Phase retrieval by coherent modulation imaging

Phase retrieval is a long-standing problem in imaging when only the intensity of the wavefield can be recorded. Coherent diffraction imaging is a lensless technique that uses iterative algorithms to recover amplitude and phase contrast images from diffraction intensity data. For general samples, phase retrieval from a single-diffraction pattern has been an algorithmic and experimental challenge. Here we report a method of phase retrieval that uses a known modulation of the sample exit wave. This coherent modulation imaging method removes inherent ambiguities of coherent diffraction imaging and uses a reliable, rapidly converging iterative algorithm involving three planes. It works for extended samples, does not require tight support for convergence and relaxes dynamic range requirements on the detector. Coherent modulation imaging provides a robust method for imaging in materials and biological science, while its single-shot capability will benefit the investigation of dynamical processes with pulsed sources, such as X-ray free-electron lasers

Standard errors and confidence intervals in within-subjects designs: Generalizing Loftus and Masson (1994) and avoiding the biases of alternative accounts

Repeated measures designs are common in experimental psychology. Because of the correlational structure in these designs, the calculation and interpretation of confidence intervals is nontrivial. One solution was provided by Loftus and Masson (Psychonomic Bulletin & Review 1:476–490, 1994). This solution, although widely adopted, has the limitation of implying same-size confidence intervals for all factor levels, and therefore does not allow for the assessment of variance homogeneity assumptions (i.e., the circularity assumption, which is crucial for the repeated measures ANOVA). This limitation and the method’s perceived complexity have sometimes led scientists to use a simplified variant, based on a per-subject normalization of the data (Bakeman & McArthur, Behavior Research Methods, Instruments, & Computers 28:584–589, 1996; Cousineau, Tutorials in Quantitative Methods for Psychology 1:42–45, 2005; Morey, Tutorials in Quantitative Methods for Psychology 4:61–64, 2008; Morrison & Weaver, Behavior Research Methods, Instruments, & Computers 27:52–56, 1995). We show that this normalization method leads to biased results and is uninformative with regard to circularity. Instead, we provide a simple, intuitive generalization of the Loftus and Masson method that allows for assessment of the circularity assumption

Self-inflicted nail-gun injury with cranial penetration and use of intraoperative computed tomography

Background: Management of penetrating cranial trauma remains a high acuity and imaging intense neurosurgical disorder. Imaging of vital structures, including angiography, is typically conducted to understand the proximity of vital structures in comparison to a foreign body and prepare for intraoperative complications such as hemorrhage. Preservation of function following initial injury in cases where minimal neurological deficit exists is essential. Case Description: Here, we present a case using intraoperative computed tomography to assist in early detection and resolution of hemorrhage in the surgical management of an intact patient with self-inflicted penetrating cranial trauma. Conclusions: This method may aid in early detection of hemorrhage and prevention of consequential neurological deterioration or emergent need for secondary surgery

Quantitative X-ray wavefront measurements of Fresnel zone plate and K-B mirrors using phase retrieval

A scanning coherent diffraction imaging method was used to reconstruct the X-ray wavefronts produced by a Fresnel zone plate (FZP) and by Kirkpatrick-Baez (KB) focusing mirrors. The ptychographical measurement was conducted repeatedly by placing a lithographed test sample at different defocused planes. The wavefronts, recovered by phase-retrieval at well-separated planes, show good consistency with numerical propagation results, which provides a self-verification. The validity of the obtained FZP wavefront was further confirmed with theoretical predictions

Airflow limitation or static hyperinflation: which is more closely related to dyspnea with activities of daily living in patients with COPD?

<p>Abstract</p> <p>Background</p> <p>Dyspnea while performing the activities of daily living has been suggested to be a better measurement than peak dyspnea during exercise. Furthermore, the inspiratory capacity (IC) has been shown to be more closely related to exercise tolerance and dyspnea than the FEV₁, because dynamic hyperinflation is the main cause of shortness of breath in patients with COPD. However, breathlessness during exercise is measured in most studies to evaluate this relationship.</p> <p>Purpose</p> <p>To evaluate the correlation between breathlessness during daily activities and airflow limitation or static hyperinflation in COPD.</p> <p>Methods</p> <p>We examined 167 consecutive outpatients with stable COPD. The Baseline Dyspnea Index (BDI) was used to evaluate dyspnea with activities of daily living. The relationship between the BDI score and the clinical measurements of pulmonary function was then investigated.</p> <p>Results</p> <p>The Spearman rank correlation coefficients (Rs) between the BDI score and the FEV₁(L), FEV₁(%pred) and FEV₁/FVC were 0.60, 0.56 and 0.56, respectively. On the other hand, the BDI score also correlated with the IC, IC/predicted total lung capacity (TLC) and IC/TLC (Rs = 0.45, 0.46 and 0.47, respectively). Although all of the relationships studied were strongly correlated, the correlation coefficients were better between dyspnea and airflow limitation than between dyspnea and static hyperinflation. In stepwise multiple regression analyses, the BDI score was most significantly explained by the FEV₁(R²= 26.2%) and the diffusion capacity for carbon monoxide (R²= 14.4%) (Cumulative R²= 40.6%). Static hyperinflation was not a significant factor for clinical dyspnea on the stepwise multiple regression analysis.</p> <p>Conclusion</p> <p>Both static hyperinflation and airflow limitation contributed greatly to dyspnea in COPD patients.</p

Azimuthal Anisotropy of Photon and Charged Particle Emission in Pb+Pb Collisions at 158 A GeV/c

The azimuthal distributions of photons and charged particles with respect to the event plane are investigated as a function of centrality in Pb + Pb collisions at 158 A GeV/c in the WA98 experiment at the CERN SPS. The anisotropy of the azimuthal distributions is characterized using a Fourier analysis. For both the photon and charged particle distributions the first two Fourier coefficients are observed to decrease with increasing centrality. The observed anisotropies of the photon distributions compare well with the expectations from the charged particle measurements for all centralities.Comment: 8 pages and 6 figures. The manuscript has undergone a major revision. The unwanted correlations were enhanced in the random subdivision method used in the earlier version. The present version uses the more established method of division into subevents separated in rapidity to minimise short range correlations. The observed results for charged particles are in agreement with results from the other experiments. The observed anisotropy in photons is explained using flow results of pions and the correlations arising due to the decay of the neutral pion

Development of a healthy biscuit: an alternative approach to biscuit manufacture

OBJECTIVE: Obesity (BMI >30) and related health problems, including coronary heart disease (CHD), is without question a public health concern. The purpose of this study was to modify a traditional biscuit by the addition of vitamin B(6), vitamin B(12), Folic Acid, Vitamin C and Prebiotic fibre, while reducing salt and sugar. DESIGN: Development and commercial manufacture of the functional biscuit was carried out in collaboration with a well known and respected biscuit manufacturer of International reputation. The raw materials traditionally referred to as essential in biscuit manufacture, i.e. sugar and fat, were targeted for removal or reduction. In addition, salt was completely removed from the recipe. PARTICIPANTS: University students of both sexes (n = 25) agreed to act as subjects for the study. Ethical approval for the study was granted by the University ethics committee. The test was conducted as a single blind crossover design, and the modified and traditional biscuits were presented to the subjects under the same experimental conditions in a random fashion. RESULTS: No difference was observed between the original and the modified product for taste and consistency (P > 0.05). The modified biscuit was acceptable to the consumer in terms of eating quality, flavour and colour. Commercial acceptability was therefore established. CONCLUSION: This study has confirmed that traditional high-fat and high-sugar biscuits which are not associated with healthy diets by most consumers can be modified to produce a healthy alternative that can be manufactured under strict commercial conditions

Spatial Dimensions of Dengue Virus Transmission across Interepidemic and Epidemic Periods in Iquitos, Peru (1999–2003)

To target prevention and control strategies for dengue fever, it is essential to understand how the virus travels through the city. We report spatial analyses of dengue infections from a study monitoring school children and adult family members for dengue infection at six-month intervals from 1999–2003, in the Amazonian city of Iquitos, Peru. At the beginning of the study, only DENV serotypes 1 and 2 were circulating. Clusters of infections of these two viruses were concentrated in the northern region of the city, where mosquito indices and previous DENV infection were both high. In 2002, DENV-3 invaded the city, replacing DENV-1 and -2 as the dominant strain. During the invasion process, the virus spread rapidly across the city, at low levels. After this initial phase, clusters of infection appeared first in the northern region of the city, where clusters of DENV-1 and DENV-2 had occurred in prior years. Most of the clusters we identified had radii >100 meters, indicating that targeted or reactive treatment of these high-risk areas might be an effective proactive intervention strategy. Our results also help explain why vector control within 100 m of a dengue case is often not successful for large-scale disease prevention

A previously unidentified Chorioptes species infesting outer ear canals of moose (Alces alces): characterization of the mite and the pathology of infestation

<p>Abstract</p> <p>Background</p> <p>During the past decade, <it>Chorioptes </it>mites occupying the outer ear canals have been a common finding at routine necropsies of moose (<it>Alces alces</it>) in Sweden, but neither the taxonomy of the mites nor lesions from the infestation have been investigated. In this study, the mites are characterized by morphological and molecular techniques, and the histopathology of the skin of the outer ear canal is described.</p> <p>Methods</p> <p>External auditory meatuses from 53 necropsied moose were examined for the presence of <it>Chorioptes</it>, and samples from outer ear canals were taken for histopathological and microbiological examination. A proportion of the mites from each moose was identified to species. The DNA was extracted from mites from three moose, and their ITS-2 sequences were determined; these sequences were compared phylogenetically to sequences from other <it>Chorioptes </it>taxa.</p> <p>Results</p> <p><it>Chorioptes </it>mites were found in 43 (81%) of the 53 moose. The mites had morphological and genetic characteristics distinct from those of <it>C. texanus </it>and <it>C. bovis</it>, the two species generally accepted within the genus. Morphology also did not argue for a diagnosis as <it>C. crewei</it>, <it>C. mydaus </it>or <it>C. panda</it>. On histopathology, lesions were characterized by a hyperplastic perivascular to interstitial dermatitis with epidermal hyperkeratosis and crust formation. Dermal inflammatory infiltrates were composed of mixed T- and B-lymphocytes, plasma cells and macrophages, whereas eosinophils were notably uncommon. <it>Staphylococcus aureus </it>was grown from the infested epidermis of five of 14 examined moose.</p> <p>Conclusion</p> <p><it>Chorioptes </it>mite infestation was frequently detected in the outer ear canals of moose in Sweden. The mites were evidently pathogenic, being associated with inflammatory lesions of the external auditory meatus. Our studies indicate infestations with a previously undescribed <it>Chorioptes </it>species.</p