Topological data analysis of Escherichia coli O157:H7 and non-O157 survival in soils.

Shiga toxin-producing E. coli O157:H7 and non-O157 have been implicated in many foodborne illnesses caused by the consumption of contaminated fresh produce. However, data on their persistence in soils are limited due to the complexity in datasets generated from different environmental variables and bacterial taxa. There is a continuing need to distinguish the various environmental variables and different bacterial groups to understand the relationships among these factors and the pathogen survival. Using an approach called Topological Data Analysis (TDA); we reconstructed the relationship structure of E. coli O157 and non-O157 survival in 32 soils (16 organic and 16 conventionally managed soils) from California (CA) and Arizona (AZ) with a multi-resolution output. In our study, we took a community approach based on total soil microbiome to study community level survival and examining the network of the community as a whole and the relationship between its topology and biological processes. TDA produces a geometric representation of complex data sets. Network analysis showed that Shiga toxin negative strain E. coli O157:H7 4554 survived significantly longer in comparison to E. coli O157:H7 EDL 933, while the survival time of E. coli O157:NM was comparable to that of E. coli O157:H7 EDL 933 in all of the tested soils. Two non-O157 strains, E. coli O26:H11 and E. coli O103:H2 survived much longer than E. coli O91:H21 and the three strains of E. coli O157. We show that there are complex interactions between E. coli strain survival, microbial community structures, and soil parameters

Associations of the objective built environment along the route to school with children's modes of commuting: A multilevel modelling analysis (the SLIC study).

As active commuting levels continue to decline among primary schoolchildren, evidence about which built environmental characteristics influence walking or cycling to school remains inconclusive and is strongly context-dependent. This study aimed to identify the objective built environmental drivers of, and barriers to, active commuting to school for a multi-ethnic sample of 1,889 healthy primary schoolchildren (aged 5-11) in London, UK. Using cross-sectional multilevel ordered logistic regression modelling, supported by the spatial exploration of built environmental characteristics through cartography, the objective built environment was shown to be strongly implicated in children's commuting behaviour. In line with earlier research, proximity to school emerged as the prime variable associated with the choice for active commuting. However, other elements of the urban form were also significantly associated with children's use of active or passive modes of transport. High levels of accidents, crime and air pollution along the route to school were independently correlated with a lower likelihood of children walking or cycling to school. Higher average and minimum walkability and higher average densities of convenience stores along the way were independently linked to higher odds of active commuting. The significance of the relations for crime, air pollution and walkability disappeared in the fully-adjusted model including all built environmental variables. In contrast, relationships with proximity, traffic danger and the food environment were maintained in this comprehensive model. Black children, pupils with obesity, younger participants and those from high socioeconomic families were less likely to actively commute to school. There is thus a particular need to ensure that roads with high volumes of actively commuting children are kept safe and clean, and children's exposure to unhealthy food options along the way is limited. Moreover, as short commuting distances are strongly correlated with walking or cycling, providing high-quality education near residential areas might incite active transport to school

Overview of Highland Valley Tailings Storage Facility

This paper presents key features of the Highland Valley tailings storage facility comprising two tailings dams, a 107 m high H-H Dam and a 166 m high L-L Dam. The construction history to date including instrumentation observations is also reviewed. Although the tailings facility is situated in a low to moderate seismic area within the Interior Plateau of British Columbia, potential earthquake sources that might have an impact on the site have been carefully assessed. Both dams are designed to have adequate seismic resistance against design earthquakes appropriate for the site. The L-L Dam valley section, involving soft lacustrine deposits beneath the Starter Dam, has been buttressed by a compacted downstream berm founded on dense glacial till. As the geometry of the tailings storage and distribution facilities and waste dumps changes with time, the quantity and relative cost of various construction materials including natural borrow, cycloned sand and pit overburden also change. Ongoing construction is planned to maintain key earthquake and flood design criteria as well as to adjust the use and placement method of various materials to achieve an efficient and cost effective tailings storage operation. Inherent in the design of the two tailings dams, both constructed by the centerline method, is the flexibility which enables the storage capacity of the tailings facility to be increased beyond the present 1.8 billion tonnes if required at some future time

A study investigating a season\u27s baseball performance while wearing SportSight soft contact lenses

Background: The use of spectacles with colored lenses in sports is well known. Athletes have worn such colored lenses in an attempt to enhance their performance for a number of years with promising results. The integration of wavelength specific filters into contact lenses may provide significant performance enhancement as well as the visual advantages usually afforded by contact lenses relative to spectacles. Methods: A small group (N=5) of collegiate baseball players were fitted with SportSight soft contact lenses and were asked to wear them during practices and games for half of a season. The players\u27 batting and fielding statistics from the first and second halves of the season were compared to each other and to those of non-participating team members. All of the subjects were existing soft contact lens wearers. Results: The test group demonstrated dramatic improvements in batting statistics while wearing the SportSight lenses. Their percentage of statistical improvement in each category far surpassed that of non-participating team members. Conclusion: The results of this pilot study imply that wearing SportSight soft contact lenses yields marked performance enhancement for baseball players. Future studies involving larger subject pools are warranted to thoroughly evaluate the possible statistical significance of these findings

Comparative study of visual performance with tinted soft contact lenses vs. clear soft contact lenses and tinted spectacles under bright outdoor conditions; Phase II

Background: Research has clearly shown the advantages of performance tinted CL wear with regard to various measures of objective and subjective responses under various lighting conditions. The current study expanded upon these results. Methods: Subjects were 38 non-presbyopic emmetropes or slight ametropes with distance Snellen acuity of 20/20 or better while wearing -0.50 D spherical Acuvue 2 CLs. Measurements of 6m tachistoscopic stereoacuity and variable distance timed and tachistoscopic texture gradient recognition were obtained with subjects wearing clear CLs, tinted spectacles, and SportSight CLs. Lens modality and test sequence were randomized. Results: Stereoacuity results showed no statistically significant difference in stereolocalization when subjects were wearing clear CLs, SportSight CLs, or tinted spectacles. Texture gradient results using timed and tachistoscopic presentations demonstrated that it was more difficult for subjects to correctly identify the seam orientation at farther distances than nearer distances, and that subjects took more time to try to identify distant target orientation versus near target orientation. In addition, tachistoscopic presentations were not found to be significant with regard to correctness of responses at any distance with any lens modality. Subjective data indicated more physical comfort with either CL modality instead of tinted spectacles. SportSight CLs were also found to be the most visually comfortable modality, followed by tinted spectacles and then clear CLs. Furthermore, a general trend indicated that subjects felt they were able to perform best while wearing the SportSight CLs. This may partially be due to the fact that subjects noted fewer perceptions of stray light with SportSight CLs than with the other modalities. Likewise, subjects reported an equal number of perceived reflections while wearing SportSight CLs and clear CLs but significantly more while wearing tinted spectacles. Conclusion: Objective findings demonstrated that SportSight CLs provide similar performance with regard to distance depth perception and texture gradient recognition to tinted spectacles. Subjective data indicate that visual comfort of the SportSight CLs was superior to tinted spectacles and clear CLs. Additionally, a trend in subjective data demonstrated that the subjects perceived improved performance on the tests while wearing the SportSight CLs

Wigs, disguises and child's play : solidarity in teacher education

It is generally acknowledged that much contemporary education takes place within a dominant audit culture, in which accountability becomes a powerful driver of educational practices. In this culture both pupils and teachers risk being configured as a means to an assessment and target-driven end: pupils are schooled within a particular paradigm of education. The article discusses some ethical issues raised by such schooling, particularly the tensions arising for teachers, and by implication, teacher educators who prepare and support teachers for work in situations where vocational aims and beliefs may be in in conflict with instrumentalist aims. The article offers De Certeau’s concept of ‘la perruque’ to suggest an opening to playful engagement for human ends in education, as a way of contending with and managing the tensions generated. I use the concept to recover a concept of solidarity for teacher educators and teachers to enable ethical teaching in difficult times

Exploring the Future of Human Factors Education; Online Learning, MOOCs, Next Generation Standards, and the Technological Skills We Need to Impart

The objective of this panel was to examine how the future of human factors education is changing given the influx of technology, a push for online learning, and adapting to the changing market. The panel will begin by Heather Lum briefly giving an overview and the precipice for this discussion panel. The panelists then provided their views and experiences regarding this topic. Kelly Steelman will discuss the potential for MOOCs and other online formats to create faster and more flexible postgraduate programs. Christina Frederick will discuss her perspectives on the technological skills we should be equipping our human factors graduates with to be successful. Nathan Sonnenfeld will give his unique take on this as an undergraduate student currently obtaining a human factors education. Susan Amato-Henderson will discuss the Next Generation Science Standards and the ramifications for educators. Lastly, Thomas Smith will focus on the advantages and disadvantages of online learning at the K-12 level. Dr. Lum will foster discussion among the panelists and questions from the general audience. Discussion time: 90 minutes

How Long Can the Hubble Space Telescope Operate Reliably? A Total Dose Perspective

The Hubble Space Telescope has been at the forefront of discoveries in the field of astronomy for more than 20 years. It was the first telescope designed to be serviced in space and the last such servicing mission occurred in May 2009. The question of how much longer this valuable resource can continue to return science data remains. In this paper a detailed analysis of the total dose exposure of electronic parts at the box level is performed using solid angle sectoring/3-dimensional ray trace and Monte Carlo radiation transport simulations. Results are related to parts that have been proposed as possible total dose concerns. The spacecraft subsystem that appears to be at the greatest risk for total dose failure is identified. This is discussed with perspective on the overall lifetime of the spacecraft