A Weakly Supervised Deep Learning Approach for Detecting Malaria and Sickle Cells in Blood Films

Machine vision analysis of blood films imaged under a brightfield microscope could provide scalable malaria diagnosis solutions in resource constrained endemic urban settings. The major bottleneck in successfully analyzing blood films with deep learning vision techniques is a lack of object-level annotations of disease markers such as parasites or abnormal red blood cells. To overcome this challenge, this work proposes a novel deep learning supervised approach that leverages weak labels readily available from routine clinical microscopy to diagnose malaria in thick blood film microscopy. This approach is based on aggregating the convolutional features of multiple objects present in one hundred high resolution image fields. We show that this method not only achieves expert-level malaria diagnostic accuracy without any hard object-level labels but can also identify individual malaria parasites in digitized thick blood films, which is useful in assessing disease severity and response to treatment. We demonstrate another application scenario where our approach is able to detect sickle cells in thin blood films. We discuss the wider applicability of the approach in automated analysis of thick blood films for the diagnosis of other blood disorders

[Photograph 2012.201.B1431.0035]

Photograph used for a newspaper owned by the Oklahoma Publishing Company

Testing neurophysiological and neuropsychological effects of power-line magnetic fields

Abstract not available

Mains 50 Hz magnetic field interference rejection in neuropsychophysiology recording

Not available

A study of heart rate and heart rate variability in human subjects exposed to occupational levels of 50 Hz circularly polarised magnetic fields

The effects of power-frequency magnetic fields on heart rate and heart rate variability (HRV) were studied in groups of adult volunteers. Exposure consisted of 28 μT (280 mG) at 50 Hz (circularly polarized) for 100 or 150 seconds either following or prior to a similar period of sham-exposure. A small but significant slowing of heart rate of the order of 2% was observed in two separate studies in which the fields were generated by continuous sinusoidal currents. Magnetic fields generated by square-wave currents or by currents turned alternatively on and off at 15 second intervals during the exposure period produced inconsistent effects on heart rate. Analysis of the HRV spectra in relation to continuous sinusoidal exposure showed a consistent reduction in the ratio of power in the Low Band (0.02–0.15 Hz) to the High Band (0.16–1.0 Hz). This reduction in ratio was significant for experiments in which respiration was controlled at 0.2 Hz (12 breaths/minute) where the order was actual exposure followed by sham exposure (On→Off). The spectral power in the Low Band was significantly reduced for both orders, but the High Band power was significantly raised only for the On→Off order. Although there are some inconsistencies, these data indicate that short exposures to magnetic fields at occupational levels may influence heart rate control mechanisms

Parasitic infestation in cancer patients chemotherapy

Parasitic infections, especially opportunistic ones are important problems of immune deficient patients. These groups of patients can encompass a broad spectrum of cancer patients. Patients receiving immune suppressive chemotherapeutic agents and those who receive radiotherapy. This group of patients has much more susceptibility to infections and suffers more complications. The objective of this study is to determine the incidence of intestinal parasitic infestations in patients receiving immune suppressive anti-cancer agents. Stool sample of 261 patients under treatment with chemotherapeutic agents were collected and sent to parasitologic laboratory of Shahid Beheshti medical school. Every sample was evaluated with direct smears formalin and ether concentration technique, shitter dilution, zeil-nelson strip stain, culture on strip of filtration paper according to Hadamvory method and on agar plates. Thus, the incidence of intestinal parasitic infestations was evaluated. In this study 34% (89 samples) of patients, who had receive immunosuppressive medicine, had intestinal parasitic infestation. 31.4% of patients with intestinal parasitic infestation were under 20 years of age, 31.6% were between 21-50 years and 36.5% were above 51 years old. Statistical method did not show significant difference between the incidence of intestinal parasitic infestation and the 2 variables of age and sex. The rate of intestinal parasitic infestations in cancer patients with 1-4 courses of treatment was 34.5% and after more than 5 courses was 33.6%. Statistical analysis with X² test did reveal significant differences. Considering the above studies, we recommend: 1) Stool exam of all chemotherapy patients for intestinal parasites before chemotherapy treatment. 2) Five to seven stool exam is necessary for high-risk group. In other patients one stool examination is enough. 3) Repeated stool examination is recommended during chemotherapy. 4) More specific method is needed for detection of high-risk patients and suspected cases

Real-time recording of neuropsychophysiological parameters during ELF MF exposure

Abstract not available

Real-time recording of neuropsychophysiological parameters during 50 Hz magnetic field exposure

In order to assess the possible effects of occupational levels of 50 Hz magnetic fields (MF) on human performance it is preferable to monitor performance during rather than subsequent to MF exposure. We previously reported studies of heart rate and cognitive behaviour where the issue of contamination was not a serious one. Our present study involves electrophysiological measures, which have a greater capacity to identify the effects and assist in localising them. The contamination of EEG signal by the MF exposure is clearly a problem in this type of study. Previous investigators have not reported these types of measurement concurrent with MF exposure due to the contamination difficulty; but this paper reports means of accomplishing this. Overall a combination of 12 methods for reducing pickup were employed. These were: 1) Distancing recording instruments from the MF source; 2) Shielding the devices and wiring; 3) Appropriate choice of cables; 4) Grounding the instrumentation; 5) Orientation of conduits; 6) Isolation of electrical mains power supplies; 7) Balancing the input impedances; 8) Applying a driven shield technique; 9) Improved electronics design incorporating pre-amplification and circuit impedance level control; 10) Analogue filtering; 11) Signal Averaging; and 12) Post acquisition digital filtering using frequency and time domain techniques

Theoretical and experimental studies on a solid containing water droplet

Heat and mass transfer to and from a single solution droplet is studied in this work. A new theoretical model to predict the evaporation behaviour of solid containing water droplets is presented. The model, implemented in MATLAB, is used to predict the process of droplet evaporation with prediction results successfully validated against data from the literature. Also, an experimental study was performed to study the evaporation of a single droplet containing NaCl and water. To investigate the influence of concentration, tests were performed with droplet having initial radiuses of approximately 0.5 mm and initial mass concentrations of 3% and 5%. Results obtained from the developed model were found to be in good agreement with our experimental data. Finally, it was shown that the current model, allowing for a smooth transition from surface evaporation to crystallisation, is able to simulate the process more accurately compared to existing models in the literature which lead to a, less realistic, sharp transition

Neuropsychological sequelae of 50 Hz magnetic fields

Purpose: The effects of occupational levels of 50 Hz magnetic fields on cognitive function were studied on 30 human volunteers. Materials and methods: The exposure system consisted of Merrit-type modified Helmholtz coils forming a 2 m cube, employing two orthogonal sets of coils producing a 28 wT (resultant) circularly polarized 50 Hz magnetic field. Subjects sat at a desk within the coils where they undertook a series of verbal and written tests of cognitive function. After these tests were concluded (~30min) subjects were either exposed or sham-exposed to fields (double-blinded) for 50min. A second set of tests (employing alternate versions) was administered 20min from the start of this period. Each subject returned after 7 days to repeat the sequence, but with the opposite field/sham status. Results and conclusions: The majority of the results indicated no significant effect of exposure on cognition. However, verbal recall of a list of 15 words after an interference (the different list) was significantly impaired in the 'field on' condition. This is indicative of a reduction in short-term memory of words. The mean baseline score was somewhat higher in the 'field on' condition. However, this difference is within the parameters of normal variation. The other significant result occurred during performance of a trail-making task (alternating 1-A-2-B-3-C, etc.), with a decrease in performance as a result of exposure to the 50 Hz field. This task requires executive functioning with a working memory load, involving parietal spatial processing coordinated by prefrontal executive processing. In summary, the data are suggestive of detrimental effects on cognitive processes, particularly short-term learning and executive functioning. However, larger sample sizes are required to demonstrate statistically a more specific pattern of cognitive effects