Shape discrimination using invariants defined from higher-order spectra

An approach to pattern recognition using invariant parameters based on higher-order spectra is presented. In particular, bispectral invariants are used to classify one-dimensional shapes. The bispectrum, which is translation invariant, is integrated along straight lines passing through the origin in bifrequency space. The phase of the integrated bispectrum is shown to be scale- and amplification-invariant. A minimal set of these invariants is selected as the feature vector for pattern classification. Pattern recognition using higher-order spectral invariants is fast, suited for parallel implementation, and works for signals corrupted by Gaussian noise. The classification technique is shown to distinguish two similar but different bolts given their one-dimensional profiles

Hormones down under: Hormone therapy use after the Women's Health Initiative

Aims:  The primary objective was to describe the usage pattern of hormone therapy (HT) in a sample of urban Australian women in 2001 and to assess the characteristics of users vs. non-users. The second objective was to determine whether there had been any change in usage since the publication of the results of the combined oestrogen plus progestagen arm of the Women's Health Initiative (WHI) in 2002. Methods:  A cohort of 374 postmenopausal women aged 50–80 years participated in this substudy of the LAW (Longitudinal Assessment of Ageing in Women) project: a 5-year multidisciplinary, observational study. Participants completed an annual medical assessment including details of the use of HT and the reasons for use, as well as demographic and psychosocial data. Results:  In December 2001, 30.8% of the participants were using HT, whereas 55.4% were ever users. The management of vasomotor symptoms and mood disturbance were the primary reasons for use. Of those who had been using HT in December 2001 (24.4%) women ceased using HT in the 3 months following publication of the WHI results. The percentage of women using HT in December 2003 (13.9%) was less than half of that of December 2001. Conclusion:  The rate of HT use and the reasons for use, in 2001 in Brisbane was similar to that of other Australian regions. Usage of HT decreased since the publication of the WHI results in 2002 which may reflect changing attitudes by patients and practitioners regarding HT.

Saving bitrate vs. pleasing users : where is the break-even point in mobile video quality?

This paper presents a comprehensive study to find the most efficient bitrate requirement to deliver mobile video that optimizes bandwidth, while at the same time maintains good user viewing experience. In the study, forty participants were asked to choose the lowest quality video that would still provide for a comfortable and long-term viewing experience, knowing that higher video quality is more expensive and bandwidth intensive. This paper proposes the lowest pleasing bitrates and corresponding encoding parameters for five different content types: cartoon, movie, music, news and sports. It also explores how the lowest pleasing quality is influenced by content type, image resolution, bitrate, and user gender, prior viewing experience, and preference. In addition, it analyzes the trajectory of users’ progression while selecting the lowest pleasing quality. The findings reveal that the lowest bitrate requirement for a pleasing viewing experience is much higher than that of the lowest acceptable quality. Users’ criteria for the lowest pleasing video quality are related to the video’s content features, as well as its usage purpose and the user’s personal preferences. These findings can provide video providers guidance on what quality they should offer to please mobile users.

Bariatric patients and the use of mobile hoists : user experiences from three hospitals in South Australia

Nursing personnel are consistently identified as one of the occupational groups most at risk of work-related musculoskeletal disorders. During the moving and handling of bariatric patients, the weight of the patient combined with atypical body mass contributes to a significant risk of injury to the care provider and patient. This is further compounded by the shape, mobility and co-operation of the patient. The aim of this study was determine user experiences and design requirements for mobile hoists with bariatric patients. Structured interviews were conducted with six experienced injury management staff from the Manual Task Services department of three hospitals in Adelaide, South Australia. All staff had experience in patient handling, the use of patient handling equipment and the provision of patient handling training. A series of open-ended questions were structured around five main themes: 1) patient factors; 2) building/vehicle space and design; 3) equipment and furniture; 4) communication; and 5) staff issues. Questions focussed on the use of mobile hoists for lifting and transferring bariatric patients. Interviews were supplemented with a walk-through of the hospital to view the types of mobile hoists used, and the location and storage of equipment. Across the three hospitals there were differing classification systems to define bariatric patients. Ensuring patient dignity, respect and privacy were viewed as important in the management and rehabilitation of bariatric patients. Storage and space constraints were considered factors restricting the use of mobile floor hoists, with ceiling hoists being the preferred method for patient transfers. When using mobile floor hoists, the forces required to push, pull and manoeuvre, as well as sudden unstable movements of the hoist were considered important risks factors giving rise to a risk of injury to the care provider. Record keeping and purchasing policies appeared to inhibit the effective use of patient handling equipment. The moving and handling of bariatric patients presents complex and challenging issues. A co-ordinated and collaborative approach for moving and handling bariatric patients is needed across the range of care providers. Designers must consider both user and patient requirements.

Can partial coherence interferometry be used to determine retinal shape?

Purpose: To determine likely errors in estimating retinal shape using partial coherence interferometric instruments when no allowance is made for optical distortion. Method: Errors were estimated using Gullstrand’s No. 1 schematic eye and variants which included a 10 D axial myopic eye, an emmetropic eye with a gradient-index lens, and a 10.9 D accommodating eye with a gradient-index lens. Performance was simulated for two commercial instruments, the IOLMaster (Carl Zeiss Meditec) and the Lenstar LS 900 (Haag-Streit AG). The incident beam was directed towards either the centre of curvature of the anterior cornea (corneal-direction method) or the centre of the entrance pupil (pupil-direction method). Simple trigonometry was used with the corneal intercept and the incident beam angle to estimate retinal contour. Conics were fitted to the estimated contours. Results: The pupil-direction method gave estimates of retinal contour that were much too flat. The cornea-direction method gave similar results for IOLMaster and Lenstar approaches. The steepness of the retinal contour was slightly overestimated, the exact effects varying with the refractive error, gradient index and accommodation. Conclusion: These theoretical results suggest that, for field angles ≤30º, partial coherence interferometric instruments are of use in estimating retinal shape by the corneal-direction method with the assumptions of a regular retinal shape and no optical distortion. It may be possible to improve on these estimates out to larger field angles by using optical modeling to correct for distortion.

The future shape of digital cars

Background. Digital information is increasingly becoming available on all aspects of the urban landscape, anywhere and any time. Physical objects (c.f. the Internet of Things) and people (c.f. the Social Web) are increasingly infused with actuators, sensors and tagged with a wealth of digital information. Urban Informatics explores these emerging digital layers of the city. However, very little is known about the challenges and new opportunities that these developments may offer to road users. As we gradually spend more time using our mobile devices as well as our car, the tension between appeasing our craving for connectedness and road safety requirements grow farther apart. Objective. The aims of this paper are to identify (a) new opportunities that Urban Informatics research can offer to our future cars and (b) potential benefits to road safety. Methods. 14 Urban Informatics research experts were grouped into seven teams of two to participate in a guided ideation (idea creation) workshop in a driving simulator. They were immersed into different driving scenarios to brainstorm innovative Urban Informatics applications in different driving contexts. This qualitative study was then evaluated in the context of road safety. Outcomes. There is a lack of articulation between Urban Informatics and Road Safety research. Several Urban Informatics applications (e.g., to enhance social interaction between people in urban environments) may provide benefits, rather than threats, towards road safety, provided they are implemented ergonomically and safely. Conclusions. This research initiates a much-needed dialogue between Urban Informatics and Road Safety disciplines, in the context of Intelligent Transport Systems, before the fast approaching digital wave invades our cars. The dialogue will help to avoid driver distraction issues similar to mobile phones use in cars. As such, it provides valuable information for future regulators and policy makers in charge of shaping our future road transport landscape.

Service convenience and social servicescape : retail vs hedonic setting

Purpose – While there have been numerous studies on the antecedents and consequences of service quality, there has been little investigation of the moderators of service quality. The purpose of this study is to demonstrate the effects of two moderators: service convenience and the social servicescape. The moderating effects are tested in two service settings: retail and hedonic (concert). Design/methodology/approach – A survey of 270 customers at kitchen display showrooms and 320 concert-goers was undertaken. The results were analysed using regression analysis. Findings – The results show support for ten of the 12 hypotheses. Service convenience moderated the relationships between perceived service quality and its three sub-dimensions (interaction, environment, and outcome quality), differently in different settings (retail vs hedonic). This supports the authors' general argument that the outcome dimension tends to be more important to customers in a retail setting, while interaction and environment quality dimensions tend to be more important in hedonic service consumption. Practical implications – These findings suggest that managers need to use different service management tactics in retail and hedonic service settings. Specifically managers in retail settings need to pay more attention to service convenience to achieve service quality and managers in hedonic settings should concentrate on the social servicescape. Originality/value – This paper is the first to test the moderating factors of service convenience and social servicescape on service quality.

The use of hypnosis in labor and delivery : a preliminary study

Self-hypnosis was taught to 87 obstetric patients (HYP) and was not taught to 56 other patients (CNTRL), all delivered by the same family physician, in order to determine whether the use of self-hypnosis by low-risk obstetric patients leads to fewer technologic interventions during their deliveries or greater satisfaction of parturients with their delivery experience or both. The outcomes of the deliveries of these two groups were compared, and the HYP group was compared to 352 low-risk patients delivered by other family physicians at the same hospital (WCH). Questionnaires were mailed postpartum to 156 patients, all delivered by the same family physician, to determine satisfaction with delivery using the Labor and Delivery Satisfaction Index (LADSI). The hypnosis group showed a significant reduction in the number of epidurals (11.4% less than CNTRL and 17.9% less than WCH, p < 0.05) and the use of intravenous lines (18.5% less for both, p < 0.05). The number of episiotomies was significantly less in the HYP group compared to WCH (15.9%, p < 0.05) and 11.5% less when compared to CNTRL. The tear rate was not statistically different. Combined use of the intervention triad (epidural–forceps–episiotomy) was less for HYP than for CNTRL (15.8% less) and WCH (10.2% less, p < 0.05). More deliveries were done in the labor room with HYP than CNTRL (21%, p < 0.05). The second stage was shortened by 10 min (HYP vs CNTRL). Overall satisfaction of HYP and CNTRL patients was similar and generally favorable.

The use of electronic portal imaging to verify patient position during intensity-modulated radiotherapy delivered by the dynamic MLC technique

Purpose: The precise shape of the three-dimensional dose distributions created by intensity-modulated radiotherapy means that the verification of patient position and setup is crucial to the outcome of the treatment. In this paper, we investigate and compare the use of two different image calibration procedures that allow extraction of patient anatomy from measured electronic portal images of intensity-modulated treatment beams. Methods and Materials: Electronic portal images of the intensity-modulated treatment beam delivered using the dynamic multileaf collimator technique were acquired. The images were formed by measuring a series of frames or segments throughout the delivery of the beams. The frames were then summed to produce an integrated portal image of the delivered beam. Two different methods for calibrating the integrated image were investigated with the aim of removing the intensity modulations of the beam. The first involved a simple point-by-point division of the integrated image by a single calibration image of the intensity-modulated beam delivered to a homogeneous polymethyl methacrylate (PMMA) phantom. The second calibration method is known as the quadratic calibration method and required a series of calibration images of the intensity-modulated beam delivered to different thicknesses of homogeneous PMMA blocks. Measurements were made using two different detector systems: a Varian amorphous silicon flat-panel imager and a Theraview camera-based system. The methods were tested first using a contrast phantom before images were acquired of intensity-modulated radiotherapy treatment delivered to the prostate and pelvic nodes of cancer patients at the Royal Marsden Hospital. Results: The results indicate that the calibration methods can be used to remove the intensity modulations of the beam, making it possible to see the outlines of bony anatomy that could be used for patient position verification. This was shown for both posterior and lateral delivered fields. Conclusions: Very little difference between the two calibration methods was observed, so the simpler division method, requiring only the single extra calibration measurement and much simpler computation, was the favored method. This new method could provide a complementary tool to existing position verification methods, and it has the advantage that it is completely passive, requiring no further dose to the patient and using only the treatment fields.

Differences in Epidural and Analgesic Use in Patients with Apparent Stage I Endometrial Cancer treated by open versus laparoscopic surgery: results from the randomised LACE trial

Objectives: We compared post-operative analgesic requirements between women with early stage endometrial cancer treated by total abdominal hysterectomy (TAH) or total laparoscopic hysterectomy (TLH). Methods: 760 patients with apparent stage I endometrial cancer were treated in the international, multicentre, prospective randomised trial (LACE) by TAH (n=353) or TLH (n=407) (2005-2010). Epidural, opioid and non-opioid analgesic requirements were collected until ten months after surgery. Results: Baseline demographics and analgesic use were comparable between treatment arms. TAH patients were more likely to receive epidural analgesia than TLH patients (33% vs 0.5%, p<0.001) during the early postoperative phase. Although opioid use was comparable in the TAH vs TLH groups during postoperative 0-2 days (99.7% vs 98.5%, p 0.09), a significantly higher proportion of TAH patients required opioids 3-5 days (70% vs 22%, p<0.0001), 6-14 days (35% vs 15%, p<0.0001), and 15-60 days (15% vs 9%, p 0.02) post-surgery. Mean pain scores were significantly higher in the TAH versus TLH group one (2.48 vs 1.62, p<0.0001) and four weeks (0.89 vs 0.63, p 0.01) following surgery. Conclusion: Treatment of early stage endometrial cancer with TLH is associated with less frequent use of epidural, lower post-operative opioid requirements and better pain scores than TAH.

Write vs. type : tangible and situated media for situated engagement

Digital media is often criticised for being intangible, transient and ephemeral. These characteristics limit the provision of long-lasting social experiences, as it is through the use of all our senses that we attach meaning to space, creating a sense of place. This paper presents a comparative study of the affordances of two design interventions, one tangible paper-based, called Print + Talk = Love (PTL), the other digital screen-based, called Discussions in Space (DIS). The emphasis is on a) how tangible media, such as paper, provides different and meaningful collective experiences, and b) how it can stand on its own as an interactive design intervention and as a comprehensive data-gathering tool in urban public places. By positioning PTL and DIS within the context of urban public places and testing their abilities to engage participants, we examine their particular situated engagement abilities through a mixed method approach. As a result, the digital aspects of DIS, e.g., using Twitter, extend the situated experience beyond the actual location of the intervention. Moreover, informing a hybrid approach, we also found that the physical aspects of PTL and its tangible presence, kept the user experience focused on the actual place and event surrounding the intervention.

Mothers vs fathers as learner driver supervisors : time commitment, driving activities and perceptions of risk

The learner licence, within a graduated driver licensing system, provides new drivers with the opportunity to learn to drive under the supervision of a more experienced driver. The Queensland graduated driver licensing system requires learner drivers to record a minimum of 100 logbook hours of supervised practice with the support of parents appearing critical to ensure that this is achieved. This paper examines differences between mothers and fathers who supervise learner drivers. Mothers and fathers from Queensland who had recently supervised their child while they learnt to drive completed an internet survey about their experiences. It appears that one strategy that parents use to provide practice hours is for the child to drive themselves or their parents to or from activities that they would have attended anyway in addition to undertaking special trips in the car for the purposes of practising. The results suggest that mothers, when compared with fathers, consider driving at all stages of licensure riskier and that mothers provided more hours of supervision than fathers. However, despite this, there are limited differences between how frequently mothers and fathers provide different driving experiences such as deliberately practising in suburban areas or with passengers in the car. This research fills a gap in the literature by providing important information about the way in which parents supervise their children while they are driving on a learner licence as well as identifying some of the differences and similarities between mothers and fathers.

Visual front-end wars : Viola-Jones face detector vs Fourier Lucas-Kanade

The performance of visual speech recognition (VSR) systems are significantly influenced by the accuracy of the visual front-end. The current state-of-the-art VSR systems use off-the-shelf face detectors such as Viola- Jones (VJ) which has limited reliability for changes in illumination and head poses. For a VSR system to perform well under these conditions, an accurate visual front end is required. This is an important problem to be solved in many practical implementations of audio visual speech recognition systems, for example in automotive environments for an efficient human-vehicle computer interface. In this paper, we re-examine the current state-of-the-art VSR by comparing off-the-shelf face detectors with the recently developed Fourier Lucas-Kanade (FLK) image alignment technique. A variety of image alignment and visual speech recognition experiments are performed on a clean dataset as well as with a challenging automotive audio-visual speech dataset. Our results indicate that the FLK image alignment technique can significantly outperform off-the shelf face detectors, but requires frequent fine-tuning.

NSAM-derived total surface area vs. SMPS-derived "mobility equivalent" surface area for different environmentally relevant aerosols

The surface area of inhaled particles deposited in the alveolar region, as reported by the TSI nanoparticle surface area monitor (NSAM), was compared with the corresponding value estimated by a TSI scanning mobility particle sizer (SMPS) for a range of environmentally relevant aerosols, including petrol emissions, ETS, laser printer emissions, cooking emissions and ambient aerosols. The SMPS values were based on a mobility size distribution assuming spherical particles using the appropriate size-dependent alveolar-deposition factors provided by the ICRP. In most cases, the two instruments showed good linear agreement. With petrol emissions and ETS, the linearity extended to over 103 μm2 cm-3. With printer emissions, there was good linearity up to about 300 μm2 cm-3 while the NSAM increasingly overestimated the surface area at higher concentrations. The presence of a nucleation event in ambient air caused the NSAM to over-estimate the surface area by a factor of 2. We summarize these results and conclude that the maximum number concentration up to which the NSAM is accurate clearly depends on the type of aerosol being sampled and provide guidance for the use of the instrument.

The use of artificial MicroRNA technology to control gene expression in Arabidopsis thaliana

In plants, double-stranded RNA (dsRNA) is an effective trigger of RNA silencing, and several classes of endogenous small RNA (sRNA), processed from dsRNA substrates by DICER-like (DCL) endonucleases, are essential in controlling gene expression. One such sRNA class, the microRNAs (miRNAs) control the expression of closely related genes to regulate all aspects of plant development, including the determination of leaf shape, leaf polarity, flowering time, and floral identity. A single miRNA sRNA silencing signal is processed from a long precursor transcript of nonprotein-coding RNA, termed the primary miRNA (pri-miRNA). A region of the pri-miRNA is partially self-complementary allowing the transcript to fold back onto itself to form a stem-loop structure of imperfectly dsRNA. Artificial miRNA (amiRNA) technology uses endogenous pri-miRNAs, in which the miRNA and miRNA*(passenger strand of the miRNA duplex) sequences have been replaced with corresponding amiRNA/ amiRNA*sequences that direct highly efficient RNA silencing of the targeted gene. Here, we describe the rules for amiRNA design, as well as outline the PCR and bacterial cloning procedures involved in the construction of an amiRNA plant expression vector to control target gene expression in Arabidopsis thaliana. © 2014 Springer Science+Business Media New York.