal exercise efforts during GXT testing have been shown to be quite repeatable among active and sedentary adults, as well as cardiac patients and the elderly. With young, healthy participants, familiarization and motivation could result in improved performance measures with repeated testing. The reliability of maximal exercise measures among healthy college-aged individuals during repeated Bruce Protocol GXT assessments are yet unclear. PURPOSE: To determine how repeatable the VO2max and other maximal exercise indices were with repeated GXT measures among healthy, college-aged adults. METHODS: Thirty-six apparently healthy participants (20 men, 16 women) aged 21.47 ± 0.5 years completed three GXT testing sessions following the Bruce Protocol. The maximal values for VO2, blood lactate, VE, HR and Borg Rating of Perceived Exertion (RPE) as well as time to exhaustion were recorded at the end of each session. RESULTS: Statistical analysis of the data was conducted using a one-way ANOVA by order of visit and a Tukey post-hoc analysis. With all participants combined, there were no differences in measured variables with one exception. Maximal RPE was higher in Visit 3 compared to Baseline (p=0.02). When men and the women were analyzed separately, there were no differences in RPE values among the men. Women reported a higher Max RPE in both Visit 2 and Visit 3 compared to Baseline. Despite the higher RPE values no other maximal measures were significantly different across testing sessions. CONCLUSION: This research confirms that repeated maximal GXT measures are very reliable among healthy college-aged individuals. The exception being a small but significant difference in self-reported maximal RPE values among women compared to baseline measures. Future studies could address potential reasons for the significant difference in women’s self-reported RPE values

The Effects of Ox66TM Supplementation on Ventilatory Threshold Performance Measures

Ox66TM claims to be the only solid form of oxygen known to be in existence. It is an aluminum hydroxide clathrate that can trap oxygen molecules within its structure and when digested the oxygen molecules can be absorbed into the portal bloodstream. It has previously been implemented in clinical settings to reduce hypoxia related medical conditions. However, it is currently unknown whether Ox66TM has an effect on performance measures at or near the ventilatory threshold during high intensity exercise. PURPOSE: The purpose of this study was to evaluate the ergogenic impact of acute Ox66TM ingestion on submaximal aerobic performance measures and ventilatory threshold during exercise testing using Bruce protocol. METHODS: 36 college age participants (20 males and 16 females) were recruited to complete this study. Participants attended three testing sessions. During the first session, baseline measurements were acquired and participants were familiarized with the testing procedures. During the second and third tests participants were randomized to receive either a placebo or the Ox66TM supplement. Heart rate, ventilatory threshold, respiratory exchange ratio and rating of perceived exertion (RPE) were recorded throughout each test. RESULTS: Overall there were no consistent differences between the placebo and Ox66TM conditions for all participants combined. However, when men and women were evaluated separately, there were a few significant differences. Under the Ox66TM condition men had a slightly higher VO2 (p=0.045) and higher heart rate (p=0.046) at ventilatory threshold. Women had a slightly lower RPE (p=0.047) at ventilatory threshold with the Ox66TM supplement. CONCLUSION: Ox66TM supplementation resulted in small improvements in a few submaximal aerobic performance measures. Although these results are statistically significant, it is unlikely that Ox66TM supplementation actually causes ergogenic performance benefits

Increasing Incidence, but Lack of Seasonality, of Elevated TSH Levels, on Newborn Screening, in the North of England

Previous studies of congenital hypothyroidism have suggested an increasing incidence and seasonal variation in incidence, which may suggest nongenetic factors involved in aetiology. This study describes the incidence of elevated thyroid stimulating hormone (TSH) values in newborns, a surrogate for congenital hypothyroidism, measured as part of the screening programme for congenital hypothyroidism, over an eleven-year period (1994–2005), and assesses whether seasonal variation exists. All infants born in the Northern Region of England are screened by measuring levels of circulating TSH using a blood spot assay. Data on all 213 cases born from 1994 to 2005 inclusive were available. Annual incidence increased significantly from 37 per 100,000 in 1994 to a peak of 92.8 per 100,000 in 2003. There was no evidence of seasonal variation in incidence. The reasons for the increasing incidence are unclear, but do not appear to involve increasing exposure to seasonally varying factors or changes in measurements methods

Temporal Changes of Neocortical High-Frequency Oscillations in Epilepsy

High-frequency (100–500 Hz) oscillations (HFOs) recorded from intracranial electrodes are a potential biomarker for epileptogenic brain. HFOs are commonly categorized as ripples (100–250 Hz) or fast ripples (250–500 Hz), and a third class of mixed frequency events has also been identified. We hypothesize that temporal changes in HFOs may identify periods of increased the likelihood of seizure onset. HFOs (86,151) from five patients with neocortical epilepsy implanted with hybrid (micro + macro) intracranial electrodes were detected using a previously validated automated algorithm run over all channels of each patient\u27s entire recording. HFOs were characterized by extracting quantitative morphologic features and divided into four time epochs (interictal, preictal, ictal, and postictal) and three HFO clusters (ripples, fast ripples, and mixed events). We used supervised classification and nonparametric statistical tests to explore quantitative changes in HFO features before, during, and after seizures. We also analyzed temporal changes in the rates and proportions of events from each HFO cluster during these periods. We observed patient-specific changes in HFO morphology linked to fluctuation in the relative rates of ripples, fast ripples, and mixed frequency events. These changes in relative rate occurred in pre- and postictal periods up to thirty min before and after seizures. We also found evidence that the distribution of HFOs during these different time periods varied greatly between individual patients. These results suggest that temporal analysis of HFO features has potential for designing custom seizure prediction algorithms and for exploring the relationship between HFOs and seizure generation

Pathogenic Potential to Humans of Bovine Escherichia coli O26, Scotland

Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx&lt;sub&gt;2&lt;/sub&gt; in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx&lt;sub&gt;2&lt;/sub&gt; phage acquisition