Undersampled Phase Retrieval with Outliers

We propose a general framework for reconstructing transform-sparse images from undersampled (squared)-magnitude data corrupted with outliers. This framework is implemented using a multi-layered approach, combining multiple initializations (to address the nonconvexity of the phase retrieval problem), repeated minimization of a convex majorizer (surrogate for a nonconvex objective function), and iterative optimization using the alternating directions method of multipliers. Exploiting the generality of this framework, we investigate using a Laplace measurement noise model better adapted to outliers present in the data than the conventional Gaussian noise model. Using simulations, we explore the sensitivity of the method to both the regularization and penalty parameters. We include 1D Monte Carlo and 2D image reconstruction comparisons with alternative phase retrieval algorithms. The results suggest the proposed method, with the Laplace noise model, both increases the likelihood of correct support recovery and reduces the mean squared error from measurements containing outliers. We also describe exciting extensions made possible by the generality of the proposed framework, including regularization using analysis-form sparsity priors that are incompatible with many existing approaches.Comment: 11 pages, 9 figure

Chiropractic Physicians\u27 Knowledge of Pediatric Concussions

Recent legislation in the state of Ohio now allows chiropractic physicians who possess certain credentials to both diagnose and clear young patients who have sustained concussions. Unfortunately, little if any existing research examines the knowledge and abilities of chiropractic physicians regarding the management of this condition. Therefore, the purpose of this study was to provide a general overview of chiropractic physicians’ knowledge regarding the diagnosis and management of pediatric concussions. A survey was emailed to 1,344 chiropractors in the state of Ohio. Of those who were contacted, 71 completed the survey. The survey included questions regarding demographics, patient scenarios, and concussion management. Although 66.7% of chiropractors qualified to care for concussions reported the utilization of guidelines, the rate dropped to 35.2% when all respondents were included. There were statistically significant differences concerning familiarity with the Graded Symptom Checklist (p=0.001) and the Post-Concussion Symptom Scale (p=0.007). In addition, the results of a question regarding the implementation of graduated return-to-play protocols were found to be borderline significant (p=0.06).The results of the study indicated that chiropractors who possess the credentials required by law are more knowledgeable regarding concussion diagnosis and management than those who do not

Planning research in the area of launch vehicle and propulsion programs Progress report, 1-31 Mar. 1968

Program and report reviews on launch vehicle upper stages and propulsion of advanced reentry spacecraf

Discrimination, labour markets and the Labour Market Prospects of Older Workers: What Can a Legal Case Teach us?

As governments become increasingly concerned about the fiscal implications of the ageing population, labour market policies have sought to encourage mature workers to remain in the labour force. The ‘human capital’ discourses motivating these policies rest on the assumption that older workers armed with motivation and vocational skills will be able to return to fulfilling work. This paper uses the post-redundancy recruitment experiences of former Ansett Airlines flight attendants to develop a critique of these expectations. It suggests that policies to increase older workers’ labour market participation will not succeed while persistent socially constructed age- and gender- typing shape labour demand. The conclusion argues for policies sensitive to the institutional structures that shape employer preferences, the competitive rationality of discriminatory practices, and the irresolvable tension between workers’ human rights and employers’ property rights

The varying role of the GP in the pathway between colonoscopy and surgery for colorectal cancer: a retrospective cohort study

Extent: 11p.Objectives: To describe general practitioner (GP) involvement in the treatment referral pathway for colorectal cancer (CRC) patients. Design: A retrospective cohort analysis of linked data. Setting: A population-based sample of CRC patients diagnosed from August 2004 to December 2007 in New South Wales, Australia, using the 45 and Up Study, cancer registry diagnosis records, inpatient hospital records and Medicare claims records. Participants: 407 CRC patients who had a colonoscopy followed by surgery. Primary outcome measures: Patterns of GP consultations between colonoscopy and surgery (ie, between diagnosis and treatment). We investigated whether consulting a GP presurgery was associated with time to surgery, postsurgical GP consultations or rectal cancer cases having surgery in a centre with radiotherapy facilities. Results: Of the 407 patients, 43% (n=175) had at least one GP consultation between colonoscopy and surgery. The median time from colonoscopy to surgery was 27 days for those with an intervening GP consultation and 15 days for those without the consultation. 55% (n=223) had a GP consultation up to 30 days postsurgery; it was more common in cases of patients who consulted a GP presurgery than for those who did not (65% and 47%, respectively, adjusted OR 2.71, 95% CI 1.50 to 4.89, p=0.001). Of the 142 rectal cancer cases, 23% (n=33) had their surgery in a centre with radiotherapy facilities, with no difference between those who did and did not consult a GP presurgery (21% and 25% respectively, adjusted OR 0.84, 95% CI 0.27 to 2.63, p=0.76). Conclusions: Consulting a GP between colonoscopy and surgery was associated with a longer interval between diagnosis and treatment, and with further GP consultations postsurgery, but for rectal cancer cases it was not associated with treatment in a centre with radiotherapy facilities. GPs might require a more defined and systematic approach to CRC management.David Goldsbury, Mark Harris, Shane Pascoe, Michael Barton, Ian Olver, Allan Spigelman, Justin Beilby, Craig Veitch, David Weller, Dianne L O'Connel

A self-contained wind speed, direction and location system for buoys and ships in the World Ocean Circulation Experiment

Knowledge of the absolute wind velocity near the surface of the ocean is a requirement of the World Ocean Circulation Experiment (WOCE) and other large programs directed towards understanding air-sea interactions and how ocean circulation and climate are interrelated. The measurement is made possible using IMET (Improved METeorology) modules, a next generation meteorological data acquisition system developed as part of the WOCE program. An IMET system consists of a set of intelligent modules for each measurement variable, with data being recorded on a computer, typically PC-based. The IMET wind module includes a propeller for wind speed, a vane and optical encoder for wind direction, a flux gate compass for the north reference, and microprocessor-based electronics for control and data formatting. The IMET Global Positioning System (GPS) module includes a five chanel GPS receiver and microprocessor based electronics for control and data formatting. These modules, as part of the complete measurement suite, result in a self-contained system that can make accurate measurements from research ships, drifting and moored buoys, and volunteer observing ships (VOS).Funding was provided by Grant No. OCE-8709614 from the National Science Foundation

Optimizing passive acoustic sampling of bats in forests

Passive acoustic methods are increasingly used in biodiversity research and monitoring programs because they are cost-effective and permit the collection of large datasets. However, the accuracy of the results depends on the bioacoustic characteristics of the focal taxa and their habitat use. In particular, this applies to bats which exhibit distinct activity patterns in three-dimensionally structured habitats such as forests. We assessed the performance of 21 acoustic sampling schemes with three temporal sampling patterns and seven sampling designs. Acoustic sampling was performed in 32 forest plots, each containing three microhabitats: forest ground, canopy, and forest gap. We compared bat activity, species richness, and sampling effort using species accumulation curves fitted with the clench equation. In addition, we estimated the sampling costs to undertake the best sampling schemes. We recorded a total of 145,433 echolocation call sequences of 16 bat species. Our results indicated that to generate the best outcome, it was necessary to sample all three microhabitats of a given forest location simultaneously throughout the entire night. Sampling only the forest gaps and the forest ground simultaneously was the second best choice and proved to be a viable alternative when the number of available detectors is limited. When assessing bat species richness at the 1-km(2) scale, the implementation of these sampling schemes at three to four forest locations yielded highest labor cost-benefit ratios but increasing equipment costs. Our study illustrates that multiple passive acoustic sampling schemes require testing based on the target taxa and habitat complexity and should be performed with reference to cost-benefit ratios. Choosing a standardized and replicated sampling scheme is particularly important to optimize the level of precision in inventories, especially when rare or elusive species are expected